Australia New Zealand South Africa Malaysia ALSO:-SIMPLE DARKROOM TIMER STATESIDE CALLING. IflNCTON' TAIMK BATTLE GAME. * s. i * r-.t" t^cn.

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1 Australia New Zealand South Africa Malaysia TT % ALSO:-SMPLE DARKROOM TMER STATESDE CALLNG flncton' TAMK BATTLE GAME m AM * s ' ^ t^cn % cri i * r-.t" 7. r / \ w p- -i -

2 T.T.L. 74.Cs by TEXAS, NATONAL,.T.T., FARCHLO FARCHLD Etc s Up Bp 30p B 2Sp 7460 Sp Sp 30p loop 70p SOp 3S0p p 7414 Mp 60p 7430 t5p p p loflp p Sp lop 4Sp 70p loop 3S0p o Up Mp lop p 5p 7470 Mp s p p Cp tp 100p p Mp Sp 25p 40p 60p 70p Sp UOp s 14p Mp 30p s 7472 Z5p f> SOp ZJ9o Sp lop p 50p 90p loop UOp «R Up p Sp p 7473 Mp 7435 Cp TOp p MP p MP p f40p 6Sp lop 70p p p loop p 140 Up p Mp p Mp p Dp aop lop Sp 130p 7Sp 90p UOp p 40s p 2Sp 7446 «S 7475 Mp S5p Mp p o Mp l4dp » ZOp asp 740? p Sp 7Sp loop 230p p 25p p p 741W 40p toos p Mp 140p p p 2Sp 7448 Kft 70p BSp asp p isp 6Sp 7414B p p Sp P Bp Mp loop MP loop p p 2Sp 7450 Sp 7485 loop Mp 30p loop 12Sp 200p loop 7410 SO Sp p p p Sp p 7< »p 50p WD Mp p p 65p Sp p f25p Sp p p Mp Mp loop 7411 Ms p Sp Sp Sp S0p p 6Sp 32Sp lisp p p 2Sp SP 250b p 7490 asp 3Sp Mp Mp p fip loop p p p SOp Mp Mp 120p ZflOp 200p p SOp S5p 18Sp SEMCONDUCTORS by MULLARD, TEXAS, MOTOROLA, SEMENS,.T.T., R.C.A. 10 tor 10 tor f TO lor 10 fot TO for 10 for! for TO lor 10 for i AD161 3»s BC1B3L Mp BC547B loop BD135 3S0s BF199 AD d E p TP293 asop TP34A 720B N p BC107 3Mp BC07 Mp BC184 90p BC184L fc5p Ms BC54B Mp BD36 350s BF200 2Mp MPSA(5 2SOp TP29C 465p TfP34B BOOp loop 6C549C BC548C f»p 120p BD137 BD37 3S0p BF224 tmp 1N B SOp MPSA062S0p TP30 3S0p TP35C 2000p BCfO0 MPSAM 250p 90o BC212 TtP30 350p Tipasc 2000B 1N p BC109 90p BC549S l«p BD B BF225 f 50s WPSA562Mp TPaoA aoop T(P4 A S60p 0YX94 70p BC09 90p loop 120p BD40 3S0p BF244B 300p 440p BCt47 Mp M p BC212L ecsial 100s Mp BC549C BC556 MP TOOp BO40 BF s BF244S aoop 425p 380p 630p 7B0p 156p BC14a BC48 90s 90p BC214 90B 90p BC557 MP 120p BFtS 2B0p BF257 BF81 28 TMp 2S0p Os BF s MJE340 2S0s TP29A 3 <40 SOp p TP30B TP31A TP4ie TP42A 2N929 2N930 2S0p BCidg 90a BCZ14L toop BC557B t4cp BFT82 2fl0p ef259 2l0p THESE PRCES TP31B 435p 43Sp TP42a TP42B 770B 110p 2N p 150~ 0C157 BC157»S 90p BC237 Ms 90p BCY70 Mp 130p BF1fl3 BF s 280p E1CO EOO 400p ARE FOR ANY TP32 SOQp SOOp TP? TlP p O 2N Sp 180p acisa Mp BC328 TOOp BCY71 T25p BF1B4 Mp E210 4aop 10 OFF. ONE T Pa2A 550 TP p 2N3053 MOp BC159 Mp 6C33a TMp BCY72 40p 0F195 Ms E p TYPE OH MX TRa?8 750 p 1N o 2N305S 5Mp BC182 Mp BCSfi 450p Q p BF196 SOp E300 4 SOp OF 10 AND T[R32C OOOp BC183L toop BCS17 4 SOp BD132 35Cp BFig? Mp E p NCLUDE POST TR33A 620p 1N p 2N p Wp BCS47 Mp BD133 4 SOp BFt98 2Ms E4M 140p AND VAT T(P p 1N4003 1N4004 <0p 40p 2N3704 2N3703 Mp SOp 10 for 10 for 10 for 10 for 10 for 10 for 10 for 10 for 10 for 10 for AD61 3S0p BC83L loop BC547B loop BD35 3S0p BF99 220p E p TP29B 380p TP34A 720p N4005 4Sp 2N p AD62 3S0p BC84 90p BC548 90p BD36 3S0p BF p MPSA05250p TP29C 465p TlP34B BOOp 1 N4006 SOp 2N p BC08 90p BC212 90p BC549B loop BD39 3S0p BF225 SOp MPSA562S0p TP30A 380p TP41A 560p BYX94 70p SCR PUTS TP30B 42Sp TlP41B 630p 2N929 SOp ETC. BC47 90p BC213L loop BC556 loop BF80 280p BF257 SOp TP29A 3S0p TP31A 380p TP42A 700p 2N930 lsop 5N2B48 2N2646 4S0p 2N6072 4»p 44S0p 5&p BC49 90p BC214L loop BC557B UOp BF p BF259 HOp THESE PRCES BR101 BR10l BRy39 BRY39 390p 300p 300p BC58 90p BC328 loop BCY71 12Sp BF194 90p E p 10 OFF. ONE TP32A SSOp TP3055 SSOp 2N p BRYSB BRY56 320p BC59 90p BC338 loop BCY72 UOp BF95 90p E204 4lOp TYPE OR MX TP32B 7S0p ln4oo1 40p 2N3055 SSOp BTJ01 KOp BTlO 12S0p BC82 90p BC516 4S0p BD31 330p BF96 90p E300 4S0p OF 10 AND TF'32C 800p N4oo2 40p 2N p BT106 f t256p 256p 12S0p BC82L loop BC511 4S0p BD p BF97 90p E310 SOOp NCLUDE POST TP33A 620p N p 2N p 6T107 BT07 «50p 12S0p BC183 90p BC547 90p BD33 4S0p BF98 220p E420 UOp AND YAT TP33B 720p N p 2N p TS88A 230p LNEAR.Cs CA330 1i LNEAR,Cs DECODER BOARD ELECTROLYTC T.T.L. CONTANS CAPACTORS CMOS OFFERS tt) for 2N3705 2N3706 Wp ETC, SCR PUTS TSMA ZJOp CA3130 loop 18)( '00 uf/y uf/y 4000 Up 4030 SSp CA31<0 CA3140 1i loop :2 x each Sp 330/25 15p 4001 Up Sp x 7410 for 100p CA3076 2> 2 * /25 200p SP 16p 4002 Up p x D m 150p CAaOS5 330/50 18p p 4047 loop CA3085! 1x74160 No technical 1/16 5p 330/M 5p 5p 330/35 16s 10 asp x details 7420 for nop Sp 12p p 4048 SSp CA3086 CA3088 1! *74150 delalle 1/25 Sp 330/60 lap loltfr lor toop 190p 1 * x T(P32 TlP32 available 1/50 5D 470/10 1ZS 10 lar f00p SCp 7430 nop 2'2/25 SP DOp SSP p CA30S9 CA p 2 :2 k x 60 way 2-2/25 5p 470/25 16p Up p Sp 7442 CA3Q90AO CA3090AQ 4" 400p EDGE CONNECTORS 2 2/35 5p 470/35 Bp 10 lor»ep 22p 4012 Up 3-3/ p 3'3/25 Sp p 2Sp 4013 SOp 4055 UOp CA3130 1' 5p 470/50 22 p D for lor MOs 350p loor 4-7/10 4'7/10 5p 1000/16 isp 10 SP 7476 for 250p 26p p Sp LM300T05 1" HOp 4-7/16 4'7/16 5p Sp 1000/35 Mp TO for tar 200b 2SOp 7483 for 700p 28p p p LM301AM LM30lAN 6Sp 4'7/25 SP 7496 for 450p 3Sp p 4066 SSp LM307N 6Sp 4'7 '50 SP for LMa07N RESSTORS 4-7/25 5p 2200/10 2dp 10 E p p p 6'8/25 Sp p LFii30BT LM308T05 OS! F 12 SERES 4? 5p 2200/16 35p 10 lor tor 700D 450q 130p 120p 4020 loop p t Sp p 40p p p LM308DL i: j WATT 6 0, 25 5p 2200/63 75s 10 llop loo p SP 42p p 4081 Bp LM309K OFF ANY 10/10 5p 2200/ to tor 200p 10/16 loop YALUE 00 SP SOP Sp 4082 Bp LM310TO5 LM310T05 11 ONE VALUE 1 CO 5P 3300/16 40b 10 tor for 4D0p 250o 10/25 5b 3300/25 «p 10 for 800s 160p 10/35 5p 3300/63 SP 4700/25 lop 4Sp p p LM311T05 2i 260p 10/50 5p Sp d?00/ /40 SOp SOP M74210? MM2102 AN-4L p p 22/6Y3 Sp 120p BT.4S0n 4027 SOP p LPif3l7K LM311K 3! 325p Sp p p LM324 1! WRE WOUND 22/6V3 5p 4700/63 120s 1024 x 1 BT.450" AN'4L SOp Sp 4029 Op 4528 loop LM34BN LM348N 2i RESSTORS 22/10 5p sec 200p BY V.T.M. 22/16 5P STATC RAM Y.T.M Sp 1 60 LP4350N LM350N 1" 0p 9K 5K 9 Walls p POLYESTER Watts SP CAPAC- 4/ 6'00.8/ LM391 tl 180p 10 lof for /35 5p 4/ / t160 each Mullard LM555! 28p 100 tor for 6 OD 22/50 6p TORS 00 33/6Y3 Sp lor SO 88A LM710T tor 50 0D 33/6V3 5p Milliard or TEXAS lor 00 BC147 6p uf/y 3-00 Y_H.F. LM710DL l 10,000 for 400 M 33/16 6p Erie BT N/OUT TS MA SPECAL OFFERS 6Sp 33/25 ep uf/v PORT 3 00 each V.H.F. FET BC48 6p LM723T05 33/40 0P 001 BC149 7Sp 0022 SP BC57 LM LM723DL /50 7p p Sp QUANTTY PHONE FOR 10 lor 2-M 7Sp '0033 BC58 LM733 1! 180p MULLARD MODULES 47/10 6p p PRCE 1M for ASSORTED 0047 BC159 6 LM74B LM748 4Sp LP p p 47/16 6p 0047 Sp 47/ p 0068 Sp 555 TMER 8 FOR 50 2'SOp BF194 LP153 6p 01 Sp LMt303N LM303N 1! SSp 47/35 p 01 A BF195 LP SP LMi45a 6 BF196 LM458 ii loop LP p 47/ Sp p 022 5p 5o AY UAR/T 10for 2 5Qp 033 Sp BF97 LM39O0N LM3900N ' 90p LP1168 each 100/10 6p 5p * OP. AMP. 047 Sp for 2 00 MC1310P MC310P 18Sp LP /16 6p 5D 1 ML74T ML Pin Pn 30p LP p 100/25 «n 1 6p 10 tor FUT 5L T02 POTENTOMETERS MM MM : 430p 100/50 loo/50 6p 22 7p PUT ABA 6LTO? 33 9p ' BYX 94 MM531S MM5316 5; 5S0p 100/ '3-3 Sp DSPLAY S SO RDTENTOMETFRS lop '47 12p DODES L1N-2M L1N NE529K 1: SOp 125/ p 5K NE555 : 6p -47 2p K 2Sp PlY FND lop 2-2 2Sp 30p BD p NE END /16 idp Cp Z5p loop 00 12p B 2S0p NE562B 4-7 SEGMENT COMMON 220/25 400p 20p 6'8 40p 220p BD609/610 MaMa'd Mullard BTY87 CATHODE DSPLAYS 220/50 12s Mp p BO44 165p 1250 P1V 1 Amp SK LN-2M LOG-2M UN LOG o R s 100 for s each 30 each for S BOX 2S0p POWER R100Va5A l00y 8 5A ci 1 M encfi 4 tor 5 00 BU p BD6C9.'6t0 6DX p BDBOTj'Ma ^ COMP POV/ER 1 M p 3817 ~~~0~/6~80 vie R 3811 DPC Clocll AU 100 BOp Clock R 2008B 210p CiP Chip 4 R2008Q 240p COMP. POWER SO pair SN7W03N SN76003N 1S0p RCA ReA T A C SN76013N MURATA ULTRASONC ROTARY SWTCHES 180p S.C.R. 100Y 12 5 l1r SN7flOl3ND SN76013ND 2N Sp AMP 2 00 LEDS OL LORLlN SN76023N 1 AMR T03 S.C.R, V 12-5 TRANSDUCERS MA40 L1R DtL SOCKETS BY 180p Z 2 50 each. 2 for 4 fld 00. '125 13p SN76023ND lp 12W t RED p 8 Pin 3p LORLN 12Sp 125 2Sp 14 Pin Up SN78227N SN76227N GREEN s P 160p 6W 2Sp 16 Pin Sp SN76228N t 180p SPECAL SCOOP OFFER YELLOW p 2P i5w 6V7 40s 40p 31' 4W Sp SN7B666N SN76666N loop 4P " 63Y for 2 2Sp TAA3W TAA300 LEDS OR 0-2" RED 2»5p 3P 1S0p ONLY.l00lor Sp TAA350 1 RED ONLY. 100 for» uf 63V lor 1 00 GREEN 2 25p AP 4 3W W 40p 40p 190p 1000/ 60'00 63V for 1'50 Display BZY88 TAA / « uf 03V lor 1 50 YELLOW 2 25p LMTED OFFER TAA550 SOp 63Y for 200p for 5 00 OY7-33Y lop TAA5S1B TAA651B uf 63V 2 lor 1 60 DL 747 DSDlay UOp 20Op 100 BC237 lor 5 06 BZYag ZENERS OV7-33V 10s each TAA p TAD100 TADOO 160p ELEKTORNADO TAOO TAD110 1 ELEKTORNAOO AMPL T2800D 400Y 8 20p GE SC51D 400Y 1 50p TSA120S FER R.C.A. T2eoOD TRAC 4O0V fl AMP 1 Z0p 6E SC151D 4O0V 15AMP TRAC f SQp TBA20S BOp TBAJOT TBA20T f WRTE/PHONE FOR 12Sp TBA550O TBA520Q DETALS 240p TBA530Q 21Sp T8A540 TBA p T8A540O LL TBA540Q i 240p UNENCODED TBAS500 TBA550Q 33Sp HEXADECMAL TSASMC TBA560C 3 HEXADECtMAL 33Sp 19 TBA6<1A12 TBA641A2 1» KEYBOARD ABCDEF. TBA720 TBA120 2S0p KEYS. T9 TBA800 A800 2 OPTONAL KEYS, 0p 15 TBA8J0S TBA810S SHFT KEY ts 00. T. POWELL 0p TBA820 1 loop T0A99O TBA990 2BOp TCA270O TCA270Q BRDGE TCA27DS TCA270S 2S0p RECTFERS 306 ST. PAUL'S ROAD PLEASE NOTE ALL PRCES NCLUDE VAT AT 8 OR 12^% 12t% XR Sp 1A60V la 50Y J5p 2Sp XR2207 i "Op la 100Y XR2316 XR2216 R 1A 100V 30p AS APPROPRATE BSOp 1A2DOV A200Y Mp lop HGHBURY CORNER, LONDON, N1 ZN<14 ZN p la 400Y 3Sp Easy access Vic:toria A 40OV 35s Ea»y accees to Highbury via Victoria Line HOp la 600Y Transport) A 600V 40p (London Tranapartl British Rail UOp 50Y 3Sp ?A 50V 35o t40p 2A 100V 100Y 50o SOP Manufacturers welcome i 140p 2A 2DQV 200Y 55p ssp enquiries. buyers/agents etc S0p 2A 400Y 60p Telephone your Manutsclurers etiqulriea. (large Overseas and small) buyers/agentt we wplcome elc. Let us know your requirements f DECODER CONTANS BOARD 18*74156 «M 2 * e*ch 2A 400V 60s ELECTROLYTC CAPACTORS uf/v UF/V T.T.L. OFFERS Let us know your reaulfements.

3 SSUE 856 JUNE VOLUME 54. NUMBER 2 BRTAN'S LEADNG JOURNAL FOR THE RADO, ELECTRONC CONSTRUCTOR Published by PC Magazines Ltd., Westover House, House. West Quay Rd., POOLE, Dorset BH151JG 11 News and Views 18 EDTORAL Crystal EDTORAL-Crystal Gazing 19 NEWS.... NEWS.... NEWS 19 KNDLY NOTE Radio NOTE-Radio 2 Tuner, July "Shoot", August C of the Month, ULN-3006T, March Multi-Range Test Meters, March Experimenter's Corner, LED Light Display, April HOTLNES Recent HOTLlNES-Recent developments in electronics Ginsberg 31 PRACTCAL WRELESS Preview WRELESS-Preview of out our next issue 48 PRODUCTON LNES nformation LNES-nformation on the latest products A/an Alan Martin 61 ON THE AR-Amateur Amateur Bands Eric Dowdeswell Dowdeswel/ G4AR VHF VHP Bands, ncluding including What do the VHFs have to offer?.... Ron Ham BRS5744 BRS15744 SW Broadcast Bands Charles Moiioy Mol/oy G8BUS GBBUS MW Broadcast Bands Charles Molloy Mol/oy G8BUS GBBUS 68 PW READER'S PCB SERVCE Prices SERVCE-Prices and details of the PCBs available 11 For our Constructors For our Constructors 20 AUDO DSTORTON METER 2 METER E. A. Rule Constructional details 27 PW PURBECK OSCLLOSCOPE 3 OSCLLOSCOPE an Hickman Front panel and power supply wiring 38 PW BOVNGTON TANK GAME David Coutts Full constructional details of this exciting TV game 49 DARKROOM TMER A. P. Donleavy A simple controller for your enlarger 11 General nterest 32 STATESDE CALLNG Joe Kasser G3ZCZ G3ZCZ/ W3 A broad look at the hobbyist radio scene in the USA 52 SO YOU WANT TO PASS THE RAE7 W RAE?-10..,. John Thornton-Lawrence GW3JGA and Ken McCoy GWSCMr GWBCMY Aerials, feeders and matching. Overcoming interference. The examination. e # Extra 39 NDEX TO VOLUME 53 Contents of our issues dated May 1977 to April COPY RGHT COPYRGHT Cl PC Magazines Limited Copyright n in all drawings, photographs and articles published in 'Practical Wireless' is s fully protected and reproduction or mitation n in whole or in part ie is expressly forbidden. Ail All reasoneble reasonable precautions are taken by 'Practical Wireless' to ensure that the advice and data given to readers are reliable. We cannot, however, guarantee it and we cannot accept legal responsibility for it. Price. are those current as we go to press. readers are reliable. We cannot, however, guarantee t and we cannot accept legal responsibility for it. Prices are those current as we go to press. Practical Wireless, June

4 Sparhrifa / the quickes~ fitting \ \ \, cup CLP on ON ~\ ' 1 /. v capacitive discharge^^^^ discharge./ ^ electronic ignition HJR -. in KT FORM _ / ntroductory SPECAL OFFER SPECAL OFFER mm^ 2 OFF Kit ^ /" /: 9 Smoother running //' # nstant all-weather starting \ \\" ^ # Continual peak performance \ # Longer coii/battery/plug coil/battery /plug life 0 mproved acceleration/top speeds # Optimum fuel consumption Sp«.Vril«Spa.-krite X4 s performance, quality capacluve electronic gnition ignition system l» a n high hit kit form, perfofmsnre, form. Tried, teited, high quelily tested, proven, capecltjve reliable and discharge, complete. eleciroolc t can be asbflmblod assembled tltted mlns. Becauie BeeRuse ol n the two superb or three deslfln hours design of the and Sparhrlte n 1/3 Sparkrite circuit mms. t it completely ellmlnale* ellmlru!tes problems breaker. ia mlsflre to breaker bounce which of the s contact i8 ellminaled breaker, eliminated electronically There le no by a mleflre pulse due suppreselon io contact suppression circuit braaher which prevents firing f points R.P.M. Contact burn prevehle is ellmlohted the unit flfing iminated by reducing " the polnia lh» the curreol bounce curr-ent to open about at t/5clh high fi.p.m, 1/50th of tha the norm. Contaci t will breaker parform perform equahy old, points and dependent equally upon well the dwell with new, lima o'd. time of the or contact even badly breakere pitted breakers for point# rechbrond end s recharging the not system- system. SoarV.rile Sparkrite ncorporates inverter problems ncorporatea of SCR lock on a short and, circuit therefore, protected eliminates nverter the which possibility eliminates pos8ibllity of blowing the the transistors capacitive discharge 'gnltl foolproof tranaislors n of in this the reaoect). SCR. (Most respect). The cepocillve circuit (ncorooretes discherge gnitions ncorporat es' n a voltage are regulated not completely output tor for greatly starting. in syatema fliestly mproved systems function cold light, startlnp. light. and eecurlty The circuit security changeover includes ehangeover switch. built All n static kits fit timing vehicles light, with coll/dtst'lbutor coil/distributor gnition ignition up to 8 cylinders. THE EVERYTHNG Die pressed KT COMPRSES epoxy coaled coated case. EVEHYTHHO Reedy Ready drilled, NEEDED elumlnium aluminium exlruded extruded base and heat elnk, sink, coli clips, accessories. guaranteed transformer coll mounting and comporenti. dlpsi and components, cabfes, acceaaorlea. cables. connectort, Top quality connector., P.C year P.C.B. nula, fluararleefl nuts, bolts end and silicon urease. qrease. assembte pol. earth illustrated installation Full nstallation nstructions nstructions to essemble kit neg. or po». eerfh and fully llluatrated NOTE Vahklea NOTE-Vehicles with w current moulsa mpulse tachometers Smiths (Smiths cod* code on dial RV1) will require a tachometer pufs* pulse slave unit. Price '35 inc. tnc. VAT. post & packing. Electronics Design Associates (Dept. PWt), PW6), 82 Bath Street, Walsall WS1 3DE. 1:-----., Electronics Design Associates, Associates. Dept.PW 6 82 Bath Street, Wolsall. WS1 3DE. Phone; 10922) Bath Street. Walsall, WS1 30E. Phone: 10922, Name 1 Address Phone your orrfsr order with Access Aucess or Sarclsycard Barclaycard OUANTTY REO'O. 1 "m." l te. VA, ind PP. OUWfUl' (SOT xi xn rjhs TACHS T PaSf PllSE SLAVE SlAVE UNT 0.3S 3.35 Arcftt ACCt'5S o' or 8arc1ayc:ard re 1 aye a id no. - i X4 KT [}j _ 2 The latest kil inovationl from the quickest fitting \ \\ f / / i eirtosach^oew. endose,haquepo'. a* for _---- Chocjua Mo Cheque No.' Seed SAt il xoctw nnfy requvel.1 ~ Re MGHTY MDGETS 5\:fR\:JB' /»\ /p^v /n\ VMATU MNATURE SOLDERNG RONS AND HU11] RONS - ACCESSORES RETAL PRCE POSTAGE each inc.v.a.i inc.v.a.t. extra. 18 WATT RON BT ' ca 3' 78 22p SPARE BTS 44p STANDS _ " 3 E p solder: SOLDER: savbit SAVBT 20' 52p 9p 10'" 26p " 4p LOWMELT 10' 65p _ 9p.C. UC. DESOLDERtNG DESOLDERNG BT SSp sap 9p BT SZES! No, 20 (3 mm) No. 21 {4-5 mm) No. 22 (6 mm) From your local Dealer or Direct from Manufacturers S R BREWSTER L TD Union St-Plymouth PU3HG Tel: (1 TRADE ENQURES WELCOME TECHNCAL TRANNG N ELECTRONCS TELEVSON AND RADO SERVCNG TECHNCAL TRANNG N CS can provide the technical knowledge that is so essential CS can provide the technical knowledge that is so essential to your success, success. knowledge that hat will enable you to take advant- advant age of the many opportunities open to the trained person. You sludy in your own home. in your own time and at yo ur 0"" pace and if you are studying for an examination CS guarantee coaching unlil you are ~ucccs,ful. study in your own home, in your own lime and at your own coaching until you are successful. ' City & Bc Guilds Certificates*. Certificates: Telecommunications Technicians Radio, TV, Electronics Technicians Technical Communications Radio Servicing Theory Radio Amateurs Electrical nstallation Work MPT Radio Communications Certificate Diploma Courses: Colour TV Servicing Electronic Engineering and Maintenance Computer Engineering and Programming Radio, TV, Audio Engineering and Servicing Electrical Engineering, nstallation and Contracting ~'}.".):.:. 1),'1=-.. ' '.J!" ":U :.::::::=-:U ;,.. =-l = S ll'ae ' ro: international Correspondence * luo Schools M Dept. No. 276V, ntertext Houu, LONDON = S 5W8 4U or telephone Subject of nterest CS To: nte.. national Co... e.pondence = = School. Dept. No. 276V. ntertext House, LONDON SW. 4U or telephone = Subject of nterest = Name = Address = i RlllllRlllimHMRHMB i ill i li~ i i... 5 Practical Wireless, June 1978

5 THERMOSTATS THERMOSTATS Refrllleratlon lullr.led wllh 38" capillary capillary R«Ma ration , ao HUBfatad with a6 v 1t. Limpet Stat mult be mounted n c108. calibrat.d callbratsri Umpat Stat O"-O"F M»-190*F mutt ha amp «rt»p ntounlod conlacl corlaci n cloaa 12. Appliance Stat fhl; like a volume control AppManca mp amo contact contact Slat 3O"-8O"F S^-ao'F (*»k«o Up. 15 volurrva p. control ditto ditto bul but fo' for high hi oh lemp temot 1 1 '11. 2S. Oven Oven Stat-wlth Slot with.enlor sanaor and and capillary caolllary Sp. Sp. MANS OPERATED SOLENODS MANS OPERATED SOLENODS. Mod.1 TT-.mall bul poworful ln. 11n.^ Modal pull-approx. pul^ appro*- TTJ amall olzo ah* but 11 J powarful x * 11 1j x Hln.U... Modal Mintti _/-iln. pull. SlO 2f Si x X 2 x X 4001/ Jin. 141n. 14Jn. d Z,.. M. pull, Sii9 Mod.1 Modal Tn TTW-Hln.... pull. pufl. Size 9lza ^ 3 x 2i 2* x X 21n Sin.. 4.,.. 4 a U..i J Prlc Pflc«lnclude nclude VAT & 6, po,ag po»t»oa. MOTOR8ED DSCO SWTCH MOTORSED DSCO SWTCH With With amp amp chang chtnoa-.. oyer 0«M wllch... awuchei. M Multl ulll adjultable dluaiable.wltch awl tehee at. are raled at 10 mp Thll would would provide provde a mag magnlflcenl dllplay. Fo, malna operating. a wltch model 1 ' wltch wjjch r^daj^cs^ts! mod.1 s T wltch model 4 7S. DELAY SWTCH DELAY SWTCH Malna Mains operated-delay b, ba accurately accuralaly oparated delay eet oat with can pointer. point#/a knob for p.,lods parlod# of of up 21 hr.. 2 contacta lullablelo aullabla to (o wltch awltch hra conucli mpl ampa 'econd second contact opana few mlnytea nut.a atter after 1st 1»t contact cpnlactosp. Hp. rated at 10 ampa. Thla ics 1 nlflcant malna oparallnp. dlepfey- For fi W2 S'/7n9t^^S fri i\' tii SMTHS CENTRAL HEATNG SMTHS CENTRAL HEATNG CONTROLLER pu Push ' h b J,1or> oltfa8 10 button glv.. 10 varlatlona follows. tollowa. '{1) (1) conllnuoui continuous hoi varlatlone hot water and aa (. c.ntrae (2) eontln~ H uoue continuous central heating l?) contln- UOU water central heating ott at nlghl hot nloht (3) walw (3) continuoue but cantrsl conlinuoul hot healing water oft wlter but at B central hbatlno h.atlng on only for s 2 perlode periodl heating " during the day (4) hot water and cantral central heabng both but day time only (5) hot water all day but cen tre) hwtlno both heatlng onty on hut only fors day fo,2 periods ilmo only perlode during t5) hot during the wale/ the day day (0) all hot day () hol watw but ceivwater and cantral healing on for2 periods during tha daytime onlyand ::;~rr!rh::~~r~rm~~:e then continuous for aummer ~~~~O::nt~'~:at\~~ :fl(~~~to::,; contlnuaul (8) (8) hot time hot water uae water day with day lime central time only only (ft) heatlnfl (8) hot hot water ofl (7) water twice hot water twice daily (10) dally (to) overythlno ev.rythlng ofl A haodaome handsome fooklng looking unit with wllh hour movsment movement and the ewltchei switch.. and other parts neceaeary neces.ary to aelectthe ect the dealred dellred programme of of heating. Supplied complete with We ofler wiring thea diagram. while Orlglnelly etocka laal sold at 6 we t5 believe each NCLUDNG at over t8. with wiring diagram. O,lglnally lold wa belieye at oyer 11. VAT W. oft,r hh. while stock. lasl at 4.,..ach NCLUDNG VAT and and Postage. POltage. LOW R.P.M. MOTORS LOW R.P.M. MOTORS Made by Crouiet Smitha C,ouz.t-5mlthl SAWA-Venner.'mUar ~r. famous SAWA Vonnor comoanloe «li and companles-ell luppliod similar lupplled... / reedy 230/2..ov SOhz malnl working ready for at at /240v 1 '" &2 n each. 50hi FoUowlng mains Following apeedb peeda n atock this thl. advert. n etock when preparing advert. \\ rav per dey day 68 r«v per day '", --~ rev per hour revs per hour 1 rev per mln 2 rpm rpm 11 rpm 'pm 4 rpm S 'pm it rpm rpm rpm EXTRACTOR FAN EXTRACTOR FAN C* Ex computer«made computerl-made by by Woode Woods Of of Colchester, Colchelter. deal for fulng fb,lng through panel reaeonahly panel-reaaonably qutat quiet running very runnlng-very powerful 2500 rpm. Choice of of two alzsa lz.1 5" 5" or or Oi" &i" di«. dla. 5 Sand and. FLUORESCENT TUBENVERTOR FLUORESCENT TUBE NVERTOR For camping-car repalnng - emergency lighting from a 12v well battarr distributed you can't light boat fluorescent and is oconomlcal. fighting. Wt ( will ofler offer nvertor plenty for ol it and 13 watt miniature tube for only J» with tubs snd tube holders aa well. MNJ-MULT MN MUL T TESTER Amailng, deluxe pocket size j n praclaion moving coll ntlrument > <5rT7^5 i stant Jawttled langes hearings lc000opv n measure tn- " DC VOtta 10. W. 250, i i?" AC DC vo am " l O-f ' w ma ' 1 5 ' end 1 K)0 CM - 00 ma ftw^ " "tvi PJ V Continuity Complete with end niutated raslstancs probas. ^t»k > faads. and nstructlona. hsttery, circuit diagram Unballevable Unbollevabl. value yaluo only only < a f«. FREE Ampa Ampa ranges,angoo kit kllonoblo enabl s yo you u f o 10 read,oad D DC C currant cu"ontfrom from ^ ampa ampl dlractly directly on on the(m0icse. hell-l0 cal t. t'llr a free if " you you purchase pu,chalo quickly quickly but bul if you afretdy own a mint tester and would Hkeone send 1 H. For camping - car repairing - emergency lighting from a 12v battery you can't beat fluore,cent lighting. t will after plenty of wall dlotrlbutod light and economical. W. oft., nyerto, for RM and 13 watt miniature tubolo, only p n with tuba and tube holde,... well. Amazing, deluxe pock.t lze pr,clllon moving colllnatrument /ewelled b rlnga-tooooopy-llln tant range. me.lure:- DC yolll 10, SO, 250, AC Yollll0, SO, SO, DC amp ma and ma Continuity and,.olltonco 1-1SOK ohml. Compl.te with nluloted prob... loadl. battery, circuit diagram and nltructlonl. "you alr.ldy own a mini loot., and would koon..nd &1 '''. l MULLARD UNLEX system. Rated one of the finest :~:::~~.~:t~ parlormera n ~~: the ~t~~:o stereo "R:rJ field f. < this lor almost would meke anyone a wonderful n easy-to- gift <wr 4' MULLARD UNLEX A malnl malne operated ltereo stereo ~. this would make a wonderful gift " for almolt anyone n.. sy-to-... esaemble amble eom-. plete with modular a pair form of of and Plelley Pfaseey com- < peakera apoakere thl 11 at 3O-but due to peelal bulk this should self at about 30-but duo to a special and as an incentive for to thil we after oner buy the end Yltem syatam aa an complete fncentlw# at at for you to buy this month wo only 15 ncluding VAT and poltage. postage. UNSELECTORS Jrv., c Thoea are pulse operated ii switches malic telephone as used n ewltchauto- By "* v - ' \ boa/da ate. The pulas moves A,*/ catod the selectors ere 25 '^K BW^Np ' S atnrvdsrd. 24v orl2v per- AF UNSELECTORS These are pulae operated wltche. al used n automatic t, wltchboardl etc. Th. pul mov.. the wltch switch arm a/m through through one polltlon. position, Exc,pt Except whir. where ndicated the,elector. are 25 fndlpolltlon position type. typea and 50v Coli Coll tandard. 24v or 12v oper ation extra at 2 per wltch. swttch, 8 e.. pole &1'14 6 pole polo 4 M 4 polo 7'12 7't2 a pol. pale &1'72 1. CUM.. t2 12 pol. pole &11'. &t 1«.. H 4 pol. poie SO 80 wly way 11'74 24 HOUR TMERS.dFRfe^' The one llluatrflted Ja' 'controls this uaea v r*-^-s ' 2 On/off'e per 24 hours 13 amp Contacte. l model one on/oft per 24 hours 3 pole S 10 TO 3 pol. pole pole SO 50 wo~ way 24 HOUR TMERS The one 11 ultrated, 'E' controll thle u,eso the tha Smlthl Smiths machanllm mechanism al as in n their lhajr auto eutosot. t. On/off'. per 24 hour. 13 amp contact. override wltch switch.». Smlthl Smiths 100 too amp emp =r:!e~0~~~c~:~1~':~er2:8t~o:~~ extra contrecis 1 -N par eel. AEG :'~:p 60 emp model t.ndby. on/oft per par 24 with hours clockwork hourl a... $, standby, one on/ofl xtra extra contacta conlacte t 1*04. per sat per set ^ NDUCTON MOTORS On. msdo Uluiuared lor TT c.tkl our'.(.rincftmut 11- tplndl. WSfi* ' 1" Brtck EJ 7S, 1J" Hack M», Vi MANS TRANSFORMERS - flv 29y 4 amp amp 1 20w n. 6 auto 3* 2 230v amp 11# H5S*^ i 25v 14" amp 2-tS. 24v i amp 2 M -Til NDUCTON MOTORS One lultrated our reference MM1t made for TT 11'1. tack 1il'l plndl, u a. i-.uci modol is, f! ~~'cr~ta~~ \l,!d~~~: :'11. MANS TRANSFORMERS Y Sv 1 amp t,... #0. t2v 1 amp 10#.,. 20Y 1 amp 20w aulo 230Y 1 '''. 1" f amp" 71. "3y amp, T. 25. tin 2' ,.. SOY BOv 2 amp 4 4.,.. M. 9v 2v 1 amp 1'5«. 1'''. 8 '5y48 5v-0-«6* v t i amp 1,.. loow 100w auto v 230-1t5* 2'i0. 2 8'Sky Bkv»'»..,.. Many more, more. aend lend for fist. l.t. y " MULLARD AUDO AMPLFERS All nk. n and modulo connection form, ouch bob, raid, data bum luoplted. comol«t«mod»j wllh bnl 1M WmW power output -M neludlna ^al,, PoitSVAT.. rtc-r -rci, Modol 1172 tw, power output 11 *1 W.LZNg ij/i-imt: - ineludlna Model CPWO0 Poet A «VAT. won powsr outpul attss^ ' twin "»e ncluding Po.t A VAT. EP 6001 ncludlno channel Poit or & etere* VAT. pra-amp 2 M THS MONTH'S SHP SNP ~. Sgfto*** Japanese mlde and match-". ng nu dacoder. made decoder. Two FM iteiri tuner teml for end Jaai matchle' than average of & ~.. the averege two. price Don't ol mlsa the tuner this, only thl., stocks 11 atockl will»? - MS <c#b glass not fait ~f:.!":lat'&~l: dial long. 1S-S*. Wooden caae with,.~ood.n cao. with ft!t J RELAYS 12 volte two 10 amp changeover plga in»5p. 12v twee ~:,:~~ 10 amp t::p1~:::ec:'1:;g::.vel:~~ changeover plug n V21.12* ~. two ~ changeov.r miniature wire.:red Mp. 11 volt op*" single alngle screw crew fixing two amp changeovect changeov.ra Dp. Up. 12 vott changeoverl &1 11. Latchlng volt open Latching relay three malna 10 amp malnl operated changeovera fi c/o contacts contactl ti a u. ll.mains Malnl opexeted operated three amp changeoveu r changloverl open type one on. ecraw acrew fixing ftxlno 1-«. &t 1S. Many othar other typea wllh with dlflarsnt difterent coll coil vollages voltaoh and contact arrangamants arrangements are n n atock, tock. enquiries nvited. MCRO SWTCH BARGANS ^ Rated at at 85 ampa ampl 2M no volte. volh. deal (o to make a ~- --^"1 switch f SWitch pan.1 calculator dozenl ~ of of other panel apdllcetlone. for a cstcoletor and for dozens., application. Parcel Pa,cel of for fo, Cl-H, 1' VAT and post poll paid. plld. ^37^ 25A ELECTRC PROGRAMMER BA ELECTRC PROGRAMMER Laarn n n your slflep. leep. Have radio playfng playing and kettle boiling as a. you yoll wake switch wake-awltch en on llghta lightl to to ward of of nstruders n.trud.rthlv. a warm house houla to to Come come hive 5, J '"JW# homo to. All thesa... and ond many atf>ar other things you con can do f f you nv'lt n an electrical pro wswc grammar. ^r,v,, [n Clock,n ' ctrlcal by by famoua profamou. fci.. 'Z,^Li ii J j^ jl meker, mailer, with amp cn/ofl on/oft switch. wltch. Switch-on Swltch-on time can be b. aet a.t anywhare anywhere to to etay ta~ on on up up (e to «houre. hours, ndependent 'ndependent minute memory b.autlful unit. Prce a H. VAT mlnule and mernqry and postage Jogger, poatage BOp, DOP. or A or with beeuttfur glass Price 1'5... front, chrome bezel bazel &.,. edra. T9rm». Price* nclude Port & VAT. But order* under 9 00 pleat* add 50p to offset packing. Bulk enqulrle* - Please Phone tor Qenerou* Dlecount* M# T.rm Prlc nclud. Poat & VAT. But ord.r. und.r 1 ' 00 pi... add SOp to off.. t packing. Bulk.nqulrl.. - Pi... Phone for G.n.rou. D.count. _ J. BULL (ELECTRCAL) LD <1. BULL (ELECTRCAL) LTD (Dept. ( P.W.), 103 t03tamworth RD. CROYDON CR«CR. SO tsg.. T'S FREE!! Our monthly Advanc. Advance Adv.rtl.lng Advertielng Bargain. Bargeln* L.t List glv gives d.tall. deteirs of bargain. bsrg«]ns arriving arrtvlng or ju.t just arrived vrlved - oft.n often bargain. bargains which sell 11 out b.for. before our adv.rtl advertisement m.nt C&ll can appear. - t's an nteresting atlng lat list and t'. t's free - lu.t Just send S.A.E. B.low Below are a f.w few of the Bargains still tlll availabl. available from pr.vlou. previous l.t Hits. MANS TRANSFORMERS All thou these have D ZM/Z46v /24tv SOH. KHz PrlmaFl/ Primary VOLTAGE VOlTAOt CURRENT PRCE 1w 2 1 ' " 2 1* 4v fi 5 amp emp t... r v 0v 7 «me a " "Sv e*8v j amp tamp.. e 5v «-5v } amo &,. "5y-O-l e-8*-o-«200 ma 5y l00ma 1 '. fl'5*-d-«*5v sv 100mA ' 5y-O-l ' 5y 750mA 7B0mA 1,11 1'..-0-1'3. looma 1 '., 6'3v «*Sv-0-6*3v.3v 100mA 1 '" a 6 2 amp Sy, t tlly S'lh* 5* + 8-5y 0-5*.p bsd winding 1 amp t ::::: 1 1t fiv \ amp &. t v 9v amp limp 'c' &,..... fi* 1 amp V core v fiv 31 a 6 a " amp amp s.,. OY 10* 25 amp 4... OY~OY Y-G-12Y Sv-O-tfiv 10v-4M0v tfil amp 4'32 1tv tv 4 i lamp amp,... 13v 13* tamp 1'11 12Y 1fiv &1 '" 12Y-O v-0-12v 1 amp SOmA 1 '. 1av-O-12v 1*V^12V 50mA '" 1Bv tapped'" 9v 1 amp v Bv 2 amp 15Y~11v 18v-0-15v 7 amp 15v~15v 1Bv-0-15v S4 amp Slamp 31 amp RF. TM TM2 TM 32 TM3 TM 37 TM 21 TM 21 TM 7 TM 33 TM4 TM 12 TM 12 TM 5 TM TMl1 TM 38 TM 15 TM 15 TM 27 TM 8 TM 7 TM 10 TM 18 TM41 TM TMf7 TMf7 TM 38 TM 12 TM3 TM14 TM27 TM 15 a,. 2' " &4 '. \7y tamp &. t v amp &, 20Y 1 amp 1 '. 20Y S amp 4. 20Y 12lamp a.. 2OY-O-2Ov Wv-O-ZOv t3y 13v COiriA Samp TM l00ma TM n.ut *SX ««'. 24y 24v 1J, amp TM ' 18 CS v 21* TM17 " * 4- + fi* rt 2y 7 amp fiomp 2 amp 7M17 TM 31 <2 3t 2 71 ll 17 24v 24* S." 21v 26v 4 H amp tl amp TM TM 40 TM J-7 Q 43 25v 28v 3t. :JOy 30* lapped u 24, _ A &. 12 3) 2 amp 31 amp TM TM C t«4'.»* :JOy lamp TM15. 37*. 6 TM 4»«S7' TM v 4Ovtappedlt:JOy,2OY&'10Y a 130v, 20v a 10* 37 6 amp amp TM TM S 4 fit... U 50v-2 SOv-2 S' 3v hrouded.»y amp with 6*3* shrouded Ow 68 amp TM TM TMt W 22 fifl 11 4-Cl. U K>v 45 Ov amp TM Cv-3 _ amp with 6-3* l ' ly shrouded 5 imp TM.hrouded TM # 7 S 99 all 75y 41 t 80Y " BOv v. tapped lapped. 60*. 60v &. 75v 75Y 4i 4 amp amp TM TM «100/ loov 7 1t COv-O-tGGv l00v~00v 1 amp tamp amp TM TM 2a TM 'i 7M. SO* 1:JOy tapped 120* 120Y i smp amp TM TM 28 3 S." 71 aa* ~ amp TM &V-0-MO* 25OY-6-25OY with 6-3* 8 3y 2A M t emp SO ma TM &, 7* «Z T AMv 250v _ SOmA too 371 SOOv ma TM TM TM «J ',71 E»m 3tmA A Volt Maine M"n. Unit, Unit. ideal d,.1 for power' 6 volt oqulpment, equipment, casaottas, C lett... recordar ampllfler requiring more tape than recorder the average or amplifier.verao' amount or of cyrrenl. other appliances current. Thie Thll s. a really reauy n plaltlc.. made for Radio ntended well originally made unit to in clip plasfic nto case poaltlon, mada polltlon. this lor Crown thl. has external Bsdlo xterm battery tyoa type conlacta contaeta but t s la a simple matter to solder lolder leads leed. suijaht onto these conlacta and thla unit employx full wave rectlflcatton ~:::~~~t~:!o and.~:~: la recommended ~:~:-=.:~:J~: in every ::~~':~~/r::!1 way. Price 4*3» 4~; Calculators, CalCU.toR. make,. Texa, nt.nded orlalnally &:~rct~~:c;~~:::~~~ to ba sold By at famous quite high mnkwa :~t~~'~~krp~~d prices like new Tsxas. and d~~~~ '!rtj.y~~ unused. niended Type origi Baelc functlone add, S ts. Type TlrP..-egain 1. egaln basic aublrmct, baolc functions multiply, function. but bul with divide rechergeabla etc. Prfce,ocheroeabl. nfcad batterl". 7'" tt.ry Ch.,..,..ame 2'7. nfced batteriaa. 1'7 Type TlrP. 3. basic Price 7*n. 3.-baolc functions BaHeiy function. but with Chargers memory for >*1. eama "11. Type Typ. 4 basic 4-b,c function" a, memory snd and rechargeabts rechargeable hstterigs, batterl.., P,lc p. AM/FM Price B4p, Complole.. ll. ho cal. polntk, pointer, volume Radio. control. CompTets control, Oft/oft chassis, on/off etc. Controls haa tuning Control. have scale hlv, oduewlao with edgewla. knob.... radlol b. Ju,t (nalde t~~:~':p. ~~~lv..:'r~n apeikor, tension Hnobi. Those radios then can R~~~P~~: you ba have mounted a ~n firs! on f':!t~a:~~~'mu~~c class or Jual "music nside whlia exb'':;:~~ than you work" han average receiver, end and oven RecBptloo even n ereas ar".1 where on both FM la AM-FM nototlouafy s better notorloully bad. good red re.ultl nils hive ha"e been obtained. The outpul output silao aloo is. ebova above average,.peaker la probablr.round "1-2. They can the be b. powered epeeker power by 6v 8Y batteries is probably batter'" or tlv around v power 11 2 supply, watte. lupply, n fact Redlo one ' deal. doubt the function Crown Radio as an AM/FM an# mentioned Tuner fm above Tuner-real bargain la datl. berglln at would **M no... + Mp. tp. UV Tubes...(Philips (Phlllpa Atlnlc). Atlnl.l. Useful lor 10' bringfng b,lnglng out water m.rb n atamps.peela' cotoufl n rocke,.'mlllr.peel.. m«ni. marks n men. We atemgs have these and special e n in two coioura af<«t lzea B* n H Cw rpcks. Sw price almllar 1*54 &1 se 4- apecj- + 12p. POll SOp + 21t p. POll 7Sp p. 1 Post Pole 60p Pol. 1* 4-. Way 4p. fitt WQ Switch, 20 watt Switch. for 2 Fo, dlflltaf M 4-1flpdloltal dlsplaya Post dllplay the 76p th.l poaitlona «p. polltlona bslng being paced through 3eO thera. no top. atop. Silver evenly Sliver plated eoeced contacts fhrough contacta are the ar. rated 360 of turn, at S 15 emps, and ampa, normally there s po an experalve expenllve switch,witch bul but oflered oftered at at Mp.. p each... ultable Morse :ft:~e Key, for ~:l'b.!r~~.::. beginners. This s Our well O~~ Pet, R~1.".'~r~P:~~y"a.~~"t.ble debloned. MKl, Price fully f edlustablt *1f. he*, key, Profeulonat Mo'" ca.t bate of struction. Prolesalonal ~t:~~':;.'si.h~u:~e~~~ thla Morse i high Key. J~ speed Heavy key cast key with base with fine ol flna adlustments. metal coned/ullmenta. Prl ce 3 *58. Our Ref. M K2. Termlnala. ~::::~:cc~::: Very good quality,.g::':n ~~:~~Yth~r~~~~w British made, ";.!,!:,; screw ::~~:n down type, d~:: hit ha' a top a hole accepti through a 4mm which plug. Oolld The.olld wire sc/ew may down be b. passed, ascuon afso paa.ed. wllh with nsulators ~r1~!a:_ for!:~, metal R:~~Tl~,n:~ panel mounting, 10r~r::~~g;or5 5 ~,~'~~.c~~~;;: oopular colours. Price l»p each, R«f. TS1» Of 10 n bag for 1 $, Ref. TS1/10. prino :~~~!t~~:~~e;::~~a~:~~~1:1a~1"'~~~:~'t:'~~= Triggar Tatmfnafs. Red and black termlnale mounted on grip nsulated g,lp lka like b a vice Dinefopprexl ylc. but bul connection mate n size n the fi}" he first x f.theeetetjnlnafa fl"l place s flufch Quick and lmpl. beck hel,lgger-tlulh n wlro-tot go of trigger, aefifiltaly almple. Hold donnltaly e time back tlmo saver. the trigoer push oaver. Price Mp hi n h. pair. wire sl go of triggir, kejetoft Sk.l.ton P,..Sot. Mlnlatu, , 10 for et. 12b. Relay R.lalr Baae. Pie-Set...*414 pin slanderd Miniature ltandord lot air# for many fi-sk, m.ny plug-in 10 ror 1*N plug ln relsys raleye Mp p, p. ~p. AC Malnl R.l/. Plug n to tondard bale, to changeover Mains Relay. chong.oyer contacti. PJug contacll. Price n Prlc. 1'#t to standard,. + 14p, base, 14p. but bul2 2 three * x amp 10 amp c/o contecte contact. 1 lot»..t basea baae' Up Sp extra... Heavy Noon Duty Dbr llv.v Rat R.Q. ay. This Thll haa h.1 33 pairs pain of of changeover chong.. yer conlscla contact. whfch., b'"er than ulual capabl. of of dealing which dnllng wllh eta 1815 amp rather (OiOa. bigger lhan usual and look capable loodl. Ditto but but. Volt Coll. Coli. Price Prlc. 3 U 1t p. l.p. Practical Wireless, June

6 BENTLEY ACOUSTC DAFt BKO ''10 KTn 1 00 pbnd UA 'H AA~' 18 1)1'17'... Dil" 1 00 BetS." BLn 1 00 KT" 1 00 '~O 1 00 ULU.0 AA.ZU tt B' DC1O 70 BC18 M EU,! O KTU ''10 P'L mno 1 00 AC07 11 B'111." CORPORATON LTD. DD' '80 EC90 ao ELa7 a oo KTS8 1 '10 plu 1'00 UUt 1 00 ACU 80 Bpl88 " 7 DF3a 7. BC ELn 1 00 KT PLa' '10 UUl2 U AC12' U BFYO H Dl'tl '80 EC17 71 BL KT pu 'U UY' 70 AC27 80 Bl'YU OLOUCSTR ROAD. LTTLHAM'TON, SUSSlX Dl'H. BOOS BLSJ HO KT88 H pllla..,. UY'2 70 AC2. BFY02 11 All prl... nclu.lvo.f V.A.T t 11l% Telephone 674) DPS 1'00 BOOU 1 10 BL' 'U Ll3 '11 plat 10 UY88 ''10 ACl" 11 BTlOO 11 DHOa 71 BCCH 1-00 BLlS.. LNU 71 pl' 10 U AC4 ad BT11' DH7S 10.CC4O 1 00 BLO 7. LN02... l'l'.. U12/1' 1 11 AClO. 11 BTl '" UlSA 70 ftp24.. 7V ' OBHO H DH77 eo BOC.. EL." LN nt U AC BY OB2 U SAN. 70 n, Y' 10 1AQ 11 OOLlGTl'OO DHS E0C2.. EL3S pl004/oo UU. 00 AClSO 10 BYZ0 '1. OC3 60 SAQ '76 61'26 'U 7Z, '10 19BG6G 66KU 1 00 DK32 eo ECCS... 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RVB pen46 1'00 UCLe UG 1.. DE7 to 8V R7 10 S6CO... B719 '10 EB'8'." B'll eo HVB2Al'00 PEN46DD UP41 '7. latcbd ''BAl81TOa.BTJ:- 1AC7 70 DTA.. 8U '10 OD6 10 B7U 10 BBF8P co EF181 '10 HYD UF' LP13(ACU. AClU. AOU7. AA 100)' 11. SAGO.. EWS 11 BXGT K7 10 sallgt.0 BL. J OO EBL21 a oo EF18' '60 KT2 to PEN" 1 00 Ul'10 CO pe k. 1/0C1D.. ' OC. lot. UG7 70 SE 1 00 BY6G " 12SN7GT 5W' N CL 1 00 EC BF KT8 a oo pbn46dd Ul' /0C4'.. 2/ l1c46.,10,. /ocnd... SAH." 8Fl 10 Y7G H '71 saza.. CV6.. EC BBD 7. KTS' 1' Ul'88 N '/Oca. N,.,"l., ' "t. un 70 U'G 70 U ~8Q7.. 30Z4GT 70 cves 1'00 UJ8.. BF~ ''10 7B Q7GT 3DZGT 10 CV.88 ea lpeotal ol.r 01 zno.11.,..., OU",,.t 1lew ad4.. n.a. n eaoll. AK6.. 11'14 to 7B7 HO CYC 1 00 tak 'll et B B6 1. cyn 1 00 A,ood... re UDUlld, t.,.ted, and. JUaranteed. Delp&tob charr :-GOp Oil.n order. belo".25 la value. Ord.," BAKS... 81'16 1'00 71' D8 a oo ooco 70 Dl 10 otcr 120 po'" free. Ordtn d.. patebed.ame da7 at receind.. ADY paroel llured al.d.t. damage D for Gp per GAL6 11 F18.. 7B UH7 71 OOCDG nu '10 parcel OWL Term. of buaid.. a... anable QJl req,oeei.kcy" in noek too lumerou. to l.t. Pt... enclom 6AX.'10 ns 100 7K7 ' '00 ' 00 DAC A.8. for reply to any quetiee. All prioll nbject to Qange,,t.h01lt notice. r;mrnrn[ujill~rn~drn electrldics S6A Fortis Green Road Muswell Hill London N10 3HN Telephone Combln_ TTL & C MOS 'or Quantity D iscounts A! 1t" n,,,,.a T h :lo, UJO, 1. t :J1 1JO, M"lnl~ ' n 11." SO.... CD4000 n " '2,. CH CD4oo1 n 7403 'S " n ls CD4002 S ,. J " '.5 A CD400C 15 7'05, ,,2' CD4007 n 7401 H ' '000 CD H 24 ' ,. n '45 CD n, " 375 CD " 375 CD40" ts :12 ' CD n 21 " ' 57 CD H n ls '. 555 CD40" A., , 47 ' CD ' 23 ' ' CD"'8 " 1417.Jt '31 25$ N.. 75 CD ts U ' 12.,. 41 CD " ,. CH CD t ls M CD4020 ' , '12,. CH CD " : ,. CH CD4022 S 'U " CD'on n n '15.. CD'02' A ' ls.. CD ' '15 M CD4028 '71 7'40 " t tj CD4027 ' t 5H N.. 75 CD ' N.. 75 CD t ' ," '35 CD'oao ~ 7448 S ', CD " N.. 75 CD "8 ' 51 5t CD ts CD'04O ' S U N CD4042 S U '14 U 75 CD '54 15.,. ' Z S, 13 'S CD U n 74; CD ' N lsa 131 CD '85 ' CD' H " M CD H 2U CD '., 315 A '15 M CD4054 H 7478 Z ls.. CD , S.. CD , N.. 75 CD4060 '15 7," " 2H '13 ls CD Jt. m '13 '115 CD4068 H ,sa 131 CD ' J ", 51 13$ CD4070 B' Ve,a.on 10+ 2~ n 131 n U 71 m f " " '1. t.,. U 71 m A " Tt m 71 m " m. U t U m.., 5H, '.. ' '13, m.., S S 70.. Tt '15.. "H 111.A : ' * 533 TMER * 4 for 94 * 21p.ach * * 7" Ol'-AMP 5 for 89 * * 2Sp.ach * LGHT EHTTNG DODES tu (nc. cup) Tll!.lORed TlL212 YellOW (H.B) TL218 Red (H.B) TL232 Gr... n (H.B) 2" (nc. clip) t. 12* tt '25* S.,.. -21* 215- f. Tll220 Red.". ' 11 T122' Yellow (H B). '24 t.. ".,... Tl22B Red (H.B) 11' 24 TL234 Gr.. n (H.B) (H.B)-Hi Qh 8rlahtnA"4i CD l 'ts CD'53CJ CD4543 '51,.. CD4S S C MOS " 1v' CD CD4077 zo 11 C CD4082 " CD4O5 11 " CD " CD " CD'OO N, ' 31 CD4S CD4508 'll 214 CD ' 13 CD"".. 11 CD CD ' CD4518 " 3 CD'~17 3'" 3'" CD4~' CD ' 15 H. CD '75 1 '13 CD452e CD " Post aqe and Packl n9 2Sp S' ' l>, ' m m.., 35 '175 ' '01 2 ' ' '17... m ua /O\J (8 pin) ua 710 ( Din) 45 ua741(14 pin) US ua141 (T09ll) '" ua141 (8 oln) 371 CA3ON1 TDA'200 2_ CA31231 lm1820 CA3130S CASl40S CA3048 CA3OJO LM3O LM38' LM382 LM3800 LM LM301AN (80n) LM308N (80n) LM33iN LM370N MCl330P MC13llP MCl415L NE340L NES!M NE!Ml '1 565 NE!M7 SN111OO3N SN7013N SN78023N SN71033N SN785S2N SN76C1SO'l SN71118N TA20S TA800 TBA810AS TBA820 TCA"O TDA2020 ZN414 ZN417E ZN423T ZN42n: ZN425E ZN034,, ' 51 H S 15.. t Z US '".. z.. '121 " n, 30 ". Z' " S 'S t S 31t..,..,... H J. 1 ls 12J va".bl~ 42-78LC5A WC V" 78_12AWC 12V... 7L15AWC 'SV 10 7il5KC 5V 'KC 12V 2 ''' n.hc llv 2 ". 78 SJC 5V t 1812 'C 12V f 78UUC 15V t 7118UC llv t 7824UC HV t 1.O"5T sv,,,. L033T 121 1'''" L037T 15/,,,. L28 SV ". Ll30 12V ". L131 l~v ' '''' TBA82SA ~V ". TBAe25B 12V " TB'ezSC 15V "" LM3'eK 5V.. NEGATVE 7905UC - 5V,." 7Q12UC -12V, JC -15V,,,. 7818UC -18V UC -24V 11 l OUR NEW A..C. OOKLET Suoploed FREE with order. of anv C, worth,... or mor. Contain. Circuit., Din connections 4 0.,. (35. nc. P&P f!old.,one). C SOCKETS ln., ln " 2" t 16 pin pin 11* pin 3'- 40 pin 51* 0- SOLDERCON PNS loo S" 1000 J." P E \SE ~DD \; it tems followed by a add V A 8% all othersadd12 5% ALWAYSPLEASEDTOSEEPERSONALCALLERS j.... i\' TRADE AND export CUSTOMERS MOST WELCOME O ~f>rse as C u sto mer s ded uct2 27 from tems marked With a 119 trom others 4 Practical Wireless, June 1978 BENTLEY ACOUSTC CORPORATON LTD. 7» OLOUCBSTEft ROAD. LTTLBHAMPTON. SUSSEX All pric«a nclualv* of V.A.T. 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00 DEOl 1-00 DKS2 80 1)K DK91 80 nxv? 100 nl33 70 nx9«100 DL DLfl DL29 <88 DL DLB 100 DM DM DW4 116 DY DY87/0-82 DY802 SO E80OO 4'78 RBOCF 600 E80P A AO KftS? 800 EH80C 1-10 Z22CO 4 80 E100CC8 00 El OOP 680 Kl02CC8a0 KlOOCO BOO S20OF B 80 Eiiia so EAAO -40 BA XABCAO -48 EAC91-84 EAP EAPAOll 10 BB34-60 EB21 25 RBC RBGA1 100 EBOftO 00 EBC01-88 K»PHO 100 EBF8J -«B RBFR2 40 KBL EC82 'OO RCAS 100 EC EC86-84 KCM -84 EC 20 <80 EC F.C27.78 KCCS2 100 ECC8 a oo KCOA 8 00 ECC KCC81 -BE ECC82 *68 BCCAS -52 ECC84 AO BOCSi -80 EC4»e 100 BOC88-72 ECC21 <$8 KO01B2 1*00 EOC MO KCFflO 08 RCFB2-40 KCFAt 10 KCHA C OO KCH ECHA1 88 KCHA 1 90 ECHA4 '78 K<JL80-86 KOL82 <80 RCL EGL84 *80 RCLfiA 80 EOL8 -Bi ECLL800 lo-oo EF32-00 KF BF KF EK80 <40 E810G 8 00 X82CC C OO KFfi 170 KF89 88 KF21 70 RF27-70 EFflS 88 EP18S 60 Flli -84 KFK KR20-78 BKM <70 BLS EL84 2*80 K SL EL KL8 100 BLB4-48 RAS -80 BL20 78 RL20 08 RL XLA ELA02 MO jtmo 100 EM6 190 J'.MB 100 EU04 1O0 EMOA SO EH07 1*80 K Mil 803 2*0 EYA1-80 ST *83 SO RT80/7 46 KYAH 100 ET9) -60 KYflOO >41 F.ZAA DO RZAO 100 *241 l-oo FC4 100 ft Y «Z« ft CS 4 M ft237 4<00 HABC80 10 HLUC 80 HLOS -70 n J.23DD 68 HL HL41DD 'OO HL42DD 1*00 HNSOO 1-70 JHVB9 i<40 avr2al 00 KYM 48 K2 SO KTft SCO KT32 1*00 Xt KT44 OO KT09 '90 KTflO 8 <80 KT KX8 too RT80 d<7f los '48 LW LM1A2 S LNJOO SO LR18 *80 M M887 COO J1C888 2*00 MHL4 100 WHLDB 80 Mtn* 1*18 11X40 1'DO NAO 100 N30t 08 K709 '46 r«*80 PAflCSO *48 PCB -lo PC09 1*90 PC97.74 PC POC84 48 PCC8D 87 PCC88 <81 KtXAO <42 PCC189 *80 PCF80 *80 PCFAS 44 PCF34 70 PCP80 87 'OK'JOO 188 PCF POPBO '40 PCP PCFBOO f 26 PCFSOO -70 PCL09 '69 PCLflS 80 POL4 W PCL86 M PCL0O8 88 FKN2fl l-w r*n PEN4BDL 1 00 PRN rkn4a3dd 200 FKNDD PFLTOO 1M FLU 100 PLS0 *80 PL81 49 PLAlA *78 PL82 '80 FL8t *80 PL84 *40 PL96 1<00 FLAO4/B PLB03 1-8A PL PL019 2'78 PT4D 100 PY81 00 PTS/9 10 PY80 80 PYll 80 PT82-40 FYOl -80 PYM 110 PTAOOAfl 08 PT800 <80 PY0O1 80 PZlO *80 QQVOS/10 OO Q8BA/ QV04/ gvofl/ RO 6-00 R9-74 UATC80 *48 UAF41-70 VBC4 <70 UBC81 <68 DBFflO 10 UBFfl9 -t UBL91 t-oo new -BO UCC34 40 UCC8A -fo VOPBO 00 CCf21 B*M CK CH8-80 UCL82-78 DCL UF41 70 OF42 l-m UFflO <40 DFA -80 UF89 <81 UL41 99 AA139 *18 VL84 0 AAZH l-oo AO107 UD» 1-00 AC uim 48 AC20 14 ny4l 79 AC1S7 UT43 79 Acisa UY8f 70 AC1S3 uto 99 AC1B4 80 1/19/ ACT 88 D13 tm AClfll L'lB 4*00 AC ) ACJS0 D90 M ACT48 44 D» 1-78 AC176 U8 1-7* AC u*? 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AO104. AO)87. AA199)' 8lj» p«r p»ck. /OC81D A 9/OCil. B0». /OC44 * S/UC4A. SO*. l/ocld. 4 7/0082 Sip. «>r S/OC8S "Tflp. pmuj oflar ol KF60 tktm. touis. ini otw and liatad, C meb. All loodi i>r«unviiad, and ruaranteed. DMptteb ohtjh: BOp on all ord«ni balo«9fl n vala», Ordnr* aror 428 part (n*. 0r<l r»drap n.m«da/ m rtoelrod. An/ paroel nmndl ilaiii»jjo la trad*lt lor 8p per parcel Term* ol bulccaa aratlabu on Van/ othir* la rtock loo nunnrou# to Hl. Plraaa anolom B-A R. for Kplp to aa/ qnrrlm- AU prfoea aahjact to cbangt wllboat paur-, elegtnnics 56A Fortis Green Road Muswell Hill London N10 3HN Telephone C MOS far Quanlity Olacounff Al" ft-m-; hi'l.'.n 8"-; V.A T 74 TTi. TTL c- MOS 1, 38 T 1U»» i 1 iw 1 M*inly»' V trftion 7400 M W u lot S SO 9 40 CCMOOO <18 u BS its CD4001 S 11 U D CtMOOT 11 is m S ns 33 CD4OO0 as f its CO4O0/ 17 S as S3 15 C04009 so 4» S 17 li C04010 St tas <7 44 rs C04Q C D n n CD4013 4» ts 2) «S S55 CD4014 S 78 TS MS CDOS « P7S CO4O10 <t B 73 CD S S 445 CD4M8 1 7» n JS C04019 S W 0 M to to CD402t> S SS 12 S 495 CD<021 S CO m S 4BS CD t n W 1 12 t «M CO a 743T n 21 t K - 0 CD i PS M CO u S its tt CD tn 7441 S CD as 744? l> 75 COOJB 1 Of s# 52 « S 1 33 CD CD to 99 9ZS M 74 CO403* «1 its CD4035 W B N C M 18 7S CD4042 « ll M U 11 C « S CO4O40 99 fl CO n M 1 35 CD «S f 20 C < M M CD % t? OS H 00* H OS M CO40M » 2* zas to CO40M Of OS M CD M n 21 U B 75 C 0*060 1 S US CD W *3 MS CD 406$ u as C S t 1 33 CO4Q70 20 B 155 SUPER SAVERS 5M TMER for -94 2«p # MCh 741 OR-AMP 5 for 89?5p each TL918 Rod <RB) CS'» TL232 Croon (H.B) ll*» " tl«c. dip) TL2M Rod >44' -11 TUQd Yellow (MB) n' 3* TL92B Red (M,B) 28* 24" TUW G' on (H.B>»- 24 (H.e)-Hioh BrlahrnoRo Uiti to-n ' 11* 238* (8* 255* * 285* ft* ir 14' 29' 115* 24' 145* W S* lm H B ff TO TS it S tt 93 its M M tt «TtS TtS 215 t-lt m S LNEAR.C."5 REGULATORS ua'ov (0 pin) 37 uatolfioln) 48 ua74h4 pin) J73 UA741 (TOM) *4* ua7<b (8 pin) 178 casom; TOA120O 948 CA3123/ LMlfiCO *238 CA3130S M CASAOS «CA3048 *71 CA LMMO -02 LW381 l-m LM LM3900 SB LM3909 fi LM301AN <8 pin) M LM308M 1 (Spin) M LM339N B LMSTON 2 44S MC1330P t 92 MC1M1P MC149SL 4 M NE540L 2 89 NE3M K*' NE86t 4 075* NCM5 t» ' NE SH78003N 2-41 SNT9M3N SN7e023N N78033N 2 4t SN78552N U SN 700 SON S, SN760MN THAtMS t T0A8OO P T8A810AS W TBA TCAMC 51 TOA2OTO 3 11 ZN ZN417E 4 88 ZN«23T 4*99* ZN424L l-m ZN425E 3 28 ZM034E 4 B«S 72i vafianlu 42* 7flLC0AWC 5V 90* ra_12awc 12V 19* 78L18AWC 15V 49* 7095KC 5V 2 tr 78PKC 12V 2 41" 78 5<C 15V 2 41* 78 BJC 5V 1 14* 7812 'C 19V 1 11* 7018UC 18V 1 14* TflTBUC iav 1 19* 7824 UC 2*V 1 19' WST 5V 1 39* LMST 12/ Jt* LOT/Tf 18/ 1 38* V 70* Lt30 12V Tt* L13 15V '7»* TBA025A 6V 1 18* TBA V 1 18* TBA025C 1SV 1-14* LM39K 5V 1 31 * NEGATVE 7905UC -3V 1 f' 7912UC - 12V 1 B* 7B1SJC 15V 1 f* 7918UC - t$v 1 f* 7924UC - 24 V 1 11' OUR NEW A4.C. OOKLET SUDOl'WJ FREE wilb orders 0 any C't worln 4 99df OlOft. Contains Circuits, pin eonnocflont A Data. (35o nc. P4P 1 f sold clone). -.C SOCKETS pin to* «14 pin is* il- 16 pin ia* 12* 24 pin a- -n* 98 plo» )t* 40 pin 59* 45* 60LDCRCON RNS M' SO* PLEASE ADD VAT Poataon and Packing 25o tems followed by a * add V.A.T all other* add 12*5% ALWAYS PLEASCD TO SEt PERSONAL CALLERS TRADE AND EXPORT CUSTOMERS MOST WELCOME Ovorseas Cuaromers deduct?i27from ilems marked with a 1/9 from olhor* Practical Wireless. June

7 Bme's LOOK! Here's how you llasle.. elecl.. onic:s. master electronics.... the practical way. This new style course will enable anyone to * mmum iomsiiiiiiii have a real understanding of electronics by a modern, practical and visual method. No previous knowledge is required, no maths, and an absolute minimum of theory. You learn the practical way in easy steps mastering all the essentials of your hobby or to further your career in electronics or as a self- self employed electronics engineer. All the training can be carried out in the comfort of your own home and at your own pace. A tutor is available to whom you can write, at any time, for advice or help during your work. A Certificate is given at the end of every course. < ] A 1 Build an oscilloscope. As the first stage of your training, you As the first stage of your training, you actually build buld your own Cathode ray oscilloscopel oscilloscope! This is no toy, but a test instrument that you will need not only for the course's practical experiments, but also later if you decide to develop your knowledge and enter the profession. t remains your property and represents a very large saving over buying a similar piece of essential equipment. piece of essential equipment. 22Rea~drawand Read, and understand undersland circuildiagrams. circuit n a short time you will be able to n a short time you will be able to read and draw circuit diagrams. under- under stand the very fundamentals of television, radio, computors and countless other oth~r electronic devices and their servicing procedures. procedures. 1 < < S *!Carryoulover 3 out over 4O~rimenls 40 experiments on basic circuits. We show you how to conduct We show you how to conduct experiments on a wide variety of different circuits and turn the information gained into a working knowledge of testing, servicing and maintaining all types of electronic equipment, radio. t.v etc. electronic equipment, radio. t.v etc. All students enrolling in our courses receive All students enrolling in our courses receive a free circuit board originating from a computer and containing many different components that can be used in experiments and provide,p'ovide an excellent example of current electronic practice! practice: To find out more about how to (earn learn electronics in a new, exciting and absorbing way, just clip the coupon for a free colour brochure and foil full details of enrolment. British National Radio & Electronic School P.O. Box 156, Jersey, Channel slands. P.O. Box 156, Jersey, Channel slands NAME WB6 ADDRESS ADDRESS " Block caps please Practical Wireless, June

8 GREENWELD 443 ^ 43 Millbrook Millbpook Road Southampton S01 SO OHX Tel:(0703) Tel;t0703) At Alt price. Quoted nclude 25p chools, etc. n'lolce UK/BFPO UK/flFPO prk««quokd pottaob. )nclud«poltlge. Moat Wo«t VAT. order, crdtrp Add d dim- 2Sp from - Export/Whole.lle enqul,l.1 Pitched palchftd on dfiy day of receipt. r«c«lp<- SAE with wflh charge schools, 5). Export/Wholesalo ate. (Minimum enqulrlea nvoice lilt allallable enqul, onquules pl«b»o. pi... MNMUM ORDER welcome. ORDR for lor bona-flde Wholesale.. ftde tr,der.. (raderft. list Surplus now available com- m.. VALUE 1. f. Offlolal Omdat order. ord«r« accopfmd ponentl ponenli alwaya.waye wanted. BUY A COMPLETE RANGE OF COMPONENTS AND THESE PACKS WLL HELP YOU * SAVE ON TME No TME-No "_,,,,. «Moyj rt in waldn. wojting for (.r ftart. partf io to como come or.ho,.. ahapi fa to optnf 0,," * SAVE ON MONEY *ulk MONEY-8ulk fcayinr...'in. ';'eon. ffioont /owoml ow... prjcet /avl ",'c --;u.t cam- com...,uti'. par* with othtr/t otll.r.' ir * HAVE THE RGHT PART No "ART-No.ue ffuoifwork wor' or mubrtifuffon,ubjt;tution nccoiiaryf necel,a,yl ALL BRAND PACKS NEW. CONTAN MARKED FULL DEVCES SPEC. ALL PACKS CO~TA~ FULL SPEC, BRA~D NEW, MARKED DEVCES SENT BY RETURN OF POST, POST. VAT V/o,T NCLUSVE PRCES. PRCES'. KM' KM» 5CV SOV cetamk ceramic plate capacitors, capacitors. 55i, 5%. to value 22pF 1000pF. Total 10 Tolal 210, of 1 each 2.:as W valuo «2pF to tompf. Kill Extended range, 22pF O 1lF. 330 KH2 values Extandad 113 ranas. MpF to 0-ljtF, 4,1, KOO3 Polyester capacitors, each of thomo KOCJ Polyeafer these values: 0-01, cmptcllora, 0'01, 0 015, , 02?. aach 00'033, 033. ol 0 ' 0'068, 0'1, 015, 0'22, 0'33, < , , O "'luf. altogether 4' KWM W F. NON Mylar 110 mltogalher capacltora, for capacitor., mln 4 foov 71 1GOV type. 10 aach each all an vafuas values from -looopf '1000pF to to.ooopf. 10,OOOpF. Tolal 3' 75 KM5 Total 130 lor CJ-7J KOOS Polystyrene capacltor_, value from Polyilytanm lopf 10pF to cbpacleori, 10 each lo.owpe. 10,OOOpF, E12 merle series ft 160V. Total 370 tor 12 «KftM :r~60,y~nt~~a~ Tsnlalum 37g~:~ bead ~!~':cltor.. capacitors. 10 ach ot the following: 0 i , 3SVj 0 ~ai: W~.~.'~~~t :::4~7~5tit~1 3SV; 10/ , 10/25'15/16 15/1B 1. 22/18 2-2, 22/16 33/10 3-3, / /3. all Tola Total 170 lania tant. lor for 14» ". K«7 KOOl Electrolytic capacitor. wording, llectfolytlc working, small am physical capaclton phy.lcal ska,.ze. 10 each 25V of these valuel: 2'2,.. 7, 10. thnso popular values: 1, 2-2, ,22, 47, l00"f. Tolal -lor J'51 KMf 22. KM Eniended //F. Extended fanae, Total range, em 70 tor a. above, 3 50 also '.ncludlng 1000pF. Total 100 ncluding lor Li 220, 5'" *9 470 and 1000>jF. Tolal Koal K02t Miniature fllm 5" rellstor., CR2S Mlnlalura CR25 or similar. carbon.mllar. 10 «1 film of each Z% value reslatora, from TOR 10Rto a.rl.,. rell.tors, 4M to 1M,E12 mafias. Total 610 reslatorm,,." Km Extended range, total remlmtorft r.,.tor, from rom R KM1 1R KMt Zener to 10M dlodeft. 1 M dlodel, 400niW 400mW 5K 5" OZYM. BZY88. elc. etc. of 3V series. 10 ol each.arles. Tolal value Tot.1 2S0 280 lor from for 1S-3» 27V to SflV. ts U K442 KM2 A. but each value Ct 17. 7* Am above bul 5 of etch vaiuo EDGE CONNECTORS Special SpeCial purchaae these 1'" pitch double-mlde-d purchase of hote 0 1" pilch double slded gold-plated connector. anables enables urn us to gold-plalod offer oner them at connactore less lesl lhan than ono-thlrd one~thlrd thcfr their original list lat prlcal price " 41Pi C1'Pi Up; * way way lop. 4fp; 21 way 47p; 32 way Tip; lip. SOLAR CELLS As used on apace.pace labi. labl, etc.. etc., theae thea. liny tiny collm ceua give O' SV aunllght. deal lor glva for powarlng 50uA d- pclwftrlng small O-BV amall C-MOS n sunlloht. C MOS pio- projecta. etc. Can be bannad banked togelhar together lor for lecls, oreater Size 18 1S 5mm. 3 greater 310r lor 1:10 power 1; 1010r tor output.»: 2; r for Slie 7; tt 1; 100 x lor for». 25. POWER PACK Wood grained matal metal csaa'oo c x M SO x ysmm 15mm malnl tran.forml' Wing 6V 200mA, mains 2 co-mx. transformir ocksh, J~~a~~ ~t~y~u:e~:i3:; ~~:kc~:: elc. PC board Only 75p. with ti" luseholdmr R'm C's, S-DECS S.-DECS:& A T-DECS S-0 C S-DEC Breadbomrd Breadboard 2 X5 T ; T'DEC DEC Breadboa/d Breadboard 3 t» SRENS Wort Work off 4 x HPT HP7 batletfes. batterlel, emit very 'Gud noise, alze 75 Mmm.-Use loud noise. Omm.- as Overall as Burglar alza Alatm 110 x Alarm n 75 n car. x ear, house. houle, worhihcp. workshop, etc ete, ONLY»-«. t ~ '5. PC ETCHNG KT MK Now contains q. 1nl. clad hoard, conlalnm board. lib. 11b. Ferric 200 Farrlc Chloride. aq. n. copper Chloride, DALO etchcfad etch rmmlal rlllst pen, abrallve claaner, two mlnlalure.ture drill pmn, blfft. abrnlve bit., elchlpb cleaner, etching dish dlah and (wo (nmtrucmtnl- natructions. 3 M.. tknm, SEND 45o 450 FOR OUR 1277/3 1177/8 CATA- C/o, T /10, LOGUE. CONT/o,NS 500 VOUCHERS. CONTANS 50o DSCOUNT. /o,mendment No. No. 22 GVES DETALS AMENDMENT /o,ls OF OF OVER SHEET lm%1 <gend TEMS (Send SAE SLASHED f f you've B0%ll already got got cat.) Our latest Barflaln Bargain Sheet s la FREE, send lend SAE for your copy. SAE for your copy. VEROCASES top panels front and Plastic bock loo and bottom ally Dsnels ront back J x 65 x 40 Ct» x x g x85x60 t 79 x x 50 J.J x85x80 3 n 150 x 12O x120 x 40 3 M x 120 x 2,51 301)g 3WN 180x120x x 120 x 90 Jon x120* SO xl40 U S x140x40 205x140 x x 75 C3 4 St 4) S x 140 x 110 1'12 VERO PLASTC BOXES ProfeSSional Professional polystyrene alyrane quality two tone grey poly- nlerts for mount ng ing PC boards with threaded inteftm lor mount Ox«x40 12Ox65 «M x 80 x 50 5O 2-4$ x 110 x 60 SLOPNG FRONT BOXES x 121 x 75/ /37'5 4 4'" t x x '" Potting bo*. 22Ox174x100/M box. 7lx4gx2<mm»M 71 x 48 x 24mm blach black or whlta"'p while Hand 40p controller bo* bo. 1Mx61x23mm 94 x a1 x23mm While Mp VEROBOARD Our packs vera offcuts biggest pacve sellers and of vero oflcuts sellers-and no wonder, are one they of our are amazing valuel! pack 1 68 pieces valuetl lo to mafce Each make up pacx a total contains area 7 or of 100 1D0 so. sq. na. ins. All pachs packs are the atma same Jirlce. price. t 30.ach end are follows: Ollows: 1 M each and era available «ft Pack alt 0-1" Pock 6 A 8 all «(t 0-15" 0 1" pitch 0 ' pilch pitch Pack & 0' 15" Pack C D 0 all mixed O-l" 0 0 1" plain 1 A 0-13" a.ailable welghlllb 3'H 101b. 33 Also J2 M available by weight 1 b S-K lolbs 50 Regular aize vera 17x31x0-1" lire vero x 31xO' 1" 3 2 to, H. 10 skips trips 15 17x3}xO'J5" x 3lx O'15" 1-71; 1'71; O 0 ' l" 1" plain t-u 1'13 DP alze 15 x 4-5"', tan accommodala DTP Breadboard accommodate 20x14 cite x pin 8, ica JSxS-S", Cs can VQ VO Board, size m 148 x TSmm 75mm CT" 0'1" pilch. pitch. Capper Copper strips trips n rows of * 4 to fscihtsea facilitate conslructioh construction with C's. Layout cheat sheet provided Up VERO PNS AND TOOL Spot cutler 0 1 p 0 o 1" 1'" ptrs face pins single cutter for Single aided 0T Sided»p/100 or 0-15 pitch 7Sp Mp/100 OT* 0-1" sided 35ipj100 OTS" pine 0-15'" pins double tingle aided single aidsd i5p/100 sided Mp/lOO 3p/l " pins double heets Up/1oo.CALCULATOR CHP Typa Type C600 C500 by G1, G. 4 function + constant. 8 a digit. Multlplexed lmple keyboard digit- Muitiplexed nterfacing output 24 ptn for pin DfL.. almple OL._ With comprehensive date + locket 1' DARLNGTON COMP PAR BD695A B0695/1o, and BD69BA 45V B0616/1o,--45V 8A TOW 70W plaitlc pla~tlc PNP NPN pair powerll gain 750 4A. PNP- t'». 1 '51. RESSTOR OFFER. Mlnlalur. lw 5% carbon film. but the leads, although full length have been preformed (or for vortical vertical the following values mounting. Now n ihe foilowlng value. only; eer. 150R, 33OR, 390R, 470R, 47OR, k. only: lk, 1W, 1112, 2k7, BSR. 3k9, SOR. 3kg, 5k6, 5kl, Sh, 330H. 15k, 22k. 3MR, 22k, 27k. 271<, 33k. 33k, 8k look, 820k, '_19.alue. altogathor. Mk 100k, altogether k, or oft each 620k, value, 1M 19 total valusft 1800 MO reals resistors tors for 1. Or 1000 off oft each value, va'ue. total lotal resistors tor for 45 ( h(s (thl. worka works out at p per rellstorll) SPECAL TRANSSTOR OFFERS Plastic Plaltic versions of of these thale Dopular popular lypes. typel. BC108-2, BC108 9, BCY7H low PN108<BC108> BCV at very lew prices. PN08 (BC108) r PN70 (SCY70) (BCY70) iafof l 14 for 1 PN72 (BCY72! lor PN1M (BCY72) PN08 (BCOO) 19 (BC08)... 0 _. 16 for 18 for 4 lor 1 PN71(BCY71> (BCY71) r tor 1 Complementary Power Powlr Pair, Pair. BD529 B0525 &&. BD526. B0528. Motorola plastic power, 60V eov 2A devices, devlcel, Mp la' offer affer price normally prlc. 5Qp Sip pair. 94p pair. Special Small signal PNP PHP ranslstors, ranllltor., flka like 2N37M 2N3702 (Marked (Mariled MSPS1218) MSPS21B) 20 fof.ot t. 1. TANT T/o,NT BEAD CAPS 4 C/o,PS--4 7mF 7"F MV. 5OV, nor- normally 14p Up each- each. Our spsclal special offer price 13 (or malfy r l. VEROCASES x140x110 *-12 VEHO PLASTC BOXES x 110 x 60 «3 ZS SLOPNG FRONT BOXES White 44p VEROBOARD provided BSp VERO PNS AND TOOL 0-15" pins double sheets Mp/100 CALCULATOR CHP comprehfinslve dale 4- socksi DARLNGTON COMP PAR RESSTOR 5% carbon film, OFFER. bul the leads, Miniature although 1W out at p per reststorll) FANTASTC HALF PRCE OFFER TANK BATTLE r tn, " ' :.0-,, T.V. GAME AVALABLE NOW TANK BATTLE AY-3-B7 10.C. (Normal Pricei 21 -SO TANK BATTLE PRNTED CRCUT BOARD Application and»«embly notes 4 90 TANK BATTLE BASC KT ( ust add 11 pushbuttons and cases) TANK BATTLE CASES with printed facia-plateand hand controls SOUND AND VSON MODULATORS Built, Tested, Guaranteed 5 50 :-'.&.4.:- " -... '.....: GLOUCESTER NDUSTRAL SALES AND AUCTONS LTD Eastington Trading Estate, Nr. Stonehouse Gloucester Tel: STONEHOUSE 4118 OUR PRCE OUR PRCE 2-SO OUR PRCE OUR PRCE 4-95 our price m-to * lorce Hide behind you oppenent b.tricadei into and deserting..old being the battlefield hit * dodge * three the enemr's forward mines and reverse screen scoring tank speeds * 33 * rotational tank lirmg angles range * is two-thirds shells tuvel of the in an binleficld aothent.c curved * Onirtjectory W- sound direct rotn che TV ok realittie battle sounds derived irons kit available synthesiser NOW se lenks move Snd fire in all dirertioni 9r black and white ir budget-priced colour add-on unit available shorrly. All Components Cueranteed PRCES NCLUDE VAT and Post Packing Make all cheques or postal orders payable to Teleplay ACCESS phone your order BARCLAY Retail Shop and Demonstrations- d Station Road, New Bar net. Herts. For further Details and Technical Help -phone For extra speed phone your order on Barclay or Acess Cords Shop hours 10 a.m.-7 p.m. i (M.S. (M.5. MOTORWAY-EXT No. 13) We hold regular monthly Auction Sales of mostly New Electronic and Electrical Goods consisting of Tran- Tran sistors, Triacs, ntegrated Circuits, Diodes, Capacitors and Resistors, together with Fractional Motors, Transformers, Power Packs, etc, etc. etc, Phone or write to be put on our Auction Mailing List. Why not get in touch with our Mr. Jack Bailey and enquire about our terms for the disposal of your surplus stocks etc. etc, through our Auctions. Auctions, 6 Practical Wireless, June 1978

9 R RST VALVE MAL ORDER CO. CLMAX HOUSE, FALLSBROOK ROAD, LONDON SW16 SVV16 6ED SPECAL EXPRESS MAL ORDER SERVCE BCY72.n BF114 X81 BCZ11 so F15 11' BDll.5 AA, z. OA70 31 OC82 " S271 22' 2N697,. 2N1055 '5 SEMCONDUCTORS BF * BF195 Serle. OA S278 o S' 2N618 o 30 2N '" BF1" BF1K f, f* U' 11* Sertea B2X61 8» OC02 BY OA C84.. ZTX ' 2N705 0 '" 2N3441 ASY28 "41 BC51 "U' BD21 BF17 Serlel OA OC22 AAY ASY27 'SO BC187 13' '4' 'SO TX08 0,.. BD23, AAY ASS ' U BC170 AAl13. t.. BFlOO "32 CRS/l05 4S OA9O BD24,. 0 ' 25 AS "25 BC171 0 '14 AAS 03' AS17 Z5 BC172 0 " 3' AAl17 o u AS20 0'75 BC ' AC07.71 AS21 "SO BCln.,. ". BF BF ' SZYM 8 11 OC OC SN698 tn700 1 '12 2N3442, t BF20C 8 Jl OC23 "11 TXO 0 12' 2N N3525 '" 0F224»* CR 5( OCW 1 54 SN7««0 t Q OC N708 CRS/140 0 OA 0" OCl 125 TX300 0 '12' 2N N3814 ' ZO BD31 "5' Bf244 BF244 "35' 8 11* CR 3(140 Q M OCt N7C8 8 C«12 CRS/ OAS 0 " OC40 TXlO 1 '13' 2N131 BD32 ON BF 'ts 0 '" 2N3702 O-U BFW CP 5( N9M #28 " OA2OO,." 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10 1 Marshalls (!ome ad~a ~deat A. Marshall (London) Ltd, Dept: PW London: Cricklewood Broadway, NW2 3ET Tel: Telex: &. 325 Edgware /Harshall's Call n in and see us Mon-Fri 9-5, Sat Express Mail Mall Order let Tel. orders on credit cards 10 min. Trade and export enquiries welcome mln. Road, W2 Tel: Glugow: 85 West Regent Str, G2 2QD Tel: Bristol: 1 Straits Parade, Fishponds Road, 8S16 2LX Tel: Ntn 2_ 2N1131 2N303 2Nl1OS 21' Nlet3 2Nlm 2Nlno 2Num 2NK 2N2183 2N N2217 2_, N2221 tn2222 N2270 2_ 2 1_ 2N2483 RhlN13 2N2848 2Nl!848 2N?804 2N2807 2N2823 2N2824 2N2g25 2N301 N3020 2N3053 2N3054 2N3055 2N3108 2N3133 2N3242 2N3250 2N3301 2N3302 2N_ 2_ 2N33i7 «'J7 2N34J7 U~ *7 SN SN4062 ~= 'ts «== :-:1 =~=~ :. ~ ~~l:: ::: ll,':k :. ~: :::» 2N3<41 0*2 2N4t21 ZN4122 fl «~~=~ ::: 2N3442 ~~m~ nr -XT 201 2N N4T23 -*7 ~~= ::: 1 2N5248 «2N9293 2N52M AF10ft 44 AF109 0 AF114 # j BC82L BC1B3A BC1MLA f AFU8 ~~m :~: 78 ACW ~g~la: 12 U JL^ $wte <utd cfif & yneacdeal A. 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LM.'SN " MC438CO S SNlS544N tfl fin370r J;JJ; SN42M t n 2Nfl1fi ecioa 1«' BC259A B M CA3020A»» 1 CA3090Q4-48 UM380N (.Ml628(4 N MC433G5 «8NT0228N1 CA330 1-N LM381AN2 70 LM1830N M MC143SG 2 20 SN7ft53lND't2 S5 tmiailn 80 MCliaaG-TS SN70552N1M CAS LOaSTl 'U LM312N n.. SN78 UN " 0 ::: 4f : 2NS7M ~~ 3N4BS2 0,0: ' 1.4 ', :~:= : 17 2Nfl2M fl fd BC «BC257A BC8MB CA '48 CA LMJfllN 81 LM1B4SN H MC1*40S1«3N79533N1 -M ~n~= u: :gl~~ ::&1 :g::: u: CA3O3 1'10 LM14H t u LM384N 1 11 LM850N 10 MC48!!! ~ ", 5. C LM301AH o U, 2N3708 ' S BC14. a so LM388N,.., LM889N 10 MC488L 3 U SN78548N " 27 2N37W S'JJ 2N astoft 28 BC C238R Oil CA138Z CA308a tt L0B3T1 8R i.m3«2n 1 n LM1H48N ft MC1M0G2 15 an7u44n1 88 C28A ' U ' U 2N~710. Z 2N a BC2t/lB,. CA3028A... LM3O.8 _ LM387N tt LM2807N-8 MC1489R 3 tt SN '27 2NW10 W 2Nt3W 2S703 3 BC QCCfllA -25 CA3026 QH LM1UH UM301AHS 2-75 SO LM3S9N MWN Ml S LW1B50K 1 «MC14«R to S^7!!5i5Nl'fl9 LM1BS9N 4 #0 MCliBaJ. 1 «i $N7flS(6N1 M - LM388N.. " MC488L 25. U 31 2N3771 S 2N3711 "Z 2N BC C283B,. CA3028B S LM LM2987N-B MC495L se SN :.. M 2*«712 2' J f J: 31 2N4401 2N4W2 M M BC115 2N t M BC8. a BC284B S CCAA!!!A'. :!! LMLM~NH ',. f re 2N37t4 M 2N44«2 a BC " n 8Ca»B 88 fl'h LMaoi-s n LMSflTN :~:~:: 1 S ~= 0 10:= ~ : ;: :g:~ ::g :g~: :1: 0 31 P.N3794 ' 00:!! 51 t=~h; : " MC152iG71O HT _. -.- LM330N SN78570N.. 1 «2N3715 2N4403 CA303J 50 LM308N 45 t~~~~n ~:: MM SN78820A:' PN37S4 T* ' BC BC13S 9 0CM3B BC2fl4B 28 #5 CAMOTB 1 25 LM3M 2 99 LM338N SO 1-18 LM2907N-6 MC 490ft 3-18 SN !NN~!U70L 0 13 n BC37 ' 11 cmc 0 11 ' N N4W2 0« N31li _. - _ t 1O BC o a g~=a =:~ ~g~~c n: a l6. LM3401N a 55 MM SN7883GNU "15 25 ' 2NM20 U 3N4670L * BCSOTB ll CA CA3029A0-M 8 75 LM307( l.m3a9n N 1 M MC14$8L UM308H 1» Lf/555CH 18 LM2087N-B MC1495L 4 S» SO SN H MC1529G BC BC308Q 0 2N3820». 31 3f 2Ni071L 2N4371L '10 BC40. BC323,. CA LM318N 1 15 LM702C..., i LM3800N... ~~~ :: SN768Ol1N N3821 ' M 2N _ 0 11 BCW,.. BC331, 017 o n 23 2N3321 9N3S27 «2N48B9 U N3827 'X a 27 2N4901 2N4«1 1 t S '70 79 BCt38 QC309C 8 18 CAa03> 1 58 LM3WN 0 45 LMM5CN1 39 LMS301N M MC4024P 2 29 SK7fl570Nt BC327 CA3CaOA2 «LMS»KC1'f5 UMTdtB 2'M LM3302N 0 55 MM 5314 t SN79820AN 7 SC140» 8C CAS LM87K»K LM701C 2 89 LH3401N 9 W MMMC.. _.... BC142 e zz BC414.n g~= l : t:~m l; t~=ln:: ~=~ ~ :. S ~~l~nu: 2" 15 LM708-8 ' 51 LM3011N NE580 4 se SL611C 2 75,n 17 2N38WA 2ri49ft? '10 ~~=A :.: :~:= H: ~~~~8 :.:: :gm ::l: i :g:l: :. ;~ 4 10 LM320T LM o u LM4250CN : : ~ 2N3858A o tt 2N ACU.... C ~~~ ::: SL612C z n 17 3N3fl55 JS w 2M 40596»n 0C141 2N4«« BC14Z 32 BC337 '2* C A LM31BN 19 LMT02C «LM3000N 18 MM SB 4 20 SN79M0N1 «BC4t4 28 CA9035 C547A 013 o n LM320MP SLE120C 3'1S N3adeA O-fA 2N1W4 1 «ACtZB 41 aci N3S53A 2N3858A N1««2N4805 Z Z 40 H AC BC BC4f CA303fl 1 #5 LM320T LM320Tl?2t5 LM703LN 1 18 LM3805N 1 15 HESK» 33 SN70H3N» H 0 15 BC41fl H.. C CA3038A4 A 3030 _ t 99 LM320T152 LM UM3909N 71, NE SN79WflN8l# 19 LMK0T242 S LM709-0» LM3911N 1 10 NE560 AC12S '43 C153 '31 BC547B U CA3040 S, '.15 LM71o LM78L05CH ~~= l.u SL821C _A, a 2N42O 0 13 AC1S1. 43 BC BC N5550A 922 2N42S0 2_ ' 11 2NS088 e. AC52 54 ' "1 BC54iB 14 gt~ ;:: LM320MP~2'5. t~~gn :.: LM78U2C~ 15 NESl7.. ~= :.: -75 2N3ttO «18 2N60W 0 83 AC128 M AC BCt«4S BC1&3 O 75 2N_.. 2N5O7. AC53 ' -51 BC58B. 15 BC558. S Z a LM320MP5 LM723C-14 NE558N t.. Sl.e4C N38«2 N N N5088 AC53K. 5. BCl598, n BC CA304S \S. 43 LM78L15CH NE571N 4'1S SL70lC M 2?mot 1 fl W 8 30 AC BC1M 8 38 H BCS47B BC547A CA M3WMP5 LM LU4S50CN MFSfll 4-» SL610C 3* BC OA 30*0 J H 2N6CeR 30 AC1M AC153K BC157A BC163H 1-15 BCS4BB 11 CA3fHl N N508i 0 30 AC BC80. ' BCY54 Z 40 C43041 o n LM320MP24 ' LM728 S O. 1. SAS TAA283 J o «l 2H3W «2N50e2 " 12N3905 ' 11 2NS29 o n AC176K 0 90 BCle7B o ts, Bcns ' U z a ' 0 LM78L24CH 2 70 TAA300 'J 35 2N3W5 2N5129 e M AC178 #54 58 ecuoa ii Bc«a i-i CA3W2 #5 LM3S0MP1Z 15J LM710 1 LMT #4 t VJ NES82 SO SLflUC 2-7* 1-15 LM711CN8-72 LM7BL05CH NF565 4 '50 SL81ZC 2 75 S NESM 38 slbzoc BC BCB59 2N3906 H «2 AC175K 2N N5130 2N513O t a 22 AC1B7 H 6C107B»*28 BCYM CA LM220MP15 LH723C 75 LM7BL12CH NE SL921C 3-73 ft SL823C 25 CA304B M723C-1* 2 44 CA3Wfl 0 77 LM320VPa4 45 S NE558K LM7BL1SCH NE371M 1 M SL640C 4«SLMC AC87 o B$ 51 BCMB *** 0CY5S BCl68B e 13 CA3:J47A 3 70 ' S LM741C-81 M 1 15 SAS580 z H BCY70 17 CA3047 2N N AC7K, S BClt111B ' 11 BCYl CA LM33tN.... LM74C740" LM7B05KC 240 ts 3* 2N35M 11 2N4031 «085»?NSt31 22 AC107K 85 BCWB ' -55 2N5137 NS137. a ACl BC70B 11 BCY72 11 CA LM34OT5.... LM747CN.... SN1OO1N. TAA350A. n 17. S 2N AC88K... BcmB. n. 43 CA LM34OT12... LM LM712KC SN75003N2. s " -17 2N4032 2Nfll43 22 CA LM340TS... LM748-14' se 1 75 SN78008KE TAA , : if l~ 2N «H 8N5W 22 AC168 AC1KK BC170B 12 B BCY CA3C147A3 2 «15 LM7» BM 85 3AS50O L701C LM323K «'85 LM741C 70 LM7BL24CH SAS570 2-TO TAAZM 'M BCYTa 26 CA30*fl 245 2N4O30 ~~= -72 ::~ 2N51M =~~l:g :::: 51 ACY H 86 BC171B 17 BCY78 CA St LM339N LH340T3 8» LM?41C-ai» AS5M Z 40 TAAMO TAA320A LM741C «ACy22 ~g~~ 8 ::: 85 BCt72C 15 BD # LM340T120 M LM74VCN0H LM7B08KC SAS SNJB001N1M TAA3S0A BCT73C :gg~g :.n! 17 <80131 :gm 2 :::» C A3 061 in LM LM74B4 S8 «CA t LM340T24... LM718,.00] LM781SKC.. Z'O CA3~S3 OUR NEW 191B CATALOGUil C A L M340TZ< 0 18 LM S-M LM7B12KC SNTflOOSNZ 38 'TS SNTflOOOKE TAAMt 188 n LM34PS. 80 LMOO 050 TS SN75013N 51 TAA5S S AVALABLE NOW CA3054 " LM341P20 1O LM LM7824KC SN75012NO TAA580 LOTS z,. OF O' NEW FRODUCTS PRODUCTS AND DEAS. CAM MM1P128 LM341P5 fl flo LM716 t-flfl LM7815KC t-m TAA522 Mfl HO K LM900 0 M 73 SN76053(4 H TAA5W DeAS. CA3059 CA Z" 18 ' LM341P15» LM34P15. W LMB11 «LM7S24KC SNTBWZNO TAASOO 8 'll *1.. LM981 LM921 SO. se T t -75 TS TAA570 t-29 z. PRCE 4Sp 45p POST PAD OR 3Sp 35p TO CALLERS. PrlCBi P,lc carrbci correc, at otl0 10 Ma/ch March All prlcaa price. (ncluds include VAT, P p" A p 40P 4Op. _ 1~ TrriiflfllJllJS S T^rlUPliS m TRAMPUS CLKCTRON1C8 LTD., W-W GROVt ROAD, TRAMPUS ELECTRONCB LTD..... GROVE ROAD. rrrd l WNDSOR. WNDSOR, BEftK9. BERKS. SL* BU 1H8. HB. TELEPHONE WNDSOR (875]S> (07535) ' Si5» Ca8h and cheque orders over 5 POlt free. Credit cards by POlt or phone 5 min. Post... Cdth packlna irtd 2(Jo. crtaqua C.W.Oordar* add Over VAT S to po9t price* free. marked Credit cards 9%. others hy poet or. phone Free prfce E5 mln. lltt Poel of o jr 4 loll t=f~::g~:.~' ~~e::!. ~~!::p~~~eu'o:at~: ;:.~~ ~t~~!~ ~Wc::::e~rl~r ~~:~!:r~ makara range makers apeclflcatlonf. eend addreaaed envelope. Ooote this Ad, aa prices may chanae. All devlcea to speelflcatlonl. Normally 24 hour turn around.round on ord»ie ord.r. for ex stock product. FULL SPEC PARS PAKB C1 1 Yi4 V : x LM301/14P LM301114P 1 1' * PAR PAl( A! A: 12 red LEDa LED.! 1 Ux U: 4 X x t la A 80V 50V SCR El 1 C:4 B: ~;: 5 x X ~ 2N30SB 741 ~~~03 6 PN T03 JJl =;: NEW PACK PAC( O: 0: x 220 mfd mid B 63V 3V PAR PAl( D112 D: 12 X x BC109 BC08 fj. \. eractrolytlca electrolytic. Cl 1 PAR PAK 0;7 G: 7 x BFY61 BFY51! 1 DEVELOPMENT PARCELS All 5. «: H: 7 x ZNMflE 2N3819E FET 1 8ET1; SET : x WV 50V cammlca ceramic. 8% 6% 10 each K; *0 x in<f4a! B:* ~~ ~o: * pairza ~::1.c: NPN/PNP 1 22p1fo0'1uf ft* SET V~t*:Oia~~~ 2: Tantalums.. uma iuf 1ut to ZOOuf 200uf 20V to 35V 5 35~ PAR PAK N: M 80 OAai/91 OAB11" 1 oft PAR PAl( P;M P: 20 x P/BCt09 P/BC108 1 t SET 31 3: Efactrolytlca Eloctrolytlce 2SV 25V 10 each 50 1/2/7/10/ ofl 5 1/217/101 PAR PAl( R: 14 X BC107 1* "' PAR PAl( 8:14 S:14 x BC108! 1 SET 100/220/503/1000uf SET4:+wottS%CFra..'or.l0.achOO 4:4 tvatf CF reafatora 10aach 10D 5 Ts T: 10 X BDt Typa Typ. 101 Mag V: 50 x 85 mtd mid lov 1 to 1 Meg total MO 5 10V 5:.. 400mW 5 volu X: 4 X 555 Timer i 1 \. STS: 3V to 1033V 33V Zenere <100 40C'mW (loo Off) 6 each 20 valuea oft) 5 Z; Z: SO 20 x PNP 7302 Type Typ. C1 t SET x,: Preeeta Preset. PR VERT 100 mixed 9 SOUTHERN VALVE CO. GO. SSPSS^V.fA"" :~~O:i:~i~,RH~l.fs~ERS 9^ ROAD, TaUptiona T..phon. 81-4*8/ MAL ORP1W ORDER ONLY. ONLV_ HfNMUM MNMUM ORDER ORDR jtp "p Bome Som. leading.adlnll mahei malt.. available. avallalrl.. VAT /n»v/ca» n."ce. luutd luued on rtquwsi.,_.f. AU New and Soxed."QuantY' > Branded Vctvea. Outranteed 3 montha. BVA etc. "" N.w.nd Boxed. "Quail,"" B,.ndid Valve Gua.. 3 monlh BVA.t. CTd (Tungaram. etco. etc.).'" % All Aliow;all owed Jn lieu leu offfy 0' uarant arantee 1 Atready Alread deducted from eur our Pricat! Prlc"1 NOTE PLEASE VSfUfr VERFY CUftRlhJT CURRENT PR/CES. PRicd Correct only at.1 l/mt time of po/w goln, fo to pftu. pro... DYB9/^ DY68/7 Upl _ EF8fl EFS 54p GYM1 GY501 i'»j U 1 PCF602 7«P lip PU3fl PL~8 Mp ipysooa PY5OOA&1'" f 'H OY802 DV802 SSp _ EFW EFi 85p! Sp PCW PCS Hp 7tp PCFK«PCF$lS Cl'ffl t." PLS1A PL81A HP Sp UBF69 UBFS; «P Gp ECC81 «p 53p EFiaa EFl83 UP 51p PC88 PCSl 75 lip p PCF&M PCF80 Tip lip PLM PL83 Hp "P UCClfl UCCJ6 HP Hp ECC82 53p EFl84 55p Pet7 72p PCF808 ~1 7 Pl.e4 sep UCH81 SZp FCCW up jefls* 59p PC97 72p PCF80S 1'70 Ppt*, Hp UCHM ECCflS HP ~gg:g up H90 ::: ~tt.1jl Op ::: PCfiCO ~g~ 5p g: PCLK m: Hp PL600\ ~: :t=} 101 UCU2 «8p ECCB5 Hp EL*! Hp PCC84 J5P PCL83 Tip PLM4/ 1.. UCL83 ~gt:: ::: ECH81 HP CHel Up Sip 1 iflfl* El.e4 98v ti PCCS5 pccas Hp lop PC PCl.e4 LB*. Hp "p PLMfl PLSO 1 &1 " 48 UFS9 um Hp lip CCHB4 ECH84 HP; "p ELH» EUO 2-71 U 7 PCC89 PCCS Mp _ PCLM PCU15 PUO.. ULAl lip ECUW ECLBO 52p BM8* EM84 Hp "p PCC189 PCC188 Hp 55p PCLBOS. PC.805 } M "p P' PU09 PL518 3 PU M UU 1t ULB4 Ul.e4 KMp p ECL82 ECLB2 HP! S!~ Ey«/7 EY88/7 44P.p PCF80 PCFBO 79 lip P PCLflfl PCU 'lip P1-802 PL802 2H a.. UY41 5p ECLflfl ~~8'r :: mg 1..': ~g~roo r.: :g~ lts UY*l 70^ EVMOA 1» PCFaa Hp PCL200 fl::: PYflfl m~o MP UY05 SMp ::: p tfbo 41 p EZ80 42 D PCF PO PY80O HP U26 ~~85 ::: EF86 EF85 4Sp: 45" lezai EZ81 «4P 44p PCF801 PCFBO 52p PFL200 88p. Hp PYMU PY801 Hp H p U2B U21 «P lop Wa W. oiler oft., ratom retu,n of pott... arvlea. _c CWO ONLY. No C.O.O. C.O.D. MANY OTHERS Port P... free over Dv.'». t. 4 a to 2»-75p Zt-7Sp (ma*.) (mal) AVALABLE teme tem. n atock stock at time of colng going p to preee preaa but «ublect_to_comlble aubiect to ClOtslbl. merkat market flucturtlona fluctuation. f (f iinavoi?bale. unavola. ble. - QnevBlva One valve poat Hp, tp. each Stra extra valve Bp. 6p. Large vatvoa valvea 2p eecb each extra.. MAX 75p. LSTS AND FNOUlRlES. ENOURES. S.A.E. S PLEASE ALL PRCES PRCeS NCLUDE VAT tlx- 121%. ENQURES WELCOMED WELCOMD FROM TRADE and... d RETAL RTAL ream# (... prteea) prle..) WE ARE ONLY A PHONE CALL AWAY )&PB WEST LONDON'S LARGEST RETAL ELECTRONC COMPONENT STOCKSTS.~P &.O Jl (A FOR WEST CONDON'S LARGEST RETAL ELECTRONC COMPONENT STOCKSTS FOR FOR FOR RESSTORS POLYESTER FUSES HARDWARE TRANSSTORS CHOKES NCLUDNG POLY- POLY METAL FLM CARBONATE TRANSSTOR KNOBS DODES FORMERS METAL OXDE POLYSTYRENE PADS THYRSTORS CASES CARBON FLM TTLCMOS WRE WOUND SLVER MCA TRANSSTOR SCR's L.E.D.'s FERRTES POTENTO- POTENTO TANTALUM SKTS SLEEVNG RELAYS METERS ELECTROLYTC METERS WRE AND CABLE LNEAR C's TRANSFORMERS CRYSTALS &. PRESETS TUNNG CAPS MANY SURPLUS VERO PRODUCTS NDUCTORS BULBS & HOLDERS CAPACTORS TRMMERS BARGANS P.C.B. FCANS LENSES &. NEONS CAPACTORS TRMMERS flj~!p & cjl:cp1&o.jl: (a (MM* JLWmiu ' )&1P8. WE ARE ONLY A PHONE CALL AWAY Trade: 270 ACTON LANE, CHS\lVCK, LONDON. W45DG. Retail: 2t7 ACTON LANE, CHSWCK, LONDON. W4 5DG. TEL: Registered in England117tJnO. FOR BARGANS P.C.B.! F CANS Trade: 270 ACTON LANE, CHSWCK, LONDON. W4 DG Reisir: 217 ACTON LANE, CHSWCK, LONDON. W4 SD6. TEL; Rlglslered n England 1173m. 8 Practical Wireless, June 1978 FOR LENSES 4 NEONS

11 45 WATT MONf> K EASY BULD SPEAKER OY DY KTS DSCO Specially designed by RT for cost conscous hi enthusiasts. kits ncorporate teak simulate EM113" x 8" (appro., - ~~~- ;.~~~.~~~~~.~ -~~""~ J AWP AMP SpiciaHT(!fl'g"'rf^*^T VC lor jost O conscious hi h imlmissts. these VMs [35 p & p 1.50.,.-. inco'po'aii two leak simu^ile enclosures, Sire Size appra*. appro. two fml 13" X r (appro* 1 woofers, two wrxsjvcr 131"', sr', Si"..::.:.~':" -. '"'!'J.J : C' t^cete(sand tweeters a a pair Ol of matching ng crossovers it 20 WAT WATT STEREO AHPLf AMPLFER ER f29 4S 2990 watts rms. 90 watts output. elg fe at ure s ( Suppliedcomplele complete wilh with an eas* easy to to lollow wails ims. 90 waits peak nuipul.sig leaiuies follow Superb Viscounl V lv uf»l umt m f' leak finished cabinet. cabmet. mclode n ud e two disc disc inputs n both loi 101 teram'c cera mc cailndges. cartfldgl! s. tape 28 0 circuit dagram fasca w~lh [ontrols p nput ne input. m l ltlng fofiod cuchit diagram and crossover components Silver fascia with aluminium rotary controls and p & p mpoi and microphone mpiii. level rnmng comiou con tr ols tilled hned STEREO nput 15 watts, watts unit., stereo 2 50 With ntegral h switches nl bass ancl»pipc5 STCREQ PAR + p & p 5 50 "pot Cabinet S C.b"" sue wallsrms. molo" 20" x 30, wans 11 x, or peak 9,' l a lappr.,.). PP ro eachunrt. (pushbuttons, red mains indicator and stetoo jack C2 50 with integral push pull swilches ndependent hass and «-)- socket. Function Functton switch SWtch for nui. mc. magnetic magnetc and crystal treble conlrols controls andmasier ancl master vo'ume. volu SP AK fls SPEAKERS AVALABLE WTHOUT CABNETS. pick ups.tapo, ups, tape, tuner,, and auviliary auxlllarv Rear pane! panel features rwu.. two t j s the units which whch we supply with wth the enclosurt* enclosures illuslrated WATT dr ' i illustrated mains oullels nput sockets, Sue Sile 13" 13' * x B" 8" lappnul,ppro<1 woolei wool". (Ml EM?} t app fl0 pe, wains oullats DN speaker and mpul sockals. plus fuse. [1700 MONO DSCO AMP per 20^ + 20 walls wafts rms. 40 < + 40 watts peak. Slle approl, tweeter. and matching crossover camponents, components. stereo slereo pair 3D. AMPlFFR 14 ~ 4 )1 10! waits watts pnk. + p & HO : package )( kit aluminium '" ) 11/;1 ". 30 i 30 WATT AMPLFtTR KT fr.-rv f-: Mill i Power handling 15 waltsrms. 30 wads peak, -k p A p 3.40 SPECAL OFFER: packbpe price with 30 * 30 Ut Brushed alummujm V ^ ' y ~ 9 Specially designed for the experienced fascia rotary conlrols COMPACT FOR TOP VALUE These mlimte nlinile balue SDuelaMy daslpned by RT VC tar hs expereenced Usua androtarv controls # bailie constructor complete n n every dotnl'. detail. Ssme Same tacllltles ',cuitl ««as Five five vertical slide cooirols coolrols masiei masler volume. f enclosures AClasuras conic tome to to you ready mi mitred (red and profession profess ionally ally Viscount Vlacount V emdiino. amplifier CO 60 pesk peak supplied with tape level m.clevel, mic level. deck level le\'el PLUS PlU$NHR NTER DECK lader FADER finished Each cabinet measuies measures appro*. x, per steieo stereo pair palt 2 GOODMANS COMPACT 12" 12,0 Bess Bass woofera woofers with to. for ptifect perfect giaduared graduated change rom from record deck Wo No 1 to 12'> 12")( 9'x 9" x S'deep, SH and is S io in wood Simulale. Smulate. rncn {8 50 cropped ildoe, 14,000 GauSS mbpnol. 30 watts 2. or... Ple fade 70 watt With 8'" (approx.) ~~::'~~~:~~~~~;~C:"~~~~~ X~~~::~~~ :na~t. 49" 57 Complete with two 8* (eppfoi ] speakers for O R M.S. handling +3J" appro*, tweeters end No. Z, or vice versa Pre lade level control W * aw J57 crossovers p&p (PFL) lets YOU next disc before lading 140 wan peak manrmirii maximum j>ow i power ha/kjling handling ol of 77 wans. wails, 8fl p S & p C2.20 erosboverc O*p i.00 {PFl}!ei5 VOU hear ne*! d»sc befoiefading M0 c"' (2.20 it t in. n. VUmeier meler monitars monllols outpul output level. p p & P P SPEAKERS Two models Duo Ouo lib.. teak ven?e«. veneer walls wall' NOW Oulpull00 wall, 100 walls. 100 wait 65 rms. rrns.?< 24 watts peak. peak, BJ" 181- '"* x: 13i'" 131' )( 7 V (app rox Output AVAtLABLE 3fl 4-30 watts fully rms. buill 60 + and 00 peak. lesled COQOO 2 p & 50 d Output CO wans RMS 200 wails peak. ^ wd " Guolll. Duo ll. 20 wattsrms its rm! 40 wans watts peak 27'* 21" )( ^"xju'app* 13 ~;( 11}- ~ ap px CHASSS PECDRD RECORD BARRARD GAllRARD DECK CCtDA CCOA Duo lib [17 PER PAR Duo PER PAR PLAYER DECKS Roconlchlnterwithcul. plltp S50 p&p 750 DeSigned tor e eapeflenced ThiS 4 l V ps'zo 0 "" 1 ADD ON STEREO CASSETTE TAPE OECK KT/,» PL A Y E R DC KS fliconl chengar with c«i. ' p&pnso Designed lor the ekpenenced 0 Y man This ' '.rw*" ' sletm si... c#r#mic cerlmic cenndfln. cartndgl. p 4 & p 2.00 DECCA ZO 20 WATTS STEREO SPEAKER steren Sleroo pair p." hil lut comprises of a tape ranspnit tr ansport mechanism., 1/ y,j.- 8SR,BSR MP50TYPE MP60 TV PE Single S, ngl. f-u-qc [15'5 This ThiS matching matchng loudspeaker system sy$tem,s is hand made kit ready built and tested lecoid re rd replay 5. Pl^r'Ecmddec* p l ayr e c o r c ~ MO" comprisas comprises ol of iwos' two 8" dlamelet diameter appro*, approx. base e drive unn. umt, wilh Wth electronics with With ivrmv twm V U meteisand ters ', L, less 10" carirtdge. carlodge. p&pc2s5 p & p 1 55 heavy die call cast chassis chasss lamirafed lamnated cones with With rolled relied P PVC V C level conlral control for mating matmg wnh With mectiamsm, mechansm. /flphhbhh s'jg- Carindges Cartfldges 10 to sun SU above surrounds twosj'd'ameter 31" dameter appio*. approx. domed fweeleis tweeters SpeCifications SenSitiVity MC. ij.-. magnell c {4 95 cempleie complete w wllh ill crossover r network nelwork 80 fd 400 OOp p 4 & p.l2(j p.{2000 c Specifications Sensilivity U>c, Acos. magnehc stereo 4 85 « mV^ "?0KnKMS 20K OHMS Din^OmV Oin. 40mV 12'x 12" xl ' " ' Ceramic CeramC sieteo ste ro. 195 [1 PERSONAL SHOPPERS./ " 400K0KMS K OHM S Outpul Oulp ul 300mV RMS S per channel nel., KK? 1 KHl pypii... 1 BSB SHOPPE~ S BSR auto malic matic record playei player deck STEREO CASSETTE fecotd/replay record fully lully built bull P.C boaid d [1-55 ftom k Tape Counter tuetnq Vce and eo ceramic p & l.s5 95 rgm 2K OHMS source Cross Talk - 30db TapcCounier* cannq device anil stereo ceramic head.p 4 p r2.55 EQSS 995 UsaiwithoulguauntM ase4wilhgut gulrlnt.. <Ej (Ex Egulpmsnt.f Equipment.1 «3 Digit-Resellable Resettable freggency Frequency R^tconse qesponse doh? 40Hz BKK?i6db 8KH z.±.. TUNER P wllh li 86. [9 50 Motor With chonrc ti BSR complete With magnetc caulldg e, AM. FM. TUNFRP C B with MullardL.P <85. q M modules 3 Deck Molar 9 Volt DC with electronic speed regulahons BSfl MP 60 type, compleft with magneuc cartridge. '23 Key Functions -Reiord, cord. Rewind. Wind., diamond stylus, lus. and de luie luxe plmlti pli nth and cover, cover. p 4 & p 4.50 ( K look Mulmurn Mulhturn Varicaptuningpois, Vamap tunng pots, 6 tot for f (100 "JOO Fast Fasl Forward. Play, Play. Slop SlOP 4 & Eject Eie ct p 4 & Home 08 Track carlndge cartfldge player This s umi unit will march match.^ Opt.. e*tr»s extras Mains irenslormer transformer to swte suite C f + C 1 p 4 & p. p. wilh Wllh 'he he Viscounl VlStounllV V 9" -,8" 8' x 3^*, 3r. p 4 & p t i O MU8TC 50 MUSC CtNTRE CNT CABNET with hlopetf hinged»m«ko smoke cyllc acyllc too. to!), lnlahwt flnl.hed (n n notural natural laah teak vflneor* veneers RECORD PLAYER SkeSO}" Site 3ot'" *)( 1*4* f4,h * X 7}* 7i'" aoofok. approx. ^15 EASY TO BULD necord KAYEB KT 515 for the D-l-Y 0-1-Y mlti men who requiris requires stem dlreo unit at at i budges budgat price. CBmpHiing comprisinlj ready rudy ai ",emblh 110"" mp. modul.. G".n.- ;. FCROUSOtt. FERGU80N. S-aoaeff, 3 speed, 7" 7'" H-F tape ransoort 323 EflGWAflt ROAD, LONDON W2 ssnmbled siwk amp irodufe. Gurird transport lulo mechan ism. complete With to!) covers. '15t5 mlnull dac:k Wth m ice. inochanlorrv, compiels with top COv«r«. 210 HGH STREET ACTON W3 6NG auto / manual deck with cuiing tfwica, ALL PRCES NCLUDE VAT At 12}^ pta-cul P1-cut and finished eibmef cabinet work Ou! Out wait. chlnnoi. phgno. socket MULLARD. CulH power aupply. AE hrn* aublbcl N Bvailitfty. frke cwtbcc put 4 w»n* per chanwl, phonns sartat * wi -Afrcl M chkaf«wittwvl m±*,nd mdrecord/rtpfaysocksi.withoutspuksrs. r""onl/lopl.y sockot. Spukors. L y p&p 20G PiisonslSfcoppmfDCWSRf ROAD DNDON W! Tel: !«?. 3.3(li». 5. JCairi. Hal! day he'sca;. ACON Mja Ordt' nnl., Ka Cillers GOODS NOT OiSPATCHO 0JfSlO_UX You'll learn a lot from the free Heathkit catalogue. NEW Computer Systems Send for lor a special 16 page brochure. NEW Si-directional Bidirectionat RF Wattmeter C» NEW De-uxe De-luxe "" - 12' i2"crt gnition Analyser Practical PracticaL Wireless, June 1978 NEW De-uxe De-luxe Coin-tracking Metal Meta! Locator The HealhkiS Heathkit catalogue is packed with scores of top quality electronic kits,. ^^lij f C l Educational, l practical and fascinating /'/ ~ "N;" items which you can build yourself. 1'~ ~ =".er;; "S;.;;ifurii.~Ttai;;;e~;:- ] Send for the catalogue now. fflahij To Heath (Gloucester) Limited, /... - 'P ':"'1 DepartmentPW68,Bristol Road,, Gloucester.GlZGEE- Gloucester, GL2 6EE. HBsj Name crc "" ' - «Address _. _......! Please tick the literature you want and enclose the appropriate amount in postage stamps. Heathkit catalogue only 0 CD (enclose p 1 p to cover postage) 16 page computer brochure only D (enclose 20p to cover postage and part i costs). N.B.lf N.B.t you are already on the Heathkit mailing list you will automatically receive a copy of ot the latest catalogue without having to use this coupon. ys- ~ When you receive i hi«ik ~ H'ATH ~ /Soldering /V \ youll your catalogue 'll get details of ol =amr:;n.:g',; >5 i iron offer 1 this free offer otter worth The ' world's wr'" s 11 BDEE } approximately apptoaimalely 4.7 C4.75. biggest pmducers producers \ r-rftt / " ^ of electronic kits. jv&aii of electronic kits. There are Heathklt Heathkit ElectroniCs Electronics Centres at 233 Tottenham Court Road, ~ ~ London ( ) and at Bristol Road.Gloucester, (Gloucester 29451). 9

12 B. B BAMBER ELECTRONCS Dept. f-w. P.W. 5 STATON ROAD.. L1TTLEPORT. LlnLEPORT. CAMBS.,.. CBS CB6 1QE Telephone;. ELY (0353) B (2mes) lines) Tuesday to Saturday PLEASE ADO ADD 8% 1% VAT UNLESS OTHERWSE STATED PLEASE please ADD 8% 1% VAT UNLESS OTHERWSE STATED A ff l/tnge ANQK OF DRAPER TOOLS FOR THE A NEW NW RANCE RANGE OF 0' SPEAKERS SPE.'KERS A 10 VDCON SCAN COLS (TrnnalHOT p.; typa. WELLER WLLR SOLDERNG SOLDRNG RONS... ELECTRONCS ENTHUSAST NTHUSAST CABNETS. 10 MANS TSTER loo SARGAN ~~~"~:~~.~r::d~~~~ wl h '1ldl"" ba EXPRT. Bulll ln..,potllght umlnat" WANS TESTER SCREWDRVERS 100 AT BARGAN BRAND PRCES. NEW 4 BOXED. 1 but H no tach. data) Brand complota New. with vldlcon taaa EXPERT. work. BuNMn-apotlloM JDumlnate* wo",. wllh Hnaortlp trlgger. to l:a':.'f) 500V. StorxJanj ««Up, Uraa 70p. TELFUNKEN TELlFUNKEt4 SPEAK et'ftclency aolderlng RADO PLERS =~"::: S}' a\'!~:efe. C1 io.fa W.l'~rli. ERS.3 3 ohm. 8 watt HGH RMS, QUALTY RMS. fit" et" dl«. dla. Full SPEAK- ranfla rang. HV f2v CONTNENTAL TYPE TYP RLUQ-N efflctancy Platol copper grip with aoldarlng flngortlp tip. tiiggar. High PLUG.N RLAY chlnge.. over, lop, XPERT SOLDR " ' DAOON DAGONAL AL SDE SD CUTTERS CUTTERa ti" et" EE a».. typo CUTTERa Loll. ~ ~ J' each (or 2 lor % VAT. RELAYS, 2 pole changa-ovef. Wp a«ch. EXPERT SOLDER GUN tlhd ';~~~~Gt:.aAil~:R~:trc~1.1; e... abov lupplled relay) SOLDR (... bite, SMALL SDE CUTTERS Uz. Standard TYPE U TRANGULAR CORNER CAB- Baaea for above (only auppflod with relaya) EXPERT SOLDER GUN KT (apar* hlta, &4... U7 (wllh wlr. device) U ' SO. Sm.rt woodgr.ln type flnl.h flp etc.) &S... u n. ur (with wlra holding davica) M M- NETS. Smart woodgraln Formica hmo flniah lop each. caaa, GLAaS BAD FlEDTHROUGH NaU SP". blte.. p MOQETOPEN MDeETOPN ENDED SPANNER SETS with nylon grill*. Overall height 23" x tz' GLASS BEAD FEEDTHROUGH NSU- Spare ate.) blta p pair. :!re.n~~~t:~'~~ r~v~ ~h~'grl ~. 4~ J~~ Solder ln typ.. ovor $ BA»Jw 'MaatQt 3 U wldo '5 5+"5 H ranae peaker. line approx. 5mm, of for fl-5 4+e MM range Conlafn tpaakera hre* n 15 parallel ohm W + 100V x 4" Full Una appro*, LATORS. flmm. Sofdar-ln Pack oi approx. typa. 50 ovarall loi Hp. dla. AVALA.L PRlC.S. aizaa.1... C4. M... aolof«. 101 tranalormer tran.former (oaally (eallly dlaco/m disconnected acted for 5 ohm AVALABLE A LARGE RANGE AT BARGAN OF CAPACTORS PRCES. DE-CAaT BOXEa a.a.. LST. MNATURE MNATUR FLE SETS. aets. S<t Sel of «8 AO*. 1' 21. operation). r:l;t!.r:,~ H each aach (or (a. 2 tor lor ) 00) + DE-CAST ALUMNUM BOXES S.A.E. FOR LBT. Send Late.t Lilt. MXD PACKS. conlaln 8«1 Solof of 10At ' W..(Round, (Round. flat, H.. «tc.) etc.) 124«VAT. Sand for Latcat Price Llat, MXED COMPONENT PACKS, contain- M104 CELNG SPAKERS. While ng re.l,tor" capacltorl. pot new. TAP AND DE STS SETS (18 place) ploco) contain conllln 1 TYPE M7M CeiUNQ SPEAKERS. White PLASTC PROJECT BOXES with tcraw ing pl.ltlc f cl., e. SZES Die N.quar., Hundredl teml. 1 pack..toeka MCh of 0. E, 4, 8, 8, BA StZES n Qlaa, Plug plaallclaaclaut aquara, for recaaa mounting on ~~~~d~~~n.~:~o~ 1~S! "2~~ b:"'~n:;::a.h l'lt. Tipa, Taper Tapa + Amarlcon typa lap into ~n':j::~~h:~:cr calling, with 8" +d~~t~ dla. 15 ohm :l~.lul full range Typa llda NB1 (n appro* black ABS) Sin Jin with 2iln braia Win 14jn43puch naerts. r.nge TypeN82appro.3j-ln 211n wranch.!::~ch~..,e~y::pt!p T lypa tap wrench, w::h,'~i. Ola ~:J:~ Hofdor, apeeker. 4-W each + VAT. Tyco ~lnslpeach VYPE U CAB N83 approx.!-'n )( 3 n ;1," Up 11 ~P~.~~~~~~~~~~-». TYPE L4 PORTABLE SPEAKER CAB- Type NB2app'Ox3; N B3 a ppro* 4- iln x 2fln fln n 45p each Hundrada roalatora, of tama. capacltora, 2 per pole. pack, etc. while All alocka newlaat. 4lnX3 tn x Hln rln$5p rlntspeach PUSH BUTTON TELEPHONES NET. Smart woodgraln grain Formica type flntah flnleh SM SV STA.LSER LARGE ELECTROLYTC PACKS. Con- Con with nvlon flrlfle, 15" high x 14" wide x l' MULLARD 5A2 l»v STABLSER with A T*fi handsat. Digit puih Hnlahed button in ntercom amarl gray ctephene plaatlc. taln range elec~olytlc capacitors, :!!.~ nl~o~~~~~~. ~~Hnr~,gn~n: ~~ ~!~~d~ ~; (Br.nd New) 7.p.ach oruor f t tain iana«of large eiectcolytlc caoacitora, daep (tapering), tye~' pieces, ohm ranlile,peak.,. Containing 10' round. 15 VALVES (Brand N aw) 70p each cr 2 lor 1 29 low and high voltage lyp^a, over 40 placaa. Ohm 1GOV n. trana T03 tranllator nlulajor for!!p Et-M ". per pack Pick (+124% l+12ix VAT). formar. full 7 range «each ftpoaker VAT. 100V line rana- TOa tfanalator naulator arta, to lorhp 1-5* E*-<fljlgm*hl, aach. but good coftdldon only 'ULL BRNARDS/.ABAN Slide. Swllch.a. pole make b.eak (a. ~" : ml~"i~t ti~x~lit CABNET. Slider Swltchea. 2 pola" mtka and"breamor TYPE HT4 HOTEL SPEAKER CABNET, PLUGS AND SOCKETS FULL RANGE OF BERNARD 8/0 ABA NT ELECTRONCa ' can ba ~ uaad uled aa as1 1 pole pol. chanoo^ovar chano-.ovef by linking Unklng Wood vaneered. veneered. 121' 121* wide x 51" 51- high x N-Type Pluga SO ohm, 90p aach, 3 for 1 -M. ELECTRONCS BOOKS N STOCK. the centre plnl). 4 Sp. 3,- orllle ~Jl:';.r.:~n~;~"i;.:~ :cv!:' :~t~'.,;l':h S.A.E. UST. jha two contra piftekj for 5»p. 31" deep, with aluminium grille + volume PL25D Plooa (PTFD brand new. packed with S-A.E- FOR LST. control and 4 way + off twitch,witch psnala panel a on reducera, reducerl, fp lip each. VARCAP VARlCAP TUNERS TUNERa Milliard Mull.rd typa type ELC1D43/ ELCl043/ A NSW N~W RANGE RANG OF QUALTY BOXES BOXEa A 10 front. Very a mart. man. Contain* Contalnl 3 a ohm 5* S'" x 3" Sockets Sod<ets (PTFE), (PTFEJ. brand br.nd new M-hola (4 hole 05. OS. Brand N New, Now % 12i" VAT. NSTRUMENT CASES. ollpllcal eltptlcal ipoaket speaker + 100V line tne traneformbr. transformer. fl*tnp filing typo), ype). Hpeach. "p.. Aluminium Boim with tlda. lid S A AB10 BO 6i-x4J<1+ 5! x 4 x lt 15P 75p TYPE W ach ~~~ -::. NT* + }Jft"R~~ijE FULL 121X RANGE VAT. SPEAKER, SPEAKER. 10" SOLDER SUCKERS (Plungar type). Stan- BARGAN ELECTROLYTC PACK CAPACTORS. OF LOW VOLTAGE Up to Q" SOV. Se.tronlc Manufacture. Approx AB'3 AB1S 8x4x2 4 2 C1 00 dla, dla. 1J 15 ohm. 5 S H each 80ch (or 2 for lor 9 0'00) 00) + dart Model. CS'#4. Skirted Modal Spare 100. '. per 12t% ABM AB14 7 5, 24 2t 1 f 25 12}% 12t% VAT, Nozxtea Hp aae.h- 100, 50V working. 1 -W P^r Seafronlc peck + 124% Manufactura- VAT. Appro* VAT. AB15 All' 8 fl 3 1 f U 50 SEMCONDUCTORs SOLDER. We Splralux Tools elec AB10 AB,. 10 x 7 x f' 1$ SEMCONDUCTORS - NEW BSX20 (VHF O.e/Mult). fa NG P. enthu.lllt. Screwdrlverl. pann.', lze., rivet Gun AB17 A17 10 * x 4t 4*x3 * a 1 f 58 se asx20 (VHP Oec/Mult). 3 tor 88p. NQ RONS. MARKSMAN RANGE OF BOLDER- Wa now atock Splralu* Tool* for the elac W U... ABW A\115 8x4x3 x4x3 +2S B C108 (malal can), 4 f or Wp. S1MD2SW 240V tronic 1 & ~~h~ji:::!~'ll:~jai~ Wo W U. PBC108 (pla a He BCOS). 5 for Stp. S 40D 40 W 240V 4 U. n«ra, anlhualaat. Scrawdrlvar*, Nut apan- Sp. elc Vinyl nstrument Cas,. FY51 Translllor. lor S1250K 2DW.c., S S. Vtnyl Coated nalrumani Cniaa BFY61 TranBleiofa.4 forup. S1Z5DK 25W 240V + bill ale.. KT etc. S.A.E. BA and for Metric llat. *!», pop rival guna,... Blu. tops lower sectlonl, Tranalstors. for Hp..ENCH STAND wllh.prlng.nd.pong.lor Light Blua top* and plain lowar aactlona. BCY72 Tranalatora. 4 io/stp. BENCH BTAND with aprlne and apongalor Dubtllur Efedrolyltca. WriF, 4»V, 2 for 549. VerY smart ftnllh.udlo ype Tr.n.lllor., 1210r Sp ronl a '11. g~~:~ ~::~~::~:: =F,4~~.W:r". Vary amarl flniah PNP audio lypa T05 Tranalatora. 12lorOp Markaman rona Dublllar WBl,x2t 2t flfl52 BF52 (UHF amp/mlxart. amp/mlx.r) for Hp. Spar. bll. MTa 15W) "P. MT5(lo. WBt p Spate bite MT9(forUW) Hp, MT5(for25W) Pleasey EleCtrolytlci. f lactrolytlca, 47(UiF. loo^f. 83V. grev.efarmp- 3 for Hp. P. ~~~.:r.~;:, f.~o:,.:'p. Hp WS2 WB2 8 x 4j 4 x 1} +35 f U 2N9B19 Fat., 3 for Hp. Hp. MT10 (lor 40W) Up. TCC WBS f.. ~~~~8 ::k ZltlC~~: lor.p. :ri. ~'ROJ~~ ~';'?~~T. Dublllor Eloclrolytlc OOOUf. 35'{;.P WB3 8x5x2 1 M NPN SLCON, for Mp. ALL PRCES + 8% VAT. Dublllar EledrolyUca, 100<y*F, 30V, 5 for Hp. TCP TMPERATUR WB4 W84 B B4 n 2f 2t 2 2. H BCM BC'58 PHP PNP SLCON. 4 for lor Hp. TCP2 TEMPERATURE CONTROLLED Dubiller CloCUolytlca. electrolytic*. MOOoF. 50DOftF,»V. BOV, Hp Hp etch. each.p. Slgn.1 Diad, 10 lor Up.?rTbl~~~~;:;~:~~~15V~ hi~pg~:~~ WM Will W a x 3 2 a 15 u BAY 31 Signal Dlodea, loforwp. RON. TT El octroi yllca, EbV, high grade Will 11 7 U 1,51 (N4) lor Sp. Tempor.lur. conlrollod U+.crew termlnll., clip., "P WB6 f 7+ X N4148 ( N914) 10 for Up. Tamperelure controlled ron and PSU. 3#+ acrew each. WBT WB7 12 8* U BCi BC07 D7 (MataJ (Met.1 can) 4 lor for Mp. VAT ( 2-40). Bach. termlnalt, with mounting dlpa. HP... ~~l~~'~~~s flt% WBa53 WBB53 8 x 54 x a 2S SCRa SCR.400V 400V at.13a 3A. atud ud type, ype. 2 lor for!-«, SPARE TPS PLEASE ADD 124% VAT TO ALL f..ngle flll. f.1 fln. TP2955 TP21S5 Silicon PNP power powor irenatator, tran..lor.ov 80V at Type CC alngle flaf. Type K double rial fine CAPACTORS. MANS TRANSFORMERS. TRANSFORMERa. Type Typ. 15^300 15/300 SA. 90 Watta, Flat peck type. 2 for 1 -H. tl ~6f";~AR~1"::lltJr' p Type P, v#ry flne tl p. 1 each + VAT {8p). VAT(Sp). aocketa 240VlnpUt.l5Vat300mA CFRMANUM G~~~ A':l~:'J{tb~r.:!.~:x a: DOPE3. appro*30torwp- ~": ~~:. Plugs (m.lal type). 410r.p. MANS :':l~~nlut~':~=:'~l't"~t~~o ':r,~: TRANSFORMERS. output Type. 1 SO 4B/100. each. MdsrSPAnES AVALABLE. TV TV Pluga PLUGS (metal AND type), SOCKETS 4 for Sip- 741CG op amp. by ReA. 4 for 1. TlCORE Line Conneetorl (back~to-back locket.) ~10~:~~~' V ov nput. npul. 45V at.1100ma l00ma oulput, MULTlCORt SOLDER TV oulpul. i:~(~1 '!26J1pi O w.g. on.. llc reol 410rSlp. l -34 each. 4 Kg, (t -11 b) 40 X 40,20 a.w.g. on plaall c reel 4 lor Una Hp. Connectore (huck-io-back aockelij, RED RD LEOa(Mln. LED. (Min. type) ype) SforTEp. 5 la. 7.p. 3+ VAT {24p). P Pi am a add 12* 12*%» VAT- VAT. Terms ot of Business' BUSiness CASH WTH ORDER.. MNMUM ORDER ALL AL~ PRCES NCJ.UDE /NCLUDE POST POS' A 1\ PACKNG /UK ' K ONLY' c..'nl \ i SAC SAE" wtfi.all rn Ai L ENQURES Uv()(,R'L 5 Please P,'dSt' PLEASE ADD VAT AS SHOWN, ALL GOODS N /N STOCK DESPATCHED BY Br PEWPN RETURN CALLEfiS LERS WELCOME,1UCOM~ BY 81 APPONTMENT APPO/NTMEN ON) ONt?. **, ci^a*ao*>a, Qxa u Q aaaa sclasi n actcaeic'&a 'mssmmmmmmm/wm i-. ' i muuun maaw m. ja: mm. - bk'vj Our new 1978 catalogue lists circuit boards for all your proiects, projects, from good old Veroboard through to specialised boards for Cs. And we've got accessories, module systems, cases and boxes - everything you need to give your equipment the quality you demand. Send 25p to cover post and packing, and the catalogue's yours. VERO ELECTRONCS LTD. RETAL DEPT. ndustrial Estate, Chandlers Ford, Hants, Hants. S053ZR Telephone Chandlers Ford (04215) 2956 & PC9M ~~ 1*25 ~ :~ SP61 ~~l ; ::i SB 255M 0 VALVES PCCM 0-45 mi T-H 85 BB/2MM / ::::~G 4-75 : ::~~T; : :: ~ggm : ~~::!.: 5B/258M i:~~g ::~sggl~.!e" A1065 Al0&5 T2S "2SEF83 EF53 PCC89 f. PCF80 f. 1' " 16KGT "55!PCF805 ARfl ARS.... BO EF35 1 '59 PCC18B4-8S 4-55 U«1-«8 50 fljtg 9 2BLBGT1-44 5B/2MM :6K7 0TO50C17 H-.30C EF PCF60 M U28 4 «c hbkig -35J30C18 M* "45 PCF82 Ull1 "75 SU4G. 156L.6M f 'O:30F3 '" ARP3.. EF88 ss PCF84 U801.. "l5i6lgt.. i30f2 21 ATP4 B 0 "5' CFflb EFai 0 55 PCFfi? 9 40 U27 1-M 5R4GY 1 T0 6KSGT 0 S5 PCFBW EF PCFM 45 US LW6 PCF UABCO 5Y3GT "15;6L7G ' es.30fl B12H dafm 3 g~~86 :::: a 09 ao CF92 EF PCE U V4G e O-tSiBLflGT ts-eum 9'4«-50F12 i-00:30+5 -H 29 m~ 9 : 45 PCF200 UA8C30 SY3GT ~ ~g~~: : :: ':'0 ffig ~ : ;m~~ ::~=r~~4 ~ : :: DET DET22 " 51 EF83 "SS "SS tl:~: :. ~ 5Z4GT "75'6SJ7 O'7:30L17. DF OF96 1 '0 80 EFm EFta* 15 PCF201 9 H 910 SZ3 4 1-M0SA '« OFL14»FL H EF84.. PCF802"15 UBLl " 6AB7 0'''BSJ7GTO'50 '30P2 '" OKM 0 80 EF8W t -84 PCF801 9-W UBF Z4S l-tlesg? O-TS-SOLS 1<44! DL02 g~ 8 :::: SO 2-90 PCF USF89 O H 8Z4GT EFL200 m~ 9-75 =:;: PCFS UBL AB SJ ML" ~g~=~. :: UBL21 ' :75 :~~ ::~~~GT::;:~~t13 ~. r. DYM;a74-58 DY88/671' SS EH40 EHGO O-H PCFSOfl i ts UBU AC7 ahp3ii7g78-»30pl2 O-HSSKT g-hmpl 1* PCF808 f. UCC85 e. 8AK5 "SS:t;SN7GTt 7S'30PL4 f ft DV802 DY802 0 O'SS» EL32 0'" PCH UCF AK8 "40;oSQ7 0'7S135L8GT... 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KTBS 4-00 PYssa D21 JXJB CL8 4-7S SC7 ft 0'5i5T53 H D6 KT88 5'75 PYBOl...;21<25 "00 :~:J :'~: 1 12SJ7 0'SS :8057 ' S ECLB2 ~gt: 0 n: 53 MH PYBOJ. 4 «2K25 15S:12SK M 99 ECL ~~ n: 'M QOV X2 M 6FA8 QQV03'~05l 1 ~~ :.: 6F12 'l5 q ~~f7 :.:= :::: ECUS ECL MLB OAZ A4 80 S'SlZSJ? Fas M! J'M sow Ft2 OA2 4 "H 55 QQV03 12 OQV63-t2 [ «12Y F17 f '''',4S7 f. _ f. ECU8 ~~3~ EF37A n:» OB2 ~:~CO"" 4-M 2-M 3D2t 20'64 fif*k 6F VS 1437 l-w OQvoe-!il.' ~~ ~:: :~a: ::=1:~~5 f:': = ~ :;: EF38 EF39 2-H PABC80 z... ou QOV06-40A M 3E2» S4 '. 18J4WA '75' S. CF40 EF40 # PC5,. OV V4 "15 6J5 "7S!laH B 4 21 EF PC85 D H "75 PC OV03.15a-04 " SC1/4004'" SC1/40Q4-00.aV4 fib/swm 4M 2w?,;L.i2 l^iaaos M 1 '75 19GB *G3 144 M M B/254M.J5GT 9J5GT T O-W l 'U,20P3 jopa «'» '. 44 EF80 B' PC88 J 9 ' 75.SC)6004 " S 01/ "50 J8 6JS 4 '. - 8ftl20 20P4 P4 1-18:8020 1'11, ' 50. POSTAGE, 1 2 2Op: OP: p: 5-10 POSTAGE: 60p; Opj Dv*r trtt2 over 10fr«« »fl! to f'h, minimum e3-8 ardor order 1. 40{»:. A Alolol1h Ot of thoaft... vftlvok ar«colomor mported and price* VALVES AND (ELEORONCS LTD.) ~~~ol~~de.:~d vory for each dallviry, de~~~~~ TRANSSTORS Goldhawk Rd., London W ao we roaervo r erve th» the right To'ephon^ongulrle* 170 lo~'e~:,',: Tel to changa change price* prlcel for for tors, etc.j r.tall Open Monday to Friday new mw itock.tock wheti when untora, valve*, atc-i tranalaraiatl un , trade avoidable , trad* and export 9*P0rt 743 WOO , p.m. lo 10 Practical Wireless, June 1978

13 NEW ROAMER TEN MODEL R.K.3 HULTBAND V.H.F. AND A.M. RECEVER. NEW ELECTRONC MASTER KT WTH SPECAL V. H.F. TUNER MODULE TO CONSTRUCT. A completely Solderless Electronic Construction Kit. Kit, with ready drilled Bikelite Bakelite Panela. Panels. Nvjti. Nuts, Bolts. Wood Screws etc. Also in the kit: Transistors. Capacitors, Capacitors. Resistors, Resistors. Pots, Switches, Wire, Sleevinj, Sleeving, Knobs. Knobs, Dials, Dials. 5" SH X A 3" Loudspeaker and Speaker Case. Crystal Earpiece, Earpiece. efc. etc. Also ready wound Coils and Ferrite Rod Aerial. These are the Projects you can build with the components supplied with the kit. together with comprehensive nstruction Manual Pictorial and Circuit Dialrams. PROJECTS: V.H F. Tuner Module * A.M. Tuner Module M.W. l.w. Diode Radio * Six Transistor V.H.F- V.H.F. Earpiece Radio * One Transistor M.W.. L.W. l.w. Radio ^ Two Transistor Metronome wjth with variable beat be" control * Three Transistor and Diode Radio M.W. L.W.. * Four Transistor Push Pull Amplifier ir * tight Eight Transistor V.H.F. Loudspeaker Receiver ir * Variable A.F. Oscillator ir * Jiffy MuftiTester MultiTester Vr * Four Transfslor Transistor and Diode M.W.. L.W. W. Radio ir * A.F. R.F, R.F. Signal Si,nallniector njector * Five Transistor Push Pud Pull Amplifier -* * Sensitive Hearing Aid AmpliFier Amplifier ir * Three Transistor and Diode Short Wave Radio ir * Signal Tracer * Three Tran- Transistol Push Pull Amplifier * One Transistor Class A Output Stage Stale to drive Loudspeaker * Sensitive Tran- Tran sistor siiror sistor Rre-Amp Pre-Amp ir * Transistor Tester ir * Sensitive Three Transistor Regenerative Relenerative Radio + Four Transistor M.W.. L.W. and Diode Tuner ir * Five Transistor M.W. L.W. Trawler Band Regenerative Radio R.dio * Five Transistor V.H.F. Tuner * Three Transistor Code Practice Oscillator * Five Transistor Regenerative Short Transistor V.H.F- Tuner ir Three Transistor Code Practice Oscillator ir Five Transistor Regenerative Short Wav* Wave Radio ir * Four Transistor and two Diodes M.W.. L.W. Loudspeaker Radio ir * Seven Transistor Tra~sistor M.W.. L.W.. Radio with loudspeaker Loudspeaker Push Pot! Pull output *99 - P p A & P 1 >10. llr One Transistor Home Broadcaster. * One Transistor Home Broadcaster. + MULTBAND V. H.F. AND A.M. RECEVER. 13 TRANSSTORS AND SX DODES- DODES. QUALTY." 4" ROUND LOUDSPEAKER. WTH Multiband V.H.F. section covering Mobiles, Mobiles. Aircraft, Aircr.ft. T.V. Sound, Public Service Band, Band. Local V.H.F..F. Stations, etc. and Multiband A.M. A section with Airspaced Tuning Tunin, Capacitor for easier and accurate tuning, tuninl. covering coverinl M.W.,.. M.W.2. L.W.. Three Short Wave Bands S.W.J,, S.W.2. 5.W.3 S.W.3 and Trawler Trawl. r Band. Built-in fernce Ferrite Rod Aerial for Medium Wave, Long Lon, Wave and Trawler Band, Band. etc.,. Chrome Plated 7 section Telescopic Aerial, Aerial. angled and rotatable for peak Short Wave and V.H.F, V.H.F. reception. Push-Pull output output using usin, 600mW Transistors. Gain, Gain. Wave-Change Wave Chan,e and Tone Controls. Plus two Slider Switches. Powered by P,P.9 9 P.P.9-9 volt Battery. Complete kit of pans parts including tarrying carry in, strap L P J. & P Building nstructions and operiltin, Manuals. r NEW MODEL R.K. MultiBand A.M. A Re- Receiver. M. W. W. L. W. W. H ceiver, Trawler Band and Three Short Wave Bands Band.. SaVCn Sc"en Tran- sistors and -Four..Four Diodes. D Push Pull Output stage, stalc. S" 5" X x 3" 3 Loudspeaker. rt nternal nte.-nal iltcon Ferrite Rod Aerial. Kit includes all pans parts to build t it op up including includina Carrying C al"ryinl Strap, Rubber f«nt Feet and ready-drilled.. drilled Panels. Comprehensivo Comprehensive nstruction Manual for stage stalc by stage staac construction. U*«* Uses P-P,9 P.P.9 Nine Volt Bitfory, Battery. NEW.. & X,' 90p MODEL R.K.2 MW. MW, LW And and Air Band Receiyer. Eight Eicht Tranti^tors Transist «nd and Four four Diodct, SvRilKO D iodes. 3" 3' LoudspeAker, Loudspeaker. Telescopic Aerial, Aerial. nternal Ferrite Rod Aerial. Complete with Carrying Carryinl Strap, Str-ap, and And ready-drilled PanoW. Panels and all components component* necessary for (or conicruction, constr-uction. A fensitivo sensitive Receiver with the addition*! ional luxury of an Air Bard Band teceion section to pick up Aircraft Aircr-aft from many milei miles JW>y- away. Full fnttruclion nltruction Manual... ~:;su~.;~a~~~s enable* ~~~~; tiage ~~n~ta~:::~~:~~;!~n by itage conttruccion.. 9 JTQ. QO 99 + P A F UlM P.P.S ind P.P. Nin, Volt 8jneri«. -* '' O ( ' 10 E V 6 PLUS ONE Build thl. excltln.!~"''''''i!i.1 with new 1 desl",. Tranllltort Now and. dlodel. MW/LW. Powered by 9V battery. Ferrite rod aerial, tunin. condenser, volume control. and now with 3in. loudspeaker. Attractive cue with red speaker rill. Size 9in. x Siin. x 2lin. approx. All parts includin, Case.nd Plans. Total Buildln, Costs P &.. and in.. top ALL PRCES NCLUDE VAT RADO EXCHANGE LTD. Building nstructions and operating Manuals. 1 ~ '' h^airti'iw WTH SPECAL V.H.F. TUNER MODUL TO CONSTRUCT. A complttely Soldcrlpjs Electronic Pictorial and Circuit Diagrams.,. _ PROJECTS; V.H F. Tuner Module A.M. Tuner Module M.W. L W. Diode Radio * Six Transistor ELECTRONC mo CONSTRUCTON KT E.C.K.2 2 S«t Self Contained Multi-Band V.H.F. Receiver Kit. 8 S transistors and 3 diodes. Push pull output. 3in. loud- loud speaker,gain control, 7 section» «chrome plated telescopic aerial V.H.F. tuning tunin, capacitor, re- resistors, capacitors, capacitors. transistors, etc. Will receive T.V. sound, public service band, aircraft, V.H.F. local stations, etc. Operates from a Complete kit of parts sisters, 9 volt P.P. 7 battery (not supplied with kit) kt) P & P -nd ns, 90p Com- Com. plete kit part* of parts in. cludin. cluding nconstruc- Conicruc- tion plant plans Total building buildin. cosu cottt P * "and P n in*, ( ci 10 d V.H.F. AR CONVERTER KT EDU-KT MAJOR COMPLETELY SOLDERLESS LESS ELECTRONC CONSTRUCTON KT BULD THESE PROJECTS WTHOUT SOLDERNG RON OR SOLDER RON OR SOLDER Batceryles* Batter-yless Cryatal Crystal «5 Trantiator Transistor Poih Push Pull Radio Amplifier 7 ~rnt~~:~stor Tran*i*tOr Loud- One TrAnliltor Radio loud. : ~ne ;::nn$~~~~: Ra::: i 4.. Trantinor Transistor Earpiece speaker. tpeaker. Radio MW/ 2 senerative Radio LW. generative Tr*ntor Radio Re- > ri~~i~ Tr-acer ~W;-. t Sl'ort. J Transistor Re.. i Signal Signal Tracer Silnal niector 9 5 Tonjiator njector Wav;aR.:dioo r Short 1 Wave Radio generative Trinmtor Radio Rea:enerative Radio Tranainor Transistor Tpifer Tester Electronic Audible Audible Continuity Continuity NPN PNP NPN-PNP Metronome Tener Teiter 4.. Tramiitor Transistor Pu*h Push Pull Electronic Noi*o Noise Sensitive Semitivo Prc- Pre AmpHfler Amplifier Gener-ator Generator Amplifier- Ampfifier Retitcor* Resistors Capacitor* Capacitors C 10 Tramistor* Transistors # 5' 5 * H x 3" Loudipeaker Loudspeaker : «2 Earpiece ~asr,~ Slider.. ~ Switches S: i t~~: Mica BHiebnard Ba.b' ~ni:llc~~za:s;.on';c; K~o:. * Tuning * 3 Condenser 12-way Cannector* 3 Knob* t 2 Volume ~o~:a:ycw~~~j Ready Control* Wound MW/LW/SW Coils Ferrite Rod* Rod. 6^ 6. yard* yards of wire. wire# yard of ileeving, sleevina. etc. Build this converter kit and Build this converter kit and receive the aircraft band by plaein. placing Jt it by the lido side of a radio tuned to medium wave Wave or the VHF band and opentinl operating as shown in the instructions supplied free 'ret with all parts Uses a r-etractable retractable chrome plated telescopic teleicopic aerial. aerial, lain gain control, V.H.F. lunina timing capacitor, capscltor, tran trsn-.. siltor. aistor, etc. All parts pana inc.ludina including ease cast and plans and pl»na 4 /d 95 W TJ + + ~: P ktta, P MD mrtd To: To; RADO EXCHANGE L LTD TO 61A High Street, Bedford MK40 SA Tel.: Til.: REG NO Callers 9Callers side entrance "Lavalls" ulavells" Shop..Open ()'. 10-1, 2, ~. Mon.-Fri Sat. Stt. Practical Wireless, June 1978 J p.::d o r enclose L.,, for. Name..... enclose ror..... Address ,... PW578

14 ~ 12 What did Flemming say to Edison about Antennas in 1912? P We're not sure, but we eon can be sure that they couldn't have been discussing dlscussln, the merits of the Joystick VFA (Variable Frequency Antenna, 5-30 '5 30 MHz). Mhz). That had to come later..... so that now, you can have a versatile antennasystemthat that acts as aground a,round plane right rl,ht through throulh the six lower amateur bands and on all an frequencies in between. Short wave listener and transmitting transmlttln, amateur alike will benellt benefit from a VFA if VFA-if you can't hear 'em, you can't work 'em. SYSTEM "A" w. p.e.p. OR for the SWL. SYSTEM "J" w. p.e.p. (improved 'Q* 'Q' on receive). PARTRDGE SUPER PACKAGES COMPLETE RADO STATONS FOR ANT LOCATON COMPLETE RADO STATONS FOR ANY LOCATON All f>2tl(is«s Packages feifure feature (He the World Record Joyitick Joystick A.riil Aerial (S/icem (System -A'), 'A'), with Sir, Sft. feeder, fe.der. til all necetstry necessary ctb'es, cables, mtechins matchinl communicttlon communication heedphonei- headphones. Deliv. Detiv. Securieor Securicor our risk. ASSEMBLED N SECONDS S!CONDS BG CASH SAVNGS SAVNGS! PACKAGE No. 210*55 Ae.boy. with R.3MRX. R.lOO RX. SAVE 11 ft '281 M! w ww PACKAGE No. 2 s. offered with the FRG7 FRG1 RX.SAVE tu J PACKAGE No. 13 Here is it a x lower.price, lower-price, hlgh-duellty... uality pacicap psckege f featuring turin. the LOWE SRXlO., SAX30,, wth with.11 ell the Partrld.e Parlrldie.xt... extrme. SAVE V! ' RECEVERS ONLY, indutivc inclusiy. delivery, deliyery, etc. be. R.100 R SRX prices are,oin, m FRG SRX All priees»re correct at time of joing to press and include VAT at 12*% 2 % and carriale. carriage. ' Just telephone ~, '.. your card number ~ Phone (ext.5) 61S35 S) " :,,,,. 'J. (or after j ~lwidl"" BuykwidiAareel '."",..,",,'. office hours) or write for details, send 9p stamp G3CED G3GED G3VFA &3VFA 5, Partridge House, Prospect Road, Broadstalrs, CTlo..LD. CT0-1LD. (Callers by appointment). l'a' il'kal rdx^fvjrj TYPE B 3 BANK UNT (lesslnmpsi m wan $f 0T LAMFS RED.VELLOW.GREEN lltmpi r/pah CLEAR fl' 50 B.C. er S, "- Finfef 50 BC Fttng E SF - "!tong - -3&:"[2-30'- 2 THE... COMMUNCATONS RECEVER THAT HAS T ALL..,.. ; ~ -... _- FRG-7 :; --~'"- ~: ~ : ;= FRG-7 The finest general-coverage synihesised synthesised communications receiver on the market inc_ inc VAT Also available from us with special 2m converter, all for just an extra * Phone for details of current stocks, both new and secondhand * AMATEUR RADO EXCHANGE 2 Northfleld Northfield Road, Ealing, Baling, London, W.ll. W.3. lel: Tel: M Easy terms up to Credit Card Sales Closed all day doy 3 years by Telephone Wednesday by Telephone *35 TWN BANK 12 LGKT mm -S & & (less lamps) ac 8'50 FS 18*50 ALBEM ENGNEERNG CO LTD., DEPt PW THE CRESCENT WORSTHORNE BURNLEY LANCS. Tel Burnley Practical Wireless, June 1978

15 Mini-p'riced breaclboarcls for maxi-sized projects. Mini-priced breadboards for maxi-sized ^ A / projects. Experimentor':' 5 low-cost solderiess solderless bread- bread /////////MA boards are the first in the world specially /////// ^ designed for 0.3"and 0.6" pitch D1 DP's. //////A They clip together by an exclusive exclusive EXCLUSVE NTERLOCK interlocking system in any configuration, system CKNG SYSTEM. (just like dominoes), so you arrange the breadboards to suit yourcircuit. circuit, not vice-versa. They are precision moulded from durable,flame-retardant plastic, _^ and feature alphanumeric.. 1 codingforeasycircuit Circuit l building.and building, non-corrosive, pre-stressed, " 'M+ nickel-silver alloy contacts contacts. reliable for well over 10,000 insertionssitjc, W ~~.,/ TOP )(... D J A C '" O' E, "' Get your hands on an Experimentor and stop wasting time' J.' y 5 '0 15 Contact resistance is a mere 0.4 mn and Centre 5-way interterminal capacitance is typically less Model Length" Width" channel" tie paints Bus Price Ail All Units units unit5are0.330'deed " 0,330' deep. than SpF.The 5 Experimentor is usable to EXP (470) 2(80) PricesincludeVAT(8"A»andp&pf< include (8%) ps p ft loomhz. EXP (230) 2(40) «4 21 «UKOrders. over 100MHz. EXP (470) 2(80) Add 5% to all orders outside UK. UK, Experimentor 600 and 650 models are EXP ,6 46(230) 2(40) 4." 4-69 All prices and specifications speciticationscon correc A 3 21 of press. ideal for RAM's ROM's and PROM's EXP4B N/A M/A N/A 4(160) '29 at thetimeot time going to (0.6" <0.6"centre C's) while the 300 and 350 expands the versatility of the system im for displays or any other circuits, buy the models are for smaller 01 DP'S s (0.3"centres). the MPU user. breadboards that are designed for you. yoi All four models,of of course,also take all Experimentor breadboards can be used Ring us ( ) ( ) 0782) with your Access. Accei Access, standard components,the0.1"grid the O.l"grid being alone or mounted on any convenient it flat Barclaycard oramerican Express numbc nun numbi compatible with transistors, diodes, diodes. LED's, LED's. surface, thanks to moulded-in moulded-in mounting and your order will be in the post that ni capacitors, resistors, pots in - fact any holes and vinyl insulation backing that E component... with lead sizes between mb 0.015" ^ Alternatively, send a cheque, or postal prevents short circuits. Mount them n from ando.032~' 0.032;' order (don't (don't( ' t send credit cards!) and it it the front with 4-40flathead screws orfrom still still s^ll only onlytakes y a few days. days. days, the rear with 6-32 self tapping screws. u.u~. ~.o.o. :ws - Otherwise ask for our complete catalogl catalogi mo.. '.!'" :: "' *,-=-'.,!.,. ~..! ~ But however you use them, them. Experimentor CON'MN-Al HtCAinES COSPORACN breadboards are the quickest and easiest way to build and test circuits. m! A useful quad bus stnp strip (EXP4B) further f you're working on C's, MPU's, MRU's, memories, memories. CONTNENTAL SPECALTES CORPORATON (UK) LTD UTO. SPUR ROAD. ROAD, NORTH FELTHAM TRADNG ESTATE. ESTflTE.FELHAM,MDDLESEXTW14 FELTHAM. MDDLESEX TW140TJP CTJP TELEPHONE: REG N LONDON: LONDON; VAT NO: NO "'TTthDE TRADE MARK APPLED FOR CSC OCSCfUKj (UK) LTO LTD DEALER ENQURES WELCOME. lelex: TELEX; CSCLTO. CSCLTD.

16 FANTASTC SPEAKER OFFER 50 WATT AMPLFER SACRFCE FANE CRESCENDO/12 FANTASTC SPEAKER OFFER FANE CRESCENDO/12 Limited. TWN 11" 12" SPEAKER CABHPT CABNE' stocks s~~~~e:f w SUPER loow 100w SPKR. PLUS PAR 12" SPEAKERS TTAN ; '.--_ ~- ~...,: 'i1 of vibt!'tion-proof co!'struction. TA/SOA Fitted Robust protective vibration-proof corner construction. ~e- G.--.. J.. -.-l HALF PRCE Filled oroicctive Vynair comer pieces. to be --_ - L O o O' movable Vsroalr covered front wuti to be cleared WHLE STOCKS to 1,' - - '--'--_._-,,,;:.:::::-..: silver -._..J.. effect trim. Sunken jack socket 10 make way with escutcheon at the rear. _ Tor for a a re-stylcd re-styled LAST Pair 12" speakers for. series 12' and 20w front sneakers WhJ Cor t wiring ks in model. series t Sohd state. 3 npus Master 12l mounting.-«j 1 Solid state, 3 sep. controlled inputs plus MMttr control. MODEL 2L in e s ~ S & Vynide cab. is the mountina?«in to above While Three Stocks Three i(.tems Cms last Bass. Treble St Presence Controls. Vynlde covered cab- This is basically the supplied corner protective. Terms: 1.7 ' 9S the plete lo 40 com- mi KM with comer protectjvcs.value 60.Tcrms; Dep & 12A with the addition plctc the AO watt AaAE 68 montbly payments ' (Total (Tota! _ of of Uncn Linen coac cone surround. unit for lead guitar 19* ). Matching MatchlnS Cabinets 1 x jp^q'qf. 39"95 State impedance when Carr ' Carr. 9~. ~ 12' 12" 49 OS 95 Carr l 1 *FU ordtrinji orderin,z 29*95 1 ~o r.i. iiiilfj ji Jsi. fvitkmupi i-itmnnpnorii u a. _ nqyfstfr/l ALL RSC PRCES NCLUDE VAT 11 d > A A * OlavtvMAJOK U i.)lu,\laju H. 'Ovv lju,", 4-K LH.. UlbCU U l:::tt.u CU.'V^ULL LU~~,~ULL with \\lh uucklal Ullc lat 'uwui 'O\\~ AinphlKl, Am"hh~r. A TWN FULL SZE BSR turntables with cueinb cueing device, device. *r4mffpsnc Styli. K:» CARTRDGES with Diamond Slvli. * 3 SEPARATE VOLUME CONTROLS for each turntable and Mte- Mic. m/m CONSOLE COMPLETE WTK WTH LD. FULL HEADPHONE MONTORNG FACLTES ni AAhA? 'yi Terms: FACLTES Deposit fjo 30 Ottand forlnlghtly fortni8htly pymts. * a (Total 20d'40> 206 ' 40) Carr. 4'00 4,00 CM Vl Li 195 WVl Also available avaliable 200 loo WATT SYSTEM 199* Carr. 4 4' 75 St. 101 ncorporatin8twm turntables &; Consi," io,c or....1',. TD1 DSCO CONSOLE ncorporating twin BSR type tumlswes & Sonotone 'T i. or Acos Cartridges Cartridaes with diamond styli. Separate Vol. controls for each turntable. (ij \ TWN N T/TABE TTABLE CONSOLE wi.i^ Also MOM 1 OK No FACLTES, FACLTES. Pius plus Treble and Bass Controls, Controls. Separate nput for 'mike" 'mike' with vol. PRH-AMP, PRE-AMP, and POWER OUTPUT control. Black Vynlde covered Cabinet with lid. / 0.OC Or DepdlS-dPA 18fTmly pymts. pym~~~~i5(!i~~\di137-99) K-7S (Total m7.») Carr *.117* STAGES (2) i Bc (3) PAR SO 50 WATT LOUDSPEAKERS LOUOSPEAKERS ineludlng including 12" w UNTS TD2S TDlS STEREO VERSON OF ABOVE Can. Carr. 3 DO 00 Mew New Branches at f* B*fd.»vc«r<l ~ PHOSE PHONE ORDERS k Accm qaotlay hah. obdebs ft eztobi laaumtej 0;- quotlu.. ATOM A17DO KOOBB. BOlJlB. HgatCOTOBS BlCODU ***, LAD, 105*01. ~, t. 11. LEEDS.,. ~ CARD NURSEE ttctcua T,l; OARD NUMBER accepted ~1~/':.'~~~:l MUST LEEDS, HANLEYand /* le St.NT SHors WSA MAL OADEA5 NOT BE SENT TO SHOPS SSB3U TB... O.W.O. a.w.o. er or C.O.D. go. 11'0. O.O.D. C.O.D. uct.r ""'or POCTAO* POTAGa 80e lib P*B P.. WOLVERHAMPTON V^r OBDKB OU.. OB 0. A tjootto. QVOTBD. Pkeoe Pho at or Wtlta Write lot lor VSEE PD OAALOOTO OATALOGV OPEN ALL PAY DAY SATS (5 Day Dalf W»«k) W.ek) Prices cntrect correct at 17.3, E. & O.E, O.E. All iicinssubicci tems subject to availability :~""~~~~~r.lt030~fr~r:.~r~:.t;~o~ r~.:r.~d. ). Tel LEY Stoke-on-Trent, Tol. MDDLlSBROUGH Lintho."e (Cr. Tol. 2470H ii3ngh*hw3tte P.Vw...em a A. d cj. e '', T8, MDDLESBROUGH 103 Unthome Rd. (Cl. Wed.) Tal, BSTOOe **** = HANlEYSt«ke^H-TWnt, 44 Piccadilly T,.8«}7M NEWCASTLE UPON TVNE TYN59 68 Gralnoei Gralngor St. (Clone (Closed Wed.) tel. T.1. 0?t-23« MULL HULL 7 Wtilt«trlaroale Whltofriargato (Cloaul (Closod Thur«Thurs.). Tal. Tel. 2050S (Clo.ed Wed.). Tol. 21'" CARLSLE 58 Enollsh English Slraet Streel (Cfoaad (Closed Thura.). Thurs.). Tal, Tel. 3S LClCESTf LEC8TR R K 32 Hiflh High SltM! Street (Clotad (Cloaed Thv'";!-T"'' Thur.). Tel. 18,50 (Closad Wed.), St, Tel. rn t/ta Street COVENTR* (Closod Thuro.).. 40l g~.r:~w~ 17_.~~~:,~o;lr~~i Shollon Sa.. ' (Jroes:: Jhe Pr«eio«, X~~i Tel. ~: m~ **LEEDS Count/ A NOTTNGHAM 1S/18A Market Svost CounlY (Mecca) A(~~~:':C3:3~~ g^5j^t) Tel, _. 44MOS (Cloaed DERBY 87 S. Peter's Street (Closed Wed.) 4411e011 SHEFFELD 13 Exchanoe Stresr (Ca*tle CCaitleMkt.Bldt.) Thufi.J. Tel. 480«B SHFFELD 13 Exchange Slreet W:,:~~M~~u~!~r~O.071l DARLNGTON g:~~:~~~~,;~ 18 Northoate N~i~~:~:/1:;~':!n~~ (Closed Wed.)..) T~~ Tel !:~:"~~~RLY duo DEWSBURY DONCASTER 6/11 Queensgate. Ktnosway Walerdale (Cloeed Tuea.) Conlre. Tel. 4e8l»e LVERPOOL TEMPORARLY NOPERATVE HOPERATYE due to (Cloa«d Mht. Thort.). Bit Taf J DDHCASTER 3 Ouacnsoele, Waterdale Centre. LONDON233Edowara 238 Edgwar. Road, W,2(Cloeed W.2(Clooed Thura.).. WOLVERHAMPTON 6 WuUrun Way {Closed ~C~~::,:u~h':Y':~). Thuri.). T9i. T.1. 2Wi HO! DNBURGH 101 Rd. (c\~~~~edw!~jrs~ejej29e: (Closed Ttiurs). Tel EDNBURGH (Ot Lothian Hd. (Closed Wed) Tel * MANCHESTER T. Tol ^MUSCAL *MUSCAL NSTRUMENTS A & ACCESSORES if) n tock.took al at GLASGOW 326 Aroyta Aroyle St, St. (Cloeed (Closed Tuea.). Tel CA loa Old Oldham Str«Bt Slr.. t (Closed (Clo.ed Wed.). T«l. Tel these brnnche*. branch le ' ~ Barclaycard.. A""".. AL OUB10 SZPO.T EJlQumm '10:- 14 J. J. BRKETT Radio Component Suppliers Radio Component Suppliers 25 The Strait, Lincoln LN2 1JF T«i! Tel: mtj zom LLUMNATED EDGEWSE SGNAL LEVER METERS at < Ji each 1OQ.O.OOuA HKFD-OOuA TUNNG METERS H" fr x X 11*31 f" at Mp 90p each. TRANSFORMERS 240volc.54v volt. 24 tapped.apped at Mvolt 14 amp at 1 L SpSpPSP). 2S (2Sp PBcP). TRANSFORMERS volt amp twite, twite. 10 volt 1 amp M 4,50 S# (95p (9Sp PBcP). PA P, AUDBLE ALARM SVSTEM SYSTEM with Transirtort Transistors and l.c..e. Made for ror Car Ca. Seat Belt! Belts No Details Oetails at 75p. GENERAL PURPOSE P CHANNEL FETS with circuita circuits 10 for ror 75p. TT CAPACTORS PNT-2R. Guf 'ur loov.w. loov.w. at lop JOp dor. doz. 20 PHOTO TRANSSTOR AND D DARLNGTO DARLlNGTONSAssorted NS Aiiorted tmte.t.d untested for. (. SMALL R.T. TELESCOPC AERALS for ror Up. 60p. DUAL 00K look LN L1N WRE WOUND POTENTOMETERS at SOp. COMPRESSON TRMMERS 10pf, lopf. 30pf. 30pf, 50pf. SOpf, S00p(. SOOpf. DOOpf. 1000pf. All at lop each. MOS HOS PRE-AMPL1FER PRE-AMPLlFER l.c..c. TYPE TAA 350 )so with 5p. Up. 50 BC ' TRANSSTORS Assorted Anorted untested for 57p. STp. 100 MULLARD C280 C180 CAPACTORS Anorted Assorted for 57p. S7p., < LFT TELESCOPC AERALS at 60p each. LARGE FLANGE SOLDER-N FEED THRU'S THRO'S at 6 for lip. 8p. AUDO.C. l.c. LM 380 with circuits at 80p. 80p- S'S $ 5 MHz MM* CERAMC FLTERS at 27p Wp each. each, MNATURE CERAMC TRMMERS 2 5 S to 6pr. «pf. 0 to 8p', Bpf. 3 to lopf, 10pl to co 20pf. t 0 to 30p!. 30pt. All at top lop each. 200 ASSORTED.'J i, i- RESSTORS for (or 7Sp.»Sp. ERE REDCAP S SUB-MNATURE O'Oluf «0lu( 100v.w. COv.w. 6. 5p Sp each. T.V. T-V. S.A.W. FLTERS Untested 3 for 35p. JSp. CLOCK P.C. BOARDS with Buzzer. Boaaer, Brid,e Bridge Rectifier, Mercury Switch Transistors etc. No data Brand $ '. 1- BAW62 BAWS2 HGH SPEED DODES at 12 ror lor )Sp. 35p. SUB-MNATURE 4 ' 7uf Dv.w. Oy.w. TANTALUM CA'ACTORS CAPACTORS 5p Sp ea. 68 ror for 25p. 12 VHF BRANDED FETS Assorted for. 1. COL FORMERS 3/16" 3/16' dia. with core at 5p Sp ea. 6 ror (or:up. JSp. COL FORMERS 3/16 10$s 3/14* less core. 100 ror for 3. AUDO PRE-AMPLlFER PRE-AMPLFER.C. l.c. TAA 435 with 45p. 2 GH" GHx STRPLNE NPN TRANSSTORS at 1 each. MCMURDO 8PN 8 20p.8PN 2«p.8 PN 15p. Sp. RCA VERSON OFBFY BN ' p SSp each. VERNTRON FM MHz CERAMC SOp. MULLARD ELECTROLYTCS ELECTROLVTCS 2240ur 2240u( "Ov.w. 4Ott. Up. 4500uf 4S00uf 25v.w 40p. Up, SOOOuf SOOOul 10v.w. Sp, $P, 6400ur 6400ul 6v.w. 2Sp,8000uf 2Sp. SOOOuf Ov.w 2Sp JSp Please add 20p 2Qp ror for post and packing. packing, unless otherwise stated. seated, on UK orden orderi under 2. Overseas orders at COst. cost. BARGAN PARCELS SAVE POUNDS =~:~~*:.rsn:~r.!:~o::. :~~~~::~. Huge Hug. quantltl.ectranlc compan.nt. mu.t cleared e. pace required. 1000'. of oepacuore. ttuimlill.a reeletota. of ttenilelora. comoenenu ~llb~~;;.~n~ Ei equipment must be cleeted ~~~: ' 7- at :~ 1:lt~-.:;:. J'vered epace requited. :; in valuable JOM'e ;:1~:~llt~~;; comot ponente- No lime to eorl. Muet sell by nelpht 7 lbs- 4'88, t4b*-b lbe- 661bi-««58lbO-Ut 96:112.; 112b.-Dl bs-tm-ee.. Handy Ha""lf P.eb Alumnum COOl plug.olor&'. 4 falumlolum Pache aluminium homa!«bo.e.,'! a )( 44 X x 38 mm dael Aluminium jk TV pg coai pole piune with alp 10 for «ltch4»or fci ea far lefelbnollnlettore.blc.blea, algna' njector., et:. At... ^ Mlnloture 5K log Pol. with.,p wlteh 4 for t. Hlnletute Miniature Edgowlae Edgewise Penel Pan.1 Metera Meter. DON'T m.a FSO. &1 11 DON'T LET LET YOUR YOUR ENVRONMENT ENVlltONMNT 100 minlelore mlnfature ^ reed. "S",BMBONbT wltches deal for DHYDltAT 6u/ YOU 0 «U Hone^S?HumSlly OR YOUR POSe burg'.r alarm., model r,hway".tc.. U H. BSSONS. Buy a Honeywell Humldll, e x e po'e 12 volt reed r.q on board Conlroller. Compact (3. x 11" x "), wide & U. range of control, adjultable by 1"" Plndle High quality computer panel, amothered n with flot. Contaet Rating 3 M:"c top onde grado componenle componento y qrqfflrhl'j, S lib. he M &4'15. m?. 7J. M 10 to ;s^; bi ",. 120VAC. de.' lor Gr.. nhou... &. Centrally HbiM Homea. Office., etc. Heated Home.. Office., etc. D LUX FBltl GLASS n, PltlNTED.-.KTrr. Build your /cut own KumlOlflore HUmldlflera or Dehydration Oeh/dratton ClltCUT ETCHNG K.'sf.Ma KTS k 9 i?«alarm.. Alerme. &t, Ef W t. ee. 4 'or fur s. ts. nclud Q. tnl, copper clad tto board. New Miniature FM Frontendl MHt. SSSSsiM: b farrlc chloride. 1 Dalo etch n"lt pn. 10'lMHt,.F. or with ntegral Tunlng.gang abrellve ebreelve cteener. cleaner. 2 mini drill bite, bltl etch m/ tr.y "* ' & S. _..... ^ and *nd liwlwctlom/only nltructlonl/only '»*»-. 8" BR "11"" 101 full "P". opoc. 85 ior!or, 1. H.. SO 150.q. n. flbr. ala.. boord &. S' eoeh Oelo Delopen.aep. «q-?n. fl6r«dla«a bd«rd «H pen, "p. SN TBA 1 b ferric chloride to mll pec. &'1 '11. SN 7al15N 76llSN t 120A Jfpetch, each. each. Sb. 1m l.rrje chloride 10 mu t'i's; spot. 1 ci^e. 20 W mm entl-uroe antl-euroe fu.. yout your aelecllen...ctlon natruc1ion?net*u*f7on sheet Hp 800MA t03 15A. 1210r '. Mlnlatur. Mlnlnliire aheet malni 28p malnl irantformtfn, tran,formerl. fully lully Component eoo«atq3-t.a.t2for4t-68 ComponentSaraaln. Dapq "n* ohroud.d. hroudid, «4UV, 240V. n 3-0-«y 8-O-tV 01 at loom. Mma out. 300mlxedre.lsto",*4.watt "M kjo rerlftort*aj watt Ct*W r:a;tr:" :~~gm:~t ~:U~p~~~e f.\jtnd,^7, 0bln C put P 1l«:;;!~ i:~:: 300»0 modern -1-~r.r.'l2T.«"l" mbed capa moat type. ' on outdut oulout top. lop. 125 ^55 milled mikdo rell,tor. r*«latora mdfthy mo.t~ 1» "*2w«h.fci. 2 Wltt. 't. S.mlconductor mlconductor a Bcrgalnt atn. 100 X p0,^«milled polyester r «?«ai»urn-nrf cap. a. f, Q m i r. TH3 TK3Tharmlscora Thermlstora 10'or ' milled {nodem miniature.ceramlc for 1. mlxad modarn mlnialure and.eoramic new" marked silicon Oermanlum plate cap.... tran,latorelncludlng tranaiilora n«w & mntked rcludlnfi alucon 8C148, BC148.8F1W. and garmantum 8F1.., 8C113. 6C13, 100 loomlsed plafa caj)t mlllted wlrewqu wlrtwoundi 1 *#. nd,a * W.. tc.«3l5...,, j. 300 prlnladc[fcullr«alitora 1 ;~, ~':54 marked tranol.toro neludlng 3OOprlntodelrcultr,.",.&'. 2N305S,... e128. BFY50. B0131. ete. 'S 25ml.odpots4pre.ets ' S. 1 Wt'ed mixed diode. dlldie 'awm N4148, ln4u8. "BOlSi* etc. ilc t tl etc SO. ie". Ei-M» High Hlub wattage watteoe b'"* re91,tor5, realltorc, 1 '"» wirewound wfrewouod 100 mixed diode. zen er. power etc. 2,20. and miiad brfctge brhtne dloda* type. troe«st. J ncluding M. xansr, povrar c- Moder" Modern 20. Vertical Praaata with' alotted aloltea,. Bridge Bi}dflefecHflar100vJ*l5 r.ctlfler 10/1'1 2'5 omp amo 410r 4 (or,. 1, knobo. knobi, 2200., 470K, SOOK. 500K, 1 MEG. MES. 25for!or ', 1, Brand new 25 kv trlpler. for Dacea Packs J 51. Bradford n«w chall'l chaaala TT 23 U 2 h* '. W- irlolera 5 B for 'or 'or t.!. Dacca 4 Small PacKe 50 tt wirewouiu wiiewotind 5». Horlz. Horlz, Convergence ConvBtgenca 50 SO Germaplum Gafmonlum diode., dlodaa. deal for crystal cryalal Preeet p f eget with wuh Knob. Knob-10'or for t. 1. oot., aela, otc.,. M~torol. "'ud/o.c. Mlnlatur' Miniature ate,. Vern1tron Vernttron 1. FM4 ' 10*7 0'7 MHz: MH* Cer... Cere- Mclorolii 1 watt Audio l.c. MFC 8010 complete e0m p O ie with wllhctrculla clrculta and Bnddatatl datl11,10 18 t?ach, each, mic mle Flfters FUlara SOp Mo each 3 for at for lor 4. :~:o~:p: ~~so l.tor Kf?nnre«3,.«r',, r TV tuner... pull\- B 100K 1»k Stereo Sllder Slider Pots Pot. Modern Modem, elim Um Hardware MerOw.r. Packa Feckt each eech containing contalnlno 100'1 M'e 0' of type. vco^mp SOP each, eech, 3 for lor Lt. " _. tem, tem. ncludln'1 nuta and bolt_. Nylon. Gang Tuning Condenso,. Self.tapplng, SeVMonpinp, ncludlrt PJsldrlye. PoslCrlve, BA nut. up" "P" end boll., clips. clip". Njlon, Cable Cibte with Double ntegral100k nleorel s» l 'a 100K A.M. pot Tunln# For v.rlcap vetieaptun'"; CondebMra tunlna clampl, clempe. Fuse holdera..8 et tl per pound. Fu». holder.- Splr. nut. etc., on. centres. centre., VHF 1. tl. oe used n modern Thorn muelc "Op 40p P & A P ON ALL ABOVE TEMS. SEND CHEQUE OR POSTAL ORDER WTH ORDER TO SENTNEL SUPPLY, DEPT PW 1,,9A 149A BROOKMLL ROAD. ROAD, DEPTFORD, DEPTFORO, SE8 SES CALLERS BY APPONTMENT ONLY CALLERS BY APPONTMENT ONLY Practical Wireless, June 1978

17 HYS HY Watts! Preamplifier HY30 15 Watts into 8n HYSO HY50 25 Watts into 8n HY20 60 Watts into 8n HY Watts into 8n HY Watts nto into 4n POWER SUPPLES The HYB is h mono hybrid amplifier fdmlfy eulted for eff ippllcetlone. All common nput Th. HYS la a mono hybrid ampllfter aultad for all appll.. tlono _ All common nput function. (rnas Cartridge, tun.r,,'e) are for nternally. The dtllred function 'a achieved :~:.~~:::::~ ;'::',~n ~":~!~n~~~:nr::::~~:~r:~t1~:.~nj:>~~~~~ ' li compatible all 7.L.P,.rnpff~.,.. and pow".uppll... con.trudlon mountng mountlnp cornpallble a «P.C. with connector nil.lp.. 1«power lupplled euppllad emdllflen wth with each end pre-empllfler, power euppllee. To eai# conefnjctlon and... mpllfl.r. FATU"ES: FATURiS: Complete pre-ampllftor prenimplffler n in lngle etnofepech MulW-lonctfon pack-mulh-luncllon equalization-low equelljeltor* Low nol node.. -Low Low dl'tortlon-hlgh dietortlon Hlflh overload-two overiobd two almply mply combined for teflo. eterao. APPLCATONS: APPLCATONS; H-F-Milora-Dlsco-Gultar H-F Mlesre Disco Guitar and Organ-Public Oroan Public addraat... SPCFCA SPKCFCATONfi: TlONS: NPUTS_ NPUTS. Magnetic Pick-up Plck-uc 3mV; SmV; Ceramic Pick-up PlcK-up 3OmV, SOmV; Tunor Tuner l00mv; WJmV: Microphone,OmV: 10mV: AoHllery 3-l00mV: nput lmpadance4'7kq al khi. ~~ ~~f~:~m:irlo'~~t.:~~d~~:::u~ OUTPUTS. Tape toomv: Main output ~~~t~~~.>s 800mV R.M,S.. ACTVE TON:!' CONTROLS_ Treblo m 12dB 1011Hz; Ba Hz. DSTORTON, TONE 0 GONTROLS 1 % at ikht, TrehTai Sipnal/Nolse 12<jB Ratio at CfcHi; MdB. Bite ± at toohl, g!je~~~}!g~3a~~ OVERLOAD. SfldB ~n"u::';~$l~~!;.":~~~~ on Meonatlc PJck-up. SUPPLY ~gi. VOLTAGE TAGE::: ± e-sov. S-MV. Prlca a + 4-.p FBp VAT PAP pap fro trie. The HY30 s an ekcluno New XU from J.L.P. tleaturae a virtoally ndeatrudlhla LC. with ahorl J~~u~t:~J J~r::r~~~~~r:,~~~:klliL:';'~~~:~; ~~. circuit ~~~~~rnk~d~~~~u::::.14c;~~1:~~r~ capacitor., capacltore, and thermal protection. The XJl conaiatt of.c.. hantalnk. P.C. board. 4 (Mlatara. 0 conltrudlon operating ruetton Thl. Thla amplifier mounting. la deally hit, lulled aulted together to the with beginner haglnner eaey to follow n audio conatructlon who with wlihaa and to u u»e openrtlng the molt moet nilruchona. up-t~date up-tp-dete lechnologyavallabl technology aveliable. FlATU"ES: Complel. K-Low Dlllorllon-Short, Opon and Thermal Proloctlon-Eaeyto Build. ouild. FAAJURCSr Compfate Kit Low Dletortfon Short, Open end Thtrmaf ProlacUen Eaeyto APPLCATONS: APPLlCATONfi; Updallng equlpment-gullar pracllce ampllfler audio oiclllator. Upditlnp audio equipment Guitar practice amplifier Teat ampllflar oleln.tor. SPECFCATONS: OUTPUT POWER 15W 16W R.M R,M.S.. nto nlo 80: BQ: DlSTORTlONO DSTORTON 0 '" t% at al -SW. 1-5W. NPUT SENSTVTY 500mV. FREQUENCY OHz-'eHz-3dB. SUPPLY.^NSmVTY VOLTAGE sfc WOmV. ± tflv. FREOUENCY RESPONSE lomz-lflhhz-jdb. BV. - Prl Price «ES 22» + Sp fsp VAT PAP pap frt».. Th. The.. dl 'a nlegrallon 10 amplifier dulgn. Th. ampllfl.r f fealuret HYSO tur., an teada ntegrel.l.p."» nttgfal heatelnk total heatalnk together nlegratiim too.ther with the approach mpllclty to power lmpllclty ol of rw no external implltlar' componanta. dealgn. The compon.nt Duifnofha amplifier During the pail P t thraa three yaera ye.,. the amplifier hat ha. been be.n reflnad r.f1nld to the extent that t fnuat mult be b, ona one of thg the moat molt reliable r.llablo and robuit robu.t Hlph High Fidelity moduiea modulol in n the ha World. FATU"ES: FATURESi Low Dlitortlon ntepral Dlllortlon-nlogrol Heatelnk Only H.atllnk-Only five ftv. connectlone 7 conn"'lon0-7 imp amp output fiti- ranelitora No lltorl-no e-ternal ed.rnal componenta component. APPLCATONS) APPLCATONS: Medium M.dlum Power H-F iyiteme Low Ylloml-low power dleco Guitar dlaco-gultar amplifier SPECFCATONS: NPUT SENSTVTY WOmV SOOmV 25W nlo % W t OUTPUT at 1kHz POWER JBW RMS nfo 80 LOAD MPEDANCE <-100 DSTORTON 0-<H% et 2BW 'khz SGNAL/NOSE StGNAUNOfSE 75dB RESPONSE 'OHl-48kHl-SdB. SUPPLY VOLTAGE RATO ± fl8v 78dB 25V SZE FREQUENCY 1M OS W SO 25mm REaPONSE "mm Prl Price «a -a 12 + Up VAT PAP pap tree fr The HY,20 1.lho.L.P.'a now rng Dellgnod m t the moll... cllng requlramente HY120 le requlrementl nctudfng the baby of ncluding load.lp.'a Old fine line and new thermel high power thermll protection fange, protectfon thla'amplflar Oaelgned to meet thl..mplffl.r eeta letl a he new moit naw etandard exacting atandant n modular deelgn. d fhatoresi FtA TURS: Very low dlatortion ntegral dlllorllon-nlogrll heatalnh Load h.alllnk-load line n. protection Thermal prol.cllon-thermal protec- prolectlon-flve connectlone No connectlona-no external component! component. tion Five APPLCATONS: H-F-Hlgh quality dllco-publlc ddr o-monllor mollfler-gullor end organ H-F High cjuellty dlaco Public add raat Monitor am oil flar Guitar and SPECFCATONS SPCFCATONS NPUT SENSTVTY MOmV. SOOmV. OUTPUT POWER SOW RMS nto nlo LOAD MPEDANCE 4-lflQ 4-leO DSTORTON 0-04at 0'04% 01 WW OW allkhz SGNALfNOSC SGNAL/NOSE RATO WdB OdB FREQUENCY RESPONSE 10Ht-45kHz- 10Hz-tSllHz-3dH 3dB SUPPLY VOLTAGE SZE tl~5ev mm 8Smm Prfca Pr.a All U -h + 1 let 27 Z7 VAT PAP free. 'r Tha The HY200 now mproved to o'^e give en n output of 120 Werta Watt. hae h.a bean be.n dealgned d.llgned to atand aland the moet moat rugged condlflona conditione euch such ae dlaco d',co Or or group while whn. till lull retaining,.talnlng true H-F H-" performance. Thermollhutdown-Very lowdlllortlon-load protectlon-ntegrol h... ln~ No FEATURES: -No extefnel external componenta Thermal ehutdown Very low dletortlon Load line protection ntegral heattlnk components APPUCATONSi APPLCATONS: Ml-Fi Oaco Monitor Power H-F-Dllco-Monllor-Powor elmve lndualrlal Public la,e-lndullrlll-publlc Addreee Add".. SPCFCATONS NPUT SPECFCATONS SOOmV OUTPUT SENSTVTY MOmV POWER 120W nlo al loow at.1 ikh*. PQ WER1»W RMS nto BQ LOAD MPEDANCE 4-t8G DSTORTON 0-05% at 10OW 1kHz. SGNAL/NOSS SGNAL/NOSE RATO MdB 18dB FREQUENCY RESPONSE 10M!-4SiHi- 'OHz-tellHz - 3dB SUPPLY VOLTAGE tizem tl~5ev mm Bamm Mm Pr ESJ W St 22 + El t VAr VAT Ftp pap f,n.,... The HYMO la LL.P.'m l:' 4 'Bln Daddy 0 of the renpe producing 240W nto 4Q u hee been deilgned for h~:h~o':~; Ldfi~~ '~~13r!!~d:~~lfiaW~'::~R ~~0:::'~~x:,.~~~n~: t~!.l.::a:o~~r~u~~~t'1~ power high gower dlaco eddreee eppllcakoni. f the ampllftor la to be ueed at conllnuoua high V tan 1 Thl amplifier include. all qullltl.. of thl r t of of the ha iemlly levele a flmlly to cooling 10 lead 1.ld the fan he marxel ia recommended. markel a».. a true ru. high Thg power emdllflet hl-fldellty ncludes hl fldellty power etl module. the qual'mea ol (he real FEATURS; FEATU".S: Thermal ahuldown Very huldown-v.rv low dlatortiort Load dlatorllon-lold line Un. protection No protecllon-no exrernal exlernol components. component,. APPLCATONS:, Public addrem Dlaco Power add"u-dllco-powor elave ndualrlal lave-lndultrlal SPCCFCATONS SPCFCATONS OUTPUT POWER UOW nto 4-110,,, al240w ot POWeR«46W RMS'nto 40 LOAD MPEDANCE 4-16Q DSTORTON 0 1S at allkhl SGNAL 1«H: NOSE RATO dB FREQUENCY FREQUENCV RESPONSE 10Mz4»H!-3(B OHl-t5kHz- 3dB SUPPLY VOLTAGE VOLTAOE ±4SV NPUT SENSTVTY RWmV SOOmV SZE 1H "4 WMmm 100 BSmm Prie. Prl EM ESZ «T 17 + ti a -57 ll VAT P*F pap fr..,... PSU35 psuse Julwule lullable for two HYSO'i HV30'1 f U S2 22 plo«plul Ms Hp VAT, P/P lt«s. fre. PSU50 lulllblt HYSO' a -n plul Sp froo _ PSU70 PSUSO KuttabU.ullobl. lulloblt for for two wo wo HY)2D MV50'. HY20'olEt, ««-lt *15 75 plu«ls plu. Up pluo" l-t» VAT. -10 VAT. PP PP fr... ffm, free. psuao lulloblefor HY200 t fs plullet " VAT. fr... PSU50 PSUM lulttbl. PSU80EH,. 51(1 + lor 1 on. " '15 HY200 VAT. 1J Mplu. t «, VAT, PP m. 81 Bl 5 0« » 0'01 «VAT, VAT. TWO VEARS' YEARS' GUARANTEE ON ALL OUR PRODUCTS.L.P. ELECTRONCS ELEOTRONOS LTD., CR0SSLAND OROSSLAND HOUSE, NACKNGTQN, NAOUNTON, CANTERBURY, KENT, CT47AD. TAD..LP,.L.P. ELECTRONCS LTD., CR0SSLAND CROSSlAND HOUSE, NAGKNGT0N, NACKNGTON, CANTERBURY, KENT, CT47AD. Please Supply El^l r% a Please Supply Total Purchase Price Enclose Cheque 0 Postal Orders J Money Order C [] Please debit my Access account Cl Barclaycard account O [] Account number Name and Address Signature Name and Address Sienature Practical Wireless, June

18 11300 ~ f t\ tf\1 ~) C 0 ~J:l 0 ~'~ 1f'11 Tf BOOKS BY BABAN Purchase Pu/chaso books booki to to the thn value wlua of of 5.00 C&.00 from ffom the tho list list below bslov* ond chodso soy eop pok from thi» page F/?. end choose anv SOp pak from this page FREE. BP2 np2 Handbook Handbook of of Rado. Rad40. TV TV & ft ndustrial lodusirial & Transmitting TianamittioB Tube Tubn & Valve Valve Equivale"ts Eaulvalsoia 60pl BOpt BP3 BP3 Handbook Handbook of of Tested Teslod TranSistor Traoiistor Crcuits Circuits 40pt 40pt BP'; BP6 Engineers Engineerb and and Machinists Machinists Reference Reference Tables Tablaa 40pt 4Opt BP7 BP7 Radio Radio &: ft Electronic Electronic Colour Colour Codes Code& and and Data Data Spl 15pr BPO 10 Modem Modem Crystal Crystal and and Transistor Tiansiator Set Set Circuits Circulta for for beginners beolnneis 95pt 95pr BP6 BP B Constructors Conslmciors Manual Manual of of Electronic Eieclronic Circuits Clrciiiis for for the the Home Mom SOpt 60pt BP6 OPie Handbook Handbook of olflecitonic Electronic Circuits Ciicuitcfoi for the the Amateur Amsiaur Photogrilpher Phoiographer 80pt 60pT BP18 R P18 Boys Boys and and Beginners Bcflinners Book Book of of Practical Practical Radio Radio and and Etectranics electronics SOpt SOpt BP22 8P Electronic Electronic Novelty Novetty Circuits Circuits 75pt 75pr BP23 0P2 J First First book bonk of ol Practical Practical Electronic electronic Projects Projecls 7Spt 75pT BP24 8P24 52 ProiocisUslf«9lC74l (or equivalanisl 52 Projects Using C741 (or equivalents) 76pt 7Bpl BP26 UP2G Radio Radio Antenna Antanpa Handbook Handbook for for Long long Distance Oislance Reception PoceDlion and Transmission 85pt BtJpT 8P27 0P27 Giant Giant Chan Chart of of Radio Radio Electron Electionlc ic Semiconductor Semicooduclor and and logic Logic Symbols Symbols &Opt 80pt BP29 RP29 Major Major Solid Solid State Slate Audio Audio Hi-Fi Hi~Fi Construction Conatructlon Projects Projects 85pl ftbpr BP32 SP32 How How to Build Build Your Your Own Own Metal Mel a 8. ft Treasure Tieaaure Locators locators aspt 85pT BP34 0P34 Piaciicel Repair & Renovotron of Colour TVs Pracficul Repair Renovation of Colour TVs 9Spl BSpf BP35 ap3s Handbook Handbook of of le C Audio Audio Preamplifier PrcnmpMier & ft Power Power Amplifier Amplifinr Construction 9Spl 9Spi BP36 BP Circuits Circuits Using Using Germanium, Germanium, Silicon Silicon & ft Zener Zener Dodes Diodes 7Spt 7Bpt BP37 BP Projecls Projects Using Using Relays, Relays. SCR's SCR's and and TRACS TRACS Ot Ct tof BP39 BP39 BOtFtTJ 50 (FET) Field Field Ettect Effect Transistor Tronsistor Projects Projects 1.25t 26t Uoiversai Universal Gfam-moto«Gram-motor Sprwd Speed ndicator ndicator Bpt Bpf Coll Coil Oosign Design and and Construction Consiruction Manual Manual 75pt 7Bpr Radio, Radio. TV TV and Electronics Data Book flopt and Electronics Data Book &Opt 196 AF-RF Ruactanco Frequency AF~RF Reactance-Frequency Chart Chart lor for Constructors Constructors 5pt 15pt Handbook HandboJok ol of intograied ntegrated Grcuiis Circuits RCsl (lcs) Cquivfllents Equivalents and and Subsiiiutvs Substitutes 75pT 7Spt First First Book Book of of Hi-Fi Hi-Fi Loudspeaker Loudspeaker Enclosures Enclosures 7Bpt 75pt ElecKonic Eleclronic CircuitE Ci rcuits lor for Model Model Railways Railways BOpf 85pt Audio Enthuaiaals Handbook BSpf Audio Enthusiasts Handbook 85pt 216 Electronic Electronic Gadgets Gadgets and and Games Games B5pt 8Spt Solid Stale State Power Power Supply Supply Handbook Handbook BSpT 8Spl Solid Stale Novelty Proiects 85pt Solid State Novelty Projects 8Spt Build Build Your Your Own Own Solid Solid Staie Stale Hi Hi Fi Fi and and Audio Audio Accessoriua Accessories 85pT 8Spl Solid Solid State State Short Short Wave Wave Raceivera Receivers far for Bagirtneis Begmners 95pi 95pt Projectfi Projects Using USing C C CA3130 CA p1 95pt SO CMOS CMOS C le Project Projects 36pt 95pl A Practical Pra ctical ntioductlon ntroduction lo to Digiial OigitallCs C s 9Ept 95pt How to Build Advanced Shon Vi/ave RaCeivcrs C1 'SOt How to Build Advanced Short WfJve Receivers 1 20t HCC Rasrsior Colour Code Oiso Calculator lopt RCC Resistor Colour Code Disc Calculator lopl BOOKS BY NEWNES No. No, Beginners Beginners Guide to Electronics Electronics Price 2'25r No Bagrnners Guide totelavlsion Television Price t 5t No Beginners Guide ::iuide to T'ansistors Transislors P/ca C at No. No Beginners Guide to Redip Radio Price C27S No, Beginners Beginners Guide Guide to to Colour COOUT Television Television Prica t 2St No Elecuooic Elec lronic Diagrams Diagrams Price C1 t1 BOr BOl No. No Elacironiq Electronic Components Components Price t No, Printed Printed Circuit Circuit Assembly Assembly Price El E1 DBf 08t No. No Transistor Transistor Pockai POCket Book Book Price Pnce 3 3 BOT 90t No, No Thyristor Projects Ubing 1 lotbyn'stor Using SCRs SeRs & Triacs Projects Triacs Price 2 5Ot No. No COS/MOS COS/MOS Digital O;gitallC C Projects Projects For the Home Const Constructor dictor For the Home Price 2 25t No, No Operational Operational Amplifier Amplifier P/ojecrs Projects for for the (he Home Home Consiruciot Constructor Price t 60t No Electronics Electronics Pocket Pockel Book Book Price C3 3,75t 7Sr No. No Photoelectric Photoelectric Circuits Circuits ft & Systems Systems Price 1 80t NUTS AND BOLTS 6A BOLTS - packs ol BA threaded cadmium plated screws BA BOLTS packs of BA threaded cadmium plated screws slotted slotted cheese cheese head. head. Supplied Supplied n in multiples multiples of of Type Type No. No. Prico Price Type Type No. No. Price 1in OBA -Jin lin tin 4BA ObA DBA jin 49A B aba jiri ;n 48A 846 4BA lin B tin 2BA 840 2BA tin l in 6BA B in Jin iin BA A 843 l ;n2ba tin B in 844 OS2 tin 6BA B n 40A 844 &45 Jin 6BA 849 4BA J in 6BA 850 BA BA NUTS NUTS -- packs packs of of cadmium cadmium o'atfid plated full full thits nuts in in multiples multiples of of SO 50 Jyp* OQA Type No. Price Type No. Price OBA 855 No Price 49A Type 857 No. Co Price 30 7BA BA BA A 6BA 858 CO 24 B A BA WASHERS WASHERS -- list flat cadmium cadmium pleted plated plain plain Btamped stamped washers washers supplied supplied in n multiples multiples of of SO 50. DRA *P. B Type f?' No. Type No. OBA Price Typo 4SA B61 No, 012 Price 28A BA 4BA 362 B BA B BA 862 SOLDER TAGS - hot tmned supplied in multiples of Type No Price Type No, Price OBA 851 [0 40 4BA BA 852 D 2S 6BA B SWTCHES Description pmhrllon No. Prlc:e Prico TRANSFORMERS MANS P,;mary DPDT urut miniature minialurfi slide "" 0 11* MNATURE MA N5 Primary 240V Secondary Toggle Toflole OPDTstandard SWitch switch SPST SPS slide * No. Secondaiv Price 6V-0 9Op" 033" 9V-0 9V To~g~ea~!t~~06pt~ Toggle U amp switch 260V DPOT e.c " QV-0-9V 6V-0-«V 100mA 100mA Mp* 9Op" Mb* 12V-0 TOOmA 9&p" 1 0mp250va.c. amp 2 50V ' Vd)-12V 100mA 9lp. Rotary on-off mains switch " P,;mary " With two independent secondary Push switch switch-push to to break make ' 018" CO 1B' will, MNATURE tw-o ind.pendenl MANS saconclary Prlmor, 240V windings Price ~Oi4 ~fibo-0-6v. 1 50" A ROCKER range of rocker SWTCH Colour RED R D No MT V 0 12VRMS " 0 Price 22" MS0-0-2V wf^ao O-SV. 0-6V O 2VRMS RMS ttsotl BOswitches iwitchnaspst-moulded " Primary in in high nsulation. insulation. WH1TE WHTE BLACK ? * 0 22' 0-22' 1 AMP MANS Ptimary 240V No. Matenal Material available avdifeble in n a BLUE 19B " * No, V~O 1 2 S0" & choice choice of colours ideal YELLOW 19B p * 202B Secondary Price for tor small apparatus LUM1NOUS LUMNOUS " 0.22* V0-9V SV0 6V lamp lamp " 00-50" P. P.&P.45P 4 P 45p 45b V 0 1 amp 2 80" 55p Deecription Doacription No. P.1ee Prk« V t2v 00.15V 0-12V 1SV 1 t amp apip emp [27S" 2 M 75- OO- P. P. & P P. 66p Sip Miniature SPST toggle, 2 amp V 0 O 30V 30V! amp emp 3 4S- f3 «B- P. & SP.OOp P.B6p 250Va.c. 0._ Miniature SPST toggle:, toggle. 2 amp * STANDARD MANS Pdmary p.imary 240V 2S0Va.c 250V a. c " 0 W Multi-tapped MuhPupped secondary mains transformers (renetaimers available evellotile in i 4 Miniature OPDT DPDT toggle. toggli*. 2 amp amp 1 amp snd 2 amp current rating. taps are 250Va.c. 250V a.c O 6S- 0 66* V U 5"!?. 10 2p lup-jia. d v! '""O curreni reiing. Secondary iap«ere Miniature DDPOT toggle. eef.tre Centre off,2 amp emp250va.c " 085' ~~~~B~ Voliaoee ~~~~~~'~,b1y7us,e9~~t~,pr,, , O~2 5V. Push button SPST, SPST. 2 amp 4.7,8 1(1, evailsbie by use ,33 ol laps; BV 250Va.c. 380V..t SS- No. Rating flailng Price Push P 250Va.c. 280V»,c, button SPST, 2 amp * t: 1 Jump amp ~~ 8 80" TOflO P P.5 & P. p B6p 86p 36p Pushbutton OPOT OPDT 2 amp amp 8.90" P. 8o P V a ec [0 80" 0 80' p &p.ti 16 MDGET M'DGETWAFER SWTCHES Single-bank wofer wafer type typa - suitable suitabln for lor switching at 250V 260V a.c. AUDO LEADS l00ma 100mA or 150V d.c. dc. in norwcactiver non~reactiver loads make before-break bofore-hiaak Aerial contacts. These switches have havo a spindle 00-2Sin 25in dia. die. and 30 30» 107 FM ndoor Ribbon Aorial mm Jack plug to ro 3 Smm 5mm jack plug indexmg indemng 0 71" Length pin DN 1 5m plug to 3.5mn», 3.5mm. Jack connacted connected Description Doecription No, Prtco Price pins 3&5. l.5m 0 81" 1 polo Zsvay Order No. 048* Prico 0 48" TT5 S 3.Smm. connected 12 pole 6 way " 0.48* 048' toplns DN 3ft5. plug Length to 3.6mm,.Sm Jack connuctod 0 85* pins 1 Length 1.Srn 0-8." 3 pale pole 4 way * 048-8erial extension. Screened nsulated 4 pole 3 way * 116 Car to pira aerial T&4. e*tun«ton. Lungth Screoncd.Sm insulated 0-66' " 0 46* 4«* & skt. 1 loo TT7 117 AC lead ~~on;~~~: mams Fitted ~o;a~~~~.'1 connacimq plug ft ski, ~ lead :~r~~r for cbss^ttb ft 10" cassene MCRO SWTCHES Prlco Price [0 88" Plastic button gives simple Order No. PrlcO Simple TT racordcrs pin DlN ft DN phono radios plug 2 ntntres to stereo staruo 0 66" on-off jack 105" Rating action ().20 TT9 2 plugs stereo :~!;~~ Button 10 gives amp ~?v:;"f 1 pole 250V ;~~~:~~ ge change a.c headphone jock socket C1 qbwith attenuation pin DN pfufls neiwaik to Rtarno network tor for jack stereo socket over action headphon~s. length O.2m 0 90" Rating 101 a amp 250V 2S0V a.c Car headpboniks. stereo connector. Length 0.2n> Variable geomotiy 0 90" geomotry plug D'ug Car cartridge cartridofl to fit ft most & Combination car cassette, combination units. 8 track Supplied with inlina and instructions. 080" 6.6m Guitar FUSE HOLDERS em whh inline Coiled fused Guiler power Lead lead Mono end Jack nstructioivs, Plug f O BO- Plu~ SO" to pin Mono DN Jack ~tug plug Plug to3 BLACK pin DN 01 N plug. 1 50* 1. m 0 75" AND FUSES Length pin DN.Sm plug to 5 pin DN plug to-tb* pluq length Description 0 7&" Deacriptlon No. 20mm k x 5mm chassis mounting Order Mo. mountmg length 1.5m Tin x Jin chassis mounting * Price Length pin DN 1.5m plug to Tinned open end. 075" 0 75" ~ t:~ ~a~i~n~~:st~~emountmg in car inline typo " r~~poi~r ~~Se~. t:n~~~ol P~u:;s. 130" Panel mounting 20nirn * 0 15* Length pin Din 1.5n» plug to 4 Phono Plugs. 0 78* 20mm 0 20 ~ ~Ug ptn SOCket. Panel mounting 1 Jin tin ^ l Spin CofeHr DN c plug? qrl to 5 pin DN ' Sm aocnel. t \ 30* 1. m 1 05" mirror QUCK BLOW 20mm Length pin DN.Sm plug to 5 pin DN plug minor fds" mage. length 1.Sm 105" Tyoo Type No- No. Type No, No. Type inllne 150mA 611 1A 615 Typa No maga. pin DN Length plug to 1,5m 2 pin DN inlmo socket 105* 3.0 5m 0 68" 250mA 612 l-ba 1 5A 016 3A DN DN plug. 1 & 4 550mA 613 2A 617 4A Length pin OfN Brn plug to 3 pin DN plug. ft4 0'68* 3& " aooma 800mA A 2 5A 610 5A All A15pooch 5p nch 132 Zpin and 3ft 2 OJN 5. Length ON plug to 2 1.5m pin DN spckui. C0 B3* socket. Length lam 0 9S" ArVT-SMHGE ANT-SURGE 20mm 2Dmm length Type E6~~~lt~cf~~~st3l pin DlN 10m plug to 2 phono G.h~e"n g~~ur.5m plugs CO 98* No. Typa Type No No. 07$" 100mA 622 1A 625 Type No, ~~~~ 62B 250mA ~g~~~lt~j~~~st3~ C.h~;nOg~~~~~~ 623 2A 626 2'5A Connected Din DN plug pirn to 3ftS. 2 phono Length sockets. f.5m 0 78* " 500mA A SA pin so~ket plugs, All A7p 7p«aoh 5A Connected pm DN socket pina 3&5. to 2 phono Length pluge.?3crr CO 68* ch pins Length 0 88" 136 Coiled Connected stereo pins hsedphone 3&5 Leixjih headphone extension 23cm sad. 0 80* lead. Black. Length QUCK 1 7&" BLOW 1 tin iln Black, length 6m 178* 178 mains lead Type 0 88" NO, No. Type No 250mA mA 632 Type No. 170 AC mainj (eed for calculators etc. CO 88' All 7p 7peach ch 800mA 634 Typa Type No. Type AVDELBOND No. Type No BQND 1A la A SA A - GA G A A 642 2A CYANOACRYLATE G2 All bp each The wondet wonder adhesive which works in seconds. Bonds plastic plastic lubber fubber transistors, components, mmediately! 0/0 0 / 0143 T43 transistors, ONLY 7dp* componentsy 7Op fa' (ora 0 2gm 2gmphial phial permanently - immedtatetyl CASES AND BDXES BOXES B-PAK CATALOGUE NSTRUMENT CASES. n n two aactlona.ectiona vinyl vinyt covered top end and akfee, sid, aluminium bottom, front end and beck back. No No. Length Width Height Prtc* NEW EDTON NOW AVALABLE Price " in 810 5}in SilO 2in 2in 1-62" Send 52" ~en!~~~~~ur for your copy lc~fy of ~~~~: our revised r~~~:~dca!!il~hgu~t:~a~l~ri~~~~e~~~~ catalogue and price list NOW! in in 6in 61n 3in 3in " 12' semiconductors. of B KTS '57 t 57 6in 6in 44tin Jin 11 Jm tin Ci-2Cr semiconduciota. H contains 127 pages packed with literally hundreds of audio modules. ' n 9in Sjin 5"4in 2 in 2 tm 176" audio modufss. components and our famous range of 01-KTS 1 78" QNLVftftp ONL": 115p POST FREE ALUMNUM eonvtruetkm aach BOXES. box complete Mode from with bright helf nch ell., deep folded lid ORDERNG Do not forget to to state order number and your name end and address. No. Langd1 W1cth Height V.A.T. Add 12J% 12t% to to prices marked' marked- 8% fo to those unmorkbd. unmarked. 159 zero rated. 160 ~~in i~n tems marked are rero rated, li :~ PftP. P.P, 35p 3Sp unless Otherwise otherwise shown 161 4,n 2.;n 1 in 162 5im 4in 1 in 163 4in ~~n 2'n 164 3in tin 165 7in 5in 21;n 166 Bin 5in in 4in 2in MDGET WAFER SWTCHES pole pole 12 pole 66 way wuy do1«196B - 4 pole pole 3 4 way 3 way w ay Prc:e a2p" a2p" 82p" 74p Mp" "",p" " alp 4Op" 4Op" 4Op" 4Op".,-PA DEPT. PW6, P.D. Box 6, Ware, Hens DEPT. PW6, P.O. Box 6, Ware, Hens COMPONENTS SHOP: 18 BALDOCK STREET, STREET. WARE, HERTS. Practical Wireless, June

19 High quality audio modules for Stereo and mono FREQUENCY R RANGE A NGt Be Mhz Mh, S450 SENSiTiviTY" SENsVtlVJTY ~ ~ a o^v - MPA30 8AN-OWDTH kh, -~ ~-- STEREO B A NO 250kHx_ -swrfousrejec-"ion ds FM TUNER 'SPUROUS REJECT]ON 50 db MAGNETC CARTRDGE,',).. ~~ Fitt»d Fitted with SELECTVTY "i ± 400 khz db~ PRE-AMPUFfER PRE AMPLlFER lock.lool> }\(foioo'utp"l,n;22-5khz deyl ltlon) ~-- the quauty of a ~ "~,,,... r phase lock.loop AUOO OUTPUT (22' 'stht deviation) jw mv Enjoy ' jq--d"a - magnetic cartridge STEREO SEPARATON " 30 db megnel the c certrl quality d ge of with a your ^ + «p p A n SUPPLY REQUREMENTS to 103QV 30V CftOmA (OmA max) max existing ceramic equipment uelng using + 121% VAT ::: ::f9.~at M 'RiA1MPEoANCE ohm the 30 la a preamplifier enabling tnt^at AERAL tmpedance" 75 ohma the ampllfjet MPA 30 which ie magnetic a high quality CBrirldgee precartrldgel lo to be be used uled where facillliee facllltl DMENSONS 240mm x llomm 110mm x x 32mm exist exlat for for the the use of of ceramic cartridge* cartrldgel only. SENSTVTY a-s 3 5 mv for lor 100mV output oulpul The 450 Tuner orovldea provides nttenl nstant proflmmme programme eelection selection at at the touch of a a button eneurlng luri ng sccurnte accurate tuning ng of of 44 pre-ieleeted pr'~'81.cted -EQUALSATON within '1 Hi 10 Btntlone, ~~~:~~:i any ~~~u~fe of which F~ii~n~~r may be s~:g~~~::i.~ a:f~~~d~atj~::,~ fluered 94 ollen ae you chooee..hs~~~ch~m~' cbli8as~lr".! atmpty hy changing the ~~~,~:r~~o. aertlnfif of the pre-eel controls. EQUAUSAT10N of the pr t controll. 20 Foaturee include FET nput atege. Vari-Cao diode tunlnc- Switched AFC LED Stereo ndicator SOkHi Wtthln ± 1 db from 20 Hr to khz NPUT MPEOANCE 50 K ohme -S- t o...::... u-t-p-u-t-p-o-w-e-r--.:...:.:...:------=7--w-a-tt-s-r-m-s------,1 ';li~..t~mped_ance -- ~ ~i.'m~v,"- --:re~ea:::rt.. h:----- OUTPUT POWER y Watta RMS SUPPLY 18 to 30 V re earth Stereo ereo 30 ~ LOAD MPEDANCE 8 ohma ohms - - "DMENSONS 110 fio ><50 x 25mmOnc -ON- COMPLETE ~~--G: V??"' TOTAL T H HARMONCDiSfORTiON ARMONSC DSTO RTtQN Lma than lilan 'S-" i% (TypicaUy (Typically 3%) sochel} x'50 x ZEmrn (nc DN, So_c_k_el_) - AUDO ~ FREQUENCY RESPONSE M 50 H«JOJO H, to20kiii±3d8. VMi i- 30Be -,- CHASSS CHASSS ii!i!!:: TTONE ONfCciNTfiOliANG-E-- CONTROL RANSE ±ii - db«at 100H7 and iqkhr 12 d8. al l00h, and 10kHZ ~\.. ~'_~ "_"~ 18'95,,. '.- SENSTVTY l1omvforfulloulpul ",':-,.-. - SENSiJiyiTY _1B0 mv for full output PA pap p&p ' NPUT inp1jtmpedance MPEDANCE 11 M ohmt ohml STEREO :.lll " /t:~~&lt + + t t% VAT V w R.M.8. R.M... -T _TRANSFQRMER 6~.;eNNS~~~~ER REQUREMENTS 22 V.A.C. rated atla PREAMPLFER sap p&p + iss VAT vfr REQUREMENTS 22 V.A.C. ralad ala ::.E~AA~=~:~r~: Pr., Z, DMENSONS (Leaa (l." conlroit contrail and penal) panel) 20Cmm 200mm x )( 130mm x 33m 33mm m The Ampllfter PA 12 Ampllfler chaesis Stereo Prechassis is i, designed de!ugned and end recommended tor for uie U8 with th# AL SOKW Audio Amplifier Modules, the PSia power lupply end the The Stereo compriae* comprises a complete stereo pre-amplincy, pr&-ampllfler, power empllflera ampllllars and power supply. Thlt. Thll, with only the addition T&M :~20+:~r~:::'!~f~~~~:e~~~~:~:e t~~/:~1~j~~:~ ~,:::~~:,n&!~: ol of a tpenblormar tranlformer or overwind oyerwlnd will produce a high quality audio unit aulteble luuable tor for uie ule with a wide range ot of nput* nputll.e mgn high and Treble TrarBformef. controls Featuree controll Complete include with on/ofl lepe tape outputvotume. flalarce. Bafk output. quamly r.,~:~~~ r:~~~g:~du!it~t1~r~l~u8~~~c~~~:~ ceramic pick-up. alerao toner, stereo ado ~~::kdf~~~:~an~~~~~l~~n~~~~. deck etc. Simple to nstall, capable ~::::Cb~~ ot f~fs:ro:nu:~~8~e~~:~:t.c~~s~~r::rl~:1 producing really flrbt ciae" reaulta. _F;;R~E';;Q;:U"'E"'N~C"'Y~R"ET-Sc.P~O~N~S~E-----2~0~H;;'c:-7.2O;..;kH::;Z~(-3~d!!:B~) FREQUENCY RESPONSE 20 Hi-20 khz {-SdB) thta mounting unit la m_ o_u_n ln_o_b_r._c_k_m_. brockela. supplied with full loslfucllona, black front penal, knobs, main rwllch, tuea and tuaa holder and umwerffti BASS CONTROL ± 1209 etsqhr _- ~ , TREBLE ~~::l~~~~~~;l CONTROL ~±!::::~:~:~~~O~~~~c, f4 db at 10 khz OUTPUT POWER 25 Wattl RMS NPUT NP'UT tmpedance MPEDANCE 11 Meg, Meo. ohm ohm AL60 fsw ~g-~l:mp~ed~a-n-c-e -----"~:cl~e ^T" o~m. ms NPUT SFNSmVlTY 300 mv ~~~;S~~NL~TVTY ---,~~;~~~;, AUDO UOO LOAD TMPEDANCE a-10ahm> CROSSTALK 80dB l'ot HAFiMONC le.. :~h... a-: n '-c l"'l«"... (T.-y--,p"Cally ' 06 %) -;;S:;:G;;:N~A~-~L/~'N~O~;S~E.,:R;; SiSNAUNOSE RATtQ - A:;;T;.;iC'oc.- ~_.:;-M~~d~B: db AMPLFER TOTAL HARMOWC DSTORTON UM«hiri ENCYRESPONS-E--~ iohitoao l^ftjip e«ny-0»ja MODULE FREOUENCV RESPONSE" JO lo 30 tihi'x «2- FB» iiii -- OVERLOAD FACTOR _ ± 20dB 2Od8 25 Watt* Watts RHS RMS ~SENSifiVTY SEN'sitTvitv _ ~ ^ SMmV 280 ij outi)uj--- TAP"e' OTTJiLi'TJ..1PEDANCE 25 ohml MA"lf.HEAT SNK TEMPEflATURE eode,'- for full ---- oatoui TAPE OUTPUT MPEDANCE 25 K ohm 2 152mm x B4mm.-~ 4 55 max, heat sink tcmperature oo*c DMENSONS 152rnm * Mmm 95r + 25p Hp p*p p&p DMENSONS loamm l00mm x"mmm x B4mm ' x Smm 15~ ~ -f + 12i% 121% VAT This hlsh high qualitybuooambllller audio amplifier modulirlslm module is for ubb use nnudlo audio aqulpmont equipment and atsrsoampllflart stereo amplifier. and provlda.oulculpovrnrj proylde. output powers up PS12 POWER SUPPLY 10 to 25 RMS with dlaloltlon distortion naln leyel~ hclow below 0-1 '%. ". Oeelgned Designed for uie uae with the AL30A Al30A S.450and MPA30 lo 'n conjunction with tranafprmer transformer T538. OUTPUT POWER 35 Watte Wattl RMS 2Ov 4~V 27-3Ov 1'30 AL80 ALSO ~A. ~.~~ SUPPLY V OUTPUT NPUT VOLTAGE VOLTAGE 27-30v 17-20v DC AC 1 *30 **** ohml 800mA Hp p&p AUDO "~-..' t LOAD MPEDANCE 6-15 ohmt OUTPUT CURRENT fiooma 2Sp pap Omm 43mm )( 28mm Ul% AMPLFER 4 ' ".4 'W, TOTAL HARMONC DSTORTON Leea Le"lhan than-1% 1%(Typically (Typlcallyoe%i 06%) SZE ecmm Wmm 4amin m x 26mm + 1«% VAT MODULE RESPONS"E-- 2oHZlo 30 khz.,~, ^7'7, -".' ~' ' FREQUENCY irii8~ SENSTVTY RESPONSE NSlT'vlff---- ' JOHr 280 mv io lor SOlH, for lull fuil aulpul x 2 db. o~ fc/'o 7'15* ~ * :(;",~~ '""'MAX.-HEAT 'MAX SNK ffmperature TeMJiERAfURE ' 90'C OO C - - GE100 NNE CHANNEL Di l00~ m 15m.n- - ::: 2Spp*P r,rrtt;. DMENSONS tosmm x Mmm x Bmm MONO-GRAPHC EQUALZER + 1% VAT The The AlSO 1,.lmller in delign the AL60 above s the lame high quality but proylde. output powers 35W with GE100 has nina nine t 1 octave adjuatmonla adjuatment. estng ullng ntegrated circuit circul t Th. ALSO la aimllar n do.lgr. to hu A160 aiiovb and la of lh«aam«hloh qubhlybul pro.ldaa outpol oawera up to 3iW wilt, active actlye fllter. Boost and Cut limits l2db. Max dl distortion atortlon leyels aveta b below slow ' % handling filters. lino 2 V RMS. Booal T,H end T.H.D D.. Cot O 0 05%, llmlta 05%. nput are npul mpedence ± 12dB. Ma* mpedonco 100K Voltage look Output A. "',- mpedance mpedence less... than 10 Ku K. Frequency Frequenc~ reeponaato respon Hz -20 KHt KHz (3dB). t.m Watt. conllnuou8 AL w OUTPUT POWER 125 Watte RMS continuous The nine gain controls ate centred at 50, too, 200, ^Afl r~~ ~~ '~~~03.~.8 :.'to:e~~r3d,:~,:. ~~. ~e OPERATNG VOLTAGE V ' 400, suggested 800..WO. suggeated gain controls 3,200. 6,400 r..ontroll a'e are 10 and K LN UN illdere H*. ellderl <not The (not u-mdijap UU + lid p&p POWER loads --- ohml lupplled he S tal;'; AMPLFER LOADS 2_ 4-18 _ supplied with the module) See Pake S31 and % VAT FREQUENCY RESPONSE H,-2O khz measured GEloo 15-G-15 'M AMPLFER ;. ';; -'. SENSTVTY 100.~ - ~oo at 100 Hi 20 Wette khi meobured SOM W~.t~!... _ 121% Ut% VAT POWER + MP SUPPLY Z5p P4P BOARD for 6E1»t VOLT 5'«+ p&p "SENSlTVtrYFOR tm WATTS ~ 0/P_AT_1 O/P 1 kh* kh, 450 mv N'PUTiMPEDANCE '33Ko hms -...-'- NPUT MPEDANCE 33 K oh ma W.. TOTAL TOTAlHARMONC~D~~S~T~D~R~T~AO~Nc--'~ DSTORTON SREN ALARM MODULE 50 W WATTS nto. 4 ohms 0'1 % yolt supply 50 M WATTS nto B 8 ohms American Police screamer powered from any 12 voll eupp'y into O oe%.. 4 or 8 ohm speaker. deal for car burglar alarm, freezer brenvdown breakdown 17 '25* +«ppap+t%vat + 401> p&p + a% and 2r::~;~~e;U'~ Only other E3 W security -h % gurocaee. VAT ~~~~~~r:&~ + 25p Order pap No. S15. No. BP124. No No. BP124. This unit, dbilsnotad designated AL250. AL250, la is a oowar power amplifier ampliflar proyldinq proyldlng an oulput output ol of up to lo 125W 12SW RMS, BMS, nto a4 a 4 ohm load. M~XMUMSUPPlYVOlTAGE mvnil 4ft.. 30V AL30A 10 MAXMUM SUPPLYVOLT AGE 30 V qja 'UWV POWER OUTPUT Oli TP(fiTo(-,02.f!%'=T-'.-:H'-;.-D;".=--.;:10,-W=.~tt"- lor 2'A TWO U WaHa. -'CR"'M"S'=- RMS _ MA60 H-F AMPLFER KT R.M.8- TOTAL HARMONC DSTORTON Laitlhan 55% AUDO R.M.s...,- ~ '...;",~;:~" ~;L." M;;H P"'~E::~:MA~O"NN;:; ~"'~,...D--~-T-O~R~T~O~~N= ~~~~~Go~~~~~:=-' 2~5~%~. ===-= AMPLFER l ' W LOAO impeoance ' ' 8^ ohma Build ohmt MAflOkilcompflsei you Own top thetollowlng quellly amplifier, Bl-klts save modulea, woyriatf 2 x pounds. ALflOamge, Tha MODULES i'. ~;: ll, j tsri'.kt, ~\~. NPUT MPEDANCE MPEOANCE 100 K ohml ohrat ohra. 1 >; Pa'OO prb>amp. 1 x SPM80 stab, powar euoply, 1 * BMT80.~...,~ FREQUENCYRESPONSE B'tSPONSt Mi-2B Hz-25 M.-2S hhl khl:o;"3 ±_- (fa.--- ranlt ; lip. ph. C^r. -,. Z''- ':...::..l-. - V SENSTVTY ~-- - 7~ 73 "mv 75 mv-foftuifoiiii)ul d' lor"frill 'ull lull n oulcul o'ulc'ut covered giving by the 17 B-PAK watte RMS aetlafactlon per chinne' or money STEREO. bach All guaranlae. modole» --- Xril tli" LB + Up. ptp ~,. ^-0* -""- DMENSONS 74mm 74mm l«mm 74mfo Ox X» x 'i3mm 53mm Mmm )( x X "mm 2Bnim abirim Detalla of tha above modulea are in thla ad. + 1«K VAT Price *82 «+ 114% VAT + Wp pap. Thl Than.. ow low coal COil Sand lnd 10 wall Wll mod"l modoiaa.. olllr ofar hl Hit "tm.11 ulmoat n rolllblllly rallablllly nd and porlormlncl. oarlarmpnca. whlllt whilal bllng ha! as.omp.,ln comstsl n alia, N"UT VOLTAlaE V SPM80 edmtn S#r llaou i ii. NPUT "butput A.C, A.C. VOLTAGt TC60 KT VOLTAGE 33-40Y oiji'lui' 0 O C. VOCt...r~1 VOLTAO ~a"v H V nominal inll btlutlfull, dtllgnld glnulnl TeAK vlnl.rld.blnlt TA.JLlED SULUtp SmT Ou"/'Jut -butpot CU" cumrff.. NT '0 15mA-1'5tmp. ma- ' m.1" 10 lo A pullhl put bhutlluli, th, prol qrcfiiiioo.i emghid.. llonll louch touch,, ganulit.. D to TCAK,our yeu, homl ham, WOOD bulll built v.bmik! mpllft impllfl,,. ctsiri!... Full.. power OWl.. SU!'PLY supply ' TmoXTcurtiirr OVi"LDAO,cul!iffi't ----~ 11 i " mol.pnr emc-i florath,l ol pirti intl From 5 Dick Fandi, Xitobi, Chtiili. Fu»l,..;: &~~:::."~~~.c~i:.rl~~afo~~~kl 9oCh,l». Moth,»le. tc,,l lor th, ~~:J.~ MA80, 'S~~~b4~1~~ ~:~U~.: Bill. 4SSinm» i»mm «, 4' *1% lli% VAT DlMNSTONs TOrBNaiONS l08mm' loflmm'x x nmm- Umm" TOmm 80mm mm + tli~vat,,1.1 ",T«" All <t> li~ iltx VAT + lip p&p pap O Dtalgnad'^""powir.. lgnld 10.. wo ALeol AL50t 1 il '1 18 W Wain oar por chin channai nil lmulllnloully almullanaoualy Circuit Cltcull Tlchnlqull Tachnlquaa ncludl include full vli hort ahort circul dteull protlcllon. prelection. FQUENCY FREQUENCY RESPONSE 20 M H Hi to khl fchj x * 1 db TRANSFORMERS PA100 To TQt flhiarmonc AL HARMONC DSTORTiON DlStORTlON C.Hih'lilf%'(fYOTCliiy Leeethen n plcklly 07.8) -67%) T538 T535 For u ul,.. with 11 S.<S0.450 Al30A AU0A MPA30 MPASO... SNSTVTY- f.' TAi'E n_ mv/loo ohm~l n Ord.r." Prlcl: &3. p pap ll" STEREO j.'" SENSTVTY 1. TAPE t«mv/too ohms) Form. mv/l00 ohml oulpul T2010 u.. S""O!'RE AMPLlFER PRE-AMPUFER w; NPUTS a. RADO TUNER 100 mv/100 K ohms > output TSM0 OrU.r No For Mil ul, with Stt,,a 30 PflC *1 M + 35o clo + H X VAT ~~. 3. MAGNETC P.U H mv/50 mv/m K ohml ohmi 250 mv Ordlr 0:3, No.OM No. MM Price: Prlc: U 51 H + Up 500 pap clo + 111~ tbjk VAT E ~ - Wlthl,; -1 d8 trom--- BMTBO U wllh AL50 EQUALSATON Wfthln ± dbfrom BMt«0 20 H, 10 kh, Order 1t3 Price: & p p&p 12i% ~<lt~ '~;p Hz n 20 khz Ordlf No For MM ul, with ALSO SPM50 Prlc; « o o4o + WiX VAT 8MT250 ule wllh AL250 BASS CONTROL RANGE ± '5 lidbeettbhi db. 75 H Order Ordor BMT250 No. For. ta Mis o,, with AUS0 Prlcl: Frlce:,a. ti M pap pio + 121% 1H% VAT!;'\ TREBTCONfRO(AANG~E--_ TREBLE CQNTROL RANGE :...-_...,+;;:",,;i;;~-:;2"'o' + 'iq^so 7d:'_B~,..'=.;kTHZ""==- dbcat 15 khz B-PAl SNGpNUTAlO/ SfGNAL/NQtSE VNEORSl'-;OEo-A"RD"'A-'C RATO T.:.:O"----_-;8~.""tt.r Bitter han hen db dfls (AH npull) ingule} Setter than:le db, nputs) NPUT OVERLOAD Better than 26 dbe (All SUPPLY to 40 V 4p 4flpc«p p&p ' 3OO x OO x (... conlroll) +Z1 + t9i% " VAT DMENSONS 303x20x 33mm (leas corurqla) BhPAK A top quality OUOhty,tetlO eterao pt,-amplifler ofe-bmp iher and tone conttol control unit. unit, the PA100 PAW provdes provides a o comprehensive comprehenilve solution to lo the front end requirements rwulremente of stereo tereo amplifier. ampllflera or audio unltl. onlti. The lx six pulh pulh button bullon selector Wltch»wltch glvee a choice of nputl npuli together with L-_W_o_fl "_,"_fo_r_h_o;.h_ two fllfin lor high an_d_lo_w_fr_e._u_e_n_c_le_"_. and low trequenclea -.;1 DEPT. PW6, P P.O..0. Box 6, Wale Ware, Herts PracticaL Practical Wireless, June

20 Crystal ^rysral Gazing EDTOR Geoffrey C. Arnold Ar'nold ASSSTANT EDTOR Dick Ganderton, C. Eng., MERE ART EDTOR Peter Metalll Meta'" TECHNCAL EDTOR Ted Parratt, BA NEWS & PRODUCTON EDTOR Alan Martin TECHNCAL SUB-EDTOR Peter Preston TECHNCAL ARTST Rob Mackie SECRETARAL Sylvia Barrett Debbie Chapman EDTORAL OFFCES Wesfover Westover House, West Quay Road, POOLE, Dorset BH15 1JG Tetephone: Telephone: Poofe Poole ADVERTSEMENT MANAGER (M Roy Smith CLASSFED ADVERTSEMENTS Colin R. Brown ADVERTSEMENT OFFCES King's Reach Tower, Stamford Street, London SE1 9LS BNDERS Binders, tor for either the old or the new format, are 2,85, 8S and ndexes are 45p (nc VAT) and can be obtained from the Post Sales Depart- Depart ment, PG PC Maaarlnes Magazines Ltd., Lavlngton Lavington House, Lavlngton Street, London SE1 OPF. Remit- Remit tances with overseas orders for binoere binclers should include 60p to cover despatch and postage. N a recent lecture entitled "Tomorrow's Broadcasting The Broadcas.ting-The Technical Possibilities", Dr. Boris Townsend, head of the Engineering nformation Service of the ndependent Broadcasting Authority, highiighted highlighted some examples of the pitfalls in trying to forecast future developments in engineering. n 1924 for example, Campbell Swlnton, SWinton, talking to the RSSB, RSGB, dismissed the topic of television (or as. he called it then, seeing at a distance) as ".... probably scarcely worth anybody's while to pursue". n more recent times, a well-known television engineer swore an affidavit to the FCC in America, that the shadow-mask colour display tube could not be mass-produced! )n n making his forecasts, Dr. Townsend saw the biggest advances in broadcasting coming from the ever-widening use of sophisticated microclrcuits. microcircuits. Their use in signal-processing circuitry would allow good quality TV pictures to be produced from scenes with low lighting levels, and reproduced from small, cheap videotape recorders. The adoption of microprocessor-based control systems has already allowed the BA to operate and maintain 400 transmitters with the same number of staff as were needed for only 40 transmitters some dozen years ago. The introduction of similar systems into studios is also having far-reaching effects. Sticking my own neck out, foresee that the domestic TV receiver itself s is likely to undergo a change of use over the coming years. The growing popularity of TV games, such as the Tank Battle which we feature n in this issue, is the first step in this process. The broadcast Teletext services, Oracle from the BA and Ceefax from the BBC, are already established and hopefully we will soon see a reduction in the price of receivers fitted with the necessary decoders. Also on the data front, the Post Office has recently announced that their Viewdata service is to be made available to the public from January All this will mean that the TV set will be used less as a source of broadcast entertainment and more as a source of nformation information and participative entertainment. The adoption of microclrcuits microcircuits should also allow the domestic videotape recorder to be reduced in mechanical complexity and hence in cost, so that we may be able to view our favourite TV programmes when t suits us, rather than when the planners deem that we should. Geoffrey C. Arnold BACK NUMBERS We are very glad to announce the re-establlsh- re-establish ment of a PW Back Numbers Service Serllice for our readers. n future back numbers dated from June 1977 only wilt will be available from our Post Sales Departmenl Department for BSp, 65p, which ncludes includes postage and packing. Cheques and Postal Orders should be made payable to PG PC Maga- Maga zines Ltd. Send your orders to:- Post Sales Department. Department, PG PC Magazines Ltd., Lavlngton Lavington House, Lavlng- Lavlng ton Street, London SE1 OPF. PLEASE NOTE CORRESPONDENCE NOTE-CORRESPONDENCE We do 'not operate atechnlcal a Technical Query Service except on matters concerning constructional articles published n PW. We do not supply service sheets sheet. or nformation information on commercial radios, radios, TV's or electronic equipment. All queries must be accompanied by a stamped self-addressed envelope otherwise a reply cannot be guaranteed. 18 Practical Wireless. Wireless, June 1978

21 ';j' ':-:-:.,::.:.. ::..:::::. ::::-:::.. ::::-"':;::;/.;:-::::::: Rally date dale The 'The Northern Mobile Rally 1978', 1975', organised by the Otley Radio & Elec- Elec tronics Society (G8JTD, (GSJTD, G3XNO) is to be held at The Victoria Park Hall, Keighley on Sunday 21 May between and 17, Talk in stations on 2m f.m. S and 70cm f.m. SU8. SUS. There will be trade stands, films for the children, bar, refreshments and many other attrac- attrac tions. Further details from: J. E. Annakin, G8DFZ, Rally Manager, 25 Ashfleld Ashfjeld Place, Otley, Ottey, W. Yorks LS213JN. Revival '78 The Martlesham and pswich Radio Club and The pswich Area Civil Service Sports Association (.A.C.- (.A.C. S.S.A.) are again organising an out- out door event for the Radio Amateur and his family, to be held on Sunday, 14 May 1978, 1975, at the.a.c.s.s.a. Sports Ground, Straight Road, Bucklesham (NGR TM ). Special attractions include; A v.h f./u.h.f./s.h.f. aerial gain competition and demonstration, measurement of transmitter and re- re ceiver performance, bring and buy stands, Ad-hoc trading tables at 1 per hour tor for visitors and home-brew equipment competition. The South Anglian Repeater Group,.West Suffolk f.m. Group and Raynet will be well represented and a 2m (R3 S22, 70cm) (RB4 SU8) SUS) and h.f. bands talk-in station will be in operation, probably using the call sign GB3 SWR. Further attractions include; Big name traders, demonstrations of Viewdata tv and microprocessor games, vintage wireless displays, raffle, raffie, pistol and archery ranges, flying display of radio controlled aircraft, aircraf.', plus many other family enter- enter tainments. The event will start at 11.00am, admission 40p (accompanied children free). A licensed bar will be open from midday and there will be snacks, teas etc., throughout the day. Further nformation information can be obtained by sending a SAE to: C.P. Ransom G8LBS, GSlBS, 79 Camden Road, pswich, Suffolk P3 8JN. SJN. First Fi'sl show The Dept. of Electrical Engineering Science at the University of Essex is organising organising the 1st 1 Essex Electronics Exhibition on 18/19 1S/19 April Admission is by free ticket issued by either the companies exhibiting or by the Department. Further details from: E. P. Strudwick, Dept. Electrical Engin- Engin eering Science, SCience, University UniverSity of Essex, Wivenhoe Park, Colchester, Essex. Tel: Ext ,1~ \1ji... t ;;;;;~;.'::::;... t: :~ :... :.;.:: ;.; :: ":::., ' :::-}i:: Hi-Fi Hi-F Seminar Seminal' Latest latest developments in turntables and pickups,.amplifiers, loudspeakers, tuners and tape recorders will be reviewed in a one day seminar being organised by the Society of Electronic and Radio Technicians. Speakers include such famous names from the audio field as James Moir, James Linsley Hood, John Berwick, Borwick, Angus McKenzieand Basil Lane. lane. The lectures will be followed by demonstrations. The seminar will be held at the nstitute of Marine Engineers, Mark Lane, lane, London ECS EC3 on Wednesday, 7 June 1978, commencing at am. Fees are 15 ( 10 to SERT members) and this includes a copy of the papers, coffee, lunch and afternoon tea. Further details from: SERT, 8-10 Charing Cross Road, London WC2H OHP. Can 1 help you! Are you the secretary, organiser or general dog's body of your local radio club or any other group whose func- func tions may interest readers of PW. f so, let me know and 1 will endeavour to publicise your rally, get-together, whatever, through this column. Re- Re member though, we compile the magazine some time ahead of poblica- publica cation day (e.g. this note was written in mid-march), mid-march), so, the earlier can have details, the better. Alan Martin NlnDlY note KinDLV HOTE! Radio 2 Tuner, July 1977 On p 213, 7 C7 is incorrectly shown as 3-3pF. This should be S-S.kF 3 3.<F as shown in the components list. "Shoot", August 1977 Certain errors in the circuit diagram on p.283 have been noted. The PCB is correct, however. ;VR4,'VR4-should should be 22k preset, and not 2-2k. 2 2k. Pin 14 of C3A lc3a should be connected to +8V + 8Y line as should shol,lld pin 14 of C4A and pin 3 of C2B. Pins 1, 2; 2, 5, 6 and 7 of C3C should be connected to 0V OY line, as should pin 7 of C4B.. Under the heading "Connection" on p.282. p.282, it is claimed that the sync, sync. output is taken from pin 16 of 101 lcl of "Tele-Games" unit; unit. This should read"pin 15". C of the Month, Sprague ULN-3006T ULN 3006T Hall Effect Switch, March 1978 PW the second paragraph following the heading "The Hall Effect", p.s45, '845, and commencing "The current carriers...". " is somewhat ambiguous, and should read "The current carriers in the silicon (which may be electrons or "holes") are both deflected to one side of the material, depending upon direction of current flow and magnetic field, field. in accord- accord ance with- Fleming's Left Hand Rule." "Multi-Range Test' Meters," March 1978 Page 839, the paragraph, commencing "The minimum measurable....". " should read; fnd: The minimum total circuit resistance neces- neces sary, if full-scale deflection defiectiop is not oot to be exceeded, exc~eded, is therefore 1500 ohms, This Tbis win will be made up of the meter movement resistam:e resistance plus a series current limiting current-limiting resistor, both both of which are internal to the instrument. External readings are from zero zero upwards. Expeihtlenter's Experimenter's Corner, p. 910 April n the circuit diagram and text, for "LED Light Dis- Dis play", the pnp transistors are incorrectly shown as AC176 (npn). These should of (:,ourse course be AC128 in every case.. Practical Wireless, June

22 E.A.RULE PART 2 E. A. RULE PART 2 Construction n general the construction is not critical and the prototype built by the author used plain Vero matrix board as shown in the photographs. However a com- com plete set of is available and the various draw- draw ings show these and the associated component placements. Leads from the front panel controls to the boards should be of screened wire, and the millivoltmeter circuit board should have a tinplate screen fitted around it as detailed in Fig. 8. t can be made from tinplate cut from a cocoa tin and is held in position by two paper clips soldered to it as shown. The better the screening of boards and components, the lower the final distortion measurement limit will be. nitial Setting Up of the Meter Set all pre sets to halfway. After carefully checking that no mistakes have been made in the construction, switch on. At first the meter will swing about fora a few moments and then settle down. Allow about one minute before setting up the dis- dis tortion meter as follows: follows:- Disconnect the bridge output lead to the millivolt meter attenuator and then connect an audio genera- genera tor directly to the millivolt meter attenuator. (The point originally connected to the bridge.) Set the output of the generator at 1kHz to give full scale deflection defiection of the meter with the millivolt meter range switch on the V range, range. Switch to the 10V OV range, meter should fall to 10% of full scale. f not, adjust the pre-set 3 for more feedback and repeat test. Only the minimum amount of feedback required to obtain a linear scale should be used. When the reading drops to 30% 10% of full scale, pre-set 2 should be adjusted so that a 5V input gives full scale on the 10V range, and O'SV 0 5V input gives full scale on the V range, etc. Switch millivolt meter attenuator back to 10V range and transfer generator to the input socket. Reconnect output lead of bridge. Set/Read switch to Set. Adjust generator output for 10V and distortion meter input attenuator to maximum. Adjust VR7 in bridge circuit for full scale on meter. (f your generator does not have 10V output, use V and switch millivolt meter attenuator to V range.) Turn input attenuator to minimum. The residual reading on meter should be less than 0-4raV 0 '4mV on the 1mV mv range with all screens etc., in place. The authors instrument has a residual noise 0-24mV 0 24mV on the 1mV mv range. This represents a 93dB measuring range for signals above 10V, i.e., down to 0-003%. O' 003%. Set genera- genera tor to V output at 1kHz. Set distortion meter to V range and adjust input attenuator for a convenient reading about two thirds of full scale. Switch genera- genera tor to V output at 100kHz, 100kHz. Adjust trimmer TC TC1 for the same reading on meter as before. This adjusts the frequency response of the meter for a flat response to 100kHz. Switch generator back to 1kHz and set its output to 10V (or V if the higher output is not available). After adjusting the input attenuator for full scale deflection, switch Read/Set switch to Read. Adjust bridge frequency and balance controls to obtain lowest possible reading on meter, reducing the volt- volt age range switch as the meter readings reduce. The final lowest reading obtained is the Total Harmonic content of the Test Signal. Operation A typical set up is shown in Fig. 13. When measur- measur ing very low values of distortion, it is very important to avoid multiple multiple earth connections, connections. Only the amplifier under test should be earthed. The other test equip- equip ment must have haye its normal mains earth removed and connected only via its connecting lead to the earth of the amplifier. Care should be taken that all test equipment is safe and fitted with mains isolation transformers or battery operated. Multiple earths can cause very high distortion readings and could be very misleading. Before commencing a measurement, connect your generator directly to the distortion meter and measure its distortion. The figure you get from this test will set the minimum distortion you can measure. This minimum should be restricted to at least twice the direct reading obtained if reasonable accuracy is to be maintained. To make a measurement, adjust the input signal of the amplifier under test to provide the required 20 PracticGl Practical Wireless, June 1978

23 Board 21 nside view of the com- com pleted instrument showing the layout of the and the controls mounted on the front panel. The power supply is is fitted to to the cabinet base and is s the only board not mounted onto the front panel Board 3 Power Supply output into a dummy load. Set the distortion meter millivolt switch to a suitable voltage range. Adjust the input attenuator for full scale reading {100%). (100%). Switch to "Read" and null out the fundamental signal. As the optimum bridge balance is obtained, the milli- milli volt meter range will have to be switched to the next lower range. Read off the distortion direct from the meter when no further reduction in level is possible. Note that the frequency and balance controls are interdependent. With an oscilloscope connected to the socket pro- pro vided on the distortion meter the harmonic content of the signal can be examined. A scope sensitivity of approximately 10mV lomv/cm fcm is required. With inputs below 10V the minimum distortion readable will be reduced- reduced. (Note: For inputs of less than 10V set the millivolt meter voltage switch to the range which will allow full scale deflection to be obtained. This range then becomes [for purpose of measurement] the 100% range and ail all other ranges move down by the same factor. For example, with V input, switch meter to V range, this is then 100% distortion full scale, the V V range becomes 10% full scale etc.) For accurate measurements the limits are shown in Table 1. However measurements of distortion to lower levels can be made, but with decreasing accuracy. Nearly ail all pre-araplifier pre-amplifier and tape recorders have This view shows the components and boards mounted onto the back of the front panel. pane). This is the prototype unit using matrix boards instead of U -Jf\ SMf'J Practical Wireless, June

24 TO,VRl wp.,.-u!!le"'_ ma To Slb-l~-::"':~E;:~ «m-y* m ma 7oR6/VR3,"""::':;;:.-~j.To R6/VR3 ToVRi/VR m C3J asm "THEh* ~f"""'''''tos1a M LiL-2 JHRTTHo C19 -WT- tim b m LEa +24V Output to, boorp 3 Output to~'&_~ board 3 o 0 0 O \'O(}$1i -bu«&n.i fim flm C^Srj ::'th () D ROQ? PG Magazines Ltd Fig. S: 5: Component placement drawing for the Bridge Circuit p.c.b. (Board 1) 1 B 1 1 ^ (chpc ~ Magazines Ltd. H ' Fig. 7: Copper track layout for Board 3. Fig. 8: (Below) Component placement drawing for Board 3 Board 2 Board 2 outputs --i--e n Fig. 6: Copper track layout for Board 1. Ready drilled boards for this instrument are available from Reader's PCB Services (See page 68) RCBoard2v '~48 '-2 Pap«r clips 2 Pap.r cups soldered sold.r.d to screen scr.en n positions shown, h 'J to clip over moiiitihg ijo m,",,' bracket. :':.~~~t'" 5 2S~ 1'Fl. i.... 1S t..-. Mounting brocket brack.t Earth C24 C23 C22 C21 ;? - SSWQ T.C.wre ^ soldered to St/54 cases. 16 SWG lc.wlr. sold.r.d to S154 cash. Flg. Fig. 8: Details of the tinplate screen for Board 2. The small bracket is soldered to the copper earth tracks at the top of Board 2 22 Practical PracticaZ Wireless, June 1978

25 To S4 wiper To S4 wiper -+-_----tl---thft..... J gj LJ C26 ~ 1,.e." Screen ",_ mtg.... brk'l b,v ^..., (S) k (langes flanges soldered soldf'rf'd to ~t~~~ roeli n ~ 6 positions shown- shown. *-pgg>* ~ *ijr} ~ c c: ~ + Meter OV G -w~ ~ ~~~::sl 8 =~47 ~ CZ8 lr~ +.C33.. R 4 < / TrC» C29 +» l r^6t--*? C ~ 29 +m. ~.~ -[R43J-* ~ ~ imu.jfu... vrsj/^xmh 8(=;t~?' 1^ MMHH* ~ +::+ ~; C31 +illj Cl2 ~ EK + li, + 24V o o M. li Ro0381 Fig. 9: Component placement drawing for the Meter Circuit Fig. 10: Copper track layout for Board 2 p.c.b. (Board 2). Note the small tinplate bracket soldered to the earth track to the earth track R008^^P^VlagaziriesLt^^^^J Mains via S5b " o 0 Mains (""utral),-+ (neutral) _ -+_-+-~ via S5b - "Tl T primary Tt L.ll~-t--f-~T primary T( 11 secondary- Tt T1 secondory- secondary -Tl primary D6Q~ D~9 08 T C34 -R52 t» T + C35 +24V OV, Malns^re]_ FS o, oalns(lvf"l-j::=>:rvlassa, Mains earlh- ~th.~ O~~! Component placement drawing for the Power Supply p.c.b. (Board 4) outputs in excess of V and power amplifiers of the accuracy. Do not be surprised if your amplifier does hi-fi type will have more than 10V output. So the not reach the lowest figures at the extremes of the t.h.d. meter should enable the hi-fi amplifiers to be audio band and do not maintain the highest frequency checked down to below 0-01% 0 01% with reasonable for longer than it takes to make a measurement. Practical Wireless, June

26 Fig. 11: Copper track layout for Board 4. A ready drilled set of boards for this instrument is available from Reader's PCB Service (see page 88) 68) 10PC Magazines Ltd, R01D 1970 To VR5,6 Fig. iz; Details of the componerfts mounted directly onto S2 wafer tags, f he drawing shows<the components bpened^out for Clarity, they should be arranged along,the axis ef-the'-.swftch mechants^ii.fn a cylindrical fashion To Stb,C3 &VH4,5 Fig. 13: A typical set up for testing an audio amplifier using the Audio Distortion Meter JAMO/OJ Audio signal generator 1 Audio signal generator Low pass Low pass filter if required _o required o- Amplifier i under test lj-l Amplifier under test? -..L -=- Earth The foliowing following procedure is to assist the operator when using the distortion measuring meter for the first time. t is confined to measuring the distortion of a 1kHz signal, and should help the operator to be- be come familiar with the basic operation. f Dummy load Distortion Distortion meter =-- [h] nput Scope The controls should be set as follows: follows: Meter Range Switch on V V range. Frequency Range Switch on range 3. Filter Out Set/Read switch on Set nput Attenuator at Zero All other controls Midway 0 Oscilloscope Mlrifrnuin Miri!mum nput Accurate Measurement Meuurement 10V. b-di% o of% 1V V 00'1% 100mV loomv 1% fomv 10rnV 10% frny mv Table Connect a sine wave signal of 1kHz, V RMS to the input socket. Advance the input attenuator until meter reads V, i.e., full scale. Switch the set/read switch to the read position and rotate the frequency dial for minimum reading on meter. Adjust balance control to reduce meter reading further. Switch the volt meter range switch to next lower range as the signal is reduced by adjustment of the frequency and balance controls. When no further improvement (reductions) can be obtained the distortion can be read directly from the Practical Wireless, June 1978

27 * components com Resistors Res.istors i t W5% W metal oxide oxde 33S5 33.Q 1 R43 toon 100f} 3 R7, 49, R6 ikfi lko 1 R5Q RSO 1-2kn 1 2kn 1 R4 2-2kn 2 2kn 3 R5, RS,8,23 2-7M1 2 7kn 1 R9 4-7ka 4'7kO 2 R10. R10, 45 ickn 10kO 9 R14,15, 15,16,18,20,21,36, , , 48 12ka 12k!l 3 R3,42, 51 Sl 22k2 22k!l 2 R40, 53 27kfi 27kO 1 R41 33kfi 33kO S 5 R26, 27, 28, 29,30 39kn 39kO 1 R2 47kO 3 Rl,19, 19,24 100M2 100W 5 R11, RH, 12, 13, 25. 2S kn 150kO 1 R38 BOkO 180kG 1 R17 220kO 220kG 1 R22 270kU 270kO 1 R39 Ra9 330ka 330kn 1 R44 41okO R37 470kO 1 R37 iw 2% metal oxide t W 2% metal oxide in 10 1 R35 ion R34 icon loo):} 1 R33 1kG ikn 1 R32 10kU t R31 10ki! 1 R31 Potentiometers Potentiometers i t inch diameter spindles loon 10W1 1 ko lko!ln. lin. 2 10kO 10kn lin. tin. 1 10kO 10kn+ + lokpin. 10kO lin. 1 20kn 20kO!in. lin. 1 look!} log. 100Wi log. 1 VR9 VR2.6 VR2,6 VR8 VR4, 5 VR3 VRl Miniature hor;z. slteleton preset look!} 1 VR7 Diodes OA2Q2 OA202 4 N400l BZY88C24 1 Transistors BC413B ,3,4 05,6,7,8 D5, 8 09 VR9 VR1 Miniature horiz. skeleton preset lookfl 1 VR7 Semiconductors Semiconductor. Diodes BZY88C24 1 Transistors BC413B 9 D1, 2, 3,4 D9 TR1, 2, 3.4.5, 3, 4, 6,7,8,9 Capacitors Polyester Polyester 2, '2nF 2 C7.12. C j4F 01/<F 2 C5, CG,11 0'047^F O'047j,F 2 C5,10 0-1/iF O' lt'f 1,C25 0'22/iF O'22/tF 8 C4, 9. 9, 13, 13,20,21,22,23, ^F O'6B/tF 1 C15 CHi 1/«F l/tf 2 C3, C3,S 8 Electrolytic Printed circuit board mounting Electrolytic Printed circuit board mounting 2-2/iF 2'21'F 63V 3 C14.18, C14, 18, 27 D/iF 10/-lF 63V ' 6 "0 C2, 16,17, 17, 28, 29, x<F l00'f 63V "1 l C30 220/i 22O'F F 63V V t, C1 Cl 470/iF 470l'F 63V 1 C33 Electrolytic Axial leads 470/iF 470l'F 63V 2 C19, /iF 1000'F 63V 63V2 2 C /<F 4700/,F 25V 1 CSS Cerawc trimmer Ceramic trimmer 3-35pF 1 TCt TCl Switches Switch.s Min. toggle s.p.d.t. C19,32 C26, 34 C35 Min, toggle s.p.d.t. 2p. 6w. midget wafer 2p. 6w. miniature rotary switch Mains switch assyto fit 52 mech. Mains switch assy to fit S2 mech. Miscellaneous Transformer 24V 20VA Miniature Transformer 24V 20VA Miniature Case RS Printed circuit boards (Four n in set) Readers PCB Service. 24V indicator lamp Knobs Sifam collet fixing type 15mm diameter W15t W151 wing knob (3) Kl50 K150 plain knob knob (3) K151 plain knob w'ith with line pointer (2) N1S0 N150 nut covers (6) C150 caps (8) Figure dial for 15mm 1Smm knobs with pointer (1) numbered 1-10(1) Meter 1mA f.s.d x '< 74mm appro*. approx. BNt:; BNC SOO son sockets (2) Tinplate sheet for screen (cut (cui from.used cocoa tin or similar) PW Front panel overlay (Obtainable from irom PW Editorial Office) Office) ,4 S2 55 meter and voltage switch. That is, if initial full scale (100%) was V and final reading was (say) 6mV, then distortion is 0 6%., The low frequency filter can be switched in for measuring frequencies above 1kHz if hum is affecting the measurement. Other uses of the Meter Other uses of the Meter With the input attenuator at maximum, the meter can be used as a normal AC millivoltmeter with full scale range of 10 and V, 100, 10 and mv. This would make it possible for example to measure the output of a magnetic pick-up directly. t can also be used for measuring Hum and Noise in an amplifier. By adjusting the input attenuator for full scale on a test signal from an amplifier and then removing the test signal and shorting the test ampli ampli- fier input to earth. The meter will then indicate the residue Hum and Noise of the test amplifier, for example: example; if full scale was obtained on 10V range with the test signal and then after removing it the reading was (say) 6mV, this represents a ratio of 1666:1,, approximately 64dB. Many other uses can be found and a few hours spent using the meter will be very rewarding. # Practical Wireless, June

28 spy Sbangel's spy Strangers Some kind soul sent me a whole heap of papers from the recent nter- nter national Solid State Circuits Confer- Confer ence and there seems to be some real goodies on the way (not available yet). One which took my eye is a single 14-pin dual-in-line package which houses a complete motion detector. t is intended for application in elec- elec tronic toys. This little beasty can be made to keep an eye on a 2ft. diameter area at 8ft. The photodiode itself is actually integrated as part of the chip. An external loudspeaker s is re- re quired and when connected up, the unit will emit a whooping noise when- when ever if it senses motion within its "sight" area. t carries on making this din lor for a set period of time, then it goes back to sleep and waits for the next "something" to move within its sighting area. t would seem to offer great possibilities as a burglar alarm, etc. A further nice feature of this little i.e. i.c. is that it has another mode of operation. To change it to this you need only add a single connection. n Us its new mode it will "search". t does this by flashing an external bulb at some 3Hz. At the same time, it croaks out a random series of squeaks and grunts (the paper offers the more sophisticated description, "emits audible notes"). When the "thing"" detects its own reflection it im- im mediately sounds an alarm and simul- simul taneously increases the bulb flashing rate to 25-30Hz. The chip uses two technologies; linear bipolar, and PL. FL. H-digi-fi Hi-digi-fi A recent report from Japan details feverish activity among audio equip- equip ment manufacturers in manufacturers-in the digital field. t is now virtually certain that the hi-fi systems of the future will be digital. To date it seems that the only "standard" to emerge is a wide acceptance of a 30cm disc as the norm. nterestingly, though, the early professional systems will use tape before moving over to disc, and it t is expected that the consumer scene will also follow this pattern. But don'f don't get too enthusiastic about digital audio. The world concensus of 'opinion is that it t will be some four years before professional digital audio E~ ~ ~~~~~~~~~ A REVEW OF RECENT DEVELOPMENTS.,,- )~) /o n gereral, general. ho the author does nol not hive have any mote more ~ inforroahor informaton on Of) products than appears in the thp article arllcle systems really catch on, and a further six years after that the consumer market will blossom. t could therefor therefore be some ten years before you see these systems advertised. The main hold up will be price. nitially, systems will be expensive and the first few years will be needed to gradually bring the prices down. Why go digital anyway? t seems that analogue hi-fi has now gone about as tar far as it can, whereas digital is in its intancy. infancy. n terms of improve- improve ments digital technology has much to offer the audio buffs. To start with, frequency response and dynamic range are both independent of the characteristics of the tapes or discs used. t is also claimed that ihere there is no crosstalk problem between channels. From all the specifications on systems that 've read, the res- res ponses are flat (very, very flat) right up to 20kHz, and dynamic range, even at this early stage is well over BOdB some SOdB-some 20dB better that most analogue systems read about these days. Another advantage of the digital approach is wow and flutter there flutter-there isn't anyl any! This is because all the signals are retimed so accurately during playback. Various individual technologies are to be employed initially, including a laser/disc system. But the comforting thing is that despite the very different techniques, the final product, be it tape or disc is compatible in that one can convert material from tape to disc and vice versa. Perhaps we'll all end up with a home computer to play our gramo gramo- phone records on. Wonder what that dog, squinting down that trumpet/horn thinks about it all? Useful Chips Another chip which could be very useful for the home constructor (when it becomes available) is a new level detector i.e. i.c. Onto the chip the manufacturers have managed (somehow) to cram five comparators, a voltage regulator, five output driver transistors, five scaling resistors and an input buffer stage with a high input impedance. By connecting five.e.d.s l.e.d.s (plus usual limiting resistors), each.e.d. l.e.d. can be made to light as the nput input voltage increases in steps of 200mV, i.e. for each 200mV input, the next l.e.d..e.d. illuminates. The open- open collector outputs on the chip can handle currents up to 80mA and voltages up to 18V. n practical terms this means versatility because the ratings allow not only l.e.d.s.e.d.s to be used as indicators, but also fitament filament lamps. By using suitable circuitry, the device can be made to flash the first lamp or l.e.d..e.d. continuously when the input level falls below the 200mV threshold level. Charge! Chal'ge! Charge those c.c.d. (charge-coupled devices) are in the news again well again-well worth keeping an eye on. This lime time it's a Japanese company that is using c.c.d.s in an experimental colour television camera. Each of the three c.c.d. chips (one for each primary colour has an array of 111,192 sepa- sepa rate little sensing elements in an area 10-3mm 10'3mm x >t 9-lmm. 9 1mm. f small is beau iful, then these devices must be fantastic. The colour television camera, when it comes on the market (probably late next year if all goes well) will come complete with zoom lens, built-in camera control circuitry, and electronic viewfinder. Price is set at around the mark. Weight will be less than 2kg. Pl'ogrammel' Programmer 11 Microprocessors are here to stay and many are available to home con- structors. One of the problems is learning how to programme these clever little electronic beasties. An answer is offered by a German manu- manu facturer. He's marketing a little "black box" which can be used in conjunction with a black and white TV receiver. The black box has a light pen and the TV receiver is used as both input and output terminal. The box comes with a 230-page manual and costs around 280. For r a further 140 (approximately) the purchaser can add a cassette control nterface interface for writing (and reading) memory data on standard, commercially available tape. The reading/writing rate is some 1 kilobyte in 90 seconds. i i 26 Practical Wireless.. June 1978

29 ~'purbeckj Part 3 T ^ x -> ^y'.' liii v«! AN HCKMAN HC{MAN Having made up the Stabilisers board, check it over to the front panel. Note that the probe power socket and mount it in the mainframe. Set all preset pots, pots. SKT10 SKT0 is also used as a distribution point for fot the to mid travel. The Raw Supplies have no current limit stabilised supplies suppiies to various controls on the front protection of course, so unless you feel 100% sure panel. that everything is going to be all right, the following A ten way colour coded ribbon cable brings the procedure is suggested. supplies from the rear of the instrument, five of Either run up the voltage between pins 9 and 5 the leads terminating on SKT10 SKT0 as detailed in Fig. 2 to +17V + using a current limited lab. bench power Front Panel Wiring. Further lengths of ribbon cable, supply or if one <of these is not available, connect up stripped down to the same five coloured leads distri- distri the OV line between Boards 1 and 2, but connect the bute the stabilised supplies from SKT10 SKTlO to the edge + 17V Raw supply from C19 to Board 2 pin 9 via a connector of Board 4 and thence to that of Board ft 330n resistor. Check that +5V + appears at pin 8 and (Note that the pins of both edge connectors axe are that the voltage at pin 10 responds to varying VR202. numbered 1 to 36 working from the bottom upwards. f so, all is well, though it may not be possible to As both Boards have the components facing outwards set the output at pin 10 to + 12V until the 330ft 330n resis- resis when plugged in, the edge contacts on the component tor is removed. The + 17V raw may now be wired in face of the Board read from right to left for Board 3 permanently and VR202 set to give +12V + at pin 10. and left to right for Board 4.) The remaining five Similarly, check out the - 6V and 12V -12V stabilised wires in the 10-way ribbon cable are used as follows: outputs at pins 3 and 2 with the 17V -17V raw from C20 Black. 0V OV from fmm Board 1 pin 6 to common earth point supplied to pin 1 via a 330ft 330n resistor, then wiring up at Board 3 edge connector. and setting VR203 for 12V -12V at pin 2. Finally, connect Brown. Pins 1 and 2 of c.r.t.. (cathode) to clockwise the +300V + raw supply from Board Boatd 1 to pin 6 of end of VR5 track. Board 2 and check that +150V + appears at pin 7. Violet. Pin 5 of c.r.t. (anode 1) to wiper of VR6 Note that due to the absence of load current drawn (focus). from the +150V + stabilised supply the" ' < +300V + Raw" Grey. R18 and D1 Dl (mounted on c.r.t, c.r.t. base) to wiper will be nearer + 560V. 360V. of VRS VR5 (brilliance). This completes the checking out of the instruments White. 800V -800V Stabilised from Board 1 pin 7 to anti- anti supplies and at this stage it is worth completing the clockwise end VRS VR5 track. mainframe and front panel wiring. Wiring confined The earthed pins on the edge connectors of Boards to the front panel should be completed before offering 3 and 4 are each individually wired direct to a 16 s.w.g. it up to the mainframe and likewise, wiring of S tinned copper co'pper wire running the length of the edge and S2 should be completed before offering them up connector, at each end of which it is supported on a Practical Wireless, June

30 i TOP pin1-«pin13 CRT 6 3V 63V< pin14 Boardl'pln6«"«Boardl Pin8j Tl N E L Board 2 stabilisers stabllis~rs Component side Component sld~ Board pins board pins- board 1 pin 9 B board boardl 1 Pin3j plns" 12-9-CH bo<l!dsl pin board pln2-" board 1 pln2 B «+ f F e E To 02 LED pilot lamp on front panel Vstab ^ GN -12Vstab V BU C pf 25 ~ C20 on front panel +6Vstob BK ov Toboqrd3 ground point r -17Vrowl Tobo~rd3 groun point -17Vraw 'CAT +17Vraw 'CAL.: to front panetskt panel5kt l Board aoait Vslob t Y 4150VstQb Red + 300V raw Board 1 raw supplies T1 S 3V Yl t:/1a---'71m7\?l' R21 v,-^wv - 1 R23 board 4 X, Xl -< //' /- 1\.(\1'...&..1 R20 >2 100 Y2---iJ1--.lQot:JO''------~~= too t Board 1 raw supplies Copper trocli track side 10 t + 12Vslab OR 0 Tog upder mounting trafisformer screw i in* View on base bas~ of CRT C 0 To S7on 57 front pan~l front panel RV5 -(frontpon^ ^ -RV5(FP) CT6L Board4 -Board4X2 C18 LBoard4 '------=-0-7 O.lpFl. 11J :';F" r" r blanking... J\f\'-Board4 X2 Fig. 1: Power Powet$!Jpply supply interwirlng interwlrlng diagram and c.r.t. (:.".t. base ~ase connections. (:onnettloris. This drawing should be read (n n conjunction conjuilqtion With with Fig, Fig. 22' Front " Panel wiring diagram. Please note thai that RV5 and RV8 RV. should shou.ld be read as a~ VR5 VRS and VR6 VH6 -'i-i solder tag under the edge connector mounting screws. Thus Board 4 ground plane, when plugged in, is earthed to the base of ()f the mainframe via the edge connector mounting bracket and to the front panel via the 4BA pillar. Board 3, whilst similarly earthed, picks up the Black wire from the ribbon cable,at at a point on the 16 s.w.g. earthwire adjacent to the nput Low contact and from the same point an earth- earth wire runs to the earth point on S3 and thence to a solder tag under SKT1 1 mounting screw. This earthing arrangement is essential to avoid instability, ensure a flat Y amplifier frequency response and avoid ringing on square waves. When making the connections between the front fwnt panel and mainframe, lay the panel down in front of the mainframe as though it were hinged at its lower edge. (This is why Fig. 2 Front Panel Wiring has been drawn the way it has.) Dress the wires from WARNNG Extra care must be taken tak~n when working on any part of (his this instrument while power s switched on, on volts can kill. When delving into the insides of the scope s(:ope for any reason with power on keep one hand in ydur your pocket the The front panel along towards the "hinge" and thence off to their destinations. This will ensure that when the front panel partel is offered up and secured in position, there is adequate but not excessive lead length. Having rechecked "echecked the wiring and removed the tem- tem porary link from Board 1 pin 6 to chassis, plug in briefly and check straight away that all the stabilised voltages are correct, indicating no shorts anywhere. Check Oheck that the slider of VR5 covers the range 750V -750V to 800V - approximately and that of VR6 350V - to 600V -600V approximately. The c.r.t. base wiring can now be completed, except for 18 C8 and the deflection plates. n fact, the c.r.t. and mu-metal screen can now be fitted and a simple check carried out if desired. To do this, temporarily connect one end of a 47kfl 47k!! resis- resis tor to -l-150y + 150Y stabilised and the other end via a lookll look!! resistor to chassis. 28 Practical Wireless. June 1978

31 Yinput skt skt2 skt3 ~ R9 earth CAL.----_51 T, 8.,~~, AC/OC~ 52 ~ ^ Beam finder Lower edge Lower edge 9 skt7 sweep ut 9 g9 skt9 alternate SKTZ 5KT 3 SKT4 SKT5 SKT6 sweep, SKT8 skt8 allernale earln CAL X nout X -i-ion output aale aate Beam tinder BoardA 9 Board 9 4 SoardA 9 Board4 Board 4 Board 4 plnl6 plnls pin2a pin24 pinzb pin25 Board A 4 t----t r'tpln4pln Pilot Mains tamo lamp on/off -U+ E F + l-zk^ S3,b nput range 54 A B C3-10,2-22pF C3-O,2-22pr i M S R10 C22.r x pqk A70pF Board 3 plnlo H ; ' M <R11 C23 r2_ >'k A.7nF CS -A- J ~a3 Board4 pln21 r i rda- board 4 pin 8 55 SS 56 R13 Trig polarity nt/ext nl/ext ink trig. trlg. -12Vst 6 SKT10 Probe cower sktlo Probe power 5-65pF Time base speed 150Vstab SOVslab +12Vslab ~ Tag undersktk mounting screw Tag under sktl mounting screw +l2vstab +12Vstab +5Vstab CRT pinsl,2 BN Trig. Rvl Trlg. RV1L Board 4 level 25k 25kt plnl0 plnlo -12Vstab -ZVstab Y flv2 Shllt Shift Y 2.2k 2 2k RV2i.. t ~ Board A Board 3 plnls Board 3 pln16 t RV3 CAL board 4 pin :Fo.. <-10k +12Vstab R14,,'\\ + ZVslab 5 k 4:;j:' X board A :V4 RVA y pin 22.. T" lk shift pin 22 +5V R15 stab 680 Rv3 TB.speed T.B.speed 10 k variable k shift C18~ RV5 -Board4 A 47k 7 k'~""'-+---j.--.;::~"""-.\f\f\r--<l~-- Blanking Brilliance O.1jJF Brilliance WH CRT pin3 pln3-800vstab Upper edge R17 look CRT, pms V CRT.-.,.,.,--.f-~ pin5 V t Mounted at CRT base k between- - aboard A t Mounted at CRT base ~ "between.... &board 4. Fig, Fig. 2: Front panel back wiring. This diagram has been drawn with the top edge of the front panel at the bottom so as to correspond with its orientation when placed on the bench for the purpose of wiring. Connect- Connect ing wires from the front panel to other parts of the instrument should be long enough to allow the panel to be lowered to the bench in front of the mainframe. This makes for easier working conditions. Please note that potentiometers labelled RV1 to 5 should be read as VR1 to 5 and also that the 220kO 22l)kO Focus potentiometer at the bottom rightfiand righthand corner of the diagram labelled RV5 should be VRG. VR6. This drawing should be used with Fig. 1 the power supplies inierwiring interwiring diagram Practical Wireless, June

32 * components FRONT PANEL AND MAN FRAME Resiiitors ResiaJors (Unless (Onless otflerwise otherwise specified 5"~ 5% tw iw cijrbon carbon film) R1 hi 'SW mn Rll R13 10kO 10kn R? R2 il,lokn lookii R14 5 6kO S-CkQ Ra R3 iomo 10Mni0% 10% fu5680n R15 680C1 R4 1MQ M-Q 1% RrB R16 330Ju) 330ksl.. RS R5 910 kfp% xn 1% RH R17 iooko iookd. R6 im01% 1Mni% R1S R18.10Mn lomft 10% R7 lmo Mft 1% Rt9 R Ra R0 njin 1Mni% 1 "l~ R20 l00q looo R9 jook1)1 jookil ~. R21 R2i loon Ri010kn1% RlO -10k i 1%.R22 loon 1000 Rf11kOf%' R11 tkol% R23 100n ioon Rl21Cl0ni';/ Rl~ 100n 1<;t o ; R24 HW 1-2kn Capaclt,,,. Capacitors ". Cl Ci ", 0T/iF l;uf~?ov 350V Ci30 1ftF Cl3 0-1pFi% 1% 63V ;',.,. W- i Cl? c2 lopf OpF Ceramic ~14 ct4 ionf tohf 1% 63V eav C3 2-~2pF 2-22pF ' Cl5 CS nf 11lF 1% 63V BaV C4 2-22pF C pF' 5-~:ipF CS C5 2~22PF 2-22pF C174' 4-7^F100V 7i-'F foov. C62-22pf 2-22pF C18 CS O O lp.f lpf 1000V lqoov Ct C7 2-22pF 1?-22pF C19tliOOp.F Cl9 2600/iF 2SV 25V ca C8 2-Z2pF 2 22pF cao C20 '2500+F 2S00/XF25V '25V. C9 2'22pF 2~~gpF C21 47p.F 47pFC~rl!mlt; Ceramic C10: C pF.. C22 470pFC.rarrtlc Ceramic 'C11 cii o O-t~p50V tpfssov. C23 4-VnF 4-1nF mel. metfllm fllrn C12 MF 1p.F 1% 63V ~V C24 47nF 4Jn'F met. film fllfi ~c).'l'ltiometers Pptentlbmeters. ',1O%Jlo,tW*ihc/l 20% llo: iw iinch shafts Scl'la(ls } VR1 25kn 25kO. VR4,1kn VR41kO VR2 V~2 2-2kn ;2 ' 2kQ VR547kfl VR6 47kn VR3i\ikll iokfl" VR6 VR,9?2uiin ; 220kn i nductors " 11 See Tent ' ~, :,;. Diodea DiodQi.' '.' D1,iN4148 OUN4i48 L2, See Si/a Text Tellt D2 Hi brightness l;e.d. 02 Hi brightn$.ss te.d, Transformer T'4nSfor.;n.,," tf T , iiV,6 3V V, , 9~O::12 ' 9V,Transformer' transformer Type V :1C!3ilrri", (Barrie Electronics) Miscellaneous Mi$.~fHlarle.ous. : ~;.",% cf1 Ft liinch, l"ki{1cb x iinch, finch, 1A fuse and holder :.~ Si, 'Mini<;lture Miniature s.px.o. s :p;c.o. toggle toggle'switch switch tllf 32 S2 Miniature Miniatuj'e push /)ush button n.o.',n.o: '~~ 53 2p Zp5w 2 '2 wafer (Maka-swltch) (Mci,ka;,s,witc.h).1)4 54 2p 2p 6w 6w. 11. wafer w.lder.'..'. SS S5 Miniature Minlatl.lfe s.p.c.o. s.p.c.o, toggle Switch lwitch S6,fMiniature.7 s.p.c.o. s;p.c.o. toggle, switch sw.itch SKT1 51<T1 BNC socket, soc.ket; round Qund SOfJ 5O!l-(UG1094/U) (Uo1094/U) SKT2 4mm'socket, 4inm ~$dcket,black,skt3 4mm,socket, i:so~!lelt. blue SKT4,4mm $1(T44mm:;ocket.,white sac'ket. SKTS, SKT5:64mmsociiet,. 8 socket,, green grijeh SKTV SKT7 4mm socket, yellow SKTS, SKT8dl4mm 9 socket, sqcket, red fad SKTip' SKTf(,l' 5,pin DN:-180-(A) DJNA ~O fa) CRT 3BP1 3BPl plus base Base Case m u.'itmg'cirps(vert)farcf9,20 rtlpufit1ng;<:lips(vert) forc19,20.. fidge-co Edge connector'q' n hector Q'l 1!nch inch pitch 36 way 2 off Knobs Knah~Si Sifam t:,lm 15mm.collet conetfi~jllg fixing with nut huteal/ers covers and caps.' eaps.. Kiso 1<150 plain plain 22'011 oft K151 line.pointer n~pointer 4"off foft W151 vy h9 vy:!ngand ll'ne'pdlnter lnep<iinter 6 Q off oft fx- " * sm-» Connect all four deflection plates to the junction of the. two resistors, i.e. approximately --100V. + loov. With VR5, VRS, VR6 and VH201 VR201 all set to midtravel, midtr:avel, switch on and allow a few seconds for the tube heater to warm up. Adjusting VR5 VRS should produce a spot on the end of the tube and VR6 should enable it to be focused to a small diameter. f at either side of this setting it looks elliptical, wider or tauer tallet as VR6 is adjusted, VR201 (astigmatism) should enable this to be cor- corrected. Mind where you put your hand when adjusting VR201, it's not far from the e.h.t.. on Board 1!! t should be possible to focus the spot down to a pin- pin rected, point, provided the brilliance control is not advanced too far, though of course VR201 will need resetting when Boards 3 and 4 are fitted. n fact Board 3, the Y amplifier is the next step and full details of this will be published in next month's instalment. Several Severa! readers have enquired about the possi- poss.i. ~bilities of using u'sing alternative altern!ltive tubes for Purbeck. We cannot advise anyone any'one as to the suitability of components other than those specified. Not only will win the mechanical construction need alteration, but revised amplifiers and e.h.t.. supplies will!llso also be required. 30 Practical Wireless. Wireless,. June 1978

33 N... NEXT MONTH NJ practical pra_~cal WRELESS '~eto~t $ e lr ~.& b WTH THE WTH THE ft r J h~ving rw' N A 2m f.m. transmitter of nominal 10 watts output, having six crystal-controlled frequencies and pro- ~WO vision vsion for an external v.f.o. FM Easily constructed on four simple printed circuit 'ui 'AVOM' boards, the transmitter is housed in a quality instru- ment ~:~~u~~se case and and provided provided with with a novel novel frequency frequency2m ransml er readout. The completed unit is both modern and professional in appearance. Pica 2m FM Transmitter ' V/ V T d H V L * s. n s *<4 *< U w.v- a150-- iilso- Pha5e- ntroducing Phase- DGTAL. Locked LOGC.-.v Calibrator A simple circuit design design which provides an accurate 200kHz output signal, phase- locked to the BBC's Droitwich trans- mitter, useful for calibration of receivers and digital frequency meters. Beginning a primer in logic, which will cover gates, flip-flops and counters, characteristics of TTL and CMQS CMOS and design techniques. 4»» 'V. A Practical Wireless, June

34 .. ST BSDB CaLLNG SnrcsiDE GiLUNB JOE KASSER NASSER G3ZCZ/W3 When one' thinks of people in another part of the world, one usually imagines that their life style is almost identical to one's Qne's own. The' fallacy of this concept cqncept is only Qnly obvious Qbvious when one Qne travels and is exposed expqsed to another way of Qf life. Contrary to' popular belief, radio radio' amateurs are no different to' other Qther people and although the hobby is international, it takes on different forms fo-rms in different countries. cquntries. This article is an introduction introductiqn to amateur radio radio' in the United States of America. The Tbe Transmitting Licence t is much easier to become a radio radio' amateur in the USA than in the UK. There are several classes of Licence, each having different examination standards and frequency privileges, as shown shqwn in the table. n general, Novices NQvices have to pass an examination examinatiqn in elementary theory theqry and a 5 w.p.m. Morse test. The examination examinatiqn is administered by a radio amateur volunteer on Qn behalf of the licensing authority (which in the USA, is the Federal Communications CQmmunications Commis- CommissiQn). sion). The Novice NQvice licence is valid for fqr two years and until recently was distinguished by the WN prefix. t allows allqws its owner Qwner c.w. only privileges in the 10, 15, 40 and 80 metre bands with a maximum power input of up to 250 watts. The Technician class of licence requires slightly more mqre technical knowledge than a Novice, NQvice, and allows operating Qperating privileges similar to' our Class B licence on Qn segments of Qf the 6 metre band and higher frequencies. The General, Advanced and Extra class licences are all allowed all-band, all-mode operation, QperatiQn, but each class of licence (except Extra) is limited to' segments of Qf the band. The test for fqr the General requires 13 w.p.m. c.w. and the test for the Extra requires 20 w.p.m. ncreasing levels of technical knowledge are required for up-grading from one class to the next. The licences are free and except for the Novice, NQvice, are valid for five years. Separate mobile or Qr TV licences are not nqt required. The segments of the bands avail avail- able to the different classes of Qf licence are summarised in Fig. 1. The band split between phone phqne and c.w. is decided by the FCC for fqr the amateurs, and not by the amateurs themselves as in most other parts of the world. n general the input power limits are kw input d.c. or 2kW input p.e.p. except on Qn Top Band, which is segmented in both bqth frequency and power depending on Qn geographical geqgraphical location QcatiQn as shown shqwn in Fig. 2. The HF Bands Operation on Qn the h.f. bands is very different to' that in Europe. EurQpe. The vast majority of the stations appear to' be using the full legal limit and beam antennas. Thus the bands are crowded with strong strqng signals all originating from frqm the states, and it is difficult to hear non-stateside nqn-stateside signals at times. The USA is so large that in general, any foreign station statiqn is DX. The bands are so SO' crowded that if you yqu want to' work the states from frqm outside, you yqu should get up into into' the General parts of the bands when they are open to the USA. You may then be giving the stations statiqns you work, wqrk, their first G contact. f they want your yqur QSL they will probably offer to QSL direct and even send you yqu RCs. Res. There are many more mqre of Qf them than there are Gs, so if they are not in a rare state such as Utah or 0'1' Delaware, let them QSL first. f they want your card, they will. f you operate Qperate in the Extra or Advanced segments of the bands the chances are greater that you yqu will be working wqrking someone someqne for fqr his umpteenth G contact. The 3-5MHz 3 band is so wide ( MH2) (3 5-4 OMHz) that the c.w. part is called 80 metres, but the phone part is called 75 metres. At this point of the solar cycle, it TABLE; TABLE: US Amateur Radio Classes.. Ctaas Cia.. Morse.Mors. Technical Knowledge Operating, Requirements Re~uirement. Required Privileges Novice 5 w.p.m. w.p,m. Hardly any to, to. ($ apd 31'!il 80m 80tn Technfclan Technician 5 w.p.m. w,p.m. About RAH RAE level 6m lim and higher General 13 w.p.m. About Abou.t RAE level All bands, bands. some frequencies Advanced 13 13w.p.m. A little more All bands, bands. more mo're than RAE R AE level levet frequencies Extra 20 20w.p.m. w,p.m. As Advanced Adva.nced All bands, bands. all frequencies 32 Practical Wireless. June 1978

35 offers cross continent contacts late at night. The 40 metre band has similar characteristics but is little used at night due to the vast amount of broadcast station interference. Sectors of the band allocated to broadcast stations in Europe are allocated to amateurs in the Americas and those broadcast stations come in loud and clear in the USA. The 20, 15 and 10 metre bands are pretty much the same as in Europe, in terms of distance worked, but are generally without the language barrier, because the common language in the states is English (more or less). There is thus very very little incentive for the American amateur to learn a foreign language. Traffic Handling American radio amateurs have third-party traffic handling privileges. This means that they can pass messages for people other than radio amateurs. For example, a station in New York can contact a station in Los Angeles and ask that station to pass on a message to a non-amateur. He can even have him connect his radio to the telephone line via a phone patch and make a radiotelephone call, thus saving on his long distance telephone bill. There is a num- num ber of countries that have reciprocal agreements with the USA about third-party traffic; in other words they allow traffic to be passed between their country and the states. Thus on all bands one can hear a number of nets passing traffic messages. Once a year the American Radio Relay League (ARRL) organises a traffic handling contest (called Sweepstakes), in which the information exchanged simulates message traffic. The VHF Bands At v.h.f. v.hj. there is no 4 metre band, but there are operating privileges at 50MHz (6 metres) and 220MHz (bj (l14 metres). Six metres opens up to sporadic E much more often than 4 metres, and thus a lot of the activity is on c.w. and s.s.b. t has properties very similar to 10 metres in terms of ground-wave communications capabilities, but DX is of course much more scarce on 6 than on 10. The 2 metre band is 4MHz wide ( MHz). The top two megahertz are filled with f.m. repeaters and simplex channels spaced 30kHz apart. Small seg- seg ments of localised s,s.b./c.w. s.s.b./c.w. activity exist close to 144 and 145MHz, but in the main the lower two megahertz comprise the wide open spaces. At the time of writing, the FCC is proposing to open some of it up for repeaters. There is OSCAR-related activity at about 145-9MHz MHz. Thus apart from narrow and sparse areas of activity at 144, 145 and 145 9MHz the lower two megahertz is an uncharted wilderness at this time. Local s.s.b. or c.w. activity on a nation- nation wide basis is rare. n most big cities, tuning the low ow end of the band by day will be very unrewarding with little to be heard. Even in the evenings you would be lucky to hear more than three simultaneous contacts taking place in the low half of the band, but during a con- con test a tremendous number of stations suddenly crawl out of somewhere and fill up the one or two hundred kilohertz. However, in the major cities the f.m. channels will be crowded. n most big cities all the repeater channels between 146 and X47MHz 147MHz are in use as well as some of the MHz ones. There is no f.m. calling channel as such, just find a repeater and use it seems to be the rule. n the states, the pioneers on v.h.f. set up repeaters to extend the range of their converted taxicab f.m. mobile equipment. As newcomers came on the band, they found the repeaters in existence and joined in. f people did not like a particular machine they were free to build and use their own on an adjacent fre- fre quency. n some parts of the country there were even repeater "wars" over choice frequencies between two repeater groups, each trying to force the other group to change frequency (this was before the days of synthesisers, when everyone was crystal controlled). Eventually voluntary frequency control was estab- estab lished by area-wide organisations. n the main how- CW *- Phone *- Tj~ V+M'ly ri.v4v ' 'A i!i 5 i' - + tv. = 'v^ yy, -A'A'.' CW fc- '. - - A//., sr, W/M'AA/^y.^\ r,h, +' YAA 1,1: --, ,/' Bittmittii ussssbs CW Phone * y /'/'./A'/yA '//A A.i 2 1*275 M t-jsc 14 2 / 14: Phone * W 9-ZXfAy; / / ' //// a J'//' '//' v * / 2*0 " 5*5 ' 29-7 lmnovice inoyice ~(jeneral j^^joeneral BAdvanced ladvonced ~:>+jextra Fig. 1: HF Frequency Assignments in the USA. Note that higher class licensees have privileges in lower class segments, the table shows the lowest class allowed in each segment Practical Wireless, June

36 ly^sa. - - A8 CDcFG, H_ oooi-'-l - - / NE\!. \ CAL. \ \ \ \ «/o^b\ rw5 / <*%%%" ascdekh ABCDEFGH ABCDEFGH N. DAK.. 0 o, ABCOEFCH /wia.., abcdefghy ^ \ uf ABCDEFGH t-~k""a~ns-. ~\ HO. - ABCDERiH ABCDEFGH ) o o tjcj ~~ "'~ HAWA /\ ABCDEFGH V / t./ KY, fess.. '"TEHN. MSS ' ALA ABCDEFGH / - \.X' > iiqqooi" v-iv w myu-- WVA / ^BCOEfGtJ y ^ M.C ^s- c x 5»V ' + KP4.KV4/ NPUT POWER (WATTS) 0 No opera 11 on, day or nigw 1 100day.25niQh1 day, ZSnighF 2 200day, SOnigW 3 SOOday, looniqhf (lay,200nighF day, ZSnight 6 250day, SOnlght SEGMENTS (khz) A B C B7S D E F G H 197S-2000 tthe range KHz is used by DX stations tthe range khz is used by OX stations attempting to contact North American stations Use of this "DX "OX Window" should be avoided by stations on this continent. stations on this continent. Fig. 2: Top Band frequency allocations in n the USA ever there have been few cases of deliberate inter- inter ference with repeaters, because the newcomers to v.h.f., especially to 2m, generally only used f.ra. f.m. and soon Soon learned the advantages of the extended range and continuous monitoring monitofing of the repeaters. n the UK the situation is different, the bands were in use before befare the advent of the repeaters. Also the 2m band is only two twa megahertz wide and everyone everyane has to fit into it. Hopefully it will take just a short while for far everyone everyane to find out the advantages of repeaters and common sense will then prevail. The 220MHz band is similar in characteristics to 2m. There is little in the way of s.s.b./c.w. commer- commer cial equipment for the band, and hence most of the activity is f.m. The same applies ap'plies to 70cm. Here, most of the activity is f.m. between 440 and 450MHz, i.e. right at the' top of the band, so that conversion of surplus equipment involves invalves the minimum of changes. The 70cm band is also used for remote control of af lower band repeaters and for inter-repeater links. Activity on higher frequencies is at par with Europe, namely very rare and due to only a few individuals. Using Repeaters Many f.m. repeaters are, connected to telephone lines. This allows for "auto patch" facilities, whereby amateurs can actually access the telephone network via the repeater and dial calls using the tones. They can report accidents to the police, call home and ask the wife if they should stop off o t! at the local.super-. super market and pick up some groceries, or do as one radio amateur did over one of the local machines here in Washington DC; while sitting in the garden by the side of the pool, he used his walkie talkie equipped with a touch-tone pad to dial his house phone and ask his wife to ta bring him out another can of beer! The number of repeaters is constantly growing. The ARRL publishes an annual directory that is free for the asking to members. The frequencies are based on a 600kHz split with a spacing of 30kHz between channels. They are known by the kilohertz values, i.e. a repeater on MHz 146 (in), MHz 146 (out) is commonly known as the 25/85 machine. n the 46/147MHz 146/147MHz region the input frequency is the lower one, ane, whilst in the 147/148MHz region the reverse is true and the higher frequency is the input channel. This was carefully arranged this way so that receivers could be peaked up at 147MHz and work with the whole range of channels. These frequencies are of course not allocated to the amateur radio ser- ser vice in Europe,and on my last trip to the UK, found that some of the American repeater output channels that had in ray my rig were in use by the police. Apart from f.m. the majority of activity on 2m and 70cm seems to involve OSCAR. Project Oscar started the whole thing in California with the launch of the OSCAR satellite in 1961, and AMSAT took over in The ARRL puts out a lot of free 34 Practical Wireless, June 1978

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Full Fail loatrucllom nairueuons supplied w or 8.A/K, ".E. tor for MT12 240v PRM. 22/0/12v50mA 12/0/l2v BBC, SEC. deulii. details. PRCE: PRCK: MT8.MTJ2 MT6, MT % VAT. Faotaatlc Fa.ntastic Value at fw W +8% + VAT. MANS DllfS TRAffSFORMEM TBAK'Oa.EB8 WTH WU'J TWO TJfUEPEBDKffr fdepejrdekt BEC0EDAB SECOlDARY LODDSPEAER L01JD8PEAXER BBLECTOJf SELECTOK WlJrDlfGS. MTOO. PRM. 240v. BEC. 0-24v, 0-2ftv + 2 % 12i% VAT MT00. WJfDUfOa. PRM, REC. O-^iv, 21'" 8. 8, 40 toa a.nd ohm at B MT160. MT1B0. looma. 240v. SEC. 0-12v, 12v (PleAse ( itate state which mpedance impedance )«ia 160m PRM. 2<0v. BEC. 0-l2v, 0-t2w 0-6v, 0-8v 3-6" 8 ohm CERAMC at *1 11'70 70 MT280. 2B0inA. PRM. 240v. SEC. O-Cv. 0-6* 8-8" GOODMANS 'Aadlom 'AudJom 8PA' 8 ohcj Ohnl PRCK: PRCE: MT100. MT00, MT150. MT50, MT2flO MT280 16w 15watl6 1t Att5 M ti 6Z + 8% VAT- VAT " 'ELAC'" Dua Dual Cone B 8 ohm] 100 la!fs TRAlSFOB.ERS at watt MATHS TRA5SP0RMFRS MT40. BEC. 20/0/20v la. PRCE: PRM. 6'M 240v. & B% 6EC. 8% VAT 1A. POWER POWEB BTTPPLY SVPPLY tffm VKTS + 8% VAT MTlO, MTO, HT15, volt line FT1 Switched PP1-Switched 3. ~. 41, 4i, 6. 6, 7J , 12t 12v al Rot trauaformcrb. MT5. MT vollllm transformers. 60~m/a. 600m/a with On/ofT on/oft switch and pilot Light. light. PRCK: PRCE: MTlO. MT0, MTJB MT % VAT. Appro.!:,dze: '( 76mm.. MT Approx 130 x 55 x Vfimm. ONLY NPUTS MTilOtt ON THEBE; M + THESE: 8 8% or VAT. J6 16 OHMS. PP6 Heavy PP6-Heavy duty 12 vpjt volt power "upply. supply. S. S.A.E. for details these of 1 6A 1-5A at 12 volt, DC. Appro*. Approx. slei x 90 above. (or detalle on them or any ol the X x Oftnun. 95mm. ONLY 6$ 18 W. 00. Please 2Gp p&p orders tor Eagle Trsnflurmera. add 26p pip to all ordera lor Transformers. BASOAHl BABGAlf TRAlfSrOEUEBa TRA1fSFOBUiBS 240v primaf prjmary. y V v COOmA 600mA secoudury secondary PEZO HOBK JlT 100 watt Approx alse; size: 60 x 40 x 60mm. 50mm. Fixing New High. ELECTRC QtmKty, HORS Quality, High UBlTB Power Tweeter. KW wait centjea centt'es?6mro. 76mm. PRCE; PRCE: LB % VAT. No Xover required. Freq. Response: Alan Also Bv&llable available Wains Mains trwulormer transformer with 33 8KHz BKMa Xovcr lo to 28KHr. required- 2-8.KHz. flpec. Preq. Spec. Sheet RespOQiit: Sbeet ceut sent on OD 18v l8v 600mA 500mA aec. sec. Price and elrc size lamr same as aa receipt oj of B.A.E. S.A.E. sbovc. above. OHR OUR PRCE: each + 8% VAT. accehb ACCESS and AND barclaycard BARCLAYCARD aookptsd phone ACCEPTED-PHONE orders ORDERS welcomej> WELCOMED ALL PRCES NCLUDE PO0TAaE POSTAGE UNLEB0 UNLESS OTHERB78E OTHERWSE STATED PLEABB STATED-PLEASE ADD V.A.T. A8 AB SHOWN B.A.B. SHOWN--B.A.E. WTH ALL ENQClRlfcB ENQURES PLKASE. PLEASE. Personal Pe.,onal cajere.auers welcoma welcome at; at: 2i 21 OEfiBfl GBU' LASSa, LAlfES, PALMEE8 PALlEBS QBEKlf, GBEEK, Jf.S,. 13. Phona: 8B8-6 0fl 888-l11l01 and 13 SOUTH S011TH MALL, -.u.l, EDMOHTQR ED.OfTOK 88 1'8 PhOM: Pb...: SM-6S t 36 Practical Wireless, June 1978

39 educational stuff about the OSCAR satellite pro- pro gramme, which by-the-way is is available to to anyone worldwide, for the asking. Worked All All States via via OSCAR is is just possible for Eastern stations and is is well within the capabilities of of anyone in in the con- con tinental United States west of of the Mississippi river. Equipment Equipment Salaries in in the states are generally at at between two and four times the level of of the equivalent salary for the same job in in the UK. Thus on a basis of of hours worked, equipment is is much cheaper over here. The large number of amateurs support a few manufac- manufac turers so that there is is quite a variety of domestic gear available as well as as the ubiquitous Japanese black boxes. Parts for the homebrewer are also readily avail- avail able by "mail". Many suppliers advertise in in the various magazines, and their wares can be ordered by post, or by telephone quoting credit card numbers. Crystals for 2m transceivers are available over the counter in most major cities and the prospective visitor can wait until he arrives in the USA to purchase the bulk of his crystals. f he is lucky the store may even have facilities for tuning the rig frequency. f you are interested in operating in the USA when visiting this country you can obtain de- de tailed information from the RSGB, or write to the FCC, Washington DC, for an application form (Form 610A). OA). Make sure that you send in your appli- appli cation at least three months before your trip, because it will take them that long to reply. Listening and Viewing Listening and Viewing The receiving side of the hobby bobby is also somewhat different. The medium waves, f.m. and v.h.f, v.h.f. TV bands are filled in most major urban areas. Medium wave DX-ing is a little easier than in Europe, because most of the stations broadcast in English. Stations are spaced 10kHz apart, which enables the inter inter- continental DX to creep in between the cracks. The majority of stations are east of the Mississippi. The FCC recognise the sky-wave effect at night and regu regu- late the 'band occupancy such that many local stations are required to close down at local sunset. This allows clear-channel stations to be heard over continental distances at night. t is thus for example possible to drive through downtown Los Angeles in the even even- ing, tune the car radio a little and listen to broadcasts from Denver, Oklahoma and owa, or to drive around in Washington DC and listeq listen to stations in Montreal, Chicago and New Orleans. The v.h.f. TV bands are also full in most cities with some additional channels in the u.h.f. bands_ in use. All transmissions in the Americas are 525-line 30-fields, thus there are no modifications necessary to the TV sets for their use in TV DX-ine:. DX-in?. The f.m. band is is 20MHz wide in in the range MHz, with 88-92MHz being reserved for public broadcasting stations. These stations, usually run by universities or local authorities, broadcast educational pro pro- grammes, classical music and selected shows from the BBC (including the Goon Show) as as opposed to the popular music or or news churned out by the com com- mercial stations. There are three major networks in in the states that broadcast commercial pr<>grammes, programmes, and each city usually has a local outlet of of each as as well as as one or or more independent stations and the public station. This allocation applies to to television as as well as as radio. Recent broadcasts on on public televsion have included, / Claudius and Upstairs Downstairs. Upstairs-Downstairs. Practical Wireless, June 1978 Many of of the independent TV stations broadcast old films and TV shows including UFO, The Saint, The Prisoner, The Avengers and Danger Man. The f.m. stations usually broadcast in in stereo. Both medium wave and f.m. stations usually churn chum out popular music, each specialising in in a particular type, and there may be one or two stations that continually broadcast news. The u.h.f. TV band is is relatively sparsely populated, its growth being curtailed by cable television systems. Citizen's Band Citizen's Band Closely related to amateur radio is is Citizen's Band Radio. The Citizen's Band is a small allocation of spectrum space at about 27MHz. t t seems to have been originally allocated for personal communica- communica tions between a fixed base station and a mobile (so that for example, a husband could talk to his wife on the way home from work) or between mobiles, so that the drivers of two cars travelling together can communicate. Licences are now available free for the asking, with no tests involved. Power input is limited to 5 watts d.c. d.e. a.m. and equipment is cheap. A forty- forty channel transceiver can be purchased for about $50. There are estimated to be millions of CB stations in service, the majority of them being unlicensed. Homo sapiens is a creature of invention. The American branch of that species, perhaps more inventive than other branches, has devised new uses for the Citizen's Band. Lorry drivers use it to warn each other of impending police radar speed traps. Prostitutes have been known to solicit customers via CB radio. Hobby operation including QSL'ing abounds and most stations use self-given "handles' "handles" 1 rather than their official call signs, always assuming that they have an original call sign. llegal power amplifiers are often used and some operators are even equipped with amateur band equipment such as Yaesu FTOls. FT101s. n the cities the channels are overcrowded and communication ranges are limited by the numbers of conversations taking place on the frequency. One 'channel has been set aside for emergency use (ch 9) and one is used as a calling channel (ch 19). Almost everyone monitors channel 19 when on the road unless they have QSYd for a particular reason to another channel, and con con- tribute traffic and police location information. Hitch Hitch- hikers also solicit rides over channel 19. One neigh neigh- bour of mine estimated that in two weeks of use he recouped the cost of the equipment due to the timely warning he received about the locations of police radar speed traps that would otherwise have caught him. Citizen's Band is a boon if used cor cor- rectly, but if 'abused is a mess. Microprocessors The latest arrival on the electronics hobby scene is the home computer based on the microprocessor. Thousands have been sold and clubs are forming all over the country. Microcomputers can be the subject of many articles in themselves, but suffice it to say for now that their use is invading the home as well as the amateur radio shack. t is estimated that within five years the vast majority of homes in the US will contain at least one microprocessor. This article has been an introduction to amateur radio and the electronics scene in the United States. Future articles will go into more detail about the various aspects of the hobby

40 tamk / R The -T0 1 DAVD COUTTS* CQUTTS* mmmt The General nstrument AY integrated circuit associated Rs and Cs, provide the shaping for the fire is a'625 a ' line interlaced "TV Tank Battle Game" for and explosion sounds. C3c does the same for the two players. The "battleground" "l>attlegro~nd" consists of white motor moror sounds which are all fed via lc3d C3d to the output barriers and 'a a series seri~s of black mines. There is one transistors TRTand TR TR2. Switches S4,, 84, 5 and 6 control white and one black tank, each controlled controiled by two the left tank and S7, S7. 8 and 9 control the right tank. single pole double throw paddle switches biased to S3 is the game reset and S2 is the tank trap switch. centre off. A push button for each player controls R2 to R4 mix the video signals sign<js and ~md...the composite composlte gun firing and a push button allows. the battle to t() be video is buffered buff,ered by the emitter follower TR3 and fed reset. Pin 22 of ()f the i.e. i.c. is switched to tp control the tank to the modulator. traps. n the open -position the tanks can drive TR4 and its associated components act as ~s the modu- modu through these barriers, in the other position lator which runs ata a frequency of approximately appro~irnately (grounded) the tanks halt when they collide with MHz, with harmonics harmonies extending ~xtending into the u.h.f. them. Motor sounds are provided -for each tank as band. well as gun fire and shell explosions, and the score is coded to each tank. The tanks are driven like real tracked vehicles, pushing both switches forward Construction causes the tank to go forward. f the switches are Construction is relatively straightforward, most of held the tank automatically speeds up after a few the components being mounted on the the: p.c.b. t is, is. seconds. f the switches are released the tank con- con however, advisable to use sockets for 102, C2, 3 arid alid 4. tinues at the speed reached at the time of release. The component layout is shown in Fig. 7._ Drill 6BA Pulling both switches back causes the tank to reverse, clearance holes for board fixing, FS1, FSl, T1 Tl and C1, C, and while holding one switch back and one forward a 6min 6mm hole for L. Ll. Drill other holes h~les to suit the com- com causes the tank to rotate. To stop st()p the tank when it ponent leads. Before mounting ' any Components components on is going forward momentary selection of reverse the board place the p.c.b. in thte the- box with a modulator is required. The shell has a range of about two at the front right, and the p.c.b, p.c.b. about 10mm from the thirds of the screen and after firing there is a re- re right side of the case. Drill 4 fixing holes in the load period before you can fire again. The shell can bottom of the case using the p.c.b. as a tem- teq'l be steered during its flight by rotating the tank. The plate. Also drill a 6mm hole in the bottom -to line up shell will pass over the mines but will explode on with L Ll core. Put the p.c.b. to one side and drill the hitting barriers. A hit on your opponent counts one box and front panel as shown in Fig. 1. Also drill a point, while running over a mine counts one against few 6mm holes in the base and rear of the case for you. you, When Wh~n one player reaches 16 hits the scores flash ventilation. Stick a small piece of speaker cloth over to show that the game has ended. the rear of the speaker hole on the front panel, fix the speaker in place with epoxy adhesive and mount the switches S, 2 and 3. The sound output is con- con Circuit Description trolled by VR3 which is mounted on the front panel. The circuit diagram is shown in Fig. 3. T1 T provides Assemble the p.c.b. using the layout Fig. Fig_ 7 and volts which is full wave rectified by Dl D1 and parts list as a guide but do not fit C2, 3 or 4 into D2 and smoothed by Cl. C1 Cl regulates the supply their sockets yet. R9 can be either a 20Mfl 20Mn resistor VP to approximately volts, VR1 VRl adjusting the or two 10MU 10MCl resistors (R9a and R9b). Fit a T05 voltage and 2, C2, 3 and 4 providing decoupling. C4 a heatsink to TR2, cut and bend a piece of aluminium and b provide the 4 MHz dock clock to the AY , L Ll sheet 60mm x 35mm as a heatsink for TR1 TRl as shown being adjustable to allow the oscillator to beset to in Fig. 4, drilling through the p.c.b., and retaining the correct frequency. C3 a and b. with their Cl C1 and the heatsink with a 6BA screw. Cut and bend *An Engineer with General nstrument Microelectronics, Glenrothes 38 Practical Wireless, June 1978

41 practical prac~ical WRELESS NDEX Volume YolumeS 53 MAY 1977 TO APRL 1978 Pages ssue ~~ ~~ May June July August September October November December January February March April 1978 The format of Practical Wireless was increased in size beginning with the issue dated September 1977 beginning with the issue dated September 1977 PC PG Magazines Ltd, Westover House, West Quay Road, POOLE, Dorset, BH15 1JG. do. Practical Wireless, June

42 Volume 53 May 1977 to April 1978 CONSTRUCTONAL-Audio Versatile AF Generator by C. Toms 108 VHF Wavemeler Wavemeter by Active by F, G, Canning M. Tooley Aclive Tone Control f. G. Cann/ng 814 Wide Range Voltmeter by M M. Tooley 486 Audio Level ndicator by W. W, Pleass ". 442 'Europa' Stereo Amplilier Amplifier by C. C, Toms Part Part Jubilee' 'Jubilee' Electronic Organ by M. M, J. Hughes Part 1 352, Part 2 426, Part 3 505, 50S, Part 4 581, Part , Kindly Note 677, 755, 837, 938 CONSTRUCT Multivib R. ONAL AL-Genera! -General Mutlivib 'Musico' by R H. Longden 732 Portable PA Amplifier by S. S, H, H. Davies Battery State ndicator by W. W, Mooney 849 Reverberation Amplifier by S, C. C, Parsons 104 Compact 2-melre 2-metre Beam Aerials by F. C. C, Judd 57 2-Way ntercom by S. S, Davies 22 Design Your Own Projects by T. Bailey and R. 20W C Audio Amplifier by F. F. G. G, Rayer 182 Whilaker Whitaker 1. Light light Trigger Cassette Recorder Power Supply Car Courtesy Light light mpedance Matching Amplifier Continuity Tester TTL nterface Circuit CONSTRUCTONAL-Receiving Economy Timing Strobe by S. B. Rarvey Harvey All-Band SW Converter by F. F, C. G, Rayer Part Extra Data 919 Part Electronic Car Voltage Regulator by C. C, Grayson 363 Atomic Time Receiver by N. C. C, Helsby He/sby 288 Handi-Mini Power Supply by. Hickman Kindly Note , Laboratory Power Supply by J. Thornton- CW Filter Unit by A, A, Langton Lawrence Direct Conversion Receiver by M. M, Tooley 652 Morse Tutor by D. J. J, Edwards. 263 Kindly Note Mystery Train Tour by E. A. Parr General Purpose SW Receiver by F G. G, Rayer Kindly Note 938 Part Proportional Power Controller by C. Toms 672 Part Kindly Note 837 LED Tuning ndjcator ndicator by J. J. P. Macaulay Protected Battery Charger by G, G. O. H. Sjogren 50 Narrow Band FM Demodulator by W. Bond S-DeCnology by D, D. Gibson Radio 2 Tuner for your Hi-Fi by R. A. Penfold 213 No. 6. The Ohm Gnome No. 7 Medium Wave Receiver 121 No. 8 Ultra-Simple AudiO Audio Amplifier 188 No. 9 Light-to-Frequency Converter 294 No. 10 Record Play'er Player Amplifier 345 No. 11 Automatic Courtesy light Light 595 CONSTRUCTONAL-Test CONSTRUCTONAL Test Equipment No. 12 The Might light Light 756 Aerial Performance Test Set by F. C, C. Judd 678 J.<-DeCnology./.-DeCnology by fay D. Gibson Audio Dummy Load by fay F. G. G, Rayer Simple Light Modulator 826 A 741 Signal Tracer by W, W. Mooney.193, The Gnp'n Grow 917 Kindly Note 305 'Seekit' Metal Locator by W. Opel Part Audio Visual Logic Probe by p P., Pond Part Extender for PW Transistor Tester (July-Aug 'Slim Jjm' Jim' 2-metre Aerial by F. C, C. Judd ) by. Hickman 'Solo Supermind' by A A.. Willcox W/7/cox Heatsink Thermometer by,. Hickman '" 750 Kindly Note Low Distortion Sine-Square Wave Generator 'Tele-Games' by D. S, S. Coutts Coutls by M, M. Tooley. 412 Kindly Note 305 Kindly Note 574 'Tele-Games' Add-on Module 'Shoot' Multirange Mullirange Testmeters by D. Jones by D. S. Coutts Couffs 280 Oscilloscope Viewing Hoods by M M., Allenden Traffic light Light Controller by P. Chambers 'Purbeck' Oscilloscope by /, l. Hickman Part Kindly Note RF Resonance ndicator by D. H. E,. King Hour Digital Clock by J. Miller-Kirkpatrick Practical Wireless, June 1978

43 EXPERMENTER'S S CORNER Basic 9V 9V Stabiliser by by R. R. N. N. Soar 762 LED Light Display by A. A. Cooper Simple Low-Z Pre-amplifier by by D. D. L. L. Jones Transistor Gain ndicator by S. S. Lamb /C C of of the MONTH by by B. B. Dance No. 62 SGS-ATES TBA820LV Audio Amplifier 34 No. 63 RCA CA3140 Operational Amplifier _ 216 No. 64 Ferranti ZN1034E Timer Kindly Note 574 No. 65 Thompson-CSF TCA900/910 Speed Regulator 604 No. 66 Thompson-CSF ESM1601 Proximity 738 Detector No. 67 Sprague ULN3006T Hall-Effect Switch 845 No. 68 2N5777 Photo-Darlington Sensor KNDLY NOTE Points arising from articles in the previous volume Gas/Smoke Sensor Alarm April ,755 Tug 'o' '0' War Game April , 222. MSCELLANY- - Technical Circuits for Audio-Amplifiers Amplifiers by F. G. Rayer (Part 1 March 1977, Part 2 April 1977) Part Part FM Front Ends by B. Dance 269 Hotlines (recent developments in electronics) by Ginsburg Ginsberg 30,111,202,286,367,440,586,670,749, 286, 367, 670, 749, 829, mproved Etching of PCBs by J. A. Kennedy Lambda Circuits by B. Dance Measuring with Operational Amplifiers by A. Sharpe 186 " 8 Monolithic Voltage Regulators by B. Dance Part 1 Fixed Regulators 26 Part 2 Variable Regulators 112 So You Want To Pass The RAE by J. Thornton-Lawrence Tbornfon-Lawrence and K. McCoy No. 1 Arithmetic (Kindly Note 454) 334 No. 2 Ohm's Law and all that 416 No. 3 Electro-Magnetism 501 No. 4 AC-nductance-Transformers AC nductance ^Transformers No. 5 Capacitance-mpedance-Resonance Capacitance mpedance Resonance 659 (Kindly Note 837) No. 6 Diagrams-Valves-Semiconductors Diagrams Valves Semiconductors 764 No. 7 Transistors-Transmitters Transistors ^Transmitters No. 8 FM-PM-Transmitter FM PM ^Transmitter Measurements 922 The Forceful Mr. Fleming-a Fleming a look at a prob- lem posed by readers of our RAE series Special Product Report - Chromasonics 'Chroma-Chime' Kit 'Stray Signals' by "Point Contact' Confacf 676 The 5-metre Story by R. R. Ham Part Part Part Practical Wireless, June 1978 ON THE AR Amateur Bands by by E. E. Dowdeswel! Dowdeswefl 65, 145, 225, 298, 368, 368,446,519,609,693,773,850, , 693, 850, 928 SW Broadcast Bands by by D. D. Bell 69, 149, 229, 302, 370 SW Broadcast Bands by by C. C. Molloy 450, 520, , 694, 774, 774, 853, 853, MW Broadcast Bands by by C. C. Molloy Mol/oy , 146, 226, 301, 369, 369,449,522,610,694,774,854, , 694, 930 VHF Bands by R. R. Ham , 150,230,302,373, , 373, , , 613, 697, 777, 855, 933 VHF Personalities by R. Ham Alan Baker G8LGQ 856 Henry Hatfield PRODUCTON LNES Abrasive Tools Tension Tools-Tension Files. 435 Raspawl and Abralile Abrafile ADE (Security) Maxi-Guard Burglar Alarm Alcon nstruments Miselco nstruments-miselco Multimeter Multimeter Master Ambit nternational AM nternational-am Tuner Module '" 434 BASF Record BASF-Record and Cassette Care Kits BF1 BF Electronics C Electronics-C Sockets i-Pak Bi-Pak Semiconductors 10W Semiconductors-1 OW Amplifier Module 212 Boss ndustrial Mouldings nstrument Mouldings-nstrument Cases 350 ABS Boxes Bywood Electronics 'Scrumpi" Electronics-'Scrumpi" Microproces- sor Kit Clock Module LT601 L Cannon-Tidy Cannon Tidy Tray 285?85 Chekits-Audio Chekits Audio Amplifier Module Kits Concept Electronics C Electronics-C Adhesive Labels Continental Specialists Protoboard Specialists-Protoboard PB Distronic-Crystal Distronic Crystal Oscillators Doram Electronics-New Electronics New Kits Eagle nternational-catalogue nternational Catalogue Eraser nternational-e105 nternational El05 Contact Cleaner Gen. nstruments Microelectronics-C Microelectronics C AY Gould Advance~Data Advance Data Book of nstruments Greenwood Electronics-Oryx Electronics Oryx 9 Soldering ron 350 Vice-Oryx Vice Oryx 1B ron GSPK-Torch GSPK Torch 'Search "Search Lite' 601 Hom(j Homp Radio-Engineer's Radio Engineer's Resistor Pack. 435 H. R. Holmes-'Versa-Vice' Holmes 'Versa-Vice' 132 ndustrial Science-Elecolit Science Elecolit 340 Conducting Paint 434 ^ TT nstrument Service-Fluke Service Ftuke8020A Multimeter 349 Jermyn~ Jermyn 3-Terminal Voltage Regulator 132 Lascar Electronics - Waveform Generator M~u~ Module ~ t-Digit Sj-Digit Panel Meter 601 Transformers Linstead Electronic nstruments-signal nstruments Signal 88 Generator 55 Maplin Electronics-Catalogue Electronics Catalogue 54 Mogul Electronics-Op. Electronics Op. Amplifier TL Op. Amplifier CA National Semiconductors-Plug-in Semiconductors Plug-in Resistor Networks W SOW Amplifier- Optocouplers piers PB Electronics-Blob Electronics Blob Board Platignum-Tidy-Tubs Piatignum Tidy-Tubs

44 Philips Electrical Clock Electrical-Clock Radio AS Language Trainer AAC Plessey C's Plessey-C's SL664 SL665 Sl Plustronics Music Plustronics-Music Centre CTA Aiko Stereo Cassette Recorder ATP Precision nst, nst. Labs Signal labs-signal njector Rastra Electronics Logic Electronics-logic Test Probe Waveform Generator C CL8038 Cl Audio Power Modules S1010/20/50 0/20/ Rawlplug-25W Rawlplug 25W Soldering ron Rhopoint Klip-Blok Rhopoint-Klip-Blok Patchboards 909 RTVC Disco RTVC-Disco Amplifiers 55 SGS-ATES Voltage SGS-ATES-Voltage Regulator L200 '" 54 Sinclair Radionics Digital Radionics-Digital Clock Microquartz 514 Digital Multimeter PDM SST Distributors Philips Distributors-Philips. Electronic Kits Tangent Electronics Universal Electronics-Universal (Mains) Con- trol Module Tempus-Casio Tempus^ Casio Digital Clocks/Calculators Tye Security Lightsticks Security-Lightsticks 210 Vessco Vision Nordemende Vision-Nordemende 'Globetrotter' Verospeed Service Etching Service-Etching Kit-Audio Warn- ing Device 284 Walmore Electronics C Electronics-C Test Clip 349 Miniature Miniatur,e Crystals Watford Electronics Stereo Electronics-St,ereo Cassette' Deck TCD MSCELLANEOUS A Mere 20 Years (since Sputnik 1) by R. Ham 594 Binders for PW ,. 848 Cover Price ncrease Note ncrease-note CQ-CQ-CQ CO-CO-CO readers ads. 222 Early Wireless Collection by R. Ham Letters letters to the Editor... 56, 200 Lionel Howes G3AYA Note G3AYA-Note.. ' 258 News News News News-News-News , 103, 180, 258, 333, 407, 485, 565,651, 651, 731,812, 891 Obituary Frank Obituary-Frank Hennig G3GSW by R. Ham 433 Potential Bread writing Bre'ad-writing for PW 690 PW Back Numbers 181 Readers PCB Service 25, 131, 190, 287,362, 415, 611, 511, 593, 658, 739, 825, 904, Reporting BBC's 500th World Radio Club by R. Ham RNARS Morse Proficiency Transmissions 222 'Special Offer" Offer' a la 1933! 494 SUPPLEMENTS ETC Component Source Directory... November 1977 Guide To Aerials March 1978 ndex to Volume 52, May 1976 to April 1977 May 1977 nformation Card,-Semiconductor 1 Semiconductor Character- istics... May 1977 SHOW REPORTS High Fidelity "77 '77 by R. Schofield RSGB Convention '77 by R. Ham The Paris Show by D. Gibson Special Offer Soldering ron Kits 569 Gift Pocket Magnifier... October 1977 LEADERS A Logical logical Step?,, 650 LST OF AUTHORS A Time Of Change 730 Allenden M. Lamb lamb S. Band-Switch Baiiey Bailey T. 1. Lang langton A. Calling All Constructors Bell D. Longden R. A. H. Comment mpossible! Bond P. Macaulay J. P.! Spy! 406 Bond W. Q3XGP G3XGP McCoy K. GW8CMY Morse Code The Code-The PW Way Canning F. G. Molloy C. G88US G8BUS Our Face-lift Cooper A. Mooney W. G3VZU Perseverance Perse-verance Coutts D. S. Opel W. Something For Nothing Dance M. MSc Parr E. A. You Lucky lucky People! 20 Davies S. Parsons S. C. Dowdeswell E. Q4AR G4AR Penfold R. A. A. Edwards D. J. Pleass W. BA BSc AMEE Gibson D. G3JDG Rayer F, F. G. G30QR G30GR Grayson C. BSc Schofield R. Ham R. FRAS BRS15744 Sharpe- A. BOOK REVEWS/NEW BOOKS Harvey B. Sjogren G. O. H. Practical ntroduction to Digital Cs D. Cs-- D. W. Helsby N. C, C. MEE Soar R. A. N. Easteriing Easterling 593 Hickman. Thornton-Lawrence J. Electronics Fault Diagnosis. Diagnosis-. R. Sinclair Hughes M. J. MA C.Eng T.Eng (CE) FSERT How to Build Advanced SW Receivers R. Receivers-A. A. MERE GW3JGA Penfold Pe-nfold 759 Jones D.. Toms C. BSc Modern Electronics Made Simple G. Simple-G. H. Olsen 778 Jones D. L. Tooley M. BA G8GKT G8CKT The Radio, TV and Audio Technical Reference Judd F. C. G2BCX Whitaker R. Book S. Book-S. W, W. Amos 432 King D. H. E. G3TQN G3TON Wiilcox Willcox A. 42 Practical Wireless, June 1978

45 SATTLEGAME battue game a piece of tinplate (cocoa tin) as shown in Fig. 5 to form a box for the modulator screening, fit the sides and bottom by soldering to four Veropins as shown in the drawing but leave the top plate off until the.. Drilling Toble Table 190 A ~ _~o To suit lamp ~ _ 66 ' ( --#:- -~- _~_ S'1 l.'s. Dimensions in ram. mm. - ( ' 0 -,1 i r 125 i ' -f- T T 95, ( ( 4^ S'2 S'S Fig. 1: 1 : Front panel drilling diagram -~- --~- S'2 S'3 to! Fig. 2: Main printed circuit board connections ~ Practical Wireless, June 1978 t ~ l j unit is working and displaying a picture on the tele- tele vision screen. Carefully check the p.c.b. p,c,b, for correct assembly and freedom from inadvertent shorts such as solder VU TSRQPONKLKJ TSRQPONMlKJ HQ F ~-;~_ 0 ls A o-+-s'- O- - :}Mains o-n C ) :1 C26 Earth to 53 Front Panel r - Black Bloch i White Tank Tank (on Controls trois 1 -cr-. 1 L:"'" 1 Controls S6 S9 L E.5 ~ --1 L~ ~~ -.J AD09S1 43

46 t S FS1 T1 1N& V 1N40016 L-.>VR1 2200uF. > 9 ^ yuF 0 2^F 1 -R1 SR2 '2 2k fwh R4 4 71'1 T1 ± ~~'V CO R '1? ----V\i 10k ~ 10M CB.rt 33k ;jj(7 r~d L..?"r; O 01,uF ~ ac3a 4., C1 VP R13 R26 5 6k ~S2 R21 «VA 270 i C8 J1 1 AAA VV' R7 F 1M C9 Ra R8 11 AAA O.l)JF 0 ' 'F 'VV' 11'1 1M R '1 (13, 0 22}1F ' R14 ~ C25 fh 1000 >'R29 <R > k R25 J 1k lk ;c2 R" R27 4 7k 1(2 C2 AY R17 SRU 100 >4-7k "'tl is o -go $:l. ~ ~ :to «l «i ~ t ~ --<J 00 u Fig. 3; 3: Complex Complete circuit diagram for thi> the Bovington BOYington tank battle game FOB % V ill f pj5 Too Tank k Cct. Cd. Diagram Fig.1 C16 «C17 15pF TlOpF ~ TRl TR C208 TR2 BFY50 BFYSO TR3 8C108..CiB TR4 BSX20 D3 tod10 1N4148 NAUB LS 8 ~

47 ,+~B:OH: 6BA Hole :p '- ~ ' Dimensions in mm. Material: 16 SWG Aluminium Dimensions in mm. Material: 16 SWG Aluminium A Fig. 4: Heat sink for C1 le1 Heatsink Heats ink lcl '\... ~~ PCB X PCB~~ x rc Fig. 5: Details of modulator screen ~ bridges, set VR1 VRl fully clockwise and VR2 to midrange and fit the unit in the case with 6BA screws through the fixing holes. Wire the unit up as shown in Fig. 2. Fix two 6 pin DN sockets in the front of case connected to points G-Q G Q & S on the p.c.b. to feed the hand controllers. These sockets may be omitted and the multicore wires wire~ fed through suitable holes fitted * 34 ^ ~ " 24~ i i 13 1 off 35 r- -Top Plate -J DJ Vero 2 0,f off PCB ' *- v ^-Vero Pins -Bottom Plate Dimensions in mm, mm. Material; : Tinplate. [AOQ97 A0097J with grommets. The hand controllers can be assembled in any convenient small plastic boxes. Switch the power on, monitor the voltage VP across C4 and adjust VR1 VR to obtain volts. f you have a scope or counter fit C4, power up and adjust L Ll for 4MHz. f not, set the top of the core of L Ll approxi- approxi mately 6mm into the former. Fit the remaining inte- * components Resistors MiV/SVo All *W 5" ft 1 R19 toon loon 3 ~ R17, ft R21 ikft R20, R20. 25, kft 1'5kfl 1 R22 2-2kn 2'2kO 2 R1,24 4-7kft 4 7kfl 2 R18,27 5-6kfi 5 '6kfl 1 R26 101U1 lokft 5 RH. R11.12,14,15, , 15, 23 22kft 221U1 1 R3 33kO 33kft 1 t R13 1MO 1 Mft 3 R7, R7.8, 8,16 tg 2'2MU 2-2Mft t 1 R10 4'7MO 4-7Mft 2 R4.S R4.5 10MO lomft 4.R2, R2. 6,9a,!!a,lb 9b Capacitors Plate Ceramic S. 3-3pF 3pf 1 e23 C23 5-6pF 5 (jpf 1 C24 10pF 1 C17 15pF 1 C16 22pF 2 C21, C Disc Olsc Ceramic 1000pF MOpF 3 C20, 020,25,26 25, 26 O'01lf 0-0?/(F 1 C7 O 1J.'F O-^F 3 C8,9.18 Polyester 0-22/iF O'22/lF 2 C2,3 Tantalum Tant8!um O' 0-22fif 22/-1F 10V 3 4 7J.'F 4-7/iF 10V pF 10/<F 10V 2 l00'f 10V 1 lotyflov 1 Electrolytic 220^F 25V /iF 25V 1 Electrolytic 220,uf 25V 2200.uf 2$V cs, C5, 6,13 Cl0, CO, 11,12,14 12,14 C19,27 CS,27 C4 C4 C15 C1 Potentiometers Pot."tiomet." kn Horizontal preset 1 4'7kn Horlrontal preset t SOU Wi rewound. 1 1kO Horizontal preset 1 VR2 4' 7k!1 Horizontlll preset 1 VR1 son Wirewound. 1 VR3 Sem S.mico.nciuctot'J conductors Diodes Dioaes TN4C01 2 P, 2 1N Pl., 2 ntegrated circuits ntegrated circuits 400M 4001A 1. C3 CS 4011A A 1 C regulator [(!'Qulator 1 C1 AY -3-&110, 1 le2 Ay-3-e C2 Transistors Transist,ors BC108 1 TR3 TRa BC208 BC20B 1 TR1 BFY50 1 TR2 BSX20 1 TR4 Swit,:h Switches Pa<!dles.p,d.t. Paddle s.p.d.t. (Arrow (Am)w CPM3 Black) 2 54, S4, 5 S(Bias~d (Biased to centre ofi) off) Paddle Paddl~$ s.p.d.t.. (Arrow CPM3 White) 2 51, S7, 8 (Biased (Blase.dto centre c;e.ntreofj) of!) Push-huttpn Pus,h-buftPf s.p , S3, TO:ggle Toggie s.p.d.t S2 Toggle TO{Jgle d.p.s.t. (Mains) {Mains) 1. 1 S Sl Miscellaneous Transformer 12V, 12y, 12V2SOmA 250mA MTiafMarshall's) MT12.(MarshaU's) loudspeaker Lousispeaker 2* 2inch fnc/,! 8ft ld. Case RS Type '608 Hand control boxes (2) RS R5 Type ' mA fuse fuse and holder Miniature multicore cable {9-way) (9-way) 4metre9 4nwtres Miniature mains cable.,. ndicator tamp lamp 12V t2v ' ~ Knob for vojljmecontrol volume 6-way OfN DN plug and sqck,et socket (2) Optional tb.r (Or hand control confrol leads.. TOS T05 heat sink Co-axial Co-axlat TV$Qc! socket surface mounting type. 28-way d.l.l. d.i.l.. socket sock!jt (1). 14.WilY 14-way d.u. socket (2) Practical Wireless, June

48 a ill : Si ' i* ~. View of the internal con- con struction of the main p.c.b. p.c.b. and case > ^ M Fig. 6: Printed circuit board copper track pat- pat tern. Ready drilled boards are available from Readers PCS pea Ser Ser- vices (see page 68) T... r--ow 0 mmsm ta o PC Magazines Ltd. R o 46 PracUcal Practical Wireless, Wzreiess, June 1978

49 RM [) Cl C4 ---()±-- o C12 78 ~ ~1] R6 Link H ~ als l nk Cl Lnk ~ ~j :"' 1 ~ 102 CS C6 : Unk : Fig. 7: Main printed circuit board component placement drawing To LED To LEDl + ~~~~:, D2~' mains nput via51 inpu - ViaSl{~ E. ~arlh to TS T 5 R Q F front fronl panel ToSKl Tl 0 C27 C20 Scr ~ ~n. Cl4 o Cf ~ l2 R ~ i ~ T~2J Ml! ~~21~ ~ 11 t 4 H t ToVR3 To, - s TS R Q F front panel M To SK i ] o Bl grated circuits, connect to the aerial input of the tele- tele vision and switch on. Push the reset button, release it and tune the television until a signal from the games unit is found. Several signals may be found, if so choose the best one. L Ll may need to be slightly adjusted. When a good picture has been obtained adjust VR2 for the optimum picture, and fit the top cover to the modulator. Check that all the switches function as required and fit the front panel. Fault Finding Fault Finding f the unit fails to function check all your con- con struction carefully, then:- then: 1. Check that the voltage across C4 is volts. 2. Vary VP over the range 6 to 7 volts by means of VR, VR1, if this does not help reset it to volts. C2 Pin Functions, 1 Ground , 3, B, 18.27, 28 Video outputs 4, 5, 6, 7, 7. 8, , Control inputs 10.Reset ' 16 VP (+6'5V) 19-4MHz 4MH2 clock input 20,21, ; 2 23,,~ 25, 5.26 Sound output 22 Tank trap select 11,12,13,14,15,17 Do not connect Practical Wireless, June Check with a scope that pin 19 of C2 has a 4MHz clock input and pin 16 is at volts. 4. Check that composite sync is appearing at C2 pin 18, pushing and releasing the reset. S. 5. Check for composite video at TRS TR3 base and again at VR2 wiper. f it is appearing at VR2 wiper try again to tune the television to the game signal. f you still cannot get a picture, substitute a new transistor for TR4. 6. f the tanks only go forward under control of the switches you will probably find that one pair of wires to the switches are crossed. Four Players Extra excitement and skill can be introduced into the game by splitting the tank controls between four players, two to each tank. The steering controls are operated by tihe tlhe "drivers" while the tank commanders have control of the firing buttons. The modifications needed to make this a four- four player game are very simple,especially especially if DN plugs and sockets are used for connecting the control boxes to the main unit. The commander's firing control can be fitted into a simple box wired into the DN plug. f a duplicate set of controls is not desirable then a permanently fitted "commander's" control can be wired into the game unit with a switch arranged to select either the firing button on the "driver's" box or the button on the "commander's" box. 0 47

50 PllftltlJf;rl'ftN PKOUJ 1 ~N~S LM K ^ir J nm alao marlin elanmertii) PsssK Pusl wanna watch? walch1 When l.e.d. Le.d. and l.c.d. Lc.d. watches first came onto the British market, they cost between 50 and 100 and any available in the 20 range were either advertised on 'Police Five' or came off the back of that proverbial lorry. loity. We are informed by W.K.F, W.K.F. Elec- Elec tronics, that they have a selection of watches available at very reasonable prices. First, an l.e.d. Le.d. watch (left in photo- photo graph) that features a rather novel touch sensitive operating pad to dis- dis play hours and minutes, seconds, day and date, also day and month. Price plus VAT. Second, the standard i.c.d. Lc.d. watch (centre in photograph), which dis- dis plays hours and minutes continuously, press the button for day and month, press again for seconds. The watch also has a separate back-light tone.ion. func.ion. Price Pri<:e '50 plus VAT. Finally the chronograph l.c.d. Lc.d. watch (right in photograph) whilst posses- posses sing the standard watch functions of hours, minutes, seconds, day, date and month, also teatures features a lap and continuous stop watch facility, with timing to 100th of a second. Price '95 plus VAT. All the watches are supplied with an adjustable stairless stainless steel bracelet and the two l.c.d..c.d. watches are powered by batteries costing only 42p (retail) with an estimated life fife of twelve months. W.K.F. Electronics, Fleet.House, Wel- Wel beck Street, Whitwell, Workshop,Notts. Tel: No lick TAC-1 TAC The Polycal TAC-1 T s is a pocket size, liquid crystal display, travel alarm clock. Measuring 65mm x 32mm x 11'5mm, ll-smm, it weighs only 45g with batteries. The 3V d.c. power input is provided by two silver oxide or manganese alkaline batteries (type GS-14, A-76 or equivalent). Power consumption is 3mW max. (with (wi~h the alarm sounding). Accuracy is claimed to be ±30 seconds per month at 20'C 20 C (68 F). With a separate back- back light, the multi-digit liquid crystal displays hours, minutes, clock-working sign and am/pm indication. Priced at 22-50, 22'50, which includes VAT V and p & p. p, the TAC-1 T is available from: Tempus, Tempos, Dept. P. W., 19/ Fltzroy Fitzroy Street, Cambridge CB1 1EH. Tel: Vero Vel'o interesting inlel'esllng Vero Electronics Ltd. introduce a new range of cases with their 'Series 11 Boxes AB 010'. These boxes are moulded in light grey high-impact polystyrene in two parts. The anodised aluminium front panel supplied with the box s is re- re tained between the two halves, avoid- avoid ing the need for fixing screws. Slots and bosses are moulded into the interior of the box, so that a choice of mounting positions, either horizon- horizon tal or vertical, is available for p.c.b.'s v V- or component decks. Many of the boxes have a battery compartment which whiclj s is accessible without dismantling the box. The standard range consists of fifteen boxes varying from 110mm X x 68mm X x 33mm to 190mm X x 138mm x 91mm, and other sizes are available to special order at a minimum quan- quan tity of 100. Further details from: Vero Elec- Elec tronics Ltd., ndustrial Estate, Chandler's Ford, Easlleigh, East/eigh, Hampshire SOS S05 3ZR. Tel: Rechugeable Rechargeable ron il'on A new version of the Engel B.50 Re- Re chargeable Soldering ron is now available from Kelgray Products Ltd. and is complete with charger unit. The iron now ncorporates incorporates a built-in spot- spot light to illuminate the working area and uses long-life rechargeable nickel- nickel cadmium batteries. Providing up to 100 intermittent operations (300 continu- continu ous use) without recharging, which can be achieved in a about 8 hours (over- (over charging is impossible). A safety switch is fitted to the trigger-switch to prevent accidental operation. The ron iron heats up to an operating temperature of approx 350 C o C in about 7 seconds; a variety of bits are available. Designed for recharging from a.c. mains, the B50 comes complete with cleaning pad, protective cover, 2 lighting fittings and screwdriver. A particular advantage of this iron is that no stray eddy currents which might damage a sensitive i.e. i.c. are generated when the iron is being used. Priced at '50 which includes pip p&p and VAT, the B50 is obtainable from: Kelgray Products Ltd., Kelgray House, Sandy Lane, Crawley Down, West kvesf Sussex RH10 4HS. Tel: Practical Wireless, June 1978

51 SimPLE DR HRoom TimER SimPLG TimER A.R A.P. DONLEAVY This article describes a simple timer which switches an enlarger on and off for predetermined periods. The instrument can handle exposures up to 32 seconds although this can be easily increased as will be des- des cribed. The accuracy is better than 10% which is adequate for black and white printing. The instrument uses a switch which enables the exposure time to be set by feel rather than by having to Co peer at some dimly lit switch setting. seco Of Circuit The circuit is shown in Fig. 2. The 555 i.e. i.c. is connected as a monostable multivibrator and on application applicat~on of a negative pulse to pin 2 a positive pulse emerges at pin 3. The duration of this pulse is determined by the R-C values of R1 R to R8 and Cl, and also by the voltage on pin 5-5. This pulse is applied to the gate of the s.c.r. which causes it to conduct for the duration of the pulse. The s.c.r. is essentially being used as a mains switch. f the mains were applied directly to the s.c.r. it would only conduct on the positive-going part of the cycle and the light would only have about one third of its normal intensity. A bridge rectifier is used to rectify the mains supply and thus overcomes this problem. SW2 applies the pulse to start the timing. Pin 2 is tied to Vcc V via R9 to prevent unwanted triggering. Application of a negative pulse via SW1 SWl will prema- prema turely terminate any timing interval. The length of the timing pulse is proportional to the value of the resistance at pins 6 and 7. The values R El to R8 are chosen to give sequence times of 2, 4, 6, 8, 12, 16, 24 and 32 seconds, within 10% but the values can be altered to suit the needs of Of the in- in dividual constructor. Every 27kn 27kU added to the resistor chain will give an extra two seconds time. Hence if a 48 second timing period is required, an extra 8 x 27kQ 27kn or 216kfl 216kn resistor would be needed to be added in series with R1 R to R8. n practice a 220kft 220kn resistor would suffice. The final calibration is made by adjusting VR1. VRl. The unit should consume no more than 8mA, BmA, so the power supply uses a miniature mains transformer, with a full wave rectifying circuit. The timer s is built nto into a smalt small instrument case with all the controls on the front panel Components Any 555 timer i.e. i.c. can be used, e.g. LM555, SN72555 NE555, and any s.c.r. and bridge rectifier that can handle at least 400V at 500mA can be used for SCR1 SCR and Dl. SW3 is made up from a Doram Mini-Maka switch. The minimum requirement is one pole eight way. The prototype had an open position at one end of the scale, which gives a timing pulse of almost indefinite length. This is used for leaving the enlarger perman- perman ently switched on. The mains transformer need only be capable of supplying between 6V and 15V at 50mA SOmA at the secondary. Construction The unit is built on a printed circuit board 105mm x 57mm. The layout of the copper tracks is shown in Fig. 4 and the component layout in Fig. 3. The unit is housed in a metal instrument case and to complete the front panel a PW overlay is available. The p.c.b. is supported by two short 4BA screws with a nut between the board and case bottom. Remember that some of the copper tracks carry live Practical Wireless, June

52 1 li y i> off. 2.4 stop * m 16 20",6 12 KROOM TMER DARKROOM TMER.. i Front panel layout of the darkroom timer. timer, A trans trans- parent overlay is available from the PW Editorial Offices which will enable readers to achieve a pro- pro fessional finish to their equipment. The overlay is cut out and placed over the front panel, being held in place by the switch nuts and washers. A coloured background can be used behind the overlay if desired... ^nside view of the complete unit showing the posi- posi tioning ofthe transformer, p.c.b. and switch Fig. 1: Pin connections for the 555 timer i.e. i.c. and the C106D C106O thyristor > _. j i Ground GrouM' C! 8 B ~ J V(t Vcc Trigger 2 7 l ' 1 Dischorgi- Oischargi. Outpiir OutpUt C 3 6[) 6,. Threshold' nreshpi4.1.!.cathode (obode Reset C k sh :i Control Voltage Viii tag~ 2, Anode Anodll L-_ --.c.> 3. Gate Gale '555 Timer C1060 C 106P Thyristor TnyristCit * components com Resistors Resistors AlliW2% kw,r RT 27<J 27k!l R2 27kS2 27kU R3 Ra 27M R4 27kS! 27W RS R5 56kn 56kO Polenfiomefers R6 R7 R8 R9 R10 Potentiometers VR1 VRl CkO 10kn min. horizontal skeleton Capacitors. C Cl 47pF 16V lay C2 toopf 100pF 16V t6v Semiconductors R6 56kO R7 120kU R8 lookll R9 4'7kn R10 68kit 56kD 120kO 100kn 4'7kil 68k1l Semiconductors Gl Cl 555 timer limer SCRt SCRl TiC T.C CED 1060 or similar 4tlOV 400V working >ladling Dl, 01, D2 02 1A 1 Abridge, bridge.rectifier r"ctifier 400V 400Y working Miscellaneous NHscellaneous Transformer '3 0 3V 3-0-3V t'2va l Sub-miniature Slb.tnirria'ture SW3 swa 1 pole 12 way miniature it\iniiltl.lre wafer switch switch ' SW4 Mains switch to fblil fit "SW3 S'Vy3 mechanlem mech~nism SW1 and 2 Miniature MrHttture push-button j)ush~button ' push, to make. Larrip Lamp output output plug pl49 and ajid socket socket (RS (R$ components Components ,4tjil-ti67 and ' ). Fuse'and 'andqolder'2a holder..printed circuit board boatd Reaper's Rea~;er;olt>CB RGB Services Sef~ ip~s,.case RS components, compojients, l5, Knob Smm 15inm Sifam'WlS Sjfa(ll ' W15 " coliet coli~t fixing fxing with nut cover.:over arid'.cap illidj;ap ", PW pw Front Panei Overlay " 50 Practical Wireless. Wireless, June 1978

53 F1 ~:.-cr--o--... Mains i ~>---ooo6---- SW4 r----'" 1^ D1 ^ '" +. +H~""'-" BZ 02 Enlarger Lamp a LP1 c SCR1 R9 4 7k 8 Vfil VR1 5 10k C1 RO R V V V 68k Fig. 2: Circuit diagram of the darkroom timer <R5 >27k 1 R2 R3 Off r Z7k" 27k fib R8 R7 vw-»-vw 100k 120k 100k 120k R4 27k RS 56k R6 56k Fig. 3: Component layout diagram. Care must be taken to avoid solder bridges or other forms of short circuits between tracks or components as mains voltages appear ~ppear at several points on the board. A piece of self adhesive plastic sheet should be placed on the metal base of the case underneath the p.c.b. to avoid any possibility of component leads shorting shortlng to chassis Fig. 4: Copper track pattern for the darkroom timer p.c.b. Ready drilled drlrled boards are available from Reader's PCB Service, Service. (see page 68) To instrument case frame To nstrument case frame f.- ---===="'"i'. SKT1 SKTl earlh earth R1/SW3-+"" ~!l-... -Mains earth 1({'.))J:f f-Malns earth Tl screen PCMassilnes A R011 tb70 W T13V_--+---(e) -SW3/wlper...:..~~-_+.SW3/wlper o \.V c a m Cl 1 SW ,.. SW2 T SW1 P! Q o Toenlargerl To enlarger lamp via SKTU llampviashl lamp SKTl TlOV TA)V T11240V T1/240V V^l mains voltages and that these should be kept well the wafer switch. Resistors R R1 to R8 are soldered clear of the supporting bolts. directly on SW3. SW3- A shielded miniature mains plug and socket are used to connect the enlarger lamp to the unit and Switch to the maximum time period of seconds, this is fitted into the back of the case. f desired the then depress SW2 and measure the period. Adjust fuse can be a panel mounting type and also fitted VR VR1 until a 32 second period is obtained and your into the back. back, A mains switch is fitted to the end of darkroom Hsrlrrnnm is calibrated. A Practical Wireless, June

54 wald_ che So you want to pass the R.A. E.(Radio Amateurs'lxamination)1 E.lBailin Amateups'tnamiiwiinnJ * John Thornton Lawrence GW3JGA & Ken McCoy GW8CMY Here is the final section of this series and this month we are too consider aerials, feeders, matching and also interference. At the conclusion, we give some hints on actually sitting the examination, examination. AERiALS, AERALS, TRANSMSSON LNES AND MATCHNG The subject of aerials is a complex one and in the space available we will be confining our attention to basic essentials. For further information please refer to the appropriate section in the RSGB Radio Com- Com munication Handbook or the Radio Amateurs' Exami- Exami nation Manual. The fundamental aerial is a length of 'Of wire which is half a wavelength long; this is known kn'own as the half-wave dipole and is shown in Fig. 85. The aerial is said to be resonant at a specific frequency which is determined by its length, and the distribution of voltage and current along the wire is known as standing waves. The ratio of voltage to current varies along the conductor, but at the centre of 'Of a resonant half-wave dipole it givfes gives a convenient impedance of approxi- approxi mately 70 ohms. f the aerial is broken here, the r.f. power can he be fed into the dipole at its resonant point. v i ==~,.. L Hali Hoif-wav«Ungth - wavelength,=== Feed Point mpedance Apprtw. 70 Ohms Feed Point mpedance Approx. 70 'Ohms Radiation Pattern Plan View Radiation Pattern Plan View Full- - wavelength Feed Point mpedance Approx Ohm* Feed Point mpedance Approx 'Ohms Half-wave Dipote Dipole Fuil-wave Full-wave Dipole Fig. 85; 85: Dipole characteristics 52 The full-wave resonant aerial has, as might be expected, a standing-wave pattern similar to two half- half wave aerials joined end-to-end. end-ta-end. The centre impedance in this instance is very high; inconveniently so in fact and special matching arrangements are called for, as we shall see later. The radiation pattern of a half-wave dipole is in the form of a "doughnut" shape which in section becomes the characteristic figure "8" shape, as shown sh'own in Fig. 85. With a full-wave resonant aerial, the radiation patterns of the two half-wave sections affect one another, producing the four-lobe fqur-obe shape shown. Dipole Length The length of a haif-wavelength half-wavelength in free space is given by: 300 x L = metres Frequency (MHz) However in practical application, due to (a) capaci- capacitanoe tance effects at the ends, (b) the velocity of the radio radiq wave being slower in the wire than in free space and (c) the effect of the wire diameter, it has been found that the actual aerial dimensions are about 5 per cent shorter than the calculated free-space length. (Free- (Free space length x 0-95.) 0. For example, the length of a practical, resonant, half-wave dipole for fqr 3-6MHz 3 would be given by: L = 300 x x = = metres MHz 3 6 The Vertical Aerial (Quarter wave )./4) A/4) When looking at the radiation radiatiqn characteristics of a quarter-wave vertical aerial, it is necessary to take into consideration the reflective properties of "f the ground. f we consider the ground as a mirror to the radiation from an aerial, it will be seen that the vertical aerial AB, in Fig, Fig. 86 has an image BC in the ground mirror (just as in optics). Thus, radiation leaving the aerial from point D will travel by two paths in the direction E; E: one direct from D and the other from the ground reflection. (The position F is a mirror-image of the aerial in the ground). The radiation pattern is similar to the half- half wave dipole but being in the vertical v,ertical plane it is omni- omni directional in the horizontal or plan view. Vertical aerials fitted on the roofs ro'ofs of vehicles for v.h.f. and u.h.f. utilise the excellent excelent reflective proper- pr'oper ties of the metal as ground. Directional Aerials The pattern and direction of the maximum radia- radia tion of an aerial can be modified by the addition of extra elements, which may be driven by feeding Practical Wireless, June 1978

55 F«ed mp»danc» Vary Low i E 11 ((mage' mags Fig. 86: The ^-wave i-wave verticai vertical aerial E Good Low-Angl» Low-Angle Radiation power to them or parasitic, where no direct electrical connection, is made. The "Yagi" array shown in Fig. 87 has a half-wave dipole with parasitic director and reflector elements. The lengths and spacings are chosen to give increased "gain" in the forward direction and reduced gain in the reverse rev erse direction (as compared with a plain dipole) '1 0 ' 15 X X 1:.1.. ). ~ Pv Good -'^Radiation Rod ia! ion \Patt»rn / One of the consequences of adding parasitic elements.eements is that the dipole impedance becomes incon- inoon veniently low (about (aoout 20 ohms) and to overcome this a folded dipole is often used. This has the effect of transforming transfo,rming the impedance up by a factor of four to give giv'e a value v:alue of around 80 ohms. Transmission Lines and Feeders The source of r.f. power is quite often not the place of utilisation. For convenience we need to have the transmitter indoors, but the aerial has to be outside, as high and far away from buildings as possible. n some instances it may be possible to bring the aerial directly to the transmitter but in most cases a transmission line or feeder cable is required. mpedance Matching For maximum power transfer from one circuit to another the input impedance of the circuit receiving power must equal the output impedance of the circuit delivering it. The output impedance of a valve-type transmitter final amplifier is in the order of a few thousand ohms and a transistorised version would present about five ohms or less. The aerial impedance required can therefore vary between about twenty ohms and several thousand ohms, depending on the type and the point of connection. The impedance of the transmission line or coaxial feed cable connecting the transmitter to the aerial is defined by its physical construction. Usual values for coaxial cables are 50 or 75 ohms and for twin transmission lines, 70 to 600 ohms, depending on the method of manufacture. Some form of matching arrangement is therefore required between the various sections of the system whi,ch which convey r.f. power from transmitter output stage to aerial. A typical example is shown in Fig. 88. There are three basic types of lines or feeders. (a) Single wire feeder (which carries a true travelling wave.) (b) Coaxial feeder. (c) Parallel wire line. Maximum. Gain Maximum_ Gain ~ ^ i."",.,-'" ~ Approx. ApprOX. ~Ohms 200hms Oirtclar f y < i Dipole~ Rellector 2 Oipola R«!l ctor 2 >.. X 3-Element 3-ElBm»nf Yagi >- 2 Oi Approxima!# Radiation Patforn Approximate Radiation Pattern ~ ~ " Mn'rhmo Trnnsmissian Lint or Feeder Matching Transmitter -"J Network 3 Network Aerial Mt - Be ncluded Hay Be ncluded in. ansmitter. in Aerial Configuration. Dielectric /' Mediuin Appro 80Chns 3-Element 3-E!»m«nt Yagi with F'olded Folded Dipole Coaxial feeder Parallel Open-wire Feeder Coaxial Feeder Parallel 0p.en-wire Feeder Distributed T' Distributed 'C nnnfrrririrnnrrw TTTTTTTT^' o o ooinn Transmission Line Model Transm ission Line Model. Fig. 87: Simple directional aerial arrays Practical Wireless, June 1978 Fig. 88: Transmission lines 53

56 Single feeders (a) are not commonly used because they rend tend to act as ' radiators themselves. n the coaxial type (b) <b) the r.f. field is restricted to the inside of the structure, whilst in parallel wires the field is confined to the immediate vicinity of the conductors. Characteristic Characferistic mpedance (Zo) 0 ) A transmission line or feeder may be considered as oonsisting consisting of a distributed inductance with asso asso- ciated distributed capacitance, as shown in Fig. 88. lt t is the relative value of inductance and capacitance which gives the transmission line a property known as characteristic impedance (Zo). When a transmission line is connected to, or terminated with, a pure resis- resis tance which is equal to the characteristic impedance, a current travelling along it does not see any change in conditions when it meets the load. n other words, a short transmission line terminated in a purely resis- resis tive load equal to the characteristic impedance of O'f the line, acts as though it were of infinite length. Such a line is said to' be matched, and here power travels outwards from the r.f. source so'urce until it reaches r,eaches the load, where it is completely absorbed. Let us look l~ok at what happens if the transmission line is terminated t'erminated by its characteristic chara teristic impedance and then by an impedance other than Zq.This Zoo is shown diagraraatically diagramatically in Fig. 89. Where the line is terminated in its characteristic impedance (Zo) 0 ) the voltage or current will have the same value at any point p(}int along it. (a) f however it is terminated with (b) an open circuit or (c) a short circuit, then standing waves are produced along the feeder as shown. This is because the power is not being absorbed at the end of the line but is being reflected: the reflected reflect,ed wave adds to the incom- incom ing wave and produces a standing-wave pattern along the line. These Thes e examples are extreme cases, but any mismatch produces a resultant standing-wave pattern. patrem. 54 >-. }., 4 "2 T 0 r-~1----~ ~1~---- ' ~ i zo~:rtf;~t or V (a) L r-~----~ ~------o Open Circuit l ~---'-----'-l tsksps±?sl _0 i i i i o. (bl (b) i ^ J _-l.!? _ Short Circuit _L -~ 1 " J- - r1. 1 "-\~ E( i i Sh", Ci~";' ~~ lc) Note!-Amplitude :'Amplltude Only is S Shown.Potarily. Polarity is Disregorded is Disregarded (c) 0 Fig. 89: Transmission lire line terminations 02 OA9l ~m From ~d Transmitter T"Ml=te=r ===::::,::,,:::=========~ J:_~-1-n-F --s-en-s-it-iv-it~yjl~ ~ Fig. 90: A simple standing wave ratio meter AD10s1 The ratio -of the maximum value of the standing-wave to the minimum is known as the standiug-wave standing-wave ratio (s.w.r.). Values ValUJes will vary from unity {matched (matched con- con dition) to infinity (complete mis-termination). Standing Wave Ratio Meter A useful device for looking at the s.w.r. S.w.r. in a coaxial feeder cable is shown in Fig. 90. Loops of O'f wire, (a) and (b), sample forward and reverse power passing through the centre conductor (c). The voltages developed in the coupling loops are rectified by D1 Dl and D2 and the resulting d.c. output deflects the meter Ml, M1, thereby giving an indication of the forward and reverse (reflected) (re.flected) power. The s.w.r. meter is particularly useful when making adjustments to aerial matching and tuning. Construc- Construc tional details for a v.h.f. unit were carried in the May 1978 issue of PW. Matching Forw'd Fopwd Refd "5? _ Sensitivity Most transmitter and aerial matching circuits are of the resonant type and ane tuned tun.ed to the operating frequency. We have already described the "Pi" match- match ing network for a valve output stage (PW March 1978, p. 821), shown again in Fig. 91(a): an "L" type network for transistorised output stages is shown in Fig. 91(b). This configuration allows for more con- convenient Vienient component values when working at the low output impedances encountered. n both circuits the impedance transformation is adjusted by the relative capacitances of C1 Cl and C2, whilst maintaining resonance at the operating fre- fre quency. t is usual in this instance instanoe to arrange for the transmitter network to provide an output impedance which matches the characteristic impedance of a readily available type of coaxial cable, e.g. 50 ohms or 75 ohms. When the coaxial cable is operated with a low s.w.r.,., losses within it are also low, so it is very convenient to fit any filters necessary here. Some aerials, such as the dipoie, dipole, have a charac- charac teristic impedance at the feed point which will match directly the characteristic impedance of the feeder cable and an aerial matching network is therefore unnecessary. However, if a symmetrical or balanced aerial such as the dipoie dipole is fed by coaxial cable, a Practical Wireless,. June 1978

57 f:w L f"'lzoof Transmission.. ' Lino. «g. g. 50/7Sn 50/75/\ "= -= -=--= Transmission Tr.ansmisslon Lin line eg e.g. 1Z00f 50/ /75/\ - - (b)'l'matching ' NBtwork Network jados Fig. 91: : Transmitter output matching networks state of Qf imbalance will exist, because one Qne arm of Qf the dipole is connected cdnnected to' the centre conductor whilst the other Qther is connected cdnnected to' the outer shield. The currents flowing in the shield cannot canndt be cancelled by those th{lse in the centre oentre conductor cdnductd,r which it surrounds. surrqunds. Balance to mbalance Transformer (Balun) (Balun) Diagrams of balun transformers are shown sh{lwn in Fig. 92. n (a) a quarter-wavelength q coaxial sleeve sur- sur rounds the coaxial cable and in (b) a quarter-wave- quarter-wave length of Df rod, rqd, forming fdrming a "stub", balances the output Qutput to the aerial. For FQr low DW frequencies, f1equendes, it is more mqre con- CDn venient to' wind the balun transformer transfqrmer on Qn a ferrite ring. This type is less frequency-conscious frequency-consciqus and may be used over a wide range. ~ D.C.Blockmg Capacitor L ).. lal la) P TT) Tt) Matching Network - " 2 2 "7 MetQ.-). Tube "4 U Q) (o) Balun (oaxial Feeder Balanced Output to Dipole -Ferrite-^ Ring ~ Balanced Output _ to Dipole Coaxial nput CooKiol Feeder (oaxial Feeder (oaxial nput '1./ Wound Balun Fig. 92: Balun transformers Zo of. Tronsmissioa ). Zo of b) (bl Balun ---.t - Elecfricully Connected fo Outer Shield Number pf for Clarity Turns Reduced for (arity Quarter Wave Transformer Quarter Wave Transformer Where it is is necessary to transform transfdrm an aerial im- im pedance to match a particular feeder cable, use can be made of a quarter wave "stub" as shown sh{lwn in Fig. 93. Here, a full-wave aerial is to' be fed in the centre (where the impedance is around 5,000 ohms) Qhms) with twin feeder whose characteristic impedance is 72 ohms. Dhms. f the quarter-wave stub is made to have the correct CDrrect characteristic impedance then the aerial impedance is transformed down ddwn by the stub to t{l match that of the feeder. Zm raatcmng ( matching atuw st ub ) =..; Zaerial X ZUnp = v/5000 ";5000 x 72 =600 ohms (An open-wire Qpen-wire line of 16 s.w.g. conductors cqnductqrs spaoea space.a 112mm H'zin) (4 1 2in) apart would have a Zo of 600 ohms). ~"~------) ~ Full-wave- FUt-wa:~ ---=---=--i Aerial 600n 600/\ Open Wire X ), Feeder ' X 14 nsuloted Spreader^ ' KC L S.WQ. f 11 > i Wire \ xl nterference f-72/\ 72n Twin Feeder J Lot of Any Any Length Length Practica~ Practical Wireless, June n Fig. 93: A -wave k-wave traosforme transtorm~ Non-interference NDn-interference with other radio radio' users, whether they be military, commercial, cqmmercial, amateur or Dr domestic, is a conditiqn condition Qf of the Licence. An understanding of the way in which interference is caused and how hqw it can be avoided avqided Qr or cured is needed, ndt not Qnly only for the RAE, but later Qn, on, when YDU you obtain your yo'ur licence; you will then be in a positiqn position to maintain a good clean transmissiqn transmission and live in peace with yqur your neighbours (and the HDme Home Office nspectdr). tor). nspec- NO' No practical transmitter is abs{)lutely absolutely perfect and in additidn addition to' its CQrrect correct {lutput, output, is bo'und bound to' radiate SQme some spuriqus spurious signals, hqwever however small. f these are nqt not kept to' a ",ery very low level, interf.erence interference with receivers (TV Qr or radio) Qperating operating nearby may result. Similarly, no' no practical receiver is absdlutely absolutely per per- fect, so' so when it is tuned to' a particular frequency it may be subject ed subjected t{l to interf,erence interference by strqng strong signals Dn on Qther other frequencies, as may be the case if it is situated in dose close prqximity proximity to' a radio' radio transmitter. nterference can also' also be caused to' audio' audio systems, etc., when subjected to'- strong rj. r.f. fields. Here, the signal enters the equipment and is then rectified Qr or amplitude demddulated, demodulated, usually by the emitter-base junctiqn junction Qf of a transistqr transistor in the audio' audio pre-amplifier stages, resulting in breakthrough. An increasing number Qf of hi-fi systems emplqying employing transistqrs transistors are prdne prone to interference of this nature.

58 R.F.Choke R.f Choke R.F.Choke L~L L L 0 ol LL:TL ~"nf /~ E 11r-... disc ~' ihi i/~~;--i.,./ cer. '.,. mb N~N )N N ~N (al All Capacitors 750V wkg Mains Supply Filters D.e. Supply Al! Copacitors 7S0V wkj!nf Feed-thru R.F.ChO~ R.FChok (bl L >, ~L > *'n~,s:\s>s\s',s'~:s:'$', ~.. ~11'nF ~ r, L Ferrite Rod N - -' Ferrite Rod '...l N Mains Supply Filters Typelbl Using Ferrite Rod nf ~Transmitter ~DiSC cer. Type (bl Using Ferrite Rod -Transmitter Disc cer. [" -Screen 0C,Supply- r-screen D.C.Supply D.C. Supply Filler D.C. Supply Filter Fig. 94: Power supply filters Supplies Transmitter Transmitter )------With Matching Unit Feed-thro Capacitor Harmonic Trap Harmonic Trap VRF V.H.F. Band-Pass Filter Filter for V.HF Transmitter ~':'~:;tt.. TV, BC, AND D AF nterference can usually be separated into three main categories: television (t.v,i,), (t.v.i,), radio' radio broadcast (b.c.i.), and audio (aj,i.). (a.f.i.). Television and radio broadcasting" are "protected" services and the Post Office may be called upon to investigate cases of interference with these and other authorised transmissions. Audio amplifiers, on the other hand, are not intended to be radio receivers and so will not be afforded the same facilities, facilities. n general, all interference results either from deficiencies in the transmitter or the apparatus being interfered with, with. Let us look initially at the trans trans- mitting end. DEFCENCES AT THE TRANSMTTER Design and Construction Tm_ t JR, Transmission ag144-u5 MM? S.W.R. Meter S.W.R. Meter MH, f -tq:r ttit---. r:- "--A--'--- erial -----'! r - --Tuning Unit Untt T i ~ ~ Filter Design and Construction t is important that the various r.f. signals present within the transmitter arre are not allowed to radiate directly. Efficient screening is essential, as is the filtering of h.t. and other power supplies, particularly the mains input. A suitable mains filter is shown in Fig. 94. Decoupling and bypass capacitors should be of mica or ceramic, having low inductance properties. (See section on capacitors.) Wiring should be short and direct to minimise stray inductance and capaci- capaci tance. Filler V.HF. Band-Pass -or- H.F. H.f low-pass Low-Pass, Aerial Switch 1 1 L 1.: Dummy Load Harmonic Trap Harmonic Trap or Rejection Filler Transmission HF Low-Pass Filler For HF Transmitter Harmonic Frequency Transmission Cut-Off 35 MHz f Fig. 95; 95: Block diagram of a well-screened transmitting station 56 Practical Wireless, June 1978

59 Tuning capacitor spindles protruding through front panels are often Qften a source of spurious signals and should therefore be of 'Of an insulated material or Qr have an insulated coupling. The cut-out for a panel meter can often Qften cause problems prqblems and a screening can over Qver the rear of the meter is desirable. n general, try to ensure that the case of the transmitter is radiation-proof. Commer- Commer cially made transmitters, including those for the amateur market, already incorporate incorpor:ate most of these features and the maker's data sheet usually quotes the level of 'Of spurious emissions one may expect. The block diagram of a well-screened transmitting station statiqn is shown in Fig. 95. The transmitter is well protected and its supply leads filtered, ensuring neg- neg ligible direct radiation. The output passes via a coaxial cable to a harmonic trap, which wlrich usually consists of a series-resonant circuit, housed in a screened box bqx and tuned to the particular harmonic likely to cause interference. For example, it might be tuned to tq 42MHz, attenuating the 3rd harmonic harmqnic of 14MHz which wlrich could be the source of t.v.i. in a Channel 1 reception receptiqn area. The output then passes via a coaxial cqaxial cable to the standing-wave ratio. (s.w.r.) (s.w:r.) bridge, which indi- indi cates relative forward and reflected power levels.. From here it is fed through a filter, again housed in m a screened box which, in the case of a transmitter operating on bands up to tq 30MHz, would WQuld be of the low-pass type, attenuating spurious spuriqus signals above this frequency. For Fo~ a v.h.f. (2m) transmitter, a band-pass filter attenuating attenuatmg spurious signals either side of the pass-band frequencies, would be used. n practice, the transmitter tuning would first be adjusted into. a dummy load. The output would then be switched to. an aerial tuning unit which is used to. provide optimum matching to the aerial with the minimum of reflected power (indicated on the s.w.r. bridge). Note: All interconnecting coaxial cables and termina- termina tions should shquld be well soldered. Aerial and Feeder Aerial and Feeder The aerial should be sited as high as possible away from neighbquring neighbouring buildings, TV and radio aerials, etc. A vertical transmitting aerial is more mqre likely to. induce strong fields into nearby equipment than a hqrizqntal horizontal one. Qne. This is due to the fact that it relies Qn on a ground gro~nd connectiqn connection which can cause interfering curre~ts currents m. in nearby conductors. n addition, vertically polarsed polarised signals Sgnals are much mqre more likely to be picked up by vertical dqwn-leads, down-leads, such as those used for televisiqn television aerials. t is impqrtant important that all the transmitter power should be radiated by the aerial proper and that no. emission should take place from the feeder cable itself. Tlris This means that the currents in each conduct()r conductor of the feeder should be equal and opposite. Where a dipole aerial is fed by an unbalanced coaxial cable, there is significant imbalance in the current distribution and some radiation from the feeder results. The feeder, usually being vertical, readily causes interfering currents to. be induced int~ into nearby television dqwn-leads. down-leads. To overcome this problem, a balance-to-unbalance transformer (balun) S. is connected at the centre of the dipole, as shown in Fg. Fig. 92. n other types of aerials and feeders, CQrrect correct adju~ment adjustment Qf of the tuning unit is all-important in reducmg reducing feeder radiatiqn radiation to a minimum. Practical Wireless, June 1978 Operation Operation. Excessive drive in any of the transmitter stages will increase mcrease the level of harmonics, so power should be kept ~ept to. the minimum consistent with efficient opera- opera tion. Tuning of the final power amplifier and adjust- adjust ment of the aerial tuning unit will have a considerable effect on the amount amqunt of spurious spuriqus signals radiated. When tuning the transmitter power amplifier into. a dummy load, increase the coupling CQupling only 'Only until the correct power level is obtained. Do not overcouple the transmitter or the Q of the p.a. tank circuit will be reduced, with a consequent increase of Qf spurious emissions. This also applies when adjusting the aerial tuning unit. An abrupt keying characteristic causes excessive side frequencies, so check each side of your trans- trans mission for fqr key clicks (see page 819). Overmodulatkm Overmodulati<ln produces excessively wide side- side bands and causes splatter; always monitor mqnitor the modu- modulatiqn level and ensure that overmodulation overmodulati()n does d()es not occur Qccur (see page 925). The audio audiq bandwidth necessary for good goqd speech communication communicatiqn is about 3kHz. The modulation circuit of Qf the ~he transmitter should therefore have a rapidly falling fallmg response above 3kHz in order ()rder to avoid the radiation of excessive and unnecessary sidebands. lation Summary Let us summarise the requirements for keeping deficiencies at the transmitter to. a minimum; minimum: 1. Use correct: components cqmpqnents in the transmitter, well laid out. ' ttff1tv TVAtnol H moc,.1 Transmission Transmission Hi-Pass FitlBr TV S»t ~ t -Approx. Appro* AO MHz ~ 40MHz. Hi-Pass Filter f ' Parallel Parallel',;,1., f +~ TV Transmission TV TV i Set Aerlol TransmisY,\ rt<_rejection Rejection Filter or Trap -Rejection Frequency ~equency f 'Series' TV Aerial~---1-~Set Fig. 96: TV nterference interference rejection filters 57

60 2. Prevent direct radiation from the transmitter and associated leads by screening and filtering. 3. Use appropriate filters in the transntitter transmitter output. 4. Use a dummy load fqr for tuning up and a suitable aerial tuning unit. unit, Do not overcouple. 5. Keep aerials jn an the clear and avoid radiation from the feeder cable (balun transfqrmer). transformer). 6_ 6. Tune up carefully: do not overdrive or Dvermodu overmodu- late. Check your transmission regularly. DEFCENCES AT THE RECEVER The latest statistics (fdr (for 1976) indicate a dramatic fall in the number of cqmplaints complaints reg'arding regarding transmitt-er mitter interference. HQwever, However, the gc,eater greater proportion of those made were attributed too defidencies deficiencies in receiver design. n many instances, interference is the result of a receiving installation of poor standard; e.g. indoor aerial, aerial incorrect type for area, downlead incor incor- rectly installed, receiver incorrectly installed, exces- exces sively long mains leads or speaker leads, etc. etc. Considering the problem of t.v.i., strong signals can enter the receiver via the aerial aeri,al and cause inter inter- ference by cross-modulation in the r.f. or subsequent stages. A high-pass or rej,ection rejection filter for the fre- fre transquency concerned must be fitted in the ~he aerial lead, as shown in Fig. 96: the series-tuned filter being generally more mo,re effective. Masthead amplifiers are a notorious cause of inter- inter ference as they have broadband input characteristics, some extending from 10MHz to i,000mhz.,ooomhz. Cross- Cross modulation and swamp effects are common. A high- high pass filter should be fitted between the aerial and the input to the amplifier, but in practice difficulties arise here because the aerial has to be taken down and the filter made weatherproof. However, the most common method by which r.f. will enter the receiver is by the presence of "braid" currents in the aerial downlead. These r.f. currents flow through earthy parts of the receiver causing r.f. voltages voltag,es to be produced in susceptible parts of 'Of the circuit. A "braid breaker", suitable for u.h.f. television, is shown,in Fig. 97. The reactance of the series capaci- capaci tors is high at frequencies up to 30MH2, 30MHz, effectively "breaking" the downlead, but at u.h.f. it is low, result- result ing in negligible attenuation of the television signal. Where "braid currents" in the downlead cause interference at h.f. and v.h.f., an alternative circuit can be used. Here a short length of the coaxial down- down lead cable is wound on a ferrite ring, increasing the inductive reactance of the outside 'Outside braid hraid without affecting the signals within. An alternative to the ferrite ring, rung, and almost as effective, is to wind the co-ax around a ferrite aerial rod. f the interference, is entering the receiver by way of the mains lead, a mains filter as shown in Fig. 94 should be installed. n the case of hi-fi hi fi systems, it can also be picked up on speaker leads, so decoupling these with a disc ceramic capacitor capa.cito,r of nf to 10nF is often effective. A ferrite fer,rite ring may be required in addition, if the problem pmblem is really severe. t is unwise to ncorporate incorporate modifications inside the receiver, as you may invalidate its warranty and be held responsible for any subsequent malfunction. n difficult cases it it would be wise to consult the dealer or manufacturer. T..~c7.4T.V ""ollc..lj Sot Summary 470 MHz 58 Practical Wireless, June 1978 ~_"" -3SdB 1. Check that the receiving installation is of adequate standard for the reception area, area. 2. f the interference is entering via the aerial lead, fit a high-pass or rejection filter. 3. f cross-modulation occurs in a mast-head amplifier, fit a high-pass filter in the aerial feed to it. 4. f the.interference is entering via the downlead braid, fit a ferrite ring or capacitive braid-breaker. 5. f the interference is.entering via the mains lead or other cables, fit a mains filter or 'Or ferrite ring. 6. f the problems prdblems are caused by direct radiation, try repositioning the aerials, feeders, etc. Wherever possible, avoid making internal modifications to receivers or audio systems. n difficult cases, refer to manufacturer. Note: U.H.F. U.H.F: Braid Breaker An excellent series of articles on interference appeared in Radio Communication, May Some back-issues baok-issues are available from the Radio Society of Great Britain, Br,itain, 35 Doughty Street, London WC1N WCN 2AE. Alternatively your local Radio Club or a nearby radio amateur may be able to help with a copy. STTNG THE R.A.E. Transmission T.V. Aerial fa?/) p- / feiw F8rrite Ferrite Ring " 9 Ferrite Ring Filter. (The t.v. l.v. feeder is made into info a coaxial choke! (Aoml ^D'"l Also useful on mains & loudspeaker leads Fig. Flq. 97: "Braid-breakers" "Braid breakers" for u.h.f. and h.f./v.h.f. STTNG THE R.A.E. t is a good plan to set yourself regular revision revsion two or three nights a week prior to the examination. Allocate specific subjects each night so that every- every thing is covered in good time and practice answering specimen questions in writing and time yourself. t is best to leave the night before the exam relatively free from commitments. This is a good time for ooilecting oollecting together the things you need, including your thoughts! Take with you, two pencils and a pencil sharpener, two pens (in case one runs out), ruler, symbol stencil (if you have one), eraser and your examination examinatiqn card. Calculators are permitted provided they are of the electronic, battery-operated battery-op.erated type. There are no restrictions on the functions the machine will perform. You should receive your card at least a week before the examination. f not, contact the Examination Centre/Night School immediately and confirm that you are, in fact, registered.

61 When going to to the Examination Centre, allow plenty of of time; your bus may be be delayed, you may have difficulty in in parking your car. Aim to to be be in in the building at at least minutes before the start. Locate the examination room, and be be seated well before the examination, commences. When appropriate, your invigilator will distribute the papers: do do not look at at them -until he he gives the signal. Timing will begin from the point at at which you are allowed to turn the paper over don't over--don't panic! Give yourself at least ten minutes to to read things- through carefully and note any special instructions. f. f, through no fault of your own, you arrive late, apologise to the invigilator then settle into your place quietly and attempt as many of the questions as you are able in in the period remaining. Remember, the paper is divided into two parts; Part 1 has two compulsory questions on licensing con- con ditions (15 marks) and interference (15 marks). Part 2 requires six questions from a choice of eight to be answered (10 marks each). Failure in either section will regretfully result in failure of the examination as a whole. Give yourself about twenty minutes for each of the eight questions and this will allow a little time at the end to look through your answers. The answers should not be over-elaborate or padded out: make your point as quickly and as clearly as possible, there is no time to waste. t is probably best to tackle the compulsory questions in Part 1 'first and then move on to Part 2 where you have a choice. Here you can vnswer "nswer the easiest first and so gain a little Uttle extra time. With answers containing calculations, it it is is a good idea to set out all the steps in detail. Then if if a slip is made in the arithmetic, the examiner will see the correct formulae and methods have been used, and will mark accordingly. Hints and tips on the drawing of diagrams were given earlier in this series (February 1978, page 764), but 'remember drawings take time, so keep them simple. You are not being examined in grammar or indeed spelling but neatness and cleanliness are relatively important, if only to avoid ambiguity. The examiner will not be impressed by illegible writing, scribbled diagrams, etc. f you make a mistake, cross it out with a single ruled line; it will then be ignored and you will not lose marks. A few minutes before the end, end. stop, read through your answers and correct any minor omissions. Make sure all are numbered and lettered correctly and that your examination reference is quoted. We wish you every success and hope to meet some of you on the air in the near future. 73 de GW5JGA GW3JGA es GW8CMY. # NOTE The syllabus and examination pattern for the R.A.E. RA.E. are changing n in We plan to publish a follow-up article to update this series TRM- lop BF213 t4p' DC12 UPl1M1A lop Pin DL: liner DOD.a: PRECSON POLY T:r.~ORS::gm S8T0R9;l8Cltfl 8C1T7 fpibcw Sp'iBDlM BF273 t4p* OC72 4Sp 7447* Mp 14 Fin OL: ZENER DODES: PRECSON POLV- MpBClML ::: :g::l Up'lBDia? :::::gm eop BF33B BF338 a7pl DC1' 45p1450 Up P400mW+-5" 3V-33V CARONAT AC107 ~gl~~ Hp SCl1» =~:g~ 2apaC1WLBtSp»[BDl38 :::gl::lb t:r; ~gl= ::: BF337 J7p^OC75 a?pf OC77 4Sp Mp, T 7450 Mp 1+ So 400trW+ 8% 3V-MV CARB0NAT1 CAPACTORS :~r~ ~Pl g~~o :: ~m :: ~t r.: lw ~tra.~~ 10/llp All alablllty-extremely AC117 l2plljc126 llp'bclm «pibd13b BF458 MplOCfllO Mp p Mp Mp tip Upl,BCtlZe tip BC187 HpfBo14O Le.kqe AC128 upieciae 1lp'BC167 M pi B 0140 lip BF458 92p 52:: ORP1Z ORP12 fti-h 1,t. t 1W 3VJ-200V 10a flflch: D/Hp AM High 1410 Hp 100+ tip tip.. 10/ t '75 ACt27 AC127 Jip;8C132 Up,BC32 npbc204 Hp 14p*iBDt45 l'p',bo45 71p Bf5»6 BF596 tlo' HD' RSOOeB R2008B E 'H H 7470 P 1 + "P Hp Mch: 10/X1TS Low Stability aabamaty LaaVaga V AC128 UpBC34 1fpBC2M BC208 lep'.bolm Up' Bol83 lip BFB97 BF581 Hp* Up' R2010B 1\2010B 1 t '] M 7473 Up 44CV A.C. RANGE : tw SUaMNATURE V.lue Dlmen.. 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All 1'14 AC187K AC1S7«42p 4Zp 8C148 tjp'lacas BC141 Op"BC252C ttp' BF115 &t'05 BFX Up TS81 Hp'14154 t,'1 BA148 tip :~~P:.f~:.h,,1~;0~0\Jg:: :~~ 0'58 50 " 22 &1 41 AC169 ~gl::k a7p ~: SCMQ tjb'.bcaisc Jlp* tip- BDYM Bftis SKS 2 :g::b U P :!BC283C Hp' BF117 :=: :~~ :: PTS&1 ^,,,5 BA148 Up BFY50 22p ~~~O 2N705 Hp, ~: ' ' t-tii g~a: ::: one lue, 1'0 10 '1 22 1'14 ACflaK 50 " 21 '4 &a,t4 AC183K AC163K 41pBCl4«B 4lp 6C14fl 4tp ac148b tt:. llp- lp-bgmc BCfMA «p- :gr,~ z:r;-:m~ 22p" BF17 8F!» BFYSl ap 2N2&4fl Tip 1, JUS ««fl 1; Up Bm2 lip 2NZe96 t 201 m= 8A,U HA68 "F Sd ona al 2p* valtfo, aachj tsp* Hp* for lor o1 of eny any ~: ~: ~~m ",r_i30_,.;.~.;;;c~;;;.;;;~~.',u;;;.~~~_i2~~_,&.2.'.2m_n, l ' 5 AC1CK BC48C Up"BC281B hp BF123 :: g~~ r,p =~=~ :p tu BB110B lip _ 2,0 10,' 25 ' 4 1,'4 ACJiiK 41pacH8C tlp'boja rfpsftj BFy62 Kp 2N «1» T «t 79 BAY13 p onovolua- SPECAL PACK: 10 ~giu ACY17 :::,:g:: 54p lp-'bcmb Up BFtJJ BFY53 Mp 2N2804A Up BAX15 9p ::::;:gm: 3::m~ alp BFYn u: 2N28O u: SN11OO1N!'~41 BB~l~ usp p R.ST 83V O,C, AD140 4p 8C1B3 up- ac2s2a Mp BFSS BFV72 fp 2NM09A Up c M BBOB Mp (730r el aach valua M fi fl al»wa) i W. BFY77 t2p SN290e Ud * SN7500f N 1 17* UP loo Up lip BFno D 2N21101A lip SN78003N - V F ~1" ~2" :1:"" Ao142 A0142.PBC1B4 t5p':bc287 lip BF52 lip BR101 4tp 2N28ZeG np' SN76013N '71: BY121 lip 5" Tal. a ue" ~ ~, AO43 AD143 Up lip ttpbcm BC151 BOB? "p-bcmj 2B8F1M 13D BF127 6FY N2907A Up 1 3 SN75003N 2-45 BY125 Hp WREWOUND RESSTORS: 63V D.C. RANGE UP'iBC281C Up BF83 lop BRC4443 '" 2N281Z1O np' SN7eot3No ~n: g~l~ ~:: ~1:~2K!~:::;~0'tl;(~4~jR.'~~ ~:~~:!:7 :: :: ::: :: ~gm AOl4fl ::: p.bcwa JJp'BCMJe Mp bfiu 2N28260 Mp* - SN BY127 Mp SXTol. Value/«F ±1K arc4<43 l4i 2 N Hp* J 3N78013NO t H "F 2 6W (0 22R'22R) Hp: SW 0 Ot-O-E Xt U \ ggl~a ~::: j C:zesA tip BF1" t7p BRY N282tY np' SN11023N t 11 '., t"- -tip. Aol82 AD SpBCtM "p!;bc«sa UPBFM BC11lB S.,Bc:zeaC 14p BF158 Up BRY58 lop' 2N30S3 4Zp SN1023No. ~... 0' l1li,ll t 10 &t,11 AF114 A01«2 12: MpBClBJB U'tlBCSMC UpBFSS SXS SN2SMY P* S 0 A " "F (10R-12K> lip: 10W (0 TRfOK) BRYM Mp* 2N3553 Up S t S OAS1 lip -Hp t 12 BCS8 up.. 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",1' ':Fl~ AF127 lip atpbc170 BCHO Up' JJP BC328 BOM np' np BF111 BFM.gH!25 U:BU204 Z 11 25=1 8 ;l TBA5400 U' G,een) ttp'; luf/3v-np'; l00"f/3v... 2_2 _J_U_'_._.'.'_" _", ~.. AFl3fl Up 45 p BCHOB BC170B '{B, BC3SS Up- BFJ BUtSS 1 " M» 9N381B 2N3709 Hp* Up 1 t 1 TAA811B 2 71* ( LM/ 22^7/1 t0yf/3sv-41p*i BV; 33^F/10V! 47«F/e'3V BaF/WV; UP' Bcm Up' BF82 lop BU20S 1'tO RCA40S3015: +:~=go g'g: ln40011a~~ -lip', ~m: AF170 ~: MpHCTOC '}P. BC337 11p"iBFlSJ BU2iM tj U J3381 Up ) gggf :::: BCS38 t5p' BF83 Mp BU20S 138 RCA p TBA5100 n' ln4002 lip LECTROLYTCS: Send ',,e, fo,'hd,lllod AF110 AF171 11p 74pBCJ7» '»; BC33S tip* BF1S3 BU2M J«RCAtOSMHo 'TBASMO TBAMOO 2 M* Groen) 1 T 2 21* tn41)01amv -Mp*. al *tp*i M4iF/3V-1p*: 100»iF/aV BUOft 4S M RCAttHMTp- TBAHOCQ 3 35' _ «P BC111A tsp' BCS41A tip BF1B4 U AF181 AF1S0 Up Tip BCH1B BC^74A jjp. BC3<7A Up BF1M 15..' BC311 ttp BF85 P ~~,~ Busoe 2:' 2 u ' TBAS700,TBAB41 ^ t 3!" ELECTROLYTC 8: Send a.a.e, for free dalallad Hate (Bl1) la l00v Axl.1 0' Rodl.1 Leado: 01 addlt'on,'.ock plugo AF181 AFO lop TSpBCUB C- i«" MplBFlSJ BCH2 Up.,BCSB4 tip' BF88 4ZP GETl12 up NTE. ' Z O ln4003 1p ('olu "F) and.ockol., fu... dll... poly AF238 AFBO Up MpBCtTS BC3M tip- BFtS C1«p TfiAtMl ffltll ^ tn4003 ^A toov 7p Axial or Radial Leada: of additional aloch Ueme. pluga BC121 Up,:BC440 Up BF14 t ~ GET881 ts P GRATED ' TBA7200,tS' la itv , 41, e le, clpocllo'l, b"dgerecl,flo.. AF278 AF236 lip 45p BC112C tjp.bctto MPBF1M GETJ72 So NT«-, (voluat n mf) end aocketa, futei. dlica, polytlp BC460 38p,BF104A p. p ' TBA1" t 'l1 ln4004 7ip lip': 41. l1li. hlgh.olleg.".cl,ol"'lcl Whol. AF276 0p BC172C tlp.'ss" BD-'SS Up GET882 ASY01 t O,BC113 tip' BC541 Up' tsp : T8A8QO~ :1 U' la 400V uip" m-up",.,. 12p MEeGOl Hp,- Up 1N4005 'p t. ' o' 1~ 18le prlc. lilt, Vlllabl. to bona AU110 ASYO? AUltO t 1 C1 M.8C173 jsj.bcmt 410 SETSS1 Up CRATO TBA720D tip-."pbfiata "OBFBtA BF95 GETM2 Up CRCUTS; i tbsjm 0 C2-1S* 200V HV B , ealerctpachora, bridge reclulara 75 BC113B 8C1738 tlp"bc548 JJP. 8CMB Up' Up* BFte5C BF19SC MEM01 MB." 7400 Hp, TBAMO " 1 ir 32*.J* l oov 22. 3^ p*: 47, 60, high voltage el eciro lyilca.whole-. 12}p*: Up'MEOOO2 MEMOi Op'1401 Mp* 740j t7p 47 TBAll0AS t 12' la500v 31:': 22oci-4ap' p. flde componl.., ADD 8% AU113 t U BC118 t'pbc558a Up' BF96 Up' ME8001 Up"1402 t7p, 1'10 ln4008 p. BC101 AUin i Up.'BC111 45BC176 jjp'bcjsaa Up* BF1H MESM Uo*.7«a Hp' 1 D TBA5J0AS 1 «ta«0v J6p* : 860, 220 Hp*: p*: 330, lele price Hate available to bona,tca2700 Cl*»* iwom tp, J5p*; p*. flda ccmpanlaa. AOO VAT tip BCY31 lip BFte1 15p' MJ2855 t t7p ftp la HV-l. 2'2, 33.4'7. e'l. BC101A BC107 t4p'bc111a»lp : 8C177 j plscy3t Jp BfU7 MJMS5 1 Mi 7403 Ho NE555 ' Up* f A 800V «V. 2-2, 3 S. <-7, 8 B. tlp,bcy38 lip BF , t5, TO ALL TEMS EXCEPT THOSE WTH' BC07A Mp;8C177A UpBCYsa i BC B t4pibc Hp;BCY42 Mp'.BCYW Up BFiga Hp BF82 :::: MJE340 Hp, 7404 ~~~g :: ~= =:: Up, he6h F 1-25 ~~ ~~PlnOL~~!! '~~OOioooJlp ~~t:;;~:p!~.24r~ 1 12i'" PLEASE ADD 25p Po.1 BC1~ tzp BC118A ttplbcy10 t'pibf200 lop' MJES20 S4pl1408 U pi ln p : 880. l00g-3sp' : and Pocklng 10 all o,d.,. bporl BC108A SClCt BC10SA Mp Up BC118B BC170A J!p BCY7ll JipBFtlS MJE37! tip 74M 24p T 1N 4O07 1lp 27 tip*: 33,47, M p*: MARKED * WHCH ARE llpbfsm MJESM Mp 74M Up.7«(BBlflDL)Up* f A 1O00V Bp*: 220 Mp*: 330, «. PLEASE ADD 25c Poaf BC17flB Zp 2fp BCY11 BCY71 Hp:BF224J Up' MJE521 "P 1410 &t ". ' ln4148 p 22OC)-43p'..dd co.t of 01,/... m.l, BC108B scioea Up BC118 bcub Up BCY12 BCY72 Mp BF224 J MJE52t Mp 741P Mp v ZN l «p imn4148 1fM006 tp, 7p 27p*: *: and Pa Eking lo all ordera. 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Shrop.hl,e av4 SR.. 34p OC44 "p, 1440 OP'0+ 11 'N8' 1,'p 3V-l.2 2 a 3, 4,7. e'8-lp': :gm BC113 BC114 ::~:gl:b HpiBCm SplSCMB :~:: Hp* tip* i ggl~~ p BF258 :l:::m: 4lp)6F269 4t~~ ggg ::: ; ~::~ :: 50+ n: l~;~ ~: t?,( , 41-tSp': T.: Whl.all 414 (STD: ) BCtB llpfficlul :gm BO 16 :::l«gl:tb fp ocbjlb :::: Mp* i ggl~ 8D133 :: 4lp)6F2M 10+ nl Jo! t'f 1N61 -,p t ls44 p, " HV , , 6-8-fip*: Worn. Shtopohlro SYSR4 S4p :~~= 8FZ62 SF26Z, W+ Tp, p Hip*: 82, 33, 47-tip*: Tol; WMxolt 464 (STO; 4)94-872) Mp*ieD135 Up'SfffSS 3lp!aF2S3 "p' OC11 4p< 'U» 100+ up! HphSW lip Hp. :;0, 330, 68, 100 tip*: 180, p*; ~~,~~ P*.. 22O-ap": (p,op., (Drop,. Mlnlco.' Minico,1 T,"dlng Trorflnfl Lld.) Lid.) Practica~ Practical Wire~ess Wireless,, June

62 Portable Calculating Power -at the f lickof your wrist! "Over22,000sold to date." AVALABLE ONLY AS A KT..n- Assembling the Science of Cambridge wrist calculator. The wrist calculator comes as finished components, ready for assembly. All you need is two or three hours, and a fine fine- tip soldering iron. f anythinggoes goes wrong, we'll replace damaged components free. We want you to enjoy building the kit, and to end up with a valuable,useful, useful, powerful calculator. Contents. Acrylic/ABS ABS case and display window parts. Two-part stitched strap and spring bar clips. peb. PCS. Special direcl direct- Wmff drive chip (no interface chip required). Display. kv Keyboard components. Batteries. Wt Each of the 34 components '*$} i is s contained in a plastic box; and neatly shrink-wrapped, {S^y accompanied by full instructions for assembling and using the calculator, calculator. A wrist calculator-ihe - the ultimate in All components common-sense portable calculating power. ymm v ponents are fully guaranteed. Goes where you go, go,ready for action at a flick. of your wrist. ^ By virtue of its size, a wrist caiculatoris calculator is different to a pocket calculator. And now this wrist- wrist machine has another difference. t has even more power than some much larger pocket calculators! And what's more, because it's a kit, supplied to you direct from the manufacture^ manufacturer, it costs just just 9.95 X9,95 (plus 8% VAT,P&P). And for that you get a calculator with extra power, and ail all the The wrist calculator kit ^<0 9f Wl^nBSiy satisfaction of building it yourselfl is available only direct from yourself1 Science of Cambridge. f,for for any Put real calculating power up your sleeve. reason, you're not completely satisfied with The Science of Cambridge wrist calculator gives you the your wrist calculator, return it to us within 10 days full range of arithmeticfunctions (+, -,~,,X X, ) =).t uses ordinary for a full cash refund. Send the coupon today! algebraic logic, which means you enter calculations as you would write them. t t has a % key, the convenience functions^, functionsi, l/.x, 1/.-.:, x x2? and a full 5-function memory. And incredibly,it it has a clear-last-entry key,pi,brackets, Science and ~/+. -/+.t even has an an automatic linear metric conversion function! Qf..~Q.~~ridge Ltd. functionl Very few ordinary calculators have the same functions for ofcombrirlqeltd. (Previously Smclnit [nslmmcnt Ltd) the same sort of money. 6 Kings Parade,Cambridge,Cambs.CB21SN. Cambs. CB2 SN. Regd No Now 10 keys can do the work of 32. Read Nc.»ia8)708a. All ~ those functions,from from just keys? n n such a small "Jo: To: Science of Cambridge Ltd.,6 6 Kings Patade.Cambridge, Parade, calculator? Cambs.CB21SN. The secret secre~ lies in in the special four-level keyboard. Cambs.C82 SN. 'Please *Please send me... (qty) Science of Cambridge Each level has a different set of of functions. Simple two-way J wrist calculators kits,at 9.95 plus 80p BOp Vat and 25p P&P switching system allows you to to select any keyboard level quickly (total 11) each. and easily. Each set set of of functions is is carefully grouped, to to let you Overseas orders may be subject to postal surcharge whisk through calculations with the minimum of of switching. *1 enclose cheque/po/money order for And the answers come up bright and clear, too.the display uses 8 full-size red LED t has wide-angle magnification, NAME and is is easily visible under any light conditions. ADDRESS- More battery power,too! With the Science of of Cambridge wrist-calculator, you'll get get up up to to hours use between battery changes (that's a a lot lot of of calculating!). 'Complete *Complete as as appropriate PW6 (please print) ^1 ~ ~~ 60 Practical Wireless, June 1978

63 THE Now here is an interesting letter from BU Bm Land BRS34761, 7 Wellbrook Road, Bishops Clare, Chelten- Chelten ham, Glos, who admits to being 72 years young and AMATEUR an addict of RTTY for which he has a Creed 7B printer running from his Eddystone 750 and Trio BANDS 9R59DS. Bill wants to hear from others using this mode and can help with a list of parts for the 7B. Another old-timer is John Whiting of Farehara, Fareham, Hants, who started with crystal sets in 1922 but now sports by Eric Dowdeswell G4AR an FRG7, listening mainly on 10m for the moment. He can cope with the code test so is contemplating studying for the RAE. Our SSTV expert Paul Barker of Suaderland Sunderland has now Fame at last! Bob Griffiths Grtmths writes for the first time become G80VD and soon will be able to look back to say we have- a keen young reader on the sle of at the other ohaps! chaps! Paul studied at home for the RAE Wight! He, too, has had a lay-off of 14 years but is and bad had only the RSGB's RAE manual and a few now back in the swim again but with a lot of perti- perti library books to see him through. He managed to nent remarks on the plethora of UA stations! Must "copy" three VKs on 20m SSTV so completing his come as a shock after the relative hush of the bands SAC! Best of luck on the air OM. Likewise John in days gone by. Bob uses an EA12, AR88D plus con- con Overton did the trick in Milngavie, Glasgow and so verters for 2m and 70cm. His aerial farm consists sports GM4GUA now, having already passed the code of 132ft wire, 20m ground-plane, 20m V-dipole and test. He's using an HW32A on 20m s.s.b. for the time a vertical for 80m. being but a KW2000B is on the way. From Morpeth, Northumberland comes John Brian Brtan Smith is well away in Barry, Glam, with his Hodgson again with DX heard on his Realistic DX160 new FRG7. Having been disgusted with what he and long wire. He has received QSL cards from CB'ers has heard of the CB band just below 28MHz he says in Sweden and Norway! John is keen on RTTY so he'll get stuck into the RAE studies and get a proper suggest he writes to Bill Land mentioned above. Bob ticket! After a spell of ten years away from the Bell of 5 Byron Avenue, Blyth, Northumberland can't amateur bands Ken Proctor of 35 Hertford Close, be too far from John just quoted above and they Eastfield, Scarborough, Yorks, Y is active again and ought to get together since Bob would like to start would like to hear from old friends including Bernard a club in the area. Bob is yet another FRG7 owner, Hughes BRS25901 who contributes to this column. having been SWLing for some 25 years and worked Ken has a Trio 9R59DS and 90ft of wire and covers his way through a number of sets. all the bands. CLUB NEWS Geoff Geoft Cole G4EMN, secretary of the The note on David Davld Greenhalgh in the February Wessex ARG, oft mentioned here, had applications column resulted in G3SHW of stockport coming up for membership from a couple of readers situated with a Lafayette HA350 for him which illustrates a long way from Wessex, Wessex. Although flattered, fiattered, he says a little of the' fine spirit of amateur radio. David, in that this is not quite the ideal So, anyone who wants Poynton, Cheshire is delighted and hopefully he'll to join a club, try to' locate your local group or write be contributing to the column in future. to the RSGB, 35 Doughty Street, London WC1 WCl for the After using a domestic portable po,rtable for a while J. address. Geoff rightly says that every reader of this Goodler of Marple, Marple', near Stockport, acquired an FRG7 column ought to belong to a club. and really found out what the amateur bands are Blackwood Blaekwood and District ARS GWeGW GW6GW meets every all about, about. He wants a good prefix list and so, as ever, Friday 1930hrs at Oakdale Community College, near the answer is Geoff Watts of 62 Belmore Road, Blackwood, Gwent. On May 12th GW8LJJ talks on Norwich who wl\o will deliver the goods for just 40p. Practical Construction and the 19th is film night, From Newport, Gwent comes a first report from Printed Circuit Manufacture. ManUfacture. Write to Steve Cole Martin liezers Liezers and a note on his local ARS, reported GW4BLE, 10 Llanthewy Uanthewy Road, Newport. later. He has 250ft of wire on his Realistic DX60 DX160 Mld-Warwickshlre Mid-Warwickshire ARS first and third Mondays and an 8ft rod aerial for "the h.f. bands". 've 2000hrs at 61 Emscote Road, Warwick with G3UDN suggested that he try the long wire on those bands on the air. They'd like to see PW readers, particu- particu too! larly Nick Smith A9050 and C. J. Roe of this column. Practicoi Practical Wireless, June

64 Contact Norman Read G8CXL, 86 Telford Avenue, Leamington Spa. Bury RS G3BRS, every Tuesday at Mosses Centre, Bury at 1930hrs with RAE courses, code training, local c.w. nets, new local repeater GB3MA on 70cm. Whew! t's all go! Hon. Sec. is Eric Thirkell G4FQE, Mosses Community Centre, Cecil Street, Bury. Stevenage and District ARS get together at hrs on first and third Thursdays at Staff Canteen, Hawker Siddeley Dynamics. Morse classes and RAE course at local college by G3SJR. May 18th is the date for a lecture by members of London UKFM Group, while on June 1st G3AGP talks on Electronics in Medicine. Contact Trevor Tugwell G8KMV, 11 The Dell, Stevenage, Herts. Silverthorn RC produces a tcn-pagc ten-page newsletter "Spurious" so they're pretty active, meeting every Friday 930hrs 1930hrs at Friday Hill House, Simmons Lane, Chingford, London E4. Contact C. J. Hoare, Hon. Sec., at this QTH. Newport ARS meets Mondays 1930hrs at Brynglas House Community Centre, Newport with RAE and code classes coming up, up. Write to Martin Liezers, 32 Barrack Hill, Newport, Newport. Log extracts B. Smith: 80m Smith:-80m C5ABC CSABC (Gambia) 4U1TU 4UlTU ZOm 20m C5AAF FC9UC JY5HH ZL2AM 15m Sm CE3BPC C31LU K. Proctor: SOm Proctor:-80m EA8QJ ZB2G PJ8CO KL7AVX 7 A ZL3BX C07RS 9Y4NP 40ra 40m C04DC HP1XYA ZL1BAQ ZL2BDP ZL3RD 20m VP8PT HP3XKB HL1J HLJ HKOBBF Sm 15m FP8DX KL7JEJ JA91WN JA9WN 10m FG7BA J. Hodgson; -SOni Hodgson:----80m J3AAG OY5NS OYSNS PJ8CO 8P6FV 40m TG4NX YV5APF YVSAPF 20m FM7WV HK1NR VE8RCF VK7AE VP2DAW W 15m Sm HKOQA KL7GRP ZS2M (Marion s) ZB2G 10m Om EA9FL HH2MC VU2DK. J. Whiting: 10m Whiting:-Om CT2AX EA8BS SV1HX. B. Land: RTTY Land:-RTY 20m DK6RY EA3ABU T9BWT JY5KR JYSKR K6XP OE2KO SM6HUG YU2BOR W2WX. M. Liezers: 80m Liezers:-80m KZ5JM ZB2G 5B4D SB4D 20ra 20m HKOQA KM6FC YB0HH YBOHH 15ra Sm KL7GRP VP1AB 10m Om C5ABC EP2RL. J. Goodier: 20m Goodler:-20m CT4YN PC9UC. FC9UC. All s.s.b. except where stated otherwise. m * by Ron Ham BRS15744 Richard Staples, G8MME, Lymn, Cheshire, is active on both 2m and 70cm s.s.b. On 2m he runs 400 watts from a pair of 4-250A 4-2S0A valves to a couple of 10-element parabeams, at 40ft a.g.l., a.g.., and on. 70cm, his 2m exciter, TS700G, drives a Microwave Modules Transverter and a home-brew 4CX250B 4CX2S0B amplifier producing 250 watts to a 48-element multibeam, mounted above his 2m array. array, Richard is looking for s.s.b. s.s.h. skeds on 70cm and will be reporting on future activity in the north-west of England. Vic Hartopp, G8COB, Northampton, uses an C201 transceiver for all modes on 2m and has Reports on 0 11 the various bands are welcome welcofneand should sho~lct be sent direct, by the 15th' of the t~emoritn. month, to:-, io:,. ",- ' AMATEUR BANDS Eric Dowdeswell.G4AR, Dowa~$wejrG4AR, Sliver Silver Firs, Leatherhead Road, Ashtead, Surrey Suer~yKrg1 KT21 2TW. 2tW. ; Logs by bands, each in n alphabetical order.... MEDUM and SW BANDS Charles Molloy Mol/oy 68BUS, GSaUS, 132 Segars Lane,. Southport, PR8 3JG. Reports for both bands band$ must be kept separate. separat~. VHF BANDS Ron HameRs,1~144. BRS15744, Faraday, Grey- Grey frlars, Storrlngton, Sussex RH20 4HE. friars, Storrington, Sussex RH204HE. recently been enjoying himself rebuilding a Mohican receiver, and listening to the American CBers on his HRO. A couple of newcomers to v.h.f., Henry Hatch, G2CBB, South Groydon, Croydon, using an C215 C2l5 is working through the repeaters and Robin Bellerby, G3ZYE, Hove, Sussex, taking part in his first 2m opening, did not realise there could be such pile-ups of stations on the repeaters. n Littlehampton, Sussex, Norman Langridge, using the v.h.f. section of his Yaesu FR4.00- Super DX receiver with a 3-element home-brew, loft mounted beam can always hear traffic through GB3SN, but, during the opening on March 7th he heard GW mobiles working through GB3BC which has encouraged Norman to modify his aerial system. Along the coast to Worthing where David Wakefield, BRS39756, BRS397S6, uses the receiver of a Pye Vanguard on 2m, with a roof mounted dipole, and CR100 and R1475 receivers, fed by a long wire aerial, on the h.f. hj. bands. David's interest in radio is further stimu- stimu lated through his activities as a Cadet Wireless Opera- Opera tor in the Air Training Corps. Despite the poor conditions and the low atmos- atmos pheric pressure, 29-Sin, 29 3in, Alan Baker, G4GNX, New- New haven, had a 59 contact on 2m s.s.b. at 1800 on February 26th with F1ENH/P, Boulogne, both running 15 watts, and at 1730 on March 2nd, in thick fog, on Beachy Head, near Brighton, Alan heard signals from repeaters ONOHT and ONOOV and a Buckingham station working through the Kent repeater, GB3KR, R4. The atmospheric pressure remained around 29-Sin 29 5in from midnight on February 27th to midnight on March 2nd when it took off and climbed to in by noon on the 6th, and, true to form, the v.h.f.s v.hj.s opened up as the high pressure began to fall. During the evening of the 6th, John Kuipers, G4GUX, Brighton, worked G8LY, in Hampshire, on 70cm, first via GB3AW, Ashmans Ashmans- worth, Berks, RB10, and then through GB3BR, Brighton, RB6, and GB3PH, Portsmouth, RB2. Later he heard signals through GB3BK, Upper Basildon, BasHdon, RB6, GB3SD, Weymouth, RB14, had a c.w. contact with ON4VN and heard 2ra 2m signals through GB3BC, R6, GB3MH, on its new channel, R3, GB3WW, Carmel, Dyfed, R7 and FZ3THF, R4. Around 1945 on the 6th, Ken Smith, BRS 20001, Horsham, received several French broadcast stations in Band 11 and patterning on u.h.f. TV channels, and earlier, Graham Laucht, G80QM, Birmingham, worked G8KSN, Ramsgate, Kent first via GB3P, Cambridge, R6, and then direct. Like Graham, Brian Fenwick, G8BTC, Brighton, heard a variety of repeater signals on 2m, including Cornwall, GB3NC, R5; Brian noticed that signals were often stronger on the input fre fre- quency than from the repeater. Frequently, on the 62 Practical Wireless, June 1978

65 6th and 7th, received a good picture from Lichfield, Ch 8, 189MHz, Continental f.m. stations in Band 11 and strong signals from GB3BC, BM and KR, with only dipoles feeding the respective receivers. At 0125 on the 7th, heard two Portsmouth stations, G8NU and G80QN/M in contact via the London repeater, GB3LO, R7, and at 2152, another pair, G4GUX and Martin Newell, G8KOE, both in Brighton carried out a similar test on 70cm and had a QSO via the Ports Ports- mouth repeater. At 0900 on the 7th, G4GNX/M using his new C-240 to a 5a 5 8 whip aerial, heard strong signals through GB3BC, from a low point in Brighton, FEBE, F1EBE, Rouen, via GB3LO, and at midday on the 6th, he received signals from the Malvern Hills, GB3MH, R3, and Paris repeaters. At 2206, from Newhaven, Alan had a c.w. contact with ON6FT and at 0011 DOll on the 7th he worked F1EVM/P, FEVM/P, Caen, on 2m s.s.b. The atmospheric pressure continued falling until 1800 on the 8th when it began rising rapidly, reach- reach ing 30-4in 30 by midday on the 10th, and then fell back to 30-0in 30 Oin by noon on the 12th which, as expected, caused a tropospheric opening. At 2230 on the 8th, newly licensed G80QM/M, using a FT227R to a 5 5a b whip aerial, travelled down to Beachy Head, Sussex, and heard GB3BM, his home repeater and then had QSOs through GB3BC. From Brighton's Race Hill, at 1900 on the 9th, G4GNX/M worked F1BBZ FlBBZ and F3KT via FZ8THF, Vichy, R0, RO, a distance of 320 miles. Roy Bannister, G4GPX, Lancing, Sussex, succeeded in accessing the Vichy repeater but owing to UK traffic on R0 RO he could not complete a QSO. Both Alan and Roy heard the Ghent, ONOON, R4, and Paris, R6, repeaters and during the evening of the 10th, Clive CHve Penna, G5PO, G3PO, Orpington, Kent, worked EA1AB EAAB on 2m c.w. and Mike Rowe, G8JVE, East Preston, Sussex, heard an EA1 EAl and worked into France and Wales on 2m s.s.b. Around Amund on that evening, Alan Belfield, G4GLN, Streathara, Streatham, contacted an EA on 70cm c.w. John Branegan, now licensed GM80XQ, Saline, Fife, worked his first three countries, G3GZX, G8JTS, and GW4GTE during the 2m contest weekend, March 4th and 5th. John said "there was a definite lift on March 4th, and by 2200, G signals into Scotland were very good and they could hear the Central Scot- Scot land repeater in G". Throughout the period, 9th to 2th 12th there was fre- fre quent co-channel interference an Band 11 and u.h.f.- u.h.f. TV and at 0914 on the 11th llth received a 599 signal from the Emley Moor MOQr beacon, GB3EM, on 70cm with only a dipole feeding the receiver. The 10m band has been open almost daily from February 20th to March 15th with a familiar pattern of strong signals from Russian amateurs in the morn- morn ing and from north-american amateur and CB stations during the afternoon and early evening. heard VKs during the early mornings of February 26th and March 7th and JAs on March 5th and 11th llth working into Europe. On most days signals averaging 539 were heard from the Cyprus beacon, bt'.acon, 5B4CY and the project TESSA beacon, ZE2JV. During the after- after noons of March 1st and 2nd, Don Butterworth, G3KO, Redhill, Surrey, heard the Bermuda beacon VP9BA and.and logged the Bahrain beacon, A9XC, during the afternoons of the 5th and 6th. February 26th was a good day on 10m for Gordon Goodyer, BRS 37345, Petworth, Sussex, who heard both A9XC and VP9BA in the morning as well as signals from amateurs in 22 countries. Although Practical Wireless, June 1978 signals were very strong throughout the day Gordon reports a drop off in strength around midday and a quiet band from 1430 to lsls Roger Bunney, DX TV columnist, using his Hallicrafters S receiver logged transatlantic signals up to 37MHz on the 26th. Nigel Golds, BRS 36910, West Chiltington, Sussex, noted the powerful American stations around 1730 on March 11th llfh and the Russians during the afternoon of the 12th. The exceptional 10m conditions observed by Gordon and Roger on February 26th were followed by ionospheric disturbances, reported by the BBC World Service, on the 27th and 28th which may well have been caused by the solar storm recorded by Cmdr Henry Hatfield, Sevenoaks, Kent, John Smith, Rudg Rudg- wick, Sussex, and myself from February 21st to 26th. What's more John Branegan, reported auroral activity, with plenty of 2m c.w. from El, GW and LA, from B to 1912 on February 27th and from 1657 to 1912 on March 1st. John has built a projection box attachment for his 2m 2in telescope so that he can record the number of sunspots and since 204B 2048 on March 5th Sth he has been monitoring the telemetry signals from the new amateur radio satellite, OSCAR-8. OSCAR-B. Despite frequent overcast skies, Henry Hatfield got a glimpse of the sun through his spectrohelioscope on March 6th when, in addition to sunspots, he saw several filaments and a ribbon flare, on the 10th he counted some 15 S spots in four fqur main groups, and on the lsth 15th he noted a bright plage on the east limb. Henry, John Smith and myself recorded solar noise at 136 and 142MHz on March 2nd, and then daily from the 6th to the 13th with noise storm conditions on days 6th, 8th, Bth, 10th and 15th. lsth. According to comments heard both on and off the air by Alan Baker and myself the "Slim Jim" 2m aerial described in our April issue works well and is very popular. Let's hope that conditions will be good to provide plenty of DX for the RSGB's HF National Field Day on June 3rd and 4th and VHP VHF NFD and SWL contest on July 1st and 2nd. Thanks again for all your reports, and good luck if you compete in the contests. What do the VHFs have to offer? The accepted part of the radio frequency spectrum known as Very High Frequency ranges from 30 to 300MHz, (10-1 (l0-1 metres), and is generally used for communications by aircraft ( MHz), (lob-136mhz), amateur radio (4m, OS-70'7 and 2m MHz), private and business mobile radio (71-88 (71-8B and MHz), 16S-174MHz), shipping ( MHz), (ls6-16smhz), satellites ( MHZ), (l36-137mhz), military, various emergency services and broadcasting by f.m. radio, Band (88-O8MH2) (BB-0BMHz) and television, Band (41-7MHz) (41-67MHz) and Band ( MHz). (l76-21smhz). The effective range of a v.h.f. signal is naturally limited by the terrain beneath its path and the pre- pre vailing atmospheric conditions. Broadly speaking, the propagation of signals between 30-80MHz is governed by the E region of the ionosphere, and above 80MHz, by conditions in the troposphere. These bands are therefore a challenge to both the listener and the transmitting amateur, to be ready for sudden sporadic- sporadic E disturbances between April and August and at any time, for a tropospheric opening, when the weather 63

66 is fine and the atmospheric pressure is high. These Sections of the 2mband are used for Slow Scan TV, v.h.f. openings are exciting, because the signals travel RTTY, the Radio Amateurs Emergency Network more than ten times their normal range and as the (Raynet), and scientifically, for moon-bounce experi- experi v.h.f. bands are shared throughout Europe, there is a ments, meteor scatter and the study of auroral mine of DX, both sound and vision, to be found among propagation. the mix-up of continental signals while the event suggest that readers who are interested in v.h.f. lasts. should obtain a copy of the RSGB VHF/UHF Manual During sporadic-e events, very strong signals are and talk to the v.h.f, v.h.f. operators in their local radio heard in the UK from east-european broadcast club. stations between 65-73MHz and even stronger signals, from a variety of continental mobiles, interfere with the Band television channels. There are two beacons in the 4m band to listen for, GB3SU, 70'695MHz and GB3SX, MHz. 70 The 2m band is full of surprises throughout a BROADCAST tropospheric opening; and like most v.h.f. enthusiasts, our readers have heard and worked amateur stations, using all modes, over a wide area from Scandinavia BANDS to the Mediterranean Sea, and all parts of the UK. First indications of an opening can come from any of the chain of 2ra 2m beacons ranging from Cornwall, SHORT WAVE BROADCASTS GB3CTC, MHz, to Angus, GB3ANG, MHz, 144 and northern reland, GB3G, by Charles Molloy Mol/oy G8BUS MHz, 137MHz, to Wrotham, Kent, 144' MHz. 150MHz. Having decided, from the number of UK beacons heard, the Harmonics, though familiar enough to the radio extent and predominant direction of the prevailing amateur, may well be an unknown phenomenon to lift, it is worth looking for the continental beacons the broadcast band DXer. A harmonic in this context such as; DLOPR, MHz, MHz, EA3URE, MHz, MHz, is a spurious transmission on twice or three times PX3THF, FX3THF, MHz, LA1VHF, MHz, ()MHz, the frequency of a broadcasting station. The basic OH6VHF, MHz, MHz, OKOEB, MHz, frequency is called the fundamental, twice that fre- fre ON4VHF, , , az7gy, OZ7GY, MHz, PA0JTA, PAOJTA, quency is the second harmonic, three times the fre fre MHz, 148MHz, SK4MP, MHz, 144 SP2VHF, quency is the third harmonic and so on. Harmonics MHz, and YU1VHF, to name na:me a few. occur naturally inside a radio transmitter but great A beacon's signal is a continuous note, frequently efforts are made to suppress them so that they do interrupted with its call-sign, call-sign. not reach the aerial and radiate. High power trans- trans Another good propagation indicator is the 2m mitters are now commonplace and when connected repeater network, using f.m., which now provides to a directional array the effective radiated power considerable coverage of the UK and is rapidly spread- spread (e.r.p.) may easily be in megawatts. Under these ing through Europe, Europe. Each repeater shares a carefully circumstances it is easy for a few watts of the second planned channel numbered from R0 RO through R9, or third harmonic to be radiated along with the covering a series of input frequencies from fundamental. Normally, this is not a problem as the MHz, 145-OOOMHz, in 25kHz steps, to MHz. The s.w. broadcaster ought to be transmitting near ne'ar to the range of output frequencies, also in 25kHz steps, is maximum usable frequency (m.u.f.) to obtain 600kHz higher, from to MHz. 145 n optimum results. Harmonics would then be above addition to handling the amateur radio traffic, these the critical frequency and will penetrate the iono- iono unmanned, unm,anned, automatic duplex transceivers periodically sphere and not come back to the earth. identify themselves by transmitting their official call- call Now that the higher frequencies are opening up signs. again after the recent sunspot minimum, reception At some time during a tropospheric opening, con con- of harmonics should occur more often. Radio ama ama- tinental f.m. broadcast stations will be heard in Band teurs make world-wide contact on 10 metres using 11, n, often stronger than the "local" BBC stations, and only a few watts, and reception of harmonics in the Band television will suffer from co-channel inter- inter range 23 to 30MHz should occur over a similar range. range'. ference. Harmonic DXing is the broadcast band DXei^s DXer's equiva- equiva Space enthusiasts can use the AMSAT-OSCAR AMSAT OSCAR 7 lent of QRP (low power) and as such has a challenge satellite which has two repeaters (transponders) and fascination fasc'ination all its own. One snag though. Be aboard, 2m to 10m Wm and 70cm to 2m. Signals received sure you are listening to a genuine harmonic and not by the satellite between and MHz 145 are to a spurious signal generated within your receiver. re-radiated re radiated,between and 29-5MHz 29 and signals A check for the fundamental or a check of conditions going in between and MHz. come out, on 10 metres is a help. inverted, between and MH2, MHz. The From Guernsey in the Channel slands comes a satellite's telemetry beacon can be. heard on letter from George Le Couteur who heard Radio MHz. Moscow when he was tuning through the 10m band. Every year, the HSGB, RSGB, in,conjunction with the The exact frequency was MHz 28 which is three ARU, arrange a number of contests, on 4m and 2m, times in the 31m band and sure enough he for licensed amateurs and SWLs. These events are "found them putting out their usual huge signal on interesting because they are well supported by in- in the frequency". The second harmonic is and dividual and group, entries -operating,operating from their home George found them on this out-of-band out-of band frequency as QTH, or from portable or mobile locations. Should a well. Other DX heard, on fundamental this time, is contest oontest coincide with an atmospheric disturbance then Radio New Zealand regularly around 0830 on there is plenty of DX about kHz, faint but dear clear of QRM. 64 Practical Wireless, June 1978

67 WTH UNT THREE WE NTRODUCE OUR Stirling Sound v Audio Plan ts t's "telescopic"! Aydlo P^n Unit Three treo pueh-botton toreo Audio Plan pu.h bo"on Unit Throe 6 efector/flfter,elector/filter unit unit with tront ronl panel.onel tnsclq. c;o. SiZf. Size: 2<0 240 t.. losmm. 10Smm. 58.1" Ut 110 Ut 110..,," HS.11O H "" w 75 6 ~O.T FlUE.. NC TAX POWER AMPLFERS Output. quoted n watts R.M.S. into 4 ohms :l:.fdb. Flpuree Figure. n n brecheie brackets indi- i ndi cate the appropriate Stlilinfl Stirling Sound lull tun range, power see supply. For our new calalogue. catalogue. J.C..C. amp. 3 WRrta watt. R.M.S, R.M.S. (3S.3te) (SS.318) tf Stereo veraion version of above 2.C.a.e ' waits wottl R.M.S.. nto nl0 3Q 30 (Car Ball.) aolt.) to 10 watts watt. R.M.S. Si" 3." x 2" x l''(ss.32<) 1" (SS.324)... 4 S S 20WBb watt. R.M.S, R.M.S. (55.334) (5S.334) CO 0' watts R.M.5. R.M,S. OistOrllPO Di,tortion tvplcelly typically 0-1%. 0'1% 5" 5" x Si" 31" x J-fSS.Wh) fi" (SS.345) '50 U.. watt.. Distortion 0 1". 5" watts 5" x 31" R.M.S. x J" 11" (55.300) Dlstorllon typically 0-1 %. (SS.38O) 'M 1 ' welts watts R.M.S. Dlstorllon Di,tortlon Bl at holf-oower, half-power typically 0-1%. 0 1 ". 5" S" x 34" 31" x ir(ss.3fl0) fi" (SS.360) M 10'50 Heetsmk H.atalnk (orss.ho for SS.140 orss.m SS.leG p OUo 01"0 lor for SS.1100 SS.l1oo ti 15t so Powtt Units hstt low voli D.C. Ukt-cff point. Pow., Unit' h,~e low volt D.C. taa~" point. UNT TWO MONEY SAVNG, VERSATLE with a new module every constructo~ constructor is going to welcome Audio Plan lets you build it your way! Using the vast experience gained from sellin, direct to thousands of constructors. we have put to.ether from our sereamlined ranee of constructor modules the three hi-fi assemblies most wanted for power. performance and price (see below). Each features our unique Unit Three stereo push.button selector/filter module (or ceramic p.u., mag. ma,. p.u.,. radio, tape record/repiay record/replay and high cot cut and low cut filters. filters, Connections Connectioni are via three 5-pin S-pin Dm Din sockets mounted ac at rear, rear. UNLKE ANY OTHER MODULES. MODULES, YOU CAN EXTEND OR SHORTEN UNT 3 l TO MAKE HAKE T FT ANY CABNET SZE BY SMPLY CUTTNG ACROSS THE P.C.B. AND POSmONNC POSTONNG TWO SECTONS AS REQURED. These are then connected to each other again. Simple! Sensible! and so very useful to anyone wanting hit his assembly to have that extra professional appearance. Note 'Unit Note-Unit 3 may also be used with other than Stirling Sound modules if you aren't changing <hanging to Audio Plan just yet. Provides treble cut/boost :1:.15 db at 10KHz: ba ±15 db at 30Hz: vofuma volume control! ; storso stereo balanco balance control. nput consltivlty sensitivity 1-5 mv. my. R..A,A, R..A.A. oomponoatbd. compensated. S/N SN rbtio ratio SdB 75dB lor for 5mV SmV in. i Output 200 mv to 1 volt according to nput voltage. Yoltage. Black front 1ront panel, white titles. 220 x 80 x SOmm. Supply Yoltage V.D.e POWER AMPS. CONTROL SELECTOR POWER PRCE SUPPLY POST FREE & ire. V.A.T. 34V r; 11 i j) 11~["111J~J ~11i1JJ V!1 ~ illl" i'!l~ ~J ; Modular D..Y. a.. emblies for great economy: Control/Mixer Console.: Sound~light Units including (he cable ~tre e Spectra onic: Mbers; Ampa: Speakers: Ampower' ampllfled spe.~.,s. etc. Mention 'Disco' when sending for npw catalogue as a. below. ALL PRCES NC. V.A.T. & POST FREE * ACCESS OR BARCLAYCARD-JUST GVE YOUR NUMBER TO^R^F& wnwfcti ORDER Ca3h order ~~se~o~~~~~~l~e~~i'af~r:ye~rd1l~~ or fcheque/money your AccesB/BarclBycerd order} with No. Goods Stirlm! (except heavy dlsca) disco) post at free n in U.K. U.<' All prices r ~ To STtRUNG STRLNG SOUND. SOUND.37VANGUARD 37 VANGUARD WAY. SMOtBURYNESS, SHOEBURYNESS. ESSEX ncl incl V.A.T. to notice. V.A.T, Prices subject to alteration without prior Stirlim mm New Stirling Sound Catalogue PLEASE SEND. SflUnd. VC DP product READY A nv U technical with full... as list attached) & 10r producl jnlormaticm. technical nlormatlon, ranges, etc. informa1ion, prices, Send etc:.. (or ae hat atlached) A CATALOGUE for Send ^ -* U^^Ulf 20p n.tamps for nyjn NOW return. 200?0f> in m stamps for your copy by which analose en.lose... "..... "...-f. + 2bp 20p for Cat. Dept. PW6, ,., VANGUARD WAY, SHOEBURYNESS, ESSEX Addre Tel: (03708) SHOP AND SHOWROOM West Road, Weatclifi-on-Sea. Westcliff or-sea. Telephone; Telephone: Soulhend Southend (0702) L _..;... ~. ~.~.~..;,;,;,;... ~. ~.. ~.. ~.~,'.;.;.;. ~ P:_6... Practical Wireless. Wireless, June *,V POST FREE (, NC TAX Oulpule R.M.S. nto quoted 4 ohma n ±130. wttta Audio Plan lets you build c your way! Using the vast experience gained 7>f^\ from selling direct to thousands of conscructort, we have pur together ^ V fromour streamlined range of constructor modules the three hi-fi aisemblics ' ' most wanted for power, performance and price (see below). Each Features vi» our unique Unit Three stereo push.button selector/filter module for ceramk Audio Plan just yet. PRE-AMP PRE AMP AND CONTROL UNT Ptoddos tr.bl0 cut/boost ±1S db b lokhrj bait ±1S t)b Bl 30Hi; tltlee.220 a 00 a somm. Supply vollaga V.D.C. POST FREE & inc. V.A.T. ASSEMBLY POWER AMPS. CONTROL SELECTOR POWER PRCE )& inc. V.A.T. AUDO PLAN A 2 x 60 W. r.m.s. Unil Unit 2 Unil3 Unit 3 60V AUDO PLAN B 2 x 40 W. r.m.s..s. Unit 2 Unit 3 45V AUDO PLAN C 2 x 20 W. r.m.s..s. Unit2 2 Unit 3 34V 38 3& 95 BS Modular D..Y. assemblies for great economy: ConUoiMfaor Consoles: Sound-llglit Units incfudinoinacahle-uflft Spacfraaonicj MlAers: Amps: Speat.era: 'Ampower' amplified Bpeakets, etc. Mantion 'Disco' when sendmq for new catalogue 65

68 Harold Brodribb, St Leonards-on-Sea has also to listen to it until Subsequent night listening picked up harmonics of Radio Moscow,on on MHz 23 between 0100 and 0330 produced WHN New York on (2X11960), (2X12055) on (?) and , CHUM Toronto 1050, CFRB Toronto 1010, GHNS OHNS (?). Harold is now using a home-made converter with Halifax 960, CJYQ St John's 930, WCAU Philadelphia his CR100 CRlOO which gives very much better results in 1210, WOWO Fort Wayne ndiana 1190, CJCH Hali- Hali the range 25-30MHz and he reports increased activity fax 920. Mike now intends to obtain one of the new in the 11m broadcast band (25605 to 26095kHz) with Yaesu Musen digital receivers and he also plans to reception of Tel Aviv on at midday and of the oonstruct construct a loop. A number of points arise out of Voice of America (location unknown) on 26000kHz at Mike's letter , Reception of North American m,w. m.w. stations is not Short-wave crystal sets are in the news again with limited to the winter. DXing is possible throughout a report from Rod Hunt of Darlington Darling:ton who pulled ill in the year. All that is required is a path of darkness Radio Canada, Finland, Norway, Sweden, Austria and between transmitter and receiver and this occurs a number of others, using a home-brew crystal set some five hours after local sunset in the UK. Even on and a 50ft outdoor aerial. Rod says that one definitely the longest day, sunrise occurs seven hours after sun- sun needs patience and persistence and it is only a matter set at this QTH though this period may vary according of time until Australia is caught! to location in the UK. At my QTH this means me'ans about Radio Australia has attracted the attention of 112 1*2 hours DXing of NA before dawn on June 21st and George Norris Noms of Stowmarket (FRG7 and Windom much longer periods during April, May, July and Antenna) who says that propagation on this path August. Only stations on the eastern seaboard of at the moment seems to favour the morning between North America will be heard in June Jume but on the 0700 and "Try cHz 11740kHz (25m) first and then other hand European QRM is light as Central and and (13m). The former seems to hold Eastern Europe will be in daylight. DXing North up well most of the day with QRM at times". William WUllam America in summer can be rewarding. once logged Stevenson (Manchester) has a Vega 206 which he the 40 watt relay at Glovertown in Newfoundland on uses with a folded dipole in the 10ft loft for the 19m 1090kHz during the month of July. band and a 45ft Zepp with a.t.u. for the rest of the Mike noticed that fade-outs lasting for periods of bands. His log included Radio Australia on 11705kHz several days are common on the North American at 1500 SO 434. Fifteen-year-old Robert Pound of path and he wonders if there is any set pattern for Cambourne in Cornwall is a regular listener to Radio good reception. Fade-outs do recur sometimes after Australia on but has been trying without suc- suc 28 days, which is the period that a disturbance or spot cess on 4920 for the lokw 10kW VLM4 which relays the on the surface of the sun takes to rotate and face Domestic s.w. Service between 1930 and Has the earth again that again-that is if it lasts that long. Reception anyone logged this station? Robert, who uses an ex- ex is often at its best just before a fade-out so it might WD receiver (type unknown) and an end-fed aerial be possible to predict such a peak. Matters are not situated in the loft, has beeen trying to pick up Radio so simple, though, as the ionosphere is a complex Kaduna, Nigeria on 3396kHz in order to hear the medium and long range propagation on the medium talking drum interval signal. The NBC international waves has not been studied to any degree. After all service is also using this interval signal, signal. Chris Howies Howles the band is intended for local broadcasting! n any of Lichfield (Vega 206 and 50ft long wire) reports event the medium waves are never dead, there is hearing Lagos signing on at 1800 on 15120kHz in the always some DX to be heard. f North America can- can 19m band and according to the World Radio and TV not be heard at all then South America will be at its Handbook the interval signal precedes signing-on. best. f you hear an American voice during a fudeout fadeout then listen carefully for it may be something special such 'as Puerto Rico or perhaps the American Virgin slands. 1 shall give up medium wave DXing if it ever becomes possible to predict what can be heard as most of the fun will then have disappeared. Finally, Mike offers a tip to QSL hunters. nter- nter national Reply Coupons cost 25p in the UK but stamp BROADCAST dealers can supply unused postage stamps st,amps for most foreign countries. These are more convenient for the recipient to use and, a lot cheaper to buy (for Canada BANDS in Mike's experience). A very good idea if you know what value V'alue of stamps to obtain for a return letter. Central,and South America are often heard well MEDUM WAVE DX during the summer. D. R. Mayhew (Littlehampton), by Charles Molloy Mol/oy GBBUS G8BUS who uses a Philips receiver and the PW 40m 40in loop reports hearing Radio Managua, Nicaragua Nioaragua on 620kHz, La Voz de Mexico on 730, Radio R adio Oadena Cadena el Salvador on 760, 'ROK 80' in Juarez Mexico on 800, A long interesting letter, just bursting with enthu- enthu Radio Sutatenza Colombia 810 and Radio la Versatil siasm from Mike Kuske of Folkestone describes how El Salvador on 1300kHz. More Latin American DX is he heard his first North American m,w. m.w. station. His reported by Steve Whltt Whitt (Cambridge) who used an National Panasonic GX600M had been purchased for Eddystone 940 with a 2ft square loop and the PW short wave listening but after reading PW he decided balanced bal'anced amplifier to pull in Radio R'adio Margarita 1020 to try the medium waves for, although interested in and Radio Rooio Coro 1210, both in Venezuela. "t was very North Americam AmericaJl domestic radio, he never thought it interesting to receive my first South American DX, could be heard in the UK. With 100ft of wire wound don't know how missed it before," writes Steve. around the loft for an aerial he pulled in WNS in t is very easy to pass p,ass over Latin Americans, especi especi- New York City on 1010kHz at 0045 and he continued ally during a North American fade-out, and class 66 Practical Wireless, June

69 HERE S THE NEWS One of the major problems confronting today's electronics designer/enthusiast HERE S THE NEWS Oob of the m8 or problems confronting today's alectronics designer/enthutiast Much of tht Mtiifectran in our new approach to ipacialized features, is the feet that vou our new i il the th.t you the incessant Cs S also abl. obhin the nocassary parts for circuit ll, is (h«incstiont stream of new types of 1C«and components. So, where radio is will alto be able to obtain all tha nacasiary parti foi your drcuh. from (S, at prices prlcas that concerned, concemed, our new catalogue s is a revalatioo revelation to the circuit user. The new Ambit a* are to 10 campeleiitva competetitve that Chit we've been number one on. n in cods/filters coill/filten since w«we started stlrted trading: cetaloguo catalogue contains oil all that is new and worthwhile, plus feature articles TOKO will '1 f'l R.d,. 10: Po..., "',. F.",'.. n>ds: COt 1 and 4 fllmw: ters:.- n. H 'SnOME CAJ089E 1, Cn'T.W 723CN cm0 14x9.6cmO 30 lo describing applications work, providing ideas and suggestions - and some radio Ab.stnc A bigger manm.tbisxil than ever range of Fl Fs (or ml, for kHz. 043,age CA3l89E 2,7S 2.75 NESMB NE550B 080' O.SO& ia«9.s 16x theory basics - like tuned circuits and impedance matching - that cut through 5bt MHz in 7mm. lommsqu.r. styles HA1137W 2.10 TAA & 17.5,,9_ including WHr ncludingtvvid8) TV n video 7fTima and 10nimiQiwr»lvl«~mdsoundF$ wuhd (Ft.. rrorti30.j3p. Now HA1T37W 2.M TAA6W 0,W '/-6x9 5 0,30 f ro",3()'33p. TBAl L )( the flannei flannel to give you essential euential practical details to help you with your own T 6At20 1 MxQ.B Coin Coils tor for snortweve, Shonwave, coin calls for vkf. VHF, cods COil. for T6A'20 TBA120S 1 & misc mw COil 0.27 design work. We also invite customers/readen customers/readers to submit their own features for LW/MW'. with OOQ.POQ 800,000 >r) in ttockl stockl ua720 T6At2n5 T6A ua too 7B eo30cc PLL pi 1300 LA Smite 105-'20*9.5 wrcaii S03aCC LW co.1 O-M Our our radio magaiine magazine supplement on modem Rf R F circuitry and techniques. WFL455 MFL45S l4khrssfl 24kHz SSB titter fil ter 99b 9.95 T0A6G1 ua730 TBA$S O30CC 4.50' NE555V ty55" coupling LVVfiO'l couphng CM CFM2 T0A NEBSSV LFVABS ~~~l55 Aelarrwnt mintbiu<*fn*chenk«l :;~::~:l:'-::~i~:'r ladder filter Mler 0.65 fdter 1.2S 125 HA1107 ~~~: MC135QP MC136QP 1,40 ~~~~~p 120 NF56SV! :~ NCWOS 2,60' ~~=~ 3.W ^'P ~ :~: txlub 4 ~:r,15101~ 1 V0.25. g: CFSel07 ceramic NE5618 b&lun 0.12 Featured in our catalogue/magazine supplement: CFSEl07c*rarr>lc FM F filter 0 50 MC HE56\B H bsiun 0 12 B8R3132A 8BR3132A 6pole line.r ua753 Ne Trim",., et CA31S9E CA3189E The new RCA FM F lyitfm system dsscrihed dllcribed in deuu.whh detail, with an 'ultimate hdr'appl- hili' appl B8R3125 Qpo't 4t»i«Hnwr linear phue phate FM FM " 25 A7s3 ication mour in raftmce ret.rnee writi series FM F F uiritbawd unit based Qf> on linear linellr ptosir phase filten filt.n BLR3107N :~=~~~~N 19/38kH; ~/~~H~:t~~ «larw> tiller ~:' 1.00 J.M UA7B3 ~ :~ TDA1062 MC1498 MC NEB86K NE862B l.b^pf r»rtm»rq 0.18 ~1~:2 ~.;~ ~,E=K 1~ ':: ~ : t~gf g.~ : Ratlodlscnminetorl for 10.7MHz 0 ULN22041 The now AM/FM Audio C that hs ~yolution i zed 1.95 SP ULN22W/ T>i n«w AM/FM/Audio combination 1C tbar hti revolutionlmd portable Ratio dftcnmlnelon lor 10.7MHr 0,66 1«0 TDA1083 TD4106J 1 9E 11C Ratio diicrlmlneton discrlmln.tors lor for 45M70WKj kHz 135 TOA lN' ' V.ric.p di ode$ Tt>Al TDAl radio design. de.ign. 2 to 12*f 12. froltspt voltage rwige ranga 10'14mA 10 14mA tot»l tolll itandbv- ULN S y.kvaom standby. OEMirn*fn*9l*MfTK*tvnto<*ifoc*offft DEMs: Ktth... tmrnotuniqw,tock ofrf TOA PNdicdas.rc 2 13{1lm) O.11 TOA1OB2 TDA1082 LF/H LF/HFNHF F/VH F osadctor, OQllator, balanced balancad nuxer, mixer, R RF F nage Slgo and pm pin diodo diode. egc dnva dri.a 9. ttfuml signal co/li/cho**i CO/,chok. in m fa» rh. wjita world - and Mid outr flf off. r a TDA2M " 10A1220 TOA pihiiinfattc mlO A, $ venatite venatil. RF pmcaiiing processing dairtco device iliat that istrunn d... rves a mucb much widar wide, audiaika, audience. full fullcvttom cvltompnrhrvic. ptt vhvk* tor fo, "roec-'etr" fr» "q»e1.,," DtcoOan TOA109Q D«othrs i 3,35 B4lo j O30 i formpx SA121 S locer HAH HA11219 mpulm mpuhe noiie no!.. blanker blanko, for mobile mobila and fixed radio/audio. radio/.udio. t can even ayen 'dean* TOKO '' chokes: cok..: MC31OP D*tad*ft fat MPX Dcr. 0,18 MC310P co'.... ajuu from luh to l20mh in typll CA3090AQ MODULE5.. ooltiry noiray tignai sitn" otharwiw othorwi.. knaudiblel inaud,ble' Owtined Destined for for. a blgfuturt. Stock MC130P 2 20 TT210 0, i» big tuturo, 7Ba 7Bal 1000uH: l vefum looooh; trorrr flp gr 16pone-off Ona-otf M tn three tvp«*i CA3O0OAQ HA B81Q ilfod MA1012 clc.ctt TDA1220 TDA1,220 SGS" Sas' entiv entry into the AM/FM r*5lo radio C battte battle with a promiwng promiting approach approoeh that 8RB 8R8 loouh-33rr>h: l00uh 33mH: pone-off one-off HAl MtO40 0,45 waiojcmx 1( t24 ht94slepatbtei seplrates AM and FM functiom functions into taparate separate bloeki blocks 10RB4.7 R mH: 33p 33p one one off *04400 off. tf MVAM2 1.4B 12cM24nrg45* MVam115, 1ransfO ~ CFM?fLFV CFM2/LFY The worldi world. imdlatt smallm ceramic caramic laddar ladd.r and end mechanical machonieal filtan filters from TOKO Alto Also tuneable high valua nductor*, inducton, with Wit h Over Audio ov.r fmtadn LM380N 1.00 MVaml % adju.tment rlnges from "'ijllues LM381N 1.81 BA " dlspt8v MA1023 Switched Swtched 12/24 hour 0.77" o.n" LEO LED ditplay display alarm dock module modul. with no RF 60% adjuitmint'enpn tnxn nom vaiuet t.m381n t.m380n 1,00 Syrs? MVemllS 35!'?! 05 MA1023 t.anilo, 1.60* tunerheadl 1.00 d.1ogl 096 1nl osc The chences chances are that our catalogue will be the first piece place many of you will eee TOKOtunerhaads 2283 uaisii i.oo liei ' B"", 0 f'xx 1 mt rre.w alarmwc see EP6600 EF6600 RtbCKin Renoun wricw/moitti... ncap/mosf.t TJoT T048O TBA8l0AS BA1S /24hr 112&- these new products. Backed with our extensive R&D, we aim to provide a EC3302 -pumium 'premlum Ul/vir f.t/... Plcap w , TCA04OE T0A81OAS TCAWO TCA940E A9 1 SO OA91 ' BJJ trenjlo , 11 trlln,fo 166* 26" 165- regular summary of new products in the radio and associated fields of elec- elec E!ff!l.3!Y!- AT/NT3302 Co«V4nnW1.. Combined T>in*r/8Y1 tuner/em 8"b^ 1lr::~'!n!lL 8.25 TDAjflO? TDAJOO :::ZA~~ 1.75 ~.~ :~::::~:fn am/fm ::'J'i'tun.r lunar tronics and we nvite invite alf all submissions for consideration. R8t4HnC» Reference HliB seriel tu041 tuner mooulsi modules for FM Op :mp,. cat/pric. prey~~:~s Mlv. As well as.j1 rhos. p,...,iously ld 'l.rti~ed.... LM301N lilt. EF n the theory wction section this issuer AT mil at *tl f4c«a pravlowly r*lv*n't*d r TOA A new rs-ipi n modulates ',VT Or>amp< LMMl N ourcsi/eilca pravlously adv. issue: EF6B03 EF M05FET MOSFET very highaam gain (ownoae low noise UA74 LMMN O.aS' l!», f«4cn Mer.n EF Tunod Tuned drcult circuit impadaocoi impedances and matching... coing - tradnng tradung and bendtpraed band.praad -1 a nonel 1 approach to lt»ge staoe vuicap tun*' tuner with With CA3 ua ,34' Molur* ef ,45 0,86- Mm edge wvith kH2 100kHz to 30MHz continaouify continuolllly timed tuned radio and the ditcriminatlng discriminating metal motallocato, locator,... save ainpllliad/'buffarad oscillator o^lpvl ] ' CA3130 LM30OOV DOT'Ueriely 0 85' MinedQ ol»mi«with ;;,:::~-:,:~!r:=: ~~=or o~~~ LM3900N arietv of sc. let your monav money before you buy one, ono,.nd and me... bov* how they're they',. made mado! Spaclrvm x6po1, filt. rs, AGe MOSFET Po.",.r~lJl.rof'S ilium. 2.50j comp.te kitl n a 8 world of electronics electronics that comtantty constantly expands and divocsllies diversifies into an incrcesing SaSodla inalyzer aligned 19 '5 Hluo>, ZM* comaleta kits increasing F F fih»r». 2 AGC MOSF6T Poworn^lnors 1^,.. prnmp, CA3l 89E All 7B05UC 1 55' 1 3~)c 5 0 flce for tunen/lf, number of specialities, we offer you a refuge where we stick to one main fheme, theme, and turklloni pmampf. functions etc, CA31.fc, mute, WE mure, malera AJ. tuner meters etc. 7e05UC rda14l2 TDA ; W th..."etv y of T»ettl metal lowton - f ' locl'ton Spectrum an.lyur aligned UC 1.&5- scalm see lilt keep you informed to a 8 standard not possfbte possible n in publications without direct every-dav every-day Spectrunt anaiywr alioiwd 16, UC 1.56' Amfttinavilue» price list decodert af montor Amaz ing ' 'alue nvolvement involvement in project research, development and evaluation. 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SEEM ET AVALABLE N KT FORM THE FAMOUS L'T POCKETSZE M METAL DETECTOR Seemet readily detects concealed ferrous and non-ferrous metals within range of its detector field. deal for finding concealed pipes, wires, nails etc. One-handed operation, uses standard PP3 Battery (not supplied). ONLY 3.2& plus p. & p, 25p. (inc. VAT), Oil fun instructions supplied. UNBEATABLE DMMER OFFER from Britain's largest Dimmer Makers. Complete Kit of Parts for our VCl VCL 500M, SOOM, 500W SOOW Dimmer Switch. s Only 2.00,, plus p. ft & p. 25p. (inc. VAT) full instructions supplied. Send coupon bdow below with your remittance. Please suoplv: supply :- PW2 NAME SEEMET KTS O r ' AV " : at E3.S ncl.of incl. ot p. & p. ADDRESS DMMER KTS D at 2JSinc.Ofp of Bp. & bucosb enclose cheque/p.o. cheque/p.o. POSTCODE for lorf ( BLOCK CAPS PLEASE HQ w Fotherby, Fotherby,Willis Willis Electronics Ltd. GLADSTONE TERRACE,STANNNGLEY, LEEDS,LS28 NE. GLADSTONE TERRACE, STANNNGLEY, LEEDS, LS28 SNE. L Telephone. TelBphone Leeds LeedafSTO0532) (STD Telex 657t1t GLYNWEol q^ynwed ~ Practical Wireless, June

70 them, as one newromer newcomer to this column did, as un un- pea identified Spaniards. At this time of year listen for Latin Americans,after iafter midnight, the peak occurring just before sunrise. There are very strong signals to be heard at times. Steve asks what type of equipment is in use at; at, my Q'iH. QTH. The main receiver is a GEe GEC BRT400, a valved SERVCE communi<jations ooramunioations type that was designed some 25 years ago for broadcast band monitoring. Also in service is an Eddystone OC0 EC0 which is very useful as a second receiver if it is necessary to check two channels. channels, A 90ft long wire wirh with a.t.u., a 40in loop, crystal cali cali- brator, audio notch filter, portable tape recorder and a home-made switching unit to switch aerials and cali'brator, calibrator, completes the set-up. Another DXer who continues to use valved equip equip- ment is J. Gaines Gaincs of Surbiton who has a Marconi CR00/8 CR100/8 which is giving splendid service. used a Oec Dee 75 Disco Dltco System, Llpht Light Modulator AM0423 3' Mar 78 7# CMOS Cryetal Crystal Calibrator AM0438 A M CR100 for m.w. DXing for a number of years and it is 0 July 78 Disco Dleco Preampllller Preampllfler AOO3 A003 0' a really first-class receiver on this band, though its 0 Aug Am 78 Cassette Caseetla Player Power Supply A performance on the short waves leaves a lot to be 0 Oct Digital Dioltal Car Clock (eat) (set) A011/012/013 2' desired. One "mod" carried oarried out by J. Gaines was to Oct 78 nterwlpe ntnrwipa ONBJM DN8JM 0' split the d. r.f. and i.f. gain controls. Oct78 Oct 78 Video-Writer video-writer (set) 0002/3/4/0 0002/3/4/8 A ' This is a feature of the BRT400 that appeals to me Nov 78 Clrtaet Clrtest Probe A018 0' as the r.f. gain control on many receivers controls Nov7a 78 Burglar Burolar Alarm AOtO A019 0' both r.f. and ij. i.f. gain at the same time. With the Oec Dec Chromachaae Chromachase A02t A021 5' BRT400 the two are separate and there is an advan- advan Jan Jen 77 Oscilloscope Oecllloecops Calibrator A023 1, tage to be gained at times by adjusting them separ- separ Apr 77 Gas/Smoke Gae/Smoke Sanaor Sensor Alarm A02a A028 0' May 77 ately, Overloading and cross-modulation occur at, or 2-Way (nlarcom ntercom D '28+12 O 0 May 77 Protected Battery Charoer Charger A027 2' before the mixer and it is often necessary to reduce May 77 Seeklt Metal Locator A031 3' r.f. gain to eliminate this, with of course a reduction 0 June 77 Reverberation Amplifier Ampllfler A '38+'2 0 in i.f. gain as well when a common control is in use. t ft June 77 Versatile Voraatlle AF Generator A03a A033 2' is in the mixer stage that the bulk of receiver noise June 77 Tele-Gamee Tele-Games '22+' O 0 is generated -and,and in order to obtain a good signal-to- signal-to July 77 20W 1C C Amplifier Ampllfler AOM A noise ratio, the r.f. gain should be as great as possible. July 77 Radio 2 Tuner A03S A035 1' n 0 Backing off the i.f. gain is the way to follow signal July 77 Dlflllal Digital Clock Timer A Aug (Telegames) 0035 strength in this case, especially with the a.g.c. Auo 77 Shoot (Toleoamee) D "55+'5 0 switched off, which should be normal practice when Am Aug 77 Atomic Time Receiver ' Aufl g'ain Aug 77 DXing on the medium waves. 1 set the r.f. gain as Moree Morse Code Tutor Cards (SRBP) A ' Sept 77 Jubilee Electronic Organ A038 19' high as it will go without giving trouble and then 0 Sept 77 Electronic Car Voltage Regulator D ' control signal strength with the i.f. gain control. 0 Oct 77 Audio Level level ndicator DOM ' O 0 A good substitute for an r.f. gain control, if none Oct77 Oet77 Slno-Squoro Sine-Square Wave Generator D04O ,35+15 O 0 is fitted, is an external attenuator. The simplest is a Nov 77 Laboratory Power Supply A039 A ' potentiometer of about 1000 ohms. The lead from the Jan 78 Direct Conversion Receiver D ' D 0 aerial goes to the central tag. One of the outer tags Jan 78 Proportional Power Controller DN9JM ' 0 goes to the receiver laerial socket and the other outer Mar 78 Audlo/Vleual Audio/Visual Logic logic Probe R '40+15 P 0 tag goes to the receiver earth socket. Overloading Apr 78 Eurepa Europa Stereo Amplifier Amplifler R002 ROO '55+45 P 0 and cross-modulation cl'oss-modulation can be controlled very easily by May 78 DX'ers OX'ers Audio Filter D ' this method. June 78 Bovlngton Tank Game R006 ROO June 78 Audio Distortion Meter (eel) (set) R007/8/0/10 R007/8/9/ '75+25 From Farum in Denmark comes a letter from Mick 0 June 78 Darkroom Timer R '55+15 Evans who describes himself as a London guy who 0 has gone to live and work in Denmark. Mike says that Poet Post and packing t s for one board or set of boards. Prices nclude PW is very expensive in DK land, working out at well VAT. Remittances with overseas orders must be sufficient to cover over 1 'a a copy. Why not take out an annual subscrip- subscrip despatch by sea or air mall as required. tion? This service has recently been re-introduced at enclose Postal Order/Cheque ACCESS welcoms welcoma per annum to any UK or overseas address. Send card number only. Mike's main trouble though is a buzz spread over a No.... portion of the medium wave band and he asks if a mains filler filter would help. f the buzz is being radiated for... made payable to READERS PCB pca SERVCES LTD by the house wiring, as seems the case, then it would be necessary to -filter filter the whole mains supply to the NAME house. Contact the Danish Shortwave Club nter- nter national, Greve Strandvej 144, DK2670 Greve' Strand, ADDRESS Denmark, who should know the correct body to com- com plain. to. The D-SWC nswc incidentally, is international, it publishes a bulletin in English called Short Wave.... PostCode Code,.... News, which contains -a 'a medium wave w.ave section, in spite of the name. Enquiries in the UK should go to Noel Any correspondence concerning this service must be addressed ' Green, together with a stamped addressed envelope. Noel's address is 14 Marsden Road, Blackpool FY4 L J 3BZ. 68 Practical Wireless, June 1978 r T ::-R~D~S READERS -;C;-S;V~S PCB SERVCES -:T~ LTDT PO BOX 11, WORKSOP, NOTTS Plea.e Ploago supply PCB'g pcels as indicated by tlck/s tlck/«n box/es. bo*/ea s.ue i*u* Project Ref Price PP P/P Dec7S Dae 75 Sound-To-Llght Sound-To-LlQht Display ON079a DN0798 1' Oec Dec 75 Disco System, Amp. (2 req'd) each AM0421 4' Any correspondence concerning this service must be addres.ed J^^o^READERS to PCB pca SERVCES and not to the Editorial offices.

71 ELECTROMCS ELECTRONCS LTD HF 7948 FRONT END Fl F F AMP AND DECODER l_---- \- \: -. THE MOST COMPREHENSVE RANGE OF TUNER MODULES EVER DSPLAYED ALS1500 STABLSED POWER SUPPLY nc. VAT, P&P TECHNCAL CHARACTERSTCS: Outputlerminal terminal for digital frequency meter; Antenna impedance -15 impedance-75 to 300 Ohms; Frequency ranges ST'S 87 5 to 104MH2 104MHz or to 108MHz: ; Sensitivity 0-9uV26dB Sensitivity-O'9uV signal to noise ratio ±75kHz ± deviation; ; tntermodu- ntermodu lation 80dB SOdB image mage rejection 60dfi; rejection-60db ; Tuning voltage tv voltage-l V to V; 11 Total gain 33dB: gain-33db; ntermediate frequency 10-7MHz; frequency-l0' 7MHz: Power supply voltage + SV; 15V; Power consumption 15mA; Dimensions 104 x 50mm, 50mm. TECHNOLOGY: Double sided epoxy printed circuit board with plated through holes; Dual gate effect transistors; Silvered colls. coils. nc. VAT, V A P&P TECHNCAL CHARACTERSTCS; CHARACTERSTCS: ntermediate frequency -10' 10-7MHz: 7MHz; F Bandwidth 280kHz; Bandwidth-280kHz; Signal to noise ratio 70dB -70dB with mv lmv input; Distortion mono Distortion-mono 0'1%, stereo 0-3%: 0'3%; Sensitivity 30u Sensitivity-30uV V up fothesdblimit; to 3dB Channel separation 40dB separation~db at 1kHz; 1 ; Pass band 201o15,000Hzi band-20 to 15,OOOHz; Rejec- Rejec tion at 38kHz greater than 55dB: 55dB; Am re- rejection-45db: De-emphasis 50 De emphasis-50 to75rrs. 75p.s. jection 45dBi Pilot capture at 19kHz +4%; +4%: Channel matching within less than 0-3dB; 0'3dB; Output impedance 100 impedance-loo Ohms: Ohms; Output voltage voltage- SOOqiV; 5OOJ;Tl Phase locked loop stereo decoder; Output for LED VU-meter; Null indicator; Outputs for AGO, AGC, AFC and nter-station inter-station muting; Consumption 55mA Consumption--55mA LEDs extin- guished. 100mA LEOs LEDs illuminated; Power supply 15V: supply-15v; Dimensions 195 x 76mm. CRCUT TECHNOLOGY: Epoxy printed circuit board. Monolithic integrated circuits, ceramic filter. OPTOELECTRONC OPTONS 806. nc. VAT, V A P&P l,p&p 2,53 nc. VAT, P&P TECHNCAL CHARACTERSTCS; CHARACTERSTCS: Output voltage 15V: voltage-15v; Max. output current 500mA; -500mA; Thermal coefficient less than 1mVrC; 1mV/ 0 15V power supply for modules HF 7948 and Fl F 2846; Supply protected against short circuit (power and current protection); Dimensions 65 Dimensions-65 x 65mrn. 55mm. TECHNOLOGY: Double sided epoxy circuit board; Mono- Mono lithic ntegrated integrated circuit. - ^'-.t mm LED LEO VU-METER Station strength indicator nc. VAT, P&P LLUMNATED PONTER Station finder 22,74 nc. VAT, P&P " FREQUENCY METER Digital display of received station frequency 8-77,77 nc. VAT, P&P TOUCH CONTROL PRE-SELECTON UNT LED channel indication ' / * fia'c i 4,35 nc. V VAT, P&P NUMERCAL DSPLAY Pre selected Pre-seiected channel number CROSSLAND HOUSE Telephone (0227) NACKNGTON. CANTERBURY KENT Telex Practical Wireless, June

72 LYNX ELECTRONCS (LONDON) LTD 92 BROAD STREET, CHESHAM. CHESHAM, BUCKS Tel. Tel, (02405) P. end and P. 30d 30p - Ovorton Ovo"'e Wp Op - Mnlchlno Matching 20p p«r per pair. ACCESS WEL WELCOME COME VAT 0% 8% axcopt except for llpma tema " which» 181% 12.% - No VAT OvoraoM. Overleas. HOME MCRO COMPUTER NASCON ONE 197" plus PLUS VAT MMS314 MM53l4 MM5310 MM53l8 MC1310P SG309K SG309K THYR9T0R9 PJV 1A 3A 3A 4A OA 8A 10A 18A SUPER SAVERS SUPER SAVERS TL209 T1L FCS800 FCS8000 } i 34 Digit Dlap. Disp. j* 2 95 ** FCS8024. }\ 4 Digit Disp Digit Disp. J* MPORTANT NOTCE THYRSTORS PlY la 3A 3A 4A SA 8A loa 18A MPORTANT NOTCE (T05) (TD5) (ST- (C (TO (TO (TO (TO (TO All school., colleges, universities and UO) 108) 220) 220) 220) amateur radio and electronic clubs may UD) 100) 920) 290) 920) 220) 220) 208 0' ' deduct 10% off pra-vat prices. ORer valid GO o ' ,88 SS B till 31st Dctobor. COO '85 00' , , '28 11,80 '00 BT1M BTl08 1 \'00, 00, BTC; BTlO 110, \'10, BTOfl BT108!», \ n, DTM BT109 d \ 00. DD, BT11B BT116 1 \'00, OO, Diode. canld 2N3523 2N3525 CO-SO. PRCE LST Dlodea contd 0,50. BYX3& p BVXSO-OOO 9 0'\1 BYX3B-t200 BYX ,.2\ 0-21 TRPAC»-Pt c TRACS-Pla.tlc TO-Z20 TO-220 PacVrop Package lnolatid solated T«b Tab nyx3b-300 BYX A 8 SA 8'5A loa 15A 0 O'SO 50 BYX3e«(W BYX38-6oo (a) (b) (a) (b) (8) (b) (a) (b) (8) (b) 00, V 100Y O'W) 0,60 00,50 « ,7878 0'78?«0-B3 0' B ,01 VC BYXaa BYX38-9oo Y 0'84 0 ' , '80 200V OM CM 0-7B M7 117 BXY30-12OO 9 50 BXY38-12oo 400V 400Y 0'7? fl7 0' M ' ,85 05 MOV 600V O 0-98 M 00'99 W 101 1' M 1' ZX0 BZX61 Seilee Serlel 0,21 N.B.-(a) without nlflinal nternal dloc, dlae. <b) (b) with nl«rnal nternal d #c 0 21 dlec. BZX63 BZX83Serle. Serloa TTL "7$ 380 0'''' Regulators o 0'\\ S., '4$ 747 \ i& PH Pin S BZYBB BZY88 Surlea Serle. 0 \ '" ' \ SO 750 \ Pin Q 0' OAS DA on 7480AN \. 50 L.E.O. DA , SO L.E.D, Diode AN 0 o 05 SS 748 0'3$ Red 0 13 DA '50 8 Rad O U Dlodaa OA * ' Groon Green 8-25! O'ZO BA145 o 14" OARS DA90 0,01 "SO NE , 'SO 2 2 Clear 0 D 10 \0 BA * OA * DA o 45 NE K 0,95 BA15S 013 OA o,a '15 NE566 "50-,. Chips BAl58 0 \2 LM Clock Chlpa BA ) OA91 9 M N ' ' NE ' 3'25 BA157 0'22 LM34012 LM «MM M A Z OAaDO 0-01 ea1s7 72 NB14 90' N4oo CA3045 8S MM5316 sas BA15S o 22 0'1 LM340-15' 35 MMB310 N4002 "OS '07 AAY A BA CA3046 0'10" LM \'35 N4oo3..' CA LM34y AAV A S 55 BA158 0 «N4001 BA139 n N <002 9 M" 05" S'25 BY206 0' Dlaolaya AAY-S-4007D BY2D0 9 S N4003 o Mr AAY D BY207 o 20' N MCl3Q4P 0'95" Clati g::~!.~.,.gs 5S BY * (N40O4 0 07* BYX BYX36-3oo N400S N4oo5 o '''- o«- MC1307P 8 S 704 0'11 C SockaU Socke.. 0 \2 N4008 O ot N< * MC1310P \ 50' BYX N4oo7 0 10' 7420 o,e 0 Pin ns BYX N " MC1351P,, "S 14 Pin #-14 0,'4 0\5 N ' Oil 0 15 N41<8 0 00" , 30 MC1352P 075" NPN TO-3 TO.3 Power Transistors. Transistors, Fully lested tested but '" on MC1333P 075 unmarhed. unmarked. Similar to 2N3055 except: BVCEO - = D ,13 MC1458P 077 HFE(galn)=20+at3A, SAT<1'3V at3a. Spes H37 0' , 40 MC1'96L 082" HFEtoalnj^M+at 3A.VCE -OVat 5 pea 7441 AN 0' SAS500 2,25 1'00,25 pea pcs «4'00, pea pcs 7'50, M, 100 pea pes 13'00_ 1J OO o ',01 SAS TO-O TO.1. NPN Transistors. Medium Vollaoe, Voltage, HlBh High '" '70 TAA300 -' Gain unmariiod. unmarked. Similar to BC107/8/9. BC107/8/9, 7447AN , 33 TAA310A, 31 pcs. 20, pes ' ' TAA " 25 pea pea o '-35 TAA611B21-25' TO.3 TO-3 Hardware. Hardware_ Mica Wsshera, Washers, Solder tag, Nuts, 7472 o ,,20 TAA881 o n Bolts, Bolls, 50 sets tor for 85p. Up Rectifiers DO-4 Poehaao. 10A 50V A loov A 200VO A 400V Please ' '-S' TBA530 1-" Rectifiers 00-4 Package. loa 50V 045. loa T&A530Q, V loa 200V 0 60_ loa 400V Please Llnnir Linear.C.a TBAS ' A A 5' * TBA specify Polarity, Stud Cathode or Stud Anode D * TCA270SQ'.". deal lor for Power Supplies. SUDDlles, nverters, etc. Tran»l»(on> Translator. BC147 0,01' B BFX "30 DC4S N CMOS AC BC148 ',01" B " BFX845 0 '23 DC4& 020 2N3056 O'SO AC BFK045 9 PLASTC 0'" BCU9 019" BO31 031' BFX8 0'25 DC70 o S 2N3137, " 0 AC BFX0 0't 4000BE <000BF AC128 0"1 BC1S7 0 0' B ,40' BFX88 0 ' 25 DC N ' ACM AC128K 0,25 BC BO ' BFX87 1 ' 20 DC N3442 '20 4oo2BE 0-20 AC123K f» 4002BE BE AC141 0'22 BC159 B " "51' BFX88, 20 0C N SO 4008BE, 'OS AC «BE 195 AC141K 0'34 BC160 0,32 BOl44 2,20 BFX89.. DC131, 30 2N3702 0'10 ACt4lK BE 400BE o» ZO AC BC BOl BFY11 ",0 DC140 '30 2N3703 0'0" AC OC BE. 13 AC142K 0'31 BC ' B01Bl 0'" BFY1B OSO DC N3704 o \0' 4oo9BE ACH2K 9 37 OC BC "52 BOl82 o 12 AC178 0,'1 BC69 O'\Z' BFY40 O'SO TP28A 1-44' 2N3705 0"0 OBE 052 A C TPMA 9 U* 4OO0BE f 0» E AC176K 032 BClagC 0".' BO BFYCl 0'" 0'52' 2N3708 o 10 AOTaK 0 M TP30A 0 82" 4011BE.011BE B0184, 20 AC187 0 \1 BFYSO BC82 0'1' "20 A 54 2N3707 0"0' AC1B TP41A 0 o 20 AC187K 0'31 BC1B2l 0 \2" B0232 0," BFY51 0" TP32A 0'14 2N AC167K D M TlPMA 9M 4012BE AC B BFY52 0"1 o n 2N ',00 AC1M 9'tl TP41A 0 M 4013BE» 4014BE 111 fl-m BC AC188K 032 BC83L 0"0' B '$5 BFY TP42A N371 0 AC1B0K 0 32 TP48A 0-72 "' E 4015BE '-ts A B0238 0," BFY84 0'31 ' 2N3711 0,'0 4018BE 014 AD BC184 A0181 0'S5 0"" B0410 0'" BFYO... 2N BE 2N N3715, '/0 4017BE AD N0M 0».. BC184l 012' A BOX BSX19 0'" 2N887 0'20 2N3718 \ BE AD N097 0'» Ml 09,." AF BC " BOY10 1'5' BSX20 0'" 2N708 0-\5 2N3771 ', BE AP N70e 15 40l»Be OM O'SO AF15 0'20 BC87 o 24" BOYll BSX21 o 20 8N1131 2N N3772 1' BE E 1, 12 '2 BC207B 0 12" Z'OO BSY N1132 2N " 0 "'1 \ 03 AF BC212 0,'" BOY20 o 8N1132 OH 4021BE 10 2N ' AF117, 20 BC212L 012' BOY3S 0,10 BSY53 o 38 2N BE AF18 0'50 BSY N N4347, \0 4023BE 0 20 BCZl3 0,12-8N «4O830E 0 M 20 BOY80 1'71 AF BSY N4348 \, BE... AF BC213L 0'14' BOY6',,15 2N BSYSS Nl N ' 4025BE 020 AF126 0 Z5 BC214 0,14- BOY82," 2N <026BF OM BSY78 o 20 2N ' 4026BE,,, 20 BC214L 0 S" BOY95 2," 2N1300 2N1308» O'SO 4028BE 1 W 2N4918 AF39 0,35 0-"- BOY6 401 BSY78 0'75 2N307 O'SO.12 AF23' BC237 "37 0''' BSY95A BSYl5A 01. 2N N BE 0'.' AL102 ".5 BC238 0,11- BF179 0'30 BU1Da, 9... an BE BU05 'M* 2N13M * «2N N4920 o 4O2B06 «50' 40'~9BE AL103 ',30 BC300 o 34 BF180 O'SO BU BU105/02 05^02 2N BE « N N4922 0'51 O'S 3 30 BC301 0 '32 BF \ -80' 2N4.23 2N2102 o 0'.' AU AUll0, BC BF N BE 05 AU " 0'30 BUOS BU108 W 2N21W 4i 4041 BE 10 3'00' 2N2217 0,30 '13 AU113 1, 00' 80' BC BF183 0'30 BU N25S. 0, BE, BCY BF BU12S,... 50" 2N Jf 4042BE 2N2308A 0,'4 BC97 12 BU126 1W 2N2359 2N2309A f MEMORES E H 0 14 BC107B 00\2 12 BCY BF BU33 ' 00 2N A-8 3'" 4048BE ',32 BC BCY32 0'" BF94 0,'0' BU204,-... 2N2403 0» 2102A' BE 2N2484 Oil A A-4 44' BE BE 054 BC108B 0 12 BCY BF18S BC103B 0-12 BU2Da 1'10-2N2M0 2N264S O-SO O SO BE 7 " 4050BE 084 BC)08 BC '12 BCY34 o 55 BF197 0,12- BU206 2'40* 2N ? ' MBE BE BC09B 9'1 0 \2 BCY38 0'50 BF224J. U- BU N \ M \O'DD O'SO BC109C OtS 0 15 BCY39, \5 BF244 o n" MJ N2B04A 2N2804A t ? M 4070BE '28 BC117 0 \9' BCY BF MJ481 \,05 2N SO sen? o-ir 4072BE 0'21 BC111 0'25 BCY BF MJ N2ftOS W 4071 BE 0 0» 20 2N2805A 0 3 Z'SO BCfi N2005A «2602 ZH E BC125 0,'" BCY54 ',88 BF Z MJ491, \5 2N29M 2N ," 40fl1BE BE BC125 #1l* BC128 BCl28 00'20-20* BCY70 0 \2 BF338 0'.5 MJE340 o 40" 2N2925 0"4' Re.lstors 4510BE '42 BC14a BC140 0M 0 32 BCY71 0"1 BFW30 \-25 MJE " 0' N2920O ZN29Z N2828D 0-19 Of R««r»to»»* 4510aE 4511BE \ BC BCY72 0 \2 BFW59 0,30 MJE321 MJE ," 2N2920R 2N2928R ,'0' 10 10DHM-l0M OHM-10M Sl5fiE BE 4518BE 1 \ BC B0115 o 55 BFW80 "38 OC43 001S 55 2N2926Y 2N282eY 0000" 0»* j jwat1 Watt 1 5p 4518BE ',25 BC43. Z3 B0131 0'31 BFX29 0,21 OC44 on. 32 8N292«G91' 2N2828G 0 10" i lwalt Watt Z 2 0p ip SBE BE E 1 ' Practical Wireless. Wireless, June 1978 DSCOUNT SPEAKERS mp! Oumrantai or Sapp. mp 8 or SO pp. Gua... nt : TTAN y... FANE E yaara yaara OTHERS yaar y.. r ALL PRCES NC, VAT NC. VAT Prica* correct at Prices correct at H F H-F TYPES Sonic Lin/Valoe List/Value Prlc# Price 5-5 FANE H 50f 501 Mid or Full rang«ran&e 5p. Priue 8" Sw Various makes B 0: 8- x A.F. 5" Model 5w Varioui Ou*l makca. Cone 3 Q 0 O Sp. Sp. Pr Price Price to 8" S" A.F, A.F. Model 83 Dual Cane Cone Sp. Pr Price ce FANE 8" 808T Price WH'FEDALE 6" 0O8T Dual Cone Sp. Pr c a l'ton kit O" OENTON L'TON DENTON 2XP OT 3XP KT Pair U\i Pr " GLENDALF. GLENDALE 3XP KU S" FANF FANE MODE ONE KT Sp. Price Pair 10" ELAC Model 10RM Sp. Price 4'" ," 6 " 3." 44." 17," ,.,. 3-8' 1 10" ELAC Model 0RM Sp. Pric«GROUP/DSCO TYPES 12" 2"TTAN T2/45R T12/45R 15'SO " TTAN T12/60 T12/6OR R SO 50 \~: 2" TTAN llte~tt6w~11~00w T2/OOA loow m:gg " CELESTlON G2M <» " CELESTON G 12H " CELESTJON CELESTlON CELESTON G2/50 CsllH 30w G12/50 50w SOw " GOODMANS 12 PD Sp. 12" GOODMANS 12 PG Sp. Price 12" FANE'SPECALST'P.A. P.A. 80 SO 627-9S Price 12",, DSCO ".. DSCO " GUTAR 90L SOL "" 12" "GUlAR 100L "" 12",, "GUTAR GUTAR GUHAR BOB 1001 SOB S'95 12" la " FANE FANE CRESCENDO..,,12l 2L 2A " " S" FANE.. 12 BASS (CS6-70 TS/ " TTAN TTAN 715/70 T15/60 T15/70 70w 60w S".,." TTAN Tl T15/100 OOw 100w "" 15" ," 15"" S" FANE 'SPECALST' BASS " '50 15".. fl.. BASS S" SP Sp. Price Prico 13 " GOODMANS CELESTON G5C 5P 36'00 16'" 15" S" 15" FANE CELESTlON CRESCENDO/S CRESCFNDO/S G5G " " 15" FANE S" CRESCENDO..,,15/100LT 15/OOLT 15/OQLT BASS " 71," 15" :~= " :: cot~mt~6foow?o~:gg 15" 15/160 60w 200w S" TS/OO 100w U8-95 " 10" TTAN.. S" TG/ /100 COLOSSUS 8P OOw 200v. 18P Sp p. Price B" B" GOODMANS " S" CELESTON 0P GSC '95 la- 18" CELESTlON S" FANF CRESCENDO GBC BA SA '" B" B* S" FANE CRESCENDO BASS '" 95 la" le" S".,.. " 'COLOSSUS'200w 'COLOSSUS'20Ow M TS-00 7' 00 PLEASE STATE MPEDANCE. HORN UNTS <c.rr.8so) (Carr.85p) CELESTON MHOOO 15w U 75 FANE CELESTlON 910 MK MH1000 f SOw 25w LlO'" w OOw «44 50 J44 30'50w ," ," j SOw -SOw )l '70w 50 70w LlO'95 HGH POWER CROSSOVERS' CROSS OVERS' FANEHPXlRor HPXR HPX2RCarr.35p ea < ADD-ON HGH FREQUENCY UNTS 'Add-on' S TTAN F.A.L. 'Add-on* Carr TH C... 1." TTAN TM TS2H 70w loow Carr. 100w Carr ll " TTAN T2K T2H Cirr. Ca CM 16" 95 EXTRA SPECAL MAL ORDER OFFER TTAN TA 50A SOA 50w SOw AMPLFER, ~-.,,,,,.,.. Hilh sensitivity. Multi purpoie High idnjliivity. Muki purpose three inputs. controlled ihree ind Cantroli* B»«. Controls~ Bass, Treble & 81 Presence. Robust. styled ubi Black Prei«n<e, Vynide Robuit. covered. well Attractive tcyled compact BltcV/Sllver cabinet Black/SlJver Fatcia. Fascia. 12 monthi months Guarantee. Carr PAR FANE POP 15 12' 11" SPEAKERS Suitable use in series and housed for in u»e lealed with sealed cabinet above when wired n 9-95 lorle*.. 9S SUTABLE TWN SPKR CABNET Alia Also for personal ahoppera shoppers only y AMPS, riables, T'TABLES, JHGLE JNGLE MACHNES. MACHNES, DSCO CONSOLES. CONSOLES, LGHTNG. LGHTNG, CABNETS. CABNm, CREDT TERMS AVALABLE o:~:~. 20 lo Phon* Phone order* orden Kce«pt*d accepted from rrom Acceea... A Barclay aarelay card ho'i-"- hold... Branches at 403 «3 SAUCHEHAU. SAUCHJEHALL STREET fil Tel: 3]1 GLASGOW AtfiflW T«l! «LHJUU T» 24 NEWGATE SHOPPNG CENTRE T«li T.1l Mil 0631 U1M NEWCASTLE Mail Ordara & Export enquirl" to NEWCASTLE Branch. Hi-Fi pkrs. kit$. Otherwiie Add 1 carr. on H-F»pkrs, or kit*. Otherwise 25 (12" ~_ add (15") 1-25 (l2"spkr). (S") 2 2,50-50 (16") (S") ~:::! 11,., 16-" m:r, 19," 1'," Ll9'" 11'" Ll8'" Ll9'" Ll9'" 41," D." Ll7'" Mail Orders & Export enquiries to NEWCASTLE

73 -C.E. MULTMETERS SWSS The Le.E..C.E. range of multimeters provide an unrivalled. combination of maximum perfor perfor- mance within minimum dimensions, at a truly low cost. Plus, a complete range of add-on accessories for more ranges, more functions. "4 t - a/t Supertester 680R (illustrated) Supertester 680G M Microtest 80 * 20kn/V,± 20kfl/V, ± 2% fsd on d.c. * 20kn/V,±1% 20kfl/V, fsd on d.c. * 20ka/V, 20kfl/V, ±2% fsd on d.c. 4kfl/V, 4kn/V 1 ±2% fsd on a.c. 4kfl/V, 4ka/V, ±2% fsd on a.c. 4kfl/V, 4kfi/V 1 ±2% fsd on a.c. * 40 Ranges - 8 Functions * 80 Ranges - 10 Functions * 48 Ranges - 10 Functions ' Complete with case - * 140 x 105 x 55mm * 109 x 113 x 37mm only 93 x 95 x 23mm VAT VAT VAT (Pot (Fm Mil.1 Mall Ottlot O" ler add 80p BOp Pf.P) PoP) (For Mail Mad Orde^add Order QOo BOp P&P] P&P) (foi (For Mall M ail Orrfat Order add BOp 80p PS'P) P&P) All.C.E. multimeters are supplied complete with unbreakable plastic carrying case, test leads, etc. and a 50-plus page, fully detailed and illustrated Operating and Maintenance Manual. Now available from selected stockists. Write or phone for list, or for details of direct mail-order service. Now available - from selected stockists. Write or phone for list. or for details of direct mail-order service. Electronic Brokers Ltd Pancras Road, London NW1 2QB ^ Tel: DGTAL CLOCK KTS... thousands sold Your career in Electronics?... thousands sold TEAK or PEHSPEX PERSPEX cases,r ^ t " Red LEOS LEDS. A 4 digit T2hr 12hr display PM - indicator. Mains frequency accuracy Complete instructions. Povrer Power cut flasher. Real wood or Perspex: : White, _ Black. Black, Red Green, Green. Blue.6''x 6" x 2^ 21" x 3" - DELTA ACAflM.'Auto ALARM : Auto Brightness. Pulsed Tone. 9 min snooze Electronics only kit: Won Alarm Alarm Complete with case: Non Alarm Alafm 1BOO Alarm Ready Built Tested Working: add 1.00 Timor Timer Focitlty: Facility: Display Seconds Slopwatch Stopwatch use. use, Sleep Delay: 50p extra DSPLAYS: ; -f' Red LEO LEDFND500 FNDS each. 6 for 8.4«6.48. NS85430 i" -j-" red Enrol in the BNR 4 '" H E School and you'll have an entertaining and LED. Stick of 4 f T07 5LT02 stick of 4 Green 5, fascinating hobby. Slick Stick with if it and the tile opportunities and the big CLOCK CHPS: MK5d253 MK50253 Alarm 12/24hr 4;6 digit MM538S MM _32. in MKS0362N MK50362N calendar digit counter 60395/6/ /6/ money await you, if qualified, n every field of Electronics today. MCRO PROCESSOR: i'-races-sor: 280 Z80 CPU CTC & all P10 Pia MK4696N We offer the finest home study training for ali subjects n radio, MK40 300ns 300n5 4KX_ Dun RAM A UV PROM 450nS 450n television, etc., especially for the CTY AND GULDS EXAMS BATTERY iaffery-ilecharger: RECHARGER: Mains Adaptor with w 4 way Plug. 4XAA (1.2vl (1.2v) Ni j Brit. Cads plus holder 8.64, AA Ni Cads separately ~~ 1.20 (Technicians' Certificates)! the Grad. Brtt..E.R. Exam; the RADO AMATEUR'S LCENCE; L1CENCEj P.M.G. Certificates; Certificatesj the R.T.E.B, R.T.E.B. BARON BARON(PW).6 f P W). 6 Gower Road. Royston. Herts. (07B3) (0763) 43B95, Servicing Certificates; Certificatesj etc. Also courses in Television; Televisionj Transis- Transis Use BsrclaycBrrf cracebss tors; j Radar; i Computers; Servo-mechanisms; Mathematics and Practical Transistor Radio course with equipment. We have OVER 20 YEARS' experience in teaching radio subjects and an PRACTCAL PRACTCAl WRELESS U. T.V. SOUND TUNER unbroken record of exam successes. We are the only privately {No*. (Nov rticl*.rtlel. by bj A, ". C. C. Alnillo) "nlll.) Cw COl" vf of ottplml Mllllnll vudt or//c/. tup/jl/td on 0t W/**f,.ef run British home study College specialising n in electronics F Sub-Assembly (G8) (GB) P d & P 75p. subjects only. Fullest details will be gladly sent without any Mullard ELC1043 V'cap UHF Tuner ; P P& A P35p. obligation. 3-way Station Stati,on Control Unit fl-zo P 4 & P 25p. 6-way Station Control Unit (Special (SpeCial Offer) 1-M ~ ~ Power Supply Prtd Circuit Board P & P 30p.. BRTSH NATONAL RADO & ELECTRONCS Res, Caps, Semiconds, etc. for above ,80. SCHOOL, Mains Transformer for above ,50. P & P 30p. ri P.O. Box 15, 156, Jersey, Channel slands. Add 121 % VAT to price of goods. P 4 & P «ll all tems 85p. NAME Callers welcome 8{ at shop hop premises. J ADDRESS MANOR SUPPLES 172 WEST END LANE, LONDON NW6.. rrypr-g WO 6 (Block caps please) (Near W. Hampslead Hampstead Tube Sin.) Stn.) Tel ~ Practical Wireless, June

74 WATCH BATTERES 65p Ray-O-Voc Ray O Vac life- Most types. DY KT 35p. (with battery order) Case opening tool, fits most watches. Tweezers, Equiv. Eqlliv. Chart, chart, nstructions. 'FROM CASO^jJj, CASO," F-DO F 100 SPORTS WATCH Chronograph with up to 25 luncllont Chfonoo'.gh functions ncluding wl'h ng ncl "P net lime., 1 ss times, leg 'ap 1lmo» times.nil and Ut 1st 1 & 5nd 2nd oluci- place llmet times to second. Water r..intent 10 1/100 resllstant (10011) necond. (100ft) end Wetor and nlioc. shock resistant plasuc case &. strap. renlntant pleelln one A atiip RRP 2e 24 '»S 95 32QS-14B brncvlet RRP < QS 14B Melal Metal nnca.ed encased version Yersion ol of f-100 F-l00 wllh with tlelnlsnn stainless ilenl steel brllcelet RRP Vn 'u-vc QR 16B Thli This new wulch watch it is really w»ll well lylud, st:t1ed. + 2 plus mopivatch stopwatch hom functions from one iftcond d'uo aecond to 13 hours_ 7 45mm thick. 13 hour ' 45imn thick RRP 44 g QR-17B 31QR 17B As ebovo above bul but 8 4mm RRP '95. ALARM WA1 CH (illustrated above) At o t last thpy they hsvo have smvedf arrlvedl Six digit dloplay. display. Hrs, Mm, Mina, Sec* Sect plus Day Hr., Mlns, Cate Day. Month and P'vi Dr»y or Hrs, Mlno, Dalt plus Do*. Monlh demand. with on/off indication. date on dsmand. Loud 24 hour alarm wllh onoff n. 2SCR.. t. Round fllted watch. RRP 64 as. 25CFM8B. Round faced w lch, RRP 64 93, SCS-19B. 2SCS-UB. Superbly slyled styled auare square faced watch. Slim case. RRP CS 11B WORLD TME Times areas plus and optional dates in optlonel time. ten world One touch summertime adjustment. Second aumniertimeadjublmenl. display, display. ± :t: 10 seconds/ secondsl month. 15 month months battery. 9 ' &mm thick. 9 dmm thick RRP QR-16B ALARM WATCH (illustrated above) 29CS-11 B Unlisa otherwue slalod CASO watches have a conalmu LCD display o! hour, minutes, seconds, Unless otherwise stated CASO watc.he. have a constant LeO display of hours. minutes, seconds, am/pm with day, dole date and monlh month on demand. With night light. 28, 30, mineral glase Ughl. automatic 29, day calendar, mlnerel gl811 stninlels they resistant face to and i00 all too feel. talnless feet. One ballery steel cases, battery l s o (hey lasts npproxlmbteiy are water ftpproximatety 12 months Accurate to le86 than :: 15 seconds/month 12 months Accurate lo less than ± 15 seconds/month BCO 075 Ciock/calendai Clock/calendar disd'ays displavs Hours. Hours, Mln- Minutes, Date measures ule. Dale Net and end Day. and Lao lap time? STOPWATCH times from 1/ second aver. Full access to 10 Memory. hours, Pe'centoges. with rollover. Percentages </..;,.. a (9mm 5000 hrs x Mmm batteries, 64mm y y, 115mm) leatherette wallet. ~, CASO AQOGO AOOM fil "'95. es. BT-1 ST. 21 2' «S. S. MQ-reM MQ.2 3C S.»- CASO SCENTFCS CASO SCENTFCS Dlglt.on Dlgllron i : FK31 FX31 t JS. S. FXJ9 FX3, es, S. FX1«FX48 in-js. 17,'5. FXla LCD: : FKZZOO FX t9 13. H. TXMW FX «5. S. LC12 LCan LC7 16 '9$. 95. Senri Send 25p lor for our imustreiied llustrated catalogue. cl'ltalogue. Prices Pike include nclude VAT and P4P P&P Send cheque cheque. P.O,. or Or phonp, you' your cedlt credit card number to* - '- DeptPW Fll2loy Fibraii FW stftii S... t T frhjupjsts 'EMPlJS Cambrldg. Cambrldgt cal EH Tolephone T>l> r)ia*» CB11 (0223) (tin) 312U JMM GOOD NEWS,FOlt FOR DX-ERS! Now you really can anord a i rcuucncy Counter. Now you really can afford a J-reQUCOl.':Y Counter. We proudly announce our model RQ-3. a horoubhly thoroughly reliable no-nonsense no nonsense desirn. design. available 10 to the home conslrociot constructor n in kit form. The RO-3 RQ 3 t is equally at home n in the DX-er's DX er s shack, shack. school science lab. or servicing workshop. t will display FREQUENCY. PEROD, PEROD. and WAVE- WAVE LENGTH. Coupled to the he local oscillator of o[your Rx. it will accurately measure lite the receiver tuning, tuning. ABRDGED SPECFCATON SPEClFfCA Operation -Operation up lo to 30MHz. SOMHz. Power -Power tcquliemcot; requirement:?a0v 240V AC. Movable -Movable decimal point; point: 6 digit d accuracy. Switch -Switch lo to select frequency, frequency. period, or wavo- wave~ cngih. length. A -:: % accuracy, accuracy. High -High input impedance and sensitivity. Send Now. Complete KT * % 8 % VAT. r RocivKHn* Also available: Crystal Calibrator model RO*l> Also available: Crystal Calibrator model RQ J. A novel design. which gives CW or arapliiudc amolitude modulated harmonics of 1MHz, MHz, 100 KHz, lokhz, 10KHz. Kit at unbeatable price 2-7J % + 8 % VAT, VAT. Send for details our details-our aim is your complete satisfaction. satisfaction. R0CQUANE ROCQUANE ELECTRONCS, Aldabaran, Aldebaran, L«Le Coudr«, Coudre, St. Peters, GUERNSEY, CHANNEL SLES. ETCH RESST TRANSFER- TRANSFER KT SZE 1 :1: 1 Cornplcie Complete kif kit 13 jheers sheets 6in X x ~t in with all symbols for direct application to P.C. Board. ndividual sheen sheets 25p 15p each.. () Mixed symbols (2) Lines D 0 05 OS (3) Pads (4) (~) Fish plates and connec- connec tors (S) (5) 4 ~ lead and 3 lead and pads (6) Oils OLs (7) Bends 90 and 0 130" (8) 0 B-0-U TO.5. T 0 cans (9) Edge Ed,e connectors nectors 0* O S 15 (10) Edge Ed,e connectors nectors 0-1 O (jl) (11) Lines (12) Bends (13) Quad in line CRCUT LAYOUT TRANS- TRANS FERS SZE 2:12 : 1 One sheet 12 n in X 9 in giving all transfers as in etch resist from No. 3 to No. 10 nclusive inclusive makes circuit layout easy. Black only. Price 1. J. Also lines and bends. Price l. 1. FRONT AND REAR PANEL TRANSFER SGNS AM All standard symbols and wording. wordin,. Over 250 symbols, symbols. signs and words. Also available in reverse for perspex etc. Choice of colours red. red, blue, blue. black or white. Size of sheet 12 rn in x X 9 in. Price P. 1. GRAPHC TRANSFERS WTH SPACER ACCESSORES Available also in reverse lettering. letterin,. Colours red, blue, black or white. Each sheet 12 in x 9 in con- con~ tains capitals, lower case and numerals. in _in kit or iin 1 complete. State slie size required. ALL ORDERS DSPATCHED PROMPTLY, ALL ORDERS DSPATCHED PROMPTLY. ALL POST AND VAT PAD. Ex. Ex, U.K. add 50p sap for air mail. Shop and trade enquiries welcome. enquiries welcome, E. R. NCHOLLS P.C.B. Trlnftfort Transfer. Dept.,. PW, Lowfleld Road, Stockport, Ch Lowfield Road. Stockport, Che WHAT'S NEW? ME, semiconductor riwe, semiconductor \f«aclitnj] eachi"s left kit The most MODERN. RAPD ECONOMC way to master Space space aie ale electronics. Starting even from ZERO by performin, over ~ (,' XS"! ce~: ' EXPERMENTS creating more than 20 practical applications You learn all about the most up to date electronic circuits; circuitsj haw how ro to calculate, repair, repair. and design them, while pursuing your favourite hobby, hobby. Start from scratch, or improve your present knowledge, knowledge. train and earn money in your )'our spare time, turn your pastime into valuable job lob opportunities. Compare our prices: you receive the entire course, "mini Hmini laboratory" and components for LESS than the price of the components alone. COMPLETE KT; KT: nothing else to td buy* buy. You get: - nstruction manual: : over 200 pages of detailed step-by-step. instructions. Start from rra m scratch, scratch. exolains e xplains basic laws and ohysics physcs of Electricity, Electncity. semiconductor semconductor principles and operation electronic circuits; rcuits: form diodes (including diac, dlac. zener) transistors. transistors, triacs to intecratcd integrated circuits (CMOS, (C.MOS. operational amolilieri) amplifiers) etc.... Over 200 Electronic components; components: aerospace tech- technology. Printed circuit it experiment e board, board. ohoto- photo noloev. transistor, transistor. triac, triac. thyristor l,c.5. LC.S. transistors (including PET., FET. MOSFET) LEDS Plus plus resistors, resistors. capacitors, capacitors. milliameter. potentiometers, Dotentiometers. variable capacitor, capacitor. etc.... etc... etc..., measuring instruments (you (YOU assemble yourself from among components furnished in kit), kit). ELECTRONC VOLTMETERS. LOW FREQUENCY MEASURNG AMPLFER. LOGC NDCATORS. REGULATED POWER SUPPLY. MULTAMT6R. MULTAMTER. You perform; perform: Over O 100 different experiments; experiments: from the most basic basc voltage measurements to radio radio transmitter circuits and including H Fl, F. Flip Flops, c le aoohca- applications. Triac T nac use etc... etc..., etc... tions,. You construct: construc:t: More than 20 complete functional systems: light modulator, modulator. high Fidelity fidelity amplifier, amplifier. radio radio control set. set, radio receiver and transmitter, transmitter. electronic gadgets and games and many, many. many more. Hand -Hand tools not furnished" furnished Practicai Practicat Wiretess, Wireless, June 1978 > The more MODERN. RAPD by performlnf over 0 /y You learn all about the most up to date electronic LESS than the price of the components alone. SAVE 10 - mail coupon today - SAVE 10 P.O. Box Bo* 401, Klnosmead, Kingsmead. saga sacia Kings Lane, Chlpperfleld, Chipperfield. Nr. Kinps Kings Langley. Lanplcy, Herts WD4 9PB. Please Pieiie J»nd.end me --(QTY) (QT) K2 CT(S) KT(S) enclose entiose cheque (money order) for - Name Address A. A.

75 JONES SUPPLES TTL CMOS P p P p P p P t n 4047 H S 7451 _ » :so , A :za < A :so S , e S 4508 Z alg H :so 7475 _ t e 19 ft S G a all _ M :se S , t :si Z t _ U S S BARREL KTS MSCELLANEOUS slz. N Batts. GUARANTEED 100% U2 size Nl CAD Batte. 2 a pin 741 op. amp. '15 "1 GOOD COMPONENTS Scope ScopeProb Probo-x. x 1 x 10 t4'k 10&14'. ftpeachllne. T.rml,natlon... Wp Line. BNC Termination. 30p P 4 P BMC BNC W 50 ohm Socket. Sock.t. -to } T03 NPN Silicon Slicon Power Slflnal SlgnallnJ.ctor: (njeetor: AF/RF TO-220 Plastic Power aop 30pP&P p i p # lamp Multimeter Multlmet.r 1,000 OPV «1S 8' Aaeorted Assort.d Volteoo Voltage *OOmW 400mW 11 Rengea Ranges P 4 & P 50p. SOp. Zenere Zeners Telephone Plek-Up Pick-Up Coll Coli S 55 5, 5. MMOT M340T Voltaoe Voltage fteoula- Regula- 240V 12/0/ /12 1»mp amp lore- tors. Aeiorted A.orted Voltaoee Voltages throuded hrouded trane. 80p lop p P 4 & p P 25. PNP/NPN TOS, T018, T V 16/0/15 15/0/1511 emp amp 2-T Traneletore Tranllstorl ehrouded shrouded trane. tranl. 60p SOp P 4 & P BO P1V PV 500mA. SOOmA. Silicon 240V 30/0/301 1 a amp " Diodes Dlod.. ehrouded shroud.d trane. trans. 80p SOp P 4 & P 10. Low Noiee ptoll. 2N V 30, 24, , 15, 12, 2 amp V 12/0/12 100mA. unehrouded unshrouded trane. trans ,40 Tranatormer Transformer plus PCB «0p 80p P 4 & P, P. Prices. Prces. Please Add 6% 8% VAT. PAP, P & P. 10p. except where shown n n Jones JODes Supplies Aihton Alhton Roid, Road, Hatherihaw, Hathenhaw, Oldhant, Oldham, Lanes. Lane.. 01^ FANE FA"E NEW ^POP" "POP" RANGE SPEAKERS mproved appearance app.arance - higher hl,her sensitivity R»c. Ree. Frfes Prlc. ~.--;.ij) 12' 12" 'POP' 40^45* 40g:~~45w ". 12* 12" 'POP* 'POP' 50H SOH 50w SOW ' 12" *P0P' 'POP' 75 75w m 95 15' 15" 'POP' 65 70w \ 15''POP' 15" 'POP' 80 80w / 18"P0P'100 'POP' 100 loow 100w *'POP'SO 18" 'POP'150 50w 150w SPECALST RANGE R... Prlc. Each designed to oro- pro 12* 2 D$C0/80 DSCO/80 80w BOw fin.dl.r.. Fin.d lar,o # eq S duce tho the ndividual 12* 12 DSCO/100 DSCO/lOO DOw 100w T~:~.r Com 31 nl.95 *95 sound requirement for '2' r GTAR/80L GUTAR/80L BOw f-uje FG"ult:~d ,95 B ts purpose. Robust 12* 12 GUTAR/80B GUTAR/lOB" &:::r;.t:: em'95 Cast Aluntinium Aluminium 12'PA/80 SOw t>uu Cm!! For rhsttls 12" PA/80 BOw.o~~ ;::;'~.:O;.A Clwsls.».n.r.l purom. P.A. 15 BASS/as For... '39 95 #Llnen Linen Tf ^ ellnen Cone i-one COil. surround u S'BASS/OO 15'BASS/OO 15'BASS/85 85w 15 OOw loow 100w s Gu, M r HGH FREQUENCY J04 J 104 Ran,.: HORNS ~ 2KHz-15KHz Po... r: jwa.n..: J44 ".n,.- mm i A with HPX'" 12'5KHz-15KHz SKHx-lSKMr JS B Mfl Lpxia r:'p~~ with Powor: HrX2a ";',," SOw w wi,h with mp' 8 ohm r:x~~th HPX" mpioahm.. Slu Si." ipprox 'ppro" lof xh-x?!* lot"" ml'iris, mp.,w Ran : Power: ~'::.:'.~;::'':' Sohmi f Ji 7.OK -95 «> \ts '"'/A. 920/2 00w 100w with with 1 KHx-SKHi HfX. HPX. mp: mp: Powxr: 6 ohm. fv?'", ",. ohm. 3 3t',,3t' * rl,,3' ~ Ajk ^ S" 4*xrxl5- rprox ~~~e:;e~75' Prlc. *" ~;i~e S9-95 "7 /59.05 VS J73 ".n,e: ^ s-asrl HGH POWER "CROSS-OVERS" 'SkHi-lOkHz a'5khz-10khz HPXK Powor: HPX'" <3'SKHx)/^.^r Paw«r:50w (3'5KHz) 3.25 SOw. HPXlR HPX1" <5KHj) (5KHz) " * * with With HPX 1R R, "" mpbdaneg mpedance or tot«l total mpbdrneo impedance of Bua 8... nh»:8ohmt mp: 8 OhM' 1OrlvarB. Driver. not to Co uxcw exchd id. 80. Oth^rwlj Ocherwi.e Sii* Size approx: /ll.t! «J** u.e writi Hr'e, Ho Horn, mi or or itcgnuttlon attenuacion pro- TrKS'xfti" 7f"" 3'" it' «gc Roc Pric# Price ''* - vitjotj vided with HFXfl HPX" and HPX2R. HPX1R. FANE SPEAKERS SUPPLED SPEAKERS-SUPPLlED TO MOST LEADNG U.K. MANUFACTURERS OF CROUP GROUP &.. DSCO EOUPMENT EQUPMENT 2 yl.r, year, juirx^taa nrante. on ip.«keri,peake... 4 : Horn, Rxc. Rec. Prl«i Prices NCLUDE VAT. Diltributo" DiitritxiEOrt (WholBMle... le 4 a R«uU) Reuil) Roc. Rec. pricf» pric., ihown.hown eorrocc correct tc at l/lf7 LNEAR PRODUCTS LTD. ELECTRON WORKS, ARM ARMLEY. LEY, LEEDS LEDS Monuficturtn Manufacturen 4 le Exoort Export enoulrlsi.nqui,i to: to:- FANE ACOUSTCS LTD. X84 BRADFORD ROAD, BATLEY, YORKS FANE ACOUSTCS LTD, ZN BRADFORD ROAD, BATLEY. YORKS fflfllns KTtRl NO BATTERES BATrEHES NO WRES OtTLT OlLT 29*99 29"99 l'dl'aja Please + YAT'711 The Tho' of inltant 2~w., communicatlonl. with frknif 8>Core ro w 3-core Wlr6. rj- uf wire. Jmt iniudt Jwt plug G-wty loto cominunlcaucnj. nto power eoch«t> locket. Jleady Supplied Ready Jof fot UN. me, Crytal clear communications room Ran,e BuLDgr CrysUl t-ml!c rlor -mile on tbe comoiualcatlcno the Bame nuilos mains phasefrom rtwro phale. Oo/otT to On/off RiHtCb. room..wjtch. Volume VoJume conlzol. control. Useful UeefUl sa a8 fnter-owee loter-otftce lotercorn. Jntercom. betwem between nlftce An.l W&l'f'houlle n <urjfe:ry onllln bnmf'l. P. &: P.99p. nflloe Rn<l warphouee io hnrgefy aiyl n hnmes. P. k P. 14 STATON NTERCOM A i"* flj V.A.T. neo Solve your communlo. tion problem, with tbla 4-8taUon Trr.nalltor otereom 'Yltem (1 muter &Dd 3 8ub,), n robuat pl&auc cabinet. for deak or mounting. CaUl t&lk/u.ten from... ter to SUN &Ad SUM to Master. deally Ut.a.ble tor Bualne.., 8urgery, Schools, Hoepltall and Office. Operatu OD one 9V battery. On/off switch. Volume coatrol. Complete with 3 connectlog wlre8 each 66ft. A Battery nn.) of h"'r :lff"~,,orlf'''. P.,\' P. 99p. NEW NfW AMERCAN TYPE CRADLE TELEPHONE AMPLFER! $2:::: ~vl~;~! ~. ONLY ~ J Laleat plag-lc trkiiaiutorlwd spestcer. Placing Telephono the receuer ^mpllfler oa with to the detached cradle Latest tr,ulllitllturiaed Telephone Ampllfter with detached plug-n speaker. P.clDg the reeeher on to the cradle acu acttvelta... tel & 1"'lteh mmedjate without a iwltoh for mmedlato two-way conversation holding tbe handeet. l.ten time. ncreue Tncre&M boldlag emc1ency offlcleocr the baadbet. n office, Many otftce, ebap, rtop, people workabop. can Jat«D Perfect at a for (w "codference" call.: leave. uaet', hand. Dote., notes, "conferrnee" COllWt oomutl tuu. fues. eslli: No Toavm loog Long w.jun,. waiting, the DMt* Avea e&vea band* time lime free to make with lougdbtanee c.ll. O%t! wltch. volume control, duk* converuuon = recordld, recordlcg model Bo4p at.17 Cl7.. W + -f VAT 1 *1-44, 44. P P, * P. T. 89p. fi9p, lo-rjay c;~~ud~d:ctanruep.~ price refund arutantee oa all l~';.) tenu WKT toroo* DBBCT soppum PWA) 1.. DDOTO mob TaUT. L01lDO W distance oatla. Od/dR awlleh, volame control, conversation let KtHKCTQTOR HKJH TBE*?, tohdos. W nu 6648 H.A.O. SHORT-WAVE H.A.C. KTS WORLD-WDE RECEPTON Please mention Practical Wireless when replying to Advertisements H.A.C.' 'H.A.C.' well known by amateur amaleur constructors for its ils Short Wave rc<:ctvers. receivers, now offers olfers a complele complela rflnyc range of kits and accessories to suit the novice and the expert. expert nclusive-the tuclusive the ever popular and caly easy to construct DX receiver Mark DJ: 111; contalnlnlj containlns all.. genuine short wave componcnis. component.. drilled chusls. chassis, valve. valve, accessories accessorlca and full instructions. NEW T Twin transistor receiver. receiver, selective, &elective. &ensitive sensitive and with fantastic reception. recepuon, yet needina needing only a sinalc single PP3 battery. Special introductory offer at & inclusivc-can inclusive can only bo be held at this price while stock. stocks alt. 1*81, Lastly the K and K plus (illustrated {Ulostrated above) for foe the more mote advanced constructor. Ths This receiver has recenuy recently been r«<.igned rc^jcsigned for even betler better reception. All orders despatched withig wlutio 7 days. Send stamped and addressed envelope now for free descriptive catalogue of kits and accessories. SORRY, NO HO CATALOGUES CATAlOCtlES WTHOUT S.A.E. JJU. "H.A.C." SHORT WAVE SHORT-WAVE PRODUrn PRODUCTS P.O. Box No. 16, 14,1010 Windmill Lane Una Lewe. Lewai Road, Eut East Grin.tead, Grlnstaad, W Wait.. t Suo.ex Sussex RH' RH9 3S% 3SZ Practical Wireless, June

76 1 NOTCE TO READERS When Whan rtplyini replyin, to Cluiificd Classified Adv»rtiiera»n<» Advertisements plstt* pleu. tmurni ensure: (A) Thit That you hivo have cuihy clearly ttnod stated your roguiro- requirements. monu. (B) (8) Thit That you fuvo have tndoitd enclosed the ritht ri,ht remlctmco. remittance. (C) Thtt That your nimc name nd and iddrtu address is wrilttn written in block capitsls. capitals, snd and (D) (0) Thst That your letter s is correctly jddresnd addressed to the advercitar. advertiser. Tbii This will assist sdvcrcixert advertisers in processing and a.nd daspatchlnt despatchinl orders with the minimum of delay. Receivers and Components COMPONENTS FOR P.W. P PROJECTS. Com- Com ponents lists with prices available for P.W. projects from October 1977 onwards. Send SAE stating project and month of publica- publica tion (maxinium (maximum four projects per SAE). Lists sent by return together with ACE order form/catalogue, form/catalogue. ACE MALTRONX, Tootal Street, Wakefield.W.YorksWFl Wakefield, W. WFl 5JK. SJR. 0'''" t'o VNTAGE RADO ~(.. <'), o.a,. o,; / VNTAGE RADO "V ~ + 0 % ~. 1920to 1950 Receivers, Receivers. valves, valves. componania, components. aurvlce service data, historical research, r.. earch, books. books, maoatlnbs. magazines. repairs reoafrs and rebtoratlona. restorations. A complete servlca service For for tha the collector and enthusiast of vlntap* vintage radio. S.a.e. with anqulnes enquiries and for monthly newstieot. newsheet. Full Full19T 1977 catalogue, 70p post paid. TUDOR RCCS REES (Vintage Sarvlcos), S.rvlce.). M, Broad Street. SUpl*.tapl. HD, Hili, Br/alol. Brlltol, QS1 BS. SNL. 1NL, Tsl. Tol. Bristol Brlltol TRRO ELECTRONCS the mail order divi sion of RiTRO RTRO ELECTRONTCS ELECTRONCS UK offers a wide range of components for the amateur enthusiast. Large SAE or Z0p 20p brings list. GRENFELL PLACE, MADEN- MADEN HEAD, BERKS SL6 UL. VALVES Radio - T.V. - ndustrial - Transmittin, and Projector Limps Llmp~ W» We Oispitch Oispatch Vilves Valves co to ill all picts parts of the world by return of post. Air or Sea msil. mail, 17O Types in stock, 1930 to Obsolete types a speciality. List 20p. Quotation S.A.E. Open Opon to callers Mondsy Monday to Ssturday Saturday 9.30 to closed Wednesday.0O W. We wish to purchase all types of of new and boxed Vafves Valves and Projector Lemps, Lamps. COX RADO (SUSSEX) LTD. LTD, Dept. P.W. P_W_ The Parade, Parade. Eaet Ealt Wltterlna, Witterinll. Suesax SU.. X POJO POlO BN Welt Witterinlll0l3 (STD Code ) BARGANS GALORE: LM555CN 35p, 4148 Sp. 3p. Log Fots Pots SK 5K 16p. Chassis Sockets Up p, 3p. Cahbon Film Resistors 'i l Z W for 80p. Veroboard 3'. in x Sin 5in 40p, 4Op. Send now for complete list. Only extra Sp 15p postage. CLEVELAND SUPPLES, P.O. Box 20, Howard Drive, Redcar, Cleveland. 74 ft? A '4 ( % TRRO ELECTRONCS the mail order divi- HEAD, BERKS SL6 HL. Rsdio - T.V. - ndustrlsl - Trsnsmkcint and Weet Wittering J0J (STD Code ) BARGANS GALOBE; LMS5SCN 3Sp Howard Drive, Bedcar, Cleveland. SMALL ADS The prepaid rate for classified advertisements is 20 pence per word {minimum (minimum 12 words), box number 60p extra. extra, Semi-display setting 6 80 per single column centimetre (minimum cms). ems), All cheques, postal orders etc., etc" to be made payable to Practical Wireless and crossed "Lloyds Bank Ltd". Ud". Treasury notes should always be sent registered post. Advertisements, together with remittance, should be sent to the Classified Advertisement Manager, Practical Wireless, Room 2337, PG PC Magazines Limited, King's Reach Tower, Stamford St., London, SE1 9LS. 9LS, (Telephone ) '-c:d on 24 HR. CLOCK/APPLANCE TMER KT Switches appliance to DP Swltchas any appllunco of up io 1kW 011.t t tlmo. once a - KT and contains: of! «t preaoi AY tlmos onco Clock/ n day. " : lsb rct N Appliance display, Timor.C., O S" LED ~~~~~~~ce m!:~ser ~~~pty,o'5~18~fa~ dflvorn, drivers, nwltchos mains switches ED«. supply, LEO., trfac, display trlae, PCBa pes und and full notructiona. nstructions. ONLY C13'TS 13'75 Whlto Whit. box56x131 71mm red 2 20 Whlln bo* White bo* Wk box at 88 above 131 x 71 drilled with roady rod ready tor Acrylic for KT window «2 M W SO DL727 D"al 0'5".og. Dioplay 1 AY On«AY Clock 0-5" 7 Apcllance aag. LED Appliance Timor Diepfay Timer.C. 4 i SO Thermometer/Temperature.C. SM LM3911 Thormomntor/Tompomturo Control l-c. 1 0# 555 Timer i.c. dii Hp 1 00) 741 Op Timor Amp LC..C. 8 pin i.c. 8 pin dll dll 8p dil 24p (5 (3 (510r lor for 1 1 ' 00) 00) 400V TRACS PUllk* WN MN MANS p ~ OA i p TRANSFORMERS 8'5.0.- lip 6'5.0.' with e-(hjv 6-O-6V 100mA looma Up. 1Z-0-12V 100mA Bin p trlgger"p t2-g-12v looma Up tfsp Dlac Zp l.e.d. 0'2" Gr n Zp -aolated lab Rod lop (11 for 1) QUANTTY DSCOUNTS ON REQUEST ADD 6% 8% VAT+25P VAT+25p PftP. P&P. MAL MAil ORDER ONLY TO; TO: T. K. ELECTRONCS (PW) tol STUDLEV GRANGE ROAD, LONDON. W7 2LX. LED's. Mixed bags of 4 diffe,'ent sizes and 4 different colours. 50 at 5-25, 5'25, 100 at including VAT and post and packing. CWO. ewo. Michael Williams Electronics, 47 Vicarage Avenue, Cheadle Hulme, Cheshire, SK8 7JP. itmfittml T. K. CLf CTRON1C9 <PW 1M STUDLEV ORANOE ROAD, LONDON. W7 2LX. ' LED's. Mixed bags of 4 different sites and Avenue, Chcadle Hulme, Cheshire, SK8 7JP. BRAND Htw COMPONENTS BY RETURN. BRAND NEW COMPONENTS BY RETURN. OMT, Electrolyrlc ~!:~~rr!r.j~'2 10, 2-7, Capacitor,. ~~fa.itio 4-7 & 10 mfui 16V. mfd!~ Jp. 22, UV. ~~'47~:: 67 Up. 50V. (50V Op). (SOV_p) p p, (50V «p). (SOV_p). 210 Sp. ~0-8.,. (50V (50VlOp. (Op. "ro-lp, (SOV-6p). OCOtlSV-... OOO/2SV Up. 670 Up. 1000/l5V-Sp. OOO/50V 22p. (50V Op). looo/sv Up, 1000lSOV-llp, Subminiatur* hcf tantalum alactrolyelca, 01, g~l~mj~~f~"'o~471 ~ec:~r-!l~:: 2'2/35V 0-22, l ' ll35v A & 4-7/25V 9p. t o Q 35V V-9p. 0/25V. 4-7 O Oll5V, 15/J6V lip. 6 3V 8p V-12p, 22116v 2ltl6V, f 33/10V. 47/6V. 4716V. 68 A & 100 3V 4p. 3V-14p. Mutlard HioiatuF-e Caramlc Ell Sarlas 83V 2%- 10 ~ul~(~d pf, io t:'i~~at:f.~i::as6ic 47 pf. p. 56 pf. p~.ll to t:.'ii 330 3,,; 6:f~: pf, 4p, Vartksl Vertical Ceramic Plate SQV. 12 E2 22 2l pl 1000 Mounting pt.-ooo pf Caramit p. E PlatB pf Caps. pl pf. 2p MV. pf.-2p Polyityrana 'ol-r-tyrene E2 Ell Saria* Series AJV. 61V. Hor. Moundns. Mountln 10 pf. pi. to 1000 pl Jp. pl.-jp, 1200 pf, p. to pf. 4p pl.-4p, Hullard ~f"a:od Rolyastar ~i~:~ r. 250V 'tfv.j.~p. Vert, Htf. H~!j, C6 E6. 17~:: Sarias. r Lip. TO 4p. '68-lp, 1' 0 4p. 15, 0-14p_ 1-5 lop p. -33, '47 Bp, 1 S-lOp p. 2'2-24.,. Mylar ~~r.~~!~~lp,filci'i', (Poire** * - ) FiJm OOV- 1:~p~~O~,~~~:: Vertical Mt« , 005 3p p6-04, 05 Sp Mlnimtupa ril~:-~~ W«tt ion Film K~~o to 1M2Q Haiiitors Hiahstab. C2 i%. :Mi~~~.~~... ~~~~~~~:.. ~~~.. ~t'p p watt.. in n to 0MQ. 10MQ. <O%over (O% M)... p 0?:ggg 1 SOO 000 watt watt :::: OQto2M7n 10 tgb:~ 0 to 0MQ ~~g::::::::::::::::::.:::::. :.:::.:. lip li: 2p N4148-1p, N448 3p, [ N4002-5p, N4tMJ2 Jp. N40O6 7p, N4006-7p, [N4007 flp N4007_p BC07/B/0, BC071S19. BC147/0/9, BC , BC157/9/9. 571S19, BE BF & 7 9p. 7-9p, 20mm. 10rnm.luses l5, '5, ,3 '0 & SA-lp, Printed fuses Circuit <15, -25. Holders -5, 1-0, fur 2 for 20mm. 0, 3-0 ft fuses 5p. 5A 3p, (uses-sp. Post lop (Free over 4). Prices VAT Jnciuslve. inclusive. THE C. R. SUPPLY CO ChesteHietd Boad, Sheffield 58 0RH 127, Chesterfield Road, Sheffield 58 ORN SCONOUCTS CAPACTORS S'CONDUCT'S CAPACTORS BC t M O /egovsp 8C p 14 t.p p BU BY p tfl p O'l/MOvSp 29/25v 25/25. 5p Sp BC 293Sp ec2mb9p 147 p TP 204B tp N e45l1p 20 3Sp 645 ttp W/W RESST'S BC 351 tip lip 1S O 4p 2-SW 2' 5W Axial 12p t2p BD 131 Mp NT'G'D C'C'TS SW Rodl.1 p BD p :~ ~g: f, P NT'G'O C'C'TS 5W Radial Bp 6T BD138J7P l0 M252 LM 741 r~~5j~18~f~71:::g~ B1 8P AA DFLplOW 7 M 15W Axial Radial fp ~:~~~t'rp lip BU 205 1, W 80 (Rhythm Gen.) BRDGE BOb (A'SOv) 8p 2. p&p 26p BRfDCC 25p. Pflc&a RECT. Prlco. nclude S VAt B05{1A'50v) 16o VAT SAE Mln Order FOR 2, LSTS pip f Export jporf */Jtf and WAo/esale Who/~sale enquiries welcome K & A DSTRBUTORS. DSTRBUTORS, BARKBY BARKBV ROAD, SYSTON, LEFCtSTER. LECESTER. TEL. 4M mw CONDTONS OF ACCEPTANCE OF CLASSFED ADVERTSEMENTS t. 1. Adv.rtl ment. uro are ncccptvd accepted sublael subject to tha the conditions condition. appoarlng on our currant cu"ent advortjiomont adv.rtl.ement rat* rate card and on the axpratt undarttandlno und.rstandlng that tha the Advartlaar Advertt, warranti warranb that lha the advirtlaa* adv.rtl... mant ment doaa.. not contravana contravene any Act of Parllamant ParUament nor la s t an nfrlnoamant nfringement of tha the British B,ltllh Coda Cod. of Adyartlalno Advertlllng Practlea. Practice. 2. Tha The publlshara publlaherl raaarva re rve tha the rioht right to rafusa refu or withdraw any advartlaamanl. advertl ment. 9. S. Although avary ev.ry car# care (a, takan, taken, tha the Publlshara Publl,h.l'.hall shall not ha b.llable llabla for clarlcat clerical or printars prlnt.rl' 1 arrora erro... or thalr censa- consequene Tiuaneaa. ELECTRONC COMPONENTS Since ELECTRONC COMPONENTS Since Price List and 50 Mixed Resistors FREE on request. J. R. Hartley, 78B High Street, Bridgnorth, Salop WV16 4DY. Bridgnorth, Salop WV16 4DY. DGTAL BONANZA LatasC Latest allowl even bigger bargains!! PACK stock altows evan birrer bapgminsfl H 2 keyboards. < Ml (100% Good)2Calculator keyboardj. PACK Ml (100% Good) m 202L bk PA~~atr:~.1.'~?(~:;~~e~ Static RAM. Low pow«r PeQuirament r~qluli~:~!~t'e;~si~i~ veriion 01l PACK of Ml (100% With data. Good) x MM function PACc'!ic~!t~:O~t~ calculator 1~~~) ~e:ib~~5~~~ 4ufs~nc.!ii~~ P.rk Pack M1). M). With.C. (Not data. deiisned for use with PACK (800/0 Guaranteed )( 7 seiment El <00% scgmento 127" O-127" Guarsncead LED diiplayt. Good) displays. ( 5, 1-00 *00 x MAN3 PACK E2 (looo;. 8 d;c;t 0 33" h;ch 7 icg'ncnt C2 (100% scement Calculator Good) calculator ttyle x 0 digit style Liquid 0 33" Crystal high data, 0 " 5 PACK display. 3 EJ (100% With data. Good) 2*95 x 8 digii dicit 0-5" 0'5'" high hia:h 17 segment scament calculator stylo style Liquid Cryiul Crystal 4 U PACK display. T1 T (100% With data. Good) 4-25 x digital diaital wristwatch,c. Plrcutlv drives L.C.O. watch display (see ~~~~ ~~ke i). ~~~i:~e~ ~~D~ w~i:~~a:ihp~~~ could Pack T2). Designed for a wristwatch but to clock. 100 be used co build a dock. With data PACK T2 T1 (100% Good) % x 3^ 3t digit wnstwatch wristwatch Liquid Crysut Crystal display with centre colon. data. : 1 00 PACK With L data, 20 Assorted 100 AlSorted op-amps. op amps. Marked and unmarked E~:ir:n~dva1::ifoe: devices,r~oo you dentify identify and and test. test. PACK Excellanc L Ll 20 value LM709 for LM109 op-amps, l 00 ~amps. (L/ntested). (Untested). An- An bareain 15 PACK other Dl bargain D (80% at (800/0 Guaranteed 1 25 Good) 15 S x DTU OTL logic. C.'t. C.'s. Mainly dual ] < J.K flip flops. Aepfates Replaces those costly TTL TTl flip nip flops Jo in most projecti. projects. 's.,00 PACK Saves 02 tc». D1 25 X 100 x SN7400 type.c.'s..c.' two p aates. luarantee at. least. SO A t/p t. giveewny nand gates. aiveaway at only We gusrantao good.. 00 percenta,e luaranteed aood alongside Minimum pcrcencaga Park Pack number. guaranteed Where good no guaranteed is shown auaranteed minimum J* is seated, stated. we'll gujrant e guarantee < that after testing, testing. (rom chese pr-ove t.o be the yield from these packs will prove to muc:h c:heaper than buyinl average mail order much price!. cheaper prices. Satisfaction Chan buying guaranteed at avbragc cuaranteed or return mall complete pack for a replacement or refund. MAL MAil ORDER ONLY- NO CALLERS PLEASE Postage Posta,. and Packing pltusn please add 20o 20p codespeed CODESPEED 11, l4 S.afi.ld Copnnr, P.O. Copnor, Portsmouth, Box 23, 34 Seafield Hants. Road, PO POl 5B) 5BJ TRANSSTORS, RESSTORS, CAPS, POTS, TRANSSTORS. RESSTORS, CAPS. POTS. Plugs Hugs & Sockets, Zcners, Zeners, TTL, Tl'L. Cable. Boxes. Bo.xes. All at very gooii good prices. 65 Railway Road, Road. Leigh, Lancs. Telephone'Leigh Leigh, Lanes. Telephone Leigh Radio Receivers SHORTWAVE S-Z-Z MHz+M-W. Small SHORTWAVE 3'2-12 MHz+M.W. Small Portables (SupcrhetT-NT.Speaker) (Superhet+NT.Speaker) 10-95, ' headphones for use us.e with this set 4-95, VHF/Airband VHF/Alrband MHz+M.W. Pocket Sets (Superhct+nt (Superhet+nt Spur.) available without Air 1) ( MHz) Band at Mains-Battery MW+VHF+Air ( ( MHz) Portables '55. Prices nclude include P 4 & P, Accs Aces 4 & VAT. Noble Electronics, 26 Lloyd Street, Altrincham, Cheshire WA4 W A14 2DE. me. Tel: Tel: Electrical LST NO. 28 now ready Styli ready-styli illustrated equivalents also cartridges, leads, etc,, etc., free for long SAE. Felstead Electronics (PW), Longley Lane, Gatley, Cheadle, Cheshire SK84EE. Practicat Proctical Wireless, Wiretess, June 1978

77 Educational GO TO SEA as a Kadio Radio Officer. Write; Write: Prin- Prln cipal, clpal, Nautical College, Broadwater, Fleet- Fleet wood FY7 BJZ. 8JZ. TELEVSON TRANNG 15 MONTHS full-lfme course for 15 MONTHS full-time course for beflinners. beginners. Short course can be arranged f if you have previous electronics knowledge. electronics knowledge. 13 WEEKS ELECTRONC FUNDAMENTALS 13 WEEKS MONOCHRME TELEVSON 13 WEEKS COLOUR TELEVSON 13 WEEKS CLOSED CRCUT 13 WEEKS CLOSED CRCUT TV i & VCR The fralnlng ncorporates a'high The training ncorporates.. high percentage of practical work. Next session starts on September 11th. Next session starts on September 11th. Prospectus from: LONDON ELECTRONCS COLLEGE COllEGE Dept. B6, 20 Penywern Road, Dept. B6, 20 Penywern Road, London SWS 9SU. Tel T i m Situations Vacant Radio Technicians Government Communications Headquarters has vacancies for Radio Technicians. Applicants should be 19 or over. STANDARDS required call for a sound knowledge of the principles of electricity and radio, radio, together with 2 years experience of using and maintaining radio and electronic test gear. DUTES cover highly skilled telecommunications/electronic work, including the construction, instalfation, installation, maintenance and testing of radio and radar telecommunications equipment and advanced computer and analytic machinery. QUALFCATONS: Candidates must hold either the City and Guilds Telecommunications Part 1 (ntermediate) Certificate or equivalent HM Forces qualification. SALARY (nc. (inc. supps.) from 2,673 at 19 to 3,379 at 25 (highest pay on entry) rising rising to 3,883 with opportunity for advancement to higher grades up to 4,297 with a few posts carrying still higher salaries. Opportunities for service overseas. Further particulars and application forms available from: GCHQ Recruitment Officer, GCHQ,Oakley, Priors Road, Cfieltenham, Cheltenham, GL52 G 5AJ. Cheltenham (0242) Ext 2270 ' j Courses MCSOPEOCESSOK PROGRAMMNG. Cor- MCROPROCESSOR PROGRAMMNG. Cor respondence courses Courses including personal tuition., for various machines. Also basic microprocessor course and BASC and FORTRAN courses. Contract programming undertaken. Details from; from: Micro Produc- Produc tions, "Greenfields," L Llantwit Fardre, Pontyprldd. Pontypridd. Wanted COLLECTOR WANTS ZCs Art Deco/40's and please. Non-working OK OO4- COLLECTOR WANTS 30's Art Deco/4O's and early 50's Bakelite radios and TVs, TVs. Cheap please. Non working OK "RADO AND TELEVSON SERVCNG" "RADO AND TELEVSON SERVCNG" books wanted from edition.!dition up to date '00 plus postage paid per copy by return of post. Bell's Television Sendees, Services, 190 Kings Road. Road, Marrogate, Harrogate, N. Yorks, Yorks. Tel: (0423) (0423) WANTED.. "Practical Wireless" "Apollo" WANTED.. "Practical Wireless" "Apollo" F.M. Tuner F.M.-Tuner abandoned kit parts. "Murree" Watling Street, Hindkley, Hinckley, Leicester. Tel: Ladders LADDERS. Varnished 20ft Sin extd., 29-72, LADDERS. Varnished 20ft 9in extd., 29'72, can-. carr '40. Leaflets. Also alloy ext. up to 62ft 6in. 61n. Ladder Centre <WLS2), (WLS2), Halesfield (1) Telford. Tel: Callers welcome. (1) Telford. Tel: Callers welcome. Practical Wireless, June 1978 SMPLFED TV REPARS. Full repair SMPLFED TV REP Al,ltS. Full repair nstructions ndividual individual British sets 4-50, 4'50, request free circuit diagram. Stamp brings details unique. TV pubucatlons Publications (Ause PW), 76 Church Street, Larl<hall, Lanarkshire. 76 Church Street, LarKhall, Lanarkshire. HOW TO DEAL BUCCCSSniLLY N HOW TO DEAL SUCCSSFULLY N USD'COLOUR TtLtVlslOHS T1iLEVSONS Exciting raw new bualnaaa bualne guide gulde 'reveale r«v«afa how anyona anyone with Bvarago l.,e,lg8 ntelligence can inake make a high apara-tlme pare tlme CASH NCOME aelllno used TV'. ftom h.ome. mainly aalllng uaad colour TV's from home. Written non-techntcal. mmediate appfication. cntlona for lor the for the enolnaer, noivtochnkat. engineer, thla thl. comprohenaive but with mmedlnte campt.henllve oubllcallon aopllpubllcallon deacilbee; d.acrlbe.: atart- - eta t. to avoid how avoid to - recondlllonlrg where reconditioning and - hew, what how, whote to buy where and which whan when to 10 adverf'le - presentation - - comprehensive sectlona Deneral bullnes. formalltl, guaranteed, prehenalva advoftlae oreaenlatlon how to expand comaectlona gulfenteea, manglacturefa, on general manulacturer., aparee, bualnosa paree, and monochrome lormallllea,»eli. 1. PLUS 'MUCH MORE! MORE Thll Thlt presents r.,utable profitable profltabla unique guide oreaenls a sound, reputable and very buslnes. b, atarted lel. han then 201 home bualnfiaa which can be tailed for leaa Send ~::~~~~~ luat 1 ~R~» lodav t::.'j.:~rg tot fael f::~t:~~yery. deflvery, ncludaa free ncludes FREE advice and FREE up-dating eervlce, CTY PU8USHN0 (P.W.) t Nottingham PM.. Spondon, Darby DtZTNH CTY PUBLSHNG (P.W.) Nottlnllham Rd., Spondon, D... l/ DZ 7NH, HOW TO START A BUSNESS. By popular HOW TO START A BUSNESS. By popular de.mand dtynand a fully illustrated manual has now been produced,' produced; showing, in n easy, step by step, stages, how to rewind ARMATURES A &:& FELD COLS as 'used in n Vacuum Cleaners, Drills and Portable Tools, Tools. Chapters on taking data, materials required, test instruments required, rewind instructions, nstructions, charts, etc. How to cost instruction manual :00 plus 30p P &: P, P. ewo. CWO. COPPER SUPPLES, Parrswood Road. Road, Withington. Withington, Manchester Manch~ter 20. Dept. PWA. PWA, Books and Publications THE DALESFORD SPEAKER BOOK THE DALESFORD SPEAKER BOOK by b~ R, R. F. C, C., Slophon TW«Thle, mult for the ".en home conltructor. Lat Lotoit book t lochnoioo* lo muit teehnoloo)' D'V (ot DY opoakor ho koon p.,ker Ooitooo. homo d lanl. Cootalno comtnjctor. Contain. full planl for nnnlt. baffle and reflex d.,lanl for 1D-100 wail,, Diana for otso nontu unuaoal bafllb contf#-baaa nod rofioa oyatam flaalcm lo' hpaa for who wanl ::~:Hj!ft~o Ml-fl to u.:'.u ~~~.r~ ~~~n~ :.:~~!. ~ ba "Moafd ond not laao", Ct ':S M (CO-tO (t;;.;: Don :oh.~ paid. S3 Oyarooao). paid. $5 Ov.r ). VAN KAREN KAl!N RUBUSHNB PUBLSHNG S.SWANSTRElT SWAN WLMSLOW STRBfT CHSHRE Service Sheets SERVCE SHEETS for Radio, Television, Tape Recorders, Stereo, etc. With free rree fault-iinding faulhinding guide, from SOp 50p and SAE. Catalogue 25p and SAE. HAMLTON RADO, 47 Bohemia Road, St. Leonards, Leonards. Sussex. LARGE SUPPLER OF SERVCE SHEETS All models at 7Sp 75p PO/Cheques plus s.a.e. Except Colour and Car Radios. Free TV fault flndino finding chart or TV list. sl Sbictly Strictly by return. C.CARANNA 71 Beaufort Park, London NW11 NWU 6BX lax aaz 4882 SERVCE SHEETS, Radio TV. etc., 10,000 SERVCE SHEETS, Radio TV, etc., )0,000 models. Catalogue, 24p, plus SAE with orders, enquiries. Tetray, Telray, 154 Brook Street, Preston PRl 7HP. Preston PR 7HP. - 75

78 SERVCE SHEETS - COLOUR TV SERVCE MANUALS MANUAU S«rvlc«Service ShNta tl Radio., Record Player. TP' Recorder. Pi '.fgl Stamped d Enyalopa.Wa for Mono E.Wllope. W. can TV. cln aupply Radio*. lupply manuala Racord a foi Pluyara for moat molt makaa and Tapa make. of Colour Racordara Talaylalon Tip. Plaata Talevlllon Racalvara aand Recllver. by larpa raturn SlamDid return of poat. Addraaaad POlt. S.R.C. B.R.C. PY KCKO CKO PHLPS TT/KB TT/KS SONY Q.E.C. G.E.C. HTACH BARD SARD ULTRA NVCTA FlROUSON FERGUSON H.M.V. MARCON AND MANY MAPlY MOR MORE Lai Let ui U ouofa quote you. Plaaaa Pi a Stamped d Envelope reply, Allo compr.henllve T,V. repllr manuala aand «manual. by Stampad d. J. M. Court. Addrtaiid S.A.E. Envalopafor lor datalia. a prompt d.t... MAL raply. ORDER Alao ONLY comprabanalv* T.V. repair G. T. TECHNCAL NFORMATON SERVCE 10 DRYOEN DRYDEN CHAMBERS, tl» 1111 OXFORD ST., LONDON WR 1PA PA BELL'S TELEVSON SERVCES for Ser- BELL'S TELEVSON SERVCES for Ser. vice Sheets on Radio, TV, etc., 75p plus S.A.E. Colour TV Service Manuals on request. S.A.E. with enquiries to B.T.S., 190 King's Road, Harrogate, N Yorkshire, Yorkshire. Tel: (0423) Tel: ) Aerials ANT-TV TRAP DP0LES DPOLES CUT OUT TVl TX lng and SWL lng, MODtLS;- MODELS:- SWL, CM., 18.'1; M0 loo W.ll Wltt or SWL, Aerial Aorl.l Matching loo Wltt & metrellne. Shipping Milchlna Btnd. Unit Band. 100 Wntt i SWL mclrm inc. 1'.25. nc. VAT MP* and P &. P. Srntf Send ir 10" * x V 7" rf o 12ip... s.a.e. and j 3 x So 9p stimps stamps Tot (or ditalh, d.tal/s, aerial athth, artlcl~, lasl test repotla, reports, lestlmonlals testimonials GDTM. G2DYM. LAMBDA, WHTEBALL, WELLNGTON, SOMERSET For Sale COMPUTEKSED COMPUTERSED CHESS Challenger Olallenger Three Levels ol' of skill normally , our price only '95. Mall Mail Order only. JAGBERRY LTD., L''D., 9Sb 95b Ardwell Avenue, Barklngside, Dford, nford, Essex. NEW BACK SSUES of "PRACTCAL "PRAC'tCAL WRE- WmE LESS" available G5p 65p each post free. Open P.O./Cheque returned f not in stock- stock Bell's Television TeleVision Services, 190 Kings Road, Harrogate, N. Yorks. Tel: (0423)) SEEN WHBTONS WmSTONS CAT? 5000 odds and ends, ends. Mechanical/Electrical Cat free. WHSTON (Dept. PW), Ncs* New Mills, Stock- Stock port. LOGC PROBE, suitable TTL/CMOS 5-16V ndicates indicates Logic states and Trigger Trgger Pulses 12 inc. C. Marshall, 22 Oakhelri Oakfield Road, Croydon, Surrey CRO 2UA. S.W.L.s are you missing dx? Then try our aerial system system complete with tuner. 26 inc. CWO. MDH Radiotelephones, Minister Munster House, Priory Road, Milfoni Haven, Dyfed. MARCON SGNAL GENERATOR, TF801 D/l. Dl. lomhr lomhz to 470MHz. Xtal Calib, Calib. Excellent condition 120 ono. Tel; Tel: Henlow Camp 695, 695. 'VDU, "Practical Wireless" design, just needs 5V and keyboard, suit mltroproces- micropr~ sor. Bargain at 40 ono. Tel: Newbury 47()71. Miscellaneous MORE DX? OX? RARE OX und.r QRM! DG T OUT from whistl.s and CW with a Tunibla Tunable Audio Notch Filter, Filt.r, speaker ipoftkor implifiar, amplifier, bypustd.. sed when off. off, only NO LONG WAVE! WAVE? X K Hi Hz Converter Convert.r feeds f your '5 " MHj MHz receiver, only 68 ", SPOT RARE DX OX with «a Celibntor, Calibrator, MHr, MHz, 100,25 KHz khz merlten markers to VHF, only 13-80, "3,80. EXPLORE VLF O-SO KHr KHz Receiver only SG, SG. GEN Hi, Hz, ilne/iquere,.ine/.quare, only SEND off NOW. Eich Each euy-issembly e.. y... klc kit includes includ.s all parti, part5, printed circuit, cite, case, connectors etc. ete, instructions, posuge postq:e ind and money beck back isiunnco. assurance. CAMBRDGE KTS 45 (PF) Old School Lane, Milton, Cam brid,e. OUTSTANDNG 2200 m F FM TUNER. Latest silicon superhet design, Varlcap Tuning, Full Coverage MHZ, MHZ. deal for Push button/manual tuning. Supplied Bunt Built & Tested with full nstructions instructions only '95 (PAP (P&P 50p). SOp). GREGG ELECTRONCS. ELECTRONCS, Parchmore Rd, Thornton Thomton Heath, Surrey. 76 COT OUT TV TX-lns intf 8Wl-lno, LAMBDA WHTfBALl, WELLNGTON, SOMERSET LOGC PROBE, suitable TTL/CMOS 5-15V Croydon, Surrey CRO 2UA. S.W.L.s are you missing dx? Then try our House, Priory Road, Milford Haven, Dyfed. MARCON SGNAL GENERATOR, TF801 'VDU, "Practical Wireless" design, Just sor. Bargain at 40 ono. Tel: Newbury RARE OX und.r QRM1 DG T OUT from whlitles 45 (PF) Old School Lane, Milton, Cembrfdge. OUTSTANDNG 2200 H-F FM TONES. Surrey. CKAMLLED COPPER WRE ENAMELLED COPPER WRE wd wg t 1 lb b Bor 80% % t 139 4oi 2oz n n t O-2t M.. 12 'H " M n 94 'M '1$.. M '75 nelullve of pip 2 plr.p md K and VAT. 1 N SAE 8AE bring. Catalogue copper and 'H'atance n oil brlngi all covirlngo, Csl.looua of coppor ind rmtilonco wlr.i cov.rlnga-. THE BeiENTEC SCENTFC PO Box M. 31, London WRE E4 COMPANY lew taw Rea. Olll.e: U Garden RoO. OfRco: Q Conlna.Pv Gordon., PRNTED CRCUTS und and HARDWARE Roadlly Readily avallahln available nupplltta supplies ol of Canatruclora' Constructor.' Hardware. Printed circuit boardi, boards, top quality tor for ndividual daalona. d lunl. Prompt aorvlco. larvtee. 5«nd Send 25p for calalogua catalogue from: RAMAR CONSTRUCTOR SERVCES Maaana M.. onl Road, Slratford-or-Avon, Stratford-on-Avon, Warwkkv Warwick. Tel! Tel: 4 Ti 4t71 BULD THE TREASURE TRACER MK Metal locator» Vmicao lumng t DHtain'a b«al Ulna maim locator kit; Spaakf Fm«d with r nd Faiiday arphona ahlald. oparatlon alraady aold Knock«down lo only 17ln. Thoroulhly PrabuMi arch prof«jional c«ll_ flnlih 9 You At n only on ntad BBC ow«rlno anb B0C2 ron, TV crawdrlvvr, plltrt and tnlp* 9 Tiv* tmnililor circuit Stbd lampkl, tdrfrtfitmfl nvalop* for fohfltt Complei Built A levied Foil gf 29+ t '47 VAT Poil 1!» + g1-77 VAT MNKT9 ELECTRONCS, la CLEVELAND ROAD. LONOON, Ell JAN (Mall enter enlyl SCOPE CALBRATOR, portable, battery SCOPE CALmRATOR, portable. battery operated. operated, SAE details, details. Rarnar Ramar Constructor Services, ServiCes, Masons Road, Stratford-on-Avon, Stratford-an-Avon, Warwicks. Warwicks. GOVERNMENT SURPLUS GOVERNMENT SURPLUS SUPER PACK Jd 36 PLUS 52 BCY30. BFX6J, BFX85. 2 Varley Raleyt. Relays. 4 J 5 D.P. toggle logolo switch. multi "PVC cables. M c'oohonb/spbbk«r». iwltchob, 2 72" mulhcore.pvc Microphone/Speakers. 6 mlcroawltcho. covered mlcroswltches. 1 cablofi. magnet. 2 4T 1 Buczar. :~~~ek~s6~'5~: 1 bpd- 85 yd ~~ tlngla ~~ng8 or muitlatrand wire PUS. or multlatrand wife PLUS. Send Mp PP to B.B. Suppliai, Supplies, Dipt. P.W., Hlght 8tr«tt, Str t, Dial, D, Kent. 4T naerta nserts 1J 11 x ohm DC. deal for mlcrophona microphone or speaker use. SOp each ncl. P " P discounts avadabla. peaker ube. 60p o«ch nc. PAP Quantity dlacounu available. W» would K«you to know that wa We would like you to know that wa make. * BEC SEC Cabln«ta Cabinets Special Spactat cablnctft.ablnoll ~ Prololypa Prolotjrpo DflnUd printed drculta clrculb _)- ilr * nttnimtnt n.trumont pantlt panell Wt We alao... have a quantity quantltjr GB3/AT Cabinet punching tarvlca, and undartaka und.rtak. artwork. H. M. ELECTRONCS 275a ZTila Fullwood FullwDOd Shelllold S. SD Tql: Rd Tel: (0742) : Bham»ld (07U)--" &»3BD Send lap (Refundable) lor leaflet. Sand 19p (Rofundablo) for ARMATUR1 A COL W1NDNO ARMATURE & COL WNDNG ENAMELLED COPPER WRE Only lop top quality qulllty mattflolp. materllla applied. luppllad. All ordera order. dlapatchfld dllpat.hed within hrt. hrs. S.W.Ba M'!'fi llbrml ~~~eel tlbraal U~~'O "to" 29 A3 2 a'l Ct'H it M 1.. M '41 1'" ntom to 34 «« a a.,»9 t'i* 2.,. All pr(ca» prices ar* ra nclutlv* nelull.o of P. A & P. n U.K. COPPER SUPPLES, 199 Parmwoed Road. WHhlnoton, ~ rttr..~~o:'u::"~~.~ie: :,.p~~w~~~44sr~~ Manchaalor». T«l: 991^ WATT OTAR/PA/MUSC 100 WATT GUTAR/PA/MUSC AMPLFER With superb treble. bllll. Overdrive, sllmllne, 12 guarantee. gunrnnfmh. tuparb Unboalablo tr«bl«, bnaa. Unbeatable offar OvardrlvA. offer at tjt. ammdna. 31. Alao Allo twin S channel months with saparoto separate (reblo/baaa treble/baas par per chnnnal channel CM- e4l. Monay Money r«- returned f not obaolutaly absolutely dallohtod delighted wflhfn within 7 day*. Also fu«i fuzz turnod boioa boxes great sound, robult construction... Allo watt 12 preat n. RpaaStan tound, robust speakerl 22 22,50. S. conatrudlon J M. Alao 100 All Alllnclullve nclualva of P.P. Sand Send cheque or P.O. to: d2 62 THORNClFFE WLLAMSON HORNCUFFE AVFNUF, AMPLFCATON AVENUE, OUKNFELD. DUKNFELD, CHESHRE. TEL: G007 CHESHRE. TL: CUSTOM METER Scales 2 (Ml. Send CUSTOM METER Scales Send original scale (returnable) with require- require ments. Meltor, Melor, 1 Orchard Bead, Road, Fairfleld, Fairfield, Stockton, Oeveland. Stockton, Cleveland. alfac alfac SYSTEM ALfAC ETCH RESST Dry Trinafar lldctronlc ALFAC ETCH RESST Dry Transfer Electronic.ymbols symbols can b«be uiad used to m*l<«make R.C,B. P.C.B.'s V by trtn*- tran. ferring ferrinn directly on lo to coppor copper clad did boardi bolrds or tracinf tracine piper. paper. Almosc Almost 100 different symbols for cuy, easy, iccurtto accurate and quick results.. W«We invite bonaflde bon.flde reuilert retailers and whoresaran wholesalers to distribute the Alfnc Alfrac ranje. ranee. Generous trada trade discounts are offered, tof together other with fully illustrated support.upport brochures for distribution. A free catalogue, caulofue, simple lample and tnde trade terms term. ere are available from us u..on receipt; of your official company's request. Please Pleas. write to Pelltecfi Pelltech Ltd.,' A Church Green, Witney, Nr. Oxford. Green, Witne/, Mr, Oaford. SPECAL OFFER ~l~~ ~Q. Magnetic Contacla for Burglar Alflrmi. «lc. 101 tlgeh 4 wire Mp. 1M surface 5 terminal tip. 100 fluah 2 MagnetiC Contacts for Burglar Alarml, etc. 101 flulh 4- wire Sp. 104 lurface 5 terminal Up. 105 flush 2 terminal Mp. Hp. Prlctt Prices fully nclualva. nc/us/~e. Send croued cheque, 11 Oenbrooh crotaed Denbrook Walk. cheque. Walk, Bradford P.O. to: Bradlord BO* CWAS BD4 OQS. oos, W. ALARM, Yorka.. or S.A.E. for complele complete Price Llat of Profeaslonal ProfesSional Alarm E~ulpm.nt. Equipment. SDPERD NSTRUMENT CASES by BazelU, SUPERB NSTRUMENT CASES by Baze1U, manufactured from P.V.C. P.V.c. faced eteel. steel. Hundreds of people and ndustrial industrial users are choosing the cases they require from our vast range. Competitive prices start at a low 90p, r chassis punching facfhtles facilities at very competitive prices. 400 models to choose from, free literature (stamp would be appreciated). BAZELL, Dept DePt No 25, St. Wilfrid's, Foundry Lane, HaJton, Halton, Lancaster LA2 6LT. Lancaster LA2 6LT. EX MNSTRY EQUPMENT EX MNSTRY EQUPMENT Atrral Aerial Rotation Motor units, units. complate complete with Ramota Remote Position ndicator connectors and Data. Transistor Curve Tracers. DC Motors. 5V DC Stabilised Power Supplies. Thumb Wheel Swrtchn. Switch. Ten Turn Potentiometers. DC MllNampnifCers. Milliampmeten. Lever Switches. Seven Segmenr Segment Ga» Gas Display*- Displays, Terminal Blocks. 12 Way Cabfe. Cable. 100 Way Cable. 240V 2.. Solenoids. Push Pu.h Button*, Buttons. Odd ftemi of Te*t Test Equipment. Aircraft tiitrumenti nstruments and Equip- Equip ment. Lots of tems in Stock. 9" 9 X 0 x 3" 3 S-A.E. D S.A.E. For List. Mail Order Only. Only_ Eldun Electronics. Electronics, 31 Alexander Drive, Timperley, Ch.shire, WAS6NF. Alexander Drive, Timperlay, Cheshire, WA56NF. NOTCE TO READERS Whilst prices of goods shown in classified advertisements are correct at the time of clos- clos ing for press, readers are advised to check with the advertiser both prices and availability of goads goods before ordering from non-current non issues of the magazine. Practical Wireless, June 1978

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BF97 8F97 ecs9.11 ad 1015 T03 POWF.R ln30ss) n BCS9 PHOTO ill at. eich. TRANSSTORS RCA 10S 3Jp. TOl n... FETS POWER SMLAR TRANSSTORS TO N 2N 3819 (SM. Tp. 1N3055) MOFSET lip. SMLAR MRD *0073 GATE J»p, ~om WR PER JNKO 3m4~DM~m;r~ FET 40p, MOSFETS S130 DUAL SOp- M103 ~0Ar~~.pCUHAE'oMp~1~~~~ MATCHED DUAL MATCHED PAR SL, NPN PAR KOSFETS, ~1.~ TRANSSTORS SNGLE ~~~~\Tlt~~sG;:' Ft, 300MH MHZ. 30b. ]OD. NTEL N!fEL C03 101* 1024 BT MOS RAMS 9Jp, BBl BB] TRPLE TR'PLE VARCAP V P MC , Te... aoo C', to,., CD.OS'C, 7*1 DODE 8 PN 33p. C's MC31OSTEREO 13p, DODES; DECODER N*0Ol*p, C lf*«005 l-30p. 7p. TEASOOC. RED LEO'a «p. 0 1" CD<0S cr 0.115" C'i Mp, Up. so... NE5SS ~4M:~~~~~ TMER C'i ~P.')~~~L~EW~:~ 3*p- LM 391 9Sp. 4D.N RED LED', 02" or 0'115" p. MCOPHONES, GRUNDG PREAMP MCROPHONES; *1 L 50D. SOp. CRYSTAL GRUNOC... L MKE ELECTRET NSERTS 37mm MCROPHONE *Sp, tld. ELECTRET NSERTS ELECT'UT CONDENSFr WTH FET CONDENSER MXES, UN K MP, WTH STANDARD ACK PLUG (1«!. EMS0* CONDENSER MKES. 30~8KH2 ~~~EJi~~~~'6~W.Uf DRECTON 1~~~~.'i~~:J-,li~CLt 5~~ /:~sg~a~~~~~~~~sj:~~~ 3G-18KHZ tll-oo, AU L OD. EH FET EM04 10* AMP HN. DUAL MN. TE MPEDANCE TE CUP CLP CONDENSER 50K/600 OHMS MKES. ON OMN, (OFF SWTCH OMN. K K MP. MP. USES MORSE DEAF \!.S6~~~...tE~j', KEYS; AD BATTERT ALL ~~r~na~~~:s~:?6 METAL (SUPPLED) H-SPEED 4-PS. TYPE ~:: Ll 3 ' s. 1S. TL 105ALPHA-NUMERCAL DSPLAYS,0-38-FG.SZE, DSPLAYS. 0 38" SZE. WTH DATA D... SHEET, SHEET. 1 Ll SWR/POWER SW"/POWE" MTE" SW"50 :. POWE~ G-KW, 3'5 S0MHZ. 150MHZ OHMS METER OHMS MPED. TYPE MPED. 1-7S. SWRSO 11'75. SWR SW" AND SWR AND F.S. 1:3-1: F.S. METER. POWER M!TE" DHMZ, 0-KW. OHMZ. So 3 50 OHMS S TO OHMS MPED.,.. L9'50 FX KHZ 50MHZ (LESS XTAL) p. FXOGO CRYSTAL MARKER GENERATOR OOKH2 TO S0MHZ ~L6~0~~Ai\~t~':is TYPE.... CE"'BLE NOZZLE. PROTEC- TON SOLDER SHELD. SUCKERS HGH SUCTON PLUNGER 4 TYPE, 9S. REPLACEABLE NOZZLE, EYE PROTEC. CRYSTALS. ~1~~s~~E;~~(:ci~~z 300KHZ 40p, S~;:~~~ML~z'~TV 4.43MHZ CTV XTAL... L 43p. '5". BDGE EDGE CONNECTORS CONNECTORSO' 0-1 MATRX MATRX 6* 64 WAY WAY Mp, 65,., WAY WAY *0d top. 0 1" 1" B 18 WAY WAY Sp. 15". RELAYS MN. ~~~.A SEALED MN SEALED ~tarj~ 1*0V ~~~E~ZiP~o'L~ogo AC TYPE 2 POLE * POLE CO CHANGEOVER C~:L'1~~O~~~ RELAYS 40p pg~r POLE OHM REED (WTH mljh RELAYS. BASE) 41b. R~t!~S ~5rl 12 VOLTS Mp, lop. MN. REED RELAY, RELAY. N.OPEN. N 30m/m >; X l0m,' 10m/m m 3-6VDC, 3-6VDC. Mp. Up. MOTORS. MOTOS. -STOSVDC MODEL MOTORS Mp, lop, SUB. MN.. 'BG '81G NCH" NCH' 115 S VAC 3RPM 3 301'. BOXESi MOTORS 80XES, BLACK lop-... CK ASS... BS PLASTC PROJECT BOXES, BOXES. BRASS NSERTS AND... UD: L'D: x X X ) 35mm 44p. 95 9S K x 71 x X 35mm Sip, 5lp, 115 J 15 x X 9S x X 36mm 60p. 6Op. Tfiiyf«^«yjO0MA, TANSFO"ME"S,6-0-6V loom... 75MA. l-o-2f SOM... E... Jl-O-llV l-o-2v OOMA 100MA 9!p VOLT VOLT SOOMA MA 9Sp. 7SMA. 95p. 1:1 1:1 TRAC/XENON l-o-f 50MA ALL PULSE 75p TRANS- EACH. TRANS FORMERS Op MH 3 AMP CHOKES Mp. lop. BUZZERS. 8UZZES. CPO GPO TYPE 6-12 VOLTS SOp, lop, 11 VOLT LARGE PLASTC DOMED SDp.. 14 VOLT, BUZZERS. ALL (SOmm) ALL 15MA 73p LOUD.. 7p eich.6-l2v NOTE SOp V ALL-METAL MN. SOLD... LL METAL BUZZER, STATE BUZZER. lom/m, BUZZERS. 30m/m. HGH PTCH. OR 13p. 24 U". O.H.F. U.H.F. TONERS. TUNE"S, PUSH PUSH BUTTON BUTTON T T.V. V. TYPE TYPE (NOT (NOT VARCAP)... P) NEW NEW AND AND BOXED BOXED L150. TAPEHEADS; HEADS: STEREO CASSETTE 3 ] MN330 DUAL, DUAL. MPEO. MPED. RP HALF H"'LF JfA'rl STEREO ~tr1~ 1 '1~A7~~ A 75. -P S TDlO SOp- ~~O SRP90 S~rrN DUAL t HEAD TRACK J:A~'its':M~tl'E~S2 ASSEMBLES R P HEADS 2 1 L~E91gs.S1~~SAt~R~~~ HEADS, 95p. STANDARD BOTH i TRACK B TRACK... RP WTH ~/~ BULT N N ERASE, ERASE. MOUNTED ON BRACKET 1 LilO". Mp. SPECAL S.. OFFER, ZN414 ZN.. RADO "ADO CHPS 75p. 75p. LM3B0 LM380 90p SOp METERS: METES, 200 loo MCRO AMP MN.. LEVEL METERS Tip. 75p. GRUNDG MA 'M... BATT. LEVEL METERS *0 40 x X 40mni 40mm f' L ' Op. Op, STEREO TUNNG METERS 100 MCROAMP PER MOVEMENT <2-7J. 2,75. )0 TURN DAL "'RM... SCALED?i AL MECHANSMS WTH LOCKNG ARM. ALUMNUM LO ]0. llmm * DAL 1-JSp. O-OO, WNDOW SCALED 0 30, 33mm DAMETER. 1 SPNDLE NEW 1 75,.. TRANSDUCERS. T"ANSDUCE"S. ULTRASONC... MADE BY BY MURATA 40KHZ a Ll pmr. pair. (Smm (15mm DAM). SWTCHES, MN TOGGLE. SPST 7mm '5p, DPDT 7mm 5Op. DPDT Syt'J'SMES: CENTRE MN OFF TOGGLE, 12 x 11 SPST x»mm 8 x TSp. 5 x MN, 7mm PUSH 43p. DPOT TO MAKE 8 x 7 OR x 7mra RUSH SOp. TO MAKE SPST ~~~1 g~">m~ ~~B\?E;K ~ :6!~15~5~AC~n(:E~~~!:x~~je~ SPST Up, OR PUSH '1", SLDER TO SLDER SWTCHES; BREAK 16 x6mm SWTCHES, DPDT Sp EACH DPDT MN. TYPE. MN. 2p, 12D, DPOT 10 AMP DPDT ClOFF ROCKERSWTCHES COFF Op. 10", 4F2W 4P1W Op 10" MCRO SWTCHES: SWTCHES, STANDARD SZE SZE ROLLER ACiON ACTON Up, 15.., MN. MN x x 4mm lop. PLESSEY WNKLER SWTCHES. ADJUSTABLE STOP STOP 75" TERMS- TSp : CASH FLESSEY WTH WNKl ORDER - Eft SWTCHES, (OR (OR OFFfCAL POLE OFFCAL ORDER 30 WAY FROM 2 BANK COLLEGES ADfUSTABLE ETC.,). ) POSTAGE 30P. OVERSEAS POST COST.... T. NCLUDED ALL S S A... E A E. FOR USV VERS AS, LSTS. ' AT C0ST - V A r - NCLUDEO N *0"- PRCES. ORDER ORDE ADDRESS PROGRESSVE RADO, 31, CHEAPSDE, LVERPOOL. 2 T«1; B1 P"OGESSVE "AD 10, ]1, CHEAPSDE, LlVE"POOL. 1 Tel: 051 1] Practical Wireless, June TH is the CatalD9UB you ne THS is the Catalogue you nee V ^ \ to td solve your YDU" ^ component collfk!n~nt fv. o.:.. r" R/wxe R/wie PHS~ write wjlc writ. your rour - Namy Ntmw Nlm.,M and tnd Ada Addftaa AddreSS in block caoifafs c,pi/,. ~ ~ NAME Q~ \J~ AOOUS. ~~ ~! :t~ r uxing problems! prtlblems! The finest componeolb The flnest components catalogue yet published. Over 200 A-4-afze A-4-slze pages. About ,000 tems clearly listed and indexed. Nearly 2,000 HuslfBttons, iustr8tlons. Bargain List sent free. At '40. ncl. p. i & p.. p., the catalogue is a bargain. catalogue s a bargain, Se/id he coupon below now. Send the coupon below now. HOME RADO.. AOO (Compon.nU) (Compon.nll) LTD.. LTO. Dept. ~1fclh:~s~::;!~~~~~"8 PW.,13*-2«LoTirfon Roil!. MRclum, Surrey CR4 3HO --. "oad. 1Ri-: rf ~~ Cla' ~ t.i HOME HOM( "AOO (Componfnt.1 L TO De"t. PW t) : RADO {CompantMD LTD Dept. RW 234 2tO london "Old. M,le",", 5""" ell. _ --- **'9* Ho ^ 2J4-24C London floid Svrr# 7 Cfl4 3HD )HO London jj London.,Ztli6'J 77

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TERM# TERMS OFBUUNtSSr BUSNESS: Acnl' 11 BC83 flfw BF84 M 30 0C23* 0C TSH 45 2N2483' 21 CABH/CHEOUE/P-O.. iq~h.gtl~'i'?~~n~'~ OR ~~~~':J~~~=:~:~-:[T~R~~:~RA~g~:~::'ENT BANKERB DRAFT WTH ORDER. OOVRNMENT AC BCS4 BFM BF84 10 OCS5* OC25 in 120 TS N2484' 31 AND EDUCATONAL NSTTUTONS OFFCAL ORDERS ACCEPTED. ACA ZO BC2L 10 8F99 BF C TSO 11 2N2646" 41 NQURY WLCOME. P & P 3Op. ACY17 35 BC83L 10 BF.. to OC TRADE AND EXPORT NOU1RY WELCOME, PAP ADD MB* TO ALL BFlflf 10 ocaa* 99 TS N ORDERS ORDRS UNDER «1» &10 «E.... OVERSEAS OVRSAS ORDERS POSTAOE POSTAGE AT COST, ACY8 40 BC84L 10 BF107 BF97 10 OC20' 110 ZTX07 2N ACY18 40 BC86 21,. OC29* f«ztx BF198 ia ocas* 0C35' n 10 ZTxioe ZTXOS 2N21105A ACY20 40 Z B# AT J\ V EXBDrloldEra :::::: :::;:'::,~:~ri~::~~:b~::iu~~~' no VAT. Apptkobloto U.K. ~u~~;' ;:::~:.~~\y' Cu»tom»rp only. UnllM BCS7 Z BFt99 BF" n 11 OC36' 0C36 80 ZTX109 ii ACYl device. marked. the r t add 121%. ACY22 " 40 " ZTXO t 2N2Q06 11 V otharwti*. All prlcbi hia oxcuava of VAT. Paaxa add 'A BC212 QF200* BF200' OC41' OC ZTX " 2N21107 SO BC212L 10 to davlcaa markad *. To tha tait Add 1 JiM- BF2Z4A BF224A 11 OC42* OC42 32 ZTXSOO ZTX tl 11 2N2907A 22 w Wa Biook tock m many aov raota more.tam HtmA. t payi p.. ya to vlailui. vlalt us. Waafa W. ar. AllUAtAd situated bshlnd behind WAttoid Watford ACY20 41 BC213 8 BF OC43" OC43* ZTX301 ZTX801 t 2N2921G to 'ootball FoethAll Dtound. Ground. NaAfAAl t UndAroTound/Br. Und.rground/Br. Ral! Rail Stationi Station: WattdTd Wattonl Hlph High StfAAt. Str t. ACn8 71 BC213L t BF244B M 30 OC44* OC44' ZTX302 tl 11 2N Opait Open Manoiy Monaay to SatordAy Saturday' t A.m.-Ep.m. m.- p,m. Ampto Ample Fiaa Fr Car Ca, PATRtnoapBeoavAllAWA. Parking spac vallabl ACY40 41 BC214 BF256* BF OC4B* OC4S ZTX3CO H ZTX N ACY41 n BC214K. af2s7* BF fi* OC4S 21 ZTX3W ZTX304 2N POLYESTER CAPACTORS: Axial l«td trca. type. (Yakai (Value. are ore n id). "). ACY44 31 BOUL 10 BF258* BF288'» Z 1 OC70* OC70 18 t rtx ZTX311 2N3OS5 11 <MV: 4HV: O-OO. 0'001,0'0015,0'0022,0' , O OOa. O-DOB 0033 p; p: 0'0047, 004T, 0-00M, O ooea, 0-01, 0'01, '015,0'018 Ep; p: 0-<B2. 0'022, A0148' 88 BC807B 14 BF259* BF '033, lop: 0'047,0'068, 14p: 0'1, tip: 0'15 0'22, 22p: 0'33, 0 47 Pp: p, A0161' 42 3' OC71' OC71 25 ZTXa14 2N31OS 1 0-0H, tflpr 0-047, p; p; , Up: 0-85,0-47 Mp; ap. 2S ZTX BC BF536 BF336 M 30 i OCTZ* OC72- M 30 Z7X320 ZTX320 2N WV: nov, Q'038, 0 15,0'22 p: 0'33,0'47 tip: 0'68, p: 1 5 Zp: 2 2 Up: 4'7 pp. AO2 42 BC BF384 OC74.5 ZTX32S 2N OUDUER: o-mo-)!, DUBLlER, tooov: p: a 22 Hp; 0-S3,0-4r lhov: 0'01,0'015 tep: 0'tC218p: l»p; '022 lip: OUp; 0'047 tip;0-t i-a J»p; tip: 0'1 S4p: a-2 34p: 0-47Mp: S2pi p: MP. SEP. BF OC7** 43 ZTX '"p. AF.. 70 BC3S 13 BFB84 BF OC75' OC7S" TX341 ZTX341 SO 2N3614 AF BC BF886 OC7S' 31 ZTXSOO 2N POLYESTER RADAL LEAD (VallWA (Value. n pi)- "). MOV: 25OV, FEED THHOUOH BF5Q6 31 OC7B* 38 ZTXMO THROUGH AF BC441 " 30 BFR38 ocn ZTX501 2N3883 0'01,0' J Ep;0-022, p: 0 022,0' Sp; 5p: 0-M ,0 0'033, 0'047, 0' 0« , 0 '1 7p; 7P: CAPACTORS BFft38 25 OC77* 71 2TX AFl1l' 25 BC4." 30 BFR40 OC79 71 ZTX502,. 2N3M3 2N3702 tp; p: '22, 0' 3310p: top; p; 0'47t4p: fp; "p: t 1'0-0 >2p! Hp: 11'5-5 gp 29p p p 1000pF»»y looopf/3sov Ep BFa40 25 OC7B* 78 ZTX6M 2N37U p AF17' 25 BC BFR<1 BFR41 26 OCSO* OC810' 21 ZTX t5 2N AF1S 11 BC CAPACTORS, A.lal lead ype (Value. are /LF). BFR78 OCB N3104 " 10 ELECTROLYTC CAPACTORS: Axial load type (Vpubs oto n (if>. BFR79 21 OC620* 49 ZTX Ni704 AF121" 41 BC BFR OC83" OC ZTX Z5 2N3TQ9 19 2N370' 25Ov. loo 15p' Qv, 0'47, 1'0, 1'5, 2' 2, 2'5, 3'3, 4'7, 6'8, S,O, 15, 22 Sp; 47,32, SO, tip; AF BC549C t BFRal BFR81 a Z ocw OC84 <4 44 ZTX N N loo Z7p' iov"'0,7p; 50,100, 220, Z5p, 470, lop; 1000, Up; 22OO,lp;4OV:22, AF125 BC ~F,,p; 1'00, lzp; 3300, 12p; 4700, 14p; 35V: 10, 33, 7p; 330, 470, 32p; 1000, 41p; AF126 " BFR98 BFR9S S OClW OC * N37C7 2N BC BFX20' BFX29 26 OC123- OC123' N D 25V' p; SO, 100, 160,lp; 220,250,13p; ,25p; looo,z7p: lsoo,30p; AF127' 35 BC : 41j,; '3300, BFX81' OC1M* oclae 15 S 403,, 50 2N3701 D 52p; 4700,54p; tlv, 10, 40, 47, 68, 7p; loo, 125, p; 470, lip; 1000, AF139. BCY30 57 BFX84* BFX84 24 OC p' 34p' 10V, loo, p; 640 lop; loooiup AF17S BOQ.JOp: pi t»v: 4, loo,ep; e*otflpr iuw.tap. OCW 95 2N3710 2N BCY34 75 BFX85-2e OC141 S TAi-sBb TAG.Nb TYPE: TYP!, 70V! 70V: ,»lp! lip; 4700, 4700,12lp; 12lpl mv: 50,,0, JB! 24lp; p; 40V: BFXM* 4OV, AF60 70 BCY38 10 BFX6 21 OC N3772 no 2500, 2SO0,41p; 85p; MVV« V, 4700, 4P1 4p; 2000, Hp; 37p: 40V: COV: , E5p; 15p; SMV: 350V: , Mp. BFXM* U 28 OC141* OC170* tn3772* 2N lisp, AF186.1 BCY40 11 BFX07* BFX87 23 OC171* OC N3773* 2N3773 AF BCY42 41 BAD POTENTOMTERS (AB or EGEN BFX86 Carbon Track, 0'25W Log.. 0-8,J AFZ ' N3818 TANTALUM BEAD CAPACTORS POTENTOMETERS (AS at ESEN BFXM* 24 OC200* 41 2N BCY43 75 BFYS 50 OC N AFZ2 lz1 BCY58 22 BFY50 :~~~?3'.~~'''7,2~'.:-~M ~~is,o;~'jj; 11V: 0-ipF, 0-22, 0-33, 0-47, 0 08, 1-0. Caibon TncL 0-2SW Loo 4 O-OVl BFYia* 60 OC201" 73 2N3fl20 Linear valuel 0C202 ASYl N3828 S S-2(iF UVl 1-6, 10. JOV: Llnsar valuta BFVM* 20 occoz 95 2N3B23*» 22 BCY58 22 BFY5 1'5"F 13p each, tv, 22"F, 33. SOOO,K" (LN Single zt p 0C2Q3' ASY N »uF 1Sp AAClv. lev l 22)17, 33, N»a^KA2K{LlN ONLY) Slnola #! BFY61* n OC203* 96 2N3824* 41 BCY70 15 V, 22"F, 47, V, loo"f 28p each. Kl-2Ml.ngle gong Z p BFY52 OC204 ASYSO' " EViSOuF, , JVl MOpF Mb ASCh. 5Kn-2Mn alnota Qang 2i flfv52* 20 OCW* «2N38«88 78 BCY71 15 BFY53 10V, loo"f "p.v, loo"f 41p 8K0-2MO.ngle gang O/P.wllch 51 p SJE5039' U 11 lov: 100uF JSp. 11V l 47, 100pF 48p. BK n -!M a ai n Ola 01 no D/P awltch H 8FY53' 21 9JG9038* 95 2N3903 ASY7S' S BCY72 t BFY55 5KO-2MO dull gang etareo 11 p cs BC,107" TP BKO-2MO ifull Otnp atino 7f BFY85* 43 TPW 41 2N f BCY78 20 BFY84 TP20A S., 2N39OS,. MYLAR FLM CAPACTORS 8FY6*' 40 OOV, 0'001,0'002,0 005, O'O"F SLDER POTNTOMETERS BC07B' 11 BCZO.. BFY71 TP20B O'SUiW log value. OOmm BC N31108 MOV; , OlpF p BDDER POTENTOMtTCRa TP29A 4* 8NS9M H SFYin BCZ 145 BSX2O 1 TP28C g:v~5f,ooo;zli,o~o:i~', 04, ~~; g:~r';f : 5K0-800KO.ngle gong 71 p BC08B" N ,0-03, 0-04, 0-03, l)-««"f 7p O abw loo and Unaar yatyflt 50mr«track 8SX20* 20 7<PM8 54 BD12 S BSX N4041 O-tpF Ep. WV: 0-47PF Hp SKO-COOKCl affiflla Qana "Jil 11 Tipaoc 88 JN4037* 2N3M6 17 BZ BSXZC* 7J 10KO-500KO gong '.... )OKO-MOKO Dual Ofnff»«TP30 47 ZN<041» BC08C 12 BD BSX«* BSX TlP3flA TP30A < fJ405H 2N ft CERAMC CRAMC CAPACTORS 88V. 50V. Stll-Stlck S.-Sllck griduflt^d grldualed Alum. Baiala Bezels p BC08 8 BD21 15 BSX78* BSX7S TlP30a TP30B 44 BCOB" Z N4067 2N4", n Rsn»: ~5an"~ k~~v.f 0'6pF ~~:?n:7nf, to 10nF _ Sp loonf :: PRST POTNTOMETERS BO28.. BSYl5A 25 TP30C BC08C Z S N4062 tsnf. 22nF, 33nF. 47nF. 4p. QOnF p PRlSCT POTtNTtOMETERS BSY66A O W BO 0-2' 2M Mini. Vert." Horlz. p B0124',. BUOS TP31 BC13 n N4084. twmf^-smmnl, Varl.AHorl*. 9\ BUtM* n 7P30C M 2N4M TP3t* * 2N4064* CAPACTORS, 0'2aW lno0-3'3mo Horlz.} larger 10 p B013 BC TP3A' N4088 POLYSTYRENE CAPACTORS; 2BW1ftOn-3-3MO Hodt. \ i O0, ]«BU205 10pF nf, lp, 1'5nF 10 lop. 0'25W 2S00-4'7Mo Vert. te.. BO32" P BU206 Z28 TP3B BCllS t ' 15 2N4238 HpFtolnF.lp. -SnF to 47nF, «p. 0 23Wa»a-<*7MO Van / BO33 43 E421.. l * T0 * «Buzoa 184 T1P31 A* 40 *0412* 2N4M9 *5 221 TlPatB* 0 40*67* E4Z1 TP3C' BC18 t N4286 '" SLVR MCA CRYSTALS ReSSTORS-Erl. make 5Y. carbon BD135' n E5587 TP32 BC le 2N irlver»ca (pf) CRYSTAL! RESrSTOftS'EKa etrban ES567 K 15, i T1P31C* 71P32* S 405M' 2N42S8 ZN M5* BNitBB B MD8OO1 151 TP32A 40803' S 2N ,27 ' 3,4'7,1'8,10,12,18, 4-7, , 12,11, lookhx 100KHz Slip nip Mlnl'lu:A~~~ Slab~~r: L~~ol~~+ 5 33, 47, SO, 68, 75, BC B MElllO 25 TP32B N lmhz snp BC118 82, 8, loo, 110, SO,,. SMHz 0'2aw 2 '20+7M E24 1'lp lp 21 Sl5p BC134,. BO38' 31 TP32C ' 2N5135 4Z ~'W 2'20-4'7M E12 1 5p BD138' 31 ME8002 TP33 t 2N6D1 21 2N513S U =: S " h W,f- U MDfiOOl 1M 1 T(Pa2A* 1! # J""V«> * 2N MF1120 «' O fs W2.5S5 E 3M B4 itp 1p + ME4102 «TP32B* ' 2N48K * 2N Soil Eiliib ' '"P f-sw 2-2n-4-7M El2 gg, 3:' :~~.. N185MHz HOp lw 2'20-10M E2 p p 1!p WE TiPW* 96 2N697* 9N913B 42 BC BD140' 31 MJ TP33A 2N So" SOO KW MH UOp 1W _ E12 ip 4p MJ400* «7P33A* 10 2N098* 2N5138 BClse 820pF ,MHz 125p 2% Melal Film lorl-m p 4p 11 BD42-51 MJ491' MJ481 TP33B loo 2NS9t 31 2N MOpF^'Mp Aa«t tEHHi Mp f«1m T1P33B' 100 2Nfl«* 2N572 2* 9* BC pF 28p.ach. Holder HCU tip 1% 0'5W 50-M E24 p 21 p B MJ2855 " TP33C' A 11 2N5178 le 1000, 220QpF Wpatch. HocJir HCOU lip )%0 6W5n-1M Eg< MJ2955* rt TP33C- 103 ZN706A 2N6179 BC140' 21 BO45.. MJE340- MJE340' 45 4S T1P34* TlP34' S. 2N707 2N707* 50 2N BC142 Z5 BOl81 85 MJE TP34A 85 2N N5181 S JACKSONS VARABL CAPB. CAPS. HEAT SNKS* MJE370* M TP34A- S 2N7O0* 2N5191 #5 M SNKS' Slicon Grease BC43 25 B0205 MJE TlP34B "0 2N N5305 Dlafoclrtc Dielectric 0 o 2 W6pF 315pF wllh llo«f.ow TOW T082 to Silicon Create MJt37n id TP34B* tfl 2N914* 2N p Sml. 41 p BC147 7 BD222 le MJE TP34C' t. 2N816 Z7 2N5457 loo/joopf loo/300pf PSp Ulp motion Ofly» Drive MBp 30P T05 P Bml. Tub <lp MJF520* 46 TP34C- 118 ZNBia* 2NM57 p BCH7B 10 B037S.5 MJfSZJ" MJE TP35* TlP ND NM58 12 MOpF OOpF Jp llp /17B 208/171 Wp Hip t/jir T01S..p 218 2N9ia* 2N 32 Oml. Syringe 125 p BC4S 7 B0434 4Z MJE2955 TP35A Z28 2Nezo lit 2N54S8 S fl;1 1:1 Ball Prlva Drive " "with with alow 20ml. SyilrtO«ttlp MJF2855* TP35A* 229 2N520* 2NB ow 4511/0AF "7p drive 305p T0220 Up BC48B 10 BD TP35B 240 2N N5485 U 4BU/OAF «7p* motion drlva 3Mp.CH0 Kp loaulaflon noulotlon Kit K for T03, 113 7P350* 140 ZN1131" ZN5485 BC48C 10 BD695A 75 MJE30S5* 9 MJE305S 10 1 T1P35C* TP35C 270 Z70 2N32 2N1J32' 21 2N5777 BB 51 Drive 4103 C804-5pF: 10; 15; 25, T03 Up 8,13S:1 128p nip TO~ 22p T088 T0220 3pK BC148 B0696A 75 MPF02 TP3S 210 2N NS027 6:1/38:1 Dial Driva 4t03 Mp CWH-SpF: BOpF 10i fb: itp* 2S; J03 TQBB Mp «p TOM or TO220 3p KJk MPF102 30, TPSfl* SO BC49C 10 BOY TP38A 215 2N N6109 Drum Wfiim 54mm Mp' Hp" BC BOY17".. TP36B 300 2N S l-l-385pf l4p 100. SBOpF tllp' cannunucc MPF ~:O~rpF 214U; EARrHONES 1 2N13CO" 2N6027 TP3BA' 365 8N1304' 2N W-MSoF ««t» 'L' 3h31QdF «lp afp EARTH MRTHONES FOARO FGARO CAB GAS and MPF npaaa* 390 2N1305* 23D234* 59 BCM 14 BOYBO 110 MPF10S TP38C 3Z5 2N N «dF 315pF 17B» l75p 00-3* 00 3x25pF 35dF 3«lo Jlio 31'p Meonatlc Mattnattc MOKE MPF TP3fiC' 329 2NiaO«' Magnellc ~rfli~\ors. BC57 10 BDY61., MPF06 TP41A 83 2N807" 11 3N CRAMC 2 5m", tip T/ipe., 108, 301, S DEC 225p 3'5mm tip p He h r BC68 t BF MPF07 TP4B 7S 2N308'.1 CHAWC TRMMER 2-Bm<n Hp DCTCTORB* MPFW 50 TP41A* a 2N1907- BC158 t BF54' S MPS3904 4e TP42A 14 CAPACTORS s-oec 223 D' J-Bmm 1#p Type#: 1W. 308 BZ or MPF TP41 0* 73 2N130fl* 2N1813' n 2-7pF; 4-15pF:... 25pF; T-DEC -p. Cry.lal 13p Sockat. for bov. 25 BC1BO Z7 Matched Pair BF58 29 MPSA0524 TP42B 2N tip extra T-OEC W8p* Cfyttal ]3p 8(3 41 p aich MPS39W49 1 TP42A' 94 M atchtd S a ckatt abdva 23 p 24 TP420* ZNBS- Fair 12 2N1670* 18p axlra B-30pF 20p 'A' 425p MNATURE TYPEi TYPE,»>.ncr U-OEC *A* 4Mp' U-OEC 'B' p R' LNARC'S CM7 2"-pF: a-l0pf, 'w B' Mn* CHOKeS 702 LM H 1110 NE5A 121 TL , S^DF;3~10pF; U-DEC B (Hp Mp* j LNEAR CS 3-MpF;tO-«pF 178 NE5ot' ".. 3-3QpF: l... 22p 1MH. 1/LH, 4*7 S 71 LM3WH «f6 NEM5A* 4'7, 701C Spin S A SO NE887V n Z B-MpF: 1\-25pF: BBoF; S8pF: BSpF 86pF Mo SOp W. ltfh.4-7, , 33, 47, 723* TOfrC gli» 31 LM301A 179 NEM8* S ^ pin 41 LM304 M NEM7V* TTL 74* (TEXAS) *154 * H 53 3B9 5B < NE S07 11 CAMPABRBON COMPRESSON ULTRASONC , 100,200t 741'a 8 pin H U 22 LMSCCT LM30eT W NES71 LM30 T QpF, lo-8opf 470,7SO, pin 70 H RAM no CDF; 10-80pF Hp TRANSDUCERS , 747C LM31BH JJ! RAM210Z-2' *% ft mh, 2'5, pF 31 S US RC t 4071 lgo-500pf 12SOpF 45p 40 KH. 35p A 71 ROM t za-zoopf Up Jfjipj JmH. 2-8, 5 748C 8 pin M LM318S "J RC4138D S S loo-boopf ZSOpF «p KHa 10 9Sp Mp each a 783 7B3 8 pin 1M LM324A ftom " LM SG3402' fc J» m _ a\q 810 1U tm33«lm339 to 3G8402* «B 74" n AUD.L Warning ClOp per pair 43mH, loo AY-l-0212 ld LM SL n 7484 mwnsxsssbwn S Buzzer'12V lip lop each 4071 S 215 im f f; % 1 SH AY--1313A ld LM Sl4a7A AY TRANSFORMRS' (Main. Prim. 22O-R~OV) '".. 1 "' J 00 WM AY* AY-1-021? m W LM34fl LM34a d 5L403D MO AY-1-13iaA 140 LMS7B j" 8U3A m SN AVa1-60W 841 LM380 al SN72710* < AY S TRANSFORMERS* <MilnsPf(m.22O-240V) AY N S " V looma lop e.o-evl 5A 341p+ PANEL AY -721/6 241 SN78003N 211 SO SO 4025, :8Z «-0-8V tooma tip 6-0-6V 1"8A 14lp+ RANEL A Y-l-8721/8 146 H LM381N LM381AN 241 SN76003N SN72733 til lit o-V O-SO-SV HA METERS AY_ LM SN75018N V 75mA lip 0-18H8Vl*aA MlTERfi AY-3-a500-4»» LM382 ts SMTWiaN M O-12V looma.p 371p+ FSD AY ls LM38 l RV lboma l4p 8-o-8V 3,.p+ SO l sjgn V 100mA tip T7Bp-l- FBO AY-3-WM»M LM3QQ0 «SN76023N SN78023N D 7482 P S V iboma 14lp B-O-BV 2A 3tao+ 60k«x AY * ** LM3fl09N 74 8N760MN SN78033N til t V '2A i«p+ 1t0p V 12 l-12v fla 2A «0p+ UOp+ 3Bmm 35mm AY-S-am* AY LM3911 LM N78115N SN78115N tlb 1'1' M O'SA 2Dp l-5o/la AY A.O SN78227N ~-12V 0'5A 21Op+ 417p+ l-oo/la AY--12W 450 A " S x4'5V 0*6A 2Wp UA AY A *210 LM N76227N H TAA8SO t 74" SOS " V 0*6A 2Mp A 4l7p ^ A AY-B.1230* 4» M252AA- Tto TAAB50 H 74W '" lu A 240p VA 240p l-500/la AY M253A A TAA2AX225 t A 24ep+ O-fl 0-6V 6VA 2Mp 0-M0mA AY-B-1318 MO M2S3AA* 711 TAA621AX1 ttt B M «B 4SZ?.. 1" 18-O-15V O'5A 21Op+ l-lma AY A SO MC TAA88A , t8V O'BA»0p + Ay-5-iai7A 24-o-24V 0'6A 25Op+ Purbeck l-5ma AY-5-35OO" 110 "'C724 n. TAA700 Sl " ^ J«P+ AY-B-aSOO* 1» BO VC724» MCOM 275 TAABfllA 1«74» H M 4B2B B TAAJOO lit lit O-8V A Z7lp l-loma V la 7lp+ OlolllolCOP. AY-5-3B01" 4,. MC.. TAA Z ", 4011 US l-soma AY l V la Z75p+ Transform.rllll ld MC 504P 211 TAOlOO Z O-OOmA CA MC31 OP n5 '" 4038 Q lz V 1A J75S + 0 «c 'RJ AY-5-3M7* 411 MC1303 M TAAflBO MO M 115 TADll0 no '" 7421 Z la : 12'11-0- l-looma CA3014 n7 MC31 2PQ '" O-12V1A Z7ap+ Tran»farin#r75S# AY-S-W07 AV-S-WOZ WO WCT304P 2W TAD1W 1W 1U 74" 742S Z '" _ M2-0 1A ZBO-O-^M; CA3011* CA30J1* «WC5310P i?s TAD no 170 «?«TBA20S 70 Mulll lapping. SlOp+ 12'8; 6'3V 25p 0 1 A " M U 108 CA3Q14* 137 MCSSTO K T 74180,. CA80S" 11 MC 4433L Q 4188 tol 4838 MuJUtapDlnoi 340p+ 12*0, 8-3V TBAMO 211 3O il-12~ \,P" add lip) l-2a CA8020 no MC 4p t, tt tt. RA mulll lap 44P+ Up l-25v no MC 458' 431 TBA840Q Z , A multltap (p A p mdd 75p) 0-2A CA3016* BAi «S V 15-O-15V 1A la 2J5p 445P+ 27lp+ LT44 4Zp 0-25V C A 3020,H M!aaV 1l Q 170 Mcusap* 55 tba54o Hi 7«S «J L noo Min. p,1, l-50v CA3028A 10 MC TBAOQ n 7411S Q ts laV la 21.p n 42p 0-300VAC CA MC48 8L TBA84-A2/ , BV1A M»p E7lp+ LT700MP. O/P Tn. 0-50V AC CA MC14W Jj TBAMCO t» r«s lit 3O-l-80V la :1lp+... Min. Prl 7440 CA303S 2O l-lo 2A "0 MC171 OCG 71 BX BX 211 n 348p+ 1 2K, Soc p CA OP 150 '" SO-O-SOV 1A 3lBp n»p+ 1"2K. Sec. 3-2 H 4Jp WWVAC CA3028A" to MC140S TBA BA J46p+ M9p+ JlBp+ MOT l-sk. Mir. S«. O/P BO Rfl»p "VU" "S" CA MCt49BL TBA641-A1S/ TSA888Q 38«"' " CA "' (Pie 48D p&p charge price. 410p each CA P F " 71 {Plaaae add 48o pip charga to all prlcet TBASOO.. <lfl P " ch C A MClTfCCC n exi or axil us i!:? tlb S 188 MC3340P marked +. above normal poltal charge.) 4i.3i.t" CA304e MC DNCO B8A Valve... ztp l-5o/la CA SO '" V 1310 markad +, abov» our no<moi poslal charga.) 4}*aj*lJ" CA MC33MF 1M TSA651 in t!» » T5A600 M S 4SM CA MCS '1 TBASOS 10' S 11 44SF 71S 4568 TBAB "7 - Dual Purpo 'OP' l-loo/la CA3076 n5 4000B V 711 DEHCO COLS B»A V.L. B.,4 Mp tj&f. CA304S Mo MEM TBAaiOS 10B H 150 ''BA82OQ ROT! VALVE TYPE l-5oo/la CA8080E CMOS Ou,l Puroo,. 'DP' rote Hp (tssula CA307B 175 MFC4050B EM W TBA9200 TBA820» * S TCA270Q Z Jp O-OQuA CA30ME* to MFC6041J" 7 TCA270O m 7* RFC 5 choke. lip Range 1 5 B,Y.R,W SJOp CA3OS1.. MK03 12" 151 TCA270SQ 22D 744S ^va E..r p e y,r,w o M P SMp each lip RFC 7(18mH) " CA3081 CA305BE iw MKB0S62* lit TCA270SO tm CMOS* "p.. 8E 21. MM211 22N 211 TDA022 ls B,Y, 7p 1FT 13/14/15/18 CA3OOAQ 310 NEMO.. 3: n n «7 B.Y, R, 76p ft 13/14/18/18.. DUAL"VU' CA3000AQ JM 211 M8 NE380 MMBUZBN* 180 EM TOA2020 TOA B 328 MS Ht fas SS 4SS OUAL"VU" 1-5 Groan 2p 17 lip CA NU,. A 210 TLOSCp US SO " l-5graanmp JL-,,,,. "»> METER CA3130' S NU5 21 TL08ZCp.. M MFTER ""ER CAST23 2fr4 204 NE61SA tlb TLOBlCP* 7484 n 'T' Type (Trnl. 1FT 18/1'8 or 485 "p St T* Typa (Trm, tun- "JJ*' 18 <>'405 Mp BMp CA3130* 15 NEflM* 28 TLOB2CP* ffl BS T 1J75 m p 82 NES OB'.. TLOS4CP' 130 n 400S U ng) TOC 44p.p CLM38CC CA3140 ft NE8HDB* CL8038CC' 350 NE60 3Z5 UAA70 Z U 4009 SO F Rng , B, Y, R, W, MW MW5FR 8FR 12p EOGWSE CL7101 8" NE goV 121 :~ 4H «2p 'Zp MW/LW5FR 2Q ED G WSE CL6038CC* 354 NEB60* 1U 60 TLOB4CP- UAA M « t 299 4K9 191 *008 T p lup 15C«A1Mp 160/LA 110p )CL7107* CL7106* 871 NEMl* M5 ZN * CL7107" 175 NE ZN424E m 49BO S5., MPSA55 p p.. 2N671 B,ra 78 Practical Wireless, June

81 ono LECTlONCS' WATFORD ELECTRONCS LEDS C" 7 Segmenl,. tiljw Leos + TU!O n«i cim Rod t» i TOGGLE -L T.., Futaba Tlliff TLlll 6m Grn S3 " 8RST SA SMV TU2'S" C.An (Continued from opposite aide) side) 711*1* TLl2 Yallo* Vellow TJ 11 0P8T 21 M BUS TU3 'S" C.Cth 0 2- R4d Rod T ' DPDT 93 TU21 ' a" C.An o o-r r Yoirow, 4 polo op off M Yall_. TL822 -a" C.Cth,)OOES -URDOC! 'BRDGE... EAKEU, All' 11 RECTlFR. BD 0 ' 3W O:~! Cm. Am bar 21 BUB-MK 11 RCTFCRS ORP61 Am... M t g~~ : ~: ~ : ~~od TOOOLS (pl.otc...) r ; 2r".. DL747. " An 5 ",no 11 (d'trtlo caw) ORP12 S SPchonooo/or M» 1A/B0V AjlOV M 2N ,AZ5 A/1GOV 11 :o~r.5" 11 ~Wo M BPST or> oil 64 :~=.. 11 Gr.. n.. SPST.. od AEY.. 1A/100V ORTO 3P9T bloood» A/200V ' 5" t....olators XANet a" Gr.. n Ut OPOT' la 1A/200V» SOLATORS DPOT " A/400V 11 ad SW TLlll/2 ts MNTRON 30taF 2" DPDT ~OFF 8YlOO :11, 1A/400V «T Lit 1/2 145 DPDT 4 C/OFF floa 74 7» 7". 4",.. TL14 tt Lkluld c.v... Dlepl.)' DPOT - j; ] A/«OV A/fOV w TL OPOTBloMd US :11 8Ylte H Ba 3W 2A/SOV as TLttT '3i OR Hlg 7p J 2A/WV» TL i SLDE ~l'g~~.4 *9tV 8V2T lfj H O"' x"... 1A DPDT A/100V S 2A/lGOV " VOLTAGE REGULATORS' ll. 2AttOOV.. TlACS OA4T.1 8A/J0QV TRACa* VOLTAOl REGULATORS* t A DPDT C/O S TGa Con Type P (T02O) c.e la la SA/400V 2A/400V ftl., BA400V TOa C n Typo PlaoUc (70220) caio UA DPDT A400V t ll. +. av 12V. -veo aa:av.a 2V.4pol.t-way :11 2A/eOQV 2A/fOOV ts K 11 6A5O0V AGOOV K ts 1A +.«: 8V, WV. V.SSV. 4 Oct. 2-*^ t 4A/lGOV 11 BA400V 11 lav. BV '.up each B V S U.H 7t 0A4MV E 118V, 18V 14ls «>eh '* S 4A/200V 15 8AOOV U. LM.OK -v. 16V * biibu ll. av. 12V ns... PUSH KU BUTTON 7S it... 8!:.: 4A/400V 7. BA500V BAMOV loasoov loaooov MR3K 1-WS«K LM323K i* _ t:l~::: in :: SPS~n of!.. g!: _ 4A/f/OOV iff.ts 1SA4MV 15A400V 145 MVRS MVR5 or 12 7S.. BSStlirvJ LM 'S '2 X V "" 11 SPOT Co : 4A/e00V 4A/fOV th JJJJjg}' laa400v ^ ls ll. -.e: V. V 211 Variable T,pe DPDT a Ta. S OAlOO.. A/lGOV n AGOOV 21. 1A -vo: BV. 12V 2*4 Vorlablo Typo ** SPDTCovof DPDTQTBH 71 1BA6MV 214 ta/200v D +87V 41 MNATURE 7i in 45 MfNlATURC P.. tlc CUe: +va OA202.. ~ l400v S lit LM304HOlo +40V:t4 Non S !S fo 1.*?i: ll. (TOl) ay. v "2. * LM3MH0O+40V244 Hon Locking l~tt4, & ts LMatTH + 1' Pu.h 10 make S B-2V. 12V. 15V t (N9ie _» 45 S 0 B-SV, raw/- 12V, 1BV A 61 LM317H N., UM317K+1 +1«2 LM3tTK+ *2( '210373M 854 Pu Py»l1 oh ta Pu.h Br««k mflho Break B S VM8 «DJ DAC 1A la (TO220) (T0220) 5V, 5V. 12V. 1N4001/2' LM325N,!:15V U ROCKER:(Bld STt S 15V. BV. 11 inaooa* sr* «*5 16V. flv. 24V H J5J«N f US fjs ROCKER*. (BKU "PURBECK 4MMBN LM32N *t2v,!:v 248 U on/oll10a2ovu (OA ES0V13 OSCLLOSCOPE" Z!"!RS N40W/5' -" Rno:3'3V-33V VElOBOARD' Pitch ROCKERi ROCKER: (white! (white) BA SA 2MV 2SOV SP chanfla- chanoe- AUTHOR APPROVED PARTS ^4006/7- _/T' 1 400mW 0-1 0' '1 o ts oyer cenlr. oil ~" 4 1 3W t7 (copper 0'13 clad) o*ar camto oft X x ar 3i" (~~r 41p Up =) ai.!plaln~ 0 '" 1 ncluding PCBs available. "^ :'~~~R~e"3::, ' nllod. red) Chro,; 7 75 a '" A/lOOV' 11 t VARCA... t t" - X x 8-5".p", 4tp g BezalBAZMVSP ROCKER j fill uml naiad, rad) Chrome U Cathode Ray Tube 3PB 7-75* - t" A/400V' t 31-" Up ROTAlY: "Make-A-Swllch" (p&p 9Op). MVAM2 3 x 3i" 49p 45p. ^ ROTARYj "Maha-A-SwHch" Make (pip nsured 90p). S" 511"... 4Sp tp your muluway SWllch. Adlu.table A/000 A/fOV' V 11 3x3" Up MVAMS S a!! S.A.E. A/lOOOV' 11 BAO 11 ~ 1~ :=: ::: P 45p lup Zlp.ap Tip 99p Stop /our own Shaftlno multtwav Aiaamhly. Switch. AdluJtahla Send S.A.E, for leaflet.,~: ~~~,:::,:~:;el':~~ef'" 11 A/OOOY 3 A/fOV.. BB04 4 x B ~tto'~ X 17" T- Mp Mp 1«p <*tp tlp AccommDdataa up lo 6 Wafart Pkt of 34 pin* P'::" 'BP '::: Mfllm Man. Switch DPSTlo 10 fit flt 34 3f JACK.. LUG..0CKTa tch'i* BBO Spol lac. cutte, lip Break Belore Wale... pcl./ - -- 'OyHitow: Spot fac«cvtlar jjjj Sraok Petora Make Wafen, 1 pou/ rtlonlool 11",1~/2W'w'a' y2p/'way.3p/4way.4p/3wa,. _ Screenod P AOV AlOOV 41 ZU.41 M!fN 41 A«fN a ALUM-BOXES llcl op.n Mouldod " body metal with 80V 94 Note* DofJ* Pin neertton tool i-j 12 way. 2p)e way. ap/4 way. 4p/3 way. Screenod p/2 way 41 chrome A ZSJ 141 «i Xo ~:= V:;"!~Gv::N;r:'J'Cte,:"e a'e S... r and Screan n:::::::,:: ::, 5f.^r:!f o v^n;a. we ar Spacer and Screen S **5mm * i 3*8mn» lip c:~::ta ROTARY FEllllC CHLORDE' ~OTARY t (Adjuatabla 8(00) HOKO Hp tip ALUHLBOXES FERRC CHLORDE* 1 pola/s to J CAdJu way,...?o/8 to Stop) 0 way, 3 pole/ STEREO ~~:lt~o Jfp ff: :::::: :: AftOV 11 AOV p with wllhlld' ltd* lib bap be. Anhydroua Anhydroue Anhydrou. 4Sp 45 lip +»0 atp P- p. 4 & P. p. 2 21': to t# 4 :'!:~.': way, 4 pole/s pole/b :"~i~~2jow~:'" to 3 way 3 po~ 41 _==:'::"'''':'':'~-'-'-:::!:",,_=-'-_,=!:''-'' AlOOV 3<1.1" U A200V A400V ".. 11.,.,'11".. :.~~t::~=~::+::e~~pe::c:-:~lr~p 1:.:::::.:::T::::::-_...:Tp::r ROTARYi l0tary Maine Malna2S0V 250V AC, AC. 4 Amp Amp 41 Din.. lug..ock... ln n. EE "GOOV... lid.' "W.. ROUCTS :~~ ~op~~'l~~:r Up p ~p U. ::rh:llr" 41 :x1 " : COPPER CLAD BOARDS* PW PROJECTS 7. Flbra Fb.. Slnplo- Slnole- Double- $HBP SR8P Euybulld ".ybulld Organ, OrOln. General G.neral Coverage dim Coyerage A400V 4d M Glaet G... aided.,dod tided.,dod B'xlO-B" '".,0 5" Recalver, RecelYer, Rhythm G«n«rator, Generalor. Chroma' Chrom.. CO-AXAL CO.AXAL (TV) 14p 14p 4p A400V.11 Wit'" 6".A400V,.4A1" a :=! 4" ~;" Tip nr.. Hp ~p 73p * 12- thp TSp lip chaea.slhra h... Digital Clock. 'JUBLEE' iiiiciii)---, p -way Electronic E. ctronlc OfOtn, Organ, General Sen.ral Pgrpoea PU'PO" SW PHONO... iiortad rt.d COlOufa c.'ou.. Up p -way TO... SOLOCRCON SOLDlCON PNS* PNS Recelvar. RecelYer. Gae Ga. 4 & Smoke Senior S.n.or Alarm, A.rm. me m.ta1 til creaned.c,.. nod lip S" _ey :1110 S =" Gx7A3" ::: pint pin. $4p: Sp: 1000 pine pin. 9S4P MP 'SEEKT Metal Locator, Locator. "PURSECK" " PURECK" ~:-:- --+-~-i-.:...-::.~-- lc il3" '41 Olt. DLSOCKTS.L.w"roflla(TEXAS) BOCKtrS'LowP«o1tl»(TlxA») OiclllB.MpB, O.clll.,cope. TBnk Tank B«in«Battle " Bo-lnolon BoYlnolon" BANANA ::::::: U: p tb ::: C4S lip 41 hs.3" '41 N_ bl!!3"»:;~~":i;'u~nl" lplniei44p:ii1i ie»liilj!l8plnmt Bin»7: 24 pin 34; '::~~nu~:t~~nau 28pln 4149ollt JS SAC SBmB, :~~e~u~"a'!'~::~:~rtlon pluj Auttlo So P4«Dlatoitton l Bl, Malar. S«nJ M.ler. Send WANDR~::: Jp :: P *P :: OPTO tuctbom swrrcius* TANK BATTLE Build this fantastic fllntsstlc TV GAME with realistic battle sounds Steerabla sounds-steerable Tanks- Tanks Controllable Shell Trajoc- Trajec tory and Minefields to avoid. A really exciting and aklltul skilful game simply con- con structed with our easy to follow instructions. nstructions. C le AY * "'78" Basic easlc Kit (Just Oust add controls) Only (p&p (pl.p 30p) 3Op) Complete Kit ncl. eases cues 4.t. conlrole controls Pries: Price: Only 24,30" SO- (p&p (p.t.p 30p) 3Op) 3i Si DGT LCD PANEL METER KT Completo Compl", Kit K for or low currtnl curronl (1mA (ma at ally) #V) WOmV 200mV or2v F.S.D. Digital D'.'ta' Pan«l Penel Mettf Meter Board. Boa,d. Aufo Aulo jero :zero and fifwcnco reference are built n. Only Onl, on a C and a f«w f_ com- componenl_ullt n hall holl hour^ hour ponento Built Very Vory high hloh noul npul mpodinca mped.nce (t (1 mltllon mllll.n Mag Moo Q) 0) to.0 work! worke with potanllal polenllal dlvldor dlylder lor DMM tic c Sixe Size «- st" * 3J' Si" ncl. laroa large LCD LCO dlipley.,. Completawlth Complete wltll aiiflmbly... mbl' Jntlructlons n.uudlon. fc & C le Data. Price: 21 Z1 -." M* ONLY (pip (p.t.p 30p) 3Op) NDEX TO ADVERTSERS Partridge Electronics Ltd, Partridge Electronics Ltd. 12 P. B. Electronics Pelltech Ltd Alfaen Alben Enjineering Engineering Fane Acoustics 73 Progressive Radio... n 77 Amateur Radio 12 Fotherby, Fotherby. Willis Electronics 67 Powell. Powell, T T. cover 11 Ambit nternational nternati.onal.. _ 67 G.C.H.Q.... 7S Rocquaine Samber Bamber B B Gloucester ndustrial Sales & Radio Components Specialists cover 1)1 Baron Electronics. 71 Auctions Ltd 6 Radio Exchange Ltd. 11 Barrie Electronics G. T. nformation nformaton Service Ramar Constructor Services B. B. Supplies Greenweld Electronics R.S.C. (Hi-Fi) Bentley Acoustic Corpn. 4 R.S.T. Valve Hail Mail Order Co Bentley Acoustic Corpn ,17 Short-Wave 73 Bi-Pak Ltd H.A.C. Short-Wavc Supplies Radio & T.V. Components Ltd Birkett] J. 14 H.M. Eioctronies Electronics 76 R. 2 9 Ltd. 72 Brewster S. R Heathkit Saga British National Radio & Electronics ict Home Radio... n Science of Cambridge 35,60 School 5,71 Scientific Wire Co., The J. Bull (Electrical) Ltd. 3 Sentinel Supplies 14.L.P. Electronics Ltd ntertext CS Sonic (Hi-Fi)... 2 Southern Valve Co. 76 S Cambridge Kits... 7S 65 Caranna C Stirling Sound Jones Supplies Chromasonics Swanley Electronics 4 City Publijhing Publishing 7S Technomatic Ltd Codespeed K. & A. Distributors Technomattc n 72 Colomor Tempus Continental Specialties Lambda - T.K. Electronics 76 6 Copper Supplies Logic Leisure (Teleplay)... Trampus Cox Radio (Sussex) Ltd.., - London Electronics College Tudor Rees (Vintage Services) Crescent Radio 36 Lynx Electronics 70 Van Karen Publishing 75 C. R. Supply Co. 74 Vero C. T. T, Electronics 8 Manor Supplies C.W.A.S. 76 Maplin Electronic Supplies cover V Watford Electronics Marco Trading T West London Direct Supplies 73 Eldun Electronics 76 Marshall A. (London) Ltd" Ltd Williamson Amplification Electronic Brokers Min Mimkits ikits Electronics Wilmslow Audio 36 Electronic Design Associates... 2 Electrovalue Nicholls E. R Z & Aero Services Practical Wireless, June

82 Hud Office end Werthcuu Head 0MCe and W.Nhou.. 44A WESTOURNE WESTBOURNE GROVE LONDON W2 5SF SW Tal: Tel: /113 SM/2/] Z & AERO SERVCES LTD. Retal Mp 1$ TOTTEllHAM TOTTENHAM COURT ROAD LONDON W Wl Tal: Tel; 510 MO 40l M01 0- all day Saturday A SELECTON FROM OUR STOCKS OF FULLY AC/DC TAUT SUSPENSON GUARANTEED FRST QUALTY VALVES PCL80s 0 75 B3GT AK6 ' CW4 6CW< BA6 PC1805 MULTMETERS 3'751 11BA ECL80 ' :::1 POslO 3 ' U U41S R4 o so 6AK7 0 '1$ 85 6CYS ACTS 1' BE6 2BE«ECUO 060 EZ80 PDS ECLB ECU) GysO GYSO PL36 Pi 3 5 TYPE U RS ALS 6AL '40 6CY BH7A 2BH7A ECLBl ECL82 0'60 GZ PL AM6 6AH6 ' 70 6DQ6B ODQSB Y7A 2BY7A Z30 PL ECLB3 ECL GZ31 GZ PLBl 0' AMB 6AM3 0 ' 70 6Dn &DT , 3SW4 35 W4 PLB ECLM ECL KT PLB n AN5 4AN5 2 ' SO 50 6GH8A SOCS S0C ECL85 ECL8S KT88 PU PLB4 PL U4 0 ' 70, 6AN6 6AN8 '1$1 85 6GK5 5GK *75Ct ~sc ECL86 ECUJ6 '1$ OM o ss 0 70 US AQ } *85Al *B5A2 OSS OA2 PL '1$ EF80 EFBO 0 40 OA] OA PLS~ 1'05 X1B AR5 OARS )5GT t SGT O *toc >900 PL EF85 EFBS D OB2 OBl 0 60 PLSOB PLSOfl 1 30 lcw AS6 1' ) ' *807 1' 100 EF86 EFS OB PL80l PL "loll AS7G ) "BA 'SA EF91 EF92 0'75 75 OC2 OCl 1 40 PYB PY "3-S00Z AT '75 6K6GT 0 85 "B19B ' EF OC3 0'75 PYBl 0 ' 55 *3E19 ' SO 6AU6 0 O' SO M 6L6GT $ *83lA 832A PY EF ' OD Q AV6 0'15 0*75 6N7GT '1$ *866A 864A. PY83 3' EF83 '70 PABCBO O'SO 6AWSA 6AW6A 0-7S Q S72A 'STA 0-70 PABC80 PY88 6 ' ' EFB4 EF84 0 '70 PC PysOOA 1' 30 5AQ AX~TB 6AX4GTB 1' SA "5763 '1763 PY500A 2-85' ' 8S ' EFL200 EFLlOO PC / TTl TT SATa AXSGT 6AX5GT l 1 ' 30 ld 6SG DAF96 0' EH PC9l PC92 0'85 Tll n D TS 6BA '45 6SK DF96 rm Sensitivity D.C. 20,000 o.p.v. of ' 70 1 U25 1'00 ~ : = m: 5U~ BE '481 6SL7GT ok92 DK EL34 PC9S ins 1-00 EL PC96 D'SO U16 U26 Sensitivity A.C. 2,000 o.p.v SU4G8 0"5 68FS 00*85 '1$ 6SN7GT 0-70 ' 70 1 ol" Dt , ' 60 ELB EL PC97 0'951 UA8C80 0 ' 58 Current SOpA-2 SA 5U F6 0'75 D SQ ECCM UABC80 D.C. C u 5Q/iA-2-5A 0'40 ' 60 ELBl EL PC U8C SmA-2'~A 5V4G 0'60 6BH V6GT '65 ECC85 UBCB1 ECCB5 0' EL83 O-M: 60 PCC84 PCCfl4 A.C. Current 0-5mA-2-SA 0 ' 50 UBFS n:1 :~~GT 5X4G B) X4 UBFSS ECCS6 ECCB ELM EL84 0'45, 0 PCC85 PCC8S 0 60 UBLl 0 85 SX N X5GT 6XSGT O-iD 0 60 ECC88 ECCfi9 UBL2 D.C. Volts 7SmV-OOOV Et86 EL , PCC UCCM 0 75 SY3GT Q7A lac6 12AC6 o pccbb UCCB4 A.C. Volts V-OOOV ECC89 Eccas EL9S fcl9s PCC UCC85 0'55 300n-SOOkO SZ~T RSA lao6 2AD ECC89 UCC8S EL504 ELS~ PCC89 PCCB9 Resistance 300O-S00kXJ 1 00 UCF AH 0 ' 55 6BUS O' SpF 0 ' 85 81, 12AE6 UCFBO lae6 0'1$ 0-85, ECfOO ECFBO O; EM80 EMBO PCF UCHS AB BW7 1 00, 2AT6 UCH8 Capacity 0-S/<F ' ECF86 ECf86 80 EMB EMS 60 PCFBl PCFB UCLB UCU Accuracy 2-5% 2 5% D.C., 6AC BZ6 0-4S ~ : : ' 12AT7 :~~ 0-SO. ECF EM84 '60 PCF UCLBl 0 '75 "%A.C. 6AF4A BZ AU6 ::rsl OAS 1 0 EMM 0 10 PCFM ECF20 UCR ~g~~ 0'90 0»0 EM87 11' 00 M PCF20 pcnol 1' 10 0'80 6AGS 0 ' 65 6C4 0 OSS ' 2AU7 UCL83 4% lau ECF80 ECFBO o,s! 0-95 EYSJ Eysl 60 PCF806 PCFB UF8S AG7 0'1$ 6C86 0' AV6 UF85 Price complete with pressed lav *85 ECF ' 95) EY8 EY81 ' 50 PCLB PCL ULM ULS4 0'1$ carryin. 6AH CS7 0 '1$ 85 2AV7 lav7 1' ' ECHB1 ECHB 0' EYB7 EY87 0 O' 50 SO PCL82 steel carrying case and test PCLB As CUs AX7 UM80 0' ECH83 ECH.S3 o 60 EY88 EYB PCLB UM " 6AKS O'SS 6CU AY7 0-5S PCU84 UMB leads * lay '1$ ECH EY500A EysOOA 1-50 SO PCL86 PCLB6 0 '8S ' UM84 UMB Packing &.& postage * VAT ii i. not ncluded. included. Pleue Please add 12i% on all items except those marked with asterisk, uterisk, on which VAT is 8%. Postage and packing charges are per subject to a minimum of OUR NEW 1977/1978 CATALOGUE S NOW READY AND WLL BE SENT ON RECEPT OF REMTTANCE FOR 0.]0 TV GAM. octl, oct oc4 AMPUFlR. TV OAM1B game*,.m" *n«na m.ln, adaptor iv V lootne JC12. JCtf AND JC4a AMPUFKRS 100ma r.nae ntegrated.. tablllted tablllled... Fully aibembled... aflrac- A ott_... ouppllod... dllla prlntod flvely cased caleel TV ot'ne* aam.. (tonnll, (tennll. football, fterm range supplied of ntegreted with free circuit data audio and printed ampll- clrcults.jcl2 8 wlttl t N. D wott" oueth qullh and pcloto): block pelota) :-black and white clrcutte &z H. Jeco Sond "0 t1 '''''!Z'''a Allo e game ELECTROVALUE AiTtS. Colour 22 ts- Aleo 6 oanie colour 2 15, JC40 dcz 20 «watt* watta 1 4 W.». JC20 Send 10 ate watt* for model wlfh with pletol pl.tol otlechment ttkhment 21 t... H. free pr.amp d... -AH cha many m.n, typae... o# of componence eom... w«w supply u.. ply are BRAND NEW Modified Modlflod shoot hoot kit C4-H. 4 N. Stunt Slunl motor and data preamp on our kite, range of matching power molor game &17' FERRANTl ZN4t. ixf gwafvntmd au.rant... and only, from manufacturer* m.nufacture.. direct dlr.ct or approved cycle oeme chip + economy kit C17-M. FSRRANT ZN414.p.. ro"." rodlo 1 '0'. Extra Plrts pcb auppliar*..uppll....(no aurpfui. aurpluo, no -saconds) Tank lacondl) i:;... bolho flame chip + economy kit 17 fb. ~ X~-3: AY^SOO 4-fa. il'.r..\:.c~~~m~y~ Kit* for AY-3- lor C radio for radio chip radio 3 15 t-#5. U Caie Crtre elle 1. parte t. Send and aaa peb for _:-black whit..tanda'" modol data. CMOS buff*red CMOl-buff.rad and protected (BE) 8S00: black and white standerd model free date. ( 8E)... version & tip Up 4013 ~u Sip 40 ~13 J 5 Up U.. 40< tandard eft. BATTRY LMNATOR BARGAN p 4014 ~14 1 ~~ ~ Up Ci M- Economy veraien Colour 4011 &tl "'. H. generator oam unit tablllz.d 7' 7V 4001 Up B: H4 402S ~:15 Up p model tlandord CtT. Economy colour BATTERY ~ '1t - kit, adds mo.t aamel loom. U t. J-way model. swllched DD6 M4 1' ~16 Sip Ol6 1 ~\~ ~" ~9 J4p Send.. data Up 40)7 ~ 1 7 t ~1 7 60p p 4910 l-«up Rifle kit 4 is. Colour oeneretor TV gamem ELMNATOR power unu afabllijied BAROANB 7-7V Wt. ~50 J. f~~1 ~n:a. t/~:/~v m~~~a:i. 3':::'~ Np r'" J~ :;: 4010 ~1'. tn n 4028 ~28 «Sp 4050 Sip 4511 l<s0 Sand add* in for colour free date. to moat flrmei 7 W. output loomm 3 and 10.3-way i-wey models multi-jack- with iwllched 3/44/OV... POllc voro'on" BC108/D 2N30S5B mode.,.me z8 al ppg 4004 Mp 4019 ~19 Mp 4029 ~9 1 '~ 7J M COMPONENTS looma /7J/»V 300m B 3 JO. *Nma ~ -, ::: 4511 U tud. QV a ~D Alp 4020 *lo in 40 ~]O JO 3lp 4069 SOp Pleetlc verslona of BC108/ft Sp. 2N30SSB radio modet* earn* *l<ea* a PPg battery, S' ~70 4S2O U ::~~tl:: ~~':o ~l~.r=~~o: :; ~ Up ftp 4021 ~ 1* ~ a4p 4070 SOp Trp,lN4l48Jlp. ~71 454] ' le Pm" pota lub-mlnlalure O '1 ~ :~ ~~.:1.~.~!'.ie~~J~~~ ~l Up u: 4022 ~ll 1-13 J 4042 ~l Np p cerbon Elfl 1fi to 1N M- JW Sp. etsp. Resletois W tp. 5% SV with 1 pre** BL 4iV etud 2 connectors V +»V 9V Jt. ::: n 26p >0 451] 1 '''' 49 Praeet pata eub-mlnltluro O-W horlz or 0V vert 100 to 4M7 alp. recorder + 6V 4 record.r mains si. 4*V malnl unit + 4*V 7*V 4 7iV 1&0mn SO. Caasette 100ma with 5 CO"''UTR = ~.:t~~~o"::!!*fw 4K7o 2M2 log n. U U. lablll.. d modal OUR i :OMrUTCR TAKES GOOD CARE OF TOUR YOUR ORDERS Potentkmetera W to am2 loo or lln. pin Single Slng'e 25p. lip. Dual DUll Tip. "Jp. Pelyaetar Poly"ter C'Qe- cap. witched din plug MN CA'ACTOflS' cllo.. 2SOV El 0110 O8mUiP. O lmflp. ~tc:::v!::~ output 2 S/O/ft/SV Fully BlabHzed :4~7j~D~p~ 400 ma model O:p~ ~ SEMENS CAPAClTOflS*. RESSTORS cltofthsov E6 01 to - WWmf 5*p, 0 1mf2p. 15mf 5p.... '33. 47ml... Polyatyrene capacitor. 83V 15pt pf 300ma t N. Oulpul71V 300ma &t N. WorJd-fainoui World famoul for autlky quality and depend- 15mt lp. 22mf 4p. -33, <7m1 Bp. Poly- 300mB Car convertore Output 12V dc nput. SOOme Output 1-M. V depend i. f watu-2tt each": mocal film. ibillty 4Kt«ption»lly abillty_xcepuonally lar, nocks stockl h«1d. i. i watti 2p «ach'; m«t«l Urn, held. metal oxide nd wacc 5.. 2iP. c:.ramlc capacitoro!lcv 12 22pf 10 LMNATOR KT. m«t»l okida artd watt carbon 5p tkl. Btyrene Ceramic cadadtore capacltorb E12 e3v flov tsof E12 to 22d1 MOOpf to BATTERY PC. TYPS-7'Smm 0'001 ldoopf ZiP llioopf each : quclncicy H, 10 OOpf lip. Myla. e frh. t... PCS TYflf 7-5mm PCM to ttch*: Good quendtf discounts. Mai- 1000pf 2 p. Ee 500pt to MOOpt 1*P. Mylar Send tae capacitor. ' '002, ' OO!5mf (p. typ wtth f' conn.ctare. 01 ~.ach: , neeic dependene ". SO. lo for ELMNATOR free leaflet on KTS range. Nma *»5 to «p each: netic field depondenc from caoaclloie 100V OOSmf 4a. radio 0 068,0 1 MS p«ch, 7.. each. Hall av,:.t affect effece from from" 1* mf 4*p. (U, Mmf Sip. Elaclro- 4*V 1 iypee ~~ a:.~~\~j:~f!i:.s~jtf :~~W~i e + UV with ~~ pree* ~~:SO: BV stud ;V+ :V~14t.: 111. connectore C~~ 4tV lytlce MV mf Sp. 15V Bmf Sp. flmf 2 St. fl -f flv S6. «+ flv 1 M. Ca»-..ttolype 7iV loom. wllh t CERAMC l-smnr N. ClRAMC:-2'SmmPCH PCM 0 O O.O Oll 01, p. «V Mmf Sp , loomt»p. MO,..,1 0 ' S.. Mach: 068 6p ~:~p~rjm~pit:,,~~rfi~. ~~=... to,.tablllaod -.. (yp_ for 4pi Sp #«ch: 0 0M dp SEMENS TRANSSTORS 330ml 8p. 470mt Hp. toocmf tip. Zenef* Tranmlstor ette type 7i:V looma with din plug 1 - P. 5mm PCM PCH pj 7p iqp. JO... Silicon npn»nd and pnp from tp... each: 400mW E24 2V7 to 3SV 7Jp. low :ra~:sf~i~~~f~~~rs k"3wlt.h,u~m:/:/~~~~:~s/~~~y hum etablllied 3/41/6/71/8/12/15/tBV. S-way typae t~~': toome lor UCTROLYTCS-/OO. LECTRO LYTlCS /100, 10/25, 10/25. LEOt, LEO.. red f tp: p: yellow y.llow or graen,reen 2lp MANS TRANSFORMERS 1». 1 Amp Cfl-40. Heavy doty S way Up O-O-OV &4eV 100mm looml tp. lip. fl-o-uv t4-9v 79fna 75ma Mp. types Y_ 4i/S/7/8i/11/13/14/17/11/'15/lt/34/42V Amp 4 U. Amp l S. Car 10/63. conv_r 100/25. *tc, atc. (3 or 5mm): smm): Photo Craniinort tranlinon from is-o-iev some «P, isv 4A Hp. a a iia 1 4*/6/7/a*/1t/13n4/17i21/25/2a/34/42V 'or ran,. loo cur,,-,nt lilu. "p. ~~.o-j.~~~l:"a~~. \~J'jUt i:. npul12v Oulpull/7i/lV la ltabl- For full rann s««our «urr»iit lists. dp.» t. a-o-av 11A l tt- M-«V 1A «-H. kit Amp input 85, 2 dc. Amp 1 25, «/7*/BV Cui- converter 1A mtehlit-o-tav KEEN KilN PRCES PRCS GOOD SERVCE SEWCE WDE RANGES 1S-6-1SV looma l~l~~ 1A ~~m:z':l. 2 Np, 71. ' V V 1A ~~ 1A 2 ~: 3'», g:::: «.» tlied. ~l :' «. Btabtllied.~~lir&r':~~~ 3-30V A 1 power H. 3-30V kite 2A 3-8V :t~~~ 14 loome «..o:.'. _ev2a a N. OFFR. DSCOUNTS U V,A.T^Add V.A. T.-Add 8% to vatu«value of of ordtr M>.9V ZA ct-ae order PRNTED CRCUT MATERALS BULK BUY OFFERS MATRALS MlnJmum &1. mix thll 9% '% f f lilt valua of order over 10 ih- or 2i% lt% with it«mi iteml mspk«d*. marked". PC elchlng etching Utei oconomya kltl:-economy t -Ta, '70, etmndard Minimum.tandard lactlon AC78023N ex.ct Qulv. of '11. q n" pcb 4Op. b t '01. 10%,0*" if if Uu lite valua value of order ordar ovei* ovef 15 as {No (No V.A,T. V.A.T. on on oveneu oveno.. ordan) »q ni peb 40p 1 lb FeC 1 OS. section only. purchaie AC76G23N 11 any exsct ml* equlv. from tma ol orda~ wllh h 1.nk lip. Goods sant pott frta on C.W.O. Etch tealet re,lat oene; economy penl:-economy dp, UP. dalo dala TSp. SN76023N 71p. ZN.14 43MHZ cry.tall Up. Dbcounca Discounts gvaifabla.avanabla where.. cwh^ cash, P.O. or or ordar* ~:d.~ in f:n~l~~y~:- :iisf'val~~: U.K. over 5 lilt valu#. Smell Small drill bit ZBp.... Etching Elchlng dieh dloh ftp. 2N<14 Mp. with 4'43MHZ mproved PAL heet crystals sink Tip, 4Sp NEtS 8 lip. dalo pen. chaqua Laminate lip. chequa h is tent.ent with order. ordor. f f under, under. add 27r> 17 per order. Umlnato cutter 7Sp. 741 S-OECS S-DECS AND T-DfCS' Up. 8 Pleetlc dll 2»p. eoulv, NEWS of a BCW/B dll no. 3 dale Ep/l'Sp. pens T-DCS' r/aa:s~'~ ~r~"~ ~C~~/~~'~/4~: MONTHLY S-OoC U. T-OeC 3 N. u-ooca BARGAN LSTS S>.E. S.A.E. brings brin,s momblr monthly lilt of of b%r ains. S-DeC t t3. T-DeC 3 M. u-deca 2NMM8 blr,ainl. C07 7,. 'Cl 011 lp. BC211 '1'. N400 u n. u-o.cb n. 18 Alto dll OTO. 'p. AJto currant cu,..."t aufck quick refarance reference prke price liieof lilt all all ranfet. CJf7. u-dbcb Ci-VT. 16 du or 10T» BC107 p. 27p. BC1DB N4t4S 7p. l'»p. BC212 BOt3l «p. N40Q2 Up. ranee'. 2SOV polyootor ClPO 'Olllmf t t... adaolora: with adoplors:-wlth tocket locket C t lt. M. Plain P'.'n Hp N'. '058mf 1' 41'. 'mf t Sp. '33mf 2... Caih Cuh with ordar order (P.O. or cheque psyabla payable to co Eloctrovmlue Electronlu. Ltd) Lld) or your New Now S-de-klt S-do-kll C4'ta. OMmf 260V l-4p, polyeater -mf 1«p, csps -Mmf -QlSmf X Bp. l-ip, iw ol.lora Ell 10 OM... Zen.r Accost.NCLAR PRODUCT.' Acces. or Sardaycard Bardaycerd number. SNCLAR PRODUCTS* resistor* numbor. dlod.o El P0M35 dlg""1 mulllmolor S H. Molno TRADE TRAD AND NDUSTRAL ENOURES ENQURS NVTED POMSB dlgltel multimeter 13'». M«ln» diodes 400mW 5% C12 E34 3V3 1 to So fqm 33V 9 Sip. lp. Zentr NVTD adaptor i J t. i*. Dnlime Deluxl padded carry cam c B-PAK MODUL. For for all an round mhfaction be saeisraction-be safe buy safe-b it it from ELECTROVALUE ELECTROVALU 3-M- U S. 30hV 30kV proha probe U 31. Cambridge m-pak prlc.o. lunor 21 H. ALO aclentlflc clentltlc programmable calculator calculalor ts t5. 13-S. New low AUDO D'loee. S450 MODULKB luner «ts- AUJO 4 U. 1'14100 U S. MKSO.udlo kll Prog, Prog. library br.ry '15. hfalna Molno edap1or 3.dlPtor S 2fl. 4*14. PA100 13»5. MKftO audio kit. &31'45. 51"00 t 75. SpM80 1'47. CambTldqeaclenmic cambridge clonllftc M... S H. sa. dllla. ELECTRt ALUELTO BMT Stereo Send 30 man for free SPMB0 dot* Dipt PW7, Z St Judas Rd, Englaflald Green, Efham, Surrey TW2» 0HB. SWANLEY ELECTRONCS Phofia Eiham 3603 ^ Tek* D'T. pw. po Ba. ". 3Z Rd. Swa.lav. Kent TQ Wall ord.r only. Pi co.t of poltag. Price, nclud. Northern Branch (Penonil shopper* only) 680 Surniia Lane, Bumiie, Me l DEPT. PW.PO M, U Gotda.l ltd.,, BRTO VAT. 0..,.... cuatom... 7" tom. m.rlled and 11" othero. Ofclal Man chatter M f 1N A. Phon a (061) VA oider Only- Pleeas add 30p to the total cost ot order for-postage. Price* nclude credit T-. order* order, welcome. cuetomsr* deduct 7% on Hems merkod end li% on other*. Offldil PnbSisbed otl epprojjmeiejy tie 7lh of each mootb by PO Keasslaee Limited, Wcatover Hoase, W«t Qua> fiuad, roolt, tj(t»e. Biilu Pilnltd ui ^iibau bi ifidci Duuat.xblc, Dcdr.. Sole Agents for AasUolia aotl K«w ZtsJand Gordon and Ooioh (Arts) Ltd.; Booth AfrlOv-C^oUal News Aszacr Ltd. BobacripttoM NLAND and OVERS BLAB «10M payable to PO Bervkes, Oskftnld Toose, PeoymooDt bo Jrat, rteold. Boad, hired HAywsHa oot or otherwise Hsatb, dirpoeed PmoWiL of by way Wyaia.*Bi of Trade i at»c»ld more subject ttmn to the lie rbcomffltadrf following ecodluona, efllllob price nambly shown that on t the afaau cover, not, excjadlnjr wtlfcout the Biro written where the idling of (he price Pobttshera s subject first to hartaj Y-A/. been and that flretl t fcjj nca be Jeol, reeold, hired out or otherwise ivrp!*m ot to a muulated coudhlod or La any nnafrthorlsrd coeer by way of Trade or affixed to or oa port of any pnmlcatlfm or adverttaln*, literary cs plo* torhu nutter whatsoever. P" P/eeec... aand lend all ell correipondenc*... and Mail-Ord Heil-Ordere... to Haad Heed Office A SELECTON FROM OUR STOCKS OF FULLY Retell Shoo Open ell dey Satwdev AC/DC TAUT SUSPENSON OUR NEW 1077/1978 CATALOGUE S NOW READY AND WLL BE SENT ON RECEPT OF REMTTANCE FOR 0-30

83 U.K. RETURN OF POST MAL-ORDER MAL ORDER 11" fls OO.""... --J 90-14,500 c/. 12m. doable coae,p::!r!!. ",.t ;:r~~:-!:!.:::: ~~::bi,w~~hjd~~kf!.... densit, of gau & fluj: "" SERVCE ALSO WORLD WDE EXPORT SERVCE R.C.S. 100 watt MXER/AMPLFER BAKER MAJOR 12 4S-00 BAKER DSCO SPEAKERS ALL VALVE - Foil 1 HGH QUALTY-BRTSH MADE ' W-14,600 ind tweelar c/«. cone Zi'n. logather double wflh cone, a BAKER wcolw 2 x X 12" CABNETS «* ceramic magnet anembly baying a flux '[V denitty oi of 146,000 ot 14, ,000 Msiwelli. gann n wenl. Ban and.. reionanca a total flat relodance 40 vynide covered. Other cabinetl in. tock. C 25 watt. HOTE : 8 Wv ci fl ohm* rated mml 85 witti ba atalad. NOTE: 4 or 3 or WATT R.M.S. 52 With one horn :.,ati ~'.:~ -:-:-:-:-'R-m-:-'~_bD- ' -:'-~-:d- 'K--T--- X V, MAJOR MODULE KT 40 60,,91! M c/a cl. with witb tweeter, t.r. croaaoyer, crollnver, With two horns 68 itite bafbe 19 :< 12Jld. Plaaia f 10. fin Chllsi. 94 :i.'f: 4 f:r or 8 ~ orlbohmi.!; t~ ~ :~: *" 1 19 '. uv Cart, Ca.n Chusls only ty^ Cirr. Po.tll BO oorlrola. Pour lupoli. Bail* Pour all ipikken. WAV Thli muter profsnjoiial voluma. qublllr trebla aal ampllflsf bin 'our input. Four way mb:ing, master volume. treble and ball aontrojl. Suitl all,peakera. This protelliona) Quality ampltfter cfanili ch... i. il awtabje all group', disco, P.A. where high quallty powar power li li 11 reaolrad. luiubla tor required. b 6 ipvtlier All ctonpj,.peaker outputs. Ako, outputl. A/C P,A.. Ale milni whoro mains operated. burb quality Sliva Slue output. Produced demand a quality valve amplifier. Send for Fxoducod delaila. by daajtnd tor t qqaut *avb unpllfler. efim Send tor detajl.. CASSETTE CAssmE TAPE TRANSPORT MECHANSM Compile with moao reoord/pltybaclr ard crese hesili. Five push battoiki, tmotd.^ur, forward, rewind and pauar. Less L", motor, motor. brand b;.dd new 3 SO 50 Foal po.t 50P- 50p. Complete with mono record/pjayback and erase head. Five pu.b button record. play, forward, rewind and,ule. 10" ELAC H-F H F SPEAKER LarKe Large magnet. Reipoma: ceramic maxnat. Relponle: cp., fiaaa 60-18,000 cpa. BalS r810nance 66 ep., fl fg ohm teionanca (mpednnco 65 epi. ' fa ~~,::.i.m p::t"40p 4. Crt 10 waits. Post «p JV 50 TEAK VENEER H-F SPEAKER CABNETS KODEL."A". MODEL."A" x x 2in, 12in. For Sn. 12in. dia. llubtrakd. ~~~.~:a~2~~ or 101n apeaker. ^ peaker cn 50,u «1 Poit :~~to AO MODEL "Bit For ~;:a1:r 13 x "fl" Sio, BOOKSHELF 8in. or or 8Jn, 8in. XQ CA Poal p O:i apeiker ta Cl MODEL "C" BOOKSHELF For Por filiu 61iD and tweelor. t.... t. r DMt,t 7B ) 75_ LODDSPEABBR LOUDSPEAKER 18ln. l 8in. wlda. wide. 20p 20" ft. CABNET WADDNG U. GOODMANS CONE TWEETER 3lin. dl4m Cl bin, 3ila. 6in. EBO dlnm. El mid fauea C.P.S. range Sfi. fi5 WATTS 9 (i 15. *-* 3 25, 9 R loln. loin, GOODtANS , ELAC 30 TWEETER watt GOODMANS 4 ohm 20 woofer watt 2 * ohm SO BS. BARGAN 4 CHANNEL TRANSSTOR MONO M.ONO MXER. Add mailcal mu.ical huhligblb 1 hkhlights rrix and aound sound eftects recordings. Jr.b: Mkrophono, «Recli to Microphone. rocordlorj. records;. iepa Will tape and l A -A with separate codtrola into single Oalpnt. tuner wltbieparata ~:!~~~:. 0 volt volt faallory coolroliinto balt. r, fft'tk eioqle _ op era led w ' ^ TWO CHANNEL STEREO VERSON OP OF ABOVE ^ ~O BAROAN :::?l~~~ a: 3.. WATT AMPLFER. 4 TriDBiilor dv: ~~ft ~;:Pv~~~~e~ i r:bl;~~~~!:! OC Fcah-Poll conlroli. controla. 10 Raady 18 volt built bittery wilh battery operaled volume, operated or trablo Mtlnt and Mainl Supply baai S2 2 95, J 95. THE " NSTANT" HEAD "[NETANT" DEMAONET3ER BULK TAPE ERASER & DEMAGNETSER Saitabla Suitable for culette a n. ize. 01 raala. reel. A.C, tor cmettei. and all alzei o! tape A.C. mains malnl SOO/249V. 2OO/249V. g^ Leafiet 8-A.E. 4'95 Po " 1 L d.t S.A.E ~g~' ELECTRC MOTORS ELECTRC MOTORS 240V. l43 0 2l 2in Pole, Pole, Pole. 84DV, 3flOV. 240V Amp. Arap. Spindle Amp. Doubla Double fiplndla «Spindle l-7fi X n. x 0 tl o 0tn in '50. Pole, 120V.,5 Amp '< 0 2in. Two Each in 150. aeriei 2 Pcln. series - 840V. 120V, 240V. 75p 5 Amp, each. Spindle Brnah - 0 Brush Motor. s 0 From 2ln. Prom a Food Uizer Mixer 240V, -3 3 Amp. Hicli High Speed and Power!ul. Powerful. Spindle io each. Spindle ZSin each. 0 BLANK x 6to, 1-40; ALUMlsniSl 10 7in,2155:l4 CHASSS. 18 x j.w.r. 0b, 190; 2}ln.dd#». 19 x 6 6Jn. ain. 185; 06p; BLANK ALUMNUM CHASSS,lS S.W.K. 2!in. Sdes. 0 41n.96p; S x 6in, n -40: 10 7in. 155; 14 x Din. ; 1 90; 16 Y 6in. n 'S:5: J2 12 X x Sin. 3in.!l 1 20; x Join. loin ; 20; 12 X x &!. Sin.!l S.W.g. 6 4in, 20p; Oin. 40p~ 10 ALUMNUM «Tin, 7in. eop; PANELS. 50p; 12 -) Sin. 18 s.w.r Mp; 50p; 12 0 x 4in. Sin. 2Dp; 8in. S0p; 8 5Op: fl 16 x Bin. )( flio. 40p; Sin. 75p; 14 x Bin. 9in. 80p; J2 12 x 12tn. Sin. 80p; SOp; B 16 /( loin. 95p, 95p. 6 1,iD. 15_. ALOMK3DM ALUMNUM ANGLE BRACKET 9 x? iin. 15p. ALUMNUM STOCK. 4 x 82 y x 2in.B6p. BOXES. 86p; 3x2 MANY 3 x 2 Un. SZES lin. flop; N OOp; 98 x STOCK, 4 x Zlcv. l; 2in. 1; 8. B 3in. 1'00 ; 9 x 4 X 4iD. 2; 12 x ~ 4in id. 1.80:9 x 4 y, 41n. 2:12 >; 4 4<a. Z 4D. DE LUXE BSR H-F AUTOCHANGER Play* 12(n_ JOb. or 7ln. recordi Play. 12tn. 101n. or 7in. record. Auto Aulo or ZffsDual. Manual. A tlfb :high quiltly quamy i unii unit bicved backed by BgR BSR reliability nljability f \?{lb 11th 12 Diontbi month, Euaiantee. guarantee. A.C..'i ilmtap^blj ioo/ssov..00/250v.81 Slae lljin, Ulin. Aboye Above motor bnard S{in. 311n. Below motor board 2J!fl. 2Un. ^ >-* ^ r Wllb With MAOKETC MAGNETC STEREO CARTRDGE ti-l'lv CueJd Device, Blal Compensator. Balanced Arm, All Po.t 76p Cuetrti Device. BlaeCampeniBtor, Balanced Arm. All Foil 76 p KEW NEW DECKS BBR Bsa MP80iF12S M.P60/Pl28 u-rh with Goldting Goldring OB50 G8liO magnega magnetic carlrsflge. cartridge, BSR Budget ActocbaoeBr Autochanger with ceramic cartridge. l2-9o Gorrard Garrard AP76. AP78. Sine!* Single player lem less cartridge BSR. P63- P183. Belt drive Tarnlable, Turntable, lest less cartridge Uarrard Ganard AntocfaanKer Autocbanger with ceramic cartridge Garrard Qarrerd Minichanger, Play. size. Ceramic Ceramio carlridge, UtQlchajiiCer. Plays all aiza records, cartrjdg"-e.' BSR. BSR, P182. flared turntable. cartridge. P182, Snake arm, Btrod turntable, ceramic BAKER SPEAKERS "BG SOUND" ftobnilly!tobultt, comtfucted conl tructed to tl&dd stand up n to long periodi " riod. 01 A. u.ed leading leadidg groupa. ot electronic power. Ai used by. U.eful relponle 30-13,000 Cpl. Ban Dielul BU raionanca raiponie ruonance , cp«. cpi.. GROUP "25" 7,AA 121n. 80 ao watt * ^ W V 4. 4, 8 or fl 16 obmi. ohm Poat 1 GROUP "35" 12tn. 40 watt 8 or 16 ohml POlt! ?rz:^' i4-oo GROUP "50/12" n, 121n. 60 watt prcteiaioaal profe.lional model. 4,8 or X9 16 ohmi. ohms. Poit Po.t l UO 60 ReiponRe Response = 30 16,000-16,000 cpi. cps. WUh With alumlclam aluminium prrabnce pretence dome. GROUP "SO/ S" n. 76 watt frrj; 08 or ohmj. 50 " 5 " 26-oo ohmt. Foil POlt 1 60 Send for leaflet! leaflets on Dim. Ditco, P.A. and Group Qsir. Gear. BAKER SO WATT QUALTY imuaf BAKER 150 WATT QUALTY TRANSSTOR MXER/AMPLFER. :... ',baker;;" ' 1 "-:-'-'~ Profeiilonal djjco, groapb, ampufler P.A. or mualcal naln«adtauced loalnub«nta. circuit 4 npuli deiign- 4 way deal miring. lor Protellional amplifier using advanced circuit delign. deal lor groupl. P.A. or mu.icallattrumentj. 4 nput. 4 wa.y mixing. Kaiter Mstter treble, treble. baai ball and yolume volume conttola. controla. 3 apeaket peaker output aocketi lockets W to suit various combinationa 01.peaken ohm. lull yarloua comblnalloni ot apaakarr output. main. Quiranteed. Slave Guaranteed. Details Dutpul. A/C ma)oa, X / Ctrr. Detaill S.A,E. S.A.E. Mm 75 m SLfiO HO 100 WATT DSCO AMPLFER MADE BY JENNNGS lennngs MUSCAL NSTRUMENTS 4 Speaker outputi output. rolume, volume, treble, baai, bu., conlroli controll CAN CAll' BZ BE USED Afl AS 100 WATT SLAVE E B.S.R. SNGLE PLAYER DECK 3 ipeed. Play* all ilae record', 3.peed. Play. all.ize recorda, SEarec Stereo Cartridge, Cartridge. Cueing devlca, device. deal Dlico Deok. Deck Post?6d 76p 75 Carr. 59 Carr.!l DRLL SPEED CONTROLLER/LGHT DMMER KT. Eaiy Ea" 10 to bnlld build kit. Will oonlrol codtrol up u. to 600 watd watt. AC malm. m~~~~. 36. Poit 36p t,j f-> C STEREO PRE-AMP Kit. KT. All parti part. to build thli thil pre-amp, pre-amp. 3 i input. nputa Lor lor volume and high :~~e~ ~::r~~d. P.C. medium Board. Can or low Can be be ganged gain per ganged to channel, to make make maul-way with voluma m,!t;ta:: /T-OS control ilereo mbera. Poet 3Sp 2.95 ' " R.C.S. SOUND TO LGHT DSPLAY MK2 2 Complete partl ohlnneli. channell. 900 kit 800 to of parti 1,000 walti with wattl each. R.C.S. Will printed operata circuit. operate front from 20MV. Three to 100 watti watts lignal signal lource. Suitable s1t::l:.~o:j:~roam!~ Cabinet Lor e»tra borne 4, uie..upe~jce Price * / * BOO 200 Watt ReftecUng White Bulbi. deal Llgbtf. Wall Light. Edlion Rear Reflecting Edilon Screw Fitting Wblle 7fip. Light 75p. Each, flulbi. de&l for Di«co Each. Poat MANS TRANSFORMERS X AMP VOLT VOLT * AMP. 300 MA HO 00 3 AMP MA VOLT t 30 3 AMP AD C.T EC 20 VOLT VOLT 6 1 AMP. AMP. 2 AND VOLT VOLT 2 AMP. 1 AMP. C T. f« AMP AMP VOLT U VOLT AMP, 1 2 AMP VOLT x AMP, 18 VOLT AMP. &, 9. GENERAL PURPOSE LOW VOLTAGE. Voltaftel Voltage. available at 2A, 2A. 3, fl. 6. B, B. 9, 9. 10, D, , 26, , and 30V D 1A. la. B. 16, A. 2A, 6, , B , , 20, lb , 30, , , B A. B l lj.oo M. 6A. 6. 6, 8. 0, 10, , 18, , 20, , 24, 30, 30, 40, 48, , , , , lho 60 R.C.S. ^. R.C.S. BOOKSHELF SPEAKERS SPEAKERS j i <j % i i 13 ~~j 60 to x 14, x Bin. epi. v]., ' J l' f'" Wj" 1;?, 12 walll imp. 8 Ohma t 19 pair Post p o.t HO 41-SO rt 13 x 10 x Bin. 50 to cps. 12 watti rml, 8 0hml L lor Dlico or PA,11 ettrd wilb crrriiur htndlti mi coraari. Black vyniio COrrreil. Olbar cabiorlh in,(ock. 8AE for f tflcl for Di. co or P A all ft Ued with carrying ba ndlel and cornerl. Bllck SAE for teaftd 80 WATT R.M.S. 80 WATT R.M.S With one horn 64 With two horns 72 Can. Carr WATT R.M.S. R.M.S, With one horn 78 With two horns Carr. t6 5 SNGLE 2inch 12inch CABS COMPLETE 30 WATT R.M.S , WTH HORN WATT R.M.S. 34. WTH HORN WATT R.M.S. 41. WTH HORN 49. CARR 3 EA. "SUPERB H-F" H F" 2in 12in 25 watts 10ud.peater, it. remnrbable A high quality remarkable low loudipeaker, conn cone reionance Ub re.onance eniutf enlure. 01 deepeit clear reproduction of the deepelt bass. Fitted with a special copper bail. drive Fltlad and wilb a concbnlric & ipeclal concentric tweeter cone reiultlng relulung n in Tall full range reprodaclfon reproduction with remark- remark efficiency reg able regilter. later. efftelenoy in the upper Ban Ball Relonance 25cp. Flux Reionsnoe FluJ: DenBtly Denlily 10,590 16,500 gau Stjcpi gau Useful Diaful reiponae relpodlfl BO-lT.OOOcpi CD 8 or ohmi ohml models f ~f'jo % "AUDTORUM" 12in. 2in. 35 watts run ranr'e tor high power, A full range deal reproducer for lot Hi-F lot blgb Bi-Fj and Diioolhequea, Dilcotheque.. Gutan. public addren, Electric addre... multl-bpeaker Guilari, multi apeaker yatqini, sy.tem organ. Ba«* BaBS Resonaace electric Otgaai. Relonance 35cpi 35cp. Flux FluJ: Denaity Den.ity 15,000 gaafl gaull Ulelul relpod8e.. 16,ooOcp. 8 Utefui or 16 reiposie 25-10,00 Ocpi 18 ohm* ohm. models fi"o WJo CARR 3 EA. "AUDTORUM" 15in. Sin. 45 watts WAttage loud.peaker 01 exceptioaal A high wattage ncepuonal Quality loudipeaker Quauty with & a level ol reiponce retpon.e to above 8,000 cpa.. deal 1 tor Publio Addrell. Dilcotbequel. Electronic Poblio Addren. Diicotheiaei, injtrument. and home bome H-F. nitromenti end the Hi.. Fi... Reaonance 36cp Flu* Baie Reiciience Flux Density 16,009 16,000 gsun 36cpi gau Ueeful Ulelul re'don.e cp. 8 of or 16 reaponae ohmi ohm. model#. 2O-14,00Dcpi modell ffi'o TjOUflsjifiLltfr CnlijncL WarJdlag Slll wide, 20p por ft, H-F ilata and COLloaurc cujiic Ublty, Manual 68p, containing plans, dehigmi, crosbover E.M.. 13t 13^ x X 8in Sin SPEAKER SALE! With 10W, tweeier. ~W. Bialea ~~:r~8; 0~~do~r:~lover. or And 8ohm, croiioyer. fy 7.95 QC 4? Po.t Pen 4Gp ^ W 5W model 10* a Obmi. ohm., Poitfl5p POl185p GOODMANS 20W Woofer 1 WfcJJ Size loin 40bml. Rubber 12 cone x a 10ln PO Burroond. Burrormd. 4 obmi. surround QC ), ' Post 65p 337 WHTEHORSE ROAD, CROYDON RADO COMPONENT SPECALSTS Open 9-6 Wed. 9-1 Sat. 9-5 (Closed ror lunch ) Minimum poat post 30p, lop. Componenta Components List 20p. lop. Cash price includet includes VAT. Acces* Access & 4r Barclay cards welcome. Phcme Phone your order Tel. 0-6B [

84 n1(1pllln rmpum everything for the modern D.lY. Q.Y electronics enthusiast and more. ~ if 1~~J~Q1) 'L* 1 i~1 Q a- THE 'ORUMSETTE' 'DRUMSETTE' RHYTHM?~~~'dMi nil mil 1 ~!. f: fs.: fl ;, ~ ~ 1 GENERATOR imimi 11lHlli Aninui ~ n 111 m: Oroanlvti, Organists, plhnlvtg, pianists, gultarlbls... guitarists e an utomallc automatic drum tat let D lo accompany youl l Nine Nln. highly rcallillc r.allollc nalmmanlt nstrumento play REVERBERATON SYSTEMS High quality aprlng line driver module uaea nlegrated cfrculta two transistors. Built tested fllleen filteen dlboront dlfferenl ahythma, rhythm.. Flllcan Fllteen rhylhro-aalort rhythl11-aelect touch Mlph (luallly prlno Una drlyor modulo u«o» 4 nto- owllchoa swllches and a touch louch plala plate lor for alop/alart atop/start without wllhoul rhythm ori««d tlrculu and wo tronalslori. aulll and leatad circuit wiring nstructions for spring line. chanpn change olvaa gives atrnoluta absolute aaaa ease ol of oparnllon. operation. Build t youraall clfoull board with wlrlno nalructlona lor iptlnu na, BOARDS AND PCB's.. lf XB«5G, XB85G, price M 1" M, 0. Power aupply supply to auit suit driver Papos Pages 59 to 61 ol of our catalogue lot for undar under Ml 15 ncludlno ncluding amart smart loahrhact teak eflect cablnat. cabinet. Saa See t modulo modute coele costs erounu around 2'50 *50 end and conatrucllon coiultructlon dalalta details show you our range of Verohoards Veroboards and hoar hear t it n our y~ are aro n cetplopue, catalogue, or oatr ask for lor naltot leaflet and S-Decs 5-0ecs or if you prefer to make ohopl ahopi Sand Send for full MSSW. MES24. Mochdnlcal Mechanical eprlnp spring llnoa! line., pcb's eonatrudloa conotructlon d.tolll delalls line (XLOaJ) 4-41', Long line 9-CHANNEL including etch now: MES49 prlco B-CHANNEL RADO Short llnolxumd) M'4*'i Lone Una your own peb'a a range of etching price (XB84f) (XB84F) J«. (All price. prlc.o ncluda systems ncluding the novel etch- nclude aip. 25p. CONTROL SYSTEM V.A.T. and p A & p). in-a-bag system, plus printed circuit tnlllbfers the (All prlcaa prices nclude include comprehensive V.A.T, V.A.T. and - p A & p). A comprphenslvb model tranafers for he professional finish to your boards. control system, teatur- featuring ng nine e ndependent fully proportional chan- chan - r nels achieved by a dealgn design using very few components thus keeping the cost to a minimum. Full construction de- de tails in our booklet (XF03D) (XF030) T.V. GAME price A faaclnallng fascinating TV game kit that plays (All prices include football, tennis, squash and practice for V.A.T. and p i &. p). only Seprlnt Reprint of conslructlon construction } details delails 25p. Add on rifle MASSVE RANGE OF kllonly 1060.(Allprices kltonly COMPONENTS AUDO MXER include V.A.T. and p&p). For instance the capacitor section A "superb superb alorao stereo audio mixer. mlxer. t can bo be equipped.; ) in includes non with up ull,to ta 16 nput input modules o( of your choice end o w w.miri e o n our catalogue ncludes nonand U ta perlormance performance matches malchea that hal of the very best iliiluauiuiuiii; polarised electrolytlcs and our tape^recordera tape~recordera and hl-fl equipment. t /noefa meet. the resistor section includes even requlrementa requirements ol of professional recordlno recording eludloa. studio 1% tolerance types. Get our FM radio olatlons stations. concert halla halls end and theelrea theatres. now-you "Full full conelfuctlon conatructlon details n our catalooue- catalogue. A fascinating catalogue now you component schedule s S available on reguaat. won't regret it. requeat. ELECTRONC ORGAN The only organ you can build n stages and tailor to your requirements as you go along and along-and at each stage you'll have a lully fully working instrument We haven't got the gimmicks yet (they're yet-(they're coming soon) but we have got the most beautiful sounds-you sounds you won't find them on any organ lass less than twice our price. So 50 get our MES50 ME5SO series leaflets nowl 65p buys MCROPROCESSOR Build a mlnl-computpr mini-computer with our mlcroproch mlcroprocesaor..or the three available so far. hit. kit. FeHtures: Features: 4e 46 dlfferant different nitructlon instruction types: 5M 256 bytes of read/write memory (more are aaslly easily Our bl'manthfy bi-moathty nawelarer new.~.r kaapa keeps you up to dac«date with lataht li&est added] added) mlcroproceasor microprocessor cap can addreaa address up to ei.see 65,_ guaranteed price. - our epeciel offeredetaile projects and new fines. Send etc. elc. (XBSY) (XB9Y) datail* of new proiacta end naw lines. Bend 30p the nen eia (Sp di.count with copy). 8 a bll-bytee. bll byle Complete kli kit (or lor use with wllh leletypa guarantied phcaa cur stastapaciiloffsra - teletype 2O-key 20-Key keyboard for lor uee use with wllh above(ln (n place of ollelelype) (elelypa) for tha naxtsic imua* 9p discount voucher wfth each copfl, (XB92A) t t!. Both Bolh ilia kits with wllh datallad detailed mtiuctlon nslructlon books. i. See our newsletters for delails details of additional RAM's, RAM's. trl'ilata trl~st8te nterfacing chips, nurnber-cruncher number-cruncher and Knndsld standard cassetta cassette laue-recorder tape recorder nterlace nterface to stor# store yaurpfogramniea. yourprogrammes.(a (AJ prlcaa prices nclude include V.A.T. V and p&p), P&p). FS ob A FANTASTC._ ,... BESTSELLER! ~ big (11" x X 8") pages!.over a thousand llustrstions! lustratlons! Over 30 pages of complete rejects rojects to build! Thousands and thousands of iseful components described and illustrated! ~o Jo wonder it's a bestseller! ONT ON'T... MSS OUT! SEND BEND GOp aap NOW! t/apln APLlN ELECTRONC SUPPLES.' P.O. p.o. BOX 3 RAYLEGH RAVL8GH ESSEXSS6 SS6 SLR ala Telephone; T~ Southend ( (0702) Shop; Sqt 284. London Road, Road. Westcliff-on-Sea, Westc6ff-on-See, Essex icloiad on MwvtavtTerHVmns Saulhene (OTOP71S157 lcamdanmandllvlt"""" 8auchend107Ol!J 7115'151»,c com.. rr* ADDF ADDRESS. li POST THS COUPON NOW FOP YOUR COPY OF OU POST THS COUPON NOW FOR YOUR COPY OF DU CATALOGUE PRCE BOp SDp Please rush me a copy of your 216 page catalogue Please rush me a copy of your 216 page catalogue enclose SDp, SOp, but understand that if am not comple satisfied may return the catalogue to you within 14 days and have my BDp SOp refunded immediately. immediately_ ADDRESS