ELECTRONIC TECHNICIAN / DEALER · All the versatility of the EICO 240 plus: AC/DC Milliammeter, 1 ma to 1000 ma in 7 non -skip ranges; single all-purpose DC/AC-Ohms - MA Uniprobe®;

ELECTRONICTECHNICIAN / DEALERWORLD'S LARGEST TV -RADIO SERVICE & SALES CIRCULATION

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The first and only solid-statetest equipmentguaranteed for 5 years.

Now EICO, because of its emphasis on re-liability in engineering and manufacture, offersthe industry this breakthrough.

EICO's new line of solid-state test equipmentcomes with an unprecedented 5 -year guaran-tee of performance and workmanship. (Send

240

for full details of this EICO 5 -year GUARANTEEon factory -assembled instruments.)

Additional advanced features include: newfunctional design, new color -coordinated es-thetics, new PC construction, new easier -to -build kit designs.

New EICO Solid -State Test Equipment

379

7

Pi P1

242

EICO 240 Solid -State FET-VOM $59.95 kit, $79.95 wired.One all-purpose DC/AC OHMS Uniprobe®. Reads 0.01V to 1 KV(to 30 KV with optional HVP probe). 7 non -skip ranges, in 10 dBsteps. AC or battery operated. RMS & DCV: 0-1, 3, 10, 30, 100, 300,1000V P -P ACV: 0-2.8, 8.5, 28, 85, 280, 850, 2800V. Input Z: DC,11 M; AC, 1 MD. Response 25 Hz to 2 MHz (to 250 MHz with op-tional RF probe). Ohmmeter reads 0.2 to 1 MD in 7 ranges. 41/2"200 AA movement. HWD: 81/2", 53/4", 5". 6 lbs.

EICO 242 Solid -State FET-TVOM $69.95 kit, $94.50 wired.All the versatility of the EICO 240 plus: AC/DC Milliammeter, 1 mato 1000 ma in 7 non -skip ranges; single all-purpose DC/AC-Ohms- MA Uniprobe®; and large 61/2" 200 µA meter movement.

EICO 150 Solid -State Signal Tracer $49.95 kit, $69.95 wired.Muiti-purpose troubleshooter for TV/FM/AM & Audio Equipment.Independent RF Audio inputs. Speaker and meter output indicators.400 mW continuous power output. Substitution amplifier, outputtransformer, speaker. Input for rated output: 1 mV RF, 63 mV audio.

New EICO High Performance Instruments

385

465

111111.111"

tt- 1025

EICO 385 - Solid -State Portable Color Generator $79.95 Kit, $109.95 Wired.EICO 465 - Wideband Vectorscope/Oscilloscope $179.95 Kit, $249.95 Wired.EICO 1025 - Solid -State Power Supply $34.95 Kit, $49.95 Wired.EICO 443 -- Semiconductor Curve Tracer $79.95 Kit, $119.95 Wired.EICO 633 -- CRT Tester & Rejuvenator $79.95 Kit, $119.95 Wired.EICO 635 - Portable Tube Tester $44.95 Kit. $69.95 Wired.

150330

Hum 60 dB below 400 mW. 105-132 VAC, 50/60 Hz, 5VA. HWD:71/2", 81/2", 5". 6 lbs.

EICO 330 Solid -State RF Signal Generator.$59.95 kit, $84.50 wired.5 fundamental bands 100 kHz to 54 MHz. Vernier control 0-100%.Output 300,000 AN into 50 -Ohm load. External signal modulationor internal 400 Hz, 0 to 100%. 105-132 VAC, 50/60 Hz, 1.7 VA.HWD: 71/2", 81/2", 5". 5 lbs.

EICO 379 Solid -State Sine/Square Wave Generator.$69.95 kit, $94.50 wired.5 sine wave and 4 square wave bands. Low distortion Sultzer feed-back FET circuit. Sine: 20 Hz to 2 MHz; 0-7.5V rms into hi -Z, 0-6.5Vinto 600 ohms Max. distortion 0.25%. Square: 20 Hz to 200 kHz;0-10y p -p into hi -Z, pos. direction, zero ground. Rise time at 20kHz less than 0.1 µ sec. 105-132 VAC, 50/60 Hz, 10VA. HWD: 71/2",81/2", 81/2". 9 lbs.

New EICO Probes for the ProsHI -Voltage Probe HVP-5, Wired $19.95.Convenient built-in voltmeter. Barrier sections isolate HV tip from handle andmeter. Measures up to 30 KV. Lightweight, compact.

Solid -State Signal Injector Probe PSI -1, Kit $5.95, Wired $9.95.Pen -size, 1 -ounce, self -powered signal generator. Frequency range from 1kHz to30MHz,1ieid with harmonics. Clip it to your pocket - ideal for signal tracing in the

Solid -State Signal Tracer Probe PST -2, Kit $19.95, Wired $29.95.Flashlight -size, 2.2oz, self -powered. Hi -gain amplifier, 50Hz to 200MHz withdemod tip. Input Z: 35000, 351(0, 3501Q; Output: 0.3 p -p volts. Noise -45dB.Distortion <5%. Complete with earphone, all probe tips. AA battery. pocket clip.

"Mi PST -2

es

HVP-5

PSI -1

SEND FREE 1970 CATALOG

Name

I Address

City State Zip

tCQJ LIE/CO® EICO Electronic Instrument Co., Inc.

283 Malta Street, Brooklyn, N.V.11207EICO Canada Ltd.20 MOIwick Drive. Weston. Ontario

for more details cicle 115 on Reader Service Card

1281ADMIRAL

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SYMBOL DESCRIPTION EMERSON PART NO. T101-sound output xformer 983762TR-201,202- trans 983742 T102- vert output xformer BH-8000TR-203 - trans 983743 T103- horiz output xformer 983763SIF-1-sound IF xformer 983749 T104- filter choke power supply 983764SIF-2-sound det xformer 4.5MHz 983750 C222,501,502,503 - elect cap - 150 4-150L108 -video amp sound trap 4.5MHz 983758 +33+33µt@ 180v 983771L201 -sound take off coil 4.5MHz 983759 CR301- couplate-vert integlator 039001L303- def yoke ass'y w/clamp 983760 CR302- couplate-sync, separator 039004L401- horiz osc coil w/knob 983761 VRI - control-cont 983778

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P012019

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1279 COPYRIGHT 1970 BY ELECTRONIC TECHNICIAN/DEALER HARBRACE BUILDING. DULUTH. MINNESOTA 55802

vR206251

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"---DDT TRANSISTOR BASING5-110110* 91(1,IC9,

094,09* 04,04,05,06,041,091,

092,093,05.091,099,0100,

0101,0107,0103

01,00.596

200

TRANSISTOR MEASUREMENTS (USE X100 SCALE)

Coll. to Gnd.

+ -Emit. to Gnd.

_, -Base to Gnd.

+ -Coll. to Emit.

(-) (+)+ -

Coll. to Base(+)

+ -Base to Emit.

(*) i-)_

01 880 230 970 (800) (950) (970)1.1K 1.1K 1.6K

Q2 750 430 1.4K (820) 1K 1K1.2K 5.8K 5.5K

03 580 120 1K (700) (900) (920)710 2.2K 1.9K

rQ4 1.1K 500 1.3K (2.2K) (3K) (1.2K)

1.2K 870 880

Q5 INF. 1.2K 1.2K (2.3K) (750) (800)INF. INF. 1.9K

06 260 1.1K 790 (1.4K) (800) (760)1.3K 4K 4.9K

Q41 30K 0 860 (21K) (760) (850)23K 100K 100K

091 550 2K 525 (2.5K) (30) (900)880 30 2.5K

092 690 790 925 (1.5K) (850) (900)1.5K 1.6K 1.8K

Q93 1.2K 300 1K (1.4K) (770) (2.2K)1.4K 3K 840

Q94 2.2K 100 1.1K (16K) (850) (870)2.4K 90K 50K

Q95 13K 11K 4.5K (810) (1.1K) (830)8.5K 1.2K 2.4K

Q96 1.4K 70 1.3K (840) (1K) (1K)1.3K 5K 3.7K

097, 1.4K 2.4K 2.5K (4.1K) (760) (850)4.3K INF. INF.

Q98 810 6.7K 2.2K (8K) (850) (870)1.9K 16K 45K

Q99 530 80 800 (620) (810) (820)620 1.4K 1K

0 100 3.9K 540 800 (2.2K) (640) (690)4.5K 5.1K 2K

Q101 3.8K 540 800 (2.2K) (640) (690)4.4K 5.1K 2K

Q102 1.3K 180 1.3K 1.4K (890) (930)1.5K 9K 7.2K

Q103 2.2K 78 790 ( 1.8K) (650) (690)2.3K 8K 6K

0200 1.4K 290 950 (1K) (550) (580)860 2.2K 3K

Q201 INF. 200 740 (2.9K) (690) (710)INF. INF. 10K

Resistance measurements of transistors in circuit (power off).

All measurements are in ohms and taken with a B&K Model 175 VTVMwith an allowable tolerance of 20%.

--

TRANSISTOR VOLTAGES

E B C

Q1 .45V 1.15V 18.8VQ2 1.16V 1.86V 18.5V03 1.79V 2.41V 14.5V04 17.9V 18.2V 1.1V05 17.5V 15V 21.4VQ6 10V 4.9V 4.2VQ41 OV .5V 23VQ91 10.4V 11V 14VQ92 6.3V 7V 9.8VQ93 3.9V 4.5V 14.3VQ94 OV .55V 9.2VQ95 3.2V -.025V 36VQ96 .18V .88V 17.5VQ97 .1V -.6V 20V098 7.1V 9.2V 19VQ99 .68V 1.34V 18V0100 1.05V 1.37V 13V0101 1.08V 1.37V 13V0102 .43V .15V 20V0103 .43V -.33V 9VQ200 20.2V 21V 28.2V0201 .56V 1.18V 112V

I. C. 91

1 11V3 1.52V4 OV

5 1.52V7 11V8 11.45V -.- ..-

PHILCO-FORDColor TV Chassis 19FT6OB

LTAGES

PIN NO.V41 V42 V91 V92 V200 V201

6JZ8 6BL8 6ML8 12GN7 6JS6 6CG3

1 OV 84V 185V 26V FIL FIL2 88V -36V 153V 24V OV3 OV 145V 183V OV 110V4 278V FIL FIL FIL OV 295V5 0 FIL FIL FIL -59V -6 58V 172V 0 FIL -7 58V .17V 2.5V 248V - DO NOT

MEASURE8 282V 4.3V .35V 145V9 93V .15V .3V OV -59V -

10 -19V - - OV 295V11 OV - 110V -12 OV FIL FIL

VR422 VR42B VR424750., 5CORAr..OR VI IT VERTeas

VR41CI SyNlU

SCREE..

1"'"st"sub i-VIP

v*ItSIwo

SOWER

10141A 041Ism IVORID SM.

WOKEN DIP

V416.:11

&

BOTTOM VIEW

P1 DEFLECTION PANEL

COPYRIGHT 1970 BY ELECTRONIC TECHNICIAN/DEALER HARBRACE BUILDING. DULUTH. MINNESOTA 55802

1277PHILCO-FORO

Color TV Chassis19FT6OB

FEBRUARY 1970

IF AND DETECTOR PANEL

ELECTRONIC 7 /-7--wETTECHNICIAN / LP/


1102711

5%

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133

SYMBOL DESCRIPTION PHILCO-FORD PART NO.

C204 -200µf, 50rd, 501.0, 202.(1 30-2616-15C207 - 500211/500µf/200µ1/100µf 30.2616-14CB200- circuit brkr 42.2136-6IC91- 3.58MHz osc 46-5002.4J202 - del yoke , 41.4385-4L9- peaking det 32-4762-13LIO - RF AGC 32-4762-3L41 - horiz hold ,,,,,,,, 32-4891-2L91 - snd interstage 32-4936-2L92 - S.T.0. 32.4936-1L93 - snd det 32-4928-1L94 - tint control 32-4942-1L95- burst 32-4931-1

C2I6

= 11044

111

14 0274033 120 1131

1ST IFCIS .T.

3° 11

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19933- C3,8

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VR I -3K, RF AGC emit 33-5628-7VR2-750(1, 4I.25MHz trap 33-5628-3VR41 A -C - I.5M, CRT screens 33-5595-20VR42 - A-vert, ht., B-vert. lin.,

C-horiz bias 33-5627-3VR93- 250K, CRT bias 33.5628-12VR201 - 750K, vert hold 33-5631-14VR202 - 25K, volume . 33-5634-1VR203 - 1.2K, tint 33-5631-5

CHROMA AND SOUND PANEL

(.11114

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VR204- 100(2, contrast 33-5631-7VR205- 5000, bright 33-5631-22VR206- 500C1, color 33-5631-3VR303- 18011, L horiz blu 33.5609-13VR305- 500(1, V cliff R/G amp 33.5609-14VR307- 18011, L vert RIG 33.5609-13A.O.T. - Audio out 32-10119-1E.G.- filter choke 32-10095-2H.O.T. horiz out 32.10092-2P.T.- power 32-10096.1V.O.T.-vert out 32-10117-2

chrome ass'y, w/comp 38.10478dell ass'y, w/comp 38-10569tuner, VHF 1TT-181) 76.14100-1tuner, UHF ITT -152C) 76-13827.4

T. PPIER SOPPY 1100

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1277 COPYRIGHT 197o By ELECTRONIC TEcHNICIAN/DEALER HARBRACE BUILDING. DULUTH. MINNESOTA 55802

ELECTRONICTECHNICIAN / DEALER

2_r'CXLMTCOMPLETE MANUFACTURER S' CIRCUIT DIAGRAMSAND TECHNICAL INFORMATION FOR 6 NEW SETS

SCHEMATIC NO.

ADMIRAL 1281TV Chassis T7H2-1A, T9H1- 1A

SCHEMATIC NO.

PHILCO-FORD 1277Color TV Chassis 19FT6OB

AIRLINE 1279 PHILCO-FORD 1276TV Model GEN-11760A TV Chassis 20R27

EMERSON 1280 RCA VICTOR 1278TV Model 1 2P60/12P61W Color TV Chassis CTC47

SYMBOL DESCRIPTION PIIILC04011D PART NO. NU- isolation, CRT

C48 - 240/240/160/51d 4. 200v,8 filter

DI - phase comp02- 2nd detD3- rect, silicon

30.2601-3334-8037.134-8022.634-8054.7

LI -180µh, plate series 32-4762-7L2- 330µh, plate shunt 32-4762-20L7 - quad, snd det 32-4876.1L8- 4.5MHz trap 8 S.T.O. 32-4688-13LIO - tuner cplg 32-4652-96L12 - horiz stab 32-4754.3L13- 47.25MHz trap 32.4652-78L15- 47.25MHz trap 32-4652-79L18- video det 32-4652-79N3 - vert int 30.6030-12N4 - horiz osc 30-6057-1

30-6035.2N5 - phase comp

V1IEUY8

AUDIO OUT.

GATE

M14

iS

IP3LI

MCSA

V617121

VERT OSC. 1

VERT. OUT.

PIN KILTS15#/83V- 302.6014801450

N2

0111

2

L76 V

V2ICS6

SOUND

I.

21V 400usv

1ST 11.1.F.-170

1450lv

PIN2

VOLTS15v000750

0 c2,4). MS

0=43/11 52

upn

M 16A

PIN VOLTS50

V4E17

C

V5BOHN

SNO LF ISYNC SEP

30-6058-2R40 - varistor, 560v glOma 33-1373-6R63 - 3[1, fusistor 33-1383-5Si - on -off (part of VR-7IT1 - audio otpt 32-10013-2T2-8 filter otpt 32-10118-1T3 - vert otpt 32.10012-5T4- horiz otpt 32-10008-7VR1- 500K, vert size, 2.5M, vert lin,

60K, horiz hold 33-5595-8VR3- 3K, width 33-5620-1VR4- 100K, bright 33-5605.36VR5- 15K, contrast 33-5605-38VR6 - 150K, vert hold 33-5605-37VR7 - 1M, on -off vol 33-5634-7

panel, fusistor 76-11072.11tuner, UHF, TT152E 76-13872-2tuner, VHF, TT182A 76-13579-6Yoke ass'y 76-14170-1

PIN VOLTS34v60 v580

v9 -13V

V31011R11

HID OilNOISE IOW

, 7RD- IR L Luirit98 ,211,""Cfnia

1113

III2

01:03-IXF1-

PIN VOLTS1 6014001450

NEER vdarSIZE_IL LIN. AL

VR

TOP VIEW - PERMA CIRCUIT PANEL

PIN vats

2 -75068V

6509 5.4

V4178E3 17823

DAMPER

X135

N5S

DEIEEi313E]

PIN vOLTS4 1500

HOR \x,./HOLD

AUX

C)DI

PHASE

COOP

V721115/21116

NOR OUTPIN VOLTS

1200-200

VSalai

OOP OSC

PIN VOLTS

1000

2 .10

&IV120V-9.40

To

TUNERTuNER.GC -20 41/NO 9054 IF 2T 9/5161481. GC

220

C01101,47LENMI

V7 V421405/21226 711(3/1,523

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ELECTRONIC TECHNICIAN/DEALER is pub-lished monthly by Harbrace Publications,Inc., Harbrace Building, Duluth, Minnesota55802, a subsidiary of Harcourt, Brace &World, Inc. Subscription rates: One year $5,two years $8, three years $10, in the UnitedStates and Canada. Other cOuntries: Oneyear $9, two years $14, three years $18.Single copies 60it. Second class postage paidat Dansville, New York and at additionalmailing offices. Copyright 1970 by HarbracePublications, Inc.POSTMASTER: Send Form 3579 to ELEC-TRONIC TECHNICIAN/DEALER, HarbraceBuilding, Duluth, Minnesota 55802.

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1276 COPYRIGHT 1970 BY ELECTRONIC TECHNICIAN/DEALER HARBRACE BUILDING DULUTH MINNESOTA 55802

©1J

PROVIDES YOU WITH ACOMPLETE SERVICE FORALL YOUR TELEVISIONTUNER REQUIREMENTSAT ONE PRICE.

UNER REPAIR 111,

VHF Or UHF Any Type $9.75.

In this price all parts are included.Tubes are charged at cost.

24 hour service at our convenientlylocated service centers.

1 year guarantee backed up by thelargest tuner manufacturer in the U.S.-SARKES TARZIAN INC.

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

TSC

TUNER REPLACEMENT

Replacement Tuner $9.75.

This price buys you a complete newtuner built specifically by SARKES TAR-ZIAN INC. for this purpose.

The price is the same for every typeof universal replacement tuner.

Specify heater typeParallel 6.3VSeries 450 mASeries 600 mA

All shafts have the same length of 12".Characteristics are:

Memory Fine TLningUHF Plug InUniversal MourningHi -Gain Lo -Noise

If you prefer we'll customize thistuner for you. The price will be $18.25.Send in original tuner for comparison pur-poses to our office in INDIANAPOLIS,INDIANA.

TUNER SERVICE CORPORATIONFACTO,. )1 -SUPERVISED TUNER SE, .

MIDWEST 817 N. PENNSYLVANIA ST., Indianapolis. Indiana TEL: 317-632-3493(Home Office)

EAST 547-49 TONNELE AVE., Jersey City,

SOUTH-EAST 938 GORDON ST S. W.. Atlanta. Georgia

WEST

New Jersey TEL: 201-792-3730

TEL: 404-758-2232

SARKES TARZIAN, Inc. TUNER SERVICE D/VIS/ON10654 MAGNOLIA BLVD., North Hollywood. California

for more details circle 140 on Reader Service Card

. TEL: 213-769-2720

FEBRUARY 1970 19

"QT" is a Quick Turnover Inventory system thatbrings you a steady supply of the fastest-movingRCA Home Instrument replacement parts. Itpractically guarantees you'll have the parts youneed for most of your servicing jobs.This means you get the jobs done, withoutbacklogging and last-minute dashes to yourdistributor for essential "QT" parts.A "QT" inventory helps you cut down on thosestacks of dusty boxes and trays of unused parts-and the dollars you have tied up in them.The entire system is incredibly handy and efficient

. for more details circle 131 on Reeder Service Card

... lets you find parts quickly while you'reworking ... reminds you to reorder when yoursupply is low ... makes inventoryingand reorderingso fast that it's almost automatic.

Suddenly you'll find yourself with a lot more timeto devote to additional servicing jobs.Check it out with your RCA "QT" Parts Distributor.He'll discuss the different "QT" inventory planswith you and help you select one tailored toyour operation.

After that, things go very smoothly.Parts and Accessories, Deptford, New Jersey.

HUGH "SCOTTY" WALLACEPublisherChicago:

(312) 467-0670PAUL DORWEILER

EditorJOSEPH ZAUHAR

Technical EditorDONALD W. MASON

Associate EditorKATHIE PONTINEN

Production EditorBOB ANDRESEN

Graphic DesignLILLIE PEARSON

Circulation FulfillmentJOHN KESSLER

Manager, Reader ServicesBERNICE GEISERT

Advertising Production

OFFICES

757 Third AvenueNew York, N.Y. 10017

Phone: (212) 572-4800Telex: 01-2628643 East Ohio St.

Chicago, III. 60611Phone: (312) 467-0670

Telex: 02-535491901 West 8th Street

Los Angeles, Calif. 90057Phone: (213) 483-8530

Harbrace BuildingDuluth, Minn. 55802

Phone: (218) 727-8511Telex: 02-94417

MANAGERS

HUGH "SCOTTY" WALLACEChicago: (312) 467-0670

DEAN GREENERChicago: (312) 467-0670ALFRED A. MENEGUS

New York: (212) 686-2200DONALD D. HOUSTON

Los Angeles: (213) 483-8530ROBERT UPTON

Tokyo, JapanI.P.O., Box 5056

CHARLES S. HARRISON,CY JOBSON

San Francisco:(415) 392-6794

HARBRACE PUBLICATIONS, INC.

JOHN B. GELLATLYPresident

RICHARD MOELLERTreasurer

LARS FLADMARKSenior Vice President

HARRY RAMALEYVice President

JAMES GHERNAArt Director

EDWARD CROWELLDirector of Marketing Services

ELECTRONICTECHNICIAN / DEALERWORLDS LARGEST ELECTRONIC TRADE CIRCULATION

FEBRUARY 1970 VOL. 91 NO. 2

41 TEKLAB REPORTThe new Magnavox 23 inch console with automatic color gets the 'fine-tooth'treatment from our ET/D lab technicians as they give you a complete rundownon circuit operation of the new T940 chassis.

46 COLOR SERVICE HINTSBy William I. Spero, Field Service Engineer, Sylvania Electric Products, Inc.Technicians will find this feature of special interest as it outlines a novel diag-nostic technique using only the TV receiver as the test instrument and offers abetter understanding of color reception.

48 SERVICING CASSETTE RECORDERSBy Homer L. Davidson. Here is a timely discussion of practical procedures forthe maintenance and circuit repair of the popular cassette recorders.

53 COLOR SERVICE CASE HISTORIESBy Paul Goldberg. Some of color television's toughest service problems are des-cribed in this article along with practical guidelines to help you find the defectiveparts and solve the problems.

55 TESTLAB REPORTThis month's report offers a schematic diagram, operating characteristics, speci-fications and an evaluation by our lab technicians of the new Sencore ModelTC154 Tube Tester.

24 EDITOR'S MEMO 58 DEALER SHOWCASE26 NEW PRODUCTS 72 COLOR FAX

28 LETTERS TO THE EDITOR 85 CATALOGS AND BULLETINS30 TECHNICAL DIGEST 86 AD INDEX

COVEROn this month's cover the aerial camera captures the bevy of television towersthat cap the highest hill overlooking the city of Duluth and coincidentally theeditorial offices of ET/D.

TEKFAX 16 PAGES OF THE LATEST SCHEMATICS Group 210ADMIRAL: TV Chassis T7H2-1A, T9H1-1AAIRLINE: TV Model GEN-11760AEMERSON: TV Model 12P60/12P61WPHILCO-FORD: Color TV Chassis 19FT6OBPH ILCO-FORD: TV Chassis 20R27RCA VICTOR: Color TV Chassis CTC47

A HARCOURT, BRACE & WORLD PUBLICATIONHarbrace Publications, inc. 411:

ELECTRONIC TECHNICIAN/DEALER is published monthly by ElectronicsTechnician, Inc., a subsidiary of Harbrace Publications, Inc. Corporate Offices:757 Third Avenue, New York, New York 10017. Advertising Offices: 43 EastOhio Street, Chicago, Illinois 60611 and 757 Third Avenue, New York, NewYork 10017. Editorial, Accounting and Circulation Offices: Harbrace Building,Duluth, Minnesota 55802. Subscription rates: One year $5, two years $8, threeyears $10, in the United States and Canada. Other countries: one year $9, twoyears $14, three years $18. Single copies 75c; in the U.S. and Canada; all othercountries: $2. Second class postage paid at Dansville, New York 14437 and atadditional mailing offices. Copyright 1970 by Electronics Technician, Inc.POSTMASTER: Send form 3579 to ELECTRONIC TECHNICIAN/DEALER,Harbrace Building, Duluth, Minnesota 55802.

FEBRUARY 1970 21

STILL A LOUSY PICTURE ANTENNA LEAD-IN

600 BUCKS WORTH OF TVSET AND ANTENNA AND HERE'S A GUY

WHO NEEDS BELDEN

r-C7ft \ThColor or UHF set perfect? Antenna perfect? Then obviouslythere's a missing link. Check that antenna lead-in cable.Old, worn-out, weather-beaten cable, or the ordinary flatribbon kind designed for black and white VHF, causes morefuzzy, distorted pictures than you can count. It's youropportunity to upgrade these customers to a cable matchedto their particular signal reception situations. One of

7

Belden's Big Four-the link to perfect reception.

FOR CONGESTED AREAS ...

3290 SHIELDEDPERMOHM

In congested, in -city areas, stray electrical interference and noise areat their worst. For perfect, all -82 channel reception-color or B/W-replace old cable with Belden's 8290 Shielded Permohm. Its aluminumBeldfoile shielding prevents pickup of ghost signals and electrical noiseby the lead-in. Weather-proof and water -proof. You can tape it right tothe mast. Or install it underground, in conduits-even in rain gutters.

Nom.AWG 8 0. D.

(Stranding) Color (inch) Propagation (mmf/ft.) me db I

22 (1 x 30) Brown .305 7.8.5x15

Copperweld, 2 conductors, orange polyethylene insulation and webbetween conductors, cellular polyethylene oval insulation, Beldfoilshield, stranded tinned drain wire, polyethylene jacket.

5/85

177213473671887

1.72.13.23.55.46.67.7

Lengths in50', 75'. 100' coils`have terminalsattached.Available in counterdispenser.250', 500' spool.

22 ELECTRONIC TECHNICIAN/DEALER

FOR FRINGE AREAS...

Antenna cable in uncongested or fringe areas picks up littleelectrical interference. But does get a lot of weathering, whichdegrades an already weak signal. These customers needencapsulated cable. Belden 8285 Permohm. Its special poly-ethylene jacket protects the energy field, regardless of weatherconditions. It delivers the strongest signal of any unshieldedtwin lead under adverse conditions. Requires no matchingtransformers and connectors. For all 82 channels, color or B /W.

AWG &(Stranding) I Color

1-411rmiMNom.0. D.

1 (inch) 1

=Velocity ofPropagation 1

22 (7 x 30) Brown .255x

.468 1

321;5 P AtIONA1

Capacitanc(mmf/ft.)

Nom. Attena111111111111arnper 100' I Package

me dt Lengths in ft.5.3

Copperweld, 2 conductors parallel, orange polyethylene insulation andweb between conductors, cellular polyethylene oval jacket.

I I I

FOR LOCAL BLACK AND WHITE...

ii0 elk NE p=1.1111.1.1111AINI,

100300500700900

1.4,2.83.84.85.6

50', 75', 100' coilshave terminalsattached.Available in counterdispenser.250', 500' coils and1000' spool.

Cracked, corroded, weathered cable, full of dirt and moisture,loses signal strength; prevents any TV set from delivering aquality picture. Upgrade B/W VHF and local UHF customersto Belden 8275 Celluline. Performance is improved becauseall possible moisture between conductors has been elimi-nated. Abrasion -resistant and weather -resistant for a long,long service life. And, it requires no end sealing.

20 (7 x 28) Brown .300 80% 4.6 100 1.05 50', 75', 100' coils200 1.64 in counter dispenser.

.400

Bare copperweld; 2 conductors parallel, polyethylene jacket with inert

300400500

2.122.52.9B

250', 500', 1000'spools.

gas filled unicellular polyethylene core. 700 3.62900 4.3

EN DUOFOIL

FOR MATV AND CATV...

112211 I/11017011i

Got an apartment or townhouse complex in your area? Motelsor hotels? Or is CATV coming? Use Belden's new 75 ohmcoaxial cable -8228 Duofoil. Shielding is 100%-sweep tested100%. Spiral wrapped drain wires provide long flex life. Smalldiameter saves space in conduit installations. Use Duofoilfor all coaxial color and B/W VHF, UHF and CATV applications.

COAX

StandardAWG &

Stranding)FYeloelfy ofPropagation /ft.) MC dh

PackageLengths in ft.

18 Black .242 I 7.3 50 1.5 100', 500', 1000'Solid, Bare 100 2.1 spools.

200 3.1300 3.8400 4.5500 5.0600 5.5700 6.0800 6.5900 6.9

See your local Belden distributor for fulldetails or to order. For a free copy of therecent reprint article, "Electronic Caole,"write: Belden Corporation, P.O. Box 5070-A,Chicago, Illinois 60680.

BELDEN

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

FEBRUARY 1970 23

WHININGIn the late 1930's certain clever Japanesemerchants named a small island USA.leaving out the periods. Then they floodedthe U.S.A. with cheap inferior productsstamped "Made in USA." The Japanesehave long since stopped using clevertwists on words to deceive buyers. It'shard to believe that an American firm hasstarted this practice. but it has.

In June 1968 TECH SPRAY introduced dnew revolutionary product BLUE STUFF FORTUNERS. The name and distinctive shade ofblue were chosen so as to identify the factit was different from all others. We are veryproud of the reception that the industry hasgiven it.But now a competitor has introduced a prod-uct called BLUE FOAM FOR ALL TUNERSusing the same identical shade of blue color-ing and is selling it to distributors under aprivate label program with the distributor'sname on the can but not the manufacturer's.Using the identical color and twisting thename slightly is so clever that many of ourfriends in the industry have called to tellJS they thought it was BLUE STUFF FORTUNERS packaged by TECH SPRAY underprivate label for various distributors.

We want our customers to knowthat BLUE FOAMis NOT BLUE STUFF FOR TUNERSis NOT made by TECH SPRAYand cannot be expected to performlike BLUE STUFF because eventhough the color is the same,the formula is not.

YOU CAN BE SURE .IF BLUE STUFF IS IN THE CAN THE NAME BLUE STUff WILL BE ON THE LABEL!

At TECH SPRAY we're proud that we're honest

in our chemistry and in our merchandising.

TECH P. 0. Box 949 Amarillo, TexasCanada: Wm. Cohen, Montreal

SPRAY Export: Empire Exporters, N.Y.C.

EDITOR'S MEMO

Sencore Visit

I recently took a tour of the Sen-core manufacturing facilities at thekind invitation of Mr. Herb Bowden,president of Sencore and his seniorfield engineer, Jim Smith. Sencore,as you know, is one of the major man-ufacturers of electronic test instru-ments for use by TV and radio tech-nicians. Their plant is located in Ad-dison, Illinois, not far from O'Harefield. I was impressed with Sencore'squality control system in which pur-chased components are given a thor-ough check out prior to being used ina circuit. Completed instruments are100 percent tested.

This means that any recurrent troublecould be nailed down to a defective com-ponent or design problem before it getsto you the customer, thus preventingany inconvenience. As technicians, wecan all appreciate what that means.The Sencore plant was also about ascrowded for space as ten men on askate board. Herb Bowden happilyannounced they would soon be movinginto large new quarters. He also toldme of their large new factory recentlycompleted in Sioux Falls, South Da-kota. I didn't have time to see the newplant, which was not in use at the time,but I hope to soon. We did get a chanceto talk about how a test instrument isborn. Jim Smith tells me that one of thetoughest design problems is to makea unit as obsolescence proof for aslong a time as possible. One way todo this is to make provision for up-to-date modifications. I guess it's nosecret that we need new and bettertools to keep up with the consumerelectronic market. Since the tools weneed are also electronic in most cas-es, we need and appreciate the con-cern of the test instrument manufac-turers to keep us well equipped. Butthey also need our help. Let them knowof your likes and dislikes about aninstrument's capabilities.

for more details rircle 139 on Reader Service Card

ELECTRONIC TECHNICIAN/DEALER

Theabsolute endof an old fear.

The new B&K Sweep/Marker Generatordoes for TV sets what no other instrumentor instruments can do. It makes alignmentof color, as well as black & whiteTV, simpler and easier than ever.

Remember all your old fears about TValignment (especially color)? Well, nowyou can forget them!

In the past, a marker generator and a separatesweep generator were used with a markeradder and a bias supply. All four of these now arecombined in one easy -to -use instrument.

(We've made benchwork so much simplerby doing away with the need for hooking togethera lot of cables and costly instruments.)

The Sweep/Marker Generator is both aninstrument and a guide. As a guide, the bandpass

and chroma bandpass curves are visuallyreproduced and the individual markers are clearlyindicated by lights-right on the frontpanel-for quick, easy reference.

As an instrument, the Sweep/Marker Generatornot only generates the marker frequencies(all crystal controlled), but also sweeps the chromabandpass, TV -IF, and FM -IF frequencies.

See it soon at your B&K distributor or write usfor advance information on the product thatmakes TV alignment procedures of old a fearlessoperation: s mple, fast, accurate. The newSweep/Marker Generator, Model 415, Net:$399.95

New B&KSweep/Marker Generator.

PRODUCT of DYNASCAN CORPORATION1801 W. Belle Plaine Chicago, Illinois 60613Where electronic innovation is a way of life.

tor more details circle 104 on Reader Service Card

FEBRUARY 1970 25

NEW AND NOTEWORTHY

INVERTERS 700Stability allows for the operationof CCTV

Announced is the production oftwo new frequency stable invert-ers for closed circuit television opera-tion. The Continental Model 50-191-3 (275-300w cap) and the Dual Con-tinental Model 50-202-3 (550-600wcap) provide 117vac power fromstandard 12vdc battery input. Theclaimed frequency stable featureof both these units, 60 ±1/2Hz, pro-vides the type of power for the opera-tion of sensitive TV cameras, re-corders and monitors. Units comecomplete with convenient remotecontrol and heavy-duty 15ft copperleads. Both units are ideal for operat-ing many pieces of peripheral equip-ment within wattage, capacity ofunit, used in direct conjunction withCCTV systems. Other higher watt-age 24v units are available at addi-tional cost. Terado Corp.

4111

FOR MORENEW PRODUCTS SEEPAGES 58 & 78

STEREO TAPE DECKFeatures crossfieldbias head

Introduced is the Series 1600X, three -speed, all solid-state stereo tape deck,featuring a crossfield (bias) head toassure better frequency response andsignal-to-noise ratio. The Model 1600Xmay be used with high output, low noisetape and offers these important fea-tures: V. U. meter; new, automatic tapestop assembly; pushbutton record/play-back control; channel selector switch;"joy -stick" four-way tape motion lever;four digit illuminated revolution count-er; instantaneous start -stop control;and a new tape arrester assembly forlow wow and flutter. Heads includerecord/playback, erase and crossfield(bias); tape speeds are 1 7/8, 3 3/4 and7 1/2ips. For FM multiplex recording,an FM multiplex filter must be added.Specifications are: frequency response-7 1/2ips - 40-20,000Hz (±2dB); 3 3/flips40-16,000Hz (-±- 2dB); 1 7/8 ips - 40-9,000Hz (± 2dB); wow arid flutter - 0.1%(71/2); 0.2% (33/4); 0.4% (17/8). Signal-to-noise ratio is 60dB weighted; micro-phone input - 200U; speed tolerance is± 1.5 percent absolute; transistors -

36. Weight is approximately 19 1/2 lb.Approximate dimensions are 15 3/8 Lx 11 7/8 W x 6 3/4in. H. Retail is $249.Tandberg.

701

TELEPHONE AMPLIFIER 702Solid-statebattery powered

Announced is a solid-state, bat-tery powered telephone amplifier,Model TA100. The portable deviceallows "no -hands" telephone con-versation between individuals orgroups. The telephone amplifierset is composed of two units, theamplifier unit and the speaker unit,and is simple to operate. Just placethe telephone handset on the cradleof the telephone amplifier with themouthpiece of the telephone hand-set in the "well" at the front of theamplifier unit. With the amplifierunit arranged so that the user talkstoward the mouthpiece of the tele-phone as it rests in the well of theamplifier unit, his voice is picked -up enabling the listener at the otherend of the line to hear him. The voiceof the party on the other end of theline comes through the speaker unitwhich is positioned by the user foreasy listening. The speaker volumecan be raised or lowered by turn-ing the volume control on the am-plifier unit. After a call is complet-ed, the amplifier shuts off automat-ically, when the phone is lifted offthe device. RCA.


Guns are her business...SHE'S GOT TO BE TOUGH!

She makes the final inspection of everytri-mount electron gun we manufacturefor Channel Master Color CRTs ... andshe's tough aoout it!The six different tests fcr spacing, align-ment, angle of deflection end coivergenceof each gun ... hand -crated to micro -inchtolerances in our dust -f ree arsenal ...guar-antee precise aiming at the rare earth tar-get. All 0' t-er guns must meet OEMspecs. Any that don't arefired cn the spot.

The tests she makes are just part of the117 inspections that each Channel MasterColor CRT must pass before it's fina OKfor shipment. Just part of the reason whythere's no finer color CRT you can recom-mend. The Rest? We use only the finestmaterials, and assemble them to hicher-than-industry specifications.

Color is our specialty ...that's why somany people are watching Channel Master!

At Channel Master YOUR Reputation is OUR Business.

OPTI-CH ROMEOPTI-VUECOLORLUX

S CHANNEL MASTERDIVISION OF AVNET, INC., ELLENVILLE, NEW YORK 12428

FEBRUARY 1970

hi more details circle 110 on Reader Service Card

27

LETTERS

TO THE EDITOR

Antennas for SaleI have been a subscriber to ELEC-

TRONICS TECHNICIAN/DEAL-ER for about 10 years and find it veryinteresting.

A few years ago I used to installmany more outside antennas thanI do now and I still have to stock ap-proximately 50 Conicals, 50 FM Turn-

stile and 50 Single Channel 5 & 10element Yagis. I would be willing tosell these for approximately half cost.

AL SVIRMICKAS

2512 West 69 StreetChicago, Ill.

Closing ShopAfter 20 years of honest TV and

radio servicing, I will be closing shop.I am giving it all up for a cleaning job

U thevehicular basegain antenna.

With five words, Antenna Specialists Co. creates afar-reaching new concept of mobile performance-

THE VEHICULAR BEAM ANTENNA SYSTEM.

Breakthrough! Up to 2.5 dB gain-first true gainmobile antenna system in CB history!

'/Breakthrough! World's first mobile beam!

\I Breakthrough! Antenna Specialists' exclusive Scanner tprinciple of electronic sector focusing goes mobile!

/Breakthrough! Dashboard control of yourmobile antenna performance!

Write forillustratedbrochure!

Mobile ScannerVehicular Beam Antenna Systems.

UR

the antenna specialists co.Ov 4 Alit, I ,,ctr, and qu,44,ent Company

12435 luck! Avenue. Cleveland. Ohm 44106Export Offices. 2200 Shames Dr., Westbury, N.Y. 11590

1I

rassm...onaseN

. . for more details circle 103 on Reader Service Card

Strim of Quatity

at $2 an hour which I find is more prof-itable in the long run. As I see it, allfuture sets will be solid-state and afree for all in circuit design. Techni-cians will have to waste a great dealof time repairing these fine printedcircuit boards and ruining their eye-sight. The only way for future elec-tronic equipment to be profitable isto standardize the circuits and havebetter quality control. But now I canstop worrying about it. I have a paidvacation, bonus, sick benefits and plen-ty of overtime. Also plenty of timeto sail and fish. Now I can read yourfine magazine and learn besides. Ican repair TV and radio on the sidewith no big overhead and no morelong hours.

ANTHONY AMMELLI

Overwhelming ResponseThis is to express my appreciation

for printing my letter of last Octoberregarding the Japanese made radio andour want of Rider Manuals.

We have had an overwhelming replyto the letter. A total of 33 answersthus far from all over the United States,including offers to sell us antique ra-dios, tubes, etc.

A subscription of ELECTRONICTECHNICIAN/DEALER is one of ourmusts each year. The many fine articlesrelative to service and keeping ab-reast of the new innovations warrantshighest praise.

Our most heartfelt appreciation foryour assistance.

W. 0. (BURNIE) WATKINS

Reader's AidCan any of your readers help me lo-

cate service information on a FreemanModel 600 stereo tape recorder? Any as-sistance will be greatly appreciated.

MICHAEL RICE1595 Blountstown StreetTallahassee, Florida 32304

We would like to obtain Schemat-ics for the following equipment. Ifsomeone will loan them to us, we wouldphoto copy the drawings or manualsand return them within 48 hours.

The schematics we need are fora Paco Model V-70 Vacuum Tube VoltMeter and for a Hickok OscilloscopeModel 195B.

G. M. BOYES127 W. Limestone StreetP.O. Box 557Carthage, Missouri


We've gatafull line.No bull about it.

When it comes to wire and cable, we'vegot the works: TV wire, control cable,inter-com and audio cable, coaxial cable,hook-up wire, cord sets, antenna wire, leadwire, power cord and cable, rotor cable.

And not only do we have them all, wemake them all easy for you to get. There'sa full supply of every one of the items weoffer, ready and waiting to be delivered

to you, in every one of our warehouses.What's more, all our products are in

distinctive, new packages that makethem easy for you to find when you puttogether an order and easy for you tocheck when you take an inventory.

Why buy wire and cable helter-skelter?Get it from one source, get it from us!For complete information on Columbia

wire, cable and cordsets write ColumbiaElectronic Cables.150 Hamlet Ave.,Woonsocket, R.I. 02895;Warehouse, 4045 North Rockwell St.,Chicago, Ill. 60618; West Coast SalesOffice and Warehouse, 1950 Naomi Ave..Los Angeles. California 90011.

Columbia Electronic Cablesa division of AVNET. INC.

. . . for more details circle 113 on Reader Service Card

d TECHNICAL DIGESTThe material used in this section is selected from informationsupplied through the cooperation of the respective manufacturers or their agencies.

ADMIRALRadio Models PRF121/PRF131 -AC Power Supply

These radios include a separate ac power supply whichallows them to be operated from an ac line without batterydrain for home use and from the 6v battery pack for por-table use. When the set is operating with the switch in the

RADIOCIRCUIT

LOAD

5.9V

de position, the ac power supply circuit is opened so it doesnot recharge or affect battery operation.

The full wave ac power supply for the PRF121 is illus-trated in the simplified circuit diagram. The power supplyfor the PRF131 is the same but different symbol numbers

are used in the schematic diagram for identification.Transistor Q14, connected as a reverse common base

amplifier (signal applied between collector and base andtaken off at the emitter), functions as a voltage regulatorand electronic filter. The emitter load resistor for Q14 con-sists of the radio circuits. Zener diode D12 provides a -6vreference for the power supply.

The avalanche characteristic of D12 prevents Q14 basevoltage from exceeding -6v. The characteristic of the for-ward biased PNP Germanium transistor Q14 maintainsthe emitter voltage within 0.1v and 0.3v of the -6v basereference. Since Q14 functions as a reverse amplifier, anyvoltage fluctuations at the collector will be even less in theemitter circuit. Therefore, any ripple will practically dis-appear at the emitter. A constant, well filtered power willhe provided at all volume and signal levels.

RCA VICTORCassette Tape Player ModelsYLB18/YZB525-Cassette Cartridge Ejection

A recent design change in the assembling of cassette tapecartridges provides for the two halves of the cartridge to

SYLVANIAFM Stereo Automatic Mode Switch

The automatic mode switching circuit is made of a highpass filter C114, a noise voltage amplifier transistor Q24,a diode rectifier switch SC16 and the 38kHz amplifier tran-sistor Q26.

The purpose of this circuit is to switch to monaural whenthe stereo FM signals get objectionably noisy. A manual"Auto" switch on the front panel defeats the decoding cir-cuit when the noise level holds the switching circuit at thethreshold level, switching the decoder in and out of its operat-ing mode.

Under normal conditions the noise level is low allowingthe 38kHz amplifier to maintain conduction. The 38kHz

NOISESIGNALFROMRATIODETECTOR

-/5

C114100PF

.R110127K

R108 tt100K .

4 osCI20

SWITCHMANUAL

.`4

024VOLTAGE CI22

AMP I SCI6R11947

/-470):57uH

RII2 CI20IK 05

FROM 19kHzFULL WAVERECTIFIER

FROM 19kItzFULL WAVERECTIFIER

RII722K

sine -wave energy is injected into the time division multi-plex switch for left and right channel signal recovery.

When the FM stereo signal level drops, the noise levelrises. The high pass filter, C114, feeds the noise voltageto the base of Q24. Q26 base is forward biased by the volt-age drop across R117 because of the voltage divider cur-rent flowing through SC16, R119, R117, R118. L32, a highimpedance collector load for Q24, develops the noise sig-nal SC16 rectifies.

SC16 becomes reverse biased by the noise signal rectifi-cation producing a negative de potential at its anode. Thecurrent through the resistance network R119, R117 andR118 is switched off and the forward bias removed from Q26.The 38kHz sine wave is removed turning off the multiplexswitch. Only monaural sound is recovered.

1

1 R331201

Ril8

02638kHz /AMP

T201I-1-1-- 11'-j. 330KCI30 41,1 1

.- JVYY1330PF

if (COLLECTOR PULSES/

1>-- f n n r 38kHz

IUUJ38kHz_TANKSIGNAL

LOW NOISE

SC16

38kHzSWITCHING SIG.

RI2682K

irR10733K

38kHz SWITCHING SIGNAL

EQUIVALENT DIODECIRCUIT

HI NOISE -)IRII9

SC16 RII9

CLOSED RII7 OPEN RII7SWITCH SWITCH ir

e+ RII8 6-8+ RII8

IL CH

T ),RcH

\AAAL- VOLTAGE DIVIDER CURRENT FLOW-

- - CONDUCTING PAT H

30 ELECTRONIC TECHNICIAN' DEALER

There's more hereWhat you are looking than meetsat is RCA's solid-state

A whole lot went into thatcolor chassis-the CTC-40.

chassis. Like fifteen years of tech-nical research. Pioneering in the developmentof Solid State. And the backing of a nationalworkshop program like nobody else's.

That's where you come in.We've written a technical manual

on the CTC-40 especially for Elec-tronic Service Technicians. It has color

diagrams, pictures, andeverything there is to know

about our CTC-40.eye.You can buy it from your

RCA Consumer Electronics Dis-tributor, but there's a better way.

Attend the next RCA Consumer Elec-tronics Distributor CTC-40 Workshop and get

the manual free. Our distributor can tellyou when it will be held next in yourarea. See you there.

11111 1"111111111

1111,1111 111111111',1111111

FEBRUARY 1970 31

To service Color TV you need:

1. vectorscope

2. color bar generator

and you can't

use one withoutthe other!

One YearWarranty

portable

for homeor shop

only the V7 gives you both

The only complete one unit color vectorscope/color-bar gen-erator available anywhere!

Completely portable for servicing color TV in the home ... noneed to bring set to the shop!

The only one with detailed instructions on color circuit align-ment and color adjustment. And, additional instructions areavailable as new sets are introduced!

Recommended by leading TV manufacturers! Proven performance . .. over 4 years of use in field and shop

by thousands of technicians . . . no other vectorscope manu-facturer can make this claim!

V7 Checks and aligns demodulators to any angle. Checks and aligns bandpass-amplifier circuit. Pinpoints troubles to a specific color circuit.

Exclusive Features: Self-Calibrating-adjust timing circuit with-out external test equipment, Dial-A-Line-adjust horizontal lineto any width from 1 to 4. Plus: All Crosshatch, Dots, and ColorPatterns; Voltage Regulated; Fully Enclosed Cable Compartment.Free copy of Wayne Lemon's Book, "Color TV ServicingSimplified with Vectorscope'.' Net 18950

Remember . . . V7 - the complete one

Ilk See your distributor or write Dept. ET -2

m LECTROTECH, INC.4529 North Kedzie Ave., Chicago, III. 60625.. for more details circle 123 on Reader Service Card

TECHNICAL DIGEST

be sealed together by an ultrasonic process resulting ina much more rigid cartridge. The more rigid cartridge willundoubtedly become universal.

While steps have been taken to make the cartridge com-patible in the YZB525, there may be instances where thisnew type cartridge will not eject freely from the YLB18.If this difficulty is encountered, the following procedureshould be followed.

In some manner remove a small amount of each taperedrib as illustrated (only enough to allow cartridge to fit snug-ly against back edge of compartment).

Note: This could be accomplished by using a sharp knife,end cutting chisel or wire tipped soldering iron.

Radio Models RLD3O/RZD435/RZD946-Hum Modulation

There is a possibility of hum in these radios when a strongsignal is received.

AC Line

VolumeContro'

Knob

TuningKnob

R24Add or

changeto 47 ohm

WhiteWire

Under conditions where the radio may be in the vicin-ity of a strong AM transmitter, hum modulation may beevident.

In these isolated instances requiring correction, add orchange R24 to 4701/2w, as illustrated.

continued on page 34


Don't sell a colorpicture tube unless its

been on a test ride.

Down at the bottom of the page, you have a major advance in space-age homeliness.

And a major advance in color tube testing as well.That machine squatting down there is our beloved Iron Horse, the

fully -automated, revolving carousel we use to test our color bright 85'tubes for emission, gas leakage, shorts, arcing and screen uniformityprior to shipment.

Now we don't intend to go into a song and dance on how total auto-mation reduces testing error.

But we will tell you one thing.Our Iron Horse test ride, combined with our life

testing and 100% set testing, makes it almost im-possible for you to get a defective color tube fromus.

Which in turn makes it almost im-possible for you to get chewed outby a customer.

Next time you need a color re-placement tube, remember thegreat thing about the colorbright 85. We don't send it toyou till it's been around.

SYLVANIAGENERAL TELEPHONE & ELECTRONICS

:41IFYR

Ot°4 r-444ill Ell k

I ,P.7-giP

FEBRUARY 1970 33

you don't have to bea magician to sell . . .

This deluxe UHF -VHF and FMStereo antenna with exclusiveGold -Guard finished elements andhandsome base complements anydecor. Features that help you sellinclude 6 -position tuning switch

telescoping 4 -selection elementsassure maximum signal strength beautifully packaged in full colorshelf talker carton complete withlead-in wire and mounting termi-nals. Model No.32-306. Suggestedretail $12.95

These GC products sell like magic, too.

All Channel UHF -VHFAntennaGold -Guard finish, 6position switch, packagedcomplete with lead-inwire and terminalsNo 32-303. Suggestedretail $5 60

VHF AntennaDelivers peak VHFreception, aluminumdipoles extend to 38".Supplied complete withheavy no -tip base. lead-inwire and terminalsNo 32-300 Suggestedretail price $2 10

Economical VHF AntennaBack -of -set modeldelivers top performanyeon all channels. One of acomplete line of exactreplacement antennas madeto original manufacturersspecifications. Completewith mounting screws,lead-in wire and terminals.No 32-304 Sugg. retail $3.75

All New 312 page G CElectronics General Catalogfeaturing thousands ofitems is yours for theasking Write toaddress below

GC] GC ELECTRONICSELECTRONICS 400 SO. WYMAN ST., ROCKFORD, ILL. 61101

A DIVISION OF HYDROMETALS, INC

TECHNICAL DIGEST

DELCO RADIOTape Player T400-Twist Lug BreakingOff On Push Bar Assembly

When removing the volume or fadercontrols from the tape player, it be-comes necessary to remove the pushbar assembly to acquire access to thetwo screws that hold the control brac-ket. When bending the twist lug firstup then back, the twist lug may breakoff.

LINK

If the lug breaks off, drill a small holein the shaft at the point where themetal changes its width. See illustra-tion. Place a small piece of wire throughthe hole and bend so the wire will notfall out.

Tape Player 69T-4-Intermittent Bias Pots

Condition: Some shops have foundsome 7294878 bias pots being intermit-tent.

SOLDER TAB TOiMOUNTING PLATE

Cause:This bias pot is of a two-piece con-

structions as shown in the illustration.The mounting plate is effectively groundin all mounting applications. If it doesn'tget a "good stake" in the manufactur-ing process, the pot becomes intermit-tent. Cure: Solder at least one of thetabs to the mounting plate. (This isbeing done in the manufacturing pro-cess at this time.)

Use Zip Code

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


You're making money in electronics now.

RCA offers 4 ways to make more.

Study at home ...set your own pace.RCA Institutes has an easy approachto bring you bigger earnings.

COLOR TV During this course you'll performover 50 experiments-and receive all parts and instruc-tions to build your own color TV.

The cost of the Color TV Kit is included in the tuition-in both the beginner's program and the advancedcourse in color TV servicing.

Course is based on the latest receiver circuitry andequipment.

FCC LICENSE TRAINING Get yourlicense-or your money back! We're that sure you'llsucceed with RCA Institutes Home Study Training.Course is all new-both in content and in the up-to-date method of study.

Choose the course for the FCC License you want: third.second or first phone. If you need basic training first.apply for the complete License Training Program.

TRANSISTORS Transistor circuitry is whatthe TV repairman must cope with in most receivers to-day. This course gives you the necessary background.

You'll discover an easy way to an effective understand-ing of semiconductor technology, including character-istics of tunnel diodes rectifiers and other solid statedevices. Transistorized TV Receiver Kits also available.

CATV TRAINING Technicians are inshort supply in CATV '.Community Antenna TelevisionSystems).

That's because CATV is expanding, as people seekbetter reception and more than local stations.

You'll receive two comprehensive lessons, covering thepractical phases of CATV systems in either the Tele-vision Servicing or Communications courses.

WHEN YOU STUDY THROUGH RCA INSTITUTESHOME TRAINING, YOU CAN PAY FOR LESSONS ASYOU ORDER THEM, OR TAKE ADVANTAGE OF EASYMONTHLY PAYMENT PLAN. LICENSED BY NEW YORKSTATE EDUCATION DEPARTMENT. APPROVED FORVETERANS. ACCREDITED MEMBER NATIONAL HOMESTUDY COUNCIL.

"If the return postcard is detached, send coupon today-"

RCA

RCA INSTITUTES, Inc., Dept. 225-002-0320 West 31st Street, N.Y. 10001Please rush me FREE illustrated catalog. I understandthat I am under no obligation, and that no salesmanwill call.

Name Age(please pr.nt)

Address

City

State ZIP- - - - _... for more details ce de 130 on Header Service Card

FEBRUARY 1970 37

Ford's Econoline Van gives you up to1325 more pounds of payload than

othervans! Whatever your business, Ford Econoline's extra big payload canbring you bigger profits with fewer trips. Ford Econoline's top payload is 3600pounds, as much as 1325 more pounds than other vans. Econoline's clear floorspace totals 23% to 32% more than others-a real bonus in work area. Threepopular series: E-100, E-200 and E-300. Select any one of them and you'll getall the additional Econoline advantages. Solid road stability on long 1051/2 -in. and1231/2 -in. wheelbases combined with a wide 51/2 -ft. stance. The load -bearingstrength and riding smoothness of Ford's Twin -I -Beamfront suspension. The convenience of Econoline'soutside service center. The ease of Econoline'sdriver "walk-through." These and many moreFord better ideas make Econoline your firstchoice in vans. See your Ford Dealer.

Econoline exclusive:outside service center

Econoline exclusive:Twin -I -Beam suspension

Econoline exclusiveup to 32% moreclear floor space

Econoline exclusive:driver "walk-through"

FORDECONOLINE

VANS

38



The back. The front.

The back ofour B&K 1450Oscilloscope /Vector6copeput us in front.Notice the back. Clean, isn't it? That's becauseit's the back of the only oscilloscope/vectorscope with front vector inputs andcontrols.Now you can troubleshoot with this oneinstrument as an ultra stable oscilloscope; oras a vectorscope with this important exclusivefeature: the inputs are amplified! With thecontrol available up front, you can troubleshootat high level (the output of the color amplifiers),or at low level from the demodulator.The 1450 shows vector patterns exactly asspecified by color TV manufacturers.It also permits direct reading of peak -to -peakvoltages from two calibrated scales. (Simplyswitching to the range you want lights up theappropriate scale.)

DIAGNOS77C

el 01,

,SCLLOSCOPE

.1(/11111/IT 4,11,111

""at'

1101110.'

41,

The front (and inside)of our B&K 1450Oscilloscope! Vectorscopekeeps us there.Our scope has an exclusive diagnostic devicecalled the intermittent analyzer, with electronicmemory and optional audio/visual remotealarm (model MON-45).With this sophisticated detection -reportingsystem, elusive intermittent conditions canbe caught and identified in your absence. Justpre-set one control: if the stage is faulty, itwill eventually be detected. And when it is, theintermittent indicator on the 1450 will turn onand stay on until you return from service calls.And all patterns are locked in at any signal levelor frequency by automatic synchronization.

Any way you look at it, the 1450 Oscilloscope/Vectorscope means greater shop efficiency, more time forprofit -making calls, and a lot more mileage from a very fine diagnostic oscilloscope. All from B&K-thecompany that put an end to ordinary test equipment (the kind that puts an end to your patience).Of course, we've tried to show you our good side-both of them. Now it's up to you to side with us. See yourB&K distributor soon-or drop us a note for more detailed information.

Model 1450. Net: $299.95.

Product of DYNASCAN CORPORATION 1801 W. Belle Plaine, Chicago, Illinois 60613

B&K puts an end to test equipment.We've developed "Silent Partners!'. . . for more details circle 105 on Reader Service Card

FEBRUARY 1970 39

Give them the world's most fully equippedantenna lab ... and what do they do?

They take their work to lunch with them.

Our Engineers are that way ... no matterwhere or when they get an idea, they de-velop it on the spot.

Deciding one day that the Color Vectorcould be made even better, they ruined aperfectly good tablecloth designing changesthat give the antenna new mounting flexi-bility and increased gain on the VHF, UHFand FM Bands.

And they gave it greater wind stability,

and made the whole thing easier to handle,assemble and mount.

Then, with lots of tablecloth left, they wentahead and designed an entirely new modelfor near fringe areas ... just to be surethere's a high gain Color Vector for everyspecific area.

Don't misunderstand ... our Engineers areperfectly free to do what they want at lunch,and if they spend it improving products,that's fine with us. We'll even pay for thetablecloths.

THE NEW IMPROVED COLOR VECTOR

BY CHANNEL MASTERDIVISION OF AVNET, INC., ELLENVILLE, N.Y. 12428

40... for more details circle 111 on Reader Service Card


ELECTRONIC TECHNICIAN /DEALER FEBRUARY 1970

TEKLAB REPORT

Magnavox's Total AutomaticColor Chassis T940This interesting automatic tint circuitelectronically performs one of the most annoyingadjustments of the television set

Color television has advanceda long way toward simplifyingcustomer control adjustments.Automatic fine tuning employedfor a number of years practicallyeliminated fine tuning betweenchannels; then the automaticchroma control was introduced.Until now perhaps the most an-noying part of the adjustmentsstill remained, the tint control.If we switched from one sourceto another (such as different chan-nels, studio cameras, film cam-eras, video taped network pro-grams, etc.), variations of color

Magnavox Model 2C6927 Color TV employing theT940 Total Automatic Color Chass s.

in the fleshtone region and smallphase errors are noticeable.

We recently received the Mag-navox Model 2C6927 employingthe T940 chassis with total auto-matic color (TAC) automatic finetuning, color and now automat-ic tint.

We found the chassis, tuner,and the power tuning units easyto remove and other featuressimplifying chassis servicing.The tuner and control clusterwas pulled by removing two boltson the mounting bracket andtwo on the control shafts fromthe front. Plug-in sockets areused on all wire connections. Chas-sis hold down bolts can be removedfrom the top of the chassis with-out the need to get under it orto tilt the cabinet. The powerrectifiers and large wattage re-sistors are mounted on an uprightpanel making these componentsmore accessible and eliminatinga number of terminal strips asshown in Fig. 1.

This chassis employs a newHV cage and flyback transform-er. Alter removing one screwthe back cover lays down to ex-pose the rectifier tube and trans-former. The cover may be takenoff completely by removing twoadditional screws from the bot-tom of the cover.

Fewer components are mount-ed on the flyback transformerand the 1V2 focus rectifier tubeis replaced with a stick type di -

FEBRUARY 1970 41

making components more accessible and eliminat ng a nu m Der of term nal strips.

Automatic int Circu,t

Fig. 2-The power tuning cluster which includes al front adAistments and is pulled byremoving r. our etainin3 tolts and all wire harnesses have plug-in connectors reducingservice titre. Ths autona tin circuit is also placed an tuner bracket

ode which fits in a special hold-er on the side of the HV cage. Aslide switch is located on the rearapron of the chassis to simplifychanging the high line voltagetap on the transformer. A 6MU8tube is used as the sync and vid-eo amp replacing the 6LM8. Thisnew tube has better linearity,more gain and is not so prone to"slump." Do not use the 6MU8as a substitute for the 6LM8 with-out making appropriate circuitchanges. With the exception ofthe 6MU8 and the focus rectifierchange, the tube lineup is iden-tical to the later versions of theT933 chassis.

Also employed in this chas-sis are a number of new and modi-fied circuits which are worthyof review.

AUTOMATIC TINT CIRCUITThe nevi> automatic tint con-

trol employed in this chassis sens-es fleshtone errors and automat-ically corrects them to the de-sired hue. The ATC circuit is lo-cated in a metal box attached

Fig. 1 - Powe rectifier; and large wattage resistors are mounted on an up right panel to the tuner mounting assem-bly. See photo, fig. 2. Viewingthe set from the front panel youwill notice an additional slideswitch, the automatic tint. Thisswitch has three positions: OFF,PARTIAL and FULL correc-tion. The FULL position is usedwhen variations of fleshtonesare extreme; the PARTIAL po-sition is used when only minorcorrection is needed. Locatedat the back of the set on the sec-ondary control panel we foundthe PREFERENCE control whichdetermines the hue of fleshtonesproduced after correction bythe ATC. This control allows thecustomer to set fleshtones tohis peisonal likes; more red orgreen may be added as desired.

To overcome error in flesh -tones, the ATC employed in thischassis is designed to sense phaseerrors in the chroma signal inand around the fleshtone regionof the color spectrum and addphase correction to produce cor-rect fleshtones. This correctionis developed by two transistorscalled the Red and Yellow Gatewhich sample chroma informa-


CHRO A

OA 2 TYELLOW -

GATE

OA I3.58MHZSWITCH

PREFERENCECONTROL

TOOEMOO

Schematic of the automatic tint control (ATC) circuit.

tion coupled to the base of each.Each gate is sensitive only tocertain chroma phases on eitherside of the correct fleshtone phase,a transistor switch is used to com-plete the emitter circuit of bothgates. This 3.58MHz switch isturned on by a CW signal fromthe 3.58MHz oscillator which

I OUTPUT 1

Fig. 3-The 3.58MHz switch is switchedon by a CW signal from the 3.58MHz os-cillator which is very near the phase ofa yellow chroma signal.

is very near the phase of a yel-low chroma signal. (See Fig. 3)

The switch is biased so thatconduction occurs during theinterval that the CW sine waveis passing through its positivepeak. Similarly, both gates are

biased to conduct only when thechroma signal applied to the baseof each is positive going. Fromthis it can be seen that the yel-low gate will conduct heavilywhen a yellow chroma signal ispresent on the base of the stageat the same time the switch iscompleting the emitter circuit.

The chroma signal appliedto the red gate is phase shiftedso that red chroma informationis also near peak positive dur-ing conduction time. See Fig.4. If it were possible to transmitboth yellow and red chroma phas-

son ..

Fig. 4-The chroma signal applied to theRed Gate is phase shifted so that redchroma information is also near peakpositive during switch conduction time.

es simultaneously, it could beseen by observing the two chro-ma phases that the switch con-duction time is equal distance fromthe peak of each chroma sine wave(see Fig. 5) when correct flesh -

Fig. 5-Switch conduction time is equaldistance from the peak of each sinewave.

tones are transmitted. A devia-tioh in chroma phase from thatshown in Fig. 5 will cause one orthe other of the gates to increaseconduction while conductionof the alternate gate is reduced.The gates are then able to dis-tinguish an error in fleshtoneswith the red gate conductingmore when red errors are trans-mitted and the yellow gate con-ducting more when yellow er-rors are transmitted.

The combined correction sig-nal from both gates is added tothe original chroma signal bythe chroma amplifier transistor.This stage is emitter driven bythe same chroma informationwhich is applied to the base ofboth gates. The base bias of thechroma amplifier is developedby the individual phase shift net-work in the collector circuit ofeach gate to develop a correctiontowards yellow and the yellowgate to develop a correction to-wards red. The combined out-put of both gates will mix withthe chroma signal being fed tothe emitter of the chroma am-plifier to produce a resultant atthe chroma amplifier collectorhaving the proper phase to pro-duce correct fleshtones.

Since chroma phases otherthan those capable of producingyellow through red are negativegoing during the time the 3.58MHzswitch is turned on, the gatesare sensitive to only fleshtonehues and the remainder of thecolor spectrum is unaffected bythe correction circuit.

The troubleshooting proce-

FEBRUARY 1970 43

Front control panel showingthe three position

automatic tint switch and othercustomer controls placed

near the top of the cabinet forease of adjustment.

Fewercomponents aremounted on the

flyback transformerand the

1V2 focus tube isreplaced with

a stick type diode.

Pincushion Transformer

Pincushion Phase

Focus Rectifier

XII

Automatic Fine Tune

Automatic Tint

On/Off

Low Voltage Power Supply

Autprnatic Fine Tuning Circuit

Circuit BoardControl Panel

Top view of the T940 color chassis showinglocation of various circuits.

dure for the ATC circuit can befound in the December issue ofELECTRONIC TECHNICIAN/DEALER on page 64.

AUTOMATIC COLOR CONTROLThe automatic color control

(ACC) shown in Fig. 6 functions

4

-

Fig. 6-Schematic of the automatic colorcontrol (ACC) circuit.

to minimize large variations inchroma amplitude so that fre-quent adjustment of the colorcontrol becomes unnecessary.This circuit is a neW and improvedversion over previous years.

Control is accomplished by chang-ing the gain of the bandpass am-plifier with a dc voltage. The ACCcircuit utilized in the T940 chas-sis uses two signals to developthe control voltage-the Burstsignal and the Chroma , signal.An increase in either or both ofthese signals causes a negative -

going voltage to be applied tothe control grid of the Bandpassamplifier to reduce gain. A reduc-tion of either signal causes thegain of the amplifier to increase.

The Burst signal is rectifiedby the Killer Detector diodesto produce a positive and a nega-tive de voltage. The negativevoltage is coupled through an8.2M resistor to the control gridof the Bandpass amplifier to es-tablish a certain amount of gain.When the Burst amplitude in-creases, the amount of negativevoltage produced becomes larg-er and causes the gain of the


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Fig. 7-The high voltage hold down circuit.

Fig. 8-A simplified schematic of the Burst amplifier and 3.58MHz oscillator.

GA08 T 702BURST AMP

ClRDIAA0_4INPUT

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Ln2

1111TVSOI

MEI

ACCTO

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1703

Bandpass amplifier to decrease.The amplitude of the received

chroma signal varies with chang-es in color saturation. A Chro-ma ACC amplifier, located onthe ATC board, is used to mini-mize extreme level changes. Thechroma signal at the top of theCOLOR control is coupled to DA4.The positive peaks of the signalsforward bias the diode and chargeCA13. The charge on the capaci-tor follows the amplitude var-iations of the Chroma signal. Thepositive dc voltage on the capaci-tor is used to control the conduc-tion of QA5. As the chroma sig-nal increases in amplitude, morecollector current flows. The col-lector voltage decreases and al-lows the grid of the bandpassamplifier to become more nega-tive and reduce gain. Low lev-el chroma signals provide lessforward bias for the chroma ACCamp and the collector voltage

moves toward the positive sup-ply. The grid of the bandpassamp becomes less negative andgain is increased. In this man-ner, the gain of the bandpass am-plifier is adjusted automaticallyto minimize extreme variationsin chroma amplitude.

HV AND SHUNT REGULATORThis chassis incorporates a

high voltage hold down circuitas shown in Fig. 7 which reducesthe output of the horizontal out-put tube in the event that thehigh voltage increases abovethe desired limits. The correc-tion circuit consists of resistorsR634, R601 and a voltage depend-ent resistor, VDR601. A 405vreference from the cathode ofthe shunt regulator is appliedthrough a 12M resistor to thejunction of R634 and R601. A fly-back pulse from the HV trans-former terminal FC is capacitive-

ly coupled to the VDR. Since theresistance of the VDR decreas-ei as the voltage across it increas-es, the VDR presents a low re-sistance path to ground to theflyback pulse and the rapid cur-rent flow through the circuit plac-es a negative charge on the pulsecoupling capacitor proportion-al to the amplitude of the flybackpulse. The reference voltageand the negative capacitor dis-charge balance when the highvoltage is within normal toler-ances. With an increase in highvoltage however the greatercapacitor charge becomes suf-ficient to overcome the positivereference voltage and adds re-verse bias to the output tube thusreducing conduction of the stageto hold the high voltage at thecorrect level.

The shunt regulator is usedto regulate the high voltage, be-ing applied to the CRT. This regu-lation prevents changes in thehigh voltage from affecting theover-all convergence of the beamson the face of the CRT. In addi-tion to the usual boost voltage,an additional boost voltage isdeveloped by a selenium recti-fier. This is designated as boost-ed boost and measures approxi-mately 1200v.

BURST AMPLIFIER AND 3.58 -MHz OSCILLATOR

As shown in the simplified sche-matic Fig. 8 a potentiometer isused as a tint control to changethe phase of the oscillator sig-nal applied to the phase detec-tor and killer detector. The dcvoltage developed by the phasedetector correct the phase ofthe 3.58MHz oscillator signal.The significant change to be not-ed is that the field AFPC adjust-ments for this circuit have beenmodified. The oscillator trans-former T103, is adjusted moreprecisely than in earlier chas-sis. It is important that this trans-former be tuned so that its re-sponse curve is centered at 3.58 -MHz.

In next month's Teklab reportwe will cover the eight -functionremote control system used inthis chassis.

FEBRUARY 1970 45

The color television service technician today hasthe responsibility of facing a more knowledge-able customer. This demands that the techniciaicontinually upgrade his efficiency and under-standing of color reception

Color Service Hintsby WILLIAM I. SPERO,Field Service Engineer- Sylvania Electric Products Inc.

Color television servicing hasproblems that technicians work-ing with monochrome TV nev-er dreamed possible. It is an en-tirely new dimension which mustbe treated and evaluated withextreme proficiency. Servicemanagers who refuse to acceptthis fact are missing out on thefacts.

After all, the average purchas-er of a color television is purchas-ing one item - entertainment,truly an intangible. His magiccolor box can't cook, clean thehouse or physically transporthim from one place to another.It can, however, take him to theopera, to a movie or to the fourcorners of the world- withoutever leaving the surroundingcomfort of family and home-andin the living kaleidoscope of breath-taking color. All this, of course,is predicted on the assumptionthat the color TV receiver is op-erating satisfactorily. By sat-isfactorily, I mean that it is per-forming to manufacturer's spec-ifications, and reproducing col-or as close to the original as thestate of the art will allow.

The service community hasa responsibility to the consum-er. And since color is a whole newdimension, color receivers can-not be serviced entirely with mon-ochrome techniques. A widebandoscilloscope and a good sweep/marker generator are mandatory.

Modern solid-state circuits re-quire modern thinking and a-nalysis to intelligently trouble-shoot them. One trend of devel-opment which color receivershave been taking is towards moreautomatic control. This type ofcircuitry goes under various names(you are all familiar with them,I'm sure!) -Remote Control,Automatic Color Control, Au-tomatic Fine Tuning, Automat-ic Frequency Control, SignalSearching UHF, TAC, etc.

With the rising costs of laborand materials, the average shopcan't afford to stumble throughits service. Someone must takethe initiative and responsibil-ity of upgrading the technicalpersonnel.

Many manufacturers now pro-vide field service training sem-inars to help technicians under-stand the product and its oper-ation. Some also have institutedtraining schools to improve thetechnical competency of servicepeople. Fortunately, those ser-vice managers who are lookingto the future of the televisionservice industry and for waysto increase their business pro-fits see that their personnel takeadvantage of these programs.

NOVEL DIAGNOSTIC TECH-NIQUE

One of the most important re-quirements of a satisfactorily

Fig. 1-Vertical Interval Test Signals asobserved on television receiver.

Fig. 2 -Composite Video -Vertical, show-ing VITS pulse.

operating color television receiv-er is its alignment status-RF,IF and Chroma. If one were toview a monochrome picture on-ly, RF or IF misalignment wouldnot greatly detract from the vid-eo content. Some degree of mis-alignment can be tolerated. How-ever, poor alignment or poor highfrequency response in a colorreceiver will destroy its aesthet-ic value. A color receiver lack-ing in good high frequency re-sponse will not pass adequatechroma information throughthe IF stages. After all, peopledo buy color TV to watch colorprograms-in color.

How do you recognize thatalignment is needed? There aresome ways, by observing a pic-ture: a classic one being the tune-able ghost. While this gives someindication of a problem, it doesnot visually describe the wholeRF-IF frequency capability ofthe color receiver. A quick wayto assess this frequency -responseis by utilizing the video test sig-nals transmitted by the broad-casters.

Perhaps a short descriptionof these signals is in order. Ver-tical Interval Test Signals (VITS)are generated and transmitted


along with the composite video.They are keyed into lines 18 and19 of both fields and transmit-ted with the picture signal. Thiscan be seen on home receiversas a light horizontal line in thevertical blanking interval. Tosee it, just off set the vertical holdcontrol to move the vertical blank-ing to the center of the screen.(Fig. 1)

The network people utilizeVITS to establish a continuousquality control of television sig-nals. These signals are monitoredon an oscilloscope and can be ob-served and photographed. Thenetwork use is beyond the scopeof this article; however, we canconveniently use these signalsto establish proper (or improp-er) receiver performance.

A photograph of how the VITSappears on the composite vid-eo is shown in Fig. 2. Figure 5is a simplified drawing of the VITSsignal as transmitted. Figure4 is a photograph of the same sig-nal as it appears at the 1st vid-eo amplifier of the television re-ceiver. The relevant part of theVITS signal which we will usefor our receiver evaluation isthe multiburst signal. This con-sists of six sine wave bursts of

Fig. 3 -Multiburst and 3.58MHz modu-lated staircase -horizontal.

Fig. 4- Multiburst signal -Blanking withburst on back porch -horizontal.

"momImam

constant amplitude at 0.5, 1.5,2.0, 2.9 and 4.2MHz respectivbly.(Fig. 5)

As shown in Fig. 4, the 4.2MHzsignal is attenuated. This is nor-mal. We are looking after theoutput of the video detector andthe 4.5MHz traps, when prop-erly tuned, will attenuate thisfrequency. Attenuation of anyother burst frequency wouldindicate poor frequency response

ttltrf 1,0110 1111421

.4'13 I. 10 t 14 OC ate

41O CIOCO

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Fig. 5-Multiburst signal -horizontal.

at that particular frequency.A shift of the burst frequenciesabout the de axis would indi-cate frequency -selective harmonicdistortion. This could be due tooverpeaking- which may bedeliberate to obtain a "sharp"picture. If one were to visualizethe response curve obtained us-ing video sweep modulation tech-niques, the similarity betweenVITS and VSM is apparent.

To set up the receiver for VITSwaveform observations, one hasonly to tune in a channel trans-mitting this signal, adjust thefine tuner for best picture (justout of the 920kHz beat in a col-or receiver), and connect the lowcapacitance scope probe to theemitter of the 1st video ampli-fier transistor or to the plate ofthe 1st video amplifier tube. Bycentering the VITS waveform(Fig. 2) on the oscilloscope andchanging the horizontal sweepfrequency, the signal can be ex-panded to that shown in Figs.3 and 4. The one catch, of course,is that your oscilloscope mustbe wideband, triggered and ca-pable of displaying the frequen-cy burst to 4.2MHz without at-tenuation. However, any up-to-date service shop equipped forcolor servicing should have notrouble here as there are a num-ber of relatively inexpensiveservice oscilloscopes which fit

this category and do the job.The advantage of using the

multiburst signal should be ap-parent by now. It takes less thanone minute with no special shoptest equipment to assess the RF-IF alignment status of a colorreceiver by observing the ampli-tude of several critical video fre-quencies. Certainly a worthwhileprocedure for any conscientiousservice shop. And since servicetime is money, make the best useof it.

Figure 6 is a waveform of themultiburst when the fine tun-

L-v

Fig. 6-Multiburst signal -horizontal, Finetuner adjusted approximately one-halfturn past 920kHz beat.

Fig. 7-Multiburst-horizontal, Fine tuneradjusted just past color threshold.

er is set approximately one-halfturn past the 920kHz beat (to-wards smear). In Fig. 7 the finetuner was adjusted just past thepoint of color threshold (towardsthe smear portion). Note howthe response drops off at 2.9MHzand the burst on the back porchof the horizontal blanking pulseis attenuated. (Compare Figs.6 and 7 with Fig. 4)

Remember, this techniqueis not meant to be used to aligna receiver-no short cuts here-you still have to refer to the man-ufacturers' service literaturefor proper bandwidth vs. frequen-cy data. It is only meant to be atool, helpful in increasing diag-nostic efficiency.

FEBRUARY 1970 47

ServicingCassette

Recordersby HOMER L. DAVIDSON

Portable cassettetape recorders arethe "in thing- with

today's young crowdand learning to service

these units can helpyou earn a piece of this

booming business

Today's cassette tape record-ers are produced for mono andstereo track cartridges. The de-luxe recorder will tape in fourtrack stereo and mono positions.Small portable units record andplay two track mono on easy -load-ing, drop -in cartridges. Manyof these units will record up totwo hours at 1 7/8 1ps, on bothtracks.

The typical portable cassettemay be only a player or a com-bination recorder and player.Most units have a frequency re-sponse from 80Hz to 10 kHz. Someunits are battery operated oroperate from ac power line.

The new cassette tape unitshave many features: level me-ter, input for radio and outputfor external amplifier, automat-ic level control to reduce distor-tion caused by overloading, con-venient "pop-up" cassette load-ing, remote control mike or built-in mike and speaker, and somedeluxe cassette home systemshave push-button controls witha digital counter for indexing.Still others may have satellitespeakers and can be used as aPA system.

CIRCUIT DESCRIPTIONThe portable cassette record-

er or player amplifier may have

from five to ten transistors andonly one tape head while a larg-er stereo recorder may haveup to thirty transistors and di-odes. Most cassette recordercircuits are comparable to thereel tape recorder.

The unit shown in Fig. 2 hasa separate erase head and oscil-lator stage. In the playback po-sition, the record/play head isswitched to the input circuit ofa pre -amplifier stage. Three pre-amplifier stages are used in thisparticular model with a volumecontrol located between secondand third pre -amp stages.

The audio driver, Q4, is direct-ly coupled to the third pre -ampcircuit with the driver outputsignal transformer coupled to apush-pull output circuit. An eightohm PM speaker is switched intothe voice coil circuit.

The portable cassette record-er may be either battery oper-ated or ac operated. Most ac pow-er supply circuits employ a step-down power transformer andsilicon diode fullwave rectifica-tion (Fig. 2). Large electrolyt-ic capacitors and choke or resis-tance filtering networks are alsofound in the ac power supply cir-cuits. Capacitor C27, and chokeL2 are the filter components(Fig. 2).

Fig. 1 -Cassette tape recorder has pop-up feature for easy loading.

4H ELECTRONIC TECHNICIAN/DEALER

SPEED PROBLEMSIf the speed of a player varies,

always re -check player opera-tion with a new cartridge. Lis-ten to the pitch of the recordingto see if the cassette player isrunning fast or slow. In most cas-es the tape is running too slow.

Since it is possible to have adefective cartridge, substitu-tion is the fastest test. Also, whensome cartridges are played fora number of hours, the small taperoller inside the cartridge maybecome sluggish. A drop of oilon each side of the rubber rollerwill cure the slow or erratic tapecartridge.

Tape speed problems can alsobe caused by a defective belt andcapstan pulley assembly. Checkthe drive belt for stretching orfor oil spots. Clean the belt anddrive assembly with alcohol ora non-toxic cleaner. See if thebelt is properly aligned with thecapstan drive pulley. In somecases the capstan drive assem-bly mounting screws may becomeloose and move the pulley outof proper alignment. A crackedor broken belt should be replacedwith an exact part. In some ofthe small players the motor drivebelt looks like a small rubber band(Fig. 3). We don't suggest a rub-ber band as a belt replacement.

CLEANING AND LUBRICATIONTape heads should be cleaned

periodically to keep them in tip-top shape. Anytime a cassetterecorder comes in for repair, acomplete clean up job should bemade. Clean the tape head andguide assemblies with alcoholand a "Q" tip. A can of tape headspray will remove most tape dustresidue. Also clean any tape ox-ide from under the pulleys, fly-wheel and tape heads. Removethe motor and pulley drive beltsand wipe them with alcohol anda clean cloth. (A special tape headcleaning cartridge is also avail-able which is simply run throughthe player like an ordinary car-tridge.)

Remove the capstan flywheeland clean the top bearing. A "Q"tip or round brush are useful forremoving oxide dust from insidethe capstan bearing. Wipe thebottom nylon bearing clean andapply a coat of lubriplate grease.A spot of oil on small motor andpulley bearings is sufficient. Smallmotors found in portable cassetterecorders are normally self-con-tained and do not require lubri-cation.

Complete the cleaning oper-ation by spraying the operatingswitches and relay points. A thinpiece of cardboard will also help

Fig. 2-Schematic diagram of cassette recorder/player (Courtesy RCA)

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to clean up those dirty relay points,but do not use an abrasive mate-rial such as sand paper on thecontacts.

CHECKING THE AMPLIFIERA cassette recorder that will

not record or playback is possi-bly the victim of .a defective tapehead or amplifier. First, try anew recording and make surethe cartridge is properly seat-ed. If the recorder will playbacka new cartridge but will not re-cord, suspect a defective micro-phone and cable. You can assumethe play/record tape head is func-tioning.

Check the amplifier by inject-ing a signal from an audio gen-erator at the tape head termin-als. Signal trace the defectiveamplifier by going from the baseto collector terminal of each tran-sistor and make voltage and tran-sistor tests of the circuit (Fig.4) where signal is lost. When sig-nal tracing from stage to stagenotice the loss or gain of each stage.Compare the injected signal ateach end of a suspected electro-lytic capacitor. Remove it andtake a leakage reading. A goodelectrolytic capacitor will causethe meter hand to charge upwardand slowly decrease. Leaky ca-pacitors will show a lower resis-

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FEBRUARY 1970 49

Fig. 3-Some of the smaller tape players have motor drive belts the size of a rubber Dand.

Fig. 4-A defective audio amplifier stage can be located with a pencil type signal tracer.

tance reading and should be dis-carded (Fig. 5).

Always signal trace the au-dio circuit by starting at the out-put stage and work towards theinput when the amplifier appearsintermittent. Start at the collec-tor circuit and then apply thesignal to the base terminal. If

the signal "pops on and off," atransistor is intermittent. A freezecan be used on suspected tran-sistor to see if it becomes inter-mittent. Several applications offreeze spray may be needed to ob-tain the intermittent condition.

A defective transistor mayalso be located with voltage mea-

surements. When the collectorvoltage is higher than normal,suspect a transistor that is notconducting or has open emitterbias resistor. With all voltagesclose to the same potential sus-pect a leaky transistor. A lowcollector voltage also can indi-cate a leaky transistor or improp-er bias. When the collector volt-age is the same as the supply volt-age the transistor is open. Usea meter with a high input imped-ance to make voltage tests.

Another way to check a sus-pected transistor is with an in -

circuit transistor tester. Remem-ber that an open transistor willnot indicate a beta reading andin directly -coupled circuits, itis best to remove the collectorlead for more accurate leakagetests. If in doubt, remove thetransistor from the circuit andmake your tests. The record/playtape head can be checked for opensor shorts by taking a resistancereading. These readings will varyfrom 50 to 50011 and should bechecked against the schemat-ic. When in doubt substitute anew head. In stereo units, a de-fective head in one channel canbe checked by swapping heads.

HUM AND DISTORTION

Hum appearing on a portionof a cartridge that has normal-ly recorded material ahead ofit can be caused by a bad mikecable or connection. Check thecable for possible breaks at theplug or close to the microphonecase. Flex the mike cable whilemaking resistance measurementsfrom plug to mike connections.Excessive hum can also be pro-duced by a worn spot in the vol-ume control, a poor ground ter-minal or a broken foil on the groundsection of a circuit board.

Distortion conditions are oftencaused by leaky output transis-tors or improper bias resistors."Crosstalk" distortion can beremoved with proper height ad-justments upon the tape head.Excessive recording volume,with excessive bass response,will also produce a distorted re-cording as will a tape head cakedwith oxide dust. Excessive tape


noise may be caused by a mag-netized tape head.

Check the audio output tran-sistors for possible distortionby taking accurate voltage read-ings across the base and emit-ter bias resistors. Be sure to re-place any bias resistors with theexact values. Power output tran-sistors should be removed fromthe circuit to make a beta leak-age test. Often it will save valu-able service time to replace bothoutput transistors. Make surethe base and emitter resistorsare the correct value before re-placing the power transistors(Fig. 6).

Leaky directly -coupled pre-amplifiers or interstage tran-sistors are also candidates fordistortion. Make careful volt-age measurements at the tran-sistor and remove the collectorterminal to test with in -circuitbeta transistor tester. Make in -circuit beta leakage tests on bothoutput transistors in a push-pullstage.

HEAD ADJUSTMENTSExcessive crosstalk and poor

frequency response can resultfrom improper tape head align-ment as previously indicated.Height adjustment screws areusually located on each side andto the rear of the record/playtape head. Many of the small cas-sette tape player heads are sta-tionary and adjustment requiresthat the tape head be bent or twist-ed into position. Some of the lowpriced cassette players have apiece of rubber underneath thetape head and one side screwthat will allow for the azimuthadjustment.

In the higher priced modelsside tension springs with adjust-ment screws are provided forboth height and azimuth adjust-ments. The height adjustmentis made to eliminate crosstalkwhile the azimuth adjustmentis set for the best frequency re-sponse. The tape head adjust-ment screws in higher pricedcassette units are similar to thoseused in regular tape recorders.The following is a handy list ofchecks you can make to insure

e leaky electrolytic couplogpacitors

Fig. 5-Leaky electrolytics can cause loss of signal at the input of the amplifier.

FROMPRE AMP

R2412K

C12

R203 3K

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. POSSIBLE COWONENTS THATPRODUCE DISTORTION

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Fig. 6- Distortion can be caused by a number of components in the audio driver andoutput stages as shown in the schematic.

the overall operation of the cas-sette unit.

1. Completely demagnetize thetape head after servicing the unit.

2. Automatically clean the tapehead and guide assemblies witha "Q" tip and alcohol or audiotexblast off head cleaner.

3. Give the cassette record-

er a complete operation test withtest tape or a known recording.Check out each phase of opera-tion.

4. Clean up the entire cabi-net and plastic parts with foam-ing window spray. A convenienttroubleshooting chart is providedon the next page.

FEBRUARY 1970 51

Cassette Recorder/PlayerTrouble Chart

FAILS TO PLAY Check batteriesCheck battery terminalsFaulty power switchDefective ac cord and plugBroken drive beltFrozen capstan bearing

TAPE PLAYS SLOW ORERRATIC (WOW)

Belt too largeBelt partially off trackMisaligned capstan assemblyGlazed belt and pulleyOil on belt or capstan pulleyDefective motorDefective cartridge

NO SOUND Check batteriesCheck power supply on ac oper-ationCheck for defective play/recordheadCheck for proper cartridge seat-ingCheck the audio section

DISTORTION Locate distortion in particularstageCheck power output transistorOn difficult distortion problemsuse a square wave generatorand scope.

NOISY RECEPTION Isolate noisy transistorCheck all common ground ter-minalsResolder whole circuit -boardDemagnetize record/play tapehead

CROSSTALK Incorrect height adjustmentHeight mechanism bindingDefective erase head and cir-cuits


Color Service Case Historiesby PAUL GOLDBERG

Some of the toughest service problems in a colorTV chassis are caused by the most easily

over -looked components; as you will learn inthe following case histories

WEAK COLOR -NORMAL B/WThe first problem dealt witha Zenith color receiver 20Y1050.The complaint was that the blackand white picture appeared nor-mal, but the color was weak. Wereplaced all tubes affecting col-or amplification (refer to Fig.1); V6B, 6KT8, first color amp.,V11B, 6KT8, second color amp.and V12 and V13, 6ME8's colordemodulators. The tubes hadno effect on the trouble. The col-or level control was then variedto check it for bad spots but ittoo, checked normal. The tun-er selector was then rotated fromstation to station and no colorsync bars appeared on stationswith a color picture. Thus, thecolor sync section seemed to befunctioning normally. The HUEcontrol varied properly frommagenta to green and the fleshtones also seemed within toler-ance. At this point we decidedto make a few voltage checksof the 1st and 2nd color amplifi-er sections which seemed to bea logical approach to the prob-lem. Voltage measurements atthe plate, screen and cathodeof V11B, 2nd color amp checkednormal. We varied the color kill-er control, R40, and measuredthe voltage variation at the con-trol grid, pin #7, of V11B to seeif the color killer was biasing thechroma down. This also seemedto be functioning properly. Theplate and screen of the 1st col-or amp, V6B, had a differenceof potentfal between the plateand screen of about 20 volts. Themanufacturer's noths indicat-

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Fig. 1. Partial schematic of color amplifier section in a Zenith 20Y1050 chassis showingL15 in plate circuit of V6B.

Fig. 2. Partial schematic of Z demodulator and B -Y amplifier in Magnavox T904 serieschassis showinc L704.

COLOR 7411-OSC.

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FEBRUARY 1970 53

CHROMA AMP1/28AC9V8A

ed that the plate and screen wereconnected by L15, the chromaplate coil, which measured thecorrect value at a couple of ohms.Reflecting awhile, we remem-bered that sometimes these coilsdevelop cold solder connectionsat their pigtail terminals anddevelop a high resistance undercurrent flow. We resoldered thepigtails of L15 at its terminalsand turned the receiver on. Thecolor popped in beautifully andas we rotated the color level con-trol, the quality of chroma seemedto be fine.

LOST BLUEAnother problem was with

a Magnavox T904 series colorreceiver (Fig. 2). The complaintwas no blue in the B/W or colorpicture. The picture remaineda reddish green. The blue screengrid control had practically noeffect, but the red and green screengrid controls worked properly.The red and green drive controlsalso seemed to function normal-ly. Replacing the B -Y amp, R -Yamp and the G -Y amp tubes hadno effect on the problem. We thenremoved the CRT socket andmeasured voltages at the screens,cathodes and grids of the CRT.The red screen, pin #4, measuredproperly. The green and bluescreens also measured correct-ly. However, the blue controlgrid, pin #12, measured low. Itread in the area of 100v, whilethe red and green control gridmeasured about 195v. This re-duced voltage on the blue con-trol grid would effectively biasthe grid to cutoff. The manufac-turer's instructions indicatedthat voltage is "effectively" ap-plied to pin #6 of the B -Y ampfrom two sources through R738.The plate current of V706B pass-es through the plate load resis-tor R732, and the plate currentof V709 passes through R725B.These voltages are applied toeach side of R738. A voltage mea-surement at pin #6 of V706 mea-sured low at 100v. A resistancemeasurement of R732 provedthat the resistor was normal,but what was causing the lowvoltage at the plate? A resistance

8

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Fig. 3. Partial schematic of chroma stage in Sylvania D03-2 chassis showing coaxialcable which was causing intermittent color sync.

check of the cathode resistor,R737, also proved fruitless andreplacing V709 had no effect onthe problem. In order to see ifthe trouble could be caused bysomething in the V709 circuit,we measured the plate voltageof this tube at pin #5 and foundit to read normal at about 240v.By consulting the manufactur-er's schematic again, we noticedthat the signal was transferredfrom V709 to V706B by L704 andC738. Measuring the voltageon each side of L704, we foundthat on one side we read 100vand on the other side about 240v.A resistance measurement ofL704 proved it to be open. Weresoldered the pigtails of thiscoil and it did the trick. After turn-ing the receiver on, the blue screenworked properly. We next ad-justed the screen and drive con-trols for a normal black/whitepicture and checked out the re-ceiver on a color program-allwas functioning like new.

INTERMITTENT COLOR SYNCThe next problem is one of in-

termittent color and color sync.

A Sylvania D03-2 chassis wouldfunction normally for a few min-utes, then the color level woulddrop and the color sync wouldbecome intermittent (Fig. 3).Tapping the tubes in the solorsection in an attempt to localizethe trouble turned up an inter-mittent chroma amp, V8A, butthe problem corrected itself onlyfor a short time after the tubewas replaced. Using a plasticprobe we jiggled the pin connec-tions of V8A. At pin #9 the col-or would correct itself the mo-ment it was touched. A shieldedcable connected L600, the chromatake -off coil, to pin #9. We ex-amined the cable and its connec-tions at both ends and found whatappeared to be a cold solder con-nection. The connection was re -soldered and the color poppedin beautifully, but then droppedto a low level again. The colorsync was also irratic. Using aplastic probe we jiggled the shield-ed cable and the color again cor-rected itself. At this point wedecided the best bet was to re-place the cable. The new cablesolved the sync problem.


TEST LAB REPORT

Sencore Model TC154Tube TesterA tube tester can speed servicing of electronicequipment and make yourservice business more profitable

Most technicians may feel thatthe best test for a possible defec-tive tube is substitution with aknown good tube and observingcircuit functions. This approachmay be the best but not alwaysthe most practical considering thenumber of new tubes needed forsubstitution.

We recently received the Sen-core Model TC154 tube tester forevaluation.

From the portability standpoint,the tester is easily carried on homeservice calls as it weighs about

Sencore's Model TC154 Tube Tester.

nine pounds and is housed in avinyl -clad brushed chrome trim-med steel case.

The instrument is completelysolid-state and employs an FETin a balanced bridge circuit. Itoperates instantly without wait-ing for warm up and stabilization.

The tester is quick and fairlyeasy to use with four setup con-trols and four push button switch-es. The four controls use markedA -Filament, B -Load, C -Setupand D -Setup and are set accord-ing to the set-up chart. The tube

FEBRUARY 1970 55

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Schematic of the Sencore Model T C154 Tube Tester.

is inserted into one of thirteensockets numbered from one tothirteen. The desired function isselected by depressing the buttoncorresponding with the test de-sired, EMISSION, SHORTS orGRID LEAKAGE. We found thepush buttons easy to use and theyspeed setup time.

By depressing the SHORTSbutton, then rotating the "D"switch through all its positions,the short light will glow if a shortof 300K ohms or less is present.If the shorts light glows on a pointother than that marked in thesetup book, a short is present.

Tests can be made in any orderwithout damage to the testereven if the tube is shorted.

When the EMISSION buttonis depressed, the emission qual-ity of the tube is read on the topscale of the meter. If the tubeemission reads in the GOOD areaof the meter, then depress theGRID LEAKAGE button andread the leakage of the tube onthe bottom scale.

The shorts light may flickerindicating a high resistance shortin The tube. The applied voltageis kept below the 50v maximumto prevent damage to frame gridtubes and nuvistors or the pos-sibility of introducing a short.

The setup chart which is se-cured to the inside of the cover,has large print and appears tobe quite up to date on new tubetypes.

As new tubes appear they couldbe a problem by not being listed inthe setup chart. But with an under-standing of the setup controlson this unit, you can set up to testnew tubes by following specifi-cations listed in the tube man-ual.

If a tube manual is not handy,then use Ohms law to computethe cathode current. Simply div-ide the voltage drop by the val-ue of the cathode or plate loadresistor in the circuit from theschematic.

CIRCUIT DESCRIPTIONThis instrument is reportec!


as being the first completely solid-state tube tester. It uses the newFET or Field Effect transistorin place of the usual tube provid-ing instant operation for fasterand more accurate testing.

The basic circuit of the test-er is a balanced bridge meteramplifier consisting of FET TR1and diode CR4. The zener dioderepresents a constant currentsource and takes the place of thesecond FET needed for the bridgecircuit. The METER ZERO con-trol on the front panel is just likethe zero control of a VTVM andbalances the circuit so duringa no signal input, the bridge isunbalanced and the meter willread in proportion to the appliedsignal.

The cathode emission test putsan ac voltage between the con-trol grid of the tube under testand the cathode with a load re-sistor in series to develop a pul-sating de voltage. The B LOADswitch selects the different sizeload resistors and applied volt-age so that a full range of currentfrom less than .5ma to 120mais available. The tube under testrectifies the applied ac voltageand develops across the load re-sistors R1 through 1t7. The pulsat-ing de voltage is coupled throughthe filter network of R17 and C6to smooth it to a pure de volt-age. This voltage is applied tothe gate of TR1 through an addi-tional isolation and filtering net-work of R14, R15, R20 and C3.The resultant dc voltage upsetsthe balance of the circuit caus-ing the meter to read upscalein proportion to the emissionquality of the tube.

In the grid leakage test, thecontrol grid of the tube undertest is made negative to all otherelements in the tube by connect-ing the grid to ground throughthe 30M gate resistor consist-ing of R15 and R20 and applyinga positive 8v to all other elementsin the tube.

If the tube has grid leakageor contamination causing thetube grid to emit electrons, the

flow of electrons will be throughthe gate resistor. Any currentflow through the resistor willcause a voltage drop across theresistor and, in turn cause anunbalance in the bridge circuit.The meter will then read in pro-portion to the amount of grid cur-rent in the tube under test. Aleakage of 100M or less will causethe meter to read into the BADarea. A leakage of 100 to 200Mwill cause a meter reading in thequestionable area and a leakageof 200M or more will read in theGOOD area. A leakage of 100Mrepresents a grid current in thetube under test of .5µa.

, The shorts test uses the Sen-core Stethoscopic approach inwhich every element in the tubeis checked against all other ele-ments. A capacitive voltage di-vider consisting of Cl and C4 isplaced across the upper wind-ing of the primary of the filamenttransformer. The ac voltage atthis point is 75 volts and capaci-tor C1 drops this to approximate-ly 34 volts RMS which is appliedacross the tube elements. Thisvoltage is below the maximumthat can be applied to nuvistorsand frame grid tubes to preventarc over and breakdown in thesedevices. Capacitor C5, a .10, isin series with the shorts testto prevent any de action of thetube from turning on the shortslight. A true short will cause bothelements of the neon bulb to light.If the short is higher in resistance,the shorts light may only flick-er.

SPECIFICATIONSCathode Emission Tester:

Full load current drawn throughtube up to 120ma. Max appliedvoltage, 40vac RMS. Grid Leak-age Test: Good area, infinityto 200M, ? area, 200 to 100Mand the Bad area 100M or less.Shorts Test: 300K or less willcause shorts light to come on.Maximum applied voltage, 40vacRMS. Power: 105 to 125vac,50/60Hz al 32w maximum. Price:

FEBRUARY 1970 57

DEALER SHOWCASEFor additonal information on products describec in this section, circle thenumbers on Reader Service Card. Requests will be handled promptly.

WINDOW TV ANTENNA 703Permits orientationfor best reception

An 82 -channel swiveling windowantenna for VHF, UHF and FM isintroduced. The antenna features sep-

arate swivels for the UHF and VHFantenna elements. The Model C119-82 window antenna is ideal for apart-ment buildings, hotels, institutionsand wherever it is impractical to in-stall a rooftop antenna. Mounting issimplified by a spring -loaded bracketthat expands to fit any window frameup to 42in. wide, and is locked intoplace by a single bolt. Extension barsare available to accommodate win-dows up to 5ft or 6ft wide. The antennais constructed of a golden -colored alo-dized heavy-duty aluminum. All ele-ments are held securely in place withsnap -out spring contacts, assuringexcellent electrical and mechanicalcontact. Gain is provided by six VHFelements and four UHF elements.The C119-82 window antenna listsfor $14.95. JFD.

CCTV SYSTEM 704Designed forcontinuous operation

A closed-circuit television sys-tem designed for continuous opera-tion is announced. The 616/617 Cam-

era System is a split (camera -cam-era control) system employing solid-state circuitry throughout with the

exception of the one -inch vidicontube. The Model 616 camera util-izes integrated circuits and offersadjustable delay -line type aperturecorrection; adjustable gamma andwhite clipper; and FET hybrid cas-code input amplifier for the maxi-mum obtainable signal-to-noise ratio.All controls are located in the Type617 Camera Control Unit, includ-ing focus, beam, target and blank-ing, with pan -tilt and zoom functionsas an integral part of the controlunit. The electronic circuitry is con-tained in three glass epoxy print-ed circuit boards or modules, withthe power supply module locatedacross the top of the camera. Ray-theon.

TAPE RECORDER 705Features bias selector for standardor low noise tapes

Introduced

deck. Three

are two stereo "Au -recorders and a tapemodels are available:

Model 6360, with separate acous-tic suspended, pedestal -mountedcube speakers; Model 6250, withself-contained acoustic suspensionspeakers; and the Model 6150, athree -headed deck version. Report-edly the new cubical speakers' re-produce full -range frequencies withexceptionally low distortion andhave a built-in thermo overload pro-tection circuit. A five-year warran-ty is offered on the speaker system.The amplifiers for all units haveoutputs of 62w dynamic (IHF) pow-er at 1 percent harmonic distortionwith 811 loads. A complete stereosystem can be built around the re-corders with the addition of a turn-table and FM radio tuner. All ofthe models feature a record biasselector which makes it possibleto obtain optimum performance witheither standard or low noise tapes.Other features include open frontthreading; a patented self -aligning

pressure roller which assures per-fect tape alignment; an exclusive"see-through" head cover whichpermits easy tape editing; a two -motor drive system, and dynam-ic braking. List prices are: Model6360, under $439.95; Model 6250,under $359.95; Model 6150 (with-out base) under $259.95; and ModelA-1-50 cube speakers with pedes-tal, $79.95 a pair. 3M.

STEREO MODULAR SYSTEM240w of peak 706music power

A custom stereo modular system,Model CS2OW, is among five stereohigh fidelity phonographs introduced.

The system has a contemporary wal-nut cabinet of hardwood solids andveneers with tinted glass panels. Thestereo reportedly has 240w of peakmusic power. It features linear slidecontrols for cut/boost for bass andtreble, stereo balance and acousticlevel. Twelve pushbutton functionsare included in a control panel withweighted flywheel tuning providedfor FM stereo and FM/AM radio. Thephonograph has a Dual 1015F auto-matic turntable with ceramic cartridge.Suggested list price for the CS2OW,exclusive of speakers, is $339.95. Listprice for the 10in. speakers is $179.a pair, and $249. a pair for the 12in.Sylvania.

ANTENNA TRANSFORMER-BALUN 707Eliminates need foradditional antenna

Introduced is the Model TRS-57Transformer-Balun to adapt theSWL-7 and RD -5 short wave listen-ing antennas (and any short wavelistening doublet) to receive stand-ard broadcast bands below 4MHz.On these bands, the transformer-balun automatically transforms thedoublet into the long wire anten-

continued on page 64


This NEW Sweep -Marker GeneratorDoes Every Color Alignment Job That

Needs Doing-and Saves You Up To $260

Heathkit IG-57A

Exclusive HeathkitAttenuator

15 Crystal -ControlledMarkers

.8

11.

AT TaNUATOR

III Ili Ili Illa,/ 4,911 On .11 A. 4115 41. .9..

009,9 .m11. MOM

(1,010; Att wit410 MI nn I

t Mao M.O.

90.1or orr

Kit $135*-Assembled $199*Now With Video Sweep Modulation & Second Bias Supply

Compare the Features - Compare the CostNew Video Sweep

allows you to inject chroma sweep directly into the IF ampli'iers or throughthe antenna terminals ... permits 'tore accurate matching between colorbandpass amplifiers and IF and observation of overall response.lets you quickly and accurately determine 6 dB points without guessing.Gives up to 70 dB total attenuation in 1 3. 6. 10 and 20 dB steps.

provide all the most used marker frequencies ... 3 for color bandpass, 1for TV sound IF, 8 at the IF frequencies from 39.75-47.25 MHz includingspecial markers for B&W bandpass. Markers also included for picture& sound carriers on channels 4 & 10. The 15th crystal marker is at 10.7MHz for FM IF. A coil -tuned 100 kHz marker is also provided. A front -panel input accepts an external marker generator.two individually adjustable bias supplies can be switched for eitherpositive or negative output ... up to 15 V at 10 mA.of any individual marker for fast simple trap alignment and FM tuneradjustment.produces stable, linear sweep signals that cover the five most used fre-quency ranges.switchable Retrace Blanking enables accurate Phase Control adjustment.Just switch on Retrace Blanking fcr convenient zero output base line.Trace Reverse function permits cis3lay of markers in proper sequence.for quick. easy set-up changes.

Modulation

New Built -In BiasSupplies

400 Hz Modulated OrCW Output

Proven Saturable ReactorCircuitry

Complete ScopeMatching Controls

Quick -Disconnect BNCConnectors

Complete With AllProbes, Test Leads &Terminated Cables

Compare The New Heathkit IG-57A With All Others ... you get more useable features,better performance, more versatility per dollar with the IG-57A. Order your IG-57Anow ... and keep up to 5260 in your pocket.

NEWFREE 1910 CATALOG!Now with more kits, more color. Please send model (s)Fully describes these along with ' Please send FREE Heathkit Catalog. J Please send Credit Application.over 300 kits for stereo/hi-ft.color TV, electronic organs, gun- Nametar amplifiers, amateur radio,marine, educational, CB, home Address _8 hobby. Mail coupon or writeHeath Company. Benton Harbor, City State Zip

Michigan 49022. L.Mail order prices; F.O.B. factory. Prices 8. specifications subjec: to change without notice.

..includes terminated RF cable viith built-in DC blocking capacitor ...Demodulator Probe for envelope detection in color circuits . .. shieldedScope Vertical lead ... shielded Clip Lead cable ... Scope Horizontal lead... two Bias Leads.

How -To -Use the famous Heathkit manual includes a comprehensive, well -illustratedApplications Section that shows you how to align TV IF, Traps and Color 26 pages of Instructions andBandpass ... how to do IF & RF Video Sweep Alignment, VHF Tuner Illustrations - show you ex -checking, FM Tuner Tracking & IF alignment. actly how to use your IG-57A

for greater efficiency, greaterprofit.

All Cables. Leads. & Probes areincluded. Nothing extra to buy.

]

HEATH COMPANY, Dept. 24.2 - 111111CMCCOBenton Harbor, Michigan 49022 a Schlumbefger company

Enclosed is 1 . plus shipp.ng.

TE-214

FEBRUARY 1970for 1110111 details circle 118 on Reader Service Card

59

Electronic Circuit DesignHandbook RCA Color TV Service Manual

TV Troubleshooter's Handbook-New 2nd Edition

New Third Edition-Abrand-new, enlargededition of the ever pop-ular circuit designer's"cookbook," now con-taining over 600 provencircuits, for all types offunctions, selected fromthousands on the basisof originality and prac-tical application. Nowyou can have, at yourfingertips, this careful-ly -planned referencesource of tried and

tested circuits. Selected from thousands sub-mitted by distinguished engineers, these"thought -starters" are a collection of originalcircuits selected on the basis of their useful-ness. This detailed compilation of practical de-sign data is the answer to the need for an or-ganized gathering of proved circuits . . bothbasic and advanced designs that can easilyserve as stepping stones to almost any kindof circuit you might want to build. 384 pps.,19 big sections, over 600 illus., 8%" x 11".List Price S17.95 Order No. T-101

How to Use Signal Generators ...in Radio, Color TV, Hi-Fi Servicing

How to use

Signal GeneratorsIn servicing

RadioTelevisionHi-FiColor TV

GIANT "2 -Volumes -in -One" coverage- ALLthe know-how requiredto use any type of sig-nal generator in yourtroubleshooting work.Covers the use of RF,audio, sweep, marker,stereo FM, keyed rain-bow, NTSC, and videogenerators of all types,and is devoted strictlyto signal generatorsused in service shops;written specifically to

provide guidance in the use of such equipmentfor troubleshooting and aligning all types ofhome -entertainment receivers. A variety oftest procedures, using specified generators asthe basic tool, are clearly detailed in step-by-step form. Shows how the various instrumentswork, and how to test and calibrate your owninstruments. 240 pos., 182 illus., 16 chapters.List Price 58.95 Order No. 274

Handbook of SemiconductorCircuits

Contains 124 examplesof standard transistorcircuits, complete withoperational data foramplifiers, oscillators,logic and switching cir-cuits, power supplies,and various nonlinearcircuits. The broadrange of circuits includ-ed were selected on thebasis of application andpracticality. A designphilosophy section is

included with each group of circuits, therebyproviding a basis for understanding circuitsother than those selected as examples. This isnot a handbook of "preferred" circuits, butrather a collection of practical circuits whichhave wide application and exemplifying goodengineering design. Each circuit descriptionincludes data concerning any unique design oroperational data, along with schematic dia-grams. Hundreds of illustrations and diagrams.448 pps., 6" x 9". Hardbound.List Price $8.95 Order No. G-30

A brand-new full sizemanual, covering 23RCA Color chassis. In-cludes complete sche-matic diagrams for 12chassis, from the CTC-12 to the CTC40 all -transistor model. Herein one compact, handymanual is everythingyou need to quickly andcompetently repair anyRCA color set-fromthe CTC12 to the 1969all -transistor CTC40.

Encompasses both general and specific trouble-shooting data applicable to all RCA chassis.The text delves into each section (Video, chro-ma, vertical, horizontal, etc.), and points outspecific problems as well as general servicingprocedures. Troubleshooting tips on each chas-sis, including circuit changes and factory mod-ifications, are covered. While this material isrelated directly to RCA sets, much of it is ap-plicable to other sets patterned after RCA de-signs. 176 pos., 81F, x 11, plus 36 -page sche-matic foldout section. Over 175 illus.List Price $7.95 Order No. 496

Modern ElectronicTroubleshooting

MODERN ELECTRONIC

TROUBLESHOOTING

A down-to-earth hand-book that deals withtoday's electronic ser-vicing problems on apractical level, usingmodern test instrumentsand advanced trouble-shooting procedures tocope with the specialproblems created byprinted boards and sol-id-state circuitry. It ishard to conceive of abook that encompassesmonochrome and color

TV, multiband radio receivers, hi-fi equipment,tape recorders, two-way communicationsequipment, and test instruments for servicingall this equipment. Yet this book does! By get-ting right to the subject of how to service theequipment without the usual wordy theoreticaldiscussions of how the circuits work. An all-inclusive servicing guidebook service techni-cians have been asking for. 256 pps., over 100illus., 5 big sections, 24 chapters.List Price $7.95 Order No. 474

The Oscilloscope

An all -new revised thirdedition of the classicwork on understandingand using oscilloscopes.Completely expandedand updated to includetriggered sweeps, dual -trace scopes, electronicswitches for multi -waveform displays, DC -to -DC supplies, DC -to -AC inverters, and DC -to -DC converters, thisbrand-new book is rightup-to-date. Revised to

include the latest information in keeping withtechnology. It is a virtual handbook on thesubject, explaining scope operation from thesimplest to the most intricate uses. Beginningwhere the scope manual stops, the author cov-ers basic waveforms (DC, sine, sawtooth,trapezoid, and pulse) clearly detailing theirgeneric characteristics and how they are in-terpreted in oscillography. 256 pps., over 179illus., 8 chapters.List Price $7.95 Order No. 498

A completely updated.quick -reference sourcefor scores of tried -and -tested solutions to"tough -dog" TV trou-bles. This detailed com-pilation of practicalhelp is the answer tothe need for a well -or-ganized file of proventroubles and cures, fieldfactory changes, newand unusual circuit,and descriptions of hos,they work, etc. This

brand-new edition represents the only knownup-to-date digest of specific TV troubles andcures, for both color and monochrome sets, upto and including 1969 models. Every majorbrand is included, from Admiral to Zenith, asare such "off" brands as Gamble Skogmo,l'ackard Bell, and Montgomery Ward. Alltroubles are categorized by make and model.Included in the color TV section are hints fortroubleshooting chroma circuits, making ad-justments, etc. 288 pps., over 150 illus.List Price 57.95 Order No. 521

Pinpoint Transistor Troublesin 12 Minutes

A giant of a book 495pages . . a virtual li-brary of practical dataof value to everyonewho works with tran-sistor circuits. Here isa unique servicing textyou can put to immedi-ate use, whether yourinterests are orientedtoward home -entertain-ment or industrial typeequipment. Organ izedso that needed infor-mation can be located

quickly and easily. A quick -reference tabletells you exactly where to find appropriatetrouble -shooting charts and service proceduresfor practically every type of transistorized de-vice. In all, nearly 100 different types ofequipment are categorized under general head-ings such as amplifiers, radio receivers, radiotransmitters, power supplies, test instruments,and special equipment. 495 pps., 243 illus. 78tables, 10 sections. 5,.,"List Price $7.95 Order No. 430

Semiconductors From A to Z

Here it is-everythingyou need to know aboutsemiconductors - frombasic diodes and tran-sistors to FETs, MOSFETs, tunnel diodes,integrated circuits, var-leaps, photoFETs, light-sensitive and light -emissive devices, in-candescent and lumi-nescent optic -electroniccircuits, unijunctiontransistors, field-effect

diodes. SCR and zener diodes, etc. Explainshow these various devices work and how theyare used, with descriptions of all the commonand unique circuits used in modern semicon-ductor technology. Attention is given to inte-grated circuit applications - variable -currentand constant -current sources, unbalanced dif-ferential amplifiers, IC applications in FM andTV receivers, TV sound circuits, discriminatorcircuits, and cascade amplifier networks. 272pps., over 300 illus., 26 Chapters.List Price $7.95 Order No. 493

AN EXTRAORDINARY OFFER..BO ELECTRONIC TECHNICIAN/DEALER

An Extraordinary Offerto introduce you to the benefits of Membership in

ELECTRONICS BOOK CLUB

kNY464

for a limited time only you can obtainOFTHESEUNIQUEBOOKSRAO ... with Trial

(Combined List Price $35.85) Cub Membership

yours fnr nnly

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.

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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 $35.85) for only 990 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. 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.

How the Club Works

Forthcoming selections are describedin the FREE monthly Club News.Thus, you are among the first to knowabout, and to own if you desire, sig-nificant new books. You choose onlythe main or alternate selection youwant (or advise if you wish no bookat all) by means of a handy form andreturn envelope enclosed with theNews. As part of your Trial Member-ship, you need purchase as few as fourbooks during the coming 12 months.You would probably buy at least thismany anyway . . . without the sub-stantial savings offered through ClubMembership.

Limited Time Offer!

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 actpromptly, for we've reserved only alimited number of books for new Mem-bers.

To start your Membership on theseattractive terms, simply fill out andmail the postage -paid airmail card to-day. You will receive the three booksof your choice for 10 -day inspection.SEND NO MONEY! If you are notdelighted, return them within 10 days

and your Trial Membership will becancelled without cost or obligation.Electronics Book Club, Blue RidgeSummit, Pa. 17214.

Typical Savings Offered ClubMembers on Recent Selections

101 TV TroublesList Price $7.95; Club Price $4.95

Zenith Color TV Service ManualList Price $7.95; Club Price $4.95

Servicing Electronic OrgansList Price $7.95; Club Price $4.95

Blocher ics Reference Data BookList Price $7.95; Club Price $4.95

Digital Computer AnalysisList Price 310.95, Club Price $7.95

How To Test Almost Everything ElectronicList Price $5.65; Club Price $3.95

How to Use Your YOM. YTYM & ScopeList Price $6.95; Club Price $4.95

Radio Operator's Q & A ManualList Price $8.95; Club Price $7.50

Motorola Color TY Service ManualList Price $7.95; Club Price $4.95

Installing & Servicing Home AudioSystems

List Price $7.95; Club Price $4.95Tap. Recording For Fun & Profit

List Price $7.95; Club Price $4.95Electric Motor Test & Repair

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List Price $8.95; Club Price $5,95Audio Systems Handbook

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List Price $7.95; Club Price $4.95Pinpoint TY Troubles in 10 Minutes

List Price $6.95; Club Price $4.95Easy Way To Service Radios

List Price $6.95; Club Price $3.95Practical Color TY Servicing Techniques

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SEND NO MONEY! Simply fill in and mail postage -paid Airmail card today!

... for more details circle 107 On Reader Service Card

FEBRUARY 1970 63

Clipthecoupons!Present one or more to your participating RCA Test EquipmentDistributor for big discounts on these four instruments duringRCA's big Spring Coupon Carnival. (Only one coupon will beaccepted per instrument.) Do it today. Offer good only betweenFebruary 15th and April 30th, 1970.

I IMII it, 4ii ill 1116 , MI MI 1111 VII El t 1111111111111111 11111111111111111111

Transistor Testerof RCA WT -501A I

;Toward Purchase I m

$10.00II I I1I II I II I II II I

I

I I! I I I II I

57.50

I

I

E Mr. Distributor, please refer to RCA1970 Carnival announcement. Void

IIII where prohibited, taxed, or restricted.I. Cash value 1/204. Offer expiresI April 30, 1970.

Toward Purchaseof RCA WT -509APicture Tube Tester

I Mr. Distributor, please refer to RCA I 1970 Carnival announcement. Void II where prohibited, taxed, or restricted. ' Cash value 1/204. Offer expiresApril 30, 1970.

III MIMI NI = IN NI 1110 MI 1111 Ina Iii .acst mil MI 1111 NI NI Ell 11111 NI II11..1.11 In MI IM NI IN all NS MI MI I 'I '7144 111111 IM = MON MI 1111 al In 111111

$ IF Toward Purchase I

I II $20.00of RCA WR-99A .Crystal Calibrated Marker Generator I

I7.50 Senior VoltOhmyst

Toward Purchaseof RCA WV -98C

6 rA

it I

111 1

1 le gi

gI c== I111 1 ..... : I

til._.I I IMr. Distributor, please refer to RCA I I Mr. Distributor, please refer to RCA I1970 Carnival announcement. Void . 1970 Carnival announcement. Void .where prohibited, taxed, or restricted. wnere prohibited, taxed, or restricted.Cash value 1/20ii. Offer expires Cash value 1/204. Offer expiresApril 30, 1970. I I April 30, 1970.

INIIIIMIIMINII___1110_1MIIMI INIIIIIIIIIMIIMIIMIIMIIIIMUNIIIIIIIIMINIII

Look to RCA for instruments to test/measure/view/monitor/generate

RCA Electronic Components, Harrison, N. J. 07029

DEALER SHOWCASE

continued from page 58

na necessary for broadcast bandreception; it eliminates the needfor an additional antenna to receive

local stations and distant cities. Onregular short wave bands, the trans-former acts as a balun to providebalanced receiver input. Mosley.

ZOOM LENS 708Camera operator adjustszoom and focus from rear of camera

A zoom lens which can be con-trolled from the rear of a viewfind-er camera is introduced. Designat-

ed Model RC-ZL1, the unit is de-signed for ETV, CATV training andother studio applications. It enablesthe camera operator to adjust bothzoom and focus from the rear of theviewfinder camera while he watch-es the monitor. The zoom lens hasa focal length adjustable from 22.5mmto 90mm, 15 hand coated lens ele-ments and F stop apertures from1.5 to 22 with click stop settings.The rear control is made of anodizedaluminum. Since all moving partsutilize teflon bearings for smooth,easy movement, no lubrication ormaintenance is required. The lenscan easily be attached to any view-finder CCTV camera with two mount-ing screws. It carries a full yearand 100 percent unconditional guar-antee. Price $495. GBC.



WHATYOU DO

FOR ANENCORE. after you have sold your customersthe best home TV towers.

That's one of the big advantages when you stock and sell SpauldingAX Series Home TV Towers. You're offering a tower in which they'llnot only see the quality, which is apparent, but they'll also see thetrouble -free performance they are looking for.

The Spaulding AX Home TV Tower is designed for quick economicalinstallation . . . and is all -steel, galvanized and all riveted constructionwith no welds to rust.

The AX 48' Home TV Tower package only requires 2 sq. ft. of floorspace . . . the AX series packages are available in heights up to 64'.Package includes base stubs, hardware, mast and mast kit.

The Spaulding AX Series Tower is a self-supporting tower andis extremely rigid under most erection situations. The higherthe tower goes, the greater the strength at the base. The windresistance at the top decreases with height. The "tapering"effect adds to the attractiveness of the tower.

Get specifications on this complete tower package, and profitin two ways-bigger sales and greater goodwill from yourcustomers.

ROHN - SPAULDING, INC.Poona Illinois B rmingharn. Alabama Frankfort, Indiana

. for more details circle 135 on Reader Service Card

FEBRUARY 1970 65

simplest v. -

top

quality

modular

amplifier

system

NEWCOMBTOP QUALITY CUSTOM K

.sQQQQ0G.,Newcomb's finest, the Custom KSeries is the climax of 30 yearsdevoted to developing and producingthe very best public address ampli-fiers. You quickly and simply get thecombination of channels and poweryou need. A power output module isdropped into either a front-end orbooster chassis. Two electrical plug-in connections; no soldering. Put acover over the top or insert thechassis in a rack mount. You canplug in a transistorized VU meteraccessory which has a sensitivitycontrol and monitor jack for crystalheadphones. The 4 -channel modelshave provisions for a remote controlaccessory. There are 3 power ampli-fier modules: 40, 60, and 125 watts,and a power supply when you wantto use a front end as a mixer -preamplifier only. There are threepreamplifier modules: 3, 4, and 5channels, and a chassis for makinga booster amplifier out of any of theoutput modules. All in all, only 14components permit 70 combinations.Performance is superb. Frequencyresponse is 1 db 20-20,000 cps;distortion is extremely low. CustomK amplifiers run remarkably cool.Easy -to -trace, easy -to -service vacuumtube construction is used through-out. Colors are soft shades ofgray -green. Write for Catalog K-15.

NEWCOMB AUDIO PRODUCTS CO., Dept. 11.2

12881 Bradley Ave.Sylmar, California 91342

DEALER SHOWCASE

TOOLS 709Everything storedin upright position

Introduced is the Tool -Mate whichsolves the problems of storing and carry-ing both hand tools and small parts.

It contains 39 different tool holdingslots; two jumbo storage wells for stor-ing large items, hammers, flashlights,etc.; four dust -free drawers for stor-ing small parts, nails, screws, nuts,bolts, etc. Everything is stored in anupright, easy -to -use, easy -to -find po-sition plus it has a large sturdy carry-ing handle. The unit measures 11 1/2in.high by 14in. long by 7in. wide and coloris beige and brown. The price is $5.35.Whicon.

CAPACITORS 710Low capacitancechange over temperature range

Deltafilm LP88 Metallized Poly -carbonate -Film Capacitors in 50 and200wvdc ratings for design engi-

neers is introduced. The capacitorsare designed to provide the advan-tages of metallized polycarbonate-film within smaller case sizes thanmolded or metal -encased tubularsof comparable ratings. Highly sta-ble, these capacitors exhibit lessthan four percent capacitance changeover their entire operating tempera-ture range. A feature of the capaci-tor is "Fuz-ion Sealed" construction.A heat -shrinkable plastic case is

fused to epoxy to insure maximumseal efficiency. The case is noncon-ductive, fungus -proof, corrosion -proof,and humidity resistant. The mini-mal effects of temperature and thelow -power -factor of polycarbonatefilm make the capacitors well suit-ed for ac and RF applications aswell as for dc usage. Operating andstorage temperature range is -55Cto +125C without voltage derat-ing. The capacitors are availablein 50 and 200vdc ratings, with ca-pacitance values ranging from .010to 50µf. Sprague.

TAPE ERASER 711No electric currentis required

Introduced is the Voice -Master MX -

500 Erase-O-Matic which erases allprevious recordings on Memocord,Philips type C30 and C60, Norelco85, Mini Memo and other magnetic

tape cassettes. The unit is service -free and guaranteed indefinitely. Re-quiring no electric current, it maybe used anywhere and is ideally suitedto clearing recordings for securityreasons or prior to re -use. The unitmeasures 3-3/4 x 4 x 2in. Audio Ap-plications.

MOBILE ANTENNA 712Beam direction can be changedas desired

Directional gain at 27MHz and elec-tronic beam control in a mobile citi-zens two-way radio antenna systemare two radical developments featuredin a new class of mobile antenna sys-tems introduced. The new systems,designated "Mobile Scanner," corn -

prise a matched pair of 50/1, base -loaded mobile antennas inter -connectedthrough a dash -mounted control boxsimilar in function to the A/S ScannerBase Station. Employing a three-posi-

. for more

66

details circle 126 on Reader Service Card


Now theChromacolor revolution

comes toreplacement tubes too!

Now you can install Zenith's patented Chromacolorpicture tube that outcolors, outbrightens, outcontrasts and outdetails

every other 23" diag. color picture tube.

With a full 2-year warranty!After years of pioneering researchand development, Zenith has per-fected a color TV picture tube differ-ent than any other on the market. Sorevolutionary that it outcolors, out -brightens, outcontrasts and outde-tails every other 23" diag. color tube.And it's a Zenith exclusive-coveredby U.S. Patent No. 3,146,368.

Before Chromacolor, every giant -screen color picture was made up oftiny dots on a gray background.

But Zenith made the dots smaller,surrounded them with jet black and,for the first time, fully illuminatedevery dot. Result: the brightest,sharpest picture tube in giant -screencolor TV.

The Zenith Chromacolor tube willreadily replace the 23" diag. tube inalmost any TV, whatever brand. And,unlike most replacement tubes, it'swarranted for two full years.

A A A A AV YA A A A

y

Magnified drawing of Magnified drawing ofordinary color TV screen Zenith Chromacolorbefore Chromacolor TV screen

Order the Zenith Chromacolor picture tune from your Zenith distributorfor your next installation. And putyour customer in a better light.

At Zerith, the quality goes in beforethe name goes on.

TWO-YEAR WARRANTYZenith Radio Corporation warrantsthe replacement CHROMACOLORpicture tube to be free from defectsin material arising from normal us-age for two years from date of orig-inal consumer purchase. Warrantycovers replacement or repair of pic-ture tjbe, through any authorizedZenith dealer; transportation, laborand service charges are the obliga-tion of the owner.

Simulated TV picture

ONLY ZENITH HAS IT

FEBRUARY 1970 67

DEALER SHOWCASE

tion switch, the radiated or receivedsignal is fed through the dividing cir-cuitry to produce a highly directionalpattern higher forward, rearward or si-multaneously to the sides of the ve-hicles. In the "forward" positions,directional gain is reportedly 2.0dBwhile attenuation of unwanted sig-nals and interference is 17dB front -to -side. "Rear" gain is slightly greater-2.5dB. "Sideward" gain is 1.0dB eachdirection if whips are center -mounted;

2.0dB may be achieved in one direc-tion with offset mounting, such asright cowl and right rear fender. Mount-ing separation of the two antennasis an optimum of 9ft with a toleranceof 6in. in this spacing acceptable forgain performance. Ideally, the antennashould be centered laterally on thevehicle; diagonal or offset mountingwill produce a corresponding direc-tional offset of the pattern althoughidentical gain will be achieved. Theantenna is available with a choice ofmounts; swivel -type, for cowl or curvedsurface (Model M-230) or deck/roofmount for flat surface (Model M-231).Antenna Specialists.

easy answers to common color complaints

Perma-Powerputs back Color TV Quality!

Puts backbrightnessColor-BritePicture TubeBritenersColor-Brite brings out lostsharpness and details offading color picture tubes.Provides increasedfilament voltage to boostelectron emission, returnsfull contrast and colorquality.MODEL C-501for round tubesDealer Net $5.85

MODEL C-511for rectangular tubesDealer Net 55 85

Puts backblack -and -white

Color-BriteIsolationBritenersNo Boost. Corrects forcathode -to -filament shortcausing loss of black andwhite video drive. Isolatesthe short, restores theblack and whiteinformation that gives thecolor picture its quality.MODEL C-502for round tubesDealer Net $7.25

MODEL C-512for rectangular tubesDealer Net Si 25

Put Back Profit-UsePerma-Power Briteners

Free technical literature on request)

Puts backfull voltageAutomaticVoltageRegulatorAutomatically boostsvoltage 10 volts whenline voltage drops below110 volts. Eliminatesshrinking, loss ofbrightness, loss ofconvergence. Combatspoor line voltageregulation, overloadedcircuits.MODEL D-210for appliancesrated up to 400 wattsDealer Net $14.95

TamarPow/L. COMPANYDivision of Chamberlain Manufacturing Corp.

5740 North Tripp Ave. Chicago, Ill. 60646Phone: (312) 539-7171


STEREO FM RECEIVER 713Frequency response from20 to 30,000Hz

Announced is the KR -70 FM receiv-er which combines a sensitive FM tunerand a 75w amplifier with terminals toaccommodate record player, tape re-

igf fi Ok mime

corder, auxiliary, two pairs of stereospeakers and center channel output.The tuner section features two inte-grated circuit FM IF stages and twoFET four -gang tuning condensers,an FM sensitivity (IHF) of claimed 1.9µv;harmonic distortion of less than 0.8percent; a capture ratio of 2.5db; and FMselectivity of 45db (alternate channel).A new luminous dial, tuning meter andFM stereo indicator are also included.Keyboard controls regulate LOUD-NESS, NOISE FILTER, TAPE MON-ITOR and MODE; and front panel jacksprovide convenient access for stereoheadphones and dubbing/tape record.The silicon power transistor amplifi-er incorporates a power transistor pro-tection circuit to safeguard againsttransistor blowouts. The unit has aclaimed frequency response from 20to 30,000Hz and a power bandwidthof 20 to 30,000Hz. The unit is pricedat $199.95. Kenwood.

TOOL KIT 714Tools mount ontwo removable pallets

A 100 -piece multi -purpose tool kitis announced. Designated JTK-17,the attache" -case kit includes virtuallyevery standard tool required in the

field for maintenance of complex elec-tronic and data processing equipment.Most of the tools are mounted on tworemovable pallets. These pallets holdthe tools securely in an organized man-ner and at the same time present themto the view of the user. The case fea-tures hardwood construction with


llama -grain covering and solid brasshardware. Three roomy compartmentsare provided in the bottom for largetools, a test meter and spare parts. Aspace for service manuals and documentsis provided in the cover. The comple-ment of 100 tools includes 7 regular -slotscrewdrivers, 4 Phillips -type screw-drivers, a jewelers screwdriver set,a hex screwdriver set, a spline screw-driver set and two special-purposescrewdrivers. Seven pairs of pliersare furnished including cutters, chain -nose pliers, instrument pliers, power -track pliers and retaining -ring pliers.Also included in the kit are electronicalignment tools, burnishers, a crimp-ing tool/bolt cutter, feeler gauge, ham-mer, center punch, flashlight, scribe,electrician's knife, dental mirror, nut -driver set, instrument oiler, pin -punchset, stainless rule, scissors, solder-ing iron, solder aid, solder brush, tweez-ers, spring tools, and wire stripper.Wrenches include 4in. and 8in. adjust-able types, an ignition -wrench set,a 1/4in. drive socket set with ratchethandle and a metrictype hex -key set.A Simpson VOM tester is availableas an optional accessory. Kit price$169.00. Jensen.

AM/FM MULTIPLEX 715STEREO RECEIVERMonolithic ICin multiplex section

Introduced is the Model SX-1500TDreceiver with advanced circuitry. AnFET front end ensures sensitive FMreception with four IC's in the IF anda monolithic IC in the multiplex sec -

to -40 410

tion for improved separation. Silicontransistors ensure low -noise musicpower of 180w. Microphone mixingis also a feature of the unit which issupplied with a unidirectional dyna-mic microphone and an on -off switch.A microphone jack on the front paneland an input level adjustment knobprovides mixing. Three speaker out-puts on the rear panel and a five -po-sition speaker selector on the frontpanel give a variety of speaker com-binations, A, B, C,; A plus B; or, Aplus C. The pm -amplifier and the mainamplifiers can be used separately bymeans of a switch on the rear panel.A center channel output on the rearpanel provides the composite left andright signals for a three-dimensionalsystem when another amplifier is con-nected to the center channel output.Price $399.95. Pioneer.

3 GUN SALUTE

Only the Sencore CRT Champion has three gun control. . Just like the color TV set.Only Sencore has automatic color tracking to make yourjob easier.Only Sencore has the simplified instructions in thecover so that you can analyze any color CRT tube inseconds. Just flip the "Color Gun" switch from red togreen to blue (after setting the three G2 controls) andthe CR143 Champion will tell you if the tube hasadequate emission and if it will track in the TV set.Why don't you salute the Sencore Champion today bymarching in and asking your distributor to try one.You won't bring it back because it is 100 percent.

NO. / MANUFACTURER OF ELECTRONIC MAINTENANCE EQUIPMENT

426 SOUTH WESTGATE DRIVE, ADDISON. ILLINOIS 60101. . . for more details circle 138 on Reader Service Card

FEBRUARY 1970 69

DEALER SHOWCASE

STEREO PRE -AMP 716Distortion reportedly less than.01 percent

Introduced is the Model SP -1A pre -amp. The stereo control panel mea-sures 15-5/8in. wide by 5in. high and

the overall depth is 14-1/2in. The panelmounting cutout is 4-1/2in. high by15-1/4in. wide with depth behind thepanel at 14in. Weighing 301b., the unithas a harmonic distortion of report-edly less than .01 percent at 5v RMSoutput 1kHz on either auxiliary ofmag input, gain max., high impedance.The noise and hum are aux: 90dB be-low 2v input and mag: 60dB below10mv input. Maximum output levelis at least 30v RMS 1kHz into highimpedance. Maximum input levels with-out overload is aux: 50v RMS@ lkHzand mag: 750mv RMS @ 1kHz. It ispriced at $750. Peploe.

AMPLIFIER 717Six individual microphoneandlor program inputs

Introduced is the LT -1005, a profes-sional quality amplifier rated at 100w(RMS). The amplifier incorporates

ft h6141.multiple inputs and a number of otherfeatures not available on competitivemodels. The output of the unit isachieved with reportedly less than 1percent distortion (50Hz to 15kHz).Distortion of less than 2 percent (40Hzto 18kHz) can be achieved at levels upto 80w (RMS). Six individual micro-phone and/or program inputs are avail-able and all are transformer balancedand have low impedance. Inputs one,two and three are directly coupled fromtheir respective preamplifiers to thetone amplifier. Input four has a selec-tor switch for conversion to RIAAphono input. Input five is switchablefrom microphone to an auxiliary 10Kunbalanced input. Input six featuresselection of either of two high levellines. Tone controls are a full 15dB

for bass and treble at 50Hz and 15kHzrespectively. Microphone inputs maybe changed to a 10dB controlled roll -off at 30Hz during installation. All in-puts and the master gain can be re-motely controlled through LDR circuitswith remote volume controls. The unithas an automatic protective circuitwhich protects the output stages.McMartin.

CASSETTE PLAYER 718Front loadingis simple and fool -proof

Introduced is the Model 20 stereoautomobile cassette player. Weigh-ing only 7 lb, the player permits up totwo hours of listening. Primary fea-ture is its Insta-Load facility, with a

push -in front loading operation that re-portedly is simple and fool -proof. An-other exclusive feature of the player isits 18w (IHF) music power output. Otherfeatures include automatic cassetteejection, which ejects a cassette whenthe end of the tape has been reached,and then shuts off power to the unit;a program search capability with fast -forward and rewind to permit instantlocation of a selection; complete com-patibility with any prerecorded cas-sette, mono or stereo ; and stereo balance,tone and volume controls. The cassetteplayer is compatible with any type ofautomobile, operating on both nega-tive and positive ground and on any12v electrical system. It comes com-plete with car mounting bracket andhardware. Specifications: frequen-cy response -50Hz to 10,000Hz @ 1 7/8ips; signal -to -noise -ratio -45dB; wowand flutter -0.28%@ 1 7/8ips; head con-figuration -1 quarter track playback;outputs -2 extension speakers (one foreach channel), plug type, pigtail; imped-ance, 3.2f1; dimensions -2 7/8H x 73/16W x 8 1/4in. D. The price is under$119.50. Super Scope.

INTERCOM 719Six separate conversationsat the same time

Introduced is the IE series solid-state intercoms which may be employedin either an all -master system, a sin-gle master -multiple remote configu-ration or a master system which oper-ates one or two non -private remotes.

The IE-13 masters have 12 and 6 sta-tion -selector buttons, respectively,all of the non -interlock type whichenable the master station to call sev-

eral or all of the stations simultane-ously. This is a convenient means fora conference call. In the all -mastersystem as many as six separate con-versations may be held at the sametime. By adding the company's TBR-1 relay accessory to an IE system,paging through any PA system is pos-sible with hands -free response fromloudspeaker or horn. The RIE-1 re-mote may function either non -privatelyor privately i.e., when the privacyswitch is on, the remote cannot bemonitored. IE systems are operatedfrom a 120vac power source, 50/60Hz,but can easily be adapted for a 12vde battery supply. Bogen.

PROMOTION DISPLAY 720Scale modeltrucks offered

True to scale models of cargo -trail-er trucks that are seen every dayon the highways are being offered

to distributors for resale to theircustomers. The toy replicas, nor-mally priced at $3.98 are being of-fered by distributors at a special$2.49 price. Packaged in a displaycarton holding 24 pieces, each truckis in a clear plastic front box allow-ing the potential buyer to readilysee the handsome toy. The play safe


toy is designed from drawings ofan actual vehicle to a scale of 3/16in.equals one foot. It has 40 separateparts of the same materials usedin its real life counterpart. Authen-tic detail, bright true to life colorsand rugged construction add up toa quality toy. Finco.

AMATEUR ANTENNA 72120 meter single -band beam

Announced is the CLASSIC 20,a 20 meter single -band beam anten-na featuring the classic feed sys-

Classic '`20

CL -20

ArmSdrifetat.as.WO M.

tem. The improved electrical bal-ance, "balanced capacitive match-ing," reportedly combines with op-timum spacing to provide maximumgain and increased bandwidth. High -impact insulators, clamping blocks,aluminum tubing and stainless steelhardware are some of the construc-tion features.performance data: Electrical - Band:20 meters. Power Rated: lkw AM/CW;2kw PEP SSB input to the final.Forward Gain: 9.8db compared toreference dipole; 11.9db over iso-tropic source. Front -to -back Ratio:20db. SWR: 1.5/1 or better. Mechani-cal-Number of Elements: 5. Maxi-mum Element Length: 38ft. 1 1/2in.Boom Length: 46ft. Assembled Weight:approx. 139 lb. Mosley.

RADIO 722Four band operationon either ac or dc

A low-priced, all transistorizedtable model broadcast and short -

Model S -120Awave radio receiver

that provides the user with the meansfor literally "tuning in the entireworld" is introduced. The shortwavereception has been boosted up to

200 percent over conventional setsincluding both CW (code) and SSB(single-sideband) due to special ad-vanced circuitry. It can be operatedon 117vac, 50/60Hz power and asan exclusive feature, the unit isequipped with an external powerjack making it possible to operatefrom a battery source. The receiv-er is attractively housed in a com-munications equipment type steelcabinet with full front panel con-trols and a large, easy -to -read, multi-color coded, lighted dial scale markedwith countried broadcasting on shortwave. It is fully transistorized andincludes a number of features. Fre-quency coverage is .54-31MHz infour bands: standard AM broadcast(550-1600kHz); Shortwave Band I

(weather marine and amateur - 2.0-5.0MHz); Shortwave Band II (af-ternoon and evening shortwave re-ception- 4.8-11.5MHz); ShortwaveBand III (all day shortwave moni-toring-11.0-30.0MHz). The frontpanel controls consist of: main tun-ing control; electrical band spreadcontrol; volume power on -off; bandselector; BFO on -off; standby on -

off; receiver/standby. The receiv-er is styled in a light grey color withblack, white and silver trim to fitor match any decor and measures12in. wide by 5 1/2in. high by 5in.deep. Weight is 8 lb. Hallicrafter.

STEREO TAPE DECKS 723Synchronous drive meter assuresprecise speed regulation

Introduced are three high fidelity,reel-to-reel tape decks in the luxuryclass. The new solid-state electronic

41111.1111"

units are designated the Mark Series.Features for all three models includea hysteresis (high torque) synchro-nous drive motor; solid-state electron-ics with integrated circuit preamps;three heads-wide-gap record head,narrow -gap 2 micron playback head anderase head for optimum fidelity and fre-quency response; tape and source moni-toring; flip -up head cover with head po-sitions marked for easy editing, whichprovides easy access to tape heads;built-in head cleaner. Other featuresinclude automatic sound -on -sound re-cording, variable echo control for re -verb effects and cue control for instan-taneous "stop" and "start" operation.Supply and take up tension arms pro-

vide instantaneous startup of the trans-port mechanism and eliminate tapeburble. All Mark Series recorders havethree operating speeds -71/2, 3 3/4 and1 7/Sips-and are equipped with inputsfor microphone and auxiliary and out-puts for line and headphones. The tapedecks may be operated in either a ver-tical or horizontal position and havea reel capacity of 7in. Additional fea-tures include record -indicator lightfor each channel, built-in tape clean-er, automatic tape lifters, automaticstop, stereo headphone jack for per-sonal listening and monitoring, flut-ter filter and dynamic muting. TheMark II (shown in photo) has a frequen-cy response range of 20 to 23,000Hzat 7 1/2ips and a suggested retail priceof less than $230. Concord.

MAGNIFYING SYSTEM 724Full 360deg sweep overan 8sqft area

Introduced is the Stereorama Work/Viewer, a widely used magnifyingsystem which has two new versions,

each with specially engineered light-ing installed as an integral part ofthe instrument. The instrumenthas a piano -convex lens that canbe turned for individual viewingthrough the flat side or for relaxed,distance or group viewing throughthe convex side. The panoramic sus-pension arm provides a full unob-structed 360deg sweep over an 8sqftarea. The viewer has a special fluor-escent lighting built into it. Thiscool -light, glare -free illuminationprovides excellent supporting light,the sort of shadowless illuminationrequired for many work operations.The other viewer has two flood lightsbuilt into it for work operations thatrequire intensive illumination. Eitherflood light can be used alone or bothcan be used at once, and both canbe adjusted to any desired angle.Ednalite Corp.

FEBRUARY 1970 71

graalitan COLORFAXThe material used in this section is selected from informationsupplied through the cooperation of the respective manufac-turers or their agencies.

GENERAL ELECTRIC

Testing the TDR

The TI)1{ is a non-linear resistor whose resistance is afunction of temperature. The heat that influences the TDRcan be externally applied or developed by the current pass-ing through the device. Characteristics of a typical nega-tive coefficient TDR are compared with an ordinary resis-tor in the graph shown.

1101009080

RESISTANCE 70IN 60

OHMS 5°40302010

COMMON RESISTOR

-r-20 40 60 80 100 120 140 CENTIGRADETEMP 68 104 140 176 212 248 284 FAHRENHEIT

TDR's were used initially in filament systems for control-ling warm-up or limiting surges. They were commonly re-ferred to in the past as "glow bars." Currently they are beingused extensively in automatic degaussing circuits and deflec-tion yoke circuits. In degaussing circuits they provide a fad-ing effect which results in a gradually decreasing magneticfield that eliminates undesired magnetism. In deflection cir-cuits they correct for the increased resistance of the windingsas they heat up.

TDR's can usually be checked with an ohmmeter. To test aTDR, connect an ohmmeter to the device and apply a sourceof heat (such as a soldering iron or heat lamp). The resis-tance of the TDR will change as the temperature changes.For low ohmic values, the heating effects of the meter cur-rent will have to be allowed for.

Some of the TDR's currently being used include:EP14X10EU14X147EP14X206EP14X5ES14X213

1000 @25°C3.811@ 25°C1.052M @25°C1200 @ 25°C30000@ 25°C

(C chassis)(C chassis)(G chassis) (H chassis)(G chassis)(TC/T--1 chassis)

25° C is assumed to be normal room temperature and all re-sistance figures are ±25 per cent.

RCA VICTOR

Color TV Receivers-Sound Trap Adjustments

Color television receivers use tuned trap circuits to min-imize or eliminate undesired signals. In most chassis, theseresonant traps serve to attenuate three frequency compo-nents.

The 41.25MHz sound trap reduces the amplitude of theco -channel sound carrier to a point low enough to preventbeats between it and the video carrier.

Another trap (adjacent channel sound) is tuned to 47.25MHz. As its name implies, this trap restricts the bandpass of

the IF system so that the adjacent low -channel sound car-rier will not cause interference.

A third trap, resonant at 4.5MHz, is located at the inputof the video amplifier system in a color receiver. This trapserves to prevent the 4.5MHz sound signal from beatingagainst the 3.58MHz chroma signal. If the two frequenciesare permitted to combine, a 920kHz beat pattern is visibleon the screen of the receiver.

All of the above traps should be checked and/or set dur-

PIX CHROMA

47. 25 MHzADD SND.

41.25 MHzSND.

ing the receiver alignment procedure. Shown in the illus-tration are the positions of the 41.25MHz and 47.2,5MHztrap frequencies on a typical IF response curve. Both trapfrequencies are at the bottom (minimum gain point) on thecurve. The alignment instructions specify that the trapsare to be adjusted for minimum marker response. Thismay (or may not) be easy, depending upon the technician'smethods and skill. At best, good judgement is requiredfor accurate settings.

ffvIt is common practice in many service shops to radiate

the marker signals into the chassis. This system, aside frommaking trap adjustment difficult, can also cause other prob-lems, such as overloading and distortion of the sweep curve.As previously indicated, the trap frequencies are at theminimum gain points in the IF system. Therefore, it is oftendifficult or impossible to see the markers without usingexcessively high levels of marker signal, and risking pos-sible distortion of the sweep curve because of signal over-load. It is also evident that it is difficult to judge the ex-act points of minimum 41.25 and 47.25 response with low


WINEGARD ANNOUNCESTHE EASIEST TO INSTALL

HOME TV OUTLET SYSTEM EVER!AND THE EASIEST TO SELL!

It's the easy to install part that helps make our HomeTV Outlet System easy to sell. If you have your owninstallation men, it's easy for them to install. And it'salmost as easy to install for do-it-yourselfers. Yousee, when we say we thought of everything, wemean everything-including a fully illus-trated installation booklet that shows,

how to install a WinegardHome TV Outlet System-easily ! We've even thought ofpackaging that makes our

System.,- easier to sell. Great -looking, colorful,easy -to -carry -home packaging that containseverything! There's anotherUnder $100. Which is waysystems haven't thought ofthat can be flush mounted,outlet boxes, which we alsolengths of low loss coaxial cable,cable clips . . . four outlet to TV set cords with VHF -UHF band separators . . . our finestquality 82 -channel, solid state booster -coupler with both 75 and 300 ohm inputs . . . and

the illustrated installation'install. And, at less thanNo wonder everybody withsets will want a Winegard

System when they find out what

step-by-step,

on.

reason why our System is easy to sell. The price.under any other system around. And the othereverything. Like four TV/FM ivory wall outlets

or surface mounted with the four low profile ivoryhappen to supply . . . two 35 -foot and two 25 -foot

with connectors already attached . . . 12 adhesive

booklet. Easy to$100, easy to buy.

two or more TVHome TV Outlet

it does. And tomake sure they find out, our System, the H SO -782, will

be nationally advertised. Any more questions? Call your Winegarddistributor, or write for Fact -Finder #289.©Copyright 1970, Winegard Co.

WinegardANTENNA SYSTEMS

Winegard Company 3019-10 Kirkwood Street Burlington, Iowa 52601... for more Midis circle 143 on Reader Service Card

FEBRUARY 1970 73

Only Admiralgives youthe Super-Britecolorpicture tubewith built-incustomersatisfaction.

The exclusiveAdmiral3-year warranty.

Now Admiral offers all new Super-Brite color picture tubeswith the exclusive Admiral 3 -year warranty. This industryexclusive provides your customers with maximum satis-faction.

Every Admiral Super-Brite color picture tube hasAdmiral -engineered thermal compensation for unexcelledcolor purity and the newest phosphors that give your cus-tomers clear, bright, sharp color pictures.

Here's another Admiral exclusive: In model 25SP22(25AP22), our engineers have developed a vacuum de-posited thin -metallic film on the inside of the envelope toassure trouble -free operation and longer life.

Admiral Super-Brite service color picture tubes aren'trebuilts. They're 100% brand new. From Admiral, pro-ducers of more rectangular color picture tube sizes thananybody in the world-the only one with the 3 -year pro-tection you asked for.

AdmiralC:=> Mark of Quality

Admiral Corporation warrants this picture tube to be free from defectsin material or workmanship for 3 years after date of sale to the consumer.Admiral's obligation is limited to supplying a suitable replacement picturetube. This warranty is effective if the picture tube is registered withAdmiral within 10 days after date of sale to the consumer.

.. for more details circle 101 on Reader Service Card

COLOR FAX

level marker signals when making sound trap adjustments.The situation can be greatly improved by using the post

detection marker insertion system in which the markersignals are not passed through the chassis and thus not affect-ed by IF gain. This is easily accomplished by using an ex-ternal marker adder. Some recently manufactured align-ment equipment includes built-in provisions for post de-tection marker insertion. Although this system representsan improvement over radiating markers into the chassis,trap adjustment still depends upon correctly interpretingthe minimum response points on the curve-often difficultfor maximum accuracy.

Modulated CW Method

There is a simple and positive method for setting trapsthat overcomes the limitations of the radiated marker sys-tem, does not require a marker adder, or rely entirely up -

O 0

MIXER PAD

MIXER TP

TUNER

DET. PROBE

LINK TP

IF STAGES

10K

4 5MHzTREAP CHROMADTPRSE7----

DET. TP

VIDEO AMP

41.25 MHz it 4725 MHz 41. 2 5MHz t4.5 MHz

on the judgement of the technician. This system uses thecalibrated marker generator to supply a modulated signal(at the trap frequency) to the input of the television receiv-er. The normal detector probe (or video detector in thereceiver) with an oscilloscope for visible indication, actsas a null detector. Trap setting then becomes simply a mat-ter of adjusting the trap while observing the scope patternfor minimum response. This is easy because the "high Q"nature of these traps makes the null quite sudden and sharpas seen with the modulated signal. With the trap nulled,it has been adjusted to the exact frequency required.

This trap adjustment procedure is accomplished by dis-connecting the mixer grid pad from the sweep generator

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74ELECTRONIC TECHNICIAN/DEALER

and connecting it to the output of the marker generator.The technician should next adjust the attenuator switch-es on the front panel of the marker generator to obtain alow amplitude signal on the lowest input voltage range ofthe oscilloscope. A suitable level is indicated when the mod-ulated sine wave is undistorted-both top and bottom aresymmetrical. (Some experimentation should be attemp-ted on a chassis known to be aligned properly before thisprocedure is adopted.) When the signal (41.25MHz or 47.25MHz with 600Hz modulation) is applied, a sine -wave patternwill appear on the scope. The trap can then be adjustedfor minimum scope response.

The reader should realize that the accuracy of trap ad-justment depends on supplying accurate, calibrated, testfrequencies. Therefore, it is advisable to review the mark-er generator frequency calibration instructions suppliedwith the instrument before using this procedure.

4.5MHz TrapThe remaining trap (4.5MHz) is located at the input of

the video amplifier. This trap is adjusted somewhat dif-ferently, in that we are now dealing with video frequencysignals. Also, the procedure will vary somewhat from chassis - to - chassis.

To adjust the 4.5MHz trap, service data will specify con-necting the oscilloscope to a particular point in the chromacircuit-usually bandpass amplifier. Once correct inputand output conditions are established as per instructionin the service data, the 4.5MHz trap is adjusted for a min-imum 600Hz response on the oscilloscope.

Although the foregoing procedures involve changingconnections of test equipment, and may on the surface seemsomewhat cumbersome, the technician will find (after alittle practice) that traps are quickly and easily adjustedwith no element of guesswork involved.

N. . .pr eviouslv Amph.

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simplifies soldering

NewTEMPMATIC'TemperatureControlled Soldering Tool

Combines all the advantages of a pencil iron,a fast heating soldering gun, and tiptemperature control. Exclusive removablePowerhead contains Weller's temperaturecontrol system. Protects components even inthe most delicate work situations. Tool weighs7 oz. Use it for light or heavy duty soldering.Model GT-7A has 700°F. 316" chisel pointPowerhead. Model GT-6B has 600°F. Ye"conical point Powerhead.

The originalDual Heat Guns

Fast leafing. Long -life tips. Exclusivetrigger -controlled dual heat. Highsoldering efficiency. Spotlight. 3models from 100/140 watts to240/325 watts.

Dependable MARKSMAN IronsThey outperform other ircns of their size and weight. Long -reach stainless steel barrels. Replaceable tips. 5 modelsfrom 25 watts to 175 watts.

zamiteee_i==

Weller 25 -watt Iron for intricate workIndustrial rated. Weighs 13/4 oz.Delivers tip temperatures to

6i)860°F. Cool, impact -resistanthandle. Model W -PS with 1A6" tip.

WELLER ELECTRIC CORP., Easton, Pa.WORLD LEADER IN SOLDERIfIG TOOLS


FEBRUARY 1970

. for more details circ e 142 on Reader Service Card

75

NEWS

OF THE INDUSTRY

GE Introduces New HorizontalOutput Tube for Color TV

A breakthrough-in the design of horizontal output tubesfor color TV receivers is the 6LW6 by General Electric'sTube Dept. Rated at 40w plate dissipation, the 6LW6 willpermit using picture tubes with increased deflection an-gles, making possible smaller-approximately 15 percentthinner -color TV cabinetry. Slated to go into productionin early 1970, GE's 6LW6 will provide a horizontal deflec-tion tube with enough reserve to reliably scan the new 110deg color tubes. The 6LW6 is GE's first receiving tube madein a T-14 bulb.

Enthusiastic Response Greets New Show Plans114 companies have already enrolled as exhibitors in the

1970 NEW Show/Conference, the national gathering ofelectronic distributors that will take place at the HiltonHotel in Chicago, May 11, 12 and 13, 1970.

Participating companies have to date purchased 155 booths.Twelve firms which require no product displays but wishan opportunity to confer with their distributors, have elec-ted to participate in conference suites.

The special "Show within the Show," Industribution Cen-ter, will cater to manufacturers and distributors whoseinterests are primarily industrial. Industribution Center,on the fifth floor of the Hilton Hotel, has already enrolled14 companies. This "Show within the Show" will allow indus-trial -oriented manufacturers to see their distributors andprospective distributors in an environment which screensout distractions and interruptions from those primarilyinterested in the consumer electronics aftermarket or inthe audio field.

Kenneth C. Prince, Executive Vice President of the sponsoring Electronic Industry Show Corporation, said that thecompanies include eight which have never before exhib-ited in an EISC event. He also indicated that more thanhalf the companies which participated in the 1969 Showin Las Vegas have confirmed their plans to repeat next Mayin Chicago.

Complete exhibitor information about the 1970 NEWShow Conference is available from the Show office, 100 SouthWacker Drive, Chicago, Illinois 60606.

Varactor Diode DevelopedA new series of low-cost varactor diodes with high Q,

linear response and a spread of five to one at 3 to 30 voltshas been developed by the Kollstan facility of StandardKollsman Industries for use in solid-state television tun-ers, instrumentation, remote frequency controls and micro-wave circuits.

The unique junction in the Kollstan varactors provideslinear capacitance versus voltage characteristics, eliminat-ing the need for matching diodes where several are used,or where repeatability from circuit to circuit is required.Elimination of matching simplifies equipment design, re-duces production costs and eases service and maintenance.

The Kollstan diodes are completely passivated devicesencased in specially formulated plastic housings. They pro-vide superior mechanical shock resistance through solidjunction -to -lead construction, and low series inductanceand simple mounting through the use of gold plated axialleads.

Specification sheets on the new variable capacitance di-

odes are available from Kollstan Semiconductors, StandardKollsman Industries, 111 New York Avenue, Westbury,N. Y. 11590.

USA Standard Requirements forElectronic Analog Voltmeters

The electric power industry, the electronics industry,testing laboratories, and radio and television servicemenare among the groups who will benefit from use of the firstcomplete set of requirements for electronic analog voltme-ters, Draft USA Standard C39.7, released by the StandardsInstitute for a one-year period of trial use and criticism.

Covered in the standard are quantitative requirementsfor conformance with a given accuracy rating; both ac anddc voltmeter specifications which manufacturers shouldfurnish to users; and testing and calibration procedures.An appendix describes how to determine total error on thecalibration tests given.

The standard also classifies electronic voltmeters accord-ing to operating principles, accuracy ratings, responses,inputs and power supplies.

Single copies of Draft USA Standard Requirements forElectronic Analog Voltmeters, C39.7, are available fromthe Standards Institute at $2.75.

The draft was developed by a subcommittee of Commit-tee C39, operating under the procedures of the StandardsInstitute, which is the national clearinghouse and coordi-nating agency for voluntary standardization in the UnitedStates. USASI is changing its name to American Nation-al Standards Institute, Inc. The change became effectiveon October 6, 1969, when the institute moved to new head-quarters at 1430 Broadway, New York, N. Y. 10018. Whenthe name change went into effect the Institute alsochanged the designation of the standards it approves from"USA Standard" to "American National Standard."

The Standards Institute approves a standard when itreceives evidence that all national groups concerned withthe application of the standard have been given an oppor-tunity to cooperate in its development and these interestshave reached substantial agreement on its provisions. TheInstitute also represents United States interests in inter-national standardization work carried out by such non -treatyorganizations as the International Organization for Stan-dardization and the International Electrotechnical Com-mission.

Instrumentation Fair GoesWest in 1970

Instrumentation Fair, often described as an IEEE Showor WESCON, devoted exclusively to electronic instrumen-tation and related products and services, has gone to theWest Coast in 1970. Enthusiastic manufacturer, rep andattendee reception to the show, which ran very success-fully in Washington, D.C., in 1968 and 1969 has pointed upthe need for a similar show in California.

Instrumentation Fair West will run February 18 and 19,1970 at the International Hotel in Los Angeles and February25 and 26, 1970 at the San Mateo Fairgrounds (just southof San Francisco). It is expected to draw over 3000 atten-dees and over 100 exhibitors to each location.

Product categories to be featured in InstrumentationFair West are: measurement - computation - data acqui-sition - calibration - control - communication - data trans-mission - maintenance services for all of the above categor-ies.

Exhibits and exhibitor workshops will be directed towardkey prospects who specify, purchase and use: small com-puters - peripheral equipment - laboratory test equipment- microwave devices - lasers - calibration and standards -


data systems - sophisticated systems components - pro-duction test equipment.

Many exhibitors will conduct one hour application work-shops in which their new products or new product appli-cations will be presented in one hour sessions to select groupsof up to 50 people.

Ultimate aim of Instrumentation Fair West is to kick-off an Instrumentation Week in California where manufac-turers, regional sales offices, independent reps and custom-ers can get together.

A no host cocktail party for manufacturers, salesmen,reps and customers will be held on the final evening of eachshow.

NAB Objects to Proposed FCC RulePermitting Coded Information on TV

The National Assn. of Broadcasters has asked the Fed-eral Communications Commission not to adopt a rule whichwould permit the transmission of coded identifying infor-mation on video tape and film.

The commission has been petitioned to allow such trans-mission by the International Digisonics Corp. (IDC), whichstressed the need for a monitoring service that could pro-vide verification of the number of times a TV program orcommercial has been broadcast.

In a filing, NAB objected that such a rule is not in thepublic interest, that it would have a deterring effect on futurerefinement and development of television receivers, andthat consideration of any coded monitoring system shouldbe considered along with other test devices now under studyand review.

Although IDC said the information would be limited toa small portion of the picture tube which is not visible tothe viewer, NAB said that in numerous instances, especial -

REBUILDYOUR OWN

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With Lakeside Industries precision equipment, you can rebuild any picture tube!

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LAKESIDE INDUSTRIES5234 N. Clark St.Chicago, III. 60640Phone: 312-2713399

Free demonstration appointmentSend me more information

Name

Address

City State

. . . for more details circle 121 on Reader Service CordFEBRUARY 1970

ly on many old receivers, the picture barely occupies thevisible picture tube area and the coded transmissions wouldbe visible.

Also, NAB said, efforts are underway to develop a pic-ture tube which would substantially utilize the entire trans-mitted picture. The adoption of a technique which is depend-ent upon the use of the masked corner areas could deterfuture development of picture tubes.

In addition, such a monitoring system "has inherent opera-tional shortcomings which could seriously affect the accu-racy of the desired information."

Therefore, NAB feels that individual station operatingtechniques and procedures could have an adverse effectupon the accuracy of the proposed system which could re-sult in controversy as to the reliability of the coded trans-missions.

Technical ClinicsFor A -V Servicemen

A series of tape recorder technical clinics for educationalaudiovisual servicemen has been initiated by 3M/Wollen-sak.

The first clinics were conducted recently in San Fran-cisco and Los Angeles with the joint sponsorship of Photoand Sound Co., San Francisco.

"The clinics are designed to acquaint school A -V equipmentservicemen with maintenance and repair procedures onthe new line of Wollensak audiovisual recorders. Instruc-tion was given in the servicing of earlier models, many ofwhich are still in use after 10 or more years of service," saidW. F. Jensen, marketing manager for Wollensak educa-tional products.

The clinics are conducted by representatives of the Wollen-sak technical service group.

Introducingthe world's only $339

triggered scope.

Before you say you don'tneed a triggered scope,look what's happening toTV servicing. tubes areout, transistors and IC'sare in.

With tubes you couldplay hit-or-miss, knowingthe tube would take theoverload. Try the samething now, and good-byetransistors.

For new -era circuitry,Leader introduces a new -era troubleshooter. Atriggered scope, just likethe ones the TV designersuse.

Now the wave shape islocked in and continuouslydisplayed. Now you canlook at a waveform con-taining high and lowfrequency components.Now you can determinevoltage directly andinstantly.

Before you say $339 is alot of bread, look what itbuys: Leader's LBO -5015 -inch triggered scope,with a bandwidth of DC to10MHz and a solid statepackage.

Going like hotcakes atyour Leader distributor.

Seeing is believing.LEADER INSTRUMENTS

37-27 27th Street, Long Island City, N Y !1101,

. for mon dank &eh 122 or Reader Service Card

77

NEW PRODUCTSFor additional information on products described in this section, circle thenumbers on Reader Service Card. Requests will be handled promptly.

FIELD STRENGTH METER 725Shielding attained byuse of feed-thrus

Introduced is the Model FM -2 fieldstrength meter, the ideal instrumentfor installation and maintenance on

all systems. New features includea silicone treated fiber glass P/C board.Circuit design employs the latest insilicon semiconductor and transistortechnology to assure stability andreliability. Complete shielding is at-tained by employing feed-thru capac-itors. Improved tuning, easy to readlog scale, switchable dial lamps, newbattery clips and battery saver arefeatured. Furnished with padded sad-dle leather carrying case and priced at$329. Video Instruments.

MULTITESTER 726Special scalespermit semiconductor testing

Introduced are the TR series multi -testers performing all of the conven-tional functions of standard VOM's

and feature simplified semiconduc-tor checking capabilities. Simplified,

easy to read scales indicate currentand voltage applied to a transistorduring test. The maximum currentapplied to a transistor for a given re-sistance range is printed above thefunction switch, providing a referencethat permits test of the semiconduc-tor within the working limits of theunit being checked. Combined withthe special scales this provides a quickeasy indication of the condition of thetransistor. The Model 501ZTRD Multi -tester also has 22 ranges, a single func-tion and selector switch, polarity re-versing switch and is equipped witha high voltage probe. All instrumentsare backed by a two-year warranty.Sanwa.

AUDIO FREQUENCY 727OSCILLATOR

Frequency coverage of 13Hz to30kHz in six ranges

An AF oscillator with an outputthat simulates a typical high -qualityphono cartridge with a sensitivity

of 2mv/cm/sec is introduced. The out-put, with a maximum of 10mv at 1kHz,conforms to the fine groove record-ing characteristic of the RIAA (Re-cording Industries of America Assn.).This reportedly enables the equal-ization response of a phono input tobe checked quickly and easily with-out using auxiliary equipment or mak-ing long calculations. In the range30Hz to 18kHz, the characteristic ismaintained at ±0.5dB. The ModelSI453 AF oscillator was developedfor the routine testing or developmentof audio frequency apparatus, in par-ticular amplifiers and associated equip-ment of a Hi Fi type. It has a frequen-cy coverage of 13Hz to 30kHz in sixranges. Total harmonic distortionis reportedly less than 0.05 percent

at 1kHz. A square wave facility is pro-vided for the checking transient re-sponse and amplifier stability in re-active loads with a rise time of lessthan 0.5p.s. Maximum output is 2vrms and output stability is ±5 per-cent. The oscillator is battery -oper-ated with all internal ferrous compo-nents plated with cadmium and pas-sivated. Dimensions are 10 by 5 by7in. and the weight is 111b. Sugden.

SOLDERING STATION 728Automatically controlledoutput and temperatures

Introduced is a series of miniaturelow voltage controlled output solder-ing stations. The W -MCP series tools

have a solid state closed loop controlsystem coupled with a curie point tem-perature sensing system to automatic-ally control output and temperatures.The units are available with fixed con-trol point temperatures of 500°F ana750°F. A 61/tin. long super lightweightpencil iron weighing only 1.35oz and fea-turing a highly flexible, burnproofsilicone rubber cord comprises theworking end of the station. The ironis normally supplied with a 1/8in. chis-el tip, however, interchangeable 1/32,3/64, and 5/64in. tips are also avail-able. The power unit is isolated andelectrostatically shielded. A special-ly designed non -sinking iron holderis provided. Incorporated in the caseare an on/off switch, indicator lightand a tip cleaning sponge installed ina convenient well. Weller.

UHF AMPLIFIERS 729Can accommodate upto 200 TV sets

Introduced is the Model M-174 andM-175 Solid State UHF Amplifiers,designated to overcome UHF frequen-


Adeet

e ofSound

e3ueress!

QUAMMODEL8C6PAX

HOTTESTMOVER IN THE

PUBLIC ADDRESSFIELD!8 inch, 6 oz. ceramic magnetspeaker handles 12 watts.Dual cone. Frequencyresponse 50-20000 Hz.Shallow construction(3" depth). Transformermounting facilities.

ONE OF MANY FINE QUAMSPEAKERS FOR SOUNDSYSTEM APPLICATIONS

Write for our Sound System Catalog

Quam-Nichols Company234 East Marquette RoadChicago, Illinois 60637

cy amplification problems found inlarge all channel/on channel MATVsystems and serve a MATV system

INPUT

M 174

143

:,

2041:. "r"".'.1V OUTPUT

-----\ Ns

that can accommodate up to 200 TVsets. The single channel UHF ampli-fier offers a 30-1-3dB gain with a lvoutput on a single UHF channel andbroadband UHF amplifier offers a30-1-3dB gain with a lv compositeoutput on all UHF channels. Both am-plifiers have a 751 single output. Thedesign and relatively low cost of bothamplifiers make them ideal for hand-ling UHF frequencies in all channel/onchannel MATV systems. Finney Com-pany.

SOLID STATE WIDE 730BAND OSCILLOSCOPESDC bandwidthto 7MHz

Introduced is the Model LBO -32B3in. scope with a bandwidth of de to7MHz making it ideal for every phase

of color TV servicing. Special inputcircuitry stabilizes the de level so thatpower line fluctuations are said tohave no effect on the position of theCRT display. The instrument has an

This new E -Vphono needlepackage helps you

buy, sell,then sellagain!

t v

Sy

11f

NEEDLEGRAPH

g ) On every new E -VYi needle package you'll find

the model number printed three extratimes on pressure sensitive tabs.Here's why:

The tabs can help you order replace-ments. Or keep track of sales. Or youcan stick one on a file card in a follow-upsystem that tells you what and when acustomer last bought (so that you cantell him when to buy again)! Or put a tabon the customer's tone arm to simplifyservice on the next call.

But don't be surprised if one of thetabs is missing. Your E -V distributor maybe using one to keep track of his stock-so that you always have the needleyou want, when you want it.

Smart ideas in packaging of theworld's finest phono service parts helpmake Electro-Voice your best buy.Ava lable only from the parts distributorwith much more than parts to offer!

Ask for your copy of the latest Electro-Voicephono needle/cartridge combined catalog.It's free at your E -V distributor's.

ELECTRO-VOICE, INC., Dept. 207-T663 Cecil Street, Buchanan, Michigan 49107

gLerearaccA SUBSIUIARY OF GULTON INDUSTRIES, INC.


FEBRUARY 1970 79

NEW PRODUCTS

input sensitivity of 10mv/cm. Thehorizontal and vertical amplifiers areeasily balanced so the instrument a-dopts itself to use as a vectorscope. Theline sweep position makes an effec-tive frequency comparator using thelissajous technique. The calibrationvoltage is set at 0.03v P -P at line fre-quency. The sweep circuit has a fre-quency range of 1Hz to 200kHz in 6steps and automatically locks to thehorizontal video pattern of the TVsignal. Power required is 105-125v50/60Hz @ 55va and measures 9in.H x 6-3/4in. W x 10-1/2in. D, weigh-ing 17.61b. Price $189.50. Leader.

PICTURE TUBE TESTER 731Simulates conditionsin the TV set

Announced is a Model 880 picturetube color tracking analyzer and pic-ture tube rejuvenator. The unit testsall color tubes in accordance with CRTmanufacturer's recommended pro-cedures. Each gun of a color tube isadjusted to cutoff before the beamcurrent reading is taken, simulatingconditions in the TV set. Universal

sockets and adapters eliminate numer-ous cables. The unit checks for shorts,interelement leakage and also pro-

vides acathode emission. Unit comes com-plete with data book. Price is $79.95.Mercury.

life test for checking useful

MATCHING TRANSFORMEREmploys heavy 732aluminum shell

Two matching transformers foruse in areas with strong local signalsare offered. The Model VMT-25 is a

guitIMMEmmmwi'1.11.11MIIIIMMt

broadband, trifilar wound, matchingtransformer featuring longitudinal

Put it on printed circuits, components anything that has to be encapsu-lated. sealed. isolated. protected.It's our spray -can -handy polyurethane coating that's fast -drying, tough.flexible. It's waterproof. Resists cleaning solvents, chemicals, marring andabrasion. Even today's atmosphere.Use it as a potting or metal primer ... finishes stick right on. It's always readyto go. So no mixing too much or not enough. No shelf- or pot -life worrieseither. Want to brush it on. dip it. use your own spray gear? OK. We'll send itover in bulk ... gallons or drums Or a tank car.Use Urethane Seal Co,it . it'll cover your problems.

CRC ChemicalsDivision of C. J. Webb, Inc.Dresher, Pa. 19025

e....tor MIMI details cirde 109 on Reeder Service Card


nu MONr

RAYTHEON

- -®j Mullard/

TVRECEIVING

TUBESTuop 755

OFF LIST

STOCK UP NOW!SEND FOR LATESTPRICE SCHEDULE

T & T SALES CO.4802 AVENUE K

BROOKLYN, N.Y. 11234

Phone: (212) 439-7935


Who needs a tunerwash? Save your

money and use

QUIETROLEThe product that cleans while it

lubricates. Zero effect on capacity

and resistance. Harmless to plas-

tics and metals. Keeps color and

black and white on the beam.Non-flammable.

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balance of at least 20dB. DC/AC isola-tion is provided by the inclusion ofthree capacitors into the circuitry.The Model VMT-26, illustrated, hasidentical electrical characteristicsbut is provided with a strap to facil-itate RF grounding to the set and hasa longitudinal balance of at least 25dB.Exceptionally rugged mechanical char-acteristics are accomplished throughthe use of a heavy aluminum shelland heavy duty twin lead. A plasticsleeving over the aluminum shell pre-vents shock hazards. View -All.

SPRAY CHEMICALS 733Selection of mostneeded spray chemicals

A complete selection of "most needed"electronic spray chemicals, packagedin a rainbow assortment of color -cod-

ed cans, is introduced. The colorfularray of cans features cleaners, cool-ers, lubricants, insulators and pro-tectors-all sprays, designed to meetthe demands of service techniciansin TV, radio, record player, tape re-corder repair, plus additional appli-cations in computer, office machine,industrial and broadcast servicing.Six of the nine cans feature a snap -on extension spray nozzle, includedfor precise application of the chem-ical to explicit circuit areas. A deal-er/distributor warranty against de-fects in material and workmanshipunder normal usage backs all of thespray chemicals for a period of sixmonths from date of purchase. RCA.

CB TRANSCEIVER 734Compact sizeand light weight

A Citizens Band mobile 2 -way radiounit designated as the Citifone 19 withfull 23 channel selection is announced.Over 25 separate features are detailedin a descriptive piece and includesreference to the size-less than 7in.deep, 2in. high and 5-5/16in. wide. The

transceiver cancan be installed on prac-tically any vehicle from smallest com-pacts to largest over -the -cab tractors.Built-in transistorized dependabilityand 23 channel feature makes theunit ideal for fleet usage. The priceis $159.95. Multi-Elmac.

SCOPE DOILY 735Steel constructionsupports 5001b

Introduced is the Model 962-S Mo-bile Scope Dolly which will accommo-date any popular -type scope up to17in.w x 22in.long. Its steel construc-tion is capable of supporting a 500lb.load and features a rubber mat -cov-ered storage shelf, felt -lined draw-er (12-3/4 x 14 x 3in.) mounted withnylon rollers (for manuals, probes,etc.), a three prong (U -type) poweroutlet and one -three -prong power

SOLVE YOUR TV REPAIR

PROBLEMS WITH

TV TECH AIDA monthly TV publication of actual re-

pairs, and troubles encountered in OURbusiness. The information will be gatheredfrom technicians, field reps, and all theleading manufacturers.

TV TECH AID will present up to 40 dif-ferent trouble shooting cases each month.Each nsanufacturer will have its own page.

Each symptom will have a clearlymarked schematic of the particular faultystage. The faulty components, and correc-tions will be listed to aid in repair. Noguess work.

It will contain current models, oldermodels. circuit changes and modificationson various models as they occur.

The days of "Trial and Substitution" areover.

Time means money. Don't forfeit thosevaluable profits.

ONE repair is worth more than fourtimes the investment.

Each monthly issue will contain a seriesof timely sheets and the cost to you isonly $7.95 for a full year's subscription.

TV TECH AIDP.O. BOX 603KINGS PARK, L. I.NEW YORK 11754ENCLOSED IS A CHECK OR M.O. FOR$7.95. PLEASE SEND 12 ISSUES OF TVTECH AIDTO:

NAME

ADDRESS

CITY

STATE ZIP

... for mote details circle 141 on Ruder Service Card

we get thru where others failkw. SONARCOM

SONAR VHF -FM TRANSCEIVERProfessional per-ormance! Perfectly designed to give theultimate in dependability for continuous heavy duty use.

Provices ins ant voice contact with base stations,mobile units and other portable transceivers

Compatible with all 2 -way systems Full frequency range for all public safety, industrial

and land trar sportation services 1.6 watt output Exclusive "Push -to -Talk"' microphone for easy to

use aztion Elect -onic mode switching, no relays Rece ver ani transmitter can be operated on inde-

pendent fret uencies Sens tive, noise immune squelch External connections for antenna, earphone and

battery charger

FIRE

POLICE

SECURITY

TES ANYWHERE -INDOORS, OUTDOORSSTEEL BLDGS

OPERA SONAR RADIO CORPORATION73 Wortman Ave., Brooklyn, N.Y. 11207

Please !end info rmation on the SONARCOM.Dept.530IND

BUSI

FCC TYPE ACCEPTEDDOT APPROVED

Mode' 2301132-174 MHz $37500

VHF -FM 1 CHANNEL Other models and1 pal- of crystals and 1 set options available.

of standa d batteries.

Name

Address

City State Zip

FEBRUARY 1970

... for more details rude 137 on Reader Service Card

81

HAS EVERYEXACT

REPLACEMENTTWIST PRONG AFH

ELECTROLYTIC

Why fool with "jerry-rigged"when there's an Aerovox exact replace-ment to give you the right rating and theright size? Aerovox actually stocks alltwist prong AFH electrolytics-this meansoff -the -shelf availability... not "we'llbuild it for you if you order it" delivery.Available in singles, doubles, triples andquads, these popular types are now man-ufactured in new values for filter bypassapplications in color TV as well as radio,black and white TV and amplifier equip-ment. Many values are now being usedfor industrial applications.Aerovox AFH Twist Prong Electrolyticsfeature ruggedized prongs and mountingterminals, high purity aluminum foil con-struction, improved moisture resistantseal and 85°C operation. Here is thequality you need to protect your profes-sional reputation.

Go to your Aerovox Dis-tributor for a perfectelectrolytic fit-he willdeliver exactly what youwant in less time than ittakes to tell. Ask him forthe new Aerovox Service-men's Catalog =SE -569or ask us. We'll be happyto send one your way.

`IEHi AEROVOXCORPORATION

DISTRIBUTOR SALES, New Bedford, Mass. 02741

Techn,cal Leadersh,o--Man,fact, .g EAcelle,ce. . . for more details circle 102 on Reader Service Card

NEW PRODUCTS

input. The unit swivels on four-5in.diameter, double ball -bearing, solidrubber wheels. It also has a conven-

ient 36in. height and 20deg viewingangle. The dolly is finished in graybaked -enamel and weighs 75 lb. MetalDynamics.

FET TESTER 736Can be added as a companionto transistor tester

Announced is the Model FT155 test-er for checking field effect transis-tors. The company stated that a field

lar-611/110"a)

effect transistor cannot be checkedon a tester that has been designedto check transistors only; the field ef-fect transistor is measured like a coldvacuum tube and requires charts thatmeasure the gain in transconductanceand leakage in different terms thana regular transistor. Use is not limitedto the service trade but is expectedto fill the need of the many industrialtechnicians and engineers who can nowtest transistors but cannot check thefield effect transistor. The mechanical

design is identical to the company'searlier model TR139 that checkedtransistors only and the tester can beadded as a companion unit at a savingsover a combination tester. Price is$94.50. Sencore.

SOLDER 737Excellent adhesion to glassand other substrates

A two -component silver -filled epoxyalloy that contains no solvents, vola-tiles, copper, carbon or plated fillersis introduced. Dynaloy 335 is claimedlower in cost than other two-part sil-ver -filled conductive epoxies, yet hasvolume resistivity lower than .0111cm.The new product cures at room tem-perature but will operate continuouslyat temperatures up to 210°F, with noelectrical drift or migration. The alloyreportedly has excellent adhesion toceramic, glass and other substrates.It is used for connecting heat -sensitivecomponents to printed circuit boards,bonding wave guides, shielding and re-placing solder where temperature orconvenience in application is required.

It is available in 2 oz. evaluation kitsfor $9.50 while prices run from $28 perpound to $40 per pound in larger quan-tities. Dynaloy, Inc.

CCTV CAMERA TRIPOD 738Adjustable heightfrom 27 to 691n.

Announced is a new heavy dutytripod for CCTV cameras and view-finders. The model T-2 tripod features

a pan/tilt head, camera turntable,elevator and indoor/outdoor leg tips.Made of aircraft aluminum, the new


tripod is light, yet able to handle loadsgreater than 201b. The unit is adjust.able to any height from 27 to 69in.by means of telescoping legs and anelevator column. A convenient crankcan be used to set the geared eleva-tor column to the height desired. Thepan and tilt head provides 360degpan and ±90deg tilt. The cameraturntable can be rotated over a 360degrange and locked into place by theflip of a lever. The three section legsare tipped by spikes which dig intothe ground for outdoor applications.For indoor use, the spikes are retract-ed, leaving non -slip rubber tips tocontact the floor without damage ormarking. All shiny aluminum partsare anodized to prevent corrosion.Coated aluminum parts are anodizedand then finished with two coats ofbaked enamel. List price $59.50. GBC.

OUTPUT METERS 739Dual db metersforstereo

Introduced is a line of dual db me-ters for monitoring stereo recordersor speaker output levels. The unit

can also be used to indicate any simul-taneously occurring functions whichcan be reduced to electrical charac-teristics. Cyclotronics.

PLASTIC STAPLE 740Provides insulation andhigh dielectric strength

A combination staple and strap isintroduced. It is made in 1/2 and 3/4in.sizes to fit new or old type No. 10,12 and 14 Romex, or UF, BX and other

cables. The staple consists of an in-jection molded plastic strap with twozinc plated nails. It is claimed thatthe strap provides insulation with

Miller High O. Coils inIC Stereo Decoder

Upgrade- modernize all existing stereo systems. An integrated FM stereodecoder (Motorola designed) provides excellent channel separation in excessof 30 db.

Smaller #1359 and #1360 stereo multiplex coils give excellent performancein a small package. Larger #1361 and #1362 coils give better channel sepa-ration in circuits where space is not critical. J. W. Miller printed circuit board(#1363 -PCB) simplifies construction. All components are available from dis-tributor stocks.

Write for 6 -page "Coil Forum" construction article.

J.W. MILLER COMPANY79070 REYES A. 'WE P.O. BO \ COMPTON \i IFORNIA 90224

for more details circle 124 en Reeder Benin Cord

MILLIONS ARE

SPENT TO FIX

2 -WAY RADIOS.

WHAT'S YOUR

CUT?

If you'd like to get into atop -paying job, maybe FM2 -way radio is for you.Each year, more and morebusinesses are buying2 -way. That means serv-

ice. And service meansmoney. We can train you

to get in on the action.Our special home studycourse is the place to start.We teach you FM 2 -way

radio servicing,and prepareyou for an FCC license.

El Send me FREE EvaluationExamination

Ej Send details on Home StudyCourse on FM 2 -way radioservicing.

lj] Send details on how you canprepare me for an FCC license.

MOTOROLATRAINING INSTITUTE OM

1301 Algonquin Road, Schaumburg, III. 60172


FEBRUARY 1970 83

A NEW AND IMPORTANTDEVELOPMENT FOR

TV SERVICING12 MODELS

SANS -A -FUSEFITS N SAM. -

SOCKET AS CHEMICALOR AMP FUSE

COLOR CODED CIRCUITBREAKER REPLACEMENT

FOR CHEMICAL ORAMP FUSE

SAVES TIME AND FUSESWHEN LOCATING SHORTSIN TELEVISION CIRCUITS

DEVELOPED ANDMANUFACTURED BY

WORKMANSOX 3818 SARASOTA, FLA 33578TELEPHONE Are. Cede 813

PRODUCTS, INC95, 4142

for more details circle 144 on Reeder Service Card

THE BEST PERFORMING

UHF/VHF/ FM HIGHGAIN 4 -SET COUPLER...

#C-4UV

Couples 4 TV and/or FM Sets to a single antennawith low loss of signal ... minimum interference be-tween sets. Two antennas, any combination of VHF,UHF, or FM, can be coupled to a single down -lead.Penetrating washers eliminate the need to stripwire. Assures simple hook-up of set and antennaleads. Wood screws are provided for mount to backof set or base board of a wall.Model C-4UV Specifications...Bandwidth 20-890 MHzSplitting Loss 20.220 MHz -7.5 db

450-890 MHz- 11 dbIsolation 20-220 MHz- 10 db

450-890 MHz- 14 dbVSWR 20-220 MHz -2.5 Max.Input . 450-890 MHz -3.5 Max.Also available- model C-2UV 2 -Set UHF/VHF Coupler.Write for Profit Details

RAM ELECTRONICS, INC.50 Antin Place, Bronx, N.Y. 10462 Tel. (212) 892-6700

NEW PRODUCTS

high dielectric strength and is notaffected by heat or cold, will not rust,rot or deteriorate. The nails can bedriven together without bending orsplitting wood, while the smooth saddleeliminates indenting and protectscable insulation. Holub.

LADDER 741Antenna installer'said is lightweight

Introduced is a ladder designedfor antenna service and installation.The ladder will hook into another lad-

der for extended use. It weighs 21 lb.and can be carried on the top of ser-vice vehicles. The ladder is made ofstrong, lightweight tubular steel withall -welded construction. The hooks arebent for strength and rigidity with U-shaped standoffs allowing steps to betaken with ease. Price $15. Winfield.

POWER OSCILLATORTwo -transistor push-pullsupersonic oscillator

Announced is the Model OS -100 atwo -transistor push-pull supersonicoscillator (2kHz to 150kHz, with design

center 60kHz to 80kHz), with sine waveoutput of relatively high power levelsat reportedly less than 1 percent har-monic distortion. Changing conden-ser Cf from the output circuit deter-mines the oscillator frequency: nor-

mally supplied value is 0.020 for 85kHz.Three taps in the output transformersupply a variety of output voltage. Theoscillator operates from any well -fil-tered de source from 18 to 22vdc, draw-ing approximately 18ma. Typical usesfor the oscillator include supersonicsignaling, biasing of tape recorder heads,supplying power to tape erasing cir-cuits and similar applications. It is alsosupplied with terminals so that theoscillator can be amplitude modulated.The oscillator size is: 5L, 3W, 2in. Hand weighs 4 oz. Price is $21.95. RoundHill.

DIGITAL VOLTMETER 743Solid-state light -emittingnumeric readout

Introduced is the Model 200A in-tegrating dc digital voltmeter, report-edly the first commercial test instru-ment to be equipped with a true solid-state light -emitting numeric readout.The voltmeter features five -digit read-out including 20 percent overrang-ing up to 1KV, automatic polarity se-lection and remotely programmablerange selection. The unit includes

---2111111111111111111111111a.

,lomat HNNANIA

7-7-7-16 444MIER

programmability, oven -stabilized ref-erence, BCD output and solid-statenumeric indicators. Price is $895. Mon-santo.

BATTERY ELIMINATOR 744742 Designed for students

experimenting in electricityIntroduced is the VirTronic Model

6ac-dc power supply. This compactlow voltage power supply, housedin a high -impact plastic case, featuresvisible components and circuit, fullprotection against dead shorts andoverloads, safety, low initial and oper-

ating expense. It may be operatedsingly or in groups for classroom use.VirTis.

.. for mono details circle 134 on Reader Service Cord


CATALOGS ft

BULLETINS

Tape Players 400A 16 -page catalog describing the

complete line of tape players is avail-able. Included are portable cassettetape recorders, radio-corders, com-plete home entertainment systemsand reel-to-reel stereo tape decks in-cluding the Mark Series tape decks,as well as receivers, speakers andan eight -track cartridge player. Thefour-color illustrated catalog coversapplications and features. Concord.

Neon Lamps 401A 12 -page technical brochure which

describes application ideas for neonglow lamps as circuit components andvoltage regulators is available.

The brochure, entitled, "Applica-tion Ideas", lists some 22 circuit ap-plications for neon lamps in vidicons,photomultipliers, power supplies,remote controls, memories, timers,proportional controls, moving signs,suppressors, photochoppers, bina-ry decoding, frequency dividers, flashtube triggering and energy transferapplications.

Most of the neon lamps discussedare new and were chosen for the spe-cific application because of their uniquecharacteristics. In each case the ap-plications discussed represent actu-al field-tested uses. Signalite.

Home Study Program 402A book, "How to Prepare Today

for Tomorrow's Jobs in Electronics,"is available. Home study programsin electronics make it possible for youto get the advanced education youneed without going back to school.You study at your own pace, on yourown schedule, with the assurance thatwhat you learn can be applied to thejob almost immediately. These pro-grams are prepared with the assis-tance of scientists and engineers whoare acknowledged experts in theirfields. CREI.

Schematics and Service 403Information

Schematic diagrams and serviceinformation on specific radio and TVsets are available at a nominal charge.Supreme Publications is offering tomail service material on almost anytelevision, radio, stereo or changer.It is able to supply such informationfrom its own service manuals, filesgoing back to the 1930's, from man-uals of other publishers (some no long-er in business) and from factory -re-

leased material. The usual chargeis $1 for radio material and $1.50 forTV material covering a specific set.Supreme Publications, 1760 BalsamRoad, Highland Park, Ill.

Music Systems 404A six -page pamphlet describes the

easiest ways to improve the qualityof your home music system and toimprove the sound characteristicsof your home music listening room.The pamphlet, "Sound Conditioning forMusic," is reprinted from the HOUSE& GARDEN magazine. The pamphletexplains how to use drapery, car-peting, upholstered furniture andother household items to enhance thesound from a component high fidel-ity system, piano or organ. It includespointers for eliminating "dead" spots,or doing away with excess reverb-eration without an acoustical engi-neer. Institute of High Fidelity.

Speaker Systems 405A 10 -page brochure featuring ad-

vanced speaker systems with "elec-tronic suspension" is offered.

Printed in two colors, the illustrat-ed "Sound of Excellence" brochuredescribes the entire LWE speakersystem line including "instant kits".The economical kits, providing theuser savings to 30 percent, consistof sound components mounted on abaffle board completely wired in anunfurnished wooden enclosure readyfor operation, The user simply addsthe wood finish and grille cloth de-sign of his own desire. LWE.

Relays 406An 8 -page catalog describing the

complete line of solid-state variabledelay relays- featuring external knobadjustment for a delay range of 0.1to 10s., 0.6 to 60s., or 1.8 to 180s.-isavailable. The time delay relays con-sist of a solid-state timing networkand an electromechanical relay ener-gized by the timing network. The unitsfind application where delays mustbe introduced as a safety factor forprotection of equipment such as mo-tors, where certain machine sequencesmust be maintained and in automatedequipment systems. Included in thegraphs, line drawings, electrical char-acteristics, plug wiring diagrams andmechanical specifications on four pop-ular solid-state time delay relay fam-ilies. These consist of (1) variable delaywith internal relay, (2) variable de-lay module requiring external relay,(3) fixed delay with internal relay and(4) fixed delay module requiring ex-ternal relay. All can be supplied tooperate from the following voltages:24vac, 115vac, 24vdc, 48vdc or 110vdc.Ohmite.

DOW...8 11010111001S

tar dozens of jobs

in a hip pocket sell

-so

No. 99PS-50

Really compact, this new nutdriver/screwdriver set features 12 interchange-able blades and an amber plastic (UL)handle. All are contained in a slim,trim, see thru plastic case which easilyfits hip pocket. Broad, flat base permitscase to be used as a bench stand.

Ideal for assembly and service work

7 NUTDRIVERS:44q3/16". 1/32". 1/4",

9/32', 5/16". 11/32"3/8" lex openings

2 SLOTTED

SCREWDRIVERS:

3/16' and 9/32' tips

2 PHILLIPSSCREWDRIVERS:

and =2 sires

EXTENSION BLADE:

Adds 4" reach todriving blades.

HANDLE:Shoceproof, breakproof. Exclusive. positivelockrig device holds blades firmly for turnmg. permits easy removal

WRITE FORCATALOG 162

XCELITEXCELITE, INC., 1-1 BANK ST., ORCHARD PARK, N. Y.Canada- Charles W Pointon, Ltd Toronto. Ont


FEBRUARY 1970 85

The Professional Way to Service TV Tunersby Tony FerrisTuners Inc. does not deal with the public.We are strictly "technicians' technicians", solvingthe really tough servicing problems that it doesn't paythe average man in the field to tackle. We handleall kinds of TV work but, as our name implies,we specialize in tuners. This article will tell youhow to cure tuner troubles rapidly - and profitably.

Types of Tuner Troubles

The following symptoms may be caused bya defective tuner: (1) snowy picture; (2) streak.ing or flashing in picture; (3) loss of soundand picture; (4) loss of certain channels; (5)picture pulling or distortion; (6) partial blank-ing of raster.

If you suspect tuner trouble, try the fol-lowing approach:

1. Clean and Degrease Contactswith Tun -O -Wash

In servicing tuners, it's important to startwith clean contacts. Poor contacts cause atleast 70% of all tuner troubles. In fact, weget many tuners in for repair that neednothing more than a thorough cleaning.

Chemtronics TUN -0 -WASH is excellent forthis purpose. It's almost like an ultrasonicbath in a can. Use this high pressure degreas-ing spray on all tuner contacts. Be sure toremove the tubes and spray the sockets thor-oughly, to remove corrosion.

A thorough cleaning will often eliminateintermittents and restore tuner alignment.

2. Lubricate and ProtectContacts with Tun -O -Foam

After the tuner has been flushed out withTUN -0 -WASH, let it dry thoroughly. Then, re-spray all contacts (including tube sockets)with TUN -0 -FOAM. Once the TUN -0 -FOAM hasbeen applied, rotate the channel selectorthrough all channels several times. Also, workthe tubes in and out of their sockets severaltimes. This will spread the lubricant to allcritical surfaces.

You will find that a thorough cleaning andlubrication will clear up about 70% of thetuner troubles you encounter (aside fromtubes, which should always be checked by sub-stitution before any servicing is attempted).

What's more, the TUN -0 -FOAM protects con-tacts from future corrosion, provides excellent

... for wore details cirde

lubricity for smooth operation, and continuesto clean and lubricate contacts each time thechannel is changed.

Most important, neither TUN -O -WASH norTUN -O -FOAM attack plastics or cause detuning.This is vital, since a spray that detunes acolor set almost always results in a profit -consuming callback.

Isolate the Trouble to the TunerIf a thorough cleaning and lubrication(which

takes only a moment) fails to restore properoperation, you will have to start troubleshoot-ing. But before you start tearing into thecircuit, make sure it's the tuner that's at fault.

IF and AGC defects often look an awfullot like tuner troubles.

If the picture is snowy, for example, toomuch AGC voltage may be the problem. To checkthis out, simply short the AGC test point toground. This makes AGC voltage zero, permit-ting the RF amplifier to operate at full gain.

Next, check out the IF stages. Start with agood TV set connected to a good antenna. Con-nect the IF cable from the tuner of the knowngood receiver to the IF input of the set youare troubleshooting, if you get a good picturewith the substitute tuner, you know you havetuner trouble. Otherwise, it's a chassis problem.

The 10 Minute Tuner CheckOnce you have cleaned and lubricated the

tuner and made sure that it is really the troublesource, give it a 10 minute check. Disciplineyourself not to spend too much time trackingdown tuner trouble. If you can't spot the trou-ble in 10 minutes, it may take you hours. There-fore you're a lot better off to send the tunerto a professional rebuilder. But the 10 minutecheck will reveal many tuner troubles.

If your preliminary checks revealed a shortedor gassy tube, chances are that excessive current has damaged a resistor. Burned resistors,of course, are fairly easy to spot.

After a brief visual inspection, make voltagechecks at the test points provided. B+ vol-tage should be accurate 20%. Then, use atest socket to make voltage and resistancechecks at tube pins. If you read a low plateor screen voltage, this generally indicatesthat a series resistor has changed value or acapacitor has shorted.

Check to see if the oscillator is working bymeasuring the mixer grid test point voltage.A dead oscillator is often caused by the plateload resistor.

Be sure to check the balun. Defective balunsoften cause snow or loss of certain channels.Your ohmeter will generally spot balun troubles.

One final word of advice: Treat all tunerscarefully. Don't poke around in coils or you'llcause misalignment. Replace defective partscarefully with exact replacements. If you dohave to send the tuner in, mark all leadsclearly, keep the brackets in a safe place,wrap the tubes well and pack them carefullywith the tuner.

Follow these simple rules and you'll make mon-ey on tuner repairs, whether you spot the trou-ble yourself or send the tuner to a specialist.

112 on Reader Service Card

AD INDEX

Admiral Corporation 74

Aerovox Corporation 82

Antenna Specialists Co. 28

B & K Division, Dynascan Corporation 25

B & K Division, Dynascan Corporation 39

Belden Corporation 22, 23

Book Club-Tab Books 60-63

CRC Chemicals .80

Channel Master Corp. 27

Channel Master Corp. 40

Chemtronics, Inc. 86

Columbia Electronics 29

Commander Electronics 75

EICO Electronic InstrumentsCo., Inc. 2nd Cover

Electro-Voice, Inc. 79

Ford Motor Co. 38

GC Electronics Co. 34

Heath Company 59

Jensen Tools & Alloys 74

Kay -Townes Antenna Company 3rd Cover

Lakeside Industries 77

Leader Instruments Corp. 77

Lectrotech, Inc. 32

J. W. Miller Co. 83

Motorola Communications &Electronics 83

Newcomb Audio Products Co. 66

Perma-Power Company 68

Quam-Nichols Co. 79

Quietrole Co. 80

RCA Electronic ComponentsEntertainment Tubes 4th Cover

RCA Institutes 37

RCA Parts & Accessories 20

RCA Sales Corporation 31

RCA Electronic ComponentsTest Equipment 64

RMS Electronics, Inc. 84Rohn Mfg. Co. 65

Sencore, Inc. 69

Sonar Radio Corp. 81

Sylvania Electric Products 33

T&T Sales Company 80

Tech Spray 24

Tuner Service Corp. 19

TV Tech Aid 81

Weller Electric Corporation 75

Winegard Company 73

Workman Electronic Products, Inc. 84

Xcelite, Inc. 85

Zenith Radio Corp. 67


A COMPLETE LINE OF QUALITY UHF -VHF -FM ANTENNAS

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CPC -33G

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5 MODELS FOR EVERY RECEPTION NEED

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82 CHANNEL

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UHF -VHF -FM COMBINATIONWITH FREE BAND SPLITTER

MODELS FOR EVERY RECEPTION NEED

CD -21G, 19G, 13G, 11G

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... for more details circle 120 on Reader Service Cad

Move ou

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4111

THE RCA FIELD SERVICE GUIDE FORRCA COLOR RECEIVERS FOR 1969-1970Contains all the field service informa-tion you need to pe-form all "at home"adjustments on 1939 and 1970 RCAcolor sets

Fully automatic MIRRO 22 CUP COF-FEE PERCOLATOR. Brews coffee to itsflavor peak and keeps it hot automati-cally!

THE STANLEY "YANKEE HANDYMAN"PUSH DRILL, great for boring holes inwood, plaster, etc. Complete with 4 drillpoints!

There's more! ... Customer giveaways,hanging mobile signs, etc. See all thebusiness, promotior al and service aidsnow available at your local RCA TubeDistributor.Visit him soon!

RCA I Electronic Components I Harrison, N.J.

Documents

ELECTRONIC TECHNICIAN / DEALER · All the versatility of the EICO 240 plus: AC/DC Milliammeter, 1 ma to 1000 ma in 7 non -skip ranges; single all-purpose DC/AC-Ohms - MA Uniprobe®;