Blueprint Section Every Month

Na ne g!' the Hour

In This Issue- JULY Ten Commandments for the Listener 1925 ,A New Super -Heterodyne Solving Tube Troubles 25? News of Radio Age's Popularity Contest

MEET YOUR BROADCAST FAV RITES SUPER SM AUTODYNE

A Perfected Super- Heterodyne Again Silver -Marshall Engineering leads the field, just as it has since the first Silver Design was offered less than a year ago. Not content with a seven -tube super- heterodyne, which has become the acknowledged standard of comparison with radio engineers and editors, McMurdo Silver, Assoc., I. R. E., has developed "The Super -Autodyne," a six -tube receiver that will outperform average seven and eight -tube sets. Read the description of this remarkable radio achievement in this issue of "Radio Age." Plans and instructions describing this set in detail may be had for 50c. Complete Parts Each Each 2 S -M 305A S -L -W Condensers . $ 5.00 2 Thordarson 3 1.2 -1 Transformers $ 4.00 2 4" Moulded Dials._ 1.00 2.002 Condensers .40 1 U. S. L. 6 -Ohm Rheostat.. 1.00 1 .0075 Condensers .75 1 U. S. L. 240 Ohm Potentiometer 150 2 .000025 Balancing Condensers. 1.51. 3 Insulated Top Binding Posts .05 1 S-M .25 Meg. Leak.. .50 1 Carter 101 Jack...... 70 1 S -M 2 meg. Leak.. .50 1 Carter 102A Jack. .80 1 Carter No. 3 Jack Switch 1.15 1 S -M 211 Filter with Matched Tuning 1 Benjamin 8630 Switch_ .30

Capacity.. - 8.00 1 Belden Color cable .85 2 S -M Charted Intermediate Transformers 8.00 1 Pair Benjamin 8629 Shelf Brackets.__ .70 1 S -M IOIB Coupling Unit 2.50 1 Bakelite panel, 7"a18 "x3 -16', drilled, 1 S -M 6 -Gang Socket shelf (536 -201A, 537 - grained and engraved 6.00 U V 199) 10.80 Spaghetti, bus bar. lugs, screws, buts, etc 1.00 Send for "The WHY of the Super- Autodyne" -It's Free; *Trade for Our New S -M Catalog Mark Dealers -Ask

114 S. Wabash Avenue, elver-Marshall, Chicago, Illinois

* Tested and Approved by RADIO AGE * RADIO AGE for July, 1925 The Magazine of the Hou:

Sta lions D0't "Bunch "' On the Dials

Showing stations "Bunch- ed" as they are found on a 100 degree dial using any ordinary condenser.

The location of the same stations on the same dial using Ultra -LowLoss Con- densers- "spread; simpli- fying tuning. a

PATENT PENDING Tunizzq Sinipif/leciNoW,

THE day of tedious fumbling about for your stations is past -science has been brought into play. Now, with the Ultra -LowLoss Condenser you can instantly tune in on any station as easy as turning the hands of a clock to the hour. With one station of known wave length located on the dial, all others can be found instantly. Each degree on a 100 degree dial represents approximately 3'/s meters difference in wave length. This applies to hoth high and low wave lengths. Other than 100 degree dials vary accordingly. 'ULTRA VCRP!ER TUNING CONTROL This simplification of tuning is made possible by the new Cutless Stator Plates to be found only in the Ultra -LowLoss Condensers. Every feature of the Simplifies radio tuning. Pencil record Ultra -LowLoss Condenser was developed with one predominating purpose -to a station on the dial -thereafter, sim- overcome losses common in other condensers. Designed by R. E. Lacault, ply turn the finder to your pencil mark and you get that station instant- originator of the famous Ultradyne Receivers and Ultra -Vernier Tuning Controls. ly. Easy -quick to mount. Eliminates At your dealer's, otherwise send purchase price and you will be supplied postpaid. fumbling, guessing. A single vernier control, gear ratio 20 to 1. Furnished Design of lowloss coils furnished with each condenser for amateur and broadcast wave clockwise or anti -clockwise in gold or lengths showing which will function most efficiently with the condenser. silver finish. Silver $250 Gold $3.50 To Manufacturers Who Wish To Improve Their Sets Mr. Lacault will gladly consult with any manufacturer regarding the application of this condenser to his circuit for obtaining best possible efficiency. t1bTR7t-bO1jJbO$ This seal on a radio product is CONDENSER your assurance o f satisfaction 116 -13 eEwa 2 St . and a guarantee PHENIX RADIO CORPORATION, c of Lacault de- sign.

i Tested and Approved by RADIO AGE l RADIO AGE for July, 1925 The Magazine of the Hour A Chat With the Editor YOU can count on the fingers The Magazine of the Hour of your two hands the basic Established March, 1922 radio receiver circuits from WITH WHICH IS COMBINED RADIO TOPICS which all the many scores of hook-ups now existing may be developed. All those basic circuits Volume 4 July, 1925 Number 7 are to appear in blueprint form in the August issue of this magazine. Our technical staff has selected CONTENTS the typical circuits which represent the various basic arrangements, Cover Design by A. P. Ehlum most of which have appeared dur- ing 1924 and 1925 in RADIO AGE. Page John B. Rathbun, the able Radio Editorials 4 draughtsman whose blueprints in this magazine have become stand- Four, Five or Six Tubes? 7 ard in schools and in many thou- By Roscoe Bundy sands of radio homes, will have Learning Tube Characteristics 11 in this de luxe edition of RADIO By H. Frank Hopkins AGE an exhibit of tested basic How Much Coupling ?____ 13 circuits which will make our August By Brainard Foote issue one of the most important The Six -Tube Super- Autodyne__ 15 radio contributions since broad- By McMurdo Silver casting began. The blueprint sec- Vacuum Tubes as Distortion Devices 18 tion of the August number will of By Dr. Peter I. Wold itself be of almost the bulk the regular magazine. With the addi- A Word on the Care of Batteries 19 tion of other standard RADIO A Simplified Portable Super- Het___ 21 AGE features the book will take By A. J. Haynes on proportions that should delight Tricks of Summer Static__ 24 the fan who wants his radio course "Gloria Confesses ": A Photograph 25 from crystal to super, all under RADIO AGE "What the Broadcasters Are Doing" one cover. Studio-Land Feature Section. 26 Notwithstanding the unusual value offered in this big issue of our RADIO AGE Institute Monthly Tests__ 34 magazine the news -stand price will RADIO AGE Blueprint Section_.._ 35 be the same as other issues; 25 By John B. Rathbun cents. It is a matter of wide Pickups and Hookups by Our Readers 43 comment that RADIO AGE costs With the Radio Manufacturers.______69 no more from month to month than other standard radio publica- tions, although its blueprint section in each issue. sets it apart from all other magazines. Now Radio Age is published monthly by RADIO AGE, Inc. complete Member: Audit Bureau of Circulations. we are to offer you a collection of blue prints with Address all communications to RADIO AGE. INC. complete constructional instruc- Executive, Editorial and Advertising Offices tion in a single issue and for the 500 N. Dearborn Street, Chicago, Ill. regular price. Publication Office, Mount Morris, Ill. We would advise readers who this FREDERICK A. SMITH, Editor wish to make sure of getting FRANK D. PEARNE, Technical Editor remarkable August number that M. B. SMITH, Business Manager they tell their newsdealer to reserve their magazine for August NOW. Advertising Director If your dealer does not handle HARRY A. ACKERBURG 500 N. Dearborn St., Chicago, IU. RADIO AGE write to us at 500 North Dearborn street, Chicago, Eastern Representative enclosing 25 cents in stamps and DAVIDSON & HEVEY, 17 West 42nd St., New York City we will mail you one on July 15, the day it goes on sale. Final Advertising forms close on the 20th of the 2nd month preceding date of issue Vol. 4. No. 7. Issued monthly. Subscription price $2.50 a year. July, 1925. Entered as second-class matter at post office at Mount Morris, Illinois. under the Act of March 3. 1879. kit:44 Coyyrieht, t5ss. by RADIO AGE. Ius. Editor of RADIO AGE RADIO AGE for July, 1925 Get a good set EVEREAI)Y HOUR EVERY TUESDAY AT 9 P. M. Time) Evereadys (Eastern Standard and For real radio enjoyment tune in the "Ever- eady Group." Broadcast through stations - To ENJOY radio for the rest of your life, get the WEAF New York WEAR Cleveland best set you can afford. There are receivers at all WJAR Providence WSAI Cincinnati prices, made by reputable manufacturers; it isn't WEEI Boston WW2 Detroit for anyone to get 'round -the -corner, un- WFI Philadelphia WCCO¿St.Pau necessary WGR unreliable merchandise at any price. That WCAE Pittsburgh WOC Davenport proved, applies to batteries too. Eveready Radio Battcries are made in so many sizes and prices that there is a correct, long -lasting Eveready for every receiver and for every radio home, ship or commercial sta- tion. Specify Evereadys for your new radio set. It is false economy to buy nondescript batteries at any time. In the long run you'll find it most economical to buy either the large or extra large Evereadys. Always buy Evereadys and enjoy the knowledge that no one can get any more in batteries for the money than you. There is an Eveready dealer nearby. Manufactured and guaranteed by NATIONAL CARBON CO., INC. New York San Francisco Canadian National Carbon Co.. Limited, Toronto, Ontario EVEREADY Radio Batteries ._ ...__ -they last longer .rAMT" 4R CEVI BADIO,IGNITION ANn ALL IOENERAL PURPOSES rNSPE:.TEa TESTER RELIABLE "ORAL CnRam7 W-

Eveready No. 766 Columbia 2254-voit Ignitor Large the proven Horizontal Dry Cell Price $2.00 for all Na. 772 Radio 45 -volt Dry Cell Large L....Tubes Vertical 1544 volts Price $3.75

No. 771 4%-volt"C" Battery improves quality, raves"B" Batteries Price

* Tested and Approved by RADIO AGE 4 RADIO AGE for July, 1925 The Magazine of the Hour

RADIO CORPORATION of America has com- of Radio Corporation's magazine, which, they assure pleted its "proof" that in adopting the name us, is called "Wireless Age." Therefore, a witness RADIO AGE this magazine stepped on the testified that newsdealers get the two magazines cloven hoof of the corporation. The RCA contends all mixed up and that although one is published in that RADIO AGE, as a name, infringes on the name New York and the other in Chicago, dealers often "Wireless Age," a publication owned by the Radio send unsold copies of RADIO AGE to "Wireless Corporation. Radio Corporation last fall brought Age." The circulation manager of "Wireless Age" formal action in the United States Patent Office at produced one letter in support of this contention. Washington opposing the application to have RADIO He said he had looked hard for other documentary AGE registered as a trade mark. evidence of the universal confusion between RADIO The $33,000,000 group apparently held the fond AGE and "Wireless Age" but the one letter was the notion that RADIO AGE would immediately yield best he could do. its rights, rather than go into a legal battle with one Another Corporation employe swore tnat at the of the Four Horsemen of Radio. On the contrary, Pageant of Progress in 1922 he heard subscription RADIO AGE engaged the services of several of the solicitors in the RADIO AGE booth telling the gullible best lawyers obtainable and we have seen the thing public that RADIO AGE was published by the Radio through. On May 5, in the Corporation offices in Corporation of America. This witness testified he New York, the Corporation completed the taking immediately complained to the manager of the Pageant of testimony of its own witnesses. The Corporation that the RADIO AGE solicitors were telling naughty labored and brought forth a peanut tube. little lies. So, he testified, the manager threw the It was an imposing array of witnesses and we re- solicitors out of the Pageant, and the RADIO AGE gretted that Mr. Sarnoff, vice president and general booth remained empty and free of guile from then on manager of the RCA horse, was unable to be present. until the show closed. This witness admitted he Mr. Sarnoff was busy preparing for a banquet. He is never brought these matters to the attention of the a banqueteer of parts. No hungry Cassius he. officers of RADIO AGE, Inc., and that he didn't At the last Hoover conference, Charles E. Erbstein report the incident to "Wireless Age" until May, 1924 faced the representatives there present in the interest -almost two years later. A long time to carry such of the Radio Corporation. Westinghouse, General a pineapple around in one's craw. Electric and American Telephone and Telegraph, Mr. Pierre Boucheron, general manager of the and told them they were the Four Horsemen of Radio. advertising and publicity departments of Radio The. name stuck. A few weeks later Mr. Sarnoff Corporation and vice president and General manager and Mr. Erbstein were present at a radio dinner in of Wireless Press, Inc., which publishes "Wireless New York. Mr. Sarnoff approached Mr. Erbstein Age" for Radio Corporation, was easily the star wit- and asked in a gently sardonic tone: ness for Radio Corporation. He, too, thought "wire- "Tell me; which one of the Four Horsemen am I ?" less" and "radio" were identical in meaning. But on "Pestilence!" responded Mr. Erbstein in a flash. cross examination he admitted that since the action "Not famine ?" inquired Mr. Sarnoff, somewhat against RADIO AGE was begun, the name of the taken back. magazine which is claiming it is suffering great injury "You, Famine? Never!" murmured Mr. Erbstein. from competition by RADIO AGE changed its own So, on the occasion of the taking of depositions name from "The Wireless Age" to "Wireless Age, calculated to prove that RADIO AGE is guilty of The Radio Magazine." The change was officially unfair competition and is injuring the business of announced in the corporation's magazine. last No- "Wireless Age," Mr. Sarnoff was preparing for another vember. It was explained in this announcement that banquet. the old title was being retained in part so that the It was necessary that the RCA witnesses swear to magazine might be more easily identified by those facts that would support the contention that the who were more specially interested in 'wireless. Yet words "wireless" and "radio" mean the same thing. "wireless" and "radio" mean the same thing! If this were proved, Radio Corporation might hope A man might be obviously right from start to to get somewhere with its argument that in adopting finish in a controversy such as this and in the end the name, RADIO AGE, this magazine was appro- might prove himself to be right. But he would have priating, in effect, the name "Wireless Age." which been compelled to finance his defense and, though does not belong to this magazine, but belongs to the he be right as a trivet, he could not obtain recourse New York monthly wireless publication, every share against predatory interests who put him to all the of stock in which is owned by Radio Corporation. trouble and expense. That's why a $33,000,000 The witnesses then swore "wireless" and "radio" band of patriots has a big advantage in opposing an meant the same thing. No distinction whatever so individual of much more modest resources. Doesn't far as the man on the street was concerned. But it seem to be quite all square with our fundamental developed, on cross examination, that all the witnesses ideals of equal opportunity and equal rights under the were on the payroll of the Corporation and therefore law, does it? We were warned three years ago that could not well be criticised if their expert views on if RADIO AGE criticised certain radio interests those the significance of words partook of the same general interests would step on us. Yet we criticised radio tendency as the views of the kind and loving old monopoly and we are going to keep it up. If we Radio Corporation. still thrive where others faint, it may be because our It also was necessary to prove that the use of the readers and newsdealers are not so confused as some name RADIO AGE was causing injury to the business folks hope they are. RADIO AGE for July, 1925 The Magazine of the hour "Radio Age" Popularity Contest Is Now d osed !

Race is Still Neck and Neck As Aldine Starts the Official Count of Last -Minute At the left is the at- tractive shield which Ballots; will be awarded the winner in the RADIO AGE Popularity Con- Name of test, which dosed on June 15. Its size over- all is six by eight in- Winner to ches, and a detailed description is con- tained in the article on Be Revealed this page by Mr. Ald- ine, the persevering Contest Editor for Next Month this magazine.

BY THE time this issue of RADIO October .- _...._.__._»..__._.__H. W. Arlin, KDKA By HARRY ALDINE November ._ Bert Davis, WQJ AGE appears on the news- stands, December Jack Nelson ,WJJD the RADIO AGE Popularity Con- January Art Linick, KYW February....__ - CoomSanders Orchestra, KYW test will have ended, as only those votes tration of the shield which will be award- John S. Daggett, KHJ received before midnight of June 15 winner ed the of the RADIO AGE STANDING TO MAY 15 will be credited to the total count of Popularity Contest. From a background Name and Classification Where Heard candidates. of artistic black will stand out in Karl Bonawitz, Organist_ WIP, Philadelphia As this review is being written (May raised gold letters The Winner's Name, Bert Davis, Entertainer WQJ, Chicago and Bill Hay. Announcer KFKX, Hastings 16,) there still remain a full thirty days, the inscription, "First Annual RADIO John S. Daggett, Announcer.__...KHJ Los Angeles during which period the winner will he AGE Broadcast Entertainers' Popularity H. W. Arlin, Announcer_ ...... KDKA, Pittsburgh Coon -Sanders' Nighthawks, Orchestra. KYW, Chi. definitely named, and judging from the Contest -1924-25." Jack Nelson, Announcer WJJD, Mooseheart heavy voting which has taken place Surrounding this will be a plain gold Art Linick, Entertainer. KYW, Chicago during the past thirty days, no candidate Harry M. Snodgrass, Entertainer border conforming to the shape of the WOS, Jefferson City is yet assured of the coveted position shield. The gold plate will in turn be Ford & Glenn, Entertainers._ WLS, Chicago at the head of the list. At no time in the mounted on a dead black bevel -edged Duncan Sisters, Entertainers_ KWY, Chicago history of the contest have the three Lee Sims, Pianist KWY, Chicago wooden plaque, to which is attached a Lambdin Kay, Announcer WSB, Atlanta leading candidates been so closely chain for hanging. The size, overall, J. Remington Welsch, Organist KWY, Chicago bunched. is six by eight inches. Fred Smith, Announcer.._ WLW, Cincinnati To further complicate matters, "Uncle E. L. Tyson, Announcer.___ WWJ, Detroit While several ideas were offered for Hired Hand, Announcer.___ _WRAP. Fort Worth John" Daggett, 'way out on the Pacific the design of the shield, the one accepted "Seu" Kaney, Announcer.. ._.._ KWY, Chicago Coast, has jumped from ninth to fourth seemed to conform most to the principles Nick B. Harris, Entertainer._... .KFI, Los Angeles place, where he stands menacingly, Jerry Sullivan, AnnouncerEntertainer, WQJ, Chi. of dignified simplicity, and was therefore Edward H. Smith, Director-Player ..._ ...... offering dangerous competition to the the most forceful manner of declaring to WGY, Schenectady three popular leaders. By referring the world the winner of the contest. Charles E. Erbstein, Announcer._... _ -WTAS, Elgin to May 15" Wendell Hall, Entertainer...... WDAF, Kansas City further to the "Standing Following is the standing of the can- Howard Milholland, Announcer KGO, Oakland it will be found that Art Linick has also didates as they are lined up at present; Scottich Rite, Orchestra.. KGO, Oakland bettered his position by stepping one Banks Kennedy, Entertainer...... WEBH, Chicago% of the ladder, WINNERS OF PRECEDING MONTHS S. Hastings, Announcer ._KFI. Los Angeles more round toward the top Robert Boniel, Announcer .WEBH, Chicago July ...... Duncan Sisters. KYW from eighth to seventh place. August...... Bill Hay. KFKX Arion Trio, Instrumental...... KGO. Oakland On this page will be found an illus- September.. Karl Bonawitz, WIP Gold Dust Twins, Entertainers, WEAF, New York 6 RADIO AGE for July, 1925 The Magazine of the Hour

Mr. Manufacturer Would you write 100 letters to 100 people to reach just two men? Then, before you invest your advertising dollars- THINK!

An analysis shows that publications of general circulation, newspapers and magazines, devote less than 2% of their reading columns to Radio -proving that in the opinion of This Association their own Editors less than 2% of their readers are inter- is comprised of ested in Radio. In fact, many general publications carry no the leading Ra- Radio editorial matter. Therefore -98% of your investment dio Magazines. is lost!

On the contrary, the Radio magazine offers 100% Radio editorial- attracts 100% potential buyers. Spend your advertising appropriation in Radio Magazines. Be sure of the greatest possible return on your advertising dollar.

Radio Magazine Publishers' Association, Inc. RADIO AGE is a member of the Radio Magazine Publishers Association, Inc. JUN 23191925 l© CI B661371

RADIO AGE for July, 1925 The Magazine of the Hour

i O

A Monthly Publication M. B. Smith Devoted to Practical Frederick A. Smith Business Manager Radio Editor

I 1 01 I IDI IDI IDG What will Tomorrow ging Four, Five or Six ThBKS? Our readers' vote is requested upon the in the way of improved performance. number of tubes that will prove most popu- By ROSCOE BUNDY The radio frequency steps were coupled lar during the coming radio season. Will with primitive untuned radio frequency economy rule with the use of the four tube transformers that were little better than set, will we adhere to the present popular To Be coupling condensers, and which peaked five tube set, or will we attain quality with Trend Seems badly on some particular wavelength, the six tube set regardless of the increased generally on the wavelength of one of price? This is a question that the radio Toward Clear Music the local stations that you were trying dealers and RADIO AGE would like to to tune out. have answered by our readers. At this stage of development the addi- 7. Secondary Tap Switch Knob. tion of tubes was a serious proposition, IT was not so very long ago that the 8. Grid vanometer Dial. for the tubes then drew anywhere from three tube regenerative receiver 9. Plate variometer Dial. 0.75 to 1.0 ampere each, so that a four marked the height of affluence in 10. Variable Grid Leak Dial. tube outfit would draw up to four am- the radio world and that the owner of 11. Detector Rheostat Knob. peres total, or four times as much "A" such a super -set was enviously regarded 12. First Stage Audio Rheostat Knob. battery juice as the largest tubes of the by his fellow B. C. L.'s who were still 13. Second Stage Audio Rheostat present day. getting their music via the single tube Knob. You could easily run down a freshly and the crystal set. In those days we 14. Battery Switch Knob. charged battery in the course of one could consistently get coast -to -coast evening and then wait over for a day reception or its equivalent on three The Man Pays This Time! while you recharged your battery with tubes, and with the tubes retailing at SOME price to pay for an attempt at some ineffective trickle charger, generally $6.50 each and the receiver itself hover- selectivity! A maze of confusing of the buzzer type. Those were the days ing around the $200 mark, the old three controls that were not half as effective when the buzz of the charger was con- lunger was held in the same regard as as the three tuning dials and two rheo- tinuous in the land and when the battery the most elaborate five tube set -of the stats that appear on the panel of the spent as much time on the charger as on present day. It tuned as broad as a present time tuned radio frequency re- the receiver. You would feed it five barn, howled like a fiend and mushed up ceiver, and which required considerable amperes all day only to have the receiver the signals, but in her day the old three practice before they could all be brought drain out all of the profits by 12 o'clock did her stuff, as the many DX records of into adjustment. p. m. 1921 -1922 will testify. The constant urge for more distance There is no doubt but what the 0.25 Repeated refinements in the regenera- resulted in the first appearance of radio ampere tube of the 201A type made the tive circuit, brought the three tube re- frequency steps which at that time were multi-tube set a practical possibility, generative up to a high degree of effici- simply auxiliaries to the original regenera- and that further increases in the number ency in bringing in distance, but in the tive receiver and increased the complica- of tubes will also depend upon the de- craze for distance we sacrificed selec- tion considerably without much return velopment of tubes of the 199 type which tivity and tonal quality. They were will make dry cell operation practicable superlatively sensitive to weak signals, with five tubes or more. but as most of the old timers were of The Reflex Enters the single circuit type or were provided ç Wí TICK with the old inefficient vario- coupler, OWING to the necessity for battery they 'were very broad- tuning and could conservation with the old tubes, the not possibly cope with the present day OUT coming of the reflex circuit was heralded congestion of radio traffic, even though with joy and much of 1923 was devoted they did have from five to ten tuning to the development of the reflex circuit controls. There were more dials and DET AUD AUD by experimentally inclined amateurs. Partly for the reason less selectivity in 1922 than at any P16.1 RE6ENER.4T /I/E that the radio other time in radio history. frequency transformers of 1923 did not Just as a review on the subject of measure up to the standards demanded RFX RFX reflex, for tuning controls let me list the dials and P by the and partly the reason knobs that commonly appeared on the DET that reflex principles were not well under- panels of the old time three tube three stood, the reflex did not attain the circuit regenerative: popularity that was expected by its gr ` \/ sponsors, and there was a decidedyten- 1. Primary Variable Condenser Dial. dency toward falling back on the old 2. Rotor of Vario- Coupler Dial. reliable regenerative circuit, with which 3. "Tens" Tap Switch Knob. Fis 2 REFLEX almost any beginner could expect to get 4. "Units" Tap Switch Knob. some sort of results. There were many 5. Series- Parallel Switch (Some- Figs. 1 -2. Three Tube Circuits Com- reflexes that gave phenomenal perform- times). monly Used. Dotted Line Represents ance, but in the main, the radio public 6. Secondary Variable Condenser Radio Frequency and Solid Line is Audio soon discovered that the reflex of that Dial. Frequency. time was not an ideal circuit for the 8 RADIO AGE for July, 1925 The Magazine of the Hour novice and that special precautions were accompaniment of the shrieks and wild fixed primary coil. In fact, a modern necessary that rather took it out of the wailings that were prevalent in the three -tube circuit with this sort of tuner home -builder's province. regenerative era and hear music and is fully the equal of an old four tube Things hovered around this condition voice without a background of hissing using the vario- coupler, and is not half for some time until a change in radio and frying sounds that formerly de- as bothersome. Further, it can be took place with the appearance of the tracted so much from the enjoyment of a "logged" so that each station comes in on five tube neutrodyne, the father of all program. In clarity of tone, the five a definite dial position, which was not the numerous five tube "dynes" now on tuber was nearly equal to the reflex at formerly the case, making tuning certain the market and the salvation of the its best, and the problem of perfect and prompt when provided with a table reflex principle. The neutrodyne was reception was therefore put up squarely of station wavelengths and a well pre- not the first tuned radio frequency to the manufacturers of loud speakers. pared "log" of the corresponding dial outfit by any means, for we had plate It was now a question of developing a positions. Logging is an essential with a tuned circuits long before this, but it horn that was a fit running mate for the modern receiver of any type. was the first stable five tube radio fre- receiver. Out of this perfection in regeneratives sprang a hybrid four -tube quency set that could be built with any New Twists Developed circuit type degree of success by the average home - which is very popular today. This con- builder. IN the meantime, we must not forget sists of a stage of tuned radio placed in With all due respect to the neutraliz- that all this improvement also stimu- front of the three tube regenerative ing principle as applied to the suppres- lated experimental work on the regenera- which both increases the distance and sion of self- oscilla- selectivity and also tion in the radio fre- counteracts the ten- quency stages, the dency of the regen- real advantage of erative unit toward the neutrodyne, ac- causing annoying cording to my idea, AGE BALLOT aerial radiations. lay in the construc- RADIO The Browning - tional details such (How Many Tubes Do You Prefer ?) Drake circuit is a as the tuned radio prominent example frequency transfor- BALLOT EDITOR, of this type, which mer and the aper- Radio Age, Inc., consists of one iodic or semi -aper- 500 N. Dearborn St., stage of tuned radio iodic coupler. By Chicago, Ill. frequency amplifi- these units we could On the following list I have checked off the radio receiver that best cation, regenerative approach a degree fills my requirements, and have written my reasons in the blank space detector, and two of selectivity hither- following the specifications. stages of audio fre- to unknown, by CLASS 1. THREE AND FOUR TUBES. (a) Three Tube regenera- quency amplifica- means of very tive with transformer coupled audio stages. (b) Four Tube tion. Both the simple units; and Regenerative with resistance coupling, (c) Three Tube coupler -tuner a n d further, we could Reflex, (d) Four tube reflex with loop, (e) Four tube regen- the radio frequency peak our radio fre- erative with one stage of radio frequency. transformer are quency amplifica- CLASS 2. FIVE AND SIX TUBES. (a) Five Tubes, two stages of special adaptions of tion on the desired radio, detector, and two stages of resistance coupled audio, the tuned coils wavelength instead (b) Five tubes, One stage of radio, regenerative, detector originally used in of adoptingthe com- and three resistance coupled stages, (c) Five Tube Reflex the neutrodyne, promise amplifica- with loop, (d) Five Tubes, Two stages radio, regenerative although much more tion of the older detector and two stages of transformer coupled audio, (e) efficient and selec- fixed transformer. Six Tubes, Two stages of radio, regenerative detector, and tive because of the Again, this was the three stages of resistance coupled audio, (f) Six Tubes, two absence of electro- first fairly high radio, detector, three stages transformer coupled audio. static coupling be- power set within CLASS 3. SUPER- HETERODYNES. (a) Six Tube, (b) Seven tube tween the primary reach of the aver- (c) Eight tube. and secondary coils. age amateur and the Such circuits are first practicable set REASON FOR MY CHOICE rapidly increasing with more than in favor, for they three tubes which have great distance had appeared. getting qualities for Tonal quality was the number of tubes improved as well as employed and are distance and selec- Name. simple and cheap to tivity, and in gen- Street or R. F. D. build. eral it took the radio world by City State... Revised Reflex storm in spite of the NOTE: If you do not wish to tear this blank out of your book, send a brief note covering Circuits cost of the five the above points. It will do just as well. OUR reflex dr- tubes, which aver- cuits now took aged about $5.00 on new life with the each at that time. advent of the aper- The rapid increase in the popularity tive and reflex circuits in which many of iodic type coupler and tuned air core of the neutrodyne brought a perfect the radio frequency construction details radio frequency transformers, with the re- flood of five -tube tuned frequency sets were employed. For example, the aperiod- sult that the modern reflex much more on the market with all sorts of weird ic type coupler was now employed on nearly approaches its theoretical advan- methods of suppressing free oscillations. regenerative and reflex circuits as well as tages. The radio frequency component is The question of battery current consump- with the tuned radio frequency outfits, now tuned by the same air core transfomer tion could no longer be leveled against at one time improving their performance units employed in the tuned radio fre- these circuits, for the 201A tube gave a and simplifying the controls. The old quency sets with greatly increased rane total consumption of only 1.25 amperes vario- coupler became a thing of the past. and stability. By the same means, ohmic against the 3.0 amperes formerly neces- Single control regeneratives became more resistance is reduced, selectivity increas- sary with the old tubes in the three and more common, both wavelength ed, and wonderful results are being tube regenerative receivers; hence we and regeneration being sometimes con- obtained with only a few tubes. Two could run longer per charge with the trolled by a single variable condenser tube reflex sets with coast -to -coast re- new five tube combination than with the while taps and tap switches were placed ception and loud speaker volume on 500 old detector- and -two -stage outfit. in the discard. mile stations are not uncommon where Under the new system, coast -to -coast A regenerative circuit of the new era the improvements have been added. reception on the loud speaker was so consisted of a dial for tuning to wave- Where fixed R. F. transformers are used common as to cause ho comment and length, and perhaps another dial for we now have true magnetic coupling in- we could bring in real distance through the tickler. This was all there was to stead of the capacity coupling had in the the most powerful, local broadcasting the proposition and we not only simpli- older types, and with modern untuned stations with ease. For the first time we fied things, but also obtained better transformers we have excellent perform- could bring in a station without the selectivity, tone and distance with the ance. RADIO AGE for July, 1925 The Magazine of the Hour 9 Three tube reflex circuits, using tuned than that of a corresponding grade of radio frequency transformers through- - radio frequency or reflex receiver, and out, give fully the results of a five tube TICK this item, of course, is sufficient to rule straight radio frequency set when proper- 3 it out among many classes of radio fans. ly built, and have the advantage that When the DX fever was at its height, they can be operated with dry cell "A" ry_ with every effort bent toward getting batteries with success. There are a distance at any cost, very little atten- number of "kit- sets" or complete sets of tion was paid toward eliminating dis- parts now on the market for building RF MT AUD AUD agreeable noises or for improving the reflexes of this type, so that the construc- F/6 3 RE6ENEA34T/VE tone of the receiver. In fact, the noise tion of a reflex no longer is a problem for in the early broadcast receivers, coupled the advanced student of radio, but is with the crude loud speakers of that entirely practicable for the rawest novice. period, was very effective in holding This is in contrast to the conditions ex- back prospective customers who possess- perienced in the old days when the ed the most elementary sense of tone. builder of a reflex frequently had to buy The field was entirely in the hands of the enough material for two sets before he distance fanatics, and they continued could find parts that would match up to hold it until the coming of the tuned and function properly when hooked up radio frequency sets, with their improved in a reflex circuit. F/6. 4. AMPL/F. REPLEX reception, made an appeal to another In writing the above paragraph it Figs. 3 -4. Four Tube circuits, Regenerative class of listeners. The latter formed the brings to mind the great advantages With One Radio Stage (3) and Reflex Four bulk of those who purchased radio dur- enjoyed by the present day radio set Tube (4) ing the past year; people who objected builder compared with the trials and to listening to the mangled remains of a tribulations of the old -timer who had sonata, just so that they could boast of little to work with in the way of materials the development of six and seven tube hearing some peanut station 1,500 miles and still less data. In the old times, a super -hets which give fully as good per- away. Better have good, clear, local smudgy illustration cut out of a news- formance as the standard eight -tube reception on a crystal set for these pros- paper with an exceeding inaccurate de- type, and have the further advantage pects than a mushed up mess coming in scription was considered a "find," and that they are more compact, cost less, and from a distant station. with a few yards of barb wire and other take less battery current. Satisfactory In addition to the inherent noises of miscellaneous junk, a valiant attempt results are being had with six and seven the regenerative receiver, which were was made toward the construction of a 199 tubes, which brings the set well down really not always so bad on the head- workable receiver. Nowadays, the build- toward the limits of dry cell operation, phones, the early audio transformers er can obtain accurate apparatus put. and with such sets we obtain wonderful were far from being perfect and added up in complete kits so that an hour's work selectivity and loud speaker operation their din to the collection of noises an- with a screw driver and pliers is all that over great distances. Their tone value nexed in the detector stage. High ratio is necessary. Each wire is cut to length is of the best, and with a little experience audio transformers with their distor- and a detailed series of picture diagrams they are easy to tune and handle. In tion, poor design and other factors made gives all the data that anyone could fact, two condenser dials and a potenti- life miserable for the musician who was possibly ask for. In one way, however, ometer are the only controls necessary. forced to hear the blasting and blare of all this spoon -feeding is a bad proposi- Super- heterodynes are essentially a the old horns or noise chutes. Improved tion, for it is getting to such a point that type designed for operation on a loop transformer design, together with the the experimenter is now too dependent aerial, and for this reason they make a use of low turn ratios, has greatly im- upon others and is rapidly losing his great appeal to those who have no chance proved these conditions so that there spirit of self -reliance. Here at RADIO to erect an effective outdoor aerial. is little distortion or noise within the AGE, we find that the slightest omission Certain radio frequency and reflex re- receiver itself. Further, the introduction in a description or in a drawing is ceivers will also give good results on a of resistance coupling in the audio stages sufficient to throw him all out of joint, loop, but the super-het is particularly made another step toward perfect tone, and instead of trying a few simple experi- adapted for this kind of service, and to a so that the tendency of today is rather ments that could be performed in five great extent, its selectivity is due to the in the direction of clear, undistorted minutes, he will write in and calmly wait directional properties of the loop aerial reception than toward mere distance. for some one to work out his simplest with which it is used. Its only drawback I am thoroughly convinced that future problems for him. is its cost, which is considerably greater improvements in radio apparatus will be along the lines of The Super- tonal improvement Heterodyne and that the buying During the past r -; public is more inter- year much work has I/ ested in tone quality been done on the than in the attain- of the ment of distance. development I 2 super- heterodyne 1 /.-- A good, clear nat- and great I -. \ ural tone with mod- principle / _ JUT progress has also - ° - -- -l' - J D Q erate distance get- been made along i / \_ i ting qualities; low these lines. Properly \ ' current consump- designed, and with `RF RF DET AUG AUD tion so that dry the proper mater- batteries can be em- ials, the super -het is ployed; stable per- the king of all re- F/6. J. STRA/6NT R4.0/0 /L7p474/ENCY formance without ceivers, but once nerve racking again we warn the shrieks and howls, novice that he and perfect select- should obtain his v` 1- î TICK ivity are the char- apparatus in kit -set acteristics of the form to insure all of salable radio receiv- the parts being prop- er of the future. erly matched so that OUT The experimenter they will work to- and the DX hound gether. To assemble have already been a super- heterodyne served, so that our out of a miscellane- RF DE T AUD AUD AU D next appeal is to ous mass of un- that class of music matched parts of FIG.Ó. ve lovers who have not different makes re- yet seen fit to buy quires a considerable radio equipment. amount of skill and The reproduction experience. must be fully equal Continued experi- Figs. 5 -6. Five Tube Circuits. Two Stages of Radio Frequency and Audio (5), and to that of the best ment has resulted in Resistance Coupled Five Tube With One Radio Stage (6). modern phono- 10 RADIO AGE for July, 1925 The Magazine of the Hour If this were not so, then everyone would 7T7 place their check mark opposite one of the more powerful and costly sets and we would be as much in the dark as ever. ouT Mark your ballot candidly; we want to know just what is on the minds of / our readers. Place your check mark opposite the type that you most desire RF RF DET AUD 4UD AUD and then make a note of why you prefer this particular circuit. This is as much TWO STAGE /PAD/O AMPL /F/EP to your advantage as to ours and is not /4/67 an advertising scheme -we want to know. DBL. FREO. HARMON. AMPLIF1ERiLt 05CILL. INTER DET AUD AUD The Universal Need r n OUT LOUD- SPEAKER operation is almost I \ / ç a universal requirement with the r) i l t h --`-7 . - receiving set of today; hence, we must I ,/ 2 a 5 G always be assured of the equivalent of at least two transformer coupled audio frequency stages. So far as marketable ------j sets go, the days of the headset are prob- ably gone, even, on distances that were F16. 5 v.5UPER-hETEROOYNE considered of the DX order several THE ABOVE S/X 7L/9L Suf.ne were..Pt7OYNE /S O. T.YE SECOND years ago. Even with portable sets, we HAotionvC TYPE /N wN/CN fNEFhPST TUBE /S.PEFLEXEo see provision for the loud speaker and in 4T So 7-1/ LON6.4N0 SNORT /FA; WAVELE//6TNS. most cases the loud speaker unit is built into the set proper. Shorter and shorter aerials, or aerials Figs. 7 -8. Siz Tube Circuits. Two Stages of Radio With Resistance Coupling (7) Super -heterodyne (8). of the indoor type, increase with the increasing numbers of broadcasting sta- tions, for a short aerial is almost a graph, and this should not be so difficult tive with good distance getting qualities fair value, a four tube necessary adjunct to selectivity in these to attain, as there are certain mechanical- but only tone to for ly connected linkages in the phonograph set with slightly better distance and tone days. Loop aerials are very popular which do not exist in the radio; hence providing that the latter only cost a few much the same reason, and also because sound without distortion should be more dollars more? Would you prefer these they avoid the trouble of erecting an perfectly accomplished where the trans- sets to a three or four tube reflex with outdoor structure. mission is performed electrically than wonderful tone value, great volume, and There is probably not any increased where loose jointed mechanisms are em- moderate distance? I am omitting refer- risk due to thunderstorms; in fact, the ployed. ence to the one and two tube sets which be less, but they are are really for the head -set and can only risk may possibly Resistance Coupling be used on the speaker with powerful not desirable. PERFECT as the modern audio fre- local stations. quency transformer may be, there is If you had more money to spend, would Talks on Cuisine even less distortion with resistance coup- you spend it on the conventional five ling, for the amplification is always in tube tuned radio frequency set with Station KYW exact "straight-line" proportion to the transformer audio stages, or would you ASERIES of eight talks closely re- drop of potential over the resistor coupler. like to add another tube for resistance lated to the cuisine in your home is As with other items in radio, however, coupling so .that you would have the being given over Westinghouse station the resistance coupling method is a corn - superlative in tone value for the R. F. at 9:15 p. m. until promise that is not without drawbacks class of receiver? How would a five KYW, each Thursday of its own. In the first place, we must tube reflex operating on a loop strike you? June 25, which will be the date of the use three amplifying tubes with the Now for the third class, which costs last talk. resistor to get the degree of amplifica- quite a little more than any of the others. KYW has secured the co- operation cf tion obtained by two tubes with trans- We speak of the super -hetrodyne with John C. Cutting, to give these talks. former coupling; and in the second place, its loop aerial, from six to eight tubes, Mr. Cutting has been telling the New we must use at least 135 volts of "B" and with its excellent tone and volume? how to manage battery instead of the conventional 90 Do you believe that these increased York women, over WJZ, volts used with the transformers. It is virtues compensate for the additional their homes and husbands. This was the same here as everywhere else. If cost over those offered by the five and six a weekly feature in New York for over we wish to gain the benefits of perfect tube sets of class two? That's what the sixteen months, and his thoughtful and reproduction, we must pay the price of manufacturer wishes to know, that is valuable home hints, so delightfully admission, and according to my ideas, what we wish to know, and that is what put forth, proved to be of such value the better quality obtained by the will affect the market in which you are that the same propaganda is going to resistors fully compensates for one extra to buy your radio. There is only one in Chicago, over West- tube and one extra block of "B" battery. way in which public demand can be be exploited The application of the resistors is simple determined and- that is by asking the inghouse station KYW. and reasonable in cost. buying public to vote on their opinion Mr. Cutting, who is secretary of the In what is to follow, add one tube to or desires just as we are doing here. Meat Council of Chicago, began his the set for resistance coupling where We have guessed until we are blue in the series of weekly talks from KYW on transformer coupling is specified. Some face, but as yet have come to no con- May 7, at 9:15 p. m. having chosen increase in amplification with little or no clusion, and there are a whole lot more for his first subject "Filling Four Stom- effect on the quality can be had by corn - in the same boat with us. achs With a Dollar Bill." Mr. Cutting, bining resistance and transformer coupl- In making your choice, please consider ing with one transformer stage and two the many factors that enter into the who enjoyed the prestige of being the resistance coupled stages. proposition. The question of tube only man on WJZ's program who dis- subjects dear to a woman's heart, How Many Tubes? economy, compactness and portability, cussed dry cells versus the storage battery, first has a faculty of putting these talks over At last we are getting back to our cost, distance, tone, volume, selectivity, with the enthusiasm and pep required original question, the subject of this loop aerial or outdoor aerial, and the cost to promote his idea. He will tell young article, after wandering around among of maintenance. There is some one com- how spank up a roast or hem- - wives to the various types of radio receivers. bination of these factors that will suit stitch hamburger in a way that will What is your preference, or rather, what your conditions best and we wish to sort of a radio outfit would you buy if know what it is. We have divided the bring them the eternal love of their you were to purchase one tomorrow? receivers into three classes according to respective husbands. With a limited amount of cash available, price, for we believe that price is the de- Tune in and let him do his stuff. would you prefer a three tube regenera- termining factor in the majority of cases. KYW, Thursdays at 9:15 p. m. RADIO AGE for July, 1925 The Magazine of the Hour 11 II Formulae and Tables for Testing and Plotting Charts for Vacuum Tubes Used in Radio Reception Learning Vacuum Tube Characteristics

By H. FRANK HOPKINS The milliameter shown above shows the plate current characteristic in milliamperes. THERE are numerous characteristics will only give a fair idea of how a tube of vacuum tubes used in radio re- will act. They will sometimes show battery terminals. The negative terminal ception and transmission that may a good plate current curve, but fail of one connected to binding post (C-) be determined, but which have no to perform efficiently when in opera- the positive terminal of this and the value to the average radio fan. How- tion. Therefore, it is worth the differ- negative terminal of the second "C" ever, there are a few óf vital import- ence in price to have a set that will battery connected to binding post ance to all users of vacuum tubes and show the filament current or voltage (C+ -) and the positive terminal of it is the writer's intention to make clear and the grid bias voltage in addition the second "C" battery to binding such of these characteristics which are to the plate current. post (C+). of importance to the fan so that he For this article, the RADIO AGE The filament rheostat (R) is moved will be able to plot curves or charts test set was used. It consists of three to its off position, a tube placed in the and match his tubes as easily as he meters; a filament voltmeter, a grid socket (T) and the set is ready for tunes his receiving set. volt meter and a plate milliammeter operation. By moving the switch (BS) The equipment required for this work with the necessary resistances to vary to point (-) and closing switch (GS) is a good vacuum tube test set, such as the filament and plate voltage and grid a negative grid bias voltage will be described in the May issue of RADIO bias voltage as desired. shown on the two -scale voltmeter (GM), AGE. An instrument such as this It was prepared for operation by this grid bias voltage may be varied may be built at a nominal cost or one connecting an "A" or filament battery at will from 0 volts to 7% volts by similar may be purchased ready made of suitable voltage for the tube under moving the potentiometer (GP) until at a good range of prices, from the test-to terminals (A BAT+) and the meter shows the desired voltage. simple one -meter affair to those having (A BAT -). By moving the switch (BS) to the (-l-) a complete set of meters. A "B" or plate battery of ninety point, a positive grid bias will be shown The -Meter Tester volts was connected across the bind- on the meter (GM) and will be varied One ing posts (B -) and (B90) with taps as above. rr HE one meter tube testers are at 22%y volts, connected to binding The switch (PS) and the rheostat limited in their use, however, and post (B22), 45 volts to binding post (BR) regulate the "B" or plate battery outside of a plate current curve at a (B45), and 67% volts to binding post voltage. By moving the switch (PS) fixed grid bias, no other features may (B67).. Two 7% volt "C" or grid to terminal (1) and moving the rheo- be determined. This type of test set batteries were connected to the "C" stat (BR) a plate voltage range from

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Figs. 1 and 2. Fig. I shows the typical curve of plate current voltage, wh le F g. 2 shows he typical curves of grid and plate characteristics, the result of tests described in the accompanying article 12 RADIO AGE for July, 1925 The Magazine of the Hour negative reading on the meter (6m) and the plate voltage will be adjusted to 0 volts. By moving the rheostat (BR) the plate voltage is increased. A reading will be taken from the milliammeter and a point corresponding to this reading and the reading of the plate voltmeter (PF) will be marked on the cross section paper, as in the chart (figure one). This reading -with 5 volts on the plate, showed a plate current of about .1 milliampere. At 10 volts it read practically the same, and so on, gradually until 20 volts was applied and read at .3 milliampere. At 25 volts the plate current was about .5 at 30 .7 and at 40 it was 1.2 milliamperes. It increased rapidly until 90 volts showed The two -scale voltmeter, showing the grid a plate current of about 4.3 milli- bias voltage. amperes-which is average for a tube The 0-10, 0-100 scale voltmeter, which of this type. shows the filament voltage and plate volt- age, respectively. 0 to 22% volts is obtained, to point When all of these points are marked (2) from 223/2 to 45 volts, to point (3) they will be joined by a line running 1.2 0 from 45 to 67>M volts and to point (4) through each, and a completed plate showing milliamperes at volts so on down .1 milli- from 67>M to 90 volts. This voltage current curve as in figure one will be negative and until is read on the meter (PF) by moving made. Simple, isn't it? This perform- amperes was obtained at slightly over 4 the transfer switch to position (4). ance may be repeated -on the same volts negative 'bias. The filament voltage will be read on chart, at different grid bias voltage - This curve will show the best "C" the same meter (PF) by moving the say a l l -2 volt negative and a l l -2 battery voltage or grid bias for a tube at transfer switch to position (3). The volt positive bias, thus giving a complete various plate voltages, and it may not be filament voltage is varied by the rheo- plate current story of the tube at various amiss to say that as we add to the plate stat (R). operating conditions. voltage, the higher the grid bias voltage may be, several curves may be made on Plate Current Curve Grid Characteristic Curves one chart for this characteristic at FOR the first test, we will use a 3 -4 TO make a grid characteristic curve - various plate voltages, as shown in volt 199 type of tube -placed in the figure 2, the plate voltage will be Figure four, on page 12 of RADIO AGE socket (T) by use of an adapter. This set at 40 volts-the grid bias voltage for May, 1925. is a high vacuum receiving tube with the will be adjusted until the meter (GM) A filament voltage curve may be filament normally operating at 3 volts shows 0 with the switch on point ( +). made and a filament current curve also and a filament current drain of .06 The reading of the milliammeter (MA) if an ammeter is included in the test amperes or 60 milliamperes. This type of will be located on the chart as before - set. This will be plotted from periodic tube is most used in super- heterodyne and readings for each fraction of a volt readings as in the other curves, and will receiving sets and is by far the most will be spotted -as in figure two. The make it possible to show an emission critical of everyday tubes. 40 volt curve showed a plate current of curve (Figure 3). This is one of the A piece of cross section paper will be 1.2 milliamperes and at 1 volt ( +) it factors so important to users of vacuum prepared by marking the plate voltage read 1.5 milliamperes and so on to 2 tubes, as the life of a tube depends upon scale on the lower edge and the plate volts ( +) it read 1.8 milliamperes. Going the proper emission of the electrons from current scale on the left edge as in figure back to O volts and shifting the switch the filament, and is usually ended by a one. The filament voltage will be ad- (BS) to a negative bias, the readings were decrease in emission, necessitating ex- justed to a point just below 3 volts, taken the same as above, except they were cessive filament voltage to keep it in say 2.8 volts, the grid will have a 0 volt inversely proportional to the grid voltage, (Turn to page 53)

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Coupling can be construed as the method by which energy is transferred from one circuit to another. It can be energy from the antenna to the detector tube; energy between tubes of a radio frequency amplifier, or again audio energy passing bettween audio stages. Coupling pusses the energy across in each case. Big Advantage in Having a Variable Coupling Scheme to Enable Adapting the Receiver to Different Aerials; Suiting Coupling to Varied Wavelengths a Real Problem

COUPLING" is a broad term in A coupler as in "A" may be wound on its interpretation. It signifies the By BRAINARD FOOTE one piece of tubing, with a primary coil method by which energy is of as many turns as are necessary for the transferred from one radio circuit to individual case. To get the maximum of another. Whether it be the energy from large aerial will increase broadness and a volume on different wavelengths, a small the antenna travelling to the detector small aerial will reduce it. Slightly switch might be provided to change the tube, or energy being transferred between greater volume may be had with con- number of turns, as follows:- -short tubes of a radio frequency amplifier, or nection "B," however, so that many waves 5, medium waves 10 and long still again the audio energy passing be- listeners prefer it even though it waves 15 turns. KSD and stations of tween the audio stages -it is through does upset the dial readings. In the case similar wavelength may then be almost coupling that the energy is passed across. of a set like the neutrodyne, the three doubled in volume, with the average set. To have coupling, there must be two dials do not read the same, but the first But for the shorter waves, the number of associated circuits carrying alternating one is lower than the other two. turns must be reduced because of the current. One circuit may consist largely It is of great advantage to have a absorption effect of so large a primary of inductance (coil) and the other variable coupling scheme to adapt the coil. largely of capacity (condenser) or the set to . different aerials. With a long Antenna Wavelength coupling may even exist because of a aerial, only 5 to 10 turns are needed in resistance which is common to both of coil P, but with a very small aerial, as THE aerial system has a "natural" the circuits. The sort of coupling with many as 15 or 20 may be used. The wavelength of its own, which must be which we must deal almost exclusively is dotted line in "A" shows where the fila- reckoned with. Users of tuned R. F. or that due to associated inductances or ment circuit is grounded, a measure even regenerative receivers with aerials coils. And inasmuch as the coupled coils ordinarily desirable because of its good having very long lead -ins have found wound on iron cores which form the effect upon inductive noises and upon certain "dead spots" on the dial. These commercial audio transformer are not hand capacity. are caused by absorption where attempt to be adjusted, our discussion will be is made to tune the set to the natural of confined to radio frequency transformers. the antenna. This natural ought to be less than R. the shortest broadcast wa''e- F. Coupling length received, in order that it may not LET us first talk about the coupling interfere seriously with short wave between the aerial system and the reception. To smooth out such a dead radio receiving set. In Fig. 1 two methods spot caused by a lengthy aerial system, whereby this coupling is accomplished either reduce the aerial's capacity or are illustrated. The type of "A" is per- use a series condenser of .00025 or .0005 haps more common and it possesses mfds. capacity. The simplest method of several distinct advantages. In the first educing the capacity of the antenna, if place, the separation between the primary it is too long, is to shorten it. Simply P and the secondary S may be made F shortening it, however, does only half fairly great, and the capacity effect of the job. The greatest improvement the aelial upon the secondary thereby comes by increasing its altitude. An minimized. In other words, a receiver so antenna of 60 or 70 feet, raised 20 feet coupled to the aerial will tune almost the A above a roof, is far superior for sensitiv- same on any aerial,-large or small. ity to a 150 foot aerial only five feet above In "B" another popular scheme is the roof. Not only does the passing shown. Here there is really a trans- radio wave induce more voltage in the former as in "A" with two distinct wind- wires because of their greater height, but ings, but a portion of the secondary acts Fig. 1 -The aerial is coupled to the set by the antenna's natural wavelength is as the primary also. Here the coupling is a "coupling coil." This may be a separate reduced at the same time. very winding as at "A" or a portion of the much closer than in "A" for the at The former method So much for antenna coupling. We same secondary as "B." now number of turns included. Its dis- is better in most cases. The aerial's natural come to a more "ticklish" coupler - advantage lies in the great effect of the wavelength must be kept low if you wish that which transfers energy from one aerial's capacity upon the broadness of good short -wave as well as long -wave re- R. F. amplifier tube to another one, or the secondary tuning condenser. A ception. to the detector. (Turn the Page) 14 RADIO AGE for July, 1925 The Magazine of the Hour, Perhaps the easiest method of adopt- ing the variable primary is to install a number of switch points and a switc,i knob and lever on the panel, where it ie readily accessible from the R. F. trans- former in the set. This, however, requires long connecting leads and is unsightly in view of modern receiver construction. °-pP11-6 A superior method is indicated in Fig. 3. At "A" the coupler itself is pictured, "G" and "F" being the secondary terminals. The smaller winding is the primary and it consists of approximately 15 turns. With a crystal detector, it may 8 be advisable to go as high as 20 turns, F although no more than this are needed if the R. F. amplifier tubes are good ones. For the average set used chiefly for D local reception, the switch may have three taps and the entire primary have only twelve turns in all. A tap is taken FI G. at the 7th turn, at the 9th and at the 12th. In sets using two stages of radio, Fig. 2 -How radio frequency tubes are coupled to each other. At "C" is the universally the primary may be smaller, even for DX popular 'fixed primary" type. This, however, is efficient only over a moderate wave work, some primary coils working well band. Varying the coupling from about 5 to 12 turns, as at "B." gives better results with a total of ten turns, tapped at the on all wavelengths. 5th and 8th and 10th. The number of turns in the primary must really be In Fig. 2, "C," is shown such a coupler amplifier and detector in the case of a worked out by the individual set opera- in circuit form. The secondary, of course, single step amplifier. By this method, tor to fit his own conditions. is of the proper size to cover the broad- the R. F. coupling is as great as possible cast band in conjunction with the variable without causing oscillations and the Back -Panel condenser that tunes it. The primary is volume as well as the selectivity are very as large as possible, but not so large that much greater. THE switch points are laid out on a it passes sufficient energy back to the In "D," Fig. 2, is shown the variable small piece of panel material, about grid to cause oscillation of the tube. In primary coupler. Here a tap switch is 2 inches square. The switch lever may practise, such an ideal transformer is out connected to change the coupling for be of the regular style or be cut from of the question, for it is perfectly efficient long and short waves. Such a plan is of spring brass or phosphor bronze. It is for only one wavelength or a very narrow most value in sets having only one stage soldered to a 3d -inch set collar. Good band of wavelengths. of tuned radio frequency and a detector, contact to the lever may be made by The average tuned R. F. transformer is either crystal or tube. With the average using a long set screw and attaching a of this type and is so constructed that its coupling coil, a fixed primary of about nut to it for holding the end of a short primary does not feed back enough 6 to 8 turns is adopted. Many tuned R. F. piece of flexible wire. This forms the energy to cause oscillation on the shorter reflex sets are made up iri this manner. plate connection "P of the transformer. wavelengths. For this reason, it is not If they are good for long waves, oscilla- The taps are laid out and so connected quite as efficient as it might be on longer tions prevent good reception on short that a left -to -right movement of the waves. This peculiarity accounts for the waves, and if excellent on short waves, panel knob brings an increase in coupling. difficulty many tuned R. F. receivers the long wave stations come in poorly, The set collar is attached to a length of experience in getting volume from long although with no trace of oscillation. bakelite or brass rod, 3d -inch diameter, wave stations like KYW, KSD and the which passes through a 1 -inch hole in like, whereas stations of much less power the sub -panel and also in the main on the shorter waves can be received with panel. The assembly is given at "C" enormous volume, by comparison. and at "B" the front panel is shown. Three small white dots indicate the posi- Variable Coupling tion of the switch arm. These are made OF COURSE, the obvious method for by filling with white wax crayon small getting around this inequality of depressions made with the twist drill. wavelength is to change the coupling, In case there is special interest in DX making it greater on longer wavelengths. reception, more taps are taken, thus giv- Shall this changing be accomplished by ing a more gradual change in coupling. a moving coil whose angular relationship The best way to determine how the pri- can be altered-like a ticklercoil? Orshall mary should be wound is to make up an we have a permanently set winding, with experimental primary coil of about 20 its number of turns controllable by a tap turns, with a tap at every second turn. switch? The first method is better from The taps are merely bared places in the the standpoint of uniformity and gradual wire, twisted into loops. A spring clip movement, but it has a big disadvantage. is then used to connect to the taps in The capacity coupling is changed too lieu of the switch arm and points. much and causes upsets in the secondary In most cases, the final result will be a dial settings. Besides, there are too coil of about twelve turns, with taps many turns on the coil for short wave- at the 5th, 7th, 8th, 9th, 10th and 12th lengths and the plate circuit is tuned so turns, or about six taps in all: The high that oscillation commences. adjustments should be tested with good Hence the better plan is to provide a "B" batteries of at least 90 and prefer- tap switch for cutting in or out the prim- Fig. 3- Details of a variable coupler. ably a little higher voltage, with good Primary and secondary are fairly well sep- ary turns. It is astonishing what an im- capacitative R. F. amplifier tubes and the coupling in signal arated, to avoid coupling. A mense difference volume may sub -panel tap switch permits the use of any coils properly in place with about 1-4 be had with such a device, with variable desired number of turns in the primary. inch separation between the primary coupling for the last stage of the radio White dots on the panel show where the and secondary. frequency amplifier, or between the R. F. lever is to be set. (Turn to page 50) RADIO AGE for July, 1925 The Magazine of the Hour 15 rrTHE receiving the input circuit. system to be ABig Step Toward Efficiency But two stages of described in this in Heterodyne Design intermediate fre- paper is the result of Super- quency amplifica- a very considerable tion were used, for amount of research due to the careful and experiment put design of the trans- forth in an endeavor A SIX TUBE formers employed, it to produce a super- was found possible heterodyne that to realize as much would give equal or "SUPER- AUTODYNE" amplification with better results than two stages as had could be obtained previously been with any existing realized with three type, yet which RECEIVER stages. In each cir- would employ a cuit, efficiency had .maximum of six The -Het to Tubes, Yet Giving been increased as tubes, for this num- Super Reduced Six much as possible, ber must certainly Results More Efficient .Than Seven and Eight and the fact that be considered the with but seven tubes maximum allowable receivers of this type limit henceforth, if By McMURDO SILVER give a fairly consis- the word "efficien- tent range of two to cy" be used in con- three thousand nection with this loud -speaker miles, system of reception. even under present In the past, there weather conditions, has been no ques- is probably the best tion in the mind of indication that this even the most un- latter method of at- informed fan but tacking the problem that the super-het- is the most logical erodyne was the one. ideal radio receiver, and the ultimate de- A Practical sire of every enthu- Combination siast has been to be THE next step the proud owner.of was obviously to a set containing combine the de- many more brightly tector and oscillator lit tubes than any functions in one other set in his com- tube. The difficulty munity. Yet this Fig- 1. The completed super- autodyne dlustrattng clearly what can be done with standard circuits m producing which has hereto- has been the real a symmetrical design that is pleasing to the eye. fore prevented the drawback of the use of one tube for super; the necessity of using from seven to The next method, and the more both detector and oscillator has been that ten tubes in order to obtain truly super- straight- forward one, is to improve the of isolating the loop or pickup circuit heterodyne results. Therefore, the aim of efficiency of each section of the system from the local oscillator circuit. It has receiver designers has not been to improve so that fewer tubes will be required to been impossible to couple a tuned pickup results, for a super that really justifies the give the same amplification that has circuit to a tuned oscillator when the two name will go down to the lowest noise -level hitherto been obtained. An example of are to operate but fifty or sixty kilocycles -the limit of practical sensitivity; but such a receiver was described by the apart throughout the broadcast wave- rather, to reduce the number of tubes used author in the March issue of RADIO length range, and not have the tuning of and at the same time retain the sensitiv- AGE. This set incorporated a regenera- one section react on that of the other. ity, selectivity and quality of reproduc- tive I first detector, thus giving the Armstrong and Houck developed the tion obtainable with the best of sets. greatest possible gain obtainable for expedient of the second harmonic system, whereby the oscillator, working at double Two Ways To Do It the desired wave, did not react greatly TO the mind of the engineer, there are A REMARKABLE upon the loop circuit. Then, a harmonic but two practical methods of attack- of the oscillator was used for heterodyn- ing this problem; either make the tubes ROUND -UP OF ing. This meant two waves were being used do more work, or raise the efficiency HOOKUPS produced by the oscillator of sufficient of each circuit of the receiver right up power to cause radiation, which neces- to the maximum limit, or do both simul- The August RADIO AGE sitated the use of a muffler tube ahead taneously. The first method of attack will be the most unusual of the detector -oscillator to prevent may be considered an expedient, and issue of a radio magazine radiation. Thus, two tubes were still boils down to reflexing, causing one or ever printed. It will con- used, though the gain in signal strength more tubes to perform various functions, sist of more than 100 pages was equal to or slightly better than that such as radio and audio amplification of basic radio hookups from obtained with a good regenerative detec- simultaneously. This is not entirely tor and oscillator. At best, the system practical, in view of the frequencies to crystal to super -het, illus- is not entirely satisfactory for home be handled, except in one section -the trated with actual color assembly. frequency changer. Here, there is no RADIO AGE blueprints. Then came the development by J. H. reason why one tube may not be used for Don't miss this wonder Pressley, a Signal Corps engineer, of the the first detector and oscillator, provid- issue. balanced autodyne circuit, which not ing the separate tuning circuits may be Order your August issue only performs the required function with satisfactorily isolated. Up to the present, from your news-dealer now one tube, but does it much better than this has been impossible, except by the or send $2.50 for a year's either the second harmonic autodyne, second harmonic method, which will be subscription. with its amplifying muffler, or what has considered later. hitherto been considered about the limit 16 RADIO AGE for July, 1925 The Magazine of the Hour

ordinarily high amplification over a 10,000 cycle band, with a sharp cutoff either side. The amplifier, employing two of these transformers, together with a sharply tuned filter which is provided with a laboratory adjusted tuning ca- pacity, C5, gives tremendous amplifica- tion, for it also employs controlled re- generation, adjustable by means of R3. More Stages Unnecessary WHILE more than two stages mrght be employed, two will go down to the best noise level, so that more are unnecessary. Further, there is a decided drop in amplification in adding more stages, which will react upon the pre- ceding two, so that three stages give only slightly better results than two. Fig. 2. Interior view of the su er- autodyne. The instrument designations will be This should really be written "slightly found in the text. The sockets, rom left to right, are: VI, autodyne, V2, 1st R. F.; more noise," for two stages give more V3, 2nd R. F.; V4, 2nd Det.; 5, 1st A. F.; V6, 2nd A. F.; Socket shelves may also than enough gain. be procured for ÚV199 or C299 tubes. Before going into a description of a receiver designed along the lines out- for sensitivity -the regenerative detec- these coils, CX, CX and CI, which is lined, it might be well to justify the use tor and separate oscillator. This auto - made variable for the purpose of tuning of the name "super -autodyne." "Hetero- dyne circuit, in actual tests, appears the oscillator circuit. As previously dyne" is generally considered to refer to give a much greater gain than any of explained, this energy cannot get into to a source of external power-a separate the frequency- changing circuits previous- the loop circuit, so radiation is confined detector and oscillator tube. "Auto - ly utilized, and, at the same time, is far to what may be experienced from the dyne" refers commonly to a tube per- simpler to build and operate than any oscillator coil system itself -a negligible forming the functions of rectification of its predecessors. amount. By means of this circuit, which and oscillation simultaneously, so it was The Circuit is surprisingly efficient when it is con- considered logical to call the six tube re- sidered that one tube delivers a stronger ceiver a "super -autodyne" -and it cer- HE actual first tube circuit is shown signal than two tubes in the conventional tainly deserves the appellation, "super," in Figure 4. The coils L2, L3 are circuit, and is consequently much more for the results obtainable are surprising. theoretically equal, as are the condensers sensitive, it is possible to eliminate one Below is a log, representing one hour's CX, CX. Actually, they cannot be tube from the receiver, and still obtain work by an operator unfamiliar with the made fixed and equal, so CX, CX are better results than with two. system. The set was located 600 feet made adjustable, to obtain substantially The intermediate amplifier is the only from WGN, one -half mile from KYW, a condition of equality. These units other unusual feature of the receiver. and WMAQ, and many other Chicago make up a bridge circuit, shown by the It employs but two stages and is on the locals were also operating. All stations heavy lines. Since L2 equals L3, the order of those described by the writer were heard on the loud -speaker. potential across them is equal, so that in RADIO AGE for March, 1925. It WCEE 19 48.5 8 KSUO 87.5 78 L WTA8 23 61 8 WCBD 29 28 L it is also equal between points 3 and 4, differs, however, in that it employs EDKA 23.5 65 8 WHAZ 33 80 L 5 6. Likewise, special laboratory WGR 31 71 8 WLW 42 41 L and and the potential charted transformers WDAF 31.5 21 L WTAC 50.5 54 L across CX and CX is equal. Since the which are a compromise between the WTAM 36 31 L KEI 49.5 69 L KSID 36.5 33.5 L KSUI 48 32 L potential across 3 and 6 is the same for extreme selectivity of properly designed WCCO 40.5 39 L WQJ 50 45 L WOB 44.5 45 L WTAY 16 37 8 both inductance and capacity, then air -core coils, and the great stability WCAP 50 63 L WBCN 18 43 8 5 WSIII 53 58 L WJJD 22.5 61 8 points 4, and the joint between CX, CX and amplification of good iron core trans- WEAF 55.5 58 L WLS 28 85 8 are at equal potential, and are also formers. But two core laminations WCX 60.5 67 L WBAP 52 68 L are WOAW 63 WEBH 32 95 8 theoretically at zero potential, since used in each transformer, of 7 mill WGN 92 2828 these points are neutral with respect silicon steel, one in the shape of an "F" The station separation was very pleas- to 3 and 6. Then, circuit B1, C2, B2, and one an "L." The air gap formed, ing on some of the unlisted lower wave may be connected at these neutral points, - together with other recently developed stations, due to the use of the straight with substantially no reaction on the features of the design, permits the realiza- line- wavelength condensers. A compari- frequency of the bridge circuit. Further, tion of almost an ideal curve -extra- son with a standard five -tube neutro- as these points are neutral with respect to 3 and 6, no energy in the bridge cir- CIO cuit can get into B1, C2, B2, since there is no potential difference across these points of the bridge. Therefore, the frequency adjustment of the bridge cir- cuit cannot react upon that of the B1, C2, B2, circuit, and vice versa. Since the signal is fed from the loop and its tuning condenser to the oscillator, it will divide equally across the bridge arms. If a tube detector is connected across one capacity CX, the drop in potential may be used to cause rectifica- tion. It would appear that some of the signal voltage is lost by this method, but actually it is not. It is, as a matter of fact, considerably reinforced when the new component is finally fed to the amplifier, probably due to regenerative amplification. The coil Ll, coupled to er L2, L3, causes the bridge circuit to Fig. 3. Bottom view of the socket shelf assembly. Notice how all parts are rigidly oscillate at a frequency determined by fastened in place -an important feature for portable receivers. RADIO AGE for July, 1923 The Magazine of the Hour 17 dyne on a 100 foot antenna was unfavor- middle. A small speaker is to be recocu; The actual assembly of the receiver able to the neutrodyne both on the count mended for its small size and general is extremely simple, providing a standard of selectivity as well as sensitivity and portability, and it certainly talks up socket gang and a drilled panel are used. volume. A standard super (see March very much "bigger" than it looks. If this is not done, it will be necessary RADIO AGE) failed to produce any The material required to build this to drill up a sub -base and panel to take better results, as did another eight -tube received is listed below, with the designa- the instruments. The panel may be set employing air -core transformers. tion letters used in the diagrams and cuts grained if desired by rubbing with fine While the outfit will deliver about the following the quantity of each item sandpaper and oil until all traces of the same energy with either dry cell or stor- required. While it is entirely permissible original finish has been removed. In- age battery tubes, the dry cell tubes to substitute any other standard parts dicating marks for the condensers can will generally be sadly over -loaded, and for those listed, it is strongly recom- be scratched with a scriber and filled it is, therefore, suggested that UV- 201 -A mended that the parts specified be used with white. space tubes be used throughout, although for several reasons. The actual If Figures 2 and 3 are carefully studied, even so, it is possible to overload the available is such that parts of larger no difficulty should be encountered in sixth tube. This will be appreciated or different dimensions could not be mounting all the parts, following the when it is realized that in Chicago it is substituted in some instances, and in the designations shown, which are also possible to get volume sufficient for case of the RF Transformers, and SLW given in the parts list. As the parts dancing from the West Coast stations condenser, it would be inadvisable to are mounted, the wiring may be started on five tubes using only a small loop, substitute, since the results of the receiver and put in progressively on the base under favorable conditions. depend in a large measure upon the use and panel, then the two joined together The portability of the set may be of the types recommended. and the final connections made. It is storage battery tubes Cl. C2-8. L. W. Condensers. realized even with 4 Moulded dials, vernier type preferably necessary to use a well- tinned soldering means of special leads if a car is R4 6 ohm rheostat by R3 240 ohm potentiometer iron, with rosin core solder and some handy. These leads permit connection BL. 112. 53 insulated top binding pots leads 32 101 jack (1- spring/ non- corrosive paste. The battery to the car battery through the dash- Jl 102-A lock (3-spring) are brought out through a color cable, C5, 211 filter with matched tunlos capacity board light socket for the "A" supply. 210, 210 charted lntermedi.te transformers coded in accordance with the A. M. E. S. is it is suggested LI. L2. Lt. coupling unit If this not possible, 6 sang Rocket shelf (536-201 -A, No. 537 -199) code, thus obviating binding posts and that the necessary dry batteries be car- T1, T2, 3X:1 or 2.1 transformers 07. Cs .5 condensers providing permanently attached con- ried in an old hand satchel, or even a C3-C4 .00025 condensers with clips C9, C10 .002 Condensers necting leads at one operation. lunch box or tool kit. Then connec- C6 .0075 condensers CX, CX .000O25 condense,, After the receiver has been wired, the tions can be made quickly with the RI .5 Mec teak cable used for the battery leads, R2 2 meg leak necessary batteries should be connected color 81 No. 3 jack switch (S. P. D. T (S. P. S. T.) to it, the rheostat just turned on, and and the receiver set up in a few sec- .b2 8630 switch -o. 701 color cable (5 leads/ tube inserted in its socket. onds' time. This battery can also easily pair No. 8629 shelf brackets the autodyne Bakelite Panel. 7a218ea.tae The phones must be connected to the set, contain the folded loop and a small Small parts: 29 6/32 R. H. C. P. Machine screws Vas 2 6/32 R. H. N. P. Machine screw., the switch SI set at "L," Cl at 40, and speaker, when they are not in use. 31 6/32 nuts. I- spaghetti. 10- bun-0ar. Il25-lusa Blanket straps will provide an easy Tools required: C2 varied rapidly throughout its scale. I hand-drill with drills and counter -sink means of carrying the receiver, so that 1 soldering iron with rosin-core solder and non corrosive A "plunk" will be heard, indicating) panto the whole set can readily be managed by I .side -anti pliers an unbalanced bridge circuit. With one man. 1 screw driver one condenser CX set all in, turn the Inspecting the Set rotating C2, Portable or Permanent other CX slowly out, mean- AS SOON as the material has been while. If the plunk does not disappear, HE advantage of this arrangement procured, each item shoud be care- reverse the operation, leaving the other is that the same set serves for camp- fully examined to see that all screws balancing condenser all in to start with. ing or traveling that is used to provide and nuts are tight, and lugs placed as Once the plunk has been balanced out entertainment at home at other times. shown in the photographs, so that those for all settings of Cl and C2, condensers It is possible, if the builder prefers, to on the various instruments will point in CX, CX should never be touched. If have a luggage shop make a carrying the best directions for short leads. squealing or clicking is experienced at case so arranged that the receiver is at Socket springs should be bent up to make low settings of C1, it will be necessary the top, the batteries below, and the good contact with tube pins. Condenser to use a smaller grid leak at R1. This loud speaker in the lower compartment bearings should be adjusted to give the leak will generally vary between .25 with them, either at the side or in the desired tension. and .5 megohms.

z R-1 R V_E ó 100 V-4

C-5 .Z 4

C. I

R-5 NOT

5.1

C -AF YELLOW SLACK- RED o TRACER Bt bz Bs Bí45 Bíeo A+ BROWN BLUE REO Fig. 4. The wiring diagram of the new super- autodyne receiver. Heretofore to obtain neutrodyne results on a loop aerial, seven and eight tubes were necessary. But in this receiver only six tubes are needed to achieve the same end. The the 18 RADIO AGE for July, 1925 Magazine of Hour Vacuum Tubes as

01110110 .._.+ ----. i 000 .2 . = 411101110..... Mila0.0=11.=m, ..... 1= .1=1.1=1110 ®11==0 sjMMa 11= a===.0=0==100u ° == ..=00 100 - Mmmm m 0 =---eY..- w 1, =- __s0 .,===o011, /i Devices Some Interesting Sidelights on By DR. PETER The Repeating Function and 1. WOLD "Distorting" Function of Tubes IN THESE days all of us have be- peating electrical variations impressed on give oscillations of an audible frequency. come so well acquainted with vacuum the grid generally with amplification and, The repeating action of the tube and tubes, through actual use or through at least theoretically, faithfully, or with- its circuit, with amplification, would the countless articles on radio sets out any distortion. By the second, I refer probably be held to be the more impor- making use of them, that anything to that property of the tube by which tant property,- for it includes such further might almost seem superfluous. electrical variations on the grid result applications as long distance telephony On the other hand, there may be some in variations, generally amplified, which and all the actions in radio work men- who have only recently acquired an are substantially different. As an ex- tioned above, except those of detection interest in radio, or it may be that the ample of the first, we may take the and modulation. On the other hand, exceedingly versatile device very com- relaying of telephone messages across its property as a distortion device is the monly but very poorly called a vacuum a transcontinental line in which the more interesting, though not so gen- tube offers some point of view which greatest precautions are taken to make erally understood. may be new to many. the repeating action as faithful as possi- Let me remind you for a moment of If you have followed the radio art ble; i. e., to reduce distortion to a mini- the essential elements of the standard for some time, you have heard of these mum. As an example of the second, vacuum tube. There is a filament tubes being used in a number of dif- we may take the detection of a radio which may be raised to a high tempera- ferent ways, as for audio frequency message in which electrical oscillations ture, whereupon it may give off electrons amplification, radio frequency amplifica- or variations of perhaps a million -those smallest particles of matter or tion, detection, regeneration, reflex re- cycles -and therefore quite inaudible electricity which we have come to generation, any or all of these occurring -are so distorted or converted as to recognize as playing so important a in your receiving sets; and if part in all our affairs. Then your interest carries over to there is a plate kept at a the broadcasting station, you positive potential by the B have heard of oscillation battery, and which therefore generators and modulation. attracts the electrons from All of these terms may the filament, thus giving rise suggest a confusing variety to an electric current to the of uses for the vacuum plate. Finally, there is the tube, but it may simplify grid placed between the two. matters if it is pointed out When the grid is made more that this tube has two positive, a larger current functions only, which are flows to the plate and separate and distinct, and through its circuit, and when the various uses mentioned it becomes more negative come under the one or the a smaller current flows. It other. These two functions is possible thus to control a may be spoken of as the current by changing the repeating function and as the potential of the grid; and the distorting function. The two important point is that the are present in every tube in energy for exercising this an amount depending on the control may be very much design of the tube; i. e., the less than the energy of the relative sizes and spacing of controlled current. It is for the elements in the tube. this reason that the device By the way in which the acts as an amplifier. tube is operated, and by the circuit with which it is asso- Getting Minimum Dis- ciated, one of these functions tortion may be emphasized. IF, starting with a small What It All Means current to the plate, you draw a line showing how this BY the first of these func- Fig. I. A typical grid charac ertsttc char for /99 type (3 volt) current changes as t he poten- tions. I mean that of re- tubes with plate voltages of 45 -80 and 90 volts tial of the (Turn to page 60) RADIO AGE for July, 1925 The Magazine of the Hour 19 The Correct"orrect "B" I-3" Battery for your Portable Success Liberal or Failure Supply of the at Start Vacation Will Radio Depends Insure on the Success Condition of Your "B" Battery By Edgar H. Outfit Felix

THE B battery is the power plant of Economical upkeep and long service with- any B battery, in milli -ampere hours, is your radio set and its failure means out renewal of batteries must give way to proportional to the quantity of active that the portable is temporarily the utmost portability. For this reason, chemicals within each cell. Only a cer- useless. At home, batteries are not the smallest and lightest B battery ob- tain amount of each essential chemical difficult to replace from the liberally tainable must be used, because the larger can be placed in a given space. Conse- stocked shelves of a nearby radio store, sizes are altogether too bulky and heavy quently, the size of the battery places but in the wild and woolly haunts where to be carried for any great distance. definite limitations upon the output many of us seek rest from the rigors of To meet these requirements, B battery which may be expected from it. The city life, B batteries are as rare as the manufacturers have placed tiny radio smaller the battery, the shorter its life proverbial dinosaur. power plants on the market. These con- and its current output. B battery costs, Hence, give this important element of sist of an assemblage of very small cells, per hour of operation, increase rapidly your Summer radio set all of the consider- sealed in a small container. They repre- as the size of the battery becomes smaller. ation which it deserves. Take the same sent the greatest possible amount of Before starting on your trip with a precautions that you would before start- electrical energy which can be crowded portable set, be certain that you have a ing on a motor trip across a hundred into so small a space. But the output of B battery power supply which will last mile desert -make over the period of sure that your fuel your trip. Do not supply will be suffi- expect long life from cient to carry you to tiny batteries called the next service sta- upon to deliver tion, with an ample heavy currents for margin to spare. multi -tube sets. There are two The smallest B bat- kinds of service for tery, shown at the which portable sets left of the illustra- are designed and tion on this page, your B batteries has all the capacity should be selected which can be incor- with these in mind. porated in a battery First, there is the of that size. It has pack set, which can a volume of 17.5 be carried on a hike, cubic inches. like other portable The next larger camp equipment; size, at the center, and second, there is has a cubic content the self- contained of 28.6 cubic inches, semi -portable, for or 63% larger. The temporary installa- tall, slim battery at tion during vacation the right is 50.3 time, in camp or cubic inches or bungalow. 186% larger than the smallest battery. The Pack Set Obviously, there is IN THE pack set, considerable advan- everything must This layout shows the various sizes of "B" batteries. It is advisable to spend tage both in milli- be sacrificed to se- liberally in equipping a portable set with "B" batteries, for a stingy investment at the ampere hour capaci- cure light weight. start usually results in woe later on. ty and economy in 20 RADIO AUE for July, 1925 The Magazine of the Hour

The illustration shows five sizes of Storage "A" Battery B batteries in such a manner that you will S'ee No. Type Total Recommended be able to identify them when you pur- Voltage of of Rated chase B batteries for your portable sets. of Tubes Tubes Ampere Amp. Hours Days The smaller sizes, shown Tubes in Set (see foot -note) Drain at 1 Amp. between at the front of Drain Chargings the illustration, should be used only when 65 22 portability requires their selection. Their UV-200 1 -or output in milli -ampere hours increases 47 16 more than in proportion to their increase 2 UV -201A 47 33 in size. Considering that the largest of 80 22 these portable units-the tall battery 1 UV-200 1,Y, - or at the right -has less than 25% of the 2 1 UV-201A 65 17 electrical capacity of the large battery 65 29 shown at the left in the back, the greater 3 UV-201A . 22 lasting qualities of the larger batteries become obvious. 95 21 The large size, back of the - 3 I UV-200 1!".; _or small bat 5 -Volt 2 UV-201A 14 teries at the left, has considerably greater Tubes 65 22 lasting quality than the next preceding 4 UV-201A 1 size. It is the middle ground between C -300 and UV -200 47 16 the utmost economy, as embodied in the are interchange- 115 22 extra large size, and the uneconomical able 4 1 UV-200 1?í r smaller sizes. There are 3 UV-20IA 80 15 several makes C -301A, DV -2 and of semi -portable sets equipped with 80 22 battery compartments which will UV -201A are in- 5 UV-201A 1!í house terchangeable 65 17 these large batteries. On the other hand, if is 115 19 it possible to 5 1 UV-200 2 employ the heavy duty battery for a 4 UV-201A g9 13 three or five tube set, as illustrated at the 95 21 right, you attain the greatest econ- 6 UV-201A 1!! or possible in radio as 14 omy receiving power supply.l These batteries will last much 125 21 longer than the smaller sizes 8 UV-201A 2 and they 95 15 represent the best buy in radio power. 140 22 Selecting Strong Batteries 2.',s using cur- For sets 95 13 1ATHEN selecting a storage rent at a rate higher battery, than 2 amperes. 140 19 every owner of a receiving set 2 desires one of sufficient capacity to make 125 16 frequent recharging unnecessary, yet Fer combinations of tubes not listed: Use the same battery combinations recommended for tubes small reduce having voltage and current requirements similar to the tubes you have. enough to the first cost to a NOTE: If you use a loud speaker operated from your "A" Battery. add 35 ampere to the total minimum. Has ideas as to just what to rated current drain of your tubes and then select a battery giving this total current consumption. specify, in order to obtain this highly desirable combination, may be somewhat This chart, recently prepared by storage battery experts, should come in handy for hazy, but he is never in doubt as to the jans whose knowledge of "A" battery characteristics is limited. Cut it out and tack result he seeks. it up near your radio set. Various types of storage battery selec- tion charts have been developed in the buying the largest possible battery which provide sufficient space for larger bat- past, which were intended to assist the you can carry with you. teries, leave the diminutive batteries owner of a receiving set in making a A pack set, intended for several weeks' home, and make space in your car for proper selection. Lately a chart has been use during vacation time, will give more large or even extra large B batteries. developed which takes into consideration satisfactory service if large batteries are If you have room for a radio set, you have number, type and combinations of tubes used outside the set, while it is used at its room for the right kind of batteries to go in a way that makes selection of a satis- semi -permanent location. When design- with it. Nothing takes quite so much factory battery a simple matter. ing your portable, therefore, equip it with space as a radio set which is useless Voltage of ,tubes, number of tubes, flexible B battery leads so that, whenever because its tiny inadequate B batteries type of tubes, rated ampere drain and re- possible, you can use larger batteries and have given out. charging interval are treated in the chart so that you may limit the service on the The realization that an adequately in such a way that the receiving set owner small batteries to those occasions when powered set is the only kind which gives has a choice of two recharging periods. convenience in portability compels their satisfaction is gradually becoming general. For instance, for a set using one UV -200 use. For instance, if you plan to take Nevertheless, many sets on the market, and three UV -201A tubes, with a rated your set with you on an all -day picnic, including some intended for permanent ampere drain of 1%, and "A" battery of use the small portable batteries; but when installation, are equipped with compart- 115 ampe -es (at one ampere drain) will you get back to the permanent camp at ments for small B batteries, encouraging give 22 days of service without recharging the shore of the lake, substitute the larger inadequate sources of power supply. when used for an average of three hours batteries for the smaller ones. Your two On any loud speaker set, the audio- daily; while with the same tube combina- sets of batteries may then last you all frequency amplifier can be made very tion, a battery of 80 amperes will have a through the summer season. economical in its current requirements recharging interval of 15 days. Similarly, The Semi -Portable Set through the use of a C battery. A 43 for a set having three UV -201A tubes at volt negative bias on the grids of the ampere drain, a battery of 65 amperes THE semi- portable set can give all of audio-frequency a mplifiertubesfrequently insures 29 days' service while the smaller the satisfaction of the permanent reduces their current drain by one -half 47 ampere battery gives 22 days' service installation, so far as battery upkeep is or two-thirds. Consequently, the little between rechargings. concerned. Thousands of motor campers C battery is well worth its weight, even By calling attention to the types of take good radio sets with them because in a pack set. The current drain to tubes that are interchangeable, it will be they provide the finest kind of entertain- which the C battery is subjected is so noted that the accompaniyng chart gives ment after the day's drive. Even if the small that its serviceability is limited practically every combination of 5 -volt battery compartments in the set do not only by its shelf life. tubes in general use. RADIO AGE for July, 1925 The Magazine of the Hour 21 A Simplified Portable Super By A. J. HAYNES Here is An Outfit Whose Cost Can Be Kept Well Below $j3o by the Careful - Home The set described by Mr. Haynes, wired and ready Builder to go into the cabinet.

A Popular Receiver That Will Give Dependable Loud Speaker Results in Summer Up to 1,000 Miles

FOR the past three years, portable article has been thought out with com- the batteries still have lots of pep. radio sets have been built in great plete portability, low cost and good per- The "What will it do ?" club is prob- profusion -in Winter conversations. formance as the primary considerations. ably becoming quite anxious by now, \Vhen the good old Summer time rolls The set is completely self- contained. and it is fair that they be answered. around, however, rarely does a radio Although the loop is built in the case First, claims of the "coast-to- coast -on- set accompany Dad in his jaunt to the cover, it will be found as efficient as the the- loud -speaker -in- daylight" type are Maine woods or the family on their ordinary loop of approximately the same ruled out. The set will give dependable annual flivver trip. dimensions. The cost of the outfit can loud speaker results in the Summer time This lack of enthusiasm in the past be kept below S130.00 for the complete on stations up to a distance of 1000 can be attributed to a number of real units and this price includes all the neces- miles. This means results which you reasons. There were only two or three sary tubes and batteries. Even this can enjoy and, if you are listening to broadcasting stations with sufficient comparatively low price can be cut con- music, dance to it without having to power to make reception pleasant through siderably by judicious shopping. imagine half of the tune. On nights static disturbances a year ago, many that are favorable to reception, you portable sets were "portable" only be- Same Constants can make a very comfortable and cause the case was leather, and sometimes YOU substitute parts other than thorough tour of the country via the the batteries were enclosed, and finally, IFthose shown in the material list, be loud speaker. the cost of a good portable receiver was sure that the new parts have constants Most of the tests run on this set were almost prohibitive for the average exactly similar with those specified. made in Chicago, which is notorious family. The circuit employed is a conven- for the difficult receiving conditiops This year these faults have been rem- tional "regenerative loop" affair. The caused by the numerous and powerful edied to a great extent. Stations have only change which you might notice is stations there, and the results were increased their power until the "static the fact that the pickup coil is placed in highly satisfactory. The set was tried level" has been pushed some hundreds the filament lead instead of in the grid in the North, West and South sections of miles into the sticks. There are now lead of the first detector tube. This of the city -each with its own particular a number of factory built portables was done to reduce body capacity effects, set of problems, and in no test was the which can be classed as real sets, and which are often severe in supers using .a set unable to pull in fewer than fifteen what is more important to most of us, grid pickup with regeneration. out -of- town- stations. These tests were the cost of both parts and accessories The battery supply indicated is wholly all made while the local stations were has moved downward in a very satis- adequate for the drain put on it. Our broadcasting. factory manner during the last year. test set ran almost continually for two You can have the carrying case con- The design of the set shown in this weeks while we were making tests and structed by a local firm or a suitable

The socket strip for the simplified portable super -heterodyne, showing one filament lead and method of binding lugs for other filament lead. 22 RADIO AGE for July, 1925 The Magazine of the Hour case may be purchased from one of a place a lug under each nut number of firms advertising them. Ow- which locks both a socket ing to the chance for confusion, it is best and condenser in place. to cut the leads only as needed and to Here is the This is done at points A10, completed set All, and Al2. mark the drawing as they are used. In ready for ac- this way a double check is kept on the tion, with a Before attaching the new type of in place, work as you go along. loud -speaker. .00025G condenser This is trulya put a 6- 32x(' machine Assembling and Wiring the Set portable out- screw conden- fit. and tests through the If the instructions given are followed in the crowd- ser at H5. Lead No. 35 is ed Chicago now carefully, particularly the order in which area showed cut to length and at- are connected, the average it cuts thou tached under the nut at L the leads locals up to fan should be able to complete the wiring 1,000 miles and the other end secured less. The on the speak. at L1, the Grid of the first of the set in three hours or er. That's time required to complete the balance good for sum- detector tube. on the cabinet. mer, isn't it? Lead No. 1 is attached at of the work depends Note the loop If you have purchased one ready -made, wound in the the end of the 5' section to the set should be operating about four cover. the first grid condenser at hours after you start work on it. HS. The only two leads which must be Leads are now partially soldered in the set itself run to the jacks completed to each of the and, owing to their posi- by-pass condensers on the tion, are easily attached. socket strip. Lead No. 25 is soldered to the .006 con- Material List denser at G4. Solder one

1 5":16.54"9/16" Bakelite Panel end of lead No. 22 to the 1 14 "s16 3/16" Bekehre Strip other .006 condenser at D6. 1 7'216 W.:3/16" Venom Baseboard 2 .0005 mld. Venable Conde ooers One end of lead No. 26 is 1 Set I. F. Transformer, 1 il.rilr.tor Coupler soldered to the .005 con- l 3 Plate Condenser lc Knob denser at C4. At L2 of the 8 17V199 Sockets 2 Audio Transformers .002 condenser solder lead 1400 Obm Potentiometer No. 23 and attach the other 1 Filament Switch 2 Jacks end to the plate of the 1 Turait Condenser second detector tube, L. 2.006 red. Condensers 1 .005 mid. Condenser The lugs which were left at points A10, I .002 mid. Condenser All and Al2 are now turned until they 2 .006-50 mid. Condens- pass under the nuts at A6, A8 and A13. e 13 Megohm Grid Leak The negative filament lead is later 15 Megohm Grid leak 110 Osm Type 301 attached to these points and the lugs form Rheostat. a very method of making 50 ft. Hookup Wire convenient 3 ft. 5-conductor Battery Cable When the panels have been drilled short leads. 29 6-32a5/16" F. H. Brae. Machin. Screws Leads 8 and 9 are now cut from two 12 632:W F. H. Brass Machine Screw, and countersunk, mount the proper parts 7 632a1 (" F. H. Brea, blastulae Screws on the panel and baseboard. Do not pieces of round bus bar and form the two 40 832 Brass, Nuts, Across Flats filament lines on the socket strip. 12 632 Bram Nuts, W Across Flat.. mount the oscillator coupler on the base- bus 2 Brackets No. 1509 board at this time, as there is some pre- Place a lug under each of the filament 2 Brackets No. 1506 8 Brackets No. 1505 liminary wiring on it which can be done terminals on the sockets projecting at 3 Brackets No. 1478 9 Dos. Small Luca more easily if it is not mounted. 6-32x right angles to the socket strip, bend 4 Length, Rosin Core Solder insert solder 18 Brass Washers sDfscóme Screws ßñ' machine screws are used to secure the tips to right angles, and Brass the instruments to the bus bar and finally bend the com- 5 Rubber Bonding Posts the board. 4 Bakelite Loop Support Store pleted leads as close to the sockets as 100 ft. Stranded Loop wire The Socket Strip 1 Portable Cabinet possible. No identifying letters have 1 Loud Speaker THE assembly and partial wiring of been placed on the diagram to show the Bakelite was chosen for the first two the socket strip should now be under- position of these leads but as the sockets panels because of its mechanical strength. taken. Where a bolt is used to attach are marked, you should have no difficulty Veneer was chosen for the baseboard only the socket to the strip, use 6 -32xW in doing the job correctly. These last because of its cheapness and light weight. machine screws. Where a bolt attaches operations complete for a moment the If,.however, you wish to use hard rubber both a socket and a condenser to the work on the socket strip and we shall or bakelite at this point, there are no strip, use 6 -32x1 %" machine screws turn to the wiring of the oscillator reasons why you shouldn't. and cut off the extra length. Be sure to coupler. SCHEMATIC DIACIRAM ,C tn.tenea IV t'! mmo se mete tB 05,5C1el esta,la.e: ue,e ,avúiw c . 144444444 retQet,R tateelaC. ftl.ul,CY . .titan µro out atta.t taw sua

- ° 1 = 1 I _: mYe SRaaK l tÓeöï,Sta a: i.iA+ ï.oi,DtMiq N

tteet,StR

A 41101=10 14 bi=MINMIalaM, , roo oar pontes ostt.ttt m Otlw ,,townnr.. The schematic wiring diagram of Mr. Haynes' receiver. By following this layout the bsginner should have no trouble in building 11the portable super. RADIO AGE for July, 1925 The Magazine of the Hour 23

LOCATION OF CONDENSERS ON BOTTOM OF SOCKET STRIP e --e 00025 y

The oscillator coupler consists of three is meant respectively. Attach one end Attach the lug at the end of the 10" separate windings: the pickup coil, the of lead No. 32 to the inside terminal of section of lead No. 5 to the outside ter- grid coil and the plate coil. In referring the pickup section at A7. Lead No. 3 minal of the plate section at Cl. Fasten to the "inside" or "outside" connections is attached to the outside terminal at lead 11 with the tap at the end of the to a section of the coil, the tap nearest H3. Lead No. 19 is attached at J to the 10 3,6" section to the inside terminal of the center or furthest from the center inside terminal of the plate section. the grid coil at El. The lug at the end

LENGTHS OF LEADS 11-4 5E1 .w s -4 2 RL z .; D u-

1 .P_ LF ------5rs c( -KY r L't- - zó s s -4 'i of the 73(1" section of lead No. 13 to o the outside terminal of the grid coil at . .. .. - lL- - K. This completes for the moment, the 11 wiring on the oscillator io[ coupler. The battery cable should be prepared m s a- zs for use by cutting away the covering for IS of 14". Whipping (}- Ty a distance the cover- M ing at this point will prevent fraying of the covering from taking place. Use D fairly heavy thread for this purpose. z. s Measure the length of the battery leads + u from the point that the covering is cut. ] i- The C battery negative is lead No. 10. S -. --z4 ; ------xl Filament negative, B battery negative i-- is lead No. 14. B battery positive de- tector is lead No. 39. Lead No. 21 is the !:5 t° .-..;Z 3s f ^7 4- filament positive. B 'Battery positive xf x II- 11 is No. 20. F S -D amplifier lead :,<¢ w L Lettering used to designate battery - circuits are based on the following list: nß--. ai S' - - --1 L "6 - A minus B minus Letter A LD o VII x S = r, 5> A plus Letter B

x;- - - --r - .- 55 B plus detector Letter C u 5) I 4 B plus amplifier...... Letter D z5- S4 TJ C minus .. Letter E x C=r11- (Turn to page 55) 3 t RADIO AGE for July, 1925 The_ Magazine of the Hour Tricks of Summer K Radio LOS A

Suppose a receiving station in Chicago is receiving both from Ncw York and Loa Angeles. A patch of radio fog might appear between .2 New York and Chicago and P,,G weaken the Ncw York sig- nals. while the signals from %m,.Eou. A Realistic Los Angeles remain un- qnIlry changed. The map shows . to,, bow we sometimes receive /Ilvir gil4_ Analysis by signals from the West bet- ter than those from the less distant East. A. F. VAN DYCK

EVERYONE who has a radio receiving that some things in space will stop, or possible to work radio communication set has met the atmospheric nuisance reflect, or perhaps absorb the travelling over much greater distances at night than called ":static." It comes in, especially radio waves, just as some other things in in the daytime. This may be explained during the warm months, and interferes space stop or absorb or reflect light by the effect of the sun upon the air, with clear reception. A particularly waves, or sound waves. We must not which causes ionization of it, and is most pleasing musical number may be on, but expect radio waves to travel out from a active in the daytime and practically that makes no difference to Old Man transmitting station, over some enor- absent at night. The sun seems to be Static. mous distance to a receiving station, responsible without question, in view of So many inquiries have been received without encountering some obstacles the fact that very erratic results in long at the General Electric station, ¡VG Y, at somewhere in its path. distance reception are always noticed Schenectady, that A. F. Van Dyck, a radio at sunrise and sunset. engineer, has prepared the following How Radio Pierces Walls Wave Power Variés paper, explaining some things that are SUBSTANCES which are obstruc- known about static and what is being tions to light or sound waves -are not .ATITH the preceding statements in done to get rid of it. Mr. Van Dyck's necessarily such to radio waves. For 11 mind, it should be clear that when explanation follows: example, we know that radio waves pass one is receiving over long distances - through the walls of a house with only several hundreds of miles -it is natural IN THE letters which WGY has slight loss. But there is some substance for the waves to come through strong at received from listeners, certain ques- in the space around the earth which one moment, and to fade away consider- tions have been asked by many does have effect upon radio waves. This ably the next moment, as some obstacle different inquirers. Some of these substance is not uniformly distributed to radio waves comes between the trans- questions involve radio phenomena which through space, but is present here and mitter and receiver. This explains, too, are not completely understood by scien- there, and is continually changing loca- why one transmitting station, of two or tists today, and the answers and explana- tion and magnitude, and consequently more which are being heard, may gee tions which we shall give should be under- has very erratic effects on the passage of weaker, while the others do not. For stood to be the ones which are believed radio waves. example, suppose a receiving station in to be nearest the truth, although they The condition is quite similar to the Chicago is receiving from New York are not subject to rigid proof. use of a searchlight in a fog, which might and also from Los Angeles. A patch of First, let us consider what radio be varying rapidly in density or location, radio fog might appear between Chicago transmission is. We know that a radio or both. This radio fog is commonly and New York and weaken the New sending station sends out from its an- supposed to be made of ionized air; York signals, while the signals from tenna in all directions, a disturbance of that is, air which by some influence has Los Angeles remained unchanged. When- electric forces. We cannot see or hear become a partial conductor of electricity. ever in reception over a considerable or otherwise observe with our senses just Of course, this radio fog never stands distance, one observes a variation in the how this disturbance behaves, as we can still and is changing from moment to intensity of the signals, it is most likely with light waves and sound waves. moment under the influence of the com- due to so- called "fading," caused by We consider it quite natural that a stone plicated conditions of our atmosphere, some obstruction to the traveling waves wall stops the light beam from a search- and so the radio wave passing through somewhere between the two stations, light, or that a bugle call can be heard space surely has an adventurous journey and not to any fault of the transmittin, much farther over water than through a because it meets electrically charged station itself. These effects are much forest, or that under certain air condi- clouds, patches of ionized air, and per- more frequent in the Summer than in the tions on a desert, the mirage phenomenon haps other obstacles of which we know Winter, presumably because of the great- is observed; and to know what to expect nothing. er influence of the sun on the earth and in radio, we need only to remember It is a fact often observed that it is (Turn to page 60) RADIO AGE for July, 1925 What the Broadcasters are Doing 25

Gloria Confesses

Gloria Swanson, who since her marriage to a dashing Frenchman is Marchioness Something-or- Other, made her first broadcasting appearance under her new name from WGN, located on the Drake Hotel, Chicago. Seated before the "Mike," she answered sev- eral exceedingly personal ques- tions put to her by Announcer Quin A. Ryan of WGN. The questions, by the way, had been sent in by inquisitive listeners who had been notified of the famous "Radio Inter- view" with Gloria as the Inter- viewee, who seemed willing to tell all her deep secrets for her radio and movie admirers.

Copyright by Duke Studio. Cbioggo) 26 RADIO AGE for July, 1925 What the Broadcasters are Doing what the Broadcasters are Doing

Portable " Pick -up" Station McNamee of WEAF Chosen for KDKA Best Announcer 9-10 TAKE care of the ever -increasing GRAHAM McNAMEE of WEAF "pick -up" situation that has con- D was selected as the best all -round fronted Westinghouse station KDKA, Iris Virginia Gruber has the distinction of broad- local announcer by the Radio Voice casting more than any artist in Philadelphia and at E. Pittsburgh, the Westinghouse is the winner of the Radio Cup presented for Technique Committee of New York department Engi- singing the greatest number of times during the University at a meeting held recently, engineering detailed January 1st neer Carrol J. Burnside to construct a concert season from to May 1st. according to announcement made by portable short wave sending station, the committee. McNamee nosed out to permit the immediate and practical Brockenshire of WJZ by the small broadcasting of various interesting and "Ford and Glenn" to margin of four -tenths of a point, the important events, as they take place in Tour U. S. scores being 87.3 for McNamee and their vicinity, despite the fact that FORD RUSH and Glenn Rowell, 86.9 for Brockenshire. location may not permit telephone wire the "Lullaby Boys," whose songs This committee meeting terminated connection with KDKA. and bed -time stories during "Lullaby the series of three which were held A one -ton truck chassis was pur- "Ford and Glenn Time" during the past four months under the Hour" and direction chased and suitable house -body built, over WLS, the Sears -Roebuck station, of R. C. Bordon and A. C. wherein the pick -up apparatus was con- Chicago, have endeared them to the Busse, voice experts of New York Uni- structed. The requirements of this hearts of kiddies and their parents versity, to determine the ideal qualities transmitter were that it be absolutely throughout the nation, will start on a to be looked for in radio announcers. dependable at all times, in any loca- transcontinental tour of the United The aim of the committee, which is tion, and make use of a low wavelength, States June 2. The WLS favorites will composed of radio editors, . dramatic which is free from interference. The broadcast their most popular features critics and members of the faculty equipment must be compact and its over nineteen of the principal radio of New York University, is not to personnel small and upkeep low, to stations clear to the Pacific Coast. standardize the voice and art of broad- justify its use. The body of the truck The journey from station to station casting, but to point out faults to be is 5 ft. wide by 9 ft. long and is 6 ft. will be made in their new sedans, in avoided and to determine what the high inside, solidly built to withstand which they will carry complete camping public prefers to hear. the jar of movement of the truck in outfits. In many of the places they Special phonograph records were made motion. All equipment is cushioned to will live out in the open with their by Mr. Borden and Mr. Busse of repre- minimize the jarring of apparatus. families, who will accompany them. sentative announcers from the following The transmitter is a quarter -KW get, nine New York stations:-WJZ, WEAF, using 110V from lighting circuit where WGBS, WHN, WEBJ, WOR, WANG, program is being broadcast, and a power WMCA, and WBBR. Each announcer transformer in the truck is used to step passed upon his own record and all up to the high voltage required to oper- those entered in the contest had been 1 ate the set. Power at this high voltage accepted by the makers as fairly repre- is passed through a vacuum tube rectifier sentative of their work. using two quarter KW air -cooled recti- Ten men out of the number considered fier tubes, which gives single phase full were chosen as the best local announcers. wave rectification. The output of the In addition to 111cNamee and Broken - tubes is passed through a brute force shire they are Barnett of WOR, Reed filter of choke coils and condensers, of WJZ, Carlin of WEAF, Squires of which delivers 2000 volts DC power to WMCA, Granland of WHN, Haupt of the transmitter, which makes use of the WEAF, Cross of WJZ and Morgan of standard Hartley oscillator circuit with WGBS. Heising modulation. The committee rated the records The equipment used in this portable upon the points which were decided set is capable of wavelengths varying upon at earlier meetings as those most from 20 to 100 meters, although the desirous for radio announcing. They set will ordinarily be operated on about are as follows: (1) Average rate of 53 meters -KDKA to pick up its broad- speaking -175 words a minute. (2) cast and rebroadcast on their standard Pitch of voice -low middle range. (3) wavelength of 309 meters. Announcements should be made with Because of a likelihood of broad- variation of rate, pitch and stress. casting from some downtown section (4) Manner of announcer -formal but of the city, where it would not be prac- friendly. (5) Distinctness and enun- tical to operate a regular antenna, a ciation. vertical oscillator type is used. A Above is "Si" Berg, nationally known ukelele A summary of the comments made copper pole of three sections, of the artist and songster, who has appeared all over the country before prominent microphones. He is by the committee during the course of telescoping type was constructed, which now appearing consistently from WHT and KYW, the meeting has been arranged by Mr. is folded and stored in the truck when Chicago, having contributed recently to the success of many RADIO AGE programs from Borden and Mr. Busse for public dis- not in use. the latter station. tribution. RADIO AGE for July, 1925 1Vkat the Broadcasters are Doing 27 alluring THEMiss adorning the perfume boute is none other than Mlle. Rosario Duprez, promi- nent New York fashion queen, who is telling the hap- Radio's pas and gay ma- trons in the East how to achieve per- sonality by means of perfume. Need- less to say, she has a large feminine "I nterview (and masculine) following, both for her radio as well as her pulchri- tudinous attain - ments. Lady'

(THE Great and Scoops the the Near Great Appear Before the WGBS "Mike- in World! New York To Be Interviewed and Reveal How to By MILTON Achieve Success. L I EBERMAN

AWOMAN has brought the news- and I waited until she had finished her them. There was Rube Goldberg, Miss paper to the radio world. She has call. Oliver Herriman, Jane Cowl, Tony woven the two togteher and has "I just did a good piece of newspaper Sarg, Victor Depew, the cartoonist, brought shortcomings of one to be val- work," she told me. "I was just inter- Willem Van Hoogstratten, conductor of uable features of the combination. viewing Mrs. Anna Norton, who was the New York philharmonic orchestra, She is Terese Nagel, the "Interview" chairman of the democratic party during Fay King, several actresses, including lady of WGBS, the Gimbel Brothers their national convention, and found Miss Blanche Yurka and Miss Mary store, New York City. A newspaper that she is going after a big political job Mellish. The Hamilton brothers, Cosmo woman of ten years experience, Miss here in New York. I rather think that Hamilton and Hamilton Gibbs, were Nagel, just a short time ago, brought she let it slip unintentionally, but I very interesting. There was also Coun- that most famous, of newspaper features, found out that she will run for the tess Caroli, whose husband was first the interview, within reach and audi- nomination for registrar of the city. president of the Hungarian Republic. bility of every radio fan. It pays $12,000 a year. I just finished "It is very interesting, and I think I The scheme is clever. Nearly every- speaking to the city editor of the New shall bring more newspaper features to one wants to become as nearly acquainted York American, and the air. I plan to as possible with famous people, but it he has congratulated start a radio column seemed a difficult matter to bring the me. and become the first celebrities to the public through radio. "That just goes radio columnist. Those who could sing or play an instru- to show," she con- The public will be ment, of course, were immediately tinued, "that the asked for a name for brought on the air, but it remained for radio has unlimited the column and con- Miss Nagel to bring those who conquered possibilities. Just at tributions like those art in its more inaudible forms before present knowledge used in newspapers the microphone in a satisfactory manner. of who will run will be accepted." for registrar is very Rosario Duprez She Gets the Celebrities important, and the is another favorite ALMOST every person of importance fact that a woman from WGBS. She in New York and visiting the city will do it makes the is the "Perfume and has spoken before the WGBS micro- scoop valuable." Personality" lady phone through the efforts of Miss Nagel. who believes that She takes them there, and then, with her How She Does It perfume, properly newspaper instinct and ability, draws SHE then told me used, will enhance forth their thoughts, their hopes and am- about her job of the personality of bitions for all the world to hear. Fay interviewing celeb- any woman. Miss King has called Miss Nagel the "news- rities, and how, by Duprez, unfortun- paper woman of the air." her clever questions, ately,cannot be seen She got a "scoop" the day that I she draws informa- on the radio. Un- visited her for an interview on her work. tion from them fortunate it is, for When I approached the beautiful studio which they proba- she is the essence of on the seventh floor of Gimbel Brothers, bly would never di- MARY MELISH, famous Broadway charm and person- having passed a group of people who were vulge in another stage star, was one of the first celeb- ality. WGBS, how- standing outside of glass- windowed reties to be interviewed by Miss Nagel ever, has many other the way. from WGBS. The radio audience en- studio, I found that Miss Nagel was on I have inter- joyed her demure confessions of stage ambitions, besides the radio. viewed hundreds, of life, but they would have enjoyed them linking newspaper She finished her interview and dashed famous people. I much more if they could have seen the work and perfume for the telephone. "A scoop," she said, can tell you some of lady in question. (M. Kesslere Photo.) with radio. 28 RADIO AGE for July, 1925 What the Broadcasters are Doing A Station Where They Broadcast ,.- tt "Personality"

By C. Clyde Real Joy Cook, who Dispensers Knows His at KHJ Keep Hollywood the Home as Marconi Fires Knows His Burning in Radio \ California Three of KHJ's scintillating stars are .shown above, in their proper atmospheric setting. From left to right they are "The Sand- man," who lulls the children to sleepy land, "Uncle John" Daggett, Oÿ the Good Samaritan of KHI, and on his knee, the little Queen Titania, who is a fairy optimist for thousands of hard -working Californians.

WHEN Signor Marconi invented has epitomized, is that intangible and cated KHJ to the horde of inhabitants the Wireless Telegraph, little did indescribable force which, of necessity, of Radioland on April 13th, 1922. Like he think that in the near future must come from within. Which, re- Aladdin's magic lamp, Uncle John has this same great invention would advance duced to understanding English, only wrought miracles with this magnificent with such strides that Personality should means that, to possess Personality in a ,broadcasting station. KHJ has bright- some day be broadcast to the inhabi- marked degree, one must radiate that ened more homes of sorrow, brought more tants of this universe. magnetic force or power from a most harmony and joy into homes of discord, Although it may sound like another dynamic source -the heart! And that than any other three stations combined. Hollywood Press Agent's stunt, this is the sole reason why Uncle John, direc- And this is because his attitude towards phenomenon has certainly been accom- torial wizard of KHJ, has such a won- his duties as an announcer has been that plished at station KHJ, The Los Angeles derful personality -he has a magnani- of a minister of humanity, and his cheery Times, Los Angeles, California, where mous heart, and his Radioland converts voice has come to mean as much in the none other than John S. Daggett, affec- are becoming legion. home as the teachings of the scripture. tionately known to Radio fans as Uncle KHJ'S Bringing to this position of announcer John, works this miracle with a resonant "Father" a splendid college education and the voice which, according to motion picture THIS famous broadcasting station invaluable experiences of a successful standards, registers "personality plus." owes its existence, perhaps, to Uncle newspaper man, there is little wonder Personality, some great philosopher John's genius, for it was he who dedi- that Uncle John's name has virtually RADIO AGE for July, 1925 What the Broadcasters are Doing 29 become a household term in the helm of the good ship Broadcast! osopher animates them with his magic Southwestern United States, and And not all of Uncle John's pro- flow of metaphors nad similes, so that wherever the powerful KHJ broad- grams are solely entertainment. Pro- grim bugbears and obstacles are soon casting station can be fessor Sylvester Hert- converted into scintillating rays of heard. For Uncle John zog lectures to the sunshine. has seen fit to arrange youngsters, in the programs which language with Queen Titania appeal to every which they are last but not least of the legion of member of the familiar, u p o n ANDKHJ broadcasters is the famous family, with a subjects which Queen Titania, who broadcasts the inner- view to entertain- stimulate thought most workings of Fairyland every Tuesday ing and enlighten- action, compelling night. In conjunction with hee father, ing his great fol- them subcon- The Sandman, who also writes and lowing of Radio sciously to master directs these unique sketches, Queen fans, for he has a precepts and quo- Titania and Uncle John broadcast the penchant for tations which they most instructuve of juvenile programs, broadcasting the thought impossi- accompanied with the most melodious best talent obtain- ble before. This of music. able anywhere. is conducted dur- Hundreds of children, ranging from Thanks to KHJ ing the "Children's five years to fifty, throng the auditorium and its progeni- Hour," from 6:30 on these nights and are taken for a tor, Uncle John, to 7:30 p. m., a pleasant journey through the mystic concerts of the time which all realms of Fairyland, under the personal highest type can G. Allison Phelps is known as the children in homes guidance of the diminutive Queen Ti- be heard in one's Radio Philosopher of KHJ, Los An- equipped with tania. home. KHJ is geles. Usually philosophy is either radio sets h o Id During its brief existence KHJ has probably the only dry or preaching. But not the way most sacred. They been responsible for more innovations, station which has "AI" tells it. He makes you cry for are also treated to perhaps, than any other station on the on its staff an more. special readings Pacific Coast. In addition to the afore- accomplished and from the Bible by mentioned features, Uncle John has famous musician. In the person of Uncle John, in that inimitable voice inaugurated Saturday morning broad- Claire Forbes Crane, Radio Editor of which children recognize as readily as casting classes. All persons are eligible, the Times, KHJ boasts a pianist who they do their parents. providing they register in advance. has been soloist with such large musical Another feature of KHJ, which has This novel Radio instruction is deemed aggregations as the Boston Symphony aided people in solving their daily prob- one of the greatest constructive influences Orchestra, the Los Angeles Philhar- lems, is the weekly lectures by Fred C. toward a better understanding of radio. monic Orchestra, and others. With McNabb on the "Care of Gardens." While performers appear before the the technique acquired as associate In over fifty -two weeks of constant broad- microphone, Uncle John stations himself artist of Madame Melba, Arthur Hac- casting, Mr. McNabb has done such down in the operating room the better kett and other renowned artists, she creditable work that his bulky daily mail to judge of the pupil's aptitude at broad- brings to Radioland a veritable "Open from grateful housewives attests the casting, and at its conclusion he lectures Sesame" to shut -ins with musical long- results obtained. Then Harold Swartz, to the class upon their broadcasting ings. Under her artistic guidance the one of America's most promising sculp- from a radio point of view. This con- musical programs of KHJ have thrilled tors, delivers a weekly lecture on "Art." structive criticism is also broadcast, music lovers throughout the nation. "Care of the Body" talks are broadcast making it possible for all members of by Dr. Philip M. Lowell, a recognized radioland to learn the profound secrets His Universal Appeal authority on this subject, while Cap- of broadcasting. BUT Uncle John's magical Radio wand tain Salisbury and other well -known When we radio converts shuffle off this . is not confined to classical music. globe- trotters tell of their thrilling mortal coil, we no doubt will consult the His musical programs are so arranged experiences in foreign countries. Recording Angel to ascertain our respec- as to carry the universal appeal, running tive positions on the great list of those. the gamut of musical emotions in the Talks Easily Understood who served their Master well in human race. Just to prove how broad DR. MARS. BAUMGARDT, noted radioland. If so, we no doubt will a scope and range these musical enter- astronomer, delivered a lecture find that Uncle John's name, like tainments cover, permit me to quote every Wednesday eve- Abou Ben Adhem, verbatim the mutterings of an alkili- ning for over a year heads the list. coated miner from the great open spaces: upon astronomical sub- "Out on the Mojave Desert we gets jects, couched in (The f ore - mighty lonesome; times we don't keer such simple lan- going account if we live or die, and along comes Uncle guage that the is the second of John with one of his side -bustin', gun - layman could ac- an interesting totin' musical fests which makes us quire a fair work- series of articles plumb ashamed of ourselves for even ing knowledge of on California thinkin' of kicking off!" the rather myster- radio stations, And through all this good samaritan ious science of work of broadcasting cheer and enter- astronomy. The which are known from coast to tainment runs that indescribable force "Radio . Philoso- -Personality. Why, the entertainers pher," G. Allison coast for their selected by Uncle John's inborn genius Phelps, has written excellence. The fairly exude it. So thoroughly saturated and broadcast over first of this with it are these skilled entertainers and thirty -six essays series appeared educators that they proceed to broadcast on momentous in the June it to the many radio fans with astonishing subjects, which are RADIO AGE, results. You can feel the personality troubling people and other equal- of various musicians, vocalists as well in the ordinary E. K. Barnes manager of ly as pianists, in your very home. Most walks of life. Tak- is assistant interesting miraculous KHJ and the boy who helps keep the stories trill be and yet a pleasant possi- ing the smudgy wheels moving day and night at this bility in this day and time, with such commonplaces of ever -popular haven of "Kindness, Hap- published in an a genuinely human announcer at the life, this wise phil- piness and Joy." early issue.) 30 RADIO AGE for July, 1925 What the Broadcasters Are Doing

z

Ten Commandments for the Broadcast Listener While excellent radio reception is frequently possible during the warm months, the best long distance records come in the Winter. A reasonable attitude will help the listener here. He should remember that he cannot expect every act in even the best vaudeville performance to be tremendously amusing and just what he wants, nor can he expect the weather every day to be clear and pleasant. Similarly he must not expect every day to be just right for long distance radio reception. Now and then a Summer storm may interfere with both radio and picnics. The listener should become acquainted with his local stations and enjoy them during the Summer, and be satisfied with the long distance records he has made, or will make, in the Winter. In other words, he should get the best there is in radio during all seasons, and above all he should be reasonable.

If the listener lives rather far away from all radio broadcasting stations which he wants to hear, there are several things he can do. He can lengthen his aerial wires and increase their height from the ground. Both of these measures make the signals louder as a general rule. He can add an audio frequency amplifier unless, of course, he already has this instrument. He can also increase the voltage of his "B" battery or plate battery up to 9Q or even 112 volts (that is, to four or five of the usual 22% -volt units or blocks). He can use a more sensitive loud speaker, or content himself with head set operation. He should also tune more carefully so as to get the very loudest signal which his set is capable of giving. If there is a tickler adjustment on his set, he should learn how to use it so as to get full volume of signals. And he should remember that the good results he will then get are going to be even better results in the Winter. If the listener is very near a powerful broadcasting station, he may get excessively loud signals from that station and have difficulty in picking up other stations when the nearby station is in operation. In extreme cases it is not possible to get the distant station at all under such circumstances any more than it is possible to hear a whisper from a dis- tance when someone else is shouting nearby. Still a good deal can be accomplished.

There are ten good rules for broadcast listeners: 1. Don't try to hear Australia in mid- 6. For the new longer waves above 450 summer. Be satisfied to enjoy the nearer meters, use a condenser connected between stations most of the time. the aerial and ground terminals of your set. 2. Don't be disappointed if an occasional 7. A little patience in-learning to handle storm interferes with your radio evening. your receiver yields rich returns in satis- There are many fine concerts coming. You faction from fine signals. Remember that can't expect to find a pearl in every oyster "Rome wasn't built in a day" and keep on nor to receive a record-breaking concert getting more and more familiar with your every night. set and how it works. 3. If you want louder signals, use a longer aerial, more tubes, higher plate 8. It is a good idea to read the radio voltage, more sensitive loud speakers and column of a newspaper or a good radio more careful tickler and receiver adjust- magazine or two. It helps you to know' ment. how your set works and keeps you up -to- date in radio. Information of this sort is 4. A pleasant signal filling a moderate an aid in getting the concerts loud and size room should be enough to give satis- clear. faction. It is not worth while producing signals which deafen the neighbors. It is 9. Ask your radio dealer for advice; he wasteful to insist on tremendous signals can probably tell you what you want to which are generally less pleasant than know and will be glad to do so. The moderate signals. manufacturer of your set is also willing to help you get the desired results from its 5. If your local station comes in too use. loudly and drowns others out, a smaller aerial will help in tuning him out, with a 10. Do not throw away the direction smaller condenser connected between aerial sheets or booklet that came with your set and ground. And if all measures to get and with the tubes. Read all such material rid of the local station fail, why not enjoy carefully now and then. If you have lost his concerts? He is working hard for you the direction sheets write to the dealer or and it is nobody's fault that you are so manufacturer for another. The direction close to him that you are bound to hear sheets answer most of the questions which him. Broadcast stations have to be closer have been puzzling you and preventing you to some people than to others. from getting the best out of your set (Cooyrf¢bt. 1925. by Radio Aae. Ino.) RADIO AGE for July, 1925 What the Broadcasters Are Doing 31 Favorites of MOVII-;DO\/I Give Snappy Show at WIP Fans Get Real Insight Into Adventures of Famous Stars IIILADELPHIA: -One of the most unusual gatherings of famous stage and screen folk was held last month. g Moving picture stars of the. Metro-Goldwyn picture cor- poration, together with such famous men as Marcus Loew and noted stage stars, gathered around the microphones in the Studio of Station WI P, the radio broadcaster of the Gimbel store, to entertain the radio public and to answer all personal questions sent in to the station. It was a real party -the stars sang, dined, danced to two orchestras; and the microphones did full duty all the while. Lillian Gish, Jackie Coogan, Barbara LaMarr, Johnny Hines, Mae Busch, Dorothy Mackaill, Marion Davies, Anita Stewart, Harry Morey, Dágmar Godowsky, Louise Glaum, Fritzi Brunette, Ben Finney, Flora LaBreton and many more screen players. Raymond Hitchcock, Eddie Cantor of "Kid Boots" fame, with Mary Eaton and her sisters, Doris and Pearl, Cecil Lean and Cleo Mayfield who made "No, No, Nanette" famous and the leading men and women of the two "Music Box Revue" shows represented the stage and Broadway. Nils T. Granlund, Above, Jackie Coogan in a speculative mood before appearing before the WIP "mike' and telling his innermost secrets to ahost of radio admirers. Mae Busch, popular leading lady, is the de- mure miss at the lower left. She was one of the principal speak- ers on this all-star movie program from the Philadelphia station.

famous "N. T. G." of Station WHN in New York City; Mar- cus Loew, president of the Metro-Goldwyn Picture Corpora- tion and head of the Loew chain of theatres, and the great "Sir Joseph" Ginzburg, Broadway's biggest "nut." Plenty of Humor FLI M. OROWITZ, the famous "Emo" whose weekly movie broadcasts from Station WIP have created a sensation all over the country, arranged the party and was the announcer for the evening. "Emo's" witty remarks, aided by those of Johnny Hines, to say nothing of the other comedians present, made the radio sets bulge with laughter. The party was strictly informal. Most of the stars spoke on the impulse of the moment. The movie fans who have seen their favorite screen star as many times as they possibly can, had the opportunity to hear their voices. And if you wondered why Dorothy Mackaill bobbed her hair, or just what Barbara LaMarr thinks of vamps, or any of a thousand questions that run through movie fan's heads, you found out if you heard this unique program. This idea of having movie stars speak from big broadcasting stations is meeting with more and more favor every day. For instance, at WGN, Chicago, recently, according to dispatches received at WIP, Gloria Swanson, the prominent Hollywood resident and fashionably cinema actress, consented to be "interviewed" by the Announcer, the questions in the inter- view having been sent in by interested listeners. This is but one example of how movie stars are gaining wonderful publicity for themselves as well as providing more or less amusement. 32 RADIO AGE for July, 1925 The Magazine of the Hour Look Out for < < THE; RAJ)IO SPIKS" By FREDERICK A. SMITH Editor, Radio Age IT IS somewhat noticeable that in the Radio Corporation of America also included Johnson in the office. Bowlby's affidavit reads as spite of the sensational nature of drawings of machines and samples of products made follows: made against the Radio by the De Forest Company. She then admitted in the presence of Mr. Harley charges Details of how Harley is alleged to have placed that at the time I had questioned her she was in the Corporation of America in the New his agents in the De Forest establishment and of his employ of the Radio Corporation of America. and Jersey Courts, comparatively few radio employment of De Forest employes to furnish him that she had secured her position with the De Forest publications and newspapers gave pub- with stolen information are also contained in the Radio Company under instructions from Harley. licity to the astonishing accusations made affidavits. Harley confirmed her statement, and they joked by the De Forest Radio Company. General Electric Accused about my catching Miss Johnson at the De Forest plant. and that I had procured her discharge, and RADIO AGE is publishing these facts Luce of the De President Theodore Forest Radio now I was seeking employment with the Radio Cor- for the reason that both parties to the Company. in an affidavit. alleges that the General poration of America." prosecution are big factors in the radio Electric Company, with which, he asserted, the Radio At Harley's request Bowlby took his wife to the in had industry. We believe that it is due our Corporation was combination, succeeded in Broad Street office of Harley, who said he had other readers to tell them the truth about this buying up the Electron Relay Company of Toledo, operatives in the De Forest plants besides Miss off from the De Forest Company its industrial scandal, not permitting the and cut source Johnson. He offered Mrs. Bowlby a position, which of filament wire. she refused. fact that the Radio Corporation of "If the defendant and its assnciates, the General America is the biggest radio advertiser Electric Company and the Westinghouse Electric Offices Kept Secret in the field to deter us from adhering to and Manufacturing Company, can control the fila- Bowlby was employed as special investigator under the straight line of editorial responsibility. ment wire output. they can. of course, prevent Harley from May. 1924, until January, 1925, and he Among publications which have given competition in vacuum tubes." he adds. reported regularly in writing to Harley in Rooms space to this situation are The New No statement was forthcoming yesterday from the 301. 302 and 303, at 25 Beaver Street. Radio Corporation of America in connection with "These were secret offices :" he says, "and, as I was York Times, New York Herald -Tribune, the filing of the affidavits. General J. G. Harbord, informed, were known only to certain officers of the Chicago Herald and Examiner, Radio President of the corporation, declined to comment. Radio Corporation of America. There was nothing Retailer and Jobber, and Radio Guide. Vice President David Sarnoff was out of town. on the doors of the offices or on the bulletin board There are a few others, but the pub- The charges of commercial espionage and theft of the building to indicate that Harley or the Radio lications named have come to our of valuable business information are contained in Corporation of America had any offices in that hands and we know that many publica- great detail in the affidavit of Charles F. Bowlby, building; in fact there was nothing upon the doors tions did not make room in their columns cost accountant of the De Forest Company, em- of those offices except the room numbers. for line of While it ployed by them between 1921 and 1923, who worked "While in the employ of the Radio Corporation, a this publicity. for the Radio Corporation from the early months of Harley asked him, Bowlby alleges, to purchase may be extremely unpleasant to the 1923 until April or May, 1924. Since Feb. 2.3, 1925, radio tubes arid roll filament wire from the De Radio Corporation of America to have he has again been employed by the De Forest Com- Forest Company. and to obtain the names of persons these court proceedings reported to the pany. or firms from which the De Forest Company was public, we will assume that the Corpora- Bowlby's employment by the Radio Corporation purchasing its filament wire. He had been unable to tion will welcome a full investigation of came about in this way, he says: do so, and Harley said he was particularly interested the charges and will be willing, as a Prior to leaving the De Forest concern he was told in obtaining the names of the makers of the apparatus Corporation admitting it was organized by his fiancee, Mildred Michael, a co- employe, that in the tube department, and of the high frequency a man who gave the name of "Jameson." and who bombarders used in the De Forest plant. He wished for patriotic purposes, to accept the claimed to have met her at a radio dinner. had to have a diagram of the layout of the tube depart- judgment of the American public as to telephoned her for an appointment. Bowlby met ment, giving the names and locations of all the whether it has done wrong. "Jameson" at his financee's home. Her sister machines. Briefly, the De Forest Radio Company, Madeline was present. "He asked me to get a position with the De Forest on May 1, 1925, obtained an injunction in "Jameson" said he knew nothing about the Radio Company as a means of getting this informa- Trenton, N. restraining the Radio details of the radio business but was devoting him- tion for him, at the same time continuing in the Corporation of AmericaA from attempting self to the merger of various radio companies. He employ of the Radio Corporation of America," scientific secrets said he had been informed that there was some asserts Bowlby. to steal business and relation between the De Forest Company and the Continuing. Bowlby says he told Harley he could from the De Forest Radio Company. Radiocrafts Company. and asked Bowlby and his not obtain employment with the De Forest Com- The injunction was granted after Vice fiancee many questions about the De Forest Com- pany. but said that Henry Thies, a former De Forest Chancellor Backes had read affidavits pany. how it kept its books, cost records, production employe might be able to get the information. and other documents tending to support records, stock records, payroll and other records, Harley directed him to employ Thies for that pur- the charge that the Radio Corporation saying that such information would be useful to pose. He took Thies to Harley who told bim what of America had introduced spies into him in connection with the enterprise on which he he desired. Two weeks later be met Thies in Room the plant and offices of the De Forest was engaged. 2t7 of the secret Beaver Street offices, "the room Hears More of "Jameson" where the investigators were accustomed to go when Radio Company and that the Radio work Two weeks after the witb they came in from their and where some of Corporation's secret agents had, with meeting "Jameson," them wrote up tbeir reports." bribes of money, seduced employes of the Bowlby was told by William W. Buckbee. an employe in the De Forest laboratory. Bowlby says he suggested that Thies obtain re- De Forest Radio Company into acts of that he had been asked employment with the De Forest Company. Harley by an employe of the Radio Corporation of America. idea directed _ treachery. calling himself "Hurley," for information regarding thought it a good and Tbies to make instruments made by the De Forest Company; that prompt application. following from "During the whole time that I was working for We publish the the he had been asked to furnish drawings of such instru- the Radio Corporation of America I was under the New York Times of May 5, 1925:' ments; that he. Buckbee, several times met a man of Harley, I was Radio Corporation of America maintained who called bimself "Hurley." supervision and direction but always The The latter was ac- by the check of Radio America," offices at 25 Beaver Street. where its special companied by a young woman called paio Corporation of secret "Miss John- Bowlby's affidavit continues. investigators, known only by code numbers, reported son.' Buckbee said be knew her to be a De Forest the results of their espionage on the DeForest Radio employe. Buckbeé s description of "Hurley" tallied Known as "C -1" Company and other concerns, according to affidavits with Bowlby's recollection of "Jameson," and "While I was employed by the Radio Corpora- filed yesterday in the Chancery Court of New Bowlby was satisfied they were the same person. tion I was designated as 'C -1' and made all reports Jersey. The papers were filed to support the injunc- At that time, Bowlby called on Miss Johnson in under that designation. I never signed my own tion suit of the De Forest Radio Company against the De Forest plant and questioned her concerning name to any reports. When I telephoned to Harley, the Radio Corporation of America. brought last week her relationship with tbe Radio Corporation of as I frequently did. I always identified myself under at Trenton. America. She denied she was in any way interested that designation. never by any name. I know, of The affidavits alleged that agents of the Radio in the Radio Corporation, but Bowlby did not my own knowledge. that all employes working under Corporation of America in the De Forest Radio believe her and obtained her discharge. Harley went by initial letters and numbers, as I Company's plant furnished John S. Harley, chief In February, 1923, Bowlby married Miss Michael would meet them in the room where their reports special agent of the Radio Corporation. with valuable and the following April he left the employ of the De were being made out and they would tell me their information concerning secret methods of manu- Forest Company. Subsequently his wife was dis- designations and I would see these designations on facturing radio apparatus, as well as the names and charged. Then he sought employment with the the reports which they were preparing. addresses of employes. the number of radio tubes Radio Corporation. While calling on a friend at tbe "While employed by the Radio Corporation of produced, addresses of persons and concerns dealing 233 Broadway offices of the Radio Corporation. Am @rica. I frequently met Cecelia Lambert at with the De Forest Company, notices posted in the "Jameson" stepped Into the room and recognized Harley's office and I knew her as 'C-3.' She was various departments, changes in the personnel. him. says Bowlby. He handed Bowlby a card on doing investigating work and reporting to Harley efforts made to speed up production. and especially which was printed "Jobn S. Harley, Chief Special under that designation. Since my recent employ- what took place in the power tube department. Agent, Radio Corporation of America, 64 Broad ment by the De Forest Company I have on several The information alleged to have been passed on to Street." He called on Harley and found Miss (Continued on page 51) RADIO AGE for July, 1925 What the Broadcasters are Doing 33

Dorothy and Mar- jorie Moline are de- termined to get across Jack Nelson's juven- ile idea even if they have to dress the part, as shown in the photo. Naturally. they have succeeded /:. T.'-vTa: a, r4. t:. ii+1!' ti( f'.i+fii!- Y4YIYAiYEIiCAKJ.' 'Tti..... r.t'- .K *.Y.s.+..w*nYI,RN-

How the Alert Jack Nelson is Making Us CI IILDREN Again RADIO SHOULDN'T BE TOO SOLEMN, IS HIS DOCTRINE

JACK NELSON is a great favorite speeches, sad music and uninteresting popular vaudeville artists, come attired among the kiddies. His best claim programs, according to Jack. He is an as little girls when they enter Jack's to fame in that line lies in the fact ardent believer in the policy that any- studio in the Palmer House, Chicago. that he has lived among thousands of thing light- hearted and juvenile will "go Not that the listeners can see them, but orphan boys and girls at Mooseheart, over" with a radio audience much better Jack describes them picturesquely and Ill., the city founded by the Loyal Order than any other form of entertainment. then lets them "do their stuff." They of Moose to care for children of de- By this Jack does not advocate a con- cut up for all they're worth, and the ceased members. In his capacity of tinual round of bedtime stories, for he radio waves virtually ripple with laugh- director of the Mooseheart radio station, has never featured that sort of broad- ter. The girls don't exactly act foolishly WED, Jack came in contact daily with casting. He does, however, believe in kiddish, but they are funny and light- these children, who formed a large part keeping people young -anywhere from hearted, and that's the kind of spirit of the station's daily programs -and still 12 to 20, he says, and in the attainment Jack wants to send out from WJJD on do. Consequently he knows whereof of that ideal he has mapped out some his popular programs. he speaks in the juvenile line. wonderful programs that have won an At other times the children themselves After several years of broadcasting instantaneous response among fans all broadcast from Mooseheart, and some- experience, Mr. Nelson is prepared to over the country who have learned to times little kiddies of 7 years of age make announce that radio listeners, whether listen regularly for the programs from the announcements. All this makes a tre- young or old, like to be reminded they WJJD every night after 10:30 o'clock, mendous "hit" with the listeners, and no were children once. They prefer this on a wavelength of 302 meters. doubt in the near future WJ J D will prob- reminder more than they do solemn For example, the Moline- sisters, ably mean "Watch Jack's Joy Diggers." 34 RADIO AGE for July, 1925 The Magazine of the Hour

DEVICES Radio Age Institute displaying this seal have been tested Manufacturers' Testing Service and approved by MEMBERS of the staff of RADIO AGE will be pleased to test devices the RADIO AGE and materials for radio manufacturers with the object of deter- mining their efficiency and worth. All apparatus which meets with INSTITUTE. the approval of various tests imposed by members of the technical staff of RADIO AGE will be awarded our endorsement, and the seal Apparatus Illus- shown to the right will be furnished free of charge. Materials for trated and de- testing should be sent to scribed below has successfully passed RADIO AGE INSTITUTE our tests for July, 504 N. Dearborn Street, Chicago, Ill. 1925

Test No, 76 STRAIGHT -LINE- WAVELENGTH CON- DENSER. Submitted by the manufacturers, Silver- Marshall, Inc., of 110 S. Wabash Ave., Chicago, Ill. This con- denser is a new low loss condenser designed for perfect S-L-W tun - ing. It is of the single - bearing type, equipped with a long cone brass bearing, adjustable, and tension adjustment mounted on, but independent of, the Test No. 70, WET 'B" BATTERIES, submitted bearing. All plates are of heavily hardened and by the Kelman Electric Co., Rochester, N. Y. Con- flattened brass, entirely silver-plated, as are all cur- sists of twelve cells in glass jars, set in a wooden frame. rent- carrying surfaces. This feature, in conjunction Tops are provided with vents for filling with distilled with the use of a minimum of high-grade insulation water. There is a sufficient plate area to allow a Test No. 73 KELLOGG SHIELDED TRANS- well out of the eloctro-static field. results in this con- generous milliampere capacity for use in receiving FORMERS. Codes 503 and 504 were tested, having denser having ven lower losses than many laboratory sets where a wet B battery is desired. A card giving been submitted by the makers, the Kellogg Switch- standards. The single end -plate, as well as the shape of is responsible for very low minimum detailed instructions for filling the battery originally. board and Supply Compan 1066 W. Adams St., the plates, the Chicago, Ill. These of audio trans- capacity and the exceptionally high capacity ratio. and for watering and charging it, accompanies the unshielded types Instead of separating by wavelengths, with this formers are of 4 1 -2 to I and 3 to I ratio respectively, battery, which arrived in good condition as a result new S-L-W condenser it is possible to separate stations of good packing. Tested and approved by RADIO and over a period of strenuous tests were found to produce a really distortionless amplification, consis- by kilocycles, thus insuring greater selectivity and AGE Institute. tently. The design is exceedingly simple. very high more separation of stations. Comprises latest design grade wire being used. The tops are of sheet bakelite.. in low loss construction. Tested and approved by passed the tests and requirements of RADIO AGE Institute. the RADIO AGE Institute.

Test No. 74, FILAMENT WARNING SWITCH. Sam - ple submitted by The Yaxley Mfg. Co., 1103 W. Monroe St., Chicago, III. Consists of a single hole mounting fila- ment switch and socket for a miniature light, the light in parallel across the A battery through the switch so that while current is on the light is illuminated, giving warning current is being used. This light sits back of the panel and a bezel of colored glass permits the set-owner to see Test No. 71. CONTINENTAL 2-GANG CON- it. It serves as a warning to Test No, 77, JEWETT SUPERSPEAKER CON- DENSER. Submitted by Gardner and Hepburn, the radio fan who gets ready SOLE. A quality loud speaker, submitted by the Inc.. 2100 Washington Ave., Philadelphia, Pa. Con- Jewett Radio and Phonograph Company of Pontiac. DX chase that his filaments are still lit, and should Mich. horn in the Superspeaker console is made sists of a two gang variable condenser, well made and extinguished in the interest of battery economy. The suitable where tuning of two inductances simul- of the same materials as the super -speaker horn, with Tested and approved by RADIO AGE Institute. the exception that the final finish coats being enclosed. taneously is desired. Or it can be used with the two are not necessary. The horn floats within the cabinet, halves in series to decrease the capacity of the con- and is thoroughly padded on three sides with piano denser. Tested and approved by RADIO AGE In- felt, there being a resonance chamber below the horn. stitute, which adds greatly to the excellent tonal qualities Test No. 75. REMOTE CON- produced by this speaker. The unit is of the Jewett TROL LIGHT. Also submitted Vemco Design. Tested and approved by RADIO by the Yaxley Mfg. Co., of Chi- AGE Institute. cago. Ill. This device consists of a single hole mounting brace and socket for miniature light, for use at a point other than right on the battery switch. It is known as a remote control light. It also serves as a warning that filaments are lighted. Tested and approved by the RADIO AGE Institute.

A ROUNDUP OF HOOKUPS - Test No. 78, REMO RADIO TUBE REVIVER. Something you've never Submitted by the manufacturers. the RemoCorpora- Test No. 72, CONTINENTAL LOW LOSS AND tion, of Meriden, Conn. This device was put on the JUNIOR CONDENSER. Submitted by Gardner seen before market in response to the popular demand for a tube and Hepburn, Philadelphia, Pa. It is known as the reviver. The Remo reviver has two sockets, for Continental lo -less condenser, with the vernier large and small tubes, and tests showed that tubes arrangement consisting of the Junior condenser in the August waning in efficiency, if placed in the Remo reviver, shown at the bottom of the above illustration. It can would practically regain their old life. Certain be used separately or in parallel with the lo-loss as periods of time, according to the degree of age in the RADIO AGE tube being tested. were necessary. The reviver a means of fine tuning. Tested and approved by connects to the electric light socket. Tested and RADIO AGE Institute, approved by RADIO ACE Institute. RADIO AGE for July, 1925 The Magazine of the Hour 35

A Timely Discourse on Conventional Radio Symbols and Crystal Detector Sets By JOHN B. RATHBUN radio dia- ('omrir,hc 1923 left, which may indicate the output of any radio CONVENTIONAL circuit receiving circuit. Abbreviation (PH). The polari- grams, the short -hand of radio, have ty may be marked by ( {.) or minus as shown, always proved a sticker to the tyro in or this may be omitted at will. The positive con- this science, and it is certain that many a nection of the phone cords is colored red and this red strand should be connected to the ( --) comrec- prospective builder has contracted a bad How to Understand tion of the circuit. At the right is the symbol for case of cold feet and quit the game when the horn or loud speaker which can also be marked he was brought face to face with the All Radio Symbols; with the polarity. zig lines of 7. CONDENSERS. A "fixed" condenser con- curley -cues and -zag the tech- sists of alternate sheets of tinfoil and paper or mica nical diagram. Not being very familiar Giving the compressed into a compact pile, and adds with the apparatus itself, It is no wonder Crystal "capacity" to the circuit, an effect opposite to of learning still more that of an inductance coil. The symbol for a fixed that the prospect condenser is at the left where the abbreviation is of the technique filled him with dismay. Its Merited Attention shown as (K) and where the capacity in micro - However, when these symbols are once farads is also added where advisable. A VARI- understood, they are more easily read ABLE CONDENSER used for tuning inductances transmitting station. The abbreviation is tbe i s shown at the right, where the rotor plates are and understood than the picture diagrams letter (L) and its magnitude is generally expressed i ndicated by the curved line and the stationary or for they show the functioning and general in mil ihenries, or by the number of turns of wire. stator plates are shown by the short straight line. of far more clearly This The Stator (Straight line) should go to the grid of a principles the circuits 2. IRON CORE CHOKE. consists of a tube, while the rotor is connected to the ground to the experienced eye than pictures of great many turns of wire wound around a core of soft steel wire or thin steel sheets called 'lamina- side or (-A) side of the circuit. This condenser the apparatus. You can see the course tions." It is used when a greater retardation must is also rated in microfarads (m. f.). taken by the current in the different he had than is convenient with an air core choke, 8. RESISTANCES -RHEOSTATS. A fixed branches of the circuit at a glance, and and can choke back audio as well as radio frequency or unvarying resistance is shown by the zig -zag can immediately classify the circuit with currents. Values in henries or millibenries. line which distinguishes it from an inductance. For 3. TRANSFORMER- COUPLER (Air Core low resistances used for controlling the filaments of little chance of error; something that Type). This transformer for radio frequency the tubes, its magnitude is given in terms of ohms. I have never yet been able to do with the currents consists of two coils of wire called respec- For very high resistances, as used for grid leaks, picture type. However, the picture tively the PRIMARY (PRI.). and the SECON- the resistance is given in terms of MEGOHMS, DARY (SEC.) coils. Radio frequency currents abbreviated (MEG). diagram has its place in the scheme of passing through the primary induce similar cur- A RHEOSTAT or variable resistance is shown things where the reader is not interested rents in the secondary coil, thus affording a means at the right and is usually employed for controlling in theory, but simply in building some- of "coupling" two circuits together magnetically. the filament current of tubes. The letter (R) is used thing that will bring in the voice and In our diagrams tbe primary coil (PRI) is shown for a rheostat, or resistance. with fewer turns than the secondary and is shown 9. BATTERIES. An "A" or filament battery music with the least delay and study. on the end opposite to the grid connection (G). or a "C" battery is shown by the symbol at the left For the benefit of those who have not The other connections are the filament (F), the which consists of alternate short heavy lines and yet become familiar with the standard plate connection (P), the positive "B" battery longer light lines. The short heavy lines indicate connection (B) and the neutral tap (N) used for the negative ( -) plates while the long lines are the conventional symbols used in radio cir- certain neutralized circuits. The abbreviation is positive plates ( +). Each pair of these lines rep- cuit diagrams, I have prepared the ac- (RFT), and it may be tuned or untuned, the resents one cell, and it is the best practice to mark companying two pages of blueprints in former by a variable condenser. the voltage below it as at (6v.) and the letter (A), 4. VARIOMETER. This is a form of variable (B) or (C) above it to designate the type of battery. which the more common symbols and inductance used in place of the air core choke, and A "B" battery is at the right where the dotted line abbreviations have been defined. In ad- consists of a movable member (The Rotor) which indicates a number of omitted cells, there being dition to the listing of the symbols, I turns inside of a stationary coil called the "Stator." too many cells in a "B" battery to draw them com- The abbreviation is (VAR). By this means the plete. When the battery is tapped at some low have taken up a short description of the inductive or choke effect can be varied through a voltage, as at ( +22), the voltage of the tap is various parts used in the receiving cir- wide range without condensen and the device is marked in this way. cuits so that the subject will be more frequently used for tuning a circuit inductively. It 10. POTENTIOMETER. This is a device which easily followed. may be tapped at the mid -point as shown at (Q). looks much like a rheostat used for the accurate 5. ANTENNA- GROUND -ARRESTOR. At control of voltages, generally the biasing voltages Circuit Symbols (Sheet No. 1) the right is shown the symbol for the antenna or applied to the grid of a vacuum tube. It consists 1. INDUCTANCE (Air Core Type). The aerial, abbreviation (ANT). In the center is the of a fixed resistance of from 200 to 400 ohms con- hollow coil of wire or other inductance coil with an symbol for a ground connection (GND), and at nected across the battery and a sliding contact air core is shown by a continuous scroll or helix the right is the convention for a lightning arrestor which taps off the drop of potential at any point of as in Item No. 1. Its purpose is to choke back or (LA). the resistance. The polarity of the slider also impede the flow of radio frequency current or for 6. OUTPUT - PHONES - SPEAKER. The tuning radio circuits to the wavelength of the symbol for the beadset or phones is sbown at the (Turn to page 38) Blueprints of Conventional Radio Symbols and Typical Crystal Receivers on pages 36, 37, 40 and 41 - - ORADI0a16E. . JULY f9s O .'

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CDPY P/GHT /905' ,Pi9D/O AWE, /itG: GH/G.-O, /GL- .. PO4T. PErV.0/NG JBQTh'BUN 38 RADIO AGE for July, 1925 The Magazine of the Hour (Continued from page 35) (SW) being used to vary the number of understandable signals on so small as varies with its position, becoming negative at one turns in circuit. amount of current that it can be esti- end and positive at the other. l: In Fig. 23 is a regenerative circuit with mated in millionths of an ampere; and 11. THREE ELEMENT VACUUM TUBES. one stage of audio frequency amplifica- yet, with all of this delicacy, the appara- The three elements of a vacuum tube are the very is simple so filament (F), the grid (G) and the plate (P), al- tion, a type of circuit, commonly tus perfectly and rugged though these parts need not be marked as shown. met with. The detector tube (T1) is a that it can withstand a considerable A "hard" amplifying tube is indicated by a single soft tube, while the amplifier tube (T2) amount of abuse at the hands of the heavy circle drawn around the elements and as a is a tube, as will be seen from the listener. hard tube is much used at present for a detector as hard well as for an amplifier. When a soft detector tube circles. A coupler is used for tuning, To most of our readers who have had must be used, two circles are used, as at the right. having the primary coil (LI) and the experience only with the cheap and simple The word amplifier is abbreviated (AMPL) and secondary coil (L2), this being used single -slide, single -circuit crystal detec- detector by (DET). sometimes instead of the abbreviations tor sets sold on the open .market, the 12. TWO AND FOUR ELEMENT TUBES. A two element tube or Fleming valve is indicated at "PRI" and "SEC." The secondary is crystal detector is considered only in the the right and has the filament and plate but no grid. tuned by the variable condensor (K1). light of a toy having only a very limited This is most generally used as a rectifier for charg- For regeneration we have the tickler coil use in reception. This, however, is not ing storage batteries from alternating current, but with is also used as a detector. The four element tube (TIC) placed directly above the second- the case, for proper attention to the at the right has two grids. ary coil (L2) and connected with it by details of construction and with as much 13. GRID CONDENSER AND LEAK. This means of an arrow. The arrow in this care taken with the tuning units as we symbol used with detector tubes is simply a combi- case indicates that the two coils are pay to the construction of a tube set, the nation of the symbol of a condenser and that of a inductively performance be in resistance (The leak). The leak abbreviation is coupled by a variable rela- can greatly improved (GL) and the grid condenser is (GC). If either of tion; that is, that the position of (TIC) regard to distance range and signal these items is variable, then this fact is indicated by can be varied in respect to (L2). The strength. If we constructed our tube drawing a slanting arrow across it as at the right. grid condenser (GC) and the grid leak sets with the same lack of care and with 14. CRYSTAL DETECTOR. A crystal detec- (GL) are shown the same primitive tuning systems tor is indicated by an arrow head for the cat - connected to the grid that whisker and a small block for the crystal. of the tube. are used on commercial crystal sets, we Abbreviation is (CD). Current for lighting the tube fila- would not get very much better perform- 15. AUDIO (IRON CORE) TRANSFORMER. ments is supplied by the six volt "A" ance. Single -slider, single -circuit tuners An iron core transformer, commonly known as an battery which is so are not of good results with audio frequency transformer, is used for increasing connected that the conducive the voltages of currents approximating voice fre- negative ole goes to the detector rheo- either the crystal or tube detector, for quencieator audible frequencies. It consists of a stat (R1). The negative pole of the they cannot be tuned accurately in re- primary winding (PRI) and a secondary winding "A" battery connects with negative sonance with the incoming waves, and (SEC) with a few parallel lines drawn between the the coils to indicate the iron core. The four connec- pole of the "B" battery, and the latter there is always a considerable loss taking tions are marked as follows: (G) for grid, (P) for is tapped at the (+22) volt point for the place that limits the distance and plate, (F) forlfilament and (B) for "B" battery detector current. The total voltage of volume. connections. These apply to vacuum tube connec- tions with which the transformer is most commonly the "B" battery at (+90) goes to the The used. Iron core transformers of a special type are last stage jack (J2). A two circuit jack Crystal Detector Circuit also sometimes used on radio frequencies, but when (J1) permits us to plug in on the detec- OUR primitive crystal detector circuit this is the case the fact will be particularly noted on tor tube alone without amplification, or consists of three principal units: the drawing. Abbr. is (AFT). without 16. WIRING AND CONNECTIONS. In lighting the amplifier tube (1) The tuning unit, by which it is general, wiring is indicated by very heavy lines, (T2). Plugged in on (J2) we get the brought into resonance with the incoming and curved by an arc where a turn is made. Where amplified or intensified current for the waves, (2) The crystal detector employed two wires connect, a small OPEN circle is used to mark the connection as at (a). Where one wire operation of a loud speaker. for rectifying the radio frequency im- crosses over another, the crows -over is shown as at An iron core audio frequency trans- pulses for the development of the audio (b). Connection posts or terminals for batteries, former (AFT) transfers the plate energy waves, and (3) The audio output mechan- etc.. are shown by a circle with a heavy black dot of inside, as shown in a horizontal row. The letters the detector tube (T1) to the amplifier ism which converts the audio frequency indicating the "A ", "B", and "C" batteries are tube (T2), and it will be noted that the electrical waves into mechanical' sound marked at the terminals, together with their terminals of the transformer are marked vibrations (Phones). All three elements polarities. In the case of the "B" battery connec- tions the various taps are marked by the voltages in accordance with the points that they must be as perfect as possible if we are to as at ( +22). ( +45) and ( +90), but the letter "B" connect. Thus (G) goes to the grid of extract the maximum output in the form is not used. (T2), connection (P) goes to the plate of of sound, for the incoming energy is 17. TAP SWITCHES. (Tap switches used for tube (T1), connection (B) goes to the exceedingly feeble and must be carefully cutting out active turns in a coil should be con- (+22) volt nected so that the contact points go to the grid or tap of the "B" battery, and utilized with the least possible loss. aerial side of the circuit with the hinge connected connection (F) goes to the (-A) through This means sharp tuning, a crystal hav- to ground or on the far aide from the grid connec- the "C" battery. A fixed condenser (K) ing excellent rectifying qualities and an tion to prevent body-capacity effect. is shunted across the secondary. A 4.5 exceedingly sensitive pair of phones, 16. INSTRUMENTS. Measuring instruments volt "C" such as the voltmeter (VM), the ammeter (AM) or battery is used for biasing the none of which are in evidence in the usual the hot wire ammeter (HWA) are shown in circles. grid of the tube (T2) and the negative $2.00 crystal detector set. In reviewing The polarity should be marked, and also the range pole ( -) is connected to (F) of the trans- the requirements, we must also remember of volts or amperes at at (0-10) and (0-5). former so that the current gets to the to include an efficient antenna into the 19. JACKS. Jacks are specially arranged con- grid of the tacts used for making temporary connections by tube through the windings. assembly, which should have greater means of plugs and may be of many types. At the Tube (T2) is controlled by rheostat length and capacity than the antenna left is shown the single circuit jack (J2) generally (R2). commonly used with tube sets. The used for the last stage connection and at the left Fig. 24 is is a two circuit jack (JI) used for plugging in a typical reflex circuit with latter item is generally neglected in the between stages. These are by far the most common the radio frequency transformer (RFT) installation of a crystal set, with the types and the audio frequency transformer result that very little volume or distance 20. SWITCHES. Different types of battery (AFT), the former being tuned by the is had. Conservation of energy is a prime switches arc shown, the left symbol being for variable condenser (K2). symbolic diagrams while the second from the left is A coupler is requisite. used frequently on picture diagrams. The switch provided with the primary (LI) and It is here that the low -loss coil and the at the right is a double pole knife switch used for secondary (L2) by which the set is heavy tuned low -loss condenser hold forth with currents. to wavelength. The grid bias on the particular advantage; spiderweb, honey- Sample Symbolic Drawings tube is varied by the potentiometer (PO). comb or barrel -wound coils being of The rest of the parts have been explained great advantage in the of SHEET No. 2 we show four repre- before. construction ONsentative circuit drawings which such a set. The phones should prefer- include most of the symbols tabulated. ably be of the mica diaphragm class or Each symbol is lettered with the standard Crystal Detector Sets with very thin flexible metal diaphragms abbreviation so that it will not be so that the slightest current in the coils difficult ToO ME, the crystal set has always will give a maximum vibration. When to trace out the relation between the the most in the table wonderful of all we look at the cheap phones ordinarily parts and the corresponding radio receivers, for with this device supplied with crystal sets, with their parts in the diagram. we employ the feeble energy A simple crystal detector set, of the radio thick cast -iron diaphragms and their tuned by waves alone to vibrate the diaphragms weak magnets, it is no wonder that the variometer (VAR) is shown in Fig. of the phones without aid or 21. Here we have the symbols for reinforce- reception is limited to 10 or 15 miles. the ment from local sources i, variometer, crystal, aerial, of energy. After This would be almost the case with a ground, traveling' fifty miles or so, there is still tube set if it were supplied with the same phones and two fixed condensers. Note sufficient energy left that when two condensors in the waves to sort of phones. The feeble impulses are shown move a. relatively stiff piece of metal and received demand the most sensitive and that they are numbered as at (K1) and to produce the audible air vibrations (K2). In Fig 22 we have another efficient equipment that we can supply single known as sound. Further, it is an exhi- if the crystal set is to be more than a circuit crystal set tuned by a simple bition of the remarkable tapped inductance (L), the tap switch sensitivity of mere toy for children's use. the modern headset which produces Please don't infer that I am recom- RADIO AGE for July, 1925 The Magazine of the Hour 39

mending the crystal set as a substitute While the complete theory of contact Galena, silicon, carborundum, cerusite, for the tube set, for I am not. I am rectification is not yet well understood, pyrites, perikon, radiocite, and hecite are simply bringing to your attention the I will explain the functioning and purpose among the most commonly used simple fact that the crystal set performance can of the crystal in a general way so that minerals, and in addition to these are the be wonderfully improved by a little care the beginner can at least get a working numerous synthetic crystals that bear a in the construction and that it is a most knowledge of its properties when in- multitude of trade names. A good galena desirable proposition for local reception stalled in the receiving set. Mechani- crystal is probably one of the most sensi- where we do not wish to go to the trouble cally it is very simple, consisting of a tive crystals, but it is not stable and must of installing batteries and similar com- small piece of mineral called the crystal, be readjusted frequently. Silicon and plications. The crystal set has a field and a thin wire making light contact carborundum do not require so frequent all its own and is almost indispensable with the crystal at a sensitive spot. In adjustment and are quite sensitive if for certain purposes, and for this reason some cases, contact is had between two carefully selected and mounted. The I believe that more attention should be crystals instead of between the wire synthetic crystals are in most cases stable paid to the development of its perform- and crystal, but in any event the radio and sensitive, and have the advantage of ance rather than to cutting down on the frequency current must pass through a having a greater effective area or more expense of construction, as has been done high resistance contact of some sort "hot spots ' than the natural crystals, so heretofore. You cannot get long distance before passing through the phones, so that it is not so difficult to adjust them. consistently, nor can you get full loud that the audio or "hearable" portion of For the catswhisker wire, we require speaker volume of the crystal alone, but the incoming waves can be developed. a metal that will not corrode under you can get locals with good volume, Owing to the rapidity with which the ordinary atmospheric conditions and one clear and sweet, without the fuss attend - radio wave oscillates back and forth, the that will maintain a bright metallic con - ing the operation of a tube receiver. diagrams of the phones cannot follow the .tact area at the point where it rests on the When loud speaker volume is required radio frequency currents in the receiver crystal. A copper wire will work well on local, with particular attention to with most crystals, but a silver or gold quality, we can add one or more stages wire is better, as it does not corrode or of audio frequency amplification to the get dull as rapidly. With the exception detector. Of course, we are now getting of the carborundum crystal, the cat - back to vacuum tube complications and A ROUND -UP OF whisker wire should make very light batteries, but with very simple layouts HOOK -UPS contact with the crystal, working best we can obtain wonderful tone values on when only just barely touching the sur- the loud speaker and a somewhat in- in the Deluxe AUGUST IS- face. With the carborundum detector a creased distance. Just as an experi- SUE OF RADIO AGE. very heavy pressure is required, which ment, it is very interesting to add resist- in itself is one reason for the stability of ance coupled stages to a crystal detector Never before have you seen such the carborundum, as the heavy pressure to discover what real tone purity is like. a galaxy of hookups, from the prevents the displacement of the contact The natural tone and life -like duality simplest though efficient crystal to when subjected to vibration. will be a revelation to you, and if you the most recent simplified super- There has been a great deal of argu- live within 25 miles or so of a broad - heterodyne receivers. Radio from ment for and against the fixed crystal casting station, I am sure that you will its humble beginning to its present detector with the immovable catwhisker, keep this circuit hooked up permanently. peaks of achievement in the Special but I believe that the fixed detector will Summer Number of RADIO AGE. Future of the Crystal Set prove best in the long run for the begin- All basic Hookups. ner, at least, as it avoids the necessity of CONSIDERING the many 5,000 watt constant readjustment and the detuning broadcasting stations now under THIRTY PAGES OF DE- effect when these adjustments are made. construction, and the increasing practice It will perhaps be of interest to know that of re- broadcasting, it is certain that the LUXE BLUEPRINTS. the crystal has a great deal of effect in crystal detector receiver will find a more Order your Copy in Advance. the tuning of the circuit and very often extended use than has been the case in we can tune a station in and out by means the past. Increased power at the stations $2.50 a year. of the crystal adjustment alone. For the and the relaying of these stations at close 25c at your Newsdealer experienced crystal set operator, the intervals over the country will mean that adjustable crystal is therefore often an the crystal will take on a new life. At advantage, as it is an aid to selectivity least ten telephone companies have and tuning, particularly where there are adopted local re- broadcasting systems as directly and nothing will be heard in the many strong local stations and other an additional service to their subscribers, phones if some sort of rectifier or "de- interferences. and I do not believe that the telephone tector" is not inserted into the circuit. It is a good plan to get a number of companies will be the only people to These waves are "alternating," that is, crystals and then select the best crystal engage in this work. If the network of they flow first in one direction and then by actual test. There is a great deal of re- broadcasting stations is fully developed in the other, and before we hear the sig- variation among crystals even of the same the use of the crystal set will be practical nals these waves must be made "uni- make, and the only way that you can be in almost any part of the United States. directional" so that they will flow in one assured of the maximum results is to One re- broadcast station equipped direction through the phones but with select the best crystal from a number of with a good receiving set and a trans- an intensity that varies according to the samples. mitter of moderate power will easily sounds sent out by the broadcasting The Hook -Up or cover a radius of 25 miles and will station. The crystal detector with its Circuit efficiently serve crystal detectors in this contacting "catwhisker" wire acts as THERE are about a thousand different 50-mile circle. The expense of main- such a rectifier and permits the passage crystal detector hook -ups from which taining such a station is comparatively of only one set of waves that are flowing to make a choice, and all of them have small and can be borne by the local in the same direction. their adherents, who believe that they Granges or community associations with With the radio frequency current rec- have the only circuit worth using. Some a great saving to their members. The tified, the "audio frequency" waves are employ variometers for tuning induct- station receives the voice and music developed so that the diaphragms of the ances, others use spiderweb coils, vario- from distant stations and then broad- phones follow the slower voice frequency couplers, honeycomb coils and straight casts these signals through simple appa- pulsations, thus producing sound. Our solenoid coils in all sort of combinations, ratus to local listeners, thus avoiding the station waves therefore consist of two but as a matter of fact, a close examina- expense and trouble of arranging pro- components, the high radio frequency tion will show that most of these circuits grams.rams. So far, this arrangement has carrier waves oscillating at the rate of can be boiled down to six distinct classes. increased the total number of listeners about 1,000,000 vibrations per second, The type of inductance does not change tremendously without appreciably affect- and the audio frequency waves impressed the characteristics of a circuit as a'circuit; ing the sale of tube sets. On the contrary, on them that will range from a few hun- it simply adds or detracts from its effi- one re- broadcasting station states that dred to an upper limit of about 15,000 ciency by the sharpness of its tuning the interest aroused in radio via crystal vibrations per second. These latter properties and the losses occuring within sets has greatly increased the sale of tube waves are produced by varying the in- the coil. A variometer may show better sets in its territory, and that a great tensity of the radio waves by "modula- results than a simple tuning coil, simply proportion of the listeners now have tion," and are not actually an indepen- for the reason that it can be more closely both crystal and tube sets in their dent series. adjusted to wavelength than the coil - homes. Tiring of the local re- broadcasts, There are a great number of minerals not because it is a variometer. An in- and desiring different programs, they that will act as detectors to some extent, ductance is an inductance no matter what turn to their tube sets and tune in the but only a few that are effective enough form it may be used. distant stations for themselves. to be used in the practical crystal set. (Turn to page 42) úci%0/s5 Fie./. BEL ow

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WATER'OR ç57-EAM P/RE FiG 4. , /NSTAL L AT/ÓiV ORAW/NG CePY,P/E,A/rir ..070/0 17._--:/v,vT. PFVa) r/,6,Pg7/45T//Y c/%/G'/10aL 1 CO- //Z 42 RADIO AGE for July, 1925 The Magazine of the Hour (Continued from page 39) a good degree of selectivity by other ductance. The crystal detector (CD) is in Fig. 1 shows the six basic circuits with means and without so much loss signal best placed as shown and should not their relative audibility value, as de- strength; hence, this type or circuit can be be mounted on the front panel where it is termined by the U. S. Bureau of Stan- neglected for the time being. likely to be thrown out of adjustment by dards. The relative signal strengths are Circuit With Coupler the jar of the hand every time we move given in terms of percentages, and it will the tuning dial. be seen that the hook -up has a great deal FOR the sake of selectivity we will con- The tuning inductance (Ll -L2) is to do with the reception, varying as it nect our aerial and ground to the wound on a cardboard tube three inches does from 10 per cent to 85 per cent. detector circuit by means of an aperiodic in diameter and about 4 1 -2 incles long. These diagrams refer only to the detector or semi -aperiodic coupler of the type so The primary winding consists of 12 turns circuit itself and do not consider the commonly use in tube sets. For the de- of No. 24 D.C.C. wire, and a space of various methods of coupling or connect- tector circuit we will adopt the circuit about 1 -2 inch is left between this coil ing the circuit to the aerial and ground. shown in Diagram (B) to obtain the and the secondary coil (L2). Starting A variable condenser is used for tuning greatest signal strength and will depend coil (L2), we wind on 55 turns of the same a fixed inductance in all cases. entirely upon the coupler construction size wire, and fasten the ends of the coil Diagram (A) shows a simple form of for our selectivity and tuning. This securely by passing them through holes circuit often used, which contains the combination will probably give us the punched in the cardboard tube. For inductance (L), the variable condenser best all -round combination for signal strong local stations, it may be necessary (C), the crystal detector (CD) and the strength and selectivity and at the same to increase the distance between coils to phones (Ph) all connected in series. For time is simple to build and tune. 5 -8 inch or 3 -4 inch to obtain the required ordinary broadcasting %avelengths there In Fig. 2 we have the schematic dia- selectivity, but this space should be no will be about 55 turns of wire in (L) when gram of the complete circuit. The greater than actually required for the wound on a three inch tube, and the ca- coupler consists of the primary coil (L1) complete tuning out of the strongest pacity of the variable condenser (C) will connected at one end to the aerial and station. If the gap is much greater than be from 0.00035 m.f. to 0.0003 m.f. The to the ground at the other end. The radio this, the signal strength will be reduced. audibility is S5 per cent. impulses from (LI) are communicated to The tentative wire (g) and the experimen- In Diagram (B) we have the same cir- the secondary coil (L2) which is identical tal fixed condenser (KI) are shown in cuit with the addition of the small fixed with the coil (L) in Diagram (B). A dotted lines as they may not be needed condenser (K) connected across the cry- variable condenser (C1) is connected with the combination of parts used in stal detector. This fixed condenser acts across the secondary coil so that it can be your set. as a storage capacity for the waves and tuned to wavelength. The fixed con- The condenser (Cl) can be either a 17 adds considerably to the volume, as it denser (K) connected across the crystal plate or.23 plate variable condenser hav- supplies an additional current to the detector (CD) serves the purpose al- ing a capacity of 0.00035 m.m. to 0.0005 crystal. This addition has increased the ready described. The phones (Ph) are m.m., but the latter is preferable. If you audibility from 55 per cent to 85 per cent, in series with the crystal detector. do not wish to wind the coil yourself, you the maximum value determined by the By means of the inductively coupled can use a nèutrodyne transformer which Bureau. coils (LI) and (L2) we can obtain much can be purchased complete and mounted The capacity of (K) depends upon the better selectivity than with the aerial and on the back of the variable condenser. nature of the crystal detector, but in any ground connected directly to the de- Such combinations cover a wavelength event the capacity must be small to tector circuit. The selectivity depends band of from 200 to 600 meters, the range prevent by- passing much of the current largely upon the distance between these of the average broadcasting stations. across the dectector. With some de- two coils. The greater the distance the It is most convenient to mount the tectors 0.00025 m. f. is about right, greater will be the tuning qualities where apparatus on a 6 in. x 7 in. x3 -16 in. panel while with other types this may be as there are many strong local stations. as shown by Fig. 4 with the tuning dial low as 0.0001 m.f. or even less. A small Properly adjusted, it is possible to tune (D) appearing on the front of the panel three-plate variable condenser will often in and out on a difference of five meters as shown. The aerial binding post is at prove of value in getting the adjust- wavelength, but with comparatively lit- ANT, the ground connecting post at ment correctly. tle loss in signal strength. With the GND, and the phone posts at PH. The In Diagram (C) we have the same cir- aerial and ground connected directly to method of connecting to the aerial and cuit as in Diagram (A), but a fixed con- the detector circuit, it is probable that a ground is also shown in this view, the denser (K) is used to bypass radio fre- nearby station will come in all around ground being a connection to a water or quency current around the phones. The the dial, no matter how it may be turned. steam pipe. average audibility under all conditions In regard to a crystal detector, it may The aerial should not be less than 60 is reduced to 45 per cent; hence, this is not be said that it is much more difficult to feet in length, and more than this is always an advisable addition. In many get selectivity with a crystal than with desirable where the necessary room can be makes of phones there is a considerable a tube receiver and that greater care will obtained. With a crystal detector set, amount of distributed capacity in the be required in the adjustment. The the more aerial wire that we hang up, the windings of the magnets and this fre- crystal has the peculiar property of hang- better wili be our reception, and any quently is sufficient to properly by -pass ing on to a station even against powerful length (L) can be used up to 150 feet. the radio frequency current around the controls, and while it has not much dis- With two wires placed side by side, 130 inductance without the addition of ex- tance or ability on weak signals, it will hold feet long and with the set located in the ternal capacity. However, in case the on likegrimf death tolfairly strong signals. open country, quite long distances can be liphones have a high inductive value with Under some conditions it may be ad- covered. However, with a 60 foot aerial ttle distributed capacity, a by -pass (K) visable to connect the lower part of the in a good locality, we can get good re- may be necessary. circuit to the ground connection (GND) ception with fair distance, providing that Diagram (D) is a type of crystal de- by means of the short dotted wire (g). the aerial is not screened by steel struc- tector circuit often used on wave -meters The rotary plates should also go to this tures such as steel factory and office and similar instruments where very sharp side of the circuit (ground) as indicated buildings, bridges, etc. tuning is necessary. The audibility is so by the curved line at (CI) and the low (10 per cent) that it is impracticable stationary plates are connected directly for a receiver and therefore need not be to the crystal detector (CD). discussed further. Its only virtue is its With some phones, which have very Higher Power Licensed extreme selectivity. little distributed capacity, it may help Diagram (E) a second variable con- matters to connect the fixed condenser To Beat Static denser (C2) is employed in addition to (KI) across the phones (Ph) as indicated THE Department of Commerce has the original variable condenser (C1). by the dotted lines. This is best deter- announced that favorable consider- This sharpens the tuning considerably mined by actual test, after the set has ation will be given to applications from and has a much greater audibility than been built and connected up to the aerial. owners of Class B broadcasting stations the circuit in Diagram (D). The audi- This may be a 0.001 m.f. fixed condenser. for permission to use higher power with- bility is four times as great as with (D) Picture Diagram of Set out requiring the increases to be made and is almost equal to that of the first in steps of 500 watts as has been the diagram. A complete drawing of the circuit with practice heretofore, provided the sta- Our last diagram (F) is the ultimate in all of the parts in place is shown by Fig. tions are situated outside of congested has low 3, the letters in this drawing correspond- receiving centers. selectivity but a very audibility ing factor. The circuit is split by means of with similar letters in the schematic In taking this action the Department diagram of Fig. 2. A detail view of the is endeavoring to satisfy the demand the coupler coils (L2) and (L3) so that coupler coil is shown which almost any degree of selectivity can be is connected of broadcast listeners that the use of to the variable tuning condenser (CI), increased power be permitted in order attained but at the expense of a great the latter being connected directly across to overcome the existing static conditions loss in signal strength. We can obtain the secondary coil (L2) of the tuning in- which are making reception difficult. RADIO AGE for July, 1925 The Magazine of the ¡four 43 . .,>. P. 1 -- ups ---_, rt d { ;1 J --- i Hook ups L$p = ót> our I eaccrs -'

material appearing under the title "Pickups and Hookups by Our Readers" in RADIO AGE, is THEcontributed by our readers. It is a department wherein our readers exchange views on various cir- cuits and the construction and operation thereof. Many times our readers disagree on technical points, and it should be understood that RADIO AGE is not responsible for the views presented herein by con- tributors. but publishes the letters and drawings merely as a means of permitting the fans to know what the other fellow is doing and thinking.

IF THE filaments of your vacuum tubes begin acting as you feel during the Summer, it is not neces- CONTRIBUTORS sarily an indication that their span of life Name Address City has been bridged, for rejuvenation of R. S. Parks___.._.._.._ .._... .-_1419 Cleveland Blvd__--_ --.Caldwell, Idaho tubes seems to be as welcome to inani- Clement Hampton 427 Jeanne Mance St.._ ...... Montreal, Canada mate thoriated filaments as it is to those Walter E. Fee.. 115 Beecher St Atlanta, Ga. who have sought the fountain of eternal Carl Wininger__ 20 William St_.._ St. Catharines, Can.' youth. Joseph A. Smith 723 Wallace Ave.__ A._w__Wilkinsburg, Pa. Tube manufacturers have cautioncd Francis Davis Cushing, Okla. their customers, via the literature ac- companying the tubes in the cartons, DIAL TWISTERS tube may be restored that a paralyzed Albert C. McKee 2306 Seminary Ave Chicago, Ill. activity by leaving it to its pristine P. French 1209 Franklin St .... -Beaumont, Texas] in the set for ten minutes with lighted A...... _..___.___.____327a Richmond process Robert St_ ... -_Montreal, Canada the "B" battery shut off, this William Laning 325 North Bambry St___-__Philadelphia, Pa. bringing the thorium from the apparently Alfred T. 280 Randol Ave_____--- .__.___ -San Calif. new Chandler Jose, filament center and giving the tube Charles H. Leach 1000 Van Buren St Chicago, Ill. life. James P. Williamson ...... _.._327 Dorian St- Montreal, Canada One of our prominent manufacturers Warren King 100 South Crest Road Chattanooga, Tenn. with a rejuve- has comc forward tube Homer W. Good...__.__ R. F. D. 1.___ Wescosville, Pa. which radio fandom's interest nator on H. Bowden. Box44, R. F. D. 1, Mt.View-_Plainville, Conn. seems to have centered. Mrs. Eva A. Taylor_-_-___---69 Murdock St Youngstown, Ohio It consists primarily of a small step - the toy Fergus Mackay _Grange St Pictou, N. S., Can. down transformer, similar to Fisher 4335 Jacob _w_.._ Va. rail- Kermit St Wheeling, W. transformers used for running toy Ackley T. Bush__...._ 941 No. University Ave Shawnee, Okla. in two road trains, etc., being made A. C. Taylor.._.....__ Steele, N. Dakota one for 110-20 volt primary with types, Floid Omond..___ ...... _._ .... ___ 16 Alsace Ave_.. Buffalo, N. Y. sixteen and eight volt second- ten, four, D. C. Atkinson_--- ._.___ 788 Hohman St Hammond, Ind. for 220- ary sections, and the other the C. C. Peugh.______. 54 Linden St_ Schenectady, N. Y. 230 volt circuits with the same secondary Kendall McNeil__- ______. Ottawa, Canada outputs. This, together with a socket Jack Cordy_- Box 251 Globe, Arizona for each size of tube, comprises the layout, C. A. Hendrick Horizon Apts.___ - Venice, Calif. to which the owner adds his timepiece. George A. Moutsatson._ 265 Ohio St_ BentonHarbor,Mich. For the UV 199 tubes the tube is E. N. Girard...... _.._ 715 South 58th St Philadelphia, Pa. placed in the socket after the transformer R. Winder Pedro Miguel, Canal Zone lighting Roy has been plugged into the Charles Markarian._ 110 Summer St___ Worcester, Mass. mains. It is given ten volts on the fila- Lyle F. White...._._ 523 So. Washington St. _Kankakee, Ill. ment for 30 seconds, then the voltage A. L. Snow 619 Hendrie Blvd Royal Oak, Mich. is cut to four volts and the tube is allowed E. C. Kelley.______.___Underhill, Vt. remain for ten minutes. The first to Earl Hamden, Jr. - Globe, Ariz. voltage is known as the shocking charge John Hogle-___ 321 Selma Ave. Kenosha, Wis. and serves to drive the thorium from the Henry W. Werner, Jr___ Box 419 Valhalla, N. Y. filament center. The ten minute lighting W. Manning, Jr.___ ...... ___.619 Princess St___.._.. Woodstock, Can. of the filament at four volts is known as Robert B. Otto 85 Lowell St__._._.___..__.___._Mathuen, Mass. the baking charge and serves to solidify Frank Barclay R. M. D. 1,.___ __ Victoria, 13. C., Can. the thorium on the filament so its elec- Edward Nolan_...._.._ ,657 Tenth Ave New York, N. Y. tronic emission is again at a maximum. Allan S. Wilson_._..___ 244 Kenwood Ave Dayton, Ohio For the UV201 -A type the shocking Harold W. Fairley____- ___-121 Gilmour Ave__.__..____Toronto, Canada voltage is sixteen volts for a period of Robert W. Barnhill______-116 East 9th Ave_.___- __Bristow, Okla. 30 seconds, and a baking charge at eight Harold A. Reynolds_-______229 North Montello St____Brockton, Mass. volts which lasts for ten minutes. The Wallace Buxton______._.4166 Emerald Ave__--______Oakland, Calif. same action takes place as with the 199. George A. Winkle______902 South 15th St _ Birmingham, Ala One Need Remains J. A. Myers, Jr____.______.___944 West Capitol St ...... _. Jackson, Miss. - M. E. Walter______.______117 Lafayette St______._. .Niles, Ohio As a result the owner of emaciated Fred Brunton____-_ Anaconda, Mont. tubes need no longer worry about a Cecil Carrigg__ .._.___..__. -._215 21st Ave____ - _.____.._San Francisco. Calif means of bringing back their life. How- William Heinochowitz___.___.135 Johnson Ave ...... _.__. _.Newark, N. J. ever, neither the tube manufacturers' George D. Hillstrom- 10135 Lafayette Ave Chicago, Ill. method of restoring life by allowing the D. Gabelhouse.__.__._.____ -__ -__.Vegreville, Alta., Canada tubes to remain lighted without the B battery on, nor the transformer method 44 RADIO AGE for July, 1925 The Magazine of the Hour Down with regeneration? No! Em- phatically no! Let's keep it, but not abuse it. "This is merely a suggestion and many an old shoe will be shied at me, I'll venture, yet I hope it may stimulate others to give their views." The writer of the above, R. S. Parks, 1419 Cleveland Boulevard, Caldwell, Idaho, seems to put the case up not so much to this department but to fan - dom, since it has been the policy of RADIO AGE to give its readers what they desire. If there has been a desire for DX lists, it is simply because the burden of the Editor's mail has been of that type. If the single tube regenera- tive has been unduly touted in these columns, it is merely because so far the majority of the contributors seem to have been most impressed with it. We realize there is a growing demand for the experimenter's section in this de- partment, but so far the genus experi- menter has not made his voice heard. Perhaps the publication of the above letter and the comment made will serve to stir up interest. Perhaps it will lead to the creation of a band of experimen- ters who have passed the one tube stage and wish eagerly for more experiences, although RADIO AGE cannot very well afford to forget the beginners who have many more problems than those who have already taken the dive into the pool of radio and have learned to swim. Henceforth, we will watch the mail very carefully, and the tenor of the de- partment will be merely a reflection of the contributions received. It is up to readers An old reliable crystal circuit, one of the early types used in the U. S. and still popular like Mr. Parks to sound the call to arms with those who do not care for the expense of a tube set for short distance reception on to his fellows; then let the station list headphones enthusiasts marshal their forces. May the better man win; we feel our readers mentioned before, will restore a filament and Hookups Department to be what it is will always wish us to abide by the de- from which the spark of life has departed -no more, but personally I believe that sires of the majority. due to a breakage. When someone you gave this section of your magazine invents a filament restorer for burned to the experimenter for a means of radio Old timers will readily recognize the out filaments he will be kissed on the development. If so, then it is up to the circuit in Figure 1 as the inductively or brow by all the broadcast listeners, the contributor to use it and use it widely. Ioose-coupled crystal set, with an arrange- amateurs and the owners of broadcasting ment for switching from the use of car - stations, although doubtless the tube Ds Lists? borundum and a potentiometer to galena manufacturers would chase him into the "DX lists do not occupy a seat of and other types of crystal on which no wilds of Patagonia with a sawed off shot- honor in my household simply because battery current is used. In the old days gun. 1 do not invite them, or to put it in the the carborundum was considered good At the last moment in our June issue words of an amateur, 'I didn't get the because it was fairly stable and rugged we were able to get together interesting Pacific Coast because I was not fishing.' and would stand the lurch of the ship data on the binocular and toroid coils To me the logging of numerous stations and the pound of the engines at sea. which are designed to eliminate the neces- merely for a long list is a waste of time. It is sent in by Clement Hampton, sity for neutralization in radio frequency The logging of twenty-nine stations in so 427 Jeanne Mance St., Montreal, Que., amplifiers. The Pickups Editor will be many minutes as given by one of the Canada, who says his old friend, W. J. glad to hear from readers of RADIO contributors is laughable. May I ask Featherstone of 213 Ella St., Hull, East AGE as to the success encountered with how many of us today would know any- York, England, passed it on to him. these new types of fieldless inductances. thing of radio and its possibilities if the The antenna variable is a .001 and the Here's a fan who is even willing that early experimenters spent all their time secondary a .0005 mfd. The inductances shoes should be shied at him, but he has at such foolish toying? Wouldn't it be can be either honeycombs, a loose coup- the courage of his convictions and writes of more interest and of more educational ler, two spiderwebs, or almost any form us as follows: value if the contributors to this depart- of good inductance. A fixed condenser "An interested observer may be intim- ment gave discussions of different cir- across the phones would do no particular idated many times before making his cuits, as many are doing, effect of weath- harm and might help a little. debut into a certain field; but, there comes er conditions, code interference and most This circuit is popular in England a time when he can restrain himself no of all, receiver interference? where no one is allowed to use a regenera- longer, and makes a headlong dash "You will also notice that this section tive set capable of feeding energy into the by giving his views on a subject. His contains hookups, nine -tenths of which antenna, and where the distances are not suggestions may be of little benefit and are of the regenerative, one-tube type. great,asis the case in the British Isles and then again they might open up a way for "Fine, I say, in the hands of one who continental Europe. something better. It is with the latter knows how to use them without spoiling in view I write this: half a dozen neighbors' good natures. Known under seventeen or eighteen "Possibly you have meant the Pickups But how few of us there are who are ideal. different names, the circuit shown in RADIO AGE for July, 1925 The Magazine of the Hour 45 Figure 2, and sent in by Walter E. Fee, of 115 Beecher St., Atlanta, Ga., is the single circuit Armstrong, noted (or its ability to squeal, and one of the oldest regenerative sets known to experimen- ters. L 2 is inductively placed against L 1 for feedback. In Atlanta this circuit works out quite nicely (though we hardly dare think what the neighbors have to say on this subject when the tube is oscillating). It tunes in the long distance stuff while WSB is batting out flies, and for a change Aar. Fee hooks it on a loop and goes fish- ing for distance, with results as follows: WSMB, WOC, WEAF, WCCO, KDKA, KSD, WOAW and WQJ. Of course, this is used on head phones only. It is one of the tried and true types of receivers, although not recommended for congested areas where your neighbor migat have one too.

Here's another one familiar to the fellows who have been following the game for longer than a couple of years. The circuit sent in by Carl Wininger, 20 WilliamSt., St. Catherine's, Ont., Canada, was originally published by Weagant shortly after Armstrong gave the world his regenerative circuit. Later Weag- ant's circuit was taken up and popular- ized by Reinartz. It has masqueraded under a thousand different names, but, the circuit fundamentally is the same This is the single circuit Armstrong. L 2 is inductively coupled to L 1 for feedback pur- poses, and its relationship is variable. change in L 1 is which is the point in which most experi- The inductance by means of taps and the condenser in the antenna circuit. Good for results but hard on your neighbor if menters are interested. you let your tube oscillate Instead of using a variable regenerative coil for control of oscillation, the Weagant circuit, alias Reinartz, alias et al, uses a variable capacity in series with an induc- tance, the two paralleling the plate and filament. The control of oscillations seems easier with this type of receiver than w ith the straight variable plate coil. The receiver shown in Fig. 3 happens to be the single circuit Weagant, which can be made up with honeycombs, spider - webs, straight winding on a tube, or any other form of inductance. While it is good for excellent work on distant stations, for the sake of other listeners it would be best to loose couple it, by having an untuned primary in inductive relation to L 1. The condensers in the circuit shown are .0005 mfd. Reinartz found that oscillations could be better controlled by inserting a small choke in series with the phone lead at the point marked X in the diagram. In the inductively coupled receiver the condenser Cl spans Ll, while the an- tenna comes down through a fifteen turn coil to ground. The secondary is then removed from direct contact with the aerial and if the receiver does feed back into the aerial it will be with lessened energy. Ll can be approximately fifty to seven- ty -five turns, while L2 can be somewhere between thirty -five and fifty turns, the condenser C2 making it unnecessary for the exact number of turns to be found for the inductance L2. Another form of the Armstrong re- Another popular type of receiver in which regenerative control is by a variable capacity generative is sent in by Joseph A. Smith, in series with an inductance paralleling the plate and filament. Known years ago as 723 Wallace Ave., Wilkinsburg, Pa., who the Weagant circuit, later popularized by Reinartz and others. Better build it boss tells of the good work it has done for coupled for the sake of the neighbors, unless you happen to live out in the exact geographic .l him. He says it is good away from con- center of the Gobi desert 46 RADIO AGE for July, 1925 The Magazine of the Hour Bested districts. His coils are wound as follows: L2 52 turns 18 or 20 DSC on a three or three and a half inch form. Around center of winding one layer three quarters inch cambric. Stick 8 pieces of hard rubber 3 -4 by 3 -16 by 1 -4 placed A76 1E. equidistant around the piece of cambric, Avv fastened with collodion. Coil L1 is wound on these blocks and consists of 3 L~ to 10 turns of the same wire. An ordi- nary plate variometer is used for L3. Cl is .0005 and C2 .001 mfd. This cir- i cuit is inductive and even if oscillating would not cause the same amount of annoyance which a single circuit would. IIM He submits a list of DX stuff that cer- tainly entitles him to the DT button. Another circuit which has proved very popular with those who wished to econo- mize on tubes and material, is the reflex circuit, originally attributed to Latour, the Frenchman, who gave it to the Allied communication authorities during the An inductively coupled Armstrong regenerative. Coils L1 and L2 are wound by the con is plate variometer. He good early part of the war and which was tributor, while L3 an ordinary gets results on it, as he should immediately pounced upon by everyone with a loose coupled regenerative set. on this side of the water as an excellent feminine fans, the first from Floid received on a manufactured four tube circuit from an economical standpoint. Omond, 16 Alsace Ave., Buffalo, N. Y., set with built in loud- speaker. She It has been rearranged countless times who finds RADIO AGE interesting in wonders if there is anybody in Chicago and additions and deletions made to the every way, and specially the Pickups who does not own a broadcasting sta- original. and Hookups. She has built a one tion, as her experience on the air seems This circuit, Fig. V, is sent in by Fran- tube and a three tube set and has re- to show that nearly everybody in Chi- cis Davis of Cushing, Okla., who tells us ceived fine DX stuff with these. So cago is broadcasting. L1 is wound on a 3 inch tube with 15 we will send her a button, but regret turns of No. 22; L2 same size tube with we haven't a little wisp of ribbon to 50 turns; L3 is the same as LI and L4 send along with it; we used up the last We got quite a laugh out of a letter is the same as L3. The variables Cl piece in winding a coil. from Albert C. McKee, 2306 Seminary and C2 are .0005 mfd. C3 is .00025 and Ave., Chicago, Ill., who says his set is C4 is .001 mfd. The other feminine ether chaser is in a second edition of "Hell's Kitchen" Davis' list of DX stations also gets Mrs. Eva A. Taylor, 69 Murdock St., where he has to contend with regenera- him the DT button. Youngstown, Ohio, who reads RADIO tive squeals and howls. In his letter AGE with a great deal of interest, espe- he tells of making a crystal detector Looks like the ladies are not to be cially since she ran across one of the out of an old mouse trap but fails to prevented from having equal rights in Youngstownian names in the magazine. tell whether he was bothered with radio as well as economics, for in this She has qualified for the button by squeaks on account of this fact. He week's mail come two letters from sending in a list of stations she has (Turn to page 48)

3 L L

A* A-

Another popular circuit, the reflex which sprang from Latour, the Frenchman, during the war. It is simple, effective and economi- cal. What more can the fan ask? This one was sent in by Francis Davis, of Cushing, Okla. RADIO AGE for July, 1925 The Magazine of the Hour t ï

wie Maga3in ofthe Hour

Offers to Its Readers the First Feature of Its Kind Ever Published in a Radio Magazine A Round -up of Hook -ups ALL Basic Circuits from which ALL Radio Hook -ups are Developed Described and Illustrated with 62 -Page Blueprint Section

FOR the first time in any unusual number will radio magazine, RADIO In the THISsell for the usual price of AGE is publishing in its 25e a copy. Of the pages August, 1925, issue, an array "De Luxe" in this number, fully 56 will of radio hookups that will contain actual constructional impress and delight every August Issue articles, of which THIRTY lover of technical radio infor- OR MORE pages will be typi- mation and accuracy. of RADIO AGE, cal RADIO AGE blueprints, In this big number, which which have made the "Maga- is to be our "Deluxe August zine of the Hour" distinctively issue," RADIO AGE will Out July 15 famous the world over. prove its superiority in the From the simplest crystal technical field by giving its readers, at no additional set, the articles in this number will enable the reader to travel by an orderly process to the super -heterodyne, cost for the magazine, many pages of hookups, from the taking in every popular type of receiver introduced early diagrams to the very latest developments' in since the advent of the radio science. multi -tube design. Where improvements have been made, the latest technical explanations will be given. Everything will Because of the inevitable popularity of this number, be strictly up- to-the- minute, and written so clearly and the demand its publication will cause, readers are and simply that either the rawest novice or the most seasoned technical expert will understand the articles asked to order copies in advance. almost at a glance. Order Your Copy of This Wonder Issue In Advance!

25 CENTS A COPY, 500 N.DEACRBOORNST., $2.50 A YEAR RADIO AGE , Inc. 48 RADIO AGE for July, 1925 The Magazine of the Hour about fifty turns of No. 18 bell wire (also known as annunciator wire), span- I ~r Dot T ß ning it with one of the Remler con- THAT IS LIEVE INI THE densers he uses. Insert in series with THE the aerial lead of your normal primary WAY1-1 WAN YOUNG and tune to Zion's wave, leaving it TA LI

Kendall McNeil, of Ottawa, who neglects to send his address, writes interestingly of his excellent results with the improved three tube Reinartz described in the May RADIO AGE by Mr. Piety. He gets all the stations in the U. S. and also nabbed two or three of the Continentals, namely Lon- don, Newcastle and Aberdeen, all of which he has confirmed.

(From page 46) did help his set to such an extent that D. C. Atkinson, 788 Hohman St., thinks J. B. Rathbun, who makes up he logged quite a batch of DX stuff, Hammond, Ind., one day used his the blueprints for the various hookups for which he is hereby awarded the downspout on the eave- troughs of the appearing in RADIO AGE, is to be D. T. emblem. house instead of an antenna, getting complimented on their uniform accuracy stronger signals. He used this on a and efficiency. He is using a five tube George D. Hillstrom, 10135 Lafayette crystal set, but says he has not tried Let's hope his reflexed radio frequency set recently Ave., Chicago, Ill., is a 14 year old it on a tube set yet. will described by Rathbun and gets won- youngster who is following RADIO experience not start an epidemic derful results with it. His list of sta- AGE circuits with great success. His of down- spouting or else all the land- tions entitles him to the button all right. letter containing a DX list entitles him lords in the country will be faced with to one of the coveted buttons. the necessity of installing tinned copper A. C. Taylor, Steele, North Dakota, downspouts with binding post con- says he finds there is no other publica- George A. Winkler, 902 South 15th nections for each experimenter. Many a tion that deals with radio that has such St.. Birmingham, Alabama, wants RA- tin roofs have worked better than a vast amount of good reading matter DIO AGE to keep on pouring it into poor antenna, but always remember as RADIO AGE has. He says he was a certain radio octopus with which there is NO substitute for a GOOD surprised to see the circuit used by we are all acquainted. He sends in a antenna. E. H. Jones in the April number, and diagram of an eight tube super which feels that too much cannot be said for he is using with good results. such a circuit. Charles Dtarkarian, 110 Summer St., How are P. E. Chapman, 805 North Preston Worcester, Mass., gets fine results with St., West Philadelphia, Pa., thinks the reflexed neutrodyne described by Your DX Lists RADIO AGE is the best on the market Mr. Hopkins in the January issue of and reads it with great interest. He RADIO AGE. Coming This thinks our invitation to readers and experimenters to forward their results T. L. Kent, 721 North Ave., Wau- Summer? with new circuits is certainly a boost kegan, Ill., formerly 6US, is now out to the amateur and a great help to all of the "ham" and into the BCL game, who are interested in radio. He is still which he likes very much. Let the using the four -tube circuit published by RADIO AGE in September, 1924, John Hogle, of 321 Selma Ave., "Pickups and and with it has logged 167 stations; Kenosha, \Vis., says he is bothered by three Europeans, two Cubans, five only one station, that being Zion. He Hookups" Canadians, six Pacific coast and one asks for a wave trap that will obliterate Alaskan that station. He has made up his Readers set from RADIO AGE blueprints. He P. French, 1209 Franklin St., Beau- gets excellent results from his three mont, Texas, took us at our word as to circuit regenerative. A wave trap might Know About Spring cleaning referred to in the May be used on Zion with-good results. Make RADIO AGE. He reports that Spring it on a cardboard form about three Them! cleaning from aerial to ground clamps inches in diameter, winding it with RADIO AGE for July, 1925 The Magazine of the Hour 49

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Sales Distributor Wanted to start now in the fastest growing business the world ever knew -Three Million radio sets were sold last year - 22 Million will be sold in the The Difference- U. S. A. When Using AMPERITE THE AMPERITE the "self -ad- justing rheostat ", automatically con- MUSIC BOX trols the flow of current, and makes hand controlled rheostats obsolete. RADIO Geared Permits the use of any type of tabes or any combination of tubes. RECEIVER Specified in every popular con - 80 struction set. is the peerless seller of them For perfect results you must use all. Think! Only two orders to AMPERITE for filament control. weekly means $600 per month. Price $1.10 everywhere. Four orders $1200 per month. 1 Another Important development in ACCURATUNE RADIALL COMPANY The Set with the Marvelous conetruction-the u of a full bra .. gear train, built Dept. R.A. -7, 50 Franklin Street. NewYork Cite exceptionally ruggedand designed for Accurate Tuning, Tone and Volume Supreme, "Absolutely essential for sensitive set.. 1. Friction Clutch. 2. Lang Center Bushing. 3. New Cur Write for the Distance getter of them Mesh. FREE all. Write now, today, for At your dealers, otherwise send price ($3.50) Hook -ups and you will be supplied postpaid our liberal 15 -day trial offer MYDAR RADIO CO-, 9 -IC Campbell St., Newark, N. J- and protected territory. L I4 MP TE THIELEN, Manufacturer CCURATUNE "means tight amperes" 1207 North Shore Ave., Chicago, MIGRO M ET E CONTROLS

"The Roundup of Hookups! " -1 I2 pages of every conceivable kind of radio hookups -will be the big feature of the `Deluxe" Edition of the August RADIO AGE. On the stands July 15, but order your copy in advance if you want to get this wonder issue. More than thirty pages of blueprints and scores of hookups! 25 cents a copy. * Tested and Approved by RADIO AGE 50 RADIO AGE for July, 1925 The Magazine of the Hour The Broadcast of Plays for the listener-in a vision of the layout How Much Coupling is concerning which he hears the spoken Written for Radio version. In the movie, the audience sees Necessary? By E. E. Mattson but does not hear. In the radio, it hears (Continued from page 14) Westinghouse K Y W and will see by virtue of the impression In making the final primary coil, it is SINCE the advent of radio, its progress that will be given the listener by the has brought many improvements, best to allow taps at two or three turns personnel of the act. more than necessary on long waves and some of them expected and some not K Y W It is the purpose of Station to at least two less than necessary to pro- looked for. However, improvements from give life to this plan. Mr. Wetherbee will a technical point of view have not been duce oscillations on short waves. This supervise the writing of plays to be used makes sufficient allowance for depreciat- the only goal sought in radio. From the over K Y W. He has completed the first beginning radio was popular because of ing tubes and batteries. one act play, "The Fates Decide" which The variable coupler makes up for its newness, its mysteries and seeming will soon be put on the ether. In this intangibility. A person bit by the radio lots of little differences in sets, such as play he employs three people, Norman aerials of different capacities, tubes of bug soon became almost diabolical in his Landon, a wealthy newspaper owner, lust to grope into the distance, and spared more or less oscillatory tendencies, Marion Landon, his wife, and Franklin batteries differing in voltage, detectors no effort to purchase or build a set that Ames, his life long friend. The entire brought him clear and distinct reception. of more or less absorbing powers and the plot is laid out with the same care and like. It avoids the necessity for variable Those were fascinations that led him on. thought as given a play for the stage. It With the advance of radio activity, and feed -back coils like reversed ticklers, for will be acted by three artists of the sta- inducing regeneration on some wave- the many angles taught its leaders by tion, who have been coached in rehearsal experience and study, it became apparent lengths and counter -acting it on others. until the effect intended has been brought And it permits long wave stations to that the mere broadcasting of vocal or out to a high degree. instrumental numbers accompanied by come in as well as others; in fact, it makes announcing not suf- reception uniform all over the dial's conventional would scale. fice. The rendition was heard well but it appeared automatic, it lacked the per- Summer Radio Conditions sonality that would make it pleasing and To Be Surveyed Phonograph Stores Are beautiful. The artist was taught to im- HFRANK Hopkins and Harvey T. Handling Radio press the invisible listener -in by sound, Kelley, Assoc., I. R. E., and well what the stage artist did by pantomime. known radio engineers, plan to NEW YORK-Radio parts are now The announcer was given the idea of leave Chicago some time during August being handled by phonograph stores making his remarks fit the occasion and on an extended trip throughout the West- throughout the country and on a grow - ern and Southwestern portion of the ing scale, declared Ben Aplin, eastern blending them into the program as sales manager for Shaw of it, thereby assisting United States, to carry on an intensive the Insulator part the proper survey of broadcasting conditions in so- Co., of Irvington- Newark, N. J. Mr. balancing of the act. These, and many called "dead spots." Aplin, who is one of the best known other things were essential. Because radio reception is so difficult salesmanagers for molded radio materials After about four years of radio activity, in the Summer -time, under most condi- in this country, has been deeply im- numerous ideas have presented them- tions, the two experts will endeavor to pressed by the increasing volume of selves to radio directors, visualizing the trace the causes and record them for sales being recorded by phonograph and need of a change of venue. Wilson public use. Their findings will be sent music stores for small parts which hold for publication in RADIO AGE as the such an important part in the radio Wetherbee, director of Westinghouse industry. K Y W, has long felt need trip progresses. Station this A 100 -watt broadcasting station will "Hundreds of dealers throughout the and for some time past has been active in be part of the equipment carried on this eastern section of the country who coaching the personnel of K Y W toward trip, and arrangements have been made previously handled musical instruments this goal. Radio broadcasting demands to carry on tests in Colorado, Utah, and records, and eventually added radio new things, and it will get it. The movie Arizona, New Mexico, Southern Cali- sets have been finding that small parts industry started with one -reel features, fornia, and where static conditions at have been invaluable sources of profit and during its evolution it grew until this time of the year are unusual. Under to their sales total. today the cinema features full plays these extremely adverse conditions, an "This fact is more apparent as one, studied skill, attempt will be made to determine just in travelling throughout the greater brought out with a wherein what kind of radio circuit performs the cities, finds that dealers everywhere are the personality of the actresses and actors, best. Several circuits will be taken on, adding small parts as the direct results aided by elaborate stage settings, convey the trip and tested under varying of demands made upon them by their to the audience the same impressions that atmospheric and geographic conditions. trade. There are always some parts of the spoken drama would. The success of Communication with Eastern and their set which they desire to replace the movie is evident by its popularity Pacific broadcasting stations will be to add greatly to the efficiency of their among all classes, the highly educated maintained throughout the long trek, sets. and those less favored. which will be made by automobile. "With that idea in mind they go to Several stations have expressed a desire the music store which sold them the set A Radio Technique to broadcast the findings of the experts, and insist upon buying some particular Mr. Wetherbee's ideas have brought to guide them in reaching districts and part. If the dealer does not carry that radio listeners in isolated parts of the world part or for that matter any part in stock out that thirsts for something more who at present encounter difficulties the customer goes elsewhere. The than "one reelers." His experience has in maintaining consistent touch with natural result is that the dealer, rather taught him a technique of radio more radio stations throughout the year, and than see business going to another store, than the mere announcing of a selection especially in the Summer-time. gradually stocks up new and small and then putting it over clear and dis- Mr. Hopkins and Mr. Kelley intend to parts which he finds hold ready sales tinct. The announcer, the artists, the devise several new types of radio appa- appeal to his customer. stage setting -all are unseen by the ratus to meet the difficulties they expect "Many dealers were first of the oelief listener. The general atmosphere has to will confront them. These varied types that the carrying of small parts would impressed of apparatus, which will be designed be the means of cluttering up their be upon the listener by sound, after thorough tests, will be described to stock. Instead they are gradually finding and by the personality injected into the readers of RADIO AGE this Fall, that by simplifying the arrangement microphone in the studio. So far this thereby being of great value to those of merchandise has succeeded their they are able to policy admirably. Now fans who live far from strong stations fill the customers, demands at once. Mr. Wetherbee's plans bring forth radio's and who are bothered by static, fading and other unaccountable disturbances. "It is no longer necessary to spread demand of short acts, in which several these small parts in every section of the persons take part, and in which the Both Mr. Hopkins and Mr. Kelley have long been identified in radio store. They are now systematizing scenes are laid with the same care and their stocks of these small radio parts stage circles, having done much research and aforethought as on the or in a development work. Both are past with the result that a show case or two photo-studio. With radio, however, masters in the transmitting and receiving in a particular section of the store carries technique finds employment in drawing art. the stock required. RADIO AGE for July, 1925 The Magasine of the Hour 51 The Radio Spies (Continued from page 32) occasions seen this same Cecelia Lambert at the De Forest plant in Jersey City. I was likewise told by another employe who was working under Harley. whose name I do not recall. that there was at that time another investigator stationed at the De .ff-8' ,DENVER " From the log of From the log of Forest plant who was known as '1-10.' aG A.B.Miller MFxtC he arranged for Thies to procure A.R.Mcgoubrey After saying that S Mt TOlm rc RO. 17901 Detroit AN Cl-' certain information concerning the complainant. Yctorla,s.c ram& Lakewood,Ohto tN Bowlby declares he passed on Thiess written report to Harley. adding. "this report contained. among other things. a description of all the machinery used From log of the From the tog of in the tube department of the De Forest Radio Marshal Johnson he Wm..1. Lambert Company while he.was working there. as far as 1608 E. Seep St. 508 Ligonier St. could remember the same. together with the method Daluth,Minrt Latrobe -a. of operating these machines; also the information DENVER regarding filament wire used by that company in making its tubes and where they obtained the same." Bernice M. Jennings. employed as typist by the Radio Corporation of America from November. 1924. to April. 1925. said an employment agency sent her to Room 301. 25 Beaver Street. where she asked for Mr. Harley. She was engaged by a Mr. Silverton. There were six girls under Mr. Harley in Rooms 301 and 302. she says. Harley's private office was Room 303. She alleges that Room 217 in the same building was also occupied by a girl under Harley's direction and was also used by Radio Corporation's. investigators. Through the Locals Instructed on Secrecy Soon after she began work. alleges Miss Jennings, she was told by several other employes in the office not to give out any information regarding the people ALL-AMAX Reaches Out in the three rooms. or their business and also not to let anybody know that there was any connection ALL -AMAX between the employes there and the Radio Corpora- Every Set, wherever it may be, brings to tion of America. Two weeks later she was trans- its owner his choice of all the beauties in the air. ferred to Room 217. Once a man dropped in and asked for Mr. Harley. She directed him to Room Every day come more and more letters to our office, 301. When Harley heard of the incident he is alleged to have said to Miss Jennings. "In the future. if telling of the long distance reception, almost unbeliev- any one comes here and asks for me. you don't know able on a three -tube set, _which has rewarded the me nor anything about me. and no one here has anything to do with any radio business whatever." owners of ALL -AMAx. Harley. the affidavit continues. received written reports from many investigators. They were usually Remember, too, thatALL -AMAx is completely mounted stamped with Harley's initials and then went to Silverton, who stamped them with his designation. on panel and baseboard. You can wire it in one delightful "C-2." When she first began copying the reports. says evening, following simple photographic instructions. Miss Jennings in her affidavit. they were headed by ALL -AMAX SENIOR, three tubes and detector . . Price, $42.00 the name of the person or concern under investi- ALL -AMAX JUNIOR, cue tube and detector . . . . Price, $22.00 gation. For three months prior to April 10. 1925. she received almost daily reports from "C -3." Cecilia Lambert. reports headed "In re De Forest." ALL - AMERICAN RADIO CORPORATION but subsequently the heading was changed to "381" E. N. RAULAND, President and that number was given to the file which contain- ed matters relating to the De Forest Company. 2680 Coyne Street sc Chicago The reports covered many things. the affidavit alleges. including the time employee began and quit work, "whether there were few or many employes at work. whether they worked overtime or less than full time. whether business was brisk or slow, what employes were discharged and what new ones were taken on, the names and addresses of employes. so LL-AMÉRICAN far as she was able to give them: instructions issued to foremen and persons in charge. notices posted in Institute Correction the departments governing the personnel of superin- tendents and foremen, why a foreman had been laid Through an off, efforts made to speed up production, and espe- error, the illus- cially what took place in the power tube depart- trationsof Tests ment: on two or three occasions her reports contained No. 47 and 49 attempted drawings of machines used in the depart- in the RADIO ment in which she was working." AGE Institute EARN Several times Miss Lambert. it was alleged, sent for 1925, $50 to $200 a Week in with her report some pieces of filament wire, and May, Send forms. big FREE RADIO 6006 debt nowt See bow many wonderful motley making pc..r- she also sent in what she designated as "gold seals," were reversed. for you as a TT'aned Éap.rt tuniteIn Ìfacst, f mmg lrrowhng Big Yay field e used in connection with the manufacture of power The Quam Con- the world- RADI01 tubes. denser test was Superdon Radio Set FREE Bowlby Long distance super.powerful select. Corroborates illustrated by radio set FREE to every stud.. William Buckbee, a tester in the De Forest Labo- an engraving of who acte soul Not a cent extra charge. ratory, swears in an affidavit that in company with a the Duplex proof hTodayón succceed .k, is the young lady he met Harley. at the latter's sugges- Condenser, and the ndrful Twinserd v act witenet tion. With Harley was Miss Johnson, whom Buck - vice versa. cost. Write at once -Now! No ohlw'ution. bee says he knew to be a De Forest employe. Harley. We are reprint- 6r44N Michigan Arec, Oep92, Chicago Buckbee asserts. told him that Miss Johnson was ing views of the two an investigator for the Radio Corporation and that with she was one of five or six employed in the De Forest condensers plant who were also employed by the defendant. their proper identi- "At that interview." the affidavit continues, fications. The to Log for Your Radio "Harley offered the young lady accompanying me a view herewith NEW 64 page log. Holds 400 stations. position as confidential investigator for the shows the Quam Shows mile, calm. wave lengths. 4 dial set- Radio . tings, ke. te, TUNING SURGES. Corporation of America and stated to her TIONS Station list by ware lengths- be that as condenser, and the -- stetes, etc. Owners. Map. TROUBLE IDS. such confidential investigator he could get her Other valuable information. So mnveslenL a cut at the bottom Werth position with the De Forest Radio Company, as a De Lessslleey leather cover. Si. stenographer, and that he wanted her, after having is Duplex Matched Conden- Send No Money Pardpf Dom° é;áß. MOÑÉV RÉ (Turn to page 60) FUROEO it not DELIGHTED. Order today -NOW. Postal will de ser. RADIO PRINTERS. Dept. egos 2t Mendota, Illlneia * Tested and Approved by RADIO ACE 52 RADIO AGE for July, 1925 The Magazine of the Hour Standard Radio Receivers

Recently RADIO ACE inaugurated a new department called ' Know Before You Buy," to serve as a guide to the prospective radio purchaser in deciding on the receiver best suited to his individual needs. Fans throughout the country have shown an instantaneous response to this new feature, and accordingly it is continued and will be a feature of all forthcoming numbers of RADIO ACE. Readers are invited to write us concerning the sets in 'which they are interested, and manufacturers also are asked to send us material describing their sets

Selectivity Paramount in Chelsea Sets Chelsea Three and Five Tube THEreceivers have been designed with virtually one end in view: that of attain- ing-the ultimate in selectivity. The Chelsea Super Five, just announc- ed,isa five tube receiver embodying this selectivity with unusual volume. Dis- tortion is minimized so it is.unnoticeable, as is any annoying squealing. The Chelsea Five has all the principles of the perfected non -regenerative set, including remarkable distance. The cabinet, of the sloping type, is finished in rich mahogany with shielded Bakelite. The retail price is now $50. Chelsea step of tuned radio frequency ampli- "Tone Modulator" in The Three Tube fication, vacuum tube detector and two Clear volume on the loud speaker, with steps of audio amplification. The first Resas Receiver ability to bring in distant stations within tube is reflexed; that is, it amplifies radio THE perfected Resas Tone -A -Dyne reasonable range, is the feature of the and audio frequency at the same time; receiver embodies every advantageous Three -Tube Chelsea, Model 122. This making the Eaglet virtually a four tube feature claimed for any five tube set, set has been on the market for some time receiver. plus the Tone Modulator, a feature and has gained a reputation for its con- It gives reception equivalent to a four that is to be had only with the TONE - sistently remarkable performance. One tube dry cell set, using only the current A -DYNE. station is received at a time, proving it required by three tubes. The Eaglet is As its name implies, the Tone Modu- is also selective. portable in the sense that it is light of lator controls the tone and volume at The Chelsea 3 -Tube Set is of the triple weight, can be conveniently carried all times and under all operating con- circuit type, controlled by a single tuner. about the house and can be hooked up ditions. There is nothing complicated No knowledge of radio is necessary to to different antennas, taken out in an or difficult about it. Simply a turn of operate this simple receiver. The cabinet auto, used on camping trips, Summer is slightly sloping, as in the Chelsea homes and hospitals. Super Five. It is of attractive finish. For its operation it requires three The price is now 840.00. No. 6 dry cell A batteries 1%z volt, and four No. 23% B intermediate size or The Eaglet Receiver a "Prince one 4% volt unit C. The tubes arc UV 199 vacuum tubes or their equiva- of the Air" lent. The instrument can be operate- THE EAGLET, a three tube dry cell with ear phones or loud speaker. The neutrodyne, has been "weighed in installation is the same as the Eagle the balance" of engineer's tests, and has model B; namely, approximately 100 the knob and the musical or vocal selec- proved that it possesses selectivity feet antenna. Two antenna leads are tion assumes its most pleasant volume. provided, one for long and one for short The Tone -A -Dyne is non -radiating. aerial. Annoyance from squeals and howls is The receiver is a delicate, scientific eliminated. instrument, should The selectivity of the Tone -A -Dyne and not be tampered is satisfactory. local with unusually With by inexperienced people. The stations broadcasting on a wavelength Eaglet has been welcomed both by the only 5 meters away, station WHAS trade and the consumers and has already (Louisville) has been readily tuned in endeared itself to thousands of owners. without interference on a short indoor Families spending the hot months in aerial. camps, mountains, or sea shore will find The Tone -A -Dyne is so designed that the Eaglet a source of great joy and will it can be operated by anyone without be able to keep in touch with the wonder- previous experience. The three tuning ful open air orchestra programs that are dials are accurately calibrated and always broadcast during vacation matched so that their settings practically as well as simplicity, distance time filament volume from the eoun;ry's best correspond. There is only one and tone volume. These qualities, stations. The control, and this can be set at the best coupled with good workmanship, finish water enthusiast can listen in and have operating point on reception of the first and guarantee, constitute the last word a whale of a time with his Eaglet installed station. A snap switch controls all in radio. on yacht or motor boat, on account of tubes. Clearly marked binding posts are The Eaglet embodies the Eagle Bal- its compact design and light weight. provided in the rear for all connections. anced Neutrodyne circuit, using one The price is $75.00. The price is $78.00. (Turn to page 54) RADIO AGE for July, 1925 The Magazine of the Hour 53 Learning the Various Tube Characteristics (Continued from page 12) operation. This condition usually comes suddenly; it is not spread out over the The "Better Tuning" Control life of the tube as would be expected. It is sometimes caused by applying excessive voltage to the filament of an otherwise good tube. If such is the case, A New B-T Product it is possible to restore the tube to normal by the rejuvenation process, or by apply- ing the rated voltage to the filament with the plate voltage cut off, for about Hairline Control, Easy a half hour. Action, From the above it will be seen how Simple Mounting. an old or defective tube will cause the aging of the other tubes in a circuit. No side strain or pull This condition is readily noted by the on shaft to necessity of increased "A" battery wear out bearings or destroy most fans just voltage -but turn the alignment of your condenser or rheostats on and let it go at that - paralyzing or otherwise decreasing the coil. efficiency of all of the tubes, which is a rather expensive performance in the end. Reads O to 100 or 100 to 0, -set- Amplification Factor tling the argument as to "clock- TO DETERMINE the amplification factor of a vacuum tube experiment- wise" or "anti- clockwise" instru- ally, a high frequency current of about ments. 1,000 cycles is necessary -along with a hot wire galvanometer and other asso- ciated equipment. However, it is pos- Registers dial numbers, wave sible to determine this factor by use of lengths, or call letters. the plate current values of the tube under $2.50 test, substituting approximate values for functions of the various voltages in the Exclusive features fully protected Improves the tuning as well as tube. Thus, -I -a (y Eb + Ee -i- e) 2 in by patents pending. appearance of any set. which I equals the Thermionic current in milliamperes, Eb equals the potential (voltage) difference between the plate and filament, E, equals the potential (voltage) The new Tuning Control is distinctively a B -T product. It is of of the grid and e is an arbitrary quantity the same sensible design and careful construction that has charac- representing the small differences of potential (voltage) existing in the tube terized radio parts bearing the B -T name. under various conditions. a is a struc- tural constant. B The quantity y in this equasion is as You should know about the new -T socket. Send your name explained in volume 47- 1918 -"Physical and address for circulars on this and other new B -T developments. Review" by Van der Rijl- "That for equivalent values of Eb and Ee, a change in the cinode (plate) voltage Eb produces y times as great a change in the current to the cinode as an equal change in the grid voltage E,"-or non -technically -a BREMER -TULLY MFG. CO. change in voltage on the plate would have to be y times the voltage change on the grid that would be required to 532 S. Canal St., Chicago produce a given change in the plate cur- rent. The voltage amplification factor p is the reciprocal of this quantity or This is shown graphically in figure 2- Get this great new where the grid and plate curves are drawn $3.50 Volume with to the same scale on the same chart, indi- CLEARNESS is obtained by using MAP of THE cating that a much smaller change in AIR FLINT AUDIO A MARVELOUS new way to chart your radio grid voltage will produce a greater change Frequency Transformers exploits-a beautiful Air Map, printed in three in a like in colors with every station clearly marked and plate current than change We will supply if your dealer cannot Time zones outlined! Size 28x34 inches. plate voltage will produce. FLINT RADIO CO. There's no limit to the useful and amusing ways of 1884 Wilson Ave. Chicago you can use Collier's new Radio Map of the U. S. The ratio the two voltages required and Canada. With its help to produce a given change in plate current - is the amplification factor (p2) on the You can find out INSTANTLY chart ; the ratio of the slopes of the straight how far any station is portions of these curves is the amplifica- If you use a directional aerial, you can point the loop tion factor. exactly toward the station you want to get. The map also outlines the radio districts and gives an The amplification factor of the tube 514 PAGES- 4..,.n va book on It..dw ever wntten New - -authoritative- alphabetical list of all stations and their operators. plotted on this chart will be between 6 complete. Packed with sound. practical Thousands have already been sold. Get yours information useful to every radio fan. today! At your news -stand or radio dealer's. only and 6.25 or an average of 6.125. With Hundred, of illustrations. Send £1 twenty -five cents-or just mail a quarter to us. today. Money back if not satisfied. this average factor we have y= 1/6125 International Correspondence P. F. COLLIER !k SON COMPANY Schools, Box 8783-D, Scranton, Penna. (Turn to page 56) 256 Park Avenue New York City $ Tested and Approved by RADIO AGE 5-1 RADIO AGE for July, 1925 The Magazine of the Hour Standard Radio Receivers; LIFE, The Atwater Kent LIBERTY (Continued from page 52) and the Pursuit of HAPPINESS!

Atwater Kent Carefully Atwater Rent Receiving Sets overcome these difficulties to a marked degree, Designed so that two or more stations broadcasting THE careful construction of Atwater at the same time can be separated and Kent Radio Is apparent to the most the desired station tuned in clearly and casual observer-the easy movement of without troublesome interference. the tuning dials; the absence of intricate One of the most pleasing feature; of wiring; the sturdiness and rigidity of Atwater Kent receiving sets is their the various parts, are but a few of its sureness of securing a desired broad- features. Other structural details worthy casting station. of particular note are: A printed list is supplied with each Variable condensers: plates-coun- set which gives the approximate dial You Won't Have terbalanced; bearings- adjustable cone, setting of many of the well -known machine ground; contact spring -phos- broadcasting stations. With this key to phor bronze. list in hand, the owner of an Atwater Dials: drilled and reamed after Kent can tune in a series of desired sta- Pursue moulding, assuring balance and accurate tions, or stations operating on similar fit on the condenser shaft. wavelengths. By writing down the HAPPINESS Rheostats: phosphor bronze spring dial readings opposite the names of the You can have it right at your elbow contact, sliding on spiral resistance coil, stations, make up a list or "log." to while away the time 'til old Lady giving smooth and positive action. Model'20 is a powerful receiver capable Static gets off the line! Tube sockets: heavy brass set in of operating a loud speaker under all You'll have no trouble getting moulded Bakelite base with phosphor conditions where broadcasting is at all station Z- I- F-F -S, because you'll bronze contact springs, corrugated to practicable -hence ear phones are unne- find it is always tuned in to catch make good contact. cessary. It comprises two stages of your funny bone's wavelength, and special Atwater Kent tuned radio frequency amplification, a is more ticklish to your giggle box Transformers: than the finest cat whisker! design capable of receiving all broad- detector and two stages of audio fre- ZIFFS, Badzib's Book of Art casting. quency amplification with three tuning and Wit, is the only humorous Grid leak: special cartridge type, dials. It is non -radiating and non - monthly of its kind on the market, absolutely quiet in operation. squealing. and is crammed full of the best Wiring: tinned copper with all joints Dimensions: Height, 8 1 -2 in.; length, artists and funsters in the world! firmly soldered, spaghetti covered where 26 in.; depth, 8 3 -4 in. Number of tubes Exclusive Photo Section! Com- there is a difference in potential. required, 5. plete gallery of French- American metal panel on the No. 4640, Art Studies in color! Fifty pages of Shielding: a Part Model 20 Cabinet illustrations! Pep, Ginger, Punch! cabinet receivers and metal shields on Receiving Set, $100.00. of the open models entirely Open receiver, same as Model 20 ALL BITS! condensers but FOR TWO eliminate all body capacity. without cabinet- $85.00. Pick This Out On Loud speaker: fabricated entirely of metal, the same as the vast majority of New Studios Ready for Your Piccolo ! the finest band instruments. Even tho' your set is growling Diaphragms: of special alloy metal, WCCO 'Tit you think a cat is howling has on the new And the music comes in wailing, hissing sniffs, unusually large in diameter, assuring Work started Saint You will giggle, grin and chuckle great volume without distortion. Paul studios of the Gold Medal Sta- Til you hafts loose the buckle re- WCCO. On your belt, if you've the latest book of Z1PFS Magnets: special Atwater Kent, tion, Saint Paul- Minneapolis, e quiring no extra batteries. These studios will be among the most uni- You wouldn't go fishing without Many types of radio receiving sets quely located in the world. They are being bait, would you? Well, then, don't deliver a sufficient volume of sound from built in Saint Paul's new Union Depot, try to get Hong Kong on a stormy used by nine railroads. night with a crystal set, till you've distant broadcasting stations, but they The studios, put your John Henry on the tag are not selective -that is, they cannot reception room, and executive offices, below: separate two stations, both broadcasting will be at the left of the concourse at the same time on waves of nearly through which all persons pass going to the same wavelength. and from the trains. ! ZIFFS, 608 South Dearborn, I Chicago, Ill. Dear Badaib: A regular $25 loud speaker for 1 got a radio. I got Hawaii. 1 got drowned $16. Loud, clear, mellow tone. out. I got peeved. THE LATEST Bell 1314 in. diameter, horn I don't see nothiri to laugh at, you big bum! 22 in. high, equipped with IHere s two bits. Send me the July ZIFFS, and parts and sets are always featured in Lakeside Adjustable Unit. I will! Agents wanted, write for par- our Salespeaker. If you are a live - ticulars. wire dealer, write for your copy, now. I They Call Me HUDSON -ROSS -116 S. Wells St. Lakeside Supply Co.{ Chicago i And 1 live at 73 W. Van Buren St., Chicago * Tested and Approver! by RADIO AGE RADIO AGE for July, 1925 The Magazine of the Hour 55 A Simplified Portable Super -Het (Continued from page 23) Lead No. 14 of the battery cable is attached to Al on the battery switch. Attach the lug at the end of the 2 3 -4 inch section of Lead No:-17 to the poten- tiometer at A2. The tap is attached to the battery switch at A3 and the last lug is attached to the rheostat at A4. Lead No. 27 is now run between -can thank Jewell for de- the rheostat at AS and the negative fila- veloping a small receiving ment line at M. Lead No. 18 runs from the potentio- set instrument with self meter at B2 to the positive filament line contained switch for multi- at B3. The lug at the end of the 8 3 -4 inch ple readings. section of lead No. 12 is attached to the center of the potentiometer at G. The (,SAVES -Space and other taps of this lead are attached to the terminals marked "F" on the third, cost of additional instru- second, and first intermediate frequency ments. transformers. These are points G1, G2, and G3 respectively. (,PERMITS- Testing of Attach the lug at the 4 1 -4 inch section of lead No. 2 to the rotor plates of the Multiple reading instrument "A" and "B" batteries loop tuning condenser at Hl. The tap with self contained switch from panel of your set. on this same lead connects to the stator plates of the balancing condenser at H2. The other end of this lead later con- (,Every Radio "Fan" nects to one side of the loop. should have our 15 -B cat- Attach the lug at the end of the 7 1 -4 alog. inch section of lead No. 1$ to the rotor plates of the balancing condenser at I1. The tap in this lead connects to Order from Dealer the plate of the first detector tube at 12 and the remaining lug attaches to the "Plus" terminal of the first intermediate Jewell Electrical Instrument Co. frequency transformer at I3. The lug at the end of the 7 1 -2 inch 1650 Walnut St. - Chicago section of lead No. 6 attaches to the lower Jack at Dl. The next tap connects to "25 Years Making Good Instruments" the B Positive terminal on the second audio frequency transformer at D2. The remaining lugs attach to the "Plus" terminals on the fourth (or filter trans- former), the third and second interme- diate transformers respectively. These connections are made at points D3, D4, and D5. The oscillator coupler should now be The Radio Age Annual for 1924! bolted to the sub base. Use 6- 32x5 -16 inch machine screws for this purpose. ONLY A FEW LEFT AT 50c EACH Before attaching the socket strip be sure that all of the wires which you If you have not bought your copy of the famous have attached so far are as close to the RADIO AGE ANNUAL for 1924, you may get one base board as possible. This is one of at a special price of 50 cents by filling in the coupon the few "don'ts" in these instructions and should be observed. below and sending it with stamps, money order or The socket strip is attached by means draft, at once. The supply is nearly exhausted, and of 6 -32x1 3 -4 inch machine screws. no more will be printed, so ACT NOW! Run the bolt through the base board, place a brass washer under a 6 -32 3 -8 inch nut and secure it firmly. Then 1924 ANNUAL COUPON run another 3 -8 inch nut down the bolt Radio Age, Inc., about three quarters of the way. The 500 N. Dearborn St., socket strip is now placed in position and Chicago, Ill. the loose nuts on the underside of the Gentlemen: Please find enclosed 50 cents, for which you may send me a strip run up to the correct point. Fasten copy of the RADIO AGE ANNUAL for 1924, in accordance with your special the strip firmly in place by nuts screwed price offer for April. on from the top and you are ready to resume wiring. Name. Lead No. 25 is now completed from G4 on the .006 to Gl, the Filament terminal Address-_ of the third intermediate frequency City State___ transformer. 6-25 ------Lead No. 22 is completed by connect- ing from D6 on the other .006 condenser to the "Plus" terminal on the fourth or filter transformer, D3. Connect lead No. 26 from C4 on the .005 condenser to the B plus terminal on the first audio frequency transformer, CONSOLE C2. Perfect Reproducer AULFIDIO Now complete lead No. 32 from A7, Tona loud and pleasing. R MFG. CO.562 VEDDER ST. the inside terminal of the pickup coil to Handsome material and design. the negative filament line of the socket Slack, $22.50 Shell, $25.00 AMERICAN ELECTRIC COMPANY CHICAGO. WRITE FOR CIRCULAR strip at A8. State and 64th Sta.. Chicago (Turn to page 56) 56 RADIO AGE for July, 1925 The Magazine of the Hour Some Sidelights on Tube Characteristics Simplicity of Construction is (Continued from page 53) or .16. Substituting the values of the Vital in Portable co- ordinates of two points on the straight (Continued from page 55) portion of the plate characteristic in this equation, and solving simultaneously- Lead No. 19 is completed from J, the terminal on the fourth or filter trans- with Ec as zero -we get for the other inside terminal of the plate section to the former at B5. constants -e =3.28 Volts and a = .0134 plate of the oscillator tube, J1. Lead No. 28 attaches to the plate the equation of the curve is then Complete lead No. 5 by running from terminal of the first audio transformer at I =.0134 (.16. Eb+Eet3.28)' the outside terminal of the plate section Ll and runs to the plate of the second higher plate Cl to the B positive terminal on the first detector tube, L. For greater amplification, C2, a negative audio transformer, and to the "Plus" Lead No. 34 connects the grid of the voltage will be necessary and terminal of the first intermediate trans- first audio frequency tube, U, with the grid bias with a "C" battery in series former, C3. grid terminal on the first audio frequency will be used -the correct "C" battery Lead No. 11 is completed from the in- transformer, U1. for the desired amplification may be side terminal of the grid section, El, to Lead No. 42 runs from the grid of the readily determined by use of the tube the filament terminal on the first -audio second audio frequency tube, W, to the test set from experiment. The average transformer, E3, and to the filament grid terminal of the second audio fre- grid voltages for the 199 type of tubes terminal on the second audio transformer quency transformer, WVl. are:- E2. The grid condenser for the second From the outside terminal of the grid detector tube is now mounted on the Plate Voltage Grid Bias Voltage section, K run lead No. 13 to the grid of transformer as shown in the diagram 45 Volts ._._.0.5 to 1.0 volts negative the oscillator tube, KI, and to the stator and photograph. The easiest way to do 67)4 volts._ 1.5 to 3.0 volts negative condenser K2. 90 volts._ 3.0 to 4.5 volts negative plates of the oscillator at this is to remove the regular nut from the 11234 volts.___ 4.5 to 6.0 volts negative Lead No. 10 is attached from the grid terminal of the filter transformer battery cable to the filament terminal and screw down tightly a small 6 -32 nut. The output impedance of a tube may of the first audio transformer at E3. The regular nut is now replaced and as a be taken as an average for solving this This is the C battery negative connec- sufficient amount of thread is now ex- equation. The following values are as tion. posed the condenser can be fastened se- correct as necessary for this purpose and Lead No. 21 is the positive filament curely by a 6 -32 machine screw which may be used with a close degree of wire in the battery cable and attaches to has been cut or filed to the correct length. the positive filament line on the socket Lead No. 41 is then attached to the grid accuracy. strip. The second socket from the left condenser at Si and to the grid of the Mutual Conductance can be used for this purpose. second detector tube at S. The B battery positive detector line of Lead No. 4 is then attached to the plate The mutual conductance is the usual the battery cable, lead No. 39, may now of the second detector tube and the wiring average for each type shown. A tube be attached to the "Plus" terminal on the is completed in the set itself. should show close to that noted to operate first intermediate frequency transformer Lead No. 7 shown on the diagram is efficiently. at C3. later used to connect one of the loud Lead No. 20 is the B battery positive speaker terminals with the B battery Average mu- amplifier of the battery cable and at- positive amplifier and can be laid aside tual conduct- sec- Output ance (micro - taches to the "Plus" terminal of the until it is needed. Type of impedance mobs) of ond intermediate frequency transformer Three 22 1 -2 volt B Batteries, six tube of tube tube at D5. ordinary dry cells, and a C Battery are 199 19.600 ohms 315 The tap on lead No. 1 is now attached the battery supply. 200 (detector) 10,000 ohms Varies 201 22.000 ohms 273 from the first grid condenser at H5 to the When the set is completed, pass the 201A 15,400 ohms 345 stator plates of the loop tuning condenser battery cable through a hole drilled in WD-11 or WD-12 17.500 ohms 290 H6. front of the battery partition and cut the VT or 215A 18.500 ohms 350 at 216A (power tube) 1,400 ohms 1360 Lead No. 24 runs from the rotor covering of the cable until leads of suit- plates of the oscillator condenser, E4, able length are exposed. The battery The mutual conductance shown in the to the filament terminal of the first audio layout shown in the sketch leaves every- above table is the usual average for tubes frequency transformer, E3. thing snug but there are several combina- of their type -a tube should show close Lead No. 16 is connected by the lug tions you might try. Lead No. 7 now in good condition. at the end of the 4 inch section to the comes in for a useful career as the connec- to that to be one loud speaker terminal to it more easily understood, the upper Jack, V. The tap connects to tion from the To make B Battery positive amplifier. type of tube in the table is the usual code the plate of the first audio tube, VI, and the remaining tap is connected to the Leads No. 1 and No. 2 are now con- number used by most manufacturers. plate terminal of the second audio nected to the outside terminals of the However, to more clearly explain them, frequency transformer, V2. loop windings and Lead No. 3 connects the following table shows the rated fila- Lead No. 36 runs from the grid of the with the center tap terminal of the loop. ment voltage -plate voltage, Plate R first intermediate frequency tube, M, to When all the tubes are in the set, the "B" battery current drain, and average the grid terminal on the first intermediate batteries hooked up and the loud speaker amplification factor for each- frequency transformer, Ml. connected, pull the filament switch and Lead No. 37 runs from the grid of the adjust the rheostat to a point about three quarters of the way on. This is probably Filament Plate Amp- second intermediate frequency tube, O, TypeT of to grid terminal on second a little too high but a few minutes of the the inter- excess current won't hurt the tubes par- Volts permes Volts permes factor mediate frequency transformer, 01. Lead No. 38, connects the grid ticularly and we are at least certain of 199 3.0 0.06 40 .0009 6.125 of the having enough. Set the balancing con- 200 5.0 1.00 22.5 .0003 Varies third intermediate frequency tube, Q, denser at its minimum capacity and ad- 201 5.0 1.00 45 .0009 6.000 to the grid terminal of the third inter- 201A 5.0 0.25 45 .0007 6.500 mediate frequency transformer, vance the potentiometer until a slight WD11.WD12 1.1 0.25 45 .0012 5.200 Ql. hiss is heard in the speaker. If this VT or 215A 1.1 0.25 45 .0008 6.500 Lead No. 29 connects the plate of the is 216A 6.0 1.10 125 .0110 6.000 control advanced too far some very first intermediate frequency tube, N, with violent whistles which soon merge into a the plate terminal on the second inter- loud roar are likely to be heard. The The Chart shown in Figure four is an mediate frequency transformer, Nl. loop dial and the oscillator dial both example of matching tubes graphically Lead No. 30 runs from the plate of the tube very closely together if the loop and is a good explanation of the plate second intermediate frequency tube, P, specifications have been followed and it is current of two tubes under identical con- to the plate terminal on the third inter- only necessary to run the two dials to- mediate frequency transformer, Pl. ditions. The curve No. I shows an gether from about five on the dials up to work well normal Lead No. 31 runs from the plate of the eighty. If no station is heard, advance efficient tube, to at third intermediate frequency tube, R, while curve No. 2 the position of the balancing condenser filament current, to the plate connection on the fourth slightly and again cover the broadcast shows a tube that is old or defective, or filter transformer, Rl. range. When a station is tuned in, it producing about half as much as the other Lead No. 33 connects the positive may be brought maximum volume by tube. filament line at B3 with the filament continuing to advance the balancing RADIO AGE for July, 1925 The Magazine of the Hour 57 condenser and the potentiometer until the circuit "spills over." Selectivity in this circuit is governed chiefly by the amount of regeneration present in the first detector tube and by the position of e the potentiometer. The more regenera- tion in these circuits, the sharper the set exper e becomes. Excess regeneration in the first detector circuit will be recognized rs -parts by the "mushy" quality of the received yearsea ri t signal and by the fact that the oscillator 1g radiog ace dial becomes very broad in tuning, as angc1L the detector is then combining the func- tiull °f tions of both a detector and oscillator. tii a1nsc The grid leaks recommended are 3 ar e ba .sseíz good megohms in the first detector circuit they're and 5 megohms in the second detector 1° circuit. If the circuit tunes too sharply ad onde or if volume is less than expected on no w local signals, substitute a lower value leak in the first detector circuit. Watch Body capacity should not be present for our on any of the controls except the small "Don't balancing condenser. Even here it will Improvise- interest- not be particularly noticeable except on Pacentize" ing distant signals. If body capacity exists Pacent catalog on any of the other controls, look over all connections, particularly those of the Chicago RADIO ESSENTIALS St. Louis bypass condensers. Washington Boston San Francisco PACENT ELECTRIC COMPANY, Inc. Birmingham Philadelphia 91 Ave., New York Buffalo Jacksonville Seventh City Detroit 5KW Power for Cincinnati Minneapolis Canadian Licensees: R. Ii. White Radio Co., Hamilton, Ont. Pittsburgh Stations WLW and WSAI, two broadcasters Make 5100 Weekly -sell RADIO Demonstrate Once - Results Mean Sure Sale V located near Cincinnati, have been Coast to coast,lowest prices,attrac. authorized to use power as high as 5000 tive four -tube instrument $39.50. Big commission to you. Exclusive watts. This information may come as territory to proven salesmen. Ter- a shock to some skeptical fans who have ritory going fast, write today for ,large illustrated book No. 100. $75 to $200 a Week feared any great increase in power, for Don't fail to name your county. Right now. everywhere. big. they are the first two 5KW stations. OZARKA, Inc. easy money is being made in 029 Washington Blvd. Chicago, Ill, Radio. Field unlimited.You can The new licenses catalogue the power as master radio quickly at home 5000 watts." It is requested Easy ¿ in spare time. Nopreviousexpe- "500 to time they use discretion, observing sug- Sales l i' :. :' rience necessary. Now is the that Big e to enter this new. uncrowded field. gestions of the district radio supervisor Profits 1,000 Mile Receiving Set -FREE Our new home -study methods make everything about radio if interference is created by the increased amazingly simple. No other course like it. Makes you es- power. pert on radio operation, repaira and installations of all kinds. Send for literature telling all about epportusities The main factor, which influenced the and how we give 1,000 mile le ving set FREE. Don't miss this big offer -ACT. Write now for big free book. Department of Commerce to grant these Radio Association of America licenses, was the fact that they are both 4513 Ravenswood Ave., Dept. 27 Chicago located out of town where any reasonable interference would not be detrimental readers wish to show their MARVELOUS NEW AUDIO TRANSFORMER to the local reception of distant stations. approval of RADIO AGE'S adds s musiealaualitsioeny setter WLW, Crosley station is in Harrison, I beyond anything you ever heard the stand against the Radio before. and WSAI, The U. S. Playing Card America, KARAS HARMONIK Corporation of they can Amplifies low. middle and high Station is in Mason, Ohio. Radio do it in the most practical way by tones -al lto the same big volume, officials in disposed thus eliminating distortion. Brings Washington are to sending in $2.50 for a year's sub- out the vim harmonies and over grant qualified Class B stations similar tones of muse. Price 57.00. Write authority for increased power, if their scription or if they are already sub- liras Electric Ce., Dep1.58 -93 4042 N. ReckweIl St., Chines transmitters are set up outside the crowd- scribers, urge a friend to subscribe ed urban districts. We believe the fans are with us. Round -Up Number of RADIO WEAF, the A. T. & T. Co., station in Address RADIO AGE, Inc., 500 N. AGE -August-on sale July New York has been authorized to increase Dearborn St., Chicago, Ill. Q 15. Blueprints of a complete its power to 2500 watts, being now the radio education. next highest powered station. RADIO AGE SUBSCRIPTION BLANK Radio Age, Inc., 500 North Dearborn Street, $2.50 A YEAR Chicago Gentlemen: Please enter my subscription for RADIO AGE, the Magazine of the Hour. for one year. beginning with your next issue. for which I enclose $2.50. you Name---- ...... - ducts, the asteswanthipments and %/' ------the most liberal discounts, write on your letterhead for our catalog j. L I 003. 7 Street Address .--- ..--- --..------ff)í /j/j///j % City :;,. %uc . State.. ...- _..__- _._..- - -- %%%%%/ -,% Send cash. money order or draft. * Tested and Approved by RADIO AGE 58 RADIO AGE for July, 1925 The Magazine of the Hour Tracing the Interesting Ancestry of Your Receiver By FRANK D. PEARNE

IT DOES not seem so long ago that arrangements being only improvements this great range is of no particular value. we were listening to the now almost which are bound to come from this vast Regeneration and radio frequency forgotten spark signals with the army of experimenters. Before the amplification have made distant recep- simple little crystal set, which at that World War, Major Armstrong announced tion possible. Here, again, we find that time was considered one of the wonders his regenerative circuit, which was a we are back to the old basic circuits. of the age. basic idea, but since that time the only Radio frequency amplification is not new Interest in this, however, was confined distinctive new circuit which has but the method of tuning it, the construc- to a few amateurs who studied the code appeared is the reflex, the production of tion of the transformers, neutralizing and enjoyed an evening's chat with their which is generally attributed to Prof. the feed -back, and many other improve- friends. Then came the radio telephone, Marius Latour of France, and Arm- ments are to be found in these improved by means of which voice and music could strong's Superheterodyne. circuits. ' - be heard with these rudely constructed Today there are hundreds of sets The one bad feature of radio frequency and inefficient sets. Two broadcasting advertised, all of which are merely modi- amplification has always been the ten- stations began to send out musical pro- fications and additions to these five or dency of one stage to feed back energy grams and the amateur began to be six basic circuits. Among these are the to another, thus setting up undesirable popular. People began to call at his little single- circuit regenerative, three circuit oscillations with the resultant howling station and marvel at this new scientific regenerative, superregenerat ive, and other and squealing. Different methods of toy, to ask his advice as to how they, too, forms of regenerative or radio frequency overcoming this are found in many of might build a set and enjoy this pleasure, amplefuation. From this list many com- the standard sets now in use. The not because of any particular desire to binations have been made, radio frequency neutrodyne, for example, overcomes this learn the principles of radio communica- amplification has been added and hun- difficulty, by neutralizing the inherent tion, but because they wanted to hear this dreds of little kinks here and there have capacity of the tube. By this means all music coming from the air and to enter- been incorporated, but a close analysis the advantages of radio frequency ampli- tain their friends with this newly found will reveal the fact that no radical fication are realized and distant recep- amusement. changes in the old basic principles have tion is easily obtained. More broadcasting stations began to been made. There are many people at operate and the fever spread until at the present time who want to purchase Importance of Selectivity the present time radio has grown to be sets and who are holding off and waiting ON the other hand, this radio frequency one of the greatest industries in the in the fear that something new is shortly amplification of the neutrodyne world. In the beginning, it was difficult going to develop which will make their would be of little value if the set were not to construct even the simple crystal set, selection obsolete. selective. The regenerative receiver, be constructed by makes the parts having to A Foolish Idea however, use of the feed -back the operator himself. We hadn't a radio method to gain amplification. It has store on every corner as we now have. THIS is a foolish idea which is not the bad feature of radiation, which is It was real work. borne out by the past. It is true, per- one of the greatest troubles the broad- haps, and very probable that many new Arrives cast listener has to contend with. Radia- Improvement sets will appear on the market in the tion from a nearby set will sometimes WITH the opening up of more broad - next year, but it is not at all probable completely detune a receiver which is casting stations and the increase in the that any radical change will take place. tuned to a distant station and will cause number of fans, came the demand for There is, of course, a possibility that the enough shrieks and howls to spoil a good something better in the way of a re- wave band of the broadcasting stations program. This is not the fault of the ceiving set. Vacuum tubes began to may be slightly increased, due to the regenerative set, but rather the careless- replace the crystal, because by their use fact that so many applications for ness of the person operating it, for it is the signals were not only detected as they licenses are being received by the Govern- quite possible to so adjust it that no were with the crystal, but they were ment that they find the present wave radiation takes place. amplified also, this being made possible band too narrow to accommodate all of Amplification by regeneration is caused by the addition of the third element in the them and keep the proper separation. by feeding back some of the amplified tube, called the grid, which was produced But one may rest assured that nothing signal in the plate circuit to the grid. by the inventive genius of Dr. Lee De will be done to make the present type of This builds up the strength of the signal Forest. These vacuum tubes, however, receiving set obsolete. and is really a method of amplification. were expensive in the old days and only Experiments have shown that it is When a signal strikes the grid, it is those who could afford luxuries were possible to broadcast on wavelengths as rectified and amplified in the usual way. lucky enough to possess them. low as 100 meters, but it will probably A tuned plate circuit is employed and Today they may be had for the price of be a long time before the wave band will when part of the varying current in the one dollar and up, and the simple little be broadened to this point. The fact plate circuit is fed back to the grid, the crystal has lost its prestige. With the that so many stations are now in opera- plate current is again varied. This in advent of the vacuum tube more of these tion has made the question of selectivity turn again increases the plate circuit amateurs became interested in the actual one of vital importance. In the old days, current, which is again fed back to the science and as a result of their untiring when only a few stations were sending grid. This process continues until the radio it is efforts, we now have as today. out their programs, it made little differ- signal becomes stabilized and has the They created the demand for better ence whether or not the set was selective, effect of prolonging and apparatus and improved upon the few but today things are changed. Selectivity building up the signal. basic circuits until we now have hundreds is the watchword. The question of The time required for all of this of circuits in use, with more coming all distant reception has been well taken building up is so short that it does not the time. care of, and many of the present day in any way distort the signal. But what of these circuits? As a receivers will pick up programs from There are many types of regenerative matter of fact, there are only a few of coast to coast and from Alaska to South circuits on the market today, but they these basic circuits, most of the new America, but if the set is not selective, all work on the same basic principle. RADIO AGE for July, 1925 The Magazine of the Hour ) But many of them are better than others, . . . due to the fact that different types of inductances are used, and varying methods of coupling the circuits. A loose coupling between the primary and secondary circuits will always give much better selectivity than a tight one. A fair example of this is seen in the ultra - EFFFgSI audion receiver. Here there are many variations. Sometimes the tuning in- ductance consists of a variometer which TRANSFORMERS is connected in series with a variable con- denser. Both the inductance and the condenser are variable. The same cir- cuit is often used with a fixed inductance and a variable condenser. Either of these work very well, but naturally a closer adjustment may be made if both the inductance and the capacity are adjustable. Loses Its Selectivity THIS type of receiver is known to have a long range, but because of the direct coupling between the primary and secondary circuits, it loses much of its selectivity. By using a single inductance in the aerial circuit, and placing it near the variometer so as to afford an induc- tive coupling, it still retains its long range and the selectivity is greatly increased. The super- heterodyne is well known for long range and selectivity. In this SIFT OUT THE SUMMER STATIC arrangement another bad feature of radio frequency amplification is overcome. It's the season when aggravating radio imps seriously This is the tendency of such transformers interfere with smooth reception on most sets -but to work at their greatest efficiency at there's a way to make your set behave better. Jefferson r one certain frequency and the dropping Transformers will bring in summer programs with off of this efficiency as the frequency -weather clearness. Extra care in varies from their natural frequency. In almost cold manu- this set, a local oscillator is used, which facture and the benefit of greater experience by the sets up oscillations of nearly the same world's largest manufacturers of small transformers frequency as that of the incoming wave, give Jefferson Transformers the lead in audio tone causing a beat frequency which is the amplification. They will give remarkable results for result of the two, to pass through the you this summer. You'll find them at the best radio radio frequency transformers. As the dealers. local oscillator is under the control of the operator, this beat frequency may be JEFFERSON ELECTRIC MFG. CO. made the same in any case, regardless of the frequency of the incoming wave, 501 So. Green St. making it possible to always work the Chicago, Illinois transformers at their natural frequency, regardless of what the frequency of the Makers of Jefferson Radio Tube Re- juvenators; Radio. Bell Ringing and incoming wave may be. Thus the set Toy Transformers; Spark Automobile, n is always working at its greatest efficiency Marine Engines; Jefferson Oil Burner and even the most feeble wave may be Ignition Coils and Transforme.. picked up and amplified to great volume. The reflex set is peculiar in that it will produce more amplification with less AIL w a 0 w o w S. t w A tubes. This is done by making some of the tubes do double duty. After the radio frequency tubes have amplified the signal and it has passed through the that the uninitiated beginner has a hard ',Lsóoraforq detector and reduced to audio frequency, time to decide on which one to purchase. Produce' CUSLSIìy`gV it is again passed through the radio In the August issue of the RADIO F Fi/' frequency tubes at audio frequency, AGE, all of the basic circuits will be G2EST.w6Gr! thus operating them at both radio and shown in blueprint form, which has loc DisioriloirlessJlmplficatioti audio frequency. This is not only a made this magazine so popular with the 12.000. 48.000. 50.000. 100.000 Ohm,. List SO.50 each. Special8ues to Order 52.50 each. saving in the original cost of installa- fans. In this issue, which is to bea de- Dealers, write for discounts. When Better Br.ristoncca less is also required pages made thew will be Cre :cease,. tion, but battery to luxe number, approximately eighty Crescent Radio Supply Co.,5 Liberty St , Jamaica, N. Y. operate the filaments than would be will be given over to this subject. Aside necessary in other types of receivers. from the blueprints of original circuits, Many different reflex circuits have been many modifications and methods of SAEESPEAKER devised, but while they differ in the amplification will be shown, making it is the name of the most interesting apparatus used, they all come back to possible for one to trace the history radio bulletin published. If you are a the same basic principle. of almost any set in existence. A careful dealer, we will mail you a copy, on Because of the many deviations from study of these circuits will in a measure request HUDSON -ROSS -116S. Wells St. these basic circuits, there are hundreds of give an idea of just what changes they Chicago different sets for sale and it is no wonder have gone through in the last few years. * Tested and Approved by RADIO AGE á 60 RADIO AGE for July, 1925 The Magazine of the Hour Some of the Tricks Summer The Radio Spies Static Plays (Continued from page 51) FREE (Continued from page 24) such a position, to secure certain private papers, to papers and specifications and other papers of the De Subscriptions its atmosphere during that season: Un- Forest Company and deliver the .same to him. She fortunately, no way of avoiding this declined to take the position." RADIO AGE difficulty is known today. The trans- Sylvester W. Crowley, manager of the audion division of the De Forest Radio Company. said he For Your Time! oceanic radio stations have to be equipped employed Cecelia Lambert, mentioned in the Radio Age will give a year's with high power apparatus in order to Bowlby and Jennings affidavits. She was discharged tree subscription to this mag- work through the bad periods of the day April 16, 1925, "because it was discovered that she to any reader who will of was employed by the Radio Corporation of America, azine and year, although at certain times paid a salary by them and was making reports of obtain for us a news -dealer who the year and day less power may be complainant's business secrets to that company." will handle our magazine in a town used, as evidenced by the successful Crowley says he was present on April 16, where we are not already repre- trans -atlantic transmission by low power 1925. when Miss Lambert admitted having furnished sented. confidential reports to Harley, who assigned her to If you are now a subscriber to amateur stations. work for various concerns, receiving wages from RADIO AGE, you can refer this For the sake of clearness, we have so her employer as well as salary and expenses from who far described the cause of fading signals Harley. notice to one of your friends, Mr. Luce, President of the De Forest Company, will doubtless be pleased to take as due to obstructions in the path of the says that for eleven years his concern has been mak- advantage of this opportunity. radio waves. Actually, the radio clouds ing, leasing and selling radio receiving apparatus Or you may extend your own sub- sometimes reflect the waves, much as a and auaion tubes. For several years the defendant scription for one year without cost. mirror does a light wave, and so very has been carrying on the same business with the This offer is to remain in effect sometimes possible exception of manufacturing, he declares. until further notice. peculiar reception effects are While he has no definite, information regarding the noticed. Sometimes the signals are made defendant's manufacturing business, he says that as a stronger instead of weaker, sometimes result of agreements between the defendant. the Free Subscription Blank General Electric Company and the Westinghouse RADIO AGE' Inc., they may be lost altogether, as the Electric and Manufacturing Company the defend - 500 N. Dearborn St., Chicago. Ill.: effects of reflection and absorp- ant was required to sub- several buy part of what it sells from Gentlemen: In order to get a free each scription to RADIO AGE for one year. - tion combine. company. These three companies, with the I herewith send you the name of a dealer And note, let us consider that arch American Telephone and Telegraph Company have who will sell RADIO AGE at the city men- licensed each other under various patents. He tioned. It is understood that if you already enemy of radio -Old Man Static. When adds. "the legality of this combination has been have a dealer in this city that the offer of a Marconi first began to receive messages challenged by the Federal Trade Commission and is hold good. free subscription does not over distances of a few miles, he noted, now under judicial investigation by it." The temporary injunction, obtained by the De s name besides the signals he was listening for, Dealer Forest Radio Company from Vice Chancellor John noises which had nothing to do with the H. Backes of New Jersey, directs the Radio Corpora- Street No. signals, and every receiving operator tion to appear in Chancery Chambers, Newark, on May 12, show cause why a permanent State since that time has heard those same to injunc- City.... tion restraining it from obtaining information disturbing and interfering noises. secretly from the De Forest plant should not be My name These noises have been called strays, issued. City State (7 -25) or atmospherics, or static, and the A recent issue of the Radio Guide elimination of them is the most impor- publishes a full page editorial on the tant problem in radio communication situation as outlined above. One' para- o"p today. There are at least two or three graph from this editorial follows: kinds of static, but the most troublesome "Never in its palmiest days of throttl- eeeWeemee E ing and cut -throat competition did the ame kind is the one which is due to itravelling old Standard Oil Company of New electric waves, in nature just like radio Jersey, the original octopus, undertake waves, and caused by electrical dis- anything as dastardly, as contemptibly . The 100% turbances somewhere in space. criminal, as the "dirty work" which the Self Shielded E \c ee{)] ALIGHTNING flash produces a Radio Corporation, already cited in a Transformer government antimonopoly suit, is now F r traveling electric wave, much like a accused of." has made a big hit with both set makers and radio wave, and if we can assume that set manufacturers because of its stall size, its amazing volume and most of all, because lightning flashes, large and small, are Vacuum Tubes and How of its pure undistorted tone. It is half the E occurring continuously somewhere, we size of other transformets, but its results are ;< They Distort unsurpassed. Absolutely new and scientific have a reasonable explanation of static. design and construction. Ratios I to 3, 1 to E We know that static is worse in the (Continued from page 18) E 4, 1 to S, $3.50. Ratio I to 10. $4.50. SEND FOR BULLETIN No. 94. Read all the ea- Summer when variations in the atmos- grid increases, you will find that the line elusive feature. of this and other Premier Parts. is not straight, but becomes steeper over Tells how to get free hookup diagrams, beautifully phere are greater and more frequent. printed in two colon. Also, it is often observed in the Winter- quite a range, there being a definite curva- PREMIER ELECTRIC COMPANY time that the formation of snow causes ture (See Fig. 1). Such a line or curve is Ravenswood Ave. CHICAGO Er 3803 static. spoken of as the plate current -grid voltage Without knowing definitely the origin characteristic of the tube and circuit. 7dto t of this disturbance, it seems safe to The more nearly straight it is, the more assume that the actions which take faithfully does it repeat the impulses put place in our atmosphere, due to the air, on the grid; i. e., the less distortion does el-bee-Traffic Cop the sun, sun spots, water vapor, etc., it introduce. This is a condition to be reRD D are responsible for the creation of these desired, then. However, the tube is to ofthe irresponsible very be used as an amplifier. irWave (w(ltGì//llli(/ irregular, and trouble- Add a Ferbend Trap to your Radio Set some waves which we call static. Since The curvature of the characteristic and -Police" yourreeep- lion. Regulate traffic. they are so much like the radio waves in depends on the design of the tube, and Guaranteed to tune out in any given tube may be emphasized any interfering station. nature, no way has yet been found of Widely imitated but them completely. by the circuit with which it is associated. never equalled. The eliminating originai and only suc- Progress has been made in the last Suppose we have a tube circuit which cessful WAVE TRAP. Now in its third year. few years, however, and the trans- has curvature and we impress on the Sent Postpaid upon re- ceipt of 11.50 or C. O.D. oceanic stations are much more free of grid two electric currents of different plus postage. Send for Free Booklet formerly. The frequencies. It can then be shown FERBEND ELECTRIC CO. this interference than t16 E. So. Water St. - Chicago problem of complete elimination of theoretically and is found experimentally REBUILD YOUR NEUT -Use same panel static is the most difficult one in radio, that there are present in the plate circuit same parts. No neutralization. 22 feet gold if solved, we shall have a new epoch currents of the original frequencies and wire, only extra part, circuit and complete and simple instructions -$5.00 prepaid. Hundreds in radio because the power of transmitting also currents of frequencies equal to of Neut owners use this kit. Details -10e can be greatly reduced and the the sum and equal to the difference of 48 page catalog parts -10e. Stamps accepted stations KLADAG RADIO LABORATORIES, KENT, O reliability of communication increased. these frequencies. In other words, the t. Tested and Approved by RADIO AGE at RADIO AGE for July, 1925 The Magazine of the Hour 61 resultant current is not a faithful repro- duction of the original impulses, but shows some distortion. This is a very useful thing, as may be seen if we apply the principle to a -. nes- W. St., New York City station. Suppose, for ex D10 SERVICE, Inc. ri41 43rd troadcasting ample, that we combine in a tube cir- 250 W. 49th St. MAIL ORDER DEPARTMENTS 111 S. Clark St. cuit the radio frequency of one million New York Chicago cycles with a musical frequency of one thousand. Then, in accordance with what was said above, we would have set up in the plate circuit the original frequencies and the sum and difference A Portable Super- Heterodyne frequencies; i. e. we would have in the plate circuit frequencies of 1000; 1,000,- Designed by A. J. Haynes 000; 1,000,000 plus 1000 and 1,000,000 minus 1000. The first of these is of too Complete description in this month's low frequently to affect the radiating "Radio Age" antenna of the station, but the other three, being of suitable high frequency, This new Super -Heterodyne has been made would be radiated. It is These three completely portable without the least sacrifice in equipment, set, of slightly different frequency operating efficiency. The entire waves batteries, loop aerial and loud speaker is contained which would travel out to your receiving within a strong carrying case 208 x 17%.. 8W. set. The middle one of these, one million, is called the carrier wave and Reports from far and near state that this new 8 -tube and portable is daily giving reception fully equal to the others may be called the upper standard laboratory model super- heterodynes. the lower side waves. The three to- gether constitute the modulated wave; i. e. the wave on which has been im- Right in the heart of pressed the message which is to be transmitted. The side waves or fre- New York City this quencies are the important ones, and it should be noted that they were not splendid portable gets originally present, but were brought in only by the distorting effect of the distant stations tube. The mixture of the original fre- quencies is a very intimate one. It is Mr. J. K. Cronin using the set on East 36th Complete Parts more than a mere addition of the two, Street, only 4 blocks from station WMCA, 5 8 from a scrambling of the two. blocks from WGBS, and blocks power- but ful stations WJZ and WJY, brought in sta- $98.50 KDKA, and KYW in twelve us now go to the receiving set tions WWAD LET minutes with all these local stations broad- This price includes all parts where these waves are picked up. casting! required to build the set it- They finally reach a vacuum tube. if self, including attractive port- this tube shows no curvature or dis- Many larger super- heterodynes used in the same location failed to bring in distant stations able carrying case, strongly tortion, it will merely repeat the high through this strong local interference. made and finished in imitation frequency waves which arrived, but leather. these, in that form, are of no use, for Special combination price of they are inaudible. What is desired is Complete Constructional $98.50 also includes Crosley a message of the same as the original Blueprints Ready Now! Musicone Speaker and all ma- frequency; i. e. one thousand. Obviously terial to build the loop aerial. it is going to take something radical to Construction of this new Portable has Tubes and batteries are not from three frequencies, each at been reduced to simplicity itself. Each set of included. get this and neighborhood one million. blueprints shows complete panel instru- The panel is supplied com- or in the of ment layout; schematic wiring diagram; the Suppose, however, the tube and its pletely drilled, ready to mount exact length of each lead. Every lead and the instruments. circuit has distortion then by the sane connection is numbered to make wiring easy. principle as given before; there will Detailed price list will be in Complete dimensions and specifications given mailed FREE upon request. appear the plate circuit currents for the carrying case for those who want to which are the same as the three high build it. frequencies and in addition there will be all the possible combinations of sum and difference frequencies. If you will 41Tell your friends about the Deluxe set these down yourself, as can be August number of Radio Age- i easily done, you will find quite an array; out July 15. in fact, there will be twelve of them in the simplest case. Most of these will ' ; Mitt Wònderful not be of use, but you will find two which are of the frequency 1000, the Big Money -Saving Radio Catalog original signal frequency. They repre- containing^ thousand bargains of every- sent the difference between the carrier thing radio', parte, supplies, com- - plete parte for eeta,eompleteaete. of 1,000,000 and the side waves of _ etc, sin° a mine of very lat- est i formation n all dif- 1,000,000 plus 1000 and 1,000,000 minus ;' ferent circuits. complete hat 1000. broadcasting station. ana -f other valuable Thus we see that it is as a result of '' Vasty to build wn radio t ! set- All complete paw of seta i consist of advertised its distorting characteristic that a tube ria a include We You arl Equip and lode can first modulate a carrier frequency . drilled b To be a Federal Radio Dealer and guarantee your AF4 rIna diagrams for easy anaemblingp with a message frequency; i. e. "scram- success under the "Gould Plan" which allows you to '''''.%A. merchandise which you are unable to sell. bat, lóú Free Servicer° epartment ble" the two together so that one carries return help. ,ou solve;II vaut re. Problems We sell wholesale to dealers only. Write for our Sae,í to 43 Send name. address for free Cata- the other, and then at the receiving price list and FREE Instructions "HOW TO SELL og. en names of friends:we will mail them catalogs. RADIO." RANDOLPH RADIO CORPORATION station CHICAGO "unscramble" them and give FEDERAL RADIO CO. tee North Union Assume, Oepe. 444 us the original message.g e. 115 East 13th St., Kansas City, Mo. * Tested and Approved by RADIO AGE At 62 RADIO AGE for July, 1925 The Magazine of the Hour Wherein One of Horatio Alger's Plots Comes True

To the Man with an Idea By R. H. Hopkins the executioner's desire for a negative reply, was invariably "yes." 1 offer a comprehensive, tape. HE proper way to tell about Mc- rienced efficient service for his Murdo Silver would no doubt be to prompt, legal protection and the Time," or, to become Practice Makes Perfect development of his proposition. say "Once Upon a Send sketch of model and descrip.. somewhat more modern, we might head STRANGE as it may seem, these two tlon, for advice as to cost, search the dissertation "From Nothing to Some- bits of instruction stuck firmly in the through prior United States patents, or one might even resort to the young man's mind. etc. Preliminary advice gladly thing," The next day the furnished without charge. time -honored, and (we hope) buried, cook, called to the back yard of the family My experience and familiarity style of Horatio Alger. residence by unearthly yells, beheld a with various arts frequently enable none of these styles seems to fit strange sight. Sitting a saw- me to accurately advise clients as But astride to probable patentability before properly, so we will confine ourselves horse was a young Mexican boy hurriedly they go to any expense. (not the regal, but the editorial "we ") conscripted for the part of the convict. statement His hands were Booklet of valuable information and to a plain form for properly diseiosing your of facts concerning tightly tied, and a idea free on request. Write today. the not altogether very heavy rope, al- uneventful life of a most thicker than RICHARD B. OWEN, Patent Lawyer young man badly his pudgy arms, con- 81 Owen Bldg., Washington, D. C. -M Woolworth Bldg., N.Y. City bitten with the radio nected his unwilling 2278 bug, who at the age neck with the limb of 22 is the presi- of a small tree di- dent of a prominent rectly above him. radio concern and He was calling loud- whose name is more ly upon all the saints than well known to known to him in a many thousands of somewhat unintel- radio fans. ligible imitation of Born in a small Spanish. Next to college town in west- him stood one of the ern New York, the "Silver Gang," ask- son of a college pro- ing loudly and re- fessor, his early peatedly whether he years were spent un- "joined or died." eventfully in caus- he executioner, in ing his fond parents anticipation of the RADIO just a little bit more reply, held the noz- Storage `B" Battery than the usual zle of a length of ai tnrs Lasts Indefinitely-Pays for Itself amount of conster- garden hose in his Economy and performance unheard of before. Recharged nation, for a very hand. negligible cost. Approved listed as Standard at c Pap. Radio nd Rndia melodies ras Radio L Inc. other im- early age his Some distance Si. e. Standards. o News $ o,d a portant ,n.ttltion. aed sll ba'Rueter Äa r. thoughts turned to away, in the wash - aerpatesedóaáe 'ee";ud vi things mechanical. boiler, stood the in- ° f t e SEND NO MONEY ;,°:t,:?;dOent t ?a n d The result was no stigator of this new received. Otter: g battened, Its a order Is ere°. per cent discount may e xemmaL n more than could be McMurdo Silver game, holding the b gñ os . n a,tr á WORLD BATTERY COMPANY expected. Many other end of the hose So. Wabash Ave., Dept. 81, Chicago, 111. peculiar and supposedly original con- in one hand, while in the other was 1219 Ratite "A "Stara. , Battery Mateo s of the Famous World Amp. tSAe. trivances made their appearance, most another piece of hose which reached back Aleut e vos. 111 25; A camÿped th Salad Balker Case. of them designed to provide a hearty and to the gibbet and terminated in the stimulating welcome for the college stu- grimy grip of the assistant executioner. dents who called upon his father in As the victim's cries were uttered, the Worldáoteo STORAGE BATTERIES search of wisdom. executioner shouted them into one hose, WEAF W6Nr WJ5 skit) AO=Kall Frequently the searchers were dis- through which they were presumably lhLP fa0-,kFAF couraged, but it is interesting to the transmitted to the ship at sea, simulated casual observer of later years to perceive by the wash -boiler. From there, through that these and sundry other arrange- the other hose, the verdict was again ments most frequently resulted in the shouted in a high falsetto to the assistant acquisition of wisdom. executioner, who in turn put the all - Radio first entered McMurdo Silver's important question to the prisoner. sitivEn. consciousness early in 1912. Someone, In this way, wisdom was assimilated Dealers! desiring to keep the young hopeful's by the analytical mind of the young; mind well abreast of the times, read him communication with ships could only be Send for our illustrated dealers' catalog. an account of "Wireless Telegraphy" and through rubber hose, since with latest wholesale and retail radio one couldn't bargains. Also ask for our attractive how it enabled ships at sea to keep in shout several thousand miles. And to proposition to radio dealers on nationally unbroken touch with the world while use "wireless telegraphy" one had to advertised lines. they were out upon the bosom of the have a reason, which was opportunely SILVER -MARSHALL, INC. bounding brine. provided by the recalcitrant son of a 1OSA -S Wabash Av. Chicago At the same time an account was Mexican villager, who might even yet also read, with true relevance, of be reclaimed to the cause of the law by the Mexican Rurales, a troop of mounted strong -rope methods and the marvels of police recruited from criminals by radio. MARSHALL the simple and masterly expedient Thus was the youth of this young man of catching one, putting a rope around spent, alternating between the heights of his neck, placing him upon a horse all the Sierras and the ordered calm of a ready to be gently stroked with a whip, college town, the main street of which and asking the individual so situated if was shaded by towering elms almost as ,Mailing 'Lists he wished to become a Rurale, or if he drowsy as the village itself. But this was Will l p you increase sale preferred to dismount from his steed not for long, hes and the association of garden cpfieo'bos d f arióp post-haste and remain in the unenviable hose and radio having been demolished four best rrospe .ertloua I. S tate ne dLcal-Indivld-ovocusto- position of hanging by his neck to a nice along with other illusions, the big city vaiNvats. Pawnees Concord. tree limb, separated from it by several claimed our subject. There, more stren- 7 % by retondeni J each feet of rope, and from the ground by uous pastimes being taboo, radio was several more feet. The answer, unless taken up with renewed vigor, and a posi- OSS-6ouldco. t , Sr.LouisR7 choked off by the culprit's emotion, or (Turn to page 72) * Tested and Approved by RADIO AGE st RADIO AGE for July, 1925 The Magazine of the hour 63 Underground Radio from Coast to Coast MATCHED By JAMES E. SMITH President of National Radio Institute Dr. James Harris Rogers, whose achievements with underground trans- mission are far famed, has climaxed all UPUE his waves from tests by sending radio CONDENSERS Hyattsville, Md., to Los Angeles, Calif., a distance of 3,000 miles. Signals at Los Angeles, according to the report, "were coming in finely with little fading." This record eclipses all previous under- ground records (these also having been set by Dr. Rogers' experiments), and opens the way, according to many leading More Money For You scientists, to an immeasurable develop- ment and improvement in methods of Amy eair(like radio transmission. This achievement of coast to coast in RADIO Because?hajire transmission through the ground crowns with success an undertaking which was THE amazing expansion of first Radio has opened up hundreds Know the satisfaction and ease of tuning brought forward and attempted by of wonderful new positions on that come when all dials read alike or Dr. Rogers in 1908. It overthrows the of men land and sea. Big salarles,fascinat- eliminate logging and dial by wave- dicta no less eminent than Mar- ing, easy work, short hours, and a lengths. Use DUPLEX Matched Con- coni, who scoffed at the proposal to wonderful future are offered to am- densers. Made in strict accordance with radiate waves through the earths' crust. bitious men to get into Radio now. Bureau of Standards specifications. As a direct result of Dr. Rogers' Take advantage of these wonderful oppor- Used in the famous Thermiodyne. Test- latest accomplishment, it is now possible tunities to step into a big paying position in that the broadcasting tower, expen- this great new field. You can stay at home ed, matched, packed and sealed, to the and work up to a position paying up to remain unopened until used. Ask your sive aerial extending sometimes 400 to $10,000 a year, or Radio offers you an oppor- dealer. 600 feet in the air, may become in the tunity to travel and see the world. with all near future as osbolete and unnecessary expenses paid. and a fine salary besides. One of our recent graduates, Emmett Welch as cable connections between stations. of Peculiar. Mo.. secured a position one week The "aerial" will simply be taken out after graduating. paying a salary of $300 per and buried. month. Hundreds of others report equal The "aerial" which Dr. Rogers uses success. Interesting illustrated folder. sent free on request. consists simply of 4 copper cables fifty feet long, extending toward the four Easy to Learn DUPLEX CONDENSER & RADIO CORP. points of the compass. Copper tubing, 3 -4' in diameter, is laid inside eighteen 42 Flatbush Avenue Extension, Brooklyn, N. Y. Radio at Home inch terra cotta pipe, insulated and Thousands of Certified Radio-tricians supported throughout by glass rods. are wanted to design Radio Sets; to make new Radio improvements; to manufacture The pipe is buried 3 feet underground Radio equipment and to install it; to main- outside the Rogers Research Laboratory tain and operate great broadcasting stations at Hyattsville. and home Radio sets; to repair and sell Radio apparatus; to go into business for themselves; Through it the waves are radiated to operate aboard ship and at land stations. into the crust of the earth, and carried You can easily and quickly qualify in your through the ground- without atmos- spare time at home through the help of the National Radio Institute. first school to pheric disturbance, without diminishing teach Radio successfully by mail, estab- in strength through the 24 hours of the lished 1914. No previous experience or day. training needed. Prominent Radio Experts Battery Prices will help you in every problem. giving you The earth's crust is the most efficient personal attention. SMASHED! medium for radio waves, Dr. Rogers You learn by actually doing, as we furnish To Consumers Only claims, and he believes his experiments free with the course, circuits and parts for Here is a real battery quality, building latest receiving sets. making the guaranteed to you at prices now have disproved the Heaviside theory. work thoroughly practical. You learn quick- that ill satound the entire bat- tery-buying public. Order Di- "Radio waves transmitted through ly and easily -right at home. rest From Factory. Put the the atmosphere," says Dr. Rogers, This is an absolutely complete course g Dealer's Profit in your own pock- which qualifies for the real "big pay jobs" et. You actually save macb more "obey the laws of light -that is, travel in Radio and our big Employment Depart- ' than half, and no that you can be in a straight direction -and these atmos- ment helps you get one. convinced of true quality and perform- ance we give a Written 2 -Year Guaran- pheric waves are thus dissipated, not No need to itee. Here is your protection! being reflected by the Heaviside mirror. take a chance. Our battery Is right -and Send for FREE BOOK the price is lowest ever made. Convince The earth crust to a much greater extent IIyourself. Read the prices! No other field today offers such great Auto Batteries Radio Batteries retains the waves, and less power is opportunities as Radio. Take your choice required to transmit great distances." of the many wonderful openings everywhere. GVolt,10 Pate11.50 6Voit.120 Arno.£1.50 Prepare now to step into the most interesting ' 12Volt, lPbte.13.00 6VOlt,140Amo.13.00 war Dr. Rogers During the developed and best paid profession today. Read about Buy Direct -Send No Money and placed at the service of the Govern- now different We the opportunities open -the nodWI. nted. atterswilt beehq»ed ment, applications of his theory which kinds of work -the salaries paid. Write ocat urenveyour order Espreas C.Ó.D. today for the 32 -page book that tells how subject to your egguua antes made possible communication not only on d Our America's biggest Radio correspondence accompanies eachh battery. between submarine and submarine, but alo t school (government recognized) can teach you in fulli wither.T_.c> also between submarine and shore. His to become a Certified Radio- trician in your cannot lose! to those who Senóudh order today t. private station at Hyattsville, using spare time and also Special Offer NOW! act at once' Mail coupon or write letter ARROW RATTERS CO. 1t his own "underground," was pressed now. National Radio Institute, Dept. Dept.11. 1215 50. AAQl[Dliff into secret service by the officials of the 53 -JB, Washington, D. C. Wabash Ave..Chicago Rl). [RV' Government, and received messages clearly and strongly when the great National Radio Institute, Dept. 53 -JB, station at Arlington was hopelessly Washington, D. C. deafened by static. Without obligation, send me your book, "Rich Rewards in Radio," which tells all Should the day ever. come when a few about the opportunities in Radio, how spare hundred feet of buried wire will supplant time study at home will qualify me quickly and replace the towering and costly as a Certified Radlo- trician so 1 can get one of these splendid positions and how your "Get Away From aerials which now identify the radio Employment Service helps me to secure a station, all the laurels will be on the brow big pay job. (Please Write Plainly.) Me Boys, You Bother Me" of this modest, indefatigable man of is a favorite of ours. Our Salespeaker will science, of whose sixty -odd patents surely Name Age. write for it. none be a favorite of yours. Dealers can be of more far -reaching import- Street_ HUDSON -ROSS -116S. Wells St. ance than this discovery which brings Chicago the signals "in finely, at 4 in the after- State noon"- across the continent! * Tested and Approved by RADIO AGE IF 61 RADIO AGE for July, 1925 The Magazine of the Hour Corrected List of Broadcasting Stations

KDKA Weetinghotke Electric & Mfg. Co. Eut Pittaburgh. P. 309 KFUZ Y. M. C. A Virginia. Minn. 244 KDLR Radio Electric Co Devil. Lake, N. D. 231 KFVC Seashore's Music Co Camden. Ark..... 248 KDPM Wmtinghouse Elects. & Mfg. Co. Cleveland. Ohio 270 KFVD McWhinnie Electrio Co Sao Pedro, Calif. 202 KDIlL Newhouse Hotel Salt Lake City. Utah 250 KFVE Film Corporation of America St. Louis, Mo. 245 KDZB Frank E. Siefert Bakerefield, Calif. 240 KFVF Clarence B. Juneau Hollywood. Calif 208 KDZ1 Electric Supply Co Wenatchee, Wash. 360 KFVG First M. E. Church Independence, Kansas 236 KFAD McArthur Bros. Mercantile Co Phoenie, Ariz. 273 KFVH When Radio Shop (Herbert Whoa) Manikin., Kan... 218 KFAE State College of Washinston Pullman Wash. 848 KFVI Headquarters Troop. 66th Cave./ Houston, Texas 248 KFAF Weetern Radio Corporatioo Denver, Colo. 278 KFVJ First Baptist Church San Jose, Calif. 226 KFM University of Colorado Boulder, Colo. 360 KFVK Sacramento Chamber of Commerce Sacramento. Calif. 248 KFAN University of Idaho Moscow. Ide. 230 KFVL Lt. Richard F. Lussier, 5th Inf. U. S. A., Vancouver BarraekaVancous sr, Waah. 231 KFAU Boise High School Boise. Idaho 271 KFVN Carl E. Bagley Welcome, Minn. 227 KFAW The Radio Den (W. B. Ashford) Santa Ana. Calif. 280 ' KFVO F. M. Henry Kirksville Mo. 226 KFBB F. A. Buttrey & Co. Havre, Moos. 360 KFVS Cape Girardeau Battery Station Cep. Girardeau. Ieko. .. 224 KFBC W. K. Ashill -San Diego. Calif. 278 KFWA Browning Bros Co. Ogden, Utah 214 KFBC First Preebymnan Church Tacoma. Wash. 250 KFWB Waroer Bros Hollywood, Calif. 252 KFBK Kiroball-Upson Co. Sacramento. Calif. 283 KFWC L. E. Wall and C. S. Myers Upland, Calif. 211 KFBL Leese Bros Everett, Wash. 224 KFWD Arkansas Light a Power Co..- Arkadelphia. Arkansaa 266 KFBU The Cathedral laramia, Wyo. 283 KFWF St. Louie Truth Center Bt. Louis, Mo. 214 KFCB Nielmn Radio Supply Co. Phoenix. Aria 238 KFVR Moonlight Ranch Denver. Colo. 246 KFCC The First Congregational Church Helena. Moot. 248 KFWH F. Wellington Mom, Jr Chico, Calif. 254 KFCF Frank A. Moore. Walla Walla, Wash. 256 KGB Tacoma Daily Ledger Tacoma, Wmh. 252 KFCZ Ornsha Central High School Omaha, Nebr. 258 KGO General Electric Co Oakland, Calif. 361 KFDD St. Michaelis Cathedral Boise, Idaho 252 KGU Mark. A. Mulsion Honolulu, Hawaii. Waikiki Beach 370 KFDH University of Arion a 'falcon. Aria. 368 KGW Portleod Morning Oregonian Portland, Oreg. 491 KFDJ Orman Agricultural College Corvallis. Oreg. 254 KGY St. Martins College (Rob. Sebeatiao Roth) Lacy, Wee).. 253 KFDM Magnolia Petroleum Co Beaumont, Tex. 315 KHJ Timae-Mirror Co Loe Angeles. Calif. 405 KFDX First Baptist Church Shreveport, Ls. 360 KHQ Look Wanner Seattle , Wash. 273 KFDY South Dakota State College Brookings. S. Dak. 360 KJR Northwest Radio Berri. Co Seattle, Wash. 384 KFDZ Harry O. Iverson Minneapolis. Minn. 231 KJS Bible Institute of Los Angeles, In. Loa Angel.., Calif. 293 KFEC Meier & Frank Co Portland. Oreg. 248 KLS Warner Brothers Radio Supplies Co Oakland, Calif. 242 KFEK Augsbury Seminars Minneapolis, Minn. 261 KLX Tribune Publishing Co Oakland, Calif. 508 KFEL Winner Radio Corp. Denver, Colo. 254 KLZ Reynolds Radio Co Denver, Colo. 283 KFEQ J. L. Smote. Oak. Nebr. 268 KMJ San Joaquin Light & Power Corp Fresno, Calif. 243 KFER Auto Electric Service Co Fort Dodge, Iowa 231 KM0 Love Electric Co Tacoma. Wash. 250 KFEY Bunker Hill & Sullivan Mining and Concentrating Co. Kellogg, Idaho 233 KNX Los Angeles Evening Exprose Loa Angeles, Calif. 337 KFFP Fir. Baptist Church Moharly, Mo. 266 KOA General Electric Co Denver, Colo. 323 KFFV Graosland College Lamont, Iowa 280 KGB New Mexico College of Agriculture & Mechanic Arta. State College, N. Mee. 348 KFCB Haidbretior Radio Supply Co Utica. Neb. 224 KOP Detroit Police Department Detroit. Mich. 286 KFGC Louisiana State University Baton Rouge, La. 254 KPO Hale Bros Elan Francisco, Calif. 428 KFGD Chick... Radio a Electric Co. Chickaaha, Okla. 248 KPPC Paeadens Presbyterian Church Pasadena, Calif. 229 KFCH Leland Branford University Stanford University, Calif. 273 KPRC Houston Past-Diktat& Houston, Tema 270 KFGQ Crary Hardware Co Boone. Iowa 226 KQV Doubleday-Hill Electric Co. Pittsburgh. Pa. 270 KFHA Western State Collage of Colorado Gunnison. Colo. 252 KOW Charle, D. Harrold Sm Jose, Calif. 226 KFIIH Ambrose A. McCue Noah Bay, Wash. 281 KRE V. C. Battery & Electric Co Berkeley, Calif. 275 KFHL Peon College Oskaloom. Iowa 240 KSAC Kansas State Agricultural College Manhattan, Kam, 341 KF1 E. C. Anthony. Inc Las Angeles. Calif. 468 KSD Post Dispatch (Pulitzer Pub. Co.) St. Louis. Mo . 545 KFIF Benson Polytechnic Institute Portland, Oreg. 245 KSL Radio Service Corp. of Utah Salt Lake City, Utah 299 KFIO North Central /Bah School Spokane, Wash. 252 KTCL American Radio Telephme Co., Inc Seattle, Wash. 306 KFIQ First Methodism Church Yakima, Wmh. 242 KTHS New Arlington Hotel Co Hot Sprinet, Ark. 375 KFIO Alaska Electric Light & Power Co. Juneau. Alaska . 226 KTW First Preshytarian Church Seattle, Wm), 455 KFIX Rsorganised Church of Jesus Christ of Latter MY Salons Independence, Mo. 240 KUO Examiner Printing Co San Franaieco. Calif. 248 KFIZ Daily Commonwealth and Omar A. Hualsroan Fond du Lac, Wis. 273 KUOM State University of Montana MibROUia, Montana 244 KFJB Marshall Electrical Co Marshalltown. Iowa 248 KWG Portable Wireless Telephone Co Stockton, Calif. 248 KFJC R. B. Fagan (Episcopal Church) Junction City. Kansas 219 KWKC Wilson Duncan Studios Kansas City. Mo. 236 KFJF National Radio Manufacturine Co Oklahoma City, Okla. 252 KYO Electric Shoo Honolulu. Hawaii 270 KFJ1 LihertY.Theatre (E. E. Marta) Aatorla. Oreg. 252 KYW Westinghouse Electric & Mfg. Co Chicago, Ill. 535 KFJL Hartisant Manufacturing Co. Ottumwa, Iowa 242 KZM Preston D. Allen Oakland, Calif. 242 KFJM University of North Dakota Grand Forks, N. Dek. 280 WAAB Valdemar lemon New Orleans , La. 263 KFJR Ashley C. Dixon & Son Stevensville, Mont. (near) 258 WAAC Tulano Univereks, New Orleans La. 275 KFJX Iowa State Totcher'a College Cedar Falls, Iowa 280 WAAD Ohio Mechanics Institute Cincinnati, Ohio 248 KFJY Tonsil Radio Co Fort Dodge, Iowa 246 WAAF Chicago Deily DroversJournal Chicago, Ill. 286 KFJZ W. E. Branch Fort Worth, Texas 254 WAAM I. R. Nelson Co Newark, N. J. 263 KFKA Colorado State Teacher. College Greeley. Colo. 273 WAAW Omaha Grain Exchange Omaha. Nebr. 285 KFKB Brinkley-Jones Hospital Association Milfoni, Kan,. 288 WABA Lake Forest University Lake Forest Ill., 227 KFKQ Conway Radio Laboratories (Ban H. Woodruff) Conway, Ark. 250 WARB Harrisburg Sporting Goods Co. Harrieburg, Pa. 266 KFKU The University of Kansas Lawrence, Kans. 275 WAB1 Sancta Railway & Electric Co Bangor, Me. 240 KFKX Westinghouse Electric & Manufacturing Co Hasidim. Nebr. 288 WABL Connecticut Agricultural College Sorrs. Conn. 283 KFLB Signal Electric Manufmturing Co Menominee. Mich. 248 WARN Ott Radio, Inc LaCrosee, Wis. 244 KFLD Paul E. Gremlaw Franklinton. L. 234 WABO Lake Avenue Baptist Church Rochester, N. Y. 283 KFLP Everett M. Foster Cedar Rapide. T. 256 WABQ Haverford College. Radio Club Haverford, Pa. 281 KFLR University of New Marko Albuquerque. New Mexico 254 WABR Scott High School, N. W. B. Foley ..Toledo. Ohio 270 KFLU Rio Grande Radio Supply House 0.o Benito. Texas. 236 WABU Victor Talking Machine Co Camden, N. J. 224 KFLV Rev. A. T. Frykman . Rockford, Ill. 229 WABW College of Wooster Wooster, Ohio 234 KFLX George Roy Clough Galveston, Tex. 240 WABX Henry B. Joy Mt. Clements, Mich. 270 KFLZ Atlantic Automobile Co Atlantic, Ia. 273 WABY John Magaldi, Jr Philadelphia. Pa 242 KFMB Christian Chusches Little Rock. Ark. 254 WABZ Coliseum Place Baptist Church New (Mama Le. 263 KFMQ University of Akron,. Fayetteville. Ark. 299 WADC All... T. Simmone (Allen Theatres) Akron, Ohio 258 KFMR Morninmide College Sioux City, Iowa 261 WAFD Albert B. Parfet Co Port Huron, Mich. 233 KFMT Dr. Genres W. You. Minneapolis. Mino. 231 WAHG A. H. Grebe & Co Richmond Hill, N. Y. 315 KFMW M. G. Sateen Houghton. Mich. 266 WAMD Hubbard and Co Mimeapolis, Minn. 244 KFMX Carleton College Northfield, Minn. 336 WBAA Purdue 1/ulcerate W. Lafayette. Ind. 283 KFNF Henry Pieta Seed Co Shenandoah, lows 266 WBAC Clemson Aerie. College Clemeon College, S. C. 331 KFNG Wooten'. Radio Shoo Coldwater, Miss. 254 WBAH The Dayton Co Minneapolis, M ion. 417 KFN.I Central Mo. State Teachers College P7arrenaburg, Mo. 234 WBAK Pennsylvania State Police Harrisburg, Pa. 275 KFNL Radio Broadcast Men Paso Robles, Calif. 240 WBAO James Millikan University Decatur, RI. 360 KFNV L. A. Drake Battery and Radio Supple Ohms Santa Rosa, Calif.- -234 WBAP Wortharn-Carter Publishing Co. (Star Telegram) Fort Worth, Ter. 476 KFNY Montana Phonograph Co Helena. Mont. 261 WBAV Ern. a Hopkins Co Columbus, Ohio 262 KFOA Rhoden Department Store Seattle. Wash. 384 WBAX John H. Sanger. Ir Willem-Barra Pa. 254 KFOC First CM-litho Church Whittier, Calif. 236 WBAY Western Electric Co New York, N.Y. 492 KFOJ Moberly High School Radio Club Moharly. Missouri 246 WBBC Irving Vermilm Mattspoisett, Mane. 248 KFOL Leslie M. flektflanh Marengo. Iowa 234 WBBL Grace Covenant Presbyterian Church Richmond, Va. 253 KFON Echophone Radio Shop Long Beach. Calif. 234 WBBM H. Leslie AtIssa Chicago. Ill. 226 KFOO Letter DIY Sainte University' Salt Lake City, Utah 261 WBBN Blake. A B Wilmington, N. C. 276 KFOP Rohrer Elec. Co Marshfield. Ore. 240 WBBP Petoekey High School ' PatockeY. Mich. 241 KFOR David City The & Electric Co. David City, Nebraska 226 WBBR Peoples Pulpit Aseo. Roesville, N. Y. 273 KFOT Collera Hill Radio Club Wichita. Kansas 231 WBOS Fink Baptist Church New. Orleans, La. 252 KFOX Board of Education. Technical High &boot Omaha. Nebraska 248 WBBU Jenks Motor Sales Co. Monmouth. In. 224 KFOY Demon Radio Serviee St. Paul, Minn. 226 WBBV Johmtovrn Radio Co. Johntstown, Pa, 246 KFPG Garretson end Dennis Los Angeles, Calif. 238 WBBX Ruffner Junior High School Norfolk, Va. 227 KFPL C. C. Baxter Dui.. Texas 242 WBBY Washington Light Infantry Co. "B" 115th Inf Ch.l.ton, S.C. 268 KFPM The New Furniture Co Greenville.Texas 242 WBBZ Noble B. Watson Indianapolie. Ind. 227 KFPR Loo Amato, Co. Forestry Def.. Loo Amebas. Calif. 231 WBCN Foster & McDoland Chicago, Ill, 266 KFPT Cape & Mtn... Salt Lake City, Utah 268 WBDC Baxter Laundry Co Grand Rapid., Mall. 256 KFPV Hein. a Kohlmom, ¡or San Francisco, Calif. 236 WBrS Bliss Electrical School Takoma Park Md. 222 KFPW St. Johns M. E. Church Carterville. Mo. 268 WRGA Jonas Elm. & Radio Mfg. Co. Baltimore Md. 254 KFPY Symons Investment Co Spokane. Wash. 283 WBOQ A. H. Grebe a Co., Inc Richmond Hill, N. Y. 238 KFQA The Princinia. St Louis, Mo. 264 WRR Pennsylvania State Police Butler, Pa. 286 KFQB The Rearchlichi PablishIng Co. Fort Worth, Tea. 221 WBRC Bell Radio Corporation Birmingham, Ala. 248 KFQC Kidd Brother, Radio Shop Taft. Calif. 258 WBRE Baltimore Radio Exchange Wilkes-Barre. Pa. 231 KFQH Radio Service Co Be lingame.Callf. 231 WBS D. W. May, Inc Newark N. J. 252 KFQP G. S. Canon, Jr Iowa City, la. 284 WBT Southern Radio Corp Charlotte, N. C. 275 KFQR Walter LaFayetto Ellis Oklahoma City, Okla. 220 WBZ Westinghouse E. & M. Co. Springfield, Mass. 333 KFQT Texas National Guard Donning.. Team 252 WCAD St. Lawrence. University Centon, N. Y. 280 KFQU W. Riker Holy City. Calif. 253 WCAE Kaufmann A Baer Co. and 7 be Pittsburgh Pees Pittotturgh, Pa. 451 KFQW C. F. Knierlm North Bend. Wash. 248 WCAG Clyde R. Randall New Orleans, La. 262 KFOY Farmer. State Bank Bolden. Neb. 273 WCAH Entrekin Electric Co Columbus, Ohio 286 KFQZ Taft Radio Co Hollwrood, Calif. 240 WCAJ Nebraska Wesleyan University Univernity Place. Nebr. 283 KFRC City of Paris Dry Goode Co San Francisco, Calif. 268 WCAL St. Olaf College Northfied. M inn. 336 KFRM James F. Boland Fort Sill. OM.. 263 WCAO Sanders a Stemma Co Baltimore Md. 275 KFRU Ethane.' Radio Co Bristow. Okla. 394 WCAP Chesapeake a Potoms Telephone Co Weahington, D. C. 465 KFRW United Churches of Ciampi. OlYmpia, Wash. 220 WCAR Alamo Radio Electric Co San Antonio. Tee. 263 KFRX J. Gordon Klemeard Pullman. Wsca. 217 WCAS W. H. Dunwoody Industrial Inetitute Minneapolis, Minn. 280 KFRZ The Electric Shop Hartinmon. Neb. 222 WCAT State College of Mines Rapid City, S. Dak. 240 KFSG Angelus Tema'. Loo Angeles. Cali!. 272 WCAU Durham & Co Philadelphia, Pa. 278 KFSY The Van Blarioon Co Helena. Mont. 261 WCAX University of Vermont Burlington, Vt. 250 KFUJ Hopper Plumbing and Floating Co Breckenridm, Minn. 242 WCAZ Carthage College Carthage. Ill. 246 KFUL Thomas Gomm & Brae. Music Co .Clalveston. Tex. 258 WCBA Charles W. Hefiachrn Allentown. Pa. 280 KFUM W. D. Corley Colorado Sarin., Colo. 242 WCBC University of Michigan A013 Arbor, Mich. 280 KS.* Concordia Seminary St. Louis. Mo. 649 WGBD Wilbur C. Voliva Zit., Ill. 344 KFUP Fitenimmone General Hospital Denver, Colo. 234 WCBE Malt Radio Co New Orleans. La. 283 KFUQ Julius Brunton and Sons Co. San Francisco. Calif. 234 WCBF Paul J. Miller Pittahurgh.Pa. 236 KFUR H. W. Poory and C. Redfield Ogden, Utah 224 WCBC Howard S. William. (Portable) Paacagoula, Mina. 268 KFUS Louis L. Sherman Oakland, Calif. 233 WCBH University of Mies Orford, MM. 242 KFUT Uni it), of Utah Salt Lake City, Utah 271 WCBI Nicoll. Duncan & Rush Bemis, Tennant. 240 KFUU Colburn Radio Labs San Leandro. Calif. 231 WCBJ J. C. Mam ... loaning, Louisiana 244 KFUY Irvine M. Bouchard... Butte, Mont. 254 WCBM Charles Swam .Baltimore, Md. 221.,

1 RADIO AGE for July, 1925 The Magazine of the Hour 65 Another Broadcasting Boom what each potential radio entertainer is Opens glad to assert, believing that he is telling \160 -page the truth. Probably some of them could INSTEAD of quieting down for the introduce new stars, but there are plenty Reference Summer months, interest in radio as it is. They soon find that the field is Book broadcasting is reported as increasing ',pretty well covered by the 566 stations, by many exponents of this art. At which are all experienced and have their least prospective broadcasting station own talent well lined up and trained, not owners are showing more activity than to mention a large following of regular ever before, Department of Commerce fans. Every one of these stations in records indicate. Although there are operation is trying its best to learn what 566 stations on the air today, utilizing the listeners want and to give it to them; every available broadcast wavelength, many stations which failed so to do, have there are at least twenty applicants for fallen by the wayside, their experiments Mai l class B broadcast privileges and about a constituting a considerable financial loss. hundred individuals or organizations Some organizations believe they could List are said to be seeking licenses for class serve a special group in the great radio Catalog A operation. Not all these stations have audience not now furnished with what No.55 made formal application to the Depart- they desire. In a few instances this is ment of Commerce, however. This is true, particularly as some religious orders POLK'S REFERENCE BOOK not a requirement and is seldom the usual are not on the air in certain sections. FOR DIRECT MAIL ADVERTISERS Shows how to increase your business by method of procedure. Ordinarily, a All Europe, it is pointed out, has not the use of Direct Mall Advertising, 60 pages prospective broadcaster first leases so many broadcasting stations as full of vital buainess face and figure. Who, a there where and bow many prospects you have. site, then buys expensive equipment are in the United States alone. When Over 8,000 lines of business covered. and set it up before he asks the Depart- the question of international broadcasting Write for your FREE copy. ment if there is a vacant air channel for comes up at the Paris or Washington R. L. POLK & CO., Detroit, Mich. 599 POLK DIRECTORY BUILDING him. No shipping company would buy conference, it may be that we shall have Branches In principal cities of II. S. its boats and equipment before it found to release some of our much desired and out if it could get a route and a license used radio channels for inter -continental to do business; neither would an auto use, it will be pointed out, and rightly bus line, but in this new game of broad- so, that we have no more right to the casting, some of the more practical 205 -545 meter band than other countries, Get Cuba essentials and necessary requirements and that we should share the wave seem to be neglected to the cost of the lengths. If this is the case, the situation or would -be radio -phone station operators. will become worse unless a number of Some citizens now seem to realize our stations drop out of the game. Mexico City that there is no more room for Class B, The increase in numbers, however, While Big Local Stations Are Broadcasting, high- power, stations, but the congestion is continuing gradually; in April twenty- The New York Evening World got 46 stations in smaller class A four stations, One Evening including Dallas, Los Angeles, and among the stations, in mostly smaller ones, ceased Porto Rico; while testing the wonderful sensitivity consequence of the few channels assigned to broadcast, but twenty-seven new ones of the to them, is worse. There are 468 stations opened, increasing the total on the air May New in Principle -New in Design now, 54 of them operating on 500 watts, 1, by three over the figure on March 1st. the maximum power alloted to this class WERNER and there are dozens of them on the same Russo and Fiorito Radio Frequency wavelength. As the power increases, and there is rumor that many A's will Open WIBO TRANSFORMERS be permitted to go up in power this STATION WIBO came on the air last For All Circuits Summer in an effort to overcome static, month, in Chicago. Harry Geise, Director and Announcer, promises the Insist on getting them, if your dealer can't supply the situation becomes worse, from a radio audience you, send your order to us. reception point of view. With increased several new and Price $4.00, All Types power, they cover more territory and novel surprises therefore interfere with more stations, and features, and Send for Diagrams just as the higher -powered B stations do, with the assist- A wonderful interesting book "Radio Frequency ance of Dan Rus- Ampfifieation" contains popular and technical in- even when there are but two or three to a formation with many up-to -date R. F. circuit dia- wavelength. In the low A wave so and Ted Fio- band of rito, grams of greatest interest to both radio user and 226 meters for example, there are six- who have engineer. already gained a 25c postpaid teen stations now operating. multitude of ra- There is no record kept of proposed dio friends, will R. Werner Radio Mfg. Co. stations until formal applications are endeavor to 204 -206 Ninth St. Brooklyn, N. Y. filed with the district radio supervisor, please the radio but from one western supervisor comes audience with the statement that there are 32 stations the best pro- in California alone planning grams obtain- to ask for Harry Heise able. broadcasting licenses as soon as their Dan and Ted, BAKELITE stations are completed. This official co- conductors of the Oriole Orchestra, Insulated condensers give lasting can not possibily satisfy more than ten formerly playing at the-Edgewater Beach satisfaction. Write for booklet 31. or a dozen of his prospective customers, Hotel, and Harry Geise, known as the OBGiBAKELITE CORPORATIONt many of whom are understood to have "How -Do- You -Do Man," are on the 247 Perk Avenue, New York, N.Y already bought or ordered their equip- air each night to to answer requests. Û Chicago Office: 636 West 22d Street ment, despite the reiterated WIBO is located at 6310 Broadway, statement Chicago, the studio and reception room that the broadcasting lanes through the on the second floor, and the operating ether are all crowded, and rights of way room on the third floor. The studio is Radio y are no longer available except in some of equipped with Celotex walls, designed MARSHALL eeivercs the still "open spaces." in rather a unique manner, handsomely Embodying a marvelous New & The fans seem to take the view that furnished, with perfect acoustics for Non -Oscillating Principle there are enough broadcasters now, and broadcasting. The eighty -foot towers Sold Direct on Free Trial and Easy Terms are completed and Philip I. Latin, Chief Write far catalog and Special Offer that no more should be permitted to come Engineer, is on working every effort to the air unless they can guarantee assure the public of successful broad- Marshall Radio Products, Inc. unique programs. This, however, is just casting from this station. Dept-B-589 Marshall Blvd.& 19thSt..Chicago * Tested and Approved by RADIO AGE 66 RADIO AGE for July, 1925 The Magazine of the Hour

WCBN James P. Boland P. Boni. Harriaon. Ind. 266 WHN George Schubert New York. N.Y. 360 WCBQ First Baptist Church Nashville ,Tem. 236 WHO Bankers Life Co. Dee Moines. h. 526 WCBR C. H. Messner Providmce, R. I. 2419 WHT Radiophone Broadcasting Corporation Deerfield, Ill. 238 WCBT Clark University, College.. Dept. Wommter, Masa 238 WIAD Howard R. Miller Phdadelphia, Ps. 254 WCBU Arnold Whale. Supply Co. Arnold, P. 254 WIAK Journal-Stockmen Co Omaha, Nebr. 273 WCBX Radio Shop of Newark (Herman Lubinalty) Newark, N. J. 233 WIAQ Chronicle Publishing Co. Marion Ind. 226 WCCO Washburn-Crosby Co Twin Cities, Mim. 416 WIAS Home Electric Co. BurimMon. low,. 283 WCEE Chad. E. Erhstein. Villa Olivia n.r Elgin, Ill. 278 WIBA TM Capital-Times Studio Media., Wi.. 234 WCK StizsBaer-Fuller D. G. Co. 4 St. Louis, Mo. 275 WIBC L. M. Tate Poet. No. 39. Veterans of Foreign Wass. -St Petersburg. Florida 222 WCTS C. T. Scherer Co. Worces.r, M. 268 WIRD X-L Radio Service Joliet. Illinois 2v0 WCX Free Pr.s Detroit, Mich. 516 WIRE Martinsburg Radio Broadcasting Co. Martinsburg, W. Va. 210 WDAE Tampa Dad" Tunes. .. Tampa. Fla. 365 WIBF S. P. hfiller Dance Activities Wimatland. Wisc. 231 WDAF Kansas City Star Kansas City. Mo. 365 WIRG St. Paul's Protestant Episcopal Church Elkins Park, Pa. 222 WOAG J. Laurence Martin Amarillo, Tex. 263 W1130 Nelms Brother. Chicago. III. 226 WDAH Trinity Methodist Church (South) El P.e, T. 268 WIBH ' Elite Radio Stores New Bedford, Mass. 209 WDAR Lit Brothers Philadelphia, Pa 394 WIBI Frederick B. Zittell. Jr Fl.hing, N. Y. 219 WDAY Radio Equipment Corp. Fargo. N. Dak. 244 WIBJ C. L. Carrell (Portable) Chicago, Ill. 216 WDBA Fred Ray Columbus. Ga. 236 WIBK University of Toledo Toledo, Ohio 205 WDBB A. H. Wit. & Co., Inc Taunton, Mass. 229 WIBL McDonald Radio Co.. Portable Steam Joliet, III. 2157 WDBC Kirk, Johnson & Co Lancastar. P. 258 WIL Continental Electric Supply Co. Washington, D. C. 360 WDBD Herman Edwin Burns Martinsburg. W. Va. 268 WI P Gimbel Br. Philadelphia, Pa. 509 WDBE Gillsam-Schom Elec. Co Atlatic, Ga. 278 WJAR American Electric Co Lincoln, Nebr. 229 WDBJ Richardson Wayland Electric Corp. Roanoke, Va. 229 WJAD Jackson'. Radio Engineering Laboratories.. Waco. T.. 352 WDBK hl. F. Br. Cleveland, Ohio 227 WJAG Norfolk Daily News Norfolk, Nebr. 283 WDBL Wisc. Dept of Markets Stove. Point. llIs. 278 WJAK Clifford L. White Greenroom, Iowa 254 D. M. WDBN Electric Light & Power Co Bangor. Me. 252 WJAM Perham Ceder Rapids, Iom 268 A WDBO Rollin. College Inc. Winter Park. Flo. 240 WJAR The Outlet Co. (J. Samuel. & Bro.) Providence. R. I. 306 WDBP Superior State Normal School Superior, Wix. 261 WJAS Pittsburgh Radio Supply Howe Pittsburgh, Pa. 286 W DB Q Morton Redo Supply Co Salem. N. J. 234 WJAZ Chicago Radio Laboratory Chicago, Ill. 268 WDBR Tremont Tempo Baptist Chortle Bostons. Mass. 256 WJBC Hummer Furniture Co. LaSalle, Ill. 234 WDBV The Strand Theatre Fort Wayne. Ind. 258 WJBD Ashland Broad:seeing Committee Ashland, Wise 233 WDBW The Radio Den Columbia, Tenn. 268 WJBI FL M. Couch Joliet, Ill, 2142 WDBX Otto Baur New York, N. Y. 233 WJD Denison University Gmniteville, Ohio 229 WDBY North Shore Congregational Church Chicago. Ill. 258 WJJD Sum me Lodge. Loyal Order of Moore Mooseheart, Ill. 303 WDBZ Boy Scouts. City Hall Kmmtown. N. Y. 233 WJY Radio Corp. of Am New York, N. Y. 455 WDM Church of the Covenant Washington. D. C. 234 WJZ Radio Corp. of Am. New York, N. Y. 455 WOOD Chattanooga Radio Co., Inc t asattanooga, Teon. 256 WKAA H. F. Pear .C.d. Rapids, Iowa 278 i WDWF Dutee Wilcox Flint. Inc Cranston, R. I. 441 WKAD Chas. Long (Cres.nt Park) Eut Providmee, R. I. 240 WDZ J. L. Bralh Tomola, EL 278 WKAP Dutee W. Flint Cranaton, R. L 234 WEAA F. D. Fallain Flint, Mi. 250 WKAQ Radio Corp. of Porto Rico San Juan, P. R. 340 WEAF American Telephone & Telegraph Co. New York, N.Y. 485 WKAR Michigan Agriculture College East La.ing, Mich. 285 WEAH Wichita Board of Trade Wichita, Ea.. 280 WKAV Laconia Radio Club Loc.., N. H. 254 WEAL Cornell University 7th..... 286 WKBE K. & B. Electric Co. Weimer, Marisach.ette 231 WEM University of South Dakota Vermillon 8. Dak. 283 WKBF Dutee Wilcox Flint Crensteas. Rhode Island 286 WEAM Borough of North Plainfield (W. Gibson ButtlIeld)..North Plainfield, N. J. 286 WKY Wky Radio shop Okla. City, Okla. 275 WEAN Shepard Co Providence, R. I. 273 WLAG Cutting & Washington Radio Co. Minn.potie, Minn. 417 WEAO Ohio State University Columbus. Ohio 293 WLAL Fir. Chr.tian Church Tulanada. 250 WEAR Goodyear Tire and Rubber Co. Cleveland. Ohio 389 WLAP Wm. V. Jordan Louisville. Ky. 286 WEAU Deviate:on Bros. Co Sioux City, Iowa 275 WLAQ Arthur E. Shilling Kalamazoo, Mich. 283 WEAY Iris Theatre (Will Horowitz. Jr.) Houston, Tex. 270 WLAX Putnam Electric Co Gr.neastle, Ind. 231 WEB Bellwood Co St. Louis. Mo. 273 WLB University of Minnesota MilIDOOPOlitl. Minn. 278 WEBA Electric Shop Highland Park, N. J. 233 WLBL Wisco.in State Dope. of Market. Stevenspoint. Win. 278 WEBC Walter Cecil Bridges Superior, Wia. 242 WLS Sears Roebuck & Co. Chicago. Ill. 344 WEBD Electrical Equipment and &rake Co Aoderson, Ind. 246 WLW Crosley Mfg. Co Cincinnati, Ohio 422 WERE Roy W. Walker Cambridge, Ohio 248 WMAC J. Edw. Pa. (Olive B. Meredith Cosmos.. N. Y. 261 WEBH Edgewater Beech Hem'. Chicago Evening Poet Station Chicago,III. 370 WMAF Round Hills Radio Corp - Dartmouth. Mom 360 WEBJ Third Avenue Railway Co New York, N. Y. 273 WMAK Norton Laboratories Lockport, N. Y. 273 WEBM Radio Corporation of Aimed. Portable 226 WMAL Trenton' Hardware Co Trenton, N. J. 256 WEBP E. B. Pedicord NewOrl... La. 280 WMAN First Baptist Chitral Columbus Ohio 288 WEBT The Dayton Coop. Industrial High School Dayton Ohio 270 wmAq Chic. Daily News Chicago, Ill. 447 WEBW Beloit College Beloit Win. 283 WMA4 AI.... Polytechnic I.titute Auburn, Ala. 250 WEEI The Edison Electric Illuminating Co Boston, Mn.... 475 WMAY Kingshighmy Presbyterian Church St. Louie, Mo. 280 WEMC Berrien Springs, Mich. 285 WMAZ Mercer UniversitY Macon, Ga. 261 WENR All-American Radio Corporation Chicago, nunoi., 266 WMBB Trianon Ball Room Chicago. El. 250 WEW St. Louis University St. Lou., Mo. 280 WMBF Miami Beach Fla. 384 WFAA Danes News & Dailaa Journal Dell.., T.. 472 WMC Commercial Appeal Memphie. Teno. 503 WFAM Times Publishing Co St. Cloud, Minn. 273 WMCA Hotel McAlpin (Greeley Square Hotel Co.) New York City 341 WFAV University of Nebraska, Department of Electrical Engineering. Linmln, Nebr. 275 WMH Aimworth-Gates Radio Co Cincinnati, O. 321 WFBB Eureka College Eureka, Ill. 240 WMU Dour:aerial-Hill Elea Co Washington. D. C. 260 WFBC First Haphist Church Knoxville, Tenn. 250 WNAB The Shepard Stores Boston, Mn.... 250 WFBD Gethsemane Baptist Church Philadelphie, Pe. 234 WNAC Shepard Stores Boston. Ma.s. 284 WFBE John Van De Waite Sera.or, IM. 226 WNAD University of Oklahoma Norme..., Okla. 258 WFBC The Won. F. Cable Co Ahoona. Pii 261 WNAL Omaha Central High School Omaha. Nehr. 255 WFBH Concourae Radio Coporatran New York, N. Y. 273 WNAP Wittenberg College Springfield. Ohio 271 WFBJ St John's University Collegeville, Minn. 236 WNAR First Christian Chords B der Mo. 230 WFBQ Wynne Radio Co Raleigh, N. C. 255 WNAT Lemig Brothers Co. (Frederick Lennie) Philadelphia. Pa 254 WFBR Fifth Inf. Md. Nat, Guard. 5th Reg. Armory Baltimore. Md. 452 WNAX Dakota Radio Apparat. Co Yankton, S. Dak. 248 WFBW Ai.worthsGates Radio Co. Cincinnati. Ohio 309 WNY.0 Dept. of Plant and Structures New York, N. Y. 626 WFBY Signal Officer Ft. Ben Harrison, Ind. 258 WOAC Pere Organ Co. Lima, Ohio 260 WFBZ Knox College Gol.burg. LU. 254 WOAE Midland College Fremont, Nebr. 280 WFI Strawbridge and Clothier Philadelphia. Pe. 394 WOAG Apollo Theater (Belvidere Amusement Co.) Belvidere. ILL 274 WFKB Francia K. Bridgman Chicago. Ill. 217 WOAI Southern Equipment Co San Antonio. Team 392 WFUV G. Pearson Ward Springfield. Mo. 252 WOAN Vaughn Conservatory of Music (Um. D. Vaughri)....Lawren.borg. Teno. 280 WFUW Earl William Lewis Moberly. Mo. 233 WOAD Lyradion Mfg. Co Miellawaka, Ind. 369 WGAL L.caster Electric Supply & Construction CO LOOCast111, Pa. 248 WOAR Lundakow, Henry P Kanoaha, WI... 226 WGAQ Youreellotel Shreveport, La. 252 WOAT Boyd M. Hemp Wilmington. Del. 360 WGAZ South Bend Tribune South Bend, Ind. 360 WOAV Pennsylvania National Guard, 2d Bette/ion Mar Inf.try.....Erie, Ps. 242 WGBB Hamr H. Carman. 217 Bedell St Freeport, N.Y. 244 WOAW Woodmen of the World Omehs, Nebraska 526 WGBC First Baptist Church Memphis. Tenn. 266 WOAX Franklyn J. Wolff Trenton. N.J. 240 WGRF Fink Furniture Co Evansville, Ind. 217 WOG Palmer School of Chiropractic Davenport. Iowa 484 WGBG Brietenbach'e Radio Shop Thrifton, Va. 226 WOOL Hotel Jamestown, Inc Jamestown, N. Y. 275 WGBH Fall River Herald Pub. Co (Portable) 209 WODA Jam. K. O'D. Paterson, New Jeremy 203 WGBI Frank S. Megargee Smanton, Pa. 240 WO! Iowa State College Amex Ia. 207 WGBK Lawrence Campbell Johnstown, Pa. 248 WOO John Wanamaker Philadelphia. Pa. 509 WGBM Theodore N. Smutty Providence, R. I. 234 WOE L. Bomberger and Co. Newark, N. J. 405 WCBL Elyria Radio Amos. (Albert H. Ernst) Elixir, Ohio 227 WORD Peoples Pulpit Assn Batavia, M. 275 WGBQ Stout Institute Menominee. Win. 234 WOS State Marketing Buron Jefferson City, Mo. 440 WGBR Marehfield Broadcasting Affiad Marohfield, Win. 229 WOWL Owl Battery Company New Orleans, U. 270 WGBS Gimbel Brothers New York. N. Y. 315 WPAR Pen.ylvania State College State College, Pa. 283 WGBT Form. University Greenville, 8. C. 236 WPAC Doneldeon Radio Co. Okmulgee, Okla. 360 WGBX University of Maine Orono, Me. 252 WPAJ Doolittle Radio Corp New Haven. Conn. 268 WGBY Progress Sales Co R R. No. 2 218 WPAK North Dakota Agricultural College AgrimItural Colle.. N. D. 283 WOES Oak Leaven Broadcaatng Station Oak Park. Ill. 283 WPAL Superior Radio & Telephone Equipment Co. Columh., Ohio 286 WGI American R. & R. Co Medford Habits, Mn.... 261 WPAZ John R. Koch (Dr.) Charleeton, W.Va. 273 WGN The Tribune Co Chica., M. 370 WPG The Municipality of Atlantic City Atlantic City. N. J. 300 WGR Federal T. and T. Co Buffalo. N. Y. 319 Horace A. Beale, Jr Parkersburg. Pa. 270 WGY General Elec. Co Schenectady N. Y. 379 W C E. B. Gish Amarillo, Tex. 234 WHA University of Wisconsin Madison, Wis. 535 W AE Moore Radio News Station (Edmund B. Moore) Springfield, Vt. 275 WHAD Marquette University Milwaukee. Wu. 280 WQAM Electrical Equipment Co Miami. Fin 283 WHAG University of Cincimati Cincinnati, Ohio 222 WOAN Scranton Times Scrantca. Pa. 280 WHAM Hafer Supply Co Joplin, Mo. 283 WQAO Calvary Baptist Church New York, N. X. 360 WHAM University of Rochester (Eaatman School of Musk) Rochester. N. Y. 278 WQAS Prince-Watter Co Lowell, Mn... 266 WHAP H. Alvin Simmons, 290 Flatbush Ave Brooklyn. N. Y. 240 WQJ Calumet Rainbo Broadesetkur Co Chicago. ni. 447 WHAR Seaside Hou. Atlantic City, N. J. 275 WRAA The Rice Inatitote Flo.ton. Ten 256 WHAS Courier-Jot...not & Louisville Times Louiaville. Ky. 399 WRAF The Radio Club (Inc.) Laporte, Ind. 224 WHAY Wilmington Electrical Som.]. Co. Wilmington. Del. 360 WRAK Economy Light Co Escanaba, Mich 256 WHAZ Rensselaer Polytechnic Institute Troy. N. Y. 385 WRAM Lombard College Galesburg. W. 244 WHB Sweeney School Co Kans. City, Mo. 365 WRAO St. Louie Radio Service Co. St. Lou.. Mo. 263 WHBA C. C. Shaffer Oil City, Pa. 250 WRAV Antioch College Yellow Springs, Ohio 242 WHBB Hobers Store Steven. Point, Wis. 240 WRAW Avenue Radio Shop (Horace D. Good) Reading. Pa. 238 WHBC Rev. E. P. Graham Canton, Ohio 245 WRAX Fl.on'a G.r.ge Gloucester City, N. J. 268 WHBD Chas. W. Howard Bellefontaine, Ohio 222 WRBC Emanuel Lutheran Church Valparziao. Ind. 278 WHBF Beardsley Specialty Company Rock Eland, Illinois 222 WRC Radio Corp. of Ame ' Warhington, D. C. 468 WHBG John B. Skane Harrisburg, Pa 231 WREO Reo Motor Car Co Lansing. Mich. 286 WHBH Culver Military Academy Culver. Ind. 222 WRHF Washington Radio H.pital Fund W.hiturton, D. C. 256 WHBI Chesaning Electric Co. Chesaning, Mich. 227 WRK ' Doron Br. Ilsmilton. Ohio 360 WHBJ Lauer Auto Co Ft. Wayne, Ind. 234 WRL Union College Schenectady, N. Y. 270 WHBK Franklin St. Garage. Inc Ellsworth, Moire 231 WRM University of Eh.. Urhana, ni. 273 WHBL James R. Blaser Logansport, Ind. 220 WRR Police and Flre Signal Department Dallas. Tex. 261 WHBM C. L. Carroll, Portable Station Chicago, Ill. 233 WRW Tarrytown Radio Rre. Labe Tarrytown. N. Y. 273 WHBN Fir. Ave. Methodist Chords St. Petemburg, Florid. 258 WSAB Southeast Missouri State Teachers College Cape Chards., Mo. 275 WHBO Y. M. C. A.. Summer Street Pawtucket. Rhode Island 231 WSAC Clemson Agricultural Colime Clem.son College, S. C 336 WHBP Johnstown Automobile Co Johentown, Pennaylvania 256 WSAD J. A. Foster Co Providence. R. I. 261 WHBQ St. John's M. E. Church South Memphis, Tenn. 233 WSAG Loren Vanderbeck Davis St. Petersburg. Fla. 264 WHBR Scientific Electric & Mfg. Co.. 3664 Vine& Cincinnati. Ohio 216 WSAI United States Playing Cards Co. Cincinnati, Ohio 325 WHBS Edward Wm. Locke Mechanicsburg. Ohio 208 WSAJ Grove City College Grove City, Pa. 258 WHBT Thome. W. Tiszard, Jr Downer. Grove, III. 206 WSAN kllentown Call Pi.blishing Co Allentown. Pn. 229 WHBU B. L. Bing's Soon Anderson, Ind. 218 WSAP Seventh Day Adventist Church New York, N. Y. 263 WHBV Fred Ray's Radio Shop Columbus. Gs. 244 WSAR Doughty á Welch Electrical Co. Fall River, Mn.... 254 WHEW D. R. Kiensie Philadelphia Pa. 215 WSAV C. W. Vick Radio Col...hoodoo Co. on.too, Tn.. 360 WHBX J. W. Bower Punxsutawney. Fa. 213 WSAY Irving A.tin (Port Chester Chandler of Commerce/ ...Port Chester, N. Y. 233 WHBY St. Norbert.. College West De Pore Wis. 250 WSAZ Chas. Electric Shop Pomeroy, Ohio 258 WHEC Hickson Electric Co., Inc Rochester, N. Y. 258 WS'( Atlanta Journal Atlanta, Ge. 428 WHK Radios.. Company Cleveland,Ohlo 273 WSKC World'. Star EMMA CO. Bay City, Mich. 261 RADIO AGE for July, 1925 The Magazine of the Hour 6 Advertising Takes Its Place In Radio Programs

WASHINGTON That advertising is the Interstate Commerce Commission insidiously creeping into broadcast should take a hand, claiming that tele- programs and that radio "entertain- phone lines are a public utility or that ment" will eventually become "thinly connecting lines are between states. veiled publicity," is charged by some of Statements from a number of the rep- the leading exponents of radio and resentative manufacturers show that 12-Cell - 24-Volt advertising. there is no unanimity of opinion against Storage`B'Battery Positively given frost with each We have all beard what are virtually paid radio advertising, but they all purchase of a WORLD A" publicity talks on coffee, candy, flour, believe in good Storage Battery. You must broadcasting. send this ad with your order. chewing gum and other commodities, Lee DeForest believes that as more WORLD Batteries are famous for their guaranteed quality through the air, and also enjoyed en- concerns take up radio advertising, their and service. Backed by years of successful manufacture and tertainment by playing -card quartettes, programs become less interesting to the thousands of satisfied users. Eu Ipped with Solid Ru66n Ce.., automobile -tire orchestras, safety razor public, that advertising is insidious and an Insurance against acid and leek. - and grocery store musicians. The butch- becoming more flagrant; and he asserts 2Yeare You save Guarantee60 pet cent end Reta WORLD er, the baker, the candlestick maker and that he has actually become prejudiced 1 Bond in Writing woeBat- Approved whole been broad- of "tell thefriend... Thet . and Listed the of industry has against several the broadcasters' of performance. Send your order n today. casting of late. What is it coming to? products. He looks forward to a time Solid Rubber Case Radio Batteries as Standard 6-Volt. 100 -Amperes ...... 511.25 "whether advertisers when the great by Leading The question majority of programs will &oVlt S Ó Manr,, 14ÓÓ. Authorties for is causing be for Solid Rubber Caso Auto Batteries Including Radio should pay broadcasting" "thinly veiled advertising pur- 6 -Volt. II.Plste 511.25 News 6Vo14 1a.Plate ...... 13.25 Poviu concern among the broadcasters and poses." 12-Volt. 7 -Plate 16.00 Belenes toed. cute of Stand. national advertisers, as well as the radio Secretary Hoover is opposed to censor- Send No Money úr;: tvedtá we will *hip_ dey order se received. .1(adclio Lalbr . En- tech.. Radio O. . aga., industry itself, but since it will be up to ship, but through the radio conferences pre D.Doalge.cg.togrr wa Broedeeat Lab. decide a brief of Extra Offer: 6 per cent diecount for tomb oratories Radio the fans to eventually, it has been made known that "indirect In full with order. Bur now and an the Bome. get guar. y Lof ai. irae. a survey recently made by Albert E. is anteed battery at 60 per cent eeoma to you. and advertising" only permitted via broad- WORLD BATTERY COMPANY Haase follows: casts by The Department of Commerce. 121950. Wabash Are., Dept. 36 CHICAGO, ILL. However, Mr. Haase sees possible For Radio and Business Gov- AUTO ernmental intervention and ultimately and

qTCORAGEorlcl - "The radio industry is discovering that a decision from receiving set owners. BATTERI RADIO good broadcasting means good business, Views of concerns which have tried tNñgF and extraordinary broadcasting, extra- paid advertising are interesting. The ordinary business," Mr. Haase points out. Eveready entertainers, considered unique "Conversely, poor broadcasting means by many, actually pay the National Ii poor business. Many who are in the in- Carbon Co., in good will. One day 3,000 dustry realize that if the mad rush to letters came in, according to J. R. Craw- The Five Tube get the advertisers' dollar for the support ford of that company. But he does not of radio continues, radio itself will suffer. think radio advertising, even indirect, Set which Today, advertising agencies are offered would pay all types of manufacturers, 15% commission by a number of broad- except experimentally. startled casting stations for business. One sales- As a contrast, Stuart Peabody of the * the World/ man has secured the advertising rights Borden Milk Co., claims that two broad- from fifteen stations. trials failed which casting to bring adequate "On the other hand, stations responses. The Macy Co. failed to do not sell space on the air are besieged derive substantial benefits from broad- FRESHMAN by publicity men who seek to talk on casting. But Nat Lewis, owner of two viASTERPIEct certain business and collect from the gift and haberdashery shops, found manufacturers. fashion talks via radio, which he calls The Greatest Value "Overdoing advertising, will kill radio better than some a "publicity," other forms and at the same time hurt advertising, He received 5,000 is of advertising. letters Ever Offered in A representative of the Colgate Co., one talk. quoted as saying. The wholé problem of following Receiving Set radio advertising is being studied by the Officials of the United Retail Candy backers of the "Happiness Boys," Association of Advertising Agencies, Stores, At Authorized Dealers which already has decided that the say after fifteen months of broadcasting .Radio present methods of radio advertising are entertainment stunts, that they feel it is not agreeable nor desirable to fans, and "publicity" rather than "advertising," that the nuwise use of radio advertising which they use simultaneously. will be bad for all advertising." The Fisher Co., Astor Coffee manu- PWX So far the American Tel. & Tel. Co., facturers, continue radio programs after is easy to get with the right kind of through WEAF and a chain of inter- fifteen months' trial, having received over from all set. Profits are easy to get with the right connected stations, appears to be the 100,000 communications parts of write for facts. the country. kind of goods. Dealers main channel for radio advertising. The HUDSON -ROSS 116 S. Wells St. charges according to Mr. Haase, vary Through co- operation with the A. T. Chicago from $25 a minute for talks, and $250 a & T. Co., the Victor Talking Machine half hour for entertainment, from one Co. is said not to pay for space, when its station, up to $1,600 an hour for enter- stars sing and play. It is studying the tainment distributed through seven sta- results, however, and will soon report on A 62 -page tions. The advertisers, of course, furnish broadcasting. Advertising experts feel Blueprint Section all the talent. Circulation is part of sales that radio has a time limit and that its talks, but figures are naturally only circulation is uncertain, compared to in the August estimates. These rates are not guaran- other mediums; they believe it is prob- RADIO AGE teed as fixed, but may be increased, unless ably an accessory. * Tested and Approved by RADIO AGE 63 RADIO AGE for July, 1925 The Magazine of the Hour

WSMB Saunter Amusement Co. and Maison Blanche Co New Orlaa, La, 319 WTAU Ruegg Battery & Electric Co. Tecumseh, Nebr. 242 WSMH Shattuck Music House Ow0000. Mich. 240 WTAW Agricultural .k Mechanical College of Tessa College Station. Tea. 280 WSMK S. M. K. Radio Corp Dayton. Ohio 275 WTAX Williams Hardware Co Streator. Dl. 231 WSOE School of Engineering Milwaukee. Wis. 246 WTAZ Thomas J. McGuire Lamhartvila. N. J. 283 WSRF Hardem Sales and Service Broadlands. III. 233 WTHS Flint Senior High School Flint, Mich. 218 WSTA Camp Merienfeld Cbesham, N. H. 229 WTG Kansas State Agricultural College Manhattan. Kans. 273 WSUI State University of Iowa Iowa City. Iowa 498 WTIC Travelers Insurance Co. Hartford. Coon. 323 WTAR Fell River Daily Herald Puhliebtng Co. Fall River, Maw. 248 WTX H. G. Seel Co Chicago, Ill. 268 WTAC Penn Traffic Co Johnstown. Pa. 360 WWAD Wright & Wright (Inc.) Philadelphia. Pa. 360 WTAL Toledo Radio & Electric Co. e Toledo. Ohio 252 WWAE The Alamo Ball Room Joliet Ill. 242 WTAP Cambridge Radio ils Electric Co Camhridge. Ill. 242 WWI Ford Motor Co Dearborn. Mich. 273 WTAQ 8. H. Van Gordon & Son Osseo, Wu. 220 WW1 Detroit News (Evening Nm Am.) Detroit, Mich. 352 WTAR Reliance Electric Co Norfolk. Va. 280 WWL Loyola University New Orleans. La. 260 WTAS Charles E. Erbstein Elgin. Ill. 303 WWOA Michigan College of Mines Houghton, Mich. 244 WTAT Edison Electric Dlumimting Co. (portaW.) Baton. Mass. 244 Canadian Stations CFAC Colter, Herald Calgary. Alberta 430 CHXC J. R. Booth Ottawa. Ont. 435 CECA Star Pub. t Prtg. Co Toronto. ootario 400 CHYC Northern Electric Co Montreal. Quebec 410 CFCF Marconi Wireless Teleg. Co. Canada Montreal. Queheo 440 CJBC Jervis Baptist Church Toronto. Ont. 312 CFCH Abitibi Power h Paper Co Iroquois Falls. Ont. 400 CICA Edmonton Journal Edmonton, Alberta 455 CFC) Le Cie de L'Eveuement Quebec. Quebec 410 CJGC London Fra Press Pros. Co. London. Ont 430 FCKC Radio Supply Co Edmonton. Alberta 410 CJCD T. Eaton Co Toronto. Ont. 410 CFCN W. W. Crant Radio (Ltd.) Calgary. Alberta 440 CJCE Sprott -Shaw Radio Co. Vancouver, B. C. 420 CFCQ Radio Specialties (Ltd.) Vancouver. B. C. 450 CJCF The News Record !Gcebener, Out. 295 CFCR Laurentide Air Servies Sudbury, Ont. 470 CJCI Maritime Radio Corp St. John. New Brunswick 400 CFCT Victoria City Temple Victoria. B. C. 410 CJCK Radio Corp. of Calgar, Calgary. Alta. 316 CFCU The Jack Elliott Radio Limited Hamilton.n. Ont. 410 CJCM .1. L. Pbiilipe Mont Joli, Quebeo 430 CFCW The Radio Shop London. Ont. 420 CJCN Simons Agnew A Co. Toronto. Ont 410 CFDC Sp.rke Co Nanaimo. B. C. 430 CJSC Evening Telegram Toronto, Ont. 430 430 CFHC Henn Birk, de Sons - Calgary, Alta. 440 CKAC L. Prone Puh. Co. Montreal, Quebec, CFLC Chas. Co.' Hunter 851 Adabdde St., London. Ont. 410 CKCD Vancouver Daily Province Vancouver. B. C. 410 CFQC The Electric Shop (Ltd.) Saskatoon, 80.katchewon 400 CKCE Canadian Iodepend. Telepbone Co. Toronto. Ont 450 CFRC Queens University Kingston. Ontario 450 CKCK Leader Puh. Co Regie, Saskatchewan 420 CFUC University of Montreal Montreal. Quebec 400 CKCO Ottawa Radio Msocition Ottawa, Ont. 410 CFXC Westminster Trust Co New Weetmio,ter, B. C. 440 CKCX P. Burns de Co Calgary, Alberts 440 CFYC Victor Wentworth Odium Vancouver. B. C. 400 CKLC Wilkinson Electric Company Calgary. Alberts 400 CRAC Radio Engineers Halifax. Nova Scotia 400 CKOC Wentworth Radio Supply Co. _ Hamilton, Ont 410 CHBC Alherton Puhlishiog Co. Calgary. Alberta 410 CNRA Canadian National Railway. Moncton. N. B. 313 CHCB Marconi Company Toronto.Oat 410 CNRC Canadian National Railway. Calgary. Canada 357 CHCD Canadian Wireless tir Elea Co Quebec. Quebec 410 CNRE Canadian National Railway. Edmonton. Alts 455 CHCE We.tem Canada Radio dup. (Ltd.) Victoria. B. C. 400 CNRN Canadian National Railways Montreal. P. Q. 410 CHCL Vancouver Merchant. Exchange Vancouver. B. C. 440 CNRO Canadian National Railways Ottawa. Ont 430 CHCM Riley & McCormack Calgary. Alberta 415 CNRR Canadian National Railways Regina. Haab. 312 CHCS The Hamilton Spectator Hamilton, Ont. 420 CNRS Canadien National Railways Bokatoon. Bash. 329 CHIC Northern Electrio Co. Toronto. Ont. 356 CNRT Canadian National Railways Toronto, Ont. 357 CHNC Toronto Radio Re.areh Toronto. Ont. 350 CNRV Canadian National Railway. Winnipeg, Man. 384 Cuban Stations PWX Cuban Telephon Co. Hahana 400 2K Alva. Dana Habana 200 2DW Pedro Wan Habana 300 2HS Julio Power Habens 180 2AB Alberto S. de Boatman. Habana 240 201 Oscar Collado Habra. 290 20K Mario Carci. Velez Hehans 360 2WW Amadeo Sams Habana 210 2BY Frederick W. Horton Habana 260 5EV Leopoldo E. Figueroa Colon 360 2CX Frederick W. Barton Habana 320 6KW Frank H. Jones Tuiuuou 340 2EV Westinghouse Elec. Co. Habana 220 611J Frank H: Hone. Tub.. 275 2TW Roberto E. Ramiro. Habana 230 6CX Antonio T. Figueroa Cienfiego. 170 2HC Heraldo de Cuha Habana 275 6DW Eduardo Terry Cienfego. 225 2LC Lui, Casas Hahane 250 6BY Jo,, Cando., Ctenfegoe 300 2KD E. Benches de Fuentes Habana 350 GAZ Valentin Ulliverri Ctenfiega 200 2MN Fau.to Simon Habana 270 tBY Alberto Ravelo Stgo. de Cuba 250 2MG Manuel C. Salsa Hahe 280 IFU Andre. Vinet Sego. de Cub. 225 2JD Raul Para Falo. Habana 150 8DW Pedro C. Ando, Stun de Cuba 275 European Broadcasting Stations British Stations 210 London 365 5NO Neweeatl. 400 51T Birmingham 475 5SC Claogow 420 5WA Cardiff 350 2BD Aberdeen 492 613M Bournemouth 385 6SL Sheffield (relyet tioo) 303 2ZY Manchester 375 'French Stations YN Lyons 740 SAJ Paris 1780 FI. Parie (Eiffel Tower) 2,600 ESP Paris 450 End your Radio Troubles for 30c in Stamps We have laid aside a limited number of back issues of RADIO AGE for your use. Below are listed hookups to be found in these volumes. Select the ones you want and enclose 30c in stamps for each desired. The supply is limited, so enrich your store of radio knowledge by laying in an ample stock of copies NOW! January, 1924 September. 1924 February. 1925 -Tuning Out Interference -Wave Trope- Eliminator, -How Careful Mounting Will Improve Reception. -A Sure Shot Super -Het . Three Circuit Regenerator. - Junior Super- Heterodyne. --One Tuning Control for Hair's Breadth Selectivity. -A -A -Four Pages of Real Blueprints of New Bahy Hetorodyne -A R.I. Low Loss Set. -Pueb -Poll Amplifier. a 3-tuhe Reflea. Circuit. and an Aperiodic Variometer Set -Blueprint. of -Raeohlam -Data Sheets. March. 1924 -An Fight-Tube Super-Heterodyne. March, 1925 -A simple, low loss tuner. October. 1924 -A Permanent Super -Het. -A Tuned Radio Frequency Amplifier. -A 5-Tube R. F. Receiver. --Slane'. Reflex Set. -An Emily Made Super -Het. -How to Wind Low Las Cone. -Two Radio and Two Audio for Clear Tone. Shan Wave Receiver April, 1924 Simple Regenerative Set. -A Efficient Super- Heterodyne (fully illotrsted) -A -Blue Prints of a Two-Tuhe Ultra Audioo and a Re- -An -The Ultrcdyne for Real DX. generative Reflex. -A Teo -Dollar Receiver. -Rea! Blueprinta of a 3 -Tube Neutrodyne and a Midget -Anti-Body C.pcity Hookups. Reflex Set. -Refextn¢ the Three -Circuit Tuner. April, 1925 -Inde. and fast two iatalimenta of Radio Age Data Sheet.. -A 3-Tube Portable Set May, 1924 November, 1924 Voltage from the Socket Portable -"B^ A. C. -Construction of Simple Set. -- Blueprints of a Single Tuhe Loop Set and a Capacity -An Amplifier for the 3- Circuit Tucker -Radio Panels. -Blueprints of s Five -Tube Radio Frequency Receiver of Radio Age Data Feedhack Receiver. -Third Installment Sheets. -A 3-Tuhe Low Lose Regenerator. June, 1924 -Mastering the 3.Circuit Tuner. -Important Factors in Constructing s Super-Heterodyne. May, 1925 -A Universal Amplifier. -A "Quiet" Regenerator. -A Sure Fire Reflex Set. December. 1,924 -A Power Supply Receiver -Adding Radio and Audio to Baby Heterodyne -How to Make a Tube -Tester. -Radio Age Data Sheet.. -Blueprints of a New 8-Tube SoperHeterodyne. -A Unique Super -Het and an Improved Reinerts. -How to Make a Receiver that Minimises Static. -A Sis Tube Portable Receiver Illustrated with Blue- July. 1924 -A Tra aAthintie DX Receiver. prints. -A Portable Tuned Impedance Reflex. -How to Make a Home Made Battery Charger and Loud -Operating Detector Tube by Crid Bias -A Three-Tub. Wlsard Circuit. Speaker st s Small Cat June, 1925 -Data Sheets. -Reducing Static Disturbances Aug.., 1924 January, 1925 -A Seven-Tube Super- Heterodyne -Breaking Into Radio Without Diagram. -A Relieved Neutrodyne -The Double Crid Tube in Ordinary Sets -The English 4- Element Tube. -A Six Tuhe Super -Het Browning-Drake Receive( -Filtered Heterodyne Audio Stages. -An Efficient Portable Set. -Overcoming- Osciletioa m the Roberts Receiver -An Audio Amplifier Without an "A" Batten. -A Tuned Plate Regenerator. -An Idas) Set in Practical Form -Date Sheets. -Malting a Station -Finder. Soldering Secrets RADIO AGE, Inc. 500 N. Dearborn St., Chicago RADIO AGE for July, 1925 The Magazine of the Hour () 1

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Dry Cell Tests Held Stewart-Warner Radio, Freshman Announces New for First Time Model 305 Sales Policy ON May 10, from the Great Lakes The Stewart- Warner Speedometer Cor- The Chas. Freshman Co., Inc. of Naval Training Station, Great Lakes, poration, 1826 Diversey Parkway, Chi- New York has just announced its Ill., the first tests in history were made cago has placed on the market a com- sales policy for the coming season. This the new plete ensemble of matched radio units. concern, manufacturers of the line of from an airplane in flight, using This ensemble consists of the line of Freshman Masterpiece Receiving Sets, 37 meter radio transmitter and receiver Stewart- Warner Radio Instruments; the has decided to eliminate the jobber and operated by dry cells only. Stewart- Warner Reproducer especially distributor in the sale of their products. Heretofore, all airplane radio equip- built to give perfect harmony with Stew- Freshman Masterpiece Sets will be sold ment has had its source of power from a art- \Varner Instruments; Stewart -War- to Authorized Freshman Dealers, care- small generator which was driven through ner Radio Tubes, designed to give beau- fully selected, and granted an exclusive a fan -shaped propeller by the force of tiful tone quality; Batteries, Aerial and franchise in their territory. In towns of wind. In other words, when the engine Ground Equipment. approximately 25,000 and under, one the representative dealer will be appointed and the airplane were out of commission to exclusively handle the line, and in -so was the radio. This new transmitter larger cities, additional dealers will be which is being tested is the first of its granted franchises in proportion to the kind and is one of the transmitters which population and trading area. A staff will be used by the MacMillan Polar Ex- of salesmen is now at work signing up pedition which sails from Boston, Bun- dealers to the Freshman Masterpiece ker Hill Day, June 17, under the auspices Contract, which assures dealers of abso- National Geographic Society. lute protection, as far as stability of prices of the is concerned; also, all business from each The value of this type of equipment can individual dealers' territory will be credi- be immediately realized when it is remem- ted to him. In this way, the appointed bered that the airplanes that are to ac- dealers will be practically direct factory company the MacMillan Expedition representatives of Freshman. manned by U. S. Navy personnel, under The Stewart - Warner Instrument shown The Freshman Company enjoyed re- the command of Commander R. E. Byrd, is Model 305-a five tube set in which markable success with their one model, is incorporated the U. S. Navy Circuit. the original Freshman Masterpiece, dur- U. S. N., will fly over that great unex- There are three tuning controls, mounted lying between Point Barrow ing the last year. The fact that with one plored area on a sloping front panel. The cabinet model, priced at $60.00, over 125,000 and the North Pole, in quest of new land. is finished in dark walnut. sets were sold from July 1924 until Feb- Should a landing be forced, this type of In this instrument, the special Navy ruary 1925, speaks highly for the tre- apparatus, if efficient, will be able to tuned radio frequency circuit has been mendous hold this product has taken communicate after the airplane itself is developed to a high stage of perfection, with the radio public. With the realiza- out of commission, and the flyers will be and the set is especially suited to opera- tion that the trend in radio buying is for from tion by men or women without technical leaning strongly towards furniture effects, able to call help the planes held knowledge in or training. the company has placed a complete line reserve back at the advance base of The Stewart -Warner Reproducer is Axel Heiberg Land. of Freshman Masterpiece Receivers on built by the Stewart - Warner Speedo- the market, ranging in price from a The Zenith Radio Laboratory an- meter Corporation of Chicago, especially Five Tube Radio Frequency Set, in a nounced that the tests made at Great for use with Stewart - Warner Radio In- massive cabinet with sloping panel at Lakes Naval Training Station on 37 struments. This Reproducer is so de- $39.50, up to the Franklin Console, a meters were not satisfactory, as the great- signed and constructed that it covers the dignified piece of furniture of vigorous est distances at which they were heard entire musical scale with full, rich tone lines and fine proportions, made entirely were Newton, Iowa, and Minneapolis. volume and without distortion or scratch- of genuine solid mahogany by the manu- ing noises. The horn is made from fibre facturers of the highest class talking Failure to reach greater distances is by special process and is vulcanized to the fact that the on machine Company in the world at $115. attributed amateurs its outer surface. The core of the horn The Franklin Console is composed of two of the United States were not properly is allowed to remain soft which absolutely separate and distinct units, one of which advised of the time at which these tests prevents the horn from vibrating at is a receiving set with built -in loud would take place. any note. speaker, and the other the console for The Stewart- Warner Reproducer is batteries and accessories -everything be- finished in a dark walnut, leather -like ing concealed. Campaign for Jewett surface, and stands on a metal base which is deep green with gold- bronze high - WILKINSON and T. F. W. Meyer, lighting. This Reproducer harmonizes New "Hercules" Masts EH.General Manager and General Sales perfectly with the walnut cabinet work HULL & Company, 2048 East Manager, respectively, for the Jewett of Stewart -Warner Radio Instruments. W. Radio and Phonograph Co., Pontiac, e 79th St., Cleveland, Ohio, announce Michigan, have returned to the factory a new -series of "Hercules" Aerial Mast. after an extended trip through the East These masts are made in three standard putting the finishing touches on the new come well recommended as to their sta- lengths, 20 ft., 40 ft., and 60 ft., all steel distributors' and dealers' franchise plan bility by a Jewett Distributor, or one of construction. in that territory which has been under the factory district representatives in the way for several months. All masts are made of a special angle field, it is announced. construction that gives great strength The Jewett slogan, "Fair prices, rigidly The dealer will be benefited in this maintained" must be very strictly saine respect by knowing that his cus- and light weight, thus making a rugged adhered to under this new system, be- tomer cannot buy a Jewett product from mast easily erected, at the same time cause every dealer handling Jewett any but another authorized dealer who presenting a pleasing appearance by its products throughout the country must is holding to the standard Jewett prices. graceful lines. (Turn to page 72) 70 RADIO AGE for July, 1925 The Magazine of the Hour CLASSIFIED ADVERTISEMENTS If you have anything to buy or sell, don't overlook the value of RADIO AGE'S classified advertisements. Many such messages have paved the way to independent incomes. The classified advertising rates are but ten cents per word for a single insertion. Liberal discounts are allowed on three, six and twelve -time insertions, of five, fifteen and thirty per cent respectively. Unless placed through an accredited advertising agency, cash should accompany all orders. Name and address must be included at foregoing rates and no advertisement of less than ten words will be accepted: All classified ads for the August issue must be sent in by July 1.

AGENTS WANTED INVENTIONS RADIO CIRCUITS FORDS. 60 miles on o gallon of Ga.. It has been NEW IDEAS WANTED -Well known Radio Manufac- SPECIAL FOR JULY proven such mileage can be made. AIRLOCK gear - advertised and old turer whose product. are nationally The Reinert: Radio Booklet. by Frank D. Pearne, fully teea to in Barra gas mileage; also prevents radiator everywhere want new Radio device to ell. Will pay illustrated. and RADIO AGE, boiling in freezing in winter. Cool., Fuels, outright or royalty for idea or invention which is really for $2.50. Price of Book- Decarbonizes let alone i 5oc. Send check, currency or money order the Ford motor. Splendid territory new and saleable. Address: Mr. R. F. Devine, Room to RADIO AGE, 500 N. Dearborn open. AIRLOCK PRODUCTS, Boz 703G, Willow Street. 1101. 116 Weet 32nd St., New York, N. Y. Street, Chicago. Long Beach, Calif.

RADIO -Join our .des organization and make big MAGAZINES RADIO DEALERS man in every county to sell well DREAMS. A magazine for all who dream. If yo advertised .et..vá parts made by the leading manu- facturers. Widener of Kansas City makes $150.00 health, love and romance, you cannot affordto be with- our cataloglë of reliable weekly. You can do as well or better. Write today Radio Mharndise.r Corporation, outcat this magazine. Three dollars will bring this most Dept. portion, for , county. Wave- fascinating thly publication to your home for D, 1830 Wilson Ave., Chicago,go, 111. land Radio Company, Div. 52, 1027 No. Stat t. Chi- one year. M.R. Smith Publishing Co., 508 N. Dearborn cago. III. St., Chicago, III. RADIO SUPPLIES MANUFACTURER'S AGENT calling on Radio-Elec- b ical Jobbers, Chicago and vicinity, has opening for 3 MANUFACTURING FACILITIES additional lines carrying volume business, we cater Ten per cent discount AN OLD AND WELL ESTABLISHED MANUFACTUR- on all standard radio parts, to large jobbers. Edelstein, 1804 McCormick Bid.. from Gond to transformer. to tube., etc. Send Chicago. ING COMPANY IN THE MIDDLE WEST WITH LARGE for our I price list, with special bargain. WELL EQUIPPED PLANTS AND UNUSUAL FINAN- eliminators, on Static- CIAL RESOURCES, TO ENTER THE RADIO portable loud meeker., Radiotrons, Ger- DESIRING man silver wire, etc. RADIOGRAPH LABORATORIES. AGENTS -WRITE FOR FREE SAMPLES. Sell Madison FIELD WILL CONSIDER THE MANUFACTURE AND 1234 Rosemont Ave., Dept. 4, Chicago, -B -Made" Shirts for large manufacturer direct to SALE OF RADIO SETS OR DEVICES OF OUTSTAND- III, No capital or experience required. Many ING AND UNUSUAL MERIT ON A ROYALTY BASIS. earn $100 weekly and bonus. MADISON MFGRS., 501 ADDRESS BOX 1A, RADIO AGE. Broadway, New York. STAMPS AND COINS PATENTS 90e an hour to advertise and d' 'bute mple. toc - 158 Genuine Foreign Stamps, Mexico War Issue.. Write quick for territory and particulars. FOR SALE: U. S. and Canadian Patent on an Attach- Ven American Products Co., 2130 American Building, Cin- ent for Phonographs; ' the most beautiful inven- la, Salvador and India Service. Guatemala, cinnati, Ohio. tion of the age. Address Chu. F. Smith, Huff, N. Dak. China, etc., only Sc. Finest approval sheets, 50 to 60 per gents Wanted. Big 72-p. List. Free. We BuyCentaur p. Etabliehed 20 Years. Huasman Man wanted for this territory to sell wonderful Stamp Co., Dept. 152, St. Louie, Mo. value m ., Children' hoes direct, sav- PERSONAL ing consumer g ^VeekEl unnecessary. Sam supplied. H permanent LONELY HEARTS: Exchange letter.; make in 'ng today Tanner. Mfg. Co., 1334C. St., Boston, new friend. in our jolly club. Eva Moore, Bot 908, Write Ma... Jacksonville, Florida. Enclose stamp. VOCATIONS Look! You Radio Bugs! Join Radio Correpondene "B" BATTERIES Club. Entirely new. Broaden your acquaintance, Make Big Money. Safe and Lock Expert. Wayne exchange ideas. Membership open to LADY BUGS Strong, 3800 Lan Franco St.. Lo. Angeles, Calif. also. Dime stamp brings pamphlet and Radio Novelty 100 VOLT EDISON TYPE "B" BATTERY, knocked Cards. Radio Rose, Box 662, Cleveland, Ohio. down. Parts and plans -complete, $12.50. Lane Mfg. 2937 W. Lake. Chicago. WANTED PRINTING BATTERIES FOR SALE -Four 24 -volt "Main" Storage WE print Stationery, Booklets, Catalogs. Circulars. WANTED -To complete my 'et RADIO AGE need "B" Batterie, n sed, .hipped and ready to wire Sample.. Commercial Press, Batavia, Ohio. August, September, October, November, 1923, eeee for 838.00. First vorder gets the batterie. Address bound or unbound. Advise price. Lloyd C. Henning. Box B, Radio Age, 500 N. Dearborn St., Chicago, Ill. RADIO Hellbrook, Arizona. A PRACTICAL TUBE RECEIVING SET FOR $10, BUSINESS OPPORTUNITY Postpaid, less phones and tube. Complete with WIRELESS phone, tube and battery, $18.00. J. B. RATHBUN 1067 Winona St., Chicago, Ill. WANT TO MEMORIZE THE WIRELESS CODE? The MR. MANUFACTURER: Would you be interested in Coryden Snyder Code Method. Patented, is quickest. a national advertising campaign to reach more than Send 50c coin, stamps or M. O. to C. G. Snyder, 1423 Standard soderlese radio Jacks- Binding post attach Ave., Chicago, Ill. two million prospective buyers of quality radio products ments. c Elmdale -each week? Do you want to establish agencies in Double uit. One dollar bill. Postpaid new territory and national in in your Clinton Seward, Jr., New Pelts, New York, N. Y. product -at very conservative coat? lt can be done. Three Cosmopolitan Phusiformer, each $5.50, book o WRITERS Let exain our sm without instructions included. F. A. Mall, Triopli, Iowa. d to Radio graph Labo re toss es,í1234 Rosemont Ave., Chicago, Ill., Box 6. 3 FOR SALE -3 Pfanetiehl tuning unita, Cardwell Con NEW WRITERS WANTED-Articles, stories, poems. denser.. 1 Bradleyomater, 2 Bradleyetat. All good Wis. etc. $13,500 just paid to unknown New. Earl Price, Lodi, Entirely nw field. (No. bunk.) NOT A CORRE- CRYSTALS nationally advertised set SPONDENCE COURSE. Moving picture industry and 15 to 25 per cent discount on publishers crying for new original material. YOU dp t E y't g t d. Tell u your needs IMPERIAL RADIO COMPANY, Delaware, Ohio. CAN DO IT. We buy manuscripts for books and mag- TESTED GALENA CRYSTALS, 50e pound bulk. Beta- azines. Send self addressed envelope for list of 100 ken, Geologist, Joplin, Mo. RADIO SETS. Our prices save you money. Liste free subjects. CALIFORNIA STUDIOS, P. O. Box 697, Los The Radio Shoppe, Box 645, East Liverpool, Ohio. Angeles, Calif. Radco Eliminate AT LAST The Static Eliminator. WRITERS Cash in on your knowledge of by HELP WANTED 50 to 90'7, Static. Many aatiafied users. Write fo radio Sioux Falls writing for Radio Magazines and Newspaper Supple- Particulars. Radio Specialties Company, ments. Write up your radio F RADIO SALESMEN and SET BUILDERS-We need South Dakota. hook - p. your knowledge of broadcasting stations and you and you need us. If you are reliable and well artiste. Experienced a thore will co t and improve known in your community, we will appoint you our ipts -make them typically professional and furnish you with standard work.your FREE Criticism and Advisory Service until your Bete and part. at pricer that will enable you manuscript is oldl ALL Magazines and Paper. de- to .ell at handsome profit. Write at once for cata- Maybe an manding fiction and article. dealing with radio. Here log and wales plan. Waveland Radio Co., Div. 53, 1027 is YOUR OPPORTUNITY to peefitl Send for FREE N. State St., Chicago, Ill. booklet. "How You Can Sell Your Manucripta." Willie Arnold and Associate., 210 East Ohio St., Opportunity Chicago. Ill. MEN wanting forest ranger, railway clerk and other government postions, write for free particulars of exam.. Mokane. Dept. B-33, Denver, Colo. awaits You in the Make big money writing Movie Play. Circulars free. Radio Age Classified W. C. Krug, Ashton, Illinois. Classified ad. copy for the August RADIO AGE must be sent in by Section Have you ordered your July 1, 1925. August Radio Age? * Tested and Approved by RADIO AGE $ i RADIO AGE for July, 1925 The Magazine of the Flour 71

WITH better and more THE RADIO AGE TV powerful broadcasting- and with a sensitive, respon- BUYERS' SERVICE sive Telomonic III receiver - What do you want to purchase in the radio line? Let the staff of RADIO AGE save you time and money by seeding in the coupon below. Enter the number of the article you the fascination of radio con- would like to know more about in the spaces provided in the coupon. tinues this year, regardless 1 "A" Batterie. 95 Grid leak holders 186 Rheostats, automatic 2 Aerial protectors 96 Grid, transmitting leek. 187 Rheostats, battery 3 Aerial insulator. 97 Grid leek.. tube 188 Rheostats, dial of the calendar. 4 Aerial. 98 Grid leak., variable 189 Rheo.teb, filament 5 Aerial., loop 99 Grinder., electric 190 Rheostats. potentiometer 6 Amplifier. 100 Ground clamps 191 Rheostat., power Write to Danziger- Jones, 7 Amplifying unite 101 Ground rode 192 Rheostats, vernier 8 Ammeter. 102 Handles, switch 193 Rode, ground Inc., Dept. C, 25 Waverly 9 "B" batteries 103 Head bands 194 Rotors 104 195 wire 10 B ( Rage) Head phones Scrapers. Place, New York, for book- 11 Batterie., dry cell 105 Head seta 196 Screw drivers 12 Batteries, storage 106 Honeycomb coil adapter. 197 Screw. 13 Battery charger. 107 Hook up. 198 Schools. radio let, "The Kit of a Thou- 14 Battery clips 108 Horn., composition 199 Set., receiving-cabinet 15 Battery plate. 109 Horns, fibre 200 Seta, receiving -crystal sand Possibilities." a 16 Batten substitutes 110 Horn., mache 201 Sets, receiving- knock- 17 Bezels Ill Horns, metal down 18 Binding Post. 112 Horns. wooden 202 Sets, receiving - Neutro- 19 Binding moat., insulated 113 Hydro 20 Book. 114 Indicators, polarity 2031Set., receiving-portable 21 Boxe.. battery 115 inductances, C. W. 204 Sets, receiving-radio fre- 22 Boxe., grounding 116 Insulation, molded quency TELOS 23 Bridge., heat.ton. 117 Insulation material Sets, receiving-reflex Broad.tingBroadcasting equipment 118 Insulator., aerial 206 Sets, receiving-regenera- 25 Bushings 119 Insulators, compteition tive 26 Buser 120 Insulators, fibre 207 Sets, receiving -Reinarts 121 Insulators, high 208 Sets, receiving -sectional 27 Cabinets voltage 209 Sets, receiving wawa 28 Cabinets. battery 122 Insulator., cloth -.hort RADIO 210 Sets. receiving--super-re- 29 Cabinets, loud *peskier 123 Insulators, glass 124 Insulator., hard rubber generative 30 Carbons, b.ttary 211 Sets, transmitting 31 Cat whisker. 125 Insulator., porcelain 126 Irons, 212 Slate 32 Code practises moldering 213 Shellac 33 Coil 127 Jacks 128 control 214 Slider. 34 Coils. choke Filament 215 Socket adapters 35 Coils, coupling 129 Jar., battery 216 Sockets. 36 Coil., filter 130 Keys, transmitting 217 Solder 37 Coils, grid 131 Knobs 218 Soldering irons, electric 38 Coil., honeycomb 132 Knock -down panel units 219 Soldering paste 39 Cods. inductance 133 Laboratories. testing 220 Solder flux 40 Coil., Reinert. 134 Lever, switch 221 Solder alts 41 Coil., .tabilixer 135 Lightning ern 222 Solder solution 42 Coils, tuning 136 Loee.coupler. 223 Spaghetti tubing 43 Condenser parts 137 Loud speakers 224 Spark coil. 44 Condenser plates 138 Loud speaker unit. 225 Spark gaps 45 Condensers, antenna coup- 139 Lugs, battery 226 Stampings ling 140 Lug., terminal 227 Stators 46 Condenser., by -pas. 141 Mea.uring instruments 228 Stop point. 47 Cond coupling 142 Megohmeten 229 Switch arms 48 Condensers, filter 143 Meters, A. C. 230 Switch 1 49 Condenser., fixed (paper, 144 Meters, D. C. 231 Switch points grid, or phone) 145 Mica 232 Switch stops 50 Condenser., variable grid 146 Mica sheets 233 Switches, aerial 51 Condenser., variable mica 147 Milliam 234 Switches, battery 52 Condenser., vernier 148 Mineral. 235 Switches, filament 53 Contact points 149 Molded insulation 236 Switches, ground 54 Contact., switch 150 Molybdenum 237 Famous Truly Portable 55 Cord tip. 151 Mountings, coil 38 Switches. p neltsnea The 56 Cord.. for head seta 152 Mounting., red 239 Switches, single and dou- 57 leak ble throw TELMACO Pai Receiver 58 Coupler., molded 153 Mountings. end 240 Tone ¡what 59 Couplers. vario 154 Mounting., grid leak 241 Towers, aerial Four Tubes Do the Work of Seven 60 Crystal alloy 155 Mounting., honeycomb 242 Transformers, audio free The peer of ppoortables 1n size, weight, ease of Caning, 61 Crystal holder. suene, selectivity, dietsare, volume, workmanship and ante. 62 Cry.t.l, rough 256 Mcoilo`n ing, inductance 243 Transformers, filament Aerial. loud and batteries self contained. 63 Crystals, mineral 244 Transformers, modulation speaker 64 synthetic Complete with tubes and batterie., Cry.tal, 157 Nameplates 245 Transformers, power Receiver only . $125.00 65 Crystals, unmounted 158 Neutrodyne set part. 246 Transformers, push -pull 1143.500. 66 Crystals, mounted 159 Nuts 247 Transformers. radio fre- P -1 Kit Saves You Money ! 67 De.k., radio 260 Ohmeter. quency P -1 Receiver In kit form has 68 Our offer of the Telmaro Detector units 161 Oscillator. 248 Transformer., variable m.! wit. use..,.. t.. s...fe.e. I viii' all 69 Detector., crystal 162 Panel cutting and drilling 249 Trammitteee part., as built by us including case, drilled and en- 70 Detectors. rued crystal 163 Panel., drilled and un- 250 Tube., v m -pan t graved panel, and illustrated m.traetions. $80.00 71 Dial, 251 adjusters drilled Tubes, vacuum -two le- Complete kit . . . . 72 Dial., composition 164 Panel., fibre t Ask yoordealerernwrite m. escriptive folder free. 73 Dials, hard rubber 165 Panel., hard rubber 252 Tubes, vacuum -three ele- 74 Dials, rheostat 166 Parts ment 'Radio 75 Dials, metal 167 Paste, soldering 253 Tuners 76 Dials, vernier 268 Patent attorneys 254 Variocouplers, hard rubber 77 Dials with knob. 169 Phone connector., multi- 255 Variocoupler., molded TelephoneMaintenanceCo. 78 Die. ple 256 V.riocouplee, wooden 20 So. Wells St. Dept. C Chicago,111. 79 Drill., electric honograph adapter. 257 Variometer hard rubber 80 Dry cells 171 Plates, cond 258 Variometeee, wmolded 81 Earth !sounds 172 Plugs, coil 259 Variometers, wooden 82 Electrolyte 173 Plugs, telephone 260 Vemih, insulating 83 Enamel.. betters 174 Pointer., dial and knob 261 Voltmeters polity radio exchairely ,d Established 1918 84 Enamels. metal 175 Pole., aerial 262 Washers 85 End stop 176 Potentio 263 Wave m 86 Eyelet. 177 Punching machine. 264 Wave traps 87 Experimental work 178 Reinert. set parts 265 Wire. aerial 88 Fibre sheet, vulcanized 179 Regenerative set parta 266 Wire, braided end stranded 89 Filter reactor. 180 Receiver ups 267 Wire, copper 90 Fixture. 181 Rectifier., battery 268 Wire, insulated 91 Fuse cut outs 182 R..ietance leak 269 Wire, Litz CORRECTION 92 Fuse.. tube 183 Ren.tence units 270 Wire, magnet 93 frequency 184 Rheostat base. 271 Wire, platinum Our new address is 116-118 So. Wells Gride erar.,high choppers, rotary 185 Rheostat .trip. 272 Wire, tungsten Street, Chicago. Dealers will please - - - - note this change when writing for a r------RADIO AGE BUYERS' SERVICE, -- 500 N. Dearborn- St., Chicago, Ill. copy of our "Salespeaker." HUDSON- ROSS -1165. Wells St. Please see that I am supplied with buying specifications and prices on the articles numbered herewith: Chicago

I I I I I I I I I I I I I I I I am a- O Dealer fl Jobber Mtgra.' Rep. Manufaetnrar BOOK Firm [It identified with Radio industry] FREE FtWrite for ótl page Handy-Book en rnnelr4, or B.de by eminent ,.do ..uan,r. rsemlu baob up m o,ber.un.bud.m. srnd am,,.mwte.v.,em,mq.nd onn.re. Dietrene Ine+Dept AS 71 Certlandt SL N.Y. C.

The August number will be known as Address - ...- ..._.._ --...- --- "A ROUND -UP OF RADIO," and, a City State among other features, will contain ------, 62 -page blueprint section. * Tested and Approved by RADIO AGE 72 RADIO AGE for July, 1925 The Magazine of the Hour

1 Going Horatio Alger o One Better i 0 , 0 (Continued from page 62) o With the Manufacturers 0 o (Continued from page 69) O tion finally obtained in the tube labora- O tories of the Westinghouse Lamp Com- t a pany. This was before the public ever saw even the old UV200 and UV201 tubes Loop Fall Radio Season -when 199's were but a dream, and fila- Set Preferable To Now On, ment currents of one to two amperes Antenna, Says Priess Is Claim were tolerated for receiving tubes. ARADIO statistican recently con- THE FALL radio season will corn - From this Mr. Silver graduated to a ducted a research among radio mer- mence in June, as far as manufacturers large wholsesale house where his alert chants and learned that approximately of radio apparatus are concerned, declared mind quickly grasped the fundamentals 53% of persons who enter stores to buy E. Alden, general sales manager for the of what was at that time the radio busi- radio receivers indicate a preference for Shaw Insulator Co., of Irvington- Newark, ness of the booming early twenties. Then loop sets. N. J. Mr. Alden based his conclusions another change, this time to a concern William H. Priess, a well known engi- on a trade survey which he recently which then consisted of but the chief and neer and president of the Priess Radio completed from coast to coast, during himself, but which soon grew to deserve Corporation, whose work for a number which he learned from manufacturers the title of "New York's formost radio of years has been exclusively identified in every section that the demand for shop," where he served as assistant to a with loop reception, is naturally one of radio apparatus by the buying public has prominent engineer, and contributed its strongest proponents. The percentage caused the manufacturers to advance toward the design of what proved to be of favor toward the loop which the statis- their time for production on new equip- the first popular super -heterodyne re- tician's research showed did not surprise ment to the month of June. ceiver over offered for broadcast recep- him. "Strange as it may seem," declared tion. Next, a trip to Paris, and medita- "A loop set has a number of Advant- Mr. Alden, "the new date will have a tion coupled with the salt sea air fired ages," he said. "The set can be installed favorable reaction on the trade and his never latent ambition. quickly and moved to various locations will be the means of allowing the manu- without entailing the services of a steeple- facturers to more properly gauge the "A New Era" jack. It is the ideal set to take in the buying demand throughout the country. At the present time it is apparent that THUS, in early summer car on a day's outing or to the country the of 1924, on a week -end. It can be installed in there will be many new advancements Chicago saw the retail store of silver - places where the connection of 'Antennae made in set and parts construction dur- Marshall, Inc., with the erstwhile vigi- ing the coming season. lante followed is forbidden or impossible. as its head. Events each "In addition to its inherent mobility, Notable among these will be a greater other with a rapidity characteristic of the standard of development, together with radio industry, and by fall the young the loop receiver has the remarkable property of directional reception and refinements in general construction cal- concern marketed a line of products culated to make radio equipment have designed by Mr. Silver which met with freedom from certain types of 'static' a disturbance. Two interfering signals greater appeal to the public, and, inci- instant favor. The old story was re- dentally, be the means of giving radia production could not catch up of approximately the same strength peated- and wavelength but coming from differ-. its rightful place in the ranks of the with demand, and winter saw Silver and worlds greatest medium for good his partner working shoulder to shoulder ent directions cannot be separated by enter- the ordinary antenna set. With the tainment and instruction. with the ever increasing force of the new "The entry of many new substan- growing concern. By spring the partners loop receiver, however, this separation and can be made complete by turning the tial concerns into radio fields during the saw the rewards of their labors in the coming season will ever -extending businessthey had built up. loop so that one of the stations disappears, be one of the greatest and tuning in sharply on the other means of stabilizing the industry. From Mr. Silver is probably best known to present indications there will be a variety the radio public as the designer of many station. "With the right set and the right loop, of manufacturers sound financially, and pieces of radio equipment and a number with progressive ideas in manufacturing of receiving circuits of exceptional merit, satisfaction over the antenna set is certain." in mind, which will have a stimulating several of which have been described in tone for the entire industry and be the this publication. In addition to his com- means of placing it on a more substantial bination of business and engineering Gain in Squeals Very Small, basis than in ability, his capacity for describing radio ever before its history. apparatus involving complex circuits in Says Expert "Parts will be again popular factors a manner so simple that the average lay- HE GAIN in radio reception by mak- during the coming season," declared Mr. man can easily comprehend, is one seldom ing the single circuit receiving set oscil- Alden. "One of the leading dealers in met with. His articles have appeared in late and thus set up a discordant howl in this country with whom I talked during practically every important radio publi- all the other receiving sets in the neigh - my recent trip declared that the parts cation and newspaper in this country.. bothood, is so very small that it does not end of his business has been holding up as Desiring to see the genus homo in his begin to compensate for the added an- good during the early Spring season as it lair, we called upon Mr. Silver one day. noyance, L. W. Chubb, Manager of the did during past The staff, Westinghouse Elec- the Winter. trend We were ushered into the presence of a radio engineer during the coming season will be in the mere stripling seated at an unimposing tric & Manufacturing Company, points desk, who, when he arose, proved to be out. direction of better merchandise, appeal- over six feet. In the course of our getting The gain in reception through setting ing prices, and merchandise, which is several words in edgewise, telegrams flew up oscillation, when receiving from a one calculated to bring radio to higher levels out, apparently important matters were kilowatt station, actually is a small frac- in the public's buying and mind, and settled, and ideas evolved and rushed to tion of one per cent. The electrical engi- consistent with the great appeal that the laboratory for immediate experiment. neers have determined an infinitesimal radio has heretofore generally enjoyed." From a shelf he selected one of a gain in comparison with the loss caused number of receivers, handed it to an in the sets of peoples within a radius assistant, and in an instant a volume of of two or three miles who are listening deny them the pleasure of their present sound poured out of the loud speaker that in on the station. frequent visits with relatives and friends was amazing, yet with perfect quality. The remedy for the interference caused in distant locations, would slow down "What is it?" we asked. After a by single circuit radio sets is not in pro - business and in numerous ways would moment the answer came, briefly: "Just hibiting the sale of these sets, as advocat- be a drawback. The ideal remedy for a six -tube super- heterodyne. I call it ed in some quarters, but in proper use the losses caused by use of the automobile the 'Super-Autodyne,' because it uses an of the sets, according to Mr. Chubb. lies in bringing the individual to so drive autodyne frequency changer." "The situation is somewhat analogous his machine that the losses will be elimi- "Autodyne frequency changers" not to use of the automobile," Mr. Chubb nated and the gains conserved. being in our vocabulary, we left after a says. "On occasion the automobile has "So it is with the single circuit radio few minutes conversation, impressed destroyed lives of passengers and pedes- receiving set. This type of set repre- primarily with the sudden transition of trians, or otherwise caused great suffering sents the most for the money that the the man from the capacity of executive and distress. To stop this, we might individual can buy. This simple device to engineer and back again, and the outlaw the use of the automobile, but using one or two small tubes and inexpen- sincerity, certainty and energy that this would deprive millions of people of sive dry cell batteries, gets strong signals seemed to pour forth with every word he the enjoyment of a perfectly legitimate from the broadcasting station and is uttered, either as president or engineer. pastime, that of automobile riding; would capable of getting great distances." l l0 000 000©0 0o oroo

IT Is The

r on your 0 0 CI Summer i 0 List? i a IF YOU intend to take a trip 0 this Summer, you're surely i going to keep in touch with Radio, either by bringing a set along or building one during the dull afternoons, from parts you ó can take with you. AND how are you going to build this set or study up on radio for the big season that A Big Blueprint Section 0 is bound to come in September? 0 The answer is simple. All you have to do is to invest for your Dollar! ONE DOLLAR in a RADIO AGE ANNUAL for 1925, the How many blueprints could you buy for a hookup book, dollar if you started out to buy them, one O world's most complete and authoritative i and take it with you, whether you go to Eagle River or the by one/ Very few, you'll admit. Yet in the River of Doubt. RADIO AGE ANNUAL for 1925 you'll find sixteen full pages of blueprints in actual Let the ANNUAL for 1925 be your Radio Companion this color, explaining concisely every important i Summer! It will tell you whatever you want to know in simple and complicated hookup developed the radio line -from troubleshooting of the little faults during the past year! The 32 -page blueprint that may develop far from home -to the actual construction section of the ANNUAL is worth many of simple portable sets or elaborate multi- tubers. times the purchase price of the book alone. Order the ANNUAL NOW -for the limited GET THE ANNUAL NOW -and THEN go on your vacation! first edition is rapidly being bought up by It will be your radio safeguard! eager radio enthusiasts. 8 i $1.00 a RADIO AGE ANNUAL $1.00 a 0 Copy FOR 1925 Copy 0 Some of the Features 8 0 a How to read and understand hookups. back receivers, neutrodynes, reflex hookups, Baby Het No. 2, a How to understand radio phenomena. Wonder Super -Het, and others. Building your first simple set. How to get rid of interference. How to select the right receiver. How to make an amplifying unit. Substituting a tube for a crystal -building the first tube set. How to recognize and deal with every kind of tube trouble. How to amplify any kind of set. Another super-heterodyne for the super experimenters. i Making a reflex set. Hints on tracing in Building your first Reinartz set. troubles super -heterodyne circuits. The renowned Baby Heterodyne No. 1. A three-tube long distance regenerator. Adding audio and radio stages to the Baby Het. A 3 -tube set that easily receives KGO on the loud speaker How to a battery charger. from Ohio. make Improving ever How to make a loud speaker. the popular Reinartz. 0 RADIO AGE ANNUAL BLUEPRINT SECTION with such AND MANY OTHER UP-TO- THE -MINUTE HOOKUPS AND popular hookups as the aperiodic variometer, loop sets, feed- ARTICLES.

RADIO AGE ANNUAL COUPON i RADIO AGE, INC., 500 North Dearborn St., Chicago, III. Gentlemen: I want to be one of the first to get the RADIO AGE ANNUAL FOR 1925. Enclosed find $1.00 If 0 I am not satisfied with the ANNUAL I will return it within five days and you will refund my dollar. Name------_------Address.____ 0 - City ...... _..- _- ._--- .- __-- ___ -St ate_.._.-.-...-..._ _...... _..._._.....- ....._ _ fl 7 -25 o looaoa®00000aro j a9ts

DISTJ CEE - -LONvTRADE MA RK REG. While MacMillan Charts the Arctic Zenith Broadcasts to the World! Between Alaska and the North Pole stretches great a risk, both in capital and human life, only an unexplored area one million square miles in the best in radio equipment can possibly com- extent -the last remaining "blind spot" on the face mand a place. Once more, therefore, MacMillan of the globe. chooses ZENITH exclusively, both for his ships Over this vast area will fly, this summer, two and for the two great planes flying across un- great planes of the amphibian type, piloted by U.S. charted seas of ice. Navy air pilots and equipped with the most highly Thus, while the world awaits reports from this perfected scientific apparatus obtainable by the greatest expedition of modern times, it is worth United States Government. This entire expe- remembering that the only way these reports can dition, which has rightly been described as the possibly be transmitted is by Zenith radio. greatest expedition of modern times, is under the Never in all your life, it is safe to say, will you direction of Commander Donald B. require of a radio set such outstand- MacMillan. ing performance as MacMillan re- The purpose of the expedition is quires of ZENITH in the Arctic. the study and photographic chart- But can you imagine greater satisfac- ing of this unknown area -and- tion than to know that your receiving new tests in radio transmission and set can deliver such performance, reception of unparalleled importance. any time it's called upon to do so? The section to be explored has never Call this evening at your nearest been heard from by radio. Commu- ZENITH dealer, and ask him for a nication will of necessity be day- demonstration. light communication, for in this Super- area the days are six months long. Zenith IX Zenith Radio Corporation On an expedition representing so 310 S. Michigan Ave., Chicago, Ill. Costs More But Does More

THE complete Zenith line ranges SUPER -ZENITH VII -Six tubes -2 stages tuned reproduce both high and low pitch tones otherwise frequency amplification 3 audio impossible with single -unit speakers. + in price from $100 to $475. -detector and stages Price (exclusive frequency amplification. Installed in a beautifully of tubes and batteries) $475 With either Zenith 3R or Zenith finished cabinet of solid mahogany -44á inches long, All Prices F. O. B. Factory 4R, satisfactory reception over dis- 161( inches wide, 10i1 inches high. Compartments at tances of 2,000 to 3,000 miles is either end for dry batteries. Price readily accomplished, using any (exclusive of tubes and batteries)..._. -_..$240 ordinary loud speaker. Models Zenith Radio Corpoi ation 3R and 4R licensed under Arm- SUPER-ZENITH VIII -Same as Vll except -con- Dept. C -7 strong U. S. Patent No. 1,113,149. sole type. Price (exclusive of tubes and 310 S. Michigan Avenue, Chi cago, Illinois They are NON -RADIATING. batteries) - ... -_ -- -_$260 Gentlemen: Please send me illustrated 1 iterature about Zenith 4R - $100 SUPER -ZENITH IX- Console model with addi- Zenith Radio. Zenith 3R - $175 tional compartments containing built -in Zenith loud is a six speaker and generous storage battery space. The new Super -Zenith -tube Price (exclusive of tubes and batter- Name set with a new, unique, and really Ç circuit, con- es) $355 different patented Address trolled exclusively by the Zenith SUPER-ZENITH X- Contains built-in, patented, Radio Corporation. It is NOT Super -Zenith Duo -Loud Speakers (harmonically regenerative synchronized twin speakers and horns), designed to

* Tested and Approved by RADIO AGE