Assembly Manual. Revision E, January 11, 2018 Copyright 2018, Elecraft; All Rights Reserved

Transcription

1 ELECRAFT T AUTOMATIC ANTENNA TUNER Assembly Manual Revson E, January, 208 Copyrght 208, Elecraft; All Rghts Reserved Introducton Ths manual covers assembly of the Elecraft T automatc antenna tuner. Operatng nstructons, troubleshootng procedures, schematc dagram and customer servce nformaton can be found n your T Owner s Manual. Tools Requred You wll need the followng tools to buld ths kt: Fne-tp temperature-controlled ESD-safe solderng staton wth 700 to 800 F tp ( C). Recommend a spade tp no greater than 0.05 (.3 mm) wde. Hgh wattage (approx. 00 watt) solderng gun to solder the BNC connectors. Use ths ron only where drected n the procedure. Use the temperature-controlled staton for all other solderng. IC-grade, small-dameter (.03 ) solder (Kester #44 or equvalent). Small dameter solder s mportant to avod fllng adjacent solder pads and creatng solder brdges. DO NOT use acd-core solder, water-soluble flux solder, addtonal flux or solvents of any knd. Use of any of these wll vod your warranty. Small, #2 Phllps screwdrver. Needle-nose plers. Small wrench or drver for 6-32 nut. Small-pont dagonal cutters. Flush-cuttng type requred (Xcelte MS54-5J or equvalent). Dgtal Multmeter (DMM) wth voltage, resstance and dode-checkng functons. A DMM wth capactance measurement capablty s desrable, but not requred. Magnfyng vsor or magnfyng glass wth a hands-free stand. Desolderng tools and supples are nvaluable. Narrow solder wck or a good vacuum desolderng tool such as the Soldapullt model DS07LS are recommended. Small, #2 (.4 mm wde) blade screwdrver may be requred. Elecraft

2 We strongly recommend that you use a conductve wrst strap and ant-statc mat whle handlng the MCU or the PC boards wth the MCU nstalled. Wrst straps and mats are avalable at very low cost from Jameco, Mouser, and other electroncs supplers. Refer to for tool sources and solder recommendatons. Unpackng and Inventory Preventng Electro-Statc Dscharge Damage The Master Control Unt (MCU) used n the T automatc antenna tuner s senstve to Electro-Statc Dscharge (ESD) damage. ESD damage may not make the tuner fal completely. Sometmes the unt may contnue to operate somewhat, creatng a very dffcult-to-fnd problem. We strongly recommend that you take the followng precautons whenever handlng the MCU or the PC boards when the MCU s nstalled. The precautons are lsted n ther order of mportance:. Leave the MCU n ts ant-statc packagng untl you nstall t. 2. Wear a conductve wrst strap wth a -megohm seres resstor when handlng the MCU or the boards wth the MCU nstalled. If you do not have a wrst strap, frequently touch an unpanted ground whle workng. You can collect a destructve charge on your body just sttng at the work bench. Do not attach a ground drectly to yourself as ths poses a serous shock hazard. 3. Use an ESD-safe solderng ron wth a grounded tp. 4. Use a grounded ant-statc mat on your work bench. Identfyng Capactors Capactors are dentfed by ther value and the spacng of ther leads. Small-value fxed capactors are usually marked wth one, two, or three dgts and no decmal pont. If one or two dgts are used, that s the value n pcofarads (pf). If there are three dgts, the thrd dgt s a multpler. For example, a capactor marked "5" would be 50 pf (5 wth a multpler of 0 ). Smlarly, "330" would be 33 pf, and "02" would be 000 pf (or.00 µf). Exceptons are descrbed specfcally n the text and parts lst. Fxed capactors wth values of 000 pf or hgher often use a decmal pont n the value, such as.00,.047, or 2.2. Ths s the value n mcrofarads (µf) ( µf s equal to,000,000 pf). Most of the capactors n ths kt have a lead spacng of 0.2. When a capactor wth a lead spacng of 0. s called for, t s stated n the descrpton, e.g. Capactor C20,.0 µf, LS 0. (03). Identfyng Resstors Resstors are dentfed by ther power dsspaton ratng and ther resstance value. The power ratng s ndcated by ther physcal sze. There are both /4 watt and /8 watt resstors n your T tuner kt. The /8 watt resstors are about one-half the sze of the /4 watt resstors. 2

3 The color bands that ndcate the value of resstors are shown n the text to help you dentfy the correct part. However, t s helpful to famlarze yourself wth the color code (see Fgure ). For example, a resstor wth the color bands of brown, red, yellow, gold would be a 20K ohm, 5% resstor. Ths resstor wll be dentfed n the text as 20K ohm (brn-red-yel). If you are n doubt about a resstor s value, use a DMM. Do not be concerned wth mnor devatons from the expected value. Typcal errors on most DMMs and the tolerances of the resstors normally produce readngs that are slghtly dfferent from the values ndcated by the color bands. FIRST DIGIT TOLERANCE: GOLD = 5% SILVER = 0% SECOND DIGIT MULTIPLIER COLOR DIGIT MULTIPLIER Black 0 X Brown X 0 Red 2 X 00 Orange 3 X 0K Yellow 4 X 0K Green 5 X 00K COLOR Blue Volet Gray Whte Slver Gold DIGIT MULTIPLIER 6 X M X 0.0 X 0. Fgure. Resstor Color Code. Solderng and Desolderng Use adequate ventlaton when solderng; avod nhalng smoke or fumes. Always wash your hands after handlng solder, as lead resdue s hghly toxc. When applyng solder, use the mnmum amount requred to surround the component lead and make good contact wth ts prnted-crcut pad. You don't need a "fllet" (buld-up) of solder. Ths wll avod unwanted solder brdges and any need to clean the PC boards. The solder must flow onto both the component lead and ts PC board pad. To ensure that both wll be heated at the same tme, the tp of the ron should contact both the component lead and the PC board pad before solder s appled. Solder jonts should be clean and shny. If a jont appears dull or has fne cracks, t s probably cold. Cold solder jonts should be cleaned and re-soldered. Frst, use solder wck (desolderng brad) to remove the old solder. Then apply fresh solder. If you have many cold solder jonts, t probably ndcates that your solderng ron temperature s too low, or that the tp or solder tself s defectve. 3

4 Elecraft kts use hgh-qualty double-sded PC boards. Removng components can be dffcult, snce you must get all of the solder back out of the hole before a lead can be removed. To do ths, you'll need solder wck (desolderng brad) and/or a vacuum desolderng tool. It also takes some practce. A number of suggestons are provded below. The best strategy for avodng de-solderng s to place all components properly the frst tme. Double-check values and orentatons, and avod damagng parts va ESD. When removng components: Don't pull a lead or pn out of a hole unless the solder has been removed or you are applyng heat. Otherwse you can lterally pull the platng out of the plated-through hole. Lmt solderng ron contact to a few seconds at a tme. Use small-sze solder-wck, about 0." or 2.5 mm wde. Use the wck on both the top and bottom pads when possble. Ths helps get all of the solder out of the hole. If you use a vacuum desolderng tool (solder sucker), use a large unt. Small solder suckers are not very effectve. The safest way to remove ICs and other components wth more than 3 leads s to clp all of the pns at the body of the devce frst, then remove all of the pns ndvdually. You may damage pads and traces by tryng to remove such components ntact. Invest n a PC board vce wth a heavy base f possble. Ths makes parts removal easer because t frees up both hands. If n doubt about a partcular repar, ask for advce from Elecraft or from someone else wth PCB repar experence. 4

5 Parts Lst We strongly recommend that you do a complete nventory before begnnng assembly. The nventory helps you correctly dentfy all the parts to avod mstakes durng assembly. Descrpton Qty Part Number Msc. T man PC board (larger board). Ths board has a number of surface-mount devce (SMD) capactors pre-nstalled on the bottom. E85098 Msc. T control PC board E00236 Capactor.0 µf 8 E53075 Capactor.0 µf. On the PC board, these capactors are dentfed only by the second letter (e.g. A, B, C, D...) 5 E53075 Capactor 0 pf, 500 V (0) 2 E Capactor.00 µf, LS 0." (02) E Capactor.0 µf non-polarzed, LS 0." (05) E53074 C2 Capactor, 20 pf, 500 V, NPO or C0G (20) E53073 C3 Capactor 39 pf, 500 V (39) E C4 Capactor 82 pf, 500 V (82) E C5 Capactor 50 pf, 500 V (5) E C6, C7, C7A Capactor 330 pf, 500 V (33) 3 E C20 Capactor.0 µf, LS 0." (03) E53009 Resstor, 5 ohms, W, 5% (grn-brn-blk or stamped 50J) 2 E50059 Resstor, 24K, /8 W, 5% (red-yel-org) E50055 Resstor, 3.3K, /8 W, 5% (org-org-red) 5 E50056 Resstor, 20K, /8 W, 5% (brn-red-yel) 4 E50054 Resstor, 80 ohms, /8 W, 5% (brn-gry-brn) E50057 E60020 Ref. C8,9,,2, C5, 6, 7, 8, CA, CB, CC, CD, CE, CF, CG, CH, CJ, CK, CL, CM, CN, CP, CR Photo Pre-Installed SurfaceMount Devces C, C5A C0 C9 Typcal Capactor Styles R,R2 R R3,R4,R3, R4,R2 R5, R6, R7, R0 R9 U Resstors /8 -/4 -W MCU,6F876A ESD Senstve! Do not remove from ts packagng untl nstructed to do so. 5

6 Ref. Photo Descrpton Qty Part Number Q Transstor 2N3906 E U2 I.C. L78L05 or LM78L05 E D,D2, D4 Dode N57 3 E D3 Dode N587 E J,J2 BNC female, PCB mount 2 E J3 Stereo jack, 3.5 mm, mnature E J4, J5 Conn., 0." spacng, 6 pn female, low-profle 2 E P, P2 Conn., 0." spacng, 6 pn male 2 E Msc. Socket for U, low-profle, 28 pns E D6 LED, green E57002 D7 LED, yellow E D8 LED, red E57009 Msc. LED spacer 3 E Z Ceramc resonator, 4.0 MHz E66000 S,S2 Swtch, Tactle, SPST, 6 mm, actuator length 7 mm 2 E K-K5 Mnature DPDT relay 5 E64000 T,T2 Torod, FT37-43 (Gray) 3 E L-L5 Torod, T37-6 (Yellow) 5 E68003 L6-L7 Torod, T37-2 (Red) 2 E Hardware Hex nut, 6-32 E Hardware Flat washer, #6 E Hardware Knurled thumb-nut, brass, 6-32 E Hardware Lock washer, #6 nternal tooth, stanless E Hardware Solder lug, #6 E Hardware Screw, 6-32 x 9/6 E

7 Ref. Photo Descrpton Qty Part Number Hardware Screw, #2, 9/6 nch self tappng 4 E Msc. 9-volt battery clp, wde E Msc. 9-volt battery clp, narrow E Msc. Enamel wre, #26, red 0 ft. E Msc. Hookup wre, 28 AWG stranded, black 6 n. E Msc. Hookup wre, 28 AWG stranded, red 6 n. E Msc. Hookup wre, #24 sold, green nsulaton 6 n. E Msc. T front panel label E98004 Msc. T cover spacer, x.75x0.25", foam, black, self-adhesve E98007 Msc. T enclosure top and bottom cover E20007 Msc. T enclosure end cover E20006 Msc. T owner's manual E Msc. T assembly manual E

8 Man PC Board Assembly The man PC board s the larger of the two boards. The completed PC board s shown n Fgure 2. Use ths fgure for reference, but follow the step-by-step procedures as gven. Some parts are very dffcult to nstall f done n the wrong sequence. Many parts are almost mpossble to remove wthout destroyng the part or damagng the PC board. Top Bottom Fgure 2. Completed Man PC Board. 8

9 Man PC Board Assembly Procedure Part I Install BNC connectors J and J2 as follows. When completed they must be algned as shown n Fgure O JACK BARRELS PARALLEL WITH BOARD USE HEAVY-DUTY IRON TO SOLDER MOUNTING NUBS (SEE TEXT) JACKS CENTERED WITHIN PRINTED OUTLINES Fgure 3. Installng J and J2. Poston BNC connector J on the board over the prnted outlne as shown wth the mountng nubs and center connector passng through the holes provded. Be certan the barrel s at a 90-degree angle wth the edge of the board and parallel to the board as shown n Fgure 3. Whle holdng the connector n place, wet the tp of your ron wth a drop of solder and use t to temporarly tack-solder the connector center termnal. Check to ensure the connector s stll algned as shown n Fgure 3. If not, re-heat the tack soldered jont and adjust the poston. It wll be very dffcult to adjust the connector after you complete the next step. In the followng step you wll use a large ron to solder the two mountng nubs on the BNC connector to the board. Ths s the only tme you should use anythng other than a temperaturecontrolled, ESD-protected solderng staton to assemble your T tuner. Place the board the bottom sde up on a surface that wll not be damaged f body of the BNC connector becomes warm. Apply the large ron and solder to the end of one amountng nub where t protrudes through the crcut board. Remove the ron as soon as the solder flows onto the pad. Do not put the ron drectly on the solder pad. Do not be concerned f solder flls the pad marked G near J. Solder the second mountng nub usng the same procedure. Usng your temperature-controlled ron, properly solder the center pn that you tack-soldered earler. Repeat the above procedure to nstall the second BNC connector, J2. 9

10 Use only your temperature-controlled, ESD-protected solderng staton for the remander of the assembly. Bend the leads for R, 5 ohms (grn-brn-blk or 50J), watt, at rght angles to the body. Insert the leads n the solder pad holes at the ends of the prnted outlne between J and J2. There are three holes very close together at the end of R near J2. Be sure the leads go through the proper holes n the board, ndcated by short whte lnes on the part outlne. On the bottom sde of the board, bend the leads out at 45-degree angles to hold the resstor n place. Check the poston of the resstor to be sure t s centered n the prnted outlne and flush aganst the board as shown n Fgure 4. Solder, takng care not to get solder n ether of the empty holes at the J2 end of the resstor. Trm the leads flush wth the bottom of the board. ENSURE MARKINGS AGREE WITH INSTRUCTIONS IN TEXT BODY OF PART AGAINST THE BOARD SOLDER & TRIM LEADS FLUSH Fgure 4. Installng Resstors. From ths pont forward, nstructons to nstall a component mean to poston t wthn ts outlne aganst the board, solder and trm the leads flush on the opposte sde. Install the followng resstors n the outlnes shown at the end of the PC board opposte BNC connectors J and J2. These resstors are /8 watt resstors, about half the sze of R. R5, 20K (brn-red-yel) /8 W R6, 20K (brn-red-yel) /8 W R3, 3.3K (org-org-red) /8 W R4, 3.3K (org-org-red) /8 W Locate capactor C, 0 pf (0). Note that the capactors may have markngs on ther bodes n addton to the value gven n parenthess. Insert C nto the holes n the outlne on the PC board. Wth the BNC connectors toward you, the poston for C s about half way back on the left edge. If necessary, gently straghten the leads so the capactor wll st close to the board wthout excessve lead lengths as shown n Fgure 5. When straghtenng the leads, do not tug on them. Squeeze and bend the leads wth your plers to straghten them. Chppng of the nsulaton around the leads wll not harm the capactor. 0

11 THE NUMBERS IN PARENTESIS IN THE TEXT MUST APPEAR ON THE BODY. USUALLY THERE ARE OTHER MARKINGS AS WELL. 0 GENTLY FORM LEADS SO CAPACITOR SITS AS CLOSE TO THE BOARD AS THE INSULATION ALLOWS. SOLDER & TRIM LEADS. Fgure 5. Installng Capactors. Bend the leads out at 45-degree angles on the bottom sde of the board to hold the capactor n place, then solder and trm the leads flush wth the bottom of the board. Install the followng capactors n the outlnes shown across the center of the PC board adjacent to C. C2, 20 pf (20) C3, 39 pf (39) C4, 82 pf (82) Install the followng capactors n the outlnes shown across the next to the ones you just nstalled. Be careful to nsert the leads n the correct solder pads. There are solder pads very close to those for C5 and C7 for two capactors that wll be nstalled on the bottom of the PC board later. Make sure you don t use these pads by mstake. Also, be sure the larger capactors are postoned so they do not overlap the outlnes for the relays on ether sde. C5, 50 pf (5) C6, 330 pf (33) C7, 330 pf (33) Install capactor C0,.00 µf, LS 0. (02) n the outlne at the end of the PC board farthest from BNC connectors J and J2. Look closely at the markng. Do not use (05) my mstake. Locate dode D (N57). You may need to use a strong magnfer to read the numbers. The numbers are often prnted on the body n two rows of three letters each (e.g. N5 and 7) Locate the outlne for D on the crcut board near J2 and R. Note that the prnted outlne has a band near one end. Gently bend D s leads at rght angles to the body and nsert t nto the solder pad holes wth the banded end of the dode toward the banded end on the prnted outlne. On the bottom of the board, bend the leads at 45 degree angles to hold t n place. Your T tuner wll not operate correctly f the banded end of the dode s not algned wth the banded end of the outlne on the PC board. Solder the leads and trm them flush. Install dode D2 (N57) the same way you nstalled D. D2 s close to BNC connector J2.

12 Locate the 5 relays and carefully remove them from the carryng tube(s). Check the relays for bent pns. Carefully straghten any bent pns usng needle-nose plers. Locate a small book or other smooth, flat object somewhat larger than the PC board that s easy to handle. You wll use ths to hold the relays n place on the PC board before solderng them. Hold the PC board n one hand and drop the relays nto the spaces shown for K through K5. Note that the pn spacng only allows them to go n when orented properly. Do not use force. They should smply drop nto place. Don t mss K2 that sts between the two long rows of relays. Place the book aganst the top of the relays and then, holdng the book and PC board together to keep the relays from fallng out, flp the whole assembly over and set t down. Relays K9 through K5 have small SMD capactors between ther pns. Take care solderng. Do not create solder brdges between the relay pads and the SMD pads. On each of the 5 relays, tack-solder only one corner pn to hold t n place. Do not touch the plastc relay covers wth your solderng ron. Even a small burn or melted spot may jam the relay mechansm nsde. Re-heat the soldered pn on each relay whle pressng down on t to ensure that t s squarely aganst the PC board. The relays should be algned n neat rows wth the tops level. When you are satsfed wth the poston of the relays, solder the remanng pns. Do not trm or bend the relay pns after solderng. Trmmng or bendng the pns ntroduces mechancal stresses that may cause premature relay falure. Check all ffteen relays carefully to ensure that every pn s soldered and that there are no solder brdges between pns. 2

13 Inspect the 28-pn, low-profle socket for U. Note that: Each pn has a shoulder. When nstalled, all of the shoulders must be n contact wth the PC board. You wll not be able to assemble your fnshed tuner f ths socket s not mounted aganst the PC board. The pns are hollow. The pns on controller U ft nsde the pns on the socket. Do not cut, bend or alter the pns n any way or you may not be able to nstall U. There s a notch at one end of the black plastc frame of the socket. Ths notch must be algned wth the marks on the PC board when you nstall the socket. Algn the socket wth the outlne for U on the top sde of the PC board near the opposte end of the board from J and J2. Make sure that each pn s n ts correspondng solder pad, and the solder pads reserved for P and P2 are open (See Fgure 6). Verfy that the notched end of the socket s pontng toward the holes for connector P as ndcated by the outlne prnted on the board. BE CERTAIN PADS FOR P AND P2 ARE CLEAR NOTCHED END OF SOCKET Fgure 6. Installng Socket for U. Gently press the socket down onto the board untl the shoulder of each pn s touchng the top of the board. Do not solder yet. You wll be nstructed to do so n a later step. Once soldered, the socket for U wll be mpossble to remove from the board wthout destroyng t. Before solderng, check to be certan t s postoned correctly as follows: Locate the two 6-pn male connectors, P and P2. Place the short pns of the connectors n spaces provded for P and P2. Fgure 2 shows these connectors n place on the fnshed PCB. Confrm that the socket for U s properly postoned so that connectors P and P2 can be nstalled later. Remove the 6-pn male connectors from P and P2 and set them asde. Don t dsturb the 28-pn socket. On the 28-pn socket, solder one pn, then nspect the socket carefully to ensure that the shoulders of the pns are aganst the top of the board. If needed, reheat the pn whle pressng the down on the socket. When you are satsfed that the socket s seated aganst the top of the board, solder all 28 pns. 3

14 On the top of the board, poston ceramc resonator Z (4.00 MG) n the outlne between the socket for U and the edge of the board. Even though t may have a red dot on one end, the resonator may be nstalled n ether drecton. Hold the resonator so the nsulaton on the leads s aganst the top of the board, then tack-solder one pn. Verfy that the nsulaton of all three leads s aganst the top of the board. If t s allowed to st too hgh t wll strke the control board when you assemble the tuner. Solder all three pns on Z. Poston the mnature stereo jack n the outlne for J3 on the top of the board. The round porton of the jack wll extend over the edge of the board. Hold the jack aganst the board and tack-solder one pn. Verfy that the jack s soldly aganst the board, otherwse t may not lne up wth the hole n the enclosure when you assemble your tuner. Use no more solder than s necessary for a good jont on J3. Fllng the holes wth too much solder may allow t to flow nto the jack and run t. Solder all three pns on J3. Locate the two 6-pn male connectors, P and P2, that you just test-ftted on the board, and the two 6-pn female connectors J4 and J5. Insert the longer pns of the male connectors nto the female connectors. Be sure the connectors are fully mated. There may be a small gap remanng between the plastc parts. Refer to Fgure 7. Place the pns of P and P2 nto poston at each end of the 28-pn socket on the man PC board, then place the control PC board on the pns of J4 and J5 as shown. Be sure the control board s orented wth the top sde shown n the fgure facng up. The ends of the control board should lne up wth the sdes of the man PC board. The notched corners must be over the cutouts near the corners of the man PC board. RELAYS ON MAIN PCB J4 P J5 SHORT PINS J4 THIS SIDE MUST FACE UP J5 P2 Fgure 7. Installng P, J4, P2 and J5. Hold the assembly and tack-solder one termnal on P, P2, J4 and J5. Do not to touch the relays wth your solderng ron. 4

15 Inspect the assembly to be certan the control PC board s orented as shown n the fgure. The top of the board should be level wth and slghtly below the top of the relays next to t. The connectors must be square aganst the two boards. If necessary, reheat the soldered pns and adjust the connectors. The assembly must be as shown for the tuner to ft n ts enclosure properly. Solder all the pns on P, P2 J4 and J5. At P, be careful not to create a solder brdge between pn 3 and the solder pad for resstor R4 that s very close. Unplug the control PC board and set t asde. On the bottom sde of the board between BNC connectors J and J2, nstall resstor R2, 5 ohms (grn-brn-blk or 50J), watt. Trm the leads flush wth the top of the board. Install C7A on the bottom of the board as follows: On the bottom sde of the board, locate the outlne for capactor C7A. Insert the leads for C7A, 330 pf (33) through the solder pads and fold the capactor down flat aganst the board toward the edge. Orent t so you can read the value. Do not solder yet! Remove C7A and pre-trm ts leads so they pass through the solder pads but do not protrude through the top sde of the board. If necessary, remove a small amount of the nsulaton from around the leads near the capactor body to expose the lead and solder pad. Solder C7A n place from the bottom of the board. Install C5A, 0 pf (0) on the bottom of the board n the same way you nstalled C7A. Fold C5A toward the pns of K4 at the center of the board. Resstance Checks Make the followng resstance checks between the varous pns of socket U. Pn s nearest the edge of the board at the end near the stereo jack. Count down the row, across the end and back up the other sde. Pn 28 s across from pn at the end near the stereo jack. U Pns Resstance ohms ohms ohms ohms ohms ohms ohms ohms U Pns Resstance ohms ohms ohms ohms ohms ohms > 00 k or Inf. > 00 k or Inf.

16 Man PC Board Assembly Procedure Part II In the followng steps you ll wnd and nstall the torodal transformers and nductors. They must be wound on the correct torod core exactly as descrbed or your tuner wll not operate properly. Wnd transformer T as follows: Locate an FT37-43 torod core. Ths s a dark grey core that s not panted. There are three of them n the kt. Cut a 7-nch (8 cm) length of the red enameled wre. Sew the long end of the wre through the hole n the core for a total of 8 turns. Count one turn each tme the wre passes through the center of the core. There are no half or quarter turns when wndng a torod. Match the wndng drecton shown n Fgure 8 so the leads wll lne up wth the solder pads on the crcut board. Spread the turns around the core as shown n the fgure. GREEN PRIMARY LEAD SMALLER SECONDARY LEAD SMALLER SECONDARY LEAD T READY FOR INSTALLATION GREEN PRIMARY LEAD LEAD POSITIONS ON PC BOARD T INSTALLATION COMPLETE Fgure 8. Transformer T. Strp the nsulaton and tn the leads usng one of the followng methods. Strp off the enamel all the way up to the core. It wll not hurt performance f the tnned area of the lead touches the core.. Heat strppng: Melt a blob of solder on the tp of your ron and nsert the clpped end of the lead n the blob. The nsulaton wll bubble and vaporze after about 5 seconds. Add solder and feed the wre nto the blob up to the edge of the core, then slowly pull the wre out of the solder. If any enamel remans on the lead, scrape t away. 2. Burn the nsulaton off by heatng t wth a butane lghter for a few seconds. Remove any resdue wth sandpaper, then tn the bare wre. 3. Scrape the wre wth a sharp tool. Take care not to nck the wre. Remove all the nsulaton around the entre crcumference of the wre, then tn the wre. Prewound torods are avalable from an Elecraft-approved source. See for detals. 6

17 The leads must be strpped of nsulaton and tnned correctly to provde good electrcal contact when nstalled. Carefully nspect each tnned lead for: A clean, tnned lead wth no enamel resdue left under the tnnng. The lead must be tnned all the way around the wre. The lead should be tnned all the way up to the core as shown n Fgure 8. Locate the outlne for T between BNC connectors J and J2 on the PC board. Thread the tnned leads of T through the smaller pads (See Fgure 8). Poston the torod over the outlne as shown and bend the leads on the bottom of the crcut board to hold the torod aganst the PC board n place. Inspect the lead on the top sde of the board to be sure tnned lead s vsble above the solder pad. If not, remove the torod, clean and tn the lead closer to the core and replace t on the PC board. Solder and trm both leads flush, then adjust the poston of T, f needed, so t sts wthn the outlne prnted on the PC board. Cut a 3/4 (9 mm) length of the green nsulated sold wre. Strp the nsulaton from /4 (6 mm) at each end of the wre. Thread the wre through the center of T and nto the holes on ether sde of the prnted outlne for T on the PC board to form the -turn prmary wndng for the transformer. Solder and trm the wres flush wth the bottom of the board. Transformer T2 s dentcal to T except that t uses two FT37-43 cores stacked together as shown n Fgure 9. To smplfy wndng the secondary, you may wsh to glue the cores together usng epoxy or cyanoacrylate adhesve (super glue). Prepare and nstall transformer T2 usng: _ 5 (39 cm) of red enamel wre for the secondary and wnd 8 turns (wre passes through the center 8 tmes). _ (25.4 mm) of green nsulated wre for the prmary wndng. Strp /8 (3mm) from each end. Because of the tght ft, you may fnd t easer to prepare the green prmary wre, loop t through the torod, then nsert the secondary leads and the green prmary leads nto the pc board pads at the same tme. GREEN PRIMARY LEAD SMALLER SECONDARY LEAD SMALLER SECONDARY LEAD T2 SECONDARY WOUND ON TWO FT37-43 CORES GREEN PRIMARY LEAD BE CERTAIN THE LEADS ARE INSTALLED IN THE CORRECT PC BOARD PADS Fgure 9. Transformer T2. 7 T2 INSTALLATION COMPLETE

18 Locate the fve T37-6 yellow torods. Use these torods to prepare nductors L through L5 as lsted below. Poston the turns on each torod as shown n Fgure 0 so the leads wll lne up wth the holes n the PC board. Note that L s wound n the opposte drecton from the others. Install each col wth the core uprght aganst the top of the board nsde ts prnted outlne. Solder and trm the leads. Inductor L L2 L3 L4 L5 Wre Length 6 (6 cm) 6.5 (7 cm) 7 (8 cm) 9 (23 cm) (28 cm) Number of Turns 3 close wound 5 spaced 7 spaced spaced 6 spaced L - 3 TURNS L2-5 TURNS L3-7 TURNS Core Yellow Yellow Yellow Yellow Yellow L4 - TURNS L5-6 TURNS Fgure 0. Torod Inductors L - L5. Do not use glue or other fxatve to hold the torods on the PC board. Such materals may affect ther electrcal characterstcs. The torods need no support other than ther own leads. Locate the two T37-2 red torods. Use these torods to prepare L6 and L7 and nstall them n the remanng spaces shown on the PC board. Inductor L6 L7 Wre Length 3 (33 cm) 8 (46 cm) Number of Turns 20 spaced 29 close wound L6-20 TURNS Core Red Red L7-29 TURNS Fgure. Torod Inductors L6 and L7. 8

19 Vsual Inspecton Use a magnfer and good lght to check the board for the followng: Mssed solder connectons. Look closely at each relay pn. Solder brdges. Look closely at the SMD capactors between the relay pns. Properly tnned torod leads. You should see some tnned lead above the PC board on every torod. Be suspcous of any leads where the enameled part of the wre goes nto the solder pad. If n doubt, remove, clean and tn more of the lead or rewnd the torod. Dode orentaton. The banded ends of D and D2 must be nearest BNC connector J2. Control Board Assembly The completed control PC board s shown n Fgure 2. All of the components are mounted on the top of the board. There s very lttle excess space above or below ths board when your tuner s assembled n ts enclosure. Follow the nstructons carefully to ensure the board wll ft when you assemble your tuner. It s almost mpossble to remove a part wthout destroyng the part or damagng the board. Double-check the poston and value of all parts nstalled on the control board before solderng. Fgure 2. Completed Control PC Board. 9

20 Control Board Assembly Procedure Install resstor R0, 20K (brn-red-yel), /8 watt. When your tuner s assembled, the bottom of the control PC board wll be very close to the top of the MCU. It s crtcal to flush cut all leads on the bottom of the board n the area drectly over the MCU to no more than /32 ( mm) n heght. Locate voltage regulator U2 (78L05). Ths s a three-termnal devce that looks lke most transstors wth one flat face and a rounded back. The number s prnted on the flat face, but you may have to use a magnfer and hold t n just the rght poston under a strong lght to see the letterng. Install U2 as follows: Bend the three leads toward the rounded sde of the case, then poston t on the board wth the three leads through the solder pads and the rounded sde aganst the board (See Fgure 3). LAY AGAINST BOARD FLAT SIDE UP. Fgure 3. Installng U2 on the Control Board. On the bottom of the board, bend the leads to hold U2 n place. Solder and flush-cut the center lead. Adjust U2, f needed, to center t wthn the outlne wth the rounded back touchng the board. Solder and flush-cut the remanng two leads. Install Q (2N3906) usng the same procedure as you used for U2. When solderng, be careful not to fll the open solder pad for C20. Install dode D4 (N57). Orent the band over the end ndcated on the crcut board. Install C9, µf, L.S 0. (05). Lay the capactor body n the square shown on the control board wth the leads nserted through the solder pads. Adjust the leads to allow the body to le as flat as possble. Insert the leads of resstor R7, 20K (brn-red-yel), /8 watt, through the solder pads and bend them to hold t n place, but do not solder yet to avod fllng the solder pad for R4. Install resstor R4, 3.3k (org-org-red), /8 watt. Solder and flush-cut the leads for both R7 and R4. Take care not to touch connector J4 wth your ron whle solderng. 20

21 Install the followng /8 watt resstors. R9, 80 ohm (brn-gry-brn) R2, 3.3k (org-org-red) R, 24k (red-yel-org) Poston resstor R3, 3.3K (org-org-red), /8 watt on the board and spread ts leads to hold t n place. Do not solder yet. You wll be nstructed to solder the leads n a followng step. Insert one of the pushbutton swtches n the poston for S2. It can be orented ether way. Make certan the rdges on the bottom of the swtch housng are aganst the board. Solder one termnal of S2, then nspect the swtch to make sure t s stll sttng drectly aganst the board. If necessary, reheat the soldered termnal whle pressng the swtch down aganst the board. When you are satsfed that the swtch s aganst the board, solder and flush-cut the remanng termnals of S2 and the leads to resstor R3. Take care not to touch J5 wth your solderng ron. Insert the second push-button swtch n the poston for S. It can be orented ether way. Solder one pn, then nspect the swtch to make sure t s stll sttng drectly aganst the board. If necessary, reheat the soldered termnal whle pressng the swtch down aganst the board. When you have confrmed that the swtch s n poston, solder and flush-cut the remanng three termnals. Cut a 2-/2 (64 mm) length of the black #28 AWG stranded wre. Strp the nsulaton from /8 (3 mm) at each end and tn the bare wres. Insert one end n the solder pad near R on the top of the board, then solder and flush-cut on the bottom of the board. Dress the lead over the edge of the board next to R. Slp the round spacer over the leads of the red LED. Insert the longer lead of the red LED nto the round solder pad for D8. The longer lead must go nto the round solder pad or the LED wll not work. Spread the leads to hold the LED n place wth the spacer aganst the board. Solder and flush-cut the leads. Inspect the poston of the LED to be sure t s sttng vertcally aganst the spacer. If necessary, reheat the solder pads one at a tme whle adjustng the LED poston. Followng the same procedure, nstall the remanng two LEDs on spacers. Be sure the long leads go nto the round solder pads. Yellow LED at D7 Green LED at D6 2

22 Install capactor C20,.0 µf, LS 0. (03). Even though the outlne does not ndcate t s placed aganst the board, fold t down n the drecton of the red LED D8 before solderng (See Fgure 2). Bend the leads of dode D3 (N587) at rght angles to ts body and nsert t n the space shown on the control board. Be sure to orent the band over end ndcated on the crcut board. Solder only the pad at the banded end of the dode. You ll solder the other end n the next step. Cut a.5 (38 mm) length of the red #28 AWG stranded wre. Strp the nsulaton from /8 (3 mm) at each end and tn the wres. Poston one end n the + solder pad on the top of the control board. On the bottom of the board, solder the wre and the remanng lead for D3, then flush-cut the excess wre and D3 lead. Vsual Inspecton Verfy that there are no leads or solder fllets more that /32 ( mm) hgh on the bottom sde of the board. Use a magnfer and carefully check the board for any mssed solder connectons or solder brdges. Resstance Checks Use your DMM to make the followng resstance checks. If the board fals any of the followng checks, carefully check the poston and orentaton of all parts and nspect the board wth a magnfer for solder brdges or mssed solder jonts. Resstance across capactor C9: between 37 K-ohms and 48 K-ohms. Press S2 and confrm readng drops to between 7 K-ohms and 35 K-ohms. Resstance between D3 anode (end wthout the band) and the pad near D7 (ground) where the black wre s attached: > 00 K-ohms (may show open or nfnte on some DMMs). Press S and confrm the readng drops to between 7 K-ohms and 30 K-ohms. If the resstance s hgher, try reversng your DMM leads. Set your DMM to dode test. Connect the negatve probe to ether end of resstor R9. Touch the postve probe to the followng pns on J5 and verfy that the dode tester shows approxmately.6 volts forward drop across each LED. J5 s the connector at the opposte end of the control board from R9. Pn s the round pn at the end near S2. Each LED may also lght up when the test voltage s appled (not all dode testers supply suffcent current to produce lght): Pn : Red LED Pn 2: Yellow LED 22 Pn 5: Green LED

23 Fnal Assembly Locate the enclosure. It conssts of a bottom cover, a top cover and an end panel. The top cover s drlled wth a row of holes for the LEDs and swtches. The end panel s drlled wth two large holes for the BNC connectors and one small hole for the ground lug. Locate the two battery clps. One has a narrow sprng contact and one has a wde sprng contact. On the enclosure bottom cover, remove the battery compartment cover. It s ndcated by an arrow molded nto the case. Wth the case face down and the battery compartment open, nsert the metal battery clps as shown n Fgure 4. Be sure the wder contact s closest to the bottom of the enclosure. Once fully nserted, the clps wll lock n place. SLIDE CLIPS INTO SLOTS UNTIL THEY LATCH NARROW CONTACT BATTERY COMPARTMENT DOOR OPEN WIDE CONTACT Fgure 4. Installng Battery Clps. Assemble the ground screw hardware as shown n Fgure 5. Tghten the hex nut and screw securely so that tghtenng the knurled thumb nut wll not loosen the assembly. POSITION SOLDER LUG AS SHOWN THUMB NUT FLAT WASHER NUT LOCK WASHER FLAT SIDE OF END PANEL SOLDER LUG Fgure 5. Ground Screw Assembly. Cut a (26 mm) length of the black #26 AWG stranded wre. Strp /8 (3 mm) from each end and tn the bare wres. Insert one end nto the pad marked G on the man PCB next to J, solder and trm the excess. If ths pad was flled wth solder when you nstalled BNC connector J, re-heat t and poke the wre through from the top of the board. 23

24 Ether wear a grounded ant-statc wrst strap or touch an unpanted, grounded object before handlng the MCU (U) n the next steps, or at any tme you handle the boards wth the MCU nstalled. Remove MCU U from ts package or ant-statc foam pad and nspect the pns. The two rows of pns must be straght and parallel to each other to establsh the proper pn spacng for nserton nto the socket. To straghten the pns, rest one entre row of pns aganst a hard, flat surface. Hold the body of the MCU and rock t forward to bend the pns nto poston as shown n Fgure 6. FLARED ROCK TO STRAIGHTEN DIMPLE AT PIN STRAIGHT NOTCH Fgure 6. Installng the MCU. Identfy the end of the IC where Pn s located. It wll have a notch, a dmple or both at ths end (See Fgure 6). Algn the MCU on the socket wth the notched or dmpled end of the MCU over the notched end of the socket. Carefully nspect the algnment of each MCU pn and ts correspondng socket. Pay partcular attenton to the row of pns along the relays. Put a strong lght on the relays and look under the MCU wth your magnfer to see the pns near the relays clearly. Be certan that all the pns are started down nto ther respectve socket postons before proceedng. Press down frmly on the MCU whle checkng the pns for any that fal to slde nto the socket properly. Apply pressure alternately to one end and then to the other of the MCU as necessary to ensure the pns go all the way nto the socket. The shoulder on each pn must rest aganst the top of the socket. If you need to remove the MCU for any reason, see Removng the MCU on page 29. Mate the control board on the man PC board, J4 to P and J5 to P2 (See Fgure 7). The control board must be orented so Q and U2 are closest to the relays. Be sure that connectors J4-P and J5-P2 are fully mated, wth plastc housng touchng plastc housng at both ends. Be certan that nothng on the bottom of the control board touches the top of the MCU. 24

25 On the nsde of the enclosure top cover, use your flush cutters to remove any plastc webbng on the sde of the screw housngs toward the holes (See Fgure 7). The wde round shoulders are okay, but any excess plastc toward the LED and swtch holes wll strke the control board and keep the top and bottom covers from closng properly. REMOVE FLASHING FROM BOTH SCREW HOUSINGS TRIM OFF EXCESS WITH FLUSH CUTTERS AFTER BEFORE Fgure 7. Removng Excess Plastc From Enclosure Top Cover. Place the tuner PC board assembly n the enclosure bottom cover as follows. Tlt the board assembly and poston the stereo jack n the openng n the sde of the bottom cover, then lay the board assembly down flat n the cover. It s normally a tght ft over the molded screw housngs so that t may snap nto place. Be sure the red and black wres attached to the control board are not caught under the boards. Slde the end plate over the end of the BNC connectors wth the ground nut facng away from the PC board. Lft up on the end plate and rase the end of the PC board enough to poston the end plate n the groove at the end of the cover, then reseat the entre PC board assembly back nto the lower cover. Solder the black ground wre attached to the man PC board to the ground post solder lug. Do not touch the end wth your solderng ron. If needed, bend the end of the solder lug away from the end plate. Route the black wre leadng from the control board between the red and yellow LEDs and around to the wde battery termnal as shown n Fgure 8. Tuck the wre down aganst the man PCB were t crosses to the sde, then push t down nto the slot between the end of the battery compartment and the sde of the bottom cover. The rdge along the edge of the bottom cover fts nto a slot n top cover, so the wres must leave a space clear for the top to ft down over the rdge. TUCK BLACK WIRE DOWN TO MAIN PCB ENSURE WIRES GO ALONGSIDE SCREW HOUSING WHERE THEY WON T BE PINCHED WHEN THE COVER IS INSTALLED PUSH BOTH WIRES AS DEEP AS POSSIBLE INTO SLOT Fgure 8. Routng Battery Wres. 25

26 Ft the strpped end of the black wre nto the wde battery termnal and solder. Take care not to touch the plastc case or overheat the termnal and soften the plastc. Route the red wre to the narrow battery clp, pushng t down on top of the black wre. Be sure nether wre s where t can be trapped between the screw housngs when the top cover s nstalled. Push both wres down nto the space between the battery housng and the sde of the enclosure as far as possble. Ft the strpped end of the red wre nto the hole on the narrow battery clp and solder. Ft the enclosure top cover on the assembly orented so the LED s and push-buttons ft through the pre-drlled holes. Squeeze the corners of the covers together and nspect each sde for any sgn that somethng s httng the top. The covers should ft together snug and frm on all four sdes wth no tendency to move or rock when you release pressure on the corners. If anythng s httng the top, fx t before proceedng. The most lkely causes are that the control board s not fully mated to the man board, the battery wres are trapped between the screw housngs (Fgure 8) or that you haven t removed all the excess plastc from the top cover and t s strkng the control board (see Fgure 7). When you are satsfed that the covers ft properly, remove the top cover. Remove the backng from the self-stckng spacer and place t stcky-sde up on top of the relays. Be sure t s over the relays and not touchng Q or U2 on the control board. Wthout dsturbng the spacer, replace the top cover and press down on t gently. The spacer wll stck to the nsde surface of the cover. Insert and tghten the four screws that hold the enclosure together. Do not over-tghten the screws to avod strppng the threads n the plastc. Remove the backng from the front panel label. Hold t by the ends and bend t n the mddle t so that the stcky sde of the label wth the holes for the LEDs and swtches wll touch the front panel frst. Poston the label so the holes ft over the LEDs and swtches and the edge of the label s parallel to the recessed edge of the panel, then press the label down onto the panel. Run your fngertps over the entre surface of the label to ensure t s frmly bonded to the panel. 26

27 Performance Tests Your T tuner s now complete. Perform the followng tests to verfy that the unt s workng normally. Refer to Troubleshootng on page 28 f your tuner fals any of these tests. Power On Tests Install a fresh battery as shown n Fgure 9. Fgure 9. Installng the Battery. Tap (press for /2 second or less) the PWR/TUNE swtch. The yellow LED should blnk several tmes and then stop. Hold (press for second, then release) the PWR/TUNE swtch. The green LED should lght and blnk several tmes, then stop. Transmt Power Dsplay Tests Read page 6 of your Owner s Manual and famlarze yourself wth the basc operaton of your T. Connect a transmtter and a dummy load to your T (see page 5 of your Owner s Manual). Put your T n Bypass mode by tappng PWR/TUNE then, whle the yellow LED s flashng, tap BYP/INFO untl you see the yellow LED on steady. It wll stay on for about two seconds then and go off. Tap PWR/TUNE to turn your T on, then key the transmtter. The three LEDs come on accordng to the RF power level from the transmtter (see page 6 of your Owner s Manual for an explanaton of the power dsplay). 27

28 Tune Mode Tests Put your T n Normal mode by tappng PWR/TUNE, then whle the yellow LED s flashng, tap BYP/INFO untl you see the green LED on steady. It wll stay on for about two seconds then go off. Connect an antenna to your T (see page 9 of your Owner s Manual for antenna recommendatons). Set your transmtter s power output to a safe level for auto-tunng (normally 2 to 5 watts). Do not use full power unless you re sure your transmtter s protected aganst hgh SWR. If you are not sure, use no more than /2 of ts maxmum power output durng tunng. Start an auto-tune operaton by holdng PWR/TUNE untl the green LED s on, then transmt wthn three seconds. You should hear the relays operate and the LEDs flash as descrbed under Autotunng and SWR Dsplay on page 6 of your Owner s Manual. Troubleshootng Observe ESD precautons whle handlng the tuner PC boards wth the MCU nstalled. Touch an unpanted ground frequently or wear a wrst strap grounded through a megohm resstor. Use an ant-statc pad f you have one. If your tuner fals any of the performance tests, remove the battery, dsassemble your tuner and do a very careful nspecton. Look especally for the followng: Mssed or cold solder jonts or solder brdges on ether board. Use a magnfer to nspect each jont carefully. Dodes wth the band at the correct end. The black bands on D and D2 on the man PC board must be at the end of the dodes closest to BNC connector J2 (See Fgure 2). On the control board, D2 must be orented so the black band s on the end closest to S2, and D must be orented so the black band s on the end closest to R4 (See Fgure 2). LEDs nstalled correctly. The LEDs wll not lght unless they were nstalled wth the correct polarty. Use the dode check functon on your DMM to ensure they are nstalled correctly as descrbed on page 22. Check the torods for properly-tnned leads. If your leads were not carefully tnned, they may appear to be soldered but may not make electrcal contact wth the solder pads. Check the value of each part nstalled aganst the assembly procedure or schematc dagram. Addtonal troubleshootng nformaton and a complete schematc dagram s ncluded n your Owner s Manual. 28

29 Removng the MCU Normally you wll not need to remove the MCU. However, f necessary, remove t as follows. Observe ESD precautons whenever you handle the MCU. See note above. Unplug the control board and remove the man PCB from the enclosure. Use a small blade screwdrver that wll ft between the pns of connectors P and P2. Slp the blade between the connector pns and under one end of the MCU, then lft t up slghtly. Repeat the process at the other end of the MCU. Do not press the screwdrver aganst the stereo jack. You mght damage t. Contnue to lft each end of the MCU n small steps untl t s free. Workng n small steps wll avod bendng the MCU pns. Place the MCU n ant-statc foam or an ant-statc carrer untl you are ready to replace t. 29