Radio-News-1939-09-R

SEPTEMBER 1939

he "DIALOMATIC" MOBILE RIG TINIEST RECEIV

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www.americanradiohistory.com September, 1939 RADIO NEWS 3 J a4iedpu a a&G1Z 9/lee to show how I train you at home in spare time

J. E. SMITH, President NATIONAL RADIO INSTITUTE Established 25 Years Ile has directed the training of more men for the Radio industry than anyone else. Clip the coupon and mail it. I will prove I can train you at home in your spare time to be a Get Sample Lesson and 64 RADIO EXPERT. I will send you my first lesson Page Book FREE FREE. Examine it, read it, see how easy it is to -Mail understand-hose practical I make learning Radio Coupon at home. Men without Radio or electrical knowl- - more money than Act Today. Mail the coupon now for sample lesson edge become Radio Experts, earn and 64 -page book. They point out Radio's spare time ever as a result of my Training. and full time opportunities and those coming in 'television These ; tell about my training in Radio and Get Ready Now for lobs Like Television ; show you letters from men I trained, Radio broadcasting stations employ engineers, oper- telling what they are doing and earning. Find ators, station managers and pay well for trained men. out what Radio offers YOU! MAIL COUPON Fixing Radio sets in spare time pays many $200 to in an envelope, or paste on a postcard -NOW 1 Broadcasting Stations $500 a year -full time jobs with Radio jobbers, man- Employ managers, etnginees, operators, installa- ufacturers and dealers as much as $30, $50, $75 a J. E. SMITH, President tion and maintenance men for fascinating jobs week. .Many Radio Experts open full or part time Dept. 9JR and pay up to $5,000 a year. Radio sales and repair businesses. -Radio manufacturers and jobbers employ testers, inspectors, fore- NATIONAL RADIO INSTITUTE men, engineers, servicemen, in good -pay jobs with WASHINGTON, D. C. opportunities-for advancement. Automobile, police, aviation, commercial Radio, loud speaker systems are newer fields offering good opportunities now and for the future. Television promises to open many good jobs soon. Men I trained have good jobs in these branches of Radio. Read how they got their HERE'S jobs. Mail coupon. Why Many Radio Experts Make PROOF $30, $50, $75 a Week $10 a Week Radio is youns-yet it's one of our large industries. More than 28,000,000 homes have one or more Radios. There are in Repairing Radio Sets more Radios than telephones. Every year millions of Radios Spare Time Spare work get out of date and are replaced. Millions more need new time set repair imys ust ny $5, $10, for "My work has $15 a week extra while learning. Full tine serv- tubes, repairs. Over $50,000,01)1) are spent every year consisted of icing pays as much as $35, $50, $75 a week. Radio repairs alone. Over 5,000,000 auto Radios are in Radio set serv- use; more are being sold every clay, offering more profit - icing, with making opportunities for Radio experts. And RADIO IS some Public STILL YOUNG, GROWING, expanding into new fields. Address Systems worts -all The few hundred $30, $50, $75 a week jobs of 20 years in my spare time. My earn- ago Lave grown 'to thousands. Yes. Radio offers opportu- to nities t'or ings in Radio amount -now and the future! about $10 a week. " -WI1,- 1.1ASf MEYER, 705 trudge Many Make $5, $10, $15 a Week Road. Hobart. Ind. Extra in Spare Time While Learning 'fhe dac you enroll, in addition to our regular Course, l Earnings .start sending Extra Money Job Sheets. show you how to O Tripled Radio repair jabs, Throughout your training I send plans by N. R. I. and directions that made good ,spare time money-$200 to $51111 -fur hundreds, while learning. I send you special Training equipment Radio -to conduct experiments, build circuits. "t h a v r. been Loud Speaker Systems This 5u -50 method of training makes learning at home doing nicely, easy. fascinating, practical. thankstoN. IL.I. Building, installing, servicing and operating pub- Training. Sty present earn- lic address systems is another growing held for ings are about three times men I, It lesiueel in Radio. I Also Give what they were before I took the Course. I consider N.R.I. You This Training the finest in the Professional world."- BERNARD COS- Lesson on Radio Servicing TA. 1152 Manhattan Ave., Servicing Brooklyn, N. Y. Instru- j4 . Tips FREE ment -° I'll prove my Training gives practical, mone'- ood FREE maldng information, is easy to understand -just /o2 SAMPLE LESSON what you need to master Radio. Sly sample lesson text. "Radio Receiver Troubles -Their Cause emeil . BOOK on RADIOS OPPORTUNITIES and Remedy" rovers a long list of Radio receiver Here is the instrument every Radio expert troubles in A.C., D.C., battery, universal, auto, needs and wants -an All -Wave, All - Purpose, T, Il.F., superheterodyne, all -wave, and other Set. Servicing Instrument. It contains every- I. E. SMITH, President types of sets. A cross reference gives you 'the thing necessary to measure A.C. and D.C. National Radio Institute, Dept. 9JR I probable cause and a quick way to locate and voltages and current ; to test tubes, resist- Washington, D. C. remedy these set troubles. A special section is ance; adjust and align any set, old or new. 1 devoted to receiver check -up, alignment, balanc- It satisfies your needs for professional serv- Dear Mr. Smith : Without obligation send the free the Sam- ing, neutralizing and testing. You can get tlni icing after you graduate -can help you make ple Lesson and your 64 -Page Book "Rich Rewards in Radio," I lesson Free. No ohl gation. extra money fixing sets while training. telling about spare time and full time Radio opportunities, and how I can train for them at hone in spare time. (Please You Are_Trained for write plainly.) MAIL Television Also Wilk N. R. I. you take up Television prin- I COUPON ciples right along with Radio principles- Name the correct method -since Television receiv- Age 1 ers combine both sight and sound. You also NOW get more than ten text books devoted en- I tirely to Television. Address I City tate I iti---r------l...l...-----.ill14\-I 1

www.americanradiohistory.com 4 WITHIN

Including Articles on POPULAR TELEVISION The Magazine for the radio amateur experimenter, serviceman & dealer VOL. 22, NO. 3 OF THE EDITOR WE HAVE just finished a swing Contents for September, 1939 through the Eastern States, and are ready to report, among other FEATURES things, that a temperature of 128° in sun (which we encountered in a the Want to Re An Airline Eugene A. Conklin 6 stretch in Ohio) is not conducive to Radioman' comfort. Which brings us to this ob- A fond Father tells his son what he may expect in this field.

servation. It would be a real service As I See It' . John F. Rider 9 to the many who have radios in their Radio service work is merchandising today. cars, were the local announcers to give the weather conditions that you might RADIO NEWS Attends the Big Parts Show 10 expect on the various main highways. A pictorial review of the Chicago R.M.A. Show. Thus, if you are traveling with infants, The Deluxe or with sickly people, you could put up "Dialomatic" Mobile Rig in a spot and wait until the weather Oliver Read, W9ETI & Karl A. Kopetzky, W9QEA 14 made it better for you to travel. Such Bringing the latest developments in dail controlled mobile xmtrs. a service alone might help to increase Tube Checker Jack Meeker 17 the sale of auto radios, and overcome One version of a recent R.N. tube checker. the objections that they are not worth toting cross- country. Ram Fix 20 This and other tourist information The hams in illustrations. could be arranged. When we arrived 1.4 v. Rain Superhet Harry D. Hooton, W8KPX 23 in Boston to stay at one of their larg- Constructing a fine superhet battery operated tubes. est and finest hotels, we found a con- using vention in full swing. As a result we Conquer the Code With Rhythm Don Beat 25 had to go elsewhere. This would not A unique solution for those who have trouble with the code. have been an exceptional hardship, were it not for the fact that we had Solving the Intermittent "Tester" Bradley 26 already put our car in a garage, and Where to look further for these "bugs." Part 2 of 3. we had to get it out, load it up and RADIO NEWS 1940 Transmitter -Receiver move -with the resultant loss of the Karl A. Kopetzky, W9QEA & Oliver Read, W9ETI 29 price paid for parking. Information Final details on the control and assembly of this interesting unit. that a convention was in progress would have saved us considerably. Tiniest Ram Receiver Edward Lindberg 34 * * Something that will find many QRR and extra -station uses. WAS while we were in Cleveland, ITthat we came across a pamphlet Free Point Analyzer Unit Ralph L. Stears 37 put out by the Statler Hotel manage- An instrument that every serviceman can use in his business. ment. In spite of the fact that it has little or nothing to do with radio servicemen or dealers, we found much in DEPARTMENTS which could be to busi- it applied that Book Review 22 The Video Reporter.... 44 Sight & Sound News... 43 ness. The booklet is placed in every What's New in Radio.. 28 Hamchatter QRD? 22 18 room, and expresses the ideals and pol- Radio Physics Course.. 60 Serviceman's Experiences 36 icies of the vast chain of hotels run Short Wave Flashes.... 45 Bench Notes 33 Serviceman's Cases 40 under= the Statler banner. It is para- phrased here for the serviceman to Copyright, 1939 read and to follow. It should bring ZIFF -DAVIS PUBLISHING COMPANY results! Member of the Audit Bureau of Circulerons 1. Your service shop is operated primarily for the convenience and service RADIO NEWS is published monthly by the Ziff -Davis Publishing Company at 608 S. Dearborn St., Chicago; III. to your customers. Without customers William B. Ziff, Publisher; B. G. Davis, Editor; Karl A. Kopetzky, Managing Editor; Oliver Read, Technical there would not be any service shop! Editor; Herman R. Bailin, Art Director; John H. Reardon, Circulation Director; S. L. Cahn, Advertising Manager. New York Office, 381 Fourth Ave. Subscription $1.50 per year; single copies, 25 cents; foreign postage $1.00 2. So then it behooves every man per year additional except Canada. Entered as second class matter, March 9, 1938, at the Post Office, Chicago, and woman employed by you to re- Illinois, under the Act of March 3, 1879. Contributors should retain a copy of contributions. All submitted material must contain return postage. Contributions will be handled with reasonable care, but this magazine member this always, and to treat all assumes no responsibility for their safety. Accepted material is subject to whatever adaptations and revisions customers with courtesy and consid- necessary to meet requirements. Payment will be made at our current rates upon acceptance and, unless otherwise specified by the contributor, all photographs and drawings will be considered as constituting a part of the eration. manuscript in making payment. (More Earshot on page 62)

www.americanradiohistory.com September, 1939 RADIO NEWS 5

ON RADIO ZIFF -DAVIS PUBLISHING COMPANY (Publishers of RADIO NEWS) offers these authoritative books on Radio Every one written by an authority. Giving you in concentrated, easily assimilated form, the tested experience of practical Radio men,each an expert in his field. Why not add their experience to your olvn, and so increase your knowledge and earning power in this fascinating profession.

HOW TO PASS DADE° LICENSE EXAMI NATIONS

RADIO TROUBLE RADIO PHYSICS COURSE (104) HOW TO PASS RADIO LICENSE SHOOTER'S SERVICING RECEIVERS EXAMINATIONS (107) HANDBOOK (III) By Alfred A. Ghirardi $4.00 By Means of Resistance By E. Drew C. $2.00 By Alfred A. Ghirardi $3.00 Measurements (112) A book that leading radio schools throughout the world have chosen as the (Third Edition in preparation.) A hook A new kind of servicing handbook. Es- By John F. Rider $1.00 most thorough, instructive, and interest- directed to the professional operator. sential data for your ,service jobs. A ing radio hook ever written -they use it Explains fully all the questions that are four- drawer liliug cabinet could Takes the guesswork out of servicing. met in taking the Federal Communica- hardly How to usl- an as their bask text ha their own radio hold all the mass ohnuuelrr in trouble courses. Explains in easy -to- understand tions C'ommission's examinations for all of complex, technical shooting and correctly interpret Point language all of the essential facts about classes of radio operator. Deals with servicing data t h a. I wns assembled, to point resistance measurements. Vastly both electricity and radio from simple the Baillo Act and the Federal Com- tabulated, charted and indexed to make simplifies ,ern icing- Problems. You ,riil fundamentals to the most intricate ap- munications Commission Rules and Reg- the contribution to Radio need this hook to speed up your .servic- The explanation of this greatest Let plications. Invaluable lo the radio Be- ulations. ship's ra- Literature ever published! ing accuracy, Rider show you how 972 pp.. diotelephone and telegraphy and the Servicing 52 to use a modern servicing nn ginner. Strient, Serviceman. 13{ illustrations, big Procedure 508 illustrations, 351; sell- review Ques- method of handling traffic is one of sections, 518 8Va" complicated receivers. Theory applied to tions. the highlights. by 11" pages. Practice. 203 Pages.

TELEVISION (117)

By M. G. Scroggie $1.50 'Pcicviaion, told in .straightforward manner, for the professional or the amateur. A eolaplele story sir Ieleii.-rillll, its oietll- ods, its mcch:udcs, a n d its Physics. Simple, easy -to- understand descriptions of the 'uudamrnuals of visual couuuuni- cation.

FUNDAMENTALS OF RADIO (113) RADIO OPERATING QUESTIONS PRINCIPLES OF ELECTRICAL ELEMENTS OF RADIO By F. E. Terman $3.75 & ANSWERS (I14) ENGINEERING (11.5) COMMUNICATION (II6) The basic principles of radin communi- By Arthur R. Nilson & By Timhie & Bush $4.50 By John H. Marrerait $3.00 J. L. Hornung $2.50 cation. A complete treatment of the The Electrical Engineer. Electrical units Simple laws of electric circuits. Laws subject of vacuum tubes and radio, cov- Over COO questions and answers cover- and electric currents. Electric bower particularly useful ill radin cOniunulica- ering the fundamentals of all important ing all radio operator license examina- and energy. The computation of res'st- tions. General idea of radio communications. Questions are typical of those aalce. Electrolytic conduction. The mag- tion. The vacuum tube and its uses. topics and the problems encountered in used on examinations; answers are full netic current. The magnetic field. in- h'adio telegraphy. Radio telephony. Re- their practical application. Suitable for and well- illustrated. Includes informa- duced electromotive forces. Thermionic ceiving set,. Problems. A .simplified on conduction and conduction t h r o u g h of of course. 458 tion broadcasting, marine, aeronauti- treatment principles radio com- use in an introductory radio cal. police and amateur radio operating. gases. Dielectrics. Many others. 598 munication not depending un mathe- pages. 6x9. 278 illustrations. 427 rages. 5'5x8. 100 illustrations. pages. 270 figures. matical knowledge. 286 nages 6s9.

Our book lists also present a wide variety on Photography, Aviation, Science

CHECK YOUR CHOICE ON THIS COUPON IMPORTANT! Ziff -Davis Publishing Company, Book Department R.Jci.9 Enclose remittance with order and we will 608 S. Dearborn St., Chicago, Illinois prepay postage. Gentlemen: Please send me the books whose numbers I have encircled below. and mail this coupon TODAY. Add Check to Book No. 104, 107, Ill, 112, 113, 114, 115, 116, 117. your library the books you need, or secure in- Price Enclosed $ C. O. D. (Plus Postage) formation and prices on any book on Radio you may be interested in but which is not Name here listed, DO IT NOW before it slips your Address ' mind. 3 City State

www.americanradiohistory.com 6

In the T.W.A. dispatcher and Radio Room there is constant hustle and bustle.

- xt á ' Want to be an AIRLIN lOMAN" By EUGENE A. CONKLIN Syracuse, New York

Re : Aviation Radio DEAR SON: I. just received your welcome letter in today's mail informing me that you were thinking of carving out a career for yourself in Aviation Radio. In my answer to you I have tried to point out a few of the requirements which the man sitting across the desk in the Employment office (if you are fortunate enough to get that far) will fire at you. I've also included some pretty pertinent dope on the duties and opportunities which will face you in this promising field. Let's get off to- a flying start -- by taking a quick look -see at the qualifications and duties as outlined by the number -one candidate for your pros- pective employer, the airlines. But first of all you had better decide for yourself for just which capacity you are best fitted-radioman, electrical engineer,_ or radio technician, to give each of the three classes of aviation radio employees their proper name. As a Radioman you will be responsible for trouble shooting, servicing and maintenance of aircraft radio. Once in the air, the radio reports at regular intervals on the weather. As an Electrical Engineer you will

www.americanradiohistory.com 7

The standard two way radiophone sets MANY students would like, eventual- are capable of five frequency recep- the tion. Receiving all government weather ly, to get into fascinating field reports on either of the receivers, at of airline radio. The author gives least one receiver can be operated by two separate sources of power. A mini- these tyros some valuable pointers. mum of four antennae and an auxiliary antenna for emergency are also standard equipment. The two way radiophone is used for be : responsible for communications maximum range of two hundred miles. communication with company ground research, communications standards, However point to point stations may stations and to maintain contact with radio announcing, radio design, radio have as high power as a thousand the Civil Aeronautic Authority sta- research, durability of equipment, watts depending upon the service the tions. Three frequencies are used for And as a Radio Technician you will station is designed for. Each airline daylight work while two others are be responsible for Radio construction, has its own individual radio communi- available for night reception. The delicate and exacting tests and calibra- cations network which is in turn a part ship's power supply provides the power tions, technical research work and de- of the nationwide chain system de- for both receiving and transmitting velopment in conjunction, with engi- signed by Aeronautical Radio, an or- units. All frequencies are crystal con- neers responsible for service standards ganization whose sole function is to or- trolled in both transmitter and re- used by radiomen. ganize the radio system for all do- ceiver so the pilot has only to turn a You may generally act as radioman mestic airlines into networks or chains knob for selection of the particular fre- due to superior ability. and assign each an individual frequency to be used. You will be responsible for precision quency. Each network has a distinc- The second receiver is used to pick operation of equipment to include tive identifying color, blue, red, brown, up CAA beam signals and weather Radio Operator's duties when neces- purple or green. But so much for the reports sent from the same transmit- sary. ground setup, now let's turn our atten- ting stations operated by federal air- Having picked out a promising niche tion to the standard plane equipment. way technicians. The localizer beam for yourself let's peer into the crystal Briefly there are usually three sep- used at certain terminals for condi- ball which mirrors the qualifications arate radio receivers on each plane tions of limited ceiling is also heard for the three divisions of aircraft radio and one or more dual transmitters. on this receiving unit. outlined above. Radiomen -Must have second class telephone and telegraph or better - The Clipper Plane's Direction Finder is used to take necessary bearings. must have a thorough knowledge of mechanics -must be exceptionally efficient as service and maintenance men. These men are generally accepted from leading radio schools. Elettrica'. Engineers - Must have second class telephone and telegraph license or better, with college electrical engineering training preferred - Must have experience on design and construction of receivers and transmitters; also experience in experimental research. A knowledge of communications is also desirable. Radio Technicians -Generally require a second class license although not entirely compulsory, but must be a good practical technician with considerable design and radio construction to his credit. The latter two requirements include considerable experience as evidenced by proper references. Now that that's over let's take another look into the type of radio equipment carried as standard equipment by the major airlines. The equipment described below is a typical standard installation which with minor variations will be found throughout the country. Basically the radio engineering division of all airlines is divided into two parts, Ground Station engineering, and Aircraft radio engineering. Ground stations operate a twenty -four hour watch requiring from four to eight men at each station for maximum service. About two hundred and fifty of these transmitters are scattered over the airways, both aeronautical stations for radio communication with aircraft and point to point stations for transmission of messages concerning flight operations between stations on the ground. These stations have a standard 400 watt output and have a

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known eight ball. You will note the particular stress on experience. How is this experience to be gained ? At present the only available route seems to be working your way upwards from the humble radioman to technician and thence to engineer. Experience in individual airport units while attending college is the greatest teacher but more of that anon. As a radioman a certificate from any of the leading radio schools of which there are dozens will be found satisfactory if backed up by a record of servicing airport and aircraft installations over a period of years. If you are sin- cerely impatient to "get in on the ground floor" of aviation radio, perhaps the wisest thing to do is to qual- ify as a radioman and work upwards, particularly if your finances indicate a severe lack of funds to send you through the higher institutions. On the other hand, if your goal is electrical engineering, don't let anything or any- body keep you from college, but at the same time let nothing interfere with your taking a part -time job in some capacity where practical training is available. Not only must you be a good operator, but you must be prepared to be Summing it up, you must have either able to repair, adjust and maintain the equipment under your control. experience and a second class license, and experience and the The third or auxiliary stand -by unit must understand the theory and prac- college training in fact a wide range of usefulness. tice of radio reception and transmis- license or best of all, all three to qual- has ify in of the twenty -two leading It receives on two wave -bands and is sion as applied to aircraft communica- any used in conjunction with a loop design tion. domestic airlines. If you are a grad- antenna. On one band the beam sig- As an electrical engineer particu- uate of a recognized radio school and nals and CAA reports are available, on larly the college education at a recog- have confidence in yourself by all the other band the entire range of nized electrical engineering school is means try for a position as radioman. night frequencies on which all airlines an essential of the first water. That Lack of college training where a good broadcast come in. It is equipped with doesn't mean that if you can set the practical technical background is sub- a specially built dry cell battery in world on fire with radically new design stituted is not a serious drawback to case of power failure. in the interest of portability, durability success. Ability to learn much from In addition to the transmitting and or increased range and freedom or in- daily observation, the patience to con- receiving equipment the radio direction creased range and freedom from elec- tinue when progress seems hopeless finders including a radio compass re- trical or man made static, that you and a certain strange type of initiative ceiver are carried. Transmitters must be kicked out the front door of and creative ability are important in aboard aircraft operate in the three to college training with a diploma in one any branch of radio but particularly six megacycle band with a fifty watt hand and field kit in the other, but it in aircraft where your skill and con- output level. does indicate that lack of adequate sistent plugging may save a pilot or On the point to point radio senders college training in this specialized field passenger load from death or severe radiotelegraph is used for the trans- puts you strongly behind the well injury. mission of dispatches, loaf messages, Now let's take the second of your control information and clearances be- employers to be, the CAA (Civil Aero- tween stations in the system. Radio- nautic Authority or Bureau of Air telephone is used exclusively for Commerce to you). transmission in most cases to aircraft Radio navigation aids maintained by from the ground station terminal. the Bureau are of three types, corn- So much for the equipment which munication s t a t i o n s broadcasting you will be expected to design, con- weather reports and available for ra- struct or service according to the di- diotelephone communication with air- vision you have picked out for your- craft in flight, radio range stations self. Now let's analyze the require- marking the airway routes, and radio ments for each branch of the service marker transmitters indicating the lo- a little,.more thoroughly and see what cation of strategic points on airway makes the little wheels go round and route centers. Point -to -point service is round. a part of the Bureau's work and each As a radio engineer or technician in airway has a reporting service con- addition to the 2nd class license which sisting of Bureau of Air Commerce ob- is a "must" requirement, you will be servation stations, together with a tele- transmit code typewriter circuit for sending out these expected to receive and reports. at a speed of thirty -five words per min- The average range of the com- be able to type at a speed munication system and radio range sta- ute, must tions one of fifty words per minute and must be are hundred miles and are able to enunciate clearly with good of the conventional airway transmitter English in using radiotelephone. As variety. The directional marker or either an engineer or technician you miniature radio range station covers must be thoroughly familiar with both Radio sets are installed by service only fifteen miles and serves as a hom- radiotelegraph and radiotelephone and men who know the airline's problems. (Study further on page 65)

www.americanradiohistory.com 9 S T.

By JOHN F. RIMER, Dean of the Servicemen In this article the author takes up a few of the variegated problems confronting the serviceman.

(The opinions expressed herein are solely those of When the author, and do not necessarily represent those functioning properly they serve of the Publisher nor Editors of RADIO NEWS.) an admirable purpose, yet seldom if ever are they an absolute necessity. \HREE lines in italics head this In other words, the servicemen can get department. These three lines along without a national association, - - absolve the editors and publishers yet, there is every reason why service- of RADIO NEWS from any responsibility men should join such an association. John F. Rider associated with comments made by us. The dues involved, even if they were However, we have never been inclined twice what they are, would be a sec- RSA will continue to progress so that to take advantage of a situation unless ondary consideration. it was this excellent idea will come to com- associated with competition, but We said before that we were im- plete realization. even then we refrained from compressed. That is true because the menting on test equipment during the subject which received the greatest Signal Tracing period when we were a member in the amount of attention was ways and IF YOU attended the Parts Show in ranks of test equipment manufactur- means of fostering public confidence in Chicago during the past June or ers. We now are out of that business the serviceman and thereby increasing have watched magazine advertising and you can expect to see comments the business of the average radio during the concerning serv- past few months you un- test equipment and proced- ice shop. In connection with this dis- doubtedly noticed that some of the test ure. In fact, such comments will be cussion much time was spent in clarifi- equipment manufacturers were dis- found elsewhere in this issue. It feels cation of the ideals of this national cussing equipment intended good to have the for signal shackles removed. association. From the general babble tracing as a means of locating troubles The RSA of voices came the clear thought to se- in radio receivers. Some of this equip- THE RSA -otherwise known as the lect as the final objective of the asso- ment was displayed at the show. Radio Servicemen of America -is ciation a fundamental idea : creating Our interest lies in the utility of sig- putting on a drive for members. We public confidence in the American nal tracing as a system. The past year had the opportunity during the recent radio serviceman. In line with this witnessed very critical investigation of National Parts Show in Chicago to at- thought, came the conclusion to build the performance of the system under tend one of their executive meetings this national association upon the the most adverse conditions. By ad- and one of the subjects discussed at strength of the local chapters and the verse conditions we mean that the sys- that meeting impressed us very means of accomplishing the solid foun- tem was introduced cold to men who greatly. Associations are funny things. dation for each chapter was to develop for years thought and worked with the friendly relationship between the methods diametrically opposite to what members to the highest degree, and to was being suggested. Further, it was build such confidence among the mem-. thought that the application of such a bers in each chapter, that in time to system required a tremendous wealth come the chapter would be in a finan- of supplementary technical data. In- cial position to guarantee the work of stead of an abundance of such data, its members. only a meagre amount was available, There is a tremendous amount of yet the idea of locating a defect by merit in this idea. It answers every tracing the signal proved overwhelm- question which the average doubting ingly successful. In fact, the com- public asks when it desires radio serv- ments of those who applied the system ice. Public confidence is built upon as a system, without regard to any one two words -"satisfaction guaranteed." particular piece of equipment, were Of course these two words have been such that we hazard the statement abused to the limit, but the guarantee that signal tracing will eventually sup- of a group is very much stronger than plant all other methods wherever do- the guarantee of an individual. To be mestic and foreign servicemen operate. a member of such a group is of vital We believe this to be true in the en- importance to every man associated tire communication field irrespective of with the industry the group represents. the nature of the service, be it com- This is true even of the service station mercial or military or for the safety of operator who now is successful on his mankind, as in the case of services as- own account and sees no justification sociated with marine activity. for joining such a group of servicemen. Neglecting for the moment the ad- Even he can benefit by representation, vantages gained in daily service activ- for such representation does not de- ity, signal tracing, as a means of locat- prive him of whatever honest individ- ing defects in communication systems ual effort he may wish to make. His will have a far -reaching effect upon rugged individualism is not taken from the technical advancement of service D. H. THOMPSON, of Pecatonica. Illinois, him. He retains all of it and augments personnel. And this applies equally shows how much he has progressed be it by whatever good the group effort well to instruction in schools where tween 1930 (top) and 1939 (bottom). can accomplish. communication is taught. It has been Looks like a very fine service bench. We hope that the activities of the (More servicedope on page 57)

www.americanradiohistory.com 10

Clint Bowman, of Specialty Advertising Co. N. Cook (in chair) of Mallory, K. Plunkett, A. H. Brunning of Premax, and a customer Peoria, Ill.; Margaret Jones & L. Gamache. R.Voyles,Marvin Huff and Eugene Pulliam. talk with the Premax manager, Geo. Bensen.

II o ALVNZ

Every year the members of the Radio Parts Industry get together in giving a mon- strous Show. The purpose of this is to acquaint the public as well as the dealers with the strides which the trade has made during the past year. The exhibit represents the advancement, and this is only overshadowed by t h e persons responsible for the George Bock & Phil Gotthold of Solar dis- progress. Believing our cuss prospects of the new testing unit. readers interested in seeing who the men "behind t h e scenes" might be, and what Howard H.Smith & Bob Karet of Utah Radio they looked like, we had our Products Corp. tackle a behatted customer.

G. Wright & F. A. Lennberg of Bliley Elec- United Transformer Corp.'s H. E. Watson, Ed Braun, John Olsen & A.B.Stewart(Capi- tric Co., with J. T. Watts, Pres. of Meissner. I. A. Mitchell & Sam L. Baraf, take it easy, tol Radio Wholesalers) with W. A. Marsh.

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Victor Mucher of Clarostat Mfg. Co. and L. G. Cushing discusses the Hammarlund R. B. Ritter, Mrs. Mary Becker, and Leon L. W. L. Davis of K. D. Sales Co., Freeport, La. line with Sales Manager George Shuart. Adelman, of Cornell -Dubilier Electrical. qq11

photographer, Seymour Ru- dolph, mingle with the crowds and snap these very informal pictures of what may be called a true cross - section of the industry. Most of the men are young, but that is understandable, since the industry itself is not old. Many of them have been in radio since its incep- tion. Of one thing we can be sure; they are a courageous E. S. Dietrich of Raytheon Products Co. & bunch, more than willing to Sandy Cahn, of Radio News, in conference. gamble all on new and un- tried fields. To them we owe much, if not everything. J.C. Hi Il, ExportMgr. &W. A.O'Brien, Vice Pres. of Simpson Electric Co., reminiscing.

n_. i11111111-ACT L ' PITCH

ICH PITCH

Some of the men in the RCA Booth being HarryKalker,SalesMgr.,E.L.Hollingsworth, W. M. Robinson, (Cornell -Dubilier), W. C. interviewed by Sandy Cahn of Radio News. and L. P. Still, of Sprague Products Co. Braun, (Radolek Co.) & G. W. Strange.

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Yep! Its he again! Same Sandy Cahn of our own magazine trying hard to sell a customer

Sam Ruttenberg of "Amperite" explains Pres. James P. Quam of Quam -Nichols and things to Mr. Lippman of Pittsburgh. B. V. K. French of P. R. Mallory Co., Indiana.

Henry Johnson of Hy -Grade Sylvania explains things to the young Master Moss.

W. S. Wilson, (Delaware Radio Sales), Bill Robert Wìlliams,SalesMgr. & A. A. Barricks Halligan, (Hallicrafters) & Marvin Roye. both of Hickok Electrical with customers.

In shirt -sleeves, Jack Simberkoff of the Sam Poncher, of Newark Electric SupplyCo., Aerovox Corp. displays the latest unit. talks it all over with Mr. Murray Mentzer. E. I. Guthman, of E. I. Guthman Co., seems very amused at his engineer, McM. Silver. APPAPAT

M.J. Stessin, Amer. Radio Hdwe. Co., shows J. M. Landf ear (Hickok Electrical Inst. Co.)

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Dick Laycock, in shirtsleeves, shows his Howard Radio Co. line to F. D. Terwilliger.

Samuel Milbourne of Supreme Instruments, The I.R.C. boys; Jim Hermans, rep. from S.F., describes his company's latest units. and Daniel Fairbanks of the home corp.

Vern Routh of L. A. reading Pres. Jerry Kahn's (Standard Transformer Co.) catalog.

TheArcturusRadioTubeCo.crowd: Englerth, Mrs.Zschau,W. W.Boyd,Jr.(rear),S. L.Spec- Geariner, Stobbe and Frank Langstroth. tor, Pres. of lasccihe Corp. and Mr. Zschau.

Pres. A. R. Kahn of ElectroVoice Mfg. Co., A customer examines D. P. O'Brien's Cinau- found the RMA Parts Show to his IiKing. Ralph Hill, Ohmite Co. Sales Mgr. (light da graph Corp. line of speech equipment. suit) shows H. A. Marsh the power switches.

Engineer R. B. Shimer and Pres. F. P. L. Ken- yon of Kenyon Transformer Corp., relaxing.

www.americanradiohistory.com 14

These three units comprise the entire transmitter installation.

ANY remote control systems The DELUXE have been designed that utilize standard telephone circuits to operate over two or three wires to a set of relays at a distant point. This system has limited advan- "DIALOiNATIC" tages as far as radio frequency circuits are concerned. A new mechanical system for converting relay driving power to a standard low-loss selector switch to overcome these faults will, and does have, unlimited applications for the 1:ouILE IiIG changing of frequency, the selection of antennae, controlling of additional circuits, and many other uses. by OLIVER READ, W9ETI & KARL A. HOPETZHY, W9QEA It is an established fact that modern Technical Editor, RADIO News. Managing Editor, RADIO News. bandswitching requires layouts that permit the use of extremely short leads in order to attain a high degree of effi- Three bands at the tip of a dial -finger, ciency. If the switch assembly can be any controlled at a remote position by frequency within a band! These are but a few means of dial pulses - we will have something that can be used to switch features of this newest and most unique unit. our r.f. circuits and yet keep a corn-

www.americanradiohistory.com 15 pact and reasonably priced assembly The complete system is built as two actually is used to provide the needed with a minimum of relays and asso- individual units -the exciter and con- power to rotate the switch. The ciated equipment. trol panel, and the remotely -controlled stepper finally adopted is made by the The transmitter described in the fol- amplifier-modulator in the trunk corn- Guardian Electric Co. of Chicago and lowing The requirement is known as Radio type paragraphs operates on any partment. first then, "R their stepper three amateur bands or may be used is to have a unit within easy reach of for any three widely separated fre- the driver for operating the trans- Unlike the usual stepper, this unit quencies for Ham, police, aviation, or mitter with maximum speed and min- has an extended shaft for coupling to other services. Furthermore, com- imum effort. An electron -coupled the switch shaft and the stepping re- plete choice of any frequency within oscillator could be used without relay is designed for a maximum torque any one band can be made by means of sorting to any crystals but this was not on each stroke. This relay draws 5 the universal exciter that is located at wanted as there are times and appli- amps at 12 volts, but this current is the dash position. The advantages of cations in certain services where this only drawn for a 1/10 second at a the above procedure will at once be will not be satisfactory -such as the time and will not drain the battery to appreciated by those operators that assignment of a definite police fre- any degree. have engaged in emergency or field quency. Most stepper assemblies are used to day work. Both methods are incorporated in operate a simple arm and set of con- One of the most fascinating applica- this unit so that the operator may tacts which connect to a series of re- tions for remote control is in the mo- instantly choose one or the other. The lays. These are so placed that the in- bile rig. The usual mobile transmitter amount of test equipment may be re- coming circuits connect in parallel, consists of a ten or twelve watt trans- duced by using the crystal -plate -tank with the output contacts going to the mitter operating at a fixed frequency resonance points as reference points various sections of each circuit for on one band -mainly five or ten when tuning the e.c. plate circuit to purposes of changing bands. This meters. Much dx has been worked on the same settings as indicated for the method requires longer leads, is far the latter from an automobile but con - known crystal frequencies. This is more costly, and the capacity between sistent communication has not been done by tuning the crystal oscillator to the relay contacts detract from the possible, due largely to the lack of suf- resonance and then switching over to efficiency of the unit. ficient power or the inability to QSY the e.c. side of the switch and tuning Added to the above disadvantages is within the band to avoid QRM condi- the grid tank to the point where reso- the fact that this system is limited to tions. nance will be indicated on the plate two -band operation unless special Added to the actual power available dial at the same point. types are developed. Therefore, the for communication, is the fact that the This method gives the operator a use of the stepper and selector switch antenna system is limited to a vertical knowledge of the position of the e.c. eliminates many relays (up to 12 in quarter -wave rod. We can overcome tank setting that is safely within the this unit), and we may use as many the above by increasing the power out- band. Of course, the dial may be cali- circuits as the switch will handle. put of the transmitter to the vicinity brated but this means little if the set There are forty steps on the relay arm. of 40 to 50 watts. is used in darkness and no illumination Each set of contacts on the switch are Amateur mobile transmitters are is provided. 90° apart and require that 10 pulses permitted to operate on the 5 and 10 Complete control of the trunk unit be applied to rotate the switch from meter bands while in motion and on is made by means of a standard tele- one position to the following set of con- the lower frequency bands in a fixed phone dial that has pulsing contacts tacts. position as a portable station. This which are normally open. These dials We might add one more band to this means that the equipment be actually speed through 10 pulses in 1 second; transmitter with the switch used, but portable from one location to another, and hence a bandshift takes just that this was not desired in our own par- and not a kilowatt phone rig in the amount of time. ticular installation and is mentioned possession of a person who takes up The heart of the complete mobile only for those wanting four-band oper- residence in another district from time unit is the automatic stepping relay ation. This type of switch is avail- to time. The unit illustrated may be assembly used in conjunction with a able with many more positions and removed from the car in a few mo- isolantite selector switch. This unit could be used in multi -band trans- ments time when an emergency rig is has been designed for this particular mitters. needed and where the car may not be application and differs from the usual It was further our intention to make required. stepper in that the stepping mechanism the system as simple as possible for a The compactly built exciter unit mounts in front at the driver's seat.

www.americanradiohistory.com 16 mobile installation by using a multi - When the e.c. oscillator is being a fraction of the oscillator power for wire cable from the dash control, used, these plate circuit resonance drive, we can sacrifice this power for rather than a system using special points may serve as a guide for fre- added convenience and simplicity. transformers and parts over a two - qency checks. The plate circuit will It is important that an efficient wire line that would also include the tune in the same manner for both means of transferring this output to audio from a pre -amplifier. This types of operation, and by using the the trunk compartment be made. The method is preferred where the equip - crystal frequencies, which are known, selection of Amphenol concentric cable ment is located at some great distance the danger of out -of -band operation was the answer. This cable is made from the control point, but if only a will be reduced. with an overall waterproof compound short distance between points exists, The grid circuit is always tuned to and passes underneath the car chassis it is far less expensive to use a multi - the next lower- frequency band than to the trunk. The outer shield is wire cable between units. that of the plate and the Browning grounded at several points to the We will describe the construction of coils are designed for this condition. chassis and tied down securely with the units which locate at the control The grid coils must be designed for small metal bands to prevent breakage point first. The initial requirement is high tuning capacities while the plate from vibration. to have an exciter which will be stable, coils are wound for low tuning ca- Mounting of the unit may be made both from the electrical as well as the pacities for best efficiency. The plate in any convenient manner, but should mechanical standpoint. Inasmuch as voltage supplied from the Vibrapack is be done so that it will be within reach the transmitter is operated on ten 300 volts and is kept at this value by of the operator. meters while in motion -these require- the voltage regulator tubes. The car The telephone handset is mounted ments become more important than if battery is used for the exciter unit and on two flat spring clamps which hold the unit were to be used in a fixed is therefore subject to varying loads. the unit firmly in place. The one used position. This is particularly true If the plate voltage were permitted to in this installation is á Temco 10A, when operating with the e.c. oscillator. vary, the e.c. would not be able to normally used on a police rig. The The Exciter Unit maintain a steady frequency. characteristics of the modern tele- Complete frequency control from A pilot lamp (60 ma.). is used to pro- phone transmitter for voice frequen- the dash of the car is had from the tect the crystals against damage from cies are ideally suited for close talking simple unit to be described. The en- incorrect adjustments or surges and and this feature will be appreciated tire oscillator section is built into a will indicate whether or not the cry - where there is a high background level standard Bud steel box which meas- stals are passing excessive currents. such as from moving traffic on the ures 9 "x6 "x5 ". Winding coils accu- Change -over from crystal to e.c. con- streets. rately for an electron -coupled oscil- trol is made by means of a three -pole- Two toggle switches are used -one lator to be used in a multi -band unit two- position switch and is located un- to turn on the filaments, and the other is something the average ham dislikes. der the crystal sockets. The other con- to turn on the plate voltage for tun- By using stock parts, this effort can be trol is the single -pole -five position se- ing purposes. Once the rig is tuned- spared and at the same time a higher lector switch for the choice of the cry- further operation is done by means of degree of accuracy is maintained that stals or the use of the e.c. connection. the push -to -talk switch located on the is important. The problem of coupling the r.f. out- handset. This switch connects in The Browning 5P and 5G tuners are put to the final amplifier was met by parallel with the plate relay coil. well suited for this unit. Inasmuch as winding a series of links consisting Three toggle switches or pushbut- only three bands are used for mobile of two turns of push -back wire tons are also mounted on the control or portable service, the extra coils around the cold end of each plate coil, unit and are used in the following were removed and laid aside for future and then connecting them in series manner; Suppose we wish to transmit use or when a change in band selec- with each other as shown on the dia- on the ten meter band. The 10 meter tion might be made. Further space gram. There is some loss in r.f. from switch is closed and the dial spun was saved by removing the self -con- the above method, but inasmuch as the from the 10 pulse position. If the tained variable condenser and cutting following tube, type 807, requires but (Construct further on page 48) the metal strap used to mount the R1- 50,000 ohm, 1 watt Aerovox Browning combination. R2-- 25,000 ohm, 50 watt adj. Ohmite SW -3 pole double throw. Mallory The net result of the above change C1-.01 mf. mica Aerovox SWs -dp 5 position sw. (3 sections used). C2 -.01 mf. mica Aerovox Browning was a compact assembly, designed for Cs -.01 mf. mica Aerovox Lt-Fire -band grid coil assembly. Browning 5G high efficiency, and with but a few mo- C, -.0005 mf. mica Aerovox Ls-Five -band plate coil assembly. Browning 5P C; SO mmf. variable RFC-National R100 choke ments time required for the complete C0-.005 mf. mica RFC,:-Bud 876 choke conversion. A type 802 pentode was mf. mica Aerovox Relays- Guardian Elect. 6 volt dc. Cs -100 mmf. variable M -Temco 10A Handset selected for its ideal e.c. character- SW,-spst. toggle switch (plate control) Cabinet-Bud istics and large r.f. output. An abun- SW=.-spst. toggle switch (fil. control) Sockets-Amphenol SW;, -spst. toggle switch Dials -Crowe dance of power was needed as will be SW,-push -to -talk (on microphone) Note: The Browning Tuners consist of all coils explained in later chapters. SW- single pole -5 position switch. Mallory with associated switch assembly and plate by -pass The 802 must be shielded and all SW-dp 5 position switch (3 sections used) condenser connecting leads made as short as pos- C.0 sible to prevent vibration from causing a frequency change. By mounting the tube as shown, both grid and plate circuits may be kept well apart. By -pass condensers must be located as close to TO RCVR the tube as possible to be most effec- R LY tive. S 5W

All parts with the exception of the TO 807 Mallory Vibrapack and the two volt- FIL. SW 3 age regulator tubes are included within the box. Four Amphenol steatite sockets are mounted on the front of PLATE. RLY the panel so that the crystals may be o plugged in as well as varied from the MALLORY 552 front. Bliley variable crystals are used 2 -VR 150's VIBRA PACK so that a fundamental frequency OUT range of 6 kc. on 80 m. 12 kc. on 40 m., or 24 kc. on 20 m., and 48 kc. on 10 m. BMF was available. V +300V

www.americanradiohistory.com TII. 17 CHECKER

by JACK- MEEKER Rapid City, So. Dakota.

Showing whet can he done by following an article that appears in R_V11i1 NEWS. The author's tube rheelutr would be a welcome addition to any serrire shop. The checker is portable, 'n everything!

/ HE basic circuit of the tube I connected meter, jewel, potentiom- other switches down. If the jewel checker was in the Feb. 38 issue eter and quality -short switch, and, glows some element is shorted to the - - of RADIO NEWS. The only changes fifth, connected line cord and put tester filament. If not, move all the switches which I introduced were to use some in carrying case. up and down singularly also Sw. No. 2 push -button switches, which I had on The carrying case may be bought, to the right and hand, back to the left. If instead of toggle switches and home -built, or a case that you may the jewel lights with any of the the addition of two other switches for have on hand as was my case. The switches in this position it indicates testing types 6P7G, 5X4G, 5Y4 and complete tester, in its case with cover (Conti),'iprl on page 53) 5Y4G metal tubes. The cost of con- closed, measures 5%)(914x12 inches. struction was very low as I had nearly The outstanding characteristic of the all of the parts required. tester is its sensitivity. For instance. As to the construction, I first the leakage test is just as critical as located all parts, sockets, switches, the neon lamp in a commercially built meter, transformer, potentiometer and tester. The quality selector switch set- jewel. Second, I wired in the filament ting for tube quality test is determined circuit. Third, I wired in all of the by testing tubes whose condition is circuit connected to Sw. 1, then all of known. the circuit connected to Sw. 2 and so To operate tester throw Sw. No. 6 to on througl v. S 5 and T. C. Fourth, short position, Sw. No. 2 to left, all

Compact wiring in a compact unit.

THROW SWITCHES LIP TO TEST 0-IS VOLTAGE FROM TAPS 1709 INCLUSIVE IS 1.5V 2.OV,2. 5V,3.3V, 5.0V 0-20 MA L1-9 6.3V,7.5 Vr12.OV.,30.Ov A.8 I onion S PST e.3v. PILOT IOV AC PARTS LIST PRICES I S.P.S.T. (tap) Tube sockets .25 I S.P. 12 throw .44 One 4 prong bakelite Baby Volume Control, 5000 ohms .29 One 5 prong bakelite .07 D.C. Milliammeters (0 -15) or (0 -25) 1.95 One 6 prong bakelite .07 Metal and Glass Tube Cap .12 One 7 prong bakelite (small) .07 Jeweled Pilot Bracket .15 One 7 prong bakelite (large) .07 Pilot Light Bulb (6 -8) .09 One 8 prong bakelite .09 Tube Tester Filament Switches (toggle) Transformer 1.25 Aluminum Panel 7x10 .42 6 S.P.D.T. 6i .21 1.26 Tube Tester Case (not listed) (can be 3 D.P.D.T. (it .36 1.08 home built) 1.50 S.P.S.T. .. .17 (Pushbutton) line cord .14 Cost for parts $9.55 Inscription helps to identify sockets.

www.americanradiohistory.com 1

W2LKK has a new "bug" and 50 watts in-

stead of 10. - W2IDU has new modulator power-supply so is up on 160 m. Fone again. W2JON uses his one -watt mobile rig quite a bit lately. Watsamat Al? Too much BCL QRM at home? After nine years on cw, W2APU has gone 10 -meter fone. His 6- element Yagi Array should help. W2LIP pulled the ten outta the final, and left the base in the rig!! W2LIC has a new Howard rcvr. & sez it wrks fb. W2GWJ quit 160 m. fone fer a while agn LESTER W. (W9UHN) Olson. w h o wee hit of `Hamchatter'. Hi ! "- WIIFD. and is giving 40 M cw a try. recently was giving forth on 160 from - [How about it, you hams! If you can draw; near Ellison's Bay, Wis., - is now gone pro (hi) send it in, and maybe we'll publish IBELIEVE a new record has been hung with the radio dept. of U.A.L., Municipal it! Ed.] up in 2.5 meter dx., by WIJUN and Airport, Chicago. WIBOO. According to the dope in cur- B. G. Davis, Editor of this mag, is now a From G. T. Beyer : "Find your column a rent radio periodicals, 25 to 30 miles seem full -fledged member of the Greater Camden feature of real interest and sure hope that to have been the limit for 2% -meter two -way Amateur Radio Association. you keep up the good work. Items of in- QSO, and that with beams, usually: \ \'6MPC es W6ONQ are - staff operators terest seem to be very frequent by W9ISR. W1JUN has worked W1BBM (14 watts, of W6USA - the it- tunes -itself- while -you The ! Wempusite'. story was a revelation that at No.- Harwich, Cape Cod)" from his home watch xmtr. very few of we laymen knew about, Hi !" in West Warwick, R. I., a distance of ap- W6USA Committee is composed of THE golfer who made the hole -in -one at proximately 73 miles, as near as I can figure W6GEA, W6NYQ, W6TI, W6SG, W6FBW, it out, airline, on the map. W6IBQ, W6HC, W6NGV es W6AJF. Beverly Shores Country Club (Michigan Owen Callin's colyum in The Ohio State City, Ind), which inspired Harry Gonder, W1JUN and W1BOO have worked W1SS in Mass. 14 8 Journal is super super fb, fellers! Gives all the club pro, to start a hole -in -one mara- Arlington, (also watts, about the latest ham dope and gossip. Write him thon, was none other than Bill (W9DHK) miles N. W. of Boston, Mass.), a distance of your news. Voltz, veteran ham of Michigan City. This about 55 mile's airline from both W1JUN Most famous QSL is K6OJI's. Costs 10e stunt received nation -wide publicity, with and WIBOO. W I JUN used. about 100 watts and W1BOO 30 watts at the time, neither to get one. Awah -awah -awah ! several radio flashes and hourly news service. using a beam antenna, on June 1, 1939. VE5AGO uses only 6 (count 'em) watts to Incidentally, Bill collected a $25 bet after work W8SYC! What kindofa skywire. the pro failed to produce an ace in 15 hours. I believe W1BOO was the pioneer ham on If you were observing, you probably no- ___2% _in the Fall River; -Mass. territory about AT-THE!!! Here's another one! ticed W9TO\M and \V9BIM inspecting -the 3 years ago. Since then he has built up KD6QSX requires a nickel for a RN 191ó Transmitter- Receiver on Ham day nine 2% -meter receivers and six transmitters for the hams hereabouts. The most QSL! - at the Show. Quite a coincidence, having two Did W9AOB hear that speech of Byron famous uncles together at the same time. satisfactory transmitters are push -pull Hargrove's, "The Care and Feeding of Wonder if they know each other. HY25's in a copper tubing, tuned plate -tuned Ants ?" We wonder, because his subject is And was \\'9ETI feeling his oats that day. filament oscillator, using no condensers or

titled, "The Care and Feeding of the E.C.O." You should have heard him cracking wise - resistors. (A ham can build one for just How about the "Care and Feeding of Speak- about installing voice control on your moth - the cost of the tubes, two sockets and six ers ?" Hi! er -in -law and the Jr. Ops. Bet he was kinda feet of copper tubing, costing a total of Congrats to the ARC which has gone 100% embarrassed when he found he was demon- only about $4.00.) American by eliminating all f u r r i n strating to an announcer how to cut out W1BOO has constructed a very successful, phrases, etc. For those who (like ourselves), commercials. simple, close- spaced 3- element rotary beam, were unable to understand the various words, W9VML is on 160 phone after 3 years of using no insulators or supports of any type, we append a dictionary furnished by Prof. cw. Ken just visited the RI for renewal. the parasitic elements being connected, to- U. Tellim Wye, as follows : Facta Non Verba The xmtr of W9GGZ (2 goats and a ze- gether at their centers by copper tubing- means, "How's my modulation ? ' ; Coup bra) blew up recently. Harry sez he's build - a simple version of the "plumbers' delight" D'oeil means, "Pse QRT u twerp, cuz I ing.bigger and better. Keep it out of the becoming popular on ten and twenty meters. wanna talk nw "; and Excerpta Landis basement, Harry. means, "How's my modulation? We feel W9LMH and W9NKB, who have gone Following is a list of 2% -meter stations that clears up the matter to everybody's sat- into partnership in the plating business, heard and worked- by W1BOO the last isfaction. If the ARC comes out with more haven't been on the air much lately. Willis month. I also believe there is probably more furrin words, and we don't understand 'ern and Chuck say that as soon as they get activity in this section of New England well always be willing to publish the correct straightened around they will be heard from. than in most places. Asterisk ( *) denotes translation, but we feel sure that the mean- Old Zero Zero, one -half block from phan- stations worked ; as all these stations are ing will mostly always be the same, "How's tom park, (marble orchard to you) is still WI's; the "WI's" are omitted. my modulation ?" . or somepin ! Hi ! putting out good sigs, when conditions aren't W1AHP* Fall River, Mass. The Hamfesters, Chi's biggest & finest will too had. We always like to hear Joe's husky AHP Port. mobile, Fall River, Mass. hold its usual superb outing on August 27th chuckle conün' through the spkr. AIK at Frankfort Park at the intersection of The above offering was inspired by the BBM No. Harwich, Mass. Routes U.S. 30 and U.S. 45, just S.W. of fact that I found out what a friendly bunch BGA Pawtucket, R. I. the Windy City in Illinois. Twenty -five of guys you are and your plea for more ham BJE* Port. mobile, F. R. hundred are expected to attend. A really news. Am not a ham myself (that's my BOO* Port. mobile. F. R. complete YL -OM program has been ar- fault), but I get around. Hope you like CRN* Fall River, Mass. Michigan ranged. Plan to attend if you are in the these choice bits from City. Please DTW - Apponaug, R. I. vicinity, and you'll not be sorry. delete or edit as you see fit. Chatteringly EBA* Port. mobile, Providence, R. I. yours, Edward R. Lewis. FBH Providence, R. I. FROM 0Mail wud [Tex, Ed. fer the fb dope.Ed.] FDR* Olneyville, R. I. ` P "Dear :-I like to inform you FZA Providence, R. I. that W5IFD, `Ignorant Flopeared Donkey' WHAT RN- Draftsman's face is very, FZU Fall River, Mass. is a new ham at Webb City, Oklahoma, and very red? He can't spell "separator." GIL is a double cousin of 5ELW, also of hr. so U (He has been told to write "Now I can spell GPE* Port. mobile, Providence, R. I. `separator'" 1,000 times as punishment.) GWL* Port. mobile, Providence, R. I. Tnx to W2GFW fer the hint. EOG, the IVA* Fall River, Mass. offender wore his arm off doin' the above ! IYR* Providence, R. I.

Hi ! - JCD* Fall River, Mass. T- he-Nezaark College of Engineering Radio JUN* W. Warwick, R. I. Club (W2JPK) has been shut down for the JQA Randolph, Mass. summer vacation after one of its most suc- JXO* Berkeley, R. I. cessful years. Thanks are extended to all KEL* Providence, R. I. those with whom noon -hour sheds were held KFL Apponaug, R. I. as well as to all the 40 m gang we con- KZN* Providence, R. I. tacted. LCN Georgiaville, R. I. A new Canal Zone Station is K5AP (14020 LEM So. Boston, Mass. KCT9). Full QTH is F. J. Chris, Albrook LKH* Port. mobile, Providence, R. I. Field, Canal Zone. LKN Providence, R. I. W2HHY has a HK354 in final for his new LNK Providence, R. I. KW rig. A tasty feature of Ed's rig is the LRO* Providence, R. I. detachable oscillator for portable and emer- LVN Newton. Mass. gency work. Watch out for Paley Award MFJ Providence, R. I. come floods or sandstorm to East Orange! MHB* Graniteville, R. I. [Tasty??? How's it taste? Editor.] MLB der W2HHC is putting finishing touches on MXA* Providence, R. I. 5mo his new Stancor 20 -P. Expects to start it MXW Providence, R. I. may engage this rattle -brain's script in a on 10 M. MXO Olneyville, R. I.

www.americanradiohistory.com 19

OiF Providence, R. I. FROM Helmut Giese of Port Washington, \NADIAN brother, Allen Ford of Port- SS* Arlington, Mass., and several 17 Wisconsin, we hear: 1111_} neuf Station, Quebec, gives the follow - stations in New Bedford, W9KOL, Port Washington, is now a coming dope : Mass. mercial op. at WAD, ship -to- shore station. VE1KK lias been active on 10 and has six W9OFM, Port Washington, lias gone on countries to his credit. IKK hails from the 4FFI is new Net Control for Ga. 160 cruise, un great lakes, with Naval Reserve. apple- growing district in Nova Scotia. He W Army net. \WQXI, W9WHX, \V9HNX, and \V'9NJF also works 160 phone in the 2000 -2050 ka. The Crisp County Radio Club of Cordele have formed a Marine service net for yachts band. gave a ham fest on July 2nd, with about 40 and traffic on Lake Michigan. VE11.Q, Sussex, N. B., lias been trying e.c. Georgia. Ala., and Florida pants in attend- \W9DDD, has just left a bevy of pretty near 2000 kcs. with 205D's in the final. ance. 1íQl3, FAN, CCI, GA.-\ won prizes. nurses in the hospital, and is recuperating VII0E, Halifax, another new one on \W4.ALU has a new 10 -meter beam. from an appendicitis operation. And is very 2010 be. phone. VE1FS, VE1OA, VE2JU, \W4.A l I won a scholarship to Yale. active on air these days. V1'.2AJ, VE3APC, VE3AYD and VE2PF, \V4ALS, the kilowatt from Phoenix City, all have xtals within 3 kcs. of each other on Ala., after a three -year sojourn on 20 and 10 JACK POLLARD, W9MET sent in the 2003 kcs. We are expecting a little trouble has a peanut whistle on 75. following gossip: with QRI\-I when 2AJ gets his 100 watts on \W41Ck \I is a new ham in Kellerton, Ala. \V'91-IZC has a facsimile receiver and is the air shortly. \W4E 4S is still going great guns on all trying to get a picture from Des Moines, VEIMD worked out to St. Thomas, On- band,. Iowa. It uses the Finch System and is a tario with 5 watts input on 1785 kcs. fone. \ \'4 ENS is awaiting a new ticket. Cresley Receiver. He ain't tried it yet, but VE1MJ is active again on 1785 kcs. with The Army gang at Fort Benning headed is hoping. his 6A6 final and 12 -watts input. by \W4 DX W, W4CCJ, W4ACR, are very \\''9ANZ (first person on 20), is building VE3AWF has one of the best signals on active at present. a new 300 -watt rig. it's on 160 now. 75 fone. Dillon has deserted 160 but we The Athens, Ga., gang is giving a pure \V9EKK got chased out of the living room have hopes he'll take a look around on the harnfest for the 160 -meter gang on Septem- by the XYL and built hisself a nice sound- old band sometimes. ber the 2nd, so says W4EEZ. proof room in the basement. Mike will be VELIZ is a brass- pounder on 2010 kcs. 30 \W4FAN, Jacksonville, Fla., is active on cooler there anyhow. It's rtunored that he watts to a 6L6 final. 160 with 200 watts. is going to have higher power soon. VE2OF is portable at Lorette, Que., for \W4FCW is trying to get 500 watts to work. W9FWW has just put up an 8JK beam the summer months. There are rumors of a television station at and lias high hopes. He has some swell dx VE2PG is an army station at 101 Grande Savannah, Georgia. cards too. Allee, Quebec City. 400 -watts input near Radio's Insane Engineer, AV9RIE, is sup- 1950 kcs. W4ltUZ is a new ham in Brunswick, posed to be building a kilowatt. VE2JU is a new one on 2003 kcs. fone. with FCZ and the rest of the gang Some small -power boys in Lincoln are QTH is 10796 St. Hubert St. Montreal' very active there. FOB has a new Jr. op. wondering why the high -power ones won't VE2QP, Toro Rapids, Que., contacted \W4KI; at Walpariso, Fla. gave another of talk with them. They wonder if their watts VE2PF and VE1MQ for initial contact on his annual hantfesis this year and EFD says have gone to their head. 2020 kcs. fone. that they had a FB time. VE2QN, Quebec City, is another new one. 4FNC, "JC" has a new vertical on 160 IT'S rumored that W9QMY, who has VE2AJ says that after he put up his new that the South Carolina gang says is a Class C, won't knowingly talk to anyone transmitting antenna for 160, one of his honey ! unless they have over 100 watts. neighbors complained that it was absorbing A \W9 told ARX the other night that he Some of the boys are wondering what has all the signals and that he couldn't hear any- had three RME receivers but Hinting didn't happened to \V9ZXA. thing on his radio. do any good. \V9MET followed W9ANZ portable front The Miami gang is very nil at present. Lincoln to the Bramer Picnic but lost his I MAW broke his crystal in Atlanta, with two and WW4F\VD is a new ham in signal near Wahoo due to heavy line noise W ground one -half about 10 kcs. higher \V'4GEO ditto. and 200 watters. so he can QSY when QRM lias him down. The 40 -meter gang still use the same old \V9WOA just finished building a small Hi! formula when rag chewing. portable emergency 160 rig. It uses 201 A's. VE2RO, Quebec City, uses 30 watts out- \V4K'l', Thomasville, does some swell op- \V9NKS can't be heard lately. Betcha he put ou 2014 kcs. fone. erating on 75. is building a new rig. VE3AMZ has a T9X sig. near 3800 kcs. Most of the 4 District seems badly neg- Why is it that these high- powered fone with only a 59 ose. and 11- watts input. lected in RADio News. stations can't take code? \ \'2MBH is another low -powered boy on Most f the gang on 40 are getting tired 3.5 ntegs. 15 -watts input to a 6L6 ose. of foreign interference. WSKXS advises: W2I.JN .is operating portable at Camp "On Sunday, October 16, The Penn \\ 4CCV is dx -ing on 10. Chickawah, Harrison, Me., on 160 fone. State Airmen, an organization of student WVIHXC, AV41,BJ, W1DQK and VE2PF pilots, held their first annual tiir meet at the had a four -way QSO lasting IlliT41' DE is rebuilding. State College Air Depot. The instructor from 6 to 7 Fite Florida Army net is swell FB. P. M. All signals were R7 to 9 in Canada. and owner of the airport, AIr. Sherman Lutz, Not bad for summer conditions. \W4EN I, the mighty atom front Troy. Ala., who is also my flying instructor, asked me if is 160 band. W4AVG heard by strangely absent front the -meter I could incorporate some radio into the pro- VE2PF on June 22, Rebuilding? 1939, at 11:15 P. M. on 160 fone. ceedings. VE2PL uses a 6L6G final FEI is vacationing at Jacksonville Beach. "We installed a portable five -meter tran- on 160 fone. is very active on 10 with 200 - VE4KI, Strathmore, Alta. has a 579X sig. \V4FRF a ceiver in an Aeronca 40, which is a small on the East watt Collins job. two ship. The rig consisted Coast on 40 meters. -place training CM5RV is 585X on 40 in a '19 oscillator, a '19 class Quebec. of unity- coupled Can someone gives us the JOHNNY TRINKO, W9MGH, writes: B modulator and a 30- speech amplifier. It QTH of W9ASB ? "Suh, was powered by 135 volts of B batteries. A So OiSR thinks that Wempus of his is Western Electric handset was used and a something remarkable, does lie? Ask John WHO is the station on 2013 kcs. that pair of Trimnt headphones. The antenna has been if he has ever heard of the more famous, was a four -foot piece of aluminum rod taped transmitting televisions late at night? His signal covers the entire Ca- as also more valuable, beastie commonly des- to the cabin strut and fed by an eight -foot nadian ignated by the nomenclature of "utendaciunt single wire feeder. band! ittagnutn." 'this unusual animule blames its Gleanings from the Official Bulletin of the "Tite ground installation was a haywire Toledo existence to the now extinct, though equally transceiver with a 2A5 and two '27s, using a Radio Club: It is rumored that the famous "Bisiellus. garrulas" (no relation to fishing rod and an eight -foot feeder for an Commonwealth of Pennsylvania is about to pass a law 'talkative BCL'). antenna. taxing radio receivers. . Won- "The roost important factor concerning the "In order that the crowd could hear the der why the big, BIG build -up fer "that" former beastie, whom through familiarity communications a P.A. system was set up. radiomag? \side to the sec'y of that we now call `Mendy" is the fact that all his The velocity mike was placed near the rag: If there are duplications in these col- molars when used as detectors in place of ground transceiver and picked up both the umns, it aint becuz we don't try, but a body receiving crystals or carborundum have un- voice of the ground operator and the plane can do just so much . Soto voce to L.B. believable qualities not only of detection, but operator. Chapman of TRC : Write us a letter, we also SID.ECTIVITY PLUS SENSITIVITY. "In the first demonstration, the plane rig might know where there's a loose Halli- crafter around here. . According As a matter of doubt . . . I mean . . . As was used just as a receiver. A student went to the above rag is a matter of fact, hearing Australia on the aloft and I ordered him to do various ma- HR5C unlicensed. Is that true? Pretty niag broadcast hand in broad daylight, on a ten - neuvers. The crowd got quite a kick out of nice the TRC puts out at that, (that ought to . . inch spkr, 5 ke. away front the 50kw-. AV\IAQ hearing me over the P.A..systeut tell hint to rate us a plug!) local is nothing very unusual. Another il- rock the ship and seeing it clone immedi- VR4AD has been heard in Chi very faintly lustration of this selectivity is the fact that ately, or make banks, wing- overs, etc. In by FJB. Comes in on Sundays if you fellers the' `Mendy Molar' when used on 160 -meter the next trial, AVSKXS took the plane with want to go after him. phone band cannot receive a single modu- \V8QDR on the ground and a two -way com- lated signal, due to the wide sidebands set munications was made, the crowd hearing GLEANINGS front the Kilocycle Splat- up by the supposedly 100 % modulation. both ends through the loud- speakers. er current issue: " \V/9YVK, Claude "These 'Mendy Molars' are on sale at "We all had a swell tine and in view of Winegar, is back on the job after an illness all leading paint stores. If your local dealer the fact that hardly any tinte was taken in of five months in the Veterans' Hospital at cannot supply you, send in ur QRA together preparation for the day; we were well Minneapolis. He is now rewiring his trans- with the grid caps of five 866's and the name pleased with the results. mitter and trying to figure the proper grid bias for a mousetrap. of ur local laundryman, and we will see that "This was an `amateur' day all the way - (We have seen the he is promptly supplied." both in flying and radio." (More Harchatter on page 53)

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A. L. BLdlong, ARRL's Asst. Sec'y, has a good time at the Pittsburgh Convention.

Johnny W1 QP Reinartz es his XYL attended the Pittsburgh Convention, where he spoke. ARRL's prexy E. C. Woodruff, (W8CMP), took keen interest in Pittsburgh Convention.

This is W9WKL's QTH. Notice the old oil or coal stove to the extreme left. Swell? Portable W8KXS working 56MC to airplane from in front of State College Air Depot HAM

this J. H. Hood, of Greenville, S.C., sent in W2IKV uses broadcast station fittings in fine picture of F3N4 es XYL. Notice mike? his shack. His dx contacts are impressive.

MIL G. T. Beyer sent in this pix of C T 3 A B.

9 H X. This is CT1QH. It looks 100% American. Portable G5PP, and his gang, in the field. The radio shack of Station W W

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Bill W9WZE Halligan relaxes from the ar- dours of the Pittsburgh ARRL Convention.

011ie W9ETI Read uses the big rig at the RMA Show to contact his friends in N. Y.

By Hargrove, of Johnson, caught QSO'ing with W2HXQ. Fixing it up for the fair, By?

This fine layout belongs to W- 9- triple -D. PIX The station can be heard nightly wkg. dx.

Frank W9ECA Hajek & Rex W9LIP Mun- ger pass the time of day at Pittsburgh. Rex made a fine speech on Taylor tubes.

ES5D who operates a lot on 10 meters has this superb station. That's him at the left!

ON4SG sent this fine photo of his rig to This is G5PP's rig at his home QTH. The Doc Weintraub, W9SZW visited the fa-. W1 LNK. Everything is rack and panel there. mike is one of those peculiar to Europe. mous Dr. Hard, XE1 G while on vacation.

www.americanradiohistory.com 22

TECHNICAL BOOK & BULLETIN REVIEW

RADIO'S MASTER ENCYCLOPEDIA, published by the United Catalog Publishers, Inc., 258 Broadway, New York City, is a complete manufacturer's guide on all types of radio equipment. The book contains various sections which are divided into groups in the manner of a classified directory. This publication meets the demand for a complete source of information on the source of sup- TECHNOCRATS, wherefore art thy doc- don't the tunaclippers install small Xmtrs ply and the names and addresses of the sup- trines? Things go along swimmingly, and Recvrs for the 600 meter band only? pliers. Complete listing as to names and ad- and suddenly from a clear sky comes That's his beef and here's the whyfore... . dresses are given so that the reader may word that some bright lad perfects a ma- While he was down at Magdalena Bay on easily locate practically any item now ap- chine, the Reperforator. Thousands of op the White Eagle, the whole crew of the pearing on the American market. Reprints jobs are endangered ! The darn thing does TC Funchal had to be rescued from an island from the various manufacturer's catalogs everything but eat, drink and sleep. Western on which they had beached their burning are contained and in most cases give the Union has already installed a few of these vessel. They had sent out repeated SOS on prices of the particular product illustrated. $100,000 robots and the boys at these offices the 36 mtr band, the tunafish frequency, but Much time and effort may be saved the pro- are just plug -pushing poppas. F'rinstance, it was at an hour when there were no ops spective buyer with the above information at Squeedunk, Va., will have a msg for Big - on watch. Fortunately, they were close to his finger tips. Copies may be obtained from town, N. Y., which would be xmtd via the island and the whole crew were rescued. the United Catalog Publishers at the above Washn. and N'Yoik. In the past it was If they had Xmtd their distress on the com- address. transmitted, received and then retransmit- mercial freq, there would have been a dozen ted from office to office. Now, by pushing a ships to their rescue in no time because the PRODUCTION AND DIRECTION OF plug like a telephone op, Squeedunk can work shipping lanes along the Pacific coast are RADIO PROGRAMS, by John S. Carlile, directly with Bigtown without any further close to the fishing banks. . There's the published by Prentice -Hall, Inc., 70 Fifth handling. Cute, what? But what happens to case of the TC Belle Isle which left Pedro Avenue, New York City, was written to pro- the ops who are replaced??? Ah, progress ! with 11 fishermen and was last seen at San vide a useful volume on radio production for Quentin Bay, 100 miles South of Ensenada. those who are busy performing tasks within THE CTU -Mardiv continues to chalk up She sailed out of the Bay and was never the industry and for those who hope to en- victory after victory with the counting heard from. She might have sprung a leak, ter radio's gates to create or direct, enter- of the radiops' ballots on the Waterman -Pan called for help on 18, 24 or 36 mtrs, and tain or inform, or to assist in any capacity. Atlantic SS Co. and those of the Seminole gone down with all hands in the very vicin- Few text books have been available which SS Co. CTU was voted sole bargaining ity of tankers plying up and down the west cover the intricacies as found in the produc- agent. The former is the termination of a coast. And if Eddie Barrett hadn't tion of radio programs in the studio, and the two -year attempt to get a bargaining agent walked into his shack, unconsciously turned writer has thoroughly covered all phases of for the ops of the line. We congratulate on his receiver to hear if any of the boys this type of entertainment. The book is CTU on its continual progress. were shooting the breeze, and caught the written in four parts, which include "The SOS of the TC Reliance, Brother McFadden Production and Those Who Produce It," WHEY said it couldn't be done and even and the rest of the crew of the Reliance "The Production of Musical Programs," the inventor himself had admitted it would now be feeding the fishies in tropical "Presentation and Routine," and "Speech." couldn't be done. But after years of inten- waters. The pumps could not drive the The author takes the reader through all of sive research and experimentation, Professor water out as fast as it was coming into a the various branches of radio productions, Edwin H. Armstrong has at last perfected leak in the hull of the Reliance and it was not only the musical program but the skit, absolutely noiseless, QRMless, crackleless sig- but a few hours after they had been taken sound effects, etc. The book is well suited nal reception. The elimination of static had off by Barrett's TC White Star, that the boat to the reader who is interested in staging a been put into the same category as perpetual took its nose dive. A 600 mtr call would dramatic or musical show where sound ef- motion and a few such items. So this same have completed the rescue a lot quicker . . . fects can be used to good advantage as the man who gave the regenerative circuit, the without the prayer that somewhere a tuna - author explains how all of the various sounds super -het circuit and the super -regenerative boat op would be standing a watch. . . used in broadcasting are produced in the to radio he'd take a They used headwork on the Ivan Laic when in circuit the art decided studio, which most cases make use of ma- crack at this tough nut, too. But after 8 one of the crew caught a fishhook in his terial found in the average American home. long years of effort he gave up the search. eyeball socket. He was in terrible pain and Stage setups, musical setups, cues, stand -bys, Then, after a lapse of time, Armstrong got there was the added danger of losing his eye. etc., are all explained within its pages. a new idea and tackled the problem again. The op called KFS who relayed their posi- And this time he has produced not only a tion on 600 mtrs and request for medical RADIO TECHNICAL DIGEST, published 100% elimination of static but also a 100% aid and in no time there was a tanker stand- by Radio, Ltd., 7460 Beverly Blvd., Los An- high fidelity reproduction, reduction of ing by to take the injured man on board for geles, California, for May and June, 1939, transmission costs and has made available transportation to 'Diego and hospitalization. reviews the outstanding articles appearing in more broadcast channels which hitherto had The Coast Guard planes will not go the various publications in the Radio indus- been considered commercially impossible, the further South than San Quentin Bay, which try. Among them are : "Terraine Clearance ultra -short wave bands. We insist that radio is plenty far enough. So that either union Tndicator," "The Square -Cornered Reflector should go to hat for this cheap Auxiliary is still in its infancy ! Demonstration of Frequency Modulation," xmtr -recvr. Brother Craig is absolutely "F. C. C. Watches Sun Spots," "Microphone right and for safety's sake pressure should Ratings," "Induction Tuning, Theory and OUR old friend, Putzker, makes the head- be brought to bear on the tunaboat owners Application," "Transmitter Safety Tech- lines again with a new method of go- to install this equipment. nique," "Static Suppressor," "U. H. F. Radio ing to jail . and getting paid for it ! Telephone," and a complete review of the Brother P, a staunch citizen of the thriving Field in general. The book is a handy ref- village of Hayward, California, was ap- WHERE'S cheery news on the East Coast erence to the engineer, amateur and service- proached by the local constabulary general since the Export Lines announced their man as a means of identifying outstanding (Sheriff, to you) to take over their short- possible designation as official tender vessels articles. The saine publication for July and wave broadcast apparatus. So Brother P for the Atlantic Clippers. This will mean an added radiop on each boat used. Of course, August features the following articles : now ambles to the hoose -gow each a.m., "Standard V. I. and Reference Level," "An straps on his trusty 45 and takes over the the op will be required to know all the spe- Improvement in the Constant Frequency Os- calling -all -cars system. And at $170.00 per cialized duties of the radiops at the land cillator," "Transmission Lines as Circuit month it's not bad work, if you can get beacon stations such as meteorology, etc. . Elements," "Input Resistance of R.F. Re- it, eh. It's rather clever how the Export boats will ceiving Tubes," "Pressure Capacitors," "As operate. They will continue their regular I See Ït," and "Serviceman's Experiences." TO some men honors are a mere nothing. freight schedules, but they will be so regu- ARTA is having a difficult time keeping lated that they will never be more than 600 anchored in their San miles apart across the Atlantic Ocean in a THE WIRELESS ENGINEER for May a man permanently the Atlantic 1939, published by Iliffe & Sons, Inc., Lon- Diego office. Every time they get some one path along which Clippers will don, England, includes an editorial on the to remain permanently, some tuna -fishing fly. Each op will be able to advise the Clip- measurement of the "quality" of coils. In- skipper gives him a billet and he amscrays pers about weather conditions and other data teresting reading is also found in the follow- the eachbay. Brother Jordan, who has again along the route while continuing their regular duties as freight carriers. This does ing chapters : "The New `All- Glass' Valve taken over the affairs of Local 7, ARTA, is Construction," "Input Impedance of Self- endeavoring to work something out with away with the stationary mid -ocean tenders Biased Amplifiers," "An Electrically `Cold' Brother Yurgionas in this respect. So San and about a dozen more operators will be Resistor," correspondence, abstracts and ref- Diego may be the gainer and Pedro the loser needed for this special work. Three cheers ! erences, and some recent patents. This pub- if Yurgi takes over the watch. lication is designed primarily for the engi- 'TIS sad, but one of the lads was fired neer and will provide interesting material WHILST we're down in the San Diego offen his job t'other day because he for the American student. locale, Brother Harold Craig has a couldn't repair his receiver whilst at sea. legitimate squawk coming up. Whyinell (More QRD? on page 52)

www.americanradiohistory.com 1.4v. Han Superhet

By HARRY D. HOOTON, W8KPX, Henderson, West Va.

For that field day contest. for any far- from -line- roltage Frordc, this ex-

The completed unit is attractively mounted cellent superhet trill do a real job. in cabinet with the loud- speaker separate. It corers from 200 meters down to IO.

LWAYS on the alert for new de- The separate 1N5 -G oscillator pro- operation on most of the stronger sig- velopments in economical radio vides much better stability on the nals. operation, the short wave ex- higher frequencies, around the 14 and The actual construction of the set perimenter should be interested in the 28 megacycle amateur bands, and is is not difficult but the work should be little five -tube superhet to be de- less likely to be affected by adjust- done slowly and carefully. The holes scribed. Designed around the new 1.4 ments in the antenna circuit. The for the tube and coil sockets and the volt battery -type tubes which were oscillator output is introduced into the large panel cuttings are made before recently released, this receiver oper- mixer circuit through the 1A7 -G grid the panel and chassis are fastened to- ates from only a single 1.5 volt dry No. 1, as shown, grid No. 2 being tied gether and before any of the parts are cell "A" battery, a small 4.5 volt "C" directly to the "B" plus end of the mounted. It is best to drill as many battery and two midget 45 volt "B" 70,000 ohm screen dropping resistor. of the small holes as possible before batteries, yet it is capable of extraor- This arrangement has proved quite ef- mounting the sockets, tuning condens- dinary performance. fective and should not be changed if ers, etc., in order to keep the metal The circuit, as the schematic dia- maximum performance is to be ex- "dust" off the insulation. Once im- gram shows, consists of a 1A7 -G mixer, pected. bedded in the isolantite, these small a 1A5 -G oscillator, a 1N5 -G IF ampli- The receiver is built up on a 7x13x2 cuttings are extremely difficult to re- fier, another 1N5 -G as detector and a inch chassis and a 7x14 inch panel. move and will certainly impair the 1A5 -G as output. Regeneration is used Both are supplied with the steel cab- efficiency of the set even if they do not in both the mixer and the detector cir- inet shown. The various controls on cause an actual short-circuit. cuits to boost the sensitivity, especially the front panel, left to right, beginning The same precautions must be ob- in the 14 -28 megacycle region, and to with row, : the lower are as follows (1) served when soldering the various con- provide a simple and effective means RF regeneration control; (2) mixer nections; of receiving CW code signals. use just enough of the rosin - The trimmer condenser; (3) oscillator core solder to make a good joint method of obtaining feedback in the trimmer condenser; (4) detector re- and keep the iron hot, clean and well - 1A7 -G circuit is novel-a small RF generation control. Top row: (1) AF choke tinned. Use either the solid or stranded coil, consisting of 25 turns of tone control; (2) AF gain control. hook -up wire No. 24 enameled wire wound for connecting the parts on an old The dial is of the micrometer type, together and keep all leads, especially broadcast RF choke core, is placed in capable of being read to an accuracy series with the positive filament those in the mixer and oscillator cir- lead, of one -tenth of one division. cuits, as short and direct as possible. close to the tube socket as shown in The coils are of the plug -in type, the photograph. five pairs being required to cover the After the receiver has been wired, The negative filament lead is con- range from 9.5 to 200 meters. The 10 go over each circuit carefully in order nected to ground through a small tick- and 20 meter coils are wound on the ler winding on the coil form as indi- midget one -inch isolantite, five -prong cated in the diagram. A .05 mfd. forms; the 40, 80 and 160 meter coils bypass condenser across the filament are wound on the standard 11/2-inch terminals of the socket keeps both legs forms. The coils for the three low - of the filament at the same RF poten- frequency bands carry their own band- tial. Although the 1A7 -G tube cannot setting condensers inside their forms; be made to oscillate in this manner, the 10 and 20 meter coils are tuned the sensitivity is enormously in- only by the dual 15 -15 mmfd. tuning creased; it is necessary to provide a condenser and the 20 and 35 mmfd. 2,000 ohm control across the tickler in trimmers. This results in a great in- order to keep the regeneration within crease in sensitivity on these bands. reasonable bounds. The image re- Iron -core, 460 KC IF transformers sponse, while not completely elimi- and regeneration in the detector cir- nated, can be very effectively reduced cuit boost the gain at the IF level. A by the use of the RF regeneration con- single 1A5 -G pentode AF stage pro- The parts are mounted . in rotation trol and the mixed trimmer condenser. vides plenty of volume for speaker for ease in wiring. No trouble here.

www.americanradiohistory.com 24

trols slightly and try to

tune in some weak broad- 1 TICKLER cast station operating on I MIXER 23 BOT."32 ENAM.

6,000 1 a frequency around FROM GRAD kc. Adjust the mixer and B COIL 5 COILS oscillator trimmer con- ARE WOUND densers, or the band -set- 3 ON5PRONG ting condensers, for maxi- COIL FORMS mum signal volume. E, Now, using a non -me- OSC. tallic screwdriver, beginning with the secondary 4s of the output IF transformer, adjust each IF Coil and IF xfmr construction dope. trimmer in turn for maximum volume. If the vol- Normally, the mixer regeneration Under chassis view shows clean wi ring. urne becomes too great control is turned about three -fourths during the adjustment, on while tuning. It is not necessary to to make sure that all of the connec- reduce the input from the antenna to adjust this control when changing tions are correct. It is always a good the mixer circuit; do not, under any bands; if the tickler coils are wound policy to test from each `B" plus lead circumstances, reduce the volume by exactly as specified in the coil table, to the chassis in order to determine turning down the volume or gain con- the same setting will serve no matter whether any "shorts" are in existence. trols. It is usually necessary to go whether the 10 or 160 meter coils are If everything appears to be correct, over the IF trimmers three or four in the sockets. Generally, the follow- the batteries may be connected as times in order to obtain an accurate ing operating technique is used: Ro- shown and the process of alignment alignment. tate the oscillator trimmer condenser carried out. The tuning and operation of the va to about one -half scale, turn up the It is usually best to align the IF cir- rious controls is extremely simple. The mixer and detector regeneration con- cuits from the signal of a 460 KC test dial shown on the receiver is a new trols slightly and adjust the mixer oscillator, if one is available. Trans- precision type, having a ratio of about trimmer condenser for the highest mitted high frequency signals are poor 10 :1 in 270 degrees and is capable of noise level. Rotate the dial for a sig- for this purpose because of their rapid being read to an accuracy of one -tenth nal, keeping the detector regeneration fading. If nothing better is on hand, of one division. This is extremely use- control just below the point of oscil- the circuits may be aligned in the fol- ful when tuning on the crowded ama- lation for phone and just above for be neces- lowing manner : Place the switch in teur bands and actually permits razor- CW code reception. It may the "on" position and turn up the edge logging of signals no matter how sary to readjust the mixer trimmer mixer and detector regeneration con- weak or distant they may be. (Construct further on page 61)

Coil Data C -Mica condenser, .00005 mfd. Aerovox. R1- 50,000 ohms resistor, 1 watt. I.R.C. Mixer Ose. Cs -Paper Condenser, 0.1 mfd., 600 volts. R- 100,000 ohms resistor, 1 watt. I.R.C. Range Grid Grid Ticklers Wire Spacing Sprague. R6-3 megohms resistor, 1/4 watt. I.R.C. 914 -15 4 * 4 3 No. 16 1" Cs -Paper condenser, 0.5 mfd., 600 volts. R- 250,000 ohms, 1 watt. I.R.C. 15 -30 12 * 11 6 No. 18 11/4" Sprague. R8-50,000 ohms potentiometer (regeneration). 30 -60 17% t 151/2 8 No. 22 11/2" Cm -Paper condenser, 0.1 mid., 600 volts. Yaxley. 60 -150 38 t 31 12 No. 26 11/2" Sprague. Rs- 500,000 ohms potentiometer (volume). Yax- 130 -270 82 t 65 15 No. 28 11/" C11 -Paper condenser, 0.1 mfd., 600 volts. ley. a Wound on 1" forms. Sprague. R10 -1 megohm potentiometer (tone). Yaxley. t Wound on 11/2" forms with 140 mmfd. band - C12 -Mica condenser, .00025 mfd. Aerovox. L1- Antenna coil, three or four turns around setting condensers inside the form. Range given C13 -Mica condenser, .001 mfd. Aerovox. "cold" end of the mixer grid coil form. See is in meters. Spacing is the distance between the C14 -Paper condenser, 1.0 mid., 600 volts. drawing. grid and filament ends of the coil, not the dis- Sprague. L2, L5, L4, L1 -Mixer and oscillator grid coils. tance between turns. Wind ticklers in the same Cm Paper condenser, 0.01 mfd., 600 volts. See coil table. direction as grid coil and on the "cold" ends of Sprague. L5-100 henry AF choke (AF transformer pri- the form. All wire enameled copper. Cm -Paper condenser, 0.05 mfd., 600 volts. mary and secondary in series will do). C1, C5-Variable condensers, 35 mmfd. each. Sprague. L -30 henry AF choke. 20 nia. Ham marlund. C1 -Paper condenser, 0.25 mfd., 600 volts. IFT1-460 KC, iron -core, input IF transformer. C2, C4-Dual section tuning condenser, 15 -15 mmfd. per section. Hammarlund. Sprague. Meissner. C5-Mica condenser, .0001 mfd. Aerovox. R1 -2,000 ohms potentiometer. Yaxley. IFT2 -460 KC, iron -core, output IF transformer Co -Paper condenser, 0.05 mfd., 600 volts. R2- 200,000 ohms resistor, 1/2 watt. I.R.C. (see drawing). Meissner. Sprague. R3- 70,000 ohms resistor, 1 watt. I.R.C. DPST -Switch on potentiometer.

www.americanradiohistory.com 25

Jor . p er l .eCodewit ,l y , n By BON BEAT Communications Engineer, Sarasota, Florida "It don't mean a thing if it ain't got that swing." The author stresses the importance of spacing, and describes, for the first tine, his original fire BSL. If you're trying to learn the code without knowing what a keying cycle is, it's two -baud. -N MOST electrical codes, intelli- present. Here is a state of affairs three; and a wordspace, seven. gence is transferred by a succes- where you can copy code without hear- A surprising fact transpires when - - sion of two conditions : signal, or ing the dots and dashes. If the "spaces" the BSL are arranged in temporal se- "mark "; and no signal, or "space." With are so important, we might as well quence; although a dash is three times a radio transmitter, these two condi- learn the "spaces" and "marks" to- as long as a dot, it takes twice as much tions are expressed by alternate pe- gether. When you have finished your time to send them. The reason is that riods of radiation and no radiation; sandwich, let us look at the diagram. the dots cannot be sent unless followed with a blinker, darkness and light; on In International Morse (radio) Code, by a character -space; neither can the diagram, black and white. all signaling is accomplished by vari- dashes. The combination of "mark" The two conditions need not be ab- ous successions of five Basic Signaling and "space" which compose a dot is solute. For example, a heliograph Lengths. First, the dot, of one unit two bauds long; a dash, four. Sim- utilizes daylight and sunlight; and length. Second, the dash, of three. ilarly, no letter can be used as a signal while the contrasting conditions are Third, the character -space, of one unit; unless it is followed by a letter- space. both represented by light, its intensity no dot nor dash is a signal unless it is The words "we" and "do" must be so is varied to distinguish the conditions followed by one. Fourth, the letter - designated by a wordspace. from each other. Any two things space, of three unit lengths, to which The one feature which is common to all which form a contrast might be used each code letter owes its existence. the code devices described in this text for signaling. A person could, by let- Fifth, the seven -unit wordspace, is rhythm; the relation, not only of dot ting a ham sandwich with mustard ex- which, when following a group of let- and dash, but the relation between the press a difference from one without, ters, carries the significance that a five Basic Signaling Lengths. When signal in code, although it would prob- word has been completed. you practise, keep their time relations ably take so long he would eat one be- A typical grouping of these five in mind, even before you learn the fore the message code. The reason was finished. In for this will be- that event, the THE CHARACTER SPACE. E E-.I BAUD --II THE DOT M come apparent would not when you get up other THE LETTER SPACE EIDD -3 BAUDS --i THE exist as a signal. t DASH MIN to about 10 words A telegraph THE WORD SPACE 1 1 1 1 1 1 E-- 7 BAUDS per minute-when sounder expresses THE BAUD IS A UNIT OF TIME you pass this point,

1 I 1 I 1 -I I I I I 1 I 1 I by I I I I I I i both conditions I 1 II I, r I I I I I I I I 1 you I-III I-I II L I) will stop silence. The clicks counting signal have no signaling WORDSPACE"* OT.ri DASHES.L.IMMLWORD SPACE "marks," and duration; the si- think of the code lences represent- MN IN IN 12 BAUDS EN= MMI IMMIN NMI 24BAUDS as various rhyth- ing "mark" may mic groups, rather W- R N be distinguished '..... than as quantita- from those of the tive buzzes. 1111 MI= MEN NM MM. 1111111. 11.111M other - "space" - WORN= 48BAUDS OR 24 KEYING CYCLES Start, before you by 1 21 3141 516 1 71819 I 9 21 122123 241 condition 1 1 memorize the the I I 11011 112113114I15116.I17118II 2°1

I I I 1-I- I I I I I I I I I I 1 1. I I I' 1 1. 1`-I I I I .I I 1.. 1 1 1 I"1 1 1"1. 1 1 difference in clicks II . I.I I1.1 1 chart, by feeling which precedes dB the mechanical them. One sound rhythm of dots, designates a point in time where Basic Signaling Lengths is shown on character -spaces, and dashes. Send a "mark" begins and "space" ends; the the diagram, representing in code the continual series of dots at any speed. other, the point of transition from words "we do." Notice the part of the They will be simply an alternation of "mark" to "space." Either silent pe- three "space" lengths play in the com- "mark" and "space" units of equal riod sounds the same as the other, if it bination. Of the 48 time units, 26 are length. Then practice dashes -three is heard alone; it is not a signal until "space "; 22 are "mark." parts "mark," followed by one part it is followed by another, a contrasting The word "baud" is a terminological "space." After that, memorize the signal. blessing which honors M. Baudot, in- code, add the letter -space and word - It becomes apparent that learning ventor of the five -unit printer code. It space, and practice word groups. the code concerns more than the one replaces the clumsy near -equivalents Diagram the alphabet and numerals condition represented by dots and "half cycle" and "time unit." The on graph paper; it will help you to pic- dashes. They do not represent the nec- baud is the primary structural interval ture the timing and proportion of what essary two conditions, but are "mark" in telegraphic mechanics, and has a you are sending. If the total time units lengths, differing only in duration. The duration any speed -of one -half a is odd, you will have made a mistake "space" intervals, without which dots -at in combining the five groups. All let- keying cycle. It is basic because it is ters, numbers, punctuation and dashes do not exist, are equally in which and require the shortest possible time an even group of time units. All code important. be repre- Ever copied the back -wave of an arc either keying condition can groups require a certain number of transmitter, which gives a sound, not sented. keying cycles (bauds divided by two), for dots and dashes, but for the inter- The five BSL, being built of these and all keying must come out to a vening spaces ? You can, by hearing the primary units, bear relation to them. prime number of keying cycles. Don't spaces alone, let sound represent On the diagram, this is expressed in worry about it until you get above 50 "space," and silence, "mark." In this bauds; a dot or a character -space is words per minute. The only time it manner, two signaling conditions are one baud long; a dash or a letter- space, (Conquer further on page 56)

www.americanradiohistory.com 26 SOLVING Ti Continuing the series on the bugaboo of the serviceman, -the intermittent, -the author describes some more of the places where to look.

Typical Locations thought here is that the errant part the customer call him. While the set DETECTIVE, following a must be sweated into confession. owner might not know any of the known criminal, must stay These three methods have some technical considerations behind an "in- within striking distance until basis in logic, since all "intermittents" termittent," he is no fool when he uses theI fugitive can be arrested "with the are caused by: his ears; he will know immediately if goods on him." It is the same with a Voltage failure, the original fault is still present if you serviceman seeking out the source of Heat failure, or muff the job and replace the wrong an "intermittent " -he cannot make a Mechanical defect; part. So -nurse the set with extreme replacement unless the trouble has and although one case (say) in fifty care until the source of trouble is been isolated while the closely -guarded might reveal its origin as a result of found. set has been "caught in the act." A brute force, I am against the use of The problem, after the set is in the repair made under any other condi- these overloads in routine repair work. shop, is to simulate normal operating tions is a gamble. Operating the set at an unusually conditions. (Of the total number of All repairmen who have had an "in- high temperature will certainly bring 'phone calls to service "intermittents," termittent" chassis on the bench while out -or cause -some failure, but the the majority are caused by the an- it refuses to "intermit" know how odds are two to one against the serv- tenna system; the window -strip being strong becomes the urge to mash it iceman guessing which of the three the most frequent offender. Just now, with a brick. Like the doctor who types of failure is to blame. He is we are concerned only with the chassis threw cold water over each patient playing with fire, and the odds against faults.) A simple voltage test for the upon his first call- because he knew his locating both the cause of the "in- type of fade which occurs in the cus- how to treat chills, but nothing else - termittent" and the point of weakest tomer's home when a light switch the serviceman feels that, if the set resistance to heat in one and the same is snapped somewhere in the block can could only be broken down, repairing component are too great to be practi- be made by producing similar surges it would be simple. cal. with a flasher near the set. The re- This natural urge has given birth Even if it were possible to locate sultant surge is harmless because it to various "egging -on" methods. There the trouble by "trial by fire," there is does not cause overload; it simply is the "over -voltage" method-during always the danger of introducing other saves time by "lumping" a month's which the serviceman, starting from latent sources of trouble within many clicks into a half -hour. 120 volts input, raises the pressure un- components. It appears that the cure A simple procedure for heat test til something gives way. Whatever is worse than the disease, and that the that has frequently been helpful is to goes bad is replaced with the hope that repairman would best serve his cus- retard heat dissipation from the chassis the cause of the "fleeting fade" is the tomer by continuing the heat treat- by laying a newspaper over it. Venti- component that burned out. ment to its perfect ultimate by throw- lation is slowed down; the set operates There is the mechanical, or hammer, ing the whole job into the furnace. at a temperature close to that in the method of precipitation, which in- Intentional heat, voltage, and me- customer's semi -enclosed console, and volves bouncing the chassis and chanical overload may have their there is no danger of abuse. What lit- speaker up and down on the work- place in a factory or laboratory, where tle difference there may be between bench -the height of the excursion all conditions of test are under posi- ambient temperatures in the shop and varying, not with the weight of the tive control -but there are better in the home is small compared with set, but with the extent of the bounc- means of locating trouble in the re- the normal operating temperature. er's tantrum. pair shop than by a mixture of hope Mechanical shock may be simulated Then there is the "trial by fire," and random abuse. by prodding with a non -metallic dowel, which introduces an abnormal degree The serviceman's best bet is to ob- by bending, or by snapping. The tyro of heat into the chassis by means of serve every feature of the customer's usually tries this method first, poking some unnatural outside source. The installation while he is in the house, everything that juts out from the and to preserve every possible condi- chassis, and turning to some other tion to which the set is subject in nor- method when the first fails. Consid- mal home operation. Both of these erable experience must go into prod- precautions serve to make it easier for ding : each set part requires a different him to locate the one fault in which treatment. A tap on a carbon resistor he is concerned -the one which made might indicate fault, but the same one on a wire -wound unit would be wasted. A 27 in one socket would sound differ- ently when it was struck than the same tube in another socket. Only training will determine what to listen for; but until you have become experienced, raise the volume control, tune between stations, and strike thought- fully, slowly, and thoroughly -not as if you were d'Artagnan fighting himself out of a tough corner! You will find that, as your experience increases, these methods will become simpler, and you will turn to the Faulty lead -ins are common sources. Antenna transformers cause them, too. most probable sources without deliber-

www.americanradiohistory.com 27 NTERMITTENT

by "TESTER" lMADLEY

ate thought. For instance -there is one tions are seldom worth while. (Fig. 1) loom terminated in a multiple contact Lyric model which, if bolted a certain The Columbia SG -8 (Fig. 2) some- wafer -such as the Majestic 70 strip way in the cabinet, will cut off and times presents a typical failure. Its r -f in Fig. 5 -fade when the connection is squeal. If the chassis is sprung a cer- chokes short themselves out by volt- not electrically perfect at the power tain way, the tuning is affected. Sim- age breakdown, and the set delivers a pack. The condition is usually evi- ple ? Sure -but the first one I came much lower volume than normal or denced by a slow rise and fall in vol- across took three embarrassing trips cuts off completely. (Grid -plate capac- ume, following contact and interrup- from the customer's home, and was lo- ity across the 24 usually allows the set tion in the filament leads. The trouble cated only after I swore to live with to operate at low volume.) Press each often follows re- installation after a re- the set until the trouble came to the choke as if you expected it to bend; pair job, when a serviceman mistakes surface. After that, I loosed all Lyric these coils return to normal when the a good mechanical connection for a chassis bolts with the juice on, and short "burns itself out," and some- good electrical one. To check for the have saved myself and the people who times, either by physical or electrical point of trouble, press the edges and hired me a lot of headaches. test, the condition can be artificially center of the contact strip before All "intermittents" are simple - induced. Replace them all if there is loosening the nuts. After the trouble after you have located the cause! The any reason to suspect them as a source. has been isolated by watching the recognition of typical sources is valu- A common "intermittent" source is tubes go on and off, remove the strip, able in every job; it is a time -saver, found in many of the older Philcos tighten the lower nuts, and replace the and it is the means of positive repair which used the type of bypass shown in terminal assembly. which will gain good -will by distin- Figure 3. There are various interpre- Heat and voltage failure are often guishing you from your competitors. tations of the reason for trouble in related. The familiar copper -colored Let's look at some of these typical these units, but it is fairly certain to Kennedy AC-20--which uses a 3 -sec- sources. say it was a temporary manufacturing tion 8 -mike Mershon -presented one First, I believe that instruments defect which was quickly remedied by such case when it was brought in on a play too great a part in starting "in- a change of specification in the later fading complaint. The customer said termittents" in the shop. (Before replacement parts. In working on these that operating the set was a gamble : some meter manufacturer mails me a sets, it is a good idea to press each "You snap the switch -maybe the set time bomb, let me repeat : STARTING rivet firmly with the set running, and plays, and maybe it doesn't." The them. Once the condition is estab- to move each lead at the point where power switch was snapped off and on lished, use whatever meters you find it enters the eyelet, in order to isolate repeatedly, and the trouble was found most convenient.) This does not the bad one. The customer usually to be a result of improper healing in mean that an experienced repairman notices an abrupt shift in volume when one section of the filter condenser, as should tackle an "intermittent" with a light switch is snapped on or off. indicated by leakage current through his bare hands; it does mean, however, An interesting shielding peculiarity a milliameter connected as shown in that a little knowledge and thought shows up on the RCA R -121, a 6 -tube, Fig. 6. as to the commoner causes are more 2 -band super. It cuts on and off if the This trouble is more common to the useful than a meter which is used only shield is improper around the i -f 58; condenser than to this model set; the as a sop to one's confusion or inertion. it cuts off completely if the shield is 20 stands out in my memory only be- Typical of mechanical failure is the removed. The socket layout is shown cause I delivered it too quickly. The cold -soldered joint often found on in Fig. 4. When a customer moves, he owner called me back after two days, voice coil or r.f. coil lugs. The fine often takes out tubes and shields, and reporting another "intermittent " -or wire makes factory soldering difficult, forgets to replace them all. I don't the same one -and I found a creeping and when the enamel is improperly re- suppose any serviceman ever gets ex- short between turns on the voltage moved, a cause of future trouble is cre- perienced enough to spot a missing divider. My exuberance cost me plenty; ated. For a short period some years tube cover on any set. This being so, when the resistor went out, so did my ago, AK experienced trouble from it is good practice to look for a telltale prestige! more than their share of such connec- mounting rim around the tube socket One voltage failure which has a re- tions. They are not, of course, found if the customer is in a new home with lation to many other sets was found in only a few sets; such trouble may be a blocked set showing normal voltage on the Silver -Marshall 35A -a 9 -tube found in any radio receiver, and the readings. superhet with a 10 -wire cable between blame is one of undetected production The terminal strips in sets which power chassis and tuning chassis. The peculiarity rather than neglect in de- have a power supply -to- tuning chassis (Search further on page 56) sign. VOLUME CONTROL When the cold joint is in the voice BLACK CASE MOUNTING BOLT coil leads, all chassis voltages check (ILUGS normal. If speaker hum is heard dur- CTa.41\b SHIELD ing the bottom phase of the fading ->j BOTTOM VIEW cycle, these wires are due for inspec- AK -46 ANTENNA LEAD COND IN PHILCO 90-A FIG.3 tion. FIG .I Loose strands often short at the ,t58I.F. TERMINAL STRIP CABLE LEAKAGE TEST ORF ends of shielded wire, or cause re- SCTREENS O O O TOP 11 11 peated cut -offs when the middle of the I 2 3 50 VIEW MA. o RESISTOR wire is punctured. The AK 46 has such 04 60 IIIID a shield between the antenna post and TOISWITCH RESISTORS MERSHON CONO. by bending 10,000 the volume control. Test RCA R-I21 LAYOUT FIGA MAJESTIC 70 PW'R UNIT FIG 5 KENNEDYAC _ it, or by disconnection and replace- -20 FIG.6 ment with a jumper. Visual inspec- Common sources of intermittents.

www.americanradiohistory.com 28

Hytronic Laboratories, 76 Lafayette Street, Salem. Massachusetts, present a low -power version of the popular 866 mercury rectifier known as the new Hytron 866 Jr. tube. This rectifier with plate connections at the top in- corporates all the desirable features of the The Lindberg Manufacturing Co. of 1848 plets. Model D7 -513- mercury vapor rectifier. 14th is now West Street, Chicago, Illinois, 1Q is constructed along An indirectly - heated manufacturing a high efficiency coil and con- the modern lines fol- cathode is employed for denser combination designed for the ultra- lowed by most of the increased efficiency. high frequencies. Known as the High "Q" manufacturers with the The tube has a filament Loop, this unit features simplified cir- tuned addition of the repro- rating of 2% v. at 3 cuit construction affording a minimum induction, which is lo- Amperes. Two of the sulation loss on both 5 and 10 meters. The cated on the top of the 866 Jrs. may be con- assembly consists of an air -wound induct- plastic case. Incorporated within the new nected in series to re- ance coil of stiff copper wire supported at models several exclusive features in con- place on type 83. This its center tap by an Al- struction and design are to be found, ac- tube will operate at a.c. simag insulator. The cording to the manufacturers. A television voltages up to 1250 and ends of the coil are receiving set has also been perfected and is a pair of these tubes sweated to a pair of cir- now offered to the Trade. will deliver 250 ma. It cular copper condenser may be used to replace plates. These have Radio City Products Company, 88 Park 83's now used in cir- holes in their centers Place, New York City, presents a new addi- cuits having more than through which a pyrex tion to their line in the form of RCP Model 500 volts. The 866 Jr. tube passes. The tub - 660, which is an Electronic Multitester. is not recommended as ng, together with two shorter pieces which This instrument was designed for industrial a substitute for the fit over the first mentioned tube, form a com- laboratories and for those servicemen aware standard 866 because pression arrangement for the circular con- of the importance of being properly and coin - with a filament drain of denser plates. Adjustment is accomplished pletely equipped. The vacuum -tube Volt- only 3 amperes as compared with 5 on the at the end of the tubes, inasmuch as the in- 866, excess filament voltages may be applied ductance coil itself acts as a spring, the con- when the 866 Jr. is substituted for the larger denser plates are forced outward, which tube. Furthermore, the 866 Jr. has only half counteracts the inward thrust of the pyrex the current capacity of the standard 866. compression tubes. These units are avail- for 5 10 meters. able either or Minis Radio Co. are now manufacturing complete rotary -beam antenna kits for both Sprague Products Company of North 10 and 20 meters in the two and three ele- Adams, Mass., announce the introduction of ment types. The units feature an inductive their type DR condensers which are of the method of coupling the line to the radiator can type, in addition to the Type RP rec- which eliminates the disadvantage from the tangular cardboard container condensers. standpoint of feeding the antenna with other The manufacturers claim that the actual ca- methods. A special matching transformer is pacities are from 1/3 to % those of dry electrolytics in the same size container. Leak- age and power factor are extremely low. No Ohmmeter, Model 660 has voltage readings polarity has to be observed. Thus, the new as low as 0.1 v. (full division) and as high paper units are unexcelled as dry electro- as 6000 v. The ohmmeter range is from .1 lytic replacements in the high voltage P. A. ohms to 1,000,000,000. Maximum voltage systems, power amplifiers and high voltage used in the ohmmeter is 7% v. The opera- filter circuits. Types DR (inverted can tor is protected by properly insulated termi- types) are available in four capacities, 4, S, nals and the manufacturers claim an input dual 4 -4 and dual 8 -S mfd. All are con - resistance on all ranges above 6 v. to be 2 servatively rated at 600 volts Di- megohms and 40 megohms on 6 v. Model working. 660 is mensions of an 8 mfd. can Type DR are 4-A" supplied complete with handsome high x 1N" diameter. List price is $1.75. hand -rubbed sloping walnut case. Further An S mfd. Type RP is only 4%" long x information on this tester may be obtained high x 15/16" wide. by writing to the manufacturer. Operadio Manufacturing Co., St. Charles, Eitel -McCullough, Inc., San Bruno, Cali- Illinois, announces the Model 855 AR, 55 fornia, have brought out a new transmitting Watt Base Type Amplifier. Among the fea- tube known as the Eimac 75T. This tube tures included in this new unit are four is a radiation cooled triode designed espe- channel input, electronic mixing of three mi- cially to develop a high power output while crophone circuits simultaneously with phono - requiring a low voltage graph or auxiliary input, volume compres- on the plate. The 75T sion, volume expansion, provision for remote has an entirely new fea- controller, electronic visual overload indica- ture in the form of a tor, electronic visual output level indicator, heat shield directly over the plate. This shield acts as a control to pro- included to match a 2" line to the system. tect the plate -lead seal Heavy duty construction prevents damage from excessive heat from high winds and the use of an oversize Straight line construc- shaft tends to hold the beam in a stationary tion provides a great position after it has been rotated to a given improvement over the position. These kits are stocked by many conventional type tubes jobbers in any of the four types and come in that interelectrode complete with all holes drilled and hardware capacities are extreme- furnished. The kits are complete with the ly low and electrical ef- exception of the motor control wires and the ficiencies are greatly feed line. ncreased. Short, A direction indicator is designed to show straight leads go from the operator the position of the beam right grid and plate directly from the operating position and is supplied non -resonant equalizer used as tone balancer as part of the kit. is through the glass bulb. for both high and low frequencies, master The rotator designed 1 rill The use of a rugged for 110 -120 volt, 50 -60 cycle current. A suit- five -volt thoriated tung- gain control, six stages and thirteen tubes. able transformer may be had to operate the sten filament permits extra high power opera- A neon lamp in the top of the housing gives beams from a 220 -240 volt source. tion. Tantalum elements, specially treated by warning when a power tube becomes defec- Eimac insure tive, thereby preventing damage that might the exclusive process, long life result from a shorted output tube. The elec- Bud Radio, Inc., 5205 Cedar Avenue, and trouble -free performance. The tube is tronic eye in the center of the control panel, Cleveland, Ohio, have added a new series of designed for vertical mounting and ample indicates accurately not only when the am- midget low -loss transmitting type induct- ventilation should be provided. plifier is being overloaded, but also the aver- ances to their versatile line of equipment. age watts output which is going into the This series, known as "air wound" contains Stewart- Warner Corporation, Chicago, Il- speaker system. With the "percent power" a selection of small oscillator and buffer linois, has just introduced its 1940 radio and control, one can check various percentages coils which are intended for low power television line to the Trade. Among the 15 of power from the maximum down to the transmitter stages. These are mounted on new models is the introduction of three plas- minimum. Specifications and further details glazed ceramic bases which fit into standard tic sets bearing reproductions in full color may be had by writing Operadio Manufac- five prong sockets and are available in either of recent photographs of the Dionne quintu- turing Co.. St. Charles, Illinois. (Continued on page 62)

www.americanradiohistory.com 29 1940 Radio News "ALL PURPOSE" TRANSMITTER -RECEIVER

by KARL A. KOPETZKY, W9QEA and OLIVER READ, W9ETI Managing Editor, RADIO NEWS Technical Editor, RADIO NEWS

The interconnection of the various chassas anal the putting of the unit on the air, finishes this series.

ADIOMEN are prone to keep to the well- trodden paths, partly - - ) of necessity, and partly because of the fact that there seems no reason I o stray. Their work is mostly concerned with alternating current voltage and high voltage direct current. FANT. METER low volt- RF PLATE The action of high current, METERS age direct current em! is more or less left severely alone. In building the RADIO NEWS "All- Purpose" Transmit- ter- Receiver the latter condition will S/S CONTROL --> have to be conquered, since all of the d.c. control circuit is in the primary -generators. TANK side of the motor CONTROLS A kilowatt of d.c. generators draws considerable amperage from the line, EXCITER and relays that would handle a kilo- CONTROLS watt of a.c. with ease and without sparking, are devils with arcs, flash- SPEECH overs, and the like. Unless the relays METERS act smoothly and without such electrical phenomena, the unit will fail at the very moment when it will be needed most. RME 69 RCVR - Control System Having built all of the component parts, they should be mounted as indicated in the two illustrations. The Control Relay Panel contains the four main relays and it is from this point VOLTAGE --> CHI- VOLTAGE that the whole operation of the trans- METERS METERS mitter as well as the receiver is controlled. It will be found that Relay "B" will require a condenser of 0.5 SPEECH CONTROLS mfd. across the contacts to prevent _VOX arcing. The same will have to be done CONTROLS with the transmitting contacts of the HANDSET -* VOX relay and also the push -to -talk relay. MAIN The value of the condenser is quite BUZZER & *- MANUAL critical, since a larger one will cause ON -OFF ON-OFF the circuit to lag while the condenser CONTROLS CONTROL discharges itself through one of the .A.C. INPUT relays. CONTROLS All wiring which carries the heavy D.C. INPUT d.c., low voltage, current should be of CONTROLS No. 10 gauge, flexible. We used 10 strands of No. 30 wire in a heavy cloth covering. All a.c. wiring should be A.C. AUTO - done with No. 14 tinned copper, solid F-XFMR insulated wire (Consolidated Wire CONTROLS Co.). All high voltage, d.c. emf should be wired with high tension, rubber covered (No. 4027 -Consolidated Wire Co.- Ignition wire), all wiring between chassis, which was not of the high voltage d.c., or the high current low

www.americanradiohistory.com 30

R.F. SPEECH AND V.O.X. SYSTEMS OF THE 1940 RADIO NEWS TRANSMITTER -RECEIVER 6N7G T21 BARKER R`T T4.HT TUIRRETMSON MEISSNER 155 SIGNAL RLY'H - SHIFTER 3 0- 1 TO IIOV AC ATALS

I O O R c 4 F

i.PHONE CW SWITCH EXCITER IIOVAC

TO 6647 VI T21 86 FILS

MODULATOR SPEECH 2-TZ40's 6J7

6 I ALL SHIELDING IS GROUNDED 7 i III 8 9

L VOX

II II PLY F 43, ,

AUTO

RCVG

RLY 'A" MASTER RELAY RLY

RLY. J

13 14 IS

SEE PREVIOUS ISSUES FOR ALL COMPONENT PARTS

www.americanradiohistory.com 31

POWER SUPPLIES AND GENERATORS WITH RELAYS

TO IIOV AC. 2- AME 69RCVR 550 W GEN. 3- AC D C. 4 -® s000R 6000 MIKE. PTO %TAL N ,41-LJ1 MIKE STAND PM _RLYE - SPKR 8 IO I BREAK N RLY 1 I0Á1 IOB 1T Cri PLUG FOR III 1

A . INPUT

TORO' C.

BUTTON TO SHIFT FROM HANDSET TO TO MIKE GRID

AMBER PILOT.

OPE POSITION

866 Já s 350W GEN o AC DC.

i GREEN MOD SWITCH

9 ALL SHIELDING IS GROUNDED 9A 9B 1/* CE PLUG FOR A C. INPUT

TO RLY

OVER- LOAD RLY

1 UNDE R LOAD RLY

OFF POSITION TO VOX 1 665 FIL 11

1 150 W I GEN. TO VOX 3T FILS il OC. GREEN - PILOT RCVTR6SS TO /000 SPEECH FILS.

80 TT1 O '0000 PLUG FOR A. C. INPUT

SEE SEPARATE DRAWING FOR OClAIL OF RELAY SYSTEM RLYD RLYC" RLY$'

TO360W.GCN. TO330W.GCN.

FUSES+

DOOR FOR IIOVAC OPERATION OPEN SWITCHES 9,10/.11; INSERT PLUGS 9A,IOA,IIA INTO INTERLOCK SWITCH RECEPTACLES 9B,IOB/.II8; REPLACE RLY BULBS WITH SAMP. FUSES IIOV D.C. INPUT

www.americanradiohistory.com voltage d.c., should be done with XTAL -BUF CATHODE _c_ BULBS A,B,C,D ARE I5W.t.c II T.5 VOX RLY OTHERS ARE 7.5 W.GE RLY "F" twisted rubber covered pair (No. 18- 41 - TO BUZZER - I PUSH Consolidated Wire Co.). TO 1 TALK After trying many ways in which RGVR RLY u0V.DC1f D.P.ST KEYING RLY'G" to interconnect the various controls RLY "M" "E" TO KEY (and there were some 300 of them), / TO RCVG JACK 110V.D.C.1` RME69 it was found that the best method was iTA'5 XMTG to follow commercial procedure and TO S. S. INTERNAL p R LY make a drawing of each chassis or con- .0 trol panel and give the connecting } points individual consecutive numbers. S.S.RLY T i By saving these as you worked along, J" L_-.. . RLY"G" RLY"B' RLY "D" it became a simple matter to match AC SIDE OF DC SIDE AC OF up the various outlets, following the SSO W..G 550WG INPUT ANT. OF MOD. diagram. PWR. "H" "5 SUPPLY All shielded wiring is in a two -to- the- shield type, and the shielding was The control relay circuit. grounded at several points. The en- Underload Guardian "F" Dunco RA -1 tire cabinet was bonded Overload Gua dian "G" WardLeonard 507 -531 then together "A" Ward -Leonard 81 -103 "H Guardian Ant. with braid, and the chassis inter - "B" Ward -Leonard 81 -103 "J" Ward -Leonard 507 -510 bonded with a single of "C" Ward- Leonard 81 -103 "K" Meissner Special piece braid "D" Ward -Leonard 81 -103 "L" Guardian 15 -1000 í12B3 running the length of the cabinet. "E" Guardian R -I00 "M" Dunen RA -1 After the braid has been installed, it should be run over with solder and an iron to make the braid solid, yet have ANT. RELAY -. a certain amount of give. Testing of each part before installa- RCVR tion is a necessity, since once installed, MATCHING -- , .MEISSNER XFMR. S. SHIFTER the amount of work to remove any stray "bugs" from the circuit becomes almost insurmountable. In using the relays on d.c., it was found that a 7 %- 4-S /S RELAY watt bulb in series with the coil was exactly right for all but the larger B & W TURRET,. TAN K control relays "A," `B," "C," and "D," which require one of 15 watts each. After the whole has been individ- ually tested and found working and installed, the control system is tried out without the 866 Jr. (Taylor) tubes in their sockets, and with one side of RN VOX <- AC. SPEECH --> SYSTEM each of the power transformers dis- SYSTEM connected. Testing is done as follows. Apply the d.c. to the unit, and try RME 69 the receiver relay by activating the RCVR ERME 69 correct manual switch. Then turn on RELAY the 160 -watt motor generator. The green bulb in the base of the unit MODULATORS-> should light and the a.c. meter should indicate that the voltage is being delivered. Turn on the a.c. switch to the receiver and it, too, should operate. SPEAKER -H.S -* PANEL Now adjust the voltage by means of the auto transformer (Stancor) to 115 v. a.c. The receiver should bring in signals if properly tuned. Try the re- RF POWER lay switch, and if it is working the SUPPLY MOD. POWER receiver should go on and off. SUPPLY Next start up the 350 -watt generator and apply the voltage through the a.c. switch to the various units. Check to see that the filaments that are sup- A.C.-D.C. posed to be lit, are actually lit. Turn CONTROL MAIN on the speech amplifier, and the VOX PANEL 4-CONTROL system. Adjust the voltage with the RELAYS auto -former to 115 v. a.c. Turning the d.b. meter control to the position that places the most amount of resistance in the circuit, wait for the tubes to heat, and then try the speech. Grad- 150W. MG. -- ually increasing the gain, and reducing the resistance in the d.b. meter circuit, see if there is an indication on the d.b. meter. If there is, then a pair of headphones may be connected across the 500 -ohm line and the quality tried out. It should be clear with plenty of sock. Try out the QRM- avoidance part of (Pse QSY to page 49)

www.americanradiohistory.com 33 ENCIH NQ«TE:

by LEE WARD Service Manager, San Francisco, California

That "Key" Problem I have heard stories of professional tom of the drawer space, where he 'N the July issue, this question claimants who get ambitious trades- found it a year later. was asked : "A man and a woman, men into their homes only to establish This fellow pulled his punch because - - on their way home from the bases for lawsuits. It is probable, how- of our long friendship -but I get chills movies, leave their house key with ever, that most customers order whenever I think of what dynamite you, asking you to repair their set "blind" repairs in good faith. But could have been packed into the same while they are out. Although you do even then, there is the chance that the occurrence had he been a stranger! not like the idea of working alone in most innocently- intentioned customer a strange house, business is slow, and may jump to unpleasant conclusions The Winnahs! you need the job. What would you if anything is missing after a service- ?" The serviceman who sent in the best do man has been called in for work in an solution, and who won a year's sub- I know Two repairmen -partners empty house. scription to RADIO NEWS, was Otto C. have a novel method of solution to A nearby serviceman once told me Langfield, 589 Twenty- Second Street, this problem of conduct : one of them, that -the day following a solo repair Oakland, California. He has the cus- upon receiving the key, writes down -the set owner came into the shop tomer sign an order for service when the customer's name, address, and and demanded the return of his wife's the key is accepted. He carries this make of set on a regular call sheet. ring! Things were prettily messed up order with him on the job, and re- He wraps the key in the order, laying for a few days; the customer threat- quires no one to accompany him. The them both on a stock shelf while the ened everything he could think of; and signed form not only protects him customer watches him do it. While my friend answered him by saying against damage claims following the the set owner is out, the other partner things no businessman should ever call, but also serves as his written au- packs tubes and tools in the truck in utter. thority for being in the house if any- preparation for quick flight. The set -owner's wife spent a hyster- one questions his right to be there. The customer usually drops in on ical day in bed -until certain transpi- It's easy to see how many an embar- the way home, and the first partner, rations prover her dog had swallowed rassing situation might be relieved by pretending surprise when they see the the ring! this simple procedure. The forms may key has not been touched, bawls out Although the repairman escaped be printed or typed, and should read his co- worker for negligence, and or- formal prosecution, he lost a customer. something like this: ders him to get "over to Mr. Smith's Since then, his solution has been never I have requested the bearer, John house right away -he's been waiting to work alone; he says he can't de- Doe, to repair my radio during my ab- for three hours!" pend on every dog to have a silver sence on the date below. I hereby re- The scheme invariably works, and lining! lease him from all liability for damage avoids the unpleasant and inevitable Years ago, I was involved in a sim- which might result from his acts or rise of suspicion which accompanies ilar case. A wealthy real estate oper- omissions. paper -work or special arrangement. ator, whom I rated as one of my three Customer's name No customer, of course, should ask best customers, and whose family I had Address a serviceman to make a "blind" re- known for years, suddenly cooled off Date pair, especially if he is a stranger; after I worked on his set while he was neither should the store owner be put out of town. It worried me, and final - in a spot where he must trust the cus- ly-at a local get- together-I asked Serviceman D. E. Thomas of Somer- tomer. It is the repairman who stands him point -blank what the trouble was. set, Ohio, won a six months' subscrip- to lose in such conditions, and it is up He turned his back on me. tion by being first to suggest a com- to him to decide if he wishes to risk More than a year later, he visited moner expedient : having the customer loss of a pay job in order to protect my shop with a bottle of wine and an arrange for a friend or neighbor to himself. apology. After that last job, he said, stand in your presence during the time a hundred -dollar bill had been missing. you are at work. He was positive he had placed it in a None of the letters recommended top desk drawer; it had been there for giving up the job because of the obvi- years, and no one else had been in the ous risk. Some of the contestants room. This particular greenback (or brought up certain matters of law are they yellow ?) was one to which which probably would serve to protect he was sentimentally attached, be- the serviceman, but we are repairmen, cause it was the profit he made on one not lawyers, and Nevada's presump- of his first developments. Although I tions might let us down in South Car- have been surrounded by conditions olina. which prevented sentiment ever reaching three figures, I expressed sympa- Among the runners -up were James thy. R. Pou of Courtland, Mississippi; He kept me on edge until we finished Charles G. Shaffer of Olean, N. Y.; the wine, and then told me why he Casimir Peterman of Regina, Sask.; This fine setup belongs to the Her- dropped over to see me : the bill had W. G. Oldham, Jr. of Montebello, ring Radio & Television Service. It Price, Jr. of Honey Grove, is complete in many respects and it been scraped off when he opened the Calif.; Earl shows careful thought in its assembly. top drawer, and had fallen to the bot- (More Bench Notes on page 62)

www.americanradiohistory.com J'1 TIXIEST HAM RECEIVER For something to take on that hike, or to school, try building this 9.5M-700M mighty radio midget.

HIS little all -wave receiver is just what you need to take on T trips, away to school or to listen to special frequencies that your regular receiver does not cover. It is a good general purpose headphone receiver. The antenna coupling arrangement gives the receiver a range from 10 to 700 meters with only six coils, and yet the tuning on the highest frequencies is not critical, as the tuning condenser is not exceptionally large. You can listen to the amateur bands, to broadcasting stations and even sit -in on SOS traffic on 600 meters. The antenna condenser gives satisfactory coupling at its maximum capacity for the longer waves while the circuit oscillates to 30 megacycles. The coils being wound on 5 -prong forms provide an extra unused tap which is connected to the antenna post. Then, if necessary, with short temporary antennas the tuning condenser may be wired directly to the antenna A handset dial plus a vernier and a volume control are all that are used. or a fixed condenser may be wired in the coil in parallel with the antenna condenser. Simplicity itself is used in mounting the component parts. The largest coil is a standard broadcast coil mounted on a bottom sawed from a 5 -prong tube base. A small mica condenser is mounted on it, and a small miniature blade switch installed on the coil (after the photo was made) to cut the fixed condenser into or out of circuit, to extend the range to 700 meters. After the proper size condenser has been found, it is mounted inside the coil. A capacity of about 100 to 120 mmf will do the trick. If it is desired to listen to the longer wave stations in preference to the very short waves the grid condenser capacity may be doubled and a .0001 mfd condenser wired in parallel with the antenna condenser, but it will be found the capacities given work very well over the wide range, if all specifications are followed. The 6K7 detector, which is used in preference to the 6J7 because of its smoother operation, and better behav- ior in loud signals is resistance coupled

www.americanradiohistory.com 35

By EDWARD LIl\TIIBEBG

Sherman, N. Y.

to the 6C5 amplifier. The plate resistor is somewhat smaller than ordina- Underside the chassis shows the easy wiring job. rily used, but the value given was and a shield mounted over the coil, found to be the most satisfactory with but the panel shielding is sufficient to the low -plate voltage. eliminate body capacity. The two parts The 6H6 rectifier has its elements of the shielding are connected together paralleled to double its 4 mil rating, by wires bolted to the parts. and is by- passed to eliminate tunable The panel is held to the box by four hum. As the receiver only draws small angle brackets, each having two about 3 mils, this little tube gives ex- tapped holes. Flat-head screws in the cellent service. The 5,000 -ohm resis- box and round -head screws through tor cuts down the line voltage to the the panel engage the brackets. The 6H6's rated 100 volts. various panel parts not connecting to The 4 mfd. condenser may be re- the shield are insulated by enlarged placed with an 8 mfd. unit if hum is holes in the shielding and by using in- too apparent, but the 4 mfd. value puts sulating washers. less strain on the rectifier. The coil socket comes up to the sur- This set of small coils takes up The parts under the sub -panel are face of the box, a hole for the coils very little room in your pocket. rather closely packed, but this is be- being cut in the top surface. The coil cause the parts used are larger in size socket is supported by a bakelite strip them down near the sub -panel. Ar- than necessary. By using parts of no fastened to the panel at the front and range parts so that signal leads are greater rating than given in the list, mounted on a pillar on the sub -panel short and direct. Bond all grounds. It there will be ample room. at the rear. The pillar is tapped at will be noted that the negative power The r.f. choke is a home -made pie the bottom and a threaded rod passed line is grounded as it comes in and then wound unit but good r.f. chokes are up to it so that an extension pillar may continues over the 6K7 grounded commercially available if one does not be fastened below and furnish support heater terminal. These provisions help desire to make it. by continuing to the inside bottom of insure quietness. The panel is shielded by aluminum the box. Use a good vernier dial for the tun- behind it. This shield is in two pieces, Placement of wires in a compact re- ing condenser and a small 2 -inch rheo- the lower part being an extension of ceiver is very important. Twist the stat dial for the antenna condenser to the sub -panel bent down. If desired, heater leads and run them as shown in permit lagging. A pointer knob is good the inside of the box may be shielded the drawing to minimize hum. Keep for the regeneration control. 30

C4-5 plate midget var. cond. 25 mmf. Cs, C5 -8 mid. 250 y. Electro cond. R4-50,000 ohm. 1/2 watt. C2-23 plate midget var. cond. 100 mmf. v. C, - .01 mid. 250 R -.3 meg. 1/4 watt. C4 -100 mmf. tonds. R, -3 meg. t/q watt. Ru -1250 ohm 1/2 watt. C;,, C; -.1 mid. 200 v. Ra-50,000 ohm pot. R;-5,000 ohm 1 watt. C --1 mfd. 200 v. Rs -.25 meg. I/ watt. L;, -RF choke. L4-21C -DC Filter choke.

CORD

6H6

6 K7

www.americanradiohistory.com 36 S2Avkcmwth jxp2ALQ1w1A. by LEE SHELDON Chicago, Illinois The possibility of a fatal shock is something that every serviceman should consider, -and know how to treat. r HERE is a furniture store across as if he was ringing doorbells, because he replied. "By the way, Lee -did you the street with which we main- if the juice caught him, his contract- glance through that first aid booklet - - tain a . reciprocal merchandising arm and finger muscles would I brought in for you?" ing agreement. Salutary Sales make a better contact. So I did it "Of course not," I replied. "Resus- Service will sell no table lamps as long your way -I turned my hand so the ciation is a bridge I intend to cross as Crouch's Couches don't carry ra- palm faced me. Then, just as I had after I come to it. In the meantime, dios. We get some pretty good repair my knuckles biased for anything up I have more important bridges to cross jobs from them now and then, and I to 120 volts, I came across 240. You -bridges with a more direct connec- make a habit of dropping in on the and your lineman's tricks!" tion to our food supply!" boss every day on the way back from "What happened ?" he asked, as if Al shook his head to express ex- lunch. it wasn't obvious. treme tolerance. "He jests at swoons "High, boy," he greets me. "Naturally," I said, "my muscles who never smoked a cigar," he corned. "Low, boy," I respond. "Got any contracted." "What good is food when you can't work for me?" "Did that break the contact ?" he taste it ?" "No," he answered on this particular asked. "You're getting excited about things day, "but my lights are out. Want to "Too well -my hand changed into a that never happen," I told him. "Us- fix 'em ?" fist and I hit myself smack on the ually, you're yelling at me to become "Sure," I said a better service- little realizing man, but now you what a trip to his THEY'LL DO IT EVERY TIME! by IIATLO want me to be a basement would trained nurse. SAW MY FRIEND. lead to before the GETTING A NEW RADIO? I IT'S IN THE ME Make up your DON'T BE A SUCKER. BA0-.3UST GIVE calendar changed. YOUR CHECK mind SS &S AND PAY RETAIL PRICES. FOR1/42..9 452.50 -is to replaced THEY'LL DELIVER.THE RADIO // I the fuse, GOTTA FRIEND IN THE THANKS, PAL continue as a ra- WANT TO TOMORROW. BOY! ISAVED % crossed the street, RACKET AND CAN SAVE I I SURE dio or GET A YOU ABOUT 20 BUCKS. i store - a and tried to sneak YOU UP TO 40% ON BLOOPER APPRECIATE hospital ?" into the back of ANY MAKE. WHAT $ -TUBE THIS, KIND YOU WANT ? MODEL. "Life is more our shop without c i important than Al seeing me. But livelihood," my he sensed some- i:41 4, rf partner replied, thing unusual from s "and it might in- my furtive man- +. terest you to know ner, and stopped ` that the time I me with: LWQ!,1 have spent study- "What's the iî'evoig1 -AERIAL? SERVICE ? WHY, NOr ing first aid meth- matter ? You act FRIEND 4 / CHARLIE. MY COULDN'T 121®P14 [U,080 ods is for your Cy" :i':':b:ti:F.`:..-. .. u as if you had just SET UP NO AERIAL AT THAT pQIzED safety. In other sassed your moth - PRICE. GET SOME RADIO RE- / L & St,z,veE' words, I am con- er -in -law!" PAIR MAN TO DO IT, ONLY siderate enough to There was noth- Ci0ST YOU A FEW BUCKS. learn how to take ing I could do but care of you if you stop and face him. ever made a high "Jeepers creep- voltage mistake. ers!" he da exclaimed, e.1i>r 6°se What would you "where'd you iv\w°°,u do -right now -if get -" ,.,<.6r.+ I were shocked in- oIr/ sW 9iwIq "In the line of C ?4 to unconscious- duty," I inter- ness ?" rupted hotly, "and I shall resent any nose! And right on the nose, too!" "I'd 'phone for a doctor," I said, flip comment you might make con- Al is the coarse type of fellow who "one who didn't sit up nights worry- cerning them. Haven't you ever seen laughs at such incidents. ing about what he'd do if his radio a black eye before ?" "You could have used one knuckle," broke down!" "Yes -but never two so large, and he said, just to rub it in, "and 120 Al looked at me sadly. "You'd be so evenly matched," he answered. "If would have been the most you could useless unless you had prepared for you painted rims on them, they'd look have got no matter what you touched the emergency," he said. "Why don't like sun -glasses. What happened -did in a 3 -phase supply. Or you could you study up on the stuff ? You're the you run into two doors?" have carried a test lamp. Things sort of bloke who'd lock himself in a "I was following some of your silly might look black to you just now, but lion's cage before you asked if he was advice about the precautions to be a sock amongst the face is better than herbivorous." taken when working around electrical a lily athwart the chest!" "Worry more about business," I re- equipment," I replied. "Remember "Sure," I said, "but I blame you for plied, "and be satisfied to safeguard that stunt you told me to use when what happened. If you hadn't told me your life with ordinary precautions I tested for unknown voltages ? You about the knuckle trick, nothing would against electrocution. This conversa- said it was dangerous for a person to have happened." tion is so much wasted time -I'm hold his fingers across two conductors "No-nothing you could remember," (More Experiences on page 60)

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The unit is thoroughly commercial in appearance and use. tree Poiiit Aiit1yzer Ui by RALPH L. STEARS Findlay, Ohio

Every serviceman trill want to use a free point analyzer unit. This one, which won 2nd prise in the RN The wiring is not as hard as it cash contest is a dandy. wild it: looks, if directions are followed.

A complete tube tester with RHA numbered sockets is also included.

"N THIS article is described what is believed to be the ultimate in sim- - - plicity of construction and operation yet seen in any analyzer unit. All switching is done automatically by the two 9- button pushbutton switches. This unit provides for a flexible point - to -point resistance and voltage analysis as well as the conventional current - voltage analysis. The sockets are numbered by the R.M.A. system and the numbers beside the push buttons refer to the pin numbers located around each socket. The 4 P.D.T. anti -capacity switch is a worthy addition to the unit. In neutral position both the voltage and the current sections are open and the meter is isolated from all circuits, thus being a good protective device. Pushing this

www.americanradiohistory.com 38

PANEL IS 72 X7" BAKELITE), i

8N 4 2f-5 6

2 /18 HOLES ft" o 0 0 0 0 0 0 O O ® o

I I T I I I G 2 3 4 .5 6 7 Á I 2 3 4 5 6 7 8 P

I O O z w 0 0 0 0 0 0 0 Q O ,,1 * S" -a 6" 8M Y lb /b 8u 8 t 8 t 8 8N 8M s" ,Lb o o VOLTS MA. ._4_" i OHMS /b r N ì 8

METAL BOX BUILT TO PROTECT AND COVER INTERNAL 711 PARTS

7'"

MECHANICAL DRAWING OF THE PANEL AND CHASSIS OF THE TESTER.

www.americanradiohistory.com 9 switch to the left the current section is directly to the top, or "Selector," or analyzer by means of the phone tip shunted out and permits voltage and switch. Different color wires to match plugs and leads. resistance measurements to be made. the cable wires are used to wire the The top row of buttons is the circuit Pushing it to the right disconnects the unit, thus keeping the circuits clear. selector, or current switches. Press 4 P.D.T. the milli - If the schematic circuit diagram (fig. any one desired and push voltage section and inserts will have ammeter in the circuit which the switch 1) is followed closely no trouble will switch to the right and you in wiring the unit. measured the current in that line. The has opened, thus permitting current be experienced meter measurements to be made. After all wiring is finished, mount in bottom row of buttons are the the case or on a test bench and fasten return switches. Press any two but- Construction by means of several small screws. tons, one in each row, and push 4 P.D.T. A study of the illustrations and fig. 2 Before using the unit it is best to switch to the left, and you will have will give the details of the mechanical first thoroughly check all wiring by measured the voltage between those construction of the unit. The case is means of a continuity test from the two points. made from sheet steel,andis 3 "x7 "x71/ ". pins of the adapters, when inserted into The top row of figures between the The panel measures 7"x71/, "and is made the analyzer plug, to make sure that push buttons is for 4 -5 -6 -7 prong sock- row of figures is for the from 1/e " bakelite. The numbers and all wiring is continuous to the correct ets. The lower letters are stamped on the face of the socket terminals, and to the tip jacks 8 -prong octal socket. panel and filled with white crayon. when the switches are in their respec- For resistance measurements turn All parts are mounted directly on tive positions. off the power in the set. Connect the so that two voltage -ohms tip jacks to the re- the panel. Mount all sockets for Use the heater prongs point down toward Procedure sistance ranges of your meter. Push the bottom of tester. The 9- button Plug the analyzer plug, together with the 4 P.D.T. switch to the left and the D.P.S.T. switch is mounted next to the its proper adapter into the set socket resistance will be indicated between sockets and the 9- button S.P.S.T. switch on test. Insert the tube in the proper any two points by pushing any two but- next to the jacks and 4 P.D.T. anti - analyzer socket. Connect the top caps tons, one on each row. capacity switch. The push buttons are on both the set to analyzer plug and With this tester, this serviceman can pressed on after the switches are unit to tube, if the tube is of that type. easily do many jobs which would or- mounted on the panel. Connect ground clip to chassis.. Con- dinarily require other and expensive The cable is brought into the unit nect the voltage and current jacks to equipment. through the bakelite panel and is wired the proper ranges of your multimeter (Continued on page 48)

TO 8 PRONG PLUG

pCTOGRID VOLTS-OHMS

WIRING DIAGRAM OF THE FREE POINT ANALYZER TUBE TESTER

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X_ X.'. S ST . - á . . _ .'17

Reprinted. with permission. from RADIO Trouble Shooters Handbook. Copyright. by ALFRED A. GHIRARDI, B.S., E.E. 1930, Radio & Technical Publishing Co. Copyright in Canada and Great Britain, and Author of "The Radio Physics Course," "Modern Radio Servicing"; member Radio all countries subscribing to the Berne Con- vention, by Radio & Technical Publishing Servicemen of America, New York Electrical Society, Institute of Radio Engineers. Co. All rights reserved.

ATWATER KENT 155 switch on and 10,000 ohms respectively. Hunt. 1) leaky dual and triple filter off Also check the by -pass con- Distortion condensers. Replace with 8- densers for these circuits - ATWATER KENT 96 mfd. sections by substitution 2) change in value of volume Inoperative. ...1) small i -f secondary shunt re- control from normal value ATWATER KENT 246 (high positive sho touches i -f coil, per- of 1- megohm, Replace Audio howl as 1) defective 500,000 -ohm vol- grid voltage. mitting it to "shod," to the with new unit volume control ume control. Replace with 18(1 volts, on plate winding of the input 3) adjust trimmer (between is advanced new unit i -f tube) i -f transformer. causing pos- tuning condensers and with tone con- Neon tuning in- itive p late voltage to be speaker at the top front of trol in "low" dicator inop- supplied to the grid of the chassis) for loudest volume position erative or er- i -f tube. This resistor may Weak, Distor- 1) replace the type '83 tube Intermittent ...1) poor connection at filter ratic be found by removing the taon, with a type '75 tube, mak- reception choke front plate of type '58 i -f coil shield. It is tucked Receiver gets ing the following changes in first detector tube, caused by in near the first detector out of align- the circuit: connect a 0.25r loosening and corrosion of plate coil. Insulate it from ment, megohm resistor in series the brads that hold the con- the plate winding by wrap- Screen -grid re- with the 0.1- megohm resis- nection on both sides of the ping it in cardboard, fibre, sistor changes tor and B -plus. By -pass this coil or tape and move it away in value resistor to ground with a from possible contact with 0.1-mfd., 200 -volt condenser. ATWATER KENT 260 coil winding Also connect a 4 -mfd., 30- Set requires 1) it is necessary to cool the Intermittent re- 1) heater current through the volt condenser across the chassis (possibly ception type '35 i -f tubes and type 300 -ohm resistor connected about 2 or 3 by placing 24 AVC tube too high, caus- hours after it in a refrigerator), then between the chassis and the the switch is test the individual compo- ing the AVC tube to draw a -mod -c switch grid current when heating 2) small 0.5- megohm metalized turned on. be- vents when cold. Since the and resulting in an fore it begins a -f transformer is sealed in erratic grid -return resistor for the a can with pitch, action of the AVC resistor '42 tube needs replacement. to operate. the pitch network. Insert a heavy This is only the contracts when cooled. press - It is located at the grid case in cold ing against the windings and wire- wound resistor in the terminal on the '42 t u b e heater circuit in order to cut socket weather or when possibly causing a short -cir- down the voltage the set has not cuit between two poorly in- heater used for sulated points. the slightly. This will prevent ATWATER KENT 165 been When grid current from flowing in some time pitch is heated, it will ex- the AVC tube grid circuit See also Case History listed for Atwater Kent pand. releasing the pressure 185 receiver. and eliminating the short - ATWATER KENT 99 Oscillation, ,...1) decrease in capacity of sec - circuit Hum, and electrolytic filter con - Poor tone ..1) volume control resistance Inoperative, ...1) see Case History for this Distortion denser (8- ntfd.I (usually worse has probably increased an- (high positive same trouble listed under Oscillation, ...1) wire -wound p'gtail type bias at low- volume preciably from 500.000 -ohm grid voltage. Atwater Kent 96 Weak, reception, resistor for '57 first detec- levels than at normal value. If it has in- 18(1 volts, on Cross- t alk tor- oscillator tube "open" high -volume creased to more than 550, - i -f tube) Slipping tuning 1) install new bearing race levels) 000 ohms, replace it Neon tuning in- drive dicator inoper- Vibrating noise 1) end play in variable tuning ATWATER KENT 275 ative at loud volume condensers Inoperative ....1) speaker field "shorted" due Inoperative ...1) resistor in i -f transformer Noisy. when ...1) weak contact spring in the to internal short in negative Erratic opera -..1) -shorting" to side of can. tone control is tone control. Put washer connections in triple electro- lion of neon 2) Move away and insulate operated under control arm-or re- tuning indica- place lytic condenser C -14. If re- defective neon tube. Replace unit ceiver voltages are b e l o w tor. intermittent contact between normal, check condenser for l "Tone- the end terminals of the 40,- ATWATER KENT 184 beam ") open sections (100- and the 6.000 -ohm re- Inoperative. ...1) check padder condenser be- Hum . 1) receiver does not use the sistors which constitute part low voltage tween '6C6 tube (second de- chassis as a ground return. of "Tonebeam" voltage di- tector) and i -f coil for short consequently stray currents vider system, resulting in circuit (red or brown wire) in shield and chassis are car- the shorting out of the cir- ried around to all parts of cuit of the "Tonebeam" po- ATWATER KENT 185 circuit. causing hum. Con- tentiometer. This causes a Oscillation replace the 250 - nect a short lead from the disruption of the biasing ....1) double common g r o tt n d point to arrangement. Provide a bet- (when volume mmfd. condenser which con - nects from the the chassis. being sure to make ter means of insulation be- is turned on plate of good contacts tween the two resistors full) 58 i -f tube to the two diode plates the 2A6. Use two Weak reception 1) "open" first r-f sec.-return of KENT 277 by -pass single bakelite units for re- ATWATER 2) "open" second r -f secondary placement Weak reception, 1) open- circuited first detector by -pass Distortion. cathode -bias resistor Intermittent re- 1) "open" first r -f secondary ATWATER KENT 188 Oscillation 2) leaky by -pass condenser by -pass "Rattling" at .1) replace all the control -grid Cross-talk . . . . . 1 ) use red antenna l e a d and Fading 1) "often" second r -f sec.-return the least vi- wires to the r -f tubes. The ground bias antenna lead. by-pass bration. mineral content sometimes leaky first r -f secondary re- Noisy reception present in the rubber insu- ATWATER KENT 310 turn by -pass condenser lation may make it conduc- Inoperative, .1) small AVC and second deter 2) leaky second r -f secondary tive, causing interaction. no r -f or i -f tor coupling condensers return by -pass condenser This defect does not usually plate voltage shorting to primary of sec - Poor AVC ac- ..1) replace tube in AVC stage show up under ordinary (low output and i -f transformer tion tests plate voltages) Poor tone ....1) volume control resistance has Inoperative, ...1) open -circuited r -f choke in ATWATER KENT 136 (usually worse probably increased from nor- (all voltages diode circuit (open circuit Intermittent, ..1) "shorted" (I.1 -mfd. tubular at low -vol- mal value of 500,000 ohms test O.K.. plates due to pigtails of the choke) Weak condenser (marked No. 1021 ume levels up to as much as 1,000.000 of '80 rectifier reception between 6F6 cathode and than at high - ohms. If it has increased to tube heat ex- 0.1 -meg. resistor. Replace volume more than 550,000 ohms, re- cessively) levels) place it Shadowgraph operates ATWATER KENT 145 ATWATER KENT 206 Inoperative, ...1) filter choke "grounding" to Audio squeal,. .1) remove and discard the metal Dial calibration 1) adjust broadcast -band oscil- (no plate volt- core or shield. In s u l a t e (condition is clamp around the type '2A6 at low fre- lator p a d d i n g condenser. ages) choke from chassis with a aggravated tube grid lead at the point end This is screw Thin line on strip of insulating material where it is grounded. Solder quency of the at rear of by touching broadcast chassis (looks like a mount - shadowgraph and mark it "hot" the grid cap the wire twisted around the band incorrect ing screw set back slightly Hum at reso- ..1) oscillator tube cath:htr. of the type grid lead to point w her e nance short- circuit was through an opening in the 2A6 tube- but clamp grounded. (Set rear wall of the chassis) Distortion, . .1) open -circuited section in out- is not affected analyzer does not reveal this Noisy reception. 1) increase tension of wave- Screen element put transformer primary by touching trouble.) band switch contacts of type 2A3 the grid caps No short -wave 2) clean switch contacts with tube red hot of the '2A7 reception "Carbona" "Sizzling" when 1) temporary breakdown of or '58 tubes) receiver is electrolytic condensers Operation O.K. 1) check the 730 -mmfd. broad- ATWATER KENT 217 -D switched on 21 change type '80 rectifier to on short -wave cast band series condenser direct- heater type tube bands but (1 o n g, flat paper- covered Same Case Histories as those listed for At- Intermittent ...1) particles of solder splashed "dead" on condenser riveted to rear water Kent 7 -D. reception on wave -band switch con- broadcast wall of the chassis near the tacts bands 2A7 socket. An intermittent ATWATER KENT 237Q Intermittent ...1) open- circuiting 0.0014- mfd. "open" condition develops. Intermittent ...1) poor contact in the first-de- reception, oscillator series condenser A 700 -mmfd. mica condenser operation Lector oscillator circuit. Inoperative due to poor internal contact. may be used for replace- ( affected by Check all resistors in the Replace condenser ment. Re- adjust padder con- snapping power p 1 a t e, oscillator-plate and Audio oscilla- ..1) mismatched type '2A5 tubes denser in usual manner for switch and screen -grid circuits. Their Lion in the push -pull audio stage. max. output at 600 Ice short -wave values are 2.500, 5,000 and Replace with matched tubes

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wide and sometimes contact two points at once (preventing proper opening of the circuit) file the blades down i1use a bit narrower. or replace with the later type switch available Lent the factory l'/re very popular series by Mr. I:Irirvrvli is con/inueel ATWATER KENT 525 Oscillation ..1) replace the double 250 -mm fd. with this insleulnea'nl. These lrvuble.slrooling laines are when volume condenser which connects control is from the plate of the 58 i -f turned on full tube to the two diode plates proving money-makers to llae serrieemen who use diem. of the 2A6. Use two single bakclite units for replacement ATW.1TER KENT 411, 4If. KENT 317 Inoperative or 1) replace the shorted ii.l -mfd. ATWATER KENT 545 ATWATER weak. tubular condenser narked Intermittent Stations shift 1) If stations shift on dial and Inoperative on 1) check the plate voltage on re- No. 102) between the cath- on dial over broadcast band the oscillator section of 11A8 cetition ode of the '6FIS tube and then shift baelc to t h e i r short period right numbers in a few days, (short -wave re- tube. It should be approx. the 0.1 -nteg. '6Q7 plate re- of 183 volts. lower. replace sistor time replace the leaky 0.0(10:36 - ception O.K.) If mfd. condenser C3 in the the gray :311,(1(10 -ohm, t/ - first detector -oscillator 6A7 watt plate voltage- dropping ATWATER KENT 425 circuit resistor. This is connected Same Case Histories as those listed for Atwater from the oscill. plate coil to Kent 165 the rectifier filament ATWATER KENT 557 Oscillation . ..1) disconnect the "bucking" or ATWATER while tuning -neutralizing" coil in the KENT 427-D Same Case Histories as those listed for Atwater for foreign 2nd i -f transformer. Un- Same Case Histories as those listed for Atwater Kent :318 stations on solder yellow and white leads Kent 7 -D short -wave from the transformer :und ATWATER KENT bands) connect them directly to- ATWATER KENT 435 612 gether. leaving the neutral- Inoperative. ...1) "open" (1.05 -mfd. by -pass Line fuses ....1) short -circuited buffer con- izing coil out of the circuit Constant hum condenser C3 in the grid cir- densers cuit of the 6K7 i -f tube "blow" 2) inoperative type '83 rectifier ATWATER KENT 318 Oscillations . . . 1 ) replace the oscillator g r i d tube (not burnt-out) (tunable) coupling condenser. Move Noisy. intermit- 1) loose connection to oscillator Intermittent, or 1) poorly soldered connections 0.03 -mfd. tracking condenser tent reception series condenser no reception, to either the top terminal to apposite side of °sent. coil 2) louse element in type '57 at low -fre- lug of the broadcast band tube quency por- oscillator coil (to which the ATWATER KENT 446 Noisy reception 1) open -circuited or leaky buffer tion of broad- blue lead from a tap on the Same condensers cast band third section of the wave- Case Histories as those listed for Atwater Distortion on ..1) volume control "open" band switch is connected 1. Kent 416 low volume or to the terminal lug next (clear on high to the unused lug un the ATWATER KENT 447 volume) coil. This coil may be rec- Same Case Histories as those listed for Atwater ognized by its one unused Kent 318 Sensitivity ex- 1) substitute an '80 tube for lug terminal cessive the '83 feeding the r -f stages. 2) oscillator coil section "open- ATWATER KENT 448 This will not affect local sta- circuits" tion reception 3) corroded or dirty contacts on Poor tone ..1) volume- control resistance has (usually worse increased appreei- Silent tuning ..1) this tube plays a very im- the oscillator section of the probably control irreg- portant part in the correct waveband switch. Clean con- ;tt low-volume ably from 500.000 -ohm nor - levels than at mal value. If it has in- ular in action operation of the receiver and tacts carefully must be a tube. Weak reception. 1) cathode terminal of '55 tube high- volume (- reamed to more than 550, - perfect levels) 0110 ohms, replace it When trouble is experienced Distortion (high socket grounds to one of the with the receiver. check this pitched). self -tapping screws which tube first- possibly by sub- Shadawgranh in- hold the bottom eliassis- ATWATER KENT 465Q stitution dication nar- shieIding cover. Shorten this See also all Case Histories listed for Atwater rov.s. screw, or bend cathode ter- Kent (165Q No cathode volt - minal down to give more Distortion. ..1) open -circuited 8 -mfd. elec- ATWATER KENT 627 age un '55 tube clearance (sounds like Irelytie condenser connected socket when defective between 13 -plus at speaker Oscillation, ...1) open -circuited first detector bottom chassis- speaker). cord and ground. Replace Unstable cathode by -pass condenser shielding cover "Howling" with new unit 2) add small 85 -nth. r -f choke is in place in cathode circuit of r -f First and third, 1) check the connections to the ATWATER KENT 460 stage or the second, two coils located between No signals on..1) louse rivets on 0.1450 -nt fil. short -wave the r -f type '58 sockets and Distortion, ..1) use a 0.001 -mfd. padder and low- frequency condenser located in oscilla- bands inopera- the type '3A7 socket. The Weak, or fading- a small trimmer to replace part of dial. tor can. Use a special lead leads between the lugs out on low- the 0.00145 -mfd. fixed pad - Oscillation "grounded" to the mounting tive )except short end for a "hiss" or on these coils break. either frequency der condenser located under of this condenser "rushing" noise at the coil or the grounding of dial the oscillator coil. Tone it at the low-fre- lug. Check uvnttinuiuy be- as you would the regular ends low- frequency trimmer (i -f ATWATER KENT 637 quency of tween the "control- grid" of is These bands) the type tube and chas- 130 Ice) '2A7 Poor tone ..1) volume control resistance has Inoperative on 1) plate voltage on oscillator sis "broadcast section of ')3A8 tube Intermittent re- 1) poorly soldered connections. usually worse probably increased appreei- should at low -volume ably from 5110.0110 -ohm nor - band." be 185 volts. If this volt - option Pull on all leads while re- ("Short- wave" age is low. replace the is levels than at null value. If it has in- gray ceiver operating band O.K.) 30,000-ohm plate - dropping Fading, 1) push, and on the vol- high- volume creased to more than 550_ - pall, levels (10(1 ohms, replace it resistor that lias increased Volume changes ume control shaft to aeer- in value. abruptly tain its condition. Replace the volume control if neces- ATWATER KENT 489 sary Poor tone ..1) volume control resistance has ATWATER KENT 665 Fading. 1) clean all contacts of wave- usually worse probably increased attpreci- (oscillator drift band switch. being careful at low- volume ably from 500.0011 -ohm nor - See also all Case Histories listed for Atwater on short -wave not to disturb positions of levels than at mal value. If it has in- Kent 1135 bands) the wires to the waveband high- volume creased to more than 550: Oscillation ....1) make sure that the screen switch levels (1(1(1 ohms, replace it grid stage control lead spring 2) bond frame of waveband (which serves as a shield) switch to chassis with short ATWATER KENT 509 is kept away from irn_th,- of bonding braid the 2A5 Hum . 1) try substituting several '56 t ube type tubes in the set until ATWATER KENT 328 bum disappears ATWATER KENT 663Q Noisy reception 11 eleaa volume control. Cheek action for nuise ATWATER KENT 510 Fading about I) disconnect the red positive Distortion ....1) cheek grid bias on the '6F3 See also all Case Histories listed for Atwater 15 minutes wire from the air -cell bat - (tube. It should be from Kent 31(1 after set is tery and short -circuit the re- 1?_ to 2 V. A higher value Audio oscilla- ..1) nusntatched type '2A5 tubes switched on sistm, making it possible to produces distortion and is tion in the push -pull audio stage. use the cell for several weeks usually due to an increase Install matched tubes more in value of the 22 -ohm bias Poor tone ....1) open- circuited connection on resistor eunneeted from ATWATER speaker coil. The coil is re- ground to the cerner -tap of KENT 511 -IV TUN- O -MATIC placeable on early models, the high- voltage secondary Inoperative ...1) inspect leads soldered to but on later models, the en- tone -control switch.tc Make tire unit requires replace- sure they do not touch and ment ATWATER KENT :3:17 "ground" to volume control Noisy reception 1) defective black electrolytic Santo Case Iistories as those listed for Atwater housing at low volume. condenser. Replace w i t h Kent 317 2) make sure that rubber insu- (noise some- new unit lated pieces on tone-control what like a ATWATER KENT :415 leads are back in place fog horn) Hum . 1) first try reversing the an- Intermittent re- 1) defective '2A7 detector- oscil- tenna and ground connec- eeption, labor tube. Replace with new tions if hum appears ATWATER KENT 667 Cute off corn- tube 2) try replacing the 5Z3 and pletely 2A3 tubes. as they are crit- See also the Case Histories listed for Atwater ical to hunt Kent 7 -D receiver ATWATER KENT 376 Automatic tun- I) check 9-point normal, oft Over- aceentu- ..1) tone may be improved by re- ing feature and automatic switch at the nted bass replacing 0.02 -ntfd. condenser Same Case Histories as those listed for Atwater does not shut right of the front. panel. If production C12 on the 2A5 to 0,006 or Kent 206 off the switching blades are too 0.01 mfd.

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ATWATER KENT 667 -1) Oscillation ....1) high -resistance ground con- Weak 1) "A" or "B" batteries weak Same Case Histories as those listed for Atwater nection due to a loose rivet 2) see trouble (3) under "Inop- Kent 7 -D between the dual 0.1 -mfd. erative" metal case condenser and the Noisy 1) defective tubes. Check all ATWATER KENT 708, 711 chassis. (This rivet also tubes holds one side of the second 2) see trouble (3) under "inop- Inoperative, ...1) defective tubes r -f Noisy reception 2) defective silencing adjust- tube socket.) Solder a erative" ment resistor pigtail from the condenser on short -wave 3) faulty wave- change switch. can to chassis BELMONT 420 2) re- balance tuned circuits Whistle, band Resolder all connections here. 3) if oscillation is not elimin- 1) oscillation in type '38 power Realign receiver ated by re- balancing, insert Oscillation pentode amplifier tube, due a 0.0001 -mfd. fixed condenser to change in value of con- ATWATER KENT 808 between the detector plate trol -grid and cathode -grid re- Broad tuning, .1) trouble in AVC circuit. and ground and re- balance sistors. Replace with new Frequency shift- Check the cathode voltage No plate voltage 1) 0.01 -mfd. condenser between resistors if v al u e s have on the r -f 58 and l'st i -f 58 plate of '45 tube and changed appreciably Poor tone tubes (with no signal tuned "ground" "shorting" 2) change in value of type '76 in). A reading of 110 volts r -f amplifier tube plate resistor. Replace with new should be obtained from AUDIOLA 30 -B unit cathode to ground on each No control of ..11 adapt tube. Now check the cath- the receiver for use Does not tune 1) see that green (grid) and volume on with type '35 tubes. Sub - down to 1712 ode voltage while tuning re- powerful local stitute black (ground) wires con- ceiver to a station. The a 10,000 -ohm poten- ks nested to the antenna coil reading now stations tiometer for the old volume are well separated from each should increase control, connecting one end other. Also as resonance is approached. of it keep the green If it does not increase, check to the antenna and the leads to the grid cap and the the -f other end to a 25,000 -ohm antenna away from the tube 0.05 -mfd. r and l'st i -f bleeder resistor for the shield grid filters in the secondary screen voltages; connect also returns of these stages for at a "shorted" or "leaky" con- this latter terminal the BELMONT 440 dition. Also original r -f bias resistor. check the 2- The movable arm of the po- Replacing pilot 1) the chassis must be removed meg. load resistor in the tentiometer is grounded to lights from the cabinet to do this. AVC circuit chassis. Replace tubes with Pilot lights are wired in series -use 6 -8 volt 0.15 KENT type '35s -amp. ATWATER 810 Noisy reception 1) replace push -pull i n p u t bulbs Audio howl, -.1) "open" 10 -mfd. electrolytic (intermittent, transformer Motorboating condensers. Replace with 10- frying noise) BELMONT 525 mfd., 200 -v. unit AUDIOLA Noisy 1) inspect all carbon resistors 2) check 1,000 -ohm carbon re- 31 and push away any leads sistors connected from 6F6 Intermittent ...1) high -resistance contact be- which may be resting against tube plates through 0.01 - fading, t w e e n terminal lugs and them mfd. condenser to ground. Weak at low - stator section of gang con- If heating has made them frequency end denser. Tighten screws, be- BELMONT 540 AC -DC change value, replace with of dial ing careful not to throw the 1,000 -ohm, 1 -watt units stators out of alignment po- Inoperative on 1) check the 25 -mfd. condenser sition all but strong (C13) connected from the local stations cathode of the 25Z5 tube to ATWATER KENT 812 choke See also all Case Histories listed for Atwater AUDIOLA 7330 _. Kent 612 Oscillation ....1) clean the gang tuning con- BELMONT denser 578, 585 (Series A, B, C & D) Poor tone, ..1) value of '/z- megohm poten- rotor wipers of all Oscillation, by Blocks at maxi- tiometer connected to diode graphite, etc. When replac- ....1) -pass condensers "open." ing the wipers, make Distortion Replace all defective units mum volume plate 2 of the second detec- them Hum, 1) electrolytic filter condenser setting tor has changed to about 1- sufficiently tight for good Motorboating, "shorted" megohm. Shunt with fixed contact only -friction must or defective. Re- not be excessive Low volume place with new unit 1- megohm resistor to restore Low volume. 1) open- or short -circuited potentiometer value to nor- Distortion by- mal AUTOMATIC RADIO IIF'G CO. pass condenser across type '42 tube bias resistor. Re- Double -spot ...1) set double -spot tuning trim- (See also listings under AIR MASTER) place with new unit tuning mer (fourth on 5 -gang tun- 2) electrolytic ing unit) for minimum sig- AUTOMATIC C15 Auto Radio condenser nal with test oscillator op- "shorted" erating at 1400 kc and re- Inoperative ...1) check the l e a d s from the ceiver dial set at 1240 (no plate volt- power transformer to the BELMONT 588 Noisy reception, 1) loose connection inside the ages but vi- plates of the '84 tube for Oscillation, ....1) by -pass condenser "open" brator Oper- "breaks." In st new Distortion Intermittent re- sleeving of the wires con- ates) stranded all ception necting one end of 1,450 - -wire leads for these Excessive hum, 1) electrolytic filter condenser mmfd. condenser inside os- Low volume, "shorted" cillator coil shield BALKEIT A3, A5, A7 All d -c voltages Erratic opera- 1) loose element in one of the Noisy reception 1) faulty audio transformer below normal tien of silent type '57 tubes in the silent 2) faulty phono-pickup jack tuning control tuning control stage. Re- 3) faulty electrolytic condenser BELMONT 661, 667 Auto Radios place with new tube Fading 1) worn carbon strip in volume Inoperative. ...1) defective tubes Erratic "tone- 1) intermittent shorting of 46,- control Weak, 2) beam" opera- 000- and 40,000 -ohm carbon tubes making poor contact tion with sockets resistors in this circuit. In- BALKEIT 41A Noisy 3) grid clips making poor con- sulate from each other Oscillation high- resistance tact with tube caps No "tonebeam" 1) open- circuited 40,000 -ohm ....1) or open -cir- Fuse action "tone beam" bleeder resistor cuiting contacts of loose or blows out 1) if fuse blows out frequently i m p r o p e r l y fitting tube frequently even though the insulating ATWATER RENT shields. Solder flexible pig- sleeve is in place over it 856 tails between all tube shields properly, the trouble is prob- See also Case Histories listed for Atwater and the chassis ably in the vibrator, and it Kent 317 2) interaction between the wires should be replaced Double -peak ...1) check the AVC circuit for from the diode plates and tuning high -resistance ground control -grid of the type '75 BELMONT 670-A to tube. Separate the leads Fuse blows out 1) defective vibrator unit. Re- ATWATER KENT 944 frequently place with new unit BELMONT 41, 42A Inoperative. .1) defective Weak reception, 1) "open" 1- tubes (even though megohm resistor Inoperative ..1) short- circuited primary wind- Noisy reception. they may check O.K.) Re- Sensitivity con- connected from the 4 -mfd. ing in the output trans- Weak reception place by substitution trol adjustment filter condenser to the grid former. Case "buzz ", ..1) has no effect of a '57 tube Replace with a new loose screws in top or bot- on signals unit tom case covers Case rattles 2) loose tube elements. Re- BELMONT 51 -C place tubes ATWATER KENT 976 Inoperative, ...1) defective 250,000 -ohm 57 de- 3) loose tube or r -f coil shield Same Case Histories as those listed for Atwater (no plate volt- tector plate -supply resistor. 4) loose grille cloth Kent 317 age on the type Replace with new unit. In- '57 detector spect rectifier sock et and BELMONT 675 ATWATER KENT 1935 Auto Radio tube) leads for defects also Inoperative ....1) "open" section in bleeder Noise at high..1) broken type '80 re- Inoperative ...1) faulty '6Y5G tube tube plate sistor- usually the 13,000- (no voltages) 2) faulty condenser a c r o s s volume, lead terminal between the ohm section plates of rectifier tube (banging the wafers of the tube socket, re- Inoperative ....1) 0.02 -mfd. condenser across set will bring suiting in intermittent con- (tone control output t r an s f m e r this noise out tact.- Replace the socket "shorted" or AUDIOLA JR. (WESTMINSTER) at any level) at "Bass" 2) check 13,000 -ohm screen - Inoperative ...1) check all the resistors in this position) dropping resistor for "open" direct -coupled receiver as BELMONT 71C Planetary ver- .1) cracked or broken compres- they cause frequent trouble A -f modulation 1) grid leak for the '56 tube nier -dial drive sion ring. Disassemble dial Weak, 1) 400 -ohm bleeder resistor be- of oscillator increased in value. Replace mechanism drive by removing the two Distortion tween detector screen and (head all over with one of proper resistance inoperative ^crews which fasten it to the ground "open," Also check the dial) value. Excessive hum, 1) dial bracket all resistors in receiver, and Intermittent re- electrolytic condenser replace any w hie h show BELMONT 100 ception, "shorted." Replace with large change in value Low volume new unit 2) to increase volume, replace Fading, 1) try replacing the v o l u m e Distortion, ....1) the 50,000 -ohm resistor sec- Noisy control (1- megohm unit) Oscillation by-pass condensers "open," tion in series with the screen - Replace all defective units grid lead with a 35,000 -ohm BELMONT 415 resistor, so as to raise the Inoperative 1) "A" or "B" BELMONT 685; 686 screen potential batteries dis- charged Dial drive ....1) install new type belt take -up Fading ...... 1) poorly soldered connections 2) 4 -amp. fuse in A- slippage assembly (reception re- at all three grid cap battery line now available from clips. blown manufacturer for these re- stored to nor- Resolder these connections 3) tubes make poor c o n t act ceivers mal when the with sockets, or grid clips Chassis is make poor contact with the tapped) caps of the tubes (More Case Histories on page 48)

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CBS DEMONSTRATES RADIOTYPE NEw YORK, N. Y. (Special to RADIO NEWS) : Radiotype is the name of a new communications device developed by the International Business Machines Corporation. It functions somewhat like a teletype, receiving impulses via ultra-short waves. The device was demonstrated in New York through joint arrangements with the Columbia Broadcasting System and the Ameri- can Radio Relay League at the award luncheon tendered by William S. Paley, CBS president, in honor of Wilson E. Burgess, winner of the Paley trophy for 1938 amateur achievement. Messages of congratulation were sent by amateur stations in all parts of the country to the A. R. R. L. station at the New York World's Fair and a Radiotype transmitter relayed them to the Hotel Pierre where they were projected on a large Radiotype screen.

STORES USE TELEVISION TO DEMONSTRATE FASHIONS NEW YORK, N. Y. (Special to RADIO NEWS) : Radio dealers and department stores demonstrating television are dis- covering that the tests are drawing big crowds. Although sales are slow, the dealers feel it is excellent promotion Televising the 6-day bike races for the first time over 'phone wires. to draw interested spectators. Even though many of the onlookers may not NBC are active in exploiting televi- Rapids, Michigan. be in the market for television, the sion. David Sarnoff, president of RCA, In recent announcements the Amer- dealer has the chance to interest them has written a paper entitled "Probable ican Television Corporation introduced in other merchandise. Influences of Television on Society" "telesurgery," its device for making Department stores were quick to for the Journal of Applied Physics, and televised surgical details available to recognize the drawing power of tele- Lenox R. Lohr, president of NBC, ad- medical students; "tele- sales," a sys- vision demonstrations and one large dressed the recent New York conven- tem that televises merchandise from a establishment used a transmitting and tion of the Edison Electric Institute on central studio in department stores so receiving system functioning over "The Present Status of Television." that customers can look on at remote wires to demonstrate fashions. With key men of the industry going to points in the store; and Videor, pop- Some store demonstrations have bat for television in this manner, the ular priced television sets for the home. been poorly staged from a showman- video art is receiving invaluable pres- in Recently named on the board of the ship angle, some trade observers be- tige important professional fields. television company are Adolph W. lieve. But the manufacturers of lead- Tahaney, of Holland, Michigan; Ray- ing television lines are striving to in- AMERICAN TELEVISION ELECTS mond Starr, former Attorney-General struct the dealers on good demonstra- of Michigan; and Maxwell Landsman, tion and sales methods. VICE -PRESIDENT theatrical producer. NEW YORE, N. Y. : The American Television Corporation SARNOFF announces the ADDRESSES N. Y. CON- election of Dewey Bullock as vice - THE TELEVISION PEEK -A -BOOTH VENTION president. He will continue as a mem- PASSAIC, N. J.: To facilitate the ber of the board of directors. Mr. Bul- proper demonstration of television in NEW YORK, N. Y. (Special to RADIO lock is president of Roger Verseput day -lighted or brightly illuminated NEws) : Top executives of RCA and and Co., investment brokers, of Grand stores, a handy booth referred to as the

An operation was televised for the medical students with surprising success.

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Peek -A-Booth is now made available to its dealers at actual cost by the Allen B. DuMont Labs., Inc., of Pas- saic, N. J. The Peek -A -Booth was conceived and designed by Leonard F. Cramer, General Sales Manager of the DuMont organization. Attractively finished in colors and taking a DuMont console or a table model television set, this booth forms a huge shadowbox so that television images can be viewed under ideal conditions of dim illumination. by SAMUEL KAUFMAN TWO-WAY TELEVISION COMMUNICA- THERE'S been considerable talk these proved conclusively that huge television re- TION WITH SINGLE C -R TUBE early television days regarding the lim- ceiver sales can be anticipated throughout ited service area for sight- and -sound the heavily -populated suburban areas. PASSAIC, N. J.: An improved system entertainment. The old theory that video The General Electric Company has re- of two -way television communication signals on ultra -short waves won't go beyond ported good reception of New York's tele- in which a single cathode -ray tube at the horizon has been disproved in various vision transmissions at its Schenectady, New tests but, chiefly to protect the consumer York, laboratories. This is a distance of each station serves both as pickup de- from possible disappointments, the television 130 miles. Reception was achieved through vice to develop picture signals for engineers of leading companies still see fit a very elaborate antenna arrangement. And transmission and as a receiver or view- to adhere to the fifty -mile range when dis- A. H. Whiteley, head of the Whiteley Elec- ing device to reproduce images trans- cussing "guaranteed" reception areas. trical Radio Co., Ltd., who recently visited mitted from the remote station, is dis- At this stage of the game, it is best to be the U.S.A., told the writer that London's closed in U. S. Patent No. 2,157,749 conservative in video claims. This is true, television programs are received in his Not- As- particularly from the merchandising angle, tinghamshire plant on an ordinary commer- just issued to Allen B. DuMont, manufacturers feeling that they can break cial receiver over a distance of 120 miles. signor to Allen B. DuMont Labs., Inc., down sales resistance more readily in a con- It seems that the idea of bringing televi- of Passaic, N. J. centrated area than over a vast section of sion to the entire nation is not as fantastic This system greatly simplifies and the country. And once the ice is broken in as it once seemed. But the conservative ap- reduces the cost of the apparatus over that of prior systems in which separate pickup and viewing tubes must be used at each station. Another advantage is that of simultaneous two -way communication, instead of having to go from one tube to another for the re- spective transmitting and receiving functions. The DuMont two -way television communication system is based on the use of a dual- function cathode -ray tube which includes both photo- sensitive screen (pickup) and fluorescent screen (viewing) side by side or in an otherwise convenient arrangement, but served by a single or common cathode - ray beam. Thus when the tube is transmitting an image, the cathode - Your Video Reporter (left), inter- G.E: s New York World's Fair Bldg., ray beam swings over to the photo- views A. H. Morton, NBC's vice -prexy. where crowds gather to see telecasts. sensitive screen or photo -electric mo- which in the saic, it scans conventional one spot, it is believed a gigantic thaw will proach of the trade on the point of coverage manner, while at the other end the set in and television on a mass commercial is to be commended. cathode -ray beam swings over to the scale will become an accepted thing in many fluorescent screen which it scans in parts of the United States. New Yorkers are getting used to televi order to reconstruct the images being Breaking the television ice is the big job sion program surprises. There have been so transmitted from the remote station. now on manufacturers hands and they have many eye -opening demonstrations and tele- This switching of cathode -ray beams picked New York to do it in. To the date casts recently that pioneer observers are be- of this writing they haven't chipped off coming a bit calloused about the whole thing may be accomplished manually or au- enough of the frozen water to cool a small and are accepting video developments in a tomatically, the invention covering glass of lemonade. And yet everyone con- matter -of -fact rather than awe- stricken way various means of switching, climaxed cerned seems content with the way things And this definitely infers that the new art by a revolving switching means which are going. And that's because they have is catching on. In becoming a work -a -day alternates the beams from transmit- been making progress. Slowly but surely the medium, television is rapidly passing the ting to receiving positions, for simul- public is being won over to the new art. novelty stage. taneous two -way television communi- NBC, at huge expense, has been staging sen- Although the trade observers -and that sational programs which have done much to goes for the Video Reporter, too l -have cation. stimulate a sales interest. And other key been calm and cool over numerous excellent centers are watching the New York video demonstrations, one particular test came activity avidly so that, on short notice, dupli- along that showed them that the new art has NBC DOUBLES PROGRAM HOURS cate systems may be put into operation. by no means stopped springing sensational FOR TELEVISION Considerable sales resistance arose from new things. the much ballyhooed theory that the signals This particular eye- opener was the dem- won't go beyond a half-hundred miles. To onstration of the Biard Television Corpora- NEW YORK, N. Y. : A new television many persons this would infer that the im- tion's theatre -sized television system. The program schedule, more than doubling pulses would be proportionately weaker on program the Video Reporter witnessed in the the number of program hours offered the fringe of the announced service area Gaumont- British movie projection room was to home viewers by the National than they would be close to the point of observed on a screen twelve feet by nine Broadcasting Company over Station emanation. The Video Reporter was very feet ! It was only the physical limitations of W2XBS, was announced today by Al- much concei ned with this belief so, one re- the room, Baird engineers assured the on- fred H. Morton, NBC vice -president in cent night, he journeyed some forty -seven lookers, that prevented showing the images charge of television. The new sched- miles out of New York to the home of O. B. as large as twenty by fifteen feet -the size Hanson, NBC Vice -President and Chief En- that will probably he adopted by theatres ex- ule will become effective Tuesday, gineer, at Westport, Connecticut. pected to use Baird apparatus at an early June 20. There he witnessed a solid hour of flaw- date. Television for theatres is quite a Under the plan, evening studio tele- less television entertainment coming from thing in England and there have been im- casts from Radio City are to be in- W2XBS atop the Empire State Building. pressive stories from London regarding the creased to three a week. Two are Reception on an RCA Victor receiver at the popularity of the system with persons paying telecast at present. These studio pro- virtual extreme service location was equal to ten shillings each to fill several Baird - grams, which will include several fea- any reception the Video Reporter witnessed equipped theatres to witness the Derby. The big Baird picture is achieved through tures of one hour's duration in the in New York ! Image definition and audio (More Video Reporter on page 61) (More S & S New on page 62) quality were tops ! The demonstration

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COLOMBIA -Martin Olthoff of Inde- pendence, Kansas, notifies me that the slo- gan for HJ7GAB (4.89). Apartado 37 of Bucaramanga, is "Radio Santander." CUBA -COCQ, Havana, announces its official frequency as 8.83, but it is actually operating on 8.85 nightly until midnight. DOMINICAN REPUBLIC -HI5P (6.565) has not been heard lately. ECUADOR -The Guayaquil station on 9.188 is HC2ET, "Radio Telegrafico," which formerly operated on 4.56. . John Larsen of Geneva, New York, reports hearing HC IGQ (9.17), from 8 :30 to 10:30 p.m. and JOHN D. CLARK GUADELOUPE -The ILA advises that FG8AH (7.44), "Radio Guadeloupe," is soon to be increased in power to 1000 watts. The ny Charles A. Morrison eign language, being heard nightly from 8:55 schedule will then be changed to 9 :30 to 11 Frequency in megacycles Time is Eastern Standard to 10:15 p.m., which some listeners believe p.m. and announcements in English will be to be located in Moscow, U.S.S.R., accord- instituted. The address of the station is Special Good -Will Programs ing to Martin Olthoff of Independence, Kan- Pointe -a- Pitre, French West Indies. UNDAY, August 20, front 1 to 3:30 a.m. sas, is "Radio Bucharest," at Bucharest, GUATEMALA- Prizes are n o w being EST, over TGWA (9.685), TGWB Roumania. He further states that the pro- awarded weekly, for the best ; the most com- (6.49), and TGWC (2.32), all of Guatemala gram opens with the Roumanian National plete and the most distant report received on City, Guatemala . . . Sundays, of Septem- Anthem, which is followed by the news in the dx program broadcast each Sunday ber 10, 17, 24th, at 12 :01 a.m. EST, and Roumanian. There are no interval signals morning from 2 to 2:30 a.m. EST, over Sundays, of November 12, and 19th, at 10 or other identifying announcements. TG2 (6.195) of Guatemala City, Guatemala a.m. EST, over YL2CD, operated by A. Vito - TAIWAN -Roger Legge of Binghamton, . . The programs for North America, heard lins of Miera Isla 52 -5, Riga, Latvia, on a New York, writes that JIE (7.295) and on Mondays, Tuesdays, Thursdays and Sat- frequency of 14.04 mc. for the first three JIE2 (9.695), of Tyureki, Taiwan, both urdays, over TGWA of Guatemala City, are programs, and on 28.08 mc. for the latter 10,000 watts, are transmitting simultaneously normally broadcast on a frequency of 9.685, two programs. from 9 :05 to 10:20 a.m. EST, for Chinese but during the summer months these broad- Lawrence and South Seas listeners. casts are sometimes radiated on TGWA's -Thaw Trans -Asiatic Expedition optional frequency to Use Short -Wave Radio VENEZUELA -YV1RT (4.77), "La. Voz of 15.17. The four mobile motor units in the Law- de la Fe," a new station at Maracaibo, is rence Thaw trans- Asiatic Expedition, which being heard near 9 p.m. recently left Paris on the first leg of a 14,000 Under Construction TC.2 mile tour that will take them to Budapest, Istanbul, AUSTRALIA -A new 2000 watt national ;-AD;O E Damascus, Baghdad, Herat, through transmitter now under construction at Wan - the Khyber Pass, Delhi, Calcutta and finally fJSRECCiC R.eL- Uç,. CG.`.tUlJICìßC!ONt. neroo, Nest Australia, will operate when CAlStEMA(.A. CENTRO RAtEP1CA into Bombay, India, sometime next Spring, completed on frequencies of 6.13, 9.56, and will be able to maintain contact with each 11.83 mc., under the call VLR6. other by the use of u.,_.__ ___..-_... four ultra -high frequency BERMUDA- A powerful short - wave transmitters and communications receivers transmitter, capable of radiating programs installed in the cars. to the United States, and other parts Two medium -high frequency transmitters of the and receivers world. is soon to be constructed by the Wire- have also been installed in the less Section of the Bermuda Volunteer En- cruiser sedan and trailer, which will permit clear reception gineers at Smith's Hill, near Hamilton. The up to distances of 200 miles latest Bermuda news will be broadcast on or more. The equipment is powered by Mondays, Wednesdays and Friday evenings. standard car batteries. Antennae for the ultra -high frequency IRAN -Two powerful short -wave broad- sets are of the one - cast transmitters, ordered from the British quarter wave fishpole type, while a 128 foot span of wire strung firm "Standard," for erection near Teheran, from the transmitter to are expected be in A sample a collapsible 30 -foot pole will act as antenna to ready the spring of of the QSL from TG -1, Guat- for each of the two medium -high frequency 1940. In addition a powerful short -wave emala, C. A., which is entirely written sets. Short -wave telephone transmitter for commercial pur- in the Spatari Radio Language. fb. listeners and amateurs are poses, purchased the Vy invited to listen for transmissions from the from German firm Expedition's radio stations. "Telefunken," is being installed at Kasr Kajar on the road to Shimran, and should HAITI -The special Wednesday night Daventry's Extended Service be in operation by next September. programs for Jamaica, radiated by HII2S Further extensions have been made to the UNITED STATES-The new 50,000 watt (5.98) of Port -au- Prince, have now been BBC's services. On June 4 daily bulletins in transmitters for WBXAL at Mason, Ohio, discontinued for the summer months. Portuguese and Spanish, broadcast respec- will probably not be completed before Jan- HONDURAS- Despite reports to the con- tively at 5 and 5:15 p.m. EST, were added uary of 1940. trary, HRN (5.875) of Tegucigalpa, is still to the service of news bulletins in foreign on the air and broadcasting nightly from ap- languages radiated expressly for European Notes of Interest John Larsen of Geneva, New York, proximately 6 to 11 p.m. listeners over GRX (9.69) and GSA (6.05). writes IRELAND -August Balbi of Los Angeles, On July 3, the BBC's new program service that an unidentified station on 15.12, nights until after 10:25 p.m., using a language California, writes that EIRE (17.84) of especially for Latin- America was inaugu- simi- Athlone, is broadcasting irregularly front rated. This all -Latin transmission lar to French, may be CSW4, Lisbon, Portu- is now gal. 11 :30 a.m. to 5 p.m. radiated daily from 6:25 to 9:20 p.m. over JAVA -The Semarang, Java, station be- GSO ARGENTINA ( 1 0 . 3 5 ) , B u e o s (15.18) and GSC (9.58) ; the former -LSX n lieved to be YDF, is now operating on a fre- frequency being intended for reception south Aires, is now broadcasting on Fridays from quency of 4.945. It carries the same proof the Amazon River, the latter frequency 4 to 5:45 p.m. according to A. Tuff of Lon- gram as don. PMH on 6.72. being intended for reception north of the NEWFOUNDLAND -VONG (5.975) of Amazon River. AUSTRALIA -VLR (9.58) has replaced St. John's, uses chimes similar to NBC's in Simultaneously with the initiation of the VLR3, Melbourne, in that portion of the connection with announcements which are new Latin services, an increase of twenty - daily transmission front 12 mid. on. Both made approximately every quarter -hour. five minutes in the program time of trans- VLR and VLR3 are now issuing QSI. cards SPAIN -EAQ (9.86), Madrid, now starts missions 5 and 6, cause into effect, the for- in place of the former letter verifications its nightly program for North America, at mer now continuing to 9:15 p.m., the latter . . . 9MI (6.055), the S.S. Kanimbla, is 7 :45 p.m. with the words, "Hello North now extending from 9 :40 to 11:40 p.m. EST. now broadcasting a children's program Sat- America, Hello United States, Hello Can- Reports on reception on the above new serv- urdays near 2:45 a.m. ada, this is Radio National Spain, Station ices are requested by the British Broadcast- BAHAMAS-ZN S (6.09), Nassau, power EAQ, ing Madrid." Following this a woman Corporation at Broadcasting House, Lon- 200 watts, is now relaying Daventry nightly gives the news in English, after which a dis- don. The BBC does not issue verifications from 6:20 to 8 p.m. before the opening of cussion on some topic concerning the future for reports on the Daventry transmissions. the usual program which extends from S to 9 outlook of Spain, is given and the balance of New Short -Wave Stations p.m. and on Sunday nights to 10 p.m. EST. the program up to sign -off at 8:30 p.m. con- COLOMBIA- HJ4DAX (4.795) of Medel- BOHEMIA -The usual nightly program sists of musical numbers. lin, has been heard relaying broadcast sta- for North America, from Prague, is now SPANISH MOROCCO -Roger Legge of tion HJ4ABA of the same city, from 9 :30 to being broadcast from 6:55 to 9, or 10 p.m., Binghamton, New York, reports that EA9AI 10:30 p.m. irregularly. over OLR5A (15.23). (7.18) of Melilla, is still being heard Satur- PHILIPPINES-According to C. J. Fern BRAZIL -PSE (now 14.94), is being days from 9 to 10 p.m. with loud signals. of Maui, Hawaii, a new station KZEH, pre- heard with loud signals from 6 to 7 p.m. URUGUAY -CXA2 (9.57) of Montevideo, sumably to relay KZEG of Manila, was heard BRITISH HONDURAS -ZIK3, Belize, is may be heard irregularly to as late as mid- testing on an announced frequency of 9.58, supposedly broadcasting three nights a week night or 12:30 a.m. although actually closer to 9.585, near 7 a.m. on 5.3. Has anyone heard this station re- UNITED STATES-The Magic Key of EST, and requesting reports, to be sent to cently ? RCA program which is now being heard at P.O. Box 119, Manila. CHL1'A- August Balbi of Los Angeles, a new time on Monday nights from 7:30 to ROUMANIA -A mysterious new station, California, writes that XMHA (11.86) of 8 p.m., over the NBC -Blue network, and with all announcements in an unknown for- Shanghai, often relays W6XBE near 9 a.m. WSXK (11.87) of Pittsburgh, specializes in

www.americanradiohistory.com 46 unusual short -wave stunts and pickups from 3 :30, and from 7 to 10 :15 p.m. ; Wednesdays BOLIVIA- According to a QRC item fur- remote corners of the earth . . . Each Sat- from 7 :15 to 8:40 p.m. and Fridays from nished the NNRC, CP 12 (6.255), "Radio urday at 10 :45 a.m., a program describing 8 to 9 p.m. . PCJ2 (15.22), Sundays, Fides," at La Paz, power 250 watts, operates the natural wonders of Rocky Mountain Mondays and Thursdays, from 7 :10 to 8 :30 from 7 to 8, 11 a.m. to noon and from 7 to National Park, is broadcast direct from this a.m. ; Tuesdays, Fridays and Saturdays from 9 p.m. It is owned and operated by a Jesuit paradise of wildlife, fields and forests, by 7 :10 to 8 :15 a.m. and Wednesdays from School. The address is : Observatorio San means of a short -wave pickup, which is then 7 :10 to 8 :15 and from 9 :30 to 11 :30 a.m. Calixto, P.O. Box 283, La Paz. relayed to the NBC -Red network, and short- JAPAN -The present schedule for the To- CANADA-CHNX (6.13) Halifax, power wave station W2XAD (15.33), via KOA in kio transmitters follows : 1 :30 to 2 :30 a.m., 500 watts, operates weekdays from 7 a.m. to Denver, Colorado ... The Rattlesnake Placer over JZK (15.16) ; 7 to 7 :30 a.m., over JZK 11:15 p.m. and Sundays from noon to 11 :15 Mine, near Downieville, California, is now and JZJ (11.8) ; 8 to 9 :30 a.m., over JZK, p.m. A Mail Bag program is broadcast on using two short -wave transmitters, KQDL JZJ and JLU3 (15.135) ; 2 :30 to 4 p.m., over Sundays at 5 and 9 p.m. Reports are so- and KQDK, each with a power of 20 watts, JZK and JLG3 (11.705) ; 4 :30 to 5 :30 p.m., licited. The QSL card is pink with blue and operating on a common frequency of over JLG3, JLT2 (9.645), and JZL (17.785), lettering. 2.726, for emergency communications . . . and S to 8 :30 p.m., over JZL. CHILE- CB1174 (11.745), "Radio Hucke," A new coastal harbor radiotelephone station NORWAY -The correct schedule for the P.O. Box 6009, relays CB93 of Santiago, un- will soon be in operation at Mackinac Island, Norwegian National transmitters is as fol- til 10 :30 p.m. . CB946 (9.46), to relay using frequencies of 2.738 and 2.55. The lows : Daily, over LKQ (11.735), from 2 to CB150 and CB118 of Santiago, is reported to coastal harbor radiotelephone station WAY 6 :40 and from 10 a.m. to 3 p.m. ; over LKV be under construction. It will have a power at Lake Bluff, Illinois, is now operating on a (15.17), from 7 :40 to 10 a.m. and over LLG of 5,000 watts. frequency of 2.55, with a power of 400 watts (9.61), from 3 to 6 p.m. LCL (8.025), is CHINA -XGOY (11.9), operated by the The news reports broadcast to Latin used for test broadcasts. Central Broadcasting Administration at America over NBC shortwave stations SIAM -HS8PJ (9.51), is broadcasting Chungking, transmits daily from 5 :30 to W3XAL and W3XL are prepared by a jour- Thursdays from 8 to 10 a.m. and on Fridays 7 :10 a.m., directed to Japan ; from 8 to 10 :30 nalist of more than 25 years experience, and Saturdays irregularly from 8 to 10 a.m. a.m., directed to South China ; from 11 to namely, Hudson Hawley, news editor of UNITED STATES - W1XAL, Boston, 11 :30 a.nl., directed to the U.S.S.R. and from NBC's International Division. He gradu- Mass., is broadcasting on the following 4 :30 to 6 :30 p.m., directed to Europe. ated from Yale in 1914, and successively schedule : on 21.46, Sundays, from 9 or 10 to XGOX (17.8), broadcasts nightly from 9 :30 held jobs with the Hartford Times, the New 11 a.m., and Tuesdays and Thursday's from to 11 :30 p.m., directed to the United States. York Sun, and as bureau chief of the In- 9 to 10 :15 a.m.; on 11.79, Mondays, Tues- The power of the station is 35,000 watts . . ternational News Service in Paris, Rome, days, Wednesdays, Thursdays and Fridays, Alan Breen of Dunedin, New Zealand, writes from 2 :30 ; XMHA (11.855) Berlin and London . . . CBS station W2XE to 5 :15 p.m. on 6.04, Sundays that of Shanghai, power at New York City, is now radiating French, from 2 to 6 p.m.; Mondays, Wednesdays and 500 watts (to be doubled soon), transmits German and Italian news broadcasts week- weekdays from .5 to 11 a.m. and from 11 p.m. to 1 a.m. and on Sundays from 10 p.m. to 11 days, starting at 4 p.m., on a frequency of Fens ,his.,.. a.m. Monday . 17.83 . According to word XPSA (7.01), the Kwei- mes. U.S.S.R.- COMMONWFALTRp OF from Radio Center, Moscow, the transmitter ''''STRALI' s an 437357 chow Broadcasting station at Kweiyang, that operates on 9.52 and 6.03 is not RW96 Wirzlm Td,ophy Ad 1905 -1919. verifies with a carbon copy of a circular let- as it is given in the program releases from BROADCAST LISTENER'S LICENCE../4,- ter signed by T. L. Tung. The schedule is Moscow, but RW96. daily from 5 :30 to 11 a.m. with news in VENEZUELA -John Larsen of Geneva, English at 9 a.m. relayed from XGOY. The New York, advises me that YV4RD (6.3), program opens with the Chinese National is the only Venezuelan, so far as he can as- Anthem and closes down with "Song in 674:`,7FR N Memory of Dr. Sun Yat -Sen." . . Accord- certain, that is still broadcasting on its old 3. í----us frequency in the 49 meter band, all of the FOR A PFIOOO OF 12 ÌI0N1115 MOM_..._4.' ing to a verification received by Gail Beyer other stations having definitely shifted to , P a _, I , w.,Q , . of Chicago, Illinois, the Chinese station near their new frequencies in the 62 -meter band...... Y1ct,a.Me,.J 11.4, is XRVG, Chungking. This transmit- Revised Schedules ter went off the air the latter part of Feb- :.P ruary. AUSTRALIA -VK2ME (9.59), Sydney, COLOMBIA- HJIABP (4.925), a- from 12 midnight to Cart now broadcasts Sundays gena, signs -off nightly at 10 :30 p.m. with 2, from 4:30 to 8:30 and from 11:30 a.m. "Under the Double Eagle March." to 1 :30 p.m. BRAZIL -PSH (10.22), Rio de Janeiro, COSTA RICA -TIPG (9.612), San Jose, is now operating from 7 to 9 :30 a.m., 12 broadcasts weekdays from 6 to 7 p.m. in noon to 2, and from 8 to 11 :30 p.m. ; Mondays, from 8 to 8 :30 p.m. license Portuguese This is what an Australian ECUADOR (9.19), in English, and on Fridays, from 7 to 7 :30 like. Sent in -HC2ET Guayaquil, for listeners looks broadcasts nightly from 8 to 10 p.m., some- ; Ja- p.m. in Spanish PSE (14.94), Rio de Leo Hertz, who collects radioana. neiro, now operates Wednesdays from 4 to by times signing oft a few minutes before 10. The interval signal consists of 12 chimes, 4 :10 p.m. in German ; Thursdays, from 3 to 3 :30 p.m. in Italian, and Saturdays from 3 Fridays, from 6 :30 to 8 :30 p.m.... W1XAR, which are sounded when the station first : 15.13, comes iden- to 3 :30 p.m. in French, also the first Thurs- Boston, Mass., operates as follows on on the air and before the station day in each month from 11 :18 a.m. to noon. Sundays from 9 or 10 to 11 a.m., Mondays, tification is given . HCJB (12.46), Quito, FRANCE -The latest schedule for the Tuesdays, Wednesdays, Thursdays and Fri- issues a white card with black call letters 2 :30 to 5 :30 p.m. and Mondays, which gives the schedule as daily except Paris stations is as follows : from I to 4 a.m., days, from 8 :45 to 9:45 Mondays; from 7 to 8 :15, 11 :30 a.m. to 2 :30, over TPB6 (15.13), for Africa ; from 5 to Wednesdays and Fridays, from 10 a.m., over TPA2 (15.243), for East and p.m.; and on 11.73, Sundays, from 2 to 6 and from 5 to 10 :30 p.m. and Fridays, Eduardo Perez Figueroa, Far -East ; 8 :30 to 10 a.m., over TPB3 p.m., Mondays, Wednesdays GUATEMALA- (17.85), for East and Far-East ; from 10 :15 from 6 :30 to 8 :30 p.m. EST. Director General of Communications for a.m. to 12:15 p.m., over TPB11 (7.28), for Frequency Changes Guatemala, notifies nie that announcements ; in West Africa ; from 1 to 5 :15 p.m., over CUBA -COBC to 9.99 ; COBZ to 9.025 Spatari, the new universal radio lan- TPB11 (7.28), for West Africa; from 6 to COCH is varying from 9.436 to 9.44; COCM guage, are now being given on the regular 8 :15 p.m., over TPA4 (11.718) and TPB12 is still variable in the vicinity of 9.82 ; COCO weekly dx programs which are radiated from TG2 (6.195) of each (11.885), for South America, and from 8 :30 to 8.695 ; COCQ now on 8.845, and COJK Guatemala City, Sun- to 11 p.m., for North America, over TPA4 to 8.65, where it seems to be operating from day, from 2 to 2 :30 a.m. Reports in Spatari (11.718) and TPB11 (11.885). 8 to 8:30 p.m. only. will be verified with special TG2 Spatari ITALY- According to the latest official DOMINICAN REPUBLIC -HI1J, San QSL cards. schedule from the E.I.A.R. at Rome, the Pedro, to 5.92, where it signs -off nightly at HUNGARY -According to several differ- short -wave transmitters of the Short -Wave 8 :30 p.m. ; HI9B to 6.39, where it seems to ent listeners the new experimental Budapest Center at Prato Smeraldo, are now in oper- be operating from 5 to 8 :40 p.m.; HITS to station on 7.221, is HAAT2, H for Hungary, ation as follows : 2R03 (9.63), daily from 6.43. A for America, A for America, T for Tibet, 12 :05 to 9 p.ni.; 2R04 (11.81), 100,000 HAITI-HH2S to 5.99 ; HH3W to 9.78. No. 2, instead of HAAQ2, as given in this watts, daily from 4 :30 to 8 :45 (also Sundays NICARAGUA-YNOP to its old location column for last issue. from 3 :15 to 4 :30 a.m.), and from 10 a.m. on 5.76. IRAQ -Alan Breen of Dunedin, New to 9 p.m. ; 2R06 (15.3), 50,000 watts, daily PERU -OAX4G is reported to have moved Zealand, writes YI5KG (7.14), the Qasr El- from 4 :15 to 4 :55, from 10 a.m. to 5 :30 and to 6.205. Zehoor Broadcasting Station, at Baghdad, from 7 :30 to 9 p.m.; 2R08 (17.82), 50,000 URUGUAY -CXA6 to 9.625. Iraq, issues an attractive photograph of watts, daily from 5 to 8 :45 a.m. and from Data H.R.H. Prince Faisal, bearing call letters in 6 to 8 :25 p.m.; 2R09 (9.67), 25,000 watts, ALBANIA -ZAA is now broadcasting black with blue shading and the address in daily from 12 :40 to 9 p.m.; 2R012 (15.1), weekdays from 6:30 to 8, and Sundays from arabic characters, as a QSL card. Power of 25,000 watts, daily from 3 :45 to 5 and from 6 :30 to 8 :30 a.m. on 7.85, and daily from 1 the transmitter is given as 1000 watts. 5 :30 to 8 :10 a.m., and 2R013 (11.9), 25,000 to 2 :30 p.m. on 6.085. LITHUANIA -LYR (9.29), power 500 watts, from 10 a.m. to 12 :30 p.m. The last AUSTRALIA -VK2ME (9.59), Sydney is watts, has been testing daily from 12 noon two named frequencies are being used on an now issuing an attractive white QSL card, to 2 p.m. and from 12 midnight to 1 a.m., experimental basis only. with the call in yellow, featuring an outline since last February. NETHERLANDS -The present schedule map of Australia, and a picture of a Kooka- MACAO -CRY9 (6.08), of Macao, oper- of the Dutch stations is as follows : PHI2 burra bird. ates' Mondays only, from 8 :30 to 10 a.m., (17.77), Sundays from 6 :10 to 9 :35 a.m.; BOHEMIA -According to A. V. Deterly closing down with the words, "CRY9, Macao, Mondays, and Thursdays, 7 :10 to 8 :30 a.m. of Baton Rouge, La., the QSL card from closing down until next Monday at the same and Tuesdays, Wednesdays, Fridays and OLR4A, has a picture of the world famous time." Saturdays, 7:10 to 8:15 a.m. . PCJ astronomical clock with moving figures on NICARAGUA -YNDG (formerly (9.59), Sundays from 1:40 to 3, and from the Old Town Hall at Prague. The address 7 :15 to 9 :50 p.m.; Tuesdays from 1 :45 to is still given as Prague, Czechoslovakia. (More Flashes on page 51)

www.americanradiohistory.com September, 1939 RADIO NEWS 47 JUST GLANCE OVER THIS PARTIAL LIST OF CONTENTS TELEVISION Television Occupations of the Future Television Words and Terms Building a Television Receiver RECEIVER SECTION The Jones S Tube Superhet. Radio Tuner for P.A. Systems TRANSMITTER SECTION Visual Deviation Meter 20 -watt Bandswitch Transmitter Il. S. Government Amateur Radio Regulations INSTRUMENTS An Electric Calibrator Home -Built Audio Oscillator A Vac Tube Volt -meter GENERAL SECTION Wire Table- Winding Turns per inch Building a Radio Treasure Hunter International "Q" Signals EXPERIMENTER SECTION Dual Diversity Coupler Constructing a Polarized Relay Home-made Scratch Filter Single Tube Announcer SERVICEMEN'S SECTION Service Problems with Interference How to Advertise Your Shop Handy File System Measuring Power Output Servicing A.F.C. Systems Tips on Radio Noises AMPLIFIER SECTION An AC -DC 4 -watt Amplifer A Scotchman's Special Amplifier Making Your Own Records DB 2 -4000 ohm Conversion Chart 1939 GADGET SECTION Home-made Pilot Light Socket R® NOS Meter Kinks A Increase Voltmeter Utility Television Fish -pole Antenna and Plugin Resistors nadio ll®ak Projection Device for CR -913 Tubes Pata Numerous illustrations, charts, hook ups and diagrams. Many different items and articles, giving complete radio coverage. A wealth of invaluable radio informa- FOR THE tion. Actual size, 8 "xl I ". SERVICEMAN Radio News, Dept. 99D EXPERIMENTER 608 S. Dearborn St., Chicago, 1H. Enclosed find $1. Send me the next 12 issues of RADIO NEWS and rush a AMATEUR copy of the 1939 RADIO DATA BOOK to me without charge. (If renewal, check here .) You can obtain this great book absolutely free of charge! Fill out and return the Name coupon with your remittance of $1 for 12 issues of RADIO NEWS, and we will rush a copy to you without any additional cost! If Address you are already a subscriber and want this book, mail the order blank with your remit- City State tance and your present subscription will be extended. Act now -our supply of these valuable books is limited! Please describe your occupation:

www.americanradiohistory.com 48 RADIO NEWS September, 1939

fastest speed to which the dial can be plate of the 6F5 tube to the primary of the input transformer.) Replace with a 0.1 -mfd. 600 - Dialomatic Rig set, and the change from one band to volt unit (Continued from page 16) the next requires only about one sec- BELMONT 1171, 1172 ond. See also Case Histories listed for Belmont 685 will describe receiver original position of the switch is set to Next month's article Pilot lights do 1) 2 -amp. line -fuse blown (in the remote amplifier which features not light those chassis equipped with proper position, the stepper will ad- a '5Z4 rectifier tube and a vance the switch in the trunk compart- pre -tuned r.f. circuits, simplified audio line fuse). First disconnect i c all power. Then remove fuse cover located on ment exactly ten steps. As soon as the peak- compression, and automat back flange of chassis. Replace blown fuse pilot contacts are reached by the loading of all bands to an eight foot with a 2 -amp. fuse. If replacement fuse also blows out, check all tubes (particularly the stepper -the stepping relay cannot vertical antenna. This versatile unit '5Z4 rectifier) circuit, repair or replace inoper- operate the switch beyond the proper has self -contained Eicor Generator, ative tubes or parts - setting and the lamp will light above for furnishing power to the amplifier BELMONT - GAMBLE 777 Series B -C, the 10 meter selector button. modulator and is ideally suited to 778 Series A many radio services. 30 Intermittent ...1) Intermittent open- circuiting The next band is selected by closing hum, of the common lead of the the proper switch in the same manner. (disappears dual condenser unit (0.1- when line 0.25 -mfd., 220 -volt) c o m - If the next band is not to be used, it is switch is prising the bias voltage hum Servicemen's Cases snapped off filter and screen by-pass con- only necessary to close the proper and on) densers. Replace the entire switch and to dial until the proper (Continued from page 42) unit with two separate units pilot lamp goes on. As the stepper of same capacity and voltage reaches proper position, the relay will BELMONT 740, 741 BEST 4 TUBE MIDGET Same Case Histories as those listed for Inoperative, ...1) defective type '25Z5 tube, automatically drop out and stop rota- Belmont 588 (only voltage caused by an open- circuit in- tion. This stepper will operate at the present side one of the cathode leads. BELMONT 750 across speaker Replace with new tube field) Failure to oper- 1) defective type '2A7 tub e ate over both (even though it may test Difficulty in ...1) loose tension of the springs bands O.K.) Replace wit h new tuning, on the tuning condenser ro- tube by substitution Set drifts off tors. Solder pigtails across 2) defective wave- change switch frequency set- rotors and springs contacts ting Slipping dial ..l) slide the bronze washer drive drive assembly either c l o s e r or B.O.P. Auto-Radio Receivers farther away from the vari- See also Case History listings under United able shaft, in the slot in Motors which it is mounted B.O.P. "AIR MATE" Auto Radio BELMONT 770 Inoperative ...1) substitute a new vibrator Hum, ...... 1) common lead of the dual 0.1- Distortion, ....1) decrease of value of condens- (intermittent, and 0.25 -mfd., 200 -volt con- Poor tone ers in electrolytic condenser appearing denser "opens" at the point at high volume block. Replace the complete after receiver of attachment of the lead to section if any unit is defec- is "on" for the foil of the condenser. tive (never replace single NEW 61/a to 612 METER some time and Replace the entire condenser units) disappearing if unit by two separate units HIGH GAIN PRE -SELECTOR line switch is of identical capacity and B.O.P. -Bi ICE snapped "off" voltage rating as the rom- Inoperative ....1) faulty vibrator. Substitute and "on ") ponents of the original unit. new one The 0.1-mfd. condenser is a (jolting the re- a The new GUTHMAN U -42 Pre -Selector connected ceiver starts it, screen by -pass for the '657 dead again between antenna and an all -wave receiver, will tre- tube; the 0.25 -mfd. cond. is after it has mendously increase amplification and selectivity. a hum filter for the bias been turned voltage of the '42 tube off) Designed by McMurdo Silver, it tunes in five bands Frying noise ..1) due to scintillation of the Motorboating ..1) (in 1934 receivers) generally meters, with large, well - (heard only special "regulator" type elec- of an r -f from 6.5 through 612 until tubes trolytic filter condensers used Steady whistle due to breaking spread out directly calibrated smooth vernier dial. cathode by -pass condenser warm up) in this receiver. Do not re- I e a d. Inspect the largest Complete power supply is built in. place condensers because of between this scintillation noise it condenser of cluster of three, jammed shows normal operation- lid and the other two Through controlled regeneration, enormous ampli- BOSCH CB 49 fication and extreme selectivity is obtained BELMONT 777 -to Same Case Histories as those listed for greatly boost weak signals and reduce noise inter- Same Case Histories as listed for Belmont 578 and 770 receiver Bosch 16, 17, 18 ference most amazingly-to bring in signals never heard before. BELMONT 777 (Series B, C) [This interesting series by Mr. Ghir- See also Case Histories listed for Belmont 770 will be continued next month. Inoperative oscillator e 1 i n g coil ardi - Complete kit priced at only $16.50 net to amateurs. ...1) oup "shorted" by terminal of 19,- ED.] --Li- It can be had from any up -to- the -minute jobber - 000 -ohm resistor (in '76 os- or mail your order directly to factory for prompt cillator tube plate circuit) making direct contact with terminal of 100 -ohm resistor in this shipment if your jobber can't supply you. same plate circuit. Keep these two resistors apart Free Point Analyzer from page 39) BELMONT 778, 786, 787 (Continued Dial drive slip- 1) install new type belt take -up page assembly now available from manufacturer for these re- PARTS LIST ceivers. (Note: some Model E- CO.. I N C. (Bud) EDWIN I. '787 dial drives are equipped with a wide red 1 -8 prong octal analyzer plug belt. In these receivers, this belt will still give plug adapters trouble even if the newer type belt take -up as- 5-Analyzer 8 8 -6; 8 -5; 8 -4 (Bud) ST. J.S.A. sembly is installed. It is advisable to replace 8 -7L; -7S; 400S.PE0RIA CHICAGO. the belt with a newer two -ply type) I -9 wire cable, 51/2 ft. (Bud) CABLE ADDAEtt: DOTNCO- CNICAEO BELMONT- 804 I -9 button switch (2 S.P.D.T. on each button) Same Case Histories as listed for Belmont 415 (Oak) receiver S.P.S.T. on each button) 1 -9 button switch (.I BELMONT 878, 879 (Oak) Dial drive slip- 1) install new type belt take -up 1-4 P.D.T. Anti -capacity switch (Federal) page assembly now available from 3 Insulated Phone Tip Jacks (Bud) manufacturer for these re- -Black ceivers 2- Red Insulated Phone Tip Jacks (Bud) -Black Insulated dual grid cap (Bud) BELMONT 888, 889 -Red Insulated alligator clip (Bud) Same Case Histories as those listed for Belmont 588 receivers -Black Insulated Phone Tip Plug (Bud) -8 prong octal socket (Eby) BELMONT 1170 -7 prong universal socket (Eby) ALL TYPES OF '. Same Case Histories as those listed for Belmont 588 and 685 receivers -6 prong standard socket (Eby) FIXED CAPACITORS-, -5 prong standard socket (Eby) FOR RADIO AND_ :; BELMONT 1170B -4 prong standard socket (Eby) See also Case Histories listed for Belmont 588 TELEVISION . and 685 receivers -Bakelite panel, 1/2"x7 "x71/2" Inoperative ....l) check the 0.1 -mfd. condenser -Steel case, 3 "x7'x71/2" (tubes check (Part No. 100.20) located at O.K.) the base of the 6F5 tube. 4- Rubber feet; hook -up wire, mounting (It is connected from the screws, etc. center of the two 100 -ohm resistors which are connected in series from the 30

www.americanradiohistory.com September, 1939 RADIO NEWS 49

RADIO NEWS Transmitter (Continued from page 32)

the speech (tone control). If correctly built there should be a deep bass tone in one setting. That is the one which will cut through the QRM. Next advance the sensitivity control of the VOX system and listen for the VOX relay to throw over. If it cannot be heard, put the receiver on, and place the receiver in the VOX- opera- tive condition. The VOX should cut out the receiver and throw the relays for the transmitting side (as evidenced by the resistance lights lighting). If previous checks have been made as indicated above, everything should function perfectly. DEVE-OwMEeassR ñ°,On intoutoat}Ots Testing and Tuning the RF ATE ytnite- {O' It is assumed that the r.f. is now Tete tsjOn,e°SeTVieWgdevel Pleu- ready for test. Place the final r.f. be have The mrs ol. H P,aésér itoP eTT °tint will phone -c.w. switch in the neutral posi- TO sotvt YOU WER tecetvet erste °e wlteTTCr se tion, to ANS uutnt et °te monuiact e new prevent the high voltage from need n volum ttttcli getting to the final. Turn on the fila- octaTT .; e' any ° h, ` WOOS"fj ORKS on the ments of the (Taylor) 866 Jr.s and being Pá°bped 10 e ét in5 d 4 of s ÑEW ..HQ s at lableat explanations w'he ond tot t in allow them to heat for at least one - bave cOmaere be aÚsuáv da te. ndetstón cae sec- will t lo -oi Televtséts half hour. This precaution should be such e sy- etOWpRKS cost. o th ?tales, lat oxtta observed with any of the high voltage tJolor' head theory na ths ° átA ncl Yon mercury rectifiers when they are first 0 oed °T' lnew. 64-page includedintottnation on SERVIGE RidE placed in service. Later they need tion tYpeo belPiul NE w sti wh the s a l 11-sis tonna covets only be warmed up for a few minutes. ser°TCl,9 r° Y°"t otilYp get n index le nowould in ea X Next turn the auto -transformer Ó this volet ve otunte which governs a.c. of ltte TeCe'vet°u Yu vManuats- the output the asked 550 -watt to the minimum position intot tot You N°ve'nbeT the The X (about 10 v. a.c.) and turn on the a.c. 19 volnrne toy ---1" 1,s to the various power transformers. cal Rider. Using any one of the variable crys- {oTOd Volume tals, adjust in the normal manner. X Check each crystal in turn, and also "SERVICING BY SIGNAL TRACING" RIDER the Meissner Signal Shifter. The tun- by John F. Rider MANUAL Use the system of servicing which is proved ing of the crystal, 1st buffer and 2nd and endorsed. The fast- modern system you OUT buffer sections should be without hitch can apply to all receivers regardless of since the former requires no neutral- age, type or make- independent of every izing (used only as a doubler) and the limiting factor heretofore encountered. In AUGUST 19th latter is a beam -power pentode. There this new book you learn what happens to should be at least 20 -30 mils of grid the signal currents - the development of 1650 PAGES -$10,00 current available at the final. control voltages -and how all receivers are Once everything is in resonance, the brought to a common servicing level. There unamanrs is one thing which is common to every radio Volume Price Covering voltage of the 550 -watt generator may set -the signal. Read this book and you IX be brought up to 115 v. a.c. The read- 810.00 1938 -39 will be able to service the most complicated VIII 10.00 1937 -38 ings of the various meters should be set with greater speed and less effort. VII 10.00 1936 -37 VI as follows: (for the 20 -meter band) 300 pages $2.00 7.50 1935 -36 V 7.50 1934.35 xtal- buffer plate -65MA; 2nd buffer IV Out Soon! VOLUME II 7.50 1933 -34 plate -90MA; Amplifier grid -22MA; III 7.50 THE CATHODE -RAY TUBE AT WORK 1932 -33 1st buffer grid -4 -8 MA. 7.50.....1931 -32 by John F. Rider Next the final is neutralized in the 7.50 1920 -31 fashion. New applications of the cathode -ray tube normal require that the 1939 serviceman know Reducing the voltage to the final more ORDER about its operation, characteristics and per- YOU NEED power supplies again to about 10 volts, formance. The cathode -ray tube as the TODAY the phone -c.w. switch is placed in the principal factor in television receiving sets c.w. position and the rig turned on. is but one of the applications with which A«, Place a load across the output termi- you will soon be faced. Use of the Oscil- nals and increase the voltage steadily lograph in industry is increasing every day e RIDER until the final reads just 200MA at 115 in testing vibration, strength, engine pres- v. a.c. input to the final power supply. sure, etc. Industrial users need servicemen to maintain their oscillographs. Be up -to- MANUALS The r.f. is now adjusted. date on this vital subject. Turn the rig off, and place the phone -c.w. switch in the phone position. Turn it on again, and the under - load relay should pick up and the modulators should be in the circuit. The idling current of the (Taylor) TZ40's should be about 35 -50MA, and they should be able to be swung to about 150MA under full speech impetus.

www.americanradiohistory.com 50 RADIO NEWS September, 1939

The rig is now ready to be placed moving slightly by either crystal or on the air. Signal Shifter control will enable the operator to complete almost every Conclusion QSO, 100%. That is the purpose of the It will take a little time before the variable frequency control in the unit. amateur becomes thoroughly familiar with the operation of the rig in all [The authors wish to thank the following manufacturers who, by their of its features. This is true because the of the fact that it contains probably cooperation and assistance, made many construction of the RADIO NEWS 1940 as of the outstanding advantages All -Purpose Transmitter -Receiver pos- which have been developed for ham sible.-ED. radio today as is possible to place in one cabinet. Radio Manufacturing Engineers, From time to time certain of the Browning Laboratories, Bliley Elec- circuits will require slight "touching tric Co., Cardwell Mfg. Co., Aerovox up" and occasionally a "bug" may ap- Corporation, Ward -Leonard Mfg. Co., pear which can be easily located. But Guardian Electric Co., Shure Bros. Co., MILLION all in all, the rig is so constructed American Phenolic Corporation, Con- that it should be one which can be solidated Wire Corporation, Taylor NEW DF TUBE CHECKER kept intact for a considerable period Tubes, Inc., Triplett Electrical Instru- of time. ment Co., Par -Metal Products Corpo- FOR ALL NEW TUBES In building the rig the authors had ration, Pioneer Genemotor Corpora- in mind that most of the amount of tion, Standard Transformer Corpora- New. with wider application range. Tests emission of all tubes. Ten sockets cover all types from change would come in the r.f. section tion, Barker & Williamson, The Na- "hearing aid" peanut tulles to the new loktals and and with the type of construction used Co., P. R. Mallory & Co., Inc., S series. Fila nient switch covers 1.4 to 110 volts tional with spare positions for the future. Gives instant it is a simple matter to replace the Ohmite Manufacturing Co., Meissner "good -bad" readings on oversize D'Arsonval meter. Makes neon short or leak test with tube hot. Tests present r.f. chassis with one of newer Mfg. Co., S. S. White Mfg. Co., and by -pass condensers, etc. Literature on request. design when the latter will be evolved. Martin -Flash Key Corporation.] Some complaint may be found be- MODERN cause of the mounting of two tubes ACCURATE under the r.f. chassis, making them DEPENDABLE hard to replace. Information from the "I'ZE ON THE AIR" ECONOMICAL NET manufacturers of these tubes (Taylor '16" O you advertize to "Alkalize," and RCA) led the authors to believe If your Jobber cannot supply you, And radioize to slenderize; that replacement need only be made But it's gosh darn hard to mesmerize write us direct. at the end of several thousand hours The air waves all the time. of operation. In ordinary ham par- MILLION RADIO AND TELEVISION lance this would mean about once While you synchronize to vulcanize 577 No. Union St.. Chicago, Illinois every 18 months. To replace these And pasteurize to iodize, tubes it is necessary to remove the Don't you think its time to realize r.f. chassis. In doing so, be sure to What the air waves lack is RHYME? of connector leads so glatIJi2. VO-U. ,5121211- tag all the that For you hypnotize with alibis, they will be replaced in proper order. And paralize with lullabizes; The NEW Meissner 1939 -40 Catalog -just off In building in the RME receiver, the But you've still got time-apologize, the press that describes in its 48 pages over connections to the a.c. input and to And give the air lanes RHYME. 800 new, different and improved Radio and the relay are by means of male and Television items including: female connector plugs. This was used Must you burglarize to commercialize? and 5 TELEVISION KIT for $139.50 -pages 4 so as to make it possible to remove Can't you systematize and organize? 9 -TUBE "TRAFFIC" SCOUT -page 8 the receiver with the minimum amount The South Sea Islands visualize - 10 over RHYME. PRESELECTOR and 5 and METER CON- to get They're "daffy" VERTER -page 9 of effort enabling the operator to the VOX or speech amplifier sys- PORTABLE BATTERY OPERATED KIT - While you humanize and specialize, page 19 tems. Don't dramatize but sympathize SIGNAL CALIBRATOR AND AUTOMATIC The modulators are accessible at With those too dumb to patronize ANTENNA SELECTOR -page 22 once as are the power supplies and Until they hear this RHYME. DELUXE SIGNAL SHIFTER -page 23 the generators. Any generator may You could carmelize to appetize, ADAPTER KITS AND 6 PUSH BUTTON be taken from the cabinet simply by TUNER -pages 24-26 pulling the plugs which connect it to (Never atomize to spiritualize few with nerve to criticize POWER RELAY AND ANTENNA CHANGE- the a.c. -d.c. control panel. Those 29 of a RHYME). OVER RELAY-page The equipment should be taken care The author IMPROVED PLASTIC I. F. TRANSFORMER tor $1 -page 33 of and should be dusted on the inside Can't you Evangelize to emphasize, and hundreds of other up -to- the -minute de- and outside regularly. The generators Or capsize to compromize? velopments in radio and television. should be oiled with a light grade of And show the spunk that petrifizes x a ,e The ones who dial this RHYME. e. mw machine oil about once every month, FREE!!! toayd for your and if the rig is inoperative for an specialize and popularize, SENI) 50 CENTS for Steissner's "NEW GLIDE appreciable amount of time the gen- Next you TO RADIO AND TELEVISION," a complete, And tantalize the "publicize," Book and Trouble- Shooter's be run from 15 minutes scientific Instruction erators should Who'd censorize and penalize Manual for Kit Builders and Operators. Fully il- to a half hour once a month, without 11 Just 'cause they ain't got RHYME. l.nated. ;5 rages. load, to prevent the brushes from sticking and to keep the commutators Boy-to fraternize and chastize shiny. Let's summarize and memorize One last word of warning: in con- The fact that you will capitalize A FAMOUS NAME FOR TWO DECADES structing the RADIO NEWS 1940 "All - And "air" this little RHYME. Meissner Mfg. Co., Transmitter - Receiver, the -Dept. N -9. Purpose" Mt. Carmel, Ill. Signal Shifter was included for rapid So long; No time to eulogize E Mail me \leissners New 1939 -40 catalog. To generalize nor sterilize; Enclosed find 50 cents for Instruction Book. QSY. This does not indicate that it WE'VE JUST GOT TIME TO BAPTIZE - should be used to comb any one the THE AIR." Name THE RHYME GOES "ON band used from one end to the other, (By "Anna Lize." ) Street causing unnecessary QRM. It will be City Ct1te found that staying on one frequency,

www.americanradiohistory.com Septernbel, 1C39 RADIO NEWS 51

163, Haifa. is being heard near 5 p.m. Re- 42.8. . \V4XA (26.15) of Nashville, Tenn., ports to ZC6HS and other ZC6 stations operates weekdays from II a.m. to 8 p.m., or Short Wave Flashrs should be sent in sealed envelopes with no later. \ \'4X:\ originates most of its pro- (Continued from page 46) mention of radio or call since all amateurs grams and features an excellent variety of operating in this country are believed to be classical music. Radio (healers in the vicin- unlicensed. ZC6RL will soon be operating ity of Nashville. are reported to be doing a 1' N 3 UG ) of Leon, Nicaragua, operates reg on phone on 14.07. land office business, building. and installing ularly on a frequency of 7.66, but shifts to PHOENIX ISLAND -According to Roger converters to adapt any broadcast receiver 13.9. Saturday nights at 10 p.m., in order to Legge of Binghamton, New York. KF6DI-IW to \V4XA's frequency. Full information transmit a special program for dxers. Spe- (14.378), verified with a white QSL card about the convertor may be had by writing cial announcements in Spatari are given. having large red and silver call letters. The to Tom Stewart of the station . XBXUJ All correct reports enclosing a dime to de- operator Charles Calley, Jr., has returned to (26), Cincinnati. Ohio, transmits facsimile fray return postage are promptly verified. Honolulu. his place at Phoenix, having been with a power of 1000 watts, daily from 2:15 An attractive photograph of the station is taken by KF6PMO. to 3:15 p.m. . . . \V9XA of Kansas City. available for 25c. TIBET- AC4YN, whose new 100 watt rig Missouri, may soon shift to a frequency of NOkIVAY- -The Oslo station has been as- was built by FN i C, is reported to be on the exactly 26 rte., where it will maintain a signed a new call and frequency, to be used air on 14.292 and 14.290, with a beam di- constant frequency so exact that it may be whenever the occasion may demand, namely, rective to North America. He is supposedly regarded by amateurs and others as a sub- 1.I.N (17.825). being heard near 1, 6:30 and 8 to 10 a.m. standard of frequency . . . John nl. Sher- PA RAGE) AY -ZP14 (11.72) of Villarica, EST. man, the Technical Director, for \VTCN. broadcasts Mondays through Fridays from 5 Ultra High's Minneapolis-St. Paul, writes that relay to 8 p.m. and on Saturdays and Sundays. W2XMN, the 40,000 watt, static -free sta- broadcast station \V9XTC has been tem- from 11 a.nt. to 6 p.m. tion of Edwin H. Armstrong, at New York porarily withdrawn from service. P. I -KZIB (9.49), broadcasts direct from City. may still be heard conducting tests on (Continued on next page) the floor of the Manila Stock Exchange. nightly from 8:30 p.m. to 2:40 a.m. l? 'N/ON-"Radio St. Denis." located at THIS P. A. LEADER Si. Denis, power 60 watts, broadcasts ir- RCA OFFERS regularly on a frequency of 9.6. .,IA/.Y -The official announced schedule for E. \Q (9.86) of Madrid, is weekdays from 7:45 to 8:30 p.m. SWEDEN-According to the Newark News Radio Club, the new calls and frequencies for the Swedish stations are: SBT (15.155), SBI' (11.705), SBU (9.535) and Slit) (6.065). SBT rplaces SM5SX, the experimental station at Alotala. TURKEY-An official letter from TAP (9.465), informs me that the Correspondence Outstanding RCA Junior Velocity Section of the station is in the process of catching up on back correspondence, and Microphone -the favorite of service that just as soon as this is completed, QSI. cards will be prepared for future reports. and sound engineers everywhere TAI' broadcasts a Post Bag program in Eng- - now available for only lish and German on Saturdays at 3 p.m., and dance music daily at noon and 4:20 p.m. new low price! EST. Take advantage of this Get this microphone that is so amazingly MI -4036 URUGUAY-The correct schedule for with service and sound engineers SPECIFICATIONS OF ('X. \6 (9.62), Montevideo, is, according to popular FREQUENCY RANGE, 50 to 9,000 A. 'Full of London, daily from 10:30 a.m. -now! It is Model MI- 4036 -a true velocity unit cycles. OUTPUT LEVEL, -59 db (to- to 12:.30 and from 3:311 to 9:30 p.m. of small size and light weight with ball -and- bar- open- circuit). OUTPUT IMPE- 11,V/TED STATES- According to socket mounting. One of the family of RCA mi- DANCE, 50, 250, 15,000 ohms. the CABLE. 30 feet (less plug). FINISH. IRM. weather reports may be tuned in from crophones -many of which are used in major 1/2" various Chromium and Black. FITTING. stations as follows: front \VM1 broadcasting studios-as well as by leading mo- pipe thread. NET WEIGHT, 31/2 Its. ( 2.55, 6.-17 and 11.37) of Lorraine. Ohio, at tion picture companies. DIMENSIONS, 7'4" high, 23/4" wide, 11 a.m. and 10 p.m.; front NNG (2.662), 21/2" deep. Motile, Alabama, at 12 midnight and 10 a.tn. and from NNC (2.662), at San Francisco, California, at 10 a.m. and 12 midnight. VENEZUELA-John Larsen of Geneva, "FB" FOR AMATEURS -This RCA New York. tvrites that '\'5R0 (4.94), "The NEW! RCA PRESSURE MICROPHONE - Voice of Venezuela," in Caracas, announces Aerodynamic Mike in Spanish at five minutes after the hour and Designed for every fifteen minutes, in This smtmll, str-eam and English at 9:55 Outdoor Use linehid p.m. before signing -off at 10 p.nt. is especially suited This mike is pres- for close talking. Amateur Reception Notes sure operated with Available in high a styrol diaphragm low impedance BELGI. I. \' CONGO - OQ5A A (14.10), and moving coil and is back on the air again and being heard element. Extremely models. Its fre- small in quency range is 100 near 6 to 6;30 p.m. . . . OQ5AE has sailed rugged, size, attractive in appearance. Ball -and- to 8,000 cycles ... output level -66 db for the Congo and expects ( to be on the air socket joint (with thumb screw clamps) (10 bar -open- circuit) ... 30 feet cable less in the Fall. affords easy adjustment. Its Frequency plug) .. Chromium finish ... IA" pipe CEYLON- -VS7GJ is now enjoying a visit range is 60 to 10.000 cycles ... output thread fitting or 5/27" fixture thread. to Europe. but he will QSI. level bar -open- Low impedance model (output 5,995 when he returns -54db (10- circuit)...output is Price to Ceylon in about 6 months. impedance 50 and 250 ohms. Cable less 250 ohms) MI.6226, FRENCH /.VD/4-(;ail Beyer of Chicago, plug is 30 feet long. Has VI" High impedance model (output 40,000 pipe thread fitting. Price . 57495 ohms) is model Mí.6228, Price $2195 Illinois, writes that FN IC (14.084) of Chan - dernagore. operates with a power of 100 watts, almost daily from 7:30 to 9 a.m. His QSI. card is a real beauty, picturing a ball of blue in the center with the head of a Bengal tiger within it in yellow, and the call Listen to the Magic Key of RCA every r letters in black. Monday, 8:30 to P. M., E.D.S.T., Send today for your 9:30 FREE! RCA G /HRAl.7 AR (14.135), P.O. on Blue Network copy of the new -ZB2B Box the NBC Commercial Sound Catalog... 56 201, is being heard front 6 to 8:30 p.m. ir- big. illustrated pages. regularly. GREECE--There is under consideration a Commercial Sound Section, Dept. )IM -8 law authorizing issuance of new licenses for RCA Manufacturing Co., Inc., amateurs under certain conditions. Stations Camden, N. J. now licensed are S\'ICA, SVINK, SVIKl, Please send ree my copy of the new SVIGR and SV'1MP. RCA Sound Equipment Catalog. JAkI'iS ISLAND-John \V. May of \Vil- kinsburg, l'cnna., informs me that KG6NVJ COMMERCIAL Name I verified with a QSi. card having the call in blue outlined in black against a silver back - Address ground. V'O11' SOUND ,VEIVFOUNDLAND- finally veri- City fied a report of reception submitted in 1937, RCA Mfg. Co., Inc., Camden, N. J. stating that VOS are no longer allowed to State-. operate on phone on 40 meters. A Service of Radio Corp. of America L J PALESTINE -ZC611S (14.3), P.O. Box ANY SOUND SYSTEM SOUNDS BETTER EQUIPPED WITH RCA RADIO TUBES

www.americanradiohistory.com 52 RADIO NEWS September, 1939

Television Straits Settlements NBC's television station W2XBS has in- ZHP of Singapore lias evidently shifted IDEAL FOR RECEIVER creased its studio telecasts for viewers in to 9.7 meg. permanently to avoid interfer- the New York area to three a week, namely, ence. Although scheduled to sign -off at 6 :40 Tuesdays, Thursdays and Fridays, from 7 :30 a.m., this popular station often stays on the MODERNIZATION to 8 :30 p.m. EST. Outdoor telecasts relayed air until 7 o'clock when relaying programs by the NBC mobile television station from from London, and closes at 7 :40 on the first the World's Fair will likewise be stepped up Wednesday of each month. ATTACHES to three hours weekly. These will be seen Several reports indicate that a Singapore and heard Thursdays, Fridays and Satur- station is working on approximately 6.04 EASILY day afternoon. Movie telecasts will be made meg. near 5 or 5 :30 a.m. It has been signing 6 :10 TO on Tuesdays, Wednesdays, Thursdays, and off at a.m. with "God Save the ANY Saturdays from 11 a.m. to noon. . . . Con- King," indicating rather conclusively that it trary to theory that television programs can must be located in Straits Settlements, al- RECEIVER be received only 40 or 50 miles from the though definite identification has not been transmitting station, General Electric engi- accomplished as yet. neers on a mountain -side near Schenectady, which is 130 miles from New York, have Australia been receiving the telecasts from W2XBS A new English -speaking station has been regularly with good definition and clarity logged on approximately 6.12 or 6.13 meg. . . . A feat, long considered impossible, was near midnight. It is very possible that this accomplished recently in an NBC telecast of may be the new Australian broadcaster the six -day bicycle race at Madison Square which was to be located near Perth in West 'Antenna-Scope' Garden in New York, when images were Australia. According to the latest available transmitted over an ordinary telephone line information this new transmitter has been With to station W2XBS, and then sent out over assigned frequencies of 11.83, 9.56 and 6.13 the air for viewers in the metropolitan area. meg. No reports have been received as yet Iron Core This opens up an enormous field of possi- on either of the two higher frequencies, but bilities including the possible projection of it seems quite probable that the station Permeability Tuned pictures at a later date over network wire which so many fans have been hearing on Tracking Coil facilities . . Latest applicants to apply for 6.13 meg. is the new Australian. licenses for construction of television sta- VLR of Melbourne, Australia, has in- tions are : Don Lee Broadcasting System, creased its power for both frequencies. It The Consolidated "Antenna-Scope- introduces a Inc. of Los Angeles ; Leroy's Jewelers, and appears that the schedule has again been self-contained, loop antenna which is easy to May Los Angeles, attach to any broadcast receiver with the double the Department Store, of shifted, since the 9.58 meg. frequency has vacuum cups provided. Eliminates static. Re- Calif. . . . On June 14, the General Electric been reported several times before midnight. duces noise -to- signal ratio. Screw -driver adjust- Company of Schenectady, New York, inau- It is possible, however, that this was mis- ment allows the "Antenna- Scope" to meet the gurated for the first time, the sale of tele- taken for the 9.56 meg. wave of the new inductance requirements of either super-het or vision receivers. Five models are featured. Perth broadcaster. TRF circuits. This compact unit (6 ,A" x 11h" x Picture images range in size from 3 x 4 to ") comes complete with instructions for in- 12 stallation. Servicemen will find new profits in inches square. Japan modernizing old receivers with the `Antenna - A new and unidentified Nipponese station Scope." SHORT WAVES FOR DX'ers on the is operating irregularly on about 6.13 meg. See Them al Your Pails Jobber's Today! near 10 p.m. This is evidently a phone sta- WEST COAST tion, but call letters and location are still by JOHN D. CLARK undetermined. o11SöL1AT All Times Are PACIFIC STANDARD There has been no change in the schedules of Overseas Broadcasts from the Broad- 4í1pöRÄTl011ts Indo -China casting Corporation of Japan. JZK (15.16 526 S. Peoria St. Chicago, Illinois ADIO SAIGON," located in Saigon, meg.), however, will probably soon be re- Indo- China, and recognized as one placed by JZJ (11.8 meg.) for the daily 9 :30 1of the strongest Orientals now being heard to 10 :30 transmission. in the short wave spectrum, is still not fol- The Broadcasting Corporation of Japan lowing its printed schedule. This powerful informs us that the scope of the overseas transmitter is on the air daily until 7 a.m. programs will soon be considerably extended, "AIR RACING and even later. The first part of the trans- but no definite information on this is avail- mission, beginning at 3 a.m. is released on able as yet. 6.12 meg., while the last hour or so comes through on a frequency of 11.785 meg. The Miscellaneous

exact time for changeover seems to be rather . is HELL!' Our listeners tell us . that the new irregular, sometimes taking place as early Javanese station YDF is heard with good 6 :15 a.m. as 5 a.m. and as late as The sta- volume on 4.96 meg. near 4 :30 a.m.. . . that tion requests reports on both frequencies a station announcing as ZMDF, location un- from American listeners, and address is known, has been logged several times on given as P. O. Box 412. Announcements are about 9.4 meg. near 11 p.m.... that FO8AA made in French, English, and Chinese; and of Papeete, Tahiti, now remains on the air a special English program is given at ap- until after midnight Friday, but has evi- proximately 5 :45 a.m. daily. dently cancelled the Tuesday transmissions "Radio Boy Landry," after being unre- that Japan's JVW3 is on the air as early ported for several weeks, is again being re- as 10 p.m. irregularly (11.73 meg? . . that ceived by several Pacific Coast listeners near two new Orientals are working on about 6.28 5 a.m. on its 9.7 meg. frequency. Although and 6.54 meg. irregularly near 4 :30 a.m. . . its schedule calls for operation until 6 :40 that the mysterious Nipponese transmitter a.m., signals usually fade out near 5 :30. on 7.325 meg. is signing off at 5 :30 instead of 7 :30 now . . . that another new Oriental China station lias been logged by many fans on Station XGOX of Chungking, China, is about 8.5 meg. between 3 and 4 a.m. 30 just concluding a series of special tests as we go to press. This government- operated transmitter sent test broadcasts on 15.19 meg. from 10 p.m. to midnight for a short QRD? de Gy Sao,: COLONEL time and then shifted to 17.8 meg. on the (Continued from page 22) same schedule. Announcements just received indicate that these experimental programs ROSCOE TURNER will shortly be continued on the same wave- It seems that the bewitched box would quit lengths, but probably on a new time sched- whenever it seemed to get the notion. It FAMOUS SPEED PILOT ule. XGOX is attempting to find the most was as temperamental as a Hollywood movie suitable wave and schedule for regular star, always going off at a tangent whenever The world's most famous speed flyer, and broadcasts to America which will probably it was most urgently needed. Well, upon his of the Thompson Trophy, be inaugurated in the near future. The next return to port he was given his discharge. last year's winner series of tests will be run near 8 or 9 p.m. Sadly, he related this tale to a friend of his tells the startling facts about air racing. Another Chungking station, believed to be who told him everything would have been XGOY, is relaying the programs of XGOA OK if he had only done one simple thing. on 7.17 meg. from approximately 330 to 6 Does any bright lad in the audience know Read the September Issue a.m., then shifting to 11.9 meg. and continu- what he should have done to take the tem- ing until fade -out near 8 a.m. perament out of the receiver? (Remember, XTC of Shanghai, China, is reported to be the boat is in tropical waters.) The answer POPULAR back on 9.295 meg. after a silence of several will be in next month's column, but we'd like months, but a careful check has failed to re- to hear what you would have done in like veal any trace of this one at our headquar- circumstances. AVIATION ters. The schedule is supposed to be from Now on Sale at All Newsstands 5 to 6 a.m., although one listener reports it jT is with deep regret and sorrow that we only from 3 :30 to 5 o'clock. learn of the passing of our friend, Harry

www.americanradiohistory.com September, 1939 RADIO NEWS 53

Chetham. He was one of the original old switches separately up and down until timers and gave many hours of his time cor- a reading results. While reading con- responding to cheer up old shipmates and Sw. aiding in many other ways to help all and dition of tube on meter depress sundry. His last duty was as Chief of the No. 7 and if meter needle does not re- ftC Police Radio Xmtr at Somerville, Mass., turn to zero the tube has Cathode which he installed. His memory lingers on. Heater Leakage. and crvaaP/ vow filament IT is with great pleasure we note the many Be sure to use the proper replies which came to ye Ed in answer voltage on all tubes. On all filament TITRBBLB, to last month's police radio equipment in- type tubes it is not necessary to throw the stallation. The scope of education and Sw. No. 3 in upper position, but sim- previous experience of each applicant was indeed gratifying to me because it bespoke ply to read meter. The diodes of duo - MONEY the advanced knowledge and continual study- diode triodes may be tested independ- Each letter is t-Ias ing that each op had done. ently by throwing the switch connected Your dish- person in question catalog is being turned over to the 2 to FREE thousands and if any one is chosen they will hear di- to one diode down, Sw. No. the This ound men, with qualifica- right and all other switches up. Then everything s, Test Instrunsents, rectly from him. When tubes, build- it-yourself tions such as were sent in, are out to con- be in the parts, Receivers, adver- the other diode may tested nationally nect up with a good berth, there is no ques- ky item fere same way. and tion lint that it is only a matter of getting Save trouble. This tester has proven itself as to er their applications into the proper hands be- tised,ts, S sav- Men such at home. of real money fore they are permanently placed. accurate performance and I would rec- Notag some items. as these are needed in this radio art. It is nd take just on ommend it to anyone. 30 right through forever expanding, forever building up and ing pricvale after value "knowledge is power," especially in radio. There's You for l88 pages- at once Just another case of doing something worth- this book's buy! Send Just . . . so the chin you FREE! while and darn well keep Hamchatter everything it's W -11 up ... and with 73 . . ge .. . GY. (Continued from page 19) your ya the coupon NO d mail 30 tear oout need for a grid -controlled mousetrap our- Tube Checker selves, Ed.)" 17) W9CLR writes that he has organized a LAFAYETTE (Continued from page new radio club in Alexandria and that so RADIO CORPORATION far he is the only licensed amateur in the WHOLESALE RADIO SERVICE CO..INC. a short between two other elements of club. Mr. Young also says that one of the members is working on a radio -controlled SALES OFFICES IM the tube. Rush New FREE Catalog No. 76 model airplane and promises us an article I NEW YORK If tube is not shorted, proceed as fol- and possibly a picture of it in the near I 100 Lam Anna. CHICAGO ! Nice going W9CLR !" SOI W. 'wawa BIN. lows for tube quality test. Throw Sw. future I NAME PLEASE PtIMT ATLANTA No. 6 to quality position, Sw. No. 3 up 765 PeCltree Street Reston. Man Owm, N. 7. and all other switches down. Set po- ADDRESS Ironic though it was, a tornado swept I Neeatt, N. I. Jamaica, L I. tentiometer to predetermined position through Anoka, Minnesota, and surrounding I and read tube quality on meter. If no towns right during the height of ARRL CITY...... STATE reading results Sw. No. 3 is not the Field Day activities, Sunday, June 13th. The LAFAYETTE RADIO CORPORATION Saturday Minneapolis Tribune carried an Dept. 2J9 100 Sixth Ave., New York, N. Y. cathode connection of the tube under article headed, "PRACTICE SET FOR CA- I - test. If such is the case move the LAMITY BY RADIO CLUB. Pretending PASTE COUPON ON PENNY POSTCARD HISTORY IN REVERSE Original Radio Script Suppressed by CBS!

COMPLETE IN THE The Story They Were Afraid To Broadcast OCTOBER ISSUE

Here's a story that will make you sit up and take notice. CBS refused to air it. The Federal Communications Commission suppressed all similar stories from the air. Presented now, for the first time, in its original form, exactly as written for broadcast, exactly as rejected by the Columbia Broadcasting System, because of its potential effect on the STORIES radio public, it has a dramatic tenseness that will hold you spellbound. NOW ON SALE AT ALL NEWSSTANDS

www.americanradiohistory.com 54 RADIO NEWS September, 1939

that Minneapolis has been struck by a ca- and a trailer into the house and yard of lamity such as an earthquake or flood, mem- W9CWI, at Anoka, -the very house where BRUSH bers of the Minneapolis Radio Club will dem- the permanent Disaster Committee had its onstrate Saturday and Sunday what they can first meeting a few weeks ago ! do to provide emergency communication." The St. Paul Club activities at Mounds Similar activity was carried on by the St. Park broke up on hearing of the disaster. BJ HEADPHONES Paul Radio Club resulting in them running W9PKO was dropped oft in St. Paul where: up a high score in the National Field Day he maintained valuable contact with W9IBD. operating mobile on 10 meters enroute to Anoka, assisted by W9VED. In Minneap -. Communications olis, W9NNO, W9OTE, W9ITQ, and N9BP type light- got together and started activities on 10 - and 80 meters. W9NNO rushed out to weight, durable the Minneapolis field clay location, but found aluminum case - the bunch had already left. N9BP and phones encased W9ITQ called on 80 meters and listened on 80 and 10 from about 5 p.m. on, as did in molded rubber W9HCC at Wayzata. W9MZL drove to jackets -good Anoka with his 10 meter mobile rig, but received zero cooperation from the local po- earseal. lice department, so he returned. It was apparent that a relay point was needed be- Write for your Brush Catalog today. tween W9IBD (assisted by W9VED in Anoka on 10 meters) and the Twin Cities. W9OTE and THE W9JFH jumped in to fill this gap and BRUSH DEVELOPMENT CO. set up a few miles this side of Anoka at 3312 Perkins Ave. Cleveland, Ohio the home of John Dick, Jr., where a gas driven power plant was placed at the dis- posal of our gang. Messages were relayed, W9IBD to W9OTE to W9NNO, with W9QKX later taking some of the load from W9NNO by receiving and delivering alternate messages. A large volume of highly valuable emergency traffic was handled from Anoka to Minneapolis. The storm was still close enough so that static was very bad on 10 meters but nothing compared to SO meters where everyone said it was the worst they had ever heard. With Ye Technical Ed at the RMA Show. the gain control open one -third, the noise was terrific, and to hear low power emer- Contest and almost completely tiring them- gency rigs more than a mile or so was a selves out when the tornado hit nearby to- feat. Stations in the cities on high power ward the end of the contest. Adding insult could scarcely hear each other. It is little to injury, the tornado heaped trees, a roof wonder that the Minneapolis Club station, moved to Anoka by W9TAT and W9YPT, was unable to get through, but these lads deserve plenty of credit for trying desper- IT'S LIKE HAYING ately. YOUR OWN BROAD- The St. Paul Radio Club portable station CASTING STATION MYSTIC MIKE v!JR"k" was ably handled by a gang of old timers, Nun This perfected Myetie Wireiess Outfit. with vane bee fre- mostly presidents and ex-presidents of the uuene y control. enables you to do your own broadcasting from any part COMPLETE SET, WITH of your hom, office or store WITHOUT the use of any inter- club, such as W9BHY, W9JIE, W9ZWW eleacting wires. Simply plus thin unit into any AC or DC MICROPHONE . d TUBE ctric socket, speak or play m into the microphone and and W9BBL. They got through with St. Yourvo the music. will be ' picked up by ANY adio ANYWHERE within the same building. Use it at home Paul Police escort and set up right in the for entertaining . . . office or store as a center of the disaster strip. N9YCR and nubile address system . . for rtrrditiona for r he:rronls , fact it c ..i sere you in hundreds of N9ZGT following later with the best antenna ways. order today. ,395 could not crash the police and National MONEY BACK GUARANTEE! FREE RETEIN NS POST avt" PAID Guard lines to get through to Anoka. Sched- MYSTIC MIKE CO., 362 Wooster Ave., Akron, Ohio ules had been arranged with W9ORA, and Tear out this ad, write your name and address in the margin, mail $3.95 and we will send outfit at once W9ITQ, N9BP and W9BQY were attempting also to make contact front the cities between about six and ten p.m., but listening to "Chinese Press" all this time was very tiresome and it seemed apparent no signals on 80 meters could get through the awful racket, so most of the gang in the THESE RELAYS cities went to bed just as the fun began. W9KYC, the St. Paul Club station, contacted N9BP in Minneapolis shortly before USED IN RADIO NEWS rr eleven p.in. and through horrible static pro- "All-Purpose ceeded to unload distress messages. At times each word would have to be sent many TRANSMITTER times, the signais were so down in the noise, while at other times fair speed was made with BP copying on the mill and his wife AND RECEIVER phoning the messages. One news report, The dependability, responsiveness, low power handled after urgent messages were off, con -' consumption and long life, characteristic of tained 960 words. When BP was asked hOw' Ward Leonard Relays, have prompted their use he managed to copy anything through the in means terrific static, he replied, "Well, it was tough, the Radio News model set. This that but I tried various combinations until I used no better Relays are obtainable. the combination of the selectivity of the SX -17, the noise silencer, a five meter vertical receiving antenna, and a heavy chin Ward Leonard Remote Control, s trap on the phones to keep the static from Antenna Changeover, Push -to-talk, blowing them off!" Perfect break -in was Safety, Time Delay, Overload, Under - used both ways, being on opposite ends of load and Keying Relays are described the 80 meter band, and all operators had in Circular 507B. Send for it. nothing but the highest praise for the others. At about 1 a.m. W9HCC copied parts of W9KYC's messages to N9BP on his Super - Pro, and when static and traffic let up at six a.m. W9BPK was worked, and the nets con- cluded at about 8 :30 a.m. While N9BP WARD LEONARD fought static fifteen hours after a day's work, those that had participated in the field day ELECTRIC COMPANY activities had not had much sleep the night before, so in a way were poorly prepared for 47 South Street, Mt. Vernon, N. Y. the emergency than ordinary, being all tired out practicing for an emergency !

www.americanradiohistory.com September, 1939 RADIO NEWS

Actually, the stricken area was narrow dred watt fore rig in half the space it would and wire communication was possible a few normally occupy. MIDWEST FACTORY-TO-YOU miles distant, but amateur radio was more W9KRK is making a bicycle trip from Chi- 20'_hANN/NERSARYSPEC/AL convenient and a time saver. The main point cago to the West Coast. We bet Ed doesn't is that the gang jumped in and did a swell ride a bike that far. He must have a trailer S.4vesróv Ta s®/ job under actual distress conditions and concealed somewhere along the route. He gained valuable experience not to be learned started out with another ham who returned in a dozen practice field clay contests-put- to Chicago within a few clays. ting up antennas where things are blown W9RLH acquired a 35T and intends to ADAPTATION flat; getting through police lines; operating increase his power to 225 Watts on 14 mc under martial law ; working with the Red fone within the next week. Be careful of Here's today's biggest radio that high voltage, Marshal. PUT THI51940 value - the 1940 TELEVI- 30 Cross, Boy Scout messengers, and National SION-ADAPTED Midwest DAYS Guard ; operating under most freaky weather W9TLO spent the nite with W9TB and -at sensationally low 14TUBE factory -to-you price. Exciting TRIAL conditions ; relaying short distances on 10 worked a lot of DX. Johnny hasn't been CHASSIS IN YOUR world-wide reception. Abso- meter phone with mobile rigs -these and having much hick at his own station. lute satisfaction guaranteed other conditions encountered have never be- W9ISR has just built a new speech am- PRESENT CABINET on money -back basis. Send EASY is IC postcard for FREE fore been even simulated in a field day con - plifier but isn't satisfied with the way it 1940 catalog. (User- agents TERMS test. working. He also installed a crystal micro- make easy extra money!) 4, phone. Tó$413 TRADE -IN ALLOWANCE V the July issue of QST, hams were MIDWEST RADIO CORPORATION warned not to pass up VS6BF as just an- SCOOP!! Dept.11 -A Cincinnati, Ohio u,her VS6 because that was the call used W9AM is at present planning a trip PASTE 1,I POSTCARD-OR wR/TE TODAY I by the Pang -Jin, a Chinese junk hound from around the world. He has a 150 -watt fone COUPON'ON Hong -Kong to the N. Y. W. F. and manned rig along on the one -hundred -twenty -seven CORPORATION1O I by a group of American youths. The Pang- schooner Starling. His antenna is 120 feet I Cincinnati, Ohio Name. I Jilt was scuttled by her crew in the Red Sea above the waterline and is 37 feet long with I Dept. uLa ISend me your new Address l on June 12 after the vibration of tow ropes simple capacity coupling. Ray sez he plans FREE talog, plate details 1 and a heavy sea opened seams in the junk to take in Pitcarin Island, the Fiji Islands I of your lofferl oc. while it was being towed by a Greek steamer. and all other points of interest along the dayTrial offer foe- Town State I tory- toyouunitole- -Agents Make Easy Extra Money. way. It is a pleasure trip and he intends to I leyr User I The Pang -Jin had sailed 10,000. miles, over ó b-ti I details. half its journey, without mishap from Janu- visit as many hams as possible. The regular LTÁAUË--ÌPÌ ffcr- Check here t for ary 5 until its Red Sea disaster. The balance marine call of the Starling is KMND and can of the trip was completed in the more ortho- be heard on 3105 kc, 6210 kc, and 1285 kc dox manner. Homer Merrill, LaPorte, In- and Roy is the regular operator. He will diana, was one of the crew. Who was, or hold schedules with \V9SZY in Chicago on were, the ops ? 14 mc fone. He will also have a WIO call The Coil You Want! Just a few days after my report on which has not been assigned as yet. This Whether it's an Iron Core High Q column hopes to print the call letters as soon High Cain I F. Re ncrative Iron W9OZZ ,JJoe wasw called ouout of his sacshack tto Coe I. F. Multirc Band. or any check a neighbor's BC set. He had just gone as they are issued. At present the Starling al used nun t s or broadcast receivers, inUIF' t ans- on the air and did not throw the switch is equipping at Brooklyn, N. Y., and will set miteers. -yaa i fin it in the soon as details are to. catalog of DX precision made coils. before leaving. When he returned the trans- sail as these attended DX Coils ore used by well known re- DX mitter had blown up. This climaxes a long W9FXT is back on 20 meters after a short ceiver manufacturers. engineers. t builders. et c sof COILS a and students thecolor ordeal of neighbor squawks ; most of them sojourn on ten. Guess we will hear lot of ,art at a goad re for spite rather than interference. Hope him as he is on a two weeks' vacation. coded DX coda a circuits easy to Leaeralaod.ading radio jobbers have DX Coils Joe can raise the necessary soon to make the W9CVK, Dave, had a telephone pole put get them for v at attractive up for his beam antenna and now he is get- prices -send 15c today with your required replacements. noose and receive Deluxe catalog Uunstrathi, II cama 9DHK is apparently celebrating the win- ting out all over the world with a much full size photos. ning of bucks 25 from the would-he- hole -in- louder signal. 30 DX Radio Products Co., 1575 -C Milwaukee Ave., Chicago, III, one pro by working DX. We eavesdropped on a recent chat with Ferdy at CT2BP. Yuh gotta admit 25 cookies is a nice inspiration.

WINDY BIT.L writes: but I have a Syl- \V5HMV has bn wrking lots of DX vania Tube Complement WHICH DO on 10 fone es 20 CW. Book." 511RR is an ex -W6 in Baton Rouge wid a YOU NEED? KW on 20 CW. He is a big DX man. WSHVI is an old ham (ex -W5 1921) wid a new call. He is at present on 40 CW. \V5GXO, McConlh. Miss., is rly a swell If you haven't the regular Com- guy. He and W5HMV are planning to visit plement Book, send for No. 1. All all the hangs in La. on a tour vy sn. WSFTRC has just bought a new rcvr. Look the contents of Sylvania's standard out DX. Tube Complement Book -plus a \V5ADJ has bn on 1925 KCS. fone wid a big, complete K\V for many yrs. es is known fern coast to 56 -page Supplement coast. giving the tube complements and i -f W5HMV has sure sold lots of Aug. R.N. peaks of all the new, recently -an- and give it plenty of adv. on the air. (My PiN. Hi!) nounced sets-bound right into the center of the regular book! 221 WIEWN tells this story of a neighbor pages, all told ... and it's yours for ham whose call he will not mention for obvious reasons. Jerry had a schedule only 25c. with VK4VD on 14 mc. fone. He called on schedule but could not hear the VK at all. His Or-if you already own a Sylvania telephone rang and the neighbor pain called and informed Jerry that VK4VD was calling Tube Complement Book -just send his head off and coining in fb. Next morn- for No. 2. The 1938 -39 Supplement ing the schedule worked out OK and Jerry will bring it completely up -to -date found that VK4VD had missed the schechile on the previous day and had not called at all. -and thus improve your servicing W3E \VN began to have doubts and to won- on new sets. The Supplement is 10e. der if his neighbor was using his imagination, so waiting till he knew this party was on the air and would he listening he made a "Fine! Then keep it blind call to ZU6P calling just as if he ex- up -to -date by RITMI THIS COL sure enough the adding pected to raise him and 1938 Dept. N, Hygrade Sylvania Corp. neighbor bit taking hook, line and sinker. the -39 Supple- Emporium, Pa. He called Jerry on the phone and said be ment!" Please send me the Complement Book could hear ZU6P fine business solid copy R7. (No. 1), complete with 1938 -39 Supple- Jerry is convinced that imagination will bring ment at 25c. in more DX than his receiver. Send me the 1938 -39 Supplement (No. WIDTJ has the right idea. His high volt- 2) at 10e. age power supplies are located in the basement of his home and the leads are brought Na nie upstairs in individual conduits covering the Address highly insulated wires. He uses oil im- mersed transformers and chokes and has both Set-Tested Radio Tubes City State manual and relay switching systems. He Also Makers of Hygrade Lamp Bulbs Name of Jobber says this allows him to build his eight hun-

www.americanradiohistory.com 56 RADIO NEWS September, 1939

three articles on "intermittents" by Solving the Intermittent "Tester" Bradley. Next month, the (Continued from page 27) author invites you to go with him on a call. If you are an oldtimer, follow rubber insulation was faulty; cracked him step by step for comparison; if and crumbled at at least one point you are a beginner, it will be an ex- bend dur- cellent opportunity for you to learn because of either too sharp a how veteran handles ing shipment or from being dried out a his equipment made the and his customers under the most try- with age. Dirt and moisture conditions. set erratic. While there are many ing -ED.] similar cables in use, failures in them -El- are infrequent; for this reason the repairman often forgets to consider Conquer the Code them as a source of trouble. Flex the (Continued from page 25) loom slowly, and -if trouble is found -don't be satisfied to run jumpers to will concern you before then is when take the place of the affected leads. you estimate your code speed. Replace the entire loom. An annoying A "word," in radio code, is the job, but necessary for the protection of amount of intelligence that can be ex- shop reputation. pressed in 24 keying cycles. "Worn," Coupling condensers should always on the diagram, happens to require ex- be viewed with suspicion. It has been actly that amount. Words of various my experience that they get more at- code -and letter-length are, of course . . BRINGING A CARGO OF tention than they deserve because they mixed in transmission without regard are checked first. Failures in r -f or to the actual word length, but their EXTRA PROFITS from the filter condensers are as common, but average code length has been deter- ARCTURUS EQUIPMENT DEAL! the coupling condenser seems to be in mined at 24 cycles of keying, or 48 time such a sinister circuit position that the units. The computation involves an Signing up for an Arcturus Equip- repairman is quick to suspect it. Give elaborate consideration of word lengths ment Deal means Full Speed Ahead it prior examination if you so wish - compared with the frequency with to better tube business! Arcturus that's better than neglecting the unit. which they appear; and of the code Tube quality, the completeness of obvious "intermittents," how- lengths of letters, compared with the the Arcturus line and the sales -pull- The most ing Arcturus Dealer Helps will help ever, are never the most troublesome number of times they are used. Don't you increase your regular business - ones! bother to check the figures unless you bring new customers into your store A peculiar inversion of heat failure anticipate being wrecked alone on a -pave the way to a more profitable occurred at a call I answered two desert island, or are unoccupied until tube and service business. weeks after the set had been sold. The after Europe pays its war debts. Then too, by taking advantage of complaint was that the customer had If the word "worn" is sent in three the Arcturus Equipment Deal, you house since can equip your shop with the newest, trouble heating his ever seconds, the rate will be 20 words per most modern store and testing equip - the set had been installed! After all, minute (w.p.m.). The ratio between ment-at almost no cost to yowl No a serviceman gets a lot of queer keying speed (in cycles per second) and other Equipment Deal on the market squawks- "It plays too slow" is typ- w.p.m. is two to five. The rate in c.p.s., today gives you such liberal, easy ical-so I spent the time on my first then, would be eight. At this keying terms -Lower Down Pay- call pacifying him in order to cinch the speed, each dot cycle would last an ments, Standard Tube sale. The violence of the second of a second; each two -cycle Prices, Low Tube Re- set eighth quirements, the Latest call, though, put me to work in ear- dash, a quarter second. At ten w.p.m., Models of high - nest. They had been listening, they at a keying speed of four cycles, the quality equipment, told me, to the set while they wore dot cycles would be a quarter second a wide selection of fur coats! long, and the two dash -cycles, a half valuable, useful Naturally, I found the trouble -but second. "Worn," at this speed, would items that you need I am ashamed to confess the time it be sent in exactly six seconds. every day. took. Warm air had been rising from The five BSL proportions on the dia- NEW EQUIPMENT the console past a furnace -regulating gram, of course, hold good at any key- NOW AVAILABLE! thermostat. It was a heat failure ing speed. Estimating your speed by The recently an- which didn't affect set performance! means of BSL will give you more ac- nounced models of fa- While electrical failures play an im- curate results than by the usual mous makes of store and shop equipment portant part in the problem which "counting of letters per minute and di- are now included in the faces a serviceman tackling an "inter- Arcturus Deal! Take viding by five." The BSL method is time NOW to mail the mittent," of more importance is his based upon the code lengths being sent, coupon below for com- of the customer before, dur- plete details about the treatment while the other considers all letters of liberal Arcturus Plan. ing, and after the work is done. Cus- equal length. With the latter method, Get started now to get are unusually cynical and sus- your share of the EXTRA tomers to illustrate with an extreme, a count PROFITS Arcturus picious when they order work on a of five -letter groups of e's would indi- dealers enjoy. fading set, and so there is the problem cate a much higher speed than corre- of good -will to contend with. Unfor- sponding groups of o's, even when the tunately, smoke seldom accompanies actual keying speed was the same in an "intermittent," and the customer both cases. While e and o are both CTIUJRUS has to be prepared for a price which single letters, e requires two cycles; o, difficult pro- N-22 will cover the unusually seven. So estimate your code speed by ARCTURUS RADIO TUBE CO., Newark, N. J. cedure the remedy involves. the actual BSL total; when you are Without cost or obligation, send my copy of the The repairman must break the set tested, it will be with automatic equip- ARCTURUS DEALER HELPS Folder and details of the ARCTURUS EQUIPMENT DEAL. down, repair it following difficult ment which is calibrated in keying - methods of test, and insure himself cycle rate, not letter -rate. Name against ill -will by checking against fu- The application of these rhythmic Street ture fades from any source. These re- fundamentals will be valuable in terms City State quirements are not impossible, but of circuit operation. A good fist, aside I a serviceman. My I am a dealer am they're plenty tough! from its beautiful sound, has another jobber is intrinsic worth. As one of the most L For your convenience this coupon can he pasted on a penny postcard j [This is the second of a series of important factors in signaling is the

www.americanradiohistory.com September, 1939 RADIO NEWS 57 optimum contrast between the two car- world is enhanced because his daily ac- rier conditions, good sending -to take tivity enables him to check or estab- advantage of the available contrast- lish the practical performance of that is fully as important as good equip- which he studied in theory. What's th;s ment. Under adverse conditions of The fact that many different types of static and fading, the maximum speed defects are productive of the same final picture and distance is possible only when the effect has in the past greatly interfered BSL proportions are kept. For in- with maximum comprehensive inter- stance, if the sending is "chirpy," or got to do light, the dot "mark" does not occupy pretation of theory in practice. In as much of the dot -cycle as it should, fact, the limited scope of service oper- with loo- and hence contrast between the two ation in the past has hindered full rec- conditions is lost. If sending is ognition of the actual function of the "heavy," the dot "mark" equals more numerous components in a radio re- than half the keying cycle. The best ceiving system. Experience proves p ;IA efficiency between transmitter and re- that the consequences of the limited ceiver is maintained by dividing the scope of service operation in the past cycle into equal parts of "mark" and combined with limited knowledge of "space "; any divergence from this pro- theory has interfered with the com- portion results in either a lower speed plete understanding of such an impor- or a reduced range. A good fist, then, tant matter as the distribution of the is as important as new tubes or in- signal in a radio receiving system. creased power. Cultivate the ideal To the above it is possible to add the sending proportions and put your lack of understanding of the function ...When babies start money in the bank. of many of the components used in the crying it's oftentimes Quite frequently I am asked by be- receiver -components which, while as- pretty hard to locate ginners how the painful code -learning sociated with the signal, were located the source of their distress. And in a interval may be shortened or amelio- external of the usual coupling units - radio receiver the story is pretty much rated. There is no shortcut or anal- and when defective, were as a rule, the same ... Unless you own a Rider gesic. During the war, code students pregnant with complications and pro- Chanalyst. were told to wear live earphones while ductive of defects extremely difficult You know from experience that lo- they were asleep. The theory was that to find. Modern communication system de- cating the defect in a radio receiver they would absorb instruction more time consum- rapidly by subconscious osmosis. It sign differs radically from what has is the major problem -a might have been based on good psy- been used in the past, although it is ing and costly operation. And the more chology, but I remember that my prob- true that basically all radio receivers complicated the receiver, the greater lem was to keep the buzzing out of my are alike. But components considered the time spent time that means money ears at night after I practised code vital and necessary in the past, in order to you and for which you can't collect. during the day. to avoid certain effects, now are delib- The Rider Chanalyst solves this You will suffer more in raising your erately omitted so as to create this so- problem. With this modern service in- speed from 0 to 10 w.p.m. than from called undesired effect, for what bene- strument you can work rapidly -ac- 10 to 50. Once you pass 10, you feel ficial action it has upon the perform- curately- profitably -on any one of the code, sensing its sequence and pro- ance of the modern system with respect now in to the signal. We refer to the by -pass the 40 million radio receivers portion rather than analyzing each most basic ele- word as a number of signals. Perhaps condenser, regeneration, and degener- use. Founded upon the the best system is the one suggested ation. ment in communication -the signal by a professional friend of mine: The idea of locating a defect by itself -the simplest and most compli- "Make your ears positive, your hands tracing the signal provides the means cated receivers are serviced with equal negative, and short -circuit your brain." of studying the action of the various ease -quickly! It is a good idea to "short- circuit components, since all of the compo- You can trace the signal -hear the your brain" when you listen to music nents are associated with the signal. signal -and, if you connect your Os- -in this condition you get the great- The ability to trace the signal affords cillograph to the Rider Chan alys t, you est emotional wallop. It's the best way the opportunity of identifying the zone can see the signal, any place in the to listen to code, too; for code has of influence of the various defects and The Rider Chanalyst is a varying pitch, changing volume, and a in that way establishing the zone of receiver. basic rhythm. A good brass -pounder influence of the components. Such in- proved service instrument. Ask the puts music on the air. formation is extremely instructive be- man who has used one. 30 cause it provides a greater insight to Listen to the Magic Key, every Monday 8:30 to 9:30 P.M., Bibliography the role of the various components. It E.D.S.T., on NBC Blue Network "Time Division Mutilplex in Radio- is by Over 335 million RCA Radio Tubes have been purchased studying the effect of a repair by radio users ... in tubes, as in parts and test equipment, telegraphic Practise," by J. L. Calla- that we learn the actual function of it pays to go RCA All the Way. han, R. E. Mathes, and A. Kahn; Proc., the part. I.R.E., January, 1938. Yes sir, the process of signal tracing, [An excellent source of information whether you listen to the signal, check for those interested in a more technical the level or its character, as a means treatment of modern commercial code of establishing the defect affords tre- operation. -ED.] mendous advantages in connection with study and further familiarity with ra- As I See It! dio theory. . . . And to that we will add, by sticking our neck out, that it 9) (Continued from page will become the universal method of trouble localization. customary for many years to take cer- The Rider Ckanalyst... Stock tain operations to be found in a radio A Few Suggestions to Manufacturers and No. 162, 8107.50 net -It huill pay for itself by receiver as a matter of fact -to judge Jobbers saving your time- upping your profits! the performance of certain sections of the usual abundance of a system by the final effect. Consider- ALTHOUGHcomment has ceased, the need for ing the subject from the educational certain information still exists ' in the A74 viewpoint only, elevation of the techni- radio servicing field and those manu- .44 cal level of the serviceman of the facturers who cater to the industry RCA Manufacturing Co., Inc., Camden. N. J. can A Service of Radio CorpgratiOri of America;.

www.americanradiohistory.com 58 RADIO NEWS September, 1939

well afford to give some thought to the the financial possibilities of the part- R TRIPLE VALUE subject. The same applies to parts ners. jobbers who aim to serve their custom- Do These Stories Have a Moral? TUBE TESTER ers. THE running board on our car was A need exists for a recapitulation of damaged when another car side- ONLY radio receiver owners divided into ter- swiped us. We took the car to the ritories with a breakdown to show the .111111111,,k service station and we were "sold a bill possible customers in various parts of of goods" to have the running board $22.00 the country, with a summary in ac- replaced. It was done and later on we NET cordance with the population of towns. discovered that the running board In other words, an average of receivers could have been repaired, but the man in use with respect to population will tried to sell a new one, because it 1. afford data concerning the possible Exclusive - meant more business, and he succeeded. Handy, Hinged customers a service shop can draw on Was he taking unfair advantage or was Post Card in any one community. This is of great Reference he a salesman ? Tube Chart value to the service shop owner by en- Of course, we were angry when we abling him to decide if his present op- discovered that it could have been re- 2. erating area is sufficient -or if he has paired, and when we again approached MODEL 1213 - to expand -and if such expansion is the individual he explained the situa- Filament Voltages respect to cost and added from I to 110 justified with tion by stating that the car was in ex- business. cellent shape and a repaired running 3. MODEL 1213 contains sock- The jobber who wishes to serve his board was not compatible with the re- RED DOT Life- ets to test all present -day customers best can do so by giving in- time Guaranteed tubes. including Loctals, the mainder of the car. He could not guar- Meter new Bantam Jr., the High formation relative to the choice of lo- -The Sensa- Voltage s e r i e s recently an- antee that the repaired running board tion of the Season nounced ( i n c l u d i n g the cations in different communities. Many 117Z6G), Single End types, all would not develop a rattle but he could regular octal and Non -Octal, Magic Eye tubes, Pilot jobbers are selling nationally known new one. He compared Lamps, Ballast tubes, Plain Glass, Spray Shield tubes guarantee the and Gaseous Rectifiers. brands of radio receivers and it is very the cost of repair with the cost of the Triplett Tube Testers will not de- activate 1.4 volt or other type tubes. Approved BMA circuit. possible that such receivers can be sold new installation. Naturally the latter Exclusive New Triplett chart is made to stay in tester through well -located radio service cover for quick reference or to hang on wall. Since was more expensive, but in the final pages are post card size-new tube readings will be shops. In fact, it is highly probable mailed to keep chart always up to date. analysis lie convinced us that what we Neon short test and separate line volts control meter. that some such modification of service had done was best for our own interest. Model 1213 in new Black Electro Enamel Suede Fin- station activity is vital to the welfare ished case . complete with Leather Strap Handle We used an anti -freeze fluid in the and Snap -on Metal Cover to match. of the service industry. If such is the Dealer Net Price ... $22.00. car last year and the year before. As WRITE FOR INFORMATION case, then it is high time that service- the spring of 1939 approached we had 159 Harmon Av. men gave some thought to activities the radiator drained and flushed. The which would be founded upon efforts summer arrived and the car motor TRIPLETT ELECTRICAL INSTRUMENT CO. more direct than "word by mouth" overheated. We went to our favorite Bluffton, Ohio advertising. service station and they suggested that The average successful jobber is suc- it would be best to remove the radiator cessful because of certain activities, entirely, boil it out properly and in selling, displays, advertising, location, that way accomplish best results. It etc. In the past, the radio service in- was done. For a month things were dustry has waited for instruction from fine, then one day the family buggy the parts manufacturers. Maybe the again looked like an 1895 locomotive parts jobbers can serve equally well, running away from the Indians. Steam if not better in this advisory capacity. was coming out of every hole in the Maybe some of the service meetings hood. run by jobbers in conjunction with Back to the service station. Why of some manufacturer or without the course they would correct matters support of a parts manufacturer can without any charge. Didn't they be devoted to a discussion of such items charge for the first repair ?-therefore as have been mentioned herein. Maybe they could not charge for the work some of the catalogs furnished by parts to be done this time. That made us Allied NOW OFFERS jobbers can contain instruction mate- very happy and we went back to the 3 COMPLETE LINES! rial along such lines. office. That same day they called up The service industry is not too proud had discovered scale Now, the greatest P. A. values in ALLIED'S and said that they history! ALLIED'S new 1940 Catalog shows to accept help. It needs help and pos- in the motor and in the water pump. 14 new Sound systems, 6 to 65 watts, port- sibly a revision of its activities. Maybe Also water pump had been dis- able, mobile, and permanent. 3 complete the new lines- "Economy ", "Standard," and the ideas which have been entertained mantled before and had been cleaned, "De Luxe" -new styling, new performance, in the past are not of the best and no doubt had new features! New Universal 20 -watt AC- so that the new scale is DC - system with built -in phono -for 110 some change required. Who can come from the motor, therefore there volts, AC-DC, battery, or 32 volt use -new tell? All that is known is that the of portable P. A. design, etc. Also new Knight would be a slight charge several microphones, latest recording equipment, volume of technical service business dollars for taking the water pump discs, all types of P. A. accessories. Get the full details of ALLIED'S new Time Pay- coming into the average service shop apart and for washing the motor. Well ment Plan (lowest carrying charges, easiest is not sufficient to carry the shop. they sold us on the idea. What was terms). We mentioned several months ago supposed to be free, turned out to be SEND COUPON FOR that we felt service activity must em- a $6.40 job. NEW FREE brace appliances. It seems that this is Is there anything wrong with this 1940 CATALOG correct because a number of service- picture ? Before you answer just re- men have made connections with elec- member that the service station is the ALLIED Radio Corp. trical shops -in fact have gone into own service shop Dept. 1 -A1 -0, manufacturer's -re- 833 W. Jackson Blvd., partnership with electricians and find liable and with an excellent reputa- Chicago, Illinois. it advantageous. The electrician part- tion. They are not really taking an Send full details on new Knight Sound Systems. ner drums up trade for the service part advantage. They are selling! They Send your new FREE 1940 Radio Supply Catalog. of the business and the serviceman are converting what would be a loss Name drums up trade for the electrician. into, if not a profit, at least an even Address Both, also, try to get as much set busi- break. ness as possible these people dishon- City State -small sets of course - Would you call or at least sets priced at figures within est? I would not! This leads us to

www.americanradiohistory.com September, 1939 RADIO NEWS 59 ask the question, "Are radio servicemen too honest ?" There are moments HQ-120_X(ey when we feel that they are entirely too honest. Not that we advocate SENS4`IITI'Y "gypping," but some steps must be taken to return a reasonable income - and a profitable income. As we write these lines we are gaz- NOTS1E9.7rEL ing at a price list sent out by a radio service shop in Windsor, Ontario, Can- ada. Replacing one by -pass condenser up to 1. mfd, inclusive of pick -up and delivery, is $4.25. Replacing a triple 8 mfd filter block, inclusive of pick-up and delivery is $7.50. Replacing a single resistor up to 10 watts, inclusive of pick -up and delivery is $4.25. Replac- ing a volume control with similar pickup and delivery arrangement is $5.00 and if it is a dual unit, the cost is $6.00. HIGH SENSITIVITY and low noise \\\ Prices such as these would be con- \ \ \\ \ level have made the "HQ- 120 -X" ,....Q\c.\\ radio's outstanding low priced receiver. sidered exorbitant in these United \ The feature, the States. Particularly so, when addi- "á\\\\\ variable selectivity permits operator to tune out strong stations and tional resistors or condensers are pull in the weak distant stations that would charged for at list, but we venture to Maybe you don't need million normally be buried in QRM. Remember, say that the Machin Bros., the organi- volt resistors . yet it is the weak stations are there, but it requires zation who forwarded this price list worth knowing that the same a sensitive and selective receiver to get famous IRC Metallized re- them. If you want the best in high fre- are making money by selling their sistance principle, best known service. Of course these prices in- quency performance, use an "HQ- 120 -X." in the little 1/2 -, 1- and 2 -watt Send for booklet! clude a check -up and realignment if Insulated Resistors for radio found necessary, and lest you get some use, has now made possible HAMMARLUND MFG. CO., Ine. RN-10 peculiar ideas all receivers DO NOT outstanding advances in both 424 W. 33 St., N. Y. City voltage and ultra high Send 16 -page Booklet. require alignment, providing that you high can check the condition of alignment. frequency resistors for ad- Name Did you ever analyze the operations vanced scientific research pur- Address poses. of business in general ? The business City State 10.000 ohms at 1/2 watt -100,000 must make a profit otherwise it can- volts at 150 watts -1,000 megohms not survive and no one invests money at 150 volts ... regardless of the need, the IRC Metallized element HammARLunD in business because they wish to go can supply them all, dependably economically. Canadian Office: 41 West Ave. No., Hamilton, Ont. broke. A department store, the most and t reliable department store has "lead- "Metallized" Resistors are made under IRC patents in eight coun- ers," low priced items, to attract you tries. The Metallized type of element is the most adaptable yet pro - to the store and when you are there duced.No otherresistancematerial you buy many items which are not so holds such an outstanding record Cps low priced. They call it merchandis- of past success. None holds such broad possibilities ing. When you find some standard, for future develop- .ißt. 6:ctnbin. ment. Whatever nationally advertised product offered your need -in- at a low price and you are sold a spe- sist on the MORE ABOUT THE cially packed store brand product, that bestl is known as merchandising. Would it DIALOMATIC not be considered merchandising to sell something which the receiver installation can use, although its use is not M08ILE RIG imperative, but advantageous, each A detailed explanation of the remote- time a call is made? We don't know, ly controlled mobile unit, and instruc- we are asking you. We know that tions on how to build it. Any amateur according to the interpretations placed can build this three band transmitter- upon many acts in general business, receiver that operates from a telephone dial. Any band in one second, such selling would most certainly not any frequency in each band. Don't be classified as dishonest. It would be miss the next issue of merchandising! If check -up of the receiver on a repeat call shows that certain operations RADIO NEWS can be effected to the advantage of the -On Sale September 8 customer, although perhaps not vital to the operation of the receiver, it tt INSULATED RADIO NEWS, Dept. RN 103 would be good merchandising to sell that improvement. Naturally the re- S. St., Illinois 608 Dearborn Chicago, would be free. Don't you Enclosed find $1.00. Send me RADIO NEWS peat call for one year (12 issues) and rush me a copy think that it would be good merchan- of the 1939 RADIO & TELEVISION DATA BOOK dising ? It's being done day in and without charge. (If renewal, check here . If you are a serviceman, please check here .) day out in every other form of maintenance and the public is perfectly con- Name tent. After is done, one all said and thing TYPE BT is certain -serviceman income must be Address increased. Merchandising is a good INTERNATIONAL RESISTANCE CO way to accomplish this. 401 N. Broad St., Philo., Po. City State

www.americanradiohistory.com 60 RADIO NEWS September, 1939

RADIO PHYSICS COURSE Serviceman's Experiences by Alfred A. Ghirardi (Continued from page 36) MAN AT WORK! (Continued from August issue) going out to Wet Lake and pick up How the energy is received: The that big p -a job. If you're scared to purpose of this chapter is not to pre- snap the lights on this evening, leave sent a complete description of modern them off until I get back!" sensitive receiving sets, but simply to Maybe, I thought as I drove away in set before the student an elementary the truck, those remarks were a bit conception of how the radio energy is inconsiderate -but my partner gets received at the receiving station and after me for the most outlandish what must be done to it to convert it things, and sometimes I can't help los- most efficiently into a form that we ing my temper. are able to hear. While it is true that I pulled in with the amplifier at receivers with crystal detectors are sundown. Al had gone for supper, and used very little at the present time, had left the window lights out. Sar- .'------. the author has found that the student casm, eh ? I opened the shop, turned - can gain a great deal of fundamental the lights on, and sat down to simmer. theory concerning radio receivers by Opporchancity knocks but once! Here's how you can make more money studying a simple crystal receiver at Here was the ideal time to show Al by increasing your technical ability first. By doing this, most of the I could run the shop, and both our theory of tuning and detector action jobs, all by myself. I hooked up the . It takes ability to earn big money in Radio. New developments, new equipment, demand may be developed simply, without the equipment on the bench, wired in a men with modern technical training. The man necessity for introducing any of the shop output transformer and speaker who does not keep pace with radio advancement is deadlocking his own future. You can complications brought in by vacuum with a few lengths of twisted pair, and develop your ability. Tonight hundreds of men tubes. After these receiver fundamen- had just begun to test when in walked throughout the world are devoting their spare time to CREI training . "tomorrow" they tals are firmly grasped, the study of Al. will be equipped to take ad- vacuum tube receivers can be pur- "What's this ?" he asked, "trying to vantage of the opportunities Just off that await trained men in I sued with ease. steal my job ? Get out of here -I'll Radio and Television fields. If the press. It should be remembered that these take things over!" you have the ambition, CREI can supply the training. It fields go through every non -metallic He walked between me and the am- costs nothing to get the facts. body which may be in their path. If plifier, and pushed me to the middle Write today for details in FREE BOOKLET. now, a conductor of any kind is erected of the room. What happened .then is in their path, as for example the aerial still something of a mystery. He must CAPITOL RADIO wire, a voltage will be induced in it by have brushed against those frazzled Engineering Institute the rapidly passing fields. In the case output leads with his arm while he Dept. RN -9 3224 -16th St.,N.W. of the reception of very high- frequency had the other hand on the chassis. Washington, D. C. fields (short wave work), the antenna Anyway, he doubled up quickly, like may consist merely of a wire, but with he'd been hit in the stomach with a the receiving apparatus at the center line drive, and landed heavily at my instead of the generator. This is called feet. I looked at him dumbly for a a "doublet" antenna. In order to be moment, and then jumped for the efficient for broadcast band reception, telephone. the length of such a doublet would My hands were shaking so much I have to be too long to be practical. couldn't dial properly. I sat back to usually employed con- with 061.ad9 Home - The antenna regain composure, and hunted in the sists of a flat -top aerial portion which wrong directory for "hospitals." I Training Course is connected to the radio receiver by thought of calling the operator, but the lead -in wire. The other side of when I grabbed the handset I was so COMPLETE the receiver circuit is connected to the nervous it slipped from my hand, IN/ BIG BOOK ground either by connecting it to a struck the floor; broke cleanly in two. F I t yourself at home, in spare time. for a good-paying metal plate buried in the ground, or Then I thought maybe he was fool- radio job. You'll learn all hat's really ential ' pipe which Ghirardi's orld- famous self- connecting it to a water ing, to scare me; I took a long look at course complete the pipe trainingthis big 972 - page volume serves the same purpose, since him. He didn't move, and his face including Television, S o u n d,- Cathode - Ray Tubes, as well runs through the ground for a consid- was the wrong color for fooling. He thas Radio and Electricity. All e basic theory is here, erable distance and therefore makes lying on clearly explained, fully illus- seemed so strangely different trated, e to ras ! electrical contact with it. It is evident the floor than he did while he argued Quicyk Way Learn the combined aerial and the lead - Ghirardi's simplified method that with me! I got some water and threw is the quickest w a y to get in one of the conden- your radio education. No background" wires form plate it on his face, but it didn't help. I Ludy-no ninth. no "headaches." Easy as A.B.C.! ser and the earth and ground wire slapped his wrists, like I saw once in 36 Volumes in 1 -972 pp. -508 Illus. form the other. The distributed ca- the movies -but that didn't help. 1. Radio Broadcasting ystem. 2. Sound, Speech, Music. 3. Electron The y; Elec. Current. 4. Elec. pacity action thus set up is illustrated By this time, I was nearly frantic Units; Ohm's Law: Resistance. 5. Elec. Circuits; Bat- teries. 6. Magnetism. 7. Electro- magnetism. 8. Elec- by the small condensers shown dis- to leave him alone while I tromagnetic Induction. 9. Inductance. 10. Capacitance; -afraid Condensers. 11. A.C. Circuits. 12. Filters. 13. Measur- tributed at intervals between the knowing ing- Instruments. 14. Radio Waves. 15. Broadcasting. ran out for help, but not 16. Receiving. 17. Vacuum Tube Principles. 18. ground and these parts in this illustra- Vacuun, Tube Characteristics. 19. Vacuum Tube Con- what to do for him if I stayed. I ran struction. 20. Vacuum Tube Detector nd Amplifier Action. 21. Radio Frequency Amplification. 22. tion. The capacitance of a simple re- back and forth uselessly a few times, Superhets." 23. R.F. Amplifiers: Tuning Coils. 24. Audio .Amplifiers. 25. Speakers. 26. Battery ceiving antenna of the type shown and wondering where to find out what to Operated Receivers. 27. Power - Supply Units. 28. Elec. Aircraft Radio. used for radio broadcasting reception, yelled, like a fellow does 30 Phonot Pickups; Sound Systems. 31. Short-Wave. do; I even 32. Photoelectric ' Cells; Cathode - Ray Tubes. 33. be as 150 to 300 - Television. 34. Antennas and Grounds. 35. Testing; may as much micro when a nightmare gets too tough. Servicing. 36. Sound Films. . . . 856 Review Ques- tions! microfarads (200 mmfd. being a good Finally, I knelt by his shoulders, raised USE IT 5 DAYS -OUR RISK! average). The inductance of the wire his head in my arm, and fanned him Get it! - Read It! - Use it! If t completely satisfied, return the book t thin 5 days and get may be as much as 50 to 100 micro - Gosh, but I wished y back. You risk nothing-hot you'll with some papers. lose your great opportunity, unless you TRY IT! henries and the total resistance may I= I could help him! It was pitiful--his E. BM MAIL COUPON TODAY! Im lee ma 25 100 RADIO & TECHNICAL PUBLISHING CO. , be anywhere from to ohms, de- relying on me to help him, and me not 45 Aster Place, New York. Dept. RN -99. Here is my $4. Please send RADIO PHYSICS pending on the length of the wires, how. I called to him bro- I COURSE postpaid, with money -back guarantee. knowing NAME resistance of the ground contact, etc. kenly, remembering all we'd been IADDRESS [To CITY...... STATE. be continued next month] through together. O Send free descriptive literature. .11 30 In spite of the wrong things I had

www.americanradiohistory.com September, 1939 RADIO NEWS 61

done trying to bring him to, Al moved SERVICEMEN AMATEURS rapidly. He DEALERS No Temperature or Climate Troubles a little. I fanned more opened his eyes, spit out some water, P. A. SPECIALISTS Indoors or Out with the NEW and his face ran through the spectrum BUILDERS to pink. The TURNER "99" DYNAMIC "At last!" I shouted happily, "good /40 ., MICROPHONE old Al! Speak to me!" He groaned some words I couldn't Built to "take it." Mechan- am cArA ical shock won't disturb the understand. TURNER "99." It's not af- "What was that, again ?" I asked, fected by dampness or salt closer. air. Gives you crisp, clear bending Ht ING reproduction without low fre- "Landlord, what weak walls you /D 91410E5 quency boom. Trustworthy have," he murmured. WES range, 40 -9000 cycles. High Level 54 DB. Cable connector "Forgive me, Al, for acting and talk- PAGES! allows quick, easy cable ing the way I did this afternoon-I've 204 change. Saddle is adjustable. learned my lesson -believe me, I'll The Bieff.eat impea s. all pil antes. 2 50ÿ study first aid until I can bring a rock Professional ap- M O D E L "99" excevGavegy pearance. 9 LIST LOOKS EXPEN- to life -I didn't know -" SIVE YET IS HIGH IMPEDANCE LOW -PRICED When his eyes came into focus, the Write NOW for Full Details Beautifully finished first thing he saw was the pamphlet I Never before a Radio in durable gun- was fanning him with. He grabbed it book like this! 204 metal. Definitely pages in 5 complete The TURNER CO. semi - directional, as Hardy would from reducing feed -back disgustedly, sections, for Deal- CEDAR RAPIDS, IOWA, U.S.A. problems. 25 Ft. Laurel, and handed it back to me. ers, Service Men, cable included. Amateurs, Sound "Here," he said weakly, "take this Specialists and Builders-plus a home with you, and let me walk back big new Bargain Section where prices meet their Waterloo! from the Valley of the Shadow alone!" Sets, kits, P. A., Ham gear, EVERYTHING IN' RADIO! I took my arm away; he sighed, closed testers, the most complete parts listing ever eyes, laid his head back re- published-all arranged for quick reference, all I COMPLETE SOURCE FOR YOUR RADIO NEEDS his and at lowest prices. Your FREE copy is ready. Om tukuunse stock of radio end .plies enables you ,thé your entire signedly on the floor. cads o order. You o di lad ell your Net,onelly Known Fevotes tn th,z bq book I held the impromptu fan up to the New SETS! .vh,ch i, FREE for the esk,nq. Practically e 60 new Knight models, 4 to order d the e dey ved. light and saw it was titled "Resuscita- 12 tubes, with all the newest WRITE FOR BIG NEW CATALOG features "Air Magnet," tion Following Electrical Shock." Gem -loid- Dials, etc. -re- BURSTEIN-APPLEBEE CO. It's a swell little book, and I know corder - phono - radio com- 1 1012 -14 McGee St. n Kensas City, Mo. bination, -tube electric it by heart now. 30 phonographs, 5, 7, 11 -tube phono -radios all sensational radio values!- The Video Reporter TRANSFORMERS NewPUBLICADDRESS! For Radio and Television Applications (Continued from page 44) 3 complete new lines - Specialists i Wee roduction of "Economy," "Standard" tranformercmes s A,nd solicits your innumy. and "De Luxe" - 14 new anufacturers of transformer spa ialties such 6 new ne the the use of a projection -type cathode -ray systems, to 65 watts, ACME VOLTROL tube. The intensely bright image on the styling and performance - y ln toc. new "mikes," latest record- enrol from 0 toe 130 volts.` Panel mountedoun typo screen end of the tube is adequately enlarged ing equipment! Investigate illustrated 012.00. Write for Bulletin. our new Time Payment by a lens arrangement. The projector, when Plan. THE ACME ELECTRIC & MANUFACTURING CO. used in theatres, necessitates the ripping out 27 Water Street Cuba, N. Y. of about fifteen seats some twenty -eight feet from the screen. The unit is somewhat New KITS! bulky due to the fact that all equipment is in Dozens of new kits of all a types -new Television Kit, duplicate to prevent any lull in perform- new Beginner's 1, 2, and 3 JOIN OUR RECORD CLUB ance due to the failure of any part. All con- Tube Kits, new Wireless Send for your copy of this big 500 page trols are mounted on the projector so that Phono and 1 % Volt Kits - Record Catalog S. Encyclopedia. Contain( and Diagrams and Projects lists of thousands of famous records and mu. the entire unit can be manipulated by a sin- for Building 100 Kits. Write ical daca on pronounciations and dates of gle operator. now for FREE Parts Lists composers; 255 plus los for mailing. (scamps Approximately 50,000 volts are required to or coin) It also enrolls you in our Record Club. We carry a large selection of records operate the projection tube and a special rec- New TESTERS! from 10.' up. Write today tifier unit is employed. This power unit, too, New television - equipment is ill duplicate and is in a caged compart- testers, Rider Volt -Ohmyst, 302 Nerv York Ciry new 110 -volt tube testers, MODELL'S ment some distance from the projector itself. latest Analyzers, Oscillo- Ian C. Javal, Baird's commercial director, graphs, Set Testers, Meters, etc.-all leading lines at who supervised the New York demonstra- lowest prices. The most tion, declared that his organization would complete lines ever offered. soon be in the market with made -in- U.S.A. of a non- projection type. home television sets New HAM GEAR! Largest Ham Catalog, ever-all latest receivers Money back guarantee 1.4 V. Ham Revr. new Skyrider "Defiant," A REAL Photo Enlarger that does fine COPIES etc., Rotary Beam equip- and hFocusesasa Contact Printer Retouching (Continued from page 24) ment, Tel °vision Equip- Table. Interesting circular free. Only *5.9 4 ment, all standard lines - complete, Lens Included. at lowest [rices. New Time IDEAL 148 West 23rd St., New York City Payment Plan- lowest car- -H, occasionally in order to obtain the charge, easiest terms! proper "tracking" between the two r.f. rying circuits. Big New PARTS SECTION! More than 55,000 radio Items -the bigger. Having progressed thus far, most Radio Supply listing ever! Hundreds of new undoubtedly will wish to know tube types- duplicate parts, batteries, aerials, readers tooLs, books, etc. And a big new Bargain Sec- just what results may be expected tion. For Fastest Service, Highest Quality, Lowest Prices, look to ALLIED always. For RADIOp from the little receiver. At the au- biggest values, see ALLIED'S new 1940 TELEVISION thor's home in West Virginia (which Catalog today! No matter where you are or what you do. PhefedfedTnnuri.fa National has a complete t,,,.y, n plan for Ó is by no means the ideal receiving lo- you-to fit your r mntanees. l,aNational', Pico is tell twill its shots - VK, K6, XU, G for aste for thoxe FREE cation) numerous and ALLIED Radio Corporation, prevent employment and income.in - BOOK Slaiupl coupon below. Find out how other long distant stations have been Dept. 1 -J -0, 833 W. Jackson Blvd., vet the finest in radio and tcicvi: ion trainino. heard on the 14 and 28 megacycle am- Chicago, Illinois. NATIONAL SCHOOLS ateur bands. Also, the usual British, (NATIONAL SCHOOLS. Dept. 9-RN German and other popular short -wave Send your FREE 204 -page 1940 Catalog. 4000 5e. Figueroa St., Los Angeles. Calif. Please send free Radio and Television Booklet. broadcasters are received with almost local -like regularity and volume. The Name NAME AGE antennae used are a single wire 25 Address ADDRESS feet high and 50 feet long and a John- City State son "Q" 10 meter beam. 30 L

www.americanradiohistory.com 62 RADIO NEWS September, 1939

ENGINEERING, broadcasting, aviation and police radio, servicing, marine and Morse telegraphy taught Bench Not RADIO thoroughly. 48 weeks' engineering What's New in Radio course equivalent to three years' college radio work. School (Continued from page 33) established 1874. All expenses low. Catalog free. (Continued from page 28) DODGE'S INSTITUTE, Oak St., Valparaiso, Ind. Texas; Jackson C. Ream of Albuquer- end or center link types. The inductances que, N. M.; Anthony E. Rutkowsky of are conservatively rated to operate in stages C. G. having up to 50 watts input. In addition to Freedom, Pa.; Kimberly, Jr. of these coils, the above company has also an- Hawkinsville, Ga.; Harold Sedwick of nounced a complete new series of transmit- "CASE Washington, D. C.; Don D. Daymon of ting condensers to be known as the "Giant" Findlay, Ohio; Richard Laplander of line. These units utilize a plate approxi- HISTORIES" mately 6" in diameter and are intended for 3.313 Hubbell, Mich.; Stanley J. Bieda of high power amateur applications and com- Cleveland; and C. Burger of Fort Da- mercial installations. Copies of the new COMPILED BY vis, Canal Zone; T. H. Mackintosh, general catalog (just off the press) describ- ALFRED A. ing these items may be secured by writing Elon College, N. C. the manufacturer. GHIRARDI Thanks to all; the correspondence has indicated that the professionals over the continent are very much in- Within Earshot terested in discussions of customer (Continued from page 4) problems which are excusably absent from text -books, and that each service- 3. New Customers are just as val- man, while he might have ideas which uable to you as Old Customers -re- differ from those of his fellow- profes- member that; for each New Customer sional, is sincere in his ultimate desire is an Old Customer in the making. See to build up a respectful clientele. that you do your part to make him If your entry came in late, or if you want to come back to your shop, and didn't send one in, answer next month's bring his friends to trade there. "Problem of Conduct." I am convinced 4. Impress upon him the fine good - that the exchange of information fellowship of your shop; the "No -trou- which follows will benefit us all, and ble-to- help -you" Spirit. Never be perky, RADIO so the series will be continued. pungent or fresh -the customer pays The Reader's Right your salary. He is your immediate benefactor. Dear BENCH NOTES : TROUBLE -SHOOTER'S (The correspondent mentions the 5. Snap Judgments of men often- HANDBOOK fact he is able to align most a -c /d -c times are faulty. A man may wear a Here is the world's biggest collection of "Case His- midgets various on the tun- red necktie, a green vest and tan shoes tories" ever embled, just published in Ghirardi's at points new "speedthe- up radio This sec- and still be a gentleman -and a good tion of liook compiled' actual nsery rec- ing condenser dial by increasing or de- ords, will definitely show you how to locate instantly Customer. The Unpretentious Man the common weaknesses and troubles in 3,313 models creasing the trimmer capacities, and of receivers. available By far with the soft voice may possess the the best thing of Itssukind anywhere' continues : ) Wealth of Croesus. The Stranger Get this New TIME -SAVER Now As tentative rationalism, I offer : at This big book Is hock -Hill of all kinds of factory- checked "bench data" boiled down for split- second higher frequencies, with the trimmers with the cowhide boots, broad brim and reference-over 15.000 I -F Peak listings. Auto -Radio Data for Installation. Interference Elimination, Wir- ing. etc.; Trouble- Shooting Charts; Trade Directories; closed, this capacity constitutes most and over 30 other tables and charts. A book you can't do without -order your copy at once! of that in the circuit. The electro- 518 PAGES. 134 ILLUS. Standard Man- static field is thus compressed into one INSECT vs. MAN! ual Size (81/zx1 l). Fabrikoid-bound- R-Special Combination Offer: this book togetherl square inch or less. Opening the trim- Gbirardi's world -famous Modern Radio Alt mers puts more of the r -f voltage on Servicing Book -86.50. the relatively large, air -spaced tuning MAIL PRADIO & TECHNICAL COUPON S condenser, which squirts lines of force I PUBL. CO., Dept. RN -99, I AT ONCE all over the place. No prize is offered 45 Astor Place, New York. r Here is $3 copy. of for the correct solution, as virtue is its G TROUBLE-SHOOTERS' eHANDBOOK Sip postpaid with -day Money-Back Guarantee. own reward. I C BOTH servicing books, $6.50 enclosed ($7 Sea g, Hiram Mathematics I NAME . I Detroit, Mich. ADDRESS I CITY STATE Mr. Mathematics' analysis seem- El Please send - - s - - -q sdescr detailed' ingly flies into the face of an estab- contents of both sety- Use it 5 days icing books. lished condenser formula, but the sub- -OUR RISK! ject is interesting -who hasn't had in- triguing experiences with eccentric MONEY BACK GUARANTEE midgets ? Perhaps some sympathetic design engineer will offer a few general rules which we can use on current little jobs which refuse to respond to LEARN CODE the conventional alignment procedure. the way you'll he using it Frozen into glacial ice for 50,000 years, a giant dragonfly comes to life once S&S News more. Read this interesting story of an by SOUND insect invasion, far more terrible than The best way to learn to (Continued from page 44) any war could possibly be. read code is by listening to code. The best near future, will be transmitted on THE INSECT INVASION way to learn to send Friday eve- code is by hearing Tuesday, Thursday and by Frederic Arnold Kummer, Jr. your own sending re- nings, from 8 :30 to 9 :30 p.m., EDST. peated back to you. relayed by the NBC Just one of many entertaining stories With the new All - Outdoor telecasts, and articles in the September issue. Electric Master Tele- mobile television station from World's plex Code Teaching Machine, you learn code the Fair and other points in and about natural, easy, fascinating way. Only instrument will likewise be ever produced which records your sending in New York City, visible clots and dashes -then SENDS BACK stepped up to three hours weekly. your own key work at any speed you desire. That's These will be seen and heard Thursday, why practically every school teaching code uses TELE- FLEX. We furnish complete course, lend you All - Friday and Saturday afternoons, ac- titaStk Electric Master Teleplex. give you personal instruction with a MONEY BACK GUARANTEE -all cording to Mr. Morton. at a surprisingly low cost per month. Write today for FREE catalog RN -S. No obligation. ADVENTURES TELEPLEX CO. -67 -69 PARK PLACE -NEW YORK In Canada, Write INTERMITTENTS? Canadian Electronic Inst., Toronto, Ont. See page 26 Now On Sale M Ad Newsstands

www.americanradiohistory.com September, 1939 RADIO NEWS 63

rusty black may be President of a Rail- road or a Senator up from yonder hol- REMOVABLE -TOP CHASSIS low. You cannot afford to be superior or sullen with any Patron of your service shop! 6. Have everyone who deals with you feel that for his money you want to give him more sincere service than he has ever before received at any serv- This dual 8 -8 Makes Difficult Chassis m fd. 450 V. ice shop. Atom is only 1 x 2a/,,' a n d Work Unusually Easy 7. Sells for only Issue these instructions to your 60e net. Think Greatly simplifies drilling and wiring and, as staff, and keep them ever before your- of t Ih e ing removable tops are available separately, new you make! layouts may he made with a very minimum of self : No person in your shop, includ- waste material. Priced from $1.20 to $2.25 Net at your BUD jobbers. ing yourself, is allowed the privilege of New free catalogue No. RN -99 available by arguing any point with a Customer. writing He (and you, too) must adjust the mat- BUD RADIO, INC. ter at once to the Customer's entire satisfaction. 5205 Cedar Ave. Cleveland, Wrangling has no place Ohio in the successful service shop! It is the keeping of these rules that will make your customer say, "I had Cbrrespondence Courses ln the So- and -So Radio Shop fix my set," RMIOand£L£CTRICAL ENGINE£RING instead of "I had it fixed." It is the ELECTRICAL ENGINEERING á:e>:i;rydá following of these rules that will give electrical field. Prepare yourself nt Low Cost. for secure REure. Modern no plified anyone can understand evickly. you prestige and lots of word -of -mouth ADIO ENGINEERING Erfrn ans o pree ' radin ppbn, add re ube ork. to be vacuum-tubetube teohvicinn advertising, which will make the cus- Ecperimental kite furnished. Diploma on completion, Either course, 5oe Deferred payment tomers beat a bee -line to your door. ma' copies of AS $25 pltnloo,,intd one, etails' SEND NOW! * * * LINCOLN ENGINEERING SCHOOL. Bor 911-R9, Lincoln. Nob.. ON SUNDAY, June 28,1939, The New RADID o"RééE2RIéS York Times published an editorial Intensive, specialized course, including strong basis in which drew attention to the fact that mathematics and electrical engineering, and advanced the cost of television programs would Radio Theory and Design. Modern laboratory, thorough instruction. how tuition. Seil -hole opportunities. Alen be the stumbling block on which the ad- 2-year courses in Aeronautical. Chemical, Civil, Elec- trical and Mechanical Engineering Enter Sept. a, Dec., vance of that industry would stub its SPRAGUE March, June. Catalog. toes for many years to come. The INDIANA TECHNICAL COLLEGE ATOMS 241 -A East Washington Blvd., Fort Wayne, Ind. statement is endorsed by Gene McDon- ald, Zenith Radio Corp.'s prexy, with the following note-and we quote -"At RADIO COURSES long last-a television editorial that New Fall Classes Start in September YOU CAN BECOME A MONEY - MAKING RADIO EXPERT RADIO OPERATING- BROADCASTING makes sense." It seems that both The RADIO SERVICING -a practical course Times and Mr. WIT tew RADIO AMATEUR CODE TELEVISION McDonald have missed ELECTRONICS -1 yr. day course, 2 yrs. eve. the boat. Neither will deny that the Day and Evening Classes. Booklet Upon Request. SPRAYBERRY received picture in is Peveonalijed New York Y. M. C. A. Schools the home as close to appearing like a talking moving pic- 7 W. 63rd St. New York City 'p HOME TRAINING in ture show as it is humanly possible to make it. So the natural conclusion You Learn Easily in Your Spare Hours . must be that recourse will be had to By Doing Many Experiments with television moving pictures where the Up -To -Date Equipment studio setup is Here's a really fine, up -to- the -minute already available and Radio and Television Training that's spe- the costs can be shaved. At the re- cially designed to give you quick results. TRAINING PREPARES YOU FOR GOOD ceiving end there is not any difference, RADIO JOBS ... AT EXCELLENT PAY. and much can be done with My training starts right at the beginning location se- of Radio . unfolds each subject in a quence to bring down the cost of simplified, logical, understandable style. pro- You easily learn Television, Electronics, duction. The use of film eliminates Facsimile Radio, Radio Set Repair and the Installation Work, etc. expensive co -ax line and wire charges, NO PREVIOUS EXPERIENCE NEEDED and good kilowatt transmitters It males no difference what your education are has been. I can fit you for a good -paying Radio job. Your success is my currently available from RCA at $100,- responsibility. full TRAIN 000 each. With YOU FOR the range of each of GET PROFESSIONAL TEST EQUIPMENT PLUS such transmitters more than enough EXPERIMENTAL OUTFITS A GOOD PAY to . Includes 146 Radio Parts (to build complete JOB IN ceiver), Tools, Re- cover most of the cities of our United All -Wave, All- Purpose Analyzer, and Ex- perimental Outfits for conducting actual experiments With States, there is not any reason why your own hands. ELECTRICITY EARN television should I Supply WHILE YOU LEARN ON REAL MOTORS, ETC. not advance rapidly. My BUSINESS BUILDERS show you GENERATORS, how to put your Equipment Incidentally, use to practical there are many advertis- in handling actualal y- making Radio Service Jobs shortly, PAY TUITION AFTER GRADUATION ers who not only can afford to, but will begin training. after you Practical training on full Learn about the "Pay use the size moving picture televised film, SERVICEMEN electrical equipment. Tuition After Graduation I offer Advanced Training "Learn by Doing " -12 Plan." "Part Time Em- who now are not users of broadcast for those already in Ra- weeks shop training. ployment Plan." "Job dio. Get cornplete details No previous experience AfterGraduationService." sound advertising because their prod- in my FREE 52 -page Book. or advanced education ucts are those The Sprat/berry Course NOW...Dieselelectricity. which are sold on eye is Sold Under o Money - needed. Send the Coupon Air Conditioning and appeal back Agreement NOW for Big Free Illus- Electric Refrigeration alone. trated Book. training at no extra cost. No, we cannot agree either with The MAIL THIS COUPON TODAY SPRAYBERRY ACADEMY OF RADIO I Times nor with Mr. McDonald that pro- F. L. Serayberry, Pres. H. C. LEWIS, President 226 -J University Place, N.W. COYNE ELECTRICAL SCHOOL duction costs will be the ultimate stum- Washington, D. C. 500 S. Paulina St., Dept.69- 81C,Chicago, Ill. bling block of television. Besides, if send Please send me your Big Free Book and details it "HOW TO MONÉY IN 8ADÌ0fir were so, PURP9SE ANALYZER of your "Pay Tuition After Graduation Plan." then why has the same Mr. Name McDonald's firm taken out a televi- Age.... I Name sion Address Street license and put shows on the air experimentally for the past several Tear off this Coupon,- muti In.enve- aLY State lope or paste on penny months ? Aren't your television re- Serviceen-m -Check here CI

www.americanradiohistory.com 64 RADIO NEWS September, 1939

ceivers ready for the public yet, Gene? * * * I.ERHAPS the Times and Mr. Mc- anuiza Donald believe the by- now -old saw that the Perisphere at the New York World's Fair is really the egg layed by Television! * * INCIDENTALLY, one of the weirdest uses of the word "television" by spelling it "Tela- vision" is for a rear view mirror recently introduced by an eastern manufacturer for automobile's WIN radio antennae. Well, of all things . ..! * * * OVER IS IN THE June, 1939 issue of PARTS, INDUSTRY Colyumist C.H.F. has this to say: FAMOUS ELECTRONIC . has leased the THE WITH THESE F ". NBC already LINKED A OUS 'l three highest spots in the Windy City b1 Crarra PRODUCTS in anticipation . . .' (of television.) $3700 Guess CHF must have heard our broadcast over WBBM on March 17th last, when we made that statement, and amplified it to the extent that PRIZES Centralab plays an important part in Zenith would be on the air publicly the electronic industry . . . among set with television programs as soon as No camera owner, amateur or pro- manufacturers -on the experimenter's NBC made up its mind. What CHF fessional, can afford to miss this con- bench -in the service man's kit and in didn't say and might want to learn, is test, the largest ever held by any ham shacks ... for wherever QUAL- NBC will probably use the Chi- ITY, DEPENDABILITY and RE- that photographic magazine. LIABILITY count -Centralab serves cago Opera House as its studios since supreme there are full studio facilities available there right now. Incidentally, CHF is LEVER ACTION SWITCHES wrong in his statement; NBC only has TWO CLASSES FIXED RESISTORS options, and has not actually leased Big cash and merchandise prizes for RADIOHMS any place as yet. both color or black and white photo- CERAMIC CAPACITORS * * * graphs. we WAVE BAND SWITCHES WHILE on our Eastern trip were reliably informed that a OVER story is making the rounds that RN $1,500 was forced to drop the ARRL House- FOR COLOR PHOTOS Centralab cleaning Campaign, and that this co- ercion came from the advertisers in $500 cash first prize; $361 color DIV. of GLOBE -UNION, Inc. general and from one in particular. camera, a genuine Curtis Colorscout 900 E. Keefe Ave., Milwaukee, Wis. Let us put our readers straight from one -shot camera; $150 Lerochrome the start. The campaign is dormant, single mirror color camera; $112.50 not dropped. We were never forced to Spectra color camera; and many drop it and certainly not by the ad- other merchandise and cash prizes. YOU CAN BECOME vertisers. We feel that we said everything that could have been said about A CODE EXPERT! the subject, and should ever the cause OVER $2,100 Learn the Quick arise that more information should be CANDLER WAY! placed before the American Ham, you FOR BLACK AND WHITE Candler doesn't care if you're may rest assured that RN will be on just a beginner or if you've tried PHOTOS to develop your speed without the front line, firing away. success. If you follow the simple * * * $500 cash first prize; $250 cash sec- Candler System you will learn code right, with the correct ond prize; $158 Rolleiflex camera; fundamentals. Its a mental MANY of you experimenters are process; you must learn sound 140 other merchandise prizes rang- consciousness, and this Candler busy every night at your various will teach you as he has taught with radio problems. ing from $62.50 to $2.50. Enlargers, thousands upon thousands of others, Including tables and shops such operators as T. R. McElroy, World's Cham- Many of you would like to divert your cameras, exposure meters, flash out- pion and World's Record Holder. In a short time after you've started Candler train- energies into productive channels. You fits, tripods, range finders, and many ing You'll find yourself reading code as easily as you read the printed page, without strain or con- would like to work on something that other items. scious effort. A few weeks of Candler training are equivalent to months of undirected practice. would be an advantage to radio. Well, Write today for FREE "Book of Facts." Learn many un- how the Candler system works, read what highly we found out that there are COMPLETE DETAILS paid commercial operators any about the Candler solved problems in the field on which system. Send for your copy today! and entry blank of this giant contest you can work. For example : the air- be found in the CANDLER SYSTEM CO. line people would very much like to will Box 331, Dept. N -9, Asheville, N. Carolina, U.S. A. have a direction finding device which British Address: Rm. 59, Craven House Kingsway, London, W.C. 2 would locate airplanes in the air and SEPTEMBER make it possible for them to plot the course of the plane as it wings its way ISSUE RADIO ENGINEERING over its route. It seems that the prob- RCA Institutes offer an intensive course lem is not solved with the ordinary of high standard embracing all phases loop, because of various interferences of Radio and Television. Practical training with modern equipment at New and aberrations which enter into the York and Chicago schools. Also special- field over hilly country. No fool -proof ized courses and Home Study Courses under "No obligation" plan. Catalog Dept. RN -39. ground loop has yet been devised. Why RCA INSTITUTES, Inc. not work on that one? A Radio Corporation or America Serowe (Continued on page 65) 75 Varick St., New York 1154 Merchandise Mart, Chicago

www.americanradiohistory.com September, 1939 RADIO NEWS 65

IT IS claimed that a certain well - known radio engineer, who must remain nameless for obvious reasons, RADIO has perfected a cathode -ray system by Sàve lftm'tey/ ENGINEERING. which a spot appears on a C -R tube Complete Radio front over which Engineering course is superimposed a in 96 weeks. Bach- transparent flight map. The spot is elor of Science De- the location of the plane in RADIO gree. Radio (tele- flight. This RADOLEK vision, talking pic- DE(REE IN 2 YEARS is not to be confused with the problem tures and the vast above where the location of the plane electronic field) offers unusual opportunities for trained radio engineers. Tri- in flight is sought by the ground crew. PROFIT State graduates in Radio Engineering The engineer has the solution for the GUIDE[ can complete the Electrical course in 24 weeks. Courses also in Civil, Electrical, flight crew, if we are to take him at his Mechanical, Chemical, Aeronautical En- word. If the system is real, it will ad- gineering; Business Administration and Accounting. Also short diploma courses vance the airplane travel to a point of 164 (36 weeks) in Surveying, Drafting. Tu- safety never before experienced. Our ition, living costs low. World famous for technical two -year courses. Special pre- sister publication, POPULAR AVIA- PAGES paratory department for those who lack TION, please note! required high school work. Students from all parts of the world. 56th year. * * * Enter September, January, March, June. prediction : Write for catalog. Burton Handy, Pres. FREE The next War will be won with radio propaganda and 1699 COLLEGE AVE. ANGOLA, IND. not guns! * * * TRI -STATE , COLLEGE ONE of the better yachtsmen, when approached by us as to why he had not installed one of those ship -to -shore Radolek offers you the MOST for radiotelephone systems, answered, your money! Lowest Prices! Best Quality! Biggest values! Most Rate I 5c I O "What, and per word. Minimum, words. be bothered 'way out complete Stock! Fastest Service! here ?" Which is a hard question to Send for your FREE copy NOW CORRESPONDENCE COURSES answer! USED Correspondence Courses and Edu- * * * OVER 15,000 REP cational Books sold or rented. Inexpen- The world's most complete stock OUR younger sister's hopeful, who of radio repair parts and exact sive. Money -back guarantee. Write for duplicate replacements. All lead- Free Catalog listing 4000 bargains. at the tender age of 7 is delving ing brands. All guaranteed. Low- (Courses Bought.) Lee Mountain, Pisgah, far into the mysteries of scientific phe- est Prices! Alabama. nomina asked us why a roof could not be covered with photo -electric cells, COMPLETE TUBE S PATENT ATTORNEYS All types. RCA, Sylvania, Ray- and the resultant theon, INVENTORS- Before disclosing your in- sunlight converted Philco, etc. Includes Kel- into electricity. We log, special Majestic types and vention to anyone were rather shaken transmitting tubes. Complete se- send for Form "Evi- lection. dence of Conception; ""Schedule of Gov- by this startling question, and con- fessed ernment and Attorneys' Fees" and in- that we could, on the surface, NEWEST structions. Sent free. Lancaster, Allwine see no reason why not. "Then Read- TEST INS & Rommel, 414 Bowen Building, Washing- er's Digest must be right," was his un- The most complete line ever dis- ton, D. C. played in any catalog. All lead- usual rejoinder. But coming to think ing makes. Latest improved models PATENTS -Advice and booklet free. of it, we think he -or the author who at lowest prices. Highest references. Best results. Prompt- mentioned it in the Reader's Digest ness assured. Watson E. Coleman. - Pat- has something there. t ent Lawyer, 724 9th Street, Washington, GREATEST RADI VALUES * D. C. * * A Huge selection of super values as low as $5.20. New Phono Ra AND that about winds up the col- dio combinations. Automatic tun "- INVENTIONS WANTED :rig sets. Beautiful cabinets. New ,',` .Y¡.ei; i INVENTIONS umn for another month, excepting "Ham" receivers and equipment. Commercialized. Patented this; you can be definitely sure that a or unpatented. Write Adam Fisher Com- pany, 278 Enright, St. Louis, Missouri. deep sunburn gives off electrons. If EVERYTHING FOR AUTO RADI you could turn those electrons into Complete auto radio section. In- RADIO ENGINEERING cludes vibrator replacement guide, electricity that you could use, then you new auto aerials, custom panel control plates for all autos, newest RADIO Engineering, broadcasting, avia- could carry your own refrigeration Auto Sets. tion and police radio, servicing, marino plant with you, cool. and Morse telegraphy and stay ... Get taught thoroughly. it ? All expenses low. Catalog free. Dodge's KAK. 30 COMPLETE P. A. S LECTIO Institute, Elm St., Valparaiso, Ind. New 1940 public address amplifiers from 10 to 100 watts. Com- plete P. A. Systems for perma- RADIO nent, Mobile and Portable installations. DIRECT Coupled Amplifiers described in Airline Radioman Best values! July 1939 Radio Craft. Basic Kit 10 (Continued from page 8) 'Watt Model $9.68; 20 Watt Model $14.52. NEW ELECTRICAL A 'PLIANCES Send for Free Circular. Amplifier Co. of Extra profits for you! Standard America, 17 -21 West 20th Street, New ing device for assisting pilots to reach Brand Electric Irons, Stoves, Heaters, Percolators, Waffle Irons, York City, N. Y. their desired field. Vacuum Cleaners, Trains, Clocks, WE buy and sell used radio testing equip- The CAA at present employs up- Mixers, etc., at lowest prices! ment. Harold Davis, Inc., Jackson, Miss. wards of two thousand men and the DETECTION. New Theory; Circuits. requirements are on the whole similar Book 50e postpaid. D'Arcy Ford, Gandy to those set up by the major airlines Street, Exeter, England. with the exception that college train- RADIO Beginner's Data Catalog. Labo- ing is not stressed to as a considerable RADOLEK @a. ratories, 7700 -H East 14th, Oakland, Cali- degree; experience and graduation 601 W. Randolph, Chicago fornia. from a leading technical school, the li- Dept. B -33 QSL's- Printed saine day order received. cense requirement and code, typing and Send the 1940 Radolek Radio Profit Samples. W5GG, Cleveland, Mississippi. teletypewriter experience substitute to FREE. Guide a MISCELLANEOUS large degree. However, even in this Name YOUNG Man (radio amateur) wants field, college training pays dividends work in any radio establishment. Will go and progress is more pointed with pos- Address anywhere and work hard. Andrew Bar - session of an E.E. degree. At present berelis, 11 Kimball- Haverhill, Mass. Serviceman? D Dealer? Experimenter? the would -be candidate might find All

www.americanradiohistory.com 66 RADIO NEWS September, 1939 more encouragement in the airlines neers, technicians and radiomen is un- New Convenience, since replacements are rather slow in limited. The future indicates excep- the CAA. tional opportunities for well -qualified Simplicity and The third of your potential employ- men. Such men are hard to obtain." ers is the humble but very much alive For your convenience, I have en- individual airport (there's one in your closed a list of the twenty-two pros- Economy town). If yours is the average or even pective airlines, one of whom you hope if it isn't the chances are that it does to make happy by your presence. If maintain a radio operator. A third - at all possible, see each and every o ìe class radiotelephone license will suffice of them personally, if that proves im- plus a little practical elbow grease. An possible write and outline your re- airport station has communication only quirements, then sit down with pro- with aircraft in its immediate vicin- found hope and deep meditation. If ity, hence the power supply is low and at first you don't succed try the its design relatively simple. All trans- airports, the CAA, in fact, try every- mitting is done in the region of 278 thing and everybody until at last some kilocycles and usually fifteen watts is day in the future I may gaze proudly sufficient. Let's take a typical instal- into the oft -maligned crystal and see lation and pick it apart for a moment. that you have become a part of avi- The output circuit to start with is tion radio. With the advent of the arranged for feeding into a quarter - giant clippers and the dawn of trans- wave antenna and ground system or it oceanic service, daily, week in and may work into a r.f. transmission line. week out, in all kinds of weather, the The final power amplifier may use a opportunity for qualified radiomen was two -tube 865 layout with a third 865 never greater. Acquire the training, Yours with exciter as oscillator. Quartz crystal go after the job and you will land control of course with two type 59" safely and satisfactorily. In the mean- tubes or acceptable substitutes in par- time, I am your allel to modulate the power amplifier. Hopeful and optimistic, MALLORY -YAXLEY The first audio amplifier tube may DAD. function as an audio oscillator by APPENDIX Switches throwing a single switch to the ICW Push Button position, thus affording a single source List of Scheduled Air -Carriers for a run -way localizer or other aid in Airline Feeder System, Administration Build- When it comes to constructing and navigation. ing, Newark Airport, Newark, New Jersey. Airlines, Inc., Chicago Municipal equipment, these Several receivers, usually one of the American operating radio test intermediate frequency type and one of Airport, 5036 W. 63rd Street, Chicago, Mallory-Yaxley Type 2190 non- short- the high frequency outfits complete Illinois. Boston -Maine Airways, Inc., Boston Municipal ing switches reach a new high in sim- the bill. At some of the larger air- Mass. one Airport, East Boston, plicity of application and operation. ports as many as eight receivers, Braniff Airways, Inc., Braniff Building, Okla- for each transport frequency may ap- homa City, Okla. Mallory -Yaxley Type 2190 switches pear but that's the unusual not the Canadian Colonial Airways, Inc., Room 901, make it possible to measure a number conventional. 650 5th Avenue, New York, N. Y. Your duties will include announcing, Chicago and Southern Air Lines, Inc., Lambert of circuits with a single current read- perhaps even construction Field, Robertson, Mo. design and Francisco Bay Air- ing meter. The insertion of the meter in a small airport while the larger air Condor Air Lines, San capa- drome, Alameda, California. in the circuit is accomplished merely units will give you a specialized Continental Air Lines, Municipal Airport, is small and by depressing a button. Other circuits city. If your airport Denver, Colorado. doesn't even boast a radio station, don't Delta Air Corporation, Box Ill, Monroe, La. connected to the switch remain closed give up. Make a tieup contract with Eastern Air Lines, Inc., 1775 Broadway, New and uninterrupted. the airport manager to service all air- York, N. Y. craft, private planes and semi- commer- Inland Air Lines, Box 1807, Casper, Wyoming. These switches are also suitable for cial jobs and in so doing, absorb all you Inter -Island Airways, Ltd., Fort and Merchant meter switching on low and medium can about practical servicing and pro- Streets, Honolulu, Hawaii. A string of Marine Airways, P. O. Box 2808, Juneau, power radio transmitters and public fessional flight equipment. Alaska. from individual airports address systems. They afford added references Marquette Airlines, Inc., Lambert -St. Louis make an impressive sight to a person- Municipal Airport, St. Louis, Mo. safety in the replacement of conven- nel supervisor and aided and abetted Mayflower Airlines, Inc., East Boston Airport, tional jack and plug systems. by your license and diploma from tech- East Boston, Mass. nical school may make the connection Mid Continental Airlines, Inc., Municipal Send your QSL card for interesting you desire. Airport, Kansas City, Missouri. Inc., Whiffed Air- technical bulletin. Before I close this lengthy epistle National Airlines, Albert the em- port, P. O. Box 868, St. Petersburg, Florida. let's take a quick view toward Northwest Airlines, Inc., Holman Municipal ployment ( and more important the un- Airport, St. Paul, Minn. P. R. MALLORY & CO., Inc. employment) figures and see what your Pacific Alaska Airways, Inc., Fairbanks, Alaska. INDIANAPOLIS INDIANA chances are, assuming you have the Pan -American Airways, Inc., 135 E. 42nd Cable Address - PELMALLO makings. Street, New York City. Reports range all the way from Pennsylvania Central Airlines Corp., Allegheny United Airlines who advise that they County Municipal Airport, Pittsburgh, Pa. new employees only as replace- Transcontinental and Western Air, Municipal hire 10 Richards Road, Kansas City, ments, to the more optimistic Ameri- Airport, that they are Mo. MALLORY can Airlines who state United Air Lines, 221 N. La Salle Street, Chi- APPROVED. RADIO on the lookout for at least twenty new Illinois. PRECISION PRODUCTS cago, employees come every new Spring and Western Air Express Corp., P. O. Box 697, --- Use° Summer. Now let's take a flying leap Burbank, California. to the other extreme and ponder the White Pass Airways, Inc., Skagway, Alaska. words of the chief engineer of a large Wilmington- Catalina Airlines, Ltd., Catalina operating concern whose words are Airport, Avalon, Catalina Island, California. "The field for qualified radio engi- 3I-

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www.americanradiohistory.com SUPERIOR ANNOUNCES -FOR THE FIRST TIME!! THE NEW CHANNEL -ANALYZER Follows Signal from Antenna to Speaker of Any Set THE CHANNEL-ANALYZER WILL- I. Follow signal from antenna to speaker through all stages of any receiver ever made. 2. Instantly track down exact cause of intermittent operation. 3. Measure both Automatic- Volume -Control and Automatic -Frequency- Control, voltages and circuits without appreciably loading the circuit, using built -in highly sensitive Vacuum -Tube Voltmeter. 4. Check exact gain of every individual stage in receiver. 5. Track down and locate came of distortion in R.F., I.F., and A.F. amplifier. 6. Check exact operating voltage of each tube. 7. Locate leaky condensers and all high- resistance shorts, also show opens. S. Measure exact frequencies, amount of drift and comparative output of oscillators in superhets. 9. Track down exact cause of noise.

Fundamentally, what the Superior Channel -Analyzer does is to permit at a price much less than that usually asked for a dynamic voltmeter the serviceman to follow the SIGNAL from antenna to speaker through alone. each and every stage of any set ever made, and inferentially, of any D.C. Voltages have important bearings on receiver performance. All set that ever will be made, using the SIGNAL as the basis of measure- these voltages can be measured on the Channel -Analyzer with the re- ments. Thus if there is trouble in one particular channel or stage of a ceiver in reproducing operation. In fact, that one important considera- receiver, the serviceman can isolate the faulty stage and then proceed to tion, MEASUREMENTS WITHOUT MOLESTATION OF THE RE- ascertain the very part or component that causes the trouble. CEIVER, gets rid of the drawback of most conventional equipment which Many of the troubles in modern receivers are due to the Automatic -Vol- greatly reduces the very voltage it attempts to measure, or kills the nine- Control and Automatic -Frequency -Control circuits and ordinary in- signal completely. struments do not permit measurements directly upon these circuits, so Tubes that are used in the receiver under test are also given a thorough the Superior Channel- Analyzer includes a direct- current Vacuum -Tube check by the Channel -Analyzer and as such a specialized tube tester, Volmeter that DOES make these measurements directly and with a this new and remarkable instrument is proof against any possibility of negligible loading of the measured circuits. obsolescence. Other problems cease to be pröblems too, when the quick -solution Noise, another serious problem to servicemen, can be located with the method of the Channel -Analyzer is applied. For instance, suppose a aid of the Channel -Analyzer and can be done with incredible speed. local oscillator in a superheterodyne drifts. The Channel -Analyzer has Here are the basic components of the Channel -Analyzer: a switch operated, tuned input circuit with amplifier, whereby not only I. B Supply rectifier and filter circuit. the presence of drift may be discovered, but also the amount and direc- 2. One- stage, high -gain flat amplifier and linear diode detector. tion of drift. 3. Tuned -circuit, 'high -gain amplifier and linear diode detector, 100 Distortion is another difficulty that often nettles a serviceman. The KC. to 20 MC. Channel- Analyzer has a jack for the insertion of earphones so that you 4. D.C. Vacuum -Tube Voltmeter, for measuring the rectifier R.F., can listen to the signal directly from any stage and, therefore, discover I.F. or A.F., and for independent use on external circuits, all by the stage in which the distortion takes place. Next, the VTVM is used front panel switching. to discover the very component in that circuit that is causing the trouble. By adroit engineering and skillful application of a wide knowledge of How often have you cherished the hope that someday you would own an servicing requirements based on Superior's years of experience; the four instrument that enables you to measure the actual signal voltage across components listed above are made to do so many things and do them so the load of any stage in the set, and thus by comparison determine the well and fast that a large benefit is bestowed on servicemen, their tasks gain per stage. The Channel- Analyzer enables those dynamic voltage lightened, their work speeded and their experience greatly extended, all measurements and does a whole assortment of other work besides, yet at record -breaking low price. The Superior Channel- Analyzer comes housed in shielded cabinet and features an attractive etched aluminum panel. Sup- $ 75 plied complete with tubes, three specially engineered shielded input cables, each identified as to its purpose. Also full op. erating instructions. Size 13 "xl0 "x6 ". Shipping weight 19 pounds. Only THE NEW 1130 -S THE X- RAYOMETER SIGNAL GENERATOR FEATURES NEW GIANT 9" METER -AND A BUILT -IN WITH AUDIO FREQUENCIES POWER SUPPLY ENABLES RESISTANCE MEASURE- MENTS UP TO 30 MEGOHMS SPECIFICATIONS: RESISTANCE MEASUREMENTS IN 3 RANGES: 0.1000 Ohms, 0- 100,000 Ohms, 0 -30 Meg - ohms. D.C. VOLTAGE MEASUREMENTS IN 5 RANGES: 0 -50, 0 -250, 0 -500, 0 -1000, 0 -2500 Volts. Television and other high voltage power supply circuits easily measured. A.C. VOLTAGE MEASUREMENTS IN 4 RANGES: 0.50, 0 -250, 0 -500, 0 -1000 Volts. D.C. CURRENT MEASUREMENTS IN 6 RANGES: 0 -1 Ma.. 0 -50 Ma.. 0 -250 Ma., 0 -1 Ampere, 0 -10 Amperes, 0 -25 Amperes. High current ranges suitable for automotive and industrial work. CAPACITY DIRECTLY READ ON METER SCALE IN 2 RANGES: .005 - 1 Mfd. . . -2 Mfd. - 50 Mfd. PERCENTAGE OF LEAKAGE of electrolytics read DIRECTLY on meter scale. Actual condition of condenser quickly determined. INSULATION, INTER-ELEMENT and A. V. C. LEAKAGES directly read on meter scale up to 30 Megohms. - SPECIFICATIONS: OUTPUT MEASUREMENTS IN 4 RANGES: 0 -50, 0 -250, 0 -500, 0 -1000 Volts. Built -in I. Combination R.F. and Audio Signal Generator, R.F. 100 he. to blocking condensers enable rapid alignment 100 ato., A.F. -100 -7,500 cycles. All Direct reading, all by front of radio equipment. panel switching. 2. R.F. and A.F. output independently obtain- INDUCTANCE MEASUREMENTS IN 2 RANGES: able alone or with A.F. (any frequency) modulating R.F. 3. Ac- O - 7 Henries, 7 703 Henries. curacy is within 1% on I.F. and Broadcast bands; 2% on higher DECIBEL MEASUREMENTS IN 3 RANGES: frequencies. 4. Audio frequencies in 5 bands; 100, 400, 1000, D.B. based on 6 M.W. at 500 Ohms. -10 to 5000, and 7500 cycles. 5. Giant airplane full vision, direct -read- +29, -10 to +43. -10 to +49. Audio fre- ing dial. 6. Condenser and other leakages tested to 100 megohms. quency measurements in both radio and P.A. amplifiers. _. 7. All services on 90 -130 volts A.C. or D.C. (any frequency). ONLY Model 1130 -S comes complete with tubes, test O C X- RAYOMETER comes housed in a new army gray crystalline, heavy leads, carrying handle, instructions. Size 12 "x gauge cabinet. Complete with test leads, instructions and tabular data. 9 "x61 /z "- Shipping weight 15 pounds. 07 795 Our net price. - Shipping weight 20 pounds.

136 LIBERTY ST., DEPT. RN9 SUPERIOR INSTRUMENTS CO NEW YORK, N. Y.