Everyday Mechanic s

C u r -r e n t Sci e nee ORK either full or part time and 7hRR!.!!lg.12.1J, Wmake big money. Tremendousadve.... tising campaign helps you sell. Regard­ pOWERFUL seven-tube radio at factory price. Test it with- le ss of whether you have ever .old before, out spending a cent. We claim the Randolph Seven will be sure to get our proposition, The Ran­ out-perform any radio and we want you to satisfy yourself dolph sells on first demonstration. Men that It will. To do this, we will send you this powerful radio to try for 30 a nd women botb can make money this days. Test it for distance, clearness, ease of operation, tone and every easy way, Get your demonstration set other way you can. Unless it more than sat isfies you. return it to us. Ever,. for t h irty days FREE TRIAL Randolpb set muU make IOod before Ie il lold. Bat..~ery ALL ELECTRIC OPERATION The Randolph Seven is sold lor use 'With batteries or connected lor operadon direct to electric light socket-aooolutely batteryJess-no chargers or bat­ teries-just plug in socket and tune In. 100% efficient either way. Its construction and performance have been tested and approved by leading radio engineers abd autborities and leading radio and scientific publicationi'!. Single Control-Dluminated Drum One drum dial operated by one simple vernier control tunes in all stations with easy selec­ tivity to tremendous volume. No overlapping of stations. Illuminated drum penn its opera­ tion in the dark. Volume control for finer volume modulation. This is a 7-tube tuned radio frequency receiver with power tranaformers and power amplification. Space wound solenoid coils Full and completely shielded. A real receiver of the highest quality, Tremendous distance, wonderful tone quality. simple to opel.'8.te. The Randolph cabinets are in themselves beautiful pieces of fumiture made of carefully selected solid burl walnut. Bas-relief bronze es­ cutcheon plates are mounted on the dial panel. In design and appearance it is a cabinet worthy of the high-quality radio it contains. Solid walnut beauti­ fully sha[l€d !!Urrounds the soft verdi-green panel. Nothing has been spared tomake theRandolphSeven the leading radio receiver. We are so sure that it will surpass even your best hopes that we know how safe we are in making the 30 day lree trial oller. Read What Owners Say I have logged more than 50 stations from coast to coast.- Lloyd Davenport, Littlefield. Texas. ) have logged 52 stationB from Cuba to Seattle-the set is a world beater.-J. Tampkinson. Detroit. Mich. Your set is a revelation-has all others tied to the poat for distance and selectivity.-Waldo Powers. Vergennes. Vermont. On strength of its performance sold two more sets this week. T. Sc:anlow, Orlando. Florida. Beautiful Ampliphonic Console Set ~llIln~!::, l'aa::oS~:::t~ ~~~~b4 Made of the finest carefully selected solid walnut. Chicago, Illinois. Two-tone shaded finish. Has built-in cone loud· speaker that compares with any on the marketand Send me full particulars abou t the RANDOLPH Six a nd accurately reproduces high and low notes. Send for Seven ·Tube Table· and Console Sets with details of your thefoldertodaythatshowsthis beautiful console in 30 Day FREE Trial Offer. full colors and gives complete details. Compare. with most table seq in price. F or batter), Name ...... or ali-electric operation ready to p lug in and tUlle In. Write for complete descriptions, Randolph Radio Corporation Address ...... _ ...... ·· .....- ...... City ...... State...... _ ..... ,.. •••• _ 711 W. Lake St. Dept. 124. Chicago,ID. Mark here ( ) if interested in Agent's proposition. RADIO AGE for October, 1927

wh'iLay t=C~d ~~ ~':r. ~:k to Mtrl!! carfar~, I uud to (laze enf!wwly at the .hining C(J1'. gliding by lrW!', the pr06pt!J'OIU 11U!R and flIOlJU!R within. LttUe did I think thai. indde 01 G ye_. I. too, .h.ould hofle my own car, a ti«enl ban" account, the flood thing. of li.fe that make it lOOrth liDing.

I Thought Success Was For Others Believe It Or Not, Just Twelve Months Ago I Was Next Thing To "Down-and-Out"

ODAY I'm eole owner of the f88te8t­ voice. ,jBet he hasn't ~ot a dollar in openinp: book. I'd been wailing "I never Tgrowing Radio store in town. And those pockets." "Oh, it s just 'Useless' had a chancer" I'm on good terms with my banker, Anderson/' said another. UHe'sgota wish. too-not like the old days only 8 year bone where his back-bone ought to be." NOW I'm making real money. I drive a ago, when often I didn't have one dollar As I thought over the words in dee, to knock against another in my pocket. humiliation, a sudden thought made me I do:~o:~~~t~ng~:~~~:lulIWy~'t~b~i i·~~ My wife and I live in the snuggest little catch my breath. Why had Mary been made a substantial down payment, and borne you ever saw, right in one of the so di88atisfied with my answer that "I I'm not straining myself any to meet the best neighborhoods. And to think that hadn't had a chance~" Did Mary secretly installments. a year ago I used to dodge the landlady think that too? And after all, wasn't it when she came to collect the rent for the true, that I had a "wish-bone" where my little bedroom I called "home". ba~-e;ff'~: Ie:a~:P' BJt~Uthl:l it°~~:r~ back-bone ought to be~ Wasn't that why It all seems like a dream now, as I look I never had a ~jchance" to get ahead~ It :~~u y~u m~~~~~~: wO~ke th~~u YO~al~~~~ back over the past twelve short months, was true, only too true-and it had taken Woufd you sign a contract to stay where and think bow discouraged I was then, tbis cruel blow to my selt-esteem to make you are now for the next ten years, mak­ at the "end of a blind alley." I thought me see it. ing the same money~ If not, you'd bet­ I never had had a good chance in my life, 'With a new determination I thumbed ter be doing something about it instead and I thought I never would have one. of drifting. But it was waking up that I needed, and !n here's the story of how I got it. !~:rlhi~:s f~! ~d~~~~i:e~~n~h:h!:bl~ This new Radio game is a live-wire seen many times but passed up without WAS a clerk, working at the usual thinking, an advertisement telling of big ~rl~~f2~0~~ff:r~~~ii~:~ J?Radi~~i:fa~~l r miserable salary such jobs pay. Some­ opportunities for trained men to succeed how I'd never found any way to get into in the great new Radio field. With the ti~~~FR::i~oI~~~riut~~fd!~i aZt~~r~:~ aline where I could make good money. advertisement was a coupon offering a Radio home-study school in the world- Other fellows seemed to find opportu­ big free book full of information. I sent nities. But-much as I wanted the good the coupon in. and in a few days received h~~!r:!nk~~! iR~d1~f~!:!I~ i~o YZ~~d~~ things that go with success and a decent increase your earnings in the Radio field. income-all the really well-paid vacanciel ~0~~::'~~~lli~:4;Na:bo~~ottl~~;t~~t!~~7e~ Take another tip-No matter what in the Radio field and how a man can pre-­ I ever heard of seemed to be out of m~ tour plans are, no matter how much or line, to call for some kind of knowledge J pare quickly and easily at home to take didn't have. advantage of these opportunities. I read th:c~~t:n b~io!~~d 1~~k~1!frat~e~~k And I wanted to get married. A fine the book carefully, and when I finished it I made my decision. over. 1t is filled with interesting facts, situation, wasn't it~ Mary would have figures, and photos, and the information agreed to try it-but it wouldn't have it will give you is worth a few minutes of been fair to her. WHAT'S happened in the twelve anybody's time. You will place yourself Mary had told me, "You can't get months since that day, as I've al- under no obligation-the book is free, and ahead where you are. Why don't you ready told you, seems almost like a dream is gladly sent to anyone who wants to get into another line of work, somewhere to me now. For ten of those twelve months, know about Radio. Just address J. E. that you can advance~" I''De had a Radio business of my own! At Smith, President, National Radio Insti­ UThat's fine, :Mary," I replied, "but first, of course, I started it as a little pro­ tute, Dept. M-91, Wasbingtoo, D. C. what line~ I've always got my eyes open position on the side, under the guidance of for a better job, but I never seem to beaf the National Radio Institute, the outfit r------.., of a really good job that I can handle." that gave me my Radio training. It wasn't I J. E. SDJ..1th, Prellident, Mary didn't seem to be satisfied with the }~nfh~eAo:di~ ii:: fh!~iigq:it ~;hm~as~~ I ~:!\~M~~~~op!br:s\';,=: D. C. answer but I didn't know what else to little clerical job, and devoted my full I Dear Mr. Smith: tell her. . R d· b . I Pleasesendmeyour64-pagoCreebook,printed It was on the way home that night that I time to my a 10 usmess. I in two colors, giving all information about tb~ $/°hPped[ of! in the neighborhood drug store, .lwS.ioyc.e utbod.te.timtbee Iw'v.etcgoou"1 'giugb,.dt.oooceuoPr' I =;ma:r e!:iJ:~:ihO:ed t!0~! a~at!=: were overheard a scrap of COnfJerllation ~bf lOUD' d',b"m.o• Olbl~dti~o'.tan,.d.dthlo'b· ."equ.o~\£~acesen ":~ r::~~':I/~ltffef::'!i~;i;:/:r;rl; ~;t liiei :ie~riT::Y a!ot~d ~:!~o:~e~:!Oj~~S~; I call on me. ~.. ~~... ww With a hot Hush of shame I turned and much help, too, if I had wanted to follow I left the store, and walked rapidly home. some other line of Radio besides building I Nam"-______. So that was what my neighbors-the my own retail business-such as hroad- I people who k.new me best-really thought casting, manufacturing, experimenting, I Addreu ______... _. of mef sea operating, or anyone of the score of I :·Barg~.,in counter sheik-Io?k. ?OW that lines the¥. prepare you for. And to think. I TO...-D...-.-______.. __ SUIt fits, one fellow had said III a low that until that day I sent for their eye- '" ______J PleMe Mention Radio Age When Writing to Advertisers. 2 RADIO AGE for October, 1927

Ever\Jda\J Mechanics Chats E HAVE developed in the WRadio Age laboratory a seven tube super receiver that is remarkable for the simplicity of its construction. Notwithstanding the Established March, 1922 ease with which its parts may be as­ sembled it produces results in tone Volum67 October, 1927 Number 2 quality, selectivity and power that one would look for i" the best eight tube super. CONTENTS But the most important fact about FOR OCTOBER ISSUE the new super is that it incorporates a new piece of equipment that has never before been called to the atten­ Current Radio Wisdom in Tabloids ...... 4 tion of radio fans. This feature alone would be enough to command the in­ Bringing the Old Super Up To Date ...... terest of fans all over the country. Weare going to tell all about the re­ The Thompson Super Seven ...... 7 ceiver in our November issue and with the editorial text we are going 1928 Infradyne Presents Attractive New Features ...... 12 to print drawings, photographs and ·blueprints. We suspect that this set The New Vvorld's Record Super Ten ...... 14 will be the one many fans will de­ cide to build as a foundation for their Blueprints on Super Ten...... 18-19 winter radio adventures. Frankly, we hope thousands will build it. Amateur Radio ...... 20 * * * Everyday Mechanics ...... 21 ADIO AGE has always been a R magazine for the man who Current Science ...... · ...... 27 builds his own. We pioneered in the hook-up field five years and more ago Independents Start Battle ...... 34 and we have been printing hook-ups in blueprints for so long that the av­ Corrected List of Broadcast Stations ...... 38 erage fan calls us the "blueprint mag­ azine." The thought gives us some Radio Age is Dublished monthly by RADIO AGE Inc. pleasure in view of the fact that the Member-: Audit Bureau of Circulation•. set-makers are coming into their own Publication Office, Mount Morris, m. 404 North WeBley Ave. Address all communications to RADIO AGE, Inc. again. Manufacturers who for a Executive, Editorial and Advertising Offices time devoted most of their attention 500 N. Dearborn Street, Chicago, Ill. to making complete sets, have re­ FREDERICK A. SMITH, Editor turned to the business of making M. B. SMITH, Busine88 Manager parts. New manufacturers with solid Advertising Ma't1.ager resources and extensive experience in HARRY A. ACKERBURG 500 N. Dearborn St.• Chicaoo. m. manufacturing have entered the parts Eastern Representative field. Home experimenters are on HEVEY & DURKEE, 15 West 44th St., New York, N. Y. the increase. \Ve will have construc­ Pacific Coast Representative tional articles in ample volume for CONGER & MOODY, Sharon Bldg., San Francisco, Calif. CONGER & MOODY, Higgins Bldg., Los Angeles, Calif. them in each forthcoming issue. Final AdvertisIng forms close on the 20th of the 2nd month preceding date of issue Vol. 7. No.2. Issued monthly. SubscriPtion price $2.50 a year. Octo. bel', 1927. Entered a s second-class matter at post offi ce at Mount Morris, illinois, nnder the Act of March 8, 1879. Editor of RADIO AGE. Copyright, 1927, by RADIO AGE, Inc. Restored Encbantment

This i3 the Eveready Layerbilt that gi'VelJ you Battery Power for the longest tilne and the leo.st lllOney.

THERE is no doubt of it­ radio is belter with Battery Power. And never was radio so worthy of the perfection of reception that batteries, and batteries alone, make possible. Today more than ever you need what batteries give-pure DC, Di­ rect Current, electricity that flows smoothly, quietly, noiselessly. When such is the current that operates your receiver, you are unconscious of its mechanism, for YOU do not hear it hununing, buzzing, crackling. The enchantment of the program is complete. Batteries themselves have im­ Radio is better with Battery Power proved, as has radio. Today they are so perfect, and so long-lasting, At a turn of the dial a radio program comes to you. It is clear. as to l:e equal to the demands of the It It mooern receiver. Power your set is true. is natural. You thank the powers of nature that have with the Eveready Layerbilt "B" Bat. once more brought quiet to the distant reaches of the radio.swept tery No. 486. This is the battery air. You are grateful to the broadcasters whose programs were whose unique, exclusive construction never so enjoyable, 80 enchanting. You call down blessings upon makes it last longer than any other the authority that has allotted to each station its proper place. And, Eveready. Could more he said? In most homes a set of Layerhilts lasts if you are radio.wise, you will he thankful that you hought a new an entire season. This is the battery set of "B" batteries to make the most out of radio's newest and that hri!J,gs you Battery Power with most ~lorious season. all its advantages, conferring benefits and enjoyments tbat are really tre­ NATIONAL CARBON CO., INC. [I[!!J New York-San Francisco mendous when compared with the Unit 0/ Union Carbide and Carbon Corporation small cost and effort involved in re... placements at long intervals. For the hest in radio, use the Eveready Tuesday night is Eveready Hour Night-9 P. M., Eastern Standard Time Layerbilt. WEAF-New York WGR-Buffalo WGN-Chicago WRC-Washington WJAR-Providence WCAE-Pittsburgh WOC-Davenport WGY - Schenectady WEEI - Boston WHAS-Loui:lViUe WDAF-Kan.. a.5 City :i!~~~::~aa~~ wcco { ~!~np"::roli8 WSB-Atlanta WFI-Phlladelphia WWJ-Detroit KSD-St. LouiIJ WSM-Na:Jhville WMC-IlIemph13 ~EREADY Pacific Coast 8tations-9 P. 1\1., Pacific Standard Time Kpo-KCo-San Francuco KFI-Los Angeles Radio Batteries KFOA-KOMo-Seattle KGW-Portland HaVfJ you heard the new J'ictor record by the Eveready Hour Group-orchestra and • ••iii·. =':':·':·~~:-they last longer lJin8ers-in Jl.fiddleton·s Down South Overture and Dvorak's Coin' Home? 4 RADIO AGE for October, 1927

Current Radio "Wisdom in TabloidC' !!!

Extract from a speech by o. H. in question. Once started along that line We will not be too harsh with our Caldwell, member Federal Radio Com­ it would not be long before all available Radio Commission for their's is a tre­ mission, at meeting of manufacturers frequencies would be taken up and the free mendous task, but we would ask that they in Chicago. development of radio rendered impossible. come to this part of the country and make HERE, as I see it, is the far bigger Of course the framers of the Constitution tests. What would be perfection in New T job that faces you, the radio manu­ could have in mind no such problem, but York would be chaos here. facturers, jobbers and dealers of the the attempt is being made to cover it with country,-the job of putting adequate radio the clause permitting regulation of inter­ state commerce. From an article by E. E. Free, Ph. service into everyone of America's 22,000,- • • * D. special contributor to Radio Age 000 homes! For what will it avail the on Scientific subjects: American public to have good broadcast From an interview with David Sar­ programs and clear undisturbed reception ADIO echoes that probably travel noff, Vice-President and General Man~ entirely around the earth before if only a small fraction of our citizens ager, Radio Corporation of America. R actually have radio sets in their homes, as they are heard have been noticed by at present? HE Radio Corporation of America British radio amateurs who listen to the So far, only a bare start has been made T was formed to play its own part in powerful transmitting station PC]] at on this huge task of equipping the Great the development of the radio art and Eindhoven, Rol1and. This station has been American Family with radio, for to date the radio industry. Essentially, we are an relaying English broadcast programs and we have fitted up only 6,000,000 homes with operating and sales organization, vital1y listeners have heard two distinct sounds radios, out of the 22,000,000 homes on the concerned also with research and manu­ for each note; one a fraction of a second Continent-a saturation of barely 25 per facture. We are not merely a patent hold­ later than the other, as though some kind cent. Yet the people of the United States ing or a licensing company. of echo were present in the transmitting have 18,000,000 automobiles, 16,000,000 'rYe are licensing competitors under pa­ studio. A similar effect is heard some­ wired homes, 16,000,000 telephones, and tents necessary for the type and character times in music halls the acoustic prop­ 11,000,000 phonographs, and only 6,000,000 of set upon which they have built their erties of which are bad, one sound com­ radios. business. ing ,directly from the singer or player and 1 While it is true that our own line this the echo of this sound arriving an instant year will cover every type of modern radio later from the walls or ceiling of the room. From an address by Admiral W. H. set, fact remains that we have specialized In the case of the PC]] radio program, G. Bullard, of the National Radio Com­ in the development and manufacture of such echoes originating in the broadcast­ mission, read to the National Electrical super-heterodyne sets. It is the one ele­ ing studio have been proved not to occur Manufacturers Association. ment in our line that most distinguishes and it is believed that the second sound HE craze for radio broadcasting it from competitive radio equipment. To heard by the listeners is due to a radio T has swept Japan and in an hour's divide the use of our super-heterodyne wave which travels around the earth. It ride from Yokohama to Tokio on patents would be almost to offer our trade­ is thus delayed a fraction of a second, so the trolley, an attempt to count the anten­ mark for competitive exploitation. that it arrives slightly after the wave nae would make one dizzy. In the second ptace, the super-heterodyne which crosses the Channel directly from Broadcasting in that country is under is a circuit of such finely-balanced electrical Holland to England. The speed of radio the supervision and regulation of the gov­ precision that to give these patents to other waves is believed to be so great that such ernment though the broadcasting com­ manufacturers would be to IIsell" rather a wave would pass entirely around the panies are privately owned. The govern­ than to "deliver." The high character of the earth in about one-seventh of a second. ment says what stations shall broadcast several types of radio equipment now on This would make the radio-echo that much and what shall not. Every purchaser of the market is not the result of patent de­ later than the direct wave; a difference a radio receiving set is required to pay velopment alone-manufacturing experi­ corresponding to a real echo cast by a the government a tax which cannot even ence, equipment and organization are also wall about seventy-five feet away. be considered moderate. It is a yen (50 important factors. cents in gold) a month, and the govern­ The fact is significant that while a num­ * * • ment, after retaining its share based on the ber of manufacturers have succeeded with Transmission of tables of figures by cost of administration and clerical work other types of sets covered by our patents, wire in a manner to avoid errors is necessary to collect it, returns to owners there is no successful imitation of the described in a tei'ephone company of the broadcast stations the remainder super-heterodyne circuit. magazine: and prorates the amount among the differ­ • • * HE -Bell Laboratories Record, an in­ ent stations which it has licensed. This ternal publication of the scientific From an interview with Mrs. Lotta T provides a considerable amount for each laboratories of the Bell Telephone Harrauff, who was crowned Queen of station and allows the administration of System, describes a recent instance in which each station to acquire the best talent pos­ American Radio at the Radio World's a collection of important numerical data Fair last year: sible for educational and entertainment had to be sent hurriedly from Los An­ purposes. Moreover, all the transmitting UR Radio Commission has had a geles to New York City. The figures stations are opened freely to any govern­ O hard task thrust upon it and we were typewritten on sheets of paper and ment bureau or office that wishes to broad­ cannot be certain of the result until carefully checked. These sheets were cast events which the government desires colder weather comes, when distant recep­ then transmitted by wire, just as a photo­ to inform the public. tion is to be had, and until that time comes graph would be transmitted. The entire • • * I do not believe anyone is qualified to say process being automatic, no mistakes in that the assignment of wave lengths is, or the figures were possible. The copies re­ Extract from a speech by U. S. is not a failure. Personally I do think ceived in New York were unquestionably Senator C. C. Dill, author of the Sen~ that the best results will be gained by the true copies of the original documents in ate radio bill, at the Northwest con­ changing of wave lengths. Los Angeles. Some experts predict that vention of the American Radio Relay Living in the center of the United methods of transmitting written or printed League, in Spokane, Wash. States, I have tuned in stations from every documents will be perfected so that all HETHER or not the law will direction consistently, and my belief is telegrams will be sent in this way instead W eventually permit us to forbid that the broadcasting stations must be put of by the present translation into code ownership of frequencies is still into zones and the hours divided. and back again into words. RADIO AGE for October, 1927

Jewelers' Time Signal Amplifier incorporated in Superheterodyne receiver Bringing the Old Super Up to Date

ARKING back to the old days of lows not only the sharpest of tuning and recently, this amplifier used as an inter­ H the UV -1716 transformer-when the ability to reach out farther than any mediate unit in a super in reality amounts that item was the only available other circuit, but to make these possibilities to a "band-pass amplifier." How this one at the disposal of the broadcast listener a reality requires 100% efficiency in each of works out can best be realized when we that could be used as an intermediate trans­ the circuits that comprise the whole. On stop to consider that the signal band in former in suver-heterodyne construction, the other hand, a super-heterodyne that this amplifier is but 10, sometimes 7 K. C. and following this circuit to the present served our purpose two or three years ago wide. As all broadcast stations are separ­ day, it is apparent, above all other things, with broad intermediates, is no longer able ated at least by 10 K. C. this unit is by far that a proper intermediate amplifier is the to cope with present day broadcasting con­ the most selective and sensitive that has very key to the whole super~heterodyne sit­ ditions because where we had one station been on the market uation. Realizing this and also taking into three years ago we probably have ten today. The amplifier is peaked and wired and consideration the added density of broad­ The old set with broad intermediates was ready to hook into the circuit. The four cast station population it is not hard to see sharp enough for the condition of those component circuits of the amplifier are that receivers of this type constructed days but now the set probably wilt not even peaked as one unit instead of four, in other sometime ago were not built to function to be able to break through where broadcast­ words, our intermediates can be treated as the point of present day standards, es­ ing stations abound, especially in localities one unit rather than a number as previ­ pecially as far as selectivity and sensitivity like New York and Chicago. There is also ously. Large air core transformers with a -which means DX reception-is concerned. another item that has not been mentioned tremendous amplification gain are used in Two principal factors are responsible for before and that is the increase in power every stage-the secondaries all being this, first the situation that concerns inter­ used by broadcasting stations and this in tuned with matched fixed condensers. Each mediate frequency transformers, the other congested areas has further handicapped stage is individually shielded and the en­ the broadcast situation. Up to the present the older receiver while, on the other hand, tire assembly is housed in a copper and time the builder of a super-heterodyne was this condition with a really sharp set of in­ brass catacomb which does away absolutely always forced to rely upon individual units termediates if anything has been "pie" for with any possibility of interaction of cir­ for the construction of the intermediate the super built for present day broadcast cuits or the pick up of parasitic noises. The amplifier-usually three or four transform­ reception. amplification gain as measured in labora­ ers-most of the time selected out of ran­ Vye now find upon the market a J ewelers' tory tests exceeds considerably that of any dom stock-and at other times on trans­ Time Signal Amplifier which adapts itself amplifier that can be built of individual formers which were sold as being peaked effectively to a super-heterodyne inter­ parts for here is found an amplification but which when assembled and in operation mediate amplifier and through the use of gain of 10 per stage or a total amplification had entirely different characteristics in the which all of the difficulties experienced in factor of 10,000 for the unit with the unit receiver than when they were matched. this particular section of the receiver are non-critically adjusted. This resulted not only in a lack of selectiv­ overcome. This Jewelers' Time Amplifier This Jewelers' Time Signal Amplifier be:­ ity and sensitivity, far from the real possi­ consists of three stages of R. F. amplifica­ ing absolutely complete in itself (with the bilities of a super-heterodyne circuit, but in tion and a detector-a unit designed pri­ exception of tubes) contains all of the parts many cases resulted in a tone quality with marily for the jewelry trade in receiving the that are usually found in an intermediate which discriminating fans were not satis­ time signals from station NAA-Arlingtol1 frequency amplifier. In the assembly in ad­ fied because of the cutting of the side -whose wavelength is 2677 or 112 K. C. dition to the four large air core transform­ bands owing to improper peaking. This unit is constructed to automatically ers are four tube sockets, four fixed tuning It is generally conceded by all of those tune in that station and no other-sharply capacities (one across the secondary of who have studied the various characteristics peaked to N AA frequency and with a band each transformer) , two bypass condensers, of receiver designs on the market that the so narrow as to prevent interference from of 1 mf. capacity and one fixed condenser super-heterodyne principal of reception al- any other station. As one fan remarked of .002 mf. capacity. . 6 RADIO AGE for October, 1927 the constant reception area on a basis of five members to each family. Fifty-seven foreign countries now maintain reg-ular broadcast service with Canada, Cuba, Russia, Sweden, Austra­ lia, Germany, United Kingdom, Argen­ tina, and :Mexico ranking first in order of number of broadcasting stations main­ tained arid regularly operated. Radio broadcasting, according to Bat­ son, has attained as great importance in international, national, and family life abroad as it has in the United States, all circumstances considered, and has now been recognized by all of the principal A typical split-loop Superheterodyne circuit with the Jewelers' Amplifier sub­ foreign governments as an important stituted for old Intermediates means of disseminating entertainment, information, and instruction. Radio programs have a sfriking simil­ arity all over the world and .it is not In adapting the time signal amplifier to of the signal in what then becomes our sec­ without some basis of possibility that super-heterodynes that have been built pre­ ond detector, which is the detector in the programs broadcast throughout the whole viously our task is very simple. The out­ time amplifier, is brought about by the use ward appearance of the old set can remain of a C battery rather than by a grid con­ universe may be expected to prove more exactly as it now is, the controls in no way denser and leak, because of the advantages popular than those of local origin, the re­ being different. This is of considerable of greater handling capacity. The P term­ port states. importance because it means that the new inal carries our signal to the first audio More news and some direct adverti!ing catacomb can be dropped right into the re­ transformer. The -6 terminal is negative A find place iiI foreign programs and gov­ ceiver in place of the old I. F . amplifier. battery lead and the +6 terminal is the one ernment communications are formally As a matter of fact there is but one con­ going to the positive side of the A battery. presented to the people through the trol for the time signal amplifier, the oscil­ In the time signal amplifier we will find microphone, but in general a typical lation control which is simply the conven­ that the negative A terminal is grounded, American program is likew ise typical for tional potentiometer. In substituting this in other words, the entire housing as well any part of the world, according to Bat- efficient time signal amplifier, therefore, in as the shields in the housing that separate son. place of our old intermediates the front end each stage from the other are connected Congestion of broadcasting stations of our super and the A. F. amplifier re­ to A- . has occurred so far only in the United mains exactly as it was. T he customary Inasmuch as the J ewelers' Time Ampli­ States, Canada, and Europe. Mexico City, Buenos Aires, Sydney, and Mel­ first detector and oscillator stage are not fier is completely wired the matter of bring­ affected, the catacomb merely displacing the ing an old super-heterodyne up-ta-date re­ bourne and a few other cities having suf­ ficient number of stations to require par­ old intermediate stage and the second de­ quires but a very few hours. In all proba­ tector . Inasmuch as the Jewelers' Time bility it will take longer to tear out the old ticular attention to wave lengths in order Amplifier is but IS" long, 5" wide and 3" intermediates than to substitute this ne w to prevent interference but their problem deep we will usually be able to displace the unit. \Vith this substitution the old super­ has been simplified in these places by the fact that the full wave band is available. units which are being removed and find heterodyne is not only brought up to date room to spare. The audio amplifier system but a careful search of what the market These cities are favored, too, by the fact of the receiver, providing of course that it affords has also definitely de monstrated that there are ho other stations operated delivers the tone quality that we demand that there is nothing to be had that wilt in close proximity to the city limits, ac­ today, remains intact exactly as it is. give the results of the renovated receiver. cording to the report. On the Jewelers' Time Amplifier we wi ll As has already been said the Jewelers' Time North America and Europe have broad­ find eight binding posts, four on the left Amplifier with an amplification factor of casting stations scattered throughout the hand side and four on the right. The left approximately 10,000 gives us an amplifica­ inhabitable area. South America is well hand side binding posts are marked N, +90, tion gain in the intermediate stages far be­ se rved except in the interior and the ex­ B and P . The N terminal is connected to yond that to be found in ordinary ampli­ treme northwestern part of the continent. the center arm of the potentiometer on our fi ers. Comparative laboratory tests have Other developments are spotty except in panel and controls the oscillation of the shown that through the use of the time sig­ Australia and New Zealand where sta­ intermediates (a ~ or I mf. bypass con­ nal amplifi er owing to its tremendous per tions are well distributed. denser connects across the arm and minus stage gain, distant stations could be brought Some foreign countries regulate radio end of the potentiometer ) . \Ve all know in with loud speaker volume barely audible broadcasting on a strictly commercial that with an intermediate amplifier the with other sets with an equal number of basis with broadcasting corporations closer we approach to the oscillating point tubes. The selectivity is such that in Chi­ holding exclusive or quasi-exclusive con­ (toward the negative side), the more sensi­ cago it will allow reception of out of town cessions. \Vhere such regulation is en­ tive the receiver becomes and with a pro­ stations within 10 K. C. of powerful locals.. forced, owners of receiving sets are portionate volume increase. This control usually assessed a fee for reception priv­ works exactly the same in the time signal ileges, according to Batson. amplifier as it does with ordinary inter­ In countries where monopolies do not mediates. The +90 terminal connects to obtain, any person or firm showing satis­ the 90 volt B battery line. The terminal 90,000 ,000 Radio People factory general qualifications is granted marked B connects to the 45 volt battery Approximately 90,000,000 of the 1,000,- permission to operate a broadcasting line and the terminal marked P is the one 000,000 people living within the world's station. In a few countries where un­ that is connected to the plate of the tube constant radio reception a rea receive usual political or economic conditions socket of our first detector- this carrying radio broadcast programs, in some form prevail, the possession of broadcasting the signal from the detector tube to the according to a report on potential markets and reception equipment is rigidly denied, first stage of the time amplifier. A choke fo r receiving sets by Lawrence D. Batson, according to the report. coil should be incl uded in this lead, such as Electrical E quipment Division, Depart­ the S-M 275, if a split loop cir cuit is used. ment of Commerce. On the right hand end are four terminals About 18,000,000 receiving lets are now SEE NOVEMBER ISSUE marked -4 ~, P , -6 and +6. The terminal in use, according to Batson, who esti­ FOR SUPERHET CIRCUIT marked -47'2 goe s to the negative of our mates that 200,000,000 sets would be re­ WITH NEW FEATURES 4~ volt detector C battery. Rectification quired to service all of the people within RADIO AGE for October, 1927 7

Back panel and baseboard view of the Thompson Super Seven, showing the compact and neat arrangements of parts

The Thompson Super Seven Incorporating the Latest Ideas in Tone Quality and Selectivity By SIDNEY J. THOMPSON

N DESIGNING the seven-tube super done and many intermediate transformers so far as cost was concerned. This would I described in this article the two main were tried. Some of these were low-priced have defeated us in trying to reach one objectives were to devise a superhetero­ transformers which were immediately dis­ of our chief objectives. dyne receiver which would possess the ex­ carded because of their lack of ability to As a last resort, several manufacturers cellent qualities expected of this most in­ reach the standard demanded by the de­ of high grade products were called upon teresting of radio receiving instruments signer for this receiver. and the cooperation of their engineering but which would combine this satisfactory It finally appeared that the· only alterna­ staffs requested. Then there began an result with a low cost. tive was to produce a super that could de­ elimination contest which was to result Considerable experimental work was liver the goods but to proceed blindfolded, finally in the selection of a combination of quality parts to produce the two desired results. No attention whatsoever was paid to the products used, for the engineers List of Parts for the Thompson Super Seven were instructed to produce the finest rea­ Silver Marshall No. 340 Midget Condenser ______. ____ .. _... ____ $ 1.50 sonably priced superheterodyne that could 6 Silver Marshall Tube Sockets, SOc ea. _. ______._. ___ .... ______.... ______...... 3.00 be built with quality products. 2 Silver Marshall Drum Type Dials No. 805, $3.00 ea. 6.00 Tonal Quality and Overtones 1 Pair Silver Marshall Brackets ...... _...... __ .. .iO Let us consider what is required to 1 Yaxley Filament Switch __ .____ ...... 50 produce true rendition of the original 2 Yaxley Imp. Jacks, 25c pro .25 broadcast. It is not a difficult matter to 1 Yaxley 2 L Resistance ...... _. ______.. ___ . __ .____ .. _____ ... _..... _. .15 obtain excellent high note reproduction, 1 Yaxley 3 L Resistance ______.... ______..... _._. ____ ...... IS likewise it is not difficult to obtain excellent I Yaxley 30 Ohm Rheostat ...... 1.35 low note reproduction. 1 Tobe _006 Condenser . ___ . ______. ______.. _. __ . ______.. _... ______.______.45 Audio amplifying systems can be devel­ 1 Tobe 1 mfd. Condenser ... ______._ ...... _____ ._ ...... _.... _..... _____ ..... ___ .. _...... ___ .. _...... 90 1 Tobe .002 Condenser _____ .... _.... ______. __ .. ____ ..... ______.... ___ .. ______.... ______.... ______.40 oped to accentuate either high or low notes. In a great many cases it is more I Tobe .00025 Condenser ...... 35 pleasing to accentuate, for instance, the 1 Tobe .001 Condenser .... ____ .. _.. ____ ._ ... _...... ___ ...... _____ .__ .40 low base notes. To some this accentua­ 2 Halldorson Precision Iron Core No. 540 Transformers, $6,00 ea ... _. __ .. _.. 12.00 tion gives a soft deep tone that is rather 1 Halldorson Precision No. 541 Filter Transformer ______.. _. __ ._ .. __ 6.00 pleasing. Other tastes for music fre­ 2 Halldorson Overtone Audio Transformers, $6.00 ea...... 12.00 quently vary the other way, preference be­ 1 Halldorson Overtone Output Transformers .__ . __ ... __ .. _.. ____ .. __ ._ .... _____ ...... __ ...... 6.00 ing given to accentuation of the higher 1 7x21 Panel drilled and engraved ______... ______.. __ .. __ .______... _____ ._ .... __ .___ ...... __ .. _____ ... 3.40 notes. Obviously, neither one of these 1 9x20 sub panel drilled and engraved ... _.__ .. _...... ______. ______...... ___ .. __ ...... _____ ..... 4.95 systems can produce perfect reproduction 1 3 meg. gridleak . _.. _...... __ .... __ ._. __ .. _.. _._ ...... _...... _...... _...... _...... 50 of the original broadcast and neither one 1 Resistor Mounting ._...... ____ ...... 35 would satisfy a trained musician. . 2 Camfield .0005 mfd. Condensers, $6.00 ea..... _ ...... ___ ...... ____ .... 12.00 The perfect audio system then would 10 X. L. Spring Binding Posts 15c ea...... 1.50 be one 'wherein the loud speaker and the 1 Ellis Oscillator Coupler ...... _...... 3.00 Audio Transformers were so balanced that 1 Spring Socket ...... _.. _...... 75 a flat amplification curve is obtained not for the Audio system alone nor for the Total ...... $78.55 loud speaker, but for the entire combina­ When aerial and ground operation is desired in preference to a loop. Use-- tion of receiving set and speaker. 1 No.2 Ellis Antenna Coupler ___ . ______.______...... _.. _____ .. ____ ...... _... _...... _____ ...$ 3.00 The output from the loud speaker should represent, in other words, a perfectly flat 00

, ?:t i >­ ~~ t1 qno: o >­ Cl '-·Tou I AlIiI. M ~ /~r/~1/ ".. YdXIf'I.I. l-L&.,{$ t F"{lSw o Af ,A-a-c+ 6;45 C-:4j .8ff10 C:Ahll'. {jrAI1I~. !4.g. THOMPSON SUPER SEVEN :'

~ !§ RADIO AGE for October, 1927 9 10 RADIO AGE foy October, 1927 line giving even amplification throughout careful balancing of the component .parts far more importa.nt that the efficiency of the entire audible range. This range should of the receiver. It i5 necessary. in order each stage of amplification be taken into take in at least eight thousand cyc1C5, for to retain amplification over the entire consideration more so than the number of in many instances true amplification of audible range that we have a band of at tubes U!ed in the receiver. frequencies of seven to eight thousand least ten kilocycle5 in which to work. If The machine described used only seven cycles are required. Should they be left we increase the selectivity beyond this tubes but the efficiency of every tube is as out entirely, as is frequently the case, the point, we immediately enter the field of high as it is possible to attain. result is powerful base note amplification, reproduction and begin to cut side bands Constructional Details fair amplification of the middle register, of the music and loss of high audio fre­ but a suppression of the high notes with a quencies is the result. The first step in the construction of the corresponding disastrous loss in shadings receiver is a careful study of the different The problem, therefore, is to get as close diagrams. and overtones of the voice. as possible to the point where we do not cut side bands. When this is done we have On page 8 is the schematic from which . Overtone amplification is obtained in but a bird's-eye view of the receiver and cir­ reached what might be called the peak of onc manner. The ability of the Audio cuit may be obtained. Transformers to produce an output energy selectivity. VI/e can go no further. This On page 8 is the pictorial wiring dia­ which does not over accentuate nor sup­ point can be only obtained by precision gram. A study of this diagram before press any frequencies. This allows full peaking of the filter transformer to cut off on either side of the ten kilocycle beginning the wiring is advised. All parts amplification of both high or low notes to­ have been marked on this drawing to con­ gether with any given intermediate fre­ band, five kilocycles each side of the peak. We continually see glowing reports of form as closely as possible with the gen­ quencies and the overtones are recreated. eral layout plan and no trouble should Only in this way is it possible to obtain hair splitting selectivity, knife edge selec­ tivity. and so forth, but to the seasoned be experienced in wiring the receiver from perfect amplification accurately following this drawing. the true shadings of the artist's voice. engineer and I hope eventually to the fan On page 9 is' the layout and drilling When an Audio amplifying system over and set builder all of these superlative adjectives mean but one thing-C

Antenna Or Loop Operation Either an anterma or a loop may be used. The loop will give somewhat better selectivity on local stations but of course does not have quite the range of the aerial and ground. When a straight wire antenna is used the additional coupling coil is re­ quired and should be connected as shown in the schematic diagram of page 8, how­ ever. if the set is to be operated on a loop antenna the Ellis antenna coupler may be left off the sub-panel. The pictorial wiring does not show the connection of the antenna coupler. When this is used it should be mounted directly behind the first detector tube socket. The The handsome simplicity of the completed receiver as enclosed in cabinet is shown few simple connections required will be above seen ~n the schematic diagram. The G. A. RADIO AGE for October, 1927 II and P. leads of the coupler are connected to the loop binding posts or if an antenna will be used regularly the loop binding posts may be used for the antenna and ground and the coupler connections made in the receiver permanently. Oscillator Condensers Care should be taken to connect the rotor plates of the oscillator condenser to the plate terminal of the tube, and the stator plates to the grid. This will elim­ inate body capacity. C Battery The use of a C battery has been very liberal, a C bias being used on the R. F. tubes in preference to the usual potentio­ meter. This method is slightly more ef­ ficient and due to the fact that it decreases the B battery consumption there is prac­ tically no danger of the set motor boating on a B eliminator. Intermediate Stages One point that will probably strike the fan as being contrary to the general trend is the use of two iro1\ core transformers and one filter. It was mentioned earlier that the sensitivity of a super depended primarily upon the efficiency of each R. F. stage. By using two long wave iron core transformers with a very high R. F. gain the efficiency or amplification is brought up very high. In order to obtain the de­ sired selectivity with this system the filter transformer carefully designed by pre­ cision methods. Its amplification cuts off very sharp on either side of a ten kilo­ cycle band. Beginning the Construction The foregoing points have been covered in order that the builder may have a more general idea of the points to watch for in the construction of the receiver. The list of parts should now be procured and then carefully examined to see that all parts are in good order. Construction can now be begun. Cloyd Clevenger. world war ace and now pilot of the Alexander Airport, Denver J The front panel should be started first. who gives aviation lessons to radio listeners The condensers should be mounted then the rheostat, filament switch and regenera­ leads to the controls on the front panel, it might in the case of some eliminators tive condenser. If both condensers are and the receiver is then ready to test. with a high internal resistance, it can be the same it will be necessary to reverse Tubes eliminated by by-passing the output of the eliminator with from two to ten Mfd. by­ the shaft in one of the Camfield conden­ U. X. 201 A tubes or their equivalent pass condensers. sers first. This can be done by removing should be used throughout the entire re­ the cover nut at the back of the condenser, ceiver with the exception of the last stage An eliminator that was found to work exceptionally well on the new Thompson loosening up the set screw that holds the where a 171 power tube is recommended. Super Seven was the Silver Marshall shaft and then pushing the shaft through If the wiring has been carefully don~, Reservoir B. It derivers ample current to the other side. Tighten up the set screw there is no reason why the set should not again and replace the nut on the reverSe operate perfectly from the very start. It and is sflent in the operation. A distinct side. may be necessary to vary slightly the "e" advance forward has been made in the After the front panel has been assembled battery _voltage but it will be found in Silver Marshall Eliminator by the use of lay it aside and proceed with the assembly most cases, if the tubes used are O. K., a glow tube to maintain the output volt­ age constant. The glow tube eliminates of the baseboard. By following the lay­ that the three volt "e" bias for the radio entirely the necessity for any variable ad­ out diagram this operation will be very frequency tubes as shown on the diagram justments, as it automatically delivers the simple and should not take more than an will be correct. correct voltage regardless of the current hour. The Ellis oscillator coupler should Should a liB" battery eliminator be drawn by the Receiver. be left until the last so that it will not used. one of sufficient output should be be damaged. When the parts are all obtained, capable of delivering at least one Accessories mounted on the base board wiring can be hundred and eighty volts at a.bout forty A six volt storage battery will be need~d started. mills, since this is what the Thompson to light the filaments of the tubes. If a Wiring the Receiver Super Seven will draw when a 171 power Trickle charger is to be used, a battery of It is advisable to wire the baseboard first, tube is used on the last stage. eighty amperes capacity will be sufficient, without the front panel attached. Th~ The fact that almost every tube in the otherwise, it would be advisable to get a wiring can be done in proe-ressive stages receiver is biased with a "e" battery re­ little larger storage battery. beginning with the first detector. The duces the battery current consumption con­ The cabinet in which the set is pictured leads for the front panel must be left quite siderably and practically prevents any dan­ is the well known "Fritts." It needs no long. When the subpaned is fully wired ger of the set motor boating with a "B" introduction to set builders; it is known mount the front panel and connect the eliminator. Should this difficulty arise, as to all for its distinguished appearance. 12 RADIO AGE for October, 192i "1928 Infradyne" Presents Attractive New Features

MONG the new radio receivers and former or antenna coupler. Adjustment A equipment for the 1928 radio sea­ of the antenna compensator is made when son we find the "1928 Infradyne" the set is first put into operation after one of the most distinctive. Here is a which the antenna circuit will stay in line radio set embodying really new features; with the remaining circuits over the en­ interesting alike to the man who builds tire wavelength band. A very slight ad­ his own set and to the professional set justment of the antenna compensator builder. All the difficulties a man en­ might be desirable as a last step in ob­ counters in building, such as the tedious taining the best possible reception of a alignment of the tuned radio frequency distant station but under ordinary condi­ stages, stabilizing, preventing inter-stage tions it can be forgotten when it has once coupling, etc., have been removed before been correctly set. In the rear of the the parts for the set reach him, and he cabinet, at the end nearest the antenna has a much better· chance of immediately compensator controls, are the "Antenna" getting perfect and gratifying results; and "Ground" binding posts, the battery still there is the satisfaction which every cable and the jack for the loud speaker. radio fan knows, derived from having The whole receiver is made up of several constructed one's own set. The assembly units which are easily assembled. One of of parts and wiring is a matter of two or the most interesting features is the all three hours of in,teresting work and the Figure 3-Radio frequency amplifier with the metal case removed metal base, with noles already drilled, and result is a receiver which not only has the completely assembled radio frequency the appearance of the finest factory built amplifier which constitutes the front part set, costing considerably more money, but Remler condenser to the right. A filament of the set. The photo, Fig. 2, shows the also performs like the best of them. The control is directly beneath the voltmeter, complete layout of parts and the photo, Fig. creation of this set is certainly a progres­ the voltage applied to the tubes being indi­ 3, the radio frequency amplifier with the sive step in the industry. cated on the meter. A volume control is on metal case removed. The r.£. amplifier is Ten tubes are used throughout the set, one side and "sensitivity" control on the unique in many respects, and shows real two CX301As in the first two stages of other, both of these are rheostats mounted engineering on the part of the designers. tuned radio, one in the first detector socket, behind the condensers; extension shaft~ The three transformers are tuned with the one as the second detector, and also one connect the rheostats with the knobs on single Remler three-in-line condenser tu in the first stage of audio; three CX399 the front panel. which is mechanically connected a shaft tubes are used in the Infradyne Amplifier A switch at the bottom of the front having the primaries of the transformers unit and on~ more in the oscillator socket. panel controls all the filaments. When mounted thereto; as the capacity of the Either a CX1l2 Or CX371 is recommended the switch is at the "OFF" position all condenser is increased the coupling between for the last stage of audio. the filaments are out: when it is turned to primary and secondary of the transformers The photo, Figure 1, shows the set as "LOCAL" position the Infradyne ampli­ is increased, in a relation which tends to it looks completely assembled and housed fier is out of the circuit and only the keep the greatest sensitivity without oscilla­ in an all-metal cabinet, which provides an radio frequency tube and audio frequency tion over the whole wavelength range; also, effective shield against picking up radio tubes are lighted; and when the switch is provision is made for two degrees of pri­ frequency and other electrical disturbances turned to "Distance" all the tubes are mary to secondary coupling so that the by the coils and associated wiring in the lighted and the Infradyne Amplifier is amplifier is readily adaptable to various set, permitting only energy which is picked automatically put into operation. broadcast conditions. up on the antenna and going through the Just above the base and to the left of The coupling can also be changed by tuned channels to be amplified. Through the central control panel is a supple­ moving the secondary coils which are the efficient shielding and very selective mentary bronze shield carrying the an­ mounted on brass rods extending up ci rcuits all but the desired signals are re­ tenna compensator control. The antenna through the center of the coils, up or down, jected. The tuning controls or selectors compensator control knob is double, the thus changing the relation of the secondary are the two upper knobs on either side of larger part operating a three-point switch to the primary coils. The coils are matched the voltmeter, connecting with the two permitting variable antenna coupling and with the gang condenser at the factory, drum indicators which are mounted, one the smaller part controlling a small vario­ this eliminating trimmer condensers to on the three-in-line Remler gang condenser meter connected in series with the sec­ compensate for deviations in the coils as to the left, and the other on the single ondary of the input radio frequency trans- the wavelength range is covered. For greater selectivity the coils are moved up­ ward and for less selective tuning the coils are moved down. Shields between stages minimize inter­ stage coupling; together with the auto­ matic coupling scheme, the amplifier is very stable over the whole wavelength range, and also at maximum sensitivity over the whole range. The front part, or radio fre­ quency amplifier, of last year's infradyne was in some cases rather difficult to handle. In the new Infradyne this complication is eliminated. At the rear of the set is mounted the In­ fradyne Amplifier. This is the same ampli­ fi er which has become so well known dur­ ing the past year for its ability to sharpen Figure l-The receiver as it looks completely assembled and housed in an tuning and to build up volume of signal an-metal cabinet without an annoying increase in back­ ground noise. In construction and per- RADIO AGE tor October, 1927 13

REMLER INFRADYNE

AMPLIrtER '7/0

rrrp F-

ANT eND CA8L E TERMINAL

Figure S-Wiring diagram of the "1928 Infradyne," showing also the color scheme for the battery cables formance this amplifier has not been follows: Electrad Type P .001 mid. condenser changed in any respect from that of last Infradyne Foundation Kit-Parts List. Electrad Type P .005 mfd. condensers year. 1 Pressed Steel base Special adjustable condenser Back of the bronze panel carrying the 1 Pressed steel instrument panel instrument controls is a pressed steel panel 2 Bronze control panels upOn which are mounted the voltmeter, 111- 1 Remler No. 110 Drum Dial (Right­ fradyne Amplifier rheostat, two drum dials, hand) with brace and lamp and the oscillator tuning ·condenser. Lo­ Remler No. lIO Drum Dial (Left­ cated directly in back of the drums are the hand) with lamp two rheostats for volume and sensitivity Remler Type 659 Condenser control. From the layout it is obvious that Remler No. 50 Sockets the assembly of this receiver is far from Remler No. 35 Choke Coils with special complicated, and perfectly symmetrical. spacers The bottom of the pressed steel base :s Special coil and spacer illustrated in the photograph, Figure 4. 10 ohm rheostat, extension shaft and Since the holes are already drilled for bushing (Frost) Figure 4-Bottom of the pressed steel mounting the instruments and running the 2;4 ohm rheostat, extension shaft and base of the "1928 Infradyne" wires the job of building the set is greatly bushing (Frost) simplified. 4 ohm rheostat (Frost) 4 megohm grid leak All. the small parts used in the Infradyne 2 ohm fixed resistor Frost No. 953 Jack receiver, including nuts and screws, wire, 4 ohm fixed resistor Frost No. 954 Jack etc., comprise the Infradyne Foundation 6 ohm fixed resistor Yaxley No. 69 Switch Kit, saving a lot of troublesome shopping Electrad Type GS .00025 mfd. condenser "Antenna" binding post for these odds and ends. The parts are as Electrad Type P .00025 mfd. condenser "Ground" binding post Bakelite terminal strip 4" x %" x~" Special bakelite terminal blocks Battery cable 12 Lengths 'wire (colored as per code) Necessary screws, nuts, washers, solder­ ing lugs, spacers and brackets. The rest of the units are the Remler No. 710 Radio Frequency amplifier and Antenna Compen­ sator, two Silver-Marshall Type 220 Audio Transformers, one Silver-Marshall Type 221 Output Transformer, and a Western Model 506 or Jewell Pattern 135 0-5 volt voltmeter. A simple plan has been devised by the manufacturers for making up a cable har­ ness. A full sized template is furnished showing the positions for the various nails on which the wires are wound to make up the panel. The plan is so simple that even Figure 2-Layout of parts in the "1928 Infradyne" a man who has had almost no experience whatever can easily complete the job. 14 RADIO AGE for October, 1927

Fig. 2. Rear View of World's Record Super 10. Binding posts for a. c. filament not shown. Three by-pass condensers are mount­ ed together beneath the sub-panel instead of two as shown in this cut

The New World's Record Super Ten An Unusually Powerful and Selective Receiver with Great Volume and Fine Tone

HROUGH the courtesy of Mr.E.H. acteristics as set it apart from other re~ ing for long distances. No filament switch T Scott of the Scott Transformer Com­ ceivers of the same general class. appears on the panel, this having been pany, we are able to present herewith an The first impression upon viewing the built into a special Carter rheostat directly authentic ami accurate descrlption of the World's Record Super 10 is that it is a under the 0-8 volt Jewell filament volt­ new W arid's Record Super 10, which has truly pretty bit of radio design. Striking meter. This rheostat automatically opens just made its appearance itt the m£tmnn dis­ in appearance, the front panel controls the filament circuit when in the off posi­ plays of radio' dealers. We forecast that kept down to a minimum consistent with tion, cutting out the filament current to this recei-ver will be one of the leadiltg efficiency, the receiver as a whole has that the tubes in the set. The knob on the contenders for the favor of the set build­ finished business-Eke appearance that all extreme left of the panel is a Silver-Mar~ jtlg public this season becartse it includes set builders strive to attain. The back shall No. 340 Midget Condenser (.000025 so many tmusual and worth-while features panel'is equally neat in appearance, hav­ mfd) which is used to balance off any in­ in design. Weare part1'cula,-ly pleased ing a symmetrical and systematic equalities in the input tuning circuit caused over the opportunity to present to O1tr arrangement of the parts, so intriguing by antennae of unusual characteristics. readers this description, as we have fol­ that even the most sophisticated radio It is not a critical adjustment. The knob lowed the activities of Mr. Scott alld his engineer will stop to admire the effect. on the right end of the panel is the orgaHizatio;~ very closely, print1'Jlg from potentiometer, a Carter 400 ohm, and is The setting of the dials is easily ob­ time to time photos and descriptions of labled Modifier. A scaled drawing from served through two portholes, the varia­ models previous to the new World's Rec­ which a drilling template can be made tion of the drums whereon the dials are ord S1,per 10. We believe that Mr. Scott is illustrated in the blueprints. located being accomplished by the rota­ has an utr1ts1tally fine receiver, 'lCie know The back panel is equally as good look­ tion of two knobs s1ightly offset and be­ that he is m.akillg a good traJlstormer, and ing as the front, especially to radio enthu­ low the portholes. These two controls we knoU' that you will like this story of iasts who admire conservative workman­ form the main tuning adjustments, and a super-radio, its peculiarities, advantages ship and sub-l>ane1 mounting. The base are the ones most actively used. The left and per-formal/ce. mounting Selectone Units, which appear hand major control is that of the RF The Editor. on the market new this season, have sev­ amplifier input circuit, and serves to ro­ eral advantages that are readily apparent. By FELIX ANDERSON tate the sections of a Remled 3-In-Line­ All connections to these units are made Condenser. which are all operated by the N enumerating some of the advantages under the sub~panel, and such connections I adjustment of the common shaft. This in­ of the New World's Record Super 10, are inconceivably short and direct. Wir­ genious arrangement obviates the necess­ it is probably simplest to first discuss ing is eliminated, and. the construction those most prominent, and then consider ity of seperate adjustment of each of the RF secondaries, and simplifies operation.' of the New World'~ Record Super 10 is other departures of interest as they occur greatly facilitated, even to the extent of in our review. While there are several The right band major control is the con­ being more simple than any other pre­ denser varying the beat frequency, and is super-hetrodyne receivers now available, vious modeL A bottom view of the re­ the key, figuratively speaking, to the In­ which Use radio frequency preceding the ceiver (Figure 3) gives an idea of the ease first detector, the new World's Record termediate Frequency Amplifier which with which the set may be wired. The differs from these in a number of respects, follows the first detector and RF train: layout lends itself to the use of either and each dissimilarity is based upon in~ The three refining controls on the panel telligent thought and thorough research. are non-active in actual operation, the ad­ bus~bar, fl:exible cable or Celatsite as the It is the purpose of this description to justments being made when operation is assembler may prefer. acquaint the reader with the New World's begun and then left unattended, slight ad­ Study of the back panel photo (Figure2) Record Super and such orginat char- justments being made at times when tun- will disclose the use of Benjamin base RADIO AGE for October, 1927 IS

mounting sockets, which directly become Selectone unit is held to a rigid standard senSlhvlty for the pickup stages. One of a part of the sub-base. These sockets and of performance, uniformity and efficiency. the departures from accepted procedure is the Selectone units are 50 spaced as to The assembly of such units into a work­ evident in the grid return of the: fre­ make the plate and grid leads very short ing component is obviously rewarded with quency changing tube (first detector). and convenient. crowning and brilliant result. This has been made negative instead of E1ght Selectone series B units com­ The New Selectone B-530 and B-520 positive as is customary, research dis­ prise the essential of this receiver, and RF Couplers are manufactured with as closing that this is the best connection. these units can be identified as the Selec­ much precision and care as though each A Remler RF Choke in the plate lead tone B-530 Antenna-Coupler (looking were going to be used in a highly im­ of the tube keeps RF strays from filtering _ from left to right on the photograph Fig­ portant piece of test equipment. The into the Intermediate train where they ure 2) directly followed by the two winding of the coils is done in the most mi ght be troublesome .. Selectone B-520 RF Units, next a Selec­ careful manner as to insure high effici­ This brings us to the Selectone B-SOO tone B-5oo Intermediate Frequency ency and amplification. The assembly Intermediate Frequency transformer, the Transformer, a Selectone B-51O Filter, into cases is supervised closely by engi­ firs t in the IF train, then to the Selec­ another B-500 followed by a second B- neers to detect irregularities and defects, tone B-51O and thus on to the second de­ 510, which feeds the second dectector with and when completed, the units are sub­ tector tube, which is activated by the amplified signal. These new units are the jected to the gruelling test of a device secondary of the B-SI0 connected to its heart of the World's Record Super 10, that detects inequalities of more than one grid circuit. The intermediate stages and are the result of more than five third of a turn of wire on the coil. In ' themselves are not radical in their con­ years of constant test and experiment in this test the coils are matched to a uni­ nections, the refinements having been re­ an effort to obtain optimum in efficiency, formity of less than one turn, and so that stricted to the Intermediate Transformers appearance and sensitivity. Housed in the secondary inductance is practically themselves. The tubes are' kept at the .highly po1ished bakelite casings, all of the same. The Lorenz type of winding, exact amplification point by the proper the same appearance, they stand majesti­ is used in the RF Couplers, and the cases ratio of primary to secondary, and the cally like soldiers in a row, each of them are so placed that losses are at a mini­ relat ive spacing of the coils which governs designed to do their utmost in intercept­ mum. Referring to the circuit diagram, stability, amplification and tone. The ing and ampli fying faithfully weak and in bhieprint, it will be noted that the RF amplifier in entirety is stabilized by the distant signals as well as those of local Couplers are stabilized by the voltage drop 400 ohm Carter potentiometer which is transmitters. The oscillator unit desig­ across the rheostat, limiting the electronic connected in the usual fashion across the nated as Selectone B-S40, sets between the emission from filament to plate, that is, A negative and A positive filament po­ two Remler drum controlled condensers. increasing or decreasing the working ef­ tential. The selectivity enables the operator to ficiency of the tubes. The coils themselves Many radio enthusiasts fail to fully tune in stations far away through heavy are proportioned and designed to adapt appreci ate the importance of good inter­ local i.nterference. with ten kilocycle separ­ themselves to this method of control so mediate frequency transformers, which ation on all but the nearest ones, when a that no difficulty is experienced in obtain­ explains generally why the super-hetro­ slightly greater margin must be allowed ing stability with good tone and ma ximum dyne has been tong considered as a com­ to avoid background noise. efficiency. plicated and difficult receiver to construct All these new units are laboratory The pickUp coil of the oscillator is and operate satisfactorily. This erroneous matched products. While the World's located in the grid lead of the first de­ conception is far from true. If the Inter­ Record Super 10 is a receiver made of tector, where it has been found most effi ­ medi ate Frequency transformers are laboratory equipment, it must not be con­ cient. A grid leak and detector is used reatly matched for peak frequency, regen­ sidered as an experiment. Each unit is in the frequency changer, and a proper ad­ eration and amplification, and if they are closely matched and peaked, and every justment of this detector tube avails great intelligently designed and wound to give

Fig. 3. Bottom view of the superheterodyne showing simplicity and neatness of wiring 16 RADIO AGE for October, 1927 the greatest sensitivity and selectivity used in the second detector for the verY with tone quality, the super-heterodyne be­ apparent reason that the heavily amplified comes only a matter of the assembly of List of Parts signal impressed on the grid would over­ a few more pieces of equipment than the 1 Remler .00035 mfd Variable Con­ denser load the tube and cause distortion. Better ordinary receiver, with considerably 1 Remler 3-gang .00035 mfd. Variable tone quality is thus obtainable. The greater efficiency and enjoyment. Condenser second detector is also outfitted with a .2 Remler Universal Drum Dials Just how the Selectone Intermediate .2 Remler R. F. Chokes No. 35 . Remler RF Choke and bypass Condenser, .2 Selectone Transformers B-500 Units are kept at a uniform standard is .2 Selectone Transformers B-510 to block and bypass IF strays in the an interesting procedure. The coils of the 2 Selectone R. R. Transformers B-S20 plate circuit, so that only the direct cur­ 1 Selectone R. F. Transformer 8-530 transformers are tested before assembly 1 Selectone Oscillator B-540 rent component passes into the audio onto bobbins for open windings and short 2 Thordarson Audio Transformers amplifier transformer winding. R-200 circuited turns using two oscillators driv­ 1 Thordarson Out-put Transformer The audio amplifier is standard in de­ ing at about 100 kc with a common plate R-76 sign with the departure that the last 1 Carter 400 ohm Potentiometer supply and headset so included in the 1 Carter Heavy Duty one ohm Rheo­ stage employs a CX-310 power tube in circuit that changes can be readily de­ ,tat order to handle the tremendous ampli­ 1 Carter 15 ohm rheostate with fila- tected. ment switch tudes delivered by the RF, IF and first One of the oscillators is adjusted 2 Carter Tip Jacks audio stages. Thordarson R-200 Audio 2 Carter .00025 Grid Condensers transformers are used in the usual slightly below or above the 100 kc oscil­ 1 Carter .002 Fixed Condensers lator so as to give a beat note of 500 1 Carter .0001 Fixed Condenser cascade circuit in conjunction with an 1 Silver~MaTShalI Type 340 Midget cycles, easily readable in the phones. The Condenser R-76 Output Speaker Coupling Trans­ coil is then plugged in the test circuit 10 Benjamin sockets former which protects the speaker wind- . 1 Pair Benjamin No. 8629 Brackets ings from the 400 volt plate current used and variations in the frequency of the 4 Tobe l~mfd. By-pass Condensers to actuate the CX-31O. The tonal quality beat note are listened for, if there are ~ J:::s 3 Mueft1~~:g,G1: ~::~act such. A change in the tone of the beat 1 Jewell Pattern 135 0-8 Voltmeter obtainable with this widely known ampli­ 1 Pkg. Kester Radio Solder fier is now a tradition among radio note indicates imperfect winding and 1 Formica 26x7x3/16 inch Drilled such are unsuitable for use in the Selec­ and Engraved Panel enthusiasts, and needs no further de­ 1 Formica 25xl0x3/16 inch Drilled scription. tone IF Units. Suh-panel 60 Kellogg Soldering Lugs Battery connections are made with The condensers used to peak the trans­ 40 Ft. Acme Flexible Celestite Wire a Jones Cable, having 10 leads coded as formers are carefully tested with a stabi­ 2 X-L Binding Posts follows: A positive red, A negative green, lized oscillator and a vacuum tube volt­ B negative yellow, B positive 4S volts meter on a standard transformer. blue, B positive 90 volts pink, B positive Changes in capacity differing greater primary of the same transformer being 400 volts brown, C positive black, C 6-9 than five per cent above or below standard coupled to a standardized 20lA tube, volts negative orange. The filament·cur­ reject the condenser. operating under actual load conditions. rent for the UX-210 power tube, which Under the close scrutiny of expert The signal generated by the oscillator is taken off the Eliminator is carried by engineers, skillful assemblers put the coils is impressed on the grid of the test stage twisted leads to two binding posts, and on the bobbins, and affix thereto the con­ or first tube, and the gain between. the twisted leads connect the filaments of the densers which peak the transformers. test tube and the vacuum tube voltmeter is 310 tube to the socket. The terminals are then carefully soldered then observed on the very senitive One of the unusual features of the New into place on the new style bases, and the milliammeter in the plate circuit of the· World's Record Super 10 is the specially transformers undergo their first tests vacuum tube voltmeter. When resonance designed eliminator to suit the receiver for amplification, peak frequency and is effected, that is, when the oscillator and its various load. Mr. Scott strongly spillover point. If the units conform to is driving at the neak frequency or point recommends that this eliminator be used the standards demanded by the specifi­ of maximum effciency and amplification with the New Super 10 and will ensure cations of design, they are removed to the of the transformer, the operator reads the the very finest results. impregnating and mounting department setting of the oscillator, and with the The construction of the e1eminator is where they are dipped swiftly and skill­ aid of a powerful microscope observes simple, in fact is decidedly less involved fully in a special compound and mounted the exact maximum deflection of the mil­ than the usual type of B power supply. in the new highly finished bakelite hous­ liammeter in the vacuum tube voltmeter. The New Carter bypass condensers, ings. The impregnating operation is one The deflection of the meter is recorded as (which are guaranteed to stand contin­ of the most important of all, as a special well as the setting of the oscillator con­ uous operation at 1.000 Volts D. C.) and com pond is required and the mixture denser. The latter reading represents resistances are used in this circuit in con­ must be kept at the proper temperature the peak frequency of the transformer, nection with Thordarson T -2098 Power so as not to alter the characteristics of and the milliammeter reading gives the Transformer and T -2099 Choke Coil. Two the transformer. This operation seals gain of the transformer. CX-316 B Rectron Tubes are used, one the windings, the condenser and the bob­ The transformers are then sorted into on each side of the AC cycle so that full bins against atmospheric influences and sets having the same oscillator reading wave rectification is effected with ample further serves to lock all leads and wind­ (peak frequency) and are then sorted into current for all the loads required with ings into place so that the characteristics sets consisting of two B-SlO and two B-500 the receiver. The circuit of connections cannot alter, due to dropping or handling. transformers having the same reading on appears in the blueprint and requires no The transformers are then ready for the vacuum tube voltmeter. additional mention. The CX-301A tubes are used through­ matching into sets. The apparatus used The tests do not stop here however, for this consists of a special stabilized out the receiver, except as has been noted, as Mr. Scott feels that the one final and oscillator with a uniform output over the the last stage which requires the CX-31O. entire scale of its variable capacity and certain method to use, to absolutely pre­ The filament current is from the usual an ultra-sensitive vacuum tube voltmeter. vent any defective units from leaving the storage battery. While considering this Great pains and precautions are taken laboratory, is to give them an actual -air part of the circuit, it is strongly advised to keep this oscillator stable and uniform, test on a standard receiver. A set of that a relay switch be used for automatic and the finest precision meters obtain­ transformers can be dropped into their control of the A & B power supply. In able are used in the vacuu!1J, tube volt­ proper places on the special test set actual practice this is almost a necessity meter which is also of special circuit and in less time than it takes to insert a because of the precautions that must be taken with heavy current surges in the construction. The oscillator and volt­ set of tubes in their sockets. Every B Power Supply if tl?-e filament current meter are heavily shielded to prevent transformer is thus tested for selectivity, pick-up of energy other than that obtained is shut off before the eliminator is dis­ distance and tone quality before leaving from the voltage drop across a resistor in connected. It is well to remember that the oscillator unit. The vacuum tube the laboratory. good quality and sensitivity do not keep voltmeter is connected across the second­ To continue with the description of company with dead A batteries. ary of the transformer t9 be te§ted, th~ tn~ fr.:rejver. Grid bias rectification is This generally describes the most RADIO AGE for October .. 1927 17 prominent features of the new World's r­ Record Super 10, with the exception of the filament circuit of the nine A tubes. Referring to diagrams, it will be noted that the receiver is practically master con­ trolled, all the tubes exclusive to the two RF tubes, being fed through the Carter 1 ohm Heavy Duty rheostat. The RF tubes are operated on a separate 15 ohm rheostat ill order to furnish control of oscillation. A separate rheostat located on sub panel is provided for the first de­ tector in order to avail greater sensitivity and finer adjustment, but as this and the [ ohm are not critical once they have been set, it has been found convenient to mount them on the sub-panel where they Fig. 1. The symmetrical arrangement of parts comprising the World's Record Super are less apt to be disturbed once the 10 gives the receiver this attractive appearance proper setting has been attained. The detector rheostat is a Carter 30 ohm and comes a serious problem. The general WENR 10 kc above CJBC and WTMJ 10 is connected in series with the master. as sharpness of tuning, retained and aided kc below. Between WGN on 990 kc and the blueprint indicates. The 0-8 Volt by the careful manufacture and design WLS (870 kc) it was possible to tune in Jewell Filament Voltmeter facilitates the of the Selectone units, is maintained WGR (970) KDKA (950), WGHP (940), setting of the master rheostat, the proper throughout the amplifier bp the proper WRRS (930), WABC (920), and WBZ adjustment being between 4% and 5 on setting of the potentiometer, without loss (900 ). On each side of WLS (870) a 20 the scale. of tone due to the transformers being kilocycle separation brought in WHB Tlie foregoing description explains to peaked too abruptly. The second de­ (890) and WOC (850) the former Kansas some extent just why the World's Record tector with its grid bias rectification and City, the latter Davenport, Iowa. The Super 10 differs from other radio fre­ radio frequency blocking system delivers dials, when tuned to WSAI (830), com­ quency-superheterodyne combinatiolll, but to the audio system a wonderful signal pletely exclude WOC (850). WEBH, hardly explains the excellent range and to amplify, which the audio amplifier two miles away and only 10 kc below pickup characteristic of this new super­ truly accomplishes. The net result is a (820) does not interfere even to the ex­ radio. A general summary of the World's thundering signal in the loudspeaker, yet tent of background noise. Record Super 10 is helpful in obtaining an beautiful in tone and depth, delicately WGY transmitting on 790 kc rolls in accurate idea of what the receiver can controlled from a whisper to full volume with the familiar punch and power, while accomplish. This is best explained by by the manipulation of smoothly operat­ W EEM, two blocks distant and 20 kc be­ first inspecting the input circuit of the set. ing, non-critical controls on the panel. low is operating with 1000 watts. Twenty Here he we have two stages of RF Even the most distant stations roar in kilocycles below WBBM (770) WTAM amplification, making possible the use of with a mighty punch. is tuned in with ample volume, good tone, a short indoor antenna of from 2S to 30 Performance is the clinching argument and no background interference. WTAM feet as the pickup medium, even for the in any receiver. That being the case, let operates on 750 kc. Through WIBO or most distant stations. This eliminates us turn to the file of verified receptions WHT (splitting time on 720 kc) and the loop antenna, provides greater and notate for you just what the set will WMAQ or WQJ (splitting time on 670 sensitivity, reduces harmonics and hetero­ accomplish. kc) the World's Record Super 10 tuned dyning, and because of the amplification The laboratory where the World's Rec­ WSUI (710), W LW (700), WJR (680), of the tubes and transformers, extends ord Super 10 waS developed is located on and WJZ (660). WJZ was so well re­ the range of the set, simultaneously in­ the north side of Chicago, and every ceived that it was possible to remove the creasing its volume. The RF pickup radio enthusiast knows that Chicago has antenna and hear the signals on the stages deliver to the detector of the set plenty of broadcasting stations. WBEM speaker with such volume that it could be a greatly amplified input signal, assist­ has its home just two blocks west of the heard 200 feet distant. At the upper end ing the work of the detector in produc­ laboratory location. It operates on 1000 of the broadcast spectrum, WEAF was ing a much better beat frequency for the watts. WEBH, a 1500 watt station is just easily separated from WCFL. These [F stages to amplify. The selectiVity of two miles south. WIBO, with 1000 is stations operate on a 10 kc separation, the set is due to the action of the RF about 10 miles distant, WMAQ, KYW, and WCFL is only 10 miles away. WHO stages in conjunction with the oscillator. WGES, WMBI, WGN, WSBC, WLTS, (560) can be pried off the frequency of Ten kilocycle separation is no longer a WENR, WTAS, WCFL, WAAF, all not KYW (570) with comfortable margin, dream-having becume a reality with the less than 500 watts (and in most cases KYW being about 10 miles south. Super 10, The average radio enthusiast 1000) are located not less than 10 miles appreciates the sharpness of the super­ air line, and cover the entire broadcast heterodyne as well as the popular radio spectrum on the average five tube radio World Record frequency system and when both are com­ frequency receiver. Within a range of 50 Circuits at 30c bined into one working component with­ miles we have WLIB, WHT, WLS, Send 30 cents in stamps if you out the loss of efficiency in either system, WCED, W}AZ, and numerous others, want complete instructions and it can be readily appreciated that super ranging from small fry to heavy power. dra wings in back issues as f al­ selectivity is the result. In the World's What the Chicago stations miss in the lows. Record Super 10, the RF and Hetrohyne ambition to smear the dial with local January. 1927 systems of reception are so combined signals, these stations usually accomplish Full Data on the Super 8 that the total output is much greater, than when everything is going full blast be­ March, 1927 if one theoretically added the signal in­ tween 8 and 10 p. m. Building Ideal Model Super 8 tensity of either system operated inde­ Yet the World's Record Super 10 tunes April. 1927 pendently. Radio frequency pickup, and between them I Using a 25 ft. antenna, One Spot Super and Power Com­ superheterodyne amplification when com­ on the ground floor of the building, this pact bined, actually improve each other in ef­ amazing radio receiver accomplished tun­ May-June, 1927 ficiency and in results. ing that can only be duplicated with an­ Using 9 Tubes on World's Record Granting that we have delivered an other World's Record Super 10. Be­ Super input signal of already considerable tween WENR and WTMJ (Milwaukee, RADIO AGE amplitude to the first detector, the Wisconsin 80 miles distant) The Super 500 North Dearborn St. Selectone IF amplifier boosts the signals 10 brought in e}EC of Toronto, Canada. Chicago, Ill. to the point where second detection be- Twenty kilocycle separation-that is,

20 RADIO AGE for October, 1927

DX Reception Record States or Canada it will be interesting to Stephen Davis of the Department of Com­ hear about it. With much of the former merce-namely The Law of Radio Com­ We have an interesting and convincing congestion removed and the excellent sta­ munication. Since the present radio letter from Mr. John White who believes tions recently installed in di fferent parts laws are so new the discussion is of ab­ be holds the world's record for DX recep­ of the world there are new possibilities for stract principles. Cases paralleling those -tion on regular broadcast frequencies. He receiving foreign stations here in North has submitted for our examination a pho­ which might arise in radio broadcasting America. tograph of letters and cards varifying his litigations are cited to illustrate the judg­ ment of the law. The book explains i"eception of broadcasts from 4QG, Queens­ hnd Radio Service station at Brisbane clearly the rights of the broadcaster and Australia on 385 meters, 3AR at MeI­ the listener from the view point of the 'bourne, Australia, broadcasting on 484 Three New Radio Books judge and logical reasoning. The Linth­ -meters and using a power output of less icum Foundation prize by the Faculty of Several new books treating different Law of Northwestern University was ·than one kilowatt (the station output, ac­ phases of radio and the industry, have .cording to Mr. Whites letter of varifica­ awarded to the author who was formerly been published recently. Among them is Associate Justice in the Supreme Cour-' ·tion which he received from Australia, is the Drake's Radio Cyclopedia by Handly, now five kilowatts. This should be good of New Mexico. The publishers ar~ tht a volume to provide the non-technical McGraw-Hill Book Co., Inc. :game for DX hunters); 2FC Sydney, man with ready reference work of prac­ Australia, on 442 meters, EAJ7 at Madrid, tical usefulness in solving their problems Spain, on 372 meters, OAX, Lima, Peru, with radio receivers and reception. The ·in South America, broadcasting on 380 arrangement is alphabetic, each article Radio Warns of Quakes meters, and of course the west coast sta­ being complete in itself with cross refer- tions. All the stations were picked up in ences to all related subjects. The sub- A New Jersey radio amateur, Mr. WiI­ Brooklyn, N. Y., where Mr. Whites lives, jects are treated in a manner easily liam Andrew Mackay, believes that he .during the winter of 1926 and 27. He understood by the layman, with material has discovered an advance indicator of writes, j/2FC, Sydney, Australia, was that is useful to any experimenter or set earthquakes in the form of some internal picked up by me the second time on Sun­ builder: Practically every phrase and disturbance of the earth's crust evidenced .day morning, June 5, 1927. Held him term in the radio category may be found by an alteration of radio conditions. Mr . from 3 :07 a. m. to 3 :20, then from 3 :40 in the reference tables. Subjects such as . Mackay's radio receiving apparatus is till 3 :58." The letter of acknowledge­ rejuvenating vacuum tubes, locating located on top of the Palisades of the -ment from 2FC varified the part of the trouble in a receiver, etc., are treated Hudson, the high cliff of basaltic rock program picked up. with completeness,.as well as instructions that borders the Hudson River QPposite Mr. White attributes his successful DX for building equipment and receiving sets. to New York City. This basaltic reception to the efficiency of his receiver The book covers more than 1,500 subjects, rock contains a high percentage of iron ,which is an ordinary tuned radio f re­ with illustrations, circuit diagrams, con- and is more highly conducting for radio ,quency type. Four stages of tuned r. f. structi.onal layouts and graphic curves. waves than are ordinary rocks. Mr. and a detector and two stages of trans­ Mackay finds that occasionally the tun- former coupled audio frequency amplifi­ Another book is "Principles of Modern ing constants of his radio receiver alter ,cation comprise the set. However, each Radio Receiving," by L. Grant Hector, unexpectedly, in much the same way as stage of r. f. is well shielded in rolled cop­ Ph. D., Assistant Professor of Physics, they might if the electric condition of the -per cans measuring 9x6x6 inches each. University of Buffalo. Modern theories rock beneath were changed. Every precaution was taken to minimize on the propagation of radio waves through This alteration of radio conditions is ·interstage coupling and to keep the re­ space, the electron theory and the theories invariably followed within a few hours. sistance of the coils low. In each can is of practically all of the new circuits and Mr. Mackay reports, by a severe earth­ .a variable condenser, a tube, r. f. trans­ methods of receiving radio intelligence, quake somewhere on earth. His radio former, and two by-pass condensers, 1 are discussed in a technical but simple apparatus served this kind of advance ,m. f. each. One by-pass condenser is con­ fashion which can be understood by most notice, he states, of the unusually severe nected across the filament and the other people interested in the business and earthquake in western China in May, of technical progress of radio. None of the from the B side of the transformer to subjects is treated mathematically, except the Jerusalem earthquake in July and of neg. filament which is grounded to the can. for a few simple algebraic equations, five other severe shocks within the past lt is pointed out in Mr. Whites letter that absolute shielding is important in making New circuits and theories about which six months. the set highly efficient, not a single open­ there has been much controversy in the The warning is not invariable, some ·ing should be in the cans to permit any past are stated in an authoritative and severe earthquakes having occurred with­ leakage of energy; also the r. f. trans­ convincing manner. The contents of this out any detected alteration of the radio formers should be at least lU; inches away book were compiled by a physicist who conditions. Certain common rock miner­ from any part of the can. A variable re­ has gone into extensive research to ob- als, notably quartz which is the common­ sistance in the B battery supply lead to tain' accurate facts, and the material is est of all, alter their electrical conditions not mere quotation of general beliefs. ,control the current to the r. f. tubes is Every circuit from simple tuned detector when compressed or stretched. Geologists used as a volume and oscillation control circuits to superheterodyne and the most do not consider it impossible, therefore, in the set. Mr, White stresses the fact that his receiver employes nothing un­ complicated of balanced r. f. circuits are that the state of stress in the earth's crust usual, only care in building the set has described in detail. The Burton Publish- preceding a severe earthquake might have 'made it perform so remarkably. ing Co. put out this text. an effect on earth electricity, perhaps de- If anyone has a better record than Mr. A book dealing with an entirely differ- tectable in the way that Mr. Mackay has "'White for DX reception in the United ent phase of radio is that written by noticed. ~ I [;;~;yd~y Mechanic~

I Are You Fit To Drive An Airplane? By GLADYS MOON JONES Science Ser.ice Staff Writer (Copgri"ghl, 1927, by Science Service, Inc.) ow often have you said, "If this Would-be pilots are of two genera1 come so extended that they touch his H old bus just had wings I would fly classes with respect to altitude: fainters goggles, it does not follow that everyone over this torn-up street." It seems and non-fainters. The Army knows its should try it. The best pilots "go black" difficult to manage an automobile through unrestricted men, those who can go safely at 250 miles an hour on a turn. the dty's bottle-necks. It takes physical only to 15,000 feet and those who are still Just what per cent of . the youth of this and moral stamina. restricted to 8,000 feet. All flying above country is potentially Lindberghian is a Suppose your automobile should begin to 18,000 feet must be done with oxygen. The question of intelligence tests and physical fly. Could you pilot it? Could you handle limit of consciousness without oxygen is tests. Out of 547 midshipmen of the class an airplane? You could learn how to about 25,000 feet. This is because the of 1927 at Annapolis, 353 passed the Navy's drive one perhaps, but have you the physi­ effects of altitude depend not on oxygen pilot tests. An official estimate is that fifty cal and mental qualifications essential in a percentage, but on oxygen pressure. If per cent of those who apply for training competent flyer? pure oxygen is breathed we may still get at Pensacola get there. Of these thirty SpeciaHsts in aviation medicine have so high that its pressure is too low to sus­ per cent pass the pilot tests. And of this come to know more definitely just what tain life. thirty per cent approximately twenty per an At pilot must be. Several opinions If Lieut. James H . Doolittle of the Ar­ cent make At pilots. From these esti­ held during the war have been modified. my can do an outside loop at about 350 mates the ambitious boy can figure for Most important of these are the age and miles an hour causing his eyeballs to be- himself that he has about one in twenty- ear requirements. It was formerly thought that only young men could fly successfuly. Twenty-four was old in aviation. Now, however, you may be as old as thirty-five v'Emorional StClbi Ii ty----,------Reaction II' and still make a good flyer. X Superior Education I Coordinarionv' If you can negotiate communication with your co-pilot or co-passenger, you may be deaf and still make a good aviator. ------Eyes II 'Aviation hygiene is an important new X Ears ------NoseX subject. Today's physician is studying the matter. Tomorrow's will advise us before ~~"'J-'------ThroatX we hop off and prevent our suffering from physical causes as well as from aedal di­ seases, dope poisoning, deafness, altitude faintness and other troubles. Day-before­ V Lunc;,s ------yesterday's country doctor, who drove ------Heartv' around with: his horse and buggy at eight miles an hour, picked up those who had II'Diqestive--­ fallen from the higher plane of perfect health. More often than not, he was too Sy.stem late. However, he went out of fashion - --k'idnevsv' with his equipage. Medical men have long since seen that warnings berore the fall were simpler and more efficacious than ;;;J6--"'.H"".C i mending the troubles afterward. nessV Flight Surgeons New Specialists When flight surgeons came along with the development of aviation during and ------Bonesv' since the World War, they too, at first, gave most of their attention to those who crashed. Now with their confreres, gen­ II Joints------eral and special practitioners, they are preaching prevention. They have proved that from the very first pilot test, preven­ tive hygiene means a great reduction of danger to man and plane. They have found that people who walk the earth un­ troubled by minor var1ations from the nor­ mal encounter aggravated conditions in rarefied air and rapidly changing tempera­ tures. 22 RADIO AGE for October, 1927

to every 950 hours to one for eve ry 3,460 hours. Visual Judgment Necessary According to Comm. Robert G. Davis, Medical Corps, U. S. Navy, the eyes are the most important factor of fiying physical requirements. The flyer must see out side­ wise when he is looking straight ahead. Visual acuity alone will not suffice as there must be a perfect balance of each extrinsic muscle allowing the maximum of binocular vision with no tendencies to dip­ lopia or nystagmus. Dust, oil, wind and glare are prone to produce congestion of the lids and conj unctivae, which if allowed to progress may g reatly impair visual judg­ ment in depth perception -for landings or formations in the air. E veryone who has learned to drive eve n the slow old automobile knows how impor­ tant visual judg'me nt is. It may be im­ paired by an attack of influe nza, prolonged application of the eyes to close technical probl ems and by general staleness. A typiq l stale fl yer complains of having lost some of ,his keenness and flying jUclg- T he R uggles orienta tor in which the candidate is whirled and J tested. William ment. He is discouraged, not sure of him- Guy Ruggles is sitting~a~t .:.th~e:...::l o:.:w::,e"-r -,r~i g;:h::t~ ____ ~ ______;- _,--~~---c;:","---:;-~--;;;;;==c-, five chances to succeed in aviation, A flier does not have to go into the air to learn what the pilot testers call his reaction times or how his coordination is effected by overwork, loss of steep, expos­ ure, digestive disturbances and alcohol. Lindbergh, the pioneer, learned much about his remarkable physical machine by trying it out on his mail route, but many a good man has crashed to his death try­ ing to know what could have been told on the ground after a few physiological and psychological tests. Medical officers would have us get over calling those "heroes·· who unnecessarily expose themselves to mortal danger, The hypersensitive individual is easily coufused by rapid changes in position in respect to his environment. The tested pilot becomes immunized to rapid changes in motion. He is able to interpret his sen­ sations so that he shows little reaction to rotation or other rapid changes in posi­ tion. An apparatus was developed during the war -known as the Ruggles orientator. Some one wrote in to the ar111y asking for a picture of "that whirling bath tub." And that is what it looks like. An ex­ periment is being conducted now in the Navy Bureau of Aeronautics, which pre­ dicts even mote accurate success for thi j ­ orientator. Attached to the Ruggles "tub" is an instrument, operated electrically, which will make a graphic record of the testee's reaction times. E ight different pens are set to make the graphs 011 pape r marked o ff in tenths of seconds. T he re­ sulting graphic demonstration shows the automaticity of the man being tested. Aviation medicine is practiced in three direct ions: the selection, the classification, and the care of the fiye r. As a result of this specialization in the Army and Navy, the percentage of aviation accidents due to physical causes has decreased in a sur­ prising manner, S ince we have had well trained flight surgeons and soundly based and conducted examinations, the fatalities pe r flying hour have been reduced in a Altit ude classification test. M aking electrocardiograms during t est. Official period of four years from one fatality P hotograph U . S. Army Corps RADIO AGE for October, 1927 23 self in the air, has lost his appetite and dreams of unpleasant Hying experiences. He is irritable, short of breath and attri­ The Romance of Cotton butes his condition to trivial causes. If his condition becomes worse he must be II permanently grounded. His symptoms are those of neurocirculatory asthenia or effort syndrome. Edward C. Schneider, of \Vesleyan Uni­ n rsity, M iddletown, Conn., who years ago made experiments on Pike's Peak in a study of altitude, is one of the authoritative physiologists who have been researching in aviation medicine. He defines staler.ess a~ "a neural condition founded on chemical changes within the body," Ear Considered Less Important The inner ear was originally considered most important in this country, but not ac­ cording to the present theory. Equilibrium is important, but it is a function of vision, deep muscle sense, sensations from bones, joints and tendons, gravity effects, and tac­ tile sensations as well as the inner ear. However, the ears of the flyer demand constant attention. The necessity of equal air pressure on each side of the drum is thoroughly appreciated by the aviator. Equalization of pressure can be obtained in a measure by swallowing. Experienced flyers carry out the practice on rapid des­ cents. Unless the eustachian tubes arc easily opened the flyer should be kept out oi the air. Marked unequal drum pressures produce severe pains and probable perfora­ tion. Scarred or congested drums are dis­ qualifying on selective examinations. Some (Continued on page 37) Lightning's Odd Trick One of the few recorded instances in which a person was within a few feet of a lightning flash without being killed or re ndcred instantly unconscious has been described by the victim herself to Mr. F. 1-L Delano, of Paris. About noon of July 12, 1927, a thunderstorm crossed Paris. One bolt fell in a small park near the Photo by COOYEnT Bon Marche department store. Striking Above-Typical scene in Southern cotton the flagstones of a small court yard, the field. Circle-Men waiting their turn at bolt hroke one of these and disappeared. the cotton gin. Miss El1a Dodt, a Danish woman, was England other ships with finished Cott0l1 less than ten feet from the landing place cloths and goods clear port bound for of the bolt. Her description of the event COPYI'!ght b)· Kl'y.l lone VI~\\ Co all places that ships go. is that she saw the flash, was deafened Cotton! The very word brings to mind This great movement of cotton and by the noise and showered with frag­ pictures of many centuries and countries: cotton goods receiyed its first impetus ments of stone and masses of soil. She India, land of gorgeous potentates and in 1733, when an Englishman, John Kay. began to run, being perfectly conscious many religions, where the white and yel­ invented a flying shuttle. This machine and unhu rt. \;Vithin a few yards. how­ low fl owers and snow-white bolls of the enabled the weavers to turn out goods ever, she began to feel weak and col­ cotton plant have colored the landscape faster than the spi11ners could make the lapsed, still wi thout losing consciousness. for fifty or sixty or seventy centuries: yam. Hargreaves then came to the re­ Later symptoms included nausea, violent Egypt. home of the finest cotton in the lief of the spinners and invented the headache and a tingling sensation in the wo rld; ancient America, land of Aztecs spinning jenny. This made the mill race hands and feet, which last persisted for a nd Incas and of tobacco, potatoes, sun­ even, but created a demand for a supply over two days. flowers-and cotton. of raw cotton greater than the growers It is probable, physiologists report, that Cotton scenes of today are no less could meet. the fortunate woman was not affected by scattered. The sunny land of negroes, This time an American came to the the- lightning at all, the bolt passing in­ sunshine and song calls it king. Thou­ rescue, and with the invention of Eli stantly into the ground. The weakness sands of spindles and looms hum in New " "hitney's cotton gin in 1793, cotton b~­ and other symptoms were probably due to E ngland, New York, Pennsylvania and came the poor man's as well as the rich the effect of terror on the gland systelh, in Southern states, transforming it into man's cloth. Under old methods one man not to any electric force. M iss Dodt re­ yarn and goods. Ships ply along our At­ was able to free sufficient lint from seed ports, also, that her face, hands and lantic coast and cross the seas to Eng­ to produce one bale of cotton every two clothing were covered instantly with a land carrying bales of the fluffy down. days. Now a cotton gin produces fifteen coating of fine black dust. This dust was Ships set s·ail from Egyptian and British bales in a day. not analyzed but may have been powdered Indian coast towns for England and A s to its uses today-they are as stone from flagstones disintegrated by America laden with this fruit of their numerous as stars on a summer's night. the bolt. soil. And from our country a nd from (Continl/ed 0/1 page 26) - 24 RADIO AGE fo, October. 1927 , ios

Mr. E.H. Scott, himself, will tell you how he designed the original DXreceiver, with which he made the four World's Records described on the opposite page-how that set has been duplicated hundreds of times, each one performing as well as the original-how later developments and refine­ ments have enabled him to improve on the original in the- NewWor'd's Record Super lO-and how you can, even without any previous experi­ ence, build a World's ReC0rd Super 10 for yourself.

DISTANCE - Here is the receiver for the man realize that here at last is a receiver that it is a plea· wants the most powerful and sensitive set sure to listen to. to build. Many claim to have received far once or twice, but Mr. Scott with his EASY TO BUILD-With the parts here listed, any World's Record Super proved his claims to record one can build an exact duplicate of the New World's honors by bringing in consistently, night after night,. Record Super 10. The only tools required are a screw stations distant six thousand miles or more. The new driver, pliers, and soldering iron. The building instruc· World's Record Super 10, in actual comparative testB tions and full size blue prints show exactly where to with the original receiver on which the records were place each part and how to run every connection. and made, has proved that it is even more powerful and are so simple and easy to follow that anyone, even brings in the far distant stations with almost unbe· without previous experience in building a radio re­ lievable volume. ceiver, can duplicate this marvelous receiver and own No other receiver has approached the marvelous DX the finest radio set available today. records that the World's Record Super has established, - LIST OF PARTS - and it is safe to say none will for years to come. $ 6.70' 10 Benjamin sockets No. 9044 5.00 1 ~~j2lx7~~lIdrill~d an.d en: 1 pr.Benjamin brackets No.8629 .75 REMARKABLE SELECTIVITT-Here isa receiver 1 Formica sub panel drilled 1 Carter Imp. rheostat lR·1SS 25xl0x3As -- • • - 7.00 ohm, 1.50 for today's conditions. In Chicago, where there are 1 Remler 3·in-line condenser No. 633 00035 15.00 1 S. M. balancing condenser about forty broadcasting stations, the New World's 1 Remlerconden~rNo~638 00035 5.00 No. 340 1.50 2 Remler drum dials No_ 110 9.00 1 Carter power rheostat MW·l Record Super 10 cuts through with the greatest of ease. 2 RemlerR. F. choke coils No 35 I.BO ohm .75 It brings in distant stations only a few meters apart with 2 Thordarson audio transfonn- 1 Carter Imp. pot. lR-400 ohms 1.25 . - -- 16.00 1 Carter fixed condenser 00025 such volume that you think you have a local station output transfonn· with grid clips .50 until you hear the call letters and find you are listening - - . - . 6.00 1 Carter :fixed condenser 002 .50 L. W. transfonners 1 pr. No. 10 Carter pin jacks to a station hundreds of miles away. - . - . . 12.00 .20 2 Selectone L. W. transformers 1 Jewel Voltmeter 0.8v Pat. 135 7.00 No. B510 12.00 4 TobeBypasscondensers 1 Mfd 3.60 NATURAL TONE QUALITY-A receiver may have 2 Selectone R. F: tra~sfo~er; 1 Tobe grid leak -- • .50 No. 520 .... - 10.00 1 Jones 10contactmulti-plugand great DX ability and wonderful selectivity, but what 1 Selectone Antenna coupler 4 ft. cable type BM • 3.50 good is it if the tone is raspy or distorted? When you No.530 - • . - • - 5.00 40 Keliog soldering tugs - • .25 1 Selectone Oscitlator coupler 30 f!:.. rubber covered hook.up hear the New World's Record Super 10, you will No. 540 5.00 wire .so

Here's your chance to build a radio set that will give you all that radio has to give­ distance, selectivity, clear and natural tone. Experience is not required, for full instruc· tions will be sent you by Mr. Scott himself. Don't hesitate-don't delay. Send now for full details. Then you can't forget it, and you'll never regret it RADIO AGE for October, 1927 25 ftft G1'e4testD Wor/tIiRecoid ~'!!/ Here Are the Super]O Verified Records The authenticity of the startling achievements of the World's Record Super (as listed below) is based up­ Selectone Transformers cut on hundreds of verificatbns by leading Broadcasting through the local stations with Stations and Publications from Coast to Coast. ease, and their tremendous amp li­ fication brings in the distant stations with great volume. I ?o~ ~~~~h 1J:rai~~~~~nn~1j~rl!ile~e~~~ They are supplied in perfectly Loud Speaker Volume. matched sets, insuring maximum amplification and the finest tone Z ~~rf~,~ Re~~;d ~i~lili~~e~~~i~~~fb;~~f~r~~~ quality. stations distant 6,000 miles or more. The new Remler Three-in­ Line Condenser with the Rem­ 1l Established new World's Record for greatest ler Drum Dial represents the last ~ number of broadcasting stations heard that word ingangcondenserconstruc­ are located 6,000 or more miles away. tion. Balancing condensers are Established new World's Record for most con­ integral with the main unit, and 4 sistent reception, night after night, of Stations are easily and quickly adjusted. 6,000 miles or more distant -117 programmes from A special staggered connection 19 different Foreign Stations, heard between Decem­ of plates makes it self-shielding ber 27th and April 10th. preventing interstage CiJupling: All insulation is of genuine Bakelite. ThordarsoQ Amplifying Transformers were used in the original World's Record Super. designed by Mr. Scott. Because of the unusual tone qualityob­ tained Thorda~son apparatus is again selected. Two Thordarson R-200 Amplifying Transformers and one R-76 Output Trang. ,~·~ former are used in this receiver. ~' If you enjoy good music. insist I on Thordarson amplification. Tbelamoas BenlaminSprlng In the careful selection of parts and ac· Halli Size cessories for the New World's Record Cushioned Shock Absorbing Super 10, it is quite natural that a Jewell Socket was the choice of Mr. Pattern No. 135 Radii. .. Voltmeter should he chosen. The biac\{ enameled case E. H. Scott in his original World's encloses a fine, D' Arsonval,movingcoil Record Super. type movement having silvered parts Mr. Scott has paid the very high­ ~~efsu~~~~ ~t~~:l~7t~~~~~rJ~:'-' est tribute to the efficiency of acters. A special mounting arrange­ Benjamin Shock Absorbing mentmakes it easy to moumin a radio panel. It is the ideal instrument for Sockets by again selecting them filament control. for this newest and greatest of radio receivers. . "< . " Tobe Condenser.. Only the highest grade parts were selected by Mr. Scott for the World's Rec­ Sf. Jones Ten Contact Multi­ ord Super 10, and the fact that plug and 4 ft. Cable enable all Tobe parts are specified is one batteries to be placed out of sight and more proof of their claim for simplify wiring. Now used on over one million receivers; endorsed by leading leaderShip in the condenser field. radio engineers. Send Coupon foy gull cnetail~ 26 RADIO AGE for October, 1927 ROMANCE OF COTTON (Colltinued from page 23) Car Enters Rough Sports One, however, might be singled out as being rather unusually ingenious. That is the use of cotton in the cords attached to telephones. These cords present an unique problem. Copper has to be used to carry the current. But copper wire breaks when bent, and these cords, of course, are bent many times in the course of a busy day of telephoning. In manu­ facturing these cords the Western Elec­ tric Company, the largest manufacturer of telephones, winds flat ribbons of cop­ per no thicker than a hair spirally around a cotton thread. In this way they make cottton threads give strength to copper wires. Other present-day uses involve the cot­ ton seed and the waste from the gin, \vhich formerly were thrown away. From the cotton seed is made cotton seed oil, substitutes for lard, oil cake and oil meal. Tiniest Motor A motor so small its rotor could be wrapped in a postage stamp is used by the Westinghouse Electric and Manu­ facturing Company, for timing the OB watthour meter demand register. It is the smallest synchronous motor ever manu­ factured for practical use. Four million E. T. Trombly of the. Western Electric of these complete motors, together with team demonstrating perfect scooter polo their reduction gears, would be required poise. Above-An exciting melee in which heads might easily have served for the ball. If wishes were horses, beggars might ride. And if the horses don't material1zc­ and horses are scarce these days-the thing now is to wish for kiddie cars. For if you are equipped with one of those push and hop machines you can join in the ncw game of scooter polo. And it's great sport.- as mounted on your kiddie steed, with mallet set, you charge down the fi eld-or, rather, the gymnasium floor-for a long drive to the net and tally. Even pony polo is scarcely fraught with more excitement or danger than was the game of scooter polo played at the sports carnival held r ecently in the audi­ torium of Oakland, California, by the In­ Flyweight motor held between the fingers dustrial Athletic Association of that city. of a man, showing minute construction as compared to that of the human hand. Equipped with croquet balls and mallets you could say there wt!re no casualties at and rubber-tired scooters, the crack teams all. Melees were s tiff and the teams so to balance a large 8,000 hp. motor recently of the \Vestern Electric Company and evenly matched that the game resulted built in the vVestinghouse shops. The 1fontgomery V.,rard gave an indoor exhi­ in a tie. diameters of their shafts are in the ratio bition of two chukkers of as exiting polo The only drawback that can be seen of 512 to 1. The rotors are still smaller as ever was fought on field. Aside from to the new game is whcn both father and in proportion as 37 million are required a few skinned shins, a number of bro,ken child insist on using the family scootcr to equal the weight of the large one. mallets and many spills from mounts, at the same time. While two men, one on the other's shoulders, could stand upright in the Learn to Fly by Radio says. It is this preliminary instruction circular opening for the rotor in the he will give his radio flying class. 8,000 hp. motor, the rotor of this motor Here is an absolutely new wrinkle in Lessons began Sept. 9. They will bl' could be worn, set in a ring, on a man's radio programs-a broadcast of practical continued for 10 weeks, going on the air little finger. lessons in a irplane flying! each Friday night from 8 to 8 :15 p. m., KOA, the Rocky Mountain broacasting mountain standard time. Fine Measuring station at Denver, Colo., is to put them on Clevenger's student flyers will sit ill In the manufacture of certain telephone the air. Cloyd Clevenger, '''arid \\Tar their own homcs with perhaps electric parts, machinery of an almost unbeliev­ ace and now pilot at the Alexander Air­ fans blowing wind in their faces. They able accuracy is required. One piece in port, is to give them. can set a broomstick between their knees operation in the works of the Western Clevenger has had g reat success as a to takc the place of a "joy stick." A gen­ Electric Company is a measuring machine test flyer and instructor in flying. There uine airplane motor will be set up in the that is capable of measurements within is much that a stud('nt pilot must learn KOA studio to add greater realism to thc one-one-hundrcd-thousandth of an inch. before he takes his first flight, Cle .... enger lessons. See picture on page 11. RADIO AGE for October, 1927 27

(FI1lI' 'Ill' 'Ill' 'Ill' "~=====:JIlI' "~=====:JIl" ";l~IlI' '1lI~1lI' 'Ill' '1lI1i!j!j ICurrent Science I Iil=IlI 'Ill' 'Ill 'Ill' '1lI~1lI' Illi '",' ''''' Ill' Ill' 'Ill' 1lI~IiIEE!lI . Venus Now Visible In Daylight! By JAMES STOKLEY Science Service Staff Writer (Copyright 1927 by Science Ser vice, I n c. )

TOOK for Venus in the daytime! D Ordinarily, the only astronomical body that we are privileged to ob­ serve during daylight is the nearest of all the stars, the sun. Sometimes, when the moon is near first or last quarter we see it, in the former case in the a fternoon, in the latter in the morning. But to these two this month is added the planet Venus. Brightest o f all the planets when it is brightest, the brilliancy of Venus this month is inferi or only to the sun and moon. On October 17. it attains its great­ est magnitude, and for perhaps a week or more either side 0 f that date it will be easily visible in the morning sky, if you know where to look for it. One way of finding it in the day time would be to g et up before sunrise. T hen it will be blazing in the east, and there will be no doubt of its identity. By watching it carefully until the run r ises, you can easily WEST NORTH EAST see it in day light. But a simpler method, and one not requiring such early r ising, is fi nd the moon in the south on the morning with the aid of the photographic pla te and to use the celestial g uide, the moon, on of the twenty-fir st, and then look about invisible light, the stars can be photo­ October 2l. fi £teen times its diameter to the south, there graphed in full daylight. On that date the moon and Venus are in you will see Venus. On the 15th of the If we were on the moon, the stars would conjunction. That means that they will be month, Venus will be directly south at 9: 17 all be visible even if the sun were above t he as close together as they will get on this a. m. local time, so that will also help you horizon. The sky would look black, either particular circuit a f the moon a round its to find it. at day or night. The reason why the orbit. At 8 ;00 a. m. , eastern standard time, Invisible Light Shows Star in D ay earth's sky doesn't look black is because, V enus w ill be about seven a nd a half de­ O f course, Venus is not a star. I t is a unlike the moon, we are surrounded by a grees south of the moon. T he moon itself planet. T he only star that can be seen in gaseous atmosphere. It is the atmosphere is about half a degree in diameter, so if you the day, as was said before, is the sun. But that reflects the short waves 0 f light, the blue ones, and makes the sky look blue. A ll day, the stars are in "the sky above us, just as at night. If you look to the north, about 40 degrees above the horizon, you are looking at the pole star j ust as when you look at the same part of the sky at night. But in the daytime, the blue light from the sky enters your eye also. It is much more intense than the light from Polaris. T he star is therefore invisible. But the sky light consists predominantly of the shor t waves of light-the blue, and ultraviolet ones. T he light from the star contains t hese rays, but it also contains a large propor tion of longer waves, the wave that we call the infra red. T hese a re in­ *Fomolhou~ visible, because the retina of the human eye is not affected by their relatively slow * vibrations, but a photographic plate can be treated so that it w ill record their impr es­ sions. And a dyed filter can be made that EAST SOUTH WE5T (Continued on pag'e 30) 28 RADIO AGE for October, 1927 3,000 MILES THOMPSON limited range. Overtones that giTe depth Power-Selectivity-Distance­ and life to all music are brought to the fore­ Volume-Overtone amplification ground with a richness that is astoniAhing. The selectivity is 80 marked that powerful You'U be amazed at the results that this local stations can be tuned out and distance receiver will give you. Ha11dorson Precision brought through with ease. long wave transformers and Overtone audio Get your parts today, a few bours work Bnd transformers are the heart of the Thompson your set is ready to be initiated in the Super Seven. Because they are built like realms of distant stations, and you'D be the finest watches they will give you results surprised at the low cost of the complete that you never dreamed possible. parts for so efficient a receiver. Halldorson Overtone Audio Trans­ The ability to detect and reproduce weak formers, each $6.00 lIienals is 80 acute that the set has un· Th. HALLDORSON CO •• :223 W. JacU!lD, Ctncaa:e. W.

§.oM Vernier Drum Dials Beautify the Thompson Super Seven SN 8 .. M 805 vernier drum dial of extremely pleasing appearance is already tremendously popular and its worth is thoroughly proven through its use in such receivers as the Improved Laboratory Model, Aero uFour:' "Six" and "Seven;" the new Harkness creation, the Bodine Eight, and now lends beauty and commercial air to the Thompson Super Seven. Furnished with attractive oxidized brass panel window and universal 0 .. 100, 100 .. a left or rieht black on gold drum scale. Simple to mount, suitable for any type standard shaft con­ denser for panel or sub·panel mounting, or both and universal for either right hand or left hand position. The dial readings are vernier controlled by a panel knob and may be iIIuminated by means of a lamp bracket which is furnished. Price $3.00. If you want the story of true super-quality amplification, full data on nse ~fx n:~eA~h~~I~~~eT~nR~nl. ss~tt~~~c t~~;oi~d;r~~e~f J:~l~~dt ~\;h~i~bkA~ (r,ef:::~ -just send in your name and lOc to cover postage. SILVER-MARSHALL, Inc. 850 W. JACKSON BLVD. I CHICAGO. U. S. A.

Setbuilders Supply CO. 1500H So. Peoria Street CHICAGO, ILL. Ye~y Chosen Again for the FREE Thompson Write at once for com­ Super plete data HowtoBuild the Wonderful

Thompson Super Seven Every live dealer and set builder in radio sets, parts accessories, supplies, etc., should have a copy of this bargain catalog. You will be amazed at tbe thousands of money saving radio = items illustrated and listed in this store~ house of everything you could possibly We can make immediate need in radio. shipment of all parts as ~D:bUl.?R~~pT~KF~RB~bU specified by the engineers The bco1l: contalnl Iii the latest aDd IDMt »OVul ar kit __ 11 the famous, nlt10nally known radio Through pure merit alone partl, accellorlel and luppllf'l the very Dewest Complete Parts Yaxley Approved Radio typf'l and dfl.lgTU of table cabinets and CQDilole. Products have gained for ~,erytbfn£ at prlcel that lDeaD biiller prolltl themselves a place in the for you. new Thompson Super. Short Wave Section g~~1 ca~alo!ecTI~~ devoted to a Ihowlng of the hh:hest grade Ihort Their correct design and wa,e recel,lng and transmitting apparatus. Also superior construction guar­ the .Ilnelit fll~ctrlcal appliancel ror Ule In the antee faultless operation. home. THOMPSON SUPER EEVFN 1 Yaxley Filament All PllrW in Brock ~t&i! Price $78.65. ~tbuildera: Switch ...... $ .50 Writ_ for di.counh. SETBUILDERS SUPPLY CO. 2 Yaxley P up Jacks, SOOH So. P .... ri. St. CHICAGO. ILL. Pair ...... 25 1 -2L Resistance ...... 11i Dealers ~~~e~::~~~rit:t~~~~~Xh;te:7ii~ PI __ rush oomplil" data OD the ThomPWQ Super SeveD 1 -3L Resistance ...... 11i Make More parts, that InBur~1 Ip8(ldy Ihlp- 1 -30 Ohm Rheostat.. $1.35 Money! ~~~ts ~~~ l!.~:te::I~&f:~!ryp~i prlee lI!t and dbcount sbeet and catalCII wiD At YOUI' Dealers be sent to you on request. Nam. M ... _ ...... _ ...... YAXLEY MFG. CO. BUT WaITE QUICKLY Dept. E-9 So. Clinton St. SHURE RADIO COMPANY Chicago 337G Madion Street '- hicag;J. llIinoia A.ddre .. RADIO AGE for October, 1927 29 WITH THE SUPER SEVEN

J Fitlf~eTald. Chl'ca,Ao, 111., writes: And noW' on top of all the Aood news COQle3 On Monda,. night August 29 J logged 35 Itattoo. 111 still Hlore praiae, Louis Buck, Winnipe/!" Can­ two boun Ind the nest night when all powerful loeall ada, adds the final proof were on the 'I.1r wttnt hiH'k and pullr d In 18 of the Have had the THOMPSON SUPER SEVEN working llame JtatioM. The THOMPSON SUPER SEVEN Is DOli' for about 3 wet'ks and have ba.d several . tatlons some ftailver. over three thousand miles reilular. Can ' et the dials Henry Stuerlfl, ChiesA-a, III., Says: at -..n o'eloo11: (aieht o'clock Paclllc Time.) and KFI I have O'flled many supen hut the TbOUWSOD Super comes tbroui'h with enoui h volum.. to dance to. 5el'tJD for tonal quality and dlltanee hal everythiW!' Can alway. pick up PWX. Havana, Cuba, wben tbey beat. I can COfer the country (mm WILli to ront al­ are on tbe air and. hare also bad CYX, Mmoo most every 8'1'enlng, The tonal quality and volume on Clty two or three time ~ . Even up bere where reception dlst3Dce Ita11008 1B uncanny. Precbion built aPDan.tul 11 ralrl1 good I have never hea rd a reeaivu perform Halldorson Precision Long Wave illre make I big dltrerenoo. the wa1 thll onll wilL Transformers each $6.00 Camfield Equaltune Condensers SPECIFIED FOR THOMPSON SUPER 7

THEY ARE MANUFACTUFED IN ALL POPULAR CAPACITIES AND IN UNITS OF ONE TO FIVE A Universal Condenser designed to GANGS. give better operation in any Type Capacity Price 151 (Single) .00015 $ 5.00 radio set 251 (Single) .00025 5.60 252 (Two Gang) .00025 10.00 CAMFIELD CONDENSERS UNEQUALED FOR 253 (Three Gang) .00025 14.00 351 (Single) .00035 6.75 A CCURACY, MECHANICAL DESIGN. ELEC­ 352 (Two Gang) .00035 10.50 TRI CAL EFFICIEN CY. WORKMANSHIP AP­ 353 (Three Gang) .00035 15.00 PEARAN CE AND GENERAL UTILITY. 31:1J (Four Gang) .00036 18.00 355 (Five Gang) .00035 21.00 WRI TE FOR LITE RATURE ON COMPLETE 501 (Single) .0005 6.00 602 (Two Gang ) . 0005 11.50 LIN E OF CAMFIELD RADIO PRODUCTS. 603 (Three Gang) .0005 16.00 11 Mounting Brackets (per pair) CAMFIELD RADIO MFG. CO. M emb er R . M . A. 35 E. Wacker Drive, Chicago

FOR BEST RESULTS Immediate Delivery ELLIS " D" COILS Give that last ounce With the Thompson Super-Heterodyne of Complete Parts of efficiency. Write use the Bodine Deluxe Loop For the New for data on a ll Ellis "D" Coils. The characteristics of THOMPSON SUPER SEVEN Ellis E lect rical Labor. this loop meet per­ atories, 607 Brooks fectly the require- Write Today Bldg., Chicago, III. ,.. menU of the Thomp­ \ son hookup described For your cost on this receiver and a copy of our latest big radio cata­ Fritts Radio , ',,~, ~nt ~h~sr i8~~~e:'h~t:~~ log. Listing everything in radio • odyne sets. It has Cabinets remarkable pick-up at big savings. ability. high tuning Are Master pieces in Solid Walnut efficiency. and sur· WESTERN RADIO MFG. CO. Send for catalog and prices. 128 W. Lake St., Chicago, 1I1. i' !l-~~in~o~f~~m~eLuxe D. H. FRITTS & COMPANY Loop is only 28 inches "Dept. AU high. with a turning 604 Hearst Bldg. Chicago, Ill, radius of 6 inches. Its superbly balanced Write for circulars covering all frame of hand-rubbed Exclusively Specified walnut adds to the Halldorson prodUcts beauty of the most For the Each attractively furnished H alldorson Overtone Audio Trans_ room. The exclusive Thompson Super Seven fornlers ... __ ...... __ ._. __ ...... __ . _ _._ .... $6.00 plug and jack mount­ HaIIdorson O"'ertone Output Trans_ ing eliminates trail­ f ormers ______.... __...... _____ .. ______._._ 6.00 ing wires and a uni­ H a lldorson Precision Long Wave que de\'ice keeps the wires taut. Transformers Type 540 I. C. _ ._ .. ___. __.. _ 6.00 Order model L-500 for .0006 mfd.. and Type 541 Filter . __._ .. _ .. _ _ ._ .... _ .. 6.00 L-350 for .00035 mfd. condensers. Either model $12.00. F ull size blUe prints covering con­ struction of THOMPSON SUPER SEVEN complete set _ .. _... _ ...... __. _ 1.00 CONDENSERS All technieal letters regarding the Thomp_ MAIL THIS COUPON! son Super Seven will be forwarded to Mr. The smallest details in Tobe Conden­ Thompson for his personal attention. He BODINE ELECTRIC COMPANY, sers' have been studied to make them will be glad to tell you about tbe receiver 22.5B W. Ohio St•• Chicallo. • and to assist you in obtaining the max_ Send me full Information on the Bodine De­ the choice of every • imum results from your set. He will aJso Lun LOOD for sIiDer-hete~ setl. engineer. If you. send free to those who enclose 2 cents re­ want to be sure you : t urn postage a complete constructional have the best use ,:.- leaRet with all draw ings for the easy build­ rAJ ing of this wonderful receiver. t-,'ame ...... Tobe Condensers. ~ THE HALLDORSON CO. TOBE DEUTSCHMANN CO. Ch,cago, Ill. F""torY Sal"" OfE."" ,~ddr es s Cambridge Mass. 4745 N. "" ""tero A ve. 223 W . J...,k llOn Blvd. O"Pt.A 30 RADIO AGE for October, 1927 Electricity For Colds as it has been for many weeks. It is di­ rectly south about ten o'clock. If one were A new way of curing colds by applying Correction to watch it night by night, as it moves electric heat to the inft'amed interior of among the stars, and note its position care­ the nose is advocated by Dr. H. Bordier, fully, a peculiar feature of its motion of Lyons, France. The method is credited R200 would be apparent. Jupiter, like all the to a physician of Athens1 Greece, Dr. I planets, moves around the sun from west to Tsinouk~ :: but Dr. Bordier has improved 1 east. But this month it seems to move from and perfeCted it and has subjected it, he east to west. It is in the constellation of reports, tb extensive trial. The method Pisces, the fishes, and at the end of the depends upon the electric treatment month it will be about three and a half de­ called di~thermy. This is reatly the ap­ grees to the west of its position at the be­ plication of heal, not of electricity, but '> ginning of the month. Yet a few months e1ectricity is used to generate the heat. ago, it could have been seen moving from High-frequency electric currents, not un­ west to east, and in November it will seem like the CUrrents used in radio, are sent to turn around and start moving east again. through the body or parts of it and are How is this? Four centuries ago, as for so controlled that a part of their electric two thousand years previously, it was inter­ energy is converted into heat just where preted as an actual change in the motion of the physician wishes that heat to be ap­ the planet. According to the Ptolemaic plied. A hot poultice or a hot water theory, which was then universally ac­ 'bottle applies the heat chiefly at the sur­ cepted, Jupiter moved in a small circle. face of the skin. Interior tissues are This was called the epicycle, and its center heated only by inward conduction of the moved in a larger circle around the earth. heat. The diathermic methods, on the Though. the motion of the 'Center of the other hand, can apply internal heat with­ epicycle was always from west to east, the out heating the outer skin at all. In Dr. motion of the. planet itself was sometimes Bordier's method of treating colds metal in the opposite direction. plates are applied at either side of the nose and the diathermic current is sent Explained by Copernicus between them so that the inner mem­ In 1543, with the publication of the branes of the nose, not the skin, re­ theory of Copernicus that the sun was at ceive the major part of the heat pro­ the center of the solar system, and that the duced. The Lyons physician reports earth, like the other planets, revolved remarkable successes from a few minutes around it, a new explanation was offered. of such treatment. As might be expected, This is the one which we now know to be the treatment is more successful when a true. cold is just beginning than after it is Copernicus showed that we do not ob­ well on its way. Physicians now regard In the blue print section of the Septem­ serve Jupiter from a stationary object. The the common cold as one of the most ber issue, page 19, the circuit diagram of earth, and we with it, are moving. The dangerous diseases, because of the more the Radio Age 6-Tube A C Receiver does combination of the motion of the earth and serious troubles for which it may open not show the grid returns connecting to . the motion of Jupiter is to be blamed for the way. The new treatment will probably negative B lead. The correction is illus­ the backsliding of that orb. Anyone who be tried widely .and soon. trated in the accompanying section of the has been on a train in a station when an­ original circuit lay-put. other came in on the adjoining track can appreciate the situation. Often, it is impos­ sible to tell whether the train we are on, VENUS NOW VISIBLE IN or the other one, is moving. Frequently DAYLIGHT we are greatly surprised, when we have (Continued from page 23) been quite sure that our journey had will stop the blue waves, but will pass the started, to look out the other side, and find slow infra red ones. ourselves still in the station. This gives the means of photographing The situation with Jupiter is the same. stars in full sunlight. A photographic tele­ This month Jupiter, as always, is moving scope, which is nothing but a huge camera, from west to east. So is the earth. But we i.; employed. At the end opposite the lens is are moving faster than Jupiter, and so we placed a plate sensitized to the infra red. leave it behind. We are not aware of the Over the plate is placed a filter that s~ops motion of the earth and so the effect is that all the sky light. Then the star's light, or Jupiter moves backwards. at least a large part of it, gets through, and Square in Pegasus Conspicuous Save 50% leaves its impression on the sensitive emul­ As for the stars this month, the "Great No better "A" Socket Power Unit can be sion. obtained even at twice this amazingly Square" in Pegasus 'is conspicuous and is low price. Combines all the efficiency of At best, however, infra red plates are not indicated on the map. This figure is one of plate current with the undoubted con~ very sensitive compared to ordinary plates, venience of socket power. No bothersome the most familiar in the autumn and early hauling around of batteries to be charged. and so long exposures are required to winter sky. Over to the west, the "North­ No hum or noise. Highest quality West· record even the brightest stars. During inghouse electrical equipment. Operates ern Cross," or Cygnus, the swan, is now on .'50 or 60 cycles at 110 volts A. C. this exposure, the telescope is driven by magnificent in its upright position, with the Thousands of satisfied users prove the clockwork to follow their motion. Faint brilliant Deneb at the top. worth of World Power Units. Approved stars can hardly be recorded at all, so the by rigid tests of Radio News and other Below Deneb, and to the North, is the leading Laboratories. method of photographing stars in the day­ time is principally of interest as an inter­ bright Vega, in Lyra, the lyre. To the Send No Money !dd~e~:;ne a ann~ south is Altair, in Aquila, the eagle. Like :xepr:~~ C.hi8. ~.y s:b~~ ~~ ~~~%~~~ti~~ esting stunt. As long as we have dark nights, astronomers will continue to take the great square, the triangle formed by on arrival. 5 % discount for cash in full Deneb, Altair and Vega, is a useful guide­ with order. NOW is the time to do it. most of their star pictures between sunset and sunrise. post in finding stellar objects. Low in the ~p:JiW~~ east there appears the ruddy Aldebaran, the 1219 SD. Wabash Ave•• Dept. 61. CHICAGO.ILLa Jupiter Also Visible eye of Taurus, the Bull, which in the com­ Sw.twn WSBC owned and ope't'ated b1J W.wld Battery Cumpa'lt'll Jupiter, largest of the planets, is also ing months will be a prominent constella­ visible this month, but in the evening sky, tion in the evening sky. RADIO AGE for October, 1927 31

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AGENTS~~ZB1ID1SCcllnt Make Big Spare - Time Money IOf~~~IS Ihis Price Get your own Radio at wholenle price. It's euy to get orde n for the M .. rwood front your friend" 1:1U:-.:: ~-:- -- and nabou. Folk. buy quiek when they c<:>ntpare ~~~';:~n~u~~~e~:1~o;a~hict":~ri~:y ,,;;:nh~~di! the enornt<:>ulI . . Has Complete A·B Power Unit advertising, M A REAL ALL ELECTRIC Radio with one of the linte dentonstra capital n~ed. ::.tn!:~e~~.etr ~h~t'W:~I~?8e I,:.:::~t;;~~.b"¥h~; bigge"t ..,&lIOn in Radi Marwood can't be excelled at ANY price. If you .. Radio. Get in now. ,h coupon for 30 Days have electricity in your home. jUlt plug into the Free Trial, beautiful at"log, Alrent,,' Confi_ light locket and forge t batt"r;e... No more b,.t_ dential Prices "nd Agentll' New PI.. n. tery trouble and .,Ip"nse. eo"h I""," than 2c .. day to operate. Alway.. have 100% 'YoiuIne. ALL ELECTRIC Radiol are high priced becau.e they are neW. We cut profit to the bone and offer ~o~2~:.~ A~~~~,,~or D$!!;~O b:!"l~~r}{:dio J,I~~ ~~ MARWOOD RADIO CORP. !il"etclet.il,of thi. sen.... tional new ALL ELECTRIC Marwood. 5315 Ravenswood Ave. Dept, A-3 Chicago, Ill. 32 RADIO AGE for October, [927 Uncle Sam Needs More Radio Reports from Ships to Aid Fliers

OWARD the end of April, when T preparations were started for trans­ atlantic flights by airplane, the num­ ber of ocean weather reports received by the Weather Bureau of the United States Department of Agriculture, from ships ply­ ing the north Atlantic steamer lanes took a jump. It increased from four or five a day to twenty-five Of thirty when inter­ est in the flight projects was at its height. As a result, it was possible to keep the flyers well advised as to the winds, storms and fogs they would be likely to encounter. This weather service, without which the hazards of the flights would have been enormously increased. was made possible largely by the voluntary co-operation of shipmasters and of the radio companies, which collected ocean weather lnformation twice daily and delivered it to the \Veath­ er Bureau for charting and analysis. In future transatlatic fiying, such volun­ tary co-operation will hardly be as readily forthcoming, since the novelty of the en­ terprise wil1 be gone and public interest in it less keen. Officials of the Vl eather Bureau are accordingly figuring out what can be done to stimulate interest in ocean weather re­ ports, which are valuable in forecasting weather conditions on land as well as in adding to the safety of flying and of navigation. It is their hope that ship­ masters who have been sending out weath­ er reports in the last two months will have formed the habit and will continue the work when the present flying season is over. Nevertheless, something more perm­ anently dependable is essential. One obstacle is the cost of taking ob­ servations and making them available by radio and telegraph to the weather fore­ casters. This cost has to be met by some­ one, even if it is voluntarily assumed and widely distributed as it was during the period in which weather service was main­ tained for the transatlatic flyers. The Weather Bureau's funds do not suffice for payment of observer. services and radio tolls from all shlps. Ensign S. V. Edwards, U. S. N., seen at the radio set he will operate in the huge That a more complete and extensive Sikorsky plane recently built for trans·Atlantic flights. The set is designed to be organization of ship service is necessary capable of sending and receiving messages from France or the United States as soon is shown by the fact that on some days as it takes the air, having both a low and long wave length. The set weighs 125 while the flyers were waiting for favorable pounds and was built by the Washington Navy Yard.-Photo copyright by Henry conditions the Weather Bureau did not Miller. get a single ship report from areas a thousand miles wide in the Atlantic. Even are no ships in areas where dangerous traffic lanes in the Pacific much more com­ on May 18, two days before Lindbergh conditions exist. Moreover, when ships monly and regularly send weather reports made his successful flight, no report was are warned of storm areas they avoid than those on the New York to Europe received from any ship between longitude t-hem. The hurricane that struck Florida routes in the Atlantic. 40 west and the Irish coast. It was not last year, for example, was forecast by Apparently, moreover, the value of until he had started that weather reports the Weather Bureau,- and ships in the hur­ weather forecasts to Atlantic shipmasters from ships became nearly adequate. When ricane area were advised of its approach. lS not a sufficient inducement to them to Olamberlin made his flight the amount of They got out of the way so promptly make regular weather reports, since most information coming in was more abund­ that for twenty-four hours before the ocean liners are well able to cope with ant than in any previous period and con­ storm struck the coast not a single weath­ ordinary storm conditions. Nevertheless, tinued so even after his successful land­ er report was received from a ship in information of big blows would be of ing in Germany. the hurricane area, for the good reason value to ocean liners. Although the cost of getting ocean that none were there. Another difficulty Eventually, when funds and facilities weather reports is a difficulty, perhaps a is heavy competition for the use of Atlan­ pennit, the Weather Bureau hopes to get greater one is the fact that often there tic radio facilities. Ships on the regular reports twice daily from all the ships in RADIO AGE for October, 1927 33 the Atlantic lanes. Such reports, sup­ many miles away heard it perfectly, al­ stores throughout the country. Forty­ plemented by reports from land stations though the sounds themselves seem to have eight radio departments were included in in this country, in Canada, in Greenland been quite inaudible to the nearby ears. the contract in twenty-eight large cities and Iceland, and also in Europe would Modern radio apparatus can act as a extending from coast to coast. make possible the preparation of complete magnifier for sounds, much as a microscope According to Limes, in taking this order ocean weather charts and dependable fore­ can magnify objects too small to be vis­ the Crosley Radio Corporation acted only casts every day, ible to the naked eye. as agent for its distributors. The sets It is easy for shipmasters to give the will be delivered to the Rose retail depart­ required information. They are asked ments by local Crosley distributors and merely to state the position of their vessel, Radio's Record Order the orders handled through them. the barometric pressure, the barometric The largest order for radio sets ever change in the preceding two hours, the written was reGently given to John L. force and direction of the wind, the kind, Limes, assistant sales manager of the quantity, and movement of clouds, the Crosley Radio Corporation, by R. B. Aus­ presence Or absence of fog, and brief re­ trian and R. B. Rose of the R. B. Rose marks on any unusual weather conditions Company, New York City. The order that may prevail, such as squalls, storms, called for $1,000,000 worth of Crosley or heavy seas. Radio transmission is sim­ radio sets to be sold through radio depart­ plified by the use of a code. ments operated by the Rose Company in

Loud Speakers a Thief Trap ~I A new burglar alarm which will call for help if the wall of a bank vaul t is merely We Carry a Complete Line of Parts for I tapped once or twice with a hammer has the Following Circuits: i been pedected by the Bell Telephone Laboratories and is described in a recent I issue of the Bell Laburatories Record, cir­ culated privately by that institution. The device does not respond to the sound of the blow, as an ordinary telephone would, Worlds Record Super Ten I but to the vibration set up by the hammer­ stroke in the steel or concrete of the vault. This vibration is made to move a delicate electric apparatus, first developed during the war for the purpose of detecting enemy submarines. This device then oper­ Thompson Super Seven ates a second instrument which is a mod­ ification of the unit used in radio loud­ speakers. This, in turn, sends an alarm signal over a wire to a central office, from which help is sent. The vibrations set up in the vault by drilling into it or even by 1928 Infradyne the sputtering of the steel while being melted with an oxy-hydrogen torch or with an electric arc, will also be detected Melo-Heald Fourteen Tubes Improved Remler 45 KC Super by the apparatus. On the other hand, the Electrically Operated T. R. F. Re­ Heterodyne vibration-detector is so constructed that ceiver Aero Short Wave it does not respond to vibrations caused by St. J am.es Super Itnproved Nine-in-Line Receiver persons walking nearby or by railway A Portable "B" Eliminator Test- Aero Seven Tube er Phasatrol trains or passing vehicles. The device is Eight-in-Line Super "tuned" only to those particular vibrations Tyrman Ten Victoreen Super Ultra Powerful Distortionless which indicate danger, just as a string Amplifier of a violin is tuned to one particular note. Q. R. S. ABC Unit The "Best Lincoln" Nine Super The new system has been installed by the Aerodyne Heterodyne Holmes Electric Protective Company in Raytheon ABC Power Unit Two Tube Browning Drake two cities, New York and Philadelphia. Camfield Super 9 Amertran Power Supply Strobodyne Cam.field Seven Silver-Marshall Chicago Daily News Receiver Radio's Acute Ear Magnaformer 9-8 Karas Equamatic Two Dial The superiority of modern radio ap­ paratus to the human ear, considered as a listening device, was demonstrated re­ WHOLESALE RETAIL cently in England during an attempt to broadcast the song of that seldom-heard bird, the nightingale. A feathered song­ ster far off in the distance burst into song NEWARKELECTDIC (Co. while the experiment was going on. The engineers at the microphone heard noth­ ./rO{h0g. btll ~adzo~ ing. The distant song was too faint and the engineers were trying to hear and to 226 WEST MADISON .~nu.T broadcast the song of another bird, be­ TEl-EPHONE, lieved to be near at hand but silent. How­ ever, the distant song, missed by the hu­ MAIN. 4627 man ears that were on the spot, was pic,ked up by the specialty sensitive microphone that · was being _used and was' broiidcast, ILLINOIS without the knowledge ' of the e~gi.neers CHICAGO directing the experiment. Radio listeners 34 RADIO AGE for October, 1927 Independent Radio Manufacturers Start Battle By OSWALD F. SCHUETTE, Executive Secretary, Radio Protec:tive Association

HE case of the so-called "in­ pany and its subsidiary, the Western Elec­ cent. The American Te1ephone and T e1e­ T dependent" radio manufacturers tric Company, were put into the pool, and graph Company was given the exclusive against the Radio Corporation of another year-in June, 1921-that the pat­ right to all commercial activity in wire­ America rests upon a vital and funda­ ents of the Westinghous~ Electric and less telephony. What , does this promise mental principle that is impor'tant to all Manufacturing Company and its sub­ for the development of wireless telephony American industry. Ever since the Sher­ sidiary, the International Radio Telegraph in the United States? We are stilt using man Anti-Trust law passed in 1890, at­ Company, were absorbed under a series telephone apparatus developed thirty years tempts have been made to evade its pur­ of agreements which practically divided ago, although many improvements have pose by private corporations, under the the ownership and control of the Radio been made in the art and have long been pretext of patent ownership. The fun­ Corporation among the General Electric ill use in Europe. Wireless teleph

The Telephone's Progeny The telephone, most widely used of communication devices: has become the father of an illustrious family of com­ munication instruments. These include Triumphant! the Vitaphone which furnishes a voice to the motion picture screen; an audiometer "TONATROL" to test hearing ; an audiphone to aid the A True Tone and Volwne Control hard of hearing: an electrical stethoscope which amplifies the faintest heart sounds; Enjoy your radio to the utmost a public address system which carries a by having at all times the exact speaker's voice to crowds of thousands volume your mood and taste de­ sires. This is easy if you install and tens of thousands; and the micro­ "Tonatrol" . phone-the heart of the radio. "Tonatrol" controls volume from a whisper to the most powerful tones-quickly-instantly. ~ fine Standard "ENSCO" Kit Electric Darts addition to any set. RadlO ex­ $1 0 00 With Hardwood A tree trunk actually blown to bits by perts endorse it. • Wall Fraine, $11.00 lighting, as though by a dynamite bomb Tonatrol-8tandard Volume It cont",imI"Ensco" Direct-dri placed inside it, is described by Dr. N. Contro1. List price $1.50. hy Clyde J. Fitch. Beautifully TEX Cone l;1ateria. Ernest Dorsey, of Washington, D. C, in tle.Ke illU'ltrated Boo Tonatrol-Type W. S. (\v:ith of 8lx styles of Cone a recent issue of the Monthly Weather filament svvitch attached) Speaker, sir.e" 24, 30 or36 inches . on can build;t in lesa than a n hour. Static lIU!.terially reduced_inter results all .. urn- Revie\v, official publication of the United List price $2.00. States Weather Bureau. The tree was WrUe For free installation booklet For struck by a lightning bolt in Jacksonville. the corre<::t way to eontrol volutne. Illinois, on the afternoon of April 13, 1927. nThe World's Fined Loud Speo.ker>l Photographs made immediately were sub­ Now witbin the means of everyone. At your de. ler'. or mitted to Dr. Dorsey by Mr. Frank P. direct from any of the oflicu list.ed below. Send cheek. money order or C. O. D. Shipping CbargM D&id. In Canada Norbury, a cooperative observer of the prices are $ 11.50 &lld $ 12.50. Abllolute (money hack) r;uaran­ Weather Bur eau at Jacksonville. The ~ .. ENGINEERS' SERVICE COMPANY lightning did not strip off the bark or 2S Church 51., New York 73 Cornhill, Bulon knock off a limb or 1\vo; it literally blew 28 E. Jackson Blvd., Chieagu 331 Bay S .. , Toronto, Ontario the tree to bits. The incident supplies, Dr. Dorsey believes, support for his theory that lightning does not consist of ordinary elec­ tric sparks but of "darts" of concentrated electricity, shot do\'m from the clouds like bullets from a gun. Ordinary electric sparks \ ... ould merely follow the outside of the tree into the ground. The imagined dart of lightning, on the other hand, might penetrate the trunk, just as a bullet would To the Man with an Idea do. Inside the wet wood this electric I offer a comprehensive, experi. bullet \vould cause a powerful steam ex­ enced efficient service for hi.s prompt, legal protection and the plosion, disrupting the trunk exactly as development of his proposition. did happen in this instance. Send sketch of model and de­ scription, for advice as to cost, search through prior United States patents, etc. Preliminary advice Airplanes of the Future gladly Furnished without charge. My experience and familiarity That the airplane of the future will be with various arts Frequently en­ large enough to carry a hundred passen­ able me to accurately advise eli_ ents as to probable patentability gers; able to land almost vertically, so heFore they go to any expense. that any field will serve for emergency Booklf>t f)f valuable information fJ/nd landings ; capable of taking off or landing form for properly disclosing lIour on the roofs of city buildings; fireproof, idea free on request. Write today. and equipped for flying at a speed of three RICHARD B. OWEN. Patent Lawye. hundred miles an hour and at a height 81 Owen Bldg" Washington, D. C. 41-M Park Row, N, y, City of 30,000 feet above the ground, are pre­ dictions made by Professor A lexander Klemin, head of the Daniel Guggenheim School of Aeronautics, in a statement issued by New York University. Air planes as large as ocean liners, Pro­ fessor Klemin considers improbable, as the theory of the support of aircraft in the air calls for a limit of size at about the point of a fifty-ton machine with the hundred-passenger capacity. The higher speed at high altitudes \vill be attained by the super-charger, a device already in use to compress the air before supply­ ing it to the engine. 42 RADIO AGE for October, 1927 WCBS H. L. Lewing ...... _.. _.. _ .. _...... _.. _...... _... Springfield, Ill. 210 WGMU Atlantic Bdcst. Co____ ._._ .... _...... _. ______New York, N. Y. 201 weco Washburn-Crosby Co ______Anoka, Minn. 405 WGN The Tribune..... _.. _.. _.. _.. _.. _.. _...... _ .. _.. _... Chicago, Ill. 306 WCFL Chicago Fed. of Labor._ ...... _.. _.. _.. _.. _.. _... Chicago, Ill. 484 WGR Federal T. and T. Co...... Buffalo ,N. Y. 303 WCGU C. G. Under ...... _.. _.. _.. _...... _.. _.. _.. _... Lakewood, N. J. 211 WGST Georgia School of Technology ______Atlanta, Ga. 270 WCLO C. E. Whitmore._.. __ ...... _.. _ .. _.. _... Camp Lake, Wis. 227 WGWB Radiocast Corporation ______Milwaukee, Wis. 219 WCLS WCLS, Inc. .... _.. _.. _.. _.. _.. _.. _.. _._.. _.. _.. _.. _... Joliet, Ill. 216 WGY General Elec. Co______SChenectady, N. Y. 379 WCMA Culver Military Academy.. ______.. ______.Culver, Ind. 258 WHA University of Wisconsin ______Madison, Wis_ 319 WCOA City of Pensacola._ ..... ______.. Pensacola, Fla. 250 WHAD Marquette University______Milwaukee, Wis. 294 WCOC Crystal Oil Co ...... __ .. ______.__ ., ... __ .. Colllmbus. Miss. 231 WHAM Stromberg-Carlson Tel. Mfg. Co ______Rochester, N. Y. 278 WCOT Jacob Conn ...... _.. _...... _.. _.. _...... _...... Olneyville, R. I. 225 WHAP W. H. Taylor Finance Corp______New York, N. Y. 236 WCRW Clinton R. White._.. _.. _...... _.. _...... _.. _... Chicago, Ill. 224 WHAR F. D. Cooks Sons ____ ~ ______Atlantic City, N. J. 273 WCSH Congress Square Hotel Co. ___ .. ______.Portland, Maine 361 WHAS Courier-Journal & Louisville Times. ___ Louisville, Ky. 461 WCSO Wittenberg College.______.:. ___ .Springfield, Ohio 256 WHAZ Rensselaer Polytechnic Institute ______Troy, N. Y. 379 WCWK Chester W. Keen.__ ...... _____ .... ______.Fort Wayne, Ind. 229 WHB Sweeney School Co______Kansas City, Mo. 337 WCWS Bridgeport Bdcst. Sta.______.Bridgeport, Conn. 214 WHBA C. C. Shaffer...... 'Oil City, Pa. 261 WCX Detroit Free Press______Pontiac, Mich. 441 WHBC Rev. E. P. GrahanL ______Canton, Ohio 236 WDAD Dad's Auto Accessories, Inc ______Nashville, Tenn. 225 WHBD Chamber of Commerce______Bellefontaine, Ohio 222 WDAE Tampa Daily T mes ______Tampa, Fla. 268 WHBF Beardsley Specialty Company___ "______Rock Island, Ill. 222 WDAF Kansas City Stair______Kansas City, Mo. 370 WHBL James H_ Slusser ______Chicago, Ill. 204 WDAG J. Laurence Martia ______Amarillo, Texas 263 WHBM C. L. CarreIL______~ ___ Chicago, Ill. 201 WDAH Trinity Methodist Church __ .______EI Paso, Texas 234 WHBN First Ave. Methodist Church______St. Petersburg, Fla. 297 WDAY Radio Equipment Corp______Fargo, N. D. 361 WHBP Johnstown Automobile Co ______Johnstown, Pa. 229 WDBJ Richardson Wayland Elec. Corp______Roanoke, Va. 231 WHBQ WHBQ, Inc ______Memphis, Tenn. 232 WDBO Orlando Broadcasting Co ______Oriando, Fla_ 288 WHBU Bings Clothing-Riviera TheateL _____ Anderson, Ind_ 219 WDBZ Boy Scouts of America ______Kingston, N_ Y. 216 WHBW D. R. Kienzle... _...... _... Philadelphia, Pa. 220 WDEL Wilmington Elec. Specialty Co ______\Vilmington, Del. 265 WHBY St. Norbert's College. ______\Vest de Pere, \Vis. 250 WDGY Dr. George W. Young______Minneapolis, Minn. 263 WHDI \V_ H. Dunwoody Institute______Minneapolis, Minn_ 246 WDOD Chattanooga Radio Coo, Inc ______Chattanooga, Tenn_ 246 WHEC Hickson Electric Coo, Inc ______Rochester, N. Y. 232 WDRC Doolittle Radio Corp ______New Haven, Conn. 275 WHFC Triangle Broadcasters______Chicago, Ill. 216

WDWF Dutee Wilcox Flintt Inc ______Cranston, R. I. 375 WHK The Radio Air Service Corp.______Cleveland, Ohio 265 WDWM Radio Industries Broadcast Co _____. ______Newark, N. J. 361 WHN Loew's State Broadcasting Station __ New York, N. Y. 395 WDZ J. L. Bush...... _.. _.. _.. _...... _.. _...... _... Tuscola, Ill. 278 WHO Banker's Life Co. __ ._____ ~ ______Des Moines, la. 535 WEAF National Broadcasting Co ______N ew York, N _ Y _ 491 WHT Radiophone Broadcasting Corp ______Deerfield, IlL 416 WEAM Bor. of N. Plainfield ...... _... North Plainfield, N. J. 240 WIAD Howard R. Miller...... _...... Philadelphia, Pa. 220 WEAN The Shepard Co...... _.. _...... Providence, R. J. 319 WIAS Home Electric Co ______Burlington, Iowa 476 WEAO Ohio State University______Columbus, Ohio 283 WIBA Capital Times-Strand Theatre.. ______Madison, Wis_ 240 WEAR Willard Storage Battery Co. ______Cleveland, Ohio 400 WIBG St. Paul's Protestant E. Church______Elkins Park, Pa_ 441 WEBC Head-of-the-Lakes Radio Station ______.5uperior, Wis. 242 WIB! Frederick B. Zittell, Jr ______Flushing, 1. I., N. Y. 268 WEBE Roy W. Waller ..... _...... _...... _...... _... Cambridge, Ohio 248 WIBJ C. L. Carrell ...... _... Chicago, IlI. 201 WEBH Edgewater Beach HoteL...... _...... _... Chicago, Ill. 366 WIBM C. L. CarrelL .... _...... _... Chicago, Ill. 201 WEBJ Third Avenue Railway Co ______New York, N. Y. 256 WIBO WIBO Broadcasters, Inc ______Chicago, Ill. 416 WEBQ Tate Radio Corp ______...- ______Harrisburg, Ill. 225 WIBS N. J. National Guard...... _...... Elizabeth, N. J. 203 WEBR H. H. HoweIL.... _.. _.... _.. _.. _...... _...... Buffalo, N. Y. 242 WIBU The Electric Farm______Poynette, Wis. 217 WEBW Beloit College ______Beloit, Wis. 259 WIBW C. L. CarreIL.. _.. _ .. _.. _...... _.. _ ...... Chicago, IlL 204 WEDC E. Denemark Station ______Chicago, Ill. 242 WIBX WIBX, Inc ______Utica, N. Y. 238 WEEI The Edison Elec. Illuminating Co ______Boston, Mass. 448 WIBZ A. D. Trul1l.______Montgomery, Ala. 231 WEHS A. T. Becker ______Evanston, Ill. 216 WICC Bridgeport Bdcst. Station______Bridgeport, Conn. 214 WEMC Emanuel Missionary College. ___ Berrien Springs, Mich_ 238 WIL Benson Radio Co ______St. Louis, Mo_ 258 WENR Great Lakes Broadcasting Co ______Chicago, Ill. 288 WIOD Earl G. Fisher Co. ______Miami, Fla. 248 WEPS Matheson Radio Coo, Inc ______Gloucester, Mass. 297 WIP Gimbel Bros. ______Phiiadelphia, Pa. 508 WEW St. Louis University ______.5t_ Louis, Mo_ 353 WJAD Hotel Raleigh______. ______Waco, Texas_ 448 WFAA Dallas News & Dallas Journal ______Dallas, Texas 500 WJAG Norfolk Daily News. ______Norfolk, Neb. 286 WFAM Times Publishing Co ______St. Cloud, Minn. 252 WJAK Kokomo Tribune.. ______Kokomo, Ind. 234 WFBC First Baptist Church ______Knoxville, Tenn. 234 WJAM D. M. Perham__ .. ______Cedar Rapids, Iowa 384 WFBE ~arfield Place Hotel Co ______Cincinnati, Ohio 246 WJAR The Outlet Co. ______Providence, R. I. 484 WFBG The Wm. F. Gable Co ...... _.. _ .. _ .. _.. _.. _... Altoona, Pa. 280 W J AS Pittsburgh Radio Supply House.. ______Pittsburgh, Pa. 270 WFBJ St. John's University______Collegeville, Minn_ 273 W JAX City of J acksonville.. ______Jacksonville, Fla. 337 WFBL The Onondaga Co..... _.. _ .. _...... _ .. _... Syracuse, N. Y. 259 WJAY Cleveland Broadcasting Corp ______Cleveland, O. 221 WFBM Indianapolis Power & Light Co ______lndianapolis, Ind_ 225 WJAZ American Bdcast. Corp__ ___ Mt. Prospect, Ill. 263 WFBR Fifth Infantry National Guard ______Baltimore, Md. 225 WJBA D. H. Lentz, Jr.... _.. _...... _ .. _...... _... Joliet, Ill. 322 WFBZ Knox College..... _.. _.. _.. _.. _.. _.. _.. _ .. _...... Galesburg, Ill. 248 WJBB Financial JournaL ______St. Petersburg, Fla. 345 WFCI Frank Crook, Inc. ______Pawtucket, R. I. 225 WJBC Hummer Furniture Co ______LaSalle, Ill. 21:1 WFDF F. D. Fallain ______Flint, Mich_ 349 W JBI Robert S. J OhnSOIL._...... Red Bank, N. J. 256 WFHH Chamber of Commerce ______Oearwater, Fla. 366 WJBK E. F. Goodwin ______Ypsilanti, Mich. 220 WFI Strawbridge and Clothier______Philadelphia, Pa. 405 WJBL Wm. Gushard Dry Goods Co .... _...... Decatur, Ill. 213 WFIW The Acme Mills. Inc ______HopkinsviIle, Ky. 280 WJBO Valdemar Jensen______New Orleans, La. 263 WFKB Vesta Battery Corp ______Chicago, 111_ 224 W JBR Gensch and Stearns. ______Omro, Wis. 227 WFLA Boca Raton Radio Corp ______Boca Raton, Fla. 213 WJBT John S. Boyd ...... _...... _.. _...... _...... Chicago, Ill. 389 WFRL Flatbush Radio Labs. .. _...... _...... _.. _... Brooklyn, N. Y. 219 WJBU Bucknell University______Lewisburg, Pa. 214 WGAL Lancaster Elec. Supply & Const. Co ____ Lancaster, Pa. 252 WJBW C. Carlson, Jr.______~ ______~ ______New Orleans, La. 238 WGBB H_ H. Carman ______Freeport, N. Y. 246 WJBY Electric Construction Co. ______Gadsden, Ala. 234 WGBC First Baptist Church ______Memphis, Tenn. 278 WJBZ Roland G. Palmer... _...... _.. _... Chicago Heights, III. 208 WGBF Fink Furniture Co ______Evansville, Ind. 236 WJJD Supreme Lodge, 1. O. of Moose. ______Mooseheart, Ill. 266 WGBI Scranton Broadcasters. Inc______SCranton, Pa. 231 WJPW J. P. Wilson...... _ ..... _...... Ashtabula, Ohio 208 WGBS Gimbel Brothers______Astoria, 1. L, N. Y. 349 WJR Station WJR, Inc.______Pontiac, Mich. 441 WGCP Lanter Piano Co ______Newark, N. J _ 280 WJZ Radio Corp. of America ______Bound Brook, N. J. 454 WGES Oak Leaves Broadcasting Corp ______Chicago, Ill. 242 WKAQ Radio Corp. of Porto Rico ______.______San Juan, P. R. 341 WGHP G_ H_ Phelps______Detroit, Mich. 319 WKAR Michigan State College______East Lansing, Mich. 285 WGL International Broadcasting Corp ______Secaucus, N. Y. 294 WKAV Laconia Radio Club______Laconia, N. H. 224 WGM Verne and Elton SpenceL ______-1eanette, Pa. 208 WKBB Sanders Bros.______. ______Joliet, Ill. 216 RADIO AGE for October, 1927 43

Announcement IN making a report on tests of a new seven-tube super-heterodyne which has been developed in the Radio Age laboratories our technical depart­ ment brought in such good news about the circuit that we decided to pass it on to our readers. Full instructions on how to build the set, with illustra­ tions, including blueprints, will be published exclusively in the November issue of this magazine. THE Quadrode (Four Element) Superheterodyne does not merely present something new and differ­ ent in the arrangement of parts. It is not merely a modification of the reflex. It is not a reflex. It introduces an element into superheterodyne con­ struction that has never before been used. This new method makes it possible to obtain power, selectivity and tonal quality equal to those of the best eight-tube sets. The fans will readily recog­ nize the economy in time and effort and money in this elimination of one tube. THE editors believe that this circuit will arouse the interest and eventually the enthusiasm of fans everywhere. Simplicity, compactness, excellent performance-those are characteristics sufficient to make the Quadrode popular, but it has that new feature which makes it an outstanding phase of this season's radio development. Do not miss this illustrated article in the Novem­ ber Radio Age. If you are unable to obtain it at the newsstands send 30 cents in stamps and we will mail a copy direct The November issue will be on the stands Nov. 1. 44 RADIO AGE for October, 1927

WKBC H. L. Ansley______Birmingham. Ala. 219 WNAC Shepard Stores.. ______.. _..... Boston, Mass. 353 WKBE K. & D. Electric Co .... _.. _.. _.. ______._Webster, Mass. 229 WNAD University of Oklahoma__ . ______Norman, Okla. 240 ,\VKBF N. D. WatsoIL ______Indianapolis, Ind. 252 WNAL Omaha Central High SchooL.._ .. _.. _.. _ ... Omaha, Nebr. 258 WKBG C. L. CarreIL.. _...... _.. _.. _.. _.. _.. _.. _.. _.. _._Chicago, Ill. 201 WNAT Lenning Brothers Co. ______Philadelphia, Pa. 283 WKBH Callaway Music Co.... _...... _.. _.. ______LaCrosse, Wis. 220 WNAX Dakota Radio Apparatus Co. ______Yankton, S. Dak. 303 WKBI F. L. SChoenwoIL ...... __ .._ ...... _.. _.. _ .. _.. _... Chicago, 111. 322 WNBA M. T. Rafferty..... _.. _...... _.. _...... _... Forest Park, III. 208 WKBL MonTana Radio Mfg. Co. ______.. __ Monroe, Mich. 205 WNBF Howitt-\Vood Radio Co.______. ___ Endicott, N. Y. 207 WKBN Radio Electric Service Co. ______Youngstown, Ohio 214 WNBH New Bedford HoteL ______New Bedford, Mass. 261 WKBO Cami th Corpora tion ______. __ .. __ . ______l ersey City, N. J. 219 WNBJ Lonsdale Baptist ChurclL.. ______.._Knoxville, Tenn. 207 WKBP Enquirer and Ne'vs_ .._ .. _ .. _ .. _. ______Battle Creek, Mich. 213 WNBL Gray, Trimble & Smith Electric Co. __ Bloomington. Ill. 200 WKBQ Starlight Amusement Park.. _____ . ______.New York, N. Y. 219 WNBO John Brownlee Spriggs.. ______. _____ ..__ Washington, Pa. 21l WKBS P. M. NelsorL.._ .. _.. _.. _.. _.. _ .. _.. _.. _ .. _ ... Galesburg, III. 217 WNBR Popular Radio Shop._. _____ ._. __ .. __ ._... __ Memphis, Tenn. 229 WKBT First Baptist Church______New Orleans, La. 252 WNBQ Gordon P. BrowIL ______Rochester, N. Y. 203 WKBV Knox Battery and Electric Co ______Brookville, Ind. 217 WNJ Herman Lu binsky... _ .. _.. _.. _.. _ .. _.. _..... N ewark, N. J. 280 WKBW Churchill Evang. Ass'o______Buffalo, N. Y . 217 WNOX Peoples Tel. & Tel. Co_ .. ______Knoxville, Tenn. 265 WKEZ K. L. Ashbacker______Ludingtoo, Mich. 200 WNRC W. B. Nelson. ______Greensboro, N. C. 224 WKDR Edward A. Dato. ______Kenosha, Wis. 322 WNYC Dept. of Plans & Structures______New York, N. Y. 535 WKJC Kirk Johnson & Co. ______.. ______Lancaster, Pa. 252 WOAI Southern Equipment Co.______San Antonio. Texas 303 WKRC Kadel Radio Corp.______Cincinnati, Ohio 333 WOAN J. D. Vaughn. ___ .._. __ . __ .. _. __ . __ ._._Lawrenceburg, Tenn. 286 WKY WKY Radio Co. ______Oklahoma City, Okla. 288 WOAX Franklin J. Wolff... _.. _ .. _.. _.. _ .. _ .. _.. _... Trenton, N. J. 240 WLAC Life & Casualty Ins. Co. ______Nashville, Tenn. 226 WOC Palmer School of Chiropractic.. __ ... __ Davenport, Iowa 353 WLAP Virginia Avenue Baptist ChurclL______Louisville, Ky. 268 WOCL A. D. NewtoIL .. _.. _.. _.. __ ._...... _... _.. _Jamestown, N. Y. 224' WLB University of Minnesota. ______Minneapolis, Minn. 246 WODA O'Dea Temple of Music.. ______Paterson, N. J. 294 WLBC D. A. BurtoIL ______Muncie, Ind. 210 WOI Iowa State College ____ . __ .. _. __ .. _.. _.. __ ._.... _Ames. Iowa 265 WLBF E. L. Dillard... ______Kansas City, Mo_ 211 WOK Chicago Beach Hotel ___ .._. ____ .._ .. _.. _._Homewood, Ill. 252 WLBG R. A. Gamble. .._ .. _.. _.. _ .. _._ .._ .. _ .. _.. _ ... Petersburg, Va. 214 WOKO Harold E. Srnith... _.. _._ .. _.. _.. _.. _.. _... Peekskill, N. Y. 216 WLBH Joseph J. LombardL ______Farmingdale, N. Y. 232 WOKT Titus-Ets Corporation______~ ______Rochester, N. Y. 210 WLBI Legion Broadcasters, Inc ______East \Venona, Ill. 23& WOMT Mikado Theater... _ .. _. ______Manitowoc, \Vis. 222 WLBL \Visconsin Dept. of Markets______Stevens Point, \Vis. 319 WOO John Wanamaker... _ .. _.. _. . _.. _.. _..... Philadelphia, Pa. 508 WLBM Browning Drake Corp.______Boston,-Mass. 231 WOOD \Valter B. Stiles, Inc.______Femwood, Mich. 261 WLBN 'William Evert Hilec______Chicago, Ill. 204 WOQ Unity Sc..hooL ______._.. _.. _.. __ ._.. _Kansas City, Mo. 337 WLBO Frederick A. Tribbe, Jr..______Galesburg, 111. 217 WOR L . Bamberger and Co. ______.. __ ._. __ .. _Newark, N. J. 422 WLBP R. A. Fox. .._ .. _.. _. . _.. _.. _...... _.. _ .. _ .. _.... .Ashland, Ohio 203 WORD People's Pulpit Assn .... _._ .. _.. _.. _.. _ .. _.. _... Batavia, III. 275 WLBQ E. Dale TrouL._.. _.. _.. _ .. _ .. _.. _.. _ .. _ .... _.... .Atwood, III. 203 WOS State Market Bureau______. __ ._. __ Jefferson City, Mo. 469 WLBR Alford Radio Company______Belvidere, 111. 322 WOW Woodman of the World.... ______Omaha, Nebr. 508 WLBT Harold \VendeIL ______Crown Point, Ind_ 322 WOWO Main Auto Supply Co .... _.. __ . ______Fort Wayne. Ind. 229 WLBV John F. Weimer & D . A. Snicl<..._.. _... Mansfield, Ohio 207 WPAP (See WQAO) ... _.. _.. _.. _.. _ .. _.. _.. _.. _ .. _... Cliffside, N. J. 395 WLBW Petroleum Telephone Co __ . ______. ______Oil City, Pa. 294 WPCC North Shore Congo Church_.. _ .. _.. _. . _.. ____ Chicago, Ill. 224 WLBX John N. Brahy_._ .._ .. _ ...... _... Long Island City; N. Y. 204 WPCH People's Broadcasting Corp .... _.. _... New York, N. Y. 309 WLBY Aimone Elec ______Iron Mountain, Mich. 210 WPEP IVlaurice Mayer______\Vaukegan, Ill. 216 WLBZ Thompson L. Guernsey__ . ______.Dover-Foxcroft, Maine 208 WPG The Municipality of Atlantic City.Atlantic City, N. J. 273 WLCI L utheran Association_. ______Ithaca, N _ y_ 248 WPRC Wilson Printing & Radio Co_. __ .. __ ._ .._Harrisburg, Pa. 210 WLIB Liberty Weekly, Inc. ______Elgin, 111_ 306 \\'PSC Pennsylvania State College ______State College, Pa. 300 WLIT Lit Bros... _.. _.. _.. _.. _.. _.. _.. _.. _.. _.. _... Philadelphia, Pa. 405 WPSW Philadelphia School of \Vireless Tel. __ Philadelphia, Fa. 203 WLS Sears Roebuck & Co ______._. __ . __ Crete, III. 345 WQAA Horace A. Beale, J r. ______.. _.... _... Parkersburg. Pa. 216 WLTS Lane Technical High School..______Chicago, Ill. 484 WQAM Electrical Equipment Co.. _._. ______Miami, Fla. 322 WLW Crosley Radio Corp.______Harrison, Ohio 428 WQAN Scranton Times... _. ______.. _.. .5cranton, Pa. 261 WLWL Paulist Fathers.. ______New York, N. Y. 370 WQAO Calvary Baptist Church... _ .. _.. _ .. _...... Cliffside, N. J. 395 WMAC C. B. Meredith. ______Casenovia. N. Y. 225 WQJ Calument Rainbo Broadcasting Co ... __ .._Chicago, Ill. 448 WMAF Round Hills Radio Corp. ____ . ______Dartmouth, Mass. 428 WRAF The Radio Club (Inc.)... _.. _.. _.. _.. _.. _... LaPorte, Ind. 208 WMAK Norton Laboratories. ______Lockport, N_ y_ 545 WRAH S. N. Read____ .. _. __ . __ .. _____ . ______~ ______ProvidenceJ R. I. 200 WMAL M. A. Leese__ . ______. ______\Vashington, D. C. 303 WRAK Economy Light Co.______.... Escanaba, Mich. 283 WM:AN First Baptist Church. ______. ______Columbus, Ohio 234 WRAM Lombard College.. ___ ..__ ._.. _.. _.. _.. _.. _.. _Galesburg, Ill. 248 WMAQ Chicago Daily News __ . ____ .. _.. __ ._ .. ______Chicago, Ill. 447 WRAV Antioch College._. __ ._...... ______Yellow Springs, Ohio 341 Wf\.1A Y Kingshighway Presbyterian ChurclL ___ St. Louis, Mo. 248 WRAW Avenue Radio & Electric Shop-______._ ... Reading, Pa. 238 WMAZ Macon Junior Chamber of Commerce.. __ ... Macon, Ga. 270 WRAX Beracah Church, Inc.______.. _. . _... Philadelphia, Pa. 283 WMBA LeRoy Joseph Beebe. .. _.. _...... _.. _.. _... Newport, R. I. 204 WRBC Immanuel Lutheran Churcb. ______Valparaiso, Ind. 238 WMBB American Bond & Mortgage Co._.. _. _____ . __ Chicago, Ill. 252 WRC Radio Corp. of America______\Vashington, D. C. 468 Wf\.1BC Michigan Broadcasting Co., Inc. ______Detroit, !\'Iich. 244 WRCO Wayne Radio Co.... _.. _.. _.. _ .. _.. _.. _ .. _... Raleigh, N. C. 217 WM:BD Peoria Heights Radio Lab.______Peoria Heights, Ill. 205 WREC \VREC, Inc.__ .. _. __ .. _._ .._._ .. _.. _... _____ \Vhitehaven, Tenn. 254 WMBE Dr. C. S. Stevens.. ______.5t. Paul, I\·linn. 208 WRES H . L. Sawyer... _.. __ ._ .. _.. _. ______\Voloaston, Mass. 217 WMBF Fleetwood Hotel Corp.... _.. _.. _.. _... Miami Beach, Fla. 384 WRHF Wash, Radio Hospital Fund .... _... Washington, D, C, 319 WMBG Havens & MartiIL. __ . ______Richmond, Va. 207 WRHM Rosedale Hospital, I nco_. ___ ._.. _... __ Minneapolis, Minn. 252 WMBH Edwin Dudley AbeL.. ___ .. _.. _ .. _...... _.. _. .. Chicago, III. 204 WRK Doron Bros. ______._ .. _.. _. . _. ___ . ______. ___ Hamilton, Ohio 205 WMBI Moody Bible Institute __ .__ ._. ______._ .. _... Chicago, Ill. 263 WRM University of Illinois..__ ... ______... ______..... Urbana, Ill. 273 WMBJ Wm. Roy McShaffrey... _.. _.. _ .. _.. _.. _... Monessen, Pa. 232 WRMU Atlantic Bdcasting Co.__ .. ____ .. _. ______New York, N. Y. 201 W1\1BL Bonford Radio Studio5.. ______.. ______Lakeland, Fla. 229 WRNY Experimenter Publishing Co ... ______Coyetsville, N. Y. 309 WMBM Seventh Day Adventist Church______Memphis, Tenn. 210 WRR City of Dallas... __ .. _. __ .. ______. ___ .... _Dallas, Tex. 353 WMBO Radio Service Laboratories. ______Auburn, N. Y. 220 WRRS F. G. Leavenworth. ___ .. _.. ______. ___ Racine. Wis. 322 WMBQ Paul J. Gollhofer..._ .. _...... _.. _ .. _.. _..... Brooklyn, N. Y. 204 WRSC The Radio Shop... _ ...... _.. _.. _ .. _ ...... _..... Chelsea, Mass. 205 WMBR Premier Electric Co .... _.. _.. _. __ .. _.. _. ______Tampa, Fla. 252 WRST Radiotel Mfg. Co., Inc .... _.. _ .. _ .. _.. _... Bay Shore, N. Y. 211 WNIBS Mack's Battery Co. _____ . ______Harrisburg, Pa. 234 WRVA Larus & Brother Co., Inc .... _. ______Richmond, Va. 254 WMBU Paul J. Miller..._ .._ .. _.. _...... _.. _ ...... Pittsburgh, Pa. 217 WSAI United States Playing Card Co. ______Cincinnati. Ohio 361 WMBW Youngstown Bdcstg. Co .• Inc ...._ .. _. __ youngstown, O . .~14 WSAJ Grove City College._._ .. _. ___ ._ .. _.. _.. _ ... Grove City, Pa. 224 WMB¥ Robert A. lsaac5.. ______.. ______. __ Bloomington, Ill. 200 WSAN Allentown Call Pu bUshing Co. Inc._._._.Allentown, Pa. 222 WMC Commercial Pub. Co.____ ... ____ .. ____ .. __ ... Memphis, Tenn. 517 WSAR Daughy & \Velch Electrical Co_ .. _..... Fall River, Mass. 252 WMCA Greely Sq. Hotel Co ...... _.. _.. _...... _.... . HobokeD, N. J. 370 WSAX Zenith Radio Corp.... _. ______. __ ...... _.. _.. __ ..... Chicago, Ill. 204 WMPC First Methodist Church. ____ ._. ______.Lapeer, Mich. 234 WSAZ Chase Electric Shop____ . ____ ._ .. _. __ Huntington, '\V. Va. 242 WMRJ Peter J. Prinz______..______.Jamaica, N. Y. 207 WSB Atlanta JournaL __ . __ ...... _.. _. ______.._. _____ Atlanta. Ga. 476 WMSG Madison Sq. Gard. Bdcast. Corp ... New York, N. Y ..2 36 WSBC World Battery Co ...... _.. _.. _.. _...... _ ...... Chicago, Ill. 232 RADIO AGE for October, 1927 4S Radio Industry Standards such a height in public interest, the show will be doubly interesting to the fan. H. B. Richmond, of the engineering di­ This year, too, the display of radio ap­ vision of the Radio Manufacturers Asso­ paratus staged by the manu facturers wil1 ciation sends the following interesting in­ be backed up by the "Theater of \Vireless formation on standardization of radio Wonders" in which will be displayed the products: latest achievements in scientific research. "Much confusion has formerly existed These exhibits, or at least many of them, in the radio industry, because of two had their firs t public demonstration at the separate technical standards set up by two Radio World's Fair in New York. organizations within the industry. Each The exhibits, which will be grouped on of these standards had been set up in good the balcony of the main exposition hall, faith, and represented the accepted prac­ will inc1ude devices by which the infinitis­ tice of its particular group. mal atom can be measured, seen and even "Radio has been phenomenal in its heard. Amp1ifiers which build up sound growth. It is, therefore, only natural that to millions of times its original volume organizations within the trade should show will make flowers "talk" and other devices a similar growth. 'Vi thin a period of a 0·1 will touch them with a wireless ray which '"Mfd. Model 0 - 10 . few years the Radio Manufacturers' As­ will instantly freeze them into brittleness. grId eHps 51.50. X-L PUSH POST-Push It dow n "'Uh you r thumb. In· sociation, which is the leading trade asso­ Cold heat will be transmitted through se tt \V lre. remove pressure, \Vire Is fi rmly held. Vibra· ciation of the industry, has grown from tions wHI n nt loosen. releases instantly. Price ea~h. 1St the air and a cake of ice burned up before Uao In Itdp of 7 OD hlack panel marked 10 white. a dozen to three hundred members. It the eyes of the spectators. Another ma­ Price $1 .50. now has ten· times the membership of any ~t~f!·:;;· ttr~~a~~"Or"~ *,fnri'E!~:~~~:r':'a~;!"~r:- chine using 350,000 volts of electricity qUell",. d . euit. &nd in <>th ~ l'popu l .... hook.""". Wdt~ tod"y. other manufacturers' trade association will send a ray at the speed of 150,000 X-L RADIO LABORATORIES within the industry. miles an hour. Scientists will show how 2424 M. LIncoln "'"e., Chlnlo. III. "Inasmuch as the Association now is so they measure one-ten-millionth of an inch. neady 100% representative of the entire ]. Elliott Jenkins, radio engineer, is in­ industry, it feels that any standardization stalling a model broadcasting station in work it may do will be truly representa­ the ballroom of the annex from where tive of the industry. Under the direction nearly a score of Chicago stations will of the Engineering Division, meetings arc give special programs for the benefit of being held, at which not only are mem­ their millions of li steners. Jack Nelson, bers welcome, but every interested manu­ pioneer announcer and station manager, facturer is invited. At these meetings all has been placed in charge of arranging the previous standards, regardless of their programs to be given at the show and origin, are being reconsidered. Out of this in co-ordinating the work of the stations previous duplication of effort, the RMA taking part in the hook-up. is drawing Up, a new set of standards which, Mayor William Hale Thompson of Chi­ while sponsored by the RMA, will no long­ cago and Lieutenant Go vernor F red Ster­ er be known simply as the RMA standards, ling of Illinois will take part in the open­ but will be designated 'The Radio Industry ing exercises at the show. Miss Lois De­ Standards.' " lander, who went to Atlantic City as "Miss Illinois" and came back to her home at Joliet as HMiss America," is expected as Chicago Radio Show a specially honored guest one evening dur­ ing the show. POLK'S REFERENCE BOOK The sixth annual O1icago Radio Show, FOR DIRECT MAIL ADVERTISERS one of the most important milestones in U. J. Herrmann, who started the Chi­ Show_ how to Increase you r hulncn hy tile li se of D irect lUaU Adver tising. 60 pages the progress of the radio industry, will take cago radio show when there weren't full of vital bUllness facti aDd Illurofl. WlIo, enough sets in the entire community to where and how many prospects you hau. place in the Coliseum from Monday, Octo­ Over 8.000 lInes of buslnes. covered. ber 10, to Sunday, October 16, being open fi II the Coliseum, is again the managing Write for your FREE oopy. to the public' each afternoon and evening. director of the exposition, and G. Clayton R. L.POLK& CO.,Detroit,Mich. Jobbers and dealers will have special hours Irwin, Jr., is general manager. 599 POLK DIRECTORY BUILDING from II a. m. to 1 p. m. Many jobbers and dealers in the middle Branches in principal cities of U. S . The show will have an especial appeal to west are planning to attend the Chicago the public this year for several reasons. show to see what developments have been The Trade Show in O1icago last June achieved since the R. M. A. trade shaw gave the manufacturer the opportunity to held in Chicago in June. get into contact with hi s distributors and the dealers. Now he can bend his every effort to make a display which will he SEE NOVEMBER ISSUE primarily for the benefit of the general FOR SUPERHET CIRCUIT public. Coming so soon after the Demp­ WITH NEW FEATURES sey-Tunney fight, when radio will reach

RADIO AGE SUBSCRIPTION BLANK Radio Age, Inc. 500 North Dearborn Street. Chicago $2.50 A YEAR Gentlemen: Plell.Se enter my subscription [or RADIO AGE, for one year, beiPnning mth the _" ___'_ ...... _... issue, for whicb I enolose $2.50. Name. . ____. ___ ._._.__ •. ___. __ ...... _._ .. ___.. _. ______... __ .... _. __. ___. __. __

Street Addrcllll. __ ._ ...... : ...... __...... _...... __ . _..... _._._ ....._ .. _ ....._._ ...... _...... _.. _..... _ ....._._ ...... __ .. WINDSO R:nOdR~~~~~e~~!L;:: s~::ker. City__ . __.. __...... _ ...... __ ...... _...... Statc-_. ___ .... _ WINDSOR FURNITURE COMPANY Send cash. money order or draft 1416 Carroll Avenue. Chicago, IUinou Lo. AnceIeli Branch, 917 Maple Ave 46 RADIO AGE for October, 1927

WSBF Broadcasters... _.. _.. _.. _.. _ .. _.. _.. _ .. _.. _..... St. Louis, Mo. 441 WTAG Worcester Telegram.. ___ .. ____ .. ______...Worcester, Mass. 517 WSBT South Bend Tribune.. .._ .. _.. _~._ .. _.. _... South Bend, Ind. 238 WTAL Toledo Broadcasting Co.______.. Toledo, Ohio 2S. WSDA City Temple... _.. _.. _.. _.. _...... _.. _...... _.New York, N. Y. 227 WTAM Willard Storage Battery Co .. ______.Cleveland, Ohio 400 WSEA Virginia Beach Broadcasting Co... Virginia Beach, Va. 219 WTAQ Gillette Rubber Co. ______. ______. .Eau Claire, Wis. 254 WSIX 638 Tire & Vulc. Co ... _ .. _.. _.. _.. _ .. _ ... Springfield. Tenn. 213 WTAR Reliance Electric Co.______.. ____ .. ______.Norfolk, Va. 275 WSKC World's Star Knitting Co.... _.. _.. _.. _ .. Bay City. Mich. 492 WTAS Richmond Harris & Co ... ______...Batavia, Ill. 275 WSM Nashville Life & Accident Ins. Co ..... Nashville. Tenn. 341 WTAW A. & M. ColI. of Texas. .. _.. _ .. _ .... _... CoIlege Sta., Texas 309 WSMB Saenger Amuse. Co.... _.. _.. _.. _ .. _.. _... New Orleans, La. 322 WTAX Williams Hardware Co. ______... Streator, 111. 322 WSMK S. M. K. Radio Corp"...... _.. _...... _.. _... Dayton, Ohio 297 WTIC Travelers Insurance Co ______Hartford, Conn. 476 WSOE School of Engineering... _.. _ .. _.. _.... _ ... Milwaukee. Wis. 270 Technical Radio Laboratory. ____ .. _.Midland Park, N. 207 WSOM Union Course Laboratories...... _..... Woodhaven, N. Y. 246 WTRL J. WSRO WWAE L. J. Crowley... _.. _ .. _...... _.. _.. _.. _.. _.. _.. _... Chicago, Ill. 232 Harry W. Fahrlander... _...... _.. _.. _.. _... Hamilton. Ohio 384 Evening News Assn. ______. ____ .Detroit, Mich. 375 WSSH Tremont Temple Bap. Church. .. _.. _.. _... Boston. Mass. 250 WWJ WSUI State University of Iowa.. _.. _.. _.... _... Iowa City, Iowa 422 WWL Loyola University... _.. _.. _.. _.. _.. _ .. _ ... New Orleans. La. 275 WSVS Seneca Vocational SchooL._.. _ .. _...... _... Buffalo, N. Y. 205 WWNC Chamber of Commerce.... _.. _.. _.. _ .. _.... .Asheville. N. C. 297 WSYR Clive B. Meredith. .. _.. _.. _.. _.. _.. _.. _... Syracuse. N. Y. 252 WWRL Woodside Radio Laboratories. .._ ..... Woodside, N .. Y. 268 WTAD 111. Stock Medicine Corp"...... _ .. _ ..... Quincy, Ill. 236 WWVA John C. Strobel, Jr ...... Wheeling, W. Va. 389

Dominion of canada CFAC Calgary Herald. .. _.. _.. _ .. _ .. _.. _.. _ .. _.. _..... Calgary, Alta. 434 CKCD Vancouver Daily Province... _.. _.. _..... Vancouver. B. C. 411 CFCA Toronto Star Pub. & Prtg. Co ... _____ .. _... Toronto, Onto 356 CKCK Leader Pub. Co .... _...... _.. _.. _.. _.. _.. _.. _... Regina, Sask. 312 CFCF Marconi Wireless Teleg. Co., (Ltd.) Ca. Mont., Que. 411 CKCL Dominion Battery Co.... _.. _.. _.. _ .. _.. _._ .._ .. _... Toronto 360 CFCH Abitibi Power & Paper Co. (Ltd.) Iroquois Falls, Onto 500 CKCO Ottawa Radio Association. .. _.. _.. _...... _... Ottawa, Onto 434 CFCK Radio Supply Co. ______. __ .._ .. _. __ .. _.. _... Edmonton, Alta. 517 CKCX Int'l Bible Students Ass'n.,.. _.. _...... _.. _.. _...... Toronto 291 CFCN W. W. Grant (Ltd.)... _.. _.. _.. _.. _.. _.. _... Calgary, Alta. 434 CKFC First Congregational Church. .._ .. _... Vancouver, B. C. 411 CFCR Laurentide Air Service.... _. ___ ._ .. _.. _.. __ ..Sudburr, Onto 410 CKNC Canadian National Carbon Co.... _.. _..... Toronto. Onto 357 CFQC The Electric Shop (Ltd.)... _.. _ .. _ .. _... Saskatoon, Sask. 329 CKOC Wentworth Radio Supply Co .... _.. _..... Hamilton, Onto 341 CFRC Queens University._. ____ . __. ____ .. _._._.. _.. _Kingston. Onto 268 CKY Manitoba Tel. System... _.. _.. _.. _ .. _..... Winnipeg, Man. 384 CFXC Westminster Trust Co. ______. ___ . ____ Westminster, B. C. 291 CNRA Canadian National Railways... _.. _.. _ ... Moncton, N. B. 322 CFYC Commercial Radio (Ltd.}_. ______. __ .. ____ Vancouver, B. C. 411 CNRC Canadian National Railways. .._ .. _.. _..... Calgary. Alta. 435 CHCS The Hamilton Spectator... _... _. ______._.. _.Hamilton. Onto 341 CNRE Canadian National Railways ...... _ ...... Edmonton, Alta. 517 CHIC Northern Electric Co .... _.. __. __ ._.. _. . _... Toronto, Onto 357 CNRM Canadian National Railways... _...... Montreal, Que. 411 CHNC Toronto Radio Research Society. ____ ._._.Toronto, Onto 357 CNRO Canadian National Railways...... _.. _.. _... Ottawa, Onto 434 CHUC International Bible Ass'n.___ ... __ . __ ___ ._.Saskatoon, Sask. 329 CNRQ Canadian National Railways... _.. _.... _... Quebec, Que. 341 CHXC R. Booth, Jr.... _.. _.. _.. __ . ___ ._. ______. _____ ._Ottawa. Onto 434 CNRR Canadian National Railways...... _.. _.. _... Regina, Sask. 312 CHYC Northern Electric Co .... _.. _.. _.. _.. __ ._ .. _Montreal, Que. 411 CNRS Canadian National Railways.. .. _.... _.. _Saskatoon, Sask. 329 CJCA Edmonton JournaL ___ . __ . ____. ______._. __ Edmonton, Alta. 517 CNRT Canadian National Railways. .. __ ._ .. __ ._ ..Toronto. Onto 357 CJGC London Free Press.. ___ ._.. _.. _..... __ _._ .. __ . .London, Onto 329 CNRV Canadian ~ational Railways...... Vancouver, B. C. 291 CKAC La Presse. .. _.. __ ._. __ .. _.. _.. _. . _..... · ._• . _.. ... Montreal. Que. 411 CNRW Canadian National Railways. .._ .. _...... Winnipe2, Man. 40S

November Styles in Supers

The next issue of Radio Age will present a new group of constructional articles on super­ heterodyne circuits. Full details on how to assemble, with drawings, photographs and a specially interesting blueprint feature.

How to build a super for A. C. tubes. How to znake a seven-tube circuit (involvinA an entirely new znethod) How to znake the Caznfield 9·tube super. Other technical inforznation of tiznely value. Coznplete corrected list of stations. Everyday Mechanics and Current Science.

Readers of Radio Age write to us every day praising our "bright little magazine" and report­ ing that they have built sets from our instructions with happy results. The November issue will be on the stands about Nov. 1, or send 30 cents in stamps to insure getting one.

Radio Age 500 N. Dearborn Street Chicago RADIO AGE for October, 1927 47 lIe AUTO OWNERS MYSTIFIED NEW IIfI£NnON L-_..:.... ______~..:__'__.::.... __...=;._; MAKES1HIS , BY NEW DEVICE PDSSIBLE i The problem of high cost gaso­ A newly invented device has actually made it possible for auto­ line has apparently been solved mobile owners to ride on llc gas. This device, by utilizing air, by a mysterious little device cuts down the gas consumption amazingly. llc gas is really a that can be installed in a few minutes on any car. With this conservative estimate, as in many cases bona-fide reports have been device installed the saving in received on cars · running as high as gasoline effected will be so great that the cost of gas, as compared with previous cost, will be even 60 Miles on a Gallon of Gas less than l1c. It is estimated that if every caT were equipped With the hig!) cost of gasoline, this new Whirlwind device is the with this invention, millions and greatest thing of its kind ever discovered for auto owners. It is millions of dollars would he not an experiment, but the outcome of years of accurate tests. saved a year. Autoists also re­ Car after car equipped with this marvelous device has shown port an immediate increase in power and pick-up when this de­ amazing mileage tests. vice is installed. Instant starting This little device is worth its weight in gold, yet costs such a minimum sum that is also noticed. it pays for itself in just a short time in the gasoline it saves alone, not counting Motor Runs Much Smoother the more pleasurable driving it produces. Carbon forming disappears. The inventor claims that -this is the outstanding automobile inven­ $100 a Week Territory Open tion of the decade and has grounds for his claim. When you sell a device that actually saves gasoline, you overcome the one big point that Thousands of motorists have al­ makes selling difficult-that is, sales resistance. ready equipped their cars. They report mileage tests that seem Every auto owner wants to save gasoline. The Whirlwind is so practical, so easily ex­ almost unbelievable. Thirty, plained, that it does not require a high-pressure, experienced salesman to make big money forty and more miles on a gal­ introducing it. On the contrary, the less sales talk used, the more sales you make. The lon is nothing unusual. Motor­ literature we supply and the device itself do the seIling. All you do is to take the orders. ists who have not already Word-of-mouth advertising brings you tremendous repeat business. For those who can equipped their cars with this gas saver should get one just as devote full time, this is a knock-out proposition. It means a sure road to independence soon as possible so that this sea~ with an ever increasing future. Auto registration shows the number of cars is increas­ son their gasoline bills will not ing daily. Every new car in your territory is a prospect for you. We stand back of you worry them. 100% and supply constant sales helps to increase your business. When you get big enough to handle it, we then forward to you business in your territory that comes to us FREE direct. Even if you are not in a position to devote r------FREE SAMPLE COUPON SAMPLE full time, the Whirlwind agency offers big possibilities to you. It is easily possible to WHIRLWIND CARBURETOR CO. To sell the Whirlwind, you have 999·495-E. Third St., Milwaukee, Wis. to have one of the devices to make as high as $20.00 in an hour with this Gentlemen: I want to make big money sup· show. We have arranged a plan device. It sounds like a lot of money, but it plying the demand for Whirlwind Carburetors. that supplies you with this de­ has been done and it can be done by you if P1ease send me your free sample offer and full vice free so that you can get out you will just push it as actively as other sales­ particulars of your sales proposition. and take orders right off the jump. If you have a car, you can men have done. Name ...... equip your own car and make Big opportunities wait for no man, and this is the experiment first. Your ex· a big opportunity. You have to decide, now, if LocaL periment will make you so en­ you want to make some real money yourself thusiastic that it will make you City...... _. a doubly successful salesman. If supplying the demands for the livest agency you have no car, just carry it item of the year. Here is your chance. Just County with you. fiU in the coupon and mail it today. State...... Whirlwind Carburetor Co., 999·495-E. Third Street, Milwaukee, Wisconsin L ______..I 48 RADIO AGE for October, 1927

CLASSIFIED ADVERTISEMENTS If you have anything to buy or sell, don't overlook RADIO AGE'S classified advertise­ ments. The classified advertising rates are but four cents per word for a single insertion. Liberal discounts are allowed on six and twelve-time insertions, making rate of 3 and 2 cents a word per insertion respectively. Unless placed through an accredited advertising agency. cash should accompany all orders. Name and address must be included at foregoing rate.. Minimum contract charge $1.00. All Classified ads for November issue must be sent in by Sept. 25.

AGENTS DOGS CONDENSERS. 889 VOLT FI 511, .1 -. I. 'lit. 2. $ •• 20. s. BEAUTIFUL REGISTERED BULL PUPS SI5. Bill­ ~~9's~ l~!~.R4. ·la.~t~· E~IM~ATOR RADIO AGENTS-Make Big Money-Easyl selling Mar­ dog .. 1i01 Reek.ood. 0&11 ... Ten•• lad • $5.71. 2. 2. 8 .Itd I ,'.11. 2, • velous New Sets and Accessories. Buy frem factory at $6.80 •• 1 ud .1 In 18I'les GOt. MallY Itber .....Itl .. lowest prices. Get New Cataloll with thousands dna­ Ae., tram ....en alli tbo1t... THE RADIO CLUB, tionally advertised bargains. FREE Call Book. Write INC •• La Portl. Ind. today, Amerinn Auto and Radio Co., Dept. 138, Ameri­ ELECTRICAL can Radio Bld g., Kansas City. Mo. Large Core 3·1 Audio Transformen $1.50. Raythetrn ELECTRIC FUNI Seventy ttlfnt .. 110 volts. $1. CHUt· "BH" I

"M USIC C_poaed" b .ord.. Bluer Br.... (formerly :!7ie;:' .~lvtt;8~r.: ~dl:nl;P~'~t~· ~alb.~~~~r~'!'~ FREE-TWo big NIW Malluln61 Ind Infermatlea worth Peble Radl, Lt.beratorili. Wauwat.sa, Wlleenlln. hlfndrede ef dollars tl you. Encl ..e 21 damp. Sa16l_ of SOUsa'1 Band). Olhkub. WII. manllger. Box 74·R. Ben ... Dim. Wlleenlia. M ETERS-CONOENSERS-"B" eliminator parts. Power GILLETTE STYLE RulX' wltb 10 Blad .. IDt Prepaid. transformers $2.00 UII. High ,rade chokes $2.25 UII. L.ud Speaker $3.81. Speak .. Unit $1.10 pre,ald. Trani­ Write for lists of &lIeeials. We can quete prices on any What WUld be bett... thin IIIll1azln. UblUlptl.nl forlller 251. Me le Statioll A. New Hlvln. Cenn. materilll you reQuire. Radio Parts Sales Co .. Oranlle. fer Ilfh. Send .tamp for our sp.elal tilt fit eubserlp­ N. J. flon barilins. Midland Products. Dept. R. A •• 124 Cevrtland Ave., Park Ridge, IIIlnol .. CHOKES 100.-50. or 30 Henry 125 M. A. $5.75. 30H. PANEL ENGRAVING 50H. 8:; M. A. $2.75. 420V and IV tran$formers S4.00. 550Y $3.50. 280Y-12.00. 5·1 Ratio Audl. Transform· T.entletb C.ntUI"J B.. of Receipt.. FtnlulU Ind en 10 for $5.00. Writll for lists. Radio Parts SIIIII IIrOelM8I. u 807 elotll bound bltOk eontalalall 11.;00 SINGLE PANEL and medium Quantity engraving of Co •• Oranll&, New Jersey. ,reven ftrrllulae f.r tb. IIIfllllufaetvr.... work.llell. Ilber· highest quality. Also panel drilling. metlr cuteuts a nd atery. 0111,. lad horlle. s.at IIl'Qlld upa 1'M111t .f machine engraving on small parts. Careful attentlln to $4.00. Sead dime flM" oar 48 PIIg, IIIblog ef Iiten and single panels and sileciai work. Write for IIrice·lln. A. L. Woody. 19 S. Weill Streit. Chicago. RUBBER STAMPS ~~I=t~dD=·~!~.· :::t*"~e:'. ~~~ Ir=!~~ -r:: Park Rldlle. III. RUBBER STAMPS Ind ouppllel. tOc.ar IInl. Cushl,n PERSONAL Mounhd. Catalo. for lIamp. Newman &. Sort. Auburn. Nebraska. BOYS LONELY HEARTS: Enllaall I.tbn, .Ike Ilt_utlnl RUBBER STAMPSI Name. Address. two lines 25e. new frl,nd. In eur Jelly ala... Partlnl ... fre.. En. Three Lines 35c. C. Brush company, Auburn, Nebraska. Boys get a three foot model aeroplane free. No seillng. Moore. 8u lOB. J ....IOII.m •• Pl.-IlL ~:~::it.fO~i:~~~:~!al'l. Aero ShOll. 3050 Hurlbut Ave., SALESMEN WANTED RADIO 75 MILES ON I GALLON-New Moisture Gas Saver. RADIO SET FREE. ferm magazine clubs ameng All Cllr$. I Free. CRITCHLOW. A2-91. Wheaten. III. friends. Club list frH. Silenserian Ageneill. LH EXTRA H EAYY Antonn. wire 7 N•• 18 $1.110 100 feet. AngelM, Breatwood Holgbb. California. 17 No. 22 braided 3/8" wide $2.00 11111 feet IU pre· paid. George Senulz. Calu",et, Michigan. STAMPS BUSINESS OPPORTUNITIES 1000 different $1.00, 500 different SOc. 50 French COlon· ials 14c. Koehler, 642 Meredith St.. Oayton. Ohio. PEOAN·Oranlle_FIII Grev" "On the Gulf". Monthly payments. GUarlnteed eve. Bill. Quick returnl. So­ urlllln Orchards. Dept. R, Biloxi. Mllllnillpl.

MAKE RADIO PANEL LAMPS. InVenter can lupply necessary lIart&. Easlly as~mbled. Rene on top If radio cabinet. Lights dials. Information frel. Sample Lamp TYPEWRITERS $1.25. Pe$tllaid. Robert Stevenson, Lanoa.ter. Ohio. TYPEWRITERS, all ltandard makll. SIO UP. Filii) SILICON Trlnffermu tit"' cut tl .,.l1li11" .114". 10 Ib$. Guanntll'. Free Trial. Wrltl for COMPLETE lIIuI' LAND FREE If pl anted to brlnanas. Bananas bear a full 211 eenh. II ..... 311 ceab. 1_ tn.•• IIIL SI5 ..ab ,er crop the seeond year. $5. 00 monthly will IIlant five Ib .. 4 cublo Inch .. It the III. ,uta,. Ixtra. At least rh trated 1I1u.. Northwuterl Typewriter EXlhange. 121 N. acres. which shlluld pay $1.500 IIrollt arlDually. Reilable ealfil with erder-ltaianM C••• D. • ... 'I"alz, Calu­ Francisco Ave .• Chlcage. Companies will cultivate and market your bananas lor met. Mlcbl ..n. I.J. Ba n.lna$ rillen every day and you lIet your check every 90 daY5. For lIarticulars addre$$ Jantha Planta· WANTED TO BUY ti6n Co .• Empire BUilding. Block 980. Pittsburgh. Pol. PURE ALUMINUM llid Iflilli netlk eteMlDb, bola drilled. with bran ...... 1" luta ,... .alr 1.18". Full value ,lid fir .Id BOLD je ••lry. allver er ,1111- FOR SALE-Patent In founlaln mop and duster. I have ~;::;nb 13~idfhl~·rl c~~I1· ::::::. '~~:'la~~xlli_II.~! ~II~:~~ num. Pat:lr.al" retarlld If lur e_1f' all _tl.factery. party offerod to lake 1ive hundred dozen per month . 1·8" $1.90. Lead SI.OO IfiIIW"I ftet III ,repaid. Oee. Elaine 8peclalty Cem,an)". 1330 Ave. O. Fort Worth. Lester Doak. McMinnville. Tennenee. SehlllL CalUfliet. Mlebloaa. Teul.

II Rad io Age Classified Ads Bring Results II SN 87% at 30 Cycles!

A T 30 cycles, an 8-M 220 audio transformer in a standard amp­ ..l""1. lifier circuit gives 87 % of the amplification obtained at 1000 cycles, while its curve is substantially flat from 100 to 1000 cycles. Above 2000 cycles, the curve for a single stage falls off gradu­ ally, while in a standard two stage amplifier circuit, the curve is substan­ tially flat up to 5000 cycles above which frequency it falls off rapidly to keep static, heterodyne squeals and "set noise" at a minimum. The above paragraph sums up at once the desirable characteristics of an audio amplifier for realistic recreation of broadcast programs, and the actual performance of 8-M audio transformers. It is just this fact that has made 220's the choice of over half of the designers of the new 1927-28 circuits, for engineers know that the short cut to the finest of quality is to use 8-M audios. Experienced fans know this too, as is proven by the fact that 220's have outsold every other transformer in their class by a wide margin for over a year. And S-M audios are signally favored by being used in more broad­ casting stations than any other types. WeAE, WBBM. WEBH. KFCR. 10 this standardned black shielding ea.ae are housed the WTAQ, KODJ, WLBF and many others. WCFL, the "Voice of Labor", hmou~ 220 audio and 221 outpu~ transformef3. 222 out­ put, 230 puah-tl1lU input, 231 pWlb-pull output, 326 61a_ checks quality of al1 programs with them, Nathaniel Baldwin, Inc., famous ment, 3211, S29A and 330 power tranaformera. 331 Uni­ choke and 332 oond"Il~"r hank. And,. new 8upeJ'-powe. speaker experts, test with 220's and 221's. full wave ABC supply tnt.nl!fortnor is 00 the Wl!.y-type Your guarantee of quality is to use 8-M 220's and 221's in every circuit 328, fit '18.00, for one or two 216B or 281 tub"",. you build, and you'll find that over half the popular 1927 and 1928 circuits will give you just this same guarantee of quality. But S-M promises uncon­ ditionally that you can improve any set by using 220's and 221's, and backs the promise by the offer of your money back if 220's and 221's don't give you more satisfactory quality than you've ever heard before. The 220 audio is the biggest value on the market, and its performance measures up to its 4 pound size. It contains more steel and copper than any other transformer-the measure of transformer merit. Price $8.00. 221 output transformer not only protects loud speakers against power tube plate currents, but compensate low frequencies for all loud speakers. Price $7.50, or with cord and tip jacks, No, 222. $8.00 Silver-MarshallnQ'" o/f"'tS two emnll .... "ise audio t.,...,,­ 230 push-pull input and 231 push-pull output transformers are priced at ormer" for .eplacement work in old "ets, wber".. ". pric" $10.00 each. aDd sise is & eonsideration. Type 240 audio t....ndorme. i. eQul or Iluperior to the IIUIojority of high-grade audio tran~form"rs. hut doe3 not .",produce fr"'luenci"a below 80 cycles to the "ztellt that the 'amoDa 220 dOM. its

Laurence Co~ku.day. for the preferred audio amplifier for the LC-28 receiver, UB/lII two 240'" and .. 2'1 witb aI1 8-M pow". supplyl

The New ShieJded Six Is Ready! The Improved Shielded Six is ready. the very latest model of thill excellent receiver which has over a year of succe9llful and satisfying performance to its credit. The Improved model hOll vastly increased selectivity. greater distance getting ability, and the same fine tone that has made almost every builder say of the original "That''3 the finest set I've ever heardl" This year the Six offers the additional possibilities of push-pull amplification wi.th 210 tubes for the man who wants the utmost. All in all. the Six deserves the reputation all the finosst tuned R. F. kit you can buy. equalled only by $200 to $400 factory built sets. Yet it's priced at but $95.00 for the complete kit, or $142.00 assembled, in cabinet, and guaranteed to satisfy you, 440 JEWELERS TIME S-M will be glad to tell owners how last year's model can be converted. to the Impro'led Six. SIGNAL AMPLIFIER or push-pull 210 amplification inetalled witb simple changes. Tb" S.M 440 Amplilior is a thr,,_~ tuned R. F. W" ""D't t,,11 yoU the 1I'hole etorY of ne'" S-M develoD­ amDlifier alld detector ¢()mpletely wi..oo and sealed in a ments, eo it you'U ,u,t fill In the COUDOn, and mail,t ""tb r------COPDer and hrua ct.tacomb and tuned e:u.ctly to 112 K. 10 cente to cover tJOOItage, .. e'll ..... lId YOU free mo .... up-to­ Silver-Marshall, Inc., C .• the 2e,77lI1;('lterwa,velength orth., U. 8. Naval Obt..,rva­ I the-minute advance radio information tban you could 850 West Jacbon Blvd., Wry Station at ArliDirton, (NAA). huy iu a test book. I Ear.h of the four oirC'uits of tbe amplifier is Aectionally me;nrormation on ne" dev ..lop­ sh,eld"d. The sel"ctivity is so Itreat that interferomce I Ch;=~:~~ S-M from other .... aV('llengtbll ia impassible, while with l .. rlte I ments, forwhicb I eIlclo..e 10ceuts. low re~j"tanc" tunoo air core tran~forme .. , hermeticallY sealed, the amDlification is tremendous-biltbe. thaD that SILVER-MARSHALL I . of any 3-8tag" long wave amplifier th.. ~ can boo

Shielding is necessa.ry in a. modern radio receiver. The more sensi­ tive the set is, the more you need it. Some aeta are merely housed

APPROVED CONSOLES

in a met.al case. This helps to keep strong local signals from break­ iilg through, but it is even more important to keep them where they belong after you get them tbe proper way from t.he antenna. A set has tubes, condensers and coils. Here is a coil. The lines ScUff A~'nh for Apoo around it are the magnetio field. proud CorIfol, Facfor,u You know the earth's magnetic SIIow.".. Bro/"tr. Com- "~r.: ..,. ,field will work a com­ ll""sr ';'('(~1\" \ ,p'" d?wn in. min~, Tiu Wolf Mfg. 1,,­ ; ~~,~/, ," :~nl: ~o~~aede f~: dUlltri.., ~~ \~~.>. .' k~nt~::~d ~~hi:l~: ed coils get all uUIed up and the set howls and squeals and haa to be choked off by turning down % BANDBOX the filaments in the tube.s. A 6 Tube Receiver if ~ f:!!!\r::;.. unmatchable quality at" ~ Many features of this set have Ibeen found here .. tofore only in the most expensive radio. Since Crosley is licensed to'manufacture under nearly ;!tenift1~rl?w:::'t t1~r ciliede:i~l~ all important radio 'patents, this combination around them, the fields would with Crosley leadership and experience naturally act like those in the coils, and the produced an amazing radio, the remarkable results would be lust as bad, or value of which can be judi?,ed by the following features incorporated and by seeing it and hear­ ing it at your dealers. 1. Completely shielded coils, condensers and wiring,. 2. Acuminators f€lr sharper -run"­ jng,. 36 Completely balanced g,enuine neu­ It isn't enough to shield the coils trodyne. 4. Volume control. 5. Sing,le and t.he condensers, because even tuning knob. 6. Illuminated dial. 7. Single the wiring of the set haa fields around it. This too is shielded, cable outside connections. 8. Desig,ned for itiBinallreru­ easy installation in consoles. 9. Beautiful high grade frosted brown crystalline finished cabinet. Of course, aU in know­ AC model using, new R.C.A. AC tubes and work­ how to do ing directly from electric lig,ht socket through but that'll Crosley Power Converter is $65. Power Con­ why Crosley sets can be as good verter $60 extra. Hear this wonderful neW con­ as the best without cOllting half tribution to the enjoyment of radio. If you as much. cannot find one of the 16,000 Crosley dealers ~:~:. you, write Dept. 63 for his name and liter~- B IBB

CrOlt.II" and r",61!e.". Cincinnati. Ohio RADIO Hon - l~-1neh UUTlJ­ .It",,-:_, 11.11. Mounlainl Scanned from the collections of The Library of Congress

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