eaIt - americanradiohistory.com · 2019-07-17 · r e eaIt eDoo Whenever an ailing set needs a "physical i your local prospect will go hunting for a dependable serviceman. 'That's

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Balanced loop type receiver with locp tuned indirectly through close -coupled iron -core transforme[See page 26.]

THE TECHNICAL JOURNAL OF THE RADIO TRADE

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OWENSBORO, KENTL'C<Y

SERVICE OCTOBER, 1946 1

EDITORIALTELEVISION SERVICING received quite athorough analysis during the recent TBAConference in New York. Both manufac-turer and Service Man presented theirviews on this important subject with thediscussion centering on factory -trained fac-tory -controlled servicing and factory orprivately -trained but independently operat-ing Service Shops.

Speaking for General Electric, W. L.Parkinson disclosed that Service Men oftheir distributors and'franchised dealers willbe trained to service and maintain tele-vision receivers. The distributors' technicalgroup will be trained first, and then servicecourses will be held for dealers' ServiceMen. Discussing costs, Mr. Parkinsonsaid that installation charges will run toabout $50 and will include a one-year war-ranty service. Mr. Parkinson also re-vealed that General Electric believes thatmany independent Service organizationsare capable of installing and servicing tele-vision receivers and, accordingly, they willnot close the door to such Service Shopswho can prove themselves capable of pro-viding a guaranteed service.

Outlining the DuMont plan, Ernest A. Marxsaid that DuMont has established a school totrain their dealers and Service representatives, andService Shops. In the DuMont plan, all men arecarefully screened for background. If approved,they receive a thorough training in televisionservicing. Commenting on the equipment requiredto service, Mr. Marx pointed out that the verybest and the most complete test equipment avail-able will be necessary for servicing.

In the RCA plan disclosed by W. L. Jones,it was learned that the RCA Service Companywill arrange for the installation of television re-ceivers. Operating in conjunction with the RCAdealers, the Service Men of RCA will not onlyinstall the receivers but maintain them for a fullyear and charge from $45 to $50 for 7" and 10"model installations, respectively.

Discussing television servicing and the ServiceMan, John F. Rider said that more independentService Men should be given an opportunity toparticipate in television servicing. Analyzing theadvanced technical knowledge required, Mr. Riderpointed out that many Service Men had studiedthe art carefully and would continue their studies.These men should have the right to service tele-vision receivers, he declared. He said that thereis no technique in television receivers which isso complicated that it cannot be assimilated bythe better grade of Service Man intelligence. Infact, he said, the goal of the design engineer mustbe such that the equipment is fool proof andsimple to repair.

Mr. Rider stressed that the entire industrywould profit greatly if it fostered the technicaladvancement of independent Service Men.

A complete report on the talks by Rider, Jonesand Marx, and others who participated in theTBA television servicing panel will appear in theNovember issue of SERVICE. Watch for it.THAT VICIOUS PRACTICE of overcharging appearsto be on the loose again. Why some Service Menwill insist on price gouging is difficult to under-stand. They know it's illegal, and can only resultin complete loss of face, and yet the price jugglecontinues.

It's a pity, affects everyone and shames theindustry.

Active Service Shops have demonstrated timeand again that there's plenty of income availablefor the honest operator. The shady price packingoperator never really profits and is always doomedto business failure.

Overcharging must stop and promptly!

I.VIO II -L[715104 rtrcraouic

SERVICEReg. U. S. Patent Cedes

Vol. 15, No. 10 October, 1946

LEWIS WINNEREditorial Director

ALFRED A. GHIRARDI F. WALEN

Advisory Editor Managing Editor

Electromagnetic Deflection Systems in Television Receivers. ByEdward M. Noll 20

Industrial Intercommunications. By Maurice F. Kerr 30

New Models 28

Old Timer's Corner 29

Portable Oscillographs with 2" C -R Tubes. By M. W. Beacay. 12

Sales Helps and the Service Man. By Kenneth C. Burcaw IISer-Cuits. By Henry Howard 22

Service Aids 27

Servicing Helps. By Frank C. Keene 34

Tools and Accessories for the New Service Shop. By Alfred A.Ghirardi 16

CIRCUITS

Admiral 4AI 22

Crosley 56FA 23

DeWald A500-503 24

Stewart -Warner 9014-E (Cover) 26

Zenith 4K0I6 23

Zenith 60001 24

COVER

Balanced Loop Receiver (Stewart -Warner 9014-E) 26

SERVICE AIDS

Flexible Light Control for Repair Work 27

Loop in Cover Qf Tester as Antenna 27

Removing Meter Face Static Charges . . 27

SERVICING HELPS

Oscillators 35

Multiple Headphone Circuits 34

Index to Advertisers 48

ManufacturersNews 36

New Products 38

Jots and Flashes 48

Copyright, 1946, Bryan Davis Publishing Co., Inc.

Published monthly by Bryan Davis Publishing Co., Inc.52 Vanderbilt Avenue, New York 17, N. Y. Telephone MUrray Hill 4-0170

ABCBryan S. Davis, President A. Goebel, Circulation ManagerPaul S. Weil, Vice Pres.-Gen. Mgr. F. Walen, Secretary

Cleveland Representative: James C. Mann, 2050 E. 120th St., Cleveland 20, Ohio; Telephone CEdar 7783Chicago Representatives Lawrence webrbeim, 5510 W. Lemoyne Ave., Chicago, Mt Telephone MERrimac 7919

Pacific Coast Representatives Brand & Brand, 1052 W. Sixth St., Los Angeles 14, Calif.; Telephone Michigan 1732Brand & Brand, 1005 Monadnock Bldg., San Francisco, Calif.; Telephone Douglas 4475

Entered as second-class matter June 14, 1932, at the Post Office at New York, N. Y., under the Act of March 3, 1879. Subscription price: $2.00 perrear in the United States of America and Canada; 25 cents per copy. 53.00 per year in foreign countries; 35 cents per copy.

2 SERVICE, OCTOBER, 1946

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MEISSNER ANALYSTNow available at your jobber . the new postwar Meissner Analyst. The out-

standing modern service instrument. Tests receivers and locates faults by the signal

tracing method . . . fastest and most reliable method to date. Thoroughlyengineered to do your service job in the most efficient manner possible.

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SERVICE, OCTOBER, 1946 3

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Designed especially for speech reproduction in intercom-munication and public address applications, this SpeechMaster family of JENSEN Reproducers, delivers clean.sharp, understandable announcements and orders. Like allJENSEN products, these Speech Masters were completelyengineered to do their job efficiently and well.MODEL NJ -300 SPEECH MASTER (Railroad Type).PM design. Widely used in railroad intercommunication in loco-motives, cabooses, signal towers and yards. Rugged case protectsagainst shock and vibration; withstands dust, smoke and the ele-ments. Voice coil impedance 12 ohms; power rating. 10 watts.Space provided inside case for 500 -ohm impedance transformer.Overall height 11-3/4"; width 6.25/32"; depth 4-13/16". Holesprovided in base for mounting in any position.MODEL AR -10 SPEECH MASTER 41/1/C0 5- design. Speciallyconstructed reflex horn increases efficiency in mid -frequencyrange, giving added effectiveness and "punch" to' speech quality;prevents direct access of rain and snow to speaker diaphragm.Voice coil impedance, 4 ohms and 45 ohms; power rating, 6 watts.Space provided inside for 1/2" x 1/2" transformer. Overall diameter10". depth 8''. Complete with mounting bracket.MODEL AP -1 1 SPEECH MASTER (Panel mounting). Similar toAP -10 but without base. Mounts in 4-27/64" cut-out; clearance eye-lets for mounting screws. Depth 41/2" from front panel. Screws anddrilling template included. Voice coil impedance 4 ohms or 45ohms; power rating. 5 watts.MOD EL AP -10 SPEECH MASTER (Desk or Wall type).PM design, desk or wall mounting. Complete with base and tiltadjustment. Double dustproofed. Rubber covered 36" cord. Internalmounting bracket for 1/2" x 1/2" transformer. Voice coil impedance4 ohms or 45 ohms: power rating, 5 watts. Height 6-3/4"; depth5 ks"; diameter 5". Finish hammered gray with satin chrome trim.MODEL NF -300 SPEECH MASTER (Navy Type). Developedfor use as a loud speaker and microphone. Special case designover -rides wind and background noises for talk -back. Enclosedcase and protective screen render this model proof againstweather, dust and moisture ININICO 5PM design. Power rating,10 watts; voice coil impedance 12 ohms. Mounts in 51/2" cut-out;six screw holes in rim. Overall diameter 6-7/16"; depth (from frontof panel) 2-9/64". Finished in Munsel N4 -S gray enamel.MODEL AP -20 SPEECH MASTER Heavy-duty unit for high-level paging and call systems in noisy industrial installations.PM design. Furnished with eyebolt for overhead suspension butavailable with stand for wall or table mounting. Voice coil impe-dance 8 ohms: power rating, 25 watts. Overall diameter 131/2".depth 9"'For lull discussion of Speech requirements, see Jensen Mono-

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Model 215 Signal G ter.Designed down to the mostminute detail for highest ac-curacy greatest stability, min-imum Ileasage, and good waveform $67.35Model 305 Tube Tester Testsall tubes. Provides for filamentvoltag. from .5 volts to and in-cluding 1:0 volts. Spare sockets forfuture :ube developments....$46.25Mode 2i0 High Sensitivity SetTester- 23,000 ohms per volt. D.C.Volta*. ranges to 5,000 volts A.C.and LC Resistance ranges to 20megol-ins Current ranges to 500 mil-liampr -es $38.95

0

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The successful radio serviceman today must have the finest in test instru-ments for a very practical reason-that's his only hope of present and con-tinued profits. To meet the tremendous volume of business available hemust be able to "trouble -shoot" fast and accurately every time. Only thuscan he correct trouble speedily, with satisfaction to the customers.

Simpson offers you, in three basic test instruments, the accuracy and ad-vanced electronic engineering which have given Simpson the proudestname in the industry. They are tried -and -tested examples of the kindof instruments Simpson has always built. Their use will demonstratethat from Simpson alone can you expect "instruments that stay accu-rate" with construction and design that lead the field.

To dealer and to serviceman alike, Simpson offers today the assur-ance of continued profits that only quality can give. No Simpson in-strument is ever marketed, or ever will be, unless its makers feel that,of its kind, nothing finer can be produced.

INSTRUMENTS THAT S'AT ACCURATE

SIMPSON ELECTRIC COMPANY5200.5218 West Kinzie Street, Chicago 44


ALABAMABessemer-Bessemer Radio SupplyBirmingham-James W GaryMobile-Nelson Radio & Supply Co.

Radio LabsMontgomery-Teague Hardware Co.

Southeastern Radio Parts Co.

ARKANSASFort Smith-Wise Radio SupplyLittle Rock-Southern Radio. SupplyTexarkana-Lavender Radio Supply Co.

ARIZONAPhoenix-Radio Parts of Arizona

CALIFORNIABakersfield-Bakersfield Radio SupplyFresno-Jack C. Arbuckle

Billings Wholesale RadioHollywood-Hollywood Radio Supply, Inc.Long Beach-Radio & Tel. Equip. Co.Los Angeles-Figart Radio Supply Co.

Kierulff & CoNelson Brothers Co.Radio Equip DistributorsUnited Radio Supply Co.Universal Radio Supply Co.

Modesto-Jack WarrenOakland-W D Brill Company

E. C. Wenger Co.Pasadena-Dow Radio Supply Co.Sacramento-C. C. Brown Co.

Henderson Bros.Sacramento Elec. Supply Co.

San Diego-Coast Electric Co.Electronic Equip. Distr.Shanks & Wright

San Francisco-Associated Radio Distrs.C. C. Brown Co.

San Jose-Frank QuementSanta Ana-Radio & Tel. Equip. Co.

COLORADODenver-Inter-State Radio & Supply Co.

CONNECTICUTBridgeport-Hatry & Young, Inc.Hartford-Harry & Young, Inc.

New Britain-United Radio SupplyUniversal Radio Co.

New Haven-Thomas H. Brown Co.Harry & Young, Inc.

New London-Harry & Young of NewLondon, Inc.

Stamford-Hatry & Young, Inc.Waterbury-Harry & Young, Inc.

DELAWARE

Wilmington-Radio Elec. Serv. Co.

DISTRICT OF COLUMBIA

Washington-Kenyon Radio Supply Co.Rucker Radio Wholesalers

FLORIDA

Jacksonville-Kinkade Radio SupplyMajor Appliances

Miami-Electronic Supply Co.Mayor Appliances

Orlando-Radio Accessories Co.St. Petersburg-Welch Radio SupplySarasota-Morley Radio Co.Tampa-Kinkade Radio Supply

Major Appliances

GEORGIA

Atlanta-Concord Radio Corp.Southeastern Radio Parts Co.Specialty Dstg. Co., Inc.

Macon-Specialty Dstg. Co., Inc.Savannah-Southeastern Radio Parts Co.

Specialty Dstg. Co., Inc.

ILLINOIS

Bloomington-J. W. ArbuckleChicago-Allied Radio Corp.

Concord Radio Corp.Grant Radio Co., Inc.Nation Wide RadioRadio Parts Company

Kankakee-Radio Doctors Supply House

INDIANAAngola-Lakeland Radio SupplyRichmond-Fox Sound Equipment Co.

IOWACedar Rapids-Gifford-Brown, Inc.Council Bluffs-World Radio Labs., Inc.Des Moines-Gifford-Brown, Inc.

Radio Trade Supply Corp.Fort Dodge-Gifford-Brown, Inc.

Ken-Els Radio SupplyMason City-Radio-Electric Supply Co.Sioux City-Power City Radio Company

Sioux City Radio & Appl. Co.Waterloo-Gifford-Brown, Inc.

World Radio Laboratories, Inc.

KANSASPittsburg-Pittsburg Radio SupplyTopeka-Acme Radio SupplyWichita-Radio Supply Co.

KENTUCKYLexington-Radio Equipment Co.Louisville-Peerless Electronic Equip. Co.Newport-Apex Distributing Co.

LOUISIANALake Providence-F. H. Schneider & Sons, Inc.New Orleans-Radio Parts, Inc.Shreveport-Dunckelman-Pace

Koelemay Sales Co.

MAINEAuburn-Radio Service & Supply StorePortland-Frank M. Brown Co.

MARYLANDBaltimore-Henry 0. Berman Co., Inc.Cumberland-Cumberland Radio Whol.Salisbury-Dealers Radio Service

MASSACHUSETTSBoston-De Mambro Dstrs., Inc.

Hatry & Young of Mass., Inc.A. W. Mayer Co.Radio Wire Television, Inc.Sager Elec'l Supply Co.

Cambridge-The Eastern Co.Holyoke-Springfield Radio Co.Lawrence-Hatry & Young of Mass., Inc.New Bedford-C. E. Beckman Co.Pittsfield-Pittsfield Radio Co.

Roxbury-Gerber Radio Supply Co.Springfield-T. F. Cushing Co.

Springfield Radio Co.Worcester-De Mambro Dstrs., Inc.

The Eastern Co.Radio Electronic Sales Co.Radio Maintenance Supply Co.

MICHIGAN

Ann Arbor-Wedemeyer Elec. Supply Co.Battle Creek-Wedemeyer Elec. Supply Co.Detroit-Ferguson Radio Supplies

Radio Specialties Co.Radio Supply & Eng. Co., Inc.

Flint-Radio Tube Mdsg. Co.Grand Rapids-Wholesale Radio Co.Jackson-Fulton Radio SupplyKalamazoo-Ralph M. Ralston Co.Muskegon-Industrial Elec. Supply Co.Pontiac-Electronic Supply Co.Saginaw-Radio Parts Company

MINNESOTA

Duluth-Northwest RadioMinneapolis-Bauman Company

Sidney RosenthalSt. Paul-Electronic Distributing Co.

MISSISSIPPI

Greenville-The Goyer CompanyMeridian-Griffin Radio Supply

MISSOURI

Cape Girardeau-Suedekum Elec. Sup. Co.Jefferson City-Central Mo. Dstg. Co.Joplin-M. Brotherson

Mardick Dstg. Co.Kansas City-Burstein-Applebee Co.

Manhattan Corp:St. Joseph-St. Joseph Radio & Supply Co.St. Louis-Walter Ashe Radio Co.

Interstate Supply Co.Radonics

Springfield-Harry Reed Radio & Sup. Co.

MONTANAButte-George Steele & Co.Kalispell-McIntosh Music House

SPRAGUE PRODUCTS COMPANY NORTH ADAMS, MASS.


NEBRASKAOmaha-Omaha Appliance Co.

Radio Equipment Co.Scottsbluff-Joachim Radio Supply

NEW HAMPSHIREDover-American Radio Corp.

NEW JERSEYCamden-Radio Elec. Serv. Co.Newark-Continental Sales Co.

KrichRadisco, Inc.T. A. O'Loughlin & Co.Radio Wire Tel., Inc.

Perth Amboy-Bennett's Radio SupplyRed Bank-J. H. Kelly CompanyTrenton-United Tire Stores Co.

NEW YORKAlbany-Fort Orange Radio Dstg. Co.Amsterdam-Adirondack Radio SupplyAuburn-Dare's Radio ServiceBinghamton-Broome Dstg. Co., Inc.

Federal Radio Supply Co.Brooklyn-Green Radio Distributors

Stan -Burn Radio & Elec. Co.Buffalo-Bars Radio & Electronic Parts

Dymac, Inc.Genesee Radio & Parts Co.Radio Equipment Corp.Standard Electronics Co.

Elmira-LeValley-Mdeod-Kinkaid Co., IncFredonia-C. R. BarkerGlens Falls-Ray Distributing Co.Hempstead, L. 1.-Standard Parts Corp.Ithaca-Stallman of IthacaJamaica, L. 1.-Norman Radio Distrs.Middletown-L & S Radio SalesNew York City-Fischer Distributing Co.

Radionic Equipment Co.Radio Wire Tel., Inc.

Niagara Falls-Niagara Radio & Parts Co.Rochester-Beaucaire, Inc.

Masline Radio & Electronic Equip. Co.Schenectady-Fort Orange Radio pstg. Co.

M. Schwartz & SonSyracuse-Broome Dstg. Co., Inc.

Syracuse Radio SupplyTroy-Trojan Radio Co.Utica-Beacon Electronic Inc.Watertown-Beacon Electronic Inc.

Write for Catalog C-306

NORTH CAROLINA

Asheville-Freck Radio & Supply Co.Charlotte-Dixie Radio Supply Co.

Southern Radio Corp.Fayetteville-Eastern Radio SupplyGoldsboro-Signal Radio SupplyGreensboro-Dixie Radio Supply Co.Raleigh-Carolina Radio Equip. Co.Winston-Salem-C. R. Williams Radio Co.

NORTH DAKOTA

Fargo-Radio Equipment Co.

OHIO

Akron-Olson Radio WarehouseAshtabula-Morrison Radio supplyCanton-Armstrong Radio Supply

Burroughs Radio. Cincinnati-Chambers Radio Supply Co.

Schuster Elec. Co.United Radio, Inc.

Cleveland-Gold hamer, Inc.Northern Ohio LaboratoriesWinteradio, Inc.

Columbus-Hughes-Peters, It c.Whitehead Radio Co.

Dayton-Hughes-Peters, Inc.Standard Radio & Electronic Prod. Co.

East Liverpool-Hausfeld Rac ioKent-Kladag Radio Labs.Lima-The Northwestern Radio Co.Mansfield-Burroughs RadioMarion-Bell Radio Supply::-/nEfii/./-Standard Radio Sc Electronic

Prod. Co.Steubenville-D & R Radio Supply

Hausfeld RadioToledo-Toledo Radio SpecialtiesWarren-Radio SpecialtiesYoungstown-Appliance Wholesalers

OKLAHOMA

Enid-Standard Measuring & Equip. Co.Oklahoma City-Radio Supply, Inc.

Southern Sales Co.Tsdsa-Radio, Inc.

OREGONPort/and-Bargelt Supply

Harper-Meggee, Inc.Portland Radio Supply Co.

PENNSYLVANIAAllentown-Radio Elec. Serv. Co.Beaver Falls-Reliable Motor Pans Co.Easton-Radio Elec. Serv. Co.Erie-John V. Duncombe Co.Harrisburg-Radio Distributing Co.Lancaster-Eshelman Supply Co.

George D. Barbey Co.Norristown-Kratz Bros. Co.Phi/ade/phia-Almo Radio Company

Consolidated Radio Corp.Electric WarehouseEmerson Radio of Pa.Radio Elec. Serv. Co.

N. W. Cor. 7th & Arch Sts.5133 Market St.3145 N. Broad St.

Eugene G. WilePittsburgh-Hamburg Bros.

The John Marshall Co.Radio Parts Co.

Pottsville-Jones Radio Co.Reading-George D. Barbey Co.St. Marys-B & R Electric Co.Scranton-Broome Dstg. Co., Inc.Wilkes-Barre-General Radio & Elec. Co.

Radio Service Co.Williamsport-Williamsport Radio Supply

RHODE ISLANDProvidence-William Dandreta & Co.

W. H. Edwards Co.SOUTH CAROLINA

Columbia-Dixie Radio Supply Co.SOUTH DAKOTA

Aberdeen-Danielson & Brost Co.Sioux Falls-Power City Radio Co.

United Radio SupplyTENNESSEE

Knoxville-Bomar'sChemcity Radio & Elec. Co.C. M. McClung & Co.

Memphis-McTyier Radio SupplyNasheille-Currey's Radio Service

Radio & Appliance Corp.TEXAS

Abilene-R & R Supply Co., Inc.Amarillo-R & R Supply Co., Inc.Austin-The Hargis CompanyBeaumont-Montague Radio Co.Corpus Christi-Wicks-DeVilbiss Co.

Electronic Equip. & Engin. Co.Dallas-All-State Dstg. Co.

Crabtree's Wholesale RadioSouthwest Radio SupplyWanslow & Co.

Fort Worth-Electronic Equipment Co.Fort Worth Radio Supply Co.

Houston-A. R. Beyer CompanyLubbock-R & R Supply Co., Inc.San Antonio-Olsen Radio SupplyTyler-Lavender Radio Supply Co.Waco-The Hargis CompanyWichita Falls-Wichita Falls Bat. & Elec.

VIRGINIANorfolk-Ashman Distr. CompanyRoanoke-Leonard Elec. Sup. Co.Richmond-Johnston Gasser Co.

WASHINGTONBellingham-Waitkus Supply Co.Seattle-General Radio, Inc.

Harper.Meggee, Inc.Sunset Electric Co.

Spokane-Harper-Meggee, Inc.Tacoma-Wible Radio Supply

WEST VIRGINIABluefield-Whitehead Radio Co.Charleston-Chemcity Radio & Elec. Co.

Hicks Radio SupplyClarksburg-Trenton Radio Co.Huntington-Electronic Supply, Inc.Morgantown-Trenton Radio Co.Parkersburg-Randle & HornbrookWheeling-Wheeling Radio Supply

WISCONSINGreen Bay-Neslo Electronic Dstrs.Madison-Radio Dstrs. of Madison, Wis.Milwaukee-Radio Parts Co., Inc.

JOBBING DISTRIBUTING ORGANIZATION FOR PRODUCTS OF SPRAGUE ELECTRIC CO.


to Pull the Fuse froma $20,000,000,000 Bomb

IMAGINE a super bomb whose explosion could rock theentire nation. Such a bomb EXISTS-but you can help renderit harmless.

This bomb is $20,000,000,000 surplus national income.

Authorities estimate that this year's total income will be$155,000,000,000-personal taxes will total $15,000-

000,000-consumer goods and services will absorb nomore than $120,000,000,000. This leaves $20,000,000,000.Even if banks and insurance companies absorb one -fifth of

the surplus (as they did in 1945), there will still remain$16,000,000,000 that could be used to bid up prices.

You're doing yourself, your company, and your country afavor by continuing your payroll deduction plan for theregular purchase of U. S. Savings Bonds. At maturity, theypay $4 for every $3 invested!

THE PEACETIME PAYROLLSAVINGS PLAN

A booklet, published for key executives by theTreasury Department, containing helpful suggestionson the conduct of your payroll savings plan for U. S.Savings Bonds.

THIS TIME IT'S FOR YOUA booklet for employees ... explaining graphicallyhow the payroll savings plan works ... goals to savefor, and how to reach them with Savings Bonds.

Are you using these booklets?If not, or if you want additional copies, just ask your StateDirector of the Treasury Department Savings Bonds Division.

The Treasury Department acknowledges with appreciation the publication of this message by

SERVICEThis is an official U. S. Treasury advertisement prepared under the auspices of the Treasury Department and the Advertising Council


CHECK

the featuresin these Capacitor Analyzers

MODEL CFMost comprehensive of all capacitor analyzers, thissturdy, reliable instrument is designed to simplifyelectronic servicing.

Has exclusive, patented "Quick -Check" circuitfor qualitative tests and intermittent checks with-out unsoldering capacitor leads

Capacitance range -10 mmf to 2000 mf Power Factor range -0 to 55 percent Insulation Resistance range -3 to 10,000 meg-

ohms

Leakage Current - Reads electrolytic leakagecurrent directly on large 4 1/2" meter

PLUContinuously Adjustable 0-550 volt D -C powersupply for electrolytic tests

0-550 volt, 3 -range D -C VTVM+10-50 volt, A -C VTVM4,100 ohm to 7.5 megohm A -C resistance bridge

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Model CF EXAM-ETER

Model CBB CAPACITOR ANALYZER

MODEL CBBAn up-to-the-minute version of the famous SolarModel CB, long-time standard analyzer of the radioservice industry.

Capacitance range -10 mmf to 800 mf Power Factor range -0 to 55 percent "Magic-Eye"Tube for bridge balance indication Simplified Neon -Lamp circuit for visual check of

insulation resistance and electrolytic leakage Resistance Bridge -50 ohm to 2 megohm range

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Portability-small size and light weightReliable components for operation In humidclimates

Solar Capacitor Analyzers are fully describedin Catalog IN -2, available at your distributorsor directly from Solar Capacitor Sales Corp.,285 Madison Avenue, New York 17, N. Y.

SERVICE, OCTOBER, 1946

SYLVANIA NEWSRADIO SERVICE EDITION

OCT. Prepared by SYLVANIA ELECTRIC PRODUCTS INC., Emporium, Pa. 1946

ONEDEVICE NOW USED BY RADIO

OF

SERVICEMEN

FOR GREAT VARIETY TESTS

Electrical Measurements Made Easy With New Sylvania Unit!

174SYLVANIA

Radio servicemen now can use thenew Sylvania Polymeter type 134 tofacilitate a multitude of electronicmeasurements and tests to radioequipment.

This product of Sylvania Researchis stabilized against errors due tovoltage variations or gas current intubes. All accessories included. Seeyour Sylvania Distributor.

CHARACTERISTICS ANDSPECIAL FEATURES

Tests audio, A.C. and R.F. voltagesfrom 20 cps to 300 me through use ofproximity fuze -type tube built intohandy probe. Full scale range of 3,10, 30, 100, 300.

Measures D.C. from .1 to 1,000

volts in full scale ranges of 3, 10, 30,100, 300, 1,000.

Measures D.C. current from .1 mil-liampere to 10 amperes in full scaleranges of 3, 10, 30, 100, 300, 1,000milliamperes and 10 amperes.

Measures resistance from 1/2 ohmto 1,000 megohms in full scale rangesof 1,000, 10,000, 100,000 ohms and1, 10, 1,000 megohms.

ACCURACY

D.C. ranges ±3% of full scale.A.C. ranges ±5% of full scale up to

30 volts and ±7% above 30 volts.R.F. ranges -±5% of full scale up to

10 volts; -±770 from 10-100 volts;-±10% on 300 volt range.

Ohms -±670 to the left of 1/2 scale;±13% to the left of 3/4 scale.

Current -±3% of full scale on all but10 ampere scale which provides-±-5% of full scale.

INPUT IMPEDANCESR.E ranges -2.7 megohms resistance

shunted by approximately 3 mmf.capacity.

A.C. ranges -2.7 megohms resistanceshunted by approximately 40 mmf.capacity.

D.C. ranges -16 megohms resistance.Remember the Sylvania Polymetertype 134. It's beautifully styled,compactly designed, has easily readmeter and dials.

SYLVANIMTELECTRICEmporium. Pa.

MAKERS OF RADIO TU3ES, CATHODE RAY TUBES; ELECTRONIC DEVICES, FLUORESCENT LAMPS, FIXTURES, WIRING DEVICES; ELECTRIC LIGHT BULBS


RSERVICE

SALES HELPSAnd the SERVICE MANI'VE TRAVELED THE COUNTRY widelyon business missions and talked todozens of neighborhood Service Shopowners, big ones and little ones, in-cluding many with freshly paintedshingles. And practically everywherethere was excited talk about the shop'sfuture and the potential healthy in-come in these times of shortages andrun-down prewar sets. Some fellowswere found to be doing a fine businessbecause of an excellent shop locationand, even more important, their salesaggressiveness in the community.Others, sad to say, were strugglingalong on pay -the -rent -and -taxes in-comes, because of a complete disre-gard for salesmanship.

Many Service Men going into busi-ness for themselves have failed torealize the importance of selling. It'san old horse -sense axiom that, nomatter how expert you are, customersjust won't come to you if the fact isunknown. That puts the lie to the

by KENNETH C. BURCAWSales Manager, Jobber DivisionCornell-Dubilier Electric Corp.

favorite mousetrap analogy. In Tibetthere's an old ragged man who carvesdelicate ivory figures, so tiny theylook like dandruff in your palm, yeteach is a perfectly formed carving inevery detail. Ever hear of him ?Probably not. Salesmanship couldhave made him famous and prosper-ous even in Tibet.

You Must Be a SalesmanIf you will think of yourself as a

salesman as well as a Service Man,business will grow almost automat-ically. No one is really born with sell-ing ability. It must be acquired. The

AboveAssortment of sales helps available to the

Service Man.

same feeling of confidence you havein yourself must be instilled amongyour prospects. That's the whole es-sence of salesmanship. Doing thatwill gain more volume from a sidestreet shop than a lackadaisical Ser-vice Shop owner on Main and CenterStreets.

But there's a paradox. A busyService Man does not have the timeto keep plugging his services to thecommunity and also maintain a steadyoutput of repair jobs. Even a shopwith several assistants requires per-sonal attention and supervision. Theproblem can be solved with sales pro-motion helps that will stimulate repairbusiness while you work in the shop.There is no time lost canvassing

(Continued on page 46)

SERVICE, OCTOBER, 1946 II

Pig. 1. A 2" cathode-ray tube recently devel-oped for instrument application.

THE RECENT TREND TO MINIATURE testequipment has prompted the develop-ment of several unusual components,such as the recently -announced 2"cathode-ray tubes. With these tubesit has been possible to design unusu-ally small, yet very effective, c -r Ser-vice Shop test units.

With one type of c -r tube recentlydeveloped, the 2BP1', designers havebeen able to construct a portabletester with a screen image brightenough to photograph with anordinary camera.

In this tube, an electrostatic deflec-tion focus type, there is an improvedelectron gun with a grid (No. 2)operated at high voltage so that beamcurrent will not be affected by changesin the plate (No. 1) voltage. It alsohas a plate which takes negligible

View of oscillograph using 2" 2API-A c -r tube.(Courtesy Waterman)

PORTABLEcurrent. As a result of these features,the spot can be sharply focused on thescreen, both at the center and at theedges. Low plate current permitsthe use of a low -current voltage -divider system and hence the use of asmall filter capacitor.

Having a separate base -pin con-nection for each of the four deflectingelectrodes, the tube is intended pri-marily for use in balanced electro-static -deflection circuits. However, itis also well suited for use with un-balanced deflection because of designfeatures which minimize spot and pat-tern distortion characteristic of suchoperation.

Tube installation Data

The base pins of the c -r tube fit aduodecal 12 -pin socket which may beinstalled so that the tube will operatein any position. The socket alone mustnot support the tube; other support,such as a yoke or saddle arrangementnear the screen end of the tube, mustalso be used.

It is necessary to enclose the bulbin a grounded shield when operated inthe presence of strong magnetic fields.The shield must 'be made of high -per-meability metal having low residualmagnetism to minimize the effects ofextraneous magnetic fields. When agrounded metal shield is used aroundthe tube, it may be necessary to in-sulate the high -voltage end of the tubefrom the shield to avoid leakage cur-rents.

The heater is designed to be oper-ated at 6.3 volts. The mid -tap or oneside of the heater winding should pref-erably be connected to the cathode. Ifnecessary, the heater may be operatedwith a bias of not more than -± 125volts with respect to the cathode.

The d -c voltages for the grid andthe two plates may be obtained con-veniently from a high -voltage vacuum -tube rectifier. Since this tube requiresvery little current, the rectifier systemcan be of either the half -wave or thevoltage -double type. Likewise, the fil-ter requirements are simple. A 0.1 mfdcapacitor will ordinarily provide suffi-cient filtering. If this is inadequate, atwo -section filter is recommended. Ifthe electrode voltages are obtainedfrom a bleeder circuit, a bleeder cur-rent of 0.2 milliampere usually is satis-factory. Considerably higher values

112CA.

may require more filtering than thatprovided by a single capacitor shuntedacross the d -c supply. In most appli-cations, it is recommended that plate2 be grounded in order that the de-flecting electrodes may be operated atground potential. With this arrange-ment, the heater and cathode at highnegative potential with respect toground.

In the use of cathode-ray tubes, itmust always be remembered that highvoltages may appear at normally low -potential points in the oircuit due tocapacitor breakdown or to incorrectcircuit connections. Therefore, beforeany part of the circuit is touched, thepower supply switch must be turnedoff and both terminals of any chargedcapacitors grounded.

Application Notes

Focusing of the fluorescent spotproduced by the electron beam is con-trolled by adjustment of the ratio ofplate 2 voltage to plate 1 voltageOrdinarily, the ratio is adjusted byvariation of plate 1 voltage. For thispurpose, a potentiometer is requiredin the voltage -divider circuit.

The undeflected focused spot is nor-mally close to the geometric center ofthe tube face. However, to take care ofvariation from tube to tube, designersprovide for each pair of deflectingelectrodes, at least 19 volts for eachkilovolt of plate 2 voltage. By adjust-ment of this d -c compensating voltageon each pair of the deflecting elec-trodes, the spot may be centered.

Electrostatic Deflection

Two pairs of electrostatic deflectingelectrodes, producing fields at rightangles, are located within the bulbneck to provide for deflection of theelectron beam. The electrostatic fieldof each pair of deflecting electrodescauses deflection of the electron beamin the direction of the gradient lines ofthe field and perpendicular to theplane of the deflecting electrodes;therefore, the deflections caused by thetwo fields are at right angles within afew degrees.

Deflection Voltages

Each pair of deflecting electrodesare normally operated at an averagepotential the same as that of plate 2:Each electrode of each pair is con-nected through a resistor of not more


OSCILLOGRAPHSWith 2" C -R Tubes

by M. W. BEACAY

than 5 megohnis to the plate 2 socketterminal. Under operating conditionsinvolving high current to the screen orscanning beyond the limits of thescreen, a small amount of current iscollected by the deflecting electrodes.If the circuit resistance between eachdeflecting electrode and plate 2 is high,the current collected by the deflectingelectrodes produces negative potentialson the deflecting electrodes. Such po-tentials distort or shift the spot on thescreen. These effects are minimized byreducing equally the resistances of thedeflecting -electrode circuits, by reduc-ing the scanning width, by reducingthe beam current, or by applying asmall and equal d -c compensatingvoltage to deflecting electrodes DJ,and D J4. This voltage should be posi-tive with respect to plate 2.

Brightness

Line brightness of the 2BP1 isamply high for operation withoutshield in a well -lighted room at plate2 voltages as low as 1,000. Linebrightness is inversely proportional tothe length of the scanned line and ingrid -modulated service, is also directlyproportional to the per cent of the timethat the screen is scannned.

Brightness may be increased by re-ducing grid 1 voltage or by increas-ing plate 2 voltage. With reduction ingrid 1 voltage, line width increases.Therefore, if narrow line width (gooddefinition) is to be maintained, it ispreferable to increase plate 2 voltage.This latter procedure, however, maynot be always desirable since it resultsin reduced deflection sensitivity.

Screen Contrast

Screen contrast is an importantfactor in apparent screen brightnessand in definition. It is the ratio ofscreen brightness to backgroundbrightness. The screen in the 2BP1reduces background light to a mini-mum and, therefore, has good contrast.Contrast may be improved if glare is

TVA -G

vENT0IGAL AMPLIFIERINPUT

.5 MOD

300/

15 HENRIES

6 WO

ED0.OMB

500 v60v

Mrs

5V

ED

0 0EXTERNAL INPUT TO

HORIZONTAL AMPLIFIER

.25 MFDI

25 MOD

.25mFD

.0001 HOD

0vtlITIGAL INPUTWITHOUT AmPL,E.E.

0

HORIZONTAL INPUTWITHOUT AMPLIFIER

0

GRID

1600uLATIONoINPUT

Fig. 2. Circuit featuring the 2" 2BP1 c -r tube. Controls in the upper right hand corner of thecircuit are spot -centering controls. The C. capacitor referred to in the paper is the .0001-mfd unitconnected between the grid modulation input and the center point of grid modulation potentiometer.

minimized by reducing external il-lumination on the tube face. Whenit is impractical to reduce external il-lumination, designers have minimizedthe glare by the use of a green filtersuch as Wratten No. 58.

Photography and the Screen

Photographing should be done pref-erably in complete darkness to obtainas much contrast as possible betweenthe fluorescent screen pattern and thescreen. The time of exposure will de-pend on the speed of the camera lens,the kind of film or plate emulsion used,and the brightness of the pattern.

Where transients are to be photo-graphed, maximum brightness may berequired because of the short durationof the phenomena; where recurrentwaveforms are to be photographed,patterns having low brightness can becompensated for by longer exposure.The use cf emulsions having highgreen sensitivity is recommended:orthochromatic types of film andhigh-speed films have been found togive excellent results.

High -Speed Photography

For high-speed photographic workinvolving non -recurrent phenomena, it


Fig. 4. Schematic diagram of the portable c -r test unit using the 2API-A type 2" tube.

is permissible to increase the tracebrightness, for the short interval re-quired to make the exposure, abovethat required for visual observation.The extent to which the beam currentmay be increased without harming thescreen is proportional to the velocityof beam travel and pattern size, andinversely proportional to the durationof the phenomenon.

2101 Circuit

A circuit using the 2BP1 is shownin Fig. 2. This circuit includes desir-able features for a laboratory instru-ment, such as balanced deflection,balanced spot centering, and provisionfor intensity (grid) modulation. Bal-anced deflection is recommended tominimize spot and pattern distortion.Spot centering is obtained by adjust-ment of ganged pairs of potentiometers.

Circuit Leakage

In this circuit, one side of theheater is , connected directly to thecathode to prevent transformer or cir-cuit leakage from developing any volt-age between heater and cathode. A by-pass capacitor of about 4 rnfd may beused between the arm of the grid -bias potentiometer and cathode in casehum is present in the grid circuit.

Intensity Modulation

Intensity modulation is accomplishedby introduction of the signal through

2Waterman Products Company, type S -10-A.

capacitor C4 to grid 1. This capacitorhas a small capacitance since themodulating signal is usually a pulsehaving a steep wave front. Largevalues of capacitance for this capaci-tor may require better filtering of thehigh voltage supply for the cathode-ray tube since the grid signal is re-ferred to ground. The capacitor must,have low leakage and must be able towithstand the plate 2 voltage.

Voltage Supply

The voltage supply for the amplifiersand the sweep (timing) oscillator hasbeen combined with that for thecathode-ray tube. This arrangementprovides additional current for thecentering potentiometers and makespossible a lower high -voltage, low -current supply for the 2BP1 than

Fig. 3. Bottom view of the socket connectionsfor 2BP1. Pin 1, heater; pin 2, grid 1; pin 3,cathode; pin 4, plate 1; pin 5, internal con-nections; pin 6, deflecting electrode, DJs; pin7, deflecting electrode, D-14; pin 8, plate 2 andgrid 2; pin 9, deflecting electrode, DJs; pin 10,deflecting electrode, D.11; pin 11, internal con-

nections; and pin 12, heater.

would be possible with sepat ate powersupplies.

4 -Tube C -It Portable

Another 2" -type c -r tube, the 2AP1,was recently incorporated in a 4 -tubeportable test instrument"- using a6AU6 miniature -type pentode for thevertical amplifier, 6J6 miniature twin -triode, and 6 X 4 twin -diode rectifier.The 6J6 serves a dual purpose. Onesection is used as a horizontal ampli-fier, with a stage gain of 24, for a hori-zontal deflection sensitivity of 1 voltrms per inch. The second section isused in a multivibrator circuit as atime base oscillator, permitting lineartracing from 10 to 50,000 cps.

Bypass Switches

By pass switches on amplifier gaincontrols permit direct connection toboth vertical and horizontal deflectionplates of the c -r tube. A functionswitch is provided for the use of ex-ternal and internal or line synchroni-zation. Line synchronizing voltage isprovided by a 6 -volt filament winding.External synchronization permits theuse of an audio oscillator for the crea-tion of lissajou figures. These figuresmay be used to determine the fre-quency of an unknown audio or radiofrequency. Quite often, by knowing thefrequency of a spurious oscillation ina receiver, its removal is aided.

Other Controls

Other controls included are inten-sity, focus, and variable synchronousfrequency.

The amplifiers are said to be sub-stantially flat from 20 to 100,000 cps,with a gradual 2 db loss between lowand high frequencies.

The imput resistance for both ver-tical and horizontal amplifiers is 500,-000 ohms, at a shunt capacitance of36 mmfd.

Credits

The author is grateful to the com-mercial engineering department of theRCA Victor division of RCA and thethe Waterman Products Co., Inc., forthe engineering data supplied on the2BP1 tube and S -10-A instrument, re-spectively.


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Rider Manuals cover the things which our 16years of specialized publishing have proved youwant and need; supplying such vital materialas receiver schematics, voltage data, resistancevalues, chassis layouts and wiring, and trimmerconnections.

Further evidence of our continuing service tothe servicing industry will be found in the forth-coming Volume XV. This new volume will containspecially prepared and highly refined servicinginformation available from no other source-noteven from the set manufacturer. This supplemen-tary material is information you need, offered ina form that will make it most useful to you. It willresult in the saving of servicing time-an increase

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Fig. 1. Three useful sizes of tapered reamers; (a), (b), (c). A hand reamer (Stevens Walden, Inc.)is shown at (d).

Fig. 2 (right). A round shank and a square bit shank countersink for holes that are to take flat oroval head screws.

TOOLS And ACCESSORIESFor the NEW SERVICE SHOPCONTINUING OUR DISCUSSION of thesupplementary and special-purposetools, we come to some of the smaller,but nevertheless useful, hand tools.

Reamers

For the Service Man who does notwish to make too large an investmentfor an assortment of large size twistdrills and an electric drill or breastdrill of sufficient size to accommodatethem, there is an alternative that willenable him to drill large size holeswhenever necessary-but it entailsmore work on his part. A few taperedreamers having a square bit stockshank that fits into an ordinary car-penter's brace will serve the purpose.It is only necessary to use a few largetwist drills such as a 1/4" and a 3/8"or 1/8" drill and use the taperedreamers to enlarge their holes to anydesired size.

Three sizes of tapered reamers areuseful; Fig. 1. In (a) appears onetype with a slight taper, ranging indiameter from I/8" at the point to amaximum of %". The reamer at (b)will enlarge holes from 3/3" up to 78".The reamer at (c) will enlarge holes5/16" up to 1%". As the latter has arather sharp taper it is useful only on

[Part VI . . . Supplementary and Special -Purpose Tools]

by ALFRED A. GHIRARDIAdvisory Editor

comparatively thin stock such aspanels, chassis, etc

A very useful hand reamer, theReamawli is illustrated at (d). Thisis useful for quickly enlarging smallholes by hand.

Countersinks

When drilling a hole for a flat -heador oval -head screw, it is necessary tocountersink the hole to a taper of 82degrees to fit the head, so that its topsurface will be flushed with the work.Countersinks for this purpose are illus-trated in Fig. 2. The model at (a) hasa round shank so it can be used inthe ordinary hand drill or electricdrill. The one at (b) has a square bitshank for use in a carpenter's brace.Each can be used for countersinkingeither metal, wood, bakelite, etc. Oneof small size and having a round shankwill be suitable.

Countersinks are also useful for re-

1Produced by manufacturers of Spintitesocket wrenches.

moving burrs that are caused by drill-ing or punching. This must be donecarefully, otherwise the hole will becountersunk.

Large Hole Cutters

It is frequently necessary to cutround holes for replacement tubesockets, plugs, connectors and otherreceptables in either an old or anew metal chassis. If there is suffi-cient space in which to work, theseholes may be cut by one of the fly -cutters that will be described later,but a more accurate and rapid job canbe done (and in cramped quarters ifnecessary) with one of the hand -typechassis punches designed especially forthe purpose. Fig. 3 illustrates the twoforms in which these are made.

The punch at (a) is operated byhammering the top, punch, portioninto the lower, die, portion (with thechassis in between the two) while thedie is resting on an anvil or other solidbase. A small guide hole must be


From coast to coast

SERVICE PROFITSARE GOING UP(and operating costs are going down)

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want to know about radios, phonographs,Intercommunication systems and poweramplifiers manufactured since January 1,1946. Released in sets of 30 to 50 foldersat a time, they reach you when you needthem most-just as the products de-scribed reach the market. Yet the cost,including membership in the Howard W.Sams Institute, is only $1.50 a set. ( $1.75a set in Canada).

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1. A cabinet -view photo of the receiver to helpyou establish identity and control functions. 2. Atop -view photo of chassis and speaker to identifycomponent parts and alignment points. 3. A bot.tom -view photo of chassis and/or accessories. 4. Acomplete list giving keyed reference to all parts,alignment and schematic diagram. 5. A completefull page schematic diagram of the receiver withloads of new information shown in a uniform manner.6. Stage gain measurements listed on the schematicdiagram. 7. A complete voltage and resistanceanalysis chart for rapid check of operational values.8. Complete alignment instructions on the receiverconsistent with the keyed alignment points indi-cated in top- and bottom -view photos.

PUBLICATION DATES:Set No. 5 ... October 15thSet No. 6 ... October 26th

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Fig. 3. At (o) and (b) are two types of chassis pinches (General Hardware and Greenlee Tool,espectively) for cutting socket holes, etc. In (r) we have an adjustable By -cutter for cutting largerround holes. (Courtesy Greenlee Tool Co.) In (d) appears a shearing pinch for cutting holes of any

shape. (Courtesy Insaline Corp. of America.)

Fig. 5 (right). An automatic self -positioning drill case to keep all the twist drills conveniently in oneplace. (Courtesy General Hardware Mfg. Co.)

drilled in the chassis first to take thecentering pin of the punch.

The screw -type punch works easilyand more accurately and may be usedmore conveniently on assembledchassis. No hammering is necessary. Apopular type is illustrated at (b).2 Thecap screw shown is inserted in asmall centering hole previously drilledin the chassis and the shear punch iseasily forced into the die by a fewturns of the cap screw with an or-dinary wrench. Smooth holes, requir-ing no filing or reaming, can be cut inmetal up to 1/8" thick in 172 minutesor less. Ten punches are available forcutting N", 7/8", 1", 1 1-5/32",1-3/16", 1g", we, 17," and 2A"holes.

For cutting round holes of largerdiameter, such as would be needed formounting a flush -mounting meter forexample, and for cutting metal, bake-lite or fibre, wood, etc., adjustable fly-

cutters are very popular. These aremade in several types and sizes, theone illustrated at (c) of Fig. 3 beingtypical. The cutter is equipped with itsown twist drill for drilling the pilothole. The high speed steel cutter car-ried on the adjustable arm does thecutting. These cutters are made withthree styles of twist drill shank : 5/16"round shank, %" round shank, andsquare shank, for use in either a

breast drill, bench drill or hand brace.Several sizes are made; one adjust-able to cut holes from 7/8" to 4"diameter will be about right for mostradio uses.

Round holes are not the only kindrequired. It is often necessary to cutsmall rectangular holes in chassis forreplacement transformers, chokes, etc.These may be cut out by first drillinga hole at each corner and then using akeyhole hacksaw for sawing along thestraight sides of the cutout. Or theymay be cut out with a cape chisel. Inshops where enough of this work isdone to make the purchase advisable,the square hole shearing punch illus-trated at (d) will be found very usefulfor doing such work more quickly andaccurately. It permits the cutting ofany size odd -shape hole (square, rec-tangular, hexagon, oblong, etc.) onany size panel or chassis.

Die Stock and Dies

Although they are not absolutelynecessary, a few dies for the morecommonly used machine screw sizes,and a die stock (die holder) to fitthem, will form excellent additions,when finances allow. A set of 4-36,6-32. 8-32 and 10-32 dies is recom-

4:revolee Tool Co.

Fig. 4. A small stock and several removable dies of different sizes that fit into it. These are usefulfor threading rods or cleaning up damaged threads or screws.

mended; Fig. 4 shows a die held in adie stock. They will be useful for clean-ing up burred or otherwise damagedthreads on machine screws of thosesizes, and for other purposes.

The procedure for using dies cor-rectly is similar to that for tapping.The work should be held firmly in avise, and any burr on the end of thepiece to be threaded should first beremoved with a file. To start thethread, the large side of the opening inthe die should be placed over the workand pressed down on the stock firmly,while turning it clockwise.

Twist Drill Case

For the Service Man who wants tokeep a rather complete assortment oftwist drills on hand and likes to havethem all in one handy place ready forinstant selection, a drill case of thetype illustrated in Fig. 5 will solve theproblem perfectly. A clearly indexedhole of proper size is provided for eachdrill. The case closes into the form ofa compact box that protects the drillsand can also be used for taking themon outside jobs. As soon as the coveris lifted, the drills automatically comeup into position, the size of each drillbeing clearly shown by the index, asillustrated.

These drill cases are made in thefollowing sizes: (a) for a set of num-ber -size drills from No. 1 to No. 60;(b) for a set of fractional -size drillsfrom 1/16" to Y2"; and (c) for a setof letter -size drills from A to Z. Thecases may be purchased from yourhardware dealer. They are availableeither empty, with the complete set ofdrills, or with any particular drills youmay select. No more fumbling in tool -filled drawers or tool boxes for thedrill you want to use when you ownone of these drill boxes.


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Radio amateurs are the most versatiletechnical experimenters known-andso are Amphenol engineers. Amateurshave pioneered the greatest share ofelectronic developments since thedawn of radio-and Amphenol haspioneered in the development of com-ponents used by hams.

Amateurs have an appreciation ofthe electrical engineering problems inthe production of components to givethe best performance. They agree thatTwin -Lead, pioneered by Amphenol,is one of the most important and usefulnew products in the field of electronics.

AMERICAN PHENOLIC CORPORATIONCHICAGO 50, ILLINOIS

In Canada Amphenol Limited Toronto, Ontario

ACTUAL SIZE CROSS SECTION

75 OHMTRANSMITTING TWIN -LEADAmateurs asked for it - now here it isl It's the newheavy duty 75 ohm Amphenol Twin -Lead transmis-sion line. Conservatively rated at 1000 watts for 30

me or lower frequency. Available - now - at yourdistributor's.

Megacycles 75 ohm DB per 100 ft.3.5 0.29

Attenuation 7.0 0.4914.0 0.8228.0 1.40

Receiving Twin -Lead is available in 75 ohm, 150 ohmand 300 ohm impedances. Get a copy of Amphenol'snew Twin -Lead bulletin from your dealer.

Other Amphenol products of interest to amateurs availableat your dealer's:Radio Tube Sockets. Industrial, standard, miniature andsub-miniature-plugs and accessories. Octal angle socketsfor cathode ray applications.Connectors. All types, with fittings - from I to 50 contacts.

Cables. Coax and Twinax (also connectors). Microphonecables (also connectors).Plastics for Electronics. Plastic sheets, rods and tubes.Flexible tubing and spaghetti. Coil Dope. Molded coilforms, stand-off insulators, knobs and dial pieces.

Antennas. UHF dipoles and arrays.

cA3:ES AND CONNECTORS INDUSTRIAL CONNECTORS, FITTINGS AND CONDUIT ANTENNAS 9' CD "ONEN'S PI.ASTICS FOR ELECTRONICS


TRANSVERSEFIELD

CENTERED ELECTRONS NOT EFFECTEDBY TRANSVERSE FIELD

FOCUS COIL

ELECTRON

(A)

SPAM

SCREEN

INTENSE (B)

HELICAL MOTION CAUSED BY STRONG.......NNFOCUS FIELD

(C)

MEM

EXAGGERATED DRAWING OF PROPER FOCUSINGACTION- - PARTIAL HELIX

Fig. 2. Analysis of magnetic focusing.

ELECTR

SAWTOOTH FROMVERTICAL SWEEP

OSCILLATOR

SAWTOOTH FROMHORIZONTAL SWEEP. --

OSCILLATOR

VERTU, CAL AMPLIFIER

HORIZONTAL AMPLIFIER

L 1NEAHIT YCONTROL

VERTICALDEFLECTION

COILS

HORIZONTAL CENTERL VERTICALCENTER

TRANSIENTNET wOR1,

FROM LOW -VOLTAGEPOINT ON POWER

SUPPLY BLEEDER

HORIZONTALDEFLECTION

COILS

Fig. 1. Television receiver deflection amplifier.

°MAGNETICDEFLECTION SYSTEMSIn Television ReceiversSO THAT WE MAY trace the horizontaland vertical deflection paths in a typi-cal television receiver, the circuitshown in Fig. 1 is offered.

In the electromagnetic deflectionamplifier the output is transformer -coupled to the deflection coils. Inas-much as an appreciable current mustflow through the coils, the amplifier isconsidered to be a power amplifiersimilar to the audio power amplifierwhich drives a speaker. A small vari-able d -c current is used for propercentering. This current is obtained bytapping across two small resistorswhich are inserted across the low -potential end of the low -voltage powersupply.

In the cathode circuits of these am-plifiers are special linearity networkswhich correct the small curvature stillpresent on the sawtooth waveform.The waveform is made more linear bybiasing the deflection amplifier to anon-linear portion of its characteristic.This bias must be precisely set at theproper point on the transfer character-istic to compensate for the non -linea-rity of the sweep waveform applied tothe grid. The opposite curvature of

by EDWARD M. NOLL

[Part II]

the characteristic produces a linearchange in plate current as the sawtoothvoltage rises and, therefore, a linearsweep.

Still another defect arising particu-larly in the horizontal sweep amplifier,which causes distortion of the wave-form, are high -voltage transients.Since the horizontal sweep consists ofits high fundamental frequency plusfrequency components up to at leastthe tenth harmonic, the reactance oftransformer windings and deflectioncoil is very high. Consequently, high -

transient voltages are developed acrossthe reactances, particularly at the startof the horizontal retrace when thechange in current is very fast. Thesevoltages often shock -excite the wind-ings into a series of damped oscilla-tions which modulate the sweep. Toprevent high voltage transients, thesecondary of the horizontal outputtransformer and horizontal deflections

coils are shunted by a low -value resis-tor combination which load the indus-tors heavily at high frequencies. Thusthe fast retrace currents are shuntedoff through the resistors and do notdevelop transients across the high in-ductive reactances.

The horizontal deflection transform-ers and circuits must have a frequencyresponse reasonably linear up to 150,-000 cycles. Transformers must be care-fully constructed to have such a highfrequency response with a minimum ofself -resonant tendencies. The verticaldeflection amplifier is of much lowerfrequency and not so critical of design.The vertical sawtooth is also ofgreater amplitude as applied to thegrid of the vertical amplifier and, con-sequently, a low -impedance triode hassufficient gain to develop the requiredcurrent variation through the verticaldeflection coils. An added advantage

(Continued on rage 45)


Oluitiouisgreat line

of receivingtubes is your assurance

of bigger profits

CUNNINGHAM'S line of metal, glass,and miniature receiving tubes meetspractically every service requirement.WithCunningham tubes you won't need tocarry additional lines to round out yourstock-and you'll seldom have to turnaway a customer.

And you can be sure that Cunninghamhas or will have the right type tubes forthe new AM, FM, and television receivers

that are on the way-because Cunninghamis backed by the engineering leadershipof the Radio Corporation of America.

Remember, too, that Cunningham Elec-tron Tubes are built for service. They'vebeen famous for over 30 years for theirconsistently high quality, long life, and topperformance. That's why customers lookfor the big "C" in your store windowwhen they need new tubes.

LISTEN TO "THE RCA SHOW," SUNDAYS, 2:00 P. M., EST, NBC NETWORK

A QUALITY PRODUCT FOR RADIO SERVICEMEN

AND DEALERS BY THE RADIO CORPORATION OF AMERICA


PHONOMOTOR

IN RESPONSE TO MANY REQUESTS, weoffer additional data on portable andfarm -type receivers this month.

Admiral 4A1

An interesting permeability -tunedtype portable Admiral 4A1, is shownin Fig. 1. An external antenna is capa-city coupled to the input circuit in amanner similar to Belmont 4B17, butthe values differ considerably, a .005-mfd capacitor appearing across a 250-mmfd capacitor giving much tightercoupling. The antenna .shunting re-sistor is 15,000 ohms and the avcfilter resistor, 470,000 ohms.

An ultraudion oscillator circuit isused with the oscillator grid at oneend of the single coil and the plategrid at the other. A trimmer is con-nected from the grid end to ground;250 mmfd from the plate end toground. An r -f choke in the B sup-ply completely isolates the 1A7 fromthe remainder of the set. Bias for thei-f amplifier is obtained from a 4.7-megohm grid leak. Only the 1A7 re-ceives avc bias. An economizerswitch located on the top of the

0Cl

- O.mfd

by HENRY HOWARD

chassis inserts a wirewound .75 -ohmresistor in series with the positive legof the A battery. It is labeled NewBattery in the open position (resistorin the circuit) and Old Battery in theclosed position.

Zenith 4K016 -4K035

Fig 2 shows another 4 -tube batteryset with external antenna, Zenithmodels 4K016 -4K035, chasses 4C52-4C53. Equal avc bias is supplied toa 1A7 converter and 1N5 i-f amplifier.The power amplifier is a 105 insteadof the usual 3Q5. The C bias resistoris 820' ohms.

Crosley 56FA

A 5 -tube, 2 -band farm -type receiver,Crosley models 56FA, 56FB, isshown in Fig. 3. A 1N5 t -r -f ampli-

Fig. 1. Portable, Admiral 4A1, using an ultra-audion oscillator circuit. List of parts at right.

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fier is used on the broadcast bandonly. The waveband switch connectsthe signal grid of a 1A7 to the inter -stage transformer for broadcast or tothe secondary of the short-wave an-tenna transformer and oscillator gridfrom broadcast to the short-waveoscillator coil. Switch also connectsa 480-mmfd padder in series with theoscillator tuning capacitor; shortssecondary of the broadcast antennatransformer for short waves and by-passes the broadcast feedback coil forshort waves. The 1N5 i-f works intoan iron core output i-f transformer.In a 1H5 detector-avc-audio circuitwe have an unusual avc and detectorload arrangement. The load consistsof 150,000 ohms in series with a 1-megohm volume control, in serieswith 3300 ohms. The latter preventsturning the volume completely offwith the set turned on, thus savingmany a battery.

The avc system operates through a

CONDENSERSSymbol DescriptionCIS .002 mfd. 600 VoltCl, C7 .005 mfd. 600 VoltCIO .01 mfd. 400 VoltCS .05 mfd. 200 VoltCll. Cl2 .0001 mfd.C2. C6 .00025 mfd.CS .0008 mfd.C9 4. mfd. 150 VoltC3, C4 Dual trimmerC13, CI6 .01 mfd. 400 Volt

P.12

RIIR13

RIR4R3

R2R9,

R.6

R5, R8

RESISTORS.75 ohm %, w (wire)390. ohm w

2200 ohm Y. w15,000 ohm 5e2 w33,000 ohm 1/2 w220,000 ohm % w470,000 ohm % w

RIO 1,000.000 ohm % w2,200.000 ohm Va w4,700,000 ohm 14 w


l0-megohm resistor to the i-f and r -fstages and through another 100,000ohms to the converter on the broad-cast band only. On short waves, theconverter is biased solely by a 3.3-megohm leak bypassed by 600-mmfdcapacitor. The avc bus is shunted toground through a. 4.7-megohm leak.Bias for the 1LB4 power amplifier isobtained from a 1000 -ohm resistor inthe B- lead. The B supply is by-passed by a 15-mfd capacitor, and anadditional isolation filter of 4700 ohmsand 15 mfd serves the 1A7 plate andoscillator circuits and the 1N5 andlA 7 screens.

Zenith 6G001

Another 3 -gang 5 -tube batterymodel, Zenith 6G001, using lock -intubes, is shown in Fig. 4. A 1LN5r -f amplifier has a 2.2-megohm resist-or for bias and 22,000 ohms in serieswith the primary of the interstagetransformer. A 1LA6 converter istapped down on the secondary of thistransformer, giving higher Q andsharper tuning. A tickler feedbackoscillator uses a grid capacity windingwith 220 ohms in series.

DeWald A500 Series

DeWald 4 -tube and rectifier models,

IATGTCONVERTER

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Fig. 2. A 4 -tube battery set using an externalantenna, Zenith models 4K016 -4K035.

A500 to A503, are shown in Fig. 5.Many interesting fundamental circuitrequirements have been met in thesemodels. An antenna -resistor and ca-pacitor has been included to eliminateresonance in the antenna. Thus i-f orimage interference is minimized. The

Fig. 3. A 5 -tube, 2 -band farm -type receiver,Crosley 56FA and 56FB.

capacitor also prevents connection of

the antenna to the line plug. In thei-f stages one bypass is placed acrossthe detector load resistor which is alsothe volume control. A -f blocking ca-pacitors and suitable grid leak bias areused for the 12SQ7. A 150 -ohm cath-ode bias is in the 50L6 circuit.

Other Circuit Features

The filament string has a 35Z5 pilotlamp and an 18 -ohm surge resistor. Adual 30-mfd and 2,700 ohms for filter

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are also included. A .05-mfd r -f by-pass is connected across the filter out-put. This is an important capacitor,for as the electrolytic capacitor driesup and the resistance increases, feed-

back through the supply, producingoscillation, may result. This capacitorprevents this possibility. To preventmodulation hum, a .05-mfd capacitor isconnected to chassis.

Fig. 4. A 3 -gang 5-tabe battery a -o/d -e modelusing lock -in type tubes, Zenith 6G001.

Fig. 5. DeWald 4 -tube and rectifier, A500 andA503, with an antenna resistor and capacitor toeliminate antenna resonance and minimize i or

image interferenee-

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7/0free-a"WITH THE FEDERAL SELENIUM RECTIFIER

-FIRST OF ITS KIND IN THE INDUSTRY!

NO less than twenty-nine different types of rectifier tubesare now replaceable with Federal's new, miniature,

5 -plate rectifier. Available now, this replacemern is also animprovement! For not only does it subtract from your ownmanufacturing costs, it adds to product quality as welland to consumer satisfaction. Here's how:

Saves space- only 13/4 x 1 x "he inches-fits wheretube won't

Costs less than tube and socket it eliminates Long life - built to last the life of the set No warm-up period - starts instantly, runs cooler Installed in less time than tube only two soldering jobs Sturdy, all -metal construction - not easily damaged Withstands overloads-even when charging deformed

electrolytic condensers

Every one of Federal's line of "Center Contac:" Seleniumrectifiers is designed to give the full measure of performancethat have made them the standard of the industry. A Federalengineer will show you how to put this latest model into yourcircuits. Write for details to Department F456.

No. 403026251

aeplacenie5'13

514 S'145i4

5%.34

61°55/43 Oi%

or these 2526304gSZa

,Si53syt.

6'156Z51225

22-Is25

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mercy kieptione and Radio Cortv)ratioffIn Canada:-federal Electric Manufacturing Company, Ltd., MontrealExport Distributol%-lnternotioncl Standard Electric Corporation, 67 Broad St., N, Y. C.

Newark 1,New Jersey


,-METROPOLITAN

B-45 nSIGNAL GENERATOR

AvailableNOWfor

ImmediateDelivery!

Self -modulated Signal Generator, pro-viding a highly stable signal. Gen-erates R.F. frequencies from 150 Kilo-cycles to 50 Megacycles (150 Kc. to12.5 Mc on Fundamentals and from11 Mc. to 50 Mc. on Harmonicas).R.F. is -tainable separately or modu-lated by the Audio Frequency.

Television and F.M. as well as A.M.receivers can now be speedily aligned.Modulation in the B-45 is accomplishedby Grid -blocking action which hasproven to be equally effective for align-ment of amplitude and frequency modu-lation as well as for television receivers.

The R.F. Signal Frequency is kept com-pletely constant at all output levels. Thisis accomplished by use of a specialgrid loaded circuit which provides aconstant load on the oscillatory cir-cuit. A grounded plate oscillator isused for additional frequency stability.The Model B-45 is truly portable -noexternal source of current required.Operates on self-contained batteries.

Direct reading - all calibrations areetched on the front panel. Complete

self-contained batteries75.

and instructions.

with shielded test lead,

Net

New Model 670SUPERIOR

SUPER -METERA Combination Volt -

Ohm milliammeterplus capacity re-actance inductanceand decibel measure-ments. Includes aspecial good -badscale for checking the

quality of electrolytic con-densers at a test potentialof 150 volts. Complete withtest leads and operatinginstructions. Net $28.40

New Model 450SUPERIOR

TUBE TESTER"Speedy Opera-

tion" assured bynewly designed ro-tary selector switchwhich replaces theusual snap toggleor lever actionswitches.Tests all tubes up

to 117 volts, including 4, 5, 6, 7, 7L,Octals, Loctals, Bantam Junior, Peanut,Television, Magic Eye, Hearing Aid,Thyratrons, Single Ended,Floating Filament, MercuryVapor Rectifiers, etc. AlsoPilot Lights. Net

$39.50Write Dept. SE for FREE New

1947 Catalo !

NeaeftateraotELECTRONIC & INSTRUMENT CO.

Dept. SE 6 MURRAY STREET

NEW YORK 7, N. Y., U. S. A.Phone: BArclay 7-5556

Cable Address: METRONICS

Balanced -Loop

Receiver(See Front Cover)

BALANCED LOOP -ANTENNAS, describeda few months ago in Ser-Cuits, havebecome a design feature of manyreceivers. In the circuit shown on thecover this month appears a balanced -loop application for the Stewart -Warner 9014-E model. The loop istuned indirectly through a close -coupled iron -core transformer whichfeeds a 12SK7 tuned r -f amplifier. Theloop center tap is grounded to the avcbus, minimizing hum pickup. The ex-ternal antenna feeds the loop primaryand short-wave primary in series. Ther -f stage, used on b -c only, uses a 390 -ohm bias resistor without by pass. Aninterstage r -f transformer operates ata high Q by virtue of a reduced load-ing secondary tap for the 12SA7 sig-nal grid (3). The tuning capacitor isconnected across the entire secondary.On s -w, the. signal grid is switched tothe short-wave transformer, eliminat-ing the r -f stage entirely. The tuningcapacitor is connected in series with315 mmfd to limit the tuning range.

A tuned -grid cathode -feedback os-cillator is used with a grounded plate(screen grid) on both b -c and s -w, thegrid and cathode being switched fromone oscillator to the other. Unusedcoils are left open.

The i-f amplifier uses a 12SF7 witha 47 -ohm cathode resistor and con-ventional transformers. The diode de-tector-avc bus is biased slightly posi-tive through the detector -load resist-ance to the 12SK7 audio cathode bythe RI drop in the 2,200 -ohm cathodebias resistor. The load resistance con-sists of 47,000 ohms in series with aTA-megohm volume control. A tonecontrol shunts the volume control witha .0008-mfd capacitor. The first a -famplifier is unusual in several ways.First, it has a remote cut-off pentode.In addition the potentials of the ele-ments and circuit constants are quiteunique. There is, for instance, a 2.2megolun screen -supply resistor. De-generative feedback from voice coil toscreen is provided by a .02-mfd capa-citor which also serves as a supply by-pass. A separate supply filter in theplate supply consists of 220,000 ohmsand .05 mfd. The plate load resistor isalso 220,000 ohms.

A 35L6 output stage operates intoa tapped output transformer with theB load of the remainder of the receivertied to the other end.

NEWCOMBTHE FIELDSELLINGEQUIPME

AMERICA'STOP QUALITY

AMPLIFIERWILL GIVE

YOUMORE PROFIT

PER SALE

A sound rule for increasing jobber profitswill be sent to you upon request. Write forfree booklet.

2815 So. Hill Street, Dept ELos Angeles 7, California

TRIPLETTTUBE TESTERATTACHMENTFor Ease in Testing

FOR TUBE TESTERMODELS 2425 AND 2413

$500NET

Plus ISf for ParcelPost aed InsuroneDELIVERY AT ONCE!

Sensational! ... New! ... An external roll chart ina streamlined case. Quickly attached to tester case.Chart fits in carrying compartment in tester coverwhen not in use. Has all the advantages of a bookchart in adding new data. Replacement chartsavailable to cover new tbbes at minimum charge.Handy for checking tube stocks. Order at once!

AKiiViUSUPPLY &ENGINEERING CO., Inc.I 2 6 SELDEN AVE. DETPOIT 1 MICH


SERVICE AIDS

Removing Meter Face Static Charges. Whenpolishing the glass face of sensitive meters thepointer will often move over a portion of thescale and appear to remain at a certain position.

This is caused by a static charge being devel-oped by rubbing the cloth over the glass. Thecharge may be neutralized by blowing one'sbreath on the dial face of the meter and thepointer will return to its original position.

Loop in Cover of Tester As Antenna. A smallloop attached to the lid of a test unit with tapemakes a convenient antenna for test purposes.

As shown a test lead is connected from oneterminal of the loop to the antenna post of thereceiver, in which case the loop is used as asingle wire antenna. It also may be easily con-nected in place of regular loop.

Light to Simplify Repairs. When solderingparts in dark places it is difficult to hold solder,iron and a lamp. A strip of solder wrappedaround a pen lamp will solve the problem, thelamp guiding the solder to the desired point.This leaves the one hand free to apply the

soldering iron.

MAKES 90 OUT OF 100 RADIO

TROUBLES Easy to Repair!

TELLS WHATTO DO EXACTLY

NOW TO DO ITAs valuable to a radiorepair man as a recipe

book is to acook!

Complete, Easy Instructions for RepairingCommon Troubles in Practically EveryModel and Make of Radio in Use Today

Eliminates Needless Testing - EnablesYou to Repair Two Radios in the Time

Ordinarily Required for One

PAYS FOR ITSELF ON THE FIRST JOB!What's wrong with the radio you want to repair? A defec-

tive transformer? Wiring insulation trouble? A faultycapacitor or resistor? Don't guess ! Don't waste time inneedless, tedious testing! Just look up that particular makeand model in Ghirardi's famous RADIO TROUBLESHOOT-ER'S HANDBOOK. Nine times out of ten, this big bookwill tell you exactly what is wrong-and exactly how torepair it. You don't have to be an expert to use theHANDBOOK- and there's no better way of getting in-valuable, practical service training. Over 400 pages arechock-full of this factual Case History repair data on over4,800 receivers, auto radios and record changers of 202different manufacturers-practically every radio set in usetoday! Over 300 additional pages contain hundreds of re-pair charts, tube charts, data on tuning alignment, trans-former troubles, tube and parts substitution data, colorcodes-all designed to help you repair any radio ever madeEASIER, BETTER and FASTER. Ideal for either busyservice shops or for beginners.Only $6 complete - on our 5 -DayMoney -back Guarantee basis.

Ghirardi's RADIO TROUBLESHOOTER'S HAND-BOOK (above) is the ideal book to have on handfor training new helpers, repairing either cheap orexpensive sets quickly and profitably, eliminatingneedless test time and equipment-and MAKINGMOPE MONEY.

ALL THE SCIENCE OF RADIO-

ELECTRONIC SERVICING GIAN4TOIOOK

MAKES COMPLICATED JOBS EASY TOAlfred A. Ghirardi's MODERN RADIO SERVICING

gives you a COMPLETE, MODERN EDUCATION in trulyprofessional radio -electronic service methods of the kindthat will be your "Open, sesame!" to the big -money op-portunities that only well -trained servicemen are in a posi-tion to grasp. It is a complete, scientific servicing coursefrom A to Z. You'll be surprised how easily understandableit makes every phase of the work even if you have had noprevious service training. And, if you are already in thebusiness, you'll be pleased to learn how this big 1300 -pagebook will serve as a "refresher" course. Not only will ithelp you handle repair jobs quicker, better and moreprofitably, but it also will give you the necessary basictraining to equip you for profitable industrial electronicwork. Specifically written and designed for home study.1300 pages : 706 clear illustrations. '720 Self -Test ReviewQuestions make it easy for you to check your progressevery step of the way. Fully indexed. Only $5 on ourfamous 5 -Day Money -back Guarantee.

MONEY -BACK GUARANTEEMURRAY HILL BOOKS, Inc., Dept. S-106,232 Madison Ave.. New York 16, N. Y.

fl Enclosed find $ for books checked; or n sendC.O.D. (U.S.A. only) for this amount plus Postage. I mayreturn the books for refund within 5 days if not fullysatisfied.

RADIO TROUBLESHOOTER'S HANDBOOK $5($5.50 foreign)

n MODERN RADIO SERVICING $5 ($5.50 foreign)r MONEY -SAVING COMBINATION OFFER: Both of the

above big books, only $9.50 ($10.50 foreign)

Name

Address

City & Dist. No. State

DOI

ENDORSED BY EXPERTSEVERYWHERE

From beginning to end. MODERNRADIO SERVICING brings you thekind of modern professional "KnowHow" that will pay big dividends foryears to come. Gives complete data ontest instruments and their use, pre-liminary trouble checks, scientific cir-cuit analysis and trouble -shooting,parts repair and substitution, how tostart and operate a successful servicebusiness and many other subjects.

SPECIAL FOFFER si

Let RADIO TROUBLE-SHOOTER'S HANDBOOKsave you time on commonradio service jobs! LetMODERN RADIO SERVIC-ING train you for completeprofessional, electronic work.Get BOTH BIG BOOKS atthe special price of only$9.50 for the two. Send cou-

pon today!


WE SHIP ANYWHEREIN THE WORLD

Tecucaeioseally9401444

$219eac,,

Makes anideal workand displayfixture forselling newRecordChangers. Allnew combination sets arenow being made with Rec-ord Changers. Cash in onthis business. Order yourCHANGERAK now!

SEND FOR

COMPLETE

LIST OFAVAILABLE

RADIO TUBESAND PRICES

COMPLETE WITH

HARDWARE

LATEST DATE OF

MANUFACTURE

$1195

rgEE CATALOGSend for free catalog

and prices of hard -to -get Radios,Radio Tubes, Radio Parts, Pickups, Motors,Condensers, Tube Checkers, Volt and OhmMeters, Signal Generators, Signal Tracers, etc.Please mention Service when writing.

FLANAGANRADIO CORP.

Phila.'s Largest Stock of Radio Tubes

N. E. Cor. 7th & Chestnut Sts.Philo. 6, Penno.-U. S. A.

NEW MODELS

U. S. Television projection -type televisisn re-ceiver providing a 16" x 21" image.

Emerson model 51: a-eld-c model with built-in loop.

Stewart -Warner 9013-A five -tube three -band a -creceiver designed for the export market. Sandscovered are: 531 to 1650 ko; 2 t 7 me and 7

to 22.2 mc.

Garod 5D 8.4s/d-c battery 5 -tube miniature,three-way portable. Loop antenna in front -raising

lid. A nice V p -m speaker.

namePLEASE

Are you on the mailing list)I

our bulletins and cats-llogs? If not, you ought tobe. We've probably got Justwhat you want in parts, orcomplete rigs, and our prices

are shaved paper-thin. So,send us a note or post card.Keep smart company.

LAFAYETTERADIO WIRE TELEVISION. INC.

DEPT. FJ-6. 100 6TH AVE., NEW YORK 13, N. Y.110 FEDERAL STREET, BOSTON 10. MAIL21 CENTRAL AVENUE. NEWARK 2. N. J.

4eladdA PRACTICAL

RADIOMERCHANDISING

PLAN

.httC5911146.reitfate

SEE BACK COVER


OLD TIMER'S

CORNER

by SIRVICIR

DROPPED INTO PAUL'S MODERN andwell -stocked radio and electronic shopthe other evening and found him in avery blue mood. I knew it could not bethe store and its contents which wereworrying him, because of all the shopsin out town, his was the best stocked.He hau the same sales personnel he al-ways had; and Paul was in the habit ofmaking a pretty penny each year, as hisincome tax payments attested. So itwas with considerable curiosity that Iasked Paul to tell me what was thematte:.

"Well," he said sorrowfully, "I haveprize trouble."

Wha. do you mean by prize trouble f"I rejoined.

"Well, last week a member of theLadies Evening Society came in andasked me to contribute to their affair. Irefused because I have been consistentlyvictimized and because I felt there wasnot much good to he achieved from theirSociety.

"Today I find that I sent a refrigera-tor to one of the Society members onapproval, for testing, against a well-known gas model, and she has returnedit with the statement that if I can't helpher Society, I can't sell her anything.And that's not all. I have been told bya number of my better customers thatthey know all about my refusing theirSociety and that they will govern them-selves accordingly.

"In the past five years I have given toeach and every organization that camealong. They have had all sorts of prizesfrom me, without charge. I neverlearned the names of the winners, exceptby accident, and I finally got the ideathat this was just a polite form of black-mail, and that I would have no more ofit. Then,' with the first refusal, thishappened,' he ended sorrowfully.

"Looks like you're in a pickle," I said,"but wouldn't you be interested in con-tributing to various affairs if you knewyou could turn the gift into a nice sellingcampaign?"

"I've thought about that," Paul replied,"but I haven't been able to hit on anyparticular way that I could turn theaward into more business. If I could geta bit of publicity or advertising out ofthe gift, beyond having my name appearon the program of the affair, and havingit read over the loudspeaker at theshindig, I would reconsider the wholething.

"It's not that I begrudge giving some-thing which may be worth anywhere unto $25, but I do resent the pressure putupon me that if I don't give, I'll be madeto suffer. That I can't stand; it goesagainst my grain I" Paul declared.

"Well," I said, "if that's all that's(Continued on page 32)

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INDUSTRIALINTERCOMMUNICATIONS

DURING THE PAST TEN YEARS thou-sands of intercommunication systemshave been installed in offices, factories,warehouses and similar establishments.Nearly all of them have been of theconventional type employing one ormore amplifiers with direct manualswitching of desired circuits or sta-tions. This method of operation insmall systems, generally of ten stationsor less, has proved very practical, pro -

by MAURICE F. KERR

Fig. 1. View of dial -controlled intercom.

munications unit.

viding efficient, rapid, voice communi-cation at reasonably low cost.

In analyzing the overall require-ments of a communication system forlarger plants, however, many itemsmust be considered in addition to therequirements of a smaller system.Such a system should provide:

(1) Fully selective instant voicecommunication to any required num-ber of stations.

Fig. 2. Block diagram for a typical dial -controlled intercommunications system.

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(5) Automatic priority from cer-tain points of origin for emergencycalls, warning signals, alarms orother messages over the system.

(6) Simplicity of operation tofacilitate correct use by inexperi-enced operating personnel.

(7) Privacy of communicationthrough automatic lockout circuitwhen station is in use.

(8) Ability to work through sev-ere or high noise level at either end.

(9) Dependability of service, withroutine maintenance requirementsconcentrated at one central point.

(10) Ability to add to system asrequired in future without rewiringor obsolescence of installed equip-ment.

During the war a system' offeringthe foregoing features was developed.Recently technical highlights on thesystem were released.

In simplest form the equipment canbe controlled from any desired num-ber of instruments similar in appear-ance to a standard desk telephone(Fig. 1). From any of these identicalstations the following service is pos-sible:

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(b) Hi -power paging to anyselected area or an entire plant ifdesired.

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OLD TIMER'S

(Continued from

CORNER

page 29)

bothering you, I have an answer to yourwoes."

"Give, chum, give 1" Paul grinned."Instead of giving away some definite

item, why not give away a gift certificatefor the face value of the item you wergoing to give away in the first plac,I stated triumphantly.

"I tried that," Paul said, "but it din.work any too good. They came in andgot their prize and there I was the sameas before; no publicity and no advertis-ing."

"You didn't let me finish, my finefeathered friend," I exclaimed forcibly."There's more to it than that !"

"Continue," said Paul, "but it hadbetter be good-very good."

"One of the prerequisites of the prizeaward as written on the back of yourgift certificate is that the winner mustpermit you to take his picture receivingthe gift at your store. And you shouldalso include in writing on the back ofthe certificate award, that the winnermust permit you to use his picture andsome quotation by him about the awardin your advertising."

"I begin to see some light," Paul said,interrupting.

"Then when the winner comes to yourstore for the choosing of the prize," Iwent on, ignoring his remark, "you geta good commercial photographer andtake a picture of the person choosing theprize and receiving it from you. Thenyou write a caption that might say :'Mrs. Sadie Prey, of 1333 Pine St.,choosing a fine Red Star Midget fromPaul's Radio Shoppe, 100 BroadwayAve. Mrs. Prey was the lucky winnerof the Blotto game at last night's meet-ing of the Ladies Evening SocietyBazaar, and received as her prize a giftcertificate donated by Paul Prime,proprietor of the radio shop.'

"The newspaper editor will probablyrewrite your caption to fit the space hewants to use, and he will probably cutthe picture down to a small size, but hewill probably run it. That's the impor-tant thing.

"Then you can cut the clipping fromthe paper and paste it on your window.That will attract some people. I wouldalso cut out a copy to send to Mrs. Preyand another to send to the president ofthe Ladies Evening Society. They willappreciate your thinking of them.

"Finally, I would follow up on Mrs.Prey with a service call to see that herprize item worked properly. I would ex-plain to her that merely because you hadgiven her the item as the result of herwinning a prize certificate, you wouldnot thereby deprive her of the samesuperior service that every customer ofyour store gets. That creates good will.

"If the paper does not print the item,and sometimes they won't, then I wouldstill take advantage of the situation.Paste the picture on the window with apersonally written caption. Send copiesto both Mrs. Prey and the president ofthe Society with the comment that youthought they might like to have a copy.

"And I would use Mrs. Prey's pic-ture in advertising placed in the localpaper. Moreover, you could design an

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envelope stuffer built around the awardand the picture of Mrs. Prey. You mightuse a headline saying :

Mrs. Sadie Prey Was Lucky . . .

And You Will Be Too . . . If You Trade atPaul's Radio Shoppe

BecauseHere You Will Find the Best Equipment and

Service at the Best Prices!

"And I would use Mrs. Prey's pictureto illustrate the story. Then I wouldsend these stuffers out to as many cus-tomers and prospects as I could dreamup.

"One thing, though. If you are goingto use Mrs. Prey's picture in advertisingor even on envelope stuffers, you'll needa release from her. This is a statementthat she will permit you to use the pic-ture as you see fit. You don't need anylawyer to write the release for you. Justhave Mrs. Prey sign a statement thatreads something like this : 'In considera-tion of receiving the prize for which I

hold a certificate, I hereby permit Paul'sRadio Shoppe to use my name and pic-ture in advertising and publicity as itmay see fit.' Have her sign her nameand date it, and that's that."

"That is a most unusual way to handlewhat is really a pesky situation," Paulsaid, "but I think I'll give it a try. Butwhat if nothing happens and I don't getany new business?"

"That's the chance every advertisertakes. The fact that you might not beable to get customers hasn't stopped youfrom opening your store, has it? Well,you will find that if you try publicity andadvertising, even if the results don'tshow right away, they will eventually."

"What about the gyp affairs?" Paulwanted to know.

"Well," said I, "I don't know how anybusiness man out from underhaving to use his head and brains if hewants to stay in business. It's up to youto find out which are the gyps andwhich are not. One good way is to askyour bank about it, mentioning who'sbacking the affair. Nearly always thebanker will know as he probably willhave been solicited also. Then again, ifthe approach is by mail, you can ask thelocal postmaster; it being against the lawto defraud by mail.

"There are many ways to find out.The local pastor, rabbi or father willknow the answer if the affair is allegedlyreligious. You can't just make up yourmind they are all gyps because one ortwo might be. That would be sort of likesaying all men are murderers just be-cause some men have been convicted ofthe crime."

"Roger !" said Paul, as he reached forthe phone to tell the Ladies EveningSociety that he would contribute a giftcertificate worth $25.00 for their affair.

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WHAT THE 96A DOES FOR YOU: It makes possible the saving of one stageof amplification, and it permits the use of a long -life precious -tip needle with a high -output pickup. Such a light -weight tone arm means that the records and needles willlast much longer. The 96A "Glider" is less susceptible to floor vibrations, improvesthe playing of warped records, and is especially suitable for Vinylite records.

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SERVICINGHELPS

by 'FRANK C. KEENE

I PLAN TO INSTALL a multiple head-phone system in a hospital and wouldlike to have circuit showing a hookupfor this. Can you help?-C. H.Carrier.

The simplest and most satisfactorytype of system for bedside receptionwould be one using an audio supplyunit with a 500 -ohm line to feed head-phones at each bed. Radio type sys-tems are unsatisfactory where highr -f noise levels are present.

A typical system is shown' in Fig.1 (a). Constant load can be main-tained by using a three -circuit jack(b), which would provide for the in-sertion of a resistor of equivalent loadvalue to the headphone when theheadphone is disconnected. A furtherrefinement would be a T -pad attenu-ator, (c), so as to reduce the volumein the headset, yet maintain constantload impedance and match, betweenheadphone and line.

The carrier -current type system canbe used but this requires a complexsetup. Needed are a standard re-ceiver to feed a local mixer whichwould convert the receiver signal tosome secondary frequency, such as ani-f frequency. This signal would thenbe fed to a r -f amplifier tuned to the

Fig. 1 (Carrier query). In (a) appears anaudio supply system for a hospital receiving.rrangement, using a 500 -ohm line; (b). main-taining constant load with a 3 -circuit jack; I c),T -pad attenuator hookup for constant -load im-pedance and matching between headphones and

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new frequency. The amplifier requiredis a class A type.

What would cause a receiver to pickup static, but no signali-Jack L. Seib

This condition can almost always betraced to an inoperative oscillator.

In checking oscillator circuits, it isfirst necessary to determine whetherthe circuit is oscillating or not. Thismay be done by either of two methods.The first is by use of a v -t -v -m. If thecircuit is oscillating, a voltage shouldappear across the oscillator grid shuntresistor. This voltage should be onthe order of 3 to 12, depending on thetube used. The other method involvesthe use of a second receiver. The re-ceiver under test is first tuned to someknown frequency, preferably at thelow -frequency end of the dial. Theantenna wire of the second receiver isthen placed somewhere near the oscil-lator coil. The second receiver is thentuned to the vicinity of the first re-ceiver plus the i-f frequency of thereceiver vender test. For example, ifthe defective receiver is tuned to 500kc, and uses an i-f of 465 kc, the sec-ond receiver should be tuned to 500

465 kc, or 965 kc. If the oscillatoris functioning, a hush will be heard.If the second receiver uses a b -f -o, thesignal of the first receiver should es-tablish a beat note.

The most usual trouble encounteredin oscillator circuits, in the order oftheir frequency, is defective tube, nooscillator .-plate voltage, broken wireson the oscillator coil or poor connec-tion on the coil, open grid resistor, oropen cathode resistor. Usually, onceit has been established that the oscil-lator is not operating, the trouble willbe obvious.

Fig. 2 (Seib query). Two typical convertercircuits. Right, below, the conventional platetickler feedback circuit. The grid voltage isdeveloped between points a and b on the oscil-lator grid resistor. This voltage can only bemeasured with a v-t.v.m. A likely point oftrouble is the ground connection on the gridcoil. Left, below, the cathode type of oscillatorcircuit. Here, the cathode is connected to a tapon the oscillator coil. The screen grid of thecircuit is actually the oscillator plate, but a by-pass capacitor places it at ground r -f potential.Grid voltage is developed across the grid resistor.

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THE NEW G-55 HAND GUN was designed especially forsmall -quantity users of the larger sizes (7/32", 1/4", 9/32")of Cherry Blind Rivets. (Used with an adapter, it also installsthe smaller rivets.) The more expensive pneumatic guns areprimarily production line tools. But for small -quantity rivetinstallation, or for field work where air pressure is not avail-able, the hand gun is perfect. The relatively inexpensiveG-55 Hand Gun is light weight and easy to handle.

CHERRY BLIND RIVETS are available in aluminum, steel,brass and Monel.

For more information regarding Cherry G-55 Hand Gun, and other CherryRivet products, write to Dept. J-268, Cherry Rivet Company, 231 WinstonStreet, Los Angeles 13, Calif.

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Triplett 6061 .. Regular $16.67Voltage & Polarity Tester, Special gio I 1.94Ideal for plant maintenance work! Checks 115-220-440line at a glance! Indicates AC or DC visually! Indi-cates DC Polarity visually!

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BONOT NEEDLE DISPENSERA self-service type of needle dispenserhas been announced by the Bonot Com-pany, Stamford, Conn.

* * *

LAIRD NOW EPEM CHAIRMANRoy S. Laird, sales manager of

Ohmite Manufacturing Company, Chi-cago, has been elected chairman of theAssociation of Electronic Parts andEquipment Manufacturers. He succeedsJ. A. Berman, sales manager of ShureBrothers.

Les A. Thayer, assistant sales managerof Belden Manufacturing Company, Chi-cago, is now vice chairman. Miss H. A.Staniland, sales manager of Quam-Nichols Company, Chicago, continues astreasurer for the seventh consecutiveyear, and Kenneth C. Prince, Chicago,attorney, continues as executive secre-tary.

* * *TRI-CORE BULLETIN

A 4 -page bulletin describing Tri-Corehas been issued by Alpha Metals, Inc.,359 Hudson Ave., Brookly- 1,, New York.

Tri-Core is said to be a self -fluxingsolder, with three cores located justbeneath the outer surface of the wire.

* * *MORRIS NOW SNYDER G -S -M

Dick Morris has been appointed gen-eral sales manager for the Snyder Manu-facturing Company, Philadelphia.

Mr. Morris has been with the Snydercompany for eight years.

* * *GOLENPAUL AND JABLON NAMED

PARTS SHOW DIRECTORSCharles Golenpaul, Aerovox Corpora-

tion, New Bedford, Massachusetts, andWalter Jablon, Hammarlund Manufac-turing Company, New York City, havebeen named directors for the 1947 RadioParts and Equipment Trade Show.

Mr. Golenpaul and Mr. Jablon willrepresent the Sales Managers Club. Mr.Golenpaul was a director and the vice

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"GON- SET"F.M. Convertersare available inthree bands, cov-ering the follow-ing frequencies:

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RADIONIC EQUIPMENT CO.170 Nassau St., Dept. 2510New York 7, N. Y.Please send me a FREE copy of your1947 Catalog. I understand it has thou-sands of items illustrated, described andpriced and will be a great help to me inmy search for "hard -to -find" radio equip-ment. CHANCELLOR RADIOSName

\ AddressCity State


president of the 1946 show. Mr. Jablonsucceeds R. P. Almy.

* * *

KAHN OF AEROVOX RECEIVES ASACERTIFICATE OF APPRECIATION

Louis Kahn, assistant chief engineerof Aerovox Corporation, recently receivedthe American Standards AssociationCertification of Appreciation for volun-teering his time and experience in theWar Committee Work of the A. S. A.

* * *

BRENDEL BECOMES HALLICRAFTERSGENERAL SERVICE MANAGER

Lynn Brendel has been appointed gen-eral service manager of the HallicraftersCompany.

Mr. Brendel, who joined Hallicraftersin 1945, will be responsible for the ser-vicing of all Hallicrafters equipment andthe operation of the cqrnparty's six ser-vice centers throughout the country.

Mr. Brendel was formerly with UnitedMotors Service as a sales and serviceengineer, and with the Bendix RadioCorporation in Detroit as a sales and re-search engineer.

* * *

STROMBERG-CARLSON P -A FOLDERA four -page folder describing sound

systems, power amplifier cabinets, ampli-fiers for one, two and three -microphoneinputs, p -a portables, speakers, micro-phones, driver units and alnico V conespeakers, has been released by the sounddivision of Stromberg Carlson, 100Carlson Road, Rochester, New York.

* * *

WARD LEONARD RELAY DATAA 4 -page booklet, bulletin 104, cover-

ing midget metal -base relays, has beenannounced by Ward Leonard ElectricCo., 31 South Street, Mount Vernon,New York.

Bulletin includes coil and contact data,contact arrangement diagrams, dimensionskeches of front and rear mounted unitsand enclosing cover data for both stand-ard and heavy duty relays ; relays de-signed for use in small transmitters, air-craft control circuits and applicationswhere space is limited.

* * *

LARRABEE AND TWYMAN NOWJFD SALES REPS.

Fred H. Larrabee has been appointedsales representative for Kansas, Ne-braska, Iowa and Missouri by the JFDManufacturing Co., 4117 Forth HamiltonParkway, Brooklyn 19, New York. Salesheadquarters are located at 6033 MainStreet, Kansas City, Missouri.

B. G. Twyman & Associates, 6406North Fairfield Avenue, Chicago 45, Ill.,have been assigned the state of Illinoisby JFD.

* * *

REEVES CATALOGA catalog describing instantaneous

recording discs has been announced byReeves Soundcraft Corporation, ReevesInternational Building, 10 East 52ndStreet, New York 22, N. Y.

STAYS ACCURATE Year After Year

--4/7

Here's a sturdy, modern test oscillator that's accurate when youbuy it-and keeps its accuracy in long service. Convenient pushbutton selection of ranges from 100KC to 30MC.

MODEL 640TEST OSCILLATOR

A complete standard type oscillatorfor all general purpose work. Fullrange direct reading dial. All rangesare fundamental frequencies. Noskips or harmonics calibrated.

Accuracy guaranteed to 1/2 of1% on all ranges.

Push button selection of allranges makes operation fast andaccurate.

Glass enclosed dial preventsdust and protects the pointer.

Two circuit attenuator providesvariable ratio and also verniercontrol.

Powerful signal output usableas pure or modulated R. F. carrieris modulated at approximately30%. The A. F. voltage is availablefor external use.

Operates Irom 110 volts 60 cy-cles. Uses three tubes: rectifier,oscillator, and modulator.

Dimensions: 81/2' x81/2" x 61/2".

WeAtrewig;d* fiJACKSON ELECTRICAL INSTRUMENT COMPANY, DAYTON, OHIO


EASILY ADJUSTABLE FOR THE JOB

ADJUSTOHM RESISTORSSeven Stock Sizes from 10 watts to 200 watts

Send forCatalog D-2Gives bandy dataa d Informationen various typesof Resistors andRheostats avail-able from stock.

You can often save time, work and moneyoy using WARD LEONARD ADJUSTOHMS. Re-sistance can immediately be adjusted to the value youneed .. . or tapped .. . on the job. Besides ... youknow these Resistors will give the finest service be-cause they are WARD LEONARD quality.Available from Authorized Distributors Everywhere

WARD LEONARD ELECTRIC CO.53E W. Jackson Blvd., Chicago 4Radio and Electronic Distributor Division

WARD LEONARDRELAYS RESISTORS RHEOSTATS

Electric control devices since 1892

Automatic Combinations-NOW!The New Arnold ShureAutomatic Wired RecordPlayer ready for imme-diate delivery.The Shure automatic recordplayer connects easily to anyradio. Its featherweightcrystal pickup and quiet,smooth changer action assurehigh quality playing of ten12" records or twelve 10"records. Every one of yourcustomers can now own afine automatic combination ata remarkably low cost.

Shure players are shipped complete withA.C. cord and shielded cable-only 2wires to connect and it's ready to play.

PHONO AMPLIFIERSYour price only $21.92 net I -Tube Phone. Amplifier 82.35 ea.

3 -Tube Phone. Amplifier 4.50 ea.F.O.B. chkase, Illinois

PM SPEAKERSOPA Retail Price - $31.30 - Zone 1 4" Alnico (5)asPM Speaker 11.sa ea.

5" Alnico (5) PM Speaker 1.49 .

OPA Retail Price - 33.87 - Zone 2 6" Alnico 5) PM Speaker 1.89 ea.

Orders are now being accepted for immediatedelivery-no waiting. Terms: 2e/e cheek withorder. Or 25% deposit, balance express C.O.D.

TUBULAR ELECTROLYTICS100-MFD- 25 V...9 .22 ea.10-MFD- 50 V... .22 ea.20-M FD- 150 V... .22 ea.30-M FD- 150 V... .29 ea.40-M FD150 V... .39 ea.50-MFD-150 V... .45 ea.5-11F21450 V... .25 ea.

10-MFD-450 V...$ .29 ea.16- M F 0.450 V. .39 ea.

10.10-M F13.450 V. .59 ea.20-20-MFD- 150 V. .29 ea.30-20-M FD -150 V. .39 ie.40-30-MFD150 V. .45 ea.50-30-MED-150 V. .59 ea.

HOLLANDER RADIO SUPPLY CO.549 West Randolph Street Chicago 6, Illinois

EWPRODUCT

HI -PAR F -M ANTENNAA non -directional f -m antenna has

been produced by the Hi -Par ProductsCo., Fitchburg, Massachusetts.

Collector rods of aluminum alloy.Varnished hardwood support.

Antenna said to match any standardleadin.

* * *SOLAR DRY ELECTROLYTICS WITH

PLASTIC -FILM INNER WRAPSolar cardboard -tube dry electrolytic

capacitors now feature a plastic filmwrap in place of the Kraft paper liner.

The plastic film is said to keep theelectrolyte from drying out in highambient operating temperatures, andalso keep external atmospheric moisture,which may contain many impurities,from being introduced into capacitorsunder the alternate heating and coolingwhich is normal in actual service inreceivers.

* * *CENTRALAB MINIATURE RADIOHMSA volume control, model 1 radiolun,

that is said to be smaller than a dime,has been announced by Centralab, 900 E.Keefe Ave., Milwaukee 1, Wis. Unitwill be available in 500 ohms to 5 meg-ohms with six tapers.

* * *MASCO P -A SYSTEMS

A 50 -watt amplifier that is said tooperate from 2 to 12 speakers has beenannounced by the Mark Simpson Manu-facturing Company, Long Island City,



INTERCOM SYSTEM CAPITOL RADIO ENGINEERING INSTITUTE - Where Professional Radiomen Study

(Continued from page 30)

station originating, without calledparty even knowing point of

) Either two-way, voice con-trolled, intercom service, or uponlifting handset at called station,telephone privacy is available.'Through anti -side tone circuitsability to work through severenoise level is provided.

No ringers or other signals are re-quired: each instrument has built-inloudspeaker adequate for office or sim-ilar coverage.

On systems up to 100 stations two -digit dial operation allows direct talk-ing to called area as soon as dial stopson second number.

Three digits are used on up to 1000stations. Three or four digit selectionis employed on more complex pagingselection.

In a typical installation all ampli-fiers, tubes, relays, power supplies,selectors, etc., are located in a dustsealed and locked steel cabinet locatedin any convenient central point. Allmaintenance therefore is concentratedat one location, avoiding necessity ofreplacing tubes or other maintenancein offices, salesrooms, warehouses, etc.,with its attendant high cost and incon-venience.

Operation

Upon lifting of handset on station11 (Fig. 2) an automatic finder

//) locates and connects to an ampli-fier and output selector not beingotherwise used. This finder may checkthrough twenty or more amplifiers be-fore the handset is raised to ear level,automatically stopping and connectingto the first unused circuit. The usermay immediately dial two digits forthe desired station in accordance withprearranged listing of all circuits orfunctions.

The output selector A instantly fol-lows the dial pulses, selects and con-nects to desired station. As soon asdial has stopped, therefore, the usermay speak through the loud speakerat the selected station. Upon ceasingto speak the two-way voice controlledamplifier reverses, permitting a voiceanswer from the called station to betransmitted and amplified back to ear-piece at the originating station.

If the called station is already in useon another call, no connection would


Service M 19. Photo

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Foresighted radio servicemen are looking ahead to thefuture. A future that has unlimited opportunities andreal profits for those who have the "Know -How" toSERVICE television, FM, industrial electronic equip-ment, and the many other new radio developments.

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CREI's reputation for home study training has beenproved over 19 years. Important new developments havebeen included in our present course. Trained instructorsgive you personalized attention and guidance all the way.

Find out for yourself how CREI can help you to greatersecurity and prosperity. Send in the coupon now! Actu-ally see what CREI has to offer.

VETERANS! CREI, IS APPROVED FOR "G.I." TRAINING!

RESISTANCE-To New Ideas Has CostMany a Man a Great Fu-ture. We all know theclassic stories of the peo-ple who scoffed at Edison,Ford, Deforest. It weethe scoffers who lost outwhen the rewards pouredin. Now with radio-elee-tronics entering a great,new era, when it may wellemerge is greatly magni-fied form, you fellows whoare in on the ground floorand don't prepare now forthe future fall in the samechess as those early scof-fers.

e,(7-gtodoo left

Capitol Radio Engineering InstituteE. H. RIETZKE, President

Dept. S-10, 16th and Park Road, N.W., Washington 10, D. C.Branch Offices:

San Francisco (2): 760 Market StreetNew York (7): 170 Broadway

MAIL COUPON

FOR FREE 364PAGE

BOOKLET

If you have had professional or amateur radioexperience and want to make more money, letus prove to you we have the training YOU needto qualify for a better radio Job. To help uslatelligently answer your inquiry-PLEASESTATE BRIEFLY YOUR BACKGROUND OFEXPERIENCE. EDUCATION AND PRESENTPOSITION.

1

1

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Capitol Radio Engineering Institute S -I0lath and Park Road, N. W., Washington 10. D. C.

GENTLEMEN: Please send me your free booklet."Your Opportunity is the New World of Electron-ics", together with full details of your home studytraining. I am attaching a brief résumé of my ex-perience. education and present position.

Name

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City Zone State

Cheek Course Practical Radio Engineering0 Practical Television EngineeringI

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am entitled to training under the G. I. Bill.


INTERCOM SYSTEM(Continued from page 39)

be made, but a busy tone would beheard in the calling station earpiece.

When private conversation is desiredwithout loudspeaker reproduction, thecalled party may raise his handset anda two-way telephone service is avail-able. For executive office, a privacykey may be installed on the instru-ment, that when operated, prohibitsany party from calling in by voice orlistening to that point. An attemptedcall then produces a one -second lowmusical tone in the loudspeaker and

to the party calling, whereupon thecalled party may answer or in anycase, the caller knows of the calledparty's desire for privacy. Loudspeakervolume is controlled and set to thedesired level at the receiving pointregardless of what channel or ampli-fier the voice may pass through. Ear-piece volume is controlled by multiplestage liniiters and compressors holdingearphone volume to an optimum leveleven for wide levels of voice input, toinsure adequate amplification for ananswer remote from the pickup oranswer microphone, yet preventing ob-jectional loudness on close talking orhigh noise. Automatic voice control

STATION

5 PAIR

STATION

5 PAIR

STATION

5 PAIR

TOTAL 500 WIRESTO TERMINATE HERE

CENTRALAMPLIFIER

110 V A -C

5 PAIR

5 PAIR

NATIONa

STATION

amplifiers adjusted by oscilloscope pat-tern timing, operates on a fraction ofa syllable, permitting instant answer'or breakin.

When hi -power paging is to beused, calls are placed in same manneras calling another station except thatadditional numbers are dialed, to selectthe area or areas to be covered. Anyrequired amount of audio power canbe thus controlled from any station orselected group of originating stations.

Any station in use is automaticallylocked out against interference fromany other calls. Upon returning hand-set to cradle all circuits automaticallyreset for next usage.

Fig. 3 (below). Setup for a conventional 50 -station intercom system.

Fig. 4. Setup for a dial -type 50 -station system.

STATION

50 PAIR

1110 V A -C

STATni50 PAIR

110 V A -C

STATION

0 110V A -C

50 PAIR

5000 WIRESTO TERMINATE HERE

STATION50 PAIR

110 V A -C

STATION50 PAIR

110 V A -C

In MI Western States and Mexico

Immediate Mailing of

Howard Sams Photofact FoliosMail $1.50 and your subscription at once.

(If mailed in State of California, please add 5c statesales tax)

TO

RADIO TELEVISION SUPPLY CO., Inc.1509 So. Figueroa Sf.,Los Angeles 15, Calif.

(Also-Permanent Leather Binder for Howard Sams Folios 53.39)

J. V. Duncombe Co.WHOLESALE DISTRIBUTOR

ELECTRONIC EQUIPMENT, TUBES and PARTS1011 West 8th Street Erie, Pa.

Phone: 23-5413

ALL NATIONALLY KNOWN RADIO PARTS-AMATEUR SUPPLIES,NATIONAL UNION, SYLVANIA AND RCA TUBES

TUBES -PARTSRADIO DEALERS-SERVICEMEN

Send for our list of available tubes and repair parts.Sylvania, Tung -Sol, Ken-Rad.

M. V. MANSFIELD CO.457 LIBERTY AVE. PITTSBURGH 22, PA.

IN PHILADELPHIA - IT'S ALMO RADIO COMPANYWholesale Distributors for Supreme & Jackson Test EquipmentAerovox, Cornell Dubilier and Sprague CondensersI. R. C., Clarostat and Centralab Volume ControlsTRY US FIRST!

ALMO RADIO COMPANY509 Arch Street, Philadelphia 6, Pennsylvania

LO. 3-0513 LO. 3-4530

SCENIC has ... "hard -to -get"TEST INSTRUMENTS!

MeMURDO-SILVER "Vomax".$59.85 SIMPSON 260 v.o.m $38.95RADIO CITY 322 tube tester.. 41.50 SIMPSON 305 tube tester 46.25RCP 802-N tube & set tester. 59.50 SIMPSON 240 "Hamster. 21.50APPROVED R.F. sig. Ben 49.50 TRIPLETT 2413 tub* tester.... 40.31WATERMAN 2" oseIllossope 55.00 TRIPLETT 2432 ill. eon. 68.30TRIPLETT 825-N v.e.at TRIPLETT 888-N v.e.m 20.00Also TUBES AMPLIFIERS SPEAKERS, etc

25% deposit should accompany C.O.D. ordersSCENIC RADIO & ELECTRONICS CO., 53 Park Pl., New York 7

GET TEST EQUIPMENT AT:

SPLEriC

16:2M,St.

122.124 DUANE SI. NEW YORK 1, N. Y. BArclay 1.1140

WHEN YOU CHANGEYOUR ADDRESS

Be sure to notify the Subscription Department of SERVICE at 52Vanderbilt Ave., New York 17, N. Y., giving the old as well asthe new address. and do this at least four weeks in advance. ThePoet Office Department does not forward magazines unless you payadditional postage, and we cannot duplicate copies mailed to theold address. We ask your cooperation.


Microhmo (Dynamic mutual conductance) readings and simplified testing-are two of the 20exclusive features found in the new model 2425 tube tester. Transconductance readings are madepossible through a simple measurement directly proportional to Gm and a properly calibrated mea-suring instrument. No possibility of grid overloading. "Short" and "open" tests of every tubeelement. Gas test rounds out full check of all tubes. New Easy -Test Roll Chart. These exclusivefeatures, amplified by Triplett Engineering, make Model 2425 the outstanding 1947 tube tester.

J(ewTRANSCONDUCTANCE

READING

dwide eo-fteie

For the Man Who Takes Pride in His Work

Twevonfrt ... hp. hatTriplettELECTRICAL INSTRUMENT CO. BLUFFTON. OHIO

YOUR RADIO STORE

-111101111111111111111111100

"I CAN'TKEEP A GRILL

IN III ON

EVERY CEREALPROGRAM, HE COMES

CRASHINGTHROUGH WITH

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TO DISPLAY IN YOUR WINDOW!A crowd -pulling cartoon, size 17"z17", drawn especially

for OLSON RADIO WAREHOUSE to give you. It's yours forthe asking, absolutely FREE and postpaid. Display it

in your window or Service Dept. for laughs - and sales!

Why do we make this offer? Because we want you to becomeacquainted with Olson Bargains. We will send you a Free

Catalog with the poster; this Catalog lists nationallyfamous Radio Parts at prices that will save you plenty!

Paste this coupon on a postcardand MAIL TODAY 111

OLSON RADIO WAREHOUSE73 E. MILL ST., DEPT. 59 AKRON, OHIO

Yeti. ea! Send me the Comic Poster Age.

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Install an aerial the new way-

EASIER!FASTER.

BETTER.

As MODERN as 4 wheel hydraulic brakes-compared tomechanical brakes.

VERTROD'S -20 model's cover all wave reception...FM-AM and Television.

VERTROD-vertical models beautify buildings - eliminate poles -Insulators-filters-lightning arrester-climbing.

VERTROD-the most scientific antenna yet evolved.

the old

The VERTROD way (with patented features) Is theMODERN way. At most radio shops. Write for folder 413

VERTROD CORPORATION60 EAST 42nd STREET NEW YORK 17, N. Y.

*Cla elta tom SINAI TRACE afeel a"Peoteer'

PROVAC*Pencil -thin RF probe

The PROVAC electronic vacuum tube volt -ohmmeterpermits the laboratory engineer and radio service tech-nician to measure every voltage required in the designlaboratory and radio servicing.Measure R.F. with the same ease as measuring D.C. withthe latest development in R.F. probes. It is no longernecessary to guess at which point the signal stops.DC Ranges: 0 to 3-10.30-100.303 and 1,000 volts. All rangeshave a constant input resistance of 11,000,1:00 ohms. Accuracy3% ±

AC Roomers: 0 to 10-30-100-300 and 1,000 volts. Sensitivity:1,000 ohms per volt. Accuracy 5% ±

Electronic Ohmmeter Ranges: 0-1,000 ohms, 0-10,000 ohms,0-100,000 ohms, 0-1 megohm. 0-10 megohms, and 0.1,000 meg-ohms.

R.P. Voltage ranges 0/3-113-30-S0 Volts to be measured on 100Volt range.

Bridge Amplifier Circuit Meter individually calibrated for use with set of festleads, signal tracer probe and batteries.

Features of the EDIPROBE Smallest R.F. probe made. Frequency range 60 Cycles to

over 103 Megacycles. Effective circuit loading:

3 mmf. and I megohm. Con be used os on output

meter.

Can be used for measuringdecibels.

Checks condensers for opencircuit.

Works with any standardV.T.V.M.

PROVACModel ED 100 8E050 VTVM Model 100 snow EDIPROBE $085(with EDIPROBE) s.1 (without probe) 04. (RF Probe)._. M

Jobbers and dealers write for exclusive Territory Distribution.Orders addressed to us will be credited to your nearest dealer.

Write Dept SJ for FREE Technical Manual

IRVINGTON. NEW YORK

EDIPROBE

$985

NEW PRODUCTS(Continued from page 38)

New York. Other features include indi-vidual bass and treble equalizers; twohigh -impedance microphone inputs andone for phono pickup.

Sound systems from 12 to 80 watts arealso available.

MONOBLOCK CONNECTORSA multiple -contact connector has been

announced by The Winchester Co., 6East 46 Street, New York 17, N. Y.

Molded of Melamine plastic. Twoguide pins, acting as ground contacts,perform additional functions of align-ment and polarization.

Multiple telescoping barriers serve toisolate contacts, increase both surfacecreepage and air gap between adjacentcontacts. Minimum air gap of main-tained between all contacts. Contacts aredesigned for use with a maximum wiresize of 16 AWG.

Available in two sizes: 18 contacts(RENS) and 12 contacts (RE12S).

BRUNO TOOLS HOLE -CUTTER KITA kit, 790, for cutting holes of various

diameters in wood, metal or plastics hasbeen announced by Bruno Tools, BeverlyHills, California.

Kit contains one adjustable hole cutter(with l/4" shank) for cutting holes h"to l'A" and another cutter (h" shank)that cuts holes 1" to 2Y2".

4 * *

F -M CONVERTERA unit to convert f -m receivers from

42-50 to 88-108 me has been announced


by the Waterproof Electric Company,Burbank, California.

No adjustment or tuning operationsare said to be necessary with the unititself. Size, 1/2" x 2" x 4".

* * *G. R. 10 -AMPERE VARIAC

Adjustable autotransformers, type 10Variac, for 115 -volts, rated at 10amperes, with a 15 -ampere maximum,coinciding with the capacity of com-monly -used outlets, plugs, cords, andNo. 14 wire lines, have been announcedby General Radio Company, 275 Massa-chusetts Avenue, Cambridge 39, Massa-chusetts.

Output voltage continuously variablefrom zero to 17% above line voltage.Available in 6 models, 115 -volt and 230 -volt service.

* * *NEWCOMB PORTABLE SOUND SYSTEM

Portable sound systems ranging from10 to 60 -watts power output, have beenannounced by Newcomb Audio ProductsCompany, 2815 S. Hill St., Los Angeles7, California.

One type, a 3 -case system, includes a30 -watt amplifier, with two 12" loud-speakers.

* * *NHI LINE FILTER

A line filter with six bypass capacitors,two iron -core chokes and two r -f chokeshas been announced by New Home In-dustries, 216 Eldridge Street, New York2, N. Y.

Filter design said to provide filteringof line noises, fluorescent, elevator, andr -f noises which are superimposed on theline.

* * *

SYLVANIA SILICON CRYSTALCONVERTERS

Silicon crystal converters, types1N21B, 1N23B and 1N25, for use asfirst detectors in high -frequency super-heterodyne receivers, have been announcedby the electronics division, Sylvania Elec-tric Products, Inc. The crystals whichare permanently preset in a cartridge ap-proximately 34" long and 14" in diam-

Model 56

WEBSTER &mute/tam/Am.are made by WEBSTER

From raw materials tofinished record changer- that's the story atWebster -Chicago. Partsare made and line as-sembled under constantinspection-resulting inprecision record chang-ers that give the utmostlistening pleasure andservice.

Checi Bede

ubtanding features

Easy to playBuilt for years of use

Fast change cycle Protects records Automatic shut-off

The choice of music lovers

WEBSTER CHICAGO5610 Bloomingdale Avenue. CHICAGO 39. ILLINOIS

32 years of Continuous successful Manufacturing

eter are available in three types designedfor frequencies up to 10,000 mc.

Type 1N21B, designed for frequenciesin the region of 3000 mc, has a 6.5-dbconversion loss, maximum; thermal noise

ratio of 2.0, maximum; and 1-f resistivenpedance of 200 to 800 ohms. Corres-

ponding characteristics for types 1N23Band 1N25 crystals are: 10,000 mc and1,000 mc ; 6.5 db and 8.5 db; 150-600 and100-400 ohms.

*

CONCORD RADIO UNIT AMPLIFIERSAdd -A -Unit type amplifiers, with plug-

in type power supplies, have been an-nounced by Concord Radio Corporation,Zhicago, Ill.

Plug-in power supplies are said to)rovide power output increase from twoco nine times. Additional output stages,to a total of six, can also be added.There is also provision for a phono-



exceihwee in ekebereti.-ARADIO RECEIVING TUBE DIVISION

NEWTON, MASSACHUSETTS CHICAGO

... and put Raythettn tubes inmy set ple.ase,' :That's the cus-tomer specifying "Itaytheon--name he knows to be synonymouswith quality and dependability.Stock Raytheon tubes to keepyour customers happy; to keepyour business growing,

A MUST IN EVERY LAB . . .

ON EVERY SERVICEMAN'S BENCH .

IN EVERY SERVICE KIT . . .

o s c 11'1_7'ot-sic o Pf

kPOCKETSCOPE So SMALL in size (4" x 63/8" x 10") So LIGHT in weight (53/4 lbs.) SoCOMPLETE in performance So

INEXPENSIVE in price Plus WIDE-ANGLE VISION: on shelf, on floor,on bench Plus RETRACTABLE LIGHTSHIELD: for increased visibility.

A 2" "pocket-size" 'scope incor-porating the cathode ray tube,vertical and horizontal amplifiers,linear time base oscillator, syn-chronization means and self-con-tained power supply.

FOR DELIVERY:Contact your nearest jobber. If he doesn't have the POCKETSCOPE available, contact us direct.

WATERMAN PRODUCTS CO.INCORPORATED

PHILADELPHIA 25, PENNSYLVANIA

NEW PRODUCTS(Continued from, page 431

player, record changer, and outputvolume indicator. Portable carrying casesare available.

ANDREW F -M /TELEVISION ANTENNAAn antenna for f -m and television re-

ception, the Di -Fan, which consists of twosets of five elements extended in two dif-ferent directions, has been announced bythe Andrew Co., Chicago 19.

Impedance of the Di -Fan is said to bematched to the impedance of transmis-sion line, preventing ghost images.

Unit uses high -strength aluminumalloy elements. Supporting members areof plated steel. Available with mountingbrackets for chimney or roof.

*

G. E. COMPOSITION RESISTORSComposition resistors have been an-

nounced by the specialty division of G. E.Resistors are available in standard

RMA resistance values and in sizes ofone-half, one and two watts.

Other characteristics of the composi-tion resistors are said to be High re-sistance to humidity ; pigtail leads ; andample insulation.

* * *

STERLING ELECTRONIC TESTERA portable, graphic type servicing in-

strument has been announced by TheSterling Manufacturing Company, 9205Detroit Avenue, Cleveland, Ohio.

The desired function and range areselected by means of two switches of a


graphic selector system. A functionswitch, is set for the type of measure-ment desired; the range switch, is set forthe range of the type of measurement in-dicated by the function switch. Adjust-ment knob is used to set the meterpointer to zero ohms for the three ohm-meter ranges.

* * *

CANNON ELECTRIC LOW-LEVELCONNECTORS

Multi -contact electric connectors forlow-level sound uses, XL series, havebeen developed by Cannon Electric De-velopment Co., 3209 Humboldt Street,Los Angeles 31, California.

Size: 2 3/32" overall length, diameterY8"; provides polarized contact. Hasthree 15 -ampere silver-plated brass con-tacts in phenolic insert to accommodateNo. 14 stranded wire.

* * *

CLARK P -A AMPLIFIERS

Ten, twenty and thirty -watt amplifiersusing terminal -strip component mountingstructure, have been developed by ClarkRadio Equipment Corporation, 4313 Lin-coln Avenue, Chicago 18, Ill.

Terminal strips are mounted so thatevery part is accessible to test prods andsoldering iron. Amplifiers are said tohave a 30 to 15,000 -cps response.

TELEVISION RECEIVERS(Continued from page 20)

of th.. low -impedance triode is that itsplate load is essentially resistive andtransient troubles are non-existent.

The horizontal amplifier must be ahigh -impedance pentode which hassufficient power sensitivity to convertthe relatively low amplitude horizontalwaveform to a large current variationthrough the deflection coils. A high -impedance tube, with no damping ofinductive circuits, has a plate loadNvhich is reactive and, therefore, be-comes a circuit vulnerable to tran-sients, which is another reason forhighly damping the horizontal outputcircuit. In some receivers, a small

A BATTERY OF

SERVICE SHOP

TESTERS IN

ONE COMPACT UNIT!

WITH instruments mounted all over the shop,servicemen must hop around, like the proverbialone-armed paper hanger, to make their tests.Now, in one compact unit, you can have acomplete service shop combination of a multi -meter tube tester, battery tester and capacitortester. Model 805 is the perfect instrument forservicemen working in close quarters, andwhere time saved means money earned. Thisdeluxe RCP instrument has been fully engineeredand produced to give you the maximum in testeconomy and efficiency. See it at our jobbernow, or write direct for the new RCP CatalogNo. 129.

Low -range ohmmeter is back-up, low -draintype; medium -range ohmmeter is powered byself-contained battery; high -range ohmmeter isoperated from plug-in line supply. *Famous ex-clusive RCP Dynoptimum test circuit. *Com-plete leakage tests under rated load for allcapacitors; readings on "Good -Bad" scale.

When You Go to See Your JobberBE SURE TO SEE RCP-BEST FOR EVERY TEST

*Tests ballast and all types of receiving tubes.Neon lamp for speedy short and leakage testbetween elements. *Jack for headphone noisetest of noisy, bad or loose connections. *Fila-ment voltages, from 1.2 to 117 volts, accom-modate all present and future tube filaments.*Full loads for "A" and "B" radio batterytests; readings on "Poor -Good" scale. Testsindividual sections of multi -purpose tubes.*Built-in "Rolindex" Tube chart, mechanicallyperfect, furnishes accurate tube data at the flickof a dial.

RANGESD. C. VOLTMETER: 0/2.5/10/50/250/1000/

5000 volts.0/10/50/250/1000/5000

volts.0/10/50/250/1000 volts.0/1/10/100/1000 ma.0/10 amperes.0/2.50-2500/25000 ohms.

0/2.5/25 megohms.-8 to +16. +15 to+29. +29 to +49.+32 to +55.

A. C. VOLTMETER:

OUTPUT VOLTMETER:D. C. MILLIAMMETER:D. C. AMMETER:OHMMETER:

DECIBEL METER:

RADIO CITY PRODUCTS CO., INC.

127 West 2 6 t h Street, New York 1, N Y

amount of inverse feedback in the laststage is used to reduce the effectiveimpedance of the pentode.

Electromagnetic Focusing

Similar magnetic principles are usedin focusing a beam of electrons. In thistask, however, we rely more on thecharacteristic that there is no reactionbetween perpendicular magnetic fieldsbut as soon as the angle departs from90° there is reaction. The focus coil ismounted on the neck of the tube in aposition which produces a transversemagnetic field;, that is, lines of mag-netic force parallel. to -electron beam.

This means the magnetic field sur-rounding the electron beam is perpen-dicular to the focus field and there isno interaction. Thus those electronswhich move in a straight line throughthe electron gun toward the fluores-cent screen are not affected by thefocus field, Fig. 2 (A).

However, when any electrons de -pal t from this straight line path theirsurrounding field is no longer perpen-dicular to focusing field and the mo-tion of the beam is affected. The elec-trons now move in an arc and finallymake a complete arc returning once

(Conthiued on page 46)


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PAID CIRCULATION NOW OVER 20,000Advertising in SERVICE is read by radio and electronic servicemenwho stock and sell tubes, components, batteries, accessories, test equip-ment, sound apparatus, etc. They can best be sold through advertisingin their magazine - SERVICE.

Closing date November issue, November 5

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TELEVISION RECEIVERS(Continued from page 45)

again to the straight line path. Thespot at which all electrons converge isthe focused point, by proper setting ofthe current through the focus coil andproper positioning of the focus coil onthe neck of the tube. The focus coilfunctions, therefore, as the second lensof the electron gun, first lens remain-ing conventional.

Were it not for the original forwardvelocity imparted to the electron, thedivergent electron would make a com-plete circle and return to the center.However, its forward attraction causesit to follow a so-called helical path,Fig. 2 (B) which is a resultant of theforward attraction and the circular -motion. Thus it can be seen that anumber of points of convergence oc-cur, each of which could be called afocus point. In practice, the beam isonly under the influence of the focusfield for a short interval at which timeit is given a sufficient whirl to havethe majority of electrons return at thefluorescent screen Fig. 2 (C).

SALES HELPS(Continued from. page 11)

utround for trade or waiting monthsand months for people to hear of theShop through the community grape-vine. And no man has enough friendsor relatives to keep a business alive.

Relative Value of Sales Helps

To bring in business and to estab-lish prestige in the community, avariety of sales helps are availablefrom local jobbers: newspaper mats,illustrated direct -by -mail postcards,window displays, counter cards. decals,stationery, shipping labels and matchbooks.

Of course, no amount of sales pro-motion will do much good unless theService Man has made an intelligentsurvey of his local opportunities. Ifthe locality warrants a Service Shop,however, then the shop warrants salespromotion too. A primary source ofradio repair business can be developedthrough the newspapers. For instance,a local paper with a circulation of50,000 usually charges about $10 torun a small mat ad. Figuring in-quiries at of 1%, or 250 prospects,makes the ad an excellent investmentat such low cost. If only 10% of in-quiries is converted, the Service Man

46 SERVICE; OCTOBER, 1946

would get 25 customers spending $5w more on the average.

Use of Postcards

Let us evaluate penny postcards.There are usually several types toselect, each elaborating on the themethat the Service Man, whose imprintappears on the card, is an expert inradio repair work. The Service Manpays only the lc postage for eachcard, and in our program can orderthem from his jobber in minimumquantities of 100 for any one cardstyle. Thus, for $1.00 it is possibleto reach 100 carefully selected pros-pects. Let us assume that 10% isconverted into actual sales, each saletotaling $5 or more. Therefore, theService Man gets about $50 in busi-ness, certainly a good return. Natu-rally, larger mailings do not increasethe percentage but they do increasethe sum total in dollars received.Considering the returns, both matsand postcards are strongly recom-mended as primary sales promotionmaterial for the Service Shop. Notonly do they sell individually, but they

-

support each other's selling efforts.

Choosing Displays

Unfortunately some Service Shopwindows I've seen in my travels looklike Indian medicine shows of the olddays. Everything in it but the torn-tom, and sometimes that too. A simpledisplay sells better. It is wiser to showseveral good, attractive items thatplease the eye than a window piled uplike a stockroom. After all, the spaceis a show window to the public whichjudges the Shop's ability on appear-ances first. No more than two dis-play cards should be placed in anywindow. Too many confuse prospects.

Only one or two decals to a door !I've seen some radio shop doors thatlooked like the tattooed lady. Thepoint to remember about any displayis that if your customer sees too muchhe will remember nothing. Decals,offersA to you by jobbers, should bemounted tastefully but not to obstructthe view of the shop's interior. Theselections should best represent yourreliable service to the community.

Interior displays must be carefullychosen too. Some interiors look likeanything but a Service Shop, withcards and streamers hanging every-where to fill in bare counter space orto hide cracks in the wall. If a dis-play sells your service, and sells itwell, then it should be used. But don'tconfuse the issue with umpty-nine dif-ferent signs, some of which look nicebut deliver no sales message for youat all. Remember, what sells for youis good for your business.

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JOTS AND FLASHESTHE WEEK OF NOVEMBER 241n TO 30THwill be known as National Radio Week.The National Association of Broadcast-ing and RMA are planning quite a sales -promotion campaign for that week. . . .

The National Electronic, Radio & Tele-vision Exhibition scheduled for GrandCentral Palace on October 14th to 19thwas postponed to the early part of 1947.Curtailment of production and corre-sponding lack of receivers and parts wasgiven as the reason for the postponement.

. . Television -antenna installationmethods are now being planned for Chi-cago by R. Cooper, Jr., Inc., Common-wealth Edison and Television Associates.The latter unit was organized by CaptainBill Eddy, station manager of telecaststation WBKB. The Cooper Companyare G. E. distributors. Proposed instal-lation charges will vary from $50 to $60.... Bernard Benson has been named pur-chasing agent for the Utah Radio Prod-ucts Division of International DetrolaCorporation.. . . Don G. Mitchell, pres-ident of Sylvania Electric, has beennamed to serve on the National Distri-bution Council. . . . Major Bernard L.Cahn is now executive assistant incharge of sales and promotion at In-suline. . . . Samuel McDonald, Jr., hasbeen appointed to the sales staff of theradio tube division of Sylvania. He willserve in the New York and Philadelphiaarea. . . . Rex L. Munger has resignedas sales manager of Taylor Tubes, Inc.,2312 Wabansia Avenue, Chicago. . . .

Record receiver production was estab-lished during August when over 1,500,000sets were produced. Of these over 1,000,-000 were table models and over 100,000,console and radio -phonograph models.About 20,000 f -m sets were also pro-duced in August. . . . Barker & William-son have leased a new plant in Bristol,Pa. The present plant at 237 FairfieldAvenue, Upper Darby, Pa., will be re-tained. . . . The annual convention ofHoffman Radio distributors will be heldon November 6th, 7th and 8th at theMayfair Hotel in Los Angeles. . . . Thecurrent issue of the Centralab jobberhouse organ contains a list of pricechanges on volume controls and acces-sories. . . . M. W. Gasner, 71 FrontStreet, East, Toronto, Canada, has beennamed Canadian representative of theNational Electronic Mfg. Corp., LongIsland City, N. Y., who produce autoantennas and components. . . . Elliot A.Witten is now with the advertising de-partment of Radio Wire Television, Inc.,N. Y. C. . . . E. A. Ossmann has beennamed factory representative for AllenB. DuMont Labs. He will operate outof Rochester and cover New York Statewith the exception of metropolitan NewYork and Long Island. . . . WABC willuse new call letters, WCBS, afterNovember 1st. The call letters of thef -m and t -v stations of CBS will also bechanged to WCBS-FM and WCBS-TV.. . . Chester J. Frey has been namedeastern district sales representative forthe Belden Mfg. Corp., Chicago. . . .

Lawrence M. Braun has resigned as vicepresident of ECA and ECA Interna-tional to form a metal and plastics com-ponent manufacturing company, the Rich -Marc Mfg. Co., Inc., 42 W. 28th Street,N. Y. C. . . . Quam-Nichols has becomean Iltinois corporation. James P. Quamis president; Matt Little, Jr., vice pres-ident ; P. L. Dawes, secretary and assist-ant treasurer and Helen A. Staniland,treasurer and assistant secretary.

ADVERTISERS IN THIS ISSUE

SERVICE INDEX-OCTOBER, 1946

AEROVOX CORP.Agency: Austin C. Lescarboura & Staff

ALMO RADIO CO.AMERICAN PHENOLIC CORP

Agency: Burton Browne, AdvertisingTHE ASIATIC CORPORATION

Agency: Wearstler Advertising, Inc.BURSTEIN-APPLEBEE CO.

Agency: Frank E. %Whalen Adv. l'o

CAPITOL RADIO ENGINEERING INSTITUTE..Agency: J. Kaufman & Associates

CHERRY RIVET COMPANYAgency: Dana Jones Co.

CLAROSTAT MFG. CO.. INCAgency: Austin C. Lescarboura & Staff

CONCORD RADIO CORP.Agency: E. li. Brown Avertising Agency

CORNELL-DUBILIER ELECTRIC CORPORATIONInside Front Cover

Agency: Reiss AdvertisingCORNISH WIRE 00, INC 32

Agency: Hart Lehman, Advertising

DRAKE ELECTRIC WORKS, INCAgency: William Holtman & Associates

J. V. DUNCOMBE CO

ELECTRONIC DESIGNS. INCAgency: Rasa & Weber Co.. Inc

ELECTRO-VOICE, INC Inside Bask CoverAgency: Henry II. Teplitz, Advertising

FEDERAL TELEPHONE & RADIO CORP 25

Agency: Rickard & Co.FLANAGAN RADIO CORP. 28

Agency: Stewart Jordon Co.

GENERAL CEMENT MFG. CO.Agency: Turner Adv. Agency

GENERAL ELECTRIC CO.Agency: Mason. Inc.

GENERAL ELECTRONIC SUPPLY CO., INC

HOLLANDER RADIO SUPPLY COAgency: Turner Advertising Agency

J. F. D. MFG. CO.Agency: Bergman -Jarrett Co.

JACKSON ELECTRCAL INSTRUMENT CO 37Agency: Kircher, Helton & Collett. Inc.

JENSEN MFG. CO.Agency: Burton Bronne, Advertising

KEN-RAD DIV. GENERAL ELECTRIC COAgency: Maxon, Inc.

LAKE RADIO SALES CO 48Agency: Sander Bodkin Advertising Agency

LIFETIME SOUND EQUIPMENT CO 32Agency: The Miller Agency Company

MAGUIRE INDUSTRIES. INC. 3Agency: City Advertising Agency

M. V. MANSFIELD CO 40METROPOLITAN ELECTRONIC & INSTRU-

MENT CO. 26Agency: Bass & Weber Company. Inc.

MURRAY HILL BOOKS, INC. 22Agency: The Harry P. Bridge CO.

NATIONAL UNION RADIO CORP ... Back CoverAgency: Hutchins Advertising Co.. Inc.

NEWCOMB AUDIO PRODUCTS CO 26Agency: Stevens -Hall, Advertising

OLSON RADIO WAREHOUSE 41Agency: Jessop Advertising Co.

RADIO CITY PRODUCTS CO., INC 45Agency: Reiss Advertising

RADIO CORP. OF AMERICA 21Agency: J. Walter Thompson Co.

RADIO SUPPLY & ENGINEERING CO., INC..26, 36Agency: Karl G. Rehr Advertising Agency

RADIO TELEVISION SUPPLY CO.. INCRADIONIC EQUIPMENT CO 38

Agency: Bass & Weber Co., Inc.RADIO WIRE TELEVISION, INC 28

Agency: Reiss AdvertisingRAYTHEON MFG. COMPANY 44

Agency: Burton Browne. AdvertisingJOHN F. RIDER PUBLISHER. INC 15

Agency: Lansford F. King, AdvertisingHOWARD W. SAMS CO.. INC 17

Agency: The Aitkin-Kynett Co.SCENIC RADIO & ELECTRONICS CO 40SHURE BROTHERS, INC. 33

Agency: II. M. Gross Co.SIMPSON ELECTRIC CO. 5

Agency: Kreleker & Afeloan, Inc.SOLAR CAPACITOR SALES CORP 9

Agency: 0. S. Tyson & Co.. IncSPRAGUE PRODUCTS COMPANY 6.7

Agency: The Harry P. Bridge Co.SUN RADIO & ELECTRONICS CO 40

Agency: Bass & Weber Co.. IncSYLVANIA ELECTRIC PRODUCTS, INC 10

Agency: Newell -Emmett Co.

TRIPLETT ELECTRICAL INSTRUMENT CO 41Agency: Western Adv. Agency, Inc.

UNITED TRANSFORMER CORP. 31Agency: Shappe-Wilkes Inc.

VERTROB CORPORATION 42Agency: Bass & Weber Co.. Inc.

WARD LEONARD ELECTRIC CO 38Agency: Henry H. TeplItz, Advertising

WATERMAN PRODUCTS Co.. 1,1: 44Agency: Abner J. (Meta & Associates

WATERPROOF ELECTRIC CO. 36WEBSTER-CHICAGO' CORP. 43

Agency: William Hoffman & Associates

34

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32

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HERE IT IS AT LAST ! The radio line thousands ofservice engineers have been waiting for-yes, theradio that has everything the service trade needs tocash -in on today's big pent-up new set demand.

And who else but National Union could providea merchandising plan for radio sets-so perfectlyfitted to the service engineer's special needs ?

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THE LINE -5 models, of which one 5 -tube and one 6 -rubemodel are now ready; three others available in 90 days.THE PRODUCT-Top quality throughout; precision -builtchassis; beautiful cabinets in modern designs.PERFORMANCE-Thoroughly up-to-the-minute; N.U. setscompare with the best in thcirPRICES-Competitive with cst.; --.1ished brands.VOLUME REQUIREMENTS- None V.U. sets are not sold ona franchise basis. Order whatt r quantity you need.DISTRIBUTION-Sold only through N.U. Distributors andService Dealers.

PRESENTATION MODEL No. G619.6 Tubes. AC -DC. Tuned R.F. Stage. Super-heterodyne Circuit. Loop Aerial. AutomaticVolume Control. Illuminated Slide -Rule Dial.Standard American Broadcasts. Mahogany Ve-neer All -Wood Table Cabinet, 13" x 83/4" x 61/2".

COMPANION MODEL No.571. 5 Tubes. AC -DC. 54, 1- (dr ' Built-in Antenna. Auto-inxi, ( er .' (1.4,11.; Air Condenser Tun -

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OTHER MODELS NOW BEING PLANNED A 3 -Way (AC -DC -Battery) Portable Model. A Combination Table Model Radio -Phonograph with

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Here, for the first time, is a practical post-war radioline for the service engineer to handle-a groupof fine modern radio setsbut above all a provenmerchandising plan which fits. Ask your N.U.Distributor for the complete facts today !NATIONAL UNION RADIO CORPORATION, NEWARK 2, N. J.

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eaIt - americanradiohistory.com · 2019-07-17 · r e eaIt eDoo Whenever an ailing set needs a "physical i your local prospect will go hunting for a dependable serviceman. 'That's