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BER 1972 A HARCOUFT BRACE JOVANOVICH PUBLICATION

CTRONICICIAN/ R

ULATION

cote.

NATESA Plan to Create Confidence

Introducing Heathkit's Dual -Trace ScopeBetter Merchants Make Better Profits

There must be an easier way...

There is: Sylvania's Chek-A- Color test jig.

TV servicemen were never meant to bemovingmen.

But, that was before antique, modernand French Provincial units that includedhi-fi, tape decks and record players werebuilt around a large -screen color TV set.

Getting those units to the shop can bea big job.

That's why we developed our two Chek-A-Color test jigunits. One, our full -house model, gives everything you needto test a chassis. The other is a basic unit that practically letsyou design your own test jig.

All you have to take back to the shop is the electronic gutsof the TV monsters.

Regardless of the size of the original picture, Chek-A-Colorlets you see it on a benchtop 14 -inch SYLVANIA 100 First Avenue, Waltham, Mass. 02154

(diagonal) screen. It adapts to both highand low focus voltage sets and a full lineof adapters lets you test over 5,000 dif-ferent models.

A front -panel switch controls a yokeprogramming system that gives you arange of impedances and/or deflection

voltages to closely match both tube and solid-state systems.

For actual testing, a convenient meter lets you measure an-ode voltage and a speaker lets you check sound performance.

Since Chek-A-Color handles tube, hybrid and solid-statechassis, there won't be many complete cabinets to lug.

With a Chek-A-Color test jig all you have to take is thechassis. Get the picture? Sylvania Electronic Components,

1450SYLVANIATV ChassisB10-7/-12

ELECTRONIC /1-WM-LP/ -1.Za AirDECEMBER 1972COMPLETE MANUFACTURERS' CIRCUITAND TECHNICAL INFORMATION FOR 4

ELECTRONIC TECHNICIAN/DEALER Is published monthly by HARCOURT BRACE JO-VANOVICH PUBLICATIONS, INC., 1 East First St., Duluth, Minn. 55802. Subscriptionrates: One year $6, two years $10. three years $13, in the United States and Canada.Other countries: One year $15, two years $24, three years $30. Single copies 750 in theUnited Stales, and $2 in other countries. Second class postage paid at Duluth, Minnesota 55806 and at additional mailing offices. Copyright 1972 by HARCOURT BRACEJOVANOVICH PUBLICATIONS. INC.POSTMASTER: Send Form 3579 to ELECTRONIC TECHNICIAN/DEALER, HARCOURTBRACE JOVANOVICH PUBLICATIONS, INC.,1 East First St., Duluth, Minn. 55802.

61502LAW Pit.SWITCH

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TRANSFORMER PART NO 50-27819-2 OR -3.- USE 56PF/55.V, 100PF/55VI-HCH) WITH 1400 HOTT12.

OUTPUT TRANSFORMER PART NO. 50-35021-I OR -2

5 EXAMPLE 012) LETTER AND NUMBER NEAR COMPONENTDESIGNATES PRINTED CIRCUIT PANEL CO-ORDINATE.

COPYRIGHT 1972 BY ELECTRONIC TECHNICIAN DEALER 1 EAST FIRST STREET. DULUTH, MINNESOTA 55802

B

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SYMBOL DESCRIPTION ZENITH PART NO.

C208A-100f, electrolytic cap. 350vC2088-40, electrolytic cap, 350vC208C-40f, electrolytic cap. 350v 22.6312C208D-200pf, , electrolytic cap, 35vC321A-270pf, , electrolytic cap, 350v 22-5746C3218-15010, electrolytic cap, 350vR208-1.5 n, peak pix control 63.9942R214-5000 , contrast control 63-7975R221 -1M, brite control 63-7974R251 -15M, focus control 63.9013R254-500 n , AGC delay control 63-8543R283 -5K, AGC level control 6307976R294 -750K, vert hold control 63-7973R299-thermistor 63-6824R307 -2K, vert lin control 63-7983R315 -500K, color killer control 63-9942R351-750 n , buzz control 63.6487R378 -voltage dependent resistor 63-7658R388-thermist3r 63-8667R396 -voltage dependent resistor 63-7658L202-4.5MHz trap coil S-77669L209 -sound take -off coil S-77414L222-3.58MHz burst a output coil S-80791L224 -quad coil S-80480L226-horiz osc S-56877L233 -ac choke 95-2917T201 -Vert output xformer 95-2924T204 -deflect yoke S-92263T206 -filament xformer 95-2944T207-horiz sweep xformer S-89112A201-integ unit 87-7F201 -heater fuse link 2% in, min. loop of

No. 24 AWG copper 912061F202-500ma, bel-fuse 136.84F203 -2.7a, bel-fuse 136-76F204-100ma, bel-fuse 136-104

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COPYRIGHT 1972 BY ELECTRONIC TECHNICIAN/DEALER I EAST FIRST STREET. DULUTH. MINNESOTA 55802

1449

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ELECTRONIC J-,VETEfixaDECEMBER 1972COMPLETE MANUFACTURERS' CIRCUIT DIAGRAMSAND TECHNICAL INFORMATION FOR 4 NEW SETS

No, UStD NO1 US/ D

31

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1448MAGNAVOXColor -TV ChassisT979

000 163.5V P/PH

ELECTMN/C2/1 4=MA ArDECEMBER 1972COMPLETE MANUFACTURERS' CIRCUIT DIAGRAMSAND TECHNICAL INFORMATION FOR 4 NEW SETS

173.5V P/PH1815V P/PH19.8V P/PH202V P/P

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1447

SYMBOL DESCRIPTION GENERAL ELECTRIC PART NO.7109-xformer, horiz output ES77X15

8801 on/off vol, 10K ES49X74 T110-xformer. power ES88X48802-brite, 500K ES49X75 IC01- sound IF pre -amp ES84X3R803 -contrast, 1K ES49X77 ICO2-audio output ES84X1R804--AGC. 1K ES49X45 IC03 Flora phase det ES84X2R805-vert hold. 30K ES49X79 TH01-thermist zr ES14X39R806-vert ht, 20K ES49X78 CPO1 ES57X15R807-vert lin, 20K ES49X78 CP02 ES57X16R808 -focus, 2M ES49X42 CP03 ES57X17L112 -deflect yoke ES76X9 CP304 ES57X16L113-coll, horiz osc ES35X6 fuse la, slo blo F701 ES1OX7

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COMPLETE MANUFACTURERS' CIRCUIT DIAGRAMSAND TECHNICAL INFORMATION FOR 4 NEW SETS

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8253D293

COPYRIGHT 1972 BY ELECTRONIC TECHNICIAN/DEALER 1 EAST FIRST STREET. DULUTH. MINNESOTA 55602

SCHEMATIC NO.

120904, 911 1239120914A, B 1221

120921. 923 1290120962. 964 1303120969, 970 12881209748 1352120976, 977, 980. 981,

982, 983, 984 1313Model9P50 100511P50/12P50 137512HI302 139012P50 97512P60/12P61/W 128029P10 124835P01/35P02 1177P-1913 Stereo/Radio 790T2R2 IA

14421374T8K3-1BT10K10-1D,C 1336725H4 IA 14461800/2000 Series 742

FIRESTONE

Chassis:12 129 94U 918

FISHER

Model:800 AM/FM Amp 693

GENERAL ELECTRIC

Chassis:AA 889AB 963AC 1164AD 1148AY 832A.1 1191A-2 1370BA 1447C-1 1353C 2/L 2 1376CB 953DA 861DB 930DC 990DD 1075DI 1214D2 1345ETV 1046ETV 1AFY 866G-1 1156H-1 1173H-2 1236H.3 .... 1318H-4 1406HB 1011JA 1432KC 1037KD .. 1141KE 1184L T2 1417LX 699MXT 785Ni 1412N2 1357P-1 1195OX 772OY 828R-2 1435SA 911SB 939SC 1018S.2 1155S-3 1393TA 881TB 1004TC 10481-5 1257UI 1398U5 692VB 979V-2M597 Series 745TU 220 AM/FM Tuner 759Model:940A, B Radio 85811P31, -33, T225A. -35A,

36A Radio 845CT110, CP775 Trans Radio 619M502SBN, EB, VY,

3XBN. EB, VY 772M87OVWD, M871VWD,

R87OVM1, R870VWD 6929P70A Radio 809RP2060A Stereo Phone 725T 3000A, B Stereo Receiver 836W360A Radio Intercom 796

GRANCO

Model:704 AM/FM Radio 682

GENERAL ELECTRIC (CANADA)

Chassis.

SCHEMATIC NO.

M618 - 1030 TS -440M638 1171 TS -454M649 1101 TS -458M685 1123 TS -460 SeriesM687 1112 TS -461N-1 1307 TS -465

HEATH

Model.AA 21 Stereo Amp 829GR-22 773GR-53 839

HOFFMAN

Chassis:913000366, 386 11668P318 Trans Radio 703Model.P708 Trans Radio 703

KORTING

Model:MT 2233, 2243 Tape Recorder . .865MT3643/3633 Stereo

Tape Recorder Constellation 853

MAGNAVOX

Model:77-01 AM/FM Tuner 794Chassis.34 Series 72236-08, 09 Series 76240 Series 84943 Series 83544 Series 81245 Series 88247 Series 106248 Series 91249 Series 90170-01 FM Multiplex Adapter 702T907 Series 981T908 Series 993T910 Series 985T911 Series 10881914 Series 954T915 Series 1181T916 Series 1140T917 Series 1186T919 Series 1012T920 Series 11031921 Series 10591922 Series 10791923 Series 1076T924 Series 1135T925 Series ....... 1111T927 Series 11581928 Series 1311T932 Series 12001933 Series 1224T934 Series 1283T935 Series 12851936 1341T937 1215T938 1206T939 12711940 1254T941 1344T942 13491944 1259T944 (Late prod.) 13641945 12661946 13591946 (Late prod.) 13841948 1297T949 1310T950 1328T951 13231952 14331956 1377T957 Series 1407T958 13921959 14201960 14251961 Series 13941962 Series 1387T966 Series 1443T974 1445T979 1448

MATSUSHITA

ModelT 35 Trans Radio 719MF800 Motional Feedback Amp 810

MONTGOMERY WARD

ModelWG.399A FM Multiplex 768

MOTOROLA

ChassisOTS-436 731 PERMA POWERRTS-436 731

STS -436 731

TS -436 731

11491031

95710211298119612031232

924819951

11421225136312601296136613951419

919919731

ModelG230. 1, 1 Remote Control Receiver 806G340, 50 Transmitter 806

PENNEY. J. C.

Model:1315 1320

TS -467TS -499TS -576TS -578TS -584-05. -HTS 586

SCHEMATIC NO. SCHEMATIC NO.

G-500 & RC200 Remote Control .797

PHILCO FORD

Model.L.1532 Stereo Phono 761L1650 Stereo 764M1618 Stereo Phono 822M-1660 Stereo Phono 822NT 600 Radio 86701054 1113RC.65 Remote Control Receiver .737T-63 Trans Radio 7081-909 Trans Radio 824ChassisN1052 935N1200 932N1204 93213N51 75413N52 754I3N53 75414020 855I4N30 87114N50 86215020 905I5J25 100715J27 88415M91 89815N30 914I5N50 921I6J27 98016JT26, A 96516N35 97116NT82 1017160185 101717C21, A, V, AV 109917J25 108417J27, 27A 106317J28 109617KT50 101717N35 104917NT45 107818CT24 130518J32 1151181_33 113018LT43 113718N145 1125180T85/18MT70 111819FT6OB 127719HT15 125019KT4OB 1242

MUNTZ 19KT50/508 1207I9L21 1233I9P22 1226190T85R 119719532 123520HT70 1332

OLYMPIC 20HT71 133220L23 1264

Model' 20P22 12993P70 1430 20P24 12676P28, 6P29. 6P30 992 200774 13589P44 1275 200775 13729P45 1275 20R27 12769P46 1275 20ST30AV 14229P54 1275 20532/A 12939P94 Series 1379 20733 1287CT 910 1064 20V35 12539P56. 57, 58 1095 21HT15 . 14349P59, 60 1090 21KT41 136791.1901/1091 1245 21L23A 1439Chassis: 21ST31V 1438CTC-19/21 Series 1077 21ST90, 91 1347CTC 31 1231 22LT45/R ..1401CTC-1940 1218 220179 1396

700931

11071089104712581424

752681763913904

TS -587 919TS -588 964TS -589 899TS -592TS -594TS 596TS -597TS -599TS -611TS -612ATS -613TS -908C-02 to 1)-02TS -912ATS -914A-00 to A-07TS -921 SeriesTS -924B, CTS -929TS -930 SeriesTS -934TS -934 (Late prod.)TS 938TS -938 (Additional Inforrnaloph)TTS-587VTS 587WTS 436Model.202 Auto Radio 727203 Auto Radio 727204 Auto Radio 7272TMR Auto Radio 69112MAM Auto Radio 66119P7-1, .2, -3 7001975, 7, II, 12, 13 and

A19T8 Series 731C2AA-18806-M-N Auto Radio 741C2YA-18806-E Auto Radio 741RV2F C2OZ18875.0

Auto Radio Reverb 723

Chassis:768A14768A15768H28

940940947

CTC 400 1255JU.JCU 710NB 820NBU 820NDP 1013NEC 1365

PACKARD-BELL

Model:23DC 16 748MPX-1-1 Stereo Adapter 716MSJ-202 1134MSJ-204 1134 Model:Chassis: 193 -A -542 -MV, MU 73088-16 877 193-A-546-VM. MU 73081318C 941 193-A549.MV, MU 73088.19 970 213-0-21 -M 73698C15 1083 213 -G -23-M 73698C17 1131 213.G -23R 736

213 -G -26M 736PANASONIC 213 -G -27M 736

Model. 213 -G -27-R 736

CT -771 1402 213 -G -31-M 736213-G31 -R 736213 -G -33-M 736213 G -33-R 7364VC6 Record Player 7984VC8 Record Player 798

1316 A-89 1286 4VF606 Stereo Hi Fi 827

PHILHARMONIC

Chassis.TSL 001 689

RAYTHEON CO

ModelRaytheon Two -Way

Encoder/Decoder 895

RCA VICTOR

4VF705 Stereo Hi Fi 827KRI05/112 KRK112 with 96209 . 856KRK105/KRK66 Series 856Mark 11 Citizen Band Radio 645RFG35 Radio ...... 863

SCHEMATIC NO.

RK-295 Stereo Adapter 721RP -215-C1 Record Player 848Chassis:CTC11 706CTC12, A, B, P, R 736CTC16, X 885CTC17X 952CTC19 984CTC20 1032CTC22 Series 1109CTC25 1040CTC27X Series 1261CTC28 Series 1136CTC31 Series 1144CTC35 Series 1132CTC38 Series 1237CTC39XAA 1319CTC40 1219CTC41 1314CTC43 1308CTC44 Series 1368CTC46 Series 1373CTC47 Series 1278CTC48 Series 1444CTC49 1342CTC50 Series 1381CTC51, 52 1436CTC54 1440CTC55 Series 1378CTC59 Series 1408KCS3OF , H, K. M 687

YAC 7051008

ML Series 1161879

Series 744B 730

KCS142 834KCS142XA 982KCS143F 906KCS144E 998KCS147A. B 786KCS148 927KCS149AA, AB, AD 942KCS161A 917KCS152A 915KCS153 959KCS154A, B 948KCS155 966KCS156 1019KCS157 Series 1116KCS158 Series 1119KCS161 1022KCS162 ... 1028KCS163 Series ..... 1065KCS164 1050KCS165 Series 1104KCS I68 Series 11/5KCS169 Series 1192KCS169X Series 1306KCS171 Series 1198

Series 1385KCSI 73 Series 1180

Series 1182Series 1204Series 1269Series 1251Series 1270Series 1340

. . . 1331

. . .1315..... 1339.. . . . 1404KCS188 .... 1410RC 1214A Radio 792

1216 Radio 863RS -200 Stereo Adapter 721RS 206-A Record Changer 868

SETCHELL CARLSON

Chassis:401 1066

1201

SILVERTONE

Model.61226150

615661576164

712071217122712871317151715271547155

.1009995995995995995995995

1000102610261026103810381026102610261098109810981098

SCHEMATIC NO

7156 10987157 10987158 109881401, 411 421 1167Chassis:456 61580 955456.61581 955456.70120 967456 70121 967528.61580 955528.6J581 955528.70120 967528 70121 967528.70270, 71 1133528 71120 1120528.71150 1138528.72280 1114528.72281 1114528.72282 1114528.72500 1160528.72940 1249529 61580......955529.61581 955529 70120 967529.70121 967562 10096 972564 10000 972564 10003 972564 10000 988564.10001 988564 10002 988564 10003 988564 10004 988584 10005 968

SONAR

Model"G" CB Transceiver

SONORA

SCHEMATIC NO. SCHEMATIC NO.

018-1, .2, -3 1423 V2407-4 Radio 789sis: 11110D16-2 1338H -M1900, 01 03 Phono 734D17-1-2 1413 Chas

019.1. -2, -3 1388801-1. -2, -11, 12 1322406-3 Stereo 859558-1, -2 704562.-3,-4 757577. -1. -2 851584-1 thru 7 933585-1. -2, -4, -5 922682-1, -2, -3 Trans Radio 668

SYMPHONIC

Chassis.TSL -001 747

TELECTRO

Model.215 Tape Recorder/Radio 807MM -214 Tape Recorder 801

TELEFUNKEN

Model77 Stereo Tape Recorder 715

TOSHIBA

Model.97L-3655 Trans Radio 685Chassis.10PG 712

TRAVELER

Model563PI97S63PI97564K236MS65P198 TRUETONE

SONY2DC1300C 780

Chassis- Model1194 194 869 2DC13008 767

2DC1300C 767Model 2DC1301C 7805 303W 751 ?DC 13028 767TRW 621 Trans Radio 690 2DC1302C 780

20C13038 767SPAIITON 2DCI 303C iriuModel12M5 P Stereo PhonoChassis19L123K2

SYLVANIA

ModelGTC 3014A. B 821GTC 3114A 821

770 GTC 4014A 821GTC 4044A 821GTC-4054A 821GTC-4114A 821GTC-4t44 821GTC.4154A 821Chassis1156.89 696

8528529891080

2DC1501A, B 8942DCI605 983

732 2DC1605

765714

10792DC1803 11102DC2555 10792DC3651 9492DC3712 10732DC3741 1041

Model: 2DC3815 115619L17 Series 704 2DC3818 112721TC1-C2 851 2DC3819 116821LC3 851 200910 122221LC12.1 851 2DC3918, 19 121021LC14 1 851 2DC3920 .119323E01 757 2DC4815 117845C31 1 Stereo 738 3912 122745P36 Stereo 859 Chassis55C31.1 Stereo 738 1096 243 . 78809400 Stereo 738 1095-232 729ChassisA02 I. -2 999 UNITED SCIENTIFIC LABSA04-1,-2 1051A043 1234 Model:

A06. A07 1035 Contact 23 CB Transceiver 986

A061, .2 1085A09 1 1369 UTICA

A10-1 1409 Model804.1,-2 968 T&C11 CB Transceiver 805B05.1. -2, 3 973806.1..2, -3, 960 VOICE OF MUSIC806-1. -2. -3, 4,-5 1108809-1, -2 1122 725 Tape Recorder 850

B10-1, -2 1209610.7, -12 1450 WEBCOR

812-1,-1 1247 Model-813-1 1350 1376 Stereo Phono 735814-1 1321 1377 Stereo Phono 735D01-1, -2 925 4210 Amp/Speaker System 749001.1, -2, -8 1043D03, -3 987D05 1024 WESTERN AUTO006-1, -2 1091007-1 -2 1115 Model.

D08-2 1154 DC3438 Trans Radio 776

D09-1, -2,-4 1150 4DC7260A Tape Recorder 840

011-1. -2 1190 4DC7465 Tape Recorder 803

D12-20, -21 1343013.2 1243 WESTINGHOUSED1434 1301 Model:

V.2409-4, -5, -6, -7, -8 688V2417.1, -2, -3, -4, -5, -6 711V.2436 758V-2444-1, -2, -3 -5, -6, -9,V 2444.1,-2, -3, -9, -10

-10 ....795837

V-2446-1,-2. -3. -4 825V-245t-2CB Transceiver 774V-2451-2 CB Transceiver 817V2474-1, -2, -3, -6, -7 875V-2475-1, -4 887V2476-1, .4 900V-2478-1,-2 907V2483-1 1053V2495-11 961V.2486 Series 996V-2487 Series 1002V-2490 Series 1014V.2496 Series 1023V-2498 Series 1029V.2515-2 Phono 734V-2515.6 AM/FM/Tuner 771V-2528-3 Radio 846V.2652-2 1092V.2655-2-3-4-7-8-13 1058V-2656-1-2 1121V 2659 Series 1143V-2660 1162V-2664 Series 1157V-8001 1213

ZENITH

Model.40 Radio 857Royal 50L Trans Radio 781Royal 490 Trans Radio 811Chassis.1Y211355 11396JT40Z1 Trans Radio 7206JT41Z1 Trans Radio 7206KT4OZ1 Trans Radio 7816KT50Z8 Radio 8577KT4.5Z1 Tians Radio 8118Y4836 114512A8CI4 130212A16, M, S, Z, MZ, SZ 136012A10C15 1272121314C50 144112BC15, 12B9C16 143712CB12X 14141M30T20 97713Al2 132513M15 923I3X15 103413X18 108611Y12 117613Y16, Z 124613Z12, 13Z12S 122813Z13 1187

14A9C29 . 118714A9C50 132414A10C29 130914836 133414838Z, 39Z 135514CC14Z 141814DC15.16 144914L20 842141-25 83814M20 89314M21 105414M23 87814M27 91614M32 93414N22 100114N26 95814N27 108014N28 101014N29 96914N29Z 106714N31 98614X21 103914Y21Z 116914Y33 116314Z21. 14Z21Z 125214237 121614Z38, I4Z43 124015M22 90815Y6C15 117416J280S 69816K20. OS 739I6N24 10061628C19 128419CB36 140519CC19 139719DC20 142820YJ37 112623XC36 102724NC31 99425CC55 138325MC30 88625MC36 92626KL20, 200S 77927KC20, 0 72840BC50 1348S-54344 Hand Control 799

D15-1, -2 1333 H -883N29 Radio .846 S 60804, 44, 1013 Remote Control .799D15-3-5 1382 H M1800. 01, 03 Phono 734 175-141, -301. 302,.171 Tuner ..623

COPYRIGHT 1972 BY ELECTRONIC TECHNICIAN/DEALER 1 EAST FIRST STREET. DULUTH. MINNESOTA 55802

GROUP

241

ELECTRONICTECHNICIAN/DEALER

COMPLETE MANUFACTURER 5' CIRCUIT DIAGRAMSAND TECHNICAL INFORMATION FOR 4 NEW SETS

SCHEMATIC NO. SCHEMATIC NO.

GENERAL ELECTRIC 1447 SYLVANIA 1450TV Chassis BA TV Chassis B10-71-12

MAGNAVOX 1448 ZENITH 1449Color -TV Chassis T979 Color -TV Chassis 14DC15, 16

COMPLETE MODEL CHASSIS INDEX FOR ALL CIRCUIT DIGESTS AND TEKFAX

FROM JANUARY 1962 THROUGH DECEMBER 1972

MONTH IN WHICH SCHEMATIC APPEARS

681-686 Jan. 1962 951-953 Sept. 1965 1223-1228 May 1969687.692 Feb. 1962 954-961 Oct. 1965 1229-1234 June 1969693.698 Mar. 1962 962-969 Nov. 1965 1235-1240 July 1969699.705 Apr. 1962 970-975 Dec. 1965 1241-1246 Aug. 1969706-709 May 1962 976-982 Jan. 1966 1247-1252 Sept. 1969710.716 June 1962 983-988 Feb. 1966 1253-1258 Oct. 1969717-723 July 1962 989-995 Mar. 1966 1259-1264 Nov. 1969724-729 Aug. 1962 996-1001 Apr. 1966 1265-1269 Dec. 1969730-735 Sept. 1962 1002-1009 May 1966 1270-1275 Jan. 1970736-743 Oct. 1962 1010-1015 June 1966 1276.1281 Feb. 1970744-749 Nov. 1962 1016-1022 July 1966 1282-1287 Mar. 1970750-755 Dec. 1962 1023-1028 Aug. 1966 1288-1293 Apr. 1970756-761 Jan. 1963 1029-1035 Sept. 1966 1294-1299 May 1970762-766 Feb. 1963 1036-1041 Oct. 1966 1300-1305 June 1970767.772 Mar. 1963 1042-1047 Nov. 1966 1306-1310 July 1970773-779 Apr. 1963 1048-1054 Dec. 1966 1311-1315 Aug. 1970780-784 May 1963 1055-1060 Jan. 1967 1316-1320 Sept. 1970785-790 June 1963 1061-1067 Feb. 1967 1321-1325 Oct. 1970791-797 July 1963 1068-1073 Mar. 1967 1326-1330 Nov. 1970798-805 Aug. 1963 1074-1080 Apr. 1967 1331-1334 Dec. 1970806-811 Sept. 1963 1081-1086 May 1967 1335-1339 Jan. 1971812-817 Oct. 1963 1087.1092 June 1967 1340-1344 Feb. 1971818-822 Nov. 1963 1093-1098 July 1967 1345-1349 Mar. 1971823.828 Dec. 1963 1099-1104 Aug. 1967 1350-1354 Apr. 1971829-833 Jan. 1964 1105-1110 Sept. 1967 1355-1359 May 1971834-838 Feb. 1964 1111-1116 Oct. 1967 1360-1364 June 1971839-843 Mar. 1964 1117-1122 Nov. 1967 1365-1369 July 1971844-850 Apr. 1964 1123-1127 Dec. 1967 1370-1374 Aug. 1971851-853 May 1964 1128-1133 Jan. 1968 1375.1379 Sept. 1971854-858 June 1964 1134-1139 Feb. 1968 1380-1384 Oct. 1971859-863 July 1964 1140-1145 Mar. 1968 1385-1389 Nov. 1971864-870 Aug. 1964 1146-1151 Apr. 1968 1390-1393 Dec. 1971871-875 Sept. 1964 1152-1157 May 1968 1394-1398 Jan. 1972876-881 Oct. 1964 1158-1163 June 1968 1399.1404 Feb. 1972882-887 Nov. 1964 1164-1169 July 1968 I 1405-1409 Mar. 1972888-893 Dec. 1964 1170-1175 Aug. 1968 1410-1414 Apr. 1972894-900 Jan. 1965 1176-1181 Sept. 1968 1415-1419 May 1972901-908 Feb. 1965 1182-1187 Oct. 1968 1420-1424 June 1972909-916 Mar. 1965 1188-1193 Nov. 1968 1425-1429 July 1972917-923 Apr. 1965 1194-1198 Dec. 1968 1430-1434 Aug. 1972924-926 May 1965 1199-1204 Jan. 1969 1435-1438 Sept. 1972927-934 June 1965 1205-1210 Feb. 1969 1439-1442 Oct. 1972935-942 July 1965 1211.1216 Mar. 1969 1443.1446 Nov. 1972943.950 Aug. 1965 1217-1222 Apr. 1969 1447.1450 Dec. 1972

SCHEMATIC NO

ADMIRAL

ChassisC21812 1. 1AG, lAS, 1HR,

1N, 1R. IC 910C21813 1 910C21815.1, 1AG, 1AS 910C21C12.1AG, lAS, 1C 910C21C15-1, lAG, lAS 91004 883D11 890D42 1 883D44 1.2,4 883D61 I, -2, -4 8440412 1 883D414 1,2,4 883D415 1 88304161, 2, 4 883D610-1, -2, 4 844D761 1 928D1160-2,-6 89001161 2, -6 890D4117 1 883G2 991G3 956G4 944G5, 205, 3G5. 505, 705, 905 1074G6 93607 Series 976G11 920G13 Series 997G61 2 936G310.1, -4 956G336 1 956G416 I, 5 944G4171 944G422 1 944G610.2, 3 936G612 1 936G613 1 936G617 2 9366618.4 936G620 1, 2, -3, -4, -6 93601161.2..3 9181-41 1A. H2 1A 1016HI IA, 1H1 1A. 1AH1. H2 IA 1300H3 IA, H4 1A, 1H4 2A 1093H10 1069H12, 1H12 1044KIO 1346K15 1147K20 1351NAI IA 1273NAIO IA 1429722H4 IAX 1326T3K3 1A, T3K3-18 1294T3K4 1A. T3K4.18 1205T7H2 IA, T9H1.1A 1281TG2 1 1170TG2 2 1291TH3 IA, TH4-1A. T2H4.1A

T3H4-1A, T8H4-1A 1199TIOH1 IAX 1217T11K10-1A 1431TK2 14 1241TL2 1316TR2 1380TR3 1399104 8831011 8901013 2 8831 042 2 8831061 1 90310412.2 88310611.1, -2, -3, 4 90310760-1 92810761 1 928101160.5 890101161.5 89010310.1 95610311.1 9561031 1 95610611.1 936101155-1 9181K18 IA, .2A 1391204 8832011 8902D42-1 88320412 1 88320413-1, 3, 4 88320414-1 88320415-3 883201163 1 890204 94420421 1 9442K16 136170413 1 873804 88380418 1 8838G4 94480423-1 944930 Series 138690410.1 8839D412-1 8839G4 9449G410-1 94490413-1 94496416.1 94416A41) C 82316B4C 823

SCHEMATIC NO.

16UA4D C 82316l1B4C 82318D8B 6861988B 68619H10 1317

19K3U 81619M3U 81619R3U 816I9T3U 816I9UB8B 68619UD8B 68624A2 8082482 80824C2 8082402 80824UA2 808240E12 80824UC2 80824UD2 80824UE2 808

AIRLINE

Chassis

1078 233, 243, 10780233, 243. 76610 116.254U 8471174 184. 117U-184. 1188-184 . 83112.124.24U, 12.124-34U 909Model:

GC1-11102A. 1028. 132A, 1328 1403GC! 12102A 1411GC1.12420A. B 1295GC1 12460A .. 1337GC' 136688 1282GC! 14821A, 41A, 51A 1389GCI 17821A, 41A, 51A 1371GEN 12440C 1312GEN 13460A 1304GEN 113A Radio /8/GEN 1225A Trans. Radio 753GEN 1266A 945

N 1866A I003GEN 1867A 1036GEN 1967A 1081GEN 2485A 902GEN 8077A. GEN-8447A 1106GEN 11160A 1274GEN 11269A 1208GEN 11460A 1256GEN 11461A GEN114814 1330GEN 11469A 1202GEN 11760A 1279GEN 117698 1220GEN 11960A 1292GEN 11961 1354GEN 12069A 1183GEN 12078A 1165GEN 12349A 1183GEN 12442A 1426GEN 12448A 1165GEN 13160A 1244GEN 13168A 1146GEN 13469A 1165GEN 137688 1238GEN17148A 1165GEN 17158A 1165GHJ-1466A 978GHJ 1566A 978GHJ-1786A 978GHJ-45164 978GHJ-4548A 978GHJ-4556A 978GHJ 3067A 1042GHJ-3367A 1042GHJ 8247A 1100GHJ 8257A 1100GHJ.14098A 1128GHJ-14148A 1128GHJ 14158A 1128GHJ 14549A 1223GHJ 14829A, GHJ-14849B,

GHJ 148598 1229GHJ 17949A, 59A 1189GMW.1447A 1068GMW 1457A 1068GMW14447A 1087GMW.14457A 1087GTC I684A 831GTC 1694A 831GTC-2684A 831GTC-3914A 847GTC-3944A 847GTC-3954A 847GTC-4015A 909GTC-4415A 909GTC 4445A 909GTC 4455A 909GTC 4914A 847GTC 4944A 847GTC-4954A 847GTM 1583A 784GTM-1827A Clock Radio 814GTM 2583A 784GVC-9019A Reverb 800WG 1683A 746WG 2313A AM/FM Console 778WG 2343A 778

WG 2373A, BB 778

SCHEMATIC NO.

WG 23438 778WG 23738 778WG 2683A 746WG 2785A 888WD -4234A 694WG 4334A 694WG5220A 655WG 5226A 655WG 5230A 655WG 5320A 655WG 5326A 655WG-5330 655WG 6050E1 713WG 60518 713WG 6052E1 713WG 61508 713WG 61528 713

ANDREA

ChassisVTT323-5 818

CHANNEL MASTER

ChassisT5001 Series 1416

CORONADO

Chassis.1197-153 . 860Model:TV2-7110A 1124TV2.7112A 1129TV2 7310A 1117TV2-9368A 1015TV2-9398A 943TV2 9442A 783TV2-9453 A 1105TV2.9454A 1070TV2 9552A 1061TV2-9553A 1061TV2 9590A 643TV2 9591A .643TV2 9592A .643TV17 9386A 860TV 17 9444A 743TV21 9367A 1102TV2I -9643A 1094

CURTIS MATHES

ChassisTV -17, 17.1 1057TV 19-1 937

DELCO

Model7276605 Auto Radio 6847284742 Reverb Unit 8047284893 Reverb Unit 8047286315 Cadillac Auto Radio 815980464 Radio 777980655 Auto Radio 826980886 Auto Radio 8649821137 Radio 793983687 Auto Radio 707985332 Auto Radio 701985431 Radio 769985694 Auto Radio 833R59 and 7.59-12V Garage

Door OpenerTransmitter/Receiver 724

DUMONT

Chassis4KI6 1356120509-8 Stereo Amp 733120591A 7091205928 709120593A 709120622A 8021206238 802120633 Series 900 756120644A 802120677A 8131206788 813120679A 813120684A 813120688A 802120689A 813120699 891120708 876120712 876120722 891120725 876120780 962120783 962120804A, B 1071120805A, 8 10711208068 1071120807A, B 1071120810 962120827.A 1025120846.8 10251208478 1025120856A, B 1056120857A. B 1056

SCHEMATIC NO

120926. 28 1230120926, 928, 957, 958 1327

ELECTROHOME (CANADA)

ChassisC6 1268C8 1289M4 1185M6 1188MIOCHT 213 611 697Model20424 1 94420632 1, 2 936201156 1 918201157 1 918

2H5 11522H5, 3H5, 4H5, M2H5,

M3H5, M4H5 12113011 890301160.1, 3, 4 890301161.1, -3, 4 890301162-3 .890303 Series 105530611.1 936301155.2,-3 9183H5 11523H10, 4H10, 5H10 Series 10824D6 9034011 89041)44 3 . 68341)1160 7 890401161.7 890404115.3 88340640.1 93640641.1 93640645 1 9364H5 11527043 1 873Beaucourt 841Chancellor 841Kalmar 726Kimberly 726Orlando, U, CU 874Satan, U 854Vermount 841

EMERSON

Chassis5K1675-2-3 142730KI7 140032K1673-32, 16864, 1687.2 1421920 1362120507A, 88 6951205I5C, -160 695120530C 648120541C. 420 695120572C 7181205730 718120642-42 Chrome Board 870120655 Trans Radio 775120664 Radio 775120664L Radio 775120671 872120673 872120692A 791120697 872120698 872120702 872120708 830120712 830120725 830120732 AM/FM Tuner 880120740 872120743 872120744 872120753 872120758 929120759 929120760 929120771 938120779 946120780 946120781 946120782 946120783 946120784 946120785 946120804 1045120805 1045120806 1045120807 1045120823 1045120837 1033120839 1033t20840 1033120841 1033120842 1033120843 1033120846 1033120837 1033120848 1033120852 853 855 1172120883, 884, 890, 896 1153120894 1212120895 1212

COPYRIGHT 1972 BY ELECTRONIC TECHNICIAN/DEALER 1 EAST FIRST STREET, DULUTH. MINNESOTA 55802

PROVIDES YOU WITH ACOMPLETE SERVICE FORALL YOUR TELEVISIONTUNER REQUIREMENTS.

VHF Or UHF any Type $9.75.UHF/VHF Combo $15.00.

In this price all parts are included.Tubes, transistors, diodes, and nuvistors arecharged at cost.

Fast efficient service at any of ourconveniently located service centers.

All tuners are cleaned inside and out,repaired, realigned and air tested.

TSC

Replacement Tuner $9.75.This price buys you a complete new

tuner built specifically by SARKES TARZIANINC. for this purpose.

All shafts have a maximum length of12" which can be cut to 11/2".

Specify heater type parallel and series450mA or 600mA.

Customized tuners are available at acost of only $15.95

Send in ycur original tuner for com-parison purposes to:

TUNER SERVICE CORPORATIONFACTORY -SUPERVISED TUNER SERVICE

Backed by the largest tuner manufacturer in the U S.-Sarkes Tarzian, Inc.

HEADQUARTERS 537 SOUTH WALNUT ST., Bloomington, Indiana 47401 TEL: 812.332-7251

IN DIANA 817 N PENNSYLVANIA ST., Indianapols, Indiana 46204 TEL: 317-632-3493

ARIZONA 2621 NORTH 1st AVENUE, Tucson, Ariz. 857' 7 TEL: 602-791-9243

CALIFORNIA SARKES TARZIAN, Inc. TUNER SERVICE DIVISION10654 MAGNOLIA BLVD., North Hollywood, California TEL: 213-769-2720

FLORIDA 1505 CYPRESS ST., Tampa, Fla. 33606 TEL: 813.253-0324

GEORGIA 938 GORDON ST., S. W., Atlanta, Georgia 30310 TEL: 404-758-2232

KENTUCKY 2920 TAYLOR BLVD., Louisville, Kentucky 40:08 TEL: 502-634-3334

NEW JERSEY 547.49 TONNELE AVE., Jersey City. New Jersey 07307 .... TEL: 201-792-3730(On U S. Highway ' & 9)

TENNESSEE 1703 LAMAR AVENUE, Memphis, Tenn. 38114 TEL: 901-278-44841215 SNAPPS FERRY RD.. Greeneville, Tenn. 37743 TEL: 615-639-8451

VIRGINIA 4538 PRINCESS ANNE ROAD, Norfolk, Virginia 23502 TEL: 703-855-2518

WATCH US GROW... for more details circle 128 on Reader Service Card

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER I 19

PHILLIP DAHLEN, CETEditor1 East First StreetDuluth, Minn. 55802(218) 727-8511

ALFRED A. MENEGUSPublisher757 Third AvenueNew York, N.Y. 10017(212) 572-4839

TOM GRENEYPublishing DirectorJOSEPH ZAUHARManaging EditbrGAYNELLE DAVIDSONProduction ManagerJOHN PASZAKGraphic DesignLILLIE PEARSONCirculation FulfillmentJOHN KESSLERManager, Reader Services

MANAGERS

JIM SMITH, CET43 East Ohio StreetChicago, Ill. 60611(312) 467-0670

CHUCK CUMMINGSAd Space South/West613 North O'ConnorIrving, Texas 75060(214) 253-8678

KEN JORDANDONALD D. HOUSTON1901 West 8th StreetLos Angeles, Calif. 90057(213) 483-8530

CHARLES S. HARRISONCY JOBSON57 Post StreetSan Francisco, Calif. 94104(415) 392-6794

ROBERT UPTONTokyo, JapanC.P.O., Box 1717

ELECTRONICTECHNICIAN/DEALER

DECEMBER 1972 VOLUME 94 NUMBER 12

This month's cover photo is supplied through the courtesy of the Ford Motor Co.

3 TEKFAX: Up-to-date schematics for easier servicing.

23 EDITORIAL: Merger? We're for it!

24 LETTERS: Pertinent comments concerning past issues.

27 NEWS: Events of interest to our industry.

30 READER'S AID: What you need or have for sale.

31 BOOK REVIEWS: Our appraisal of recent publications.

32 NEW AND NOTEWORTHY: Merchandise of special interest.

FEATURES

39 TEKLAB REPORT

Some interesting features of a professional dual -trace, triggered -sweep scope thatwas assembled by our own staff.

42 ELECTRONIC SECURITY

Part II-A description of basic automatic telephone dialer circuitry by Terry Tuttleand Tom Turnbull.

45 BASIC DIGITAL CIRCUITRY

The second in a series of articles explains how flip-flop circuits can be used forcounting to ten.

50 NATESA PLAN TO CREATE CONFIDENCE

Another approach for certifying the work performed by qualified electronictechnicians.

52 BETTER MERCHANTS MAKE BETTER PROFITS

William Joseph tells how an effective direct -mail program can help eliminate thoseseasonal business slumps.

66 1912 ARTICLE INDEX

The page and issue of the articles and reference material that you may wish toreview for help in servicing or developing better business principles.

54 COLORFAX: Tips for easier color -TV set repair.

56 TECHNICAL DIGEST: Hints and shortcuts for more effective servicing.

58 NEW PRODUCTS: Instruments and components to make your job easier.

61 DEALER SHOWCASE: These items may increase your sales revenue.

62 TECHNICAL LITERATURE: Informative material that you may need.

68 ADVERTISER'S INDEX: Manufacturers concerned about you.

69 READER'S SERVICE: A source of additional information.

IL -A HARCOURT BRACE JOVANOVICH PUBLICATION Tiv:0

HARCOURT BRACE JOVANOVICH PUBLICATIONS: James Milholland, Jr., Chairman; Robert L. Edgell,President; Lars Fladmark, Senior Vice President; Richard Moeller, Treasurer; John G. Reynolds,Vice President; Thomas Greney, Vice President; Ezra Pincus, Vice President; Bruce B. Howat, VicePresident; James Gherna, Vice President.ELECTRONIC TECHNICIAN/DEALER is published monthly by Harcourt Brace Jovanovich Publications.Corporate Offices: 757 Third Avenue, New York, New York 10017. Advertising Offices: 43 EastOhio Street, Chicago, Illinois 60611 and 757 Third Avenue, New York, New York 10017. Editorial,Accounting, Ad Production and Circulation Offices: 1 East First Street, Duluth, Minnesota 55802.Subscription rates: One year $6, two years 510, three years $13, in the United States and Canada.Other countries: one year $15, two years $24, three years $30. Single copies: 75 in the U.S.and Canada; all other countries $2. Second class postage paid at Duluth, Minnesota 55806 andat additional mailing offices.POSTMASTER: Send form 3579 to ELECTRONIC TECHNICIAN/DEALER, P.O. Box 6016, Duluth,Minnesota 55806.Copyright (:) 1972 by Harcourt Brace Jovanovich, Inc. All rights reserved. No part of this publica-tion may be reproduced or transmitted in any form or by any means, electronic or mechanical,including photocopy, recording, or any information storage and retrieval system, without per-mission in writing from the editor or publisher.

20 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

Everytime we introduceanew product,

you become more important.New products mean mo:e business.Not only for us, but for you. hide -pendent service technicians. Oncea product leaves our bards, :t's inyours. Along with our reputationfor mLking quality electronicsAnd for standing behind themThat's why you're so import Art tous. You help us maintain our goodname. Product after produc:. Yearafter year.

Our products are designed not tobreak down. But the prcient stateof the art, and the contir uous lowof new and unique products, r.. -on -

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We dtink about you even 'oeforewe in:roduce a -product. We buildour eqi:pment for easy iervice-ability Service iterature and re-placement parts are orourummedtc be available when a productgoes Ic market. Not -months later,when L. customer may nr'. help.There's no delay for you. No in-,convenience for yon- cuswmer.

As a special feature, we subscribeto a country -wide, lc 4l f-= tele-

pbone referra: system. It opera:es24 hours a dab, ?65 dais of theyear. Wnen a customer calls 800-243-6000 askine fcr Panasonicservice, he is referred t 3 the imrestauthorizer: independert service.center. Yes, our nationwide net-work of authcrizedserwice (milersis mrde up of men Eke you, inde-pen3ent servim- technicians.Panasonic deperdson you. Fcrin-warrr_nty arc out -of -warrantywork. It adds up to morehusinessfor you. Anc, :es no wonder thatyou become more important to us.

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The B&K Precision Model 281. A solid-state, lab -quality portable instrumentthat measures AC/DC voltage, current and resistance

The state-of-the-art Model 281 shows readings on a large, clear,21/2 -digit numeric display. It also has positive over -range and reverse -polarity indication. There's no need to switch leads. You can reverse polarityat the flick of a switch.

Model 281 readings are faster and more accurate than analog -typemeters. Unlike hard -to -see needle indicators, you can read the large,illuminated numerals-including the decimal point-from a distance.

Featured are 26 ranges: five DC voltage, 100mV to 1000V, with 1%accuracy and 10 megohms input impedance; five AC voltage, 100mV to 1000VRMS, five DC current, 100i A to 1A; five AC current, 100/4 A to 1A; and sixresistance, 10 ohms to 10 megohms.

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. . . for more details circle 102 on Reader Service Cad22 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

EDITORIAL

Merger? We're for it!

Those publica-tions really con-cerned about youand your profes-sional future haveprinted muchrecent informationconcerning theactivities of theNational Allianceof TelevisionElectronic Service

Association (NATESA) and NationalElectronic Associations (NEA) asthey prepare to develop a workableagreement for merger. As you probablyknow, NATESA is a national associationof electronic service dealers (only),and NEA is a national association ofelectronic service dealers, plus (in manystates) electronic technicians-theInternational Society of CertifiedElectronic Technicians (ISCET) alsobeing an arm of NEA.

These groups represent the onlynational associations that we knowof that are concerned exclusively withour phase of the electronic industry.They are to be commended for the workthat has been done to improve thepublic image of the electronic technicianand service dealer, to providegovernment with a more enlightenedunderstanding of our profession, and tohelp those in our industry increasetheir revenue through more effectivesales, servicing and business procedures!

Previous issues of ELECTRONICTECHNICIAN/DEALER have given quitea bit of coverage to the First JointConvention, held last August in NewOrleans. Those of you who missed it,missed a sight that many of us willnever forget-for as we ate together asone group, we filled the huge diningarea-even at breakfast!!! And wewere not the only ones impressed byour size. So were the manufacturersthat came to see us!

As much as you and I cherish our

personal independence, it frequentlybecomes apparent that individually wecannot even hope to accomplish tasksthat can collectively be performed withrelative ease. We simply do not havethe financial, technical, business andpolitical resources to do it alone. Butjust because we work together does notmean that we cannot continue to makeour own personal decisions.

Show me someone active in nationalassociation activities, and I will showyou a person who has developedenough personal success to becomefinancially comfortable, or maybe evenfinancially independent. Show mesomeone who is unable to maintain hisbusiness, and I will show you a personunwilling to give wholehearted support toone of these professional associations.It is just that simple! (There are, ofcourse, others that do not fall intoeither category-those who have hadsome degree of success, but could comecloser to their true potential if theyreally cared.)

I know quite a number of servicedealers who want to take optimumadvantage of association membershipand thus belong to both NATESA andNEA. As an example, Jim Boyd, CET, ofRockledge, Fla., is not only ViceChairman of ISCET but an active memberof both NATESA and NEA. And he, likeso many others, is very anxious to seea merger of these two great nationalassociations-thus eliminatingconsiderable duplication of efforts.

But we are not the only ones facedwith such a duplication of efforts.Manufacturers wishing to demonstratetheir support of electronic sales andservicing must (except for our jointconventions) be faced with the choice ofputting up exhibit booths at either oneconvention or the other-or not wantingto appear partial, at both conventionsor neithe' convention. And in the samemanner, they are faced with the questionof what association activities to support,

and what efforts to duplicate or ignore.It was about 10 years ago that there

were disagreements among certainmembers of NATESA, and some leftthat association to form NEA. Sincethen, a number of those people haveleft their respective associations, andthe two associations have becomeincreasingly cooperative-NEA becomingthe larger of the two groups.

Both of these associations aresincerely dedicated to the task of up-grading our profession. Both associationshave dedicated leaders that have earnedthe respect of the industry. Neitherassociation can hope to accomplish amerger without respecting the rightsof the other.

Last month's issue of ELECTRONICTECHNICIAN/DEALER included a detailedreport of the first meeting of the JointMerger Committee. Both associationshave since had executive council orboard meetings endorsing the results ofthis first Joint Merger CommitteeMeeting. The second (and possibly final)Joint Merger Committee Meeting wasscheduled for December second andthird in Denver, Colo.-having been heldmuch too recently to be reported inthis issue.

It is quite possible that there may notbe a Joint Convention in Kansas Citythis coming August. By that time themembers of both associations may havealready approved the merger, and it mayinstead be a convention of the newassociation.

We are 100 percent behind this mergerand are very pleased to see how wellthese efforts have proceeded. The newassociation will be even better able tohelp improve the lot of the electronictechnician and service dealer.

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 23

LETTERS

Reader comments concerning pastfeature articles, Editor's Memos, previousreader responses or other subjects ofinterest to the industry.

Still Considerable ConfusionI have read the various comments

of the readers regarding CB Radio,and there still seems to be a great dealof confusion regarding what can bedone and what cannot be done. I willput my two cents in for what it isworth.

I am a holder of an FCC Licensewith a Radar Endorsement, and haveheld this license for 18 years. Accord-ing to the letter of the law, I can main-tain all types of two-way radios, in-cluding CB units. Also, I am a memberof the American Association of Engi-neers.

I have taken care of approximately125 60 -to -100w mobile units and 5100 -to -300w base stations. This inaddition to the engineering that goeswith it.

I am not bragging, but setting myqualifications down on paper so thatyou can see that I am speaking factsas they exist.

1. What could I [if without an FCCLicense] fix on a CB unit? (This is aquestion that many TV/Radio tech-nicians ask, both themselves andothers.)

A. You can fix (maintain) anythingthat does not affect the frequen-cy nor the power. You canreplace tubes in the receiverand so on. But, DO NOT RE-PLACE ANYTHING THATWILL AFFECT THE FRE-QUENCY OR POWER.

B. Should I make frequency checks?Yes-just as on the larger two-way radios that are around incars and offices.

2. Do I need a copy of the rules andregulations?In Part 95.105, it states quiteclearly that "Each licensee inthis service shall maintain as apart of his station records a

current copy of Part 95, Citi-zens Radio Service, of thischapter." This says "shall main-tain." This does not mean,"could," "maybe," "when I getaround to it," "next week." Itmeans "right now." Many peo-ple who are taking care ofCitizens Band radios do nothave the current Part 95. Thiswill spell out exactly what you

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can do and what you cannot do.Too many TV/Radio technicians

are getting all upset about what theycan do and what they cannot do. Fromthe letters that you have received, it isevident that they do not have a cur-rent copy of Part 95. As I said, thisspells out what you, as a TV/Radiotechnician, can do and what you can-not do.

You may, by rule of thumb, replacetubes, transistors, vibrators, tightenloose bolts, and then inform the ownerthat "this must be fixed by a holder ofa First or Second Class Radio Li-cense."

Just remember, neither you nor Imake the rules, we only live by them.All the "sour grape" people will haveto do is take the examination for a li-cense and they too can fix CitizensBand radios-legally.

Your magazine is very good, but Iwould like to see more two-way radioarticles in it.

Each of us (radio and televisiontechnicians) has his own special inter-est, so I realize that you cannot satisfyeveryone, but in time.. ..

Thank you for listening to me spoutoff, but I just got tired of listening toall the people complain about the menthat have FCC licenses and can fix CBradios, and they cannot (legally). It isoff my chest now.

JOHN E. BUMBALCK

Holds Same ViewAs in Editorial

Your editorial titled, "What'sWrong," that appeared in your Sep-tember issue seemed very appropriateand I thought you might enjoy a fewcomments on your philosophical ap-proach to ELECTRONIC TECHNICIAN/DEALER.

Your "Capitalism" came throughvery strong and indicated to me a typeof character of which our country isbecoming less familiar, namely, "Thehard core middle-class America, withenough sense and understanding tocriticize justly what is wrong with oursociety, and strong enough to holdtheir own individual values and pitthem against an awesome tide of shal-low, decaying minds, whose cures forthe ills of our society are suicidal."

Our nation is becoming a "nation ofsheep." The "follow -the -leader" atti-tude prevails throughout much of oursociety. Self respect, once an inbredquality in individuals, necessary forsurvival, is now a lost concept of be-lief. During much of our AmericanHistory, a man knew his own worthbecause he had to work hard to eatand provide for his family. Now, it isnot even necessary for a man to workto survive. Our welfare system, which

... for more details circle 127 on Reader Service Card

24 ' ELECTRONIC TECHNICIAN 'DEALER, DECEMBER 1972

is responsible for this undertaking, inits final analysis, is the one most singlefactor in our history that deteriorateshuman self respect, the most impor-tant ingredient in the make-up of aman and a great nation.

I'm an individualist too, and a hyp-ocrite on top of that, if that is whatyou call a person who has taken agood hard look at his country and dis-likes what he sees. It is not our youththat is responsible for our apparentdecaying condition, nor is it our gov-ernment-it is simply ourselves. We asAmericans must realize that as a na-tion we must nourish the individual interms of self respect, creative ability,and a genuine depth of character. Thisphilosophy is what it takes to be anindependent service dealer and survive,and this philosophy is what Americaneeds to survive. My hat is off to allindependent business men throughoutour country, for indeed they are thevery backbone of this country, and Ifor one, am extremely proud to bepart of that tradition.

JAMES E. OSBORNE

Afraid of Losing Business?Is Robert 0. Parsons afraid of los-

ing some C.B. Business? If his com-plaint is "unqualified butchering," lethim charge for these repairs. I do.When I get a "botched job," the re-pair price automatically increases $10.

Keep up the good work or stop all"fix -it" articles.

LES A. GOODMAN

Receives Excellent ResponseI am writing to thank you for plac-

ing my free "Ad" in the Readers' AidSection of the September issue ofELECTRONIC TECHNICIAN/DEALER.

I have received to date approxi-mately 25 letters and cards-also afew 12A8 tubes were sent.

I would like to thank all of the kindpeople that responded.

The radio, which belongs to afriend of mine, is now working fine.

MR. G. I. ROBERTS

Possessions Never FoundI want to thank you-first, for fea-

turing my letter in the September issueand, second, for sending me extracopies of that issue.

We have moved back to Mt. Pros-pect, after our disastrous trip to Kan-sas City, and are getting reestablishedagain.

As a direct result of printing my let-ter, a retired TV man in Norwich,Conn. has voluntarily sent me someof his equipment and tools-an act of

generosity that I deeply appreciate.In relation to your Crime Issue-

was the ease in which this large U -Halltruck was stolen. It was parked overnight at a motel near St. Louis, secure-ly locked and in a brightly lit area 30ft. directly in front of our motel door.The thief must have had a duplicatekey.

I might add that in the past sixmonths we have heard nothing aboutour stolen possessions or the 30 ft.truck that they were in. The policehave never contacted us and I doubtif a search was ever made.

Thank you.WILLIAM R. BURGESS

Field Work HintsThe new Vector voltage and current

test adapters are very good, particular-ly for measuring cathode and screencurrent in the horizontal output tube.This is especially useful on house calls,because I'd rather not carry the hori-zontal output tube current meteraround in the car.

I have to take a VOM anyway, andit takes a beating from the vehiclevibration.

Do you know that a meter shouldbe transported face down? The reasonis to put the wear and tear on the front

pivot. We want to protect the rear piv-ot because, for best accuracy, the me-ter lies on its back and the movementbalances on the rear pivot.

Getting back to the Vector adapter,I have one that fell apart from bounc-ing around in the tool box. So, Idrilled a hole through the center of thebase, cemented a nut in the barrel ofthe upper portion of the adapter andinstalled a nylon screw to hold it to-gether. (The screw held the nut inplace while the cement hardened.)

Now, I can disassemble the adapterfor cleaning or just adjust contact ten-sion with a turn of the screw.

EDWARD H. SAMPLE

A Smack of ArroganceAfter reading many of your edito-

rials, I am sure you do agree with meand many other CET's that licensingor certification of technicians is be-coming more and more necessary. Notonly from the consumer's standpointbut also from the shop owner's.

When commenting on a prospectivetechnician from another shop owner,what can be said? "He'll be okay foryour shop?" I consider this commentrather arrogant because how does thisshop owner know what standard of

continued on next page

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... for more details circle 106 on Reader Service Card

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 25

LETTERS...continued from page 25

competence the other shop owner islooking for in a technician? On theother hand, certification makes thecompetence of a CET more uniform.Perhaps the system is not perfect, butit is far better than none or the former.

There have been many commentsconcerning the CET Test in yourmagazine. I give more support to thetheory side of the test. Theoretical ap-plications of troubleshooting are much

more practical. The shotgun method(replacing part after part until eitherthe bad one is found or he's run out ofparts or butchered up the printed -cir-cuit board) should be done away with.

I cannot be sure of someone whocomes to me with no certificates, orwho is not willing to take a practicaltheory test. Some technicians havesaid, "I can fix any set in your shop,but I won't take your test." This againsmacks of a little arrogance. I can'tunderstand how an uneducated tech-nician can possibly locate open orleaky capacitors, open transformers,

When the picture looks good:you look good.

When a color TV picture fades, or when the black -and -white is erased by acathode -to -filament short, you can save the day, and the tube, by installing aPerma-Power Britener.

Boost models bring out lost sharpnessand detail by providing increased fila-ment voltage to increase electronemission. Full contrast and color qual-ity return immediately.

Isolation models restore the black -and -white information that gives acolor picture its quality, by isolating theshort, thus restoring black -and -whitevideo drive.

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both jobs with a Color-Brite Combina-tion Isolation and Boost Britener.

There are Perma-Power Color Britemodels for both round tubes and rec-tangular tubes. In fact, Perma-Powerhas a Britener for just about every pic-ture tube ever made! You'll look verygood to your customer when you pro-long the life of the expensive picturetube. Pick up a supply of Color-Britesfrom your Perma- Power distributor!

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open or shorted transistors without theproper knowledge of the circuitry, be-cause they certainly can't be found byjust looking at them.

It is high time that a technician becapable of more than merely replacingburned resistors, picture tubes, clean-ing tuners or anything that requiresonly the five senses. Through certifica-tion/licensing, we hope technicianswill be more qualified and the stan-dards of competence more uniform.

With proper knowledge of Ohm'slaw, Kirchoff's law and the funda-mentals of vacuum tube and transistortheory, along with the proper use oftest equipment, I am sure a technicianshould be well prepared to trouble-shoot.

Experience will help him a lot, butwith an understanding of the funda-mentals he is less apt to tell his boss,"Gee, I never ran into this before,"which is typical of the five -sensesmemory -bank -of -troubles type of tech-nician.

The educated technician will mostlikely develop his own servicing tech-niques. He should be familiar withvaractor diodes, FETs and new de-velopments. Solid-state devices arehere to stay and the more knowledgeabout them, the more proficient atechnician will be.

ROLAND (RON) MEYER, CET

Editorial Hit Too CloselyIf all the specialized fields of elec-

tronics were equated to 100 percent,the home entertainment field would be2 to 3 percent. That's not meant to bederogatory, it's a fact. In nine years asan electronics technician, I've hit near-ly 75 percent, and that's not bragging-rather, a rough way to spend nineyears. It's just a shame that one of themost interesting of all the fields ofwork is so plagued by questionabletechs and employers.

I am no longer working full time inhome entertainment electronics, hav-ing gone into industrial electronics inorder to make a decent living. Mygross wages as a bench tech for awholesaler near here were less thanmy net wages when I was dischargedfrom the Navy, and they're both far,far less than I get in industry-alongwith all the benefits of a union but nounion. Consumer electronics is ex-tremely satisfying, but `ya gotta eat!

The wholesaler that I worked forsupposedly supports the local associa-tion but is not active. Even after be-coming a CET, I was considered anapprentice. Words and actions neverseemed to coincide. I'm afraid yourJune editorial fit all too closely.

I plan to continue work in consum-continued on page 64

26 ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

NEWS OF THE INDUSTRY

TV Picture DisplayedOn Thin Matrix Panel

Research scientists from Zenith Radio demonstrated anewly developed thin -panel TV display employing the gas -discharge principle at the IEEE Conference on DisplayDevices in New York City on Wednesday, October 11,1972. The experimental unit demonstrated at the Confer-ence employed a Burroughs "Self -Scan" panel and showedonly a portion of the TV picture.

This thin panel was operated next to a 25 -in. diagonalcolor -TV set masked to show the same portion -12 percent

Front and side views of the thin -panel gas -discharge displzy. Withoutthe associated electronics, the panel is Vu -in. thick.

of the picture width and 43 percent of its height-with thebrightness and contrast turned down to match the outputof the thin -panel display.

The report indicates that other attempts to produce paneldisplays have been made in the past-employing incandes-cent lights, electroluminescence, liquid crystals and othertechniques. However, the Zenith thin -panel display is saidto be the first matrix device to produce a TV picture ofsufficient quality to warrant comparison with a CRT.

More VirginiansTake CET Exam

VEA State President John McPherson journeyed fromYorktown to Lynchburg, Va. to administer the CET Teststo interested parties in the western part of the state. Thefacilities of the Virginia Community College were madeavailable to the seven persons who assembled for the teston Sunday, October 22, 1972.

The testing session followed a Saturday evening meetingof members from VEA-Lynchburg and VEA-Danville todiscuss the pros and cons of state licensing.

The questions provided below are representative ofthose included in Section VII of the CET Exam.

Section VIITests and Measurements

1. What should be determined to safely use an ohmmeteron its lowest ohms range in measuring a transistor junc-tion?

2. Use of an attenuator probe on a scope instead of adirect probe (increases/decreases) loading of a circuitunder test by (increasing/decreasing) resistance and(increasing/decreasing) capacitance.

continued on next page

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DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER ; 27

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NEWS._continued from page 27

3. What is the voltage that would be measured with a dcvoltmeter from a generator producing the waveformshown below? On an ac voltmeter? (ti = t2.)

4. What should the front -to -back resistance ratio of a goodsilicon diode be?

5. The trouble in a set will clear up if a very leaky capaci-tor is bridged with a known good capacitor, if the leakycapacitor was the cause of the problem. (True/False.)

Explanation1. Before using the lowest ohms range of a meter to mea-

sure a transistor junction, the maximum safe forwardcurrent for that junction should be known, plus theshort-circuit output current of the ohmmeter. If theohmmeter delivers 300ma for example, and the maximumcurrent that can be safely handled by the junction is100ma, the junction could be damaged during testing.

2. Decreases, increasing, decreasing. The ac and dc loadingeffects are decreased because the probe has a resistorand capacitor between the circuit under test and the in-put impedance of the scope. The resistor increases theresistance, and the capacitor-because it is in series withthe input capacitance-decreases the capacitance.

3. The average value of the waveform is 5v, since half thetime it is at 10v and half the time it is at Ov. The dcvoltmeter would measure 5v. An ac voltmeter shouldnot be used, since it is accurate only on sinusoidal ac.

4. 100 -to -1. Germanium diodes could be less, with seleni-um even less.

5. False. A leaky capacitor has an appreciable drop in re-sistance, the resulting current remaining in the circuitto cause a problem. Hum may be reduced, but the prob-lem cannot completely disappear.

Participants in the CET Tests given recently in Lynchburg, Va. were(rear, I to r) Richard Sandige and Dan Bowling, instructors at theCommunity College in Richlands, Va.; and Julius Morris and Edwin

Fowlkes from Morris Electronics in Burkeville, Va.; (front, I to r) Joe

Henderson and Jerry Hartley from the Western Virginia Community Col-lege in Lynchburg; TA Jennings of Jennings Electronics, President ofVEA-Lynchburg; and John McPherson, CET, VEA State President (dis-

playing the October ssue of ELECTRONIC TECHNICIAN/DEALER).

Anyone wishing more information concerning theCET Exam may circle Reader Service No. 717.

Anyone wishing more information concerning theInternational Society of Certified Electronic Tech-nicians may circle Reader Service No. 718.

. for more details circle 109 on Reader Service Card

28 I ELECTRONIC TECHNICIAN/DEALER. DECEMBER 1972

Alarm System Scares BurglarSo Badly that He Leaves Car

At about the time our September issue was coming offthe press, Couch's Inc. (described in that issue as the vic-tim of many a burglary) was again being put to the test.

On September 7th, the front window at Couch's wassmashed with such a powerful blow that glass flew over 15

111111111111111).Anothe- smashed window, plus this time a "hot" car lett behind atCouch's Inc.

ft into the store. In fact, it even chipped the picture tubeface of a portable color -TV set ruined by the break.

A fine, nearly invisible wire secured to the window was,of course, also broken, triggering the amplifier -tape playershown on page 44 of our September issue. The ensuingnoise (siren and voice described in that article) must haveliterally frightened the would-be robber away.

Arriving just moments later, the police discovered moreevidence of a hasty departure. An automobile, stopped withthe motor running, was still parked at Couch's back door.The car was later found to be "hot."

Before Charles Couch, Jr., CET, arrived to deactivatethe alarm, many Gainesville residents phoned police tocomplain or inquire about the noise-some even suspectingan air raid. This certainly attested to the audibility of thesystem.

Thus, the cost of planning and installing an alarm systemwas certainly justified. The thief or thieves would almostsurely have escaped with merchandise worth hundreds ofdollars had the alarm not frightened them away.

continued on page 65

Lowest Priceddigital multimeter

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$79.95*

The Heathkit IM -1202 21/2 -Digit Multimeter sets the new low price for ahigh performance DMM. It's an easy to assemble kit that pays you foryour time - with accuracy, flexibility and features found on multimeterscosting twice as much. 1% accuracy on DCV, 11/2% on ACV and AC -DCcurrent, 2% on ohms. 29 selectable ranges measure voltage from 10 mVto 1000 V on DC in either polarity, 10 mV to 700 rms on AC; currents from10 uA to 2 A, AC or DC; resistance from 1 ohm to 2 megohms. And thebright cold -cathode display puts parallax and meter -tapping misreadingsout of :he picture. Lighted indicators for overrange, positive and negativeDC - plus a neat front -panel polarity switch make operation even easier.Internally, the IM -1202 is solid-state perfection - with a pseudo memoryfor clear, non -blinking display; a dependable ramp analog -to -digital con-verter with readout undated every 16 msec., and overload protection onall ranges. Everything's housed in a rugged aluminum case with handle,3 -wire line cord (no batteries needed) and universal banana jacks for thetest leads supplied.Kit 1M-1202, 6 lbs. 79.95*

Lowest pricedfrequency counter

NEW HEATHKIT 5 -Digit 30 MHzCounter

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$169.95*We've broken the price barrier for frequency counters, too! The newHeathkit IB-1100 has 5 -digit readout with 8 digit capability. Switch selec-tion of kHz and MHz and a 'ighted overrange indicator. The all -solid-statecircuitry features cold -cathode readout tubes; custom -designed time -basefor accuracy better than ±3 ppm from 22° to 37° C.; diode -protected.1-FET for improved triggering over inputs from 100 mV to 150 V rms. In-put impedance is 1 megohm, shunted by 20 pF. Professional features in-clude the compact aluminun case with diecast front panel, tinted viewingwindow, BNC input connec'or and bail feet. Most components mount onone large PC board - build it in two evenings.Kit 18-1100, 6 lbs. 169.95*

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without notice.*Mail order prices; F.O.B. factory. 7E-276

... for more details circle 114 on Reader Service Card

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 29

DIAL& CODERDelta's Instant

EmergencyTelephone

Warning System.

Dial & Coder guards you around -the -clock, signaling alarm for any emer-gency condition where a simple contactclosure activates the system. Completelysolid state, Dial & Coder utilizes thelatest in discrete and integrated circuittechnology to provide immediate remotesignaling between any two telephones.

CHECK THESE FEATURES!Dial any phone number up to eightdigits.

Change numbers in ten seconds. Over 100 different code combinations

allow multi -phone connections. Works with any direct contact switch.

Unlimited applications. Use with in-trusion detectors, fire & smoke detec-tors or a simple button control. Allowschildren, clerks, or physically handi-capped to call for help.

Automatic redialer when busy signalreceived.

Microphone can be added for audiosurveillance.

Self-contained power supply. Oncetripped, unit cannot be stopped.

This one's really priced right!

Made in U.S.A.Write or Call today for free sales details'

DELTA PRODUCTS, INC.P.O. Box 1147, Grand Junction, Cob. 81501,

Dept. ETD, (303) 242-9000

Superior Products At Sensible Prices. . . for more details circle 107 on Reader Service Card

READERS' AID

Space contributed to help serve thepersonal needs of you. our readers.

Equipment For SaleI have several pieces of service

equipment for sale. Please write forlisting and price.

VAL ORAL3201 S. 73 St.Omaha, Neb.

I have a Hewlett Packard SignalGenerator Model 608D for sale.Please write for price.

JOHN V. CAVASEND87-10 Lefferts Blvd.Richmond Hill 18, N.Y.

One 1972 picture tube rebuildingunit manufactured by Lakeside In-dustries with additional supplies forsale.

CARL H. MEYERP.O. Box 973Vista, Calif. 92083

Used TV Analyst, oscilloscope andelectronic Switch for sale. Selling dueto illness. Please write for information.

JACOB PETTNER1624 2nd Ave.Conway, Pa. 15027

Because of employment outside ofthe U.S., I will sell unused CRT re-building equipment for any reasonableoffer. Will deliver.

BERNARD STERNO3011 Redwood St.Brunswick, Ga. 31520

Going out of audio service and Ihave the following pieces of equip-ment for sale: Hewlett-Packard Model205AG Audio Signal Generator andModel 330B Distortion Analyzer ingood condition.

H. F. BILTERMAN, CET110 So. ConreyKnoxville, Iowa 50138

Back Issues for SaleI have back issues of ELECTRONIC

TECHNICIAN/DEALER, including Tek-fax schematics, front Sept. 1952 tocurrent issue for sale..

J. E. COHEN13457 Magnolia Blvd.Van Nuys, Calif. 91403

Business for SaleTV business for sale in central Wis-

consin, which includes a three bed-room apartment above store, alsoapartment and store rental.

WILLIAM RALLOFF2016 Wisconsin Ave.New Holstein, Wisc. 53061

I am selling a well -credited TV shopin Florida with a very good locationand low rent for a reasonable price.Please write for details

M. C. DI PIERRI213 Palm Ave.Hialeah, Fla. 33010

Service Information1 have retired from the TV repair

business and am trying to dispose ofsome Rider's radio manuals-No. 1

to 15 with indexes. I would like togive them away to anybody able to usethem, either a school or library, etc. Ialso have a Rider's TV manual No. 1.

HERMAN MARCUS4335 44th St.Long Island City, N.Y. 11104

Equipment WantedWe have a new radio and TV ser-

vice school that opened in August forjuniors and seniors in high school. Wewould like to purchase used test equip-ment and a complete set of SamsPhotofacts from No. 500 to date.

RALPH DOROUGH, INSTRUCTOR3101 Clinkenbeard Dr.Killeen, Texas 76541

Information WantedI am in need of a schematic dia-

gram, operational instructions andmaintenance manual for a GeneralElectric Oscilloscope Type SC2A. I

am willing to borrow or buy the infor-mation.

ROGER FLETCHERCumberland/Perry AreaVocational -Technical SchoolR.D. #4 Willow Mill Rd.Mechanicsburg, Pa. 17055

Schematic NeededI am in need of a schematic and

parts list for a Citreon tape recorderModel 660. I would be glad to repro-duce or pay for reproduction if anyonecan provide me with the information.

ROBERT L. HELMS1514 Auburn Dr.Colorado Springs, Colo. 80909

30 ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

BOOK REVIEWS

ELECTRONICS SELF- FAUG HTWITH EXPERIMENTS & PROJ-ECTS by Jim Ashe, published by TabBooks, 288 pages, hardbound $7.95,paperbound $4.95.

Although we have stressed the im-portance of understanding the theoryof how electronic circuitry functions,there is a lot that can also be saidconcerning the value of practical ex-perience-the first-hand observationof circuit functions-for more effec-tive servicing. This book describessuch basic circuit functions and thenhelps you demonstrate them by ex-perimenting with simple projects.

After a review of the history ofelectronics and some ideas on devel-oping one's skills in the first chapter,the second chapter goes into somepractical considerations concerningthe design of an effective bench andwork area, plus the selection andmaintenance of appropriate tools andinstruments.

In the chapters that follow the au-thor progresses from such fundamen-tals as a charged comb attracting ballsto the design of phase -shift oscillators.Each chapter concludes with completecircuit schematics and constructiontips for proving to yourself that com-ponents do function as described inthe book.

We feel that this book is excellentfor improving your understanding offundamental solid-state circuitry.

MODERN DICTIONARY OF ELEC-TRONICS by Rudolf F. Graf, pub-lished by Howard W. Sams, 688pages, hardbound, $12.95.

Dictionaries certainly do not makethe most exciting reading for a review,but on the other hand, this fourth edi-tion does contain a lot of interesting,useful information. The publisher in-dicates that it includes more than18,000 terms.

Upon looking through the diction-ary we find that a good portion of theterms included in this book are thosethat should be known by the electronictechnician. We feel that those encoun-tering an unfamiliar term when servic-ing an electronic product will find thedescription of that term very clear andeasy to understand. Illustrations arealso included in many cases to helpexplain the term.

We feel that this dictionary is amust for all electronic technicians andservice dealers that realize the impor-tance of a resource library.

NEW AUTORANGINGDIGITAL MULTIMETER...IN -PROBE DISPLAY,HIGH-SPEED READOUT,BATTERY OPERATION...$325.

9 For AC or DC voltage,resistance and even cur-rent, our Model 167 with

unique in -probe readout lets youmake time - saving measurementsdirectly at the point of me isurement.With up to 3 -month battery life. The Model167's combination probe readout, with 31/2digit LED display, automatically indicates de:imalpoint, polarity, range and function. Front panelterminals and probe receptacle allow alterrative useas a bench instrument. The neat, sweet -t3 -hold 167Auto -Probe DMM is only $325 (less in quantity). Checkit out and get our latest -How Sweet" button.

Measures easily ... 1 mV to 1000 VCC1 mV to 500 VAC RMS 1 onm to 20

megohmswith the convenience of ... 55 meg-ohms input resistance 2 -sec. readi agtime to rated accuracy 1200 volts over-load protection Complete choice ofaccessories.

KEITHLEYI IV B T R tJ M ENT SU.S.A.: 28775 AURORA ROAD, CLEVELAND. 01410 44139

EUROPE: 14. AVENUE VILLARDIN. 1009 FULLY, 5111550

The Model 167... another how -sweet -it -is Keith ley Multimeter

... for more details circle 117 on Reader Service Card

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 31

NEW AND NOTEWORTHY

For additional information on products described in tins section, circlethe numbers on Reader Service Card. Requests will be handled promptly.

TAPE PLAYER 702

Special brackets simplify insertion and removal

For motorists who love a great tape sound but who stillwant to keep in tune with their local FM Stereo soundstoo, a combination FM Stereo and Stereo 8 tapeplayer is offered. The Model 12R600, with fiveintegrated circuits plus 8 transistors, has a ratedoutput of over 16w peak power. The tape player'salignment reportedly eliminates the need for any finetuning controls. The unit can be installed with thecompany's special "Quick Release" mounting brackets,featuring smooth sliding tracks for easy insertion andremoval of players, while locking a player into positionwith the turn of a key. RCA Parts and Accessories.

FOR MORE NEWPRODUCTS SEE PAGE 58

EDUCATIONALFM/SCA RECEIVER 700Employs crystal controlledoscillator for frequency accuracy

A completely self-containedprofessional educational receiver,Model TR-E2, is designed forcontinuous use. Operation is as easyas using a standard FM receiver,with controls consisting of only acombination ON/OFF switch andVOLUME control. This unit is housedin an attractively styled metal cabinetwith a beige textured finish, and afront -mounted speaker with fabricgrill. The main channel sensitivity andhigh -Q input circuits minimize cross-talk and give wide dynamic range.The oscillator is reportedly crystalcontrolled to guarantee on -frequencyoperation, without user adjustments.Optional features include a rearmounted main/subchannel switch andheadphone jack. McMartinIndustries Inc.

FM MULTIPLEX STEREO GENERATOR 701

Compact with dual power supply

The Model LSG-231 Multiplex Stereo Generator is saidto have unusual precision and stability. The generatorhas a pilot signal frequency of 19kHz with a ratedaccuracy of ± 2Hz. The !kHz audio signal is said to beaccurate to ± 1%. Signal separation is rated at 50dBwith an output voltage of 0 to 3v rms, continuouslyvariable. Specifically designed for the field orworkbench, this unit reportedly offers such highreliability that many technicians may not find itnecessary to use a scope. It is said to be easy to operate,compact and complete with a handy tilt stand. Thegenerator has a dual power supply and measures 8 in.W by 12 in. D by 31/2 in. H. Weight 5.5 lb. LeaderInstrument Corp.

32 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1512

Giveyourselfa break!

Save up to 40 minutesper installation

Coffee, lunch or whatever kind of break with theextra time you'll have using our new Speed -Fit re-placement CRT's with premounted hardware.Speed -Fit CRT's eliminate the need for transferringhardware from the dud to the new tube and cansave you up to 40 minutes per installation. They'lldo it in all RCA 25", Motorola 908, 914 and 914Aand Zenith 20XIC36, 20XIC38, 23XC36, 23XC3823XC38Z, 25MC35, 25MC36, 25MC46. 25NC38chassis. Our Zenith Speed -Fit models even comewith a one-piece shield that slips on easily!

PATENT APPLIED FOR

We're working on other Speed -Fit models so thatsoon you'll be ab'e to install bright, sharp Speed -Fitcolor in just about every major name set on themarket. Since the guys who engineer TV sets neverseem to think about the guy who has to repairthem we think it's about time somebody gave theserviceman a break.

And we want you to have it on us ---with the newSpeed -Fit CRT line!

CHANNEL MASTER

Speed -EtALPICTURE TUBE)

FROM CHANNEL MASTER PICTURE TUBE HEADQUARTERSicr more details circle 105 on Reader Service Lard

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 33

An Extraordinary Offerto introduce you to the benefits of Membership in

ELECTRONICS BOOK CLUBfor a limited time only you can obtain

OF

ANY THESEUNIQUEBOOKS

II . yours for only... with Trial

(Combined List Price $43.80) Club Membership 9 each

May we send you your choice ofany three books on the facing

page as part of an unusual offer of aTrial Membership in Electronics BookClub ?

Here are quality hardbound vol-umes, each especially designed to helpyou increase your know-how, earningpower, and enjoyment of electronics.

These handsome, hardbound booksare indicative of the many other fineofferings made to Members . . . impor-tant books to read and keep . . . vol-umes with your specialized interests inmind.

Whatever your interest in electron-ics -radio and TV servicing, audio andhi-fi, industrial electronics, communi-cations, engineering -you will findthat Electronics Book Club will helpyou.

With the Club providing you withtop quality books, you may broadenyour knowledge and skills to buildyour income and increase your under-standing of electronics, too.

How You Profit From Club Membership

This special offer is just a sample ofthe help and generous savings theClub offers you. For here is a Club de-voted exclusively to seeking out onlythose titles of direct interest to you.Membership in the Club offers youseveral advantages.1. Charter Bonus: Take any three ofthe books shown (combined values upto $43.80) for only 99( each with yourTrial Membership.2. Guaranteed Savings: The Clubguarantees to save you 15% to 75%on all books offered.3. Continuing Bonus: If you continueafter this trial Membership, you willearn a Dividend Certificate for everybook you purchase. Three Certificates,plus payment of the nominal sum of$1.99, will entitle you to a valuableBook Dividend which you may choosefrom a special list provided members.4. Wide Selection: Members are an-nually offered over 50 authoritativebooks on all phases of electronics.5. Bonus Books: If you continue inthe Club after fulfilling your TrialMembership, you will receive a BonusDividend Certificate with each addi-

SPECIAL FREE BONUS. if you act now !

Yes, if you fill in and mail the membership ap-plication card today, you'll also get this BonusBook, FREE!

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tional Club Selection you purchaseFor the small charge of only $1.99,plus three (3) Certificates, you mayselect a book of your choice from aspecial list of quality books periodical-ly sent to Members.6. Prevents You From Missing NewBooks: The Club's FREE monthlyNews gives you advance notice of im-portant new books . . . books vital toyour continued advancement.

This extraordinary offer is intendedto prove to you, through your own ex-perience, that these very real advan-tages can be yours . . . that it is pos-sible to keep up with the literaturepublished in your areas of interest ...and to save substantially while so do-ing.

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Here, then, is an interesting oppor-tunity to enroll on a trial basis . . . toprove to yourself, in a short time, theadvantages of belonging to Electron-ics Book Club. We urge you, if thisunique offer is appealing, to act

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104 Simple One -Tube ProjectsA collection of use-ful, easy -to -build con-struction projects fortechnicians, experi-menters. hams, andhobbyists. Now youcan put those idletubes and compo-nents to work withthis vast, one -of -itskind assortment ofunique electronic cir-cuits. Included inthis convenient selec-

!tot, are test instruments, ham gad-gets, receivers, power supplies, DXaids, wireless mikes, tube rejuvena-tors, electronic games, eavesdroppers,stereo and ld-fi devices, and literallydozens . None use more thanone tube! Few will cost more than$5. Astute technicians and hobby-ists will find many gadgets adaptableto specific needs. 192 pps. Hard-bound.

List Price $6.95 Order No. 486

Sift

FRETS

Practical Color TV ServicingTechniques

This brand-new up-dated and expandedsecond edition con-tains troubleshootingguidelines and casehistories on the lat-est solid-state re-ceivers, including a4 -color section with32 trouble -symptomphotos and a foldoutsection with It com-plete TV receiverschematics. Now hi -

eluded are service tips and tech-niques on RCA. Motorola and Zenithsolid-state chassis, plus a host ofcase histories and current data onG.E. chassis. In fact. each of the12 chapters is filled with informa-tion applicable to virtually any brandof color TV receiver, enabling you tosolve tough -dog troubles quickly. 404Des- 250 illus. Hardbound.List Price $8.95 Order No. 436

Electronic Circuit DesignHandbook

New Fourth Edition-A brand-new. en-

14allostrlamed edition of theever popular circuit

piperdesigir's "cook-'book," 110W contallum. jug over 600 pro,circuits, for all tit,

111111111111of functions, selechfrom thousands t,t,the basis of original-ity and practical ap-plication. Now youcan have, at your

fingertips. this carefully planned ref-erence source of tried and tested cir-cuits. Selected on the basis of theirusefulness. this detailed compilationof practical design data is the an-swer to the need for an organizedgathering of proved circuits . . . bothbasic and advanced designs that caneasily serve as stepping stones toalmost any kind of circuit you mightwant to build. 384 pos.. 19 big sec-tions, over 600 illus. 8 Y4 " x 11".List Price $17.95 Order No. T-101

Basic Electronics ProblemsSolved

Here are easy step-by-step solutions tomany basic electronicsproblems in a conve-nient one -stop sourcedealing with bothsolid-state and tube -type circuits. Thecontent not only pre-sents a detailed ex-planation of eachpoint, but also pro-vides many actualexamples on how to

work out problems. Then. to firmlyfix the information in your mind.there are numerous example prob-lems for you to solve: answers tothese are included in one Appendix.and worked out solutions in another.Covers DC circuits. A(' circuits.powers of ten, semiconductors, powersupplies, and receiver circuits. A fin-al chapter shows how to use a sliderule to speed calculations. 192 pits..over100 illus. Hardbound.List Price $7.95 Order No. 530

Understanding Solid -StateCircuits

This brand-new booktruly eliminates themystery of solid-statecircuits and devices.Written to serve theinterests of anyone atthe sub -engineeringlevel (service techni-cians, hobbyists, stu-dents. etc.) , the con-tent thoroughly ex-plains seiniconduc-tfir circuit operationwithout delving into

electrochemical physic's and high-levelmathematics. EncompatuleS amplifica-tion, feedback, sinusoidal and Meisinusoidal oscillators, gain control.logic circuits, and integrated cirepits.Semiconductors covered include Silts,FETs. I('s, light-sensitive and volt-age -sensitive devices. The perfect textand reference on solid-state deck, -and basic circuit operation. I 92 pits..over 150 illus.List Price $7.95 Order No. 513

0) ILO

Motorola Color TVService Manual - Vol. 2

This new second vol-. inne covers the newQuasars CrI'V7 VS -11311 and CTV8(TS -9381, the Qua-sar II Models CTV5(TS -9291 and CTV6(TS -934) . plus addi-

tional alignment andtroubleshooting infor-mation on the orig-inal Quasars ITS -915 -919 I . Typicalof all volumes in the

popular schematic -servicing manualseries, this sts-ond volume on Mo-torola includes full-size schematics.waveforms, chassis and plug-in panellayout drawings and photos, and partslists. Numerous troubleshooting casehistories on Quasar and Quasar IIChassis will enable you to quicklyidentify defective panels. and to re-pair panel defects. 196 pos. 8 .6"x 11", 36 -page foldout section with9 full-size schematic diagrams.List Price $7.95 Order No. 584

TV Trouble Diagnosis Made EasyA brand-new picture -symptom set viceguide for solving ev-ery TV trouble, bothcolor and black -and -white. You simplYcompare the symp-toms you see andhear with those pic-tured or describedand you'll be able topinpoint any troubleto a specific circuitand component in

short order. In the first chapter. eachtrouble symptom is pictured and de-scribed to help you identify the prob-able cause. From there you are re-ferred to one of the remaining 19chapters dealing with specific troublesin each section of the receiver, ex-plaining how to further analyze exist-ing symptoms and pinpoint troubles.Individual conmotient tests are sug-gested, too. everything from tlybseksto transistors. 256 pos.. 225 Illus.Hardbound.List Price $7.95 Order No. 544

Jack Darr's Service Clinic No. 2h herds more of ItoJack Darr wisdom(and wit!) in bockform-a valuable col-lection of timely ser-vice hints and trou-ble solutions coveringcolor and mono-chrome TV, radio,stereo. photos, re-corders, CB gear, etc.Discusses the "en-gineering" servicingapproach, efficiency,

and how a technician may conditionhis thinking to produce more in agiven time period. Like the first vol-

, the content was selected on thebasis of usefulness to the averagetechnician, covering a wide range ofelectronics devices. Each of the 10chapters covers a general category ofinterest, and in each the subject mat-ter is arranged in logical order toenable you to find what you needquickly. Provides a wealth of infor-mation. 176 pos., numerous illus.Hardbomfd.List Price $7.95 Order No. 566

DICTIONARY OF ELECTRONICSYou'll find this huge volume extremely useful in what-ever connection you have with electronics. This dictionary of electronics defines most all of the electronicterms you will run across in your everyday reading ...from alpha particles through zoom lens . . . defines theterms you need and use most often, including thosefound in radio, TV, communications, radar, electronicinstrumentation, broadcasting, industrial electronics,etc. It provides full, complete and easilyunderstand-able explanations of thousands of specific electronicsterms (such as transistors, acoustic feedback, alphaparticles, beat oscillator, final anode, electrostaticlens, nonlinear resistance, pool cathode, etc.). A uniquefeature of this selection is the cross-indexing, wherebykey words contained in the definitions (words that are

defined more fully elsewhere in the book) are printed in small capitals so youare not left in the dark by any definition. An example of this is the definitionfor "Susceptance," which includes the words "Conductance," "Admittance,""Resistance," and "Reactance," indicating other applications. Appendix materialincludes a list of units and abbreviations, graphic symbols used in schematics,component calor codes, db conversion tables, data on the electromagnetic spectrum, tube base diagrams, etc. 420 pps., 487 illustrations. Hardbound.List Price $8.95 Order No. 300

Handbook of SemiconductorCircuits

154 k% ant -pies of standardtransistor circuits.complete with opera-tional data for am-plifiers, oscillators.logic and switchingcircuits. power sup-plies, and variousnonlinear circuitsThe broad range ofcircuits included wereselected on the basisof application anti

practicality. A design philosophysection is included with each grumpof circuits, thereby providing a basisfor understanding eireuits other thanthose selected as examples. This isa collection of practical circuit sWhich have wide application. Eachcircuit descriotion includes data con-cerning any unique deStall or opera-tional data. Hundreds of illustrationsand diagrams. 448 Pos.. 6" x 9".I I ardbound.List Price $8.95 Order No. G-30

How to Use Color TVTest Instruments

atTEST'monw

II,V to N,Ifatever

gaps there are inyour ability to usemodern. up-to-datefsiuipment designed-4)eci6cally to saveNon time and nioneY.You'll quickly graspthe author's com-mon-sense approachto using the right in-struments. therebygetting the most out

of your investment in text gear.You II improve your ability to use anoscilloscope, color bar generator.alignment generators. vectorscope.TV Analyst and sine, square -wavegenerators. The author also has in-cluded a description of his

,as

tracer." With this simple scope at-tachment, you can rapidly assess thecondition of diodes. transistors-even 1Cs-in or out of the circuit25(i pits., over 230 illus. I 1 an lhoutelList Price 57.95 Order No. 577

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line of business. Material is present-ed so that seasoned technicians eaugain from the numerous trouble-shooting tips, and beginners. with afew hours study. ran begin to turnout profitable work in a short time.Includes shortcut methods of troubleshooting. phis general test tech-niques. rovers receiver circuits andfundamentals of circuit operation.260 pos.. 170 illus. Hardbound.List Price $7.95 Order No. 580

Servicing ModernHi-fi Stereo Systems

k

(-

11,11 1.1 Ilit .1 111. 1....el/W.11,01.i alit) teedbafk. The finalchapter, tied in with a schematicfoldout section, offers typical servicedata: complete schematics. PC boardillustrations, component location dia-grams, troubleshwting chart,. andadjustment and aligot, it, -ttitans. 250 pps., inch; :

foldout schematic sectIillus. Hardbound.List Price 57.95 Order No. 534

Japanese Monochrome TVService Manual

This 1,1

uroucJAPANESE icing to.too.fl

tains all the data youneed to repair virtu-ally every Hitachi,Panasonic. and Sharpblack -and -white mod-el sold in theand Canada duringthe past three years(1969-711. In thisone compact volume.you have all the ha-

illt.,rt;ation net.tlell to service 75-i,,- Inc cp,,,lits. Included are full--I, s,h, !call. ,lial:ran, I'd ' hoar.]la) dr,t, tut:. Alt.! 1,1,.,1,. ,.1,11a111. ati,1 ?it tut t1.11..mot pat. 11-1, tI,. 21 Inll -1/t, it. .1

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List Price $7.95 Order No. 602

199 Electronic Test & AlignmentTechniques

Here's a brand-newquick -reference gllidof 199 tests that willhelp you troubleshootvirtually any elec-tronic device fount'in the average home-AM and FM ra-dios. TV receivers.antenna systems. in-tercoms. electron itorgans. garage dooropeners. auto igni-tion systems. and

many others. You'll also learn howto check out Imme interemn systkal,and electronically -controlled gang,door openers. With this Nook. it'llbe a breeze for you to tackle almostany electronic repair lob. You'll learnhow to analyze the results of eachstep you take and how to come tothe right conclusion. A concise, easy -to -use source of troubleshooting infor-mation. 224 pps.. 130 illus. Hard-bound.List Price $7.95 Order No. 593

199

AN EXTRAORDINARY ID flb

... for more details circle 183 on Reader Service Card

GTE Sylvania has the linesthat lay it on the line.

Only GTE Sylvania gives you a choice of three different price lines incolor picture tubes.

And GTE Sylvania tells you and your customer exactly what you are gettingin each line.

That makes Sylvania tubes easier to sell.You can tell your customers the advantages of the top -line color bright 85® XR.

You can show them where the savings come from in theeconomy co/or screen 85 line. And you can tell them ex-actly what they're getting for their money in the middle -

line color bright 85® RE.The way we see it, if we lay it on the line with you, you

can lay it on the line with your customers.Instead of just handing them a line.

Sylvania rare earthred phosphors

Other manufactured rareearth phosphors

All sulfide phosphors

X-ray inhibiting glass

New glass

Reused glass

Regunned

Screen blemish specs

White field uniformity

Cut off; purity currents;beam shield leakage

car4 SYLVANIA

color bright [1EXR

yes

no

no

yes

yes

no

no

OEM

color bright 1g RE

yes

no

no

no

some

some

no

OEM

OEM slightly widerthan OEM

OEM OEM

color screen 3

yes

yes

no

no

some

some

some

slightly widerthan OEM

slightly widerthan "RE"

slightly widerthan OEM

38 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

ELECTRONIC TECHNICIAN/DEALER DECEMBER 1972

TEKLAB REPORT

Introducing Heathkit'sDual -Trace Oscilloscope

by Joseph Zauhar

By assembling this kit one

can step-up to a professional -type dual -trace

scope or but a moderate cost

Each year we find moretrigger -sweep, dual -tracescopes introduced, butHeath's Model 10-105 isthe first one that we haveencountered in kit form.This scope was sent to usby the manufacturer forassembly and review. Thisinstrument has many fea-tures found in more ex-pensive scopes, making ita versatile tool for the ser-vice bench at but a moder-ate price.

The oscilloscope hascalibrated vertical andhorizontal circuits permit-ting precise voltage andfrequency measurementsof complex waveforms.The Channel 1 and Chan-nel 2 circuits are identicalwith dc-to-15MHz wide -band amplifiers. TheVOLTS/CM ATTENUATORswitches provide nine sen-sitivities from .05 to 20v/cm, with variable sensitivi-ties at each switch posi-tion. Any one of 18 cali-brated horizontal timebases can be selected bythe TIME/CM switch, pro-viding frequency measure-ments of applied signals.The triggering controls al-low the time base to be

triggered at any pointalong the positive or nega-tive slope of the input sig-nal.

The Channel 1 andChannel 2 input signals canbe individually displayedas a function of time ineither the CHANNEL 1 orCHANNEL 2 mode, while

the CHOP MODE samplesthe input signals at a 50kHzrate so that both signals ap-pear as a function of thesame time base. The AL-TERNATE MODE displaysthe input signals alternate-ly on successive sweeps.Trapezoidal and Lissajouspatterns-which are useful

Heathkit's Model 10-105 Dual -Trace Oscillosope.

in studying modulationcharacteristics and fre-quency, plus phase com-parisons-can be checkedby placing the VERTICALMODE switch in the X -Yposition. The inputs usedare Channels 1 and 2 onthe front panel of thescope.

AssemblySome electronic techni-

cians feel that they do nothave the time to assemblean instrument in kit form,but there are a number ofadvantages for those thatdo: Not only do you havethe pride of assembling theinstrument yourself, youalso become familiarenough with it to correctany difficulties which youmay eventually encounterin the scope, saving repairtime and costs. Anotherimportant feature is thecalibration of the scope,which may drift after aperiod of time. In manycases factory instructionmanuals included with anassembled instrument onlycover the calibration of thevertical amplifier and at-tenuator. The manual sup-plied with this kit clearly

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 39

instructs you on how tocalibrate any circuit in theinstrument.

We assembled the oscil-loscope in a relativelyshort time, following theclearly illustrated step-by-step assembly manual pro-vided with the instrument.We first assembled the sixmodular circuit boards inthe following order: verti-cal switching, two verticalpreamplifiers, horizontalamplifier, power supplyand the deflection circuitboard.

The vertical subchassiswas the first unit com-pleted. It contained thevertical switching circuitryand two vertical preampli-fier boards. This subchas-sis is a drawer type unitthat slides out of the mainchassis and employs sock-et connectors on the wireharness to simplify remov-al if required. The assem-bly of this as well as otherchassis units was simplifiedby factory assembled wireharnesses.

After the chassis was

swE Er CIRCUITS. PART S.

au ,

01001 DINN1101.1:100

A computer -type troubleshooting chart is included in the assemblymanual if service is required.

The assembledvertical subchassis

with the rightswitch shield

removed.

assembled, but before thescope was turned ON, wemeasured the resistance ofvarious voltage taps toprevent component dam-age in case of error in as-sembling the unit.

When the unit wasturned ON, the first checkmade was to measure thevoltages at the given testpoints on a chart. Whenany of them did not agreewith the voltages given, wewent to the "In case ofDifficulty" section of themanual and corrected the

problem before the unitwas again turned ON.

Assembling HintsWe cannot claim we did

not make any errors in as-sembling the unit, but theywere quickly corrected bygoing back to the step-by-step instructions of the par-ticular circuit in question.

In one instance, wefound the rotary yours/3cm switch shield sheet -metal screws to be just alittle long, shorting out thevertical preamplifier board

The Heath Model PP,W-101 oscilloscope probe is a high -impedance, low -capacitance isolating type probe used to examine high -frequency wave-forms without distorting the waveform or loading the circuit.

WORD POO 11/41 V L.

WARNING.40.1 VaIrrAn .141Nall

Loom G.1113 OPS110.1.

MIT

a.

IMO

...1a$1414

oula. cars.St MON run..

Rear panel of the oscilloscope showing the INTERNAL/ EXTERNAL

BLANKING switch, plus the blanking in and the gate output connectors.

The bottom of the vertical subchassis showingthe Channel 1 and 2 vertical preamplifier cir-cuit boards.

Side view of the assembledoscilloscope with panels removed,exposing the horizontal circuitboard.

40 I ELECTRONIC TECHNICIAN/ DEALER, DECEMBER 1972

Oscilloscope Specifications

VERTICAL

Accuracy

Input ImpedanceMaximum Input Voltage

SensitivityFrequency Response

Vertical Windows

Rise Time

Overshoot

Attenuator

Vertical Display inSweep Mode

HORIZONTAL

Time Base

Sweep Magnifier

External Horizontal Input

X -Y MODE

SensitivityFrequency ResponsePhase Shift between

Channels

TRIGGERING

Delay

Automatic

Normal

Source

PolarityCoupling

Sensitivity

GENERAL

Blanking InGate OutInput Connections

3°.1M shunted by 35pf600v dc

ac or dc: .05v/cmdc to 15MHz: 3dB with 4cm oetlection2 minimum24ns

Less than 10%

9 positions in a 1, 2, 5 sequence.

.05v/cm to 20v/cm. Variable gain(uncalibrated) through entire range

Channel 1, Channel 2, Channel 1

and Channel 2 alternately, or Chan-nel 1 and 2 chopped (50kHz)

Triggered with 18 calibrated rates:.21.2s/cm to 100ms/cm in a 1, 2, 5

sequence, 3%. Continuously vari-able (uncalibrated) within the samerange.

X5 (time base accuracy is 5%when the magnifier is being used)750mv/cm (uncalibrated and no: ad-

justable). 100K minimum inout im-

pedance, dc to 100kHz

05v/cm to 20v/cm, 3%

3dB at 100kHz (Channel 21

5° or less from dc to E0kHzwithin graticule limits

Approximately 600nsZero crossing to '2cm of zero

crossingWithin viewing area

Channel 1, Channel 2, or Channels

1 and 2-f- or - slopeac or dcInternal: l'2cm. External 100mv

minimum, 7v maximum

CRT Accelerating PotentialCRT Type

TTL compatible (logic 0 blank)3.5v minimumVertical: Coaxial, BNC. Horizontal:Binding post. External Trigger: Bind-ing post on center with ground2200v dc regulated8 10cm rectangular, flat face,

014-107GA

Warm up Time CRT heating time, approximately 30sec. For full calibration, aoprox. 15111111.

Graticule 8cm 10cm grid, edge lightedOverall Dimensions ... 10')8 in. wide by 123.11 in, high by

15 in. deepNet Weight 28 lb

Probe Specifications

Input ResistanceInput Capacitance RangeConnector

Maximum Voltage

Attenuation

Attenuation AccuracyFrequency Range

10M

Up to 40pfBNC

600v dc or 600v ac p.p10.1 (with oscilloscope hav-og 1Minput resistance)

3%dc to 30MHz

under the vertical subchas-sis. Also, a manufacturersuggested change wasmade to protect the inputFET transistors (0402and Q403) from transientspikes on early productionmodels. This was done byconnecting 0.1µf/100v ca-pacitors in parallel withresistors R407 and R408on each vertical pream-plifier board.

CalibrationThe instruments needed

for calibration are veryminimal. In fact, about theonly instrument requiredis a high -input -impedancevoltmeter. This method ofcalibration is advisable un-less a precision signal gen-erator is available, becausethe final oscilloscope accu-racy depends almost en-tirely upon the accuracyof the signal generator.

This simplified calibra-tion method is made pos-sible with an internal100kHz crystal -controlledoscillator built into thescope just for calibrationpurposes. We were curi-ous about the accuracy ofthe oscillator frequency, sowe checked the frequencywith a frequency counterand found it to be within17Hz of the 100KHz spe-cified, and "rock solid"without drift.

The calibration of thescope was quite easy fol-lowing the step-by-step in-structions given in the as-sembly manual. The firstpart of the calibration con-sisted of adjusting the +15and -15v supply voltages

and the dc level voltages,then the following adjust-ments: trace, triggering,vertical calibration, sweepcalibration and input at-tenuator compensation ad-justments. The voltage forthe vertical calibration isalso obtained from theregulated 15v power sup-ply terminal found in thisinstrument.

The triggering adjust-ments were the most timeconsuming and critical,but after reading the in-structions over a few timeswe got the traces to lockin very solidly.

High Frequency ProbeThe probe used with the

scope to examine the vari-ous waveforms was theHeath Model PKW-101, ahigh impedance (low ca-pacitance) isolating typeprobe.

This probe can be usedto examine high -frequencywaveforms without distort-ing the waveform or load-ing the circuit, and canalso be used in any otherapplication where a high -impedance probe is de-sired.

A trimmer capacitor ad-justment compensates forthe internal capacitance inthe probe and probe cable,and at the same time itmatches the probe to theparticular input capaci-tance of the scope. Wemade the trimmer adjust-ment in the usual way byconnecting the probe tothe output of a sine/square -wave generator set

continued on page 65

After the side panelsare removed, most of thecircuits are exposed,simplifying adjustments.Note the all shielded8 Y. 10cm rectangularflat -face CRT.

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 41

Electronic SecurityPart II -Automatic

Telephone Dialerby Terry Tuttle and Tom Turnbull

Once an intrusion has been electronicallydetected, the alarm must be transmitted to some

location where it can do some good.

TooGFFmoo Clesool

5 5.c...1.

DIALING

15 5s, 0.a.

'us'EISTFNNG

I, 5..1,

Fig. 1-Dialer sequence of operation.

,81.11611.K,..1411.1"Kw

1...c81 0 I

I

1SFS11

'mg* .11.111,

0.,t0vKV6111

01r0o.,NM. al.

CODE IF

TURN ON

TIMES.0000.

cox..0 ors- sac MY MN

GOA

Fig. 2-Block diagram of the Dialer.

WIN Glary,

otatesne

assi -tad1310.0,11

if

41 Cm? vallalPsK OVUM"

Fig. 3-Sketch showing the final installation of the electronic securitysystem.

The Automatic Telephone Dialer can be pro-grammed for dialing the police, a neighbor, friend orrelative to indicate an alarm condition. Those withshops located elsewhere, may even use the system forsignaling the alarm at their home. This system has theadvantage of not requiring any special leased wires,dialing the desired party on existing telephone lines.

The unit described in this article is completely elec-tronic-solid state-with no moving parts other than areed relay. Upon receiving a contact closure for activa-tion, the unit proceeds through the following sequence(Fig. 1):1. Line Capture-connection is made to the telephone

line and sufficient delay is provided to obtain a dialtone.

2. Digital dialing-unit proceeds to dial preset numberat the rate of 10 pulses per second, with 2 sec. spac-ing between digits. (Break/Make ratio is 60/40.)

3. Line Busy Detection-system listens for a 10 sec.period to determine if the called number is busy.If the line is busy, the unit "hangs up," waits 15 sec.,and then redials the number. This redialing continuesuntil the line is no longer busy.

4. Listening Mode-sensitive microphone is switchedON, enabling called party to listen in on the roomcovered by the detection equipment.

5. Identifying Code-tone code is superimposed on theline every 12 sec., identifying calling location.

6. Automatic Reset-the Dialer "hangs up" and turnsitself OFF after 11/2 min. of operation.The block diagram of the Dialer is shown in Fig. 2

with arrows indicating the direction of signal flow. Al-though appearing rather complex from the block dia-gram and circuitry involved, the Dialer and Coderoperate in a straightforward manner.

The phone number and code are set in the Dialer bycross connecting the voltage taken off a voltage dividerto the appropriate comparator. The cross connectionis through a 10 x 10 matrixing switch (Fig. 4).

The circuit (shown in Fig. 5 on the third page ofthis article) is activated by shortening the trigger inputjack, which latches an SCR in series with the batterypack. The battery voltage is then fed to the voltageregulator, and the voltage regulator in turn activates allcircuits, providing the operating voltage.

Upon receiving an operating voltage, the output relaycloses, presenting an "off hook" signal to the telephoneline. The first comparator is reset by the operating volt-age turn-oN. After a 5 sec. delay, dialing starts. The dialpulse generator that drives the telephone line relay alsosupplies the input to a staircase generator, with each pulsestepping up the output of the generator by 1/2v. Whenthe comparator senses that the staircase generator out-put is equal to the voltage switched from the divider, itchanges state, stopping the dialing of that digit and ac-tivating the interdigital delay. The staircase generatorresets to zero during the interdigital delay. The "switch-ing" of a comparator resets the next comparator in line.This process continues until the last of the dialing digit

Mr. Tuttle is Chief Engineer and Mr. Turnbull isDevelopment Engineer for Delta Products, Inc.

42 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

comparators activates. There are eight dialing compara-tors, but any comparator can be switched OFF, givingthe desired number of digits.

The change of state of the eighth comparator gener-ates the end -of -dial signal, which turns ON the busy sig-nal processing circuitry. If a busy signal is present, theunit "hangs up" by turning OFF the power supply. Thedialer redials after a short time and will continue thewait-and-redial process until it does not receive a busysignal.

The end -of -dial signal also turns ON the code tonegenerator and slows the frequency of the pulser to twopulses per sec. If no busy signal is present, this puts aseries of beeps on the telephone line as well as con-necting a microphone to the line through a high -gainamplifier. The beeps are counted by the code compara-tors as were the digits by the dialing comparators.

The two -digit code is produced by a recycling circuitthat causes the dialer to repeat the code digits on a 12

sec. interval. This enables a person to identify the originof the call and to hear what's going on as well.

The unit will turn OFF after about 11/2 min. of "lis-tening" generating the code.

A low -battery sensing circuit has been incorporatedinto the Dialer and Coder for recognition of weak bat-teries. At approximately 16v, this circuit switches andcauses a radical lowering of the code frequency. Thebatteries may also be checked externally, using a volt-meter connected between the trigger and microphoneconnections.

In most cases, the Dialer will be installed in an "outof the way" spot with the microphone located for bestpickup. If the KS -20721 Station Coupler (TelephoneCompany installation) is used, it will probably bemounted near the telephone. To minimize the necessaryinterconnection wiring, locate the Dialer near the Coup-ler. The only wiring left is the connection between theultrasonic detector and the trigger input of the Dialer,which requires only one pair of conductors.

To complete the system installation (using both theAutomatic Telephone Dialer described in this articleand the Ultrasonic unit described on page 42 of theOctober 1972 issue), check the ultrasonic detector forthe correct setting Of SENSITIVITY, PERSISTENCE andTIME controls.

A sketch showing an installed system is shown inFig. 3. Note that the ultrasonic unit is mounted to pro-vide adequate coverage of the counter and cash register,but not where it might be critical of door and windowconditions. The Dialer is mounted under the counterwhere it is out of the way, and the microphone placedfor adequate sound reception. The coupler has beenshown installed on the wall near the telephone, butcould have easily been more inconspicuously placed

if desired.It is sometimes quite reassuring to provide a daily

check on the system. This can be done by using a 24 hrtimer which triggers the system at a preset time (6:30a.m. would double as an alarm clock). You would thenreceive a telephone call every day at that time, assuringyou of proper system operation.

4

I

PRE

xI

NUM

EB

0F 1 2 3 4 5 6 7 8 9 0""nummuplinni

aninninumunlimsommis"I'll"!

A

S

PREF

I

X

NU -M

k

B

C

E

1 2 3 4 5 6 7 8 910

C0DE

DIAL 8 CODER SELECTOR SWITCHES SHOWING MATRIX

(DOTS REPRESENT SWITCH POSITIONS)

2 3 4 5 6 7

TO DIALING DIGIT COMPARITORS TO CODECOMPARITORS

129

27K

0

REF.

OFF

2.7K

SWITCHES ARE SET TO DIAL 9-242-9008WITH A CODE OF 64

Fig. 4-The unit contains a seriesof 10 switches (photo above), each having 11 positions for 10 x 10matrixing (schematic above), plus OFF.

DECEMBER 1972, ELECTRONIC TECHN'CIAN/DEALER 43

ELECTRONIC SECURITY...

TONERINPUT

LOCATEDON ENOBOARDC-9,4

??.

6IO

-CAL BR AT ION

22'022

05n.22R OR

SELECTOR SWITCHES 1 LOCATED OM SNITCH BOARD C 1/271

7 RIO 23 26!220720K 220K 220K 220 IT

PREVIA EWER PRIM NUM ER

STAIRCASE GENERATORI LOCATEDON SWITCH BOND C 920

02

CLOCK BOARD C-929ACTIVATOR SATO. II INPUT TIMER

RI CI

22. 1 RN,

R6

-091 .

RIO00.1

/

aRM

C4RN

a 0, 47

MAO

224

22Y

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0 5 KSB2204 2204

CLOCK K2 795 DIAL .2.5 coolCLOCK 110.480 0929

RBII" 09 120

CLOCK ElOOTO 0921INTERMIT DELAY OINERATOK

ROLTADEREGuL ATOR w

Dr1%LOCATEDCo. %Woo900170c-92

KO 220

; ;act,

17 17

CLOOT BOARD CARR

A

DIAL CIECISICOT CIRCUIT

AT. ILOCAT

21:01: 2gRIO

2

- 2 ix

IN -OUT TRAKI/004E0COOR TONE 02 ttttt ON AND NEL 47 CIRCUITS

CLOCK 00020 C - 929 CLOCN 110420 C-929

CLOCK 004010 C-929L047 00,04.7 027451701

12 vO

COOT 1110010 C -9 21 0

ROT I

0 IT DM

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C:LOOK BOARD C 125502/ 1105A KWICE550/1

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I

END BOARDCLOG

250

SENSITIVaT

Fig. 5-Schematic diagram of the Automatic Telephone Dialer.

44 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

Basic Digital Circuitryby Phillip Dahlen

Part II-The functionof IC decade -counter circuitry

Last month's article introducedthis series by referring to the tech-nological changes that have resultedin a greater use of digital circuitryin consumer electronic products.Then, using the Heathkit Model IB-101 as an example of new digitalcircuitry, the article explained (withthe aid of scope traces) how the in-put signal is modified into a signalthat can be handled by the circuitryin this instrument's first decadecounter.

Probably the most prevalent func-tion in a frequency counter, and theone most difficult to understand, isdecade counting with the use ofBase -Two mathematics. The mathe-matics that we are most familiarwith is to Base Ten. In other words,we are accustomed to counting from0 to 9 in the first column (the right,units column), 0 to 9 in the secondcolumn (the 10's column), 0 to 9in the third column (the 100's col-umn), and so on. However, whenworking with Base Two, we countfrom 0 to 1 in the first binary col-umn (the right, l's column), 0 to 1in the second binary column (the 2'scolumn), 0 to 1 in the third binarycolumn (the 4's column), 0 to 1 inthe fourth binary column (the 8'scolumn), and so on. Table I com-pares these two systems in countingfrom 0 to 15-although in this in-strument, no Base -Two counting isdone to any number greater than 10.

When referring to the Base -Twol's column, we note that with thefirst applied count a "1" is regis-tered, while with the second counta "0" is registered, a second "1" be-ing registered with the third count,and so on with every other count re-sulting in a "1." A flip-flop circuitcan be made to count in the samemanner, alternately turning fromone state ("1") to another ("0")with each applied pulse. (Notice

that in this flip-flop the occurrenceof a "1" state is at half the appliedfrequency, because every other cycle-or count-registers a "0." At thispoint, many authors introduce nega-tive logic, a subject that we will ig-nore for greater simplicity of circuitdescriptions.)

In the Base -Two 2's column asimilar action is obtained. Just asthe l's column flip-flop is switchedto register "1" (or "0") at half thefrequency of the applied count, the2's column flip-flop is switched toregister "1" (or "0") at half thefrequency it obtains a count fromthe previous l's stage-it alternate-ly flipping between the "1" and "0"state each time the preceding flip-flop switches to the "0" state.

We can also see that the flip-flopfor the 4's column functions in thesame manner-it alternately flippingbetween the "1" and "0" states eachtime the 2's column flips to the "0"

Table ICortna.ing Two Systems for Counting

from 0 to 15Base 10 Base 2

0000

0001

2 0010

3 0011

4 0100

5 0101

3 0110

7 0111

B 1000

9 1001

10 1010

11 1011

12 1100

13 1101

14 1110

15 1111

state. And the same action appliesto the 8's column, which alternatelyflips between the two states eachtime the 4's column flips to the "0"state. (Since we are not countingbeyond 10, the 8's column is as highas we need go.)

Although it may be great to havea circuit that can count, the result-ing numbers will probably have littlepractical value to us unless they arecompared to something else. (Weare not interested in total numbers,like the ticket agent at a fair, butrather in rates.) For this reason, agate circuit (oN/oFF control cir-cuit) is provided to permit the flip-flops to function only during a pre-determined period of time. Afterthis period of time has ended, thegate circuit prevents the flip-flopsfrom counting further. And after thecount has been registered, a resetsignal returns the decade circuitry toits initial "0" condition.

First DecadeEven without a frequency scaler,

which may be chtiered in anotherarticle, this particular frequencycounter is designed to directly countsignals up to 15MHz. However, onlythe flip-flop in IC21 (shown in theschematic used in Fig. 7, Page 58 oflast month's issue) need operate atso high an input frequency-sincethe other IC flip-flops are driven bythis or later flip-flops and thus oper-ate at no more than 7.5MHz. It isdue to such high -frequency require-ments that the first decade countercontains three integrated circuits( IC23 merely appears as if it weretwo IC's). Since the other decadecounters operate at no more than atenth of the maximum applied signalfrequency (1.5MHz or less), merelya single IC has the required frequen-cy response, at a reasonable price,to perform as a complete decadecounter.

A more detailed study of the 31/2IC's incorporated in the first decadecounter (Fig. 1) is required for ef-fective servicing. This is due to thefact that the function of these IC'smust differ slightly from the pre-vious description of Base -Twonumbers, since upon reaching 10each digital counter must be capableof carrying a pulse to the next digi-tal counter and then repeating the

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 1 45

0 -to -9 sequence, rather than con-tinuing on to higher numbers (nosingle decade counter can go be-yond 9). Fig. 2 shows the signalsused in this decade circuit for count-ing to 10.

The first flip-flop (IC21) remainsin a "0" condition and does notfunction until the inhibit signal, gen-erated in the master oscillator cir-cuit, allows the input signal to becounted for a predetermined lengthof time (1 ms in the kHz range andis in the Hz range). When not in-hibited (B-shortly after time To),the first flip-flop is switched to the"1" condition (C-at time T1) bythe negative excursion of a squarewave (A-at the time T1) generat-ed by the signal being measured (asdescribed in last month's article).We now have the number 0001.

The second negative excursion(A-at time To ) causes the firstflip-flop to return to its original "0"condition (C-at time To ), produc-ing a negative excursion at C thatswitches the second flip-flop to the"1" condition (E-at time To ).(This second flip-flop remains un-inhibited until after the fourth flip-flop circuit has become activated.)With a "1" conditioning existing inonly the 2's column, the resultingnumber is 0010.

With the third negative excursionfrom the square -wave input (A-at time T3), the first flip-flop is

again switched to the "1" condition(C-at time T3). Since in changingfrom the "0" to "1" condition theIC does not apply a negative pulseto the second flip-flop, that secondcircuit remains in a "1" condition(E-at time T3). We now have thenumber 0011.

With the fourth negative excur-sion of the square -wave input (A-at time T4), the first flip-flop againswitches to the "0" condition (C-at time T4), which produces an-other negative excursion at C. Thisnegative excursion in turn switchesthe second flip-flop to the "0" con-dition (E-at time T4 )-it alsoproducing a negative excursion atE. The third flip-flop responds tothis negative excursion at E and isswitched to the "1" condition (G-at time T4). We now have the num-ber 0100.

This sequence continues with theinput signal causing the first flip-flop to again switch to the "1" state(C-at time T5) when a negativeexcursion is received from thesquare -wave input (A-at timeT5). Under these conditions, thesecond and third flip-flop circuits donot receive a negative going pulsefrom the preceding circuits and re-main in their current states. We nowhave the number 0101.

The next negative excursion (A-at time TO) causes the first flip-flop to return to its "0" state (C-

at time T6), producing a negativeexcursion at C that causes the sec-ond flip-flop to switch to its "1"state (E-at time T6). This secondIC does not produce a negative ex-cursion at E to affect the third flip-flop, which remains in the "1" state.We now have the number 0110.

The seventh negative excursionfrom the square -wave input (A-attime T7) switches the first flip-flopto its "1" state (C-at time T7).Since the second and third flip-flopsdo not then receive a negative ex-cursion from the preceding ones,they remain in their current states.We now have the number 0111.

From the information containedin Table I, it would seem as thougha fourth flip-flop might be used likethe others (connected directly to thethird flip-flop) for switching to the"1" state with the application of an-other input pulse (A-at time Ts).Although this would produce the de-sired number (1000), such circuitrywould not return to the zero condi-tion upon receipt of the tenth nega-tive input pulse (A-at time T10).Slightly different circuitry is re-quired for such a function.

Each of the three flip-flop circuitsdescribed thus far actually has twooutputs-one that goes positive dur-ing the "1" condition (C, E and G)and one that goes negative duringthe "1" condition (D, F and H).Some of these outputs are used in

Cl

IC 12

BUFFER -STORAGE

0

0

1/21C23

d

L

7 1/4IC25

GATE B

Fig. 1-Diagram of circuitry in the first decade counter.

II 1/41C25

GATE C

CARRY.

46 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

regulating the fourth, and last, flip-flop circuit in this decade counter.

From Table I we see that thefourth flip-flop must be switched tothe "1" condition when both thesecond and third flip-flops,are in the"1" condition and the first flip-flopis switching to the "0" condition-the second and third flip-flops thenalso following to the "0" condition.As has been somewhat exaggeratedin Fig. 2, the flip-flops do not switchsimultaneously-internal circuit ca-pacitance causing each flip-flop cir-cuit to switch slightly after the pre-ceding one. (The fourth flip-flopwould appear to be an exception,but only if you fail to note thesource of the negative excursioncausing it to change state.) Thus,the second and third flip-flops arestill in the "1" condition (E and G-at time Ts) as the first flip-flopis switched to the "0" condition (C-at time Ts).

Gate B (a portion of IC25) hasa positive output (1-from justafter time To to just after time T8)only when the applied outputs fromboth the second (F) and third (H)flip-flops represent the "1" condi-tion. The output of Gate B (I) isinverted by Gate C, the resultingnegative output (J) beginning short-ly after time To and ending shortlyafter time Ts.

Just as the first IC flip-flop is reg-ulated by an inhibit signal applied toit (B-ceasing to inhibit shortlyafter time T,,), the fourth flip-flopis also regulated by an inhibit signal(J-allowing it to function from justafter time To to just after time T8 )-that produced by Gate C. Onlyduring this time interval is it per-mitted to switch to the "1" condi-tion upon receipt of a negativeswitching pulse.

The fourth flip-flop, like the secondone, is switched between states bythe negative -pulse output of the firstflip-flop (C). But not until aftertime T,; is the fourth flip-flop al-lowed to function-the first accept-able negative switching pulse beingC-at time T.

With the eighth negative excur-sion from the square -wave input(A-at time Ts ), the first flip-flopswitches to the "0" condition (C-at time T, ), producing a negativeexcursion at C that is now permitted

To T1 12 T3 Ts T5 T6 T, T8 19 110

8-1

1

D-I0 1 1 1 0 1

E1 0 1 0 01 1

F

G-0 10 0 1 1 1H-

J -

K

L-

1

0 0 0 0 0 0 1 1

L

r

Signals Present in Initial Decade Circuitry

A=Square-wave signal to be counted-applied to input of first flip-flop (IC21, Pin 2).

B=Inhibit signal-applied to first flip-flop (IC21, Pins 3 and 13).

C=Output from first flip-flop (IC21, Pin 10)-applied to input of second flip-flop (IC22, Pin

2) and fourth flip-flop (IC23, Pin 6). Output is half frequency of input.

D=Inverted output of first flip-flop (IC21, Pin 6)-applied to buffer -storage (IC12, Pin 14).This is the binary l's column output.

E=Output from second flip-flop (IC22, Pin 13)-applied to input of third flip-flop (IC23,Pin 2). Output is half frequency of input.

F=Inverted output from second flip-flop (IC22, Pin 14)-applied to Gate B (IC25, Pin 7)and buffer -storage (IC12, Pin 11). This is the binary 2's column output.

G=Output from third flip-flop (IC23, Pin 13)-not used.

H=Inverted output from third flip-flop (IC23, Pin 14)-applied to Gate B (IC25, Pin 6) andbuffer -storage (IC12, Pin 3). Output is inverted, but half frequency of input. This is thebinary 4's column output.

l=Output from Gate B (IC25, Pin 5)-applied to Gate C (IC25, Pin 9). Gate B output signal"0" appears only when '1" condition occurs at the same time at both inputs.

1=Output from Gate C (IC25, Pin 8)-applied to inhibit input of fourth flip-flop (IC23, Pin 7).This gate inverts the applied signal.

K=Output from fourth flip-flop (IC23, Pin 91-applied to inhibit input of second flip-flop(IC22, Pin 1).

L=Inverted output from fourth flip-flop (IC23, Pin 81-applied to next decade counter(IC17, Pin 9) and buffer -storage (IC12, Pin 6). This is the binary 8's column output.

M=Reset signal --applied to return all decade flip-flops (IC21, Pin 9; IC22, Pin 12; IC23,Pins 10 and 12) to initial state after count is completed. (Signal shown only in com-posite photographs.)

Fig. 2-Signals used in the first decade circuitry for counting to 10.

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 47

to cause the fourth flip-flop to switchto the "1" condition-in addition tocausing the second flip-flop to switchto the "0" condition. The secondflip-flop, in turn, causes the thirdflip-flop to switch to the "0" condi-tion. We now have the number1000.

The ninth negative excursion ofthe square -wave input (A-at timeT9) switches the first flip-flop to the"1" condition (C-at time T9 ) .

Since switching from the "0" condi-tion to the "1" condition does notgenerate a negative pulse at C to ac-tivate the other flip-flops, they re-main in their present state. We nowhave the number 1001.

The 10th negative excursion ofthe square -wave input (A-at timeT10, or T0 if we are repeating thecycle during the 1 ms or is countingtime for a number larger than 10)switches the first flip-flop from the"1" to the "0" condition. This pro-duces a negative excursion (C-attime T10 or T0), which switchesthe fourth flip-flop to the "0" condi-tion (K-at time T10 or T0).

Since some time (although ex-tremely little) is required for thefourth flip-flop to change conditions,it is still in the "1" condition at theinstant that the negative excursion(C-at time T10) is applied to bothit and the second flip-flop. And thepositive potential that does remainat output K is applied to inhibit thecontrol gate of the second flip-flop-thus preventing it from switchingto the "1" condition. In this manner,the decade circuitry is returned to0000. However, in returning to azero state, the inverted output of thefourth flip-flop (a positive excursionfrom L) is carried to the next dec-ade-the second decade counter re-ceiving one positive pulse each timethe initial decade circuit receives 10negative pulses from its square -waveinput. (Note that in this instrumentthe flip-flops for the first decade re-quire negative square -wave -typepulses, while the remaining decadecounters require positive square -wave -type pulses.)

Scope TracesFig. 4 is a composite picture made

up of 12 photographs taken of dual- trace scope waveforms obtained with

a Telequipment D54 scope fromvarious IC terminals when the fre-quency of the input signal (A) isabout three times that of the gatesignal (B), or nearly 3kHz. The firstoriginal photograph consisted ofdual -trace waveforms A and B, thesecond consisted of dual -trace wave-forms C and B, the third consistedof dual -trace waveforms D and B,. . . , and the 12th consisted of dual -trace waveforms M and B. Althoughthe duplicate photographs of wave-form B are not shown in this com-posite picture, they were used toalign the second waveform in eachdual -trace picture. Thus, we wereable to align all of the waveforms in

COUNT COUNT

INHIBIT INHIBIT INHIBIT

1 1

RESET RESET

Fig. 3-Photograph of dual -trace scope wave-forms showing the relationship between the in-hibit gate signal (upper trace) and the resetsignal (lower trace).

relation to waveform B and showthe approximate relationship of eachwaveform to the other. [This rela-tionship between waveforms couldhave been shown with a slightlygreater degree of accuracy had theinput signal (A) been synchronizedwith the gate signal (B), for it is thecombination of both signals (A andB) that determines the exact phaseposition of the other waveforms.However, without the aid of a ruler,the resulting error is too small to beobserved in this picture.]

Fig. 4 contains one more wave-form (M) than shown in Fig. 2.This additional signal (M) is usedto reset all the flip-flops to their "0"condition before the start of eachcounting interval determined by in-hibit gate signal B. The relationshipbetween these two signals is shownmore clearly in Fig. 3 (the gate sig-nal being the upper trace and thereset signal being the lower trace).

Referring to Fig. 4, we note that

since the input signal frequency(nearly 3kHz) is about three timesthat of the gate signal (1kHz), thedecade counter circuitry is allowedto count to three. Just prior tocounting (the time interval just be-fore the first vertical line drawnthrough the illustration), all flip-flops are in their "0" condition.Once the counting interval hasended (the time interval just afterthe second vertical line drawnthrough the illustration), the flip-flops are in a state corresponding tothe number "3" (0011). By refer-ring to scope traces L, H, F and D,we note that the voltages for L andH have remained unchanged (they

B-<c-(

GH

K

Fig. 4-Composite picture showing actualscope traces as first decade circuitry countsto three.

48 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

still represent a "0" condition).However, the voltages for F and Dhave been switched from that repre-senting the "0" condition to thatrepresenting the "1" condition. Thuswe do have the number "0011" or

The composite picture in Fig. 5was made from 12 photographs us-ing the same techniques used formaking the picture shown in Fig. 4.However, this time an input signalof nearly 6kHz is shown applied tothe decade counter circuitry, its fre-quency being about six times thatof the 1 kHz gate signal (B). Thus,at the end of the counting interval,the flip-flops have been switched to

AB

D

E-(

F-(

H-(

KL

*Rao

Fig. 5-Composite picture showing actualscope traces as first decade circuitry countsto six.

conditions corresponding to thenumber "6" (0110). Scope trace Lhas remained in the "0" condition,trace H has switched to the "1" con-dition, trace F has switched to the"1" condition and trace D hasswitched to the "0" condition at theend of the time interval.

The composite picture in Fig. 6was made in the same manner as thetwo other composite pictures, but thistime an input signal of about 12kHzis used. During this time interval,scope trace L switched from the "0"condition to the "1" condition andthen back to the "0" condition. Asit switches from the "1" conditionto the "0" condition, a pulse is

A-(B

C-(

E

J

M

Fig. 6-Cmposite picture showing actualscope traces as first decade circuitry is usedfor countirg to 12.

transferred to the next decadecounter (IC17, Fig. 7 in last month'sarticle) to indicate the number"10." At the end of the time inter-val, the first decade counter circuitry(Fig. 1), merely records the number"2" (0010), since the second dec-ade counter (IC17) must handlethe 10's portion of the number. Andfrom the composite picture (Fig. 6),we see that we do have a "0010"condition (scope trace L has re-turned to a "0" condition, trace Hhas returned to a "0" condition,trace F has been switched to a "1"condition and trace D has returnedto a "0" condition).

Counting Entire NumberHad the digital counter been

switched from its "kHz" scale to its"Hz" scale, then the first decadecounter would have been permittedto function for 1 sec. intervals ratherthan .001 sec. intervals. If underthese conditions we applied a35167Hz signal, the first decadecounter circuit (Fig. 1) would re-cord the "7" and feed 3516 pulsesto the second decade counter (IC17,Fig. 7 in last month's article),which would record the "6" andfeed 351 pulses to the third decadecounter (IC18), which would re-cord the "1" and feed 35 pulses tothe fourth decade counter (IC19),which would record the "5" andfeed three pulses to the fifth decadecounter (IC20), which would re-cord the "3." In this manner, a"0111" (7) is fed to IC12 for stor-age, a "0110" (6) is fed to IC13for storage, a "0001" (1) is fed toIC14 for storage, a "0101" (5) isfed to IC15 for storage and a"0011" (3) is fed to IC16 for stor-age. Each buffer -storage IC thencontains a condition correspondingto the frequency of the applied sig-nal.

ConclusionAlthough this is an extremely

lengthy description, it concerns thebasic function of all digital meters.The next article in this series, a rela-tively short one, will show how the11cHz and 1Hz timing signals areproduced from a 1MHz oscillatorsignal.

DECEMBER 1972, ELECTRONIC TECHNICIPN/DEALER j 49

So much publicity has been givenanother association's certificationprogram that we decided that pub-licity should also be given to theprogram sponsored by the NationalAlliance of Television & ElectronicService Associations. When contact-ing Frank J. Moch, Executive Di-rector of NATESA, concerning theirprogram, he was very helpful andsent us a large packet of material.Included was a letter from him thatis quoted, in part, below:

"TV and radio being highly so-phisticated devices, cause most setowners to keep hands off except formost obvious problems. They as -

X-RAY SAFETY CNECK

checked and adjusted the highvoltage to meet the factoriesspecifications designed to limit

'

The member affixing this labelto your set, certifies that he hos

when next serviced, whichever

x-ray iodiation.it is suggested that this check

be repeated each six months or

.omen first.SAFE SER VICERCERTIFICATE

The service establishment displaying this Certificate hos satisfactorilyproved its knowledge of service p-ocedurec poiticutorly thole that assureadjustment of color fr set high veltoge to 0,99.1 factory specifications oneroy radiation, and is pledged to fulfill these spocilmofions for the safetyof the public.

National Alliance of Television & ElectronicService Assns.

by

Ous9ons s2.9991 139 &see., a to 9.1 2.2.90000 Sow,. Troy 5990. CNcogor 111,99s 60629

, Executive Director

.196

Fig. 1-Upon receiving the Safe Servicer Certificate, employees of the certified service establish-ment may secure the label shown at the upper right to any TV set that has been given the X -RaySafety Check.

NATESA Plan

to Create Confidence

by Phillip Dahlen

National association works to upgrade quality of work

performed by employees of member shops

sumo that he who oilers his services,knows his business. They couldn'tcare less whether he knows all thetheory in the world if the servicerdoesn't approach the set problemfrom an effect and cause basis, andin a reasonable time.

"NATESA's Confidence Plan andCertification thus is predicated onthe fact that the technician does infact have the basic theory aug-mented by practical experience. Itrecognizes that new corners comingout of technical schools with diplo-mas, know theory but only after sev-eral years of experience and upgrad-ing seminars, can they truthfully call

themselves experts. When theyachieve that point, they arc ac-corded the registered title of Elec-tronician (Fig. 2), a term under-standable by the public, which longhas called an expert on house wiringan electrician.

"Since the NATESA by-lawsgrant membership only to profes-sional home electronics business,and recognizes that all affiliatesscreen their membership applicants,NATESA accepts as de -facto thatemployees of all members are pro-fessionals. At the same time it doespolice all members and customercomplaints and so is in a position

50 ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

CERTIFICATE OF MEMBERSHIP

'1972-73

HAVING PLEDGED TO OBSERVE THE CODE OF ETHICS BELOW, HAS BEEN ISSUED

LICENSE #

CODE

1. Employ qualified personnel to as-sure proper service. No studentshall be passed off as a technician.

2. Make proper arrangements for theprotection of reserve funds on con-tracts.

3. Carry adequate insurance cover-age.

4. Avoid trick advertising which of-fers to service or deliver materialsunder conditions which are ques-tionable or unfair to the set owneror your fellow members.

5. Employ professional methods ofdoing installations and mainte-nance.

6. Issue a standard guarantee.7. Ha v e available sufficient a n d

proper test equipment to assure agood job.

OF ETHICS

8. Maintain an adequate service da-ta library.

9. Render service without undue de-Icrr.

10. 'retail only parts as are reallynecessary. Use only new parts cfa quality at least equal to orig-inal.

11. Leave with, or return to customer,all parts replaced, when request-ed, (except where impractical).

12. Issue an itemized bill.13. Furnish estimates upon request.14. Service sets in home whenever

passible.15. Be honest, courteous and treat

each client in a professional ma 1-ner.

16. Observe the Golden Rule.

this Certificate is issued conditional upon adherence to the above Code of Ethics. Display after expiration date or aftertermination of membership for any cause is strictly prohibited and is subject to a lit ense fee of $10.00 per day for each day*I such unauthorized use. All communications regarding the above member .hould be directed to the address below:

National Alliance of Television & Electronic Service Associations5906-08 S. TROT ST. - CHICAGO, ILLINOIS 60629

Fig. 2-After several years of experience and upgrading seminars, technical -school graduates haveachieved the point at which they can be accorded the registered title of Electronician.

to recall Certification. It has donethis on several occasions. In this weoperate as does the AMA and BAR.

"Most current NATESA affiliateshave qualified their membership inthe past for the Plan to Create Con-fidence. All are urged to carry on(and do) a continuing program ofseminars to keep up to date.

"All individual membership appli-cants are cleared through the near-est member, distributor, BBB orChamber of Commerce.

"We have used special seminarsand tests as at the time of the x-ra-diation scare when we tested knowl-edge of proper set-up of high volt-

age. See enclosure." [The corre-sponding material consisted of a one -page reprint of Photofax Volume 2,No. 3, dated March 1968 and en-titled Color TV High -Voltage Regu-lation. Printed on the back side ofthe reprint were five multiple-choicequestions that made up theNATESA High Voltage RegulationTest. At the bottom of that page wasa NATESA Safe Servicer Pledge.Also included were the certificatesshown in Fig. 1.]

Mr. Moch's letter continued bysaying: "We urge the QualificationsOf Technicians Plan on all new Af-filiates." [This plan is not just some

recent brainstorm, having been out-lined nearly 20 years ago in the Feb-ruary 1953 issue of SYLVANIANEWS.]

Concerning that program, his cur-rent letter said: "We have updatedthe program to call for seminars onsolid-state, FM stereo, color, mod-ules, etc. We are readying video tapematerial."

Mr. Moch added, "We haveadopted EIA's 'Television SymptomDiagnosis' by Richard W. Tinnell asa proper training method and willuse tests in that text to supplementthe NATESA current 125 multiple-choice -question test, to qualify ca-pability of Techs."

In the 1953 reprint covering theQualifications Of Technicians Plan,Mr. Moch explains the following:

"Refresher courses will be con-ducted for: 1) Association memberemployees and 2) outsiders who areactively engaged in the service busi-ness.

"The course consists of one lec-ture of approximately three hoursper week (with a break of 10 min-utes at the half -way point). Quali-fied distributors and factory servicepersonnel will be asked to cooperatein the conduct of sessions. Coursesare to consist of 10 sessions as fol-lows: 1) Front ends, 2) Video I.F.,3) Audio I.F., 4) Vertical sweepand sync, 5) Horizontal sweep, 6)Hi -voltage systems, 7) Low -voltagesystems, 8) Alignment, 9) Recordchangers, and 10) Antennae. Theblack and white course should besupplemented by a three -sessioncolor TV course.

"Upon completion of the course,a clinic will be held. All set distribu-tors in the area will be asked to havebooths fully equipped and mannedto answer all technical questions ontheir products. The 12th week, awritten examination will be given onpractical theory and practice. Ques-tions asked in the test will be de-termined on the basis of practicalvalue by a committee from indepen-dent associations, distributor servicemanagers, factory service managersand RTMA. Those that pass will beissued a certificate attesting to thefact that the applicant has taken thecourse and passed the require-ments."

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 51

Better MerchantsMake Better Profits

by William Joseph

The telephone can be a cruel master for electronicservice dealers. When it rings, everything is fine; but

when it stops, many dealers only know how to sit on theirhands waiting for business to pick up again. That kind of

dependency is one of the worst profit robbersin the service business.

Healthy profits in a service or-ganization are the result of a highdegree of efficiency, and one of thedeadliest enemies of efficiency is aconstantly fluctuating workload.During busy seasons, you must havethe necessary manpower availableto give your customers prompt ser-vice. But what happens when theworkload falls off?

Some dealers know the answerto that question all too, well: Eitheryou put up with the crippling ex-pense of a lower output per man, oryou lay off help. It is hardly muchof a choice, since either alternativemust inevitably result in a loss ofprofits. Furthermore, if the scarcityof work persists long enough, it canspell financial disaster.

Fortunately, there is anotherchoice. It is fast and easy, requiresonly a small investment, and willadd strength and profits to yourbusiness. The answer? Teach your-self to be a better merchant.

As a basic premise, the servicedealer should bring himself to un-derstand that the product that heoffers is a saleable commodity.There is absolutely no need to standby helplessly when busy periodscause overtime expenses and longdelays for the customers, or when afalling -off of calls sharply reducesincome. This "feast or famine" ten-dency in the service business is botha profit killer and . . . unnecessary.

The first thing that a retail mer-chant learns is that there are timeswhen customers are going to beplentiful, and times when businesscan be expected to fall off sharply.

If he is to be successful, he mustanalyze these natural "seasons,"staff his store so that he can ade-quately take care of his customerswhen business is good, and then takesteps to bring in customers duringthe naturally slow periods. The idea,of course, is to attempt to level offthe sharp peaks and valleys in busi-ness volume that will result if natureis left to take its course. This is pre-cisely the same set of circumstancesfacing the electronic service dealer.

As is so often the case, the firststep in facing up to this problem isthe preparation of adequate records.A simple analysis of the number ofincoming calls for service duringeach month of the year will give youa graphic picture of your busy andslow periods. For most dealers, thisgraph of business volume will besurprisingly consistent. If Marchand November were relatively slowmonths for you last year, the chanc-es are that the same condition willrepeat itself again this year-unlessyou decide to do something aboutit! A prime requirement in bolster-ing your slow periods is the knowl-edge, in advance, of when they arecoming. Once you know when toexpect a drop-off in incoming calls,you can begin your plans to combatit.

Obviously, the small service deal-er cannot afford the elaborate adver-tising campaigns that his retailingcounterparts have come to dependupon to build business when cus-tomers are scarce. Fortunately,though, he doesn't have to. Directmail-easy and inexpensive-is a

powerful sales promotion tool forthe service dealer. It also has theadvantage of extreme flexibility.The number of mailings can bequickly adjusted once the responsehas been measured, and the cam-paign can be turned off almost likea spigot as soon as the slow periodcomes to its natural end.

Frequently, the method of directmail to small businessmen causesthem to think of post cards. Forgetit! Direct -mail professionals learnedlong ago that the simple post cardhas a very limited and specializedvalue as an advertising medium. Itsimply isn't adequate to tell enoughof a story. If you attempt to use it,you will surely be disappointed inthe results. Selling a potential cus-tomer on the reasons for choosingyour service firm requires, at thevery least, the dignity of a standard -sized letter.

Many service dealers make thecostly mistake of dismissing directmail because of the feeling that,"unless the letter arrives at just thetime of a breakdown, it is a waste."Actually, that is a mistake for tworeasons: First, a recent national sur-vey confirms the suspicion that mostTV sets give considerable advancewarning to the viewer that all is notwell. In this survey, 73 percent ofall TV owners who recently had ser-vice indicated that their sets hadbeen acting improperly for up toseveral weeks before they finally hadto call for an electronic technician.In other words, they were primeprospects for a well -written adver-tisement suggesting service.

Second, a good number of TV -set owners are always anxious to lo-cate an established local servicedealer upon whom they can dependfor all their service needs. A skillfuldirect -mail promotion can developnew customers from both of thesecategories.

The chances are that your localprinter will be happy to work withyou in setting up a format and let-terhead. He is experienced in devel-oping printing layouts and youshould take advantage of his help.

As far as the actual text of yoursales letter is concerned, you wouldprobably be wise to seek profession-al help. The experts stress that skill-ful wording is of paramount impor-

52 1 ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

tance in direct -mail efforts. A prop-erly written letter has been knownto bring in 10 times, or even 100times, the response of a poorly writ-ten one. Unless you have a particu-lar and obvious talent for that sortof thing, you would do well not toattempt to compose your own ad-vertising.

Considering the fact that gettingprofessional help in composing yourletter is a one-time investment, andthat it can be used indefinitely (withbut slight modifications), spendinga few dollars to get it done properlyis good business.

Some dealers have had good re-sults by calling on small local adver-tising agencies for help with theirletters. The small dealer may notget the attention that can be givento a regular account, and he mayhave to wait until the agency can

find time to work on his project, butthe effort will usually be well worth-while.

In many cities, freelance copy-writers can be located in the YellowPages. if there is a lettershop in yourcommunity, you may want to checkwith them. Many of these shops areequipped to handle your entire proj-ect from composition to mailing.

For those who will insist on com-posing their own letters, here are afew tips that may prove helpful:Write your letter in the first -person(on a you and I basis), and signyour own name. The informality ofa first -person letter will often im-prove the results for businesses lo-cated in the same general commu-nity as the addressee. While you willwant your letters to reflect your ownpersonality and that of your busi-ness, the example shown in this ar-

tide may provide you with somebasic ideas.

On a separate sheet, or on the re-verse side of your letter, you maywant to outline the various servicesyou offer and/or the terms of yourguarantee. Direct mail promotionsalso present a good chance to testthe "two dollars off on your firstservice call," type of coupon. Expe-rience shows that many people willrespond to such a savings and, ifthe service provided is satisfactory,most will remain on as regular cus-tomers. The face amount of the cou-pon can be as little as a dollar, orit can be several dollars, dependingon your own ideas.

Your direct -mail program can beas simple or as extensive as yourneeds dictate, but it should alwaysbe ready for action whenever you

continued on page 68

A. IL S. SE11111SE SS.2205 First Avenue South

Home Town, Hawaii

Phone 943-0200

Dear TV Viewer:

Satisfied with your TV-set reception lately? Is the picture as clear asit used to be? Are some channels snowy or fuzzy? In other words, are youmissing out on the full enjoyment that can be provided only by a TV setin top-operating condition?

For most people, the purchase of a modern TV set represents a considerableinvestment. My years of experience in the electronics field has taughtme that the best way to protect that investment and to get the full en-joyment built into every TV set, is to see that it gets the best possiblecare.

That's the kind of care that we provide here at A.B.C. Service Co. The

success of our business depends on satisfied customers who come back to ustime after time, and we know it. Now, we'd like to have the pleasure ofadding you to our long list of satisfied customers.

If you're not happy with the way your set is working, why not call us rightnow at 943-0200. We'll have you back on the road to happy TV viewing ina jiffy . . . and we'll do it at the lowest possible cost to you.

Roger SmithA.B.C. Service Co.

P.S. I hope your set is working fine at the moment. If so, please tuckthe enclosed coupon away so that you'll have our number if you shouldneed it in the future. Ycu'll be glad you did.

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 53

COLORFAX

The material used in this section is selected frominformation supplied through the cooperation of therespective manufacturers or their agencies.

ADMIRAL

Color -TV Chassis 1(16 Series-No Control Of Brightness

I his problem can be caused by defective diode CR402(93A69-1). Check for the presence of a negative voltageat the anode of this diode, it should be approximately-130v to -160v.

This diode and associated components provide the nega-

Yx6LU8rINTUINI

MEI r

VENT.soo. LIB

6KD6NORM OUtPut

0702

t .8.7 OMBO II

CIO 'On"77751NR

PwI7534

//a* .7.1 Li.chr

1)04.401 COM

I,4

1721

11

NY RIC?0103

X104 , 6CG3ft WC WEIv704

.11r1

fly/AN

aI 105

tive voltage for the BRIGHTNESS control through the MAS-TER BRIGHTNESS control and for the BACKGROUND controls.The circuit is not used for high voltage regulation in thischassis, as it was in some previous chassis.

This diode can also be replaced by Part No. 93A60-3.

Color -TV Chassis G11313/H10/H12/105/K16 Series-Weak Or No Color

A weak or no color complaint can be caused by defec-tive capacitor C521.

Failure of this capacitor permits a negative voltage to beproduced at the plate (Pin I) of the color killer tube,which will bias off the second bandpass amplifier. Check

1/26X9ISI BAND PASS AMP

VSOIA

1:01E;C524 II

---/15b1.505A 1 -sir 6505

560 1 I.

51504

120 I -

L_`_ "_^^J loos - 1502

-1HA 10501 010(--2110 /Y I

Inv

550519ilor

OINI

-Or

11521

1E53\1N1

1

9

L502 12"

I li511 A 1L:56' 25

J 1511 IrC504 1004

122671510

150T'.005

1/26GH8A 6512COLOR KILLER

V504A

11513

15$

II.0

-6:5,

1/26X92ND BAND PISS AMP.

V50113

N L514621,6.2n

1514 C506

350 .01N/

CR501ASC- DIODE

21510 93E58-1 -SOK

C549 .1174.,

this capacitor by substitution since measuring it with anohmmeter may not reveal a defective capacitor. Replace itwith a 0.I/.1f of higher working voltage capacitor such as a

Part No. 64A53-98 capacitor which was used in later pro-duction models.

Another possible cause of a weak or no color complaintis leaky capacitor C540 in the HIO and K16 chassis, andcapacitor C548 in the H 12 and K15 chassis. Low platevoltage on the first bandpass amplifier probably identifiesthe leaky capacitor as the cause.

Color -TV Chassis Gil-Installing Replacement High -Voltage Transformer

When you install a 98A131-5 replacement HV trans-former kit (79A148 -I transformer) in the G11 chassis,you may find some sets which require horizontal centering.

Horizontal centering can be accomplished by adding adiode, with parallel resistor, in series with the blue leadto the deflection yoke at Terminal 3 of the transformer.

The polarity of the diode determines the direction thatthe picture shifts. Diode polarity shown in the illustration

503w61A 20 - 74

_ITO YOKE

"j BLUE

TERM 3H V TRANS

93A52-1will shift the picture to the left. A special diode is not re-quired, a 500ma with 600PIV being satisfactory.

The amount of picture shift is determined by the valueof the resistor. A %I resistor will shift the picture approxi-mately 1 in. (do not exceed 1011).

Color -TV Chassis 1(20-No sound

When you check out a dead audio complaint on thesechassis and find that the 57C29-2 audio IC has failed; be-fore replacing the IC, check the ground point of the TONEcontrol capacitor (.022/Af). This capacitor must begrounded to the shield braid at the VOLUME control. If, in-stead, it is grounded on the tuner cluster bracket, change itbefore you put in the new IC.

Color -TV Chassis M20-Srvice Hint

There have been reports of an unusual condition in theM20 chassis that can result from the failure of a fuse inthe low -voltage power supply. You would not expect tofind an open fuse causing excessive brightness, washed outvideo and no control of the brightness condition. However,an open fuse-F904, 1/2a pigtail, Part No. 84A7-I6-on the power supply module is a probable cause. Thisfuse is found in the power transformer secondary ac supplyto the 400v B+ circuit. Because of the power supply con-figuration, 285v remains on the 400v line when this fuse isopen-the reduced voltage to the picture tube cathodes re-sulting in excessive brightness.

Check the circuits supplied by the 400v B+ source andthe components in the supply. When repairs have beenmade, replace the open fuse.

GENERAL ELECTRICColor -TV Chassis C-1-Troubleshooting Guide

When eneountermy. a Linn raster s) :upturn, capacitor

54 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

5E266

422V

3150.39502 (990mA

.50 6910

53-10

3C 50239501 11

3R503150

5C271that is

/6.5V14V

5C/64.01

T561266399

90267

270

047

5927330k

592,7I.BM

Via26905

NOR Ou 1 Pul

-70V79267

00

592682708

5976900K

y.0 S

ZOO 0910HYNt St.

7928079279 6K,00 5w

7c275 7 4.-280y

,bovaTP

.005

57253 157252

-14g15C-269

NC 769

18517273314,5%- VV,-.{ 280V

517274 5927740K 476M.V. 5%*DJ

5827682K5%

may be shorted. Replace this capacitor with one400v rated, Part No. EP25X4.

-/7V 3;201 TO4-i V °E° 7C276

-------iik39201

0302ACC

7 38202101(

39206 392071500 5 330 39203

96I 3(200 *GC

22

A no AGC symptom can be3Y201.

470

37701

4 2 2V

3970,

T.P.

+22V Xi

50202047_1(

597086.8k

3E207800TO7C276

39201470

37201

+22V

38204

T. P

+22V Mt

5C20247 592Il0 3306If r /V

I 4V--58206

tix 60k 2777

3920399

*GC

0501SYNC SEP

5112103301( 40V

2 8V1.1y

55120927k

4V8V

5C2o3.572022200 7

caused by open diode

(0)-00501

SYNC SEP

28V

4V8V

5C203T7200

57202

59213 5E2512 2m 820%M. )1.-

59212 59214136 1> 27002W

+140V

A symptom of no horizontal or vertical sync cancaused by a shorted diode 5Y202.

ace,' /80VT.T.P.V4 8 rxv 31501

560 CHROMA BAND PASSt.pV 3 I

I -N 3050511

240

3C503.0I

315 a 3C 5048 9.0

21V

+28ovAn intermittent color or no color can be caused by a

burned resistor, R504, after its leads short to the bandpasstransformer can.

be

49511220Vv'S.

49511100K

040,I i001( 13.589599E9

O. +22VIIIV

IF41503

TP3011X

4951745050 220K

I49513

2206

+ 280 V

9516i0OrTINT

951482,1,

4(5121100

47501

I0.3V

V7Ei64119

5719 CURRIER 0141971124 5V

4o5: I,2K

/4117 I4.7519

16001/401 .-r.

41514 r 495221800

T

^r se,a 90V

I10516 49523

6 01

471(

MAGNAVOX

Color -TV Chassis 1962 -10 --New Tuners and AFT Correction Circuit

The 340193-1 VHF tuner, 340190-2/340191-2 UHFtuner and the AFT board used with the T962-10 versionchassis differ from those used with all other T962 chassis

1

-e

versions. In the tuners, the anodes of the AFT varicapsare connected to ground reference and the AFT correctionvoltage supplied from the AFT board is centered around+5v, and applied to the cathodes. There is no +20v refer-ence source applied to these tuners. Since the AFT cor-rection voltage required for these tuners is centered around+5v rather than + I5v as for the tuners of all other T962chassis versions, the AFT circuit has been modified to pro-vide the proper voltage range. The illustrations show boththe schematic for the new AFT board and the connectionof the AFT correction voltage to the tuners for the T962-10 version.

NEW EICO TR-410Solid -StateTriggeredSweep 10MHzOscilloscope$37995

Never before has so muchbeen built into a low costsolid state triggeredsweep scope!

INCLUDES EXCLUSIVEDUAL PROBE

EICO introduces the first laboratory quality, high performance,wideband Triggered Sweep Oscilloscope, at a price you canafford!Use as Vectorscope for Color TV Servicing 3 calibrationvoltages 12, 5 End 10) Ouick connect BNC connector atVertical Input Front panel adjustable Horizontal and VerticalDC Balance Controls Vertical and Horizontal selection of ACor DC modes of amplification Sweep synchronized Gate Out-put Flat faced CRT Z Axis input Rear panel astigmatismcontrol Edge lit calibrated screen Operates on a standard120 volt, a low 100 volt or a 220-230 volt line.

FREE 1973 EICO CATALOGFor name of nearost dealer and free catalog check re-order sere ce card or send 25( for prompt first class mail EirtaL7service. E CO -281 Malta St., B'klyn, N.Y. 11207

Intermitten or weak color can also be caused by ashorted buffer transistor, Q401. ... tor more details circle 108 on Reader Service Card

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER j 55

TECHNICAL DIGESTThe material used in this section is selected frominformation supplied through the cooperation of therespective manufacturers or their agencies.

RCA SALES CORP.Amplifier Crossover Diodes

Class -B complementary symmetry amplifier circuits arewidely used in consumer electronics products. Althoughthese circuits have been previously discussed, the functionof the crossover diode connected between the bases of thetwo complementary output transistors has never been fullyexplained.

Basic theory reveals the output transistors of Class -Bamplifiers conduct on alternate half cycles. In the exampleillustrated, the active devices (tubes or transistors) areassumed to be perfectly matched and linear in response tothe input signal. Under these ideal conditions, a smooth,distortion -free transition is made from the conduction ofone output device to the other as the instantaneous signalvoltage crosses the Ov condition. In practice, however, tran-

+ 30V

01CONDUCTS

+ 15V

02CONDUCTS

Ov

IDEAL CLASS -B

CLASS -BCROSSOVERDISTORTION

sistors are non-linear at low currents, since it is necessarythat the base signal voltage exceed 0.7v-resulting from thediode voltage drop of the base emitter junction. It can beseen that the transistor that is being driven ON remains non-conductive until the base -to -emitter voltage exceeds the0.7v barrier potential. If a smooth transition is not madefrom one output transistor to the other, the signal will bedistorted.

Crossover Distortion

To overcome this distortion (known as crossover dis-tortion), Class -B amplifiers are designed so that the tran-sistors are not driven completely into cutoff. Instead, theyoperate with a small value of base bias current under nosignal conditions. This bias current assures that the base -to -emitter junction is always conducting so it can acceptsignal drive. The bias current is carefully chosen to pro-vide minimum crossover distortion and minimum no -signalcollector current. In practice, the no -signal or idle currentof a Class -B output stage is quite low, being approximately2 to 10ma. The required base bias is obtained by a resistorbias network.

Complementary ClassB Circuit

In the complementary symmetry circuit shown, comple-mentary output transistors Q1 and Q2 are biased, in amanner to be described, to provide equal conduction underno -signal conditions. With a supply voltage of 30v, thevoltage at the mid -point of the circuit (emitters of bothtransistors) assumes a voltage equal to half the supply volt-age, or in this case 15v.

To meet the requirements for base bias, let us considerwhat is necessary to allow conduction of NPN transistorQ1, and PNP transistor Q2. Assuming that the mid -point

t 30V

LOAD

voltage of the circuit must equal 15v (1/2 supply voltage),it is necessary for the base of transistor Q1 to be approxi-mately 0.7v more positive than the emitter. (The exactvoltage will depend upon the transconductance character-istics of the specific transistor used.)

Thus, with 15v at the emitter, the base voltage must be15.7v. For PNP transistor Q2 to conduct, the base must bemore negative than the emitter by approximately 0.7v.This means the base voltage of transistor Q2 must be ap-proximately 14.3 or .7v less than the supply voltage. Whenthe voltage difference between the base of Q1 and the baseof Q2 is determined, it is found to be 1.4v. It is then onlynecessary to calculate a resistance value which providesthis voltage drop for the collector current of driver tran-sistor Q3.

Although in theory a resistor can be used for bias, inpractice a diode package is nearly always used for thisapplication because it provides a measure of bias stabilityunder conditions of changing dc supply voltage and tem-perature. It is also interesting to note that in an actual am-plifier, even though the schematic symbol may show onlyone diode, in reality the circuit requires the junction dropsof two series connected diodes, even though both are in asingle package. Also, it is necessary to carefully choose thecharacteristics of the diodes used so that the exact voltagedrop required to set the no -signal operating point of theoutput transistors is obtained.

If a resistor were used instead of a diode to establish the

1.8

1.6

RESISTOR ''R"

BASETO BASE 1.4

VOLTAGE t2."

DIODES "D"1.0

.8

25 30

SUPPLY VOLTAGE

35

base bias of transistors Q1 and Q2, the voltage drop acrossthe resistor is a direct function of its current. In the eventthat the power supply voltage increases, increased bias isapplied to the base of driver transistor Q3, causing in-creased collector current and a larger voltage drop acrossresistor R. This produces a higher base voltage and basecurrent that results in increased collector idle current andmore power dissipation in the output transistors. Considernow the use of diodes.

56 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

The diodes, like the base -emitter junction of the outputtransistors, have an intrinsic voltage drop of approximately0.7v that is for all practical purposes independent of cur-rent. Thus under conditions of changing collector currentof driver transistor Q3, far less change in base -to -basevoltage results when diodes are used. For this reason, theoutput stage collector current and power dissipation re-main more constant under conditions of varying inputvoltage.

Consider the effects of elevated temperature on bias sta-bility. As the temperature increases, the base -to -emittervoltages (Vb.) of the output transistors decrease. In thecase of the circuit using bias resistor R, the decreased Vb.permits increased base current and correspondingly morecollector current. This in turn causes more heating andfinally a condition which could degenerate until thermalrunaway and transistor failure occurs. In a circuit usingdiode D, the decrease in Vbe is accompanied by a similardecrease in diode junction voltage. Because of the diodecompensation, the effect of elevated temperature on outputstage idle current and power dissipation is minimized. Thepreceding discussion should make clear the important func-tion played by the crossover diode as used in Class -B com-plementary symmetry amplifier circuits. It's obvious thatcharacteristics of these diodes are specified to provide therequired degree of circuit stability. Thus, when servicing,it is extremely important that crossover diodes are replacedwith the correct type as specified by stock number.

Tape Player Model YZD589, 593, 595-No Program Change

The symptom "Does not change channels manually orautomatically, plays one program continuously" may be en-countered in the instruments listed above. If this symptom

Clean theSwitch

Contacts

is evident, check the AUTO TRACK SELECTOR switch. Normalbuildup.of oxide from the tape can short the two switchcontacts together. Clean the contacts in the same manner asthat used to clean the head and capstan.

Tape Player Model YZD589-Tape Speed Too Fast

There is the possibility of the tape speed being too fast

in some Model YZD589 tape players. This can be causedby the rubber mounting inside the motor assembly, allow-ing the motor to tilt. As a result, the belt may ride up onthe side of the pulley as shown, thereby increasing thetape speed. Change the motor, Stock No. 165814 (includespulley), to correct this symptom. It may be necessary toadjust the pulley height after installing the motor so thatthe belt tracks on the flywheel.

It's a matterof life

and breath.

Give more toChristmas Seals.Fight emphysema tuberculosis, air pollution

Space cohtnbuted by the publisher as a public sersoce

Clamp down on service time with

RCA Clamp TesterWV -526A

$54 (Optional DistributorResale Price)

ioding tester, test leads, bat-tery, line splitter, shorting plug,splitter extension leads, carryingcase, and spare fuse.

It brings new efficiency to electri-cal servicing. Here's how: Measures AC current to 300 am-

peres, AC voltage to 600 voltsand resistance from 1 ohm to1,000 ohms on three easy -toread color -coded scales.

"Stop -lock" switch freezes me-ter pointer - simplifies handlingin dark qr hard -to -get -at areas.

High -impact plastic case for rug-ged usability.

See your RCA Distributor formore information. Or write: RCATest Equipment Headquarters,Harrison, N.J. 07029.

ReliElectronicComponents

... for more details circle 123 on Reader Service Card

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 57

SPEAKER

GUARDPROTECTS SPEAKER

AND AMPLIFIER

An overload in wattage of amplifieroutput activates circuit breaker andprevents damage. Reset circuitbreaker and make sure you use cor-rect values of Speaker Guard.

18 DIFFERENT VALUESASK FOR CAT.: 145C

WORKMANRon 382E1 SPRPSOT r,. . - PRODUCTS INC

. for more details circle 129 on Reader Service Card

REBUILDYOUR OWN

PICTURE TUBES?

With the Lakeside Industries precision picturetube rebuilding unit, you can rebuild any picture tube, be it black and white or color or20mm or etc. We offer you the most revolutionized precision equipment of our modern times.This unit is easy to operate and requires only4 z 8 ft. of space. You can rebuild the finesttube available. The picture will he clear andsharp. Your cost to rebuild a color tube is$6.60. Your cost to rebuild a black and whitetube is $1.85.

Profit? Imagine building four color tubes perday and if you sold these tubes for $60.00each. Total income $240.00. Total cost $26.40.Net profit $213.60. Multiply this figure by fivedays per week. Your profit $1,068.00 per week.Cut this figure in half! Build and sell only twocolor tubes per day. Your profit $534.00 perweek. Facts are facts, figures do not lie.For further information, please send your nameand address to Lakeside Industries, 3520 WestFullerton, Chicago, III. 60647. Phone: (312) 342-3399.

P.S. No salesman will call.

NEW PRODUCTS conies packed in a colorful showcasedisplay carton. JFD.

For additional information on productsdescribed in this section, circle thenumbers on Reader Service Card.Requests will be handled promptly.

SOLDERING IRON

Has light to indicatewattage selected for use

A 20w to 40w new pencil solderingiron, Model 540, has been developedthat is said to have an exclusive built-in operating light inside the handle-the light indicating whether the iron isoperating at 20w or 40w. A three-wayhandle switch selects either wattage,plus turning the unit oFF, so that un-plugging is unnecessary. A special at-tachment is available that converts thesoldering iron into a desoldering iron.Other features reportedly include anunbreakable polycarbonate handle,

burn -resistant neoprene cord set, stain-less steel element, solid-state controland ironclad tips. The iron is 81/2 in.long and weighs only 41/4 oz. Enter-prise Development Corp.

ANTENNA PREAMPLIFIER 704

Extremely linearfrequency response

The Model SP2300-CD preamplifierprovides VHF/FM amplification ofsignals from any VHF/FM antenna.

The silicon overlay transistor designreportedly gives 14dB VHF gain atone 30011 output or 8.5dB at two out-puts. Specifications indicate that its ex-tremely linear frequency responsemakes it ideal for color reception. In-cluded is the PS -6501 power supplythat operates on 117v ac. The unit

SCREWDRIVER 705

Handle pivots 900 to form"T -handle" for maximum torque

A screwdriver, called the "Tork-It"

703 is offered as part of a set with five in-terchangeable blades. It features a

handle that pivots90° to form a

"T -Handle" positionwhen maximumturning power is de-sired, and then pivotsback to the "in -line"position for fastspinning of screws inthe normal fashionof regular screwdriv-

ers. The T -Handle position allows theuser to apply heavy downward pres-sure to keep the blade in the screw slotand at the same time increases theturning torque that can be applied.The set contains pivoting handle, threePhillips blades (No. 1, No. 2, No. 3),two regular slotted screw blades(3/ 16 -in., 1/4 -in.), and a handy roll -uppouch. Hunter Tools.

WATTMETER-VSWR MONITOR

Displays the three prime 706RF transmission measurements

The Model 4342 Dual Wattmeter-VSWR Monitor has been designed todisplay three prime RF transmissionmeasurements at once on a singlemeter face-forward and reflected

power are indicated by individualpointers and VSWR is monitored on athird scale from the intersection of thetwo power pointers. Specifications in-dicate that the meter does not requireadjustments to full-scale deflection,or any switching before VSWR read-ings can he taken. The power and fre-quency range of the monitor depends

.. tor more details circle 119 on Reader Service Card

58 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

on two plug-in elements selected frommore than eighty choices available.Full-scale power levels reportedly have±5% accuracy from 10w to 5000wfor forward indication and 1w to500w for reflected in discrete fre-quency bands from 2MHz to2.3GHz. A choice of QC Quick -Change connectors permits matingwith N, BNC, TNC, UHF, C, SC, LC,HN, LT, GR type 874 and Vs -in.EIA lines. The monitor is a portableinstrument measuring about 7 in. by4 in. by 61/2 in. high and weighingonly 51/2 lb. Bird Electronic Corp.

TOOL SET

Solves alldriving needs

Encased in an attractive, compacthigh -impact plastic housing, the cou-pler can easily be mounted along abaseboard, to the back of a TV set or

in the basement or the attic. Being707 weather resistant, it can even be

mounted outdoors on the mast or out-side of a window. Jerrold.

The set, Stock No. 70191, consistsof a five -piece all magnetic screwdriverwith four interchangeable tips, in-

cluding 3/16 and9/32 in. regularslot and No. 1 andNo. 2 Phillips crossslot. The magnet-ism is transmittedfrom the shank tothe tip to thescrew, providing ascrew holding driv-er. The other partof the combinationconsists of a 7 -

piece hex drive -socket set including

1/4, 5/16, 3/ti, 7/16, and 1/2 -in.sockets for turning all hex head nutsand bolts. A 1/4 -in. hex key wrench isincluded free for driving sockets in re-cessed or hard -to -reach places. Thewrench is also useful for driving 1/4 -in.recessed hex head screws and bolts.Extra components are stored in thehandle of each tool, offering the userextreme versatility in a minimumamount of carrying space. Vaco Prod-ucts Co.

Vhsti12-PlICE MX SOT ""scarf m-? N 01111.5 01114

FOUR -SET COUPLER 708

Provides 90% Signal Transferwith corresponding low loss

A 30011 high -efficiency, 82 -channelTV/FM coupler is reportedly unusual-ly efficient, providing 90% signaltransfer with corresponding low loss.Designated Model MF-84, the coupleris ideal for splitting signals so that fourTV sets can be attached to a singleoutdoor antenna with low loss andhigh -isolation between sets. Specifica-tions indicate that the unit passes allfrequencies between 54MHz (Channel2) to 890MHz (Channel 83) with aninsertion loss of only 7dB and the iso-lation between sets of at least 15dB.

BROADBAND POWER 709AMPLIFIER KITCovers a range from0.5MHz to 100MHz

Kit MP -100 is an all solid-statebroadband power amplifier covering afrequency range of 0.5MHz to 100MHz. Rated at 2.5w CW, it acceptsinputs of AM, SSB, pulse, and othercomplex modulation. It delivers fullpower output when driven by any

signal or sweep source of 0.15v overthe entire frequency range-withouttuning adjustments. The unit re-portedly will not oscillate for any

O

a

1

-b

condition of load of source impedence,withstanding 15dB overdrive, includ-ing short and open circuit loads. Thekit can be assembled in approximately3 hours. A data and specificationsheet is available from the manufac-turer. Larkton Scientific.

DIGITAL MULTIMETER 710

Low cost autoranging3!/2 digit instrument

An automatic Digital Multimeter,continued on next page

START THE NEW YEARWITH A GREAT BARGAIN!

GET THESE TWO TV TECH AID BOOKS ATREDUCED PRICES:

1971 B&W BOOK - NOW $4.951970 -BOOK FORM - NOW $4.95

TV TECH AID BOOKS ARE FILLED WITH THE LATEST QUICK -SERVICING INFO ON COLOR TV, B&W TV, AND STEREO ...

TV Tech Aid Takes you right to :he source of the trouble without guesswork and wasted time. In each monthly issue you receive over 40actual causes and cures of color and B&W TV trouble symptoms. Youalso receive timely and complete information about circuit modifica-tions and other valuable service data.

USE THE COUPON BELOW TO PLACE YOUR 1973SUBSCRIPTION (12 ISSUES $7.95) OR VALUABLE BACK ISSUES

SEND YOUR CHECK 1969 12 issues $4.95 1970 -Book Form $4.95

OR MONEY ORDER 1971 B&W Book $4.95 1971 12 issues $5.95

1972 12 issues $7.95 1973 All New 12 issues $7.95TO:

Name

TV TECH AID Address

P. 0. Box 603Kings ParkN.Y. 11754 State Zip

City

. . . for more details circle 126 on Reader Service Card

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 59

NEW PRODUCTS...continued from page 59

Model 8310, reportedly features 31/2digits with 100% overrange, auto zero,auto polarity, and dual slope integra-tion for maximum accuracy and noise

rejection. Specifications include 0.1%tolerance on the dc volts scale and0.5% tolerance on the ac volts scaleat frequencies up to 20kHz. The unitfeatures resistance measurements to200M, plus dc and ac current measure-ments to 2a. Other options includeac and dc high -voltage probes. Theinstrument measures less than 83/4 in.wide by 3 in. high by 81/2 in. deep andweighs less than 5 lb. California In-struments Co.

FAIA/C117Handy -Helper

DOLLYFor MOVING and LIFTING

TV APPLIANCES FURNITURE LARGE CARTONS

N/1011 ,TRA

PADDED LOT BRACKET

WITH LEGS

I H

RUBBIR SIRIS

STEEL HOOK

SQUARE TUBULAR !RAW

AUTOMOTIVE TYPE TACK

STEEL WHEELS

FLUSH

WITH FLOOR

Model TC-1 DEALER NET S8950WRITE FOR CATALOG 20-621

The FINNEY Co.34 West Interstate Street

Bedford. Ohio 44146. for more details circle 110 on Reader Service Card

SPEAKER GRILLE 711REPLACEMENTS

Kit contains easy to -cutacoustic fabric

The Change -A -Grille kit consistsof acoustic fabric premounted on per-forated baffle board. Easily cut to sizewith household shears, the new grilleis simply affixed with self -stick tape(included). Especially -designed acous-tic fabrics in bright, decorative

,e61 Quick, easy waw to beautify yourstereo speake-s, TV sets, etc. in minutes

CHANGE -A -GRILLESELF STICKING Cover -Over

:1 .

weaves assure unobstructed, distortion -free passage of sound. Mellotone, div.of Wendell Fabrics Corp.

INDICATOR LIGHTS 712AND SWITCHES

Overall length lessthan 13A -in.

A new line of Series 81 IndicatorLights is available in various mountingstyles, which include front panel bezelmount, sub -panel mount, and bushingmount. All styles are available witheither round or square button caps.Lamps are replaceable from the frontof the panel. The button caps can belegended to your order. Overall lengthis less than 13A -in. The indicator lightscomplement a line of lighted and un-lighted pushbutton switches. The samecolor choices that are available in the

line switches are also available in thisindicator light line. Lamps are notsupplied, however, units accept stan-dard T -13/4 -in. midget flange lamps.Grayhill, Inc.

DIGITAL VOLTMETER 713

Accurate measurements in presenceof superimposed noise amplitudes

A new low-cost digital voltmeter,designated Model PM2422, is a "3+1"instrument with three -digit resolution

and an over -range digit forany of fiveranges of ac ordc current andvoltage, andsix ranges ofresistance. The

instrument is said to be an integratingDVM reportedly capable of accuratemeasurements in the presence of largesuperimposed noise amplitudes. Theintegrating period of 20msec is re-portedly accomplished through a pat-ented "delta pulse modulation cir-cuit" that is designed to give fast re-sponse with series mode rejectiondown to I% of the original signalvalue. Measurements may be madeeither grounded or floating and com-mon mode rejection is rated at 100dBfor dc and 90dB at line frequency.Philips.

4411111.111111=1111.1

ti i 5 0 0

IraAprir

Its a TALL order!

birth defectsare forever

unless you help.March of Dimes

THIS SPACE CONTRIBUTED BY THE PUBLISHER

60 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

DEALER SHOWCASE unit is reportedly constructed of alo-dine treated heavy gauge aluminum

For additional information on productsdescribed in this section, circle thenumbers on Reader Service Card.Requests will be handled promptly.

SCANNING MONITOR 714

Covers both VHFand UHF channels

A new scanning monitor can be setup on any combination of eight VHFand/or UHF channels with but simplejumper plug changes, requiring nosoldering. In addition to auto -scan, the

radio provides lock out switches to by-pass channels, as well as manual opera-tion for continuous monitoring of asingle channel. A special circuit em-ploying two ceramic selectivity filtersreportedly prevents the problem ofstrong, nearby FM transmissionscovering up the desired broadcast.Specifications indicate that the sen-sitivity of the receiver eliminates theneed for preamplifiers, even on UHF,even though the "front-end" circuitryis highly immune to overloading. Thereceiver comes complete with a built-in dual power supply for 117v ac baseoperation and 12v dc mobile opera-tion. E. F. Johnson.

INDUSTRIAL SPEAKER 715

Simplified impedance selectionand mechanical mounting

Ease of impedance selection andmechanical mounting are two of theattractive characteristics offered in theall-weather Model WR-5T reflexspeaker. Through the use of a built-inline transformer having a screwdriver -adjustable WATTS/IMPEDANCE switch,proper line connection and sound leveladjustments are achieved very quickly.The 70v impedance levels are 8000/4000/2000/1000/666a The powerlevels that may be selected are7.5/5/2.5/1.25/0.65w at 70v and1/0.62/0.31w at 25v. The all -metal

spinning and structural aluminum die-casting, assuring weather -resistance.The speaker can also be used as a sen-sitive microphone for intercom talk -back applications. Manufacturersspecifications include: Program power,7.5w; frequency range, 375Hz to10kHz; sound level, 105dB; disper-sion, 1200; dimensions, 6 -in. bell by4 -in. depth. Atlas Sound.

TAPE PLAYER 716

Designed for customin -dash installation

A new "in -dash" eight -track AM/FM/FM MPX player, Model C976,is designed to meet the need for aquality theft -proof tape player thatcan be easily and professionally in-stalled into the dash by most Ameri-

can car owners. The features reported-ly include: five pushbutton AM/FMtuning, 8w output per channel on FMand tape, LOCAL/ DISTANT Switch,VOLUME and TONE controls, front torear and left to right BALANCE con-trol, and automatic and manual trackswitching. The player is said to em-ploy a solid-state chassis with 18transistors, 12 diodes and 4 integratedcircuits-operating from 12v dc withan output impedance of 851. Dimen-sions of the unit are 754i in. w by 33;4in. H by 7 in. D. Audiovox Corp.

MOVING?Be sure to let us 1.now your new address.

Please enclose a ::omplete address label

from one of your recent issues.

YourCentralab

distributor hasjust the right one,

or all of them

Your Centralab distributor hasthe most complete line of ce-ramic capacitors available.He's your best supplier of justthe right capacitor for fast,reliable replacement service.

Choose from low voltage,transistor circuit, general pur-pose, high voltage and Gap-KapTM Ceramic disc capacitors.Available with voltage ratingsfrom 3 V to 6000 V, in valuesfrom .75 pF to 2.2 mF.

Your Centralab distributorstocks other highly reliable,special purpose ceramic capac-itors including feed-thru, vari-able trimmer and transmittingtypes. He's also your sourcefor a wide range of polystyrenecapacitors and miniature elec-trolytics in both axial and PClead styles. Check your partsstock, then call your Centralabdistributor. He has just thecapacitors you need.

DISTRIBUTOR PRODUCTS

CENTRAL0,13Electronics D,v,s,onGLOBE -UNION INC

. . . for more details circle 104 on Reader Service Card

DECEMBER 1972, ELECTRONIC TECHNICIAN DEALER 61

AUTTIESQUIRTstopsall thenoise.A squirt of Quietrolefrom the handy Spray Packsilences any moving T.V.part. Cleans as itlubricates, too. Guaranteesquiet, trouble -freeoperation. Absolutely safefor any black and white orcolor set. Try it and seewhy it's preferred by topservicemen everywhere.

Also available in bottles,and the new silicone-"Silitron."

Product of

QUIETROLECOMPANY

Spartanburg. South Carolina

... for more details circle 122 on Reader Service Card

take a quick look...

IF 12 mi...at readable

23 channel CB.Bold, illuminated numbers onthe Messenger 122 make

°channel changing fast andsure. Its unique rotary drumdial makes these largernumbers possible. But that'sonly part of the picture ...Inside is advanced solid-statecircuitry with a ceramic filter,speech compression, andmuch more. U.S.-Made -backed by our full 1 -year partsand labor warranty. For just$139.95 suggested list price.

Messenger122.

r-

/ a.SflswaS..1111.316

LIZI '''

JOHNSON°Waseca. Minnesota 56093

TECHNICALLITERATURE

Metal Cutting SnipsCatalog information is available on

a new line of metal and wire cuttingsnips. Drop forged of highest qualitytool steel, the tools are said to bespecially designed to yield maximumcutting power with minimum effort.The handles on all styles are reported-ly equipped with dipped heavy vinyl,hand -ease cushion grips. Channellock,Inc., Meadville, Pa. 16335.

Circuit Boards and ChemicalsA 12 -page catalog features new

sensitized printed -circuit boards in aline of breadboard and printed circuitsupplies. The catalog also provides in-formation on chemicals used in elec-tronic servicing and maintenance. In-jectorall Electronics Corp., 98-100Glen St., Glen Cove, N.Y. 11542.

Closed Circuit TelevisionBulletin GEZ-4996 describes the

Model TE-26 solid-state security andsurveillance closed circuit televisioncamera. The camera features complete"hands-off" operation, high resolution,excellent stability and picture fidelitywhere lighting conditions may vary.General Electric Communication Sys-tems Div., Section P, P.O. Box 4197,Lynchburg, Va., 24502.

Tool KitsA 16 -side brochure describes a line

of tool kits and cases for use in thefield. The brochure describes six pro-fessional tool kits, each engineer -de-signed to do a particular job. Includedin the publication are the JTK-17Field Engineer Kit, which contains over100 tools in an executive attaché case;the JTK-2 Electronic Technician Kitfor industrial personnel; the JTL-16Compact "Detective" Kit, which con-tains 30 multipurpose tools in a zippercase; the JTK-27/37 Electronic LabKit, a complete portable electronicstool kit with test instruments in twoattaché cases; the JTK-90 InstrumentRepair, emphasizing watchmakers'tools; and the JTK-80 ElectronicTechnician Roll -Pouch Kit, a lowerpriced kit for technicians, students andkit builders. Jensen Tools and Alloys,4117 N 44th St., Phoenix, Ariz 85018.

Selector ChartA new selector chart makes it easy

to choose and use line switches and

accessories for Fastatch II replace-ment controls. The detailed chartcovers rotary and push-pull actionline switches. Convenient wiringdiagrams are illustrated for eachswitch. In addition, photographs pro-vide a quick reference guide to re-placement push-pull line switches andto accessories for total replacementcontrol service. Centralab DistributorProducts, 5757 N. Green Bay Ave.,Milwaukee, Wisc. 53201.

Camera Tube InterchangeabilityGuide

A new four -page interchangeabilityguide, No. CAM -702A, lists over 200vidicon TV camera tube types andtheir direct or similar replacement.The guide reflects the latest changesin the RCA vidicon line. RCA Com-mercial Engineering, 415 So. 5th St.,Harrison, N.J. 07029.

Electrical Clips and InsulatorsA 8 -page catalog, 6172, complete-

ly covers all the manufacturer's clipsand insulators with illustrations andfull descriptions-a complete line,from miniaturized clips to largeground clamps. The catalog includesmaterials, sizes, characteristics, cur-rent -carrying capacities, and shippinginformation. Mueller Electric Co.,1575Y E. 31st St., Cleveland, Ohio44114.

Audio AccessoriesA new catalog, A -404A, of audio

accessories is released listing the com-pany's line of phone jacks and plugs,switches, connectors, adapters andmolded cable assemblies. Hundreds ofitems can be found quickly with thecatalog's numerical -alphabetical indexsystem. Each part is listed by numberand the page on which it is found. Ac-cessories listed include phone jacksand plugs, pushbutton and slideswitches, audio and phono connectors,audio accessory kits, microphone mix-ers and amplifiers, Hi-Fi switches andcontrols, audio adapters, special pur-pose cable assemblies and moldedcable assemblies. Switchcraft, Inc.,5555 N Elston Ave., Chicago, Ill.60630.

Fuses and Circuit BreakersA 4 -page catalog features an exten-

sive line of exact replacement fuse andcircuit breaker caddy assortments de-signed for domestic and foreign elec-tronic equipment service requirementsin the field or shop. Punched for easyreference use, the new two-color cata-

. . .for more details circle 116 on Reader Service Card

62 ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

log, "FCA," describes the new "OneStop Service Caddy" which providesthe user with a convenient two -in -oneassortment of eight popular circuitbreakers and 30 of the most widelyused fuses. Littelfuse, Inc., Dept. PR.,800E. Northwest Hgw., Des Plaines,Ill. 60016.

Microphone and Speaker Stands

A 4 -page color brochure, Form7201, is available which is exclusivelydevoted to microphone and speakerstands, stand accessories, adaptors andfittings. The publication outlines thefunctional and mechanical details of14 commercial and professional floorstand models, 12 microphone deskstands, 4 boom stands and more than50 models of stand accessories. SalesDepartment, Atlas Sound, 10 Pome-roy Rd.., Parsippany, N.J. 07054.

TransistorsA catalog listing operating param-

eters of more than 100 types ofepoxy -encapsulated field-effect and bi-polar transistors is available. The cata-log contains a detailed FET cross-index, in addition to data on general-purpose, switching and RF FET's; andNPN/PNP bipolar devices. SiliconixInc., 2201 Laurelwood Rd., SantaClara, Calif. 95054.

Outlet StripsA 16 -page, two-color catalog de-

scribes a complete line of pre -wiredoutlet strips and instrument carriers.The line of power outlet strips includesmultiple outlets, providing convenientand safe receptacles at low cost. Acomplete line of high quality carriersare shown, some models are availablefor audio-visual applications, and out-let strips are included on most models.Also shown in the catalog are motorspeed controllers. Waber Electronics,Inc., 300 Harvard Ave., Westville,N.J. 08093.

ToolsA 64 -page catalog of professional

tools and other products lists hundredsof useful products rarely sold by in-dustrial distributors or stores. This col-lection includes hard -to -find handtools and small power tools used bytechnicians and service personnel.Brookstone Co., 3720R BrookstoneBld., Peterborough, N.H. 03458.

Paging SystemsA 4 -page catalog, PG 192, describes

paging systems for immediate, selec-

tive and private paging of personnel bymeans of radio signals transmitted tolightweight pocket receivers. It coverssuch features as ease of installationand operation, negligible operatingcost, and easy add-on capability forthe systems. Included are detailedspecifications of systems with 20 -callor 110 -call capacities supplied com-plete with paging encoder, radio trans-mitter, paging receivers, antenna,coaxial and interconnect cables, bat-teries and accessories. Picker BriggsCorp., 4135 West 150th St., Cleveland,Ohio 44135.

Electronic PartsA 420 -page catalog is the compre-

hensive buying guide for everythingin electronic parts and supplies. Thecatalog lists over 50,000 separate stockitems from more than 400 manufactur-ers. Merchandise is grouped by sec-tions and numerical cover margin tabsguide you quickly to the products youneed. Allied Electronics, 2400 W.Washington Blvd., Chicago, Ill. 60612.

Electronic Servicing AerosolsA complete line of aerosol products

for color and B/W TV servicing isdescribed in this new catalog. Alsoincluded is a new volume -control andcontact restorer that reportedly willnot harm metals or change capacities,and prevents gumming when used onautomatic record changers. All theaerosol products are said to be non-toxic, contain no carbon tet, remainnon-flammable and not affect plastics.W. Gottlieb, Electronic ChemicalCorp., 813 Communipaw Ave., JerseyCity, N.J. 07304.

Silicon RectifiersA 6 -page catalog illustrates an ex-

tensive line of standard and fast re-covery silicon rectifiers. It devotesindividual pages to ratings and elec-trical characteristics, as well as di-mensional drawings of case styles forEDI bridges, high -voltage axial -leadrectifier cartridges, high -voltage recti-fier assemblies and miniature axialrectifiers. Dennis Dean, IndustrialProducts Sales Manager, ElectronicDevices, Inc., 21 Gray Oaks Ave.,Yonkers, N.Y. 10710.

MOVING?Be sure to let us know your new address.

Please enclose a complete address label

from one of your recent issues.

Alyeska Pipeline Service CompanyAmerican Standard, Inc.

Arcata National CorporationAshland Oil & Refining Company

Circle K CorporationCombined Insurance Company of America

Equitable Life Assurance SocietyFluor Corporation Ltd.Garrard & Company

General Foods CorporationGeneral Motors Corporation

Harding AssociatesHartford National Corporation

Hyde Park Bank & TrustITT

Metropolitan Life Insurance CompanyNortn American Development Corporation

Olin CorporationPhillips Petroleum CompanyPioneer Properties Company

Pioneer Systems, Inc.Prudential Insurance Company of America

S. C. Johnson & Son, Inc.Standard Oil Company (Indiana)University Computing Company

Varian Associates

FIRST

NAMES INFREER ENTERPRISE.

Fewer than 3 per cent of Americanbusinesses are owned by the black,Spanish-speaking and Indian -Americanswho make up 17 per cent of our popula-tion.

These companies have done some-thing about it.

Each is among the first sponsors of aMinority Enterprise Small Business Invest-ment Company. (Or MESBIC, for short.)

The seed capital they provided is be-ing channeled directly to promising busi-nesses in the form of long-term loans (5to 20 years), equity investments or a com-bination of both.

The leveraging potential is impressive.Through Small Business Administrationloans and guarantees, as much as $15 ofinvestment monies can be generated foreach $1 of private capital.

Headline stuff? Hardly. MESBIC spon-sorship simply means financially backingminority people who want to go intobusiness, then helping them make a goof it.

Not all will make it, even with help.The first MESBIC sponsors knew that.

But most will. And that makes MESBICa concrete way to make the Americanfree enterprise system a little freer.

Maybe a little stronger, too.If you agree that's good business, ask

for complete information on MESBICsponsorship.

You'll be in good company.Write: Director, Office of Minority

Business Enterprise, United States Depart-ment of Commerce, Washington, D.C.20230.

Advertising contributed for the public good

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER : 63

LETTERS ...continued from page 26

er electronics, but only on a part timebasis. Among other things, I am aqualified instructor and hope to get achance to teach a vocation course inthe area I'm moving to.

The percentages are against themajority of the field being as bad asI've seen, but I would feel it only fairto prepare potential technicians tosuch conditions, and the knowledgethat it's hard for one man to fight em-ployer or technical incompetence.

Unions are an extreme measure inmy estimation. The company youpointed out in your editorial neededno union, nor does the company I amnow with. But servicemen aren't get-ting what they deserve. Perhaps a tem-porary union with provision for con-tinuance or abolishment after a givenperiod would be the answer.

THOMAS E. GAL KO, CET

Thanks to Those Who Made CET

Some 31 years in electronics is along time to wait for a certificate ofrecognition. Back in the early 1950'sin Long Island, N.Y., a group of usformed an association. We were forlicensing and an upgrading of TVtechnicians. Time and time again wewere turned down by the state legisla-ture. Many of us, of which I was one,crawled into our shells. I lost contactwith everyone and everything, worked

long hours and tried to conceal thefact that I was a TV serviceman.

This year I moved to Florida andheard about CET. I purchased thenecessary study material and inquiredwhen the test would be given. Threehours a day of study and three monthslater, I was ready. The passing of thetest was no longer important now. Ihad accomplished what CET and my-self had set out to do. I had upgradedmyself through study and knew thatfrom now on a study program to"keep up with things" would becomepart of my life.

I want to thank those who carriedon and made CET a reality. You havebrought me back out of my shell-now I confess to being a TV Techni-cian.

Having been an Electronics Instruc-tor for many years, I see a way that Ican help with the program. Anyone inmy area can feel free to call on meand perhaps I can help them pass thetest.

The test is rather difficult, but I

think the computer has a heart. I be-lieve that I passed on old age!

WARREN J. QUIBELL, CETViking TelevisionSt. Petersburg, Fla.

One of the Old TimersBeing one of the "old" timers in the

electronic business, I am writing youthis letter. I notice that from time totime many of your readers speak of

old-time radios . . . this make and that. . . and so forth.

I have in my possession, probably inas good working order as the day itwas made, one of the old timers, onethat many probably never hear of. Thisradio is a Tuska Model, Type 225,made in 1922, serial number 15146.

I have been in this business since1921 and still going in the retail andservice business . . . and probably willremain in it until it is impossible.

Thought I would let you know aboutthis old set as it is now 50 years oldand workable. "Tuska" was made byC. D. Tuska Co., Hartford, Conn. andwas on the market only a few years,so they are rare.

D. A. WHITAKER

"We don't have it in stock? Well how aboutthat antique store on Elm Street?"

1971

Another vintage yearfor the both of us.

1971 was a very good year. And 1972 already tastes evenbetter. The truth is every year's a vintage year for you,the independent serviceman, and Raytheon, the largest

independent tube supplier in the business. Last year,while a lot of other suppliers were running behind,

even dropping out of the race, the two of us had anothergreat year. We've come a long way together.

And like a good wine, we keep getting better.That's because Raytheon works so well with you.

And never works without you. That's the kind of thingthat makes for a very good year for both of us. Year after year.

. for more details circle 125 on Reader Service Card

64 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

TEKLAB REPORT ... NEWS."

for a 1 kHz square -waveoutput. Then, observingthe square -wave trace onthe oscilloscope screen, weadjusted the trimmer onthe probe for an idealsquare -wave pattern.

We felt that the probe iswell designed for ease ofoperation and smallenough for working inclose areas. The hook onthe outer probe tip is ex-posed by pulling back onthe spring -loaded portionof the tip. This feature al-lows hooking on to a testpoint, leaving both handsfree to make adjustmentswhile observing wave-forms. This spring -loadedhook can also be removed,exposing a metal pin thatcan also be used for mak-ing electrical contact.

Operational Waveforms

We put the oscilloscopeto work checking wave-forms on a new color -TVset, comparing themagainst manufacturer'swaveforms at given testpoints. The optional probeused was the Heath ModelPKW-101 high -impedance(low -capacitance) isolat-ing type just described.

The first complex wave-form displayed with thescope (Fig. 1) is very fa-miliar to most TV service

.70"Akoriwirr

Fig. 1-The video signal trace dis-played with the oscilloscope. Toptrace: The video signal obtainedat the first video amplifier tubegrid at the TV vertical -sweep fre-quency, applied to scope Channel1. Lower trace: The same videosignal at the plate of the tube ap-plied to the input of scope Chan-nel 2.

technicians, the video sig-nal at the vertical sweep

continued from page 41

frequency, 60Hz. The topwaveform was obtained atthe first video amplifiertube grid, using the Chan-nel 1 input; and the lowerwaveform was obtainedat the plate of the sametube using the Channel 2input of the oscilloscope.

The waveforms shownin Fig. 2 were obtained us-ing the same TV set test

.410111111104114,

Vookipirft-

Fig. 2-The video signal obtainedat the TV horizontal -sweep fre-quency. Top trace: The video sig-nal obtained at the first videoamplifier tube grid employing thescope's Channel 1 input. LowerTrace: The video signal obtainedat the first video zmolifier plateusing the scope's Channel 2 input.

points, but this time thescope was set at the hori-zontal -sweep frequency.

We also applied a 200 -kHz square -wave signal(the highest that we hadavailable) from a sine/square -wave generator tothe input of Channels 1

and 2, producing thewaveforms shown in Fig.3.

Fig. 3-Ideal scuare-wave tracesproduced by applying a 200kHzsignal from a sine/square-wavegenerator to Channels 1 and 2.

We were very pleasedwith the operation of thescope and the waveformsdisplayed. In a future ar-ticle in the series "BasicDigital Circuits" we willbe seeing more waveformsproduced by this impres-sive scope.

continued from page 28

John Jacobson (I), Zenith Field Engineer, and Warren Foran (r), ServiceManager from Elliott & Bottom Corp., presented a service seminar inNorfolk, Va. on October 10, 1972. Approximately 140 dealers fromsoutheastern Virginia and northeastern North Carolina attended a wellpresented discussion on the new solid-state Titan Chassis. A similarmeeting, also well attended, was held in Richmond, Va. on October 19th.

Gift CertificateProgram Ends

We have been advised that ef-fective December I, 1972 theFinco $35.00 NATESA NEA GiftCertificate Program has beenterminated. In order to cleartheir books for the new year,the Finney Co. has advised itsdistributors that they should notaccept for redemption any giftcertificates after that date, andthat there will be no exceptionsto this rule.

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 65

1972 ARTICLE INDEX

COLORFAX

Admiral Month/ Year/ PageColor -TV Chassis K16-Color-Monitor

Circuit 7/72/58Color -TV Chassis K 18-Automatic Degaussing

Circuit 8/72/59edi Electronic Devices Inc.

Color -TV Service Tip 3/72/68Color -TV Chassis K16 Series-No Control of

Brightness 12/72/54Color -TV Chassis G11/G13/H10/H12/K15/106

Series-Weak or No Color 12/72/54Color -TV Chassis G l I-Installing Replacement

High Voltage Transformer 12/72/54Color -TV Chassis M20-Service Hint 12/72/54

EmersonColor -TV Models 35P03, 35PO4-Repairing

Convergence Yoke 3/72/68General Electric

Color -TV Chassis N-2-One Color Missing 3/72/68Color -TV Chassis N -2 ---Blooming Picture 3/72/68Color -TV Chassis Cl/Li-Blooming-

Excessive High Voltage and Poor ColorSync 4/72/66

Color -TV Chassis Cl/LI-TroubleshootingGuide 5/ 72/ 66

Color -TV Chassis U-I-Dark Vertical Wedgeon Left Side of Picture 6/72/58

Color -TV Chassis U-1-Picture Tube CircuitChanges 6/72/58

Color -TV Chassis JA-One PredominateColor with Retrace Lines 10/72/54

Color -TV Chassis JA-Low Brightness andOverload with Strong Signals 10/72/54

Color -TV Chassis Cl/LI and C2/ L2-Chroma Gain 10/72/54

Color -TV Chassis KE-Low-ResistanceContrast Control 1/72/58

Color -TV Chassis C-I-TroubleshootingGuide 12/72/54

MagnavoxColor -TV Chassis T938-Installing Replacement

High -Voltage Transformer 361328-1 1/72/57Color -TV Chassis T918-Installing Replacement

High -Voltage Transformer 361328-1 1/ 72/ 57Remote -Control Receiver Model 704069-

Addition of Current Limiter Resistor 1/72/57Color -TV Chassis T946-AGC

Control Added 1/72/57Color -TV Chassis T924/T939/T950-Reduced

High Voltage Caused by Leaky RegulatorDiode 1/72/58

Color -TV Models 7322,24,26-Eliminationof Static Electricity Build -Up on Controls 4/72/67

Convergence and Screen Purity Problems 7/72/58Color -TV Chassis T962-10-New Tuner and

AFT Correction Circuit 12/72/55RCA Sales Corp.

Color -TV Chassis CTC55-BrightnessLimiter/HV Adjustment 2/72/68

Focus and Picture Tube Cable Modification 3/72/68Color -TV Chassis CTC51-"Hum-Bar"

Interference 3/72/68Color -TV Chassis CTC50-Chassis-to-Test

Fixture Adaption 4/72/66Color -TV Chassis CTC51-Diode CR101

Protection 4/72/67Color -TV Chassis CTC40,44,47-Servicing

SCR Sweep Systems 5/72/67Color -TV Chassis CTC22/ 41,42,43-Damper

Diodes 7/72/58Color -TV Chassis CTC46-Troubleshooting

Focus Symptoms 7/72/58Color -TV Chassis CTC44/ 46/ 47/ 49/ 54-High-

Voltage Quadrupler Interchangeability 7/72/59Color -TV Chassis CTC36-Unstable

Vertical Sweep 7/72/59Color -TV Chassis CTC54-Horizontal

Interference 8/72/59Color -TV Chassis CTC54-Vertical

Sweep/Video Symptoms 8/72/59Slow Remote Control Operation 11/72/62Color -TV Chassis CTC46-Hum

Modulation 11/72/62Color -TV Chassis CTC52-Remote

Noise Immunity 11/72/62Color -TV Chassis CTC59-Use of Color

Bar Generator 11/72/62Color -TV Chassis CTC63-High-Voltage

Protection Circuit/Isolating "NoVideo" Symptoms 11/72/62

TECHNICAL DIGEST

AdmiralTape Cassette-Service Hint 1/72/56Three Function Remote Control 10/72/55Tape Recorder Model CTR571-Service Hint 10/72/55Repairing Power Tune Radios 11/72/64

EmersonRadio Model 31T73W-Excessive Hum at

Low Volume Level 2/72/70Ceramic Capacitor 8/72/60

General ElectricNew 3DS3 High -Voltage Rectifier Tube 3/72/71

MagnavoxRecord Changers-Slow Turntable

Speed 2/72/70Tape Recorder Model 1K8879-Replacing

60Hz Capstan Sleeves 2/72/70Amplifier Models A595/A596-Resistor

Identification 3/72/70Remote Control Receiver Models 704064/

704065-Erratic Stopping DrivingSearch Operation 3/72/70

Remote Control Receiver Model 704064 3/72/70Remote Control Receiver Model 704065 3/72/70Radio Chassis R231-Noise on AM

Band Only 3/72/70Tuner/Amplifier Chassis R243/ 244/245-

Distorted or No Audio on One ChannelOnly (Early Version) 6/72/60

Fuse Failure for No Apparent Reason 9/72/63Tape Recorders Models 1K8870, IK8871,

and 1K8877-Wiring to HeadphoneJack Reversed 9/72/63

OlympicRadio Chassis 330-1,330R-Noisy

Loudness Control Symptoms 3/72/70Radio Chassis 329-1,1-329- 1 -Interchangeable

Transistors 3/72/70TV Chassis NEC-Vertical Sweep Failure 3/72/71Tape Deck TD2O-Displaced Drive Belts 3/72/71

66 I ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

RCA Sales Corp.TV Chassis KCS17 I -0 rcu it

Modifications 1/ 72/56Varactor Diodes 5/72/68Cleaning Module Edge Connectors 8/72/60FM/AM Tuner Chassis RC1238D-Stereo

Indicator Threshold Adjustment 8/72/60TV Chassis KCS172,179,183-High-Voltage

Tube Socket Removal 8/72/60Amplifier Crossover Diodes 12/72/56Tape Player Model YZD589, 593, 595-No

Program Change 12/72/57Tape Player Model YZD589-Tape Speed

Too Fast 12/72/57Sylvania

Amplifier Chassis R62/R63/R64-PowerHum 9/72/63

WestinghouseQuadtrix Four -Channel Sound 7/72/60Matrixed Four -Channel Sound 7/72/60Discrete Four -Channel Sound 7/72/60Quadtrix Four -Dimensional Sound 7/72/60Radio Models RPA5035A, RPA5040A-

Weak and Fuzzy Sound 7/72/60Radio Models RS21P08A, RSIIP28A-

Hum and Distortion 7/72/60Radio Model RG I3S68C-No AM

Reception 7/ 72/ 60

ANTENNA AND ACCESSORIESWideband Distribution Equipment 4/72/51Satellite TV-Coming Down to Earth 4/72/64Professional Antenna Installation Methods 5/72/44The Best Antenna 8/72/43

AUDIO EQUIPMENTWorking with Commercial -Audio Equipment __ 1/72/43Quadraline Four -Channel Sound 2/72/50Working with Commercial -Audio Equipment,

Part 11 3/72/48Panasonic's Model SP -10 Turntable 4/72/48Working with Commercial -Audio Equipment,

Part III 5/72/50Which Tape System? 6/72/44Magnavox's Model 1500 DTI Receiver 7/72/40Working with Commercial -Audio Equipment,

Part IV 8/72/57BUSINESS

Selecting That Partner 5/72/57Service Contracts are Big Business 6/72/51Protecting Business Records 6/72/54Successful Advertising 7/72/51The Business Side of Things 10/72/49Reducing Check Voucher Costs 10/72/50Better Merchants Make Better Profits 12/72/52

CLOSED-CIRCUIT TV

On Camera at Central 3/72/52Cleveland's May Co. Boasts Top Security

CCTV, Mod Squads and All 3/72/54Skitch's Restaurant Goes CCTV 7/72/39

COLOR TV

Motorola's Model TU945HS Color -TV Set 1/72/39Motorola's Model TU945HS Color -TV

Set, Part II 2/72/41Panasonic's Model CT -771 Portable

Color -TV Set 3/72/43Panasonic's Model CT -771 Portable

Color -TV Set, Part 11 4/72/41

Channel Master's Model 6124A ModularColor -TV Set 5/72/39

Philco-Ford's Model C4870AWA Color -TV Set 6/72/39

Sylvania's D18 Color -TV Chassis 8/72/37Introducing General Electric's 19JA Solid -

State Color -TV Chassis 9/72/35Introducing General Electric's 19JA Solid -

State Color -TV Chassis, Part II 10/72/39RCA's Argosy Model ER475 Portable

Color -TV Set 11/72/39

COMMUNICATIONSServicing CB Transceivers 2/72/45Satellite TV-Coming Down to Earth 4/72/64

GUEST AUTHORReceiving Tubes Take a Look at

Solid -State 1/72/51Cashing in at the MATV Super Market 2/72/58

MISCELLANEOUS

Servicing with a Color -TV Test Jig 1/72/46Diagnosing Power Supply Circuits 1/72/48Search Continues for Loch Ness Monster 1/72/61The Champions of Independent TV Service 3/72/46Semi -Tips Part V 3/72/60Glad to Meet You, "Slim Jim" 4/72/60Which Tape System? 6/72/44Electronics and Crime 9/72/40Smash and Snatch 9/72/43TESA Wisconsin Feature Crime Seminar 9/72/45And Now What? 9/72/55Electronic Security Part I-Ultrasonic

Detection Circuitry 10/72/42What's New in TV Receivers for

1973-Part I 10/72/45What's New in TV Receivers for

1973-Part II 11/72/43Kenwood's KC -6060A Solid State Audio

Lab -Scope 11/72/49Basic Digital Circuitry 11/72/49Introducing Heathkit's Dual -Trace

Oscilloscope 12/72/39Electronic Security, Part II 12/72/42Basic Digital Circuitry, Part II 12/72/45

NATESA Plan 12/72/50

TEST INSTRUMENT REPORT

California Instrument's DigitalMultimeter/Counter 1/72/52

Leader's LS -5 Electronic Switch 2/72/60Heath's Model IB-1101 Frequency Counter 3/72/65RCA'S WR-5I5A Color Bar Generator 4/72/62B & K's Model 1465 Triggered -Sweep

Scope with Cali -Brain 5/ 72/ 60Triplett's Model 603 FET-VOM 6/72/51Another Step Forward 7/72/47Simpson's Model 460 Digital Volt-

Ohm-Milliameter 7/72/56Logi Metric's Model 750 RF Signal

Generator 8/72/58Leader's Model LBO -505 Triggered -Sweep

Scope 9/72/60Dana's Model 3300 Digital Multimeter 10/72/52Fluke's Model 8000A 31/2 -Digit Multimeter l I/72/60

TV -RADIO SERVICING

Servicing With a Color -TV Test Jig 1/72/46Diagnosing Power Supply Circuits 1/72/48Temporary Fixes for Etched Circuit Modules 6/72/46

DECEMBER 1972, ELECTRONIC TECHNICIAN/DEALER 167

ANTENNA POWER

RMS`STAR-TRACK'Tm#SK -111 7 VHF/UHF/FMCOLOR ANTENNA...Performance proven for Suburban andSemi -Fringe Areas. Similar design toSpace Tracking Antennas- 6 UHF DiscDirectors, 11 VHF Cut -to - ChannelElements, 1 Driven Element, and 10Corner Reflector Elements. 28 Elementsfor maximum reception- Up to 125 mileson VHF, and up to 75 miles on UHF.With VHF / UHF Splitter for singledown -lead. Suggested Retail.... $55.95

Breaking All Sales Records...since their introduction- 6 performanceproven models for all areas- See YourDistributor.

RMS ELECTRONICS, INC.

50 Antin Place, Bronx, N.Y. 10462Tel. (212) 892-6700

. for more details circle 124 on Reader Service Card

HARD -TO -FIND PRECISION TOOLS

Lists more than 1700 items-pliers,tweezers, wire strippers, vacuum systems,relay tools, optical equipment, tool kitsand cases. Also includes four pages ofuseful "Tool Tips" to aid in tool selection.

EIVSE INT TOOLS4117 N. 10th Street, Phoento, Aux 85018

... for more details circle 115 on Reader Service Card

MSTVERSATIU

CulorTelevisionSWIMS

SUE181111

FREE *trusted leorthent

Yeats Appliance Dolly Sales Inc.1307W. Fond du Lac Ave

Milwaukee, Wisconsin 53205 TUTS Male No 5 166 II

... for more details circle 130 on Reader Service Card

FREE ALARM CATA OR,MI PAGES 0 ILLED WITH 360 BURGLAR :P`AND FIRE ALARM PRODUCTS FORINSTALLERS AND ELECTRONIC 0,....10.1TECHNICIANS. INCLUDES RADAR.INFRARED. CONTROLS. HARD -TO- sr__E.610 PARTS, AND 6 PAGES OFAPPLICATION NOTES. 0

mountain west alarm 0 -V.I 4215 n. 16th st., phoenix, az. 85016

READERS

SERVICE

INDEX

ADVERTISER'S INDEX

102 B&K Div , Dynascan Corp. 22

103 Book Club -Tab Books 34-37

104 Centralab Distributor ProductsGlobe -Union 61

105 Channel MasterDiv. of Avnet, Inc. 33

106 Chemtronics, Inc. 25

107 Delta Products, Inc. 30

108 EICO ElectronicInstruments Co., Inc. 55

109 Electronic Devices, Inc. 28

110 Finney Company The 60

112 Fordham Radio Supply Co., Inc. 68

113 GC Electronics Co. 27

GTE Sylvania, ElectronicComponents 38, 2nd Cover

General Electric CompanyTelevision Business Div. 3rd Cover

114 Heath Company, -he 29

115 Jensen Tools & Alloys .. 68

116 E.F. Johnson Company . 62

117 Keithley Instruments, Inc. 31

118 Lakeside Industries 58

119 Mountain West Alarm Supply Co. 68

120 Panasonic -Service Div. 21

121 Perma-Power CompanyDiv. Chamberlain Mfg. Co. 26

122 Quietrole Company 62

123 RCA Test Equipment 57

RCA Semiconductors 4th Cover

124 RMS Electronics, Inc. 68

125 Raytheon Company 64

126 TV Tech Aid 59

127 Telematic Div., UXL Corp 24

128 Tuner Service Corpoi-ation 19

129 Workman Electronic Products 58

130 Yeats Appliance Dolly Sales Co. 68

NEW PRODUCTS

700 Educational FM/SCA Receiver 32

701 FM Multiplex Stereo Generator 32

702 Tape Player 32

703 Soldering Iron 58

704 Antenna Preamplifier 58

705 Screwdriver 58

706 Wattmeter-VSWR Monitor 58

707 Tool Set 59

708 Four -Set Coupler 59

709 Broadband Power Amplifier Kit 59

710 Digital Multimeter 59

711 Speaker Grille Replacements 60

712 Indicator Lights and Switches 60

713 Digital Voltmeter 60

714 Scanning Monitor 61

715 Industrial Speaker 61

716 Tape Player 61

DISCOUNTPRICES

TESTEQUIPMENT

LBgN.Jc OF=i

iYdUTYIW

I.E.C. Mullard Tubes SpecialsCatalog & Prices on Request

FORDHAM Radio SupplyCompany, Inc.

265 E. 149 Street, Bronx, N.Y.Tel 12 1 21 585 0330 RCA

DISTRIBUTORS OF ELECTRONIC SUPPLIES

. .. for more details circle 112 on Reader Service Card

BETTER MERCHANTS ...continued from page 53

need additional business. Not onlycan a good mail campaign help totill in thebring new customers into your busi-ness who will look to you for theirfuture service needs. And don't for-get, every customer who respondsto your direct mail program will bea good prospect for a repeat in sixmonths or a year. The names of allsuch customers should be carefullyfiled, because they will be your hot-test prospects for future promotions.

The next time your telephoneleaves you in the lurch, try directmail. You will find that it is bothexciting and profitable to run yourbusiness, instead of letting it runyou.

MOVING?

Be sure to let us know your

new address. Please enclose

a complete address label

from one of your recent

issues.

.. far more details circle 119 on Reader Service Card

68 ELECTRONIC TECHNICIAN/DEALER, DECEMBER 1972

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103 112 121 130 136 148 902 911 702

104 113 122 131 14C 149 903 912 703

105 114 123 132 141 150 904 913 704

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108 117 126 135 144 153 907 916 707

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'BONUS: With a 2 or 3 year subscription, you receive both TEKFAX 110 and theCOLOR TV GUIDEBOOK free! If you are subscribing for 1 year, please indicate

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forIMPORTANT! Please chck your business classification.Type of Business PcsitonCheck One Cre:k One

only A. Independent or Self -Employed Service D. -I Electronics. Radio. TV ManufTechnician E. I7 Islustrial Electronic Service

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B. Ej Independent Electronic Service Oruanit. F. 1 W iolesale. Jobber, Distributor J Service Manager

penniesC. -1 Retailer. with Electronic Service Dept. G. - ' Other (Specify)Be sure you have checked appropriate bones above_

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ELECTRONICTECHNICIAN/DEALERPOST OFFICE BOX 6016, DULUTH, MINNESOTA 55806

FIRST CLASSPERMIT NO. 665DULUTH. MINNESOTA

For those countries outside the U.S., please apply appropriate postage before mailing

READER SERVICE INFORMATION CARDFor more information on products or services mentioned in this issue, simply circle the appropriatenumbers below, type or print your name and address and drop in the mail.ADVERTISED PRODUCTS TEST INSTRUMENTS NEW PRODUCTS101 110 119 128 137 146 900 909 700 709102 111 120 129 138 147 901 910 701 710103 112 121 130 139 148 902 911 702 711104 113 122 131 140 149 903 912 703 712105 114 123 132 141 150 904 913 704 713106 115 124 133 142 151 905 914 705 714107 116 143 152 906 915 706 715108 117 126 135 144 153 907 916 707 716109 118 127 136 145 154 908 917 708 717

This card is usable until March 5, 1973.

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BUSINESS REPLY MAILNO POSTAGE STAMP NECESSARY IF MAILED IN THE UNITED STATES

POSTAGE WILL BE PAID BY

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ELECTRONICTECHNICIAN/DEALERPOST OFFICE BOX 6016, DULUTH, MINNESOTA 55806

718 727 736 745

719 728 737 746720 729 738 747721 730 739 748722 731 740 749

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These solid state color systems are the mostserviceable we've ever built. Because independent

servicers helped us design them.

Independent servicersawarded us theseserviceabilityratings. Proof thatforesight pays. Theforesight of thetelevision serviceindustry in devel-oping specificserviceabilityguidelines andurging TV manu-facturers to usethem. The foresightof General Electricin working side byside with indepen-dent servicers tocreate 100% solidstate sets that are 19" diagonal

easy to service.

GE's new solid

screen size

93.9%state sets are designedfor maximumaccessibility. Withextensive use ofvisual aids. Andplug-in modulesand components.Example: 95%of the total com-ponents in GE'snew solid statemodular colorconsole models canbe removed for ser-vicing without using a solder-ing iron. Solid state Porta Color" IImodels open like a book for ease of service.

Impressed ? That's only half the story. To improvelocal parts availability we are expanding partsdistribution through independent parts distributors.

We build every television as if we were going to use it ourselves.

GENERAL ELECTRIC

mA 25' diagonalsize

In many states, TV ser-0/ vicers use direct phone

AOP /0 lines to regional partscenters. We provide

specialized training. Our Tele-vision Service News

provides advanceinformation ser-

vicers need tomore easily ser-vice GE mono-

chrome andcolor models.

The serviceindustry has pro-

vided foresight anddirection. General Electric has

responded. With solid state productsto sell and service with confidence. To achieve

our mutual goal of customer satisfaction.

If you want to know more about GE service, callcollect or write

"Dutch" Meyer,Television Re-

ceiver ProductsDepartment,Portsmouth,

Virginia 23705.Phone (703)

484-3521.

OUR NO 1 GOAL:TO MAKE

GENERAL ELECTRICYOUR BEST BUY

The Solid -State System

It all works together to help youmeet today's tough demands of sol-id-state servicing. See your RCADistributor now and put SK, TheRCA Solid -State Replacement Sys-tem, to work in your business.You'll see why you can't beat it forbetter servicing and profits. It's thesystem built from your point ofview.

RCA/Electronic ComponentsHarrison, N.J. 07029

RCAElectronicComponents

. or better servicing

RCAQuality Product

Top -of -the -line pre-mium devices

Meet or exceed specsfor professionalservicing

146 RCA SKs replaceover 50,000 devices

RCASolid -StateHardware

10 sockets for tran-sistors and ICs

15 heat sinks fromTO -18 to TO -3package styles

RCAInformation Support

Replacement Guide (SPG-202M) cross-references over50,000 domestic and foreign devices and suppliesspecific application information to assure correct re-placement

SK Quick Selection Wall Chart (1L1367A) ... savesyou time making the right choice

Three slide-film/cassette tape presentations on Transis-tor Servicing cover Basic Techniques for TransistorChecking (1L1337), Identifying The Defective Stage(1L1377), Identifying & Replacing The DefectiveComponent (1L1378), plus the Transistor ServicingBooklet (1L1379). Available through your RCADistributor