HOBB A CRYSTAL SET FOR BEGINNERS. RADIO -ROCKET ERA Story on pogo 3 AND

Transcription

1 Vol. 8 No. 7 OCTOBER 1946 Registered a1 the G.P.O., Sydney, for transmission by post as a periodical. AND HOBB RADIO -ROCKET ERA Story on pogo 3 A CRYSTAL SET FOR BEGINNERS

2 RADIO AND HOBBIES IN AUSTRALIA OCTOBER Marconi School of Wireless CONDUCTED AMALGAMATED WIRELESS (AUSTRALASIA) LTD. BY AMIZMi AMATEURS The Marconi School of Wireless announces a special course to qualify candidates for P.M.G. Amateur Certificate Examinations. NIGHT CLASSES CORRESPONDENCE 6 months classes (one night per week). 8 months correspondence course. NO PREVIOUS KNOWLEDGE REQUIRED OTHER COURSES : Candidates trained for all P.M.G. Certificates. DAY OR NIGHT Next term commences 4th November, CLASSES (Enrolment to be completed by 24th October) CORRESPONDENCE Courses can be commenced at any time MATHEMATICS REFRESHER COURSE Next term commences 4th November, (Night Classes) SPECIAL CLASSES IN MORSE TELEGRAPHY RADIO REFRESHER COURSE Oscillator and Sounder always available. rarticulars on application. Call, 'phone or write for full particulars :- MARCONI SCHOOL OF WIRELESS 47 YORK STREET 163 QUEEN STREET SYDNEY MELBOURNE Tel. B 0522 Tel. MU 9161 POST THIS NOW MARCONI SCHOOL OF WIRELESS Box 2516, G.P.O., Sydney Please send me without obligation full *toils of your courses. Name Address

3 I disorla! THE heat wave which recently assailed the State of New South Wales has quite naturally turned our thoughts to the spring and summer season, with all they imply to the radio fan. And chief among these thoughts is the matter of portable radio receivers. There seems to be no lac: of interest in these sets-the main trouble from the constructor's point of, view is the scarcity of equipment, In this issue, you will find a description of a fine portable with which we have frankly set out to beat the gun. After a careful survey of the possibilities. we are of the opinion that although the new, miniature valves are likely to be on the market before very long, and have in fact been seen in some shops in limited quantities, baby coils and gangs appear to be sufficiently far away for us not to worry about them at present. We consider that there will be always a good market for a standard, 'full-size" portable with the ability to give as good reception over a distance a, any other battery set. In other words, one which will place the emphasis on performance rather than extremely small size. Al a later date-probably the beginning of nest year-it should be pos. sible to bulid a really tiny portable in which ton_, volume and distance. getting can be almost ignored task of packing as much radio receiver into a: small a space as possible. When that time corns, we will give you one, but we don't consider it will in any way take the place of our latest job. This incidentally, is easily the smallest portable we have yet described. and, using the same size batteries, is just about as small as one could be made. In passing, it might,be mentioned that the radio beginner has not been forgotten in our plans. Not only is there a fine little crystal set in this issue. but we hope to describe some rather novel small sets in the near future. These will be covered in more than usual detail to reduce constructional difficulties to a minimum. Leaving springtime out of it for the moment, although there may be some connection, we learn unofficially from the P.M.G. that there are already many more amateur transmitters licensed than there were before the war, and that applications for further licences are being received al a most remarkable rate, II would not be surprising to find that, before very much time has passed, something like 5000 licenced amateurs are operating in Australia. That's a fine thing. Not so fine is the fact that the authorities have not yet restored the full band -widths to which amateurs are entitled. It is true that portion of the old "80-metre band has come back, but what about the remainder that has not? No one seems to be able to advance a good reason why some action should not be taken, particularly as it is believed that elsewhere, these initial cuts are in the process of restoration. With all sympathy for the problem. confronting those who control these things, we are of the opinion that it is high time some satisfaction was obtained. It is a wrong thing to enforce overcrowding of our part -restorations by new and keen operators unless there is the best of reasons for so doing. Alter all, the amateur has a place in the ether just at anyone else for whom frequencies have been internationally eat aside. INDEX Page. Ths Radar -Rocket Age 3 We Could Not Live Without Dust 8 Electronic Air Cleaning II Valve For Gramo Pickup 13 How It Works 15 News And Views Il A New Portable Receiver _ 20 The Radiofron RC53 Circuit 35 A Reader Built It 39 The 2JU-100-Twin Transmitter, 40 A Simple Crystal Set 47 Page Radio Transmitting Course. - Trade Notes And News 57 English Post -War Liner 6 Rocket Propulsion In War 62 British High Speed Fighters _. b!. Hold -All Ash Tray. 66 A Nursery High Chair 67 Make This Dinner Chime. _. 68 Amateu, Notes By Bill Moore. 70 Short Wave Note<. 71 Records Reviews 75 Answers To Corre;pondents 77 I McGILL'S Est. I8011. TECHNICAL BOOKS ON ALL SUBJECTS A Brief Selection from 'our Large Range of Publications RADIO Price Po.t Learning the Radiotelegraph Code, American Radio Relay League The Radio Amateur's License Manual 2/ - Hints and Kinks for the Radio Amateur 4/- A Course In Radio Fundamentals 4/ - The ARRL Antenna Book 4/ - Mathematics far Radio Si Communication, Book 1, Arithmetic, Algebra, Geometry. Maedel :sd/- Bock 2. Trigonometry. Algebra, Complex Numbers. Maedel SR/ - Electronics, Coyne 19/e Radio Valve Manual,i/O Radio Handbook. Editors de Engineers, luth Edition 15/ - The Radio Amateur's Hand - Book. lout Edition. ARNL 11/11 Stadia Fur the Millions. Popular Science IIVd Amplifier Manual, Shaney 2/ - Simplified Radio Servicing by Comparison Method. Reitman 111,11 The Log of Amateur Radio Station, Amerirun Radio Relay League :s/a Radio Amateur Call Book Magazine CARPENTRY AND 2/ - Nd laie) ad 4d 4d 4d lod 1/- 1/g ad 1/S 1/a 7d 2',2d WOODWORK Pocket Guide to Car- The penters 2/- 132d Rorf Cuts d Rafter Lengths. Hancock 1.5/- 21/2d The Steel Square in Australian Roofing, Smith If. 1sf.d How to Plan a Home Workshop-Delta 2/5 ' Rd Elementary Carpentry and Joinery, Emery 5/- 4d Australian Building Practice. Naugle 2.5/- Sd.rut Popular Woodworking Projects, Lukesvlle. l/d 4d Australian nlethuds of Building Cons truet inn, Sharp 15/- ed Course in Wood 'turning. Milton it Wahlers M/- Rd Complete home Workshop Cyclopedia, Popular Science 21/- 1/ - Reinforced Cnnrrete Simply Explained, Faber O/d Sd Hoick Cnns/rurlims-Praelical Beadlike Problems. Slciele 13/. Rd 'rite Encyclopedia of Furniture. Aronson 24/8 1/6 A Manual of Carpentry and Joinery. Riley IS/- oil AUTONIORILE ANT) MOTOR CYCLES Motor Vehicles in a Nub shell. Branler -Moore 4/- Rd The Book n4 the Red Panther 3/p 3d The Book of the B.S.A. A/p Sd The Book id the Villiers I:n.ine em... 'frout.leshooter's II a n ri - 100k. Schaefer 21/. 7d The Autocar Handbook n/ii Id Chevrolet Sis Car and Truck. Page 21/- Itld Fard VS Cars and Trucks. Page 21/- Ind Motor Racing with Mer cedes -Benz,. Monkhouse 12/- 4d Floyd Clymer's Historical Motor Scrapbook. No. I tl/tt Id Floyd Clvmer's Historical Motor Scianboek. No. 2 1/9 Id the Modern Stearn Car and it. Background. Derr 13/- Id I peed and How to Obtain n n/n c_ Pieuse,rda exchanpe to country cheque' Mail orders by return post List un rat techníerti subjects tree McGMLL'S IR:; 5d 4d Rd AGENCY Elizabeth Street, Nlelbnurne. Ta.,on i... Phone :;R EDITOR: JOHN MOYLE, M.I.R.E. (VK2JU) TECHNICAL EDITOR: W. N. WILLIAMS. A.M.I.R.E.

4 - to to THE )4MAZ/NG ANISOTROPIC ALNICO IN THE ROLA 5C SPEAKER ROLA GEORGE BROWN & CO. PTY. LTD., 267 Clarence Street, Sydney.. Using Alr 1 I.e rr.. weiq.st, F s SC n. s III^ or lsi modern all fl'speakers. ldeal'.y - r,n a...i d.r. s, it also finds uselul appn..'.,ii.n in vibralt and ballet y aerated receivers. It occupies the bnresl al :acne, weighs only 12 oss., and le thorougil:, robust in ganstruction and reliable in operation. Bécause cl its eminent su gabilü in midget receivers, Role 5C is unquestionably the most sought after speaker taday. Retail price with KS type transformer attached or detached 26/6 (Wish small fuocore transformer detached 29/-) Role 5C (with enisotropie Alnico) is now being featured in modern midget radio receivere and limited supplies will shortly be released for resale purposes. LOUD SPEAKERS with ANISOTROPIC ALNICO JOHN MARTIN PTY. LTD., I8 Clarence Street, Sydney. PAGE TWO ' RADIO AND HOBBIES FOR OCTOBER, 1946

5 THE RADARROC E The V2 which showed the enormous possibilities of rocket propelled missiles, being raised info place before 'ring. SAiE STAND ON THE BRINK Of BEYOND How much and how soon will the major developments of the age change our lives? What use will we make of Radar, the Rocket, and the Atom? These three have given man a power to create new horizons in experience and knowledge. DURING the hard, hectic days of the last war, one of the ideas most cherished by so many of us was that eventually it would all end, and we would return once more to normal times, to our life of the good old days. Those who were away from their homes and their work would take up the threads again. Food and clothing would cease to be rationed. We would sleep at nights without the fear 'of tomorrow. War and threats of -War would be a memory. Man would have learned a bitter lesson, and return to live in peace with his fellows. We are now waking up to the fact that there is no such thing as a return to the good old days. There never has been. mire rnarrhpc on-there is. as the old Greek philosophers observed, nothing so certain as change. But do we really appreciate just how much change there is in the world around us-just how much change there will be? In the solution of urgent problems of government and society, even the atom bomb experiment, with its cataclysmic possibilities, is little more than a news item of yesterday. But whether we know it, or realise it, or can be bothered with it, men are even now working behind the scenes on projects and devices as surely and as mightily as any previous century or succession of centuries. I am speaking now as much of human thought, knowledge and experience as I am of the material evidences of these things. The amount of scientific knowledge man has Micro -wave radars such as this may be used to track the projectiles in flight. RADIO AND HOBBIES FOR OCTOBER, 1946 PAGE THREE

6 k.. F.NeioVl,..l.r...qlbb.B tied e/ eaten ew...d wt. N.v..te 1.ldm diem bt Ib. wi Hess we Immediately tan tp Minn the Oudea N611k A welded mkehe A In rant a.aaltet 0.enheio. lien tilled wittenonut lit teal. to ent oleo mm.. m:m:.n,r end landed h) nab or roam lu talget. TM V2 wem at earl, era at Cite weapon Deed!, tr+'_i:, I'. e 15th. II wee net male ueatm) r- nrat of paar end bete, Annli d oubt II wet en e bomb nel p ripe e pkwta eia am grin wutm innere> Into me inn eror lo forte Wo hfbe ten Oern:.r. ATOM with non rocket. -mi. the end of the wer ha. norm that m unamcttm en an.loon emend. entire munila«mttialm en) gum at.. aunt at a tmwh ol hull.. item ballent, Of Inh lacket. Re- 1nent% that an...inhalant atom barn In an anplin a tame men? Unman. of nn e, mere powerful Ihn any utner and Wal momle p0.11 MAY reduce the.pate rented lm loo gllnt to a 11.clnm OI Its preem. {erred hi the ten. of wet and the o., to %hlth till. kauwhdee In ahead. been plied N of nth an cadet a. lu Len him lo the balk an In mid A beyond %lath loi the h,,, urge mn of the li.linite.o lai mays n ion the.[inn. of non«4 a.. i 1 +1 Include punn other than wile awn II Mat mute IM border.- m y and *Wei unnm..e ut wh. yet he Ma not dreamed tie kye t ro Thule If too who hate ben leading i.e men.nd attempting ea.. e, al.t ` tinterpret I m term. of mown Naltoe hat the. are r. tdm not rz Them are three major nano Muth amen lu hold the km or thin roan of beyond-me t4.element of rocket leer«nd Ml propelled pro)elllee the tin of radar ma Its emanated 1«.wun tu antra e e Re. them and M. them ne. and the pmmw of.ente punt tu send them on thnr was I hen Wend to the leader Inn Age beau» both racier na mitten are here Ioda) In formi which will anus m w pea. mlble l.pso for Immediate peoduttlun Maim power mm be the Snorer to prueding power pints but In this It OW mereh take the place iii other loom of power which anent be seed f/itl«e-- PRt- The I Amnon.f ie power llee m IL note«, m?tone.-lt. Intendant put.otl1 na a tinnier among other Whim an the mete of lie potent valu monk. un We and 1.,3-1 t p, m maton I will Id. ninth/ W lay about thew meta. a i, - O tlle Intel un 110,0 now i am concerne with what we me. do won lin.. Iwo b induct..1 the let war which sat men.i e.. hr and wen by Me mien.«who proaweathem and nun imp like ms IF WE HAVE WAR e /t L untortunareh Inmabk In.tamale the lulme sunlit n et.mtnlnf the eat.t of tine new Inns tai.,..ibn war That /w,t{ le nut.ituf Iht?. cornet Marnent became ) b. mute heppl> pretenund We by nine them too.tp.nely t 1 denberout At the Dement tim. Int. «tun lath ut net y,-: natant tie. opticien In tan tn.. eeiery Meet nation le forced T to amber.poltot deelopmtn:t potential ear mecnme t` And at the.job. ere m I n th) inn h In tenor Of ann..whet e than detente let p poulder hue Ihr new am mer.meet our.tie: Iman war weapons,e Y. -Cy" A V 7 'Oeta I_ei Me mend neat/ net of hem. rod into 'U' e 1... e.e b. ti.ell... M ammonal speed. PAM FOUR IIADIO AND HOBBIES FOR OCTOBEL 1140

7 menulude. the troth of thin le eelin'deinl. It in algellllnint IIwL. even I left the RAAP ein months n{i, gutted mimeo. were among lite hew top-letel matters In ethylene, It would not be Wu men to ml that Mete lmharlanre la m great that every mdltat9 lethnique. money. sod material la betel completely tempt erhettled. If not wronged. to mwluet them to the tee concepuon 01 attack. STRANGE PROJECTILES In this collimation. you wan remember the news repolta of strange prolectnln romrren hyinover Ruben. countries. and about which h epeculatmn Mu been made. You mil remember the project to make a vecket tale- here le Auslreliaperfect We for mounting an emault Of lob kind. The almost leefnh work which Is being toew Out On 4pro. elied ammo Ircfa 1 1l limbo b. d the uller, blank allenee encountered by ayttnle. m any country ill the world. when anemone/ to extract Information of Mae malien. Or even to bream what they might be. How mull 0 mle110 e to be noun - teed any hard to tee. Ice.peed le the governing favor. Between launching and striking the litant. ln mm only w late.. Presuming thekw rocket a detected by fader when Nero. and In could be. hole ten it be Iniereemedt os,lbiy the Only oho la end Of otter rockela intended b Internet Im path. rockets which lomikally converge. by radar. la their target. to Odle IL and eaploode It In the ale. Rut could ouch h. Moue emceed pro - Abdo, min loom ldinirelnsend htt point.? p Could their trajectory be rectly leanest? And It only one of them leeched the linnet would it Inviter If all the others were deemed if that one achieved lie portae? We can elslelbe long range battle of aleh mime.. gelded In lab Bight mow when no mi. toue survive. from the ground. welt mislay at any The mimes. of Instant made dear 0oaenn la roam television e a. aircraft In the Blkml bleb ha demon - w their wader eer e.o.m. wove meted tide. halnst move in an endeavor to Inter- SPECIMEN RATE Man new ale the weapon cept, or and and the loteemplen. power to Mike out of the dark with VbWd any country ampere. the enor- mous minnow and effort needed to build. memwn. Ind beep up to date elmb foaalt arsenal. awn Iran the pomibmty e1 occidental ekplueea of tan lethal monsters end we wiple out of one own ammonite, or the neeemlly of anelennnnrn en dang erous as to read on tar who need them? REVOLUTIONISED WAR Pestent toacepuae of artillery and the eannnot damage throe boobs air power an, for the future. gone n dn. Your imagination end aloe by the bard. Bow an a man late magnified Mom to sultebe pmto Intercept In an aircraft projec- peuon,. remembering Mat ememmlk tile eeyenmg at Mounted. of miles an Women then not bombe as men hehour? And. If be did. how meld abet. safely explode R? There doe. not wan to be much future tar piloted Wrenn In a battle ni Me arum. All owe oeltnlqua of ittallek went to pale into puny 1Mgoloanse before llssa eitkn of hllh-specd,,tavonl- mr me. spud from actual warrant er..der and rxaee propyam 1,111 evn;ultomte I. M RADIO AND 00111ES FOR OC101EE. Ind A <tan te.. i lit..e t ete..r.d..er'm e..ea Wed look too.adr.e<1e. tmld. be Age I lee ut mud...a bn.. 1.e..n t4 panto. i l.n.< line.jt a.ea.te e, ule tm.eee. el wove Jew `o, i1.tyjs - x. J'l,. :1; Jp.411. Ér~e el e X, tn. e w. ' -""f. ell,: r :_Kf.Rv^' Xiiit`IS..-. reconneleame. Television -buffing aircraft well be able In said beck blatant pictures to their PM. ally Permanent record been mode by commas photographing the telettdon tureen. They Nth enter dangerous speed hitnero unlmegmed. and radar him siren hem the eyes to make the mat Of It. SECONDARY EFFECTS mat 1011 may 1101 Now. end what the aeennea ihetnvelrn e only now beginning in dleeoree. M rile pmeln0 n deadly secondte Winn ni no eedtalon Ohleh follows In the path of to aloate bomb. le effects on Men In the Immedble rkm117 it al eama, template aille. - hon. Other* duffer terrible helmet MF7/II. 1 a. Ye, k' wa í.. NC from het and Nam. Btil more Suffer the delayed death and mati eeh u result of retlm-0011eily. But we leoni now that there 4 an olmo. certain prwmbauty Mat future geliemriam that' ehoa' the effect. of HW redlaton, even Dough thee forefather. teemed aptarent dmge. Some of :1e rats which were min a epecltnent at BlbInl are producing g randchildren very sedately deformed. Evidently a ranee as been wrought in the biology of to orlmnal dolmen which.aflame' although It hat n hem or even their Immauole deuen. The menace of e alma Clint.. In maklnç Itxll apyaall In ated with an thee-.nllhuukn no longer lie third lid 0000eelec keeceatkna will they be draped recta bombing Just what are we implications In slrcmll-mkeo to story mill more all Ihb en human Idea Just how ear Impressive. You well Nun now ftalo will the when of atomic bomb pmtun. and eye -.Imam nceolnm. of moony wand? or win Mr Muth be no entrench by one loutnalbc a f who geld that the lucky people well be ' Mow me who ne killed by la Me bammb.. d not ow who tan. That Men Implications are realbro by the wollt, definer tortes a shown by twennper reports of enthely rc deebinned -nlrker" allkdllps. wheh. In the Ile Our. w weievlel better reetlae heave their rocket. than from H oek heavy gem. Of e decumbent about decenuolwng ouratlkmene, of building cur home. underground, of then Ideae may oat be blingru IWkdmUy?ARE RYE

8 e h i :e s ' r 10 II ' -1x Qwy.v..,.' -ri _ lem leanealnlei FOr.EtEllaLwaE00EfAEE< 'me«xt 97 ti faap YEIEOPa. t \l0we -,r LIpkE ant OF.emMEm M r0. ' - POWER WIt Fi HEFE l oak f.e nurdi :Ia,LDO.' to DEE LLTEF e0010lmnnemienfa t»lai AElmo (1GktvT tue ~ Wk At t1a411n111em 11100r M1 1Pl0, at the mane0t but who can say that they can be Ilno.4? Lem these devices are not likely to be entirely eucceeful agalu t ch UM«Wired. -sell clouds scalene on the t faintly Itself. and edenua it unlit tod hebor0000t penods of Ume. It «winch has the poenn«power to Matter Gall thine over the earth. It will be the butrummt uhich can Wv9 dm«actlen to our clues, burn up our vegelau0n. contaminate our ter eupphi«, and W molt theland. IF WE HAVE PEACE IC le ever7me's hope, sod I peeler to bellere-oat W the«pom«nl.ka OW prevent large -stale wars from Wtmg place In the future. Partlmlariy se Wm same tools are capable of being used In the pursues of knowledge with elmh effect that we MI ) green dluely at what lies ahead. The Ilrune/ale u. ar lot ninon... apart from :: r e i - CEJL $Ah. -.q ra. Is seed park.1 rh. V I resists. New Muew t Op.. maser,.d Mr. wan»ilene al *bees loll reeler as gare r rusty kuelnca of treveteing areas On foot Medical men believe it plwble to egolp blind people-even blind. deal mums-with` form of radar apparatus Mich. by r e«lenbg dlretrly on the nervous yuem In substitution foe Fight all leaning, w11 give them e picture of the werld.round them utterly lmp0salble et the present Ume. A radar -equipped blbld man might :t down Mc agree«es acute can - Motu of Mucks u U he could see them. emn in the dart The pmel y of such -premed y waraky- devices been :rpplsed to normal people, rod even machines. le already en accomplished lies The field of Opre pucanon nor these and many other deems 13 limited almost by our ablate to deal eh. mid nunnl0cteere them. t for mores, venture, ey min 111mM11 m10 time reginra. Ira beyond. MO wire«we lucre u , Ih13 MOM amvlna of all the PonilWtlet w hich he ahead-oul:'a L lo the outer Oarkneso-n:r dart It will De to normal 'mew-what I1at'a can we 1mpm1 The tempter«of radar rellec.klne Irom the moon wße a moat hµtarlc t It ta, a Itel bat e'.og on the question of travel Into me outer sixes. B ecause It demonstrated for the drat lime that sodio wave* not,d actually bee beyond ú1e te -route influence Of our oath. and 1h. v lo u In truth a m as toir.oatale that know n lam o1 ledge propagauou nparently mill apply. It. Ulentor* paean to answer gwer the query u to whether. If mar succeeded piercing the earth., «morphers and Mau beyond It nu,hip could be Controlled or even. contacted. ATOM -SHIPS Il would now appear that the Passibility an alum-powehed,pace.hlr leetmg IM earth. mums :he raping U. taperlevmes, and eetunnela mlely to earth. b. In fag': elliot of the lulu,. 1: qir ue rbtmenable. 11 not eermln, that In::: llirlime 01some of la, mienluµ on:1 tualyy land on the (eon. 110.dé ee relulry' explored end Dino 0 by radar. With anexcellent Idea of Noy ay will Ad there when they arrive. As a matter of fut. anal the mall ponlen of Ms article ors written. we have nem of some now..nles:llsu who are airmay designing t x1,10 fly to the moon. powered by cnln. e lice Newa and Views. page 19 Borne Opllmia k AmerkMn have already sought land rllha on diet plane redeemer«at acme ame lb the future. Beyond that it le hard for our pre. loll imagination to extend, We have yet to determine whether other planets are a:mounded by "atmomhrrre. with which OF cannot cope. One eerie be murex. try the Mme we have reached point. our «M beuu on well have extended to aunt t degree that we will be epecllaang on the nou n:111 y of. Uhl further gel«to be etp:und. We may even here Marssd to tir.0k 1: Unlike of new dlmmyma. w present Our Melted experienceand kbowledecomm(ese Can e. tir+0 OUR CHOICE IONOSPHERE TESTS IO Una short rev«w et things to Cone. Ot N already enem1bg man I have been stir Lc treat only to make the noon MMus. dyne:opener:a ee oatrvrll«ns oi the hawsehere which shall me In the l:.sure There : are enormous. Meru previously have been ImpOselm. De- Unman* of 0th. 01(1,1, w.:l 01.y harbor. in Moaner».:r tail. Ore ew being leased Of such their part In Our near woad 0 -il ll:e radar ple«re of thee and deem» us Me re :ken 'Little Oory Mlen:.11MO of these hove rm wtorrd environs Mstm0 of old laeulenrd Itlral. n :1 w1:1 veale m everal:adcw them, Al.. Ilghl-houses, with Infinitely greeter examinel, I]clp 'nee tkr e be reeptcly ernrc0rh:tut accuracy and th e11' Aerde.«olay be 01 many Ir, ` l' rhh- seen we shah have u choose.end guided hone and &Mlonahuvily bided Inatlleablc ;noose quickly. how a:1 them. by the same means. When used In television end ream welsh ill gute Tellyw we nand 0we 00 the brink guide rocket or let -propelled abwnfe an instantaneous s pram of «meet any beyond. TW we al:ould explore et or projectiles. It till revrduelunae r of condll«lts, from temperatures to Is en much more Important no. IN:s00:1 cud c0mmunkalnol. It alit meek radiation. which may be eo- and destruction M.: there IhInge a:, perform such tasks es beret«in these lvg«na only delay a Mlle :anger the day when h-n:aklhe. w11hoot the melds and C leuch emearchls eve preparing the We bell 1:010 It In Mr h PACI OSI INDIO Ah E$ FOR OCT01Ee, into

9 A Belmont pocks} redly u mu g five vdwc In a parhelerodyne 3 inches wide 6 inches high and renly 11 inch.hick Ih weight including butler, n 10 If n finished m gold del oz moroccooleo scade and ether DAMN. 'II a el between 07 and 09 ounce de - Pending upon the type Tirev may he mounted directly by their leads which will easlly support the vahe body o by usmg coinerelally m avoidable sockets The elements of these sub-mhdature fishes the filaments gilds and plates are all hated and held toketner a top and Bottom by emir thin pieces of whichhate preilously been punched atilt extremely secure. locating holes All metal par ts at held together by welding The filament or elcetron-elnittel Is made from ante rem than a thousandth of n In dlami tel made by br Me lhloubll 1ne diamond dies Iles These tale cs contain mote parrs than those used m plolmlly limes or beat mg aid, about 30 separate pelts In each Greatly fmploe peilor ante well be the lmmedlate benefit to met, of equipment requnmg small salve, Although the tiny radio valves described here are not yet available in Australia, it is interesting +o note their design end performance as an empares in every way with large con indication of what might be expected in the future. At the moment, entlonal types. Because they are Australian valve companies have no plans to duplicate them, end the rnanuraenn., on automaue machiner cost of such sets made here would place them in the luxury -less. eue -miniature valves will find wide application at little in cast. THE heart of the smallest radio re- straying their reliahillty and perform- Belmont's pocket radio Ison e s of the set being commercially pi a- fleet examples of their application in dared sing is the postwar development of t weight wet of cadi individual volve things x to come. the valve that made possible the ernee- 1ng perfm'manee of the Or fuse. De- w tails concerning these sub -miniature radio valves, only 1 9-l6in. long, have been released by Raytheon Menefncturing co., Newton, mass. The five plug -In vetoes used le the w pocket radio, as illustrated, weigh abouta half -paner, oc coy leu than cubic inch total volume, and per- form all the functions of normal sire velues blind in tw ventional superheterodyne radios. Each valve In the series has the some physical diumnelons, meeenring in. x.9001n. x 300in., ee approximately the cross-sectional coca of an val cigarette. Yet. one of them. the rouverter, has nine act ive snrfaeal between the two glas wells Wlllen only, one -quarter inch apart. a These an amazing sub -miniature valves rflh'eadva finding widel adios, o valves in pocket medics In hearing olds ana equlwne.yt, liter are demon- aemon- SPECIFICATIONS Of the five used in the Belmont,et feu ire lads,, fl equeniv amplifier Pen Wades[es one is a trmde-heptode fie quencv ester on a diode-penmd detector V ampllfiel and the filth Le output pentode similar to the type used in hearing aids Two are alit c mbinatl000 of two salves Ine o m elope The fife require less than ree -third of a watt to operate and quire a miniature B battery of only 121 volts. The valves have long life, requir little battery power, and operate from low battery voltages. Performant Midget perle require luleranoe of plus er minus five -thousands of an inch. RADIO AND HOBBIES FOR OCTOBER, 1746 PAGE SEVEN

10 I I I I I Abs,:o' Without duri in the air there would be no cloud.blovn sunsets such e this, beaulilul enough wilhouf the colors that sunlight gives, o -Below Soo macular cloud forme/ions similar to that shown here. The posstbillfy of life being impossible without dust has probably never occurred to the average man But as this article explains if might well be a fact on addition to many other almost unbelievable things which would be brought about by the absence of dust Tx word Du t has a arleth of meanings andisa useful term with which to describe certain [Baum stances or type. of behavior Fur instance think of the...piles almh would be a nntered bs the wasters of wild west vmics rf they g et the villain eaentuells to bite the duet Then [hare is to lick the dust which ma, OnahS be necessary when one wanb rise in %Mee To throw duct in le a popular pastime a[crebuted tthe poinn ll Minn holding the oppoblta melee to own Shaking the dust Off feet O what one doe, when es- m caping tram the law and fo kink up s duet u what the wire does when ou Opener pet antelope and here few bet-. an per dal Then these la to dust the seat It isle pant? term better understood bi the was ward child The duet I wish to sleek of la that oat annoying but ne erthel awful a connuhngsof111ea;whiles of solid matter suspended In the Imo - sphere IS DUST USEFUL? Did I say useful? Cernlnh gm net Only useful. Mt amps[ neruusmy for our ex Most pe if asked what were the uses of duct, dust, would reply that they were aware of mu', and coneidered Ila jolly n This would w be trueunder hie conditions in which w usually end dust, for then it is really dirt In the wrong place, and la a o health and comfort. I certaire to not be courageous enou,11 to go up into the drought country and tell the 'cocky" nt he ahouldn-t complain so much about the duet, because without It he wouldn't be able to live. The most beneficial uees see ginned from dust when It is In its proper place on the ground, or In the air in easonable quantities. Many weans i ego the blue color of the sky and the deep Ocean wt. Thought a be due to a natural coloring, so pale as to be Invisible in small p es of ah. water. and only visible when Mewed through great depths, SUNSET COLORS Thin theory' did not explain the various brilliant colorings seen In the Sky at sunset. or suise, and it was not until about the year 1085 that any PAGE EIGHT RADIO AND HOBBIES FOR OCTOBER, lila

11 e &ellar atamnt in. mane to And out the age Of diets colors. In that year Moreno, 'Tyndall aid Otte eryetlnentine. alla at.covered waste. MOM peaple have men the farticlett of duet Dana a una in aunlet tea room. atmosphere empanne much or MU.- of the clouds and air *trot. of ditterpendra line duet. and te ptlraib tot densities. and peed.. an ununrm all n the world rathee* stint enbltloe nhlh hsa ever rn been partlrlee. Rnettlne ae they do only lilt blue or violet raye. ewe the h constant and practically uniform color ealled sty blue. BM not many have res- At Limes the Sy enema mom blue plnamheric dust. n of. would Man normal This is due to the e:y deny oaf n rhos admittedly coarser dust pttrticlea near the earlh'e utlfnl at nest se. -Melts eeeminifle malts varying In quantity. When aepasble pleasure. these. Fath. to windy weather hers sullen ea onetdenble. TMs is. horses another end most ImportantImpont.pest owhich the color e at e stirred up. the Sty alinan effects are merely complimentary. The paler due to the tact that w cermln pretence Of of deal In the atmalobere ts of red and yellow raya are for the formation of clouds, reflected by the coarse'u t/add then If lheee w no duel in the Or to ellttbeasn wiou ldbe entleety mlblbe. In addition. 1f the dual, was peseta m only m:nnte yanutes. the elltehe.rl would e. blue. the Shy. Peofeusor Tyndall peed the bi petal. a cal of light from On electric lamp leninwbe Ihtaigb a &lea NMI - dee lab whlth he cou:d Introduce air containing OOYing'qu.ntltla of duet paraded. LIGHT REFLECTORS The air.from the room. when lnwaucea Into the cylinder. wit bdllianna Ili_Nnaled. When the cylinder w eohe.ted. and th MHOen ed MS air Ohtth had been Altered. the :oh: pus - tc through without any Illumuatun of he Intertor. By lntraludng dust Into the am In the cylinder In regulated quanntku a sbght blue tutu first appeared. which ebar5ed into. pore bhp ahnee to the blue of the sty. A. the quantity of duet inveea.m. the blue graduelly faded uutll the air Use cylinder assumed the skatesuluplbstbb of animus. Ton, of each. bsu n elllanatton. duet perm.the per. in oralrury air are a that they :meet light of ad wave lengths end alum the interior ot the cylinder so appear IM - meted with whim 11íM. Pre White Bahl Le mixture of vedette wad lengths which ranprlee Use of the spetrue. vie:rt. Irldip, blo., peen. yellow. wooer and red. When Mere Was o du. In the cylinder. there as nothing to Rd ile the Behr.. which puked thresh It In a lean of parallel ray.. No al. of Ugh: were therefore reflected to the sides. and Mire monde of the Cylinder appeared dent. However. When only small p.je:r or dust Wes lueeduce. blue light appeared. h... H particles Isere so Minnie that they reflected mainly the omen. gfb:e rays of shorter wave length at the blue a of the sl m. Thesewer reflected In all a:reo mra while the red and yellow ors passed...tr. am dt. Mg the blue raye from above. When viewed from high m na, the WY e Intensely blue panto 'thes absence of Ne maser duet puruc.ec MAKES SKY SLUE foe aun day. the b On S the My is more Intent when sleeted limnelalrly overhead. tir in a dlrettlat away from the sun. The reason for thl e that when looting towards the bonbon re loot through great rhlu.a of ne lower dusnmsmrre which, oentelulis coure t puttela, relien white light which Cleats the blue Of Stay &ate. An Inalcena of the peat amount of dut In Me enneapbere e gained aape., at pone, nor two we tan lase the with water vapor the flasks see sudh the las, to denly cooled. A sense cloud IS need Eeeaure the mommy of U te bight is In the al ed be the d. ol A.. co lotn:r. cruelty.r while the other remained quite lia.- At. stet the lits from the sun psnt. Rach. after parla throv a thklnees re Ne higher Myer. et ait, la the the meule dust am CONDENSATION reflect of tram no. and Ille yellow.rays.dot compliu the blue. Mruugh u u.. They greflected are awns by the Coarse dust' an an orange colored light comes to ru Finally. n Of 1.1w yellow Is reflected away. lita n diner pure re become vomie. te muchthe bluer ray AIR CURRENTS One to the omen. of air current. which shits Me var.. WWI. or dont into dl0oeret alloue, Ne *Read 69 Caitlin The Sr.our the aortas o Me Walters VARYING DENSITY earth e m le as saturated *loir carne...leatot f duet which reflect - nu so that the he at sunset Rya of ail wits fecgt.. so that r particular color is proceed. me oinuilderittge Mangling. adders.: display we prose Meier n the atm menincence Which - w culminates sphere. tete par ic:ea of aunt besoin the euh has sunk below the horizon. more minute in becau the r - Owing t the more favorable amdea, deda cagie r* coil: a1y support the and especially w cloud. a about ne dust prticlr. Almost the the hor.son. Ne raye of the sun below.:len whole of the upper reach. of the t! hoeian.bine on b Me under um Me Steen of the Stitt Ana all the le mused by drat. Non there Le Ito doubt that if e color of the sty wu the only use of inletial and [ In ISO n net. John Altheamade an epoch-making C1ecoWry. He tat mou large glen. Auks. One he All. ult. ordinary sir. and the ether he Riled With air Iran which all solid a.peded matter had been removed. Into each neat he admitted a Jet of.team. Ilse Dan containing Oelnaey al, became intently titled with a Stud - vapor, vibe le other remaaed gate n..prent. Amber experiment. mote nearly re. pe od lei& rural phenol... was mode with two nuts conlalnbog water. One ON alp contained ordinary alr and Ilse other Mete.r When me water had et p.rwd ueliciently to allow of the of the air Later espnnents gave birth to ale theory that water vapor In the auntie sphere wail not condense Into mat clouds or loin, note«there a luefent..lid matter to Irvin a nuie. linen which condeeation c. perm. The greats the number Of particle., the mute dense Will he me cloud formed. Ties It it Chet the Mat In the Mah- er of the ssneepere act nuclei upon which the water vapor In the.r toldenw, nnaliy to prednre rem and lye when the proper...- MS eels{ for then depoelt:on. Probably the most vivid flew of Mu e or Mint con be gained by vying 50 vtausi.ise what would happen It there w. r:li n: In the lr. There would be no clouds, so that thew ter vapor in the err cnstana mulatto& through evaporation of Ihe a. and Ocean womb nave to and other wee b R.. Seat whence It <me. FORMATION Of DEW One of these nee. Was be the formation of den. Dew a formed on clear, cola evenings.ter a motet aay. Much eater vapor e con - RADIO AND NOIRES FOR OCTOBER, 114. PAGE NILAR

12 » r M4Neg Iii. Ir9M*berm al..ms who..vn'o.e.id. is bounce MCI.11d remcl all «Ed objkl. bast pdriple el radar. fhb phatagropl lode le tell tie N.stxlghm.o Eked. Co.paltMo'o Enl FMaM.9b WrO, innl.d«rite p.aeipl.. lie E. Mtu..elhell is(m) eperam N.aMGc reds. arid 6. R. KSççm.p.rIn.eC.Mr. lh. d01nd lin. sr.i.g Utz Lh. Y.. s r loll destined m. M9 electronic I.M le, 1h. OM U.S. A.19.odo....rnd e1 Mined le the ale elms lo Me ground Mt It le not at anoahon point. The emu and *nu nutlet. beat turly quietly and toua eontrlbutes to the cooling of U0 air which then reaches munch.n polo, end the vapor h n111iclued 011 the gram SUPERSATURATED AIR If the air at Ihe Nrh% aurae be - verne super /sunned. dew mend be wnnuouely fanned Md deporud on every Nt of vegetation and everyunng would be CUM01.Uy amt. IMludIng ourla. Trie surface of howee, plants and animals end the land would Brin w.ter. tad a011ú40 and umbrella would be no prom... he * la Una we nn enure that 400 would be carried cep to the Nebo errata of thd ameephere by oasbnal violent a word' U Only. smell porlbn of the teal Grace Of 1e earth. Winer would lun down tole mountain elopes In Dal torten.. Codemenon on the ride el Mt manllal. would create a WRIa1 yeomen. /*WINg up *U turret. front every direction 10 re- m. e0ulllslum. Roue mum xalureled 1110 ward 1h10 he Wought m and the lesulonte eondmwmnn added to Me already vest supply. The air Itdnoght would mein In1015. end winds would be radon( 0.004, U m1un01m trout 011 dlreetlo.0 year In od year out. mounamma the nnden- flon end dnlrhar(ila vat amount Of water d ]:d n ha 111A 10e 40 days and s0.:-rho. but for all toe. RAINFALL All the rs whi,h tit hoos use r all t and or ld then fyi,,. 0.1T. 3,, nod alters T:r tort n be Inemvrl1 ramdly and WWI a high 'degree of accuracy by a nlemetz Nina or urnadbn. The evolved aupent- in t e lchuviorlea"of the (41 P0111 unied olr ld ten..ondense on Compete. The them pat1's and fall towards the pneedute 0( paling earth. These would puer r:r.and hxml: a::.. i hma up all dbleltnl colon o1 11(01 through INK,.:.' Ill4 Mete hen boithe Inolsture In that IoWity which of the net.:w: nit the o :d res.tlt la huge Mum tsamala w010)4 at lnel010 1n onus a nd of water then meowingot on the deposit of tow on halt of each falling upon the earn Melt moth No - 001r winch emerges. the ms. -10.:11 areas, because the eoetenet be to tender Our atem4 lal- fselelpinln containing paruclel of Unu.1 detain of wild blowlna le the efferent sires pomlble. rue with realist to mountalhs u Trek up the alur- Weir tmemtosol of different colon Unmet erra form of 0mdet atioh aed alt 1)01.:- the low ground. In - Prom Me 000 obllned In this Mahlon. timing pan on the mounit.m range.. eluding U. which tee Rom the not any can Me avenge ate of the * Ibr a hither t11ä1 alb', and Mete and aeatu. The would leave impended remelts be calculated. but therefore U.K OM steams or Me :r lends.oast dry and uteri), a Curvy ea11 abed be obtained Mere a:mosphare would be hgh:y eheragd. oapal:h of satw4ng ally art of More the reauve mounts of 0100 pr - A, Ma condensed on the ureatime.i, Ill. or ve4elours. They wed be are net. sloe pleaent. toe murs would be : m.ay seders 01,01311 which would. 011aí1 the The enure operation retinae* only me :Is The lard comprised hi cut by the tents al f0500 tab 110u1e-a Cawdereble advantage MTN part of W moun.ab e or the 1 mountains. over previous i. U Ma rods nice a done of the and of the M. then ere mum add to It Me spectacle praantad by a dustless 007 There would be Cobra The oky b emu' jet bled. end Me would be wllde In dgwhl The sky would render no net of felt for Mere MUM be no leneouon of hint from dust parlleles. A relentless sun ould shine down Upon W. Only plot Part Of our homes upon or into w11un the son shone would be Illumloted. There would be no mnwloo of loot mio Comers even to day tm1e. One side of the wall oo0id be Uluminted and the other side In total darkness. Ne would p0obble Ill ere were here. went l to WI the and 1se pant 03 It would be far e form of Illumination. It le ern. Met One tool ablenoe of 01st In MC ionosphere would make lunumenlsl changes In the meteorology of the world and make this plan n desolate region, Unlnhabllable by any Ming Uttn1. EFFECTS ON RAIN To refry again at ow benelehl efteea of del Tole lout be made at Its effeea on' the nln Melt. la Is well known that a Moser of rain dos more good Mao all Um watering be antiques mean, The Is due to the chemical nature of the water, brought down front the 0isnorphe0e. 11 is quite reasonable o assume Mal Una le due to the orpnk of some of the dos. This, muddy party decayed. would be rim n1 nitrogenous matter. met ammonia.as would be aka, up by the ram slops. li to MW seen thorn the oboe. 4et that dust Wes no wan tole In 01,1nge would not be *t *11 Pleam.ni. r alsbt and that w11110mt It Of wane. In Me wrong pan dust 4 a menace and Metter In dseaxe, mating It memory for p01m0weu to be taken to 011mmam eat 111 Our plates of work Ind at out boa.,. In Mdse plan a certain amount 01 duel M Iuteame to allow l0 the D.P. diffusion of mmllehl end nde00 of a0wral Into all parts ol Mt MINUTE PARTICLES MEASURED BY L(OHr PAW0ICLffi as.ma11 as OA ,11 III dldllelet-wo map to be ca01111 N ord11111y mkeewpe - Nei NY RADIO AND NOMMES FOR

13 I ' nog cell sheemg the lose worm ana the sod. whah create the eleclmatehe Reid by ehmh the partiales ts.ewe then cherga Air cleaning the electronic way is another instance of the new art pro. during methods to replace the old.' This article gives some interesting facts concerning air cleaning, and outlines the principle of the electronic method now being used in Australia. bean.. to the smoke from WNTAT a 'chimney? It dleappeara but it does not dissolve. It Is visible only an its emission ts from the stack due to the high mastics of particles. whirls a actually of molecular glee and therefore, under normaloonditlons. invisible. Or Is which c ble for cloud fóirarms for fogs and else, cub he every-day contains each cubes font of city air' as min - to foreign particles, of of s 000 pared with a réas. m of about abmnt 500,000 for counts" on crldea of the rim of these duet particles.lei be gaited from the followhrg Heavy Industrial duets-up to 8000 microns die. Pollen -15 to n microns din. Snell particles and pollen granules -10 to 20 microns die. sllicn dust-1 micron dia. smoke particles -0] micron die. Tobacco smoke partiales -0 micron dia. Gammon bacteria-up to 1 micron Elie. Generally speaking, articles larger than 1 micron tend to settle from the air unless it le In motion. IA micron is a mettle unit of length equal to millimeter or 1/55000 of an inch.) A typical analysis of dust In the Imosphere shows It to be composed W Ina following: Smoke carbons (soot) -45 to ST P. cent. Siliceous mutter -40 yt. to per cot Coal dust -20 to el per cent. Fibrous matter -8 to 40 Per clot. Miscellaneous - em8 per cent. Duet In the cities of today is far greeter problem than ever oefoof lend expansion of Intlwtriea can Only Z.Z- w Statistics ss some to some cities titleses Stara Indicthe dlcato ate that t,, tau of soot, tar, erecin ersdin hanged ash re to New Torts York's at - o surly, sod that if this overt at one time over the whole Cite, It wouldr ttotlepth the atraea of 21 feet. Diagram shoring how dust particles charged. a ELECTROSTATIC ' FIELD -e-:: 13,000 VOLTS : D.C. The average person consumes daily about Si pounds of food, about four pounds o1 water, yet about 34 pounds of air, contained In which, 1t has been proved, is about one tablespoonful of dirt, THE HEALTH ASPECT These air home Impurities Irritate, the membranes of the eyes, nail throat and lungs and thus aggravate causeor diseases of these organs o or e collapse of their sensitive tissues increase their susceptibility to acute respiratory diseases. A modern electronic cleaner consists of two major parts-the eeh and the power peck. Very fine tungsten wires are suspend. In the leading edge of the cell, the ioniser, on either tilde of tiesgrounded rods. When 19,000 volts DC is applied between the wire and rod. a strong electrostatic geld Is created within the pe1l As the air passes through this field, every Particle of foreign matter. regerdleee of size re type of material, receives a poetive charge. E000 VOLTS in the pert pert of the 0811, the collectors are parallel Pletce charged alternately positive 9000 volts or at earth potential. since unlike charges attract. the positively charged particles are e. tree. to the negatively charged plates and Grounded. Cleaning the unit is accomplished by the famine expedient of washing down the plates of the collector cells with lukewarm water. The art collected thereon le thus carried away down the drain with the cleanbng water. Principle of Precipitron Operation o GROUND =' p U O '..p 0 4 o U o' etovt lp J a! Q:yJ s+ O O Precipil.oe Unit bi ServIca 1e3 VOLTS VO0LTS LADIO AND HOBBIES FOR OCTOBER, 1941 PABS EI00E11

14 Order Now from Homecrafts!! MODEL VCT "PALEC" VALVE AND CIRCUIT TESTER Designed to cover the many serviceman or technician the and varied needs of the radio "PALEC" VCT is a man hater, Homed inattractive portable c e ifm r urns 11 s 11 s I inches and. ighf I611b. O in wppllad tics operation from 50 eyrie AC. mains etlh voltage from 400 le 350. A spacial bettmry operated modal-ma VCT/V- k also available. This is arranged for alternative AC. mains epmaion or 6 volt aceumolalor. Five Instruments in One The "PALEC" VCT does the following testing jobs without any external devices or accessories:- VALVE TESTING: All standard types of receiving valve on a "Good -Bad" scale. Also indicates short circuits between elements of the voice. ELECTROLYTIC CONDENSERS: On a "Good - Bad" scale. PAPER AND MICA DIELECTRIC CONDEN- SERS: These are tested by means of a neon tube which will indicate excessive leakage or an open Circuit. Australasian Distributors: RESISTANCE: There are four ranges of resistance measurement: 0.2/30 Ohms, 10/ 20,000 Ohms, 100/200,000 Ohms, 5000 Ohms/10 Megohmsr The Megahms range operates at 225 volts D.C. and is, therefore, useful for measuring insulation resistance of conductors, condensers, etc. 0/PT VOLTS: This function covers those A.C. voltage ranges useful for output measurement, when carrying out radio alignment with an oscillator. PrE tux For full pace list write to: - MELBOURNE: Nand ORIce, ]vo Le Ole M bool St... SYDNEY. ClerencE SlreN. NEWCASTLE 2.6 Show Stre, BRISBANE Adela,«ex e"d ROC4HAMPTON, gueensland and HonARt. AUNCEsrON a.e eupnie, TAimANiA. SPE CIA 1/STs PAGE TWELVE RAD10 AND HOBBIES FOR OCTOBER, 1946

15 VALVE 1011 USE AS GRAMO. PICK-UP The Vibrato., shown ageing a ruler giving an Idea of of its actual sire. It weighs one -fifth of an ounce. A few months ago, we mentioned in our record reviews the possibility of new type pickups being developed which, in conjunction with high fidelity recording, would greatly improve the result which could be obtained from disc type records. out through a glass seal at one end. Al the other end, a flexible metal diaphragm permits transferring externa motion notion to a movable eletrode in eld tube, fu early models, dlfticultag were experienced with the selection or a eut able diaphragm to provide for the transmission of the external mechanical motion to the inner electrode without introducing distortion. This problem was solved by the use of an extremely thm metal diaphragm -abbut half the thickneae of a human hair-which serves as a flexible window In the tube envelope. By means of this um -tight metal diaphragm, the rod or lever Is free to vibrate without distortion over e wide range of audio frequencies, AS GRAMO. PICKUP When used in a phonograph plekup, the tube will perform up t0 the highest requirements of fidelity and sensitivity, according to reports. At the same time, It provides for e system having low acoustic noise cud needle "chatter." Life tests have demonstrated the eblhty of the tube to withstand severe treatment over long periods of time and to be aspeclally stable under temperature and humidity changes. The tube operates as art Integral part I the pickup head and the radio Phonograph amplifier, without preamplifier or oupling transformer. It n be used with a very light -weight pickup arm with con pending - Ile' auction of wear on the record grooves. Apart from the immediate uses of this actual tube, It appears probable that a number of successors may even- new, valve described here repre- tually be produced to open up an THE sents not merely an Improvement entirely new approach to electronic on existing type pick-ups such as the control. mtar This view shows magnetic and the crystal, but intro- no tarsal performance [laurel the c o m duces a new principle which pact In fact the calve hale been recute the pick-up out altogether, and size of the leruing aosed, to indicate for instance, opermakes It part and parcel of the pre- Vib otron. Pro. condttfons, output, or frequency amplifier valve itself. cting trading through haracteristics when used as a pickup. It is the on, a minimums metal electron tube weighing only one-flf- /he top of It. tecnth of anwhich c warts tube is the rod mechanical motion directly into cor- REFLECTED SUNBURN or lever which he sfers erechan cal responding variations in current flow, Is not necessary to catch the direct motion iron e utcide into the in HCA tabmatoelee at and developed sun to achieve a summer- IT rays of the Princeton, NJ. time brown. People sitting In the high veseuer eith eh inner chain eri shade can become sunburnt if near WIDE APPLICATION the water,) because water reflecfe the The Vlbroton t th result of to umu Invisible violet of hi e sun. The new valve is expected to fled Wed experience in the rani[ Cur which wide application Inaiuture deeleen of unborn. of metal tubes and i r catch in many phonograph pick-ups, in m rophones ectronlc fields. Ex erience gained in Similarly, a person lying 1n the sun and in industrial equipment wherethe einop sityll act sibs at mid -day will be more yn severely sun - Iwer se translation nt mechanical motion to use proximityrdfore which burnt than if stand) g or te lkin g, be - electron circuits is dcsuoble for pur- by our a to control ehea cause lo the rot..., a he aheorba poses of control or measurement. bursts, contributed mportantly t th the full direct ra s of the sun Although then w tube is not yet in solution of many problems a n cours Fishermen are famllar with the efproduction, it is disclosed that a limited tered In this new de elopment. tecte of sunburn, due to reflection umber are being made available to a The Vlbrotron Is three -el men from the water, despite the wearing of USA manufacturers of electronic metal tube about one Inch In I ncn large protective hate. The eun should equipment who are Interested In ex- cud one -quarter Inch In dlan ter be taken in small doses fora start, to perimenting with It for nee to future Leads for supplying voltages t th mistake being sufficient for the cyst products. elements within the tube ere brough dose. RADIO AND HOBBIES FOR OCTOBER, 1946 PAGE THIRTEEN

16 r t rtue+ ' '971iÌ t I 3F A Message to All Amateurs PHILIPS ELECTRICAL INDUSTRIES OF AISI. PIT. LTD. EXPERIMENTAL RADIO EQUIPMENT SECTION, HEAD OFFICE: CLARENCE STREET, STONEY, X.S.W. I have indicated hrlow the components In which I ern interested end which I should like In see oe the market. D Amateur hand r (IL (1 F.) Am hand transmitters (H.F.). r s for amateur banda. V.H.F. ti D H.F. frequency measuring [I V.H.F. feu -to [I H.N freqeory standardegaipment rig equip m give you the right kind of equipment and com- (100 Kehl to 70I ponents. To do Ibis we need your co-operation. me Please read D Transeci.er, for the list opposite. tick Ike items that in band ( mals). D Calibrated satiable fro'.,ul,t terest on you, add your m. and address and mail to t Fields strength s for r II.F. ibands. Philips. Jolt do that and leave the reel to no This, [ Field e strength meters s for r V.H.F. hands. Special plug eons a and mountings for re. Butterfly. tune's for VILE:, D Pare t for y bean,. aerials D Tre aing oils rit, rvurlable links. Comnumication - Tra salves e (H.FJ. D Tri salves (V.II.F). Receiving selves (H.N.). Reret ring vulves (y.h.n.). D Kits ofcomponents for a n v Kits of components for amateur tr bantransmitters. band r 13 Panel nti vernier dials truth logging toiled. Paw pplv Other item_ in chirp I ma Interested arm - Please phew me m, your Experimental Redid Mailing List for future technierd information. This places me under no obligation. Nome_...- Call Sign Address Ae radio manufacturers we want to know but what you cant in the way of apparatus, so that we can make it in the right quantity and at a reasonable price. We will plan our fnlltre production to snit your needs of course, places you under 110 obligation. One of Australia's most widely known "hams," Don. H. Knock (VK2NO), M.I.R.E. (most.), an experimenter of long experience, is in charge of Philips Experimental Radio Equipment Department. His serviees e at your disposal for leehnieal advice. Fill in the form and place yourself on hie mailing list. PHILIPS LIPS EXPERIMENTAL RADIO EQUIPMENT IlE; PHILIPS ELECTRICAL INDUSTRIES OF RUST. PTY. LTD. Sydney - Melbourne - Ada/aide - Prfh - Brisbane aal Piniv4. Relia a) a,.,;iiaâ`,'l,u,maa saaw ref tpese ARI PAGE FOURTEEN RADIO AND HOBBIES. FOR OCTOBER, 1146

17 i. TRAVELL HOW IT WORKS - MAGNETIC SEPARATOR MIXTURE OF SAND AND METAL PARTICLENG F TO ES LTON OLLERS SET AT AN ANGLE TO RAISE EDGE OF ) TRAVELLING BELT (:COMMUTATOR Wu1CN.x.,,,CONVEVS CURRENT TO..MAGNETIC DRUM COILS ME B4TMÂG É7iCLAîV ACÉ ÓN AND DROP ED AFTER PASSING OUT OF RANGE OF MAGNETISM. MÂGNETÌC DRUM F'ÂDLLG MtRVEMBELT An interesting device widely used in many nduslries is the magnetic separator which can deal with a constant stream of material. A magother products can be extracted gulckly and surely in Lila way. netic separator used for picking out metal particles from sand is nis- Magnetic separators also protect frayed in the sketch. crushing and grinding machines by removing stray iron and steel which can be seen, the sand with the of the drum, getting up Wong mag- may Ca considerable damage to the As metal particles nixed In it falls netic field.. Between these cares mvehe the coal industry and 111 from a hopper on to an endless travel- non-magnetic cover. quarries, the magnetic separator ling belt. The matetial le led over a Mother type of magnetld.eparator Is used to "watch" for such obleoti isa revolving magnetic drum, winch Is wee stationary electro-magnet. In the pick -heeds and coupling plod. energized by electric current pees - front part of a rotating steel drum Other industries-such as ente lag through a r mutalur. which revolves about the magnet. As llmartmre, gypwun, phoapliatenod The particles of sand, being non- the sand and metal particles tall from tobacco-use them to protect crushing magnetic. fall from the end or the the drum, the metal Is held until it or mixing planta. bells man. while the metal particles passe. out of magnetic range. Ae in They con also play a 'minable role use held to the belt by magnetic at- the type llluetr.ted, the sand laps In m icipal, salvage and refuse detraction. Immediately and is collected on structor one plan, recovering mile, bolts, ensue bla end other tle o? As the belt pasere to the under aide of a partition, while the metal lens indesvarabiy aide of the mum and along out of particles are Carried further and tap materiel. foundagas In ell h roach of the magnetic attraction, die n the other side. Magnetic separators are also being metal particles fall off and are col- used ìn an increasingly large number of SEPARATORS arks such as steelworks and lected. The material Is thus fault- powerhouses, whiete depend on powdered or lessly sorted. Magnetic separators are widely need pulverised fuel. ge a precautionary meesuee in rood All sorts of stray The drum of this type of device bolts, nuts, spikes and rivets are reand other hewn:des. covered In [hie way. representing a bar a core with cells which reach Small serape of iron or whe which great wiring is damage end condethe outer edge at earths and both ends may End their way Into foodstuffs or Ruent delays. RADIO AND HOBBIES FOR OCTOBER Mgg FiFfgM

18 PALEC "Miiwiz" SERIES When you buy a "Poke" meter, yon buy Me product of experts who specialise in the making of biah.grode electrical equip Dependability, accuracy 0nd 1000 ""'0100 featurea of every `Paler" infileument. PALEC D.C. "MINOR" MULTIMETER ; 12 Rouge /9.5, 0/10. 11/50. 1/ npar. 0.1:. 3 e/i, 0/10, 0/00, 0/0.. Ulan tfue um Mlb exlerhal ). Ohm: 5/5.000 ohm, ohms. inie. -LOOP Mau par 1. rall. completer u / - PALER A.R.-D.C. "MINOR" MULTIMETER 13 Ranre S.C., 0/ , 0/000. Volta 01/10. 0/100. 0/ '.: 0/0, 0/00, 0/50, 0/000. Millivolt»»al: 11/ w1115 ealmal Aun : 5/5.000 ohs. 50/50,000 ohm, Nergifire.-1,11100 Amu par Poll. 2Iieries 103 olou nucee mundane.11,onlalno. Pelee WI/11A 11. Read. Deign If» d MEG "0111IETER" 4 Range Fends Continuity and RObisl a., 1,200 re.74.11,j ;:2,t19:=71".:igir.' mum barter, Mar.- a.m. natter, PALEC POWER LEVEL ANA OUTPUT METER 1339 mode....hi WM lit fella.. ronyer. 0 98ro power level Oro, 1/ / 0/ /00,11. IVA /, - 02/ / 0 150V. Oorruellun Ourt: runlets corsetlaa fur rurän. an, load re UP ro du , and nt sere love, of walla la 000 ohm. sotploduenve Ymenloa Mr@ minor. lacamorand. 211/10/. S II once0 are aai trade and gulden la 1135 Il 0ales Tux - Magenta is Ike Pelee ",II13102 Afeltininee. The plecura Ike actual al. of thla and Deer un All an homed Mel cams' wle arts...jana Pale matorlals and worlanatulalp 0* /.113er parrying ease ar at 12 '11 eau, Available from all Leading Wholesaler, fit 9) / relit eler4w II V,02021,,:ri.L ,

19 - w NEVUS IND VIEWS OF THE MONTH Radio and Bushflres IN recent weeks, New South Violet has a particularly bed Period of bushhres. There has been Considerable loss of property,, and the damage has been spread over a large The bushdre problem Ls one which has always been with w. In a land such as ours. where dry m always to be expected. I1 S probable that tires will always Ire x Each tune an outbreak occurs. fl plenty of people s!het something should be done about it. They blame each other for not haying done It in the past. And. alas, how often. when the Immediate danger has gone, or lest yar'e danger Is only a are all these good Intentions forgotten! A new Fece peck? Protective harness sandlot nine, bombs? New u tggler? No, il in ties beudgeer sfar he "Suo copi aptly den/dined I lee using and sighting gone f u Ow del If u infra-rod 'sea sed data. c n given in our August lussa. The WIA INSW division Is working speaker. Tula ix a shallow cabinet leatherette, the tuning dial being with the Bush Fires Advisory Colp- supported by a tubplar arm which will covered by a small trop door, and the hrlrteé In Sydney to obtain and operate stand the set on the flow like on else - carrying handles recessed neatly away radio equipment throughout the eo - Felt Ore,, hang it from the wall Ilke for household u try for use in fighting busnfites. Not- a picture, or prop It up on the desk loudspeakers have disappeared Into withstanding the fact that. suitable In place of the familiar photo -frame. the general design. but those Which apparatus Is available from Disposals It brings an ceptlonal tlathy of tone cn be noticed have either washable at a very nominal figure. m a of the Into the normal range of prises by grilles of pissd c Yarnor m councils ned a apathetic voiding the andresonance moulded plastic s sets which keep out oyau towards the e proposal. which would which sometimes es oc s In box sets. the duet effectively yet she Nil ex allow for a control station working Then there Is a 'personal., set which pressrun to the tone. with actual fire -fighting parties cow be carried about like binoculars Materials vary from handsome Dol. equipped with radio pack -seta, the cameraor with the aerial In the shoul- leaned woods for the more e endive whole network being fu Wach with der sling. model. e colorful plaule for the local broadcasting atatioha If re Other portables are sturdily built In the lowetir priced table meta. gaited. Il Is to be hoped that. with such salliary reminder of the need for "Don't lel him fool action. country moneys will lose no /as, Butch. h l's Mt time in doing 1l they can Le previde e model." One the event with the least possible delay. The equipment Is being veld for them, 11 they wane it The scheme 14-orkeeureeÿ 1 will on. IL is surely logical tire - conjunction go with the local lirebrigades and councils, voluntary r'adlo communication on an organised bale should be established. It may quite»ally mean the dlfiereuee between no damage and disaster, as there is no other meal metiern which a have actually fighting the fire have Instant commute with those 1 who at, onernedg the right. d not. The taw apenaa concerned could not be setter scent. Britain's New Radios THE "Britain Can Make It" Exhlbition in September demonstrated w trend in baffle board radio In e which the frame acts as the baffle II RADIO AND HOOBIES.POI OCTOBER, 1916 PAGE SEVENTEEN

20 RED LINE TRANSFORMERS and CHOKES PRECISION IN DESIGN PRECISION IN WORKMANSHIP SWALES & SWANN Technical Service, Wholesale, and Manufacturers, A. T. SWALES, Central 4773, 2 Coates Lane, Melbourne. Trade Sales: Allen SWANN, MU6895 (3 lines). 157 Elizabeth St., Melbourne. LOOK FOR THE MONOGRAM PAGE EIGHTEEN RADIO AND HOBBIES FOR OCTOBER, 1946

21 ' IOI1lreluollt American P.M. MR A C. PA111)4- N of the A l' '.. Commercial Brcmdrar:n.... man who Is rely warp nl -I.-.. la launching P.M. cud AlMlnllk. At recent BRIER Club Imo l. he reported 141 reapulmlble u4de104 it would late lu More allure PM. rued come Into 111 own 111 Mot country. Only d per cent of next ammo's 1.19A.eta worm incorporate P.M, out of O toal of on. while at the mo- ment. Me cheapen PM. ael nut lilt A nut No plan LIlo. Bro0draalero he mm. were nnl very Interested m the high-rdellly post a of PM. u o the extol Iowans It allow. A test made recently before 000 nude111. of a Bymplwuy Orchestra bmodroot shored that n per cent ni Ioteum aelu11y preferred Ile A.M. tlallannlubn. althdusll In Il GEIGER COUNTER SHOWS RADIATION DfifCTOR lbo Gole. hick.1h i1o1ur Ihe ecten, of mdie.revpy, eadkul.l. in..h.eeo lo Ibo.lemdnmb 1.411, II a rote *eel. Mafl Full details me not...pablo. bol i 4111 o/ o rod:o.01e@.ai1h i molar. le owl dldien and.mrtgeo,ale nele.edie er enh.heeke,.1lpemd be madden. 111M Ihey were te ladieunre add. The.. a11.nh are led to w alnpl.rer le which is we d more need to IL Iban the P.M. BM hod pool. o.mpboa. Ih. mij il helinq' end.hich :e1e1 It'% a pointer ae b.mellor people, p tdmy s Ih. dthe 01 tadieoellre a held i.e Th. v really do marry about the d11dmkr sowdn.. and.g1 r.e.rd 0.1dU.u.glh much.'1.50, Goa Ih. with a few `enlightened" marmot. g dan91re1. to 1.1e. who are interested for aprlal manna. He considers that color lelonalmi hu 11111tH the mnvielo0:edition loon Moon Journey But berm.0 the Onlvll Banal pull Sews In On. bh sod white Is Of 111. m only one sixth that Of now m set of dale u to am4 I1. In- Iticnll.5a hove already the earth. Ilmy will hove a mmpve troduction moat hamrduun FRENCH selected Modulo plmes antle *eight of I501b. on the moue. Willi all of which Over own ma - aqua width Nler to um *11111 tact agree. We lope all Mum m danod they nave there by apace amp. Newspaper By Radio made mental note of Mr. Paddlnpi reamrksl They are pow Ipabllve dr- FACBIMII.F. a41m of 111e altre ahlo they Ir1k1', tmnlnlwbn ut need Personal Radio mill take glprr them to the moon. by radie la Obm1 lo become Pear THERE sculls fuel WIG nut I1 it will me rwmlc cam - rcmllllllnbd Mil fur resldean of nee 411.1: a. of our lamest radio ventures wlll tensible mentions of.'h. m108e.11 e mover or later be lam personal radio. vetch ranch the The IOmtello e.i Journal from beyond old mbon Bu for. only a few Ablerlooil wedeln the Mal r the nee.1 them rams. war. have been wen here. mow of which mpin only. Mn fu Ile wa r m v. The m 'fhrse-tat+, rullected Ion, oltare 4 lll 1 n lour -last- tac - mg IIw : be chains. I '.110 Io*'1p60T. The 1011M mcasem new eels 1111 relate ro peve h.mra to drne nit gore O Maints III 12 Inr1101. and will mrry 01 the new Ivry and minln- slop Os -Mahlon. lnlne mmpollena. of 111kó (here p- An tlonl-ehleen keg would picture, 111 OIdldnn lo hilerurcu. need Ape PmM b be more 1hm1 one Alatnllwl heavy ante' shell 10 plmeet the pmrinin Wy 13 IIIInIIIIO Is atlm0104 amnufaetnrer In Ute offing, Crew Imm hú u fur the 1mn11nlmlml of the CIAO. Our urm is!hat the sets 0101 be The le. orh Ngrllllas funds 1,elc n amuel111ng of Imply M arc end 101nIrnlorlrs. 0114,hie' 111e emu Eplbslrlllenrra Bue Pnlwr 1010 efihr not to be bvnleedarls clean Aden of [ lnlnlna Omellunent loek- Iw1 a mmnkr l nidl0 or of high perfore:: rte. They 1111 mgilim'. emhe rn b 110 Iellrlill a Mehl. In pnibmy be [ duced with '1uxury- Moon nuns. 1a111. brine nlire have the 'hey *111 meld Ind0 primed type (MIA. more b a air-preadi1 and In1 llare wln'mh....amber re r dur them 11ó11111M h albag than for a hard t knocks a. dye And weigh a third nl a tom 14 radio leerier. CAMERA REGISTERS BREAKING OF AIR -SPEED RECORD r fi t Ryiee in IM gem. 150h. oboe@ th ad. 6.wp{.plain E. M. Deeeldme. 14Wr 01 tit RAF High Speed Eight ml up e.em a.-spad..tard el 616 w. 4 hie Ipec411y deg. 6411,. MN.ee jet plow. Ho covered lie ieu, Ion of he IMwademehe.alti of the nee d eoe 1 the emeiollo r.<.ded end checked fm.. el end 609 mph. Gee boring be R e. ep be G.oupC.pto H. J. Whore on November T The let plane pour, the c1 akin, W. et phologr.pi.d by the din RADIO AND 10111E5 POI OCTOMR 1941 PAGE NINETEEN

22 The, chassis from the tuner end shows clearly the size of the new valves cómpared with that of the gang condenser. A NEW PORTABLE SET FEATURING NEW VALVES, BATTERY SUPPLY, This set might well be termed "tomorrow's portable today." The release date of new valves, etc., is so uncertain that we decided not to wait until the last moment, but to give you this brand-new design in advance. It is the best all-round full-sized portable we have yet described-and the smallest. We antici pate that you will be able to build it before many weeks have passed. THE general story about portables was told in detail in our last Issue. Manufacturers are tooling up for various miniature components and promising them for some indefinite date in the future. But with labor and industrial problems, they are hard put to it to keep going, on production for conventional domestic sets. ' Meantime, listeners are clamoring in no uncertain fashion for portable sets. Of the hundred of letters coming to hand just now, nearly half of them bear the same rejuest.. "please tell us how to build a portable." Up to now, our " X194l Portable" has been the firm favorite. Though originally described in our Christmas, , issue, the sets are sä71 being built just as fast as the parts position will allow. Indeed, we were very tempted last month to feature the design all over again} to meet the requests of our readers. We didn't do so because, after all, the cabinets and chasses are on sale, and we can still supply the circuit, wiring diagram and parts list query service. No, any new set must be designed with an eye to the future. So attention was turned to various new components we had heard about and our findings were exactly as set out last month. The immediate problem was to decade just what parts were likely to be available in measurable PAGE TWENTY RADIO AND HOBBIES FOR OCTOBER, 1946

23 This rear view shows that no space has been wasted, even though we are forced to use a full -sired tuning gang. OF POST-WAR DESIGN n i i n c pr A l( ir R I v v r r A l( n l! T Awn PFRF[IIRMANCE ZS r11, Ilk r \, L7 W / -A \ Sow. 1 time, and just how long we could afford to hold up the design waiting for others. At the same time we sought other people's ideas on the subject. What the public wanted in size, shape, weight, price, range and all the rest? The answer was the proverbial lemon. Not a single complete circuit to discuss, and no very definite ideas either. It was up to ourselves entirely We decided that our new portable must use parts which were likely to be available by about the Christmas period. That ruled out new midget coils, Ik' transformers and gangs for certain. But the button -based valves looked likely and would, therefore, be included. At the critical moment, one valve manufacturer obliged with a set of American -made samples, and another manufacturer came to light with a handful of sockets to suit. From the Everready Company we were able to obtain some early samples of the new Minimax batteries, and these are the ones you saw photographed in last issue and,az2in with this seli, Zhe Yuoductloa tvp. which will be available shortly, are dressed up in a much more attractive carton. But these were just what we needed to get our new portable under way. Facing the design from an electrical point of view, we felt that this first postwar portable had best be one with adequate range, not too hard to build and capable of giving good service from each set of batteries. We wanted it to be more compact than the 1941 Portable, but capable of doing much the same kind of job. A set which can be relied upon during any ordinary weekend jaunt. Sensitive enough, under more difficult conditions, to tune distant stations with a temporary aerial slung over the limb of a tree. There is obviously a place for smaller sets for use on metropolitan beaches and near -city areas. Little fellows with the smallest possible batteries, and just as simple and compact as they can possibly be. Such sets will come in for their share of attention in the future months. With all this in mind, we felt that an RF stage would be desirable, so that the gene ral linneu of the circ RADIO AND HOBBIES FOR OC1OBER, r' PAGE TWENTY-ONE

24 . q end. e I -....`1 ).,. V 1a. M.i.Z.!, ; yjri e-",!.. " :,. ti tl.nel u. a a III bb I e. l rk. mew t, el 1 ow malted pl.tekl. la dw mot Indll n. s Mote mead lu swims tab:..1 mdws I I l I 1 and ewl.vs brewer evident. '17n. "one Io.: G limn Ir. Iho.11th..VIII.. I..td to the do I:1 Ihr toblm. par-elnflo Ifm( T..olilktn.rafïe:`R Mima. lo the : nt the opened awe v 110/1 IA be ',melded 1w. A few lm t I=I the drle nth board.ji úid mat 1 the condenser and or the In II of Ille TY nn..memelt. Met It r ki i. aile r dlnaownnv of the rho.. and bulk. 3 -yank rrlarn.rr rm1n11â I..I b; the Roo.dlne of the ado-. Iw a Ila11n11.: to. terocal ptw 1nI 1,.1 I: ralhr II.I o.1 und. 111m Vow wlll: ur M.o. dud runtrob. on the Al tall.. wild top of the rlblorl A I1111e dlthmnl the 1 tt. but wi.v on, 1:. I... on I mot.1..1 fled the dist tn.atulll.. tee 1, Ill1- II III Inn f the Ill.l Im m 'Intl Ad CHASSIS SIZE The Mewls hod In Ito mere..emuolt lilt In nndl.i It 1 Ikwm lh.f arcommmulr the tolls la'i..ii. 1, the ehomtb. The Ino ll.-nul kllmn:ln the volume control end the I1.bm Ia1VH. Mack beneath and behind rho PAGE IWEN1Y.7WO I loudspeaker. with wry Mlle wets epee.. CABINET SIZE The resulting thane Immure..ewl 121 roche high. N mat«ide. end abet SI Inch. Met 1ts regular. nth. row ahem makes It very easy b pack entry. and. reined with leather - cue,!. It Iles a ver, p11001ng eppmmnee. The WOG by the 0A7. elle. Into a What! rouge. pocket on the low mil al the detethable la. It Is easily >Mien mw place. well pmteeled from yolablt damage. and adeyoetel, sep armed from the celant. and.beaker. The Ihlekoem of Ne potlet provide mat Me amount of pocking nemney to potent the "w" latent.. team Gipping amend. All A mint. are evident.hoogh loom the emnlnpan,ng INolwmphe. of lw t.í foregoing aptedghe the»me particular rirlow and W'out. CIRCUIT Tondog to lot ekerrlr.l rhelin. the pmt val. be wen lo' be a 1T4 R!. pentode. The loop metal mmlmed In Il0 grid bet exeetly the mme four ommeetkod es an ordre,: aerial mil-'orb:' "AVC." '6r1,th add AINSI." The R.1 dan are Ohms.Ohms.while the 'Berth.' rosin tuait Mould be clod loo Ike thsthit We connected short bop.to.tht with three dare of hookup hwknp rlio loath' twined together lut Craille. Yell can Alton yourself.bait lm "Aerial connection. Foe near city re tom lull. MY up 00 AO mind-the loop A111 generally give tamm: ptek:.p!f Minted y rdvr.vd with tyrclc. rt. it,.. is a temporary Sethi e e.mean...rm. to.1m.v :hn r Iinslble to tune any station l lletenmk to. AeM "Monte la ro Mandl a enple ra0 Or pinil lic n oar. 0e nel lal e t earth aide n k rail at ted whet, tlete00n.'. The what 1Muliall o'lll donne«to the ria mwlem Inv no the Imp while the terminal MD ol11m.rrn le chetah. 1T4 OPERATION Tir 1Te npereleo nurtnelly with two initial bias. and op to G74 mks nn h. wrten. In thle nether the tales mall hews M croira with nn n input. the voltage rhum to tom 70 colle. with a large ADC Wm 1110 mimed screen.itpe sae mnprd gour drllberalely In the moment ut economy. If all the voiles In the nether were elknred 10 trot brlr maximum ruled cement. then the.awl Malt lenslo1 don would M milllam@ oithan stmt. Very nb.tmlab. mammies hare to be winded. and 1 mimed set voltage u the R.r. and 1P. amplifier.hell r Cf Inn msoawty memos. TM let converter dlitere hum pre- 1mn typas in that tit P0lllalm anode In 00.11hd. In the equal penigrb nollire the ruldmtor anode p very limited In 14 pnoperued and better RADIO ANC HOFEIES 00R OCtOEER. Nm

25 \ 1. JUST ARRIVED EDITION TWENTY-THIRD EDITION OF THE MOST POPULAR BOOK ON AMATEUR RADIO "THE RADIO AMATEUR'S HANDBOOK" BY THE HEADQUARTERS STAFF OF THE AMERICAN RADIO RELAY LEAGUE the standard manual of radio communications. Covering Electrical and radio fundamentals - Vacuum fubes - Radio -frequency - Construction practice - Receivers - Transmitters - Modulators - Power generation-radiotelephony-keying-receiver principles and design-power supply-wave propagation-antenna systems V.H.F. receivers and transmitters-equipment-tubes, etc.. etc. More than 1,398,250 copies of previous editions have been sold edition is more complete than any previous edition. 10/6 (post, 1/-4 5. A New John Rider Book! 'INSIDE THE VACUUM TUBE' By John F. Rider. A complete easy -to understand explanation of Vacuum tube fundamentals espec- ially written for the man who wants to know how Vacuum tubes function. 424 pages, hundreds of diagrams-just out. 36/. (post IOd.) 6. Get This Complete RADIO SERVICING COURSE TODAY!! "Modern Radio Servicing"-By A. A. Ghirardi; one of the foremost servicing experts In the U.S.A pages, 706 illus. trations. Everything Ls u plained clearly, simply, step-by-step. Trouble - shooting, testing and servicing all types of home and auto -radio equipment. 40/- (post t/31 2. HOW TO BUILD AND REPAIR RADIO RECEIVERS "EVERYBODY'S RADIO MAN- \ UAL," a "Pop. Science. ", ",s Monthly" puhl. Crystal clear, non -technical in - building on of set. Hints, short-cuts, a wealth of diagrams 3i. â J,.srepairrining `'f. k'i that are easy to fol. s.%:. r'' R. 'n er low. 256 pages. 7/6 (post 6d). 3. SIMPLIFIED RADIO! "The Outline of Wireless." By R. Stranger. One of the most popular books about radio ever written. Covers the whole field highly scientific subject discussed in simple Ian guege. 836 pages, 578 "easy-tofollow" illustrations. 17/6. (post 10d). 4. Ninth Edition of F. J. Comm's "THE PRACTICAL WIRELESS ENCYCLOPEDIA" An alphabetically compiled guide for the construction, operation, repair and principles of wireless receivers. s$x.,c,a- Over 220,000 copies sold. v n[wze Definitions, explanations, formulas, etc., rapidly consulted. 12/6 (post, 6d). 7. HERE AT LAST! 1946 EDITION "RADIO HANDBOOK" After four years a completely revised edition of +he original "Jones' Radio Handbook." Thousands of radio amateurs throughout Australia have been anxiously awaiting this new edition and they will not be disappointed. Latest information on dozens of wartime developments are covered; F.M., U.H.F., Tube design, etc. 704 pages, hundreds of diagrams. 17/6 (Post 1/-) ORDER FROM ANGUS & ROBERTSON LTD. 89 CASTLEREAGH STREET, SYDNEY. Please send me the books whose numbers I have encircled. NAME (.4) for which I enclose ysyment, (B) charge to my account. ADDRESS (Tech. R.H.22) RADIO AND HOBBIES FOR OCTOBER, 1946 PAGE TWENTY-THREE

26 ! l To Marl off knowing nothing and "learn as Bou go along' ie holh foalieh and Impractical. If fou plan lo build a Radia Set. Rod out all you can ghoul il lirai. If 1111,. the cirruil you are going lo follow -Ils design, and performance. Know the parle a' r going to use -make et re Ihat eerh pert of your equipment is capable of fulfilling its part. 100% In the latched circuit. Be genetical and i sial o "Croon" parts Il/C Coile, B/1T Coils, 1/F Tranafnrmere, Tuning Dials, Padders, Trimmers, rte. "CROWN parla e huill Io rigid elendards and are prep lased hrfnre they leave the factory, that i t your guarantee of anon,. Ob e:uu>f 91-9' RIORRRL STREIT \-[7nem/ pupmr)nt - SyDDF r_iy,,ii The New Model JB8 SIGNAL TRACER a quality Denradio product is available now. A really super test instrument that puts all other test gear in the shade. WRITE FOR FULL DETAILS. The new model Denradio receivers are available now. Standard model AC Consoles, AC -DC and Battery Consoles. Special High Fidelity Sets and Radiograms to order. DENHAMS (Mbro.) Pty. Ltd. MARYBOROUGH QUEENSLAND PAGE TWENTY-FOUR RADIO AND HOBBIES FOR OCTOBER, Ills

27 lw I.05 I II I 14 CIRCUIT DIAGRAM OF SPRINGTIME PORTABLE LA'S ,10 11()BBIES- SPRINGTIME PORTABLE DRAWN,OC.$ At 49 -AR The cl.kuit is oerlicularly simple. The u results have been realised by omitting it altogether and allowing the inner screen gild srnicture to substitute 1911 it. The neetessary feedback voila; must therefore hr obtained either tapping the filament or cathode In, the grid coil. or by running the screen,pply through the oscillator feedback winding. the grid and Plate leads run straight, CIRCUIT VARIATIONS INSTABILITY HINTS away from the socket and a.e direct Fta There are vedette. 1., both circuit When the reeciver was feet wired passible lo the lugs on Ille retractive arrangements shich have minor adup and lested, Lhe IF amplifier IF transformers. Every bit of strap Page v.mtages in cemunstenees. In grid -plate capaeitence will add to rethin ease. we concerned mily writ was found to be inexplleably and hope- genenstive effecte in the IF stage, and, broadcsal bona ritti 4111lit. an(, we lessly unstable. fticliculously low-oper- posellily. promote active oscillation. selected the simples. of lhe amid,, aline ioltagt. or loading n the...- Whim cure along these lbws, tie were the hope that II would work nu: sat Linnet, wax nee.sary to...bills h- able In keep the IF amplifier stable ik:./ctorily with a standard hype of ull for tio apparent reason. Ultimate- in the original set, even with rela- senile... roil. And work, it did! ly, we dropped to Llte cause of the tively high gain IP transformers. But The plate of the ire is returned bother. if you do strike trouble with oscilla- Ilwougle / at fir, IF The 1T4 ix a i nale-entled sloe and tion. which placement of leads will net LI L MPY 11/ the bert.en. whirl, is both grid end plate are brought nut tu rectify, It Is possible to calm thinsi..inecteti IiI lilcil lo the -oecillidor lilac uhr 'rite ecekel. is eunstructed down a little by connecting e resistor of Itic of the oscillator roil. The will. centre ripet.cum-shield device from.2e to 0.1 megohm In parallel -s-pith" lug on the.cillatur oil le which he conneued to cluecek, with the secondary of the lest IF returned to 13 -phis throng. a 10POO This 1.tirthied 'loiter shield anti the transformer. ohm dropping mesh., with I bypass condcn.er Ln earth. Al least, at the hid L rind. the by PARTS LIST Pass C1111denree one returned direct Chasm. 6 5,. RESISTORS Cl.eked under thew ersi - Cabinet In ;sit msg., il mog.. I.5 erse., I.1 I. 5. sillier,. II,..ellistor mew msg.. I 750 ohm W.W. off roll lei.1 she emus', Leer Amial..5 maw refonlicenele. end of Ihr cell inc down ori, Oscillato. I R.6. lull ransters I a «cep. 750 she.). 40 micromnir accordingly. the 2 I.F. MI. transformers (45bc iron core). SPEAKER: lin. or Sin. permagnetio we. E1,11dG WaY /11011 In Ile -II,. I.e.., tuning condense.. rnetehad le 354 output velve I aide of the pedder. and the addition tuning dial (DA7 or similar]. ohms. 2 of tilts padder feedback doubled the Trimmers. VALVES: 2 1T4, I IRS, I In. I 354. grid current at the low frequency eivl CONDENSERS SUNDRIES: 2 knobs, O button lyre of the band. without adversely offal I h. results elkewhere. The layout of lite rolls Tut rather Long lends in the...med..., tier, sue! I rather anuktial Irranseinam. no trouble at a.1 li.stiparent...i ls of new We vales is the mason her kerlain differ..ei from the normal, serlicularly in the ass. of the converter valve. keele. The oscillator perform.' reliably and well and continued tti du so even When the high tension supply was drcpped In 45 mate. The 11, amplifier is another.11,1 valve, operate. under the same umditions as the 1T4 IIF amplehr One point, however, deserves special en! - chine, mid. eleetrolviie. I.5 mfd. lobular. 2.1 rofd. hibukr. I reed. tubular, 3.01 mid. mice. I.001 mid nitd. Ink,. I n.k., tou disposition of the pins ensures mint - alum grid -plate capacitance and stability. go don't forget, earth that, centre shield on all rel. sockets! PLACING OF LEADS Hut go one step further In regard to the IF amplifier and see to it that SocLefs hook.up wire, euh and bolls, braided wire, I mall, I lei, grommet. BATTERIES, I "A" battery Na. 745, 2 Minima 45r. II" 61W. RADIO AND E5 FOR DC105Eft. 1,46 PAGE TWENTY.FIVE

28 Coming Soon! A SENSATIONALLY NEW MINIATURE GANG CONDENSER Specifications:- SIZE-1 ark li"x 1" CAPACITY-Min. Max. MMFD MOUNTING-SINGLE HOLE or BRACKET SHAFT-QUARTER INCH INSULATION -350 volts at 50 kilocycles WEIGHT -6 OUNCES This 2.ganq condenser has been s ei.11y designed and manufactured from highest u.lity components fer use in oaffable mantel and,mature.adios, and any other o'hpmn.her and..etch, mud be considered. k performance end efficiency it is the egoal of e mils cend.n avail. able today. Austra l a she. n.v., b.ren.n.n anything la. ifl F. N. RADIO Manufacture and Repair All Types of COMMUNICATION RECEIVERS ELECTRONIC EQUIPMENT FOR EARLY RELEASE MINIATURE RADIO SETS MINIATURE P.M. SPEAKERS MINIATURE COIL KITS AMATEURS!- Mr. A. H. Nicholls, VK2NI IA.M.I.R.E.I is anxious to hear from you concerning oil your amateur requirements Enquire from all wholesalers, or write direct to F. N. RADIO (FERGUSON & NICHOLLS) "FOR F.M. and A.M." 265 MILITARY ROAD, CREMORNE. PAGE TWENT,SIX RADIO AND HOBBIES FOR OCTOBER, 1,4d

29 B ' B s to have 041 ]8mntn4 value. The 180 areuit is 0ulle conventlohal pre tend simple Gldlng diode foe the Iwo T4 valvmes. The pee - toe action of the 183 may operate with a In met. Plate load and a 34 1 mg. wed«green resew,. We tried Thee constants without being torr Pleased with the Inull. Better 0uallee was obtained from the valve on hand with a 90 meg. amen tangor and a OA leg. plate bad. per the output sage. tee selected lips 384. since It is more likely to be available early. and amen oilers ma advantage in regard lo plate effadener. A power output of nnlliwalts ean be obuloed!ran the 384 1Mr a plate end screen current IM wonted el <tent tad... eel noel n time elwlr ma 1b. pmteanoa. There la gode a point In Mek10g of AA mlllemps. 0 &gene 11.6 mllllstable penile» Of the 11. emplifier for the 3VO. The i.ennel. Even it It dew not 00Gm11Y a114111' lower, butt differenc e It not Meillal, regenerative effees muse a elel. ocean' Nealmpm Week ruller wine foe e 011 nneed nter. Meet 1004 no the 104 h 015 volts. M then we dill and serre Oldeha.d tutting. With the the ob0wu thing of supplying the IM1ted power output available from screens of the two l'fd 0.Irm and die them mail tale... a0od treble toepan a angle dropping Meteor. wad dare la wonted If Mimi L A aepaeats dropping rmhtor wan mod for the 145 to allow, for me of the paddy feedback erode. LARGE SCREEN BYPASS It n opened), that Ole common amen circuit is Mowed to tanned with a 0.3 mid. aoderuer. A large vwlue b n<eenry to mevent Ieed0 bit effects and pmalble bowling when the volume control la turned up beyond overload poop on a strong carrier. Porluu.tely, 300 volt 0A mid. oo ndeo.em are available. wbkdm are f Uvdy In aim. The sets screen teeter work. nut Marty In this raper that. on a 1010íe Moist rime voltage It meltable aulomatlesll7 on the admen of U to dellvec normal power omtput. Ae pee101n1y teentbnedi be woven potentat vanes from about 5'.1 lo from no to a Wrote hlpul Tha 720 ohm bank -bin, Tremor line - ode. rather man than the netese.ty boa oil the outlet 1011e. agamp In the MOM, of economy verve from t0 volts without e8nal to -7.1 vole on elknai-once Ogala working out nicely In the intermit Of the output yame. Measurement of the high Make cio rat drain showed a figure of 11A einiemm wehan signal. and 10 with enal. One can hardly Amebae a Vote to drawing lest Ilion1h10 this ow - rent from a 00 ton supblr. Output load for the 9be under these mnditions b reoanmended a 0000 trims. We started Off with the Idea of.aing the new midget 30 loudspeaker, but found that there no just room to get the Manard 0 -Ina permed. wilt Into the cabinet without enisnfin the amenaen eke. The birder spr0110caker Y natwrany to be 'minted for l.8 aemhelly and power handling MOO, added to RAO1O ANO NOAg11$ FOR OCTOIER. ledo PAGE /WfNTY.1EYEN

30 "DYNSTAND" "DYNAMIKE" m phone generator for el e crisp speech. Heavy brown crackled cast brass base desk stand. Mike cable can be up fo 100 feet or more length owing fo lowimpedance. _.....d reef -vs Call -System Type Microphone "Press fo Talk" spring loaded switch gives in. and be connected so as fo automatically s i lence music when switch is press. ed. High output -will operate on any type of amplifier. 50 ohm fo Grid transformers available. This microphone is designed for loud -speaker call.y.lems lor use in Army Camps. Barracks, Stores, Factories. Railroad Terminals. Ai -Ports end Hotel.. Send for full parliculeri tc.- STEANE'S SOUND SYSTEMS In HEAD OFFICE: MILLER ST., HELB. F9110, F9119, AND AT 10 DIXON ST., SYDNEY. MA2588, M3136. For ALL P.A. WORK - Select and Install Model. REFLEX P.A. SPEAKER AVAILABLE FROM STOCK -. PASO Air Column oft. appro.. Dispersion 50 degree. Frequency 115 b 5,005 cycles Proieclion. Up fo I mile Diameter Depth Weight 25 inch.. le Inch appro.. Illustrated Pamphlet and Full Particulars from Wholesale Distributors: BLOCH & GERBER LTD. 46 YORK STREET, SYDNEY.i1h ohkr i WELDON ELECTRIC SUPPLY CO. 000ieted lb. Telegrams: LESAB-SYDNEY PAGE TWENTY-EIGHT RADIO AND HOBBIES FOR OCTOBER. 1916

31 . transformers A A S MEG VOLUME CONTROL ß SWITCH LOOKING ON PINS A} A - "RADIO AND HOBBIES" SPRINGTIME PORTABLE CONNECTIONS -EARTH f. TO LOOP 'GRID.F. AERIAL AVC t.. "B JATTERY PLUGS (LOOKING ON PINS) yin VOICE COIL 1 SPEAKER Th.,. h nel a. much room andar ih. chant with Ithe enbran, iruxtiendsex, e.. don't be afraid Ih0 there is any great which It le likely to be more readily available. the sweat of our collective brown. The design Is now available In bmeprml From the mechunlral aspect. the form, end reudyunched meet chassis nstruction of this set requires con- can be expected in quantity once the snlernblyy' more and adeptness present steel shortage begins to ease. th an h usual receiver. Space is Veil' limited, ana sinon, Lot Iron ix more PADDER MOUNT or less essential. First fob,iio mount the pedde,' and Our original chassis wax bent no gang condenser. The latter Is on Its ttom aluminium, and cut and filed by back, with the muuntittg brackets turned inwards, A little Juggling or nuls and screws is neceeeuy. but Presents no serious problema. Mount the valve sockets ne t. The type used 1n n Groat slipped down the e were through the chasslswith he mount- 1ig gauge on top. Finally, bolt the two In place, and the combined volume control and "o6-on switch. RADIO AND HOBBIES FOR OCTOBER, 1946 PAGE TWENTY-NINE

32 Operation: "PERFECT!" "AF" Type Aerial Changeoce, 4 polo ism pos. Karin. a Overload (e, if h 'camel reset) ha spacircedoo. Power Switching, High tondos witching. Noiseless. Contacts highest poesible erode lot each type of operation. TIME DELAY (Mercury) PosTy *action Does Simple tion p gat the Wide sumo Delays able. opera- et even. Noiseless. "LZ" Type Precision general swilcleng. NMssless buff for Relays as it, ti by Broutletating S 111i011S MANUFACTURED BY: NEW AIR PTY. LIMITED 8 DOWLING STREET, EAST SYDNEY. Phone FA7553 Per.. DISTRIBUTORS:,z ". i iicood. 1,2-1,6 Rundle 5,rett, AdeleNde The dial drum Mould be petitioned m the condemn. shaft so that fit face Is just about flush with the front of ne chassis Cot the condenser spindle off to the motored lei gth. The Mri olrlse spindle roust be mounted mi a small bracket Inside the gimbals, and this dern will have to be fashioned from a trump of aluminium O- steel. Bend end mount it an that the drive spindle will pass Straight out through the quarter -inch hale in Ihe front edge of 111e chassis. It n a good Idea 14., Me a small grommet over the whiffle before installing it hi place_ If the drive Cold iss run around Ilse channel lo the glum...!here is less likelihood of the cord wandering or slipplng. The mounting and arrangement of the Mal requires a /INN tattle and IngeoUlty, but le worth doing well. Have It In place and operating before proceeding further with the construe- Llon of the set HOOKUP WIRE At this stage It Is rus well to do an much of the svirine at posalble, connect up all the filaments and Instal as Our, of the ocher whim es Wm - Unable. Make sure that you make eonnections from the gang stator plates In the fir" two grids, and see Intl the stator lugs do not short anywhere to she chassis. Fur this particular chase we used plasolc coymed hook-up otre through - nut. IL takes tip less room. and is nice to work witli especially it several colors are evailoble. Du posting H-D111R Wirig in red, grids In Woe, plates In gigen. nlaments In yellow, to.. the lob of eheckine and fraying oat leads is remb When using the wire. It is well to hays a Sharp penknife or rasor blade on hand Cut the lead to the exert inciti reauired and, with blade or knife cot through the insulation about a quarter -inch from mob end. The Piece nf insulation will then slip off cleanly, leering the Mre hire for soldering. After a few toles you will be able to cut through the Insulation neatly the gite SOLDERING Yost will and that the wire la very clean and may to solder so that only the memot suggestion of flux le necessary to bemire a goad Joint with good quality resin -cored solder. you may be able to do without the flue altogether. bur use It If there is any doubt. A slight, smear of flux is to be preferred /0 dry Jonas In n tel. Reap the iron dean and preferably file the tip to a slightly diamond - shaped far ease of working In a confined space. Make the JOIMs cleanly and quickly and than anela overheating and distortion of the plastic Insulation. Finally, don't allow the bit of the iron to red. agabast one wire es You!Older to another. Plastic insulation doesn't char and smoulder hake other Insulation. It luau melts! You will find that the button tree socketa are very smell to work with after conventional anal types. Them PAGE TH RTY RADIO AND HOBBIES FOR OCTOBER, 1946

33 I Is no keyway, as such, but one missing pin and hole allows the valve to.be Inserted one woo bray. Hend the socket lug tat' adequate clearance and mow of working, but do not vend them too much or Impose heavy strain on the ocket. Make all connections ns neatly and avoid excessively rtlarge blobs of solder on the lugs. Check each Joint upon completione to see that the lug cannot shift aside far enough to short across to Ds neig r If No u get a tad much h solder o lug. hold the chassis the rightn way up add apply heat so that the soldier will drip aw off the end of 'he lug instead ofe running deem further Into the socket. COIL CONNECTIONS Nest step is to instal the 3ìi. and oscillator colis, which are mounted be shown in the photograph and die - gram, They are held in place only Ty the chi at the top the can andin this jus[ firmly, then boit and Ile the excess length of bolt protrserve ding beyond the rut. Tb conserve berth the Chassis, we red the normal mounting lugs at Che button o nana eaq. With the coils In place, proceed to make the ectlons W them At rais stage also, you can ant the loudspeaker trsnsforiuer on. the reor of the chassis and connect the leads from It to outrait plate and to H -plus. Asa matter of convenience. all 13 -plus ring ln the set av stermr- inated the H -plus lug of the RF cog. The next job is to Install the various resistors and condensers. All resistors should be of the half or thlydwait variety, except for the 750 ohm bid A small 3 -watt wire - snit'. wound unit should used here. Ilse sel Ica condensers tht'meteand see that ell tubular als re type. arge. of the vole see condens whether the larger could mild beof in- 9W dosa stalled ban - denser the 10 bue Nia was tucked away without wlahout malle balher;a Two trimmers have te be Installed, across the ne RF and onescamp the de nier tuned circuit. Tie 1ìF trimmer soldered ectc to the The acondenser clove the Chests. The djustable plate is soldered m the frame and the fixed plate to the maltase with a short length of bus-bar. Thei cillator mer beneath m the chusell between the grid" connection on the tur coil and ea. h. It la as well to shield tire lead between the Lecmrd IF transformer and volume control and thence back ta the velvet. Howeve, nose the way th.cis operate andlsee tcirc the two lthecoh l close the when nic oomrol sm1e[t is rotated In in a clockwiew When Its wining within the chassis b completed.various leads have to be brought for congeal= to the batteries, and speaker. If the output as v r Is mounted en the two the original act, the cell Ilona must be extended for con iron connection the v ex - ledgs the ids e 11 plastid these leans with a twisted plastic several the speakeror to lte with (the hoer right outside the cabinet Inc testing Three leads re necessary for corto the a loops namely, grid," "AVC" and arcli" These can be made conwniently in lastly hook-ap whe 1Näely twisted together for neat -.e es. Make these leads no longer than necesattry to allow for convenient handling of deeeloop. Excessive length may c smblllly or prevent the a roil loop from peeking. It is as well to insert a rubber grommet In the chassis where these loads emerge, to prevent the insulation being worn through, Rubber grommets should aim be used where the "A" and "D" battery leads emerge. The "A" battery leads are brought out from the chassis net behind the moundrie bracket for the dial drlve spindle. The negative lead gam Mewlto earth and the positive led to ore side of the "oft -on" switch. As mentioned elsewhere, the new "A" and "H" batteries, hero outlet sockets lustead of spring tripe, and'ihr leads have to be terminated to cult. BATTERY PLUGS At the time of building, no suitable buttery plugs were available to us, and we adopted Use only possible alternative of making them tip for uurselvesil Aaattliitgly. one large and one small pin s Iakeu rfrom old 7 -pin valve base and re -riveted a with the correct siweina into mall piece of bakelite strip. The leads were then soldered Into the top. The resulting plug was serviceable, if not very pretty. Tin'ee-plu plugs were similarly made for connection to the two Minimax "H" bails s, The negative r- ection M Met st battery returns through the back -bias network to chassis. The positive side of this battery netts OR the earnest ample. yea rill arirr need one 745, dl side ids the 1.5 volt "A" of Reeler, High number t supply is derived the s pond bat- Iran 1 number ls 081 "Minima," 45. tery. And the relf unify, Tie "Springtime Perlsble" poothe sdle t- h.. been designed especially ter these the second bat. batteries. "A" battery drain is 0.3 sap. y goes to t13 and "i" b.hoy drain between -plus circuit he 10 and II milliampa. the re e The dead connecting the two batteries was.simply looped up into the chassis and out again without being connected any- Ma grid. Care is nece ssnry hure to where. The four wrires. were then cola having the copper braiding short *plaited for a few Inches after emerto other points ru the r. the chassis, dividing The wring to the switch may dxgeeeciepluaran n pev a gille thought If.It is of the the two 'B" batteries. open typeused in the original re - It Is just sa well to make +''le 'rat AMATEURS AND EXPERIMENTERS 4 ARMY DISPOSALS EQUIPMENT 4 METER RECTIFIERS Westinghouse DN. PRICE 15/6 ea. (including po1e90) 4 CONDENSERS 4mid con type cued with ford ei insulafars. PRICE 4/6 ea. (including pottage). 4 VARIABLE CONDENSERS Midget 3 gerge, English Broadcast type. suitable Portable, Mental. Ces Radios, etc PRICE _. including portage). 4 17/6 ea. MICROPHONES Dynamic, hand type rupplied with matching Trenslormer. PRICE (ireluding postage). p 27/6 ea. All the above equipment is new PARAGON RADIO BOX 14 P.O., HABERFIELD, SYDNEY, N.S.W. TELEPHONE: UAlerl. RADIO AND HOBBIES FOR OCTOBER PAGE THIRTY-ONE

34 Here's the bench lamp every enthusiast needs- Wherever easily adjustable concentrated light is required, "FLEX" WORKLITE Bench Lamp is the ideal fitting. THESE ARE THE UNIQUE "ELEX" FEATURES Patented non -slipping ratchet arm. Definite locking position provided. Ventilated vitreous enamel porcelain reflector designed to tele maximum 60 watt lamp providing 40 degree angle cut.off, comply. ing with Lighting Code. Widest possible arc of operation with stopping arms. Mechanically sound arms pressed in complete sections from finest qualify drawn steel, eliminating welded friction elbows. Glereproof rim on Reflector. Obtainable with Bayonet or Edison Screw Cep Holders. Glass diffusers supplied for Reflectors when required. Supplied with --(a) Screw -on base. (b) Specially designed "G" clamp base having 2pn. opening. Complete with three yards T.R.S. Flexible three core end earthing screw and Ring Grip Industrial Type. e I II CLARENCE STREET, SYDNEY - BW3109 Telegrams: "Jonmor." lei del g gh to allow rot eaav connection Of the batteries, or for ouration ot the sbe with the batterie, um receiver out of the case. when installed in the carrying case, Me surplbe lead can be tucked away behind the betteries, and toll cause no tronbbe. Having eompleted the wiring of the reveller, we suggest lhat the next step Is to Pt tile whole Ming Into the cabinet so that the position of the holes, length of spindles, batbery cables, speaker,sition, and au the reet, can be checked and put right where neat:zeal, THE CABINET The cabinet photographed With this article was 71.ailommade in our own workshop Io at the receiver, nut of odd scrare of deal and plywood, It was Men sent along for eovermg to eabinet manufacturer, and served as the prototype for many nnore-at least when materials come to hand. It will be found that the DA -7 dial escutcheon will be on the centre line of the cabinet tap, and that the top of the escutcheon is just level with the bear edge of the cabinet. The two eontrol knobs are placed symmetrically below it. The chassis should be Pushed hard up beneath the MP of the cabinet, so that the spindles conne through the holes, and the dial plate appears beneath the calibrated dial glass, If necessary, the woad can be soloed away beneath the volume control hole to -accommodate the thread and mounting nut on the bentrol. If an aluminium chassis Is beed, it Is as well for the screws which attach to the ends to be countersunk, to allow the chassis to slide herd up against the cabinet top. CHASSIS MOUNTING With the chabeis hi peel el. WM drive the two screws which hold the chassis In place against the front et the cabinet, No mounting bracket te shown on Che side of our experimental chabeis. but It will be provided for M the anal design, Anolher dirt of difference is Mat our ehassis was held in place by screws and nuts right through the front of the cabinet.. It Is better not to have the screw heads showing, but It was nece5sett in our cam. as the front ut the experimenter cabinet was made of thin PIA - wood. WIth the chassls to place, slide the speaker into position. The design provides that one edge of the speaker shell slip ill under the rear edge of the chassie, and, for this purpose, the rear edge of the chassis Is cut ahoy over most of its length. It. Is necessary to take this palot into considemtion when wiring the receiver end see to It that all tg -pose condensers and wires are hard gradual the ehashv Mid 012 of the way Chen the speaker is pushed home, PACKING THE BATTERIES The Out -our on the csbhiet front naturally had to be designed With Rim eve to appearance and some Molina necessary to arrange iaas Shod PAGE THIRTY-TWO RADIO AND NORRIES FOR OCTOBER, 1946

35 er1:1 wb:a appear beneath. enough of the borer to bora the (rester e_-flunk rn.:. speaker h mour.red. the battery l:muld stand upreh: along - e. wh:le t `t" buttenea sh:u:dalt one eat or. the to.mm of the ca 0et an d the.. n ed. 0' Mate that The battery trade and paon we of.:able, length and dimension. to arrow for connernor.. tut do na plug Mur. Into the totterlea n pet. The loop should sttp Ina the pocket fn the :Id one 'l.1 _ienrend In peso Yeses:. ask"solar [Ieoh Ih the four corners. FITTING THE LID One point N worthy SI special mention In murk lithe lid You wl paw. ably led the the adjusting «re«of the Ile transformer corm will reotrede enough to but the lid. We hesitated to make the tabtnet elder. purely on this account. as ama:ler le, Ienstoemere may be available aphte,. Web of UM truck sppeiring lo print. We timely bored two holes Ilot et the woodwork of the lid deep sleuth to anrommodate the acreww. but nt right through the outer kathereue eoerlog. The mane expedient mar 0 rot your case. mne Alternatively. alter the tensfomers h ave been adjusted lentalaven. tn. unnecessaryiopb of the adeepng and This Mehemet NgeOMr silt Me atrip diagram will «table yea le idestay punting strews could be nipped off cosy pewpeeseia. ejth a slurp pale of a1ce autres Hut he n t m peso any nude se dime renon, align the Ile on madames for tune to a Mine near the low hethe amewe entra eu dalle. ilmute output Remember to keep queney end and adjust the pander. Manning tilt the whole sethat h the tweeter pin control adeamyd as for maximum output. while ro king beet tutted ettitto Into the oe. tar as poutbte. and eedsoe the Met. the output the del as see rt xs_ry. Alep Is to renon It for Irmo the mediator to the lowest sate Tune In a Nation et the low free Meting and e t. able heure. eseney end of the band and. by Imam - As with ell battery sets, the Im- 1f the IF ample«is unstable WY Ins the 4151 grue serevus. adjust the mediate is to make esse that a resistive eh across the 1! am- drum es netnews et that the pointer lire trot. eru«ve un blow the ple«geld rater Flowerer. Neel filamentsfilamentsof the «1e emend. with the calibrated mite«ires. Therefore. n entente«). measure ether than t Me staion on the dial rote. The double ment the the of each «0««0«,«,k adesible a rue for Insatuty trouble is rather awkward Mtn the DAY Mal naklttn m r that n the retende We - Il Will allow the eel m be put Mm Putt bemuse It Is part and panel of ment pepe are connected to chassa nperailon ait die taanet mure. is In the! tenson. The set must either aepanieely, or Na a pine are k out sod t«llfy tine bee bum of be slipped Into Ille enbiiet to check lend The po ins? filament pmt are the OKiliallon. the polluter setting or elm tine 4W 11 connected together and ken Coming bsrk to the "peuvent pro- teen MW In Iront cal the drum by throunh Une "oit.on" millet the "A" blem. If ro at0lat«is available. lese. emery. See Mat then le to the IN tnmformer untouched foe the entomb cl the high ausite voltage tolet! Ume being. amrtlsg abase! U te. (lament circuit Tune m a station or weak Menlo anywhere. elnlal towards tie high revueuq end Of the baud and peak the loop and RP TESTING Check au the other mnneedona and then plug le to the batteries. Meteh bar end. with the ed of a «met the volages on ell.vraa Plug in the I and PRt vnn., on. turn up the actors s. and not whether ahumm n' ' pro. dued by pacing the fines on te. 'hot end of the!tome mono. Ten we Mow whether the stoic end is G hee or not. Pintes plug In the rewmining three wale«and see whether a station mil be tuned. 11 mot. It Is ernes a mater In And let poin the by error seet e uh component. Once the Mt la operation. the a si lignmeet eel be tackled. If an gerber e *valet«, set It to 455 lee and. by tipping the output on to the stator palet of the RP pant > selmmeie rite maximum output. The BLUEPRINTS FOR THE "SPRINGTIME" PORTABLE OUR low MHable stets litais red < biss1 of < pistait sow daces. lo.. un ea Iade end <.Ills, eah have a u,d.sgl.sleepeesd s 44.4 ea. s desed«el Ms usb:ssl i blastulae lent. N Isst. sub Mss.Nin, mks MWr. sil west Ned owned ne basa ii. clonecloneans meet N tee a r. Seed 1/b new Ist year step e tm "Sptpdme N+N6N" biwa pawn.. k. nand. Narirm yet Or pointer line at the low lequvney ente at the band. 4 - lust the oscillator relater so that high heghieney stations fah in the «meet position and peak again Um loop and RP trimmers fo maximum output. Recheck the psddrr edjurtinent to make sure tha le not «teed In te proems emits. It the IF lnenstome re her not already bers peaked he on an lialoe. tue In 'est but slnel lite carefully adjust each gore for maangler» ourdis. Tbxhmg the screwdriver n sane do may slightly liter the alignment. td ale ewdriner shoed be removed te men es «flu each al aaaaattllt 1 u the actual «Net ed! ltrt'ty on n McN Having completed Me ahanent, the O ne Job le 50 Mann the set to the cabinet. If the of thune hayb a ty been attended u, MU ea onff be a matter of en«it mt.paso and putting m the anew. Put the batter«in place. slip Mop Info lu poet«. KW. the beck on, cria your post -yen porable u testy fo your, RADIO AND HOHIES FOR OCIOSIR, 1914 CASE inirtytnrrt

36 The W1 A has been co-operating with the Bush Fires Advisory Committee, In an endeavor to link the country amateurs into networks, to assist in organising a communication system to be used in the combating of bushfires SOME months aga Mettra Tarim It will met lareely wlth country :ma tolti la 9801 te, IVKOTO) and Thackeray taure as to the success of the ache,.leased foe (VK2TA), of Young, demonstrated to end all country stations who are Inter- moteur use as the committee the value of e c ested should communicate with M. H. from sautes ce.tion systemto their Werk. Meyers (VK0VN), 9VIA Sox 1034, and O urle a e result of this demonstration, is was GPO, Sydney, who is officer -in -charge, mer rb of oldd 80- decided to clrcularlse all shire coun- It is the intention of the advisom metre lane apcils, 130 Sn number, and additionally OnlismitMe to arrange demonstrable. psaretl on the band within a few da..v. ange with the Disposals - et Mudgee, Orange, Wagga, and Oren - The ZL's wore specially pli...1 to sion for the reservation f Mark 100 fell. It is a matter of crgeney, as sum- get the VW., balkroam, c and m conand 109 sets. mer is approaching. Members of the mtacts being made w oe the Tas- A sub -committee of the advtsory institute are desirous of rendering eer- n vc2xc s reedy to Stan committee, with Mr. Moyle IVKRIOI to the State in this matter. In on the old Mounds. and Me. Meyer (VK2VN), se members, emergency work in the past, amateurs Thla new allocalbrn ehould relieve was formed. Theo will dealexctucively.cd4 their ow equipment, but with the pressmc on the higher ieequcanies, with radio cota u i tla nd Its as - special equipment available, remit: fm m -city working to some degree. problems. should be much momy re satisfactory English opened up 5101nlten o:ay With Sl te fregnmm so 0.a Cil reports In e signal to the stale that Zile With HEADPHONES banda will be bfrequency requought r o line with meet Zee Ide allocations. the New Zealanders losing _tame of their extra 1001, bet, maya dttey0 are not known yet, maybe they will have an r ]Op ke the 40 - metre band. Brand New, Just Released S.T.C. and Stromberg Carlson 130 ohms impedance 10/ ohms 1 /5/ - Postage Ij6 pr. extra. DEITCH BROS. 210a GEORGE ST., SYDNEY. 'Phone: BW7687 Near Circular Osey. NEWCASTLE AND COALFIELDS visit north showed that befl n rent antennas and 10 metres featured most prominently 1 Rcoolly up In to canine.. t mtyoe per cent. af eally used exams of tort, generally rotaries of the timee relement varies. VK2A131' io mitts and three element job Worked plenty of DX on 10 moues 2MK and 2AHA also spurted three element a s. VK2ZC, with two Lazy "H" arrays four directions Overage. possiblvhad for the moat iinpressive systems. VKRXQ, a3 Maitland, el, eel the Sumter of mooing, and et metres is AMP Mewl him. VK2SC. of Kuret.her e new abece. a new a Inodlr- Woe, and anlrate's len. VK217. urrotary. a Mug wire tom an Min aeam, plus a double I. VK0PZ, With a w sheet crammed With gear. will berm all bands shortly, on 2l Wetre talent.r4 now. Simdav night on ten metes Ls the time when thetrod labie QED reveals and reviews Week's effort. WIA NEWS Latest appointments 'to the New Divisional Council include HUH Dale (VKXX) and Clive Huehlson lvklyp). 2XX becomes treumrer and 2VP councillor. Both have both smanelt WIN suppnrtern' over many and IL L. gratifying to see Limo, We forwent to take active pall. Vila affairs. dole Moyle t VK2d[1i liaa been elected a vice-precident. ICSniteeaed as Page net PAGE THIRTY.FOIIn RADIO AND HOBBIES FOR OCTOBER. 1948

37 . these CIRCUIT USES NEW TYPE VALVES ÌHa new sln.le-endrd 00' v will ultimately rvpenwde preeen CM MO Orr, the anvant.tera 01 In. mewed pits better high frequency performance le ended fller weem11 eature I. Ilaeii In advantage In Mat toecap con nallmu art eliminated. with Meir me0mnul ana electrical :Amman. rat 'Mr valves rl torporote In tand e ml II nil ehteldlfo. anin r MU: a ferla falot sleeve. and prusltdone rende- separate votre anlélela unnedlamry :n mdnr Cocoa CCU emphase 181t1.OT R.I. amplifier. (MAI-OT convener. leefi.0t IF amplifier and detector. The West issues of Rediolrooics Technical Sullel.n, Nos. 117 and 118, contain dot.ik of a very interesting six valve mains spar. *tad receiver. Oeslynaled es circuit RCS] R!Wore. the new Mule -ended "Gr' series of Wm. The circuit is reprinted formfl or with a few detnk taken Iron the arpl ry teat. p0 b :i::it..l:-m... lower lain anti p flop lorl punier R,the need :.... neeindimlm. Full derails of the broader. hdor.11 Mott -tore mile tc, the 08A7-0T ere given In NtOOlOd n es 117. The necessity Is armed for stud IrtedWllmt properties between pro nutty ` atootrdory of the aerial and R.P. ill. II avud ow wane «Met Me A.V.0 voltage. Only simple A.V.C. Is rued 1n the art. belt mode ueeeamry by Me tact that the 68ROT Incorporates one Mode only. Nerenhelett, the A.V.C. b quite rffew. and freedom from gs]l-ot audio voltage ampllltt. Clare? mum and 0T9 -OT 11Mlfler. As RF..magner Um I 1 -OT provides hither gain thou Une conven- tional and amures add CMmI.Ia. lolae nom. converter differs from earlier lypea m the omaunn of Me anode pnolided. by MOMll p the pulode up bp abont I Per Dent Um the earthed end of the riled as11141or geld roll No feel -back astern,/ at all la therefore required. I.F. AMPLIFIER A 000? la used as ]P. meter. W that Ile. pivicatbn erld del«. lion are tarried t UM Me Mor ram atrutmre. oatha.lmpltne Mr design of the.ddb melba. as the overotwn of Me diode deteebrdepe k w - of the lilt meadow` íâ1:1?.10íl1. arenaof T Maeda Marly as south gun *a Use o 17.0T and eetelnly.deple for Ill normal relabeheenls. A point of Inler4l II the IA01O ANO HOMES FOR OCIOIE0. roll neuueiwtlon of Uns 1?. amge. While IP. neumlwtmu Involves Ile own peruculer problems It eau overcomes, normal regenerative Iemleorlea err: eneenvely end often temee'nr n eheaper urethra or amkv- mg nobility than the lo-.t0bluoo of valse ehbla. and deeoupling Moult. The original receiver mad Aille cote and I.P. lnlllformm and the relee. ulllly wan. It alylnng. higher than namable ear en ordinary broadcael re.!elver. 11 would be grate Nero en IM dia g M 1«lwistim of Reinehew eirodt duo»,o to.. dour anima of IM rem MI. It is ore 9n1N diet Ms been IM Irv* Ooo Wv sot by Mama oho oot rerbl.s.. dew* <ealrola ils overload Mean Is mural by hnlding Me Mat tan redeem at a fee& consuma potential. while allowma that of the 0P?l.GT In vory widely wim amnia A V.C. voltage. ML11YI1 UI. 1yCMll 011RWII11e\Y MIIIN111.1 a!ii: 1EHE 1GM M JIB ÌP_JIRI: 11.pp.gÌÌ,.1 i CMii{nIppMniTh _ =WI ú i 11pp1,, i1 i i i 11 i i i p00 SO 100 * ri100114cy:(t1m PAGE 714IRTY.FIV1

38 - TYPE 9 B7 INSULATED RESISTORS rfs""'~_ RADIOTRON CIRCUIT teonamned from Preview age) The audio sectlon of Is at special interest by reason of the negative feedback and tone control system. On the assumption that the lieteetng pubic really desires oars boost, rather than treble cut, the audio system le boynte.(i to provide a low frepuene, ast of up to I2db_ according to the setting or the tine c roi. In this cult the negatirr feedback Voltage from the output plate is applied across an unbypassod action of the rodi-ot cathode redone., A Oie mid- condenser fn series with the teed -Seek path reduces the feedback at loo trequencier, and therefore boosts the bass output. The capacitance of thin series condenser etnhtnethe frequency et which the k000t becomes evident and the Particular Tonle of.oit wild. Guild the general requirements of console red Ives. Toe tone control resistor le simply en parallel with this seriee condenser and Madam It less progreaslvely effective. The audio' tenonee curves are as nmstrated. íai the Type BT Resistor, with its many superior features end special practical advantages, is the final result of more than twenty-three years of Intensive research and development work on the part of IRC engineers. The time -tried Metallized filament principle is retained, but the ingenious firmly based upon sound engineering principles, insures lower operating temperatures eei+h proportionately higher wattage dissipation in a conveniently small, sturdy light weight, fully insulated unit with an exceptionally low noise level. Available in W., I et., and 2 w. -sises. Sol Agents far.trr.lr,.ha. TRANSMITTING VALVE TYPE A NUMBERS NUMBERING system for Iranitm(tfng and special purpose helves, simmer m that In use for reeelvine types, het recently been adopted by the American Radio factnrers' Mum- Association (RIMAI. The new system provides for three Mete symbols. The first is a number which entes the approximate cathode r In walte. The second te a letter iii the nature the of electrode structure. and the third 11 a further figure, which is purely a serial.se'peking n rober for identidea the Arsr 1e s bol, n the metre I wound repfeeenl e cathode watts. ntheot atee r repreeeoit tu tom wale. ant ale for over to watt., and up ana Inducing to 20 watts. Other figures have ell -attar significance, up to which represents e cathode Pe. In excess of I066 wade. The letter :emhol with n "A." ',Inch tnonodes. much en haltcst tubes end vastsealed resistors. The latter "R" Is for diodes. and so r up to "fi" for aches«. "L" la for sealed copep' "R" for rystal detectors. "p" for phototmlesive devices. "M' for mamma noel ty'nes and "a" for vacuum switches. The numeral forming the third character is not to be kas than 21 nerd Is purely e serial number. aantrt In h to different valves of the same Witte! elessiscatlon. The official number is sheeted to the rrototyre but inner be reesined for v Imorow!d ',melon, provided corn, rets Interchenreebnity exists. Itf an!moneyed varaon will replace the orioles! directly. the scfrlx "A" map be treed. but this Infers that the olivine] will not replace the Improved version h, alt services. The suffix "R" mar b uval where n Improved type Intended to die. Ong, altogether the prototype. PAGE THIRTY.SIX RADIO AND HOBBIES FOR OCTOBER, 1946

39 ( r HEARING AID USES MINIATURE VALVES A recent RCA epplicarion e.t of. Fee.id v in.o of the w battes be.ed battery valve.. A 1051n the Itret stage provide. high audio gain. while a 111 1n the second stag Marge provides adequate power to operate a miniature a onduction earpiece. Normial c filament drain for the two calves la 100 mllilmps, but this can be reduced by the 'battery sever rheostat Ri. In tact. ALL THE PARTS for ONE and TWO VALVE RADIOS Complete Kit, One Valve Set 45/-4 Complete Kit, Two Volve Set 5I/ -e..(v4,,.-battery-h eadphone--fal at.e C h ----,-. MNII Dials _ 9;6 ea. Veggie Site S. -- ses -5 l/1 ee. Ll 0.1 r'6 gg... R4 RI aft. o.txe are std. 600 P. 0 eeg 100 elms 3.0 reg. 1.0 mg nog, Rd can be used me a volume contm idmugh lt. action I. not Ideal. With a high tension supply of 30 ma u, a s millivolt input. signal Sr' 1 produce an utput voltage of 10 Ceros he earpiece turn 4 per cons. durer Elan. This is rullai io for yades plum hearing impairment is only moderate For more difficult esses. a high ten don voltage n1 4t is desirable, pro ducing up to 10 Volta appess the car Build Your Own Windcharger EVER dec. as publi,hed the oti Teel tides ee hl,.object, we have had 'peeled regoe»a for Ili. erri_ h cula: beak numbers. Uneble le abrg.. 1 e hava Really decided to reproduce the strictes in pa m Flet farm. letting 1 aident,, thete should b. e.ed.ble by the time read Ibis hem.. t Sand e,fr11ng pastel ool. bar su 1 cape and.ndara. y. I.ei.r "Wind charger." I/- Ca 9+Ì7g R. e.ttr Coil ait6 Ce. I/S ee R.din Kee6, ed I/-, sad 0. JUST ARRIVED 1946 RADIO AMATEURS 10'6 17.I27y1 HANDBOOK Peste,. I/. Ed... CHASSIS FOR ONE & TWO VALVE SETS 4/11 TERMINALS, SLOTTED TYPE 6d VALVE SOCKETS 9d VOLUME CONTROLS 3/11 RESISTORS, ALL SIZES -,. 9d _ HEADPHONES - _ /6 IGSGT V.lae. -_.-.-_ 23/10 S.,. Gang Çondense, 14/. r v-. Avdia irenatorme.a --. 5/. ewe Gang Condensera... 11/ Prompt despatch Mail Orders. Please forward deposit C.O.D. orders. piece with e per cent. distortion. Current drs lm Bruise arc respectively 0.4 and 0.B Idlamp. To make best use of the high tension voltage, the 1T4 it impedance coupled, cul a very small audio choke la therefore required- A volume control RI Is used on the output sale, doe anything lees than 10 megohma for poet Pons A3 and RS would serloualy affect the eenamivity. STP1PDn 102 HUNTER ST.4 NEWCASTLE RADIO AND HOBBIES FOR OCTOBER, 1946 PAGE THIRTY.SEVEN

40 i PEk:. -WITH GENUINE Because ell R.C.S. radio parts and components are precision -built to exacting standards of accuracy... and because only the highest quality materials arc used in their manufacture.., you get TEST - SET - PERFORMANCE from R.C.S. equipment under all conditions. Use R.C.S. kit parts, coils and replacements in your set and get the benefit of maximum performance. RADIO PARTS R.C.S FILTER CHOKES AND AUDIO TRANSFORMERS These R.C.S. quality components incorporato heavy copper wire wound on Trolitul bobbins. The use of Trolitul eliminates alectro. 'suit, ensuring much longer 'Hen - live life. TB4. A Class. Single T85. A Class. PP 186. B Class. PP TC M/A 30. H TC M/A 30. H. TA4. Audio Chokes TCSB. L.T. Vibrator Chokes. TC70 H.T. Vibrator Chokes. Miracle -Plastic Trolitul This semi -transparent, light -weight moulded insulating plastic is exclusive to R.C.S. Trolitul is used wherever possible in R.C.S. quality R.C.S. STAR AND M/C CONDENSERS R.C.S. Midget Condensers feature trolitul und plates and are available in single and double bearing types. The ever popular DA7 Radio Dial! Absent for many years it is now back an your retailer's shelf. Ask for it-and other equally famous R.C.S. Radio parts and components. R.C.S. I.F. Max.Cap. Min. Cap. MMFD. MMFD. Plates Price CV , 4 0 Transformers CV35 IS CV For 4 short wave enthusiasts 6 CV , 4 9 R.C.S. now have available CV , 5 3 IF Transformers tuned to a CV frequency of 1600 K c/s and CV featuring full permeabiblsy M/C tuning. Careful engineer- CV ing has resulted in a de- CV42 i parts, sealing wires and connections CV , 8 4 sign giving adequate gain into one solid damp-proof whole. CV s 9 G and selectivity in conjuncguaranteeing longer life and CV tion with stabilised gain. maximum efficiency. CV Radio -plastic Trolitul s CV , II 6 used In a tropic -proofed B.C.St. RADIO PTY. LTD. 174 CANTERBURY RD., CANTERBURY construction,.-nsuring consistent performance under conditions of high humidity. NO DIRECT ORDERS PAGE THIRTY-EIGHT RADIO AND HOBBIES FOR OCTOBER, 1946

41 to Gadgets and circuits which we have not actually tried out, but published for the general interest of beginners and experimenters. A SIMPLE CONDENSER TESTER With little expenditure in time and money, experimenters can male up an instrument to measure the values of unknown condensers. The design of dia Instrument is based or, e suggestion by Mr. F. J. Martin, of 60 McFerieneerreet, Hamilton, NZ. wrlio operating principle ai the strument is easy to understand. The condenser to be checked Ls connected I acme f lie teat potala and the selector switch set to the anticipated cepacitance range. Alternating. voltages are thus applied out of plume Lu the grill cl Vi through the unknown eundemer end through ihe reference condenser Selected Ile It the unknown and the retentive condemn, happen to he ut o1000i seine. the voltages on the grid will cancel ou1 when the tapping il exactly at One centre of the WOO ulna poteullumeter. When the two condensers are of %IL - equal value. a null point Will ocel, with the tapping set tininf'd rli or the other of the rmimance element.. When the circuit la In.1 condition of unbalance, an alternating 50e volt. age Is applied to the grid of Vl. This is amplified and applied the grld of the indicator tube, CRUM., the ailedons LO close. As the condition of balance Is approached, the shadow opeux. The value of the Potentionn,er ts not unduly critical. but it should prefer. able have a bog, sännoiäly V01111a, alit» luting alraa.y 111/1311 0(01011,1 or {eh limfd,r lance. hen scble. Tu calibrate Ille matou range& many marked condemn, ob- oe possible, and note the null point pool - thins for the various alma. remember that they ran be connected n aeries III paiallei to give other calibration values_ Cati deniers vary Imo their rated,alues. and it will be nereasary Jo calibrate a. Mr CC ponible against average setttite, Values below about mtd. should preferably he tasted without long attached leads to avoid affecting the reading. The only component...mc.. Nee's] mention 0 the transformer. This requires to deliver about BO voile 0-0 Deane winding, while the other. in conlunction with the supplice the necessary 200 odd volts for the robe end Indicator tube One simple scheme lu ID use the han,vaxe Pena - tonner from an old eliminator, adding an extra GO volt winding. Most of these transformers are wound at shout eight Or Mite Mena Pr; volt. The recliner valve can be most any type, connected as a diode whose Memelal matches up la the (Anal*, filament voltage. The filter condenser and choke can likewise Or oddment parts, gaily a re./ altri, p. al, required by the teeter. The amplifier vah.r Is xenon a, a 0,17-O, hot alto. ono high gain voltage amplleet ran be ueed. A TWO -VALVE HEADPHONE SET I This little tel is lust the thing for the young enthusiast' who likes to listen to music in bed. The combinati'on of filament transformer and high tension battery ensure simplicity and economy of operation. ALTHOUGH two 0,17-G valves arc The eircuti. through the 125 screer 01,1,001 0,001001uhrran,pofentiometer should be broken whey Ille 41. ix nut in use to save con a - - triodo -ional drain on the buttery. Alter mitirel, II, und awe n 1.0 erg hill tta't Voltag, the latt be more.hull Ilia tension lire emit atillifitararli c,0 thing Ale end at all ,a,..,,0000,0., 0, o a rouwe llult light ditty or "Minim." bal ter>. ran be xpecelcations. Beeod on a sugrp.slio expected to last [or ninny months. by Mr. J. Johnson, g Rowley-etree But eme mini has to be watehed. Burwood. RA010 AND HOVIIES FOR OCTOR6R. I Ma PAGE THIRTY-HINE

42 CONSTRUCTIONAL DETAILS OF TRANSMITTER GRID CHOKES FINAL TAI7K-1 AER COUPLING UNIT 6V6 -G TANK & TUNING 807 AMPLIFIERS 6v6 -G OSC.DOUB. CRYSTAL H.T. POWER TRANS. r MAINS "OFF -ON" SWITCH HIGH TENSION "OFF -ON" 866 RECTIFIER SOCKETS WOOD ENDS BRACKETS This photograph shows the completed transmitter with +he 20 metre coils in place. Note how the Tritet Stage end 807 grid circuits are completely shielded from the 807 plate tank assembly. Panels are omitted to allow all components to be visible. PAGE FORTY RADIO AND HOBBIES FOR OCTOBER. 1946

43 unusual THE 2JU 100 -TWIN TRANSMITTER DESPITE the success we have had with the 807 valve, both as an RF amplifier and modulator, we still hear of anratetrs who strike trouble with them. Just why this should be so is something of a mystery, as, provided the proper precautions are taken the 807 is probably the most outstandingly successful valve for amateur work for powers up to 150 watts. So far we have constructed a number of transmitters using this valve in single -ended stages, and have operated it on all frequencies except the 3.5 mc. band. We have also built an 807 modulator capable of over 40 watts output on steady tone. Using the now standard precautions against parasitice, we have had completely stable and successful results in every case. Partly because we wanted a nee transmitter, and partly to see whether there were any snags In push-pull operation, we built up the job illustrated here. We have purposely avoided any complications,. circuits- regenerative oscillators, Re., in order that, in duplicating it, the constructor will have no tricks to learn, no unusual techniques to master. Within five minutes of soldering the last component in place, the trans mitter was working at ils full efficiency, and has continued to do so ever since. We tried It first of a!1 without the grid chokes for the 807's. and were rewarded as anticipated with a tendency towards parasitics when the final amplifier was detuned from resonance. PARASITIC CHOKES A dozen turns of wire wound round a pencil and soldered in place cured the trouble completely, and it is now impossible to make the transmitter operate on anything but its allotted frequency. This, of course, lines up with ii previous experiences with 807's, and Is only to be expected. To date, the maximum input we have applied to the valves on an artificial iv 450 wette at whinh flour', the 6V6 is able to provide adequate drive for operation under the valve - makers' specifications. It represents a plate voltage of 750 and a current of 200 mils. The 6V6G was doubling from 7 mc. and the final operating on 14 mc. In order to find out the capabilities of the oscillator as a driver, the next step was to use a 4.7 mc. crystal, and to triple in the 6V6G tor 14 mc. output. There was still more than adequate grid current available to drive the 807's to the optimum input of 100 watts, to which we were working, and the maximum of 150 watts wa.s still obtainable. Using si 3.5 mc. crystal, there still enough' drive with the 6V6G operating as a quadrupler td obtain 100 XTAL L 4 A i 6V6 -G 2JU 100-TWIN DRAWN; D.C.S. CHECK; W.N.W. DATE ; TRANSMITTER F 60O/. 6COV. \ 040Q,9_0_, SW.; 50 PF..U"AM'ti1 15C00n 20W 866A _4, S3 E F Lq MODUL- IOWQ ATION e-+ik=ik-lihh 6CDV1 60Dt 1000 CHOKE 6.3V 6.3s1. 7SV 'X -24ov SW The circuit is quite straightforward. A tuned cathode coil should be used il all bands are to be worked involving a change of crystal. The 807 cathode bias resistor and condenser are optional, but guard against excessive cathode current. Here is an extremely simple and efficient amateur transmitter designed esneeially few the A -Class watt limit suitable for ohone and C.W. operation on any amateur band down to 28 megacycles. It needs no neutralising, operates from a single power supply, and was built during a single weekend. Two and possibly three bands may be worked from a single crystal. watts input with adequate etficency. so that thr: a bands from a single crystal is quite a possibility. Using a 6L6G as an oscillator, even more drive would be obtained, but is likely to be a disadvantage rather than a help Used in conjunction with the modulator shown in the circuit diagram in our August issue, pertectly clean modulation was obtained on phone at the 100 -watt input, the modulator having just enough output to approach the 100 per cent, mark without fear' of over -modulation. Linearity was excellent, and one can be assured of really high-class phone when these two are operated together. THE CIRCUIT Going through the circuit in detail, the 6V6G was selected as an oscillator because of the extremely low driving power required by the 807'sapproximately half -a -watt each-and RADIO AND HOBBIES FOR OCTOBER, 1946 PAGE FORTY-ONE

44 m,' S a wrenopeners. I t,.'...p. r - 1 r W` _, +n / :...4%.,,1.v.. 'iwi a OUTSTANDING \It. tech. al rodirin het. Is, t;:. Ihm. con.en. r I hl bn pnend and Ir.rlgx.l Ih. - pne Arrow, I,1n.., lax lu-. drone..e hedge. o. enalix rdnta V. eq..,..., o-.uriwl h,,delnr..1 IsmehiF. s1. nlrn net hn...and4.rum nirnrr eivh,.. aerial onnlal.re nerd...id Inn,,., I, Imnhl gap,. thermin -tone, n e,lr. -W,1, i.i. er. e nel 1 de..unla de ln I.,lu 1 in.he aitl. the x.ral v tell. tiers.,n p.n hd t emit! R.H.II DUCON CONDENSEF.TD. eri ATERLOD, N.S.R. '!t In He foreground i, the Wpb. the c n<i, ay the 6V66 plaie...g cord.awr. The come..pond eel e pende taure b the e About il eptienel clhode.ender tied <dee*. co :melee*. lu Ike e 101í. Vwible else art ne and ciels, gril coupling and wee. lee wren brpn ceedenee ' hidden behind eke lueinq coif. A pd.g.ie eeihode coil war be aerewwadated in the Weal Sr... in from el the vale. 1M amllly el Ilee ív00 lo.nllplv the ebb have allowed It renumber beller Mire am t ware alai r.alwble Naomi.Naomi.brut,. Inene volley". bill Plat. 1113d when r..11ubm. The ann., Ire tumid,au w ev,.hiw, of gone 117 drlrr needed Ir. of!mere. nnwnenenli Winn neuron nppnrlbly more Ilan won II, Paid of 1 WIIIL. NO IIIe enter. en o. 0,41 I, +Inde loue. cagy um 1Trn11 Wow to be mdw pep. A. ball h..044,x.oe 4111 Nhag.1 haa In Ilk. bblowneelrm,ul moth her itnh 11C nod RP. Ille Inning rim OM. Ile HOhenoem Ix a RPM caul lo Coupled Ihnn,Gl ',bete o1 tute..i of 11dwa11wol,IT e 9mnluli,la rod >en -n.1 helm, long. Tide «ire under x11 runcialttm. TI116 Ine.,11.! '.'Ife,,, cl. SYM4 W madly nble ln z:1l.plr 11...ßy i x. nnln0 lu Ilea e1re The 1,1óg teen. x w.l..., 1't holnrinll. It lop very 111í1e paay.1. l hnnn I I. nwrp,,, m obi, eurrent. ant will Ruent, bhoo.. 0E Ihr b..,.,b..,.,, on. be...,, i ootoont Al 107 delve. of which the ranlar'laiade N :ren,, 11,11 II I. amok. Pentode -output" e1411eb,:11'11 II, A 3.p11. valve Ivre WOO for the eircu,l pane!.. When regoueo ao e roll. mooned Ill a write raved wrehr...dolor der grim grog O., spar 11.1 or Inn Iron ill. ella,,,. The ford.mnlral Ol Ille ervo.l. Ihr cathode..11ne,onrllere run 011 lehl up m i Iluy be talented O pel wall a mein, nt.10 renew lo Ihr OM pride Wine A ibelle, ahem. le m Mme& 1 earl. nrl. In. Inn,* of 11101, Isla -tall load n mole rnnte,orr In phare of the 0, mn' numb the cathode,role. mud Gt1«11n,pen, reol+rorz nere tere/1 III et. Wh. e 0kí04111,ml 1m Jule`'. lion 11th len.,nt In fed Anima the GYRO of T}Mtal on giber boum phut. and A blend Oie Germ Orale of II, now,nlene T ran then e role 1011,1 rut.loden We belli wt, Io1Ilmill Awn lo OW. nt x111 ht,,,,, When fond Iv lull emptily. al. n the Ilnol I. b''',1 H.ren1e 11, To Obtain Il, pith -poll Once 1,11 IIr on ni Iry CVO eement+, emc,he RPM rill. lapped 11In10,11l I. e':eeenel Muncie. Wog In Il. tent,vol. Ihr high,lwlwl reine 110,11101 In m..n101e, eli,- 1,l the eon n dente 11e lop Equal nerd on1mu1, , and en, how. Ile nennm,ller Wan Inlolt.pe. are 11e1, obtainable Ire, Ile ended manly for phone. paru pain loll end.. Were not lllnlllded mulla nren11,1. A.pli.itior m1lde0nr would probe Much of the lranamiller+ meeen PAGE FORIY.TWO RADIO AND HOBBIES FOR OCTOBER. 1946

45 do t4\.3 a\ge\end *?es S`e>0 l>a ` ay u\\ek * Sa otn * )4" u` \\d a.m 13,\-\1 Pa}e\daanllS 03 ao1 L\'o,o alrba] ua1 Ò a\o`;oè \0.saX, P auaba) Su`aeu'aQ\ o5 Maj3S ga V %L vag_ tx$da 'A 0. ep1ßn RADIO AND HOBBIES FOR OCTOBER, RAGE FORTY-THREE

46 "FERROTUNE" GANGLESS FOUNDATION KIT KINGSLEY MODEL KFTI PERMACLAD COMPONENTS The research and developments of the war have been applied to this new receiver. Entirely new in concep- KINGSLEY KFT2. FERROTUNE REINARTS KIT Comprising chassis unit, Dial and R. F. Choke. OW AVAILABLE tion and design, it is a revolutionary step forward in radio. Before you decide on ANY kit, see the permeability -tuned Kingsley KFTI. rirealls ELECTRICAL & RADIO PTY LTD

47 UNDERCHASSIS VIEW OF THE NEW TRANSMITTER a.w t,.,w. -ra= _ There era very few pt under the chases. Note the oscilla for nthoda eoll which may be replaced by a plug ie ryp. undo valve bass. eal tuned bye.0001 mid r.ri.bl. :and if desired. Note the meter shunts an the panel near the pitch --cooly when this rido. r Mimi. The second socket ofehnsb s for, modulator maize. A shed, twitch nveiled or plug may be mud for C.W. it no modulator is erailabte,or r the socket m y be emitted. le due tu the layout. As will be seen, mounting the BM on the side m tt the grid circuit lb entirely shielded from the plate circuit. and plate and urld mnnectlona are particularly.beet. Tho e v wired and bypassed stint ut the ountlug aubpnncl-ilto nrhtd e also. r The cathode bisa resistor Lat not es ential. but la advised at least for a while adjtuttog the ]rial with lull voltage. It helps to avoid exceptede plate c r It earth -don i removed. There is rtrdequnil bias p oridcd form -patent:' adjustable link, which again moved to be jet the thing. We w lucky in picking up some silver-plated capper wire for the final tank, although nipper tubing or a were -bound pieee of grad former would he quite OF:. If a Slot Is cut In the rentre le allow the oupling cell to move in and out Of the field. The 0-1 MA meter with its switched shunts has roved to be invaluable when making adjuatmenfa. The shunt. welly made with copper wire woun mall formers, and adjusted b Ihr 2othe clore gild leaks without that.allbretinp from another meter of suit - from the cathode rcelator, and 1t was bee range wired it Crop mete eventually shorted nut in our own reeds to 100 mills tope the 6V6r1 plate job. We made eta attempt to use ate particular split -stator condenser far the Output.toge. These are hard In oh - COIL GUIDE lem, although the constructor may Any d.edard coil dote ir suitable Iwrarat nut something Ilkr the Ire e hansmlfie, We..d 9 tined. Or Into. remodelled at tr-dl rf 7e-inede e rule. loose for t u Ll. olla condenser or shout the sella to.! m ryslah-13 turn. Tor 3,5 roc. ai For or 20 wire on valve It doesn't matter whether you fit base,...sire c e tapped reed for 11 your condenser under the Chase and rec.-113 i m. fer r m mount the coil on stood -Offs, or do For 1 s et., L3 has 12 turns of 16 wire did-molest it on the corde ses larger, 21" di.e ter e.d apac.d Tuai! Wl ch a pair of brackets. The coil ever 3", e gee al j" being lait in the mounted mn a subs of good bak011te centre fer the coupling link of 3 tuns. and gtnbs into small sockets lop o th- The dlern.tiae coil shown ee the photo. rentrteltnü. The PIT ot] tha am 33" disn.ter, and has 10 turns. luttr cntsld :et, Ito made through a for 7 me., 20 turns of 2j" diurnal, plug and re although In m ease. be suitable. Approximately double IL w more convenient tu use this.umber would do for 7.s oc. Aerial I. through our to le mule for the 809 grlde, and to 200 Trills for the 807 plate. A double contact five position switch is mad, using each second contact to avoid shorts between adjacent.wilco points when owdening. OPERATING Operating voltages will be between en 600 and 700 volts for the 809's, loaded to approximately 150 mills plate current with a maximum of 200 mills. Under these conditions, grid current should be approximately 7.0 mulls o any band. With a 616G, higher grid ourrent will be possible, but not necessary. About 10 nulls should represent the maximum, figure's being for both valves. t The OscIllator well run with about Ito volt. on the. plate. and 200 on the screen. When the final Is keyed, plate voltage should not rise to e than about tel volts -a mote limit for Ile eh a. It tripling or quadrupling if undertaken, rho 15.L00 ohms r s for should be reducedas [0 ohms tot extra voltage. rule, quadrupling is not rends advised, crystal snit current tends to cud a little high. mood crystals should be used. Any of the standard keying methods n be employed. When keying, the 807 rllamenta should not be earthed, but connected to thrlr cathodes. Otherwise too high a voltage will appear between the cathodes and e hinter. RADIO.ND HOBBIES FOR OCTOBER, 1946 PAGE FORTY.FIVE

48 SOLDERING IRON With Built-in Thermostat PATENT APP. No. 1929/46 HEATS IN LESS THAN 2 MINUTES NO OVERHEATING NO OXIDISATION OF TIP CORRECT HEAT MAINTAINED 4 IRONS -IN -ONE Watts RerinR A Power Con.umed 60 watt. Cure e nt Drain Therm ortot Dpen _ Current Drain Thermosrer Clo.ed.... approx. f amp. The "Heatmonarch" Soldering Iron equipped with a quick -heating 120 watt element is ready for use IN -LESS -THAN-2-MINUTES after switching an the current. The Built-in Thermostat actively controls the flow of current, maintaining constant temperature. Overheating, a cause of iron deterioration, cannot occur, and the "Heatmonarch" is free from iron -tip oxidisation, a factor which eliminates the need for frequent re -tinning. A variety of interchangeable screw -in Copper -Bits, up to 1 in. diom., provides FOUR -IRONS -IN -ONE, a feoture which allows for wider work range. The DOMEX "Heotmonarch" Soldering Iron is extremely well balanced making its use ideal for precision rodio work and a' practical necessity generol soldering jobs. Monufartnred in Australia by DOMEX APPLIANCES PTY. LTD., 161 King St.,.Melbourne J. H. WILKINSON Facto, R.P,mentetl.. T,.de Eoyul,le. Tn: 289 FLINDERS LANE, MELBOURNE. CENT SOLD BY ELECTRICAL, RADIO AND HARDWARE STORES PAGE FORTY-SIX RADIO AND HOBBIES FOR OCTOBER, 1996

49 BASICALLY Lite set h. Very simple one but nevertheless efficient Tested in a Sydney suburb with moderate outside aerial and earth it tuned B out of the n local etatten{ without troublesome interference and at useful headphone strength You at do better or noise than line 91, urdutg to the m ta of our location end a mal s stems Indeed Iceatmn und e riul ttttem e the o oing L.ctm+ Ill obtain m5 hoodrception e from a metal ett It ample, n caltai o mphflinh Car mh and it an utd mas on audible Am the egnake which It actualle lerewes m the aerie If the incomvgnal, Ore strono eo eloo 1.1 be the output to the phones A cristal et thcrefurr eels a efficient aie al and earth ond pertorms best m ]staler, ahem the monk, from loecl Mutton., are enh strung and clear If ont happens to Ilse close eon palm l station the signals from 11 Mill be catchent erenoth but mat blot out those from other ledorn o the vine on of the tt dial A patettup mat help en such a rase but there lw not much she one can do about it WHAT TO EXPECT 'Plues things ore said, not to dleurage the constructor, but to put thinge in the correct perspective. A crystal set er an excellent proposition I r a keen lad or for the bedside t hie. But don't erect it to tutee all t to!deals as cleanly ealarger set. Rent expect It to work a loud -.speaker aid don't expect recaptmn or stations more than about 26 molles away. -ere is the sel complete with its wooden cabinet. Maronite or wood may be grad for the panel Apart +rom the eccited license fee, a crystal set costs nothing to run. No connection to the power mains, ro batteries. Jus+ connect i+ to an rial and earth end it will keep going till further notice. This article sels out the construction of a crystal set for beginners. However. that Is enough by way of.b006 odd. bul its physical eharacterh- mounted to give the best economy in g nleenl remarks. Nuw for the Job of tics are rut particularly important. Bee space and to allow the tuning mü W e pair! tiou. that It rotates smoothly, eat the Mau- stand alongnlde it without hnpedtng To b raid the crystal set, you will lariat is cleats and that the plates do the movement of the rotor plates, Flood n ed a scree of n sorite or plywood tlo touch at any poin t as they, rotate, suitable positions for the terminals, for tete front panel, and piece of deal Lay the condenser on the proposed crystal mbly and earphone jack o thicker plywood for the baseboant. front panel with rite spindle ln a suit- and you will then be able to decide A noir mid. variable cendenser. tun- IatYe position foi' the tuning knob. We t the best sire forthe the front pe.nol. ing dia, ootetal assembly,.0005 mid. placed nor tuning knob on the hori- Remember to leave abouta half -inch A ed c ndenser. cardboard former end matai centre fine and slightly to the clearance all round If the set la later wire, tn-o terminals and an earphone left. to be fitted into a hex. j rk. Newrotate the condenser and note The tuning condenser should have a tn. half -circle demulbed by the rotor PANEL AND BASEBOARD maximum capacitance of about.0004 to plates. The condenser should be Otn' front, panel trod eight. Incites wide by seven inches high and wise made er m white. Plywood of bekellte would be epually entenole. A Yi XTAL The circuit is an old midis., but p,.rie olarly,rn pl.. The path will test only a few shib hew metal panel is oilers u slaty gild only makes things more ndiff sae, A basebont,l should rim be ant. about one inch shorter' than the front Panel and s deep necessary to eccommodale the coil Ors meeured seven inches by three inches, and this Y tacked and glued to the front panel. Remember to leave cbaut a punter -Inch lip of panel below rho board to tate Flung Into a box. Before Dating the Luting moister peratanently Into place, check the bearings and imnlatlon and see that Lhe plates do vol short. It should ape ale smoothly, yet with enough frt. RADIO AND HOBBIES FOR OCTOBER, tous PAGE FORTY-SEVEN

50 FS6 WALTRAM TRADING Co. 393 FLINDERS STREET, MELBOURNE. PHONE MU4719. RADIO SET BUILDERS, SHORT WAVE ENTHUSIASTS AMATEUR BROADCASTERS HAMS HAMS HAMS Have YOU Purchased your FS6 FS6. TRANS-CEIVER FS6 FS6 TRANS-CEIVER Is your boy a radio ham? Radio is the coming profession. FATHERS, buy your lad his Christmas gift now. They will be sold long before Christmas. The most instructional and educational gift he could pos. sibly receive. We are supplying the above. positively new end in Original Packing as supplied to the Forces by A.W.A. 12/101-12/10/- 12/10/- 12/10/ - 8 COMPLETE WITH VALVES. POWER PACK AND VIBRATOR THEY ARE CHOCK FULL OF USEFUL RADIO PARTS THE VALVES ARE BRAND NEW AS FOLLOWS:- 2.1K7s, I.IC7,, I I -BOT and 2-I LS,. These B vales IF sold separately. would cost., fh. Set is»piled with Pelic 0.1 Thermn-Anpeeter priced et Th. Power Pack is a "aerate unit and entirely self contained, works off a 5.9 battery end gives 090 Volts at 50 mill. or 175 Volts at40 mill. The Pack would sod se leasete build The Vibreur i. an A.W.A. geshlled Job, priced el Army trp Key. valued et Th. Trans-civer is built with the finest component. and test rho Government ever EIst. Check a.block full of condensers, Ina mad, carbon and w.e wound resistor, Nisi den.,., coils. dial., volume controls and IA.,Men. key. etc., etc, te at leap the eels, of c The total value of these ports as listed in all retail shops is epprozinrately 656/3/1 for the ports only. The completed receiver cost the Government over 100. OUR PRICE COMPLETE 12'10' - REMEMBER REMEMBER REMEMBER The Price Includes Ill The Tren.<eiver lei The Valve. (3) The 0.1 Thermo Ampmeter (41 The Power Peck (51 The A.W.A. gas.filled Vibrator (d) Be, Qualify /dome Key. The Receiver i. an excellent ahem wove Receiver in itself and works from a 6 -Volt Battery. Is ideal for country use. The trensmilter uses 3 selves. R Velvee in all. HURRY HURRY HURRY SPECIAL ATTENTION TO MAIL ORDERS W. hava only a few left. Country Customers NOTE: The Power Pack can be used on y Set sell sonlained It can be used on Amplifia... Please add 10/- fo cover of Wo wooden c chick Remiser and TrenemiRar are pecked. Please send moneyorder or pastel notes. s. t1 We will carefully ail cor 'ship anywhere in Australie, DON'T FORGET. THERE ARE NOT MANY LEFT WALTHAM TRADING COMPANY 391 FLINDERS STREET. MELBOURNE. PHONE MU4719. SAME T,OU55L4FHy RADIO AND HOBBIES FOR OCTOBER. 1916

51 1 entity I Alumni.. I Baubo.rd I WIRING DIAGRAM FOR SIMPLEX CRYSTAL SET.ODDS CRYSTAL PHONE JACK TUNING CONDENSER 0005 MFOg EARTH AERIAL RASEEOARD I clearly shorn in this abbr. diagram. The hookup is t on In the hearing. far It to hold my The earphone Jack was An alternative Is the "csiswhluker unted at tting without tendency ro.lip. Atso the top right-hand corner of the panel type In which the end of a wall wire a the connucdmle to the mov- in the original set to be clear of the spiral bears againal a crystal element. ing plates and m the (Iced plates, inn- tuning eoil. Actually, you can wally of galena. Thia Lape si 2150, grad ta respectively as the "rotors Duple mare terminals fur the phones capable of very goad results but re nd "stator's." if you prefer it that way. quires rather more careful setting, and M- The Crystal detector naturally Has the eatswhilker can be dislodged na CONDENSER AND DIAL n Imporlant bearing on the results. bumping the table or cabinet. The typo shown on the Mounting an'angemelte far original set A condemn crystal and camwhmker assembly la ere considerably from the semi -fixed variety onetype employing an r be made up by belting a small Ca another There he two crystals bearing one against ell p to a pine of bakellto and single -hole noting a simple,mud- another lire crystal I. simply ad- asounting the galena crystal within íl ea m unting r plates mourning bushes iuned to give geed results and will A small spiral of copper or brebee amy thar way without much danger soldered to the head of a second and the like. Mount sour condenser n the way intended and then Josiah 01 hllhop. bolt, will serve as a eatewhlaker. Do the front panel tuning dial A v neat of quite u PARTS LIST cary and cum vof the le hnke- or b4.li4 panel Iepproa. Coil tom, i" dim., S" tong Ilia dials Is JIM the thing. Aerne I". T") Quantify of winding wire, 20-I4 gauge lively, you ran use m modern loppro.. T' o J") hookup wire, screws, te. nickel Indicator plate a and an Instru- Cat. ment Winter knoh Imppro.. 1". T" 4") Pali 1000 ohmh.adpbcieu.000e íd. (uppro..) tuning con Mount the aerial and earth termin- 'THE TUNING COIL den sec als beneath Me tuning knob n nuy- Wound eith anything 'from 54 to 20.00oó mfd. gaud m cond.nrer Tyouthere else un the panel may fancy. d.t.ctn. unit gu.gq capper wire, oath., silk a Crystal The la of a crystali set Is not at Eerphon tack au important. Remember CO Wt a recut am.l tuning dial inkier lug at the rear of each terminal -x T.rmin.l. for attwehment of the leads, noral E Inch 10, lo. ins.lated. Wind W lures o diameter former, and t el 1e, 40, 50, be end Milsoum. RADIO AND HOFEIES FOR OCTOBER. fro PAGE FORTY.NINE

52 Mae If you Dae, all a communal nnit Wllh gate corer to exclude dust Is generally to Or VreluytU. Having muun..d the crystal. the next lob le to cupid up the mmnx exil. OblaIn four or Dee inches of cull former of two Inches diameter. A length of Cardboard mulling tube doss very first,. You will also need mull Quantity 01 copper wire of mu'thtag from 20 to 14 gauge. l't dues not matter touch what the Inmllutlen a,.1ulough you end end that a cod wound with 70 gauge doable cotton peered might be miner bulky. We med 20 gauge marvel, simply Os - mum ml of It happened to be on hand a Lake a couple of small holm through the Conner about one-itod inch from one end and thread the end of the wire through them a couple of tlmm to hold It firm. Leave about Mx nehru of wire free for connection Into Me elreult,.but tack It away Inside Me 1110e fur the time being. WINDING THE COIL Wuxi on 10 Pus In either direction. keeping Me wire to taut and eyes) as pofalbi. With mall wrap of emery tapee, dean the ineulmlan from abut Slit h f tie ire exactly In Mi e with the Mart of elm winding. Keeping a stub on the wire. Im the banal ponlml with a but Iron and solder and wipe sway eanem Dux. Now push the end of an ordinary wooden match under this tenth tarn. so that It is lifted right up ease the level uf the Muth turn. Continue tidbit 01W push the 11th turn uro denwth the rod of the mash Mal the 11th turn n flat.00. the eardbam Mawr. ` - SIMPLEX CRYSTAL SET-REAR VIEW ïr c Gunge.. ibis pheiag.aph - 201h turn mer the top of lt. and Me Connect. the bottom of Ile coil to 71st underneath It. the earth terminal and lake a wire Continue winding 0001 the Whelk completed, the soil mum have from the earth terminal to the rotor turn. Proceed to dean awe) the In- m Wm. In all, tapped at m. 40. matbn for a abort ddtanea exanut and 70. Two wooden matches. takeeaat lead from thehd1010er. pates in line with the tapping on,the 10th ituealsd la Indicated. wed sane b to the longer alining Canar on the ear turn. TM the wire smoothly and hold the tapping point. slur OI 1e phone jars. Wipe away ranee One. Now pen t of the coll. De eareml out t0 The shwdrr ' comae on the the mate lip unn you Can wind M damage the Insulation of the mors earphone laic I: re ado er the Metal deler't: fah ma mauer when. Ch::.er. + sold. rain con - adjacent to the tapphig. or pollen ut the toil may be Ohorled out. with a aerwws effect mi results. Complete the alumna by pushing a couple of oles Wraith Ute cull runnce she end 'of lb. wire tlnough them a [mope of timed. Ten sum the leimer so Mat It will et Into the alnllble spar. We miscalculated in the origine and cal the leimte after wading me 70 insu m ell. Tern wu only lust toton be Au... on tare extra 10 lures width toter poised be be necessary. C Now run a wirs pmlrreblo ei nee- Ible hookup. le the appall tepeeenttps tl:lne tuts Iran the hotam of the con. The tapvaa at IWemy tores a the t aerial tcrmm plebes the lop of the roll to Me Mawr plebes of the Landauer. and the 100 is fin - It le lut as well le lane a Intle sexe urns on the former. If possible. To loo the Crawl Met, you will just hr cue vara Pinta prole to need a good aenal led earth. Three to 11e nu calte Montt th P. necessary afar It may Plat. workk In a ftmlen with a mama - rail weird. but.arlhbm anger und WIRING PROCEDURE out-0l-lhoon e Kelly nsesaan. An tri vr earth It mbtoluely maeoaal. ' Mount the cod to the beaebuum Rimm a wire with from e eater aga re wear a small nog:e bracket Slid alter that. snout um job w'ieng. The Is wmpliclty IIatf. Any ordinary honk -up wire will mese. Or Meilli elll-lovered buabr. A clew., of as 1ux y 0la the ni.i.y dawaw. doter l::':., r.....vo connections 10 the COIL TAPPINGS p1110. or to m length ef'ptwtg driven deeply Ism moist gr00d. Il is waste al time expecting ro leer signals under any ediee enldltam. Your «fpboes alle Ihoold be efficient and of abut 2000 china lap (Continued m P.ge p) t' PAGE FIFTY RADIO AND HOMES FOR OCIO/ER. leak

53 , BRAND NEW COMPONENTS EX DISPOSALS DRY RECTIFIERS 50 MA half wave with centre tap Two will make a full wave unit. 2/- Price ach Postage 3d. extra. TELEPHONE SWITCH Push pull type. Breaks two circuits cuits Price each Postage 3d. extra. 1 / '% TELEPHONE KEY SWITCH Four pole double throw, Price each _ -_ Z/_ Postage 3d. extra_ TELEPHONE RELAY PANELS Consisting of full w ve - 50mA 48 volt dry rectifier. 2 multi contact racks. Indicator lamp assembly and relay. 7/6 Prnsitive ice each Postage and pocking 1/. CO -AXIAL CABLE CONNECTORS High grade silver-plated units with Polystyrene insulatian. Ideal for U.H.F. work. Receptical and straight plug 5/ - Price pair Rightangle adaptor. 2/6 Price, each. Postage 3d. extra MULTI CONTACT CONNECTORS Heavy daty type for transmitters, power amplifiers, mmercial app, ications, etc. Receptical and plug sold as a pair. 2, 4 er 6 Contact 5/- z cpnraar 7/6 (( Postage 9d. extra. te. ARMY MORSE KEYS (Used but fully guaranteed, A high grade well balanced key. Price each._. 5/- Postage and pecking I/. extra. BRAND NEW SINGLE ARMY HEADPHONES s with webbing e head band and chin strop. Low impedance. 2'6 EACH Postage 6d. extra. ARMY CARBON MICROPHONES Used, but fully guaranteed. Complete with cord and plug. Price each - 5/ Postage end packing I/- extra. Limited atorks of I re follossing guaranteed used valves are availables- 1C7G, 1K5 -G, 1K7G 10/ each order promptly. Postage i'. PRICES RADIO 5 AND 6SYADNNGEEYL PLACE, RADIO AND HOBBIES FOR OCTOBER, life PAGE FIFTY-ONE

54 serve COURSE IN RADIO TRANSMITTERS Written especially for "Radio and Hobbies' by the Technical Staff of The Australian Radio College Fig. I-The original ton compensation circuit. Fig. 2-Modified circuit giving similar results. The previous article in this eries dealt with the most common methods employed to vary the ampli ode of the transmitter's carrier wave. This article will review the equipment necessary to supply audio power to the modulated stage do the transmitter. IT will be obvious to them who have read the last two erticlre Elves microphone by Itself cannot provide sufficient power m mothrlme fully u modem transmitter - though ene tin! r smlheec of 00mpern-.rIely moo set. power. We must. therefore, first increase the voltage delivered by the microphone. and Weis convert the voltage to enftletent plower to modulate Lully the transmitter. MODULATOR AND AMPLIFIER To avoid future confusion it nigh be is well at this stage to make a that a e fully a of Ille die tinctienbetween u the terms r "modulated amplifier" and "modulator." The for mer refera to that stage in the trans mitten to Which modulation is applied Fig. 3-Simple chess-split/a, circuit. The letter to generally accepted as referring to the final stage of the apparatttx which convene the output of the microphone to audio frequency power. The whole unit is called the speech :amplifier. The design and conathiction of the modulator and Its preceding anmlifylne stage follow largely standard audio frequency practice, with the accent nn Mier supply filler, regulationeffi- ciency and a eeelllatlon precautions. Added attention to ouch matters b Ilee.sary been not m rely rmràering the repraducllon of musk for our own entertainment where the presence. or absenee. of bum or die- I.netlon is purely our affair. One hoe to rernether that distorted speech which might be misused by a poorly eulaied power supply. or speech which is modulated by a 100 cycle hurl, w11 apathy earn an viable reputation with fellow amateues. STABILITY The matter of stable opertlon of the speech ampllher Is of even greater Lnportunce. Parasitic usclllatlon here, often et a sopersollc Irequeuey, Inn), be strong enough L -modulate the venire wale. Mouth audio freque modulation uleilan is applied. OrmmWnialion of the transmitter is a cardil m an likely to provoke a visit from a radio inspcior. There me three pnesible lines of nl'woarh to the construction of the spelch amplifier. Ill the non place you may lavish lots of Lime and money upon the produetba col en amplifier with super fidelity eharacterbtles. B ecome, you may concentrate level frequency characteristic hetween hout OUP cycles and 9000 ccles, with restricted responseabove and below there limn. This ensuresrage of frequencies essentialnto r ntelligible reproduction o speech at come reduction u! cost. Thiediy. the mruvucmr may m elder that, becoune only Speech le to be handled, anything sae fie far as choke rt c mpunems end layout le concernrd. e m erere m Gives into elle Jung Mx and r up t all the neceseary bits ands piece, I Including the "Little Heaut" mullet tranefm'mer with a respdake curve like the Side elevation o meltonin. Method number one represents quite foal approach toc the vielen who plain; Lo make the amplifier the Algal purpose 0e modulator and domes Fig. I-Pre-ampliter using high.gein triode valve. PAGE FIFTY-TWO RADIO AND HOBBIES FOR OCTOBER, 1916

55 TYPICAL CIRCUIT FOR CLASS "B"-807 CALSTAN MODEL 511 Fig. 5-5hawieg.en s for a class "C" amplifier m mad uldtor ooeeeoled le al... "e." tie record player, If this arrangement is adopted, provision should be made for reducing the bass response Of the amplifier when it L5 useds as a modu- lalor. The desired result may be achieved by the use of the tone eo pensatlon unit described in the June, 1843, and December, 1944, ipuee of "Radio and Hobbies." Figures I end 2 show cirmlts of the two units. Flguce l Is the original One, which has a gain of about 09 times. This, of r represents a slight loss really- Figure 2 shows the modified verelnn, which has a gain ui theca m four times_ There is lit Ile, it anything. to choose hetween them se far as effectiveness is concerned. Each shoes independent oonlrol of Lass and treble frequencies, allowing quite.substantial degrees of eut and boost of either. The writer has. In fact, for some time been using the modified eircult shown by Figure 2 for the recording and reproduction cf disc records and found it admirable. TONE CONTROLS When the unit is used with the tsanemitter It should be placed between the microphone preamplifier, if any, and the main speech amplifier, When used for record reproduction the unit is nested between the pick-up and the amplifier. The second method of approach to r the construction of a modulator la probably the one which will appeal to most amateurs, for the amplifiers sole tub is to modulate the transmitter. Most mantdaetures of audio frequency components will, no doubt, be catering for the amateur fraternity by making available such medium quality euuid- They had lots of experience dhrin0 the war years In turning out such apparatus for the Services. RADIO AND HOBBIES FOR OCTOBER, 194 s le us 507 Method number three le definitely 'our and the person who carries each a technique too far to building a phone transmitter is likely lo find himself In trouble with the lfromwng author, ties. MODULATOR OUTPUT The maxima m undistorted power Output which the modulator be required to deliver to provide 100 per enta modulation of the carrier le related ro the RF input power. It le, however. desirable that the mettttiumr be able to supply- a little more power titan Is absotulely necessary for full modulation i orders to reduce the possibility of [overload and eousequeot distortion. Below we have,,set out a table showing the amatr mini - Ruin power output required from the modulator for four different Modulation method,. Plate input Pe power to output forrr of modulate p.c. Modulation otage modulation Plate 50 watts 25 watts Plate watts watts arid 1000 watts watts Grid 10 watts 5 watts Suppreesr 50 watts 2.5 watt. flupprepor 100 watts 5 weite Cathode 100 coatis 10 watts At the present time plate modulation seems to enjoy greatest popularlty. Ile principal advantage Is its greater e rier efficiency compared with other methods. Where. in the interests 01 economy of audio equipment, some efticieney in tile RF stages may ins toged, either control grid, suppreaor gelrid, or cathode modulation may be used quite suceepewly. Of the three methods lust grated cathode mrmul- MULTIMETER AND OUTPUT METER HAS ALL THE FEATURES YOU ' WANT IN TESTING EQUIPMENT including UNIQUE built-in tool compartment. a Vollage Ranges: KC. Output end RC.: 0-10; 0.50; Cameer Renees: 0.1; 0.10i 0.50, M.A. a Residence Rangen 0-000;.0.513,000; 0500,000 Ohms. This splendid instrument. is precision - built throughout Accuracy is goeran. reed and long. dependable service erred. In a handsome portable case for easy carrying. lee radio meting workshop le muneture. A product of vwlenitiv 35 PALMER 5T. lor William St.) SYDNEY. Fos 157. PAGE FIFTY-THREE

56 rcecommon CQ ALL HAMS. CQ ALL HAMS. CQ ALL HAMS. JUST RELEASED! 50 WATT MULTI-IMPEDENCE MODULATION TRANSFORMER PRIMARY 8000 ohms ohms. P -P SECONDARY 10,000 ohms., 7500 ohms., 6500 ohms., 5500 ohms., 4500 ohms., 3500 ohms. RATING -50 WATTS (speech) 125 MA Max. Secondary D.C. This transformer was used with exceptionally good results in the R & H 50 watt transmitter described in the June issue. Supplies are now available from leading radio distributors. It trouble is experienced in obtaining your transformer contact Ferguson's Radio direct. FERGUSON'S RADIO Pty. Ltd. JA6177 JA McMAHON ST., WILLOUGHBY, N.S.W. Farrow Remeu mm:r: ELECTRONIC INDUSTRIES PTY. LTD. iiiii,, We are Specialists in the Design and Manu far fore of Modulation Transformers. Elan is the most efficient when Coo-.eeuy adjusted. The necessary sensitivity of the speech amplifier will be dictated by the mage output voltage of the microiusos,e employed with it. a high output microphone will naturally demand less amplification than one haviug low input. SPEECH AMP. SENSITIVITY The overall gals reamed to actteve the necessary sary v w iry win de pend upon the output power ne 0r0 r 110 per cent modulation of the cannier, trie power s,vlll1ity of the outpus valve or valves moloyed anti whether the ompliner Includes anal pleb -pull stages. A push-pull stage requires e least Mice as much Input voltage for output as a single valve of slaarthes e type and operated under w rconditions. ample may clarify the previous stxatements. We shall assume that It is desired to modulate fully the carrier wave of a transmitter w'lth a Mal stage input pow'er of 50 watts, and rigs She particular type cf microphone used demanda that the sensitivity of the amplifier be 0.01 vats RMB. A pair of 80Ts in push -run operated under Ant conditions. with approximately SOO volts applied to the plate, 300 vols applied to the sc and a grid blaze of y5 volts, ell] deliver good 25 watts of audio power. They Mil provide 100 per cent, plate modulation of the 50 watt transmitter Willi a little to spare. For full power output from the hotu the peak audio signal voltage required on their control gilde la 50 volte The EMS grid voltage 1101 be fool fames this figure, or volts. This means Stoat the stage preceding the output valve must deliver an EMS signal of..o Hals,wr eon forget shout the PHASh SPI ITTINlet In enter to ensure r correct phase nintionshlp between lthe signal voltages applied to rho input circuits of the push-pull stage, some e Tune of phase pl' inp device i eded. This Is,nl.0 a valve with its output dd. Into tans role channels. A arrangement is lint shown by figure 3. apluse splutter of trio type contributes little ta the overall Sain e1 an amplifier, its output vafage being approximately 1.8 times its Input voltage. To arivr me output stage fully. the clpm voltage to the phase splutter would have ta he 35 divided by li, which le approximately 10 vats. The rest is racy. We want the remainder of the Modulator to deliver 10 volta to the phase spatter when..01 voles is applied stems the Input terminals. Let us teee Ç. hat this dcauda In the way pf Connor The necessary infmomahm, Ls obrained bp dividing I0 by the result of which is We know now exactly what we 001-n saurage gain of 1900 between Input to life modulator and the grid circuit of the phase mantles. With a plate supply voltage of 800 and a plate load of 0.25 megoluw, PAGE FIFTY.FOUR RAb 0 AN) HOBBIES FOR OCTOBER. 1946

57 One 6.17G pentode well provide a voltage gain of 140 times. As this Ls anima 13 times short of the total gain required, a pre -amplifier stage capable of providing the additional ampdfiaatmn will be needed. The recentll- lntroduced 69JlGT connected as triade 0011 do the lob quite ninety...-.elseof the fact that all connections b rsoli valve are brought out to the hase pins, Raring to the input ter - Vanilla or jack is simplified by allow- ing eximmely short lends to be used. The hick et hum pock -up os therefore sed. This valve, by the way. Ns very similar oharaeteristics to type With a plate supply voltage of 300 And a plate load of 0.1, the pre -amplifier stage gain wouldoold be approximately It. considerable reserve Of gain will be provided if type 89Q7GT la used ln place of the 69J7GT. Operted under the same conditions a gain of co 15 realised with the 69Q7GT. It the gain control fa placed in the grid circuit of the BJiG it may be kept fairly well back when a 89Q7GT Is abed. The input figure or 0.01 volts would represent that obtained from a relatively Insensitive microphone, If capable o1 much higher output Is use ed, IIke the popular 0104 crystal, the pre -amplifier stage Could be omitted. This, you will remember, was the eaperlenee of the editor with the 807 modulator deserlbed In the 1840 Leone. (To Be Continued) BOOK REVIEW UST twenty years ago, the Ameri- J n Rad ro Relay League prepared the C first edition of the Reds Ann:. tams' Handbook, Since then there hare been twenty-three editions. fortyseven printings and a total is of omethg in like a million and a half copies. The 1948 edition is generally slmiliar In appearance to earlier Issues and, indeed, ontains the sa e be an rial c However. in line wottr usual practlee, certain Bastions of the text have been revised to bring them right up b date With present aselles and requirements. Por the uninitiated, the opening pages deal with the background and ethics of a haleur radio as a worldwide hobby. Chapters 3 to lo inclusive deal fairly ively with the fundamental of radio. A eertaln amount of gal and rua theonetleal material is included, bat not snificient to discourage We keen enthusiast. This notion rovers fundamentals, valves, oscillators, telephony. keying, r r5, power sup - piles, wave propagation and aerial staters. The second section, from chapters 11 to vers of a practical character and covers the construeimn of receivers, transmitters, aerial systems, s, teat equipment and very high frequency equipment. Tidally, there is en gam t t f relovant data, Ineluding valve information, wire tablas, color codes, Rm. The prospective amateur does not need to know everything in this book, but it la Invaluable background read- 1ng tor the AOCP examination. "COLLINS" RADIO 409 LONSDALE St., MELBOURNE. CI. 'Phone: MUI033. THE RADIO SHOP THAT CATERS FOR THE AMATEUR AND EXPERIMENTER All kinds of Air Force and Military solvaged component ports, suitable for building Amateur Trans. matters, Receivers, Amplifiers, Test Equipment, etc. Many of these high quality ports, now available for a few shillings, originally cost pounds. Becouse of variety and limited quantities of some ports, and rapidly changing stocks, no catalogue is issued, sa call in and select your requirements. Besides solvaged parts we carry e comprehensive ronge of new ports. in short, oll components ore stocked to make Receivers, Amplifiers, Transmitters, Public -Address Systems, Inter -Office Phones, and other electronic devices. --se.-- SPECIAL ANNOUNCEMENT!! To licensed hems end rnembets of recognised radia clubs. COLLINS RADIO offer specie' discounts so odds purchased. lnterslele hems, forward your 911 nerd and mailing eddies to usure being pieced on r lisle. Write for FREE COW of the latest Redienon 50 Wett Time. miter Circuit Ne. T. toi. This is a modified version of their earlier 50 Wen Moon soit, and sins type BOT vane es e bogs, or doubler in also* of the...ruer 6P6, end there have b.en ce elm improvements made in the circuit. including the method of keying. JUST ARRIVED INb A.R.R.L. Radio Ameleurs Handbook. 468 Pages, also 308 Rage Catalogue Section. II/6 each. _eqe- Technical Service. If you need assistance may we hare the opportunity of helping? POPULAR TEXT BOOKS IN STOCK. ALL GOODS AT COMPETITIVE PRICES. A SQUARE DEAL FOR THE AMATEUR. THE FASTEST MAIL ORDER SERVICE IN THE COMMONWEALTH ' RADIO AND HOBBIES FOR OCTOBER, 1946 MGE FIFrY.FIVE

58 EFCO ANNOUNCING THE NEW USL -46 Now available in B/C & D/W.H., with new type Edglit scale in three colours, Short Wave Amber, Local Call signs in bold type Pale Amber, all other stations Cream. Separate scales are available for each State giving prominence to Local Call signs. Dimensions, 12ín. R 72in. Escutcheon Opening, 9,Lin. R 4gin. All lending diesriheinre. WEST AUSTRALIA C.,IrIe & Ce. DISTRIBUTORS VICTORIA TASMANIA W. & N. Sende-. Pry. Lid. Neyes Nos. Lid. QUEENSLAND Eienhieel Agencies. 5TH. AUSTRALIA NsMnn McLean Lfd. MADE Itl AUSTRALIA BY THE EFCO MEG. Co. Ply. Ltd. ARNCLIFFE, N.S.W. PAGE FIFTY -SIR RADIO AND HOBBIES FOR OCTOBER, 1,46

59 TRADE REVIEWS MI!IMAM NEW AIR PTY. PRODUCING RELAYS, MERCURY SWITCHES Amateur Insrnitters and electrical contractors will be interested incline of mechanical relays and mercury switches manufactured by New Air Pty. Lfd., of 8 Dowling -street, East Sydney. TYPE no. the smaller of the Iwo mechanical relays e Illuedrated, is repeatedly designed to eithstend severe vibration, temperetme and humidtty effect, as curtaitered In many ancraft inetallallons It le equally and - able for use in transmitter equipment, amphdoe, loudspeaker Installations, Arc. The coil can Ile wound to operate et from fi to 290 volts a-ci or to 98 voila d -c, and the contact. handle up to about 10 amps The larger type. Ar DC, le especally ircommended foe high-grade precision work. It makes sia Ideal keying end change -over relay and the bakelite inaulation ean he relied upon to withstand 2500 Volts between the coronets end earth. Normal cod colleges are from fr to 48 d -o. and the silver contents will handle up lo 10 empe Type AF -AC IS exactly similar In appearance but can be fitted with t ere* 191" ti:ee IFERROTUNE UNIT A NEW Fecontne foundation kit 1. tctleaeed almost umnerhately by Kingsley Radio Pty.. Ltd. Designated an type Kiel It le Intended primer -11v for use in 0-4 -valve mantel revels ers, The company flac /Weedy released a auger,nd circuit diagram for nee with thte kit, empiemll a 2J.-0 eon - eerier EEO, 5 IF amplifier and detector, EL3-NG output valve and 502-G rectlfier, Combnatton of the Furon. tune principle and rho particular valve line-up should mob, bra very pact and eeneinve receiver. Provided no unforeeen held -lies occur, lope KFT8 foundation kits should be available on the market about Use middle of October. Although the KFTI kil has already. Tolled favor In Ironer retrivera the new KIET3 kit may also be of interest in table model seta. in combination with a larger loudspeaker. Interest else centres In a Perretune sir FOR MANTEL SETS 1 itcattittie" Pi. tor renali receiverl. Designated at KFT-0. the unit in tale for erlasse shortly after this Issue eopeem in Print The circuit suggested by the manufacturers emplop3 a pentode Mentor. with re - nnngriilxt 110m lie plaid SlId The remeinder. ol /he circuit provide,: Inn tive.c. output valve and Stra-Q ecliner, along the general lines 01 nur v ell -known 'Tiny Tlm IT- circuit. Receivers using unt /11111 KFT-3 kite will probebh be dnerlbed in 'Red. 64 Hobbit,. soon ea Temple units er.. available. As intimated Inal month. Kingsley Radio. along other roil manufaetnears. Golan auention to the production of smaller loll units and 1P trenvformers Tillable Inc midget a -r and battery portable receivers. While quantity production of these items IT definitely In 0eht. il IT no early as pet to Intimate an actual ecimme date. coils for 6 to 240 veils a -c. TillaLallr able In two, three or tout poles. either Male or double throw. 'Type Ald:PEI. net Illustrated. te somewhat shadier in apreeranee In the A.P.12C but hen a mercury switch mounted on the armature bd. Cella can be aimmtl for six to 240 tuns a -c or Mr ale II 12 Vallo Il -e Mercury ma retinue are loan Ulcer In 15 All lite above relays me available' with steatite ineuluttun. For special purptece. Interest mill at titre in lite Inert:tub 11111e Mlay melt eh a Illuelmled. Totally enclosed in a crackle finish box, it exhibits excellent work- - tunnel and can be relied upon to e Pahl et' lee ov a lens period. TIME DELAY SWITCH Anplleation of the energising voltage tills the arm carrying a mercury sty.. and the mercury slowly nutetem Peal a restriction until IL 'Many rinses the circuit In be twitched. The switchea can be manufactured an give up 4u two utinultts lag in the..inake verlety, and from throe aeconds to three minutes In the -break.' Inn. Coile ale available for either a.c or d -c operation and normal mach current retina la ID 11111, Mercury relay Ivor. 1B Is elmular as oureetior and Anne/ear/cc but gives inelanlaneous make and break action. Ern/lemur If the mercury in gsn-,nge4l Mbar Neeventa dsziloitluni;aertg unde:cnnelitron'eurnich w'ooki'leorturlier other rnrrhseirnt eveitches or time delays. It la Interesting to note in Pesetne that the mercury used in three switches le mined In Auselle. RADIO AND HOBBIES FOR OCTOBER, 1944 PAGE FIFTY-SEVEN

60 Negative Trans -conductance Service OSCILLATOR Coverage 100 Kcs. to 30 Mes. R.F. Output linmodulated or Modulated at 400 cycles. Modulation variable. A.F. Output at 400 cycles. External modulation with Pick-up or Microphone. Erfirient two stage ladder attenuator Process engraved dial, Sin. diameter. A.C. MODEL & A.C. 6 -VOLT VIBRATOR. CARRYING CASE AND OUTSIDE APPEARANCE IDENTICAL WITH VALVE TESTER. Mutual - Conductance valve Tester A.C. Volts, D.C. Volts, 11LA's. Ohms, Megohms, Capacity, Output Volts, Gas test and inter -element shorts, Roller chart supplying all information. MODELS AVAILABLE A.C. I95V to 225V 50 cycles, A.C. 225V to 275V 40 cycles, or both above models fitted with 6 - Volt Vibrator. a..v Qs 4-1..ea *ea - i..,nil..v 111/f1 -am 1A71f en steif JL(,Zl MUM (,LLd G ULL! LC7 LLl L45 J.J' (i udv j.rr r 6Gr vv vvvvr v RADAMETA GUILDFORD, N.B.W. 'PHONE: UB1438 DISTRIBUTORS: N.S.W.: Martin de Launay Pty., Ltd. Lawrence & Hanson Elect. Pty., Ltd. Davis Radio Co., Wembley House. Radio Despatch Service, Wembley House. VICTORIA: Lawrence & Hanson Elect. Pty., Ltd. QUEENSLAND: Lawrence & Hanson Elect. Pty., Lfd. Mitchard Radio Co., Albion Road, Albion, Brisbane. STH. AUSTRALIA: Gerard & TASMANIA: Goodman Ltd. Lawrence & Hanson Elect. Pty., Ltd. E. L. LeRossignol Pty., Ltd. W. & G. Genders Pty., Ltd. PAGE FIFTY-EIGHT RADIO AND HOBBIES FOR OCTOBER, 1946

61 NEW BATTERIES FEATURE "PLUG-IN" Positive contact, simplicity of installation and elimination of wrong connections are obvious advantages of the new "plugin" Eveready batteries. Heavy duty 45 and 1.5 volt' units are illustrated co this page. 1,1e 2711-P la equivalent to the tainventional -superayne and Is designed tar heavy current tervice and long life. The 770-P is fitted with a three -plu ourlet socket giving -mnus," -plus 224" and "plus 45" volts. The tourney Illustrated vo the right, type X250 -P, is e heavy-duty 1.5 volt radio "A" halm, generally Almiler Ti Klee and appearance to the 770-P high tension unit. The X250 -P la fitted with a Low -pin mulct. socket. The Mini -mat portable Ltee balker pictured in these raison last month. wan actually en ca., sample, end standard r auction baiterlot nf this type have a new nod armtetive denismed carton. Designaled es le - 482, the,volt idim-max In to be - needed an Mandan, equipnlenl for new portables, or et lenol those rerplirin a 90 -volt high tontine supply. Production of Hie prewar type Of battery will ronthme and will there lore be available for prewar portabl, designed fur thin type or battery. The rampant, pulley enelnas adoption of the..plug-in" framer Or ell new equipment end hoe union, conversion or existing receivers co 01 low the sxclusive use of plier -la hot - mites in doe enorse. CRYSTAL SET truntinurd (rein Page 501 pedanee, we, impedance Amoy type phones are far from Ideal for lit purpose. Connect the set up, plug in phones and nee if you can tune in elation. Immediately you heer signal, lune lt tu the loudest palm, and My egjlesting the crystal. The tapping punitions suggesten allier were found by experiment to lic the most eft,...e. in our came, but I. additional tnpi..mga on 'she coil ere 'here to allow for ütfier..rcumslances,311 ions of the treeing' will make retuning necessary epcil time, hot you will soon note the effect Crenerally spoeking, the higher the tappings are on the coll. the louder will be the signal, end the poorer the solectivity. It In simply matter of moving them about until you get the beet overall restate hum the stati. io If your tuning condenser Is not the olio.0005 mfd. capacitance, you nil, find that the set WM not Hine the lacet ai the low frequency end of the dial, particularly If the tannings art well down toward hie earthed end of the call. In this event. add MIMI, to turns to the lop of die winchnx, making OD turns Ill all. Well, that's the story of our Metal net. simple, straightiorword, but notertheleee, quite efficient. 01 On the left is Ihe ben Mee high tension heifer,, in Us ailment.. grey. red and blue,eskel. The is voll A battery, standing on end et the kill 7, very miler in size and appearance. The 170,e etels for Ig/s and the 25n.ln 1st 25/4. ENGINEERING OPPORTUNITIES THE AUSTRALIAN TECHNICAL SCHOOLS, Assembly Hall, Jamieson Street, Sydney, h trained 2.1(11'1,S -since 1923-by Corraypandeoroca i to Eayi ',oaring loi b fret, rat oli MARKED SUCCESS. lt ',oaten/ rie bore louden's from ell troika of life, Farm, Station, 1000,001. Frorteries. Wert...Ann.% Mining. Engineering, road the 'ti/ill ICES, toll i'tteettitg on rat olo. areir dournes from all ports of 19,3r -die, oval E13.SE AS. CORRESPONDENCE COU RSES- Diesel Engineering Motor Car Engineering Workshop Practice Steam Engine Driving Building Construction Many successful correspondence :students have written and thanked us for wbal. we had done fro lbem. Here ara a txu. extr., Iron, ir letters, eteme r etenotted Sergio sowseer e FILL IN AND POST COUPON FOR?AL FREE 727,, BOOKLET OC drciyi 1 Munk 9 'n.'.;= nu. RADIO AND HOIIIIES FOR OCTOBER 1946 PAGE FIFTY-NINE

62 CO ACE FO -AS, ENIE\rTS CHANGE ' OF-VOL'TAGE -ONLY 0:55%' FROM No -LOAD To FULL -LOAD AA ANY testing processes require constant voltage v 1 to be applied to valves or other equipment during +he time that the test is in progress. It is useless to have instruments correct within I% or less if the voltage is going to vary while the currmt or other feature k being read. valve for this purpose owing to its high current capability (72 ma. per valve maximum) and its high amplification factor. This is only one of many applications in which Radiotron type,807 may he used with every satisfaction. This is particularly important in the testing of radio valves in which some of the characteristics ors criiir.ally dependent upon the applied voltages. Ar example of this is the Characteristic Tester recently constructed in the Laboratory of Amalgamated Wire-. less Valve Co. Ply. Ltd.. t Ashfield. This equipment is used for the checking of a percentage of all valves manufactured each day, to see that the accuracy òl the factory testing is maintained, and to carry out other tests not normally applied lo the whole produc +ion owing to their complexity. The equipment uses an electronic voltage regulator or 'the plate, screen and grid supply voltages. The input is from the 240 volt A.C. mains, the output is variable in voltage from 0eto 300 volts with a maximum current of 200 ma. With the maximum output voltage, the percentage voltage drop is only 0.55% for a change of load from 0 to 200 ma. The' equipment uses Radiotrcn type 807 valves, four..of.'+hicicarry the current of 200 ma. between them, The 807 is probdliy the most satisfactory type of MADE IN AUSTRALIA Advertisement of Amalgamated Wlralesf Yalve Company Ply. Ltd, PAGE SIXTY RADIO AND HOBBIES FOR OCTOBER, 1946

63 . Span A POST4VAR BRITISH TRANSPORT The Bristol Type 170 is designed to meet two of the most important requirements of air transport; the air carriage of all classes of cargo and the provision of cheap, comfortable and reliable passenger carriage. 'TYPE 170 is a twin-engined aircraft of essentially utilituriun design and of Bristol standard all -metal construction-fully proved hi' Bristol aircraft during six years _r...,._o,,r1 bnvitto disnnsable loads of 11,9501b. (5420 Kgs.) in its freighter version and 97001b..(4400 Kgs.) in the passenger, or Wayfarer version. It is a high wing mcnoplane with fixed undercarriage to render it. es- pecially suitable for air transport in remote areas where prepared runway's [flay not he available. Ease of maintenance, low operating costs and sturdiness of construction arc features of thé design. cylinder radial air-cooled sleeve -valve engines of 1675 bhp each. Cruising speed. A wide range of cruising speed from 140 mph (225 Km., n.+ to 183 mph.290 available on a power output of from IV:. vu u. vi LOn.. w }j#"' Take-off and landing. At fully laden weight the aircraft clears a 501í: 1'15 nr.) barrier in under 700 yards '640 in. The ground run is about 350 yards (320 nr.). Landing distance over a 50ft. (15 m.) barrier Ls 650 yards (595 m.). Climb. The rate of climb is i1coft.! mia (335 m. mina at sea -level, 750ft./ min. (228 m. min,), at 10, (3050 Payload and range. Still. air range cruising at. 180 mph (290 Km..'h.) with payload of 4 -tons (4060 Kg.) of cargo is 700 miles Km.) : 600. miles (9(i5 Km.) with 32 passengers and their bagg5ge Single engine performance. The OPERATING It has a low wing leading -261b., sq ft. at 30,5001b. (127 Kgs./sq.m. at Kgs.)-and is able, therefore, to,open. ate from small airfields. Power is pro- ample reserve of power. ensures adevided by two Bristol Hercules 14 - quate single -engine performance. the rate of climb on one engine being 280[t.í min. 185 m. min.) at sea level. Operating costs, estimated on a conservative basis and on annual utilisation of 2000 hours, 300 miles 1482 Nail.) still air range with 60":. reserve of fuel, are:-caoacity load 78 nenre uer ran. mile (4.8Cd per 1000 Kgs./Km.) and 1.1 pence per passenger -seat mile 4.70d per passenger seat Km.) equivalent to 12.0 pence per ton -mile (7.37d per' 1000 Kgs./Km.) and 1.7 pence per passenger mile (1.05d per passenger Kind with a 65% load factor. LEADING DIMENSIONS, &c. 98ft. (30 m.). Overall length, 68ft. 4in. X21 m,), Height over fin, 21ft. Bin. (6 m. 60). Main hold, 215 sq. ft. (19.97 sq. m.), 2020 cu. ft cu. ìn.,. Main cabin, 31ft. 8in. (9.65 m.) lcng. by Eft. 9in. wide m.), 8ft.: Oin. '.2:44 ni.) 24in. 10 in. 61). above fluor. Wing loading, 261b.'sq. ft. (127 Kg,/sq: m.). Power loading at take-oft lo.91b. bhp Kg.%bnp,). RADIO AND HOBBIES FOR OCTOBER, 1946 PAGE SIXTY-ONE

64 Mi0-al. I I I In this article ere glean many 1 eg detail. of rocket projectile. teed in 1h. bit woe by both to Get mans end the Allied laut. Soma hitherto unavailable facts ens included. 1Q ground-w-ae rotten. deemed ht Breit were ti compble COMM.. to three palued for Zile defence of the Reich. The BMA Z-baterlef. which l.4 roe. Ito.J OPERATION»e4e The pmlecdks hiring been nettled. Ile crew took up their ;ultimo. oh. Deadened by ITrlerwr Wagner, of Olt tech.we of Um p4uoru. The J I d. &Me000leeWIg 1111g. ll their Aral Ierg.aeale demonstration direction end ele- In 1047 and were key weapons in the vation t, the defence system evolved to combat to firer then de- G.ern hewer rven.+i /wrinmy yl.w-bOmb.' 'ere to emence of pnmed U4 firing. Impitlty. They eom prted W npb lever. and the rotational boat platform on wing.. elk. Wald sere Reported two edluei.ble Mooch- slresk sunny, w- ï n.te..rr kre O.mr ing fih& n h prober e n eye, h am climbing tied by tewe r of. loader d high as =ODTb leer. to reach thee ob- ewi stye jective. The oper- tetwecb+w THE Z -BATTERIES ub» were pro- W l40o00a tected agalnat The hemekeb. which were &pored- netsne end bust Oahe. ree mauty Oft. law and On. in dlem.n«. by steel aide burned ante -formed cbrdna, and sere Mete, which Reed eketrnnlly. A Acne edetu4 p eumlpred U. nee. aecuml. and lour cover Item he ample guide One sets fitted at the mends WD ollf... as they *sorter 21. aped away from ie.r Ile rout oboe. Men their lie Re-... D..M. loading me gen- 1 Set.epr eralay o nutter âee. «r.i ë.!.t r i of minute. N rem Au,/AwJ- J:ti e lee. tightly le4. Fig. 7-Peluslia.l dio0ee shooing Ike Islamel Although t 1Z227."-`" er of de Rl.ialaktr R.I. tendedyt:..e..:11 ). lareletetrains de tw.rw. Ieya1W 41eJkt1 hod provision wu to hive been homed to US target ajm. Iwr.lnl' preen. loe,did-die saannt ground- by mho. The Genu.Nconsidered e r... the ootvney of the mette t0 be such. In ull.ple o env With ee that one Allied boner molld ere plod,,., 10 a al.. they encountered the mo: el with a rer4kle -mheneldor bloat end ted sl, Iann which err l'ad 1,001: jet.. Als anele, tlama 1.. AV :endue....'ig. 7.-Th. "Leeni'melee. Pio. awe be /M P Deeld..nat Dep.0sal of the.in.lor el Sepal,. PAGE SIXTY-TWO RADIO rmlewlnw more than coldlle reckem In wan obvious duet explosive me - e nta able to rems 10 e0.000f1 per - imps roture. mate be ureded end lammed quickly. Il Ale deromund me MM. Un 114 truths, Rhineland mewl Wets to be checked betun Oerm.n Induaey Lennie au IrnWable ruin. To the end the production of Mt. dl.unet queen W delen.lve weapons em»l In (land, ae b Uuwr.i high periormellce Jet Arid.ockel-.o;elled fighters..1» elr-m-e4 roanne.iron(.. and let anundrl rocket meek. All lied en Imposant plate b an kmfe eele de nce eyelet. to pro.. le ol. Rhineland. end there 1111e e doubt Ws. bed It been panble for the Romans ro brine ue plea oe fruition de pegs oi ivory earl W lek and a very dltletenl auty. As Il mu tus arneme mitt very Inmmpiele et Me Un. W U4 bdlatwe. THE SCHMETTERLING ' been deatroyed by every one they re - leered. It was obeluudy to key upon of the ethem. ed, u men. u nnuft. piloted or otherwise. emerged bon the tnunto n delenauon -Ye.' II. Uneet ed. detelonmelt eu an Al Prup7, led ei the Ilan of U. defeat the weapon GERMAN PROBLEM net s reedy for gnullre w prodttetkll. T. Clemens. Wewrerr. found Se The 8rhmetterling appeared as turn simple nolution. Actually. heirs roll and -.row.eroplae. It eln- Pee more difficult. problem oven to bweed a long cylindrical herbes. and le o high Dying Pollee.ontg a ohortapen slog attached eppruituner hwh krforluence bouluort metric, half -.ay Blom Its lelwln. A which sere prated Iuta»nice et an emcllurn. sablber runt too fitted at loth' slo0e of We Allied Munte.,/ plan. Ise tall -end. Germany% dolen» Newly demanded The fuselage was stumbled In see - AND HONKS FOR OCTOBER. Ilk

65 niuer3ity... FOR MAXIMUM PERFORMANTE 77 AT AN ECONOMICAL PRICE! MODEL MVÂ MULTIMETER PRICE - COMPLETE IN CARRYING CASE 11 '2 '0 Plus 124% Safes Tax Ranges 10, 50, 250, 1000 Volts DC, AC, and output at a sensitivity of 1,000 ohms per volt. I, 10, 50, 250 milliu, It/a 1.lV V IVV, 1, V 1VV,VVV 011U I IIIVIjVfllll II VW internal batteries. Write to your nearest "University" distributor for illustrated brochures of this Multimeter and other "University" instruments. "University" Earthing Resistance Tester is much sought after by maintenance electricians, and is typical of "University" industrial testing equipment. "University" Supertester is an extremely versatile Valve and Circuit Tester featuring an extraordinary valve and condenser roller test chart. RADIO EQUIPMENT Pty. Ltd.,DISTRIBUTED BY: 375 KENT STREET, SYDNEY, N.S.W. Telephones: M639I.2. Telegrams: "Raquip," Sydney, N.S.W.: All leading Distributors. QUEENSLAND: Homecrafts: J. B. Chandler Pty. Ltd.; A. E. Harrold. VICTORIA: Vealls Electrical & Radio Pty. Ltd.; Hartleys Ltd.; Replacement Parts Pty. Ltd. SOUTH AUSTRALIA: Gerard & Goodman Ltd..; Radio Wholesalers Ltd. W. AUSTRALIA: Atkins (W.A.) Ltd. TASMANIA: W. & G. Genders Pty. Ltd. NEW ZEALAND: Allum Electrical Company Ltd. 16/764 RADIO AND HOBBIES FOR OCTOBER, 1946 PAGE SIXTYTHREE

66 I I TUN. each section homing one of the recllunel night and the lateral dis mein component and. with 0510 for elevation. warhead which extended town the Prom note to tall, the Oral stare Pori side of the nano'. is overall eonlwlsed the g main um - Wee was 11IL ilin. A small air. >menu: ptoamdly fuse. rontrni M stream propeller WIZ Mted at aar- meson. unten tolln. radio dlrecure 04rd an power for the eleotrlrnt agar, rocket null.with sa outward mrabm.. Inclined exhmat rentama. und. Nally. In the section dnanly behind the aft ul the tall Oil., o Chary? lof Warhead were eompreued alto tala and radio. The second ana MOU Nnlparlmenn Inukh and the eollteltied iter -mens Mmpehant seta n1 homed he control our and Muid rocket motors. The latter tomb W Other two or two 100-T.'e hi - full units. emphonma 9e per teel mette arid with 57 per rent. m-ayodole plus 49 per rent. trethylamuw. The mou se w, dry-iltel rakrt w. l: Cached ab ove Ille fuselage the oilier below. 711eie rendered highs Initial acceleration. and when Muir propel - ante became exnuated. within about four mooch they utonatictly d.- enhgaaad and dropped ares. 'nu prdurtbn Model bad rung apam of OR. 91n. and tell aeon of yii. 91n. The all -up weight was 07m0.. which wu redoned to SIlO alter the ATO racket had been ;entwined. The prrlorm,me Aluns Welt ta themselves. oohing. b ototi : ranee. 9u mow. nth a ma imam speed ut 090 nubs per loot. THE RHEINTOCHTER RI Another ntereseag am,:n.l.litas development wu Ire- ela:c',x.ztr RI. wham woe dempud by N::r.:unr: oil Rorer A innalra Iw'o-.tom aelvlrlilg nlnlnµ II low. r - tended to be erected to its :n two naio, plots. o on bomber and the Miter we r. p jro. lote. eoreated by a around Te t so RI hod a total o length tel :eft. Imlhn. of Mull. approklmalely mai ailed compr:.n: "le usenetusenetal -tamier- oar:...: Ten 00 uele immured ill'. lui. IIIu On. te Men I. she large Onl havmy., t..1 eh Yo. whirl, an r, 0, -. : jri :rod Ins erki e l:.r Mntrod::. ebhn ove < :r :r i ay. tir n..,.:.tdeomtum Ani ferldl- high euphnlre. Aso tlaeaanmeu met. aunes The nul Allo und need tamm- elum the grate nd eou- churl, resembled the vo. It was. of alnuted far A heavy moue. smeller. laving length of Vote n embodied Nft. and manmom diameter of Ift.. In the lotus, el oho tek me on but ne rt elite appeared marmme the mom n AA racket IN lout laded wriglh It is o t. a nu too Me region of 91 ans note that the There were olio lour Am...open range trolling n:p*.i:trio ate M aubll- Mulched about tlallnay between vera otre Ile :.inked ore smrrty ai nota and mall ad. as with the V- a the Caw''i: Anal aerofoil and nand.. rotel lour alt -tire m Ive with con. Out wen Out out aquannw 1:li. km!.aea narrowing team ICeodnahi em Page les cm<.. Am. we.e tww., A,e..r-- Ille. at the root to 9.91n. at the Up The MntroWr du were aimons tapered from a moan thlclmem of ant to tin. at the Up This mnaustits fulbw closely the theory of th. ranger roper -sonic aerofoil. in which It will be recalled. the section p knife -111e Nadtna rite am the nlatmnat Mbknees or:l aft. I1 MN type of oeeth. that :.nt :ee gnotell penetration st mania :i.: e rital t11111 with of sound. the te reason amprovlallay Run ra away Dom the a: the mid-metier.o to um tot tnlhuo 40e rarefaction. The Rheminhlrr il': -n froth n inouned r. Mat Os o p. a<ao.::y Ware, a.: -:I h much gave duration et full Most Sure -homer- WJna i.. of 20.audt. Tioa Incidentally. was prolalamn. This actor. < W.,1,, also the Dloprllenl el the X.4. another fuel at MI applwalmw:< t.. not to Melt- rocket orvlcta. kilometres. whereupo-,. : mahcally Jettisoned Ai :al.a WING CONSTRUCTION âawj turc. the main portion el :he :made n oua Iuelkr caler. undo«lu The method of pine eotulnklmn n unique nn that the structure no, roue. merer= mdrwndem lower w lare a run - defeet mum speed 01 appronately al IWo Mal u ampute unll me/idhe miles the men spur, trailing edge and si Fl" C.-IM Waw.laO. ter hour', TIdI net.ddia nutet rite. There were alto diagonal am tome m Wee of Replie Its niajmte appeuntaw. Me webs Interlacing :ace role und m wbnar IFt Inns 1 kt in eompunla. w omen. had an olutive UUIa 0l only It employed dry -fuel member entr::e. d from Ute Roulette in both angler-digneoldlallnte-out through the Io Innermost na an the T. -bowler- unit wax aft. 1011n In all rtlon 10 Improve the ravie the mue whit atoms The atrurlelr env long and =in. lit diameter. Iule R9 cement had liquid cowered Win sthän Ilahtail.,: vato a -foi unit powerful dry -fuel racket milt In and Mullen oil' ;Nehed the main Inhale. at.: winch at: oued from Me rear Int Mme Item..e tips for ell.:. nrorin semen nestles. Pour mu we THE WASSERFALL control. iez need. having total span of 7ft. Tee loll I. Mau 31n., a 211. elln. root chord ana lip An Rnlnot Al the A -I A -le Proered In Ilio n nue. Chord of l91n. PejectileMrOgramme at 40 m execs S tmlaa Mow rar MfdennelrMt M leer/nee, Cunw Dosoowdn Cwwnmew 1r-LiNI Je" Net too exn:ay el ennsi eeoea. Out ee u1 aid mata le <end<. Ita Ammon Yal.' nacre 'alut. Moot 11XI7.fOa1 MDIO AND NOabas POU OC101101, 1040

67 II i -TWO RECENT =_ Belt THE Two interesting machines developed by the famous de Havilland firm are the Hornet, claimed to be the world's fastest propeller -driven craft, and the Swallow, the new tail -less jet plane., NICKNAMED the Whirling Boom- and the Bret Swallow-a. Standard erang," the de Havilland 103 Vampire fuselage with the new type of Swallow tapper eight), which is a swept -back wing-first flew in May. Jet luttivoav Trials proved successful and an Slays de sign, appeseed tope other has been placed by the British 1 re vu which Is the first n tall-less]et airerelt Government with the de Havilland to have flown. litai fora let -propelled passenger liner The wings of the Swallow are.wept on the s e general lines. The probed et an angle of 13 deg. ".levain" jectedpassenger plane will r an or combined elevator-ellerbns, are used ellnp weight o e than 9s nuns 1y the outer panels of the wings to and will, it ishoped, terry passengers provide lateral stability and height. he Atlantic at errda at ap to a.cross control, Tall, angular fin and rudder 000 miles an hour. Sweep bark sharp angle from the of the besiege diree- THÇ HORNET Ronal control. SWALLOW The Swallow la built up from de Havilland Vampire laselage end It. Goblin turbo -let engine. develops the equivalent of 12,000 horsepower. Air Intakes are located In the leading edge of each of the thickened wing roots, as in the Vampire. The air is ducted book and inwards to Che plot's which s located Glanda the pilot's cockpit. i The new plane is Intended for speedo of 675 miles to hour or more. The prqjett was begun last October The other de Hnvllland machine, the Hornet, has spend of well over 470 miles en hour. 'lyds twto-engleaed tighter is acknowledged to he the stest propellor -driven tlircreft. and with the emphasis no w n lets for super -cast machines als unlikely that the Hornet's speed will be exceeded by propeller craft. It has been an - flounced that RAP Fighter Command wilt be equipped exclusively with let - propelled planes. The Honret is virtually a sealed - down of the famous Melgelte, which won emcees In a number of roles in World War II. As euch, the machine has close Interest for. Aueteslikne, eince a the' Mosquito Itself was a "big brother" of the Comet speelally built for the London-Melbour'tle Air Race 12 yews ago. With a wingspan of 46fí. -9[t. less than the Mosquito --rte Hornet le teeter end.'eleaner" ht design, It was designed as a. single -seat, long-range dot fighter. The Hornet was originally developed for operating fl nst Japan, but the Japan ender came before it could le brought Into operational use.. From the alert of the design week. the Hornet planned built and teat -flown exactlyin 12 months. Powered by Rolle -Royce o Merlle enclose of Hornet 'has horsepower each, the operatlonnl ceiling of 15,0000. It can miry aimed a ton of bombe or rockets. Range le Just under 3000 The Harriet lima alstinction at being the first twin- Jalned Beltfeh warplane to operate 1. an aircraft carrier. paolo. AND HOBBIES FOR OC(OeSR, 1941i mee SIXTY -Fiel

68 I agareffe rest is THE placed within the ashtray so that the agareffe or ash cannot fall on to the fable A snuffer Is included in which a cigarette be slipped to put if out. cen The trey is made from 16 - gauge copper, brass or other sw+able metal. A piece 51n. by 541n Is cut, and the corners rounded. The edges ere then ben+ as indicated by dotted Imes to form the fray. ASH TRAY ASSEMBLED r -er 5" I I DETAILS I I I o FOR TRAY I I OF BLANK I54 I I I CLIP CORNERS I I I I ANOTHER strip of brass 1,=m wide and 9in. long Is ben+ to shape as shown in sketch fo form the rest for the cigarettes snuffer end match box holder. The strip should be cut with ample length as any surplus is easily cut off The rest is fastened to the fray by drilling holes end riveting solder ing, or fixing with small machmo screws. 4- S NII F P ER BLANK BENT / TO THIS SN APE QV pf,iil igs ',91-AH KO 9'; RAGE sixtyslx RADIO AND HOBBIES FOR OCTOBER, 1946

69 A HIGH CHAIR FOR THE NURSERY CORNERSBACK ROUNDED LEGs.2x4 12w 12 PLY BASE T4çsT:iaap SIDES I,t 2 y r TRAY iia7 SCREW r ARM RESTS. -\ MI/ Foot Resr RACKET 2 RE6)UIRED ASTENING LEGS AND SEAT...4`\ SCREW E,3<4 JOINT" LEGS. HALVED GLUE AND NAIL - 1> II EAT I3 a 13' Although e high chair is cheap enou can be made fo serve ifs purpose STURDY con ve tien flea been e of the male sens m the design se the timber oued throughput Is tarry heavy, say gin. thick. Any general cabinet limbes will de. Dade and ends being utilised, or It may he bought new. Rudweode sew not suitable. Reference le the sketch will shove that two ses of cross pieces am req,eted, one to shut the lees. and the other Joined to the legs es well al to the underneath of the seat. Com- te this part of chair eat.the inter leg pieces are 241n. x 21e. x 2:in., and two of these are required. MAKING CROSS PIECES Set them up en edge and eroased at It degrees, then in the middle saw and chisel a halted joint. This Makes cross like 'a tructne with lour equal rhe top and bottom edam will be level. The 24in. length Is suggested to mate ahon'eneca for cutting or at the correct eagles when fitting In position. The enes for der the seat needs two pieces each 161e. x gin. x Bin. They are halved gh fo buy, one constructed at home for far looyer time than is usual. on the Rat to Joint them he the middle. DO not glue these pierre together yet. Pour legs each Plia. x Zn. x fin. are requires. These need to he dressed up smoothly. Do not bother to true pp the ends. Having made the cross ieces sad the four legs set out a full she elevation of she chelr frame Make this as though you were loot- ing from corner to conger onr e ht much the same way a le shownin the sketch. THE LEGS Iu this view the legs are 241n. apart at the bottom and lain. apart at the top. This allows ample spread, and there Is so thence of the child up- Ly!e 5-cteur setting the chair despite balsterous iehariu. As ass said set out the full mice diagram. to vertical centre line will be ltelpfui here in getting the angles correct,. On the diagram irefully mark the position of the cross pieces. Now by laying these one at a time on the drauing the ne angle of the end cut can. be rett marked on the timber. There era ight ends to he marked 1n this fashion. Cut the timber where Indicated, and glue and nail the cross elm. together. Then nail the legs to the s plee s he a similar manner end themanion end as have eeen accurately ill e made this part the frame be true and.sinr Try to keep the top piece legs. level with me Clad of the legs. but any excess be cleaned off, Also keep the bottom piece twowothree three I d from the pretends level. Put It b1ty for the glue to aee. THE SEAT The seat Will probably present m'oblem, ro If a piece of timber. Dig square and lin. thick la nef pee. LCeai)awei ea Page Sty RADIO AND HOBBIES FOR OCTOBER PAGE SIXTY.SEVEH

70 r - '-BASE 1 I ' k' MOLES %UBus BRASS ;atobing ear s%'',e,'5 5,g.9 bar e4a 304,.. ',YON) o e" i2a ayb CORE OR WOOD DISCS IN ENDS OF DOSES ha diagrams giro clear i go of fh....emotional work farelvd is making eh. Romomb.r to allow m.tala work to coal afar g holing befere you tad for p eh. Tim will be Agile lo..r is eieah who. It is yawn. If you haven't g lading wh..l, you. local g rag. man might help you eat. The barn ale cut to deb from 1-g1ee. sheet steel. Fig. y gives the length of theme and also the space between the mounting holes, which was found beet ln the case of the original model. The act point at which these holes should he drilled tram the end or the her la found by the ethod shown and deeeelbea In Fig. 3. After drilling, the holes are used as a Snide in locating the a -lain. holes to he drilled in line In the top of the tubes. The bars are toned by y grindlog away metal tram the underside, a little bit at a time, as in Fig. B. CHECK AGAINST PIANO As this is quite a delicate task. each ter d be checked frequently With a piano or other musical instrument known to be in tune_ When tor the pitch of the bars may be from seer, onehalf to three notes higher than they will be after tuning them. In the final stages of the grinding. cool the metal to mom temperature before testing, e You Will ling that ttfe pitch of the bars by slightly lowered when the metal to warm. The bon mat above the tube openings on stove belle fitted with short lengths of tubber tubing placed N the arrangement Imt shown in Fig. 1. and ere d a -type Notice that a little space should be allowed between the her and the rubber washer under the out. Fleetly, the tube ends are closed with cork or wood Macs. While the mallet may be bought, It can be made as detailed In Fig. It by glueing a 1ln dowel In a lie Wuud bell and then Dmeiing rr gnh rubber tape and heavy cloth PLUGS.. k Thum project ii somewhat more elaborate than simple woodwork but within the Scope of the average workshop, It has a soft tone and will be welcome addition to your house furnishings COSTINO little So make, the dinner chime ehtwh in Fig. l eat be finished in chrome and mounted en a maple, walnut, orimply a plywood Asa allve, she tubes and bars may be enamelled or they may be polished lord protected with cicarnlacquer. The tubeo are cut to length from standard thin -well, brats hush pope, l 341 te. i diameter, which tin be pur- chasedt from a plumber. Fig. B give. the inside length of each tube between the cork cape. To this dimension the thlckneea of the cork plug. used, Pig, u. E be added to obtain the ever -ell length. if you Wish to add the intervening totes Iorming a lull octave, the wale Ie Flg. to Is used to determine the length of the extra tubes and bare. From Figs. 2, 4, and B you can see horn the base is made. The tubes are ettslied In conc.ye notehee with flathead stove belts. as in, B. PAGE SIXly.EIGHT RADIO AND HOBBIES FOR OCTOBER, ITN

71 ROCKET PROJECTILES OF THE WAR (continued from Page Bal.!reliable tall surfaces were Owed et rlonan0e to the rear well ara Its beet liermarn counmovable gphite terpart. on Eire Jet. fi In And experle es The Medan of these ground -lo -ale, err -to-air. ale -ta-chip weapene We. ntal model., these control aerofoils prit Into the hands eta Government Were operated by a Siemens IC.I2 auto- retebliahment known as the Karel Airinatle Avro-pflol. craft Modification Unit's Pllolleli a.c Propul Imo of the Wascrfall was by Dlvtalon. the action of vleol and Miele acid. which fed into a dingle combustion WIDE SCOPE chamber moon fed Jn Are tall. The entire development was culled (eta than 50 of these...sum were fired in free -flight, and of these poly 12 were successful Needless to fray they were nor used In action. A Kale model of the missile was on view at the British Museum, South Keoaingron, during the "Exhibition of German Aeronantloal Developments.' held there earlier this year. The model in question, which was stated to be a. quarter the size of the actual weapon, had apparently been hurriedly disposed of In the local pond at Nordhausen at the tome of the surrender. loon, found when the s later investigated by the Allie,, we and still bore traces of dried mud on r s green painted surface. U.S. GUIDED MISSILES It is perhaps not widely known In this co untry that set e ill type. of guided ssíles produced in Americamr The (majority of these were original designs, and at least war proved to be superior to general out by thin Dlvlabn, Including the re - arch and testing of rocket propul- Iote001ltteut and turbo -Jet power plante, radio -control, target - seeking and telemeterìng devices. A n umber of Che missiles Incorporated television "w which enabled the controller o the ground on in the parent raft to s the Magnes r his charge on a television semen r and to guide it Into the Linnet r by radio -control. The Germans were definitely far behind the Americans in matters of radio -control and tar - king, though they were obviously more advanced in rocket technique. A particularly intereming rochet moellejoe wee "Idole Joe" IF*. at, a olio -gulled anti-aircraft weapon which could be lannohed either from the surface or the air. It Wee originally designed JO combat UmJanette. Japae "Hake" suicide plane, and was powered by Mur main rocket marges and one i. thrust Jato naming Doit. DIAGRAMS OF DINNER -CHIME IA CHILD'S HIGH -CHAIR( (Continued from Page fig] earable. it will have ro be jointed o lse built up of several layers of ply. After cleaning up the faces and edges und the clonera of say shout lin. radius. Relish on with sandpaper. The chair bark la a similar piece nl timber about notre, alto the two Lop corners see ended i much the sanie 'melon au the seat. Or If desired It can be glveu a fancy shape along Sie top edge. ARM RESTS Two Costs loin. emuue by Olin. lung are needed to support the arm tots. Thee may be honied Into the mat and armmats II desired. In fact 1t la better Co do so as 1t makes a far stronger Job. The arras rests are foin. gin. x Ira. Three f the corners rounded and e eowed pieece os am eut out of each inside edge. A glance at the sketch will gill e general Idea of this. When asmbled the curved inside edges allow ample free movement for the child. Tile fl rest'. e checked Into the bock and as this will depend on several factors u le left to each pers discretion to set ir Oat. Make re that the top of the arm rests a e parallel to the top of the neat. When all of there unmet, the seat, the back, the arm resta and the posta have been planed.10poth, check the Joints. and If all le well. glue and nail them together. Pour hole. toilet now be drilled ln the tunas piece that le to go under Ike t C tent k the holm on the underside and the seat can then be screwed in poaltion. THE FOOT REST ui a5oawpascr Final details of the dinner chime showing how fie metal strips are tuned and their length estimated. tole font rest needs two brackets of lim material. und another piece x diin. x lin, There are come trick for therequired brnets, ken so tile be method le o set them out and thon cut them end nt them by trial and e When flattened that all is correctr slue and nail the brackets position and fasten the foot piece acmes of these. The distance from the top of the seat to tilla Amulet be,hoot Bier. The tray Is made of thick ply and to the dimensions shown In the drawing. Cut out the n with a fret saw and smooth hp with a ale. The rail attached to three elder is made of strips of lin. wood, glued and nailed in place. All edges and corners are then ea refully rounded, sand -papered and then finished on. Matey high chairs have a hinged tray, but experience has proved fhb idea to have many disadvantages Place Me e chair on a flat aurface. my a table top, and pack under the until the seat is level. Theo lay your pencil flat on top efa box small block of Wop d and mart around the four edges of each lee. If the legs are euton on Elul line they will alt snugly on the floor. RADIO AND HOBBIES FOR OCTOBER, 1946 PAGE SIXTY.NIIM

72 THE HAM BANDS rotentó w e (Cnntmued han Page s l lætrâ çy23300 h%n` zolii, One often wonders whether the aver- Don 1734, GPO, Sydney: CRIME!. Victoria--See- YVIAK, CABOT, 10003K. age eretes the amount. 5', Bas 2011W, GPO. Afelbuue CX4CZ, HH3L, VQ0GW, OA3HA, sll of ntrlirinnla. workclwit by these chaps, in their Queensland --secretary, Bun asta. ltr dc, l)io, a ual DX. GPI I, intemste. With a quickly growing in- Brisbane,, South Australis-.Heeretüil t VIC2AHM, of Wentworth, Is nominstitute, the work e ailed ì colossal Be 1234K, GPO, Adelaide; Wteb n ated us Auetrella'e No. 1 low -power DX and when a subjectsuch t as disposal Australia -- Secretary, 42. Ord -stmt gear has to be desk with, n very Claremont, WA: Taamonie -Secret 12 Thine -street, New Than. hard to nt hi all the jobs. In Melbourne members have to Wok after two other Jobs, 'Amateur Radio" and Federal Heatmore tirs. making the position even ore cal pllcated. Another one of The ntd brigade Bill Zech (VKZACPI. of KAtnm1111t Gordon Cule (VK2DI) resigned from and, while he doesn't doubt lee the position of treasurer, NOW Divi- Radio pmpagallnn bulletins stime VKBHH claim as being the oldest active sion, after doing n valuable O HO' Job for possibilities for 50 me, Contacts ham. he 'would be Ilnterested to see umber of years. ups Pressure of busil0 45 me h'om 1200 in 1500 miles 1912 ran list. His oldest call elan, ness.n geed the resignat nn, and faoatble after XAHQ, dates back before World War t during teurs'm»tr, all ama eur ream must toto second oat address was iii w Annandale. Zealand a will be :.n place occasionally! Licenceó'x was then 12 and r tier tluuk-uul for Au=neilau stations. More than 120 members attended granted by the Navy Oeparnnrnt. His the August meeting of the NOW I..si- more calls have been Vm2WZ. RSGB title. A lecture was delivered by Mr. VK3WZ cant and now VTC2f.CP. Bill Is Th, RSGB Bulletin, old, la, oig'lt M Macdonald an "Transformer la - more unfortunate titer most of ho- of ihal.toddy, respired 1 'lst bin] star,' Main interest centred around lm to blind and amateur radio In, tiny liti,r year and "[Uncle Tan" 's to dtcnoeal"gear end a notice of motion a lot to him. Ho Ruggeaa a rep nwn view tel the 01 years makes Interestht. es lodged to rescind the motion of old-timers to Include Harry 0100'0 reading. The bulletin hue not. tench. '.Nd et titre July meeting m the, VK2CXI, Charlie Macinroun ivk2c9t, Sorwateling of a questionnaire to mem- and Jaok Pike IVK2JP1. Prewar sin. but is being built n Iaaually. They report tire re -twain bers on the subdivision of band s, DX et calls to Ceeehoeluvnklnu stations. Haire Kinnear ryis3knt, handling some at b umber, and area110we diepdsnl gear for tiro WIA s now PI Shorter skip on 20 metes, noticed 50 watts for rr, 0W. AC0YNin Tibe hospital. EVO wish him a speedy re during the month w'iil A1.bm and Itns a yellow ham these nays IAC4ABI, Handling has now been taken Pacific stations prednmbeating at night. the latter using only row power. over by Bob Anderson IVKSWY), VI> The South Ameercans were workable Fifty me open. up oa se col 00en torian division secretary. on and slopped hr tar sloes daring the last few months an For Intending mernbers, the lo1l0oing a of eoings some two or three heurs. contacts statiofrances awl the r ra1 outs Uddle,es of.the Stale e dlvl=ions of the WIA, NSW : 6ecrntary, OLD-TIMERS One at twonights wereremarkably good for world contacts. one teen - "POST WAR ff Thirty-eight countries postwar, 1d4 of Them on 10 metres, with inputs generally about hum watts. Latest nevi countries are VOYUAP and CRUD. Vii1EL at and ZSSCZ at 1010 hums a worked recently on 10 mettes. both telephoningcc acts. V - beams help the signal along..eursbe cen n eft,english n matte, FOUNDATION KIT - Whybuy se emateurlocking kit when a you can get this Kit -Set with the PROFES- r`{4r, SIONAL APPEARANCE. Bakelite Cabinet-Chrome +rimmed, Chassis end Dial a complete Unit. Circuit and Diagram Supplied. Easy to Construct-no previous experience required. YOU CAN BUILD THIS RADIO we Stocks now available et your local Radio Parts Distributor GRAEME PRODUCTS 'PHONE BX1359-G.P.O, BOX 1539, SYDNEY Disl,ibulort:-HOMECRAFTS RTC. LTD., Sydney, Newcastle, Melbourne, Hobs, Brisbane. Homecre!ta. Lawrence 5 Henson Elec. Pty. Ltd., Sydney. /AGE SEVENTY, RADIO AND HOBBIES FOR OCTOBER, l940

73 I Qd SNORT WAVE NOTES BY RAY SIMPSON PEAR RECEPTION ON 13 METRE BAND NEW STATIONS APPEARING A3 predicted some months ago, the 13 metre band has improved greatly of late and siafiors are now heard at excellent strength both in the mornings around 7 o'clock and also at night. The BBC especially provides excellent reception from their many stations and in addition there a e the USA and new Australian stations which c all be easily logged. Keep a watch for any others which may break through while eonditimns are favorable, X0X8 PANAMA TESTS Fine Programme NEW STATIONS REPORTING BY CONTINENTS 1600 VEP'FICATIONS "SUVA WEATHER" VERIFIES THIS MONTH'S NEW STATIONS Call. F,eg. W.L. Loos,. Tlme Head. 0034W Rangoon VLB9 HO%A VLB2 VLB2 VIM WRUA HO%8 Algiers %MTA HOOD Sin9epen WVTD Lime. pe,u 2.10 pm Rangoon, Bu,mc em Shopped..m Vic p ' Panama City, Oily, Paname 3.30 pm Sheppanon, Vic. Midnight Sheppa,tan, Vic. Midnight Mon, Vic m P S Boston. Mna am Paname City. Paname 3.00 pm Algier, Algeria 1.00 em Chine 9.00 pm Penema City. Paname 3.00 pm ingepem. Malawi 7.00 pm Japan 9.30 pm Cincinnell. Ohio, USA pm New Verb N.Y., USA pm Shapparlen. Vic. 2.4S pm Lea Angelaa, Gal.. USA 7.00 am Cincinnati. Ohi, USA am j µ3d10 AND HOBBIES FOR OCTOBER PAGE SEVENTY-ONE

74 1 I :niwyrvw.n400ia'mnaó Hobbyists ul`mtóil.»an`n~:am'ï ItÌell.l.léweaó.ld= n in :úâ n.ni. a r..ma= "1:. iìltl a. I noted eon mn IIi n iuâ.' T,II w r Nore aplva0..nc T e`ipnlwl t faue4 :`ir ï `s.` I.Ewr pai te. lâ ú ' u1ä aur :anré::' 01(000eIaM `RÓK:CIMIN.ewe.4 w' i ` q""j: â nmúnitga Il:l wrtmu`ni al KM1NCn úslwor wuw tan.r. lobed InnajnuriM» ratlumwi - eu.wleu...al "'"'11".7 na M WE DON'T CARE Which Branch Of Radio Interests Yost, Because N.R.C. Gives you Thorough Training In Any Branch. ENROL NOW.. RADIO DEVELOPMENT IN AUSTRALIA ggt.5odoo S.-W. PROGRESS SINCE 1939 n:n y Trt uttnuot.`lioirp.allulpl.l IN.a AI ll b4n1 ii Ttr`etil:eulr.w vw ILn IblN al...11onor we ere Iwven u. b Pori» V:onr Oro. n K Wn.Mr. vnxt. r.i..an a Inlwa.uesabr 1 ryul. W ú^iv v. Nen'ne.rM e. N; i n Iw ante hoe over, Mono ai...la. n`.0 Tn. '. arvlwwytm...owe Iraal bn Iy,Tw:w e bó aim w é n:m.ieae:::im n:rwni"â 4mornlu0..uva mâl:., uo-m Ott enä«mé:i ramo l:bi+!ú Po VLR ]YÌIMM ` nnn.é n.e. i' ole.aat...n. 'ümlu: u.:.» n.. nl1o` nioímnra VLM1 ^M Oro. I unn.un w.. WrËI 3.4n.Sw al.hnhmcl:».inla4ìl±l that worm. lb. nee notte wll.mi %:np;a`a tenorrta.a regeozt 91, Roo ssl:"âdo. rir :IMr nó»waa..lw' FLASHES FROM EVERYWHERE n RITA. loft.yl...; a. CII. I ::ël é7as Iw I `I 61.11`I Ïwan e N nr io»ey +IYa'11.MI tn'4 e; r,2 _ eeei yì romr. Iv RwGín510 nun1 sr. MII' i..oa wl e'tllld M.o.pye Mllrr N PII v In rnjrlall'm. lm lutllln N.e»alml.lon iìúq in..n :: n a I enlwa r Ir 4n ul:n< MTM IniMak:ï t WM..Ón ÓRvi e IiwlMlr.l.úroila` :enr I r K Ime+e;. y'il0p lvr Ì vr &e4 w Personal or Correspondence Courses available in- RADIO ENGINEERING RADIO SERVICING RADIO OPERATING AMATEUR OPERATING AND ALL EXAMINATIONS NATIONAL RADIO COLLEGE ]10 WICKHAM STREET. VALE ET E. 9LD. "'"2: I N rcwuu..ut..o. Ma m..il âïnlota:w. 'p.nlmrrory Roa. T. mu - come. qr. Pl.wll Me ewe w to Wi n. don.öwrvi.n luwr:ola riìi eúmn:ä N.I=. ro m édl nw" uilóm.s» M.uww nn lpo 0 ~ââ. TWÓr erraa. Tn. n.:1 «I a t em.n1:vì. Eat 500N. G.P.O. Phon L1024. wilmnn lur raìlrlat.a slep4rcâ ` nb n T. A a tll. Rli.ï. MI wem.tiue wr m, Tqlal M.naM 7,2"7 PAGE SEVENTY.TWO RADIO AND HOBBIES FOR OCTOEEIL Inv

75 i P `ip<. '-...i BIhÌÓM'i ÌI<a. MK-Pa'Os`<. Itim '. m1e;molmn:umiue mommmyn. OVERSEAS S.W. STATIONS NOW UflIB1E The following stations have actually been heard in this country during the past month and the majority should be audible on a sensitive receiver. All times are Australian Eastern Standard Time. P.ae ENGLAND uu-11y<. H1M. :::: ip. KNOT -110:01c m. O,N P M,Ne oy.-al.y, 41.ezm,mtr Wary Oro n i >éú - v:i`,imm. ewm. G!!-HN<'ilMl.Mr.N e me.- HN LnQÌ)llelf >f JJ.N. arwan aha stanon Y.e N mww' 'iny1 IP Nnayun In.. IL OWo iirm.n Oat 004. e rpri TPú linn o. ekn 1 b INeoW NÿiWni.. ItpY< )ionu. Y e,:e OL ßlic. Nafm. YbmN n p:nu v1.w wuu,.:n m _. +v roaae pó-i::ne 14.84n. 110I01.INI PNÌ-aaY. m a YeYnc n. vor nn, IPi eut u0uo 11<m O M-i»lúÌÌSIm. 6,'wlmt ln moms ie <N mu OM Ìi 'ZOO. 11 Om II PN M10.2iNroiewif)µpl<Oaue m epvp le ' ' vnmv.li p a.»r Nm< m wlu. On nblwao p OevÌlOe Ep<Ol,nl N u r nyle.'.n" 1 V <m'ïmlm9f:.w aem IuNn nn OÌ Nnn OPft1p1e11.10 Y.Mn C.P Y lurl, 0 1 nu Y.Ym. tlnn Im N ml n-1nk, o lvml< 16 Lem boon v.n Ay u. -r,11." Ìb:.f m:c'..l ev e.m inü W m OPÌ.i0r<. YI.MI RNN m 11W ren HeRIN Ì1MN Cel.>1m. _: IUTu OH n1'imlle, Y.1lm Ma be bonduaam ~l'10e- wua *el In Mil au woo lu P Uri onru un 1NNY< Nfn. lnnlmnt m NmP W<lie. urlaa 1iÓoiIn. wln-ii1a"31nyp `v_ìfön NHm C.mH I I. TiaW`YfY OÌÌ HHNOnYMm Ouutl bv.l.1 a w.e I o0u1.ú oo 'm 9m mfe nrì m'm. ;rm. Ylú IaP `_ n ORi11Hi< I.fau. q0 M Mod YI lhruv_hmi. m1mev a Ìf1 pm O'08-Eltla4ueirN'a.' Oo0 H..p1t ccúé:ri--1< sshlâ. IM bna 1. "Nân 4vP-1/TfOP; IIAm. 1N útoé a..oww1._ úoll»»»"m I.Zii-Zui2 'ó1n1.1nv Lmún.w.'â wn OOi170e01ïvL:b' OW. Ma«m IS. M OVD ilrno< 13.4:oAM!m. Ar Op]la.m<Ov RÖflolbc atln ia,mne Oavl= L-OYC. ó11u u W< Nary <Nrn n ImMO.rnm H9^ri,. YNm RPra I. PM mod - be,y WM MIyO CH. < vp.aowu MNtla cr ëlne RCIO Y-u,fpY<DYe1 rh uma eri Com. OOW' I iìne Mul U.'ó. NM. :-NNu Iaa1,i unv rrtl `wuiir <pyomri w -úi«n<'»:pne., ) my vnen._. m e o nlm 0 Ïw PWm Irom otmw umi.y.m...._... n0 H ' f'n sélm. R1 Y. M.T. 02P2741Y0 19 On 1 -son ON Wn.l Wbl br1 : a OM j;aa< )I 1irm. mrou tome m lh OrrmPlrlnamW w[ìolóta. ielìi. Mm :"alm m'io>inn.io ol.i 1 1:1>I N<övëqoi0p,=i 9MIi f1 usl.. Hm<mn. 1w. alr < EUROPE f)fmn ivn. fnen ep,a wi,n'rmlf'jjúì<-' m. poe`w. pmm /10.1-1e1MY<. II On No1.1ée PmOV P nin a.,.1... pp0 n MHe no.l é"`oe Ik :.::...a1n< MOn Sunday Ole lo R(M ir Y W.nu el eep. IITY1. fa.oa WwP10 Nó IINOeoe OOi< Mu» M. ójud hw-iin; P06,0 um NNNamrm 1LMroY< 'u 221 NuPMniM NMN-1>bh0 Dbf ÌfÌMYs. lomu. Lbrrin Ib N r Ìm. t r'l ear µnw1. tla';m'1s<. MY..r,.,m, :ra! wún v.n Y P:M y;.. m4 i YONrici. Lun n 0M e ern W M Mre I WPG.a1Nú.ÿm MpY<'Ibi. R bd J 11vuOOraa,, uih:irrrae uhm u.mnn enne euf r -rya- Ú Y. H 11N;, m M Wc eynf In xo. 'r, r r, é.rpwez n Hill FV`Ìf:xa III liwh,oelnnr..u. m. Mee P RMtaK 1nd0Nd N'RUN->ÌY< ISNm e re r mmn.v -1llable. I m Ib m ÿ'-:f: 5m M.Y wnl^`nlvy< P:piÓin ï` ml Imm MOÌI. ÿ Y a NriNMM.apm n NORTH AMERICA w'tt `< "m ^ os bw Rod 1MÌ-1ïMsn mw l'u R,<W 4'YK NOm W.<ImIE<Ip Cal. mm,,'' :ym - n au nvdbla ew1-iiw<onii.,x mm 11 l,mn1 YnN enn mm Cn,n,b1 n RADIO AND HOMES FOR OCTOFFR PAGE SEVENTY.THREI

76 ... ' "'iru'i.;r OuI. ` "g'im1.7.p 4.:9-..1:^z e»te.,,nt 'e-re. --:-. tr., e 92.-aiz..nit.t...z.r :47AlissorrIsit:-"re. '.1 2. n 11en zjelo. leeru... nee... ten,. ssnos. us>,...1:e2:sgr.:".:zei '22...!_._ eonenon eel, <>., m o eombe.. mo Lae eten e 1:::":1;.'s!47'.0 PiA7"'fs ''' e s e.. le.r7:1- too ed&ntelletree Bp....reg.. e ono. Dr.., Orlon, rjorze le Idee-ÌÌVe'ling.""la.me looleo: AFRICA Coto K.»le e...a.:...o.0....:«...:0 II mrt; r.tzur.:...: COCQ ZleY. Fino, Air.r: oe,r.7.,...zru, 70W.:,,rr:...z.he.:.n.....z., t.2...,, '22-".21:..' Xt.2.7,,egt..v,.T.,, en,,;,..:,,,,...: ie -,;,-nter...,i41: 4,f..p.::1:4.1.ii3x..., ,.,...,..,...,... ;:zi'.m ,-...e..., rrut'ez SOUTH AMERICA "*. s-. sues< SI eqn. Gee.. Nee. ''' "'. I.V2 4. =.2'2. '1-12h:elm, 'izz-.. '':,.ek.,it.,'. W''' 'z' '.2 "'" Soot 02 ''''2..i.' '2.'1 -.r..z..,: r.vizi,7!^l.: ,17,kr.:..^... e:,... Mee noneatte.c. It lec.c.i.r.9:_ nettie r.ri. ze.,,..-.%.:;,...2iti, -A... ce r..4..ic.,.u. j cr i c.r.e.e: ts."."4 " :.,... eilur:21 reins s:1:7:::11t. 11ä rceoase:esz 37 ;b. 0. en oneee ii lee: 2,:.4,7. 2-zrz...nr.... t t.,;, Zel... I : o..., ,11 le. C I:....:2j ,3:,see...s.... 'a t -i rot lie see. tle or,.00 :0 of c lose. Owe Wee Mono el 4,7:7"<t" '- rrelin IX: levee ' "ttjtsri ows.:4. a.. 0, , II en ezelez,ge P..'..^. '',.<.".2.1:111!. L'.'!." 24 One. rne ';:o.on Wale. * Toe In do farmer... In. Ire ne tee Mule bem.....,...:sr.bei; ''re.""r<te Lsa :!:;:trozza, tetei-110elti. 0One»... er ute bard On Meow ter.... le,n, :, p...,4::17:...?; t...,..., t.,t-tat'30;'ooi Itren... Toe.. ee. weer 0,;;,,., htll % e...8 o.n.o..,.y,._. -..."7.',..." 2-*.e.274o=c2Z0...,...o.;.r ,.g72m. 3..«..,1,:,:,z -;:z,, "'it:=2,^o'' 4 "",-41,F,:z.ZM::, 7..e.;;,_, ::: er...z.t..z.. >222:71.errrä N. evg«%.3ri eirie.;;;;,...: ä.c..to..v3-5""na'..7.0.p...v,..--rr... I* b.. le...et seb0 Al.»en.. IleSe role 0.1, it e.r. COW,..." ;.:7'ZZI:"rte:st.:7 2:::::; : c.r.st j sildr...,eiti."..hu;,2,1;...,.r ,..v.:7;..:..;...: 1e 'tc.2.,.2.4%. 0F.u ;2.2z...--e.-...,52.e10g rier.i., 0e.eac050.::.1e., OI 9.10 eo.: -12ttrOl i,,,... gr..,.,- Otte : ,..Perronollo. yooteo ere tee ore.. noel NrArt ere AZM mow< ele lee. Poo olgotr..". T.2117nei retwelarrer éll'eetleno no Meld Mel. nronerne In Itne lob. Poe on neon*. In Itee CENTRAL AMERICA...4 z< en AND WEST INDIES 14111W INDIA & ASIA -"r^... to,...ere li"<!:in.e.rsets e "Ve et:: 2:::'<dpttiZtr.ord"i:::::1 ":". 17 9re i.zi,v71..,-- ''''''''-" - 0 Tz.,;:ziiiii:23::::72:::: l.' ':'11 50,.. 0. j..,<0,i 'firn001 eres.'*""t?".14"1e.':'::74221.:ifs t'7;27::, r.zz:-.'ii 1_! -..., IteeeAine:ezoezt.- i,t,21,07.:...--,0 0,-, tef,;e,2.2p.^..:;;;2.4:": ;.,:i:.,_......,. ;74"-;,-,,_.,",,,,I T; uitieterew isrwser eno<en..r. '...: ''..".''','"'1«.."1."14:""'111 un.,..«,z.rer...,;;;;.=0:1,..31,. 2, 'm... '''''''-'''''!Or -3 ej f-rt.019:41, ' 9,7re. 21j1C:II''11:1'...21:'. et eel.«.1*"1..>" oe/.014 et get ten 4» otto 4. 1, abeoll 'r,f,ert:..4c.u, en..,,15,20... NO of Ma. mae DEVENTY40111 DADIO AND E1 FOE OCTOKR. 1944

77 OFF TOI RECORD T e most important work in the mo th's records is the Vaughan Williams fifth symphony. It is importa t not only because many will be interested in if, but also because the Williams is one of the few really importent cornpos re of the dey. Oti 5 hm 16/61Cat LE HAL run MOLIS or., BM.. Council, By JOHN MOYLE ay, a! NEWS & REVIEWS i'75.4irue:2an 'Ot she iou SYNIK ' OACHFSSII 111.,,11:ne.nr1 erne9g92r Rh MEW. MART 22r94.11: un""'ri-h1i,mi`un'n' : E sap. The violin Iule 6 magie of its own when preyed by the master Eccponenis of the concert platforrn. Sean, we bop, records will once more bring to ht people os large the opportunity to h." die axquieile per/or/none. of I fiese arti750 as often ne fancy dedotto....i SOME OF THE FAMOUS VIOLINISTS IPIIDES ART IS PRESERVED ON RECORDS: Ilei Po to Mileeeie M en uh in Eileen releier Ziumballee Hen only Hubermen Beet:die In the- n-mriket. num COLIPMMA :WS MASTER'S VOICE.: PARLOPHOME -T.e. TheGramehaneCo.LId Ono InEnglancl, CalumblaGrephaphonniAnntlA,Lid. Parlophüne 1,41, One. englendi. RADIO AND HOBBIES FOR OCTOIER, PAGE SEVENTY-FIVE

78 , OIMAIDO MULLENS Ea NM BALLROOM 4011:90E3r'T" -wait aid ea..- a. vlorme. SELFFETER AND ME BALle RAT N.. AND tor IRCARSTRA le NeSelre er. Inv Roney, QRO or QRP NOMIONE larrrek323u1 " A"» "'a "A711:eSP- e:f:32'33rr r LLINO and,,felt CENETRA 3:ORDEON dreinadries 5 1..Crnielng Dd. Foe r ',MILANI, A T-FUDT dlertd TLOOOTN3BOYS: -Bons, and nett I Juunn. 'AVes.1r In SIECCA N ITIS UNCEZETv FIT I R NEW RIC Br RADIO WINDING SERVICE UAW ect.:a4 * STEEL SWAP 2'6 WEEKLY * Clarinet : roe * Anent. Juler M. Lee.. Welt DrE Corrl'Stenley-eamerl- ""Then"FlIejrryl' "'"' 10,3 MINIATURE SHOP MANUALS FOR AUTOMOBILES chn,url. n OldemuleIle, :I LARGE SHOP MANUALS 2372S11:71C4 wri, v;7d ROBERTSON & MULLENS LTD Elisabeth Street, Melbourne. 53 SPOT. vermi SEAT. Ae2/11 ACC Ihe TARIAITDOSI GERALDO A. NIB 011.1STRA o-n lame" and 1 DoM1 Wera to be Leered 3. Anyone Elee bee Thenb. A INETOIIIR RENDERED> de NIS ORCIIES- TRA-Nne inn Clam. No. 15. ITtme Chn CM: 'Ims NM. Iltobe ttttt Member.113 demon M.., Bomar EMI,. c.o. Rex Mae. Dan Redumn %Reed, Itmeet Sm. Armemons. Joe MnIch epee, Che. Green Eirnb.:: tenarne 1311%. fummero ameri..iner Nand. 11:111 Recorded men May N. 50 le In., Honnoo and Shorbey lbunano Pas. ICE. Santo Femme frmhe Itart Nno.. rm. Pre.. t11. 3, man Teague MM.; lira Pc3lorle.1 Ile corded 5113 Oember. ISM. A GERALOD AND BIB ORCIIESTRA - 'Meng the NaVeln Trolr and 31111e Nee, of htlne. A5544. RANEY ROT AND RES 011.NEENTR am MOM A AND III& ORDIIENTile 3 Dream at Tos INore Than Ton I, 3 Der and "Everybody.ele Bet Ale A7547. T111 OROAR, TEE DANCE BAND AND Darn Ihe 111v. end 1. Chaelny elehmlaulm." INeTBENENTS. mleg AIDÉZZ' Eaduelve mod. egleter"' St.,. for all Meter and Instrument Repairs call on Me METER REPAIR SPECIALISTS FOR PROMPT EFFICIENT SERVICE ZENITH RADIO Co. Pty. Ltd. MANUFACTURED TO ORDER Con Systeln6 Complete st. ream sent Me hana ADDED ETUPPLY CO', PTY., LTD., MG E SEVENTY-SIX RADIO AND HOBBIES FOR OCTOBER, 1914

79 ANSWERS TA CORRESPIININTS sound by. I.. err eattural nrd - Und 2na s.tt nu. ca«dry= reun: tiser err:: jdreren.. rn«l'en; VinnIrrot".or:Ihrittre urn n aet.rn. tot the 1.2ee Pt i-fge pd trxrallt:ter en> T un» a, or an ravunt rear Thl tormusn %OW«It enamor to auto r. «t o. ar rree I 4: onn Väre an for Mon Mel Ir sou rto r.t.e.,; " dawn. Moaner. tr, nr Ott runr. MAY pa enereeui... re«rr I ul A Th1111 ral le real r Pelee ar rn rat, 31. ream.. tau whether the Cam.. woo Iota Werner env he ludo to me U-',: r2envolgn ret are On- o. 11 ; ,0 P auen.ii. Wet «um her -I... belle "p'elr'""g a.. :MA Ire = aretrtarnatt21... " ger» sub an ottra nah To use mu hale ter suurallaly lath * lueuneer got. ye. to man«the 46"»tt tuts.. nter.=or=t1.21net Mee II mad Ma Ira rem«u oln 10eAltereterer much ert tu KUM. =et. Utiartetal:»'"»««. lard `j. toretere»na4ente:.11». =» Mon ce notterugtofen'd :71.ter;tredeloatibtratrZ ZrZa:teni IND.0 AND HOMES FOR OCOEE& MI...ante, du. WI antral, *round.rhat. QUERY SERVICE -NEW CONDITIONS W. reader, plea» op+. that the 1Chnkrei quory service Pow Ì *petal«st follow..- Oovitt.1 be o.n.o.od throoqh Ihe rear«. of oo «non... 3 net «otnat,ed by Ion Ur dertor reply. rrallely a Yee Oel. p.11 be by mal at ord., et prettrble il letyperrprenled by I/. l posed' not«endear*..lop. 3. I. Roo of book numb o. oeof, ovelloblo, meek» of tkone. dreyreu. aod Now pot We/ pill b..00peos I. ed. ood. ot.eionoo, deonio If.. Goo 110e1l. ley... &ad pod, 10.1E eei 1/4 I. stoost o. podal o.o. Eneoreo oavoloeo o. G000.ot. of onst, ,00$ oteentiol hobo NJ se, 6.1. "I 4...SPUN a...cl. fet 2/6. Urbare envelope "IleoptIet." Do ool o0t1too soothe 000 lor ciretito. rat.. hit mu embed,. at tlo, NI leo.whod by d lo,o.t ero.n p enrh abnentrode Shot up hen boo. freed fo beol It above,d 'oy 000e «ol of <hop«to sever Net trf lis.. p3ranrh ale....obi. es h.', moot, be rolomed. And Rornornbod BE EXPLICIT-BE COMPLETE-BE BRIEF! PAGE SEVENTY -USIA

80 KP3 LET'S GET TO THE CORE OF THINGS As with all KINGSLEY radio products the reason why "PERMACLAD" I.F.'s are now spoken of as the best in Australia is found in the ferromagnetic iron -dust cores used in their construction. Apart from the inherent technical superiority of iron -core tuning, every "PERMACLAD" I.F. is turned out on a production line that sets a particularly high standard of quality. So from the first to the final step... that of oscillagraph testing and tuning each I.F. is made to give the absolute maximum in performance. The use of the enclosed pot -type ferromagnetic cores give KINGSLEY PERMACLAD I.1e.'s a particularly high degree of permeability, high "Q" and gain. OBTAINABLE FROM AUTHORISED KINGSLEY DISTRIBUTORS CENTRE IRON CORE COIL POT -TYPE IRON CORE CENTRE IRON CORE The above diagram is a cut away sketch of a PERMACLAD I.E. Tuning is done by the two centre iron -cores. e d J... s a a o i FERROTIINE FERRO -MAGNETIC IRON -CORE COILS, I.F.'s AND, GANGLESS TUNING UNITS IACSIEY QUALITY RADIO PRODUCTS KINGSLEY RADIO KINGSLEY RADIO P T Y. L T D. 380 St.. Kilda Road, Melbourne, Victoria. Phones: MX 1159, MX 3653 PAGE SEVENTY-EIGHT RADIO AND HOBBIES FOR OCTOBER, 1946

81 ANSWERS TO CORRESPONDENTS-Continued K.I. e.y. ebeul the eennecfi.n el commercial "Rein.,,i' ACORRESPONDENT, in ula li!. Ih. "All We: ,, Tb...;' "Tiny Tim II;' and olh.i. s using screen ec lion. Th. oiisoblern is the Ices coils merited for the conventional plat reaction circuit pl"doled. Reed ion acrd In all Ih. "D plate""pipin the roil g lo.c n. The TI,. Clentio.r" pin on the coil goes to lh. moving.ing a o4 thescreenoonl,o polenliom.ler end i. by-p.a.ed lo..r11, through condenser --g Ily 0.1 mld. Thera contusion about Iha egrid" and "moth" connections irhigh are the sema in all tunila. ondens go.s to the mot,' oh...,...rlb wiring, end "Grid" lo lb. honing condenser.lelor All, and thence through the grad condenser 1e 1he grid of 1h. detector..h.. AI moat or 1q1.111e, RADIO DEALERS Coils Dials 'I rnns-!ormers- Speakers- Tubular Condensers Resistors - Electrical Accessories. Valves - Wires-Flex Meters Multimeter - Telling Equipment. Radio Manuals Radio Designers' Handbook. DAVIS RADIO CO. Flo NHS Ho Bal 6eo.ge 51.I.,, Sydney.uSe Phone J I U- J I T S U BETALL. BF: STRONG W BESTLING BOXING tet..s4'. L. Power, Box 1184, G.PlI.. Sydney..eg RECORDING EXPERIMENTERS n Txuy n,,,unl n co WANTED TO BUY trust Mgt' RADIO AND NllYIIES FOR OCTOBER, I44h PAGE SEVENTY-NINE

82 WANTED TO BUY, SELL OR EXCHANGE Readers wishing to buy. sell or exchange goods are invited to *insert an advertise ment in this column. The cast is 9d. per line: minimum charge 2/3. Approximately 6 words to a lint. Advertisements for the next issue must reach our office by WEDNESDAY. October 9. Dealers' advertisements riot accepted, l,'or SALE: New "University' 08 Multtmetes 5 with leather carrying case and instructions. 28 J. Benson. Ultime, Vitt. FOR SALE; Complete kit set for electric a valve set; also 50 resistors, 30 condensers ranging from 300 mmf, speaker transformer Ct, and 10,000 CL. Valves KF C4. 657, 6E5. 3 ICS's. Ali practical') new. What offer? N C. Salford. 52 Billon - road. Gymple, SALE: Power Pack comprising 2 genemotors t-. complete with. filter units, all mounted ou same chassis. No. 1 genemotor. 24v. input. 250v. IDOma. output. No. 2 geometer, 24v. Input, 650v. 350ma. output, Will sell the lo as single unit for 10. Genemotors 3 ea DC/AC Inverter; 6v. DC Input. 240V. AC output. 10 F. H. Shannon. Tambonoe. 411d. L`OR SALE: "R & H" High Fidelity 0 1 itrpi. Just wired, tested, O.K Separ. ate power pack. 175 mil trans. and choke IS&Sl, 9 brand new valves 12-6SK7. 3-8J70T, V6GT. ov4s. slide rule deal No speaker or cabinet Best octet oyes 20, packed end,railed Struck, G.P.O. Bos 10115P, Melbourne. OR SALE Opts 1 & II Admiralty H'boole T. 01 Wireless Telegraphy. 11/-. R. Satchel) 22 Kingston -street. llaberfeld, NSW. VCR SALE: 2 -valve Battery Set, less phones..5. batteries, 9 or best offer. Also "Radio for the Millions," 9/-, S. J. Denalc. Little Swamp, ria Port Lincoln, SA. Fo R SALE: 12 inch Concert Speaker, 750 PC, and 10 Inch 1000 FC. Phone WL2144. VOA SALE: Vol. 3, Nos. 4, , 11; Vol Nos.. 1-8, 8-12; Vols 5. 6 and complete. Pittard, Downing -st., Epping. NSW. l'or SALE: One Valve Wireless Set, 3j5,- -1- B. Webb, 03 afoore-s6, Liverpool, NSW. C9ALE: R & E. "Little General" Radio. No 5-7 further use, building larger set Offers? Waterhouse. Box J2, P.O. Woolgoolga. N.S.W 71OR SALE: Meccano, No. 6. complete. elec motor, cabinet Townsend. to Rawson - place, City. SALE: 56 "R. & H." 48 "Popular I7OR Science," 20 -might- magazines Excel. lent condition. What Offers? Write G. Thomson, S Mount -street, Strathfeld OR SALE: New parts V.D., two 1 each 5 and 9 plate double bearing condensers. six each 4 & 6 -pin coil formers, with steatite sockets to match. "Aegis" 115 dial, chassis and panel for "Amateur Junior." 4/10/-. postage paid. J.. Watt. "Tarrongyle.' End -street, Denhlein. R SALE: R. Jr R Inc., E3. 1 Genemotor v. 25w., ) Rallcray-parade, Mortdale. ror SALE, Cathode Ray Oscilloscope, Mn. screen portable. complete. and in excellent order. For sale. 20 K. Alder. 61 Railway -street, Newcastle. yvh OAL.C,, MUI11r1111g 11U11 0V. 11CYC1" IISCU. 30/-. Rediokes coil unit, rf. aer.. ose dual wave, 35/-. K. Semmler. Box 26. Murton. Vic, F R SALE: Two Genemotors, Input 12v.. output 310v. 100 M.A., complete with filters. 5 each. Also velocity microphone complete twlth adjustable floor stand. ' All In neifect order 4 Eveline -ave.. Parkdale Victoria. TOR SALE: U.R.F Radio Parts. Valves and -I. Radio Books Write to K. Shambler. II Nile -street. East Orange. FOR SALE: Two Rota Deluxe 1{12 Speakers and one 10in Amplion Pertnag. T. G Cooper. 63 Rangers -ave., Cremorne. RMOOSt TOR SALE: 2000 ohms Earphones. 2 Speak. ers (one horni and (7orbon Mie Alsr Crystal Set, 1. Ring JA3310. R. Fo SALE: 50n MA Meter fi Rect., 35/ /-: Audio Trans.. 3/- Pa /e IF's. 14'-: 2 465kr. Tyr TF R. A ('hap)' Flemington -rd.. Nth Melbourne N.I.. Vic. `ALE: Astor Mantel Model, vibeetor operated. U 5 valve, less battery order. 8 4 F, Halt Camp -st.. Bright. Vic. {'OR SALE: Audio Trauslormers, Ferrant, AFS. CTS. 75/-. AF10, 2/6, AFI7C CTS. 35,-. 1 manic 115, and 1-3, 3.6 each Poem Transformers -Primary 220/240,260. Sec 385; 385 5V 2a, 3.5v. 10a. 2.5v 3a C.T., also 385;386 5v. 2a. 4v 4a, 6.3v 2s. 17/6 each Amplion Speaker. 81n. Aloi PermeS., 35/ - Letters only to T. W. Smithson. Post OQire Bexley, N.S.W. CXCHANGE: Tandem Blke, new pana chrome etc Fur service testing gear of radio parts..1. Ambers. 8Y Prince's Highway Arneliffe, N.S.W. TXCHANGE for pair Audio Trans!. 8v Cul L Battery or Mike with lransf- or small 6v A.C. D.C. Motor. Carlton. Regents Pk.. NSW. CELL: 4 valve Mantel. Brand new. 12'2 t complete, or etch. for portable ports. am cosh. 308 New Canterbury -rd Dull. Hill. ELL -High grade magnetic pickup. light - kj weight. offset head. new. 3: all wave 7 valve set for phones SIPS & ldel, with cabinet coils and phones. pertes% order. 7. IA7GT. new. 10/- Self contained ',detect 2,3 valve set, measuring only 6x3x3, wall Minimum battery, requires IPS & 108 valves, 3/10. - Write R. Greig. '9Vinlou,' Mt. Fusil. Vic. `ALE: 620 Vollends Camera with case. tj ripod. film and complete set of develdping se:d printing apparatus. Can supply films Bargain al 10 Write D. Adams.' ai Beaumont -street Hamilton, NSW. `CALE: One Palet Multimeter. model MCA. U In carrying case Both as new Have purchased Multitester Guaranteed OK Write D. Adams. 81 Beaumont -sr.. Hamilton, NSW "ELL. -Role KS F5B /J tin Permag New. Talma Converter Metres Paler K475 Meter 0-600v New. 3 Ferranti Audio Trans AF3. AFS. OPAL T. D. Ling. Box 82. Smlthton. Tus. New `ELL, complete kits!or 4 -valve Portable sei O and 4 -watt vibrator amplifier 'both tir. cults last month R. fi H.I. also complete moto' car engineering course. Cheap. write ta, details. Box 125. P.O.. Batborst. N.S.W. SELL Ghirardi's 'Modern Radio Servicing," 35/-: 12v. 75w. solder Iron, 17/6; A.W.A and Lekmek 3 -gang condensers. 10/- each: Speedo type rev counter, 10,,-; magneto for twin cyl engine. 3/S/-: steel guitar in case. 6/16/-. All good order Ail post paid C, E. Neilsen, Nikenbah, Qid. QELL R. & R,. Feb., 1940, to Feb., 1946: 1938 s7 Admiralty Handbook of Wireless Telegraphy. Sterling's Radio Manual. Valves fide EL3NG. EZ2, 1.6X5, and 2 OZ4. all good: new 100 M/A P. Trans. Dodge 12 -volt generator and Oft. prop. Rewound for slow speed. Offers :o 1.. A. Jantke. Gales. S.A. CELL: AWA Short-wave Converter, in cabi '-' net, never used. 4 wave changes, 19 to 51...tree lee vwlve s es F-'Fnlldine. Iilx Marion -st.. Leichhardt. 1,,'ANTED Urgently, loan or purchase, Dec 45 Issue of R S. H. Write B. O'Keefe Winslow, ria Warrnambool, Victoria.,\7ANTED Urgently Permag Speaker,' 12,000 ohms, 3in.-51n. W. McDevitt. its Cook street, Lewisham. Sydney. LM2801. V ANTED Urgently. Radio & Hobbies for March. 1042, anxious to obtain. Send particulars to A. D. Gain. e/o Mrs. Rickets. Roorowa-street. Yount NSW. % ANTED to buy Air Force R.1062 Loop Aerial and Sense Unit. Pert order Write L. Mansbridge, P.O., Tewantin. Queensland. N.:17ANTED. Any American Arni V -discs recordings, featuring Andre Rostelanete` and Orchestra I am ardent fan of above Orchestra and am desperately desirous of obtaining these V -discs series Anyone with information-or the above records wishing to sell or exchange, etc Price no obiert. Writ, NI A. H rostnnw 't Rose -street. Hnrstone Sydney. ' \WANTED Vol. 1. No. 1 to Dec., 1945 of R. 1 le H. Condition and price to Murdoch, Aunt. School. Peeitce Admin.. Mownan. NSW. 'ANTED All Copies Radio Hobbies. volume \\ cue ro date, wanted. Must. be perfect order. WIII pay 4 complete. set T. Saunders, log Hunter -street, Newcastle. Coll (inns for Jae. transmitter \\;ANTED: end receiver. Also sell, or exchange Chromatic Ha noon Ica for Radio Gear. It. Fitzsimmons. Frederick -1r., Horsham. Vie, V4NTED from '6, to lhp. S.P. Motor. G..7 Ray, Ix Hedges -st.. Fairfield. "ANTED: Battery operated Modulated Os- 1cllletor Will pay good price W. F. Ferguson. Girilambone, Bourke Line, NSW. \ S; ANTED to Buy: "General Electric" lnduc- \\ Lion Dc Gramo. Motor. J. G. Holt. 15 Evans Crt.. Toorak, 5E2. Melbourne, Vic. in:anted: Sanderson Hand Stand Camera. I V 1 w rl..vllh or without lens and acces- sories Write Mandy. Box 10, Connamhir. \\`ANTED: Position as Radio- Srry iceman. Grod knowledge of Servicing. Own modern egulament. Write:.4. McCarthy. Rourke Street, Deepwater, N.S.W. \\]ANTED: High voltage D.C. Generator, about Mr volts. 260 ro 1000 watts. VKSABG. Avenel. Vie.' % 'ANTED: "R. & H.." NOV,, 1944-ec., 1946 '-el P're to' N. D. goal. Spring Creek. Clifton. - Po *ling Don 'is - o STAMPS II NZ Seine, 5. 6; 4 Cook. Nue of.7t3: la Peace. 2'-. 0 Germany Meier.., 13. 4'-: 2 Great Britain Fence. lid; Tangier pence JId List Free. Ccmmo:i. wealth C,'I nlmrle. I 'r ',noted Hill Ce e ap, Postage Extra under 5 - W. ACKLAND ar Elizabeth St.. Melbourne. C.I. MODELS reehmcel Engineering Sup isle Castines And Blue Prints Sabo Ir- for Col,D R Rnitnn. Room I, 111 King St.. Sydney. ' STAMPS -Collections of accumule- t tons. purchased I to Ip00. registered post to 7'. E. Pattern i Petterev Stamp Depot,. Hobart. Tas. iiitler's HEAD. FREE! Look ID stamps. Including one with Hitler's Head. Free to those sending 212d for approvals, R. C. Smith,'11:1 Canterbary-all, Casino, NSW. I STAMP PACKETS. NEWSAGENTS Wide Variety supplied at wholesale Big range of Samples, 3/9.,No rubbish) Cliff Hpwe, Albertan. S. A. FREE.. STAMPS.. FREE! 20 all different Postage Stamps given entirely FREE if 2'hd sent for latest price list. G 1. LAKER_-1 Adelaide Street. 'r,,. Islands Pietorixls, STAMPS-Pacific 3 varieties each island: Cook. Niue, Pitcairn. Gilbert. W Samoa, Tpnga. Solomons. One island lid set 7 sets for.5/-. Send stamp for Price Lists ATLAS STAMP CO.. Box 1, Roseville. N.S.W. Universal Hubby rer STAMPS-The Young and Old..ii:Inovals sent.. Price List Free. 1laytuir ;t;, tops. Glreson-aye.. St. Peter.. N.S. ty he STAMP ALBUM, LOOSE P LE,AAFOUNn eluding graph leaves, pert guide trunslattone of foreign countries. etc. Price ;/d cash, with order Norseman Products. Enfield. N.S.W. Printed and ' Published by Associa ten Newspapers Ltd tsuccessors to Sun NPVSpapers Ltd., al the reeisterea offire of :he f'nmpanv Eltsa bet h -street. Sydney PAGE EIGHTY RADIO AND HOBBIES FOR OCTOBER, 1446

83 -hole 9i OCTOBC-R RADIO AND HOBBIES IN AUSTRALIA PAGE 111 Bakelite Novel y Clgare le Case, slide lid, out pops next smoke. 11/-. or 10/6 posted. As I lustrated Bakelite Cita ette Case. Holds le. Slide lid, up jumps next smoke, 8/6, or 0/- posted. Metal Clem ette Cases, hold 10. Chromed. 17/6. Heavy Gilt. 37/6. Enamelled with fancy designs. 21/6. Add ad post to each. De Luxe Ribbed Gold - plated Case, 52/6. De Luxe Ribbed Silverplated, 30/-. To Plastic Cigarette Case: holds lo gigs., 16/6. or 17/- posted. Very light. Mirror Finish Sheffield Knives, white handles. Table or Dessert sizes, 6 for 20/-, plus postage. Or all -metal one -niece type. 11 for Ills-, plus postage. Magnetic "LOVE PUPS." Screamingly Funny little Novelty. Fun: and what Fun. They do the most unusual, unheard things. 3/0, or II- posted. The pair could fit ht a Safety Match Box. 7 Chromed Spring Metal Gents' Wristlet Watch Bands. easily and quickly fitted; can be regulated to size, 4/6, or b/- posted. Fancy Engravings. 2/6 extra. BUG TELEGRAPH KEY. Beautifully made, Si/-. Carrying Case if desired lö/- extra. Add Freight. ELECTRIC MODEL MOTORS Works off Wet or Dry Batts, or Transformer. 21/ - and _iì-, add Od post. MORSE CODE KEY SETS AND BUZZER Morse Set, Highest Grade Adjustable Morse Key, P.M.G. Tyne. with High Tone Buzzer. Mount- JUST ARRIVED FROM LONDON. ed with Eatery. 27/6. slat Detectors, 1 Mount. :'6. sii/r Adjustable Morse ;117 Keys, 12/6, plus Postage. Buzzers, 4/3. Adjustable Morse Set. Buzzer. Buttery Fittings. Mounted ready for use on wooden baseboard. 22/6. P.M.G. De Luxe Adjustable Morse Set on wooden base, with Buzzer. Light Switch and Battery. 30/-. Morse Set. Adjustable De Luxe Key. Buzzer. Switch from light to buzzer, Battery. Mounted on baseboard, 25/-. Diesel Ope rat o Engine is Manual. A Mc- Graw-Hill U.S.A. Book. 20/3. Add postage. Smart Books from U.S.A. Add Postage. Air Conditioning in Winter and Summer. 23/6. Produced By Radio Society of G.B. SECURE YOUR COPY NOW: Splendid for Amateur or Professional. Modern Radio Servicing. U.S.A.. 2, plus onstage. A giant size book for radio amateurs and Professionals Radio Physics Course. 2. plus postage. Another slant. size U.S.A. book chock full of diagrams, drawings. cirez ils. etc. Vertical Donkey Steam Engine Working Model. No danger. complete. 25/11. add hostage. Cast Metal Black Boy Money Box, Moveable Arm and Hand. Places coin hi Mouth. :12/6 or 23/6 posted. l'1aytk,avk, 2/6 Surplus Govt. Stocks: Khaki or White Duck Haversacks 2/6. or 3/- posted. Ideal School Bags. Approx. size 10 x loin. She Bield Bread Knife serrated edge. slightly rusted. 2'- or 2l1l posted. Red Diamond Semi Fixt Cry - Also Refills. Glass Enclosed Crystal Detectors, 1/6 With Crystal, 1/- extra. Just arrived from London "COSMOCORD" CRYSTAL TYPE Bakelite all Sdts- 3/17/6, Cartridge GRAMOPHONE PICK-UPS. Suit Only. Price MIO. as illustrated. De Lase Balanced Crystal Model, All Metal, 3 í10y6. to your Radio. then to your Gramophone. "Young Atom" Bakelite Pick-up. 3/17/6. Add Postage. F Hook en Plastic Moulded TIPPERARY FLUTE. from London, 11/6 or 12/3 packed and posted. Follow the Directions and you play straightaway. No previous knowledge of music required. "Colibri" 30/6 or 2 posted. Enalish Lighter, world's best. opens and lights with flick of finger. A reliable American type Stormproof CIGARETTE LIGHTER. as illustrated, Black Crackle finish. 0/9, or 7/3 posted. U.S.A. Hard Flints. 1/6, or 1/3 posted. 50/- per 1000, plus 126 per cent. Sales Tax. Automatic Nickelled Type. to/g. or IS/- posted. As illustrated. Greenandco Nickelled Silver Lighter de Luse, Space Tank. Stormproof, 12/1i, 13/6. posted. a. fie. a w...0 BRASS BEER MUGS Made from IS -pounder Shell Cases. with Brass Kangaroo Handle. Polished Brass. 12/6; Highly Chromed. 21/, POSTAGE: New South Wales 1/6; Queensland. Tasmania, Victoria, 2/6: South Australia, West Australia. Northern Territory. 3/6. Height 64in, Diameter 3351n. Weight 31bs. BALL BEARING SKATES SPECIAL High - Grade Pipes. All' g u a ran' teed Oxford. 12/6. plus postage. De Lose Pipes. la/-. 14/6. 21,-. all plus I. Postage English All -Steel Extendable Ball -Bearing Skates, IL/- pair. Please add postage. Weight. Sib. packed. v im. 031íxsa Jeweller's Magnifying Eve Glass for Stamp Collectors. Mechanics, etc. Nickelled metal finish. 11/- Posted. with Spirit Gum..m.:, a or Thin LUMINOUS. Liquid Glue. PAINT 3/0 posted. GAS LIGHTERS. Add Postage. Gun Type.... 1/111 Press with fingers together. A model from London. Sill. Large Pressed Steel Mechanical Motor Cars. 13/6; welded Pants. length 12in. x 31/24n., height 41/2in'. Add postage. J. LEVENSON'S RADIO Games. Hobbies, Novelties. and Slot Machine Specialists. 226 PITT STREET. SYDNEY. Everything from A to Z in Radio at Sane Profit Price Phone M2525 and M Goods forwarded C.O.D. Post or Rail over 10/- (C.O.D. Rail within N.S.W. only: not Interstate.)

84 PAGE IV. RADIO AND HOBBIES IN AUSTRALIA OCTOBER, 1946 AUSTRALIA SPENDS MORE THAN X8,000,000 ANNUALLY ON RADIO RECEIVERS AND PARTS This is the last pre-war estimate and it's not hard to realise how even this colossal Spore must Jump In the post-war period. Incidentally In the figure quoted over 1,001,0011 is made up of valves servite and parts replacement: HUGE WAITING RADIO MARKET MEANS BIG MONEY FOR TRAINED MEN! Today Radio is not only the fastest growing of Australia's secondary industries but promises the brightest future. Its needs for trained men are tremendous and are growing every week. We are entering now a Radio age, an Age which has a piace for YOU, Radio, a young industry which has made remarkable progress in the past few years will require many trained men to fill vital positions. If you want security, prosperity, and a recognised status in the community start training NOW. TUU C.AN J I AK I KICa11 1 AWAY Frequently openings in Radio are greater than the number of men available to fill them. Here are two good reasons, moreover, why A.R.C. Radio Training must interest you so vitally 111 You will enter to -day's most progressive industry. (2) You will have a splendid career ahead of you now that the war is over. s. To Mi. L. B. GRAHAM. PRINCIPAL. Australian Radio College, Pty Ltd.. Broadway, Sydney. Phone M Dear Sir-I am interested in Radio. Please send me, without obligation on my part. the free book. "Careers ln Radio and Television." NAME ADDRESS Train at Home, or at Our Benches A.R.C. offers ambitious men a souna proven course In Radio Engineering. Sound because it is the result of many years' successful operation, proven because hundreds of ex -students owe their present success to the College You can learn with equal facility at home flay means of our correspondence courser Earn Good Money Whilst Learning You don't have to wait n year, or even six months, before you are ready to begin "cashing In," we will show Voti how to earn extra money almost from the word "go." Many students make 4. and up to 8, per week in their spare time whilst studying. Previous Knowledge Unnecessary You don't need a knowledge of Radio or Electricity-we'll give you all you treed of both. In a simple, practical manner, that makes learning easy presented, too, in such a way that you remember what you're taught and how to put that knowledge to practical use. Costs Little Think of this-for a few pence per day-actually less than many fellows spend on tobacco-you can prepare yourself for a man-sized Job In Radio NOW. Now is the Time To Act! Send in to -day for the free book. "Careers In Radio and Television." It's a book no man can afford to miss. It shows you the steps you can till:, -o Vet Into Radio mmediat el STILL A NEW INDUSTR ell AUSTRALIAN RADIO COLLEGE PTY., LTD. Cnr. Broadway & City Road, Sydney 'Phones: M6391, M6392 r was estimate,. prewar sates of radie receivers and parts. The next Jew years should see these figures doubled. Prewar Radio Set out put reached an estimated 280,000. with a six years tag fa commercial production, alt records are expected to be broken In near /ature. Even a 25 per cent. increase in set sales toit mean openine9 Jor perhaps 2000 more Radio dealers, 2000 mare radio mechanics. Over 130 Australian Radii, Stations employ a vas) number of skilled personnel - a team o1 specialists. which arobablu will be more than tripled with the advent of P.M 10!463.