Lemaga3ine Òf the Hour

Blueprint Section Every Month WD1O GE LeMaga3ine òf the Hour

January Blueprints of a "B" Battery- Eliminator `:Taking Care of 25P 1926 your Radio Set fl, New data on the Photo Electric Tubes OOHow Rebroadcasting 6326 is Handled Radio Age Model Receiver Type - H X 7r. íßi ; ? - >i.:e TIDE BIG LITTLE THINGS OF RADIO

The DAVEN LEAK - ANDENSER -the new com- THE DAVEN SUPER - bination grid leak and grid con- AMPLIFIER eliminates all hook -up denser all in one For any detec- prefer to assemble, tube circuit. labor. For those who tor the Type 3-K Kit is complete except for sockets. For 50% more volume use the new Daven Tuhes Type MU -20 with the Daven Super -Amplifiers. Daven Power Tube Type MU-6 -for the last stage of any set. Volume and Quality

AS an owner of a radio set you should demand two things: (1) Volume on the weakest signal, (2) Tone quality that makes criticism impossible and excuses or qualifications unneces- The biggest of all sary. Why sacrifice one for the other? Demand both. Today it is the little things -THE DAVEN GRID LEAK. Made a simple matter to have both. in 29 standard values from 2500 ohms to 10,000,000 ohms. It is easy to get volume but there is only one way to get both quality and volume. Use Resistance Coupled Amplification in the audio end of your set. We have made this very simple by developing the Daven Super - Amplifier. Or, if you prefer self -assembly, couple up Daven precision -built resistances and mountings as contained in the Clip Mounting No. 50 -suitahle for single 3 -K Kit. Then you will hear radio at its best. ResistororGrid Leak. Three new Daven Products were announced this Fall. The Daven Leakandenser is a Daven grid leak of permanent and constant value, combined with a grid condenser of fixed capacity, correct for all makes of detector tubes. Precision -built, simple, effective, uniform ( esisto- Coupler No. and very handsome. A pair of mounting clips included. 42,with special Daven Type "A" Coupling The new Daven High MU Tube Type MU -20, used with the Daven hidden in Super-Amplifier, is designed to give 50% more volume -6 volt, 1/4 ikkCondenserthehase- the original Tube MU -6 is the and most popular re- ampere. The Daven Power Type for use in last or sistancecouplingunit. output stage of any set regardless of the method of amplification used -6 volt, t2 ampere. The new Daven Special Type "A" Condensers are the latest develop- Daven Ballast Resist- ment of Daven Engineers. Their use in Resistance Coupled Ampli- ors-for use with am- fiers gives you 50% more volume than ordinary plifying tuhes in place condensers. of rheostats. There are five sizes, for one The Resistor Manual is the `rA.B.C." of Resistance Coupled Amplifi- tofivetuhes. Soldwith cation-a complete handbook for designers and builders. Send for it. mounting only. HAVEN PRODUCTS ARE SOLD ONLY BY GOOD DEALERS (, wie Sae f./1tcite" New Daven Spe- cial Type A" Coupling Conden- AVE ADIO CORPORA 10 ser increases volume with Resist- ?esis %t- Specialists ance Coupled Am- Newark Reg. U.S. Pat. 05. New Jersey plification. Sold CLIP TITIS COUPON The Resistor DAVEN RADIO CORPORATION, 157 Summit Street, Newark, New Jersey. separate, and also Manual send included in all Re- Please me the following on Resistance Coupled Amplification: - A practical handbook nn Cheek One sisto- Couplers, Resistance Coupt.d Am- Resistor Manual. 30c is enclosed. Complete Catalog (free). v, Super - Amplifiers plification. At yourdo1d- Name Address and Kits. er's25c. Bymaispoñt , tid 30c. Dealers send for free sample. To Dealer ,.: May we have our nearest distributor communicate with you?

* Tested and Approved by RADIO AGE RADIO AGE for January, 1926 The Magazine of the Hour 1

How I Earn $1009.2 aWeek as a Radio Expert A year ago I was mighty blue and It s a new field and there's plenty of a low -paid clerk in a bank. And Marian, discouraged. It seemed to me that I room for wide -awake men." who will soon be my bride, keeps saying, would never be more than a low -paid "But -but I'm not trained!" The "I told you so!" bank clerk. Of course I had a small thought excited me. To be a radio As a radio expert I can tell you that increase in salary every now and then, expert! To find my future in this there is a tremendous demand for men but I knew that pretty soon I would fascinating new field! "1 don't know who can build, sell and install radio reach my limit and there would be no anything about it, Marian," I said. sets, who can design, test, repair. Men further advancement for me. What "I wish I did, though." are needed as engineers and executives, future had I to look forward to? Where "Well, why don't you find out about all over the world. The opportunities would I be in five years? I became it," she retorted. "You can't learn are limitless, and if you like radio there restless and discouraged and began to about radio just by listening in to the is no reason why you cannot qualify look around for some other opportunity. concerts. Why don't you take a course ?" for one of these positions by studying It was then that I discovered that the But we found out that most courses in your spare time at home as I did. demand is for trained men, that the were expensive or that they would The National Radio Institute offers opportunities are all for men who can interfere with my other work. We an absolutely complete course which do some one thing better than anything were about discouraged when I dis- prepares you for the Government First else. There were wonderful oppor- covered that through the National Class Commercial License and for the tunities for men who were experts or Radio Institute it is possible to become bigger -paying jobs in Radio. The specialists -but I was --a clerk. How a radio expert by studying right at home Director, E. R. Haas, will be glad to I regretted then that I hadn't prepared in spare time. I told Marian about it and send you all details of their marvelous myself for some definite career! she was elated. "Send off for informa- new method of practical instruction, I Wanted to Marry tion, at once -today!" she exclaimed. including information concerning the Advances Quickly to $100 a Week Free Employment Service which secures The thing that made me more restless positions for National Radio Institute at that time than anything else was the I did, and the following day received graduates. Everyone interested should fact that Marian and I were -that is, an important booklet, "Rich Rewards radio op- have this information. Its free, and we wanted to be married. But we both in Radio" telling all about this coupon will bring it to you. I knew that we couldn't possibly get along portunities and how to become an ex- work. advise you to send it off today. Radio on my small salary. I f only there was pert in any particular phase of the is a new and interesting field, and it something I could do that would bring Here was my opportunity at last! offers you more money than you prob- me a larger salary! I began to study in all my spare time. ably ever dreamed possible! It was just about the time that every- It was the most interesting and absorb- one became so interested in radio. Our ing study I had ever made. The secret Important whole town became radio -mad, and of of the radio revealed to me! Day by Those who mail the coupon at once course what was happening in our town day I became more skilled and deft will also receive details of Special Short was happening all over the country - until I was able to take apart receiving Time Reduced Rate. Do it now. all over the world. I managed to save sets and put them together again as up enough to buy a receiving set I though I were playing with a toy. It and 1 National Radio Institute, Dept. AÚ3 was never quite so happy as when I was fun! In a month I was able to I Washington, D. C. was trying to tune in on stations. take a position as lineman at a bigger I am interested in radio and would like to Ifind out whether or not I am suited for a radio The thing fascinated me. Playing salary than I was getting at the bank. career. Please send me, without the slightest with air waves! Bringing melodies and This was wonderful experience for me, obligation, your interesting free book called "Rich messages out of the sky! I was never and I kept right on with my studies. Rewards in Radio." Also full details concerning I special Short Time offer. so interested in anything before. It wasn't long before I qualified for a your Marian was the first to sense the great position as radio engineer at a salary of Name opportunity. "Why don't you become $100.00 a week! That is what I am a radio expert ?" she said. "You like earning now, though I expect to make Address _.. it, and I am sure there must be a big more soon. It seems to me almost too demand for men who understand it. good to be true, after all those years as City- .... -.. - .State t I 2 RADIO AGE for January, 1926 The Magazine of the Hour

\\\\,,,,\,, \`\\ A Chat With \Q\\\\oa \\\ Q\\\\\\\\ \\u\ \\\\\\\\\\o\\\ \ \a\\`o\U ,W\Q\\a0\\\\ .0\\\\\a\ \a`\``\\ \\\\,\\\ \,,. ,\\,,, the Editor The Magazine of the Hour rTIHERE is a significant lesson to be learned from the present Established March, 1922 wavelength situation. We remember that many owners of broadcasting stations, during the Volume 5 January, 1926 Number 1 last four years, voluntarily have relinquished the licenses and wavelengths which had been assigned to them by the Department of Com- CONTENTS merce. They had lost interest in broadcasting and regarded their Cover Design by Anker P. Mehlum licenses as liabilities rather than Radio Age Model Receiver 7 assets. Distinguished leaders in By the Technical Staff the radio industry had solemnly Taking Care of Your Radio 15 assured us that the number of By Brainard Foote broadcasting stations eventually How Re- broadcasting Is Handled 17 would be reduced to a half dozen By Walter C. Evans and that this small group would be Hook It to the Minus A 18 in the hands of two or three large By John H. Miller corporations. Today Audio Amplification -Some Interesting Facts 19 there are 578 broadcast- By Frank D. Pearne ing stations in the United States and 175 applications for licenses R. F. and Regeneration Using Toroids 21 for additional on file By Piety stations are Ray G. in Washington. Some of the most Data on the Photo -electric Cell 24 important individuals in the coun- By V. K. Zworykn try have gone to Washington Getting the Most Efficiency Out of Your Set 26 recently and vainly implored Sec- By Armstrong Perry retary Hoover to give them a What the Broadcasters Are Doing- Feature license and a wave -length. Sev- Section 27 -36 eral cities are now anxiously won- dering whether stations they have RADIO AGE Blueprint Section -A Power built and equipped at great cost Supply Device 37 -44 will have to be dismantled and By John B. Rathbun forgotten. They cannot find a Pickups and Hookups by Our Readers 45 place on the air. One great news- Revised List of Broadcasting Stations 66 -68 -70 paper which had been indifferent to the popular interest in radio for several years recently offered to permit a mid -west station owner to Radio Age is published monthly by RADIO AGE, Inc. name his own price for his license. Member: Audit Bureau of Circulations. The station owner smilingly re- Publication Office, Mount Morris, Ill. fused. 404 North Wesley Ave., The lesson to be learned from all Address all communications to RADIO AGE, Inc. this is that we must maintain an Executive, Editorial and Advertising Offices 500 N. Dearbor n Street, Chicago, Ill. open mind on all questions in controversy. The same sort of folks FREDERICK A. SMITH, Editor who laughed at the first steam F. A. HILL, Associate Editor locomotive, the first steam -boat FRANK D. PEARNE, Technical Editor M. B. SMITH, Business Manager and the first airplane, have been mirthfully waiting for the radio Advertising Director vogue to wane. It waneth not and HARRY A. ACKERBURG the S00 N. Dearborn Si., Chicago, Ili. broadcast license today is worth as much as a Florida corner Eastern Representative lot, than which, they tell us, DAVIDSON & HEVEY, 17 West 42nd St., New York City nothing is more earnestly to be Pacific Coast Representative desired. V. M. DEPUTY & ASSOCIATES, 515 F. W. Braun Bldg., Los Angeles, Cal. Final Advertising forms close on the 20th of the 2nd month preceding date of issue OQP/c!il Vol. 4, No. 12. Issued monthly. Subscription price $2.50 ayear. December, 1925. Entered as second -class matter at post office at Mount Morris, Illinois, under the Act of March 3, 1879. Editor of RADIO AGE Coyyrioht, 1826, by RADIO ACE, Inc. RADIO AGE for January, 1926 The Magazine of the Hour 3

1 "These Eveready Batteries are the correct size foryour set With average use they will last you a year or longer"

"You have been one of the and over that on sets of one With sets of 4 or more tubes, many who use 13' batteries to three tubes the No. 772 use either of the heavy ditty that are too small in capacity Eveready "B" Battery used batteries No 770 or the longer - for their receivers. That is not with a "C" battery will last a lived Eveready Layerbilt No. economical. It makes you buy year or longer. On sets of four 486. `B' batteries twice as often as and five tubes the larger heavy We have prepared for your necessary. Fit the right size duty Eveready batteries used individual use a new booklet, Evereadys to your set and add with a "C" battery will last "Choosing and Using the a 'C' battery,* if you haven't eight months or more. Right Radio Batteries," which one, and you'll get the maxi- we will be glad to send you mum of service at the mini- The secret of "B" battery upon request. This booklet mum of cost." satisfaction and economy is: also tells about the proper bat- With sets of from 1 to 3 tubes, for use The life of your tery equipment with Eveready use Eveready No. 772. the new power tubes. "B" Battery depends on its LEFT- Erereads/ Manufactured and guaranteed by capacity in relation to your Layer büt"B' Ba t- tery No. 486. 45 set and how much you listen volts, for maximum NATIONAL CARBON CO., INc. economy on four, in. We know, through a care- five or more tubes. New York San Francisco Rr c nT- Erereody Canadian National Carbon Co., Limited ful investigation, that the aver- DryCell Radio "d" Toronto, Ontario Battery, 1 3 volts. age The battery built year -round use of a set is especially for dry two hours a day. Taking that cell tubes. EVEREADY HOUR average we have EVERY TUESDAY AT 9 P. M. proved over Eastern Standard Time For real radio enjoyment tune in the "Eveready *NOTE: In addition to the increased life EVEREADir Group." Broadcast through stations - which an Eveready "C" Battery gives to wEAF-New York wFl- Philadelphia wsAT-Cincinnati Radio Batteries wJAR- Providence wen- Buffalo WWJ- Detroit your `B" batteries, it will add a quality last longer WEEr- BOSLOn woo -Davenport -they w'rAG- Worcester weAE- Pittsbur8 h xsn -St. Louis of reception unobtainable without it. weep-Minneapolis, St. Paul Tested and Approved by RADIO AGE * 4 RADIO AGE for January, 1926 The Magazine of the Hour

IT IS possible that a majority of broadcast listeners WHEREAS, There can be no continuation of controversy over the terms broadcasting unless musical compositions are take little interest in the made available to broadcasters upon a fair, under which copyright music may be put on the air. equitable and permanent basis, and If the listeners are indifferent it is unfortunate. The WHEREAS, an insistent demand from the National Association of Broadcasters, in session at public requires that music be made the principal Washington early in November, officially declared that part of broadcast entertainment, and all of music is go on unless some equitable WHEREAS, practically this broadcasting cannot held by copyright proprietors and is not avail- arrangement can be made affecting copyrights. All able to broadcasters except on prohibitive and negotiations between the broadcasters and the unstable terms, and American Society of Authors, Composers and Publish- WHEREAS, the broadcasters recognize the ers have come to naught and the next step is to be right of the copyright proprietors to compensa- effort toward getting congressional tion for the use of their compositions and are a more vigorous willing to pay a fair and equitable maximum fee action amending the present antique, if not obsolete, for each broadcast rendition of each copyright copyright laws. musical number, and All radio interests should get behind national agita- WHEREAS, broadcasters believe that copy- tion for legal relief from the present situation. The right owners should have the sole, complete and Society of Authors et cetera is admirably entire right to withhold their property from all American broadcasting if they so desire; but that if a copy- organized. So should the broadcasters and broadcast righted number is released by the owner there- listeners be organized. Radio manufacturers depend of to one or more broadcasters, then such number upon broadcasting to supply a basis for sales and there- shall become available to all broadcasters, and fore the manufacturers should take a willing hand in WHEREAS, the present conditions threaten the matter. the entire broadcasting structure and the has continuation and permanence of broadcasting It is admitted that the A. S. C. A. P. a moral and depends upon the solution of this problem, and legal right to protect its copyrights. The broadcasters WHEREAS, all attempted solutions through are complaining that nobody has yet determined where negotiation between the parties have proved those rights cease and the rights of the broadcasters unavailing; now therefore begin. The fees required from broadcasters are not BE IT RESOLVED, that it is the sense of this Conference that the only possible solution lies in uniform, stable or permanent. the enactment of suitable legislation based upon A broadcast station owner may pay a $600 fee to the above principles, and it is the recommenda- the A. S. C. A. P., this year for the use of using copy- tion of this Conference to the Secretary of Corn - right music and songs controlled by the society but merce that such legislation be suggested to there is no assurance that the fee required next year Congress. will not be $6,000 or $60,000. There are many other E. C. Mills is the leading spokesman for the authors, flaws in the present attitude of the copyright people composers and publishers. We ask him whether the but they cannot even be outlined in the limited space terms demanded of broadcasters at the present time of an editorial page. are equitable and stable, or whether they are unstable What is required most of all is a campaign of educa- and in some cases, prohibitive. It appears to us that tion so that the public generally may intelligently if there is right on both sides of the argument and that judge the merits of the issue. We foresee that broad- heavy financial interests are involved it would be far casters will recognize that they have a powerful better for the opposing factions to get together and publicity weapon in their own hands-the microphone. make their own rules and regulations. But if they will If they work together they can stimulate a demand for not or cannot do this it is inevitable that this phase of proper legislation that will bring pressure upon the radio transmission and reception must have recourse national congress from literally hundreds of thousands to the uncertain currents and tides of congress. Our of homes. impulse would be to keep radio problems as far away All those interested in radio and its successful from the District of Columbia as possible. One of the future should read the following resolutions adopted blessed things about the new radio art in the United by the National Association of Broadcasters on Novem- States has been its freedom from the usual multiplicity ber 8: of federal restrictions. Look for the next Radio Age Model. Read about it in February Radio Age. RADIO AGE for January, 1926 The Magazine of the Hour 5 Send for this R4 D 1926 CloQs TheHrart o rti/fo RAD IO =:r_,;, ,o.-at.... *IL << « a'S O O ,;1 r_ ..hq,-,+l !% BARGAINS ,1 f9 °"A+axttT,tC,7 = . !:7 : ÌÌ,.. r. .. , t aye/361/2 FRE .T^ Di'.,.. y}if The World's Largest tals` 4 Exclusive Radio Mail Order House Will Send You This Wonderful Book FREE! 64 illustrated pages containing thousands of bargains in radio sets, semi -finished sets TUBE SET and radio kits of all styles, sizes and approved circuits. 5 -tube sets as low as $29.50. 5 Beautiful models of the very latest designs and types. Elaborate console models with loud speakers built right in cabinets of genuine mahogany and walnut. Ail sets guaranteed. Coast to coast receiving range. Also contains everything in radio supplies, including batteries, chargers, loud speakers, transformers, condensers, rheostats and any other parts you may want for improving your set or building a new one. Guaranteed saving to you of % to %. The Biggest 5-Tube Value on the Market Positively the world's greatest 5 -tube radio bargain. Regular $75.00 value. Our largo quantity production enables us to sell this set for only $29.50, fully built and wired in beautiful mahogany cabinet of latest design with eloping Bakelite panel of Satin finish, handsomely etched and engraved as illustrated. Constructed of the finest low -loss condensers, coils and sockets. Bakelite baseboard panel and dials. Price for Set only. Transportation charges extra. Shipping weight 25lbs. $2950 This set with all Accessories, Including the famous American Bell Loud Speaker w.th dju t Ll ut.it, l -4S v.,it ' LY Ltt

Beautiful Walnut Cabinet In two - r ie' toned effect. Two door panels inlaid with highest grade burl walnut. m Cabinet is 39 inches high. Top '4375 t i%_ -- . ` measures 13x37 Inches. Equipped i with hlgb -grade built-in loudspeaker . i with adjustable unit. Large. roomy interior for holding all batteries. World's 8 -tube Super- heterodyne. panel Grand Famous Fully mounted on ! l books, etc. The Columbia and baseboard. Comes Completely assembled ready to wire and operate. is a 5 -tube tuned radio frequency receiver. Coast to coast receiving We have testimonials from thousands of builders of this set. Some have re- Console Radlo with range. Tune In orations desired - ceived foreign stations on loop aerial. Unsurpassed in volume and tone built -In loud speaker very selective. Has latest type. low - quality. Low -loss straight line frequency condensers, vernier dials, finest and adjustable unit. loss condensers. cons and sockets. quality rheostats. Matched Columbia long wave transformers. Requires Has compartments for Bakelite baseboard, sockets and d ial only three screws for attaching panel and baseboard and set is ready to storage ',A" and "B" batter- knobs. Dials are beautifully etcbed wire and operate. 7x30 panel. Price of set only $43.75. ies. battery charger, radio in gold on walnut finish bakellte book etc. panel. Price for set only, fully Requires following accessories to complete this set: 7x30 cabinet, 8-201A tubes for stor- of instructions, built and wired-S57.95. age battery operation or No. 199 tubes for dry cell operation. 100 Ampere bonr storage Transportation charges extra. Shipped by freight or express. battery, 2-45V B" batteries, loud speaker, center tapped loop aerial. All these items This set with ail accessories, wblch Include 2-45 volt "B' batteries, one guar- are listed in onr catalog, at a tremendous saving. anteed 100 ampere hour storage "A" battery, 5-201A tubes, multicolocord cable Oor semi -finished sets come with all parta monnted on panel and baseboard ready for for easy battery connection. aerial and ground equipment, instructions for setting wiring. Do not fail to send for onr catalog. Remember-we are the largest exclneive up and operating -everything complete, nothing else to buy - radio mail order dealers in the world and carry the hest of everytbing in radio. We save Transportation charges extra. Shipped by freight or express. $84.95 yon 1 -3 to 1 -2 on everything in radio. Detailed descriptions appear in onr catalog.

Our line is complete, In- REMLER 8 -TUBE Semi- Finished 5 -Tube Radio cludes all popular sets, NEUTRODYNE COCKADAY such asSuperheterodyne, SUPER Frequency Set Gennine Licensed Nen- 3 -tube Cockaday kit Neutrodyne, Ultradyne, trodyne kit of parts come HETERODYNE Reinartz, Regenerative, of parte, fully assem- folly assembled on the bled on panel and Complete parts for Radio Frequency, Brown - panel and baseboard Best 45 Kilocycle ing-Drake,Super-Hetero- with complete instruc- baseboard ready to tions ready to wire wire Super - Heterodyne dyne Reflex and all other Genuine Remler parts latest circuits. Kits, sets and parts by well -known manufacturers such as $29.75 $15.85 $49.50 48' Frost, Howard, Baldwin, Brandes, Western Elec- . e, till , 1 1 i Yrv tric,Columbia and others. ULTRA -AUDION BROWNING HARKNESS 2-tube reflex kit of ULTRADYNE One -tube Ultra -Audi- DRAKE parts, fully assem- This special offer is astounding the radio world. Coast to Complete parts for 8- on. Wizard of radio. bled on panel and coast reception on loud speaker. Low -loss condensers Tube Ultradyne receiv- Fully assembled and and sockets. ready to wire, with 4-tube complete low- baseboard, ready to Highest quality transformers. Bakelite rheostats. er, without cabinet, loss parts wire, complete in- All wiring concealed under Bakelite baseboard. 7x18 panel complete with blue- instructions structions -fits into any standard 7x18 cabinet. Complete instructions print, instructions and for operating. Guaranteed saving to you of $50.00. diagrams Price of set all mounted, $18.75. Cabinet of same $6.35 $32.40 $16.95 model as American Radynola pictured above $5.65 extra. $45.85

Cataloglncludeslist of broad- OUR GUARANTEE casting stations, general radio Every article exactly as repro- Information and facts about RANDOLPH RADIO CORPORATION sent ed. Every article istested our free service division. 159 N. Union Ave. Dept.224 Chicago, Illinois before shipping. Complete Write tor It today. satisfaction guaranteed. 6 RADIO AGE for January, 1926 The Magazine of the Hour For "Better Tuning' B -T "The more you learn of Radio and the longer you use B -T products," says a leading jobber, "The more you appreciate that they are in a class entirely their own' ' The Season's Greatest Success As the season grows it becomes more and more apparent that its two greatest improvements are the i B -T Counterphase and the B -T Euphonic Audio Transformer. No B -T product ever made such an instant nation- wide success as the Euphonic because no other Trans- former, or system of Impedance, Resistance or other style of coupling gave the same unequalled satisfaction. Like all B -T products the value is greater than the price. 2.2 to 1, $5.00 4.7 to 1, $5.75. The Counterphase These letters indicate what users think: From Kansas City : The Counterphase is in every particular by far the most efficient receiving set that I have owned or heard in operation. One stage of audio is quite sufficient for ample loud speaker reception in five rooms of all class B stations in the U. S., and many class A. From Cincinnati: Summarizing tests on Counterphase Set I can safely say it has more volume, greater selectivity, greater sensitivity and produces higher quality of reproduction than any receiving set I have ever heard. BT Torostyle Transformers .`TOROSTYLE" FOR 3 Styles- Antenna, Intermediate and 4- Circuit EASY YYIRING $4.00 Each

The latest B -T Invention: The "Silent Socket" The only remedy we have ever found for Microphonic Noises

Price as shown $1.25 Read "Better Tuning" once-you'll read it always. 9th Edition, Postpaid, 10c Bremer -Tully Mfg. Co. 532 S. Canal Street, Chicago.

.'6 Tested and Approved by RADIO AGE 3F JAN -2'26 ©C1B689835

RADIO AGE for January, 1926 The Magazine of the Hour 7 o

\\\\\\\\u\\\\\ \\\\\o\`\ \ \\ \\\\u\ \ o ,\ \o" \\\o\\\ \ \ \\\\\\\ o \ \\\\\\\\, \/\ \ /\ \ \ QQ \\\ . \\ \\\\\\\\\ . \m\\Q\\\ A too \ \ il n\\\\b O ale Maga3ine fz'he Hour B A Monthly Publication M. B. Smith Devoted to Practical Frederick A. Smith Business Manager Radio Editor

JO! IOI IO I IC( IDI IOI IOI I JANUARY Radio ilge MODEL Has SI MPLN: TUNING Control By Radio Age Technical Staff

IN PRESENTING to its readers the The same plan of putting in all the to use two small angle braces made out January model receiver, Radio filament wiring first was adopted as was of copper or aluminum which would be Age's technical staff has somewhat the case in the December model. The affixed to the coils fore and aft by means simplified the tuning of the set as com- left hand filament terminal on all the of the screws at present holding the pared to the previous model and has sockets was attached to a piece of bus wooden core rod in place. In either case made other improvements which will bar wire running from the left to the the coils should be mounted firmly probably appeal to readers who follow right of the baseboard and terminating enough so there is no possibility of their the series. As time passes and each at the yellow and green terminals on the getting adrift if the set is to be carried model is worked on there will undoubt- Jones plug on the rear right part of the about from place to place. edly be many refinements, all of which baseboard. Thus all of the sockets had Audio Transformers could not be included in one model a common connection with the negative simply on account of the lack of time A battery. The Kellogg soldering lugs AUDIO transformers, both the 2 to 1 and the fact that association of parts were used in order to simplify soldering. and the 3 to 1 are Thordarson's and might not be susceptible to too much If more time and trouble were taken the should be mounted as shown in Fig. 2. elimination of parts. Like anything wire could be bent around the terminals, On account of the spacing between the else, radio may be improved to death, or flexible wire used, but we found the two audios grounding of the shields was so after a while we would have a tube- stiff assembly the best under these con- not necessary, although if more than less, coilless and capacityless set. ditions. two stages of audio are used it would seem advisable. Frankly we In building this set reference should Sockets do not first be made to the schematic diagram, believe anyone would ever want to put HE sockets are made by Pacent of Fig. 1 on page 9. This gives all of the rr three stages of transformer coupled electrical connections without regard isolantite and will take either the amplification on this set, although if it to the placement of the UX of UV prongs so in this respect the is desired to use resistance coupled apparatus. sockets may be termed universal. The Fig. 2 on page 10 gives you a view amplification three stages may be prop- of sockets are affixed all parts located on the baseboard but to the baseboard by erly used. without any wires showing. two screws in each socket and placed After putting in the negative filament with the grid and plate terminals away The isometric sketch Fig. 3 page line and hooking it up to its proper on from the panel and the two filament 11 gives you a pictorial view of the connections on the Jones plug, the Daven parts and their wiring, the isometric connections toward the panel. filament resistors for the quarter ampere having photographic Diagrammatically in Fig. 1 all of the tubes are inserted in each of the right accuracy as re- grid returns are shown gards the location of everything. returned to their hand filament terminals, and the positive respective filaments, but in prac- In Fig. 4 on page 12 is shown the same actual wire run to the filament toggle switch, set, looking down upon it, but with tice it was found better for the leads and thence to the positive terminal on all that are to go to the negative wires in place, while Fig. 5 on page 13 (through the connection plug. This completes gives a front panel view of the assembled the C battery which will be explained the filament wiring and after this much receiver. later) to be bunched and returned at the has been done all the balance of the con- negative terminal of the first socket on Permit Variation nections may be made. the left end of the baseboard, instead of Drilling the Radion panel is quite INASMUCH as the present receiver distributed over the length of the base- simple and may be done after the panel was not to be exhibited at a radio board. has been affixed to the baseboard. Fen- show too much attention has not been Although no mountings were supplied making the panel secure to the baseboard paid to "prettying up' set, the this being with the double -toroids made by the we drill five holes on a line about three - left more to the individual taste of the Radio Foundation, Inc., nevertheless quarters of an inch from the bottom edge builder. Some of the wires ,,in the set we found the simplest way of mounting of the panel. The first hole is at the were made flexible so as to permit varia- was to drill a small hole through the center of the 26 -inch panel. Hence this tion in connections during the time the baseboard, countersink on the under- hole would be at 13 inches. Halve this set was undergoing tests on actual re- side, and run up a long screw that en- distance and make another hole to the ception. These changes were made gages the wooden core of the double - left; halve the right 13 inches and make necessary on account of the fact we have toroids. Thus they are firmly held to another hole. This gives three holes. seldom seen a receiver which on actual the baseboard, with the grid end down The other two should be about two inches operation will follow all the hypothetical by the grid terminals of the sockets. from the panel ends, one at the left two data written about it. Another method of mounting would be (Turn the page) 8 RADIO AGE for January, 1926 The Magazine of the Hour inches from left edge, and the other at the shortest path to the grid terminals on oscillations is pretty stable and effective. right end two inches from the right edge. .the three sockets, two r. f. and one de- The other end of the resistor goes to the This gives five holes in all and should tector. In the case of the latter the positive of the 90 volt B battery. A be enough to support any kind of a panel. .00025 fixed Electrad grid condenser is Dubilier 1 mfd by pass condenser is inserted directly on the detector grid connected from the common connection Condenser Holes socket and the grid wire made fast to of the two wires from the two double THE holes for the Amsco condenser the other side of the grid condenser. toroids to the common rotor, to the may be drilled by means of the drill- This condenser has a clip into which is negative A filament line. In case you ing template supplied with the con- slipped an Allen-Bradley 1 megohm desire still more by passing another denser. After the holes are drilled and resistance; larger values may be used Dubilier 1 mfd. condenser may be countersunk, the condenser should be if desired. A connection is run from the placed across the plus and minus of the mounted temporarily and the hole drilled stator of the single condenser (on the A battery lines. The principal place for the holding screw on the Marco left) to the grid of the first r. f. tube. to look for trouble in r. f. currents is in vernier dial, a small metal template being This will complete the grid circuit of the B battery where such a battery is furnished by the Marco people for this the first tube. One wire from the grid common for all stages and it is always purpose. This .00035 condenser should of the second tube goes to one stator advisable to bypass, from the tap which be at the left side of the panel and is used on the tandem condenser. (preferably the r. f. stages use, to the negative. for tuning the secondary of the antenna the one at the rear) while the other grid Another bypass could be used on the coupler. 45 volt tap where it feeds into the audio For the second condenser a Bremer - transformer, and still another across Tully tandem variable condenser, .00035 the total voltage applied to the last audio each section, was used. This condenser List of Parts stage. These capacities and their use has a single hole mounting and another rest mostly with the builder of the set. 1 Bremer -Tully tandem condenser, hole for little trimmer capacity. A i There can be no question as the .00035 with trimmers } to the ad- template is likewise furnished by the 1 visability of bypassing as much as i Amsco .00035 SLF variable con- i manufacturer for this purpose. The i denser i possible to make a stable set. distance between the first condenser and ! 3 Radio Foundation double -toroids 2 Thordarson audio C Battery the second one is about 7 inches. The transformers ! hole for the first condenser is three inches 1 Centralab variable resistor, 200,- In making use of a C battery the 000 ohms i in from the left edge, and on the 3% 7 1 -2 volt type made by Burgess may be 1 XL variodenser type N inch line, (which is half the height of used. This is variable in 1 1 -2 5 Pacent isolantite universal sock- i steps of the panel) the hole for the second con- ets ! volts at a time. For the r. f. grids, if is 10 inches from use 90 volts denser the left end. i 5 Daven filament resistors for 1 -4 i you on the r. f. tube plates, After the tandem condenser, there is ampere tubes, with mountings i you will probably want to use from 1 1 -2 a single hole for the Centralab resistor ! for same !i to 3 volts negative bias, while for the 1 Cutler- Hammer filament toggle (this is also a single hole mounting) the 1 audio with 120 volts you may use as hole being 16 inches from the left edge. switch high as 6 volts negative. The positive 2 Marco clockwise Four inches to the right of the resistor vernier dials terminal of the C battery should be i 1 Allen- Bradley 1 megohm grid is hole for Cutler - mounting the the i leak i connected to the negative A battery line. filament Hammer toggle switch, while 1 Electrad .00025 grid condenser The flexible wire from the common rotor two inches from the right end of the and clip for leak connection and the returns of the r. f. panel is the hole in which is placed a 1 Dubilier 1 mfd by pass condenser coils is the one which should be tapped i Yaxley single circuit jack. All controls 1 1 Muter .001 fixed condenser either on the 1 1 -2 or 3 volt minus C 1 Yaxley single circuit phone are on a line on the panel and fairly jack 1 terminal. If the signals are too broad i 1 Radion 7 by 26 by 3 -16 panel evenly spaced. i and loud, biasing the r. f. grids will 5 Magnatron - quarter ampere tubes sharpen matters up a little. Rest of Wiring ! 1 Jones plug and cord ! The antenna coupler made 1 Burgess 74 Volt C Battery. by the WITH the condensers, resistor, toggle Radio Foundation has three taps on it. ! (While the above parts were used switch and phone jack fastened Use the one with the least number of in the January model receiver, any i! on the panel, you may go ahead with parts of equal merit may be used in turns so as to get greatest selectivity the rest of your wiring. The rotors of the construction of such a receiver.) _ consistent with fairly good volume. the single and tandem condensers should In calibrating the set leave the antenna be commoned by means of a piece of bus tap at one place and make the run of the bar wire, all the grid returns of the three condenser scale from zero to one hundred. double -toroids being also fastened to connection on the side away from the socket If you change antenna taps while cali- this busbar. This wire in turn is ar- detector goes to the stator of the the set the settings for some second section of the tendem brating of ranged with a flexible wire by means of (the one the stations will be a little off. on which which it may be connected to different the trimmer condenser's shaft Owing to the fact the Amsco single taps on a C battery, the positive of the extends out in front of the panel). These in grid are variable used the crcuit of the C battery being tied to the negative trimmers used to take care of any first stage of r. f. is of the type whose variation in the inductances due filament line. Thus if it is desired to to dis- capacity increases when rotated in a bias the r. f. tubes negatively it will be similar winding, or any variation in counter -clockwise direction, the reading possible to do so at will by merely put- capacities due to different tubes and first Marco vernier dial will wiring. In on the be ting the flexible wire onto a different operation after the trimmers To remedy this, make use of are once set need opposite. minus voltage on the C battery. Under they not be used again. one counter -clockwise Marco and the They are not to be used in tuning some conditions it is advisable to bias under other one clockwise. It would seem the r. f. grids, especially where too much any conditions. eventually all manufacturers will From of that volume and broadness is apparent. With the plates the two r. f. tubes the system of capacity increases one wire goes each plate adopt this in mind the ground lead on the set to tap on the as the dial is turned to the right. When r. f. coils. The other end of goes to the negative filament instead the two we remember the marvelous changes that of going to the grid returns and the rotors plate coils goes to one terminal on the variable resistor condenser ,manufacturers have made of the condensers. Otherwise you would supplied by Centralab. in products since the days of "mud" This resistor has a maximum their be grounding the bias battery instead value of we can readily believe soon 200,000 ohms and should be insulation, of putting the desired negative bias on sufficient makers of all instruments will get to take care of plate the the grids of the radio frequency ampli- almost any voltage together and adopt a standard for their fiers. used on the r. f. amplifier tubes. The fact about twenty products. By Shortest Route or thirty set manufacturers make use of such a resistor in Neutralization LEADS from the grid taps of the r. f. their factory built sets would indicate While the X -L variodenser, type N, is coils should go direct and by the this means of controllling undesired (Turn to page 10)

10 RADIO AGE for January, 1926 The Magazine of the Hour shown in the list of parts, and is a handy resistance of the unit will be in series Tune in a weak signal with the second thing to have around the experimental with the plates of the r. f. tubes and no condenser, setting the first one at ap- bench, its use in the set will be dependant oscillation can occur. As the pointer is proximately the same dial reading as the upon the type of tubes used and the turned to the right the resistance will be second one. Then rotate the front trim- difficulty of preventing the first tube decreased until a point where the l';gher mer condenser on the tandem( which has from oscillating. In using the series B battery voltage will cause the tubes to a little knob on the front of the panel) resistance in the plate circuit of the go into oscillation. The point just before until you have built up the signal to its r. f. tubes a nice control of undesired the tubes go into oscillation (accompanied maximum. During this operation to oscillation may be obtained, but if any by a howl) is the proper place for the set get the balance perfectly it will be neces- difficulty crops up it would be a good to be worked. The resistor a ill have to be sary to do a little changing of the resis- idea to make use of the type N for neu- changed slightly from wave change to tor in the plate circuit. When this is tralizing the grids of the first two tubes. wave change. The maximum resistance done it will be possible to get the signal It is very difficult to lay out hard and will be in during use on the extremely strong and clearly defined on a single fast rules for these things since there low waves while on the higher waves split -hair on the second dial. The first are so many variations in the application the resistance is decreased bit by bit dial will be nearly the same reading, but by the individual set builder. Better until on KYW at 77 degrees on the second its tuning will be slightly broader than the have a couple of the type N on hand dial there will be no resistance in the second one. anyway for use at odd -times. circuit at all and the tubes will be securing In our operation of the set on an ad- In mounting the Thordarson audio the full value of the B battery voltage. mittedly poor attic antenna in one of transformers, the 2 to 1 is the first the suburbs of Chicago, 226 meters in To Get Going stage and the 3 to 1 in the last stage. came in at zero on the second dial. The electrical connections are shown in Assuming you have checked and double This wave is allocated to WBBM and Fig. 1, the schematic. For the two checked the wiring to make sure you have WIBO. From this point all through the filament connections on the audios a made no errors in the assembly of the scale up to 77, within one hour, the piece of bus bar wire may be run between apparatus, you are now ready to tune in stations shown in the box in this a:ticle the two binding posts and a piece of stations. Insert your tubes one at a were picked up with good volume, on flexible wire attached to this bus wire, time and see they light properly. The some extraordinary volume all on loud so it may reach upto the left front of the Daven filament resistors take care of speaker. However to get best selectivity panel where the C battery is located. the quarter ampere tubes without any we put the bias of the r.f. tubes at Tapping this flexible a ire on different need for a rheostat and since we are not 1 3 volts. The volume dropped son-e values of C battery will give the set using a critical detector tube like the from that obtained when there was no maker an idea of the amount of C bias UV 200 it will not be necessary to have bias on the tubes, but it permitted a he wishes to apply to the grids of the a rheostat for the detector tube. This little sharper tuning for stations in the audio stages. With 120 volts about 6 means a saving in the form of one control local area which had a tendency to over- volts minus may be used. Lower B at least and considerable peace of mind. shadow some of the out of town stations. battery voltages will need a drop in C Put the antenna clip on the antenna For the city dweller this type of a set bias so as not to have the audio tubes tap nearest the top end of the double - would be better if it were to be thoroughly drawing too little plate current with a toroid (see photographs Figs. 2 and 4) shielded with copper. The cabinet may consequent thinning out of the signal. and the ground on the left hand filament be wood with copper sheet shielding. If Change the C battery bias until you get connection of the first tube. Use the you intend screening, do a good job and a full rich tone. second condenser for finding your sta- shield the shole thing. You might even To secure control of oscillation by tions, the one on the left being not so (we would do it if living in the city) means of right hand rotation (clockwise) critical as the tandem condenser used make use of a copper panel, mounting of the Centralab variable resistor it will on the second r. f. and detector stage. all apparatus on the panel with bushings be necessary to make the left hand resis- The trimmer on the rear section of the where no contact is desired, and letting tor connection the B battery line, while Bremen -Tully tandem should be set at the parts like condenser rotors touch the the right hand one is the common wire zero, that is, its plates should be disen- panel. This would allow you to operate from both the double -toroid r. f. primaries gaged. The front trimmer should be within the shadow of a number of the and one side of the Dubilier 1 mfd. by- used to equalize the capacity discrepancy local boadcasting stations without inter- pass condenser (whose other side goes between the first and second sections due ference from their transmitters. For to the negative filament). When the to any difference in tube capacities, those who live in the country and are pointer is at the extreme left the total wiring variations and other causes. (Turn to page 12)

Top view q sel showing all pans, but unwir..d. Refer to Fig. 1, schematic, for correct electrical wiring diagram. Tell them you read it in Radio Age

RADIO AGE for January, 1926 The Magazine of the Hour

In this photograph is shown the wired set. Several of the wires were made flexible to take care of final changes in the receiver. Flexible wire may be replaced by busbar. removed from the influence of the modern r-oo..._.._.._.,_ ,__, _..4, Further Data On December high power transmitters the matter of Set shielding does not enter in to the matter 1 Hour's Log at all. Right In the December model it was found The receiver was not tried on a Mon- dial Call Wave i more volume could be secured by elim- day, or silent, night since it was felt 0 WBBM-WIBO 226 mating the two neutralizing capacities such a receiver would not be suitable 4 KSO 242 shown in the pictures and the diagram. for use by the man or woman interested 7% WMBB 250 Probably with some other type of tubes in long distance work. The best test of 11 WBCN-WENR 266 such neutralizing capacities might be a set would be during normal operation 15% WSM 283 used, but with the set as pictured their with all of the city stations in full blast. 16 WKAR 285 use is not as desirable if full strength of Ability of a receiver to sidetrack the locals 17 WBAV 294 signals is wanted. The addition of the and bring in the distant signals should be 19 KPRC 297 grid bias to the r. f. tubes as detailed in the criterion of any receiver. The 20 WLIB 303 the foregoing account of the January staff is working towards that criterion and 21% KDKA 309 model also helped somewhat on the feels in the presentation of the January 24 WGR-WSMB 319 selectivity of the set. model considerable progress has been 25 KOA 322 When the larger value condensers 26 WSAI 325 made. (Silver - Marshall .0005) were used in the In closing this discussion we would 27 WBZ 333 December model the higher range of the call attention to the fact that while we 28 WJAx 337 set was increased so as to embrace KYW specified and made use of a certain set 30 WLS-WCBD 345 and KSD without much of a sacrifice on of parts as shown elsewhere in these 32 WWJ 352 the extremely low wave stations. pages, any parts of equal merit may be 36 WGN-WEBH 370 After these changes the three dials used with success in such a receiver. 40 WT AM 389 shown on the panel of the December In the February issue we have another 42 WHAS-WHT 400 model (Bremer -Tully vernier dials) ran receiver which will be of interest to the 45 CNRM 411 practically true to form throughout the WCCO 416 cliff -dweller and which will take advan- 46 entire range. 48 WLW 423 tage of the directional qualities of a loop 49 WSB 428 By a little experimenting this model together with the use of tuned r. f. for 50 CNRO 434 with its three controls could be reduced amplification. The full details together 53 W OS 441 to one control, since the Silver- Marshall with pictures, list of parts, blueprint 55 WQJ-WMAQ 448 condensers have a little drum mounted schematic and the performance of the 61 WBAP-WFAA 476 on each of the condenser shafts by means set may be expected in the February 63 WOC 484 of which they may be linked together RADIO AGE which will be on the stands 77 KYW 536 with fish cord so as to give single dial about January fifteenth. % ..,4 .1rm.,.w.,.=.4 operation.

The completed receiver ready to operate is shown in a front panel view. RADIO AGE for January, 1926 The Magazine of the Hour 1; Finishing Your Radio Cabinet Method of Working the Wood, Applying Filler and Staining Detailed for Benefit of the Fan By H. P. STRAND

IN THIS era of radio, where the fan Now For Filler quantity of turpentine. Allow this to likes to build his own, he usually is a filler on the market that dry over night and then sand it lightly selects some particular circuit or THEREcomes in the form of a powder that with No. 00 sandpaper. The surface hookup, buys the parts, assembles them, when mixed with water makes an excel- should now appear with but a slight makes some suitable box or cabinet, but lent paste to fill up any little places that gloss and free from lumps. what is it that gives his set that home- can not be removed by the foregoing Apply another coat the same as the made look? It is the finish, or surface. methods. This is allowed to dry and first, and after it is dry, sand as before. It lacks that smooth satin appearance cleaned down with fine sandpaper. If Be sure to dust off well with a clean that usually distinguishes a factory made you remember that mahogany is soft piece of cloth before attempting to put job from the homemade one. when you handle it around the bench, on the varnish. Now the purpose of this article is to and take care to lay some papers down We can now use the varnish as it help you get a better finish on that set and keep bits of wood and the like, came in the can. This next coat should you are building by going at the treat- from getting under your work, you won't be applied in a room where the tem- ment of the wood in the proper way. have much filling of this nature to do. perature is not less than 70 °. as the var- The cabinet is often given the least We next come to the question of stain- nish will not flow properly and an un- thought in the building of a radio, and ing, as the darker than natural effect even surface will result. Make sure that is usually because the builder is in is usually wanted. There are many that no dust is in the air, and none ignorance of the methods used to properly varieties of stain on the market, so one settled around on surrounding objects finish woodwork. should experience no difficulty in select- or the floor, that will be stirred up and settle on the work being done. Look at Surface ing one that will answer the purpose. You can A good stain will penetrate deeply into not be too particular on this point as Let us first look carefully at the surface the wood, not raise the grain, or cover the job can not come out well if the room of the wood. How particular have you the grain, and its color will not fade. is not clean of dust and dirt. Stir the been to eliminate all dents and imper- These stains come put up in liquid form varnish well with a clean piece of wood fections? Every one will show up later, and in both red and brown shades. It and make sure that it is not chilled by unless we get rid of them at the start. is a good plan to get some of each and being left in a cold place. If it does We will talk of mahogany in this article mix them until the desired color is appear thick and cold, do not use it until as that is the stock usually used in radio obtained. after it has been placed in a warm room cabinets. Clear mahogany is quite easy This is applied with a brush or a cloth or near the stove or heater, and had a to work, but stock with pronounced and allowed to stand a few minutes and chance to warm up. Of course, the grain effects, the wide dark bands so then the surplus is removed. A second can should be well covered during the above warming up process of this popular cabinet application will produce a darker effect. to eliminate characteristic the chance of dust getting into the can wood is a difficult thing to handle unless It is a good idea to try some on a small same wood first make sure A good grade of bristle brush should care is taken. If a hand plane is piece of the to great of the shade. be selected, preferably one that has been used it will be found the plane will The surface must next be filled with used before, as a new brush will loose its smooth one band but will tear up its a suitable filler. This is purchased in hairs until it has been broken in. neighbor, due to the direction of the grain paste form, and thinned out with tur- Do not use a small narrow brush on a reversing. The best plan is to have the pentine, until it is about like molasses. surface that is quite wide, as too many stock run through a small thickness Apply with a stiff brush and work well strokes will be necessary to cover the planer at the mill directing the operator into the pores of the wood, brushing work, and the varnish can not be applied to have the cutting blades sharp and to with the grain and across the grain. smooth and even. A one and a half inch small take very light cuts at a time. This can This will fill up all the little grain marks. brush on cabinets and a two inch on large ones will be found right. with 0 Allow this filler to stand about ten about be followed up No. sandpáper Apply this coat with long steady on a block, being sure to use a back and minutes and then remove all the surplus with a rag. Make sure you get it strokes, being sure to brush the varnish forth motion with the grain only. If that all off as any remaining will affect the out well. Do not put it on too heavy, a circular or across the grain motion is drying of the varnish. as several moderately thin coats are far attempted it will leave scratches that We next need a thin even coat of better than one or two thick ones. Look can never be removed. A scraper can shellac. This also helps to fill the sur- out for "runs" and "sags," both results now be used to put the finishing touches face, as well as to make a binder for the from thick applications of varnish and on the stock. A good scraper to use for varnish. Use orange shellac well thinned not being properly brushed out. this work is an old safety razor blade of with alcohol. Apply with a brush, mak- Ready to Rub the variety with the stiff back edge. ing quick even strokes. work to dry least 24 This will take out the tiny sandpaper Applying Varnish ALLOW at hours marks. Apply a pressure to the blade and then the first real rubbing job THE first coat of varnish now is Procure from a piano supply on forward motion only, throwing may ready. the be applied. This should not be used house, a piece of felt, of the variety known one away when it gets dull and using as it comes in the can, as it is much too as hammer felt, about 3x3 inches and another one. In this way we are going thick for the first coat. Dilute it with an inch thick. This makes an excellent to get a good surface to start with and about 20% turpentine, that is, pour out rubber. Thoroughly wet same in water that is half the battle in wood finishing in a small can enough for about the first and with a light sprinkling of powdered Make sure no planer marks remain. two coats, and add about a fifth of that (Turn to page 67) Tell them you read it in Radio Age 14 RADIO AGE for January, 192u The Magazine of the Hour

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(left to right) Inez - and two of the Eskimo Weaver: Hebron, Ill., / youngsters who were third prize; Flossie E. thou- Erickson, Blooming- 04,4 sands et visitors at ton, Ill., first prize; the show.of Clareic Schmall, Chi- 0 cago, fourth prize; /, r .1 ! D o r o thy Goedecke, 0. _, - e Chicago, second prize. 0 ` '. ,' ° ' ' ` f ,, '! , I if I./ /

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Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 15 Save money by TAKI \G CARE OF YOUR RADIO Neglect of both A and B batteries, antenna, ground and other connections, cuts down signals By BRAINARD FOOTE

LTHOUGH the initial cost of a There are no radio outfits thât do not a storage battery, you have a source of radio receiver is usually regarded require attention once in a while. The power supply which is practically unfail- by the purchaser as the chief item millennium will have arrived when such a ing with proper care. It lasts for yearsif of expense, in reality there are upkeep condition exists! No, there are batteries to regularly attended to. Where do you put costs just as in the case of an automobile. be recharged or to be replaced with new, your battery? Some folks hide it away As with the car, these extra expenses do worn -out tubes to be taken out and new behind the piano where they can't get at not come at once and only after a period ones inserted, aerials that break, corroded it and never look at it unless the tubes of six months to a year is there any ap- joints in aerial and ground wires that must fail to light and thus show that the bat- preciable expenditure necessary. be repaired, loud speaker and phone cords tery is "dead." The radio set owner is interested, of that become broken and others. As with You shouldn't wait so long before giv- course, in maintaining a high grade of anything human beings possess, preven- ing your battery a charge, however. home entertainment at a minimum out- tion of trouble is better than cure. Hence put the battery where you can find lay. He doesn't want to buy a new set it easily. Stand it on a board or in a glass of batteries every month, or invest in a Batteries tray to protect the rugs or put it on a new outfit of tubes any oftener than he STORAGE batteries and dry batteries special shelf or table in the cellar, and run must. Proper care of the set and its of the "A," "B" and "C" type are, two heavy wires through the floor and accessories will go far toward reducing the taken together, the most troublesome cellar ceiling to connect to it. Always cost of keeping your receiver in steady items about the receiver. Hence let's keep the top clean and dry, throwing working shape. consider these right away. If you have away any rags you have used for the purpose at once. The battery can be washed with cooking soda and water and the top scrubbed with an fiER/AL old brush to clean it thoroughly. If green cor osion appears at the positive terminal, scrape it off clean- ly and apply a coating of vaseline or automobile Us TUBES? LOUD 3. PEAK ER -? grease to prevent its re- currence. Always have clean LEAD -IN? and tight connections between the wires to the set and the battery terminals, as squeaky and scraping noises result from chemical action on loose joints. Add Water IF YOU have your charging done outside, select a reliable shop, where the place looks neat and clean and be sure the service man adds distilled water each time the battery is charged. If you do your own charging, get a good make of % charger, have a quart or so BATTER/ES of distilled water on hand F- (which you can buy at any garage or drug store) and a U hydrometer of the syringe (Volime>er) type for testing. You do STORAGE -) not need a voltmeter for BATTERY, (Hydrometer) this purpose. Just before charging, add enough distilled water to cover the GROUND? plates. If you can draw up a hydrometer -full of liquid from each cell, you have Are you taking care of your set? Here are some of the accessories that call for your attention. You will save added enough. The added money and time, besides getting reliable service by radio, if you check up on these items. Read how and why. (Turn the page) 16 RADIO AGE for January, 1926 The Magazine of the Hour

If you use dry cells instead of a storage lots of leakage. Clean the outside light- Taking Care of Your battery, the voltmeter you buy should ning arrestor. Black oxide of copper on read plainly enough to indicate 1M volts, the wire doesn't do any harm, but broken Radio Set or it should have a "low" scale for "A" wires in a flexible aerial wire DO. Try to (Continued from page 15) battery measurement. Of course, if the avoid unnecessary insulators outside and set has a rheostat and you find you can where you have to use them to turn water replaces that lost by evaporation increase its setting until the tubes fail to corners, etc., use good radio insulators during charging and while standing in light brightly enough, well and good. But and not porcelain knobs with nails in use, but no acid evaporates. Hence do be extremely careful, if you DO use dry them. Porcelain insulators are O. K. if not add acid at any time. cells that are almost dead for lighting glazed all over, but unglazed insulators The float in the hydrometer tells you your tubes, that you turn off the tubes absorb moisture. Glass insulators are the condition of the battery. When it by the RHEOSTAT and not by the good, as well as rubber composition. floats to the highest mark, or about 1250 switch. The dry cells recuperate con- Don't have the lead -in wire too close or 1275 the battery is completely charged siderably and for a few seconds can de- to the building as the loss then occurs via and the active materials have been driven liver current at the normal value. There- the little "condenser" formed by the ca- off the battery plates into the liquid by fore, with the rheostat "ON" too far you pacity between the wire and the house the charging current. If the float sinks to might burn out or at least paralyze the wall. It's all right to have the ground the bottom you have overdischarged the tubes should you turn the set on by the wire run close, nailed to the floor or any- battery. It ought to go on charge when switch. To avoid accidental short -cir- thing else, however. The ground should the float shows about 1150. Never at- cuits, use strong, heavy wire that has be made to the street side of the water tempt to get the last drop of juice from good thick insulation and scrape the in- meter on the water system, if possible. your battery, as it has the proper voltage sulation off for only a short space at the A longer wire run to this point, or as near for the set without altering the filament end, for contact. it as can be, is preferable to a connection rheostats over the entire period. Be care- Tubes Are Delicate to the radiator. It sometimes helps to ful not to light matches around a battery use both such connections ALL radio tubes are delicate affairs. for the ground on charge as there is gas given off which however. Use a ground clamp, but thor- will explode. Don't undulyjar them, shake them or oughly scrape drop them. Moreover, don't apply too the galvanizing and dirt off Dry Cells the pipe before putting it on. If possible much strength in twisting them into the don't sockets as you may break the glass part have any soldered joints in the YOU should have a voltmeter to meas- aerial or ground. One piece loose from the base and break the inside of wire from ure the "B" batteries. Otherwise, if re- the end of the aerial to the set is best. ception becomes poor, you have no possi- wires. Jarring tubes often bends the ele- ble way of determining the trouble ments inside and changes the tube's char- Reproducers exactly. You may think it is the "B" acteristics. It may then fail to act in OUD speakers and phones have deli - batteries go out and spend $6.00 for your neutralized set. If you hear scratch- and 4 cords. you move its cate connecting Tinsel wire is a new set uselessly. A fairly good volt- ing sounds as the tube in used in them sudden pulls (with set turned on) it out and are likely meter can be had for a dollar or more. socket the take to break part of the tinsel or clean prongs on the tube as well to pull a Such a meter is not very accurate and it and the connection at the end loose. The as the contact members of the socket. If cord requires a good deal of current to operate usually has a length of tape attached, it so should the prong makes contact on its end, sand- that it be connected to the which should be tied to the plug so that battery for only a few seconds in measur- paper the end of the prong. If it's a placed socket, wrap any strain is on the tape and not ing. However, with such a voltmeter, side -contact a narrow strip on connecting cord tips. the prong clean the Should the note the voltage of your "B" batteries of sandpaper around and cord become disconnected, it is way. To clean the socket con- always when brand new and write it on the it that wise to try reversing the connections to battery. Take each 45 volt or 22% volt tacts, wrap a length of sandpaper around obtain the loudest and clearest reception. unit stick. Never insert a metallic object separately -don't measure the whole a In case the speaker has an adjustment for a with metal end -piece) into thing and let it go at that. Every time (like pencil volume it is easy to find the correct you have storage socket unless you first disconnect the polar- to charge the battery, the ity. Set the adjustment very close to the make it a point to test the "B" batteries batteries. rattling point (where diaphragm with Tubes will last longest in the audio and touches the voltmeter. When the battery magnets) and then reverse the connec- falls much below 40 volts a new one detector sockets, but in a year or so may tions. If the rattling stops, the first con- should be had. It is not always necessary deteriorate sufficiently to cause them to nection was right but if it in the R. F. sockets. increases and to replace both the 45 volt units at once; function poorly It spoils the quality altogether the sometimes one will wise to have an extra tube on latter last a month or two is always connection is right and the adjuster should a reviver) and longer than the other. If you use a 22% hand (or get tube to insert be changed again. volt for while in the R. F. socket to unit the detector, it will outlast it once in a The set itself does not require much the batteries. But if is note any change in volume on a distant other the detector attention. It is best not to stand a fine tapped first 45 volt unit, or a weak local station. Often to the this unit station radio cabinet too near a window will become discharged more seems poor on DX, when the or a quickly than your set radiator so that it will not be subject because in a worn -out tube. The to the other addition to the cur- trouble is due to sudden changes in temperature, nor will for is gradual- rent the amplifier tubes it provides filament will light but the tube the sun's rays discolor the panel. Finger- detector current, too. ly going dead on account of the fact that marks should wiped "thorium" has be off and furniture Use Grid Bias the active material been polish may be used as with other wood- of filament wire. Never "boiled out" the work. Keep the lid closed, to prevent NEVER stand "B" batteries in a hot light the tube more brightly than neces- from place, as the moisture is dust entering the cabinet and set- dried out. sary. tling in delicate electrical A dry spot is parts where and cool best. So avoid If your set has a loop antenna, don't it may cause leakage and corresponding locating your set too near the radiator. read this part. The outside aerial doesn't To make last loss of volume. "B" batteries long, always need very much attention, but you should Undiminished sensitivity and use a in connection a volume "C" battery with bear in mind that the loss of little will reward you for audio amplifier tubes. This in itself the little time you costs energy through leakage or capacity con- spend in caring for your radio equipment little and lasts a long, long while. It duction will weaken or prevent a distant biases the and in addition, the average expense will grid of the amplifier tube in signal from affecting your set. Of course, be considerably reduced. such a way that the tube operates more for local stations, most any kind of in- A tube restorer, which drives clearly and with much less "B" battery stallation will work, providing the joints out tho- current. The voltmeter can be used to are tightly soldered. But for weak sta- rium on partly exausted filaments, will measure the "C" battery, too and a new tions and DX, inspect your aerial once in also help to keep your tubes in good op- one should be installed when the old one a while. Take off the insulators and wash eration. Of course there is no remedy for drops the least bit, as noises begin when them. They'll be sooty and dirty and a burned out filament, save another trip the "C" battery starts to decompose. when wet with snow or rain will cause to the radio store. RADIO AGE for January, 1926 The Magazine of the Hour 17 Now you'll know HOW RE- BROADCASTING IS HANDLED

I n which a radio relay system covering half the continent is described by veteran engineer

'rHE receiving station for KYW's short wave pickup is shown in the above photograph with the author on the left tuning in KDKA's 61 meter signal for the edification of E. E Mattson, the Westinghouse press representative at Chi- cago. Since the installation of the uni -directional antenna the short wave signal from Pittsburgh is now heard uniformly enough to allow putting their dinner music out through KYW for the benefit of Chi- cagoans and residents of the Middle West.

CHICAGO's first practical demonstra- construction and there are no obstruc- tion of the Westinghouse relay By Walter C. Evans* tions between the antenna poles and the system was made through KYW lake. Sensitive though stable receivers during the World Series. That all seven having extremely low losses on the short games were successfully handled in this ing, for all the world like the surf on the wave are connected to the antenna poles. manner is amply attested by the listeners beach, proved to be one of the worst The signal is rectified through these and from Arkansas to Ontario who sent in stumbling blocks. passed on to a multi -stage amplifier enthusiastic reports, numbering well into designed with special care in order that the thousands. Crystal Wave Control all the musical frequencies are amplified Regular service has been established be- ITH the application of the piezo to their proper value. The output tween 5:30 and 6 p. m. Chicago time when W (named after Dr. Piez) crystal control transformer of this amplifier matches the a dinner concert, originating in Pittsburgh which holds the wave length absolutely impedance of the three miles telephone and handled over the short wave relay constant, removing the slight frequency line in to the KYW station on the system to KYW is daily broadcast. shifts which were so troublesome, the Congress Hotel roof. The line is termina- operation became more stable and the ted in the station on a jack the same as How It is Done quality cleared up. the lines from the various studios and the The program is transmitted over twenty The relay system calls for specially broadcasting operator merely has to plug odd miles of telephone circuits from the developed receiving equipment and an- the circuit through to the 536 meter trans- concert hall in downtown Pittsburgh antenna. Use is made of two seventy mitter and it goes out on the "air" with to the radio station located in the suburb foot poles carrying a copper pipe, split the same volume and quality as the music of East Pittsburgh. Here the incoming halfway up the pole giving a counterpoise from the Chicago studios. and antenna. The distance between the line is connected to two transmitting All sets, one 309 meter equipment known two poles is calculated for the wave length Remote Control over the country as KDKA and the of the one station to be received. The THE relay receivers in some of the other, the short wave relay apparatus poles are connected together in such a Westinghouse stations are remotely operating on 61 meters. manner that a unidirectional characteris- controlled so it is not necessary to have Many have been the problems worked tic is obtained allowing the pick up of an attendant adjust the tuners. The out by the Westinghouse engineers be- signals over only a small arc in the direc- operator in the radio station has a dialing fore the relay system became sufficiently tion of the transmitter. Energy from switch much like those on an automatic reliable to relay a regular scheduled pro- stations or electrical disturbances in all telephone. To vary the tuning dial or gram. Slight wave shifts, long and other directions cause an opposed current tickler on the receiver several miles away short fading, disruptions of tone quality between the two halves of this antenna he has but to dial a two or a seven and the which for a long time occurred without system which cancel out. tuner handle jumps around two or seven apparent reason, all had to be analyzed degrees as the case may be. Relaying and a remedy applied. For nearly a Uni- directional Antenna is done at KYW only from the Pittsburgh year a recurring rumbling scarcely audi- THE receiving equipment for KYW is station so the tuners are accurately ad- ble, increasing to a roar and then diminish- located at 18th Street and Prairie justed to the one wave length and are Aven ue.'This location was chosen because remotely started and stopped from the * Engincerinc] large .WestinghouseKYW,Chicago,Ill. the old residences there are free from steel roof of the Congress. 18 RADIO AGE for January, 1926 The Magazine of the Hour Noted Engineer Says: "HOOK IT to the VII \US A" Good engineering demands that negative B battery lead should go to negative A, thus establishing line of common polarity for measurements

THE writer looks at a great many By JOHN H. MILLER* circuits and modifications of new circuits radio diagrams in the course of a should consider the experimenter and week or two, and has noticed there make the diagrams as clear and generally does not seem to be any fixed point to adaptable as possible. connect the negative side of the "B" bat- Burn tery. It may be connected to the negative Out Tubes terminal of the "A" battery, the positive In the majority of tuned radio fre- terminal of the "A" battery, some in- quency sets either with or without termediate point, or to the arm of a neutralizing condensers or other means potentiometer across the "A" battery. of stabilization, the grids of the radio frequency tubes are tied back to the The Old Days negative side of the filament. If such In the good old days when soft detec- a set has the B - terminal connected to tor tubes were so critical they could the A+ terminal, a grid to plate short hardly be handled at all, it was almost circuit in the tube will cause the "B" necessary to provide a variable plate battery to be shorted across the filaments potential in order to get the most out of and several tubes will be burned out these tubes. An easy way to get this immediately. If the B - terminal were was to bring the B - terminal to the arm connected with the A - terminal, this of a potentiometer connected across the rather common tube defect would short "A" battery and by swinging from one the "B" batteries, but the tubes would care side to the other a variation in plate The above meter will take of three not be burned out. was had. readings. It will measure A battery volt- potential of several volts age, and two .sections of B battery voltage. Many sets on the market today have But such tubes are no longer available, The meter case contains a three way switch their various tuning elements shielded the ultra- sensitive detector with its need which will save you the trouble of rigging in metal cases and these metal cases are for extremely fussy adjustment having up one of your own. usually connected to the negative side given way to tubes slightly less sensitive, of the filament. If the negative "B" but far more stable. There is no reason with a common negative terminal, con- battery return is brought to the positive today for the adjustment of "B" battery nections are easily made to measure all side of the filament, one must be ex- potential in steps any finer than can be voltages with a single instrument and tremely careful with the positive "B" obtained on any ordinary "B" battery. with the use of the simplest kind of a battery lead, since if it should touch any So we might as well connect the B - switch, and if the rheostats are placed in one of the metal boxes, all of the tube terminal directly to some point on the the positive leads, filament voltage as well filaments will immediately become "A" battery, and it would seem that one can be read, since the filaments are con- burned out. Therefore, tying the nega- of the "A" battery terminals would be nected direct to the common negative bus. tive "B" battery terminal to the negative best for this purpose. In the interests of good engineering, it "A" battery and filament terminal will would seem that those who evolve new frequently prevent loss of tubes due to Metering Purposes burn out, and seems to be a very logical NOW if we connect to the positive "A" scheme of connections. battery terminal we add a few volts to the "B" battery voltage for the equivalent A Milliammeter Too plate potential because of the voltage IN the case of the experimenter who drop across the filament. But we make is continually testing out one hookup it exceedingly difficult to do some other after another it would seem policy to things with our circuits because we have a have on hand a zero to fifty milliampere positive terminal and a negative terminal meter which may be placed in series with tied together. We have no common ter- the negative lead of the B battery and minal of like polarity for metering pur- by means of which the pull of each tube poses and it is questionable as to which may be recorded. The use of a zero to side of the "A" battery to ground. ten milliammeter would be all right if But suppose we connect B - direct the experimenter could provide a means to A -, we then have a few volts less than for inserting the meter in the plate cir- in the previous case, but it is doubtful if cuit of each tube so as to measure the one person in a hundred can even imagine plate current used, but this would be the difference in output. And we do rather complicated. Instead the zero have a common lead of common polarity, to fifty milliampere meter in series with which we can consider as a base or zero In testing work, and also for your own the negative B lead would tell the story information, a milliammeter is quite de- line for ground, making measurements of all the tubes. Incidentally it will also and tying our circuits to. sirable to determine the total plate current being used. If your are swapping hook- go a long ways to convince the user of Read Voltages ups and changing tubes all the time, all the necessity for a C battery to conserve the more reason for having a milliammeter plate battery current. The use of instruments is growing in series with the negative B lead so as to *Chief Engineer, Jewell Electrical Instrument Co., quite widely on radio receiving sets and read total space current. (Member I. R. E.) RADIO AGE for January, 1926 The Magazine of the Hour 19

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The Received Signal The Amplified Signal

Weak Signals Need Enormous Amplification

VERY few of the is received at some great radio broadcast Few Broadcast Listeners Realize Pro- distance from it. Sup- listeners of today posing that a station in have the slightest' con- cess Necessary to Strengthen Minute New York is impressing ception of what an infin- 1000 watts on the aerial. itely small amount of Currents Into Strong Ones for Radio The watt is the unit of energy is picked up by electrical power and 746 the receiving set, and Entertainment. watts is equal to one to what proportions it electrical horse power. must be amplified, or By If all of this power so increased before it becomes audible to radiated could be picked up on the the human ear. The actual energy FRANK D. PEARNE receiving aerial we could use it to fur- received upon the aerial is so little that nish all the power required to light up it cannot be measured directly and the an ordinary home with electric lights, only way in which some basis may be a loop aerial was used, which naturally but most of this power is lost in covering arrived at, is to amplify it many thou- would not have as great an efficiency the distance between the stations. In sands of times and then by knowing as an outside antenna, it serves the the first place it leaves the transmitting exactly what the value of the amplifica- purpose of a comparison very nicely, station in the form of a wave of very tion happens to be, the actual strength and will demonstrate beyond a doubt high amplitude. As it passes through of the signal may be roughly calculated. that such a radio signal must be am- space the amplitude grows smaller and It has been estimated by some of our plified many thousands of times in order smaller until it seems to be flattened greatest scientists that the amount of that it may be heard distinctly with a out into almost a straight line, and the energy picked up on a loop aerial in loud speaker. Twenty years ago, if amplitude of the wave determines the New York City from a broadcasting anyone had the audacity to suggest the amount of power which is produced in station in California, if allowed to pass possibility of such a thing, he would the receiving aerial. continuously for thirty -five years, would be a marked man for the rest of his life, represent the energy required for an but here it is. It is being done in thou- Lines of Force ordinary fly to climb a distance of three sands of homes every day and we think ANAVE of high amplitude will carry feet up a straight wall. This statement nothing more of it, than we do of the more magnetic lines of force than may seem impossible for some of our other more or less commonplace things one of low amplitude. It is for this readers to believe, but it was actually of today. Do we ever stop to think, reason that a receiving station located made and proven before one of the best when something goes wrong with the a short distance from the transmitting known scientific societies in the United set, what a wonderful thing it is to station will pick up a strong signal. States and there were none present who receive signals, music and speech over The amplitude of the wave has not could disprove it. Imagine then, if such great distances? No, we say that decreased to any great extent, con- you can, dividing this time (thirty -five the set is no good and we do not appre- sequently more magnetic lines are made years) by the length of time required ciate what wonderful things the little to cut through the receiving aerial and for a signal to be impressed upon the set will accomplish with so little com- more current is produced in it, but if grid of a vacuum tube, and you may plicated apparatus and how easy it is the receiving station is a thousand miles gain some idea as to the amount of to hear from all parts of the country away, the amplitude has been con- energy which is picked up on the aerial in a few minutes' time. Perhaps a siderably reduced and fewer lines cut of the receiving set. better understanding of these things the aerial and this results in a much Must Amplify Signal will give us a reason for having more weaker signal. A receiving station patience when some trivial thing inter- which is so far away that the amplitude WHILE this of course might be called feres with our reception. In the first of the wave has been reduced to almost an extreme case because of the place let us consider what amount of a straight line will have great difficulty great distance between the transmitting power is sent out from the broadcasting in picking up the signal. Before the and receiving stations and the fact that station and why so little of this energy coming of the vacuum tube, reception Tell them you read it in. Radio Age 20 RADIO AGE for January, 1926 The Magazine of the Hour What Happens to Weak a radio signal is impressed upon it, it is the fact that not enough energy varies the amount of electrons which reaches the detector tube to cause it to Signals reach the plate. In other words , it operate with any degree of efficiency. attracts, or repels some of the was limited to much shorter distances, electrons Need Plenty of Tubes as detection of the signal was accom- which are flying past it according to the plished by means of the crystal detector. charge which the signal may impress THIS is why many of the radio re- The vacuum tube of the three element upon it. In fact, it has been called the ceiving sets which have only one or type made it possible to amplify the trigger of the tube because even the two tubes have so much difficulty in signal at the same time it was detected. smallest change in the signal which is receiving signals from great distances. From this, the amplifier was developed too small to estimate, will greatly vary The incoming wave has grown smaller and now it is possible to pick up this the resistance between the plate and and smaller in amplitude and when the minute amount of energy, which is too filament and make enormous changes in signal reaches the detector, it refuses to small to be measured and to increase it the strength of the current flowing function at ordinary efficiency, and to such an extent that the signal may be between them. This is often called the what little energy there is will not be heard at a distance of half a mile from relay action of the tube, and by this enough to pass a signal to the amplifiers. the receiving station. In fact, were it method a signal which is entirely too Now if more tubes are used as amplifiers not for this little three element tube, weak to be measured, or recorded can even this small amount of energy may we might still be using the old time be greatly increased in strength. This be built up before it reaches the detector crystal detector without any form of action takes place while the tube is also tube. This is accomplished by placing amplification. The addition of the third acting in the capacity of a rectifier, or one or more amplifying stages ahead of element to the two element tube by detector of signals. After this, the the detector, which build up the signal Dr. Lee Deforest made it possible to rectified signal is passed through more before it is rectified, and to such an amplify radio signals. This third ele- stages of amplification which may be extent that when it does reach the ment is called the grid and is located accomplished in several ways. Each detector, it has been brought up to the between the plate and filament of the additional tube which it passes' through point where it is strong enough to have tube. The hot filament throws out a will multiply the volume from seven some effect upon it. This is called radio stream of electrons which are attracted to ten times and if a high ratio trans- frequency amplification and in this by the plate and form a conductive former is used in each of these amplifica- process only the amplifying character- path between them. The positive tion stages the volume increases rapidly. istics of the tubes are used. After passing terminal of a high voltage source of A fairly strong signal from the detector through the detector the frequency is current is connected to the plate and may pass to the first stage with a tube greatly reduced, hence the term "audio the negative terminal is connected to amplification of eight to one, and then frequency amplification." The nature the filament. As long as the filament through a transformer which has a of the radio, or high frequency signals is hot the stream of electrons pass from ratio of ten to one, which will bring the is such, that usually only the amplifica- it to the plate and the current will total amplification of this stage up to tion of the tube is used. Transformers flow from the high pressure source from eight times ten, or eighty. The next are employed of course, but the ratio of the plate to the filament. A pair of stage then would raise it to eight times the transformer windings in this case are phones, or a loud speaker connected eighty, or six hundred and forty and the generally one to one which leaves only in the circuit would produce no sound next transformer would multiply this by the tube amplification available. How- because the flow of current would be ten, or six thousand four hundred times ever, if three of such stages are used ahead steady and would not change. that of the signal when it leaves the of the detector we have eight times eight detector tube. Thus the weak little times eight, or an amplification at radio Grid Goes to Work signal which at first was entirely too frequency which is five hundred and IF HOWEVER, any change takes small to be heard is built up into an twelve times that of the original signal. place in the current flowing through extremely powerful signal, which when Now if we multiply this by the previously the tube the diaphragms of the phones passed through a loud speaker may be mentioned audio frequency amplification would be affected and a sound would heard at great distances. In some we find that by the use of three stages of result. This is where the third element, cases the incoming signal is so weak radio frequency amplification, a detector or grid does its work. This grid is be- that even with all of this amplification, and two stages of audio frequency ampli- tween the plate and the filament and if it cannot be heard. The reason for this (Continued on page 53)

In the picture above the reader may see the amount of apparatus involved in producing the primary current necessary for a station like KDKA at East Pittsburgh, Pa., to radiate from 10 to 50 kilowatts of energy from the antenna. This enormous current at the transmitter dwindles to a few millivolts by the time it has reached your receiving antenna and must be rejuvenated in order for you to hear the signals through a loud speaker. The startling difference in size between the transmitting and receiving sets also represents the difference in the cost of transmission and reception. Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 21 Piety has more Data on Four Tube Tuned R. F. Set

Fig. 1. Pic- tured here is the completed set mentioned by the author in the accompanying article. Close inspection of all details will By help the con- structor to get Ray everything placed right G. in building this receiver. Piety

Stable method of oscillation control; restricted field inductances and only two dials on this good performer

THE many favorable reports received discovered the next logical step °is the sound is set up. The explanation of this regarding the operation of the four addition to this detector circuit of a stage action is that some original impulse is tube hookup described in the February of radio amplification, of itself efficiently picked up by the transmitter; actuates number of Radio Age together with designed, without setting up such action the receiver, which in turn re- excites the similar expressions of satisfaction that between the two tubes as will decrease transmitter and so the original impulse have come to the writer's attention leads the efficiency of either. It will be seen keeps swinging around from transmitter me to believe another article embodying that if this can be accomplished we to receiver to transmitter indefinitely. the more recent developments along the should have a four -tube set that will show This action is called oscillation and takes same line would be found interesting. unusual results. place because the amplified output of a There are a great many who would be The circuit shown in Fig. 2 is agreed system is so coupled back to its input, interested in constructing a set that will by all to possess a high degree of am- that it can re- excite it with sufficient give at reasonably small expense a high plification when properly designed parts strength to sustain a continuous inter- degree of selectivity, good volume, as are used. You will note there is a tube action. It should be noted this is not in good tone quality as can be expected and with an ordinary transformer coupled the nature of perpetual motion as the one that is simple in adjustment and input together with a coil in the output output must be amplified, and further easy to tune. to transfer the amplified signal to the this amplification must be sufficient to Since radio frequency first became a detector. The primary, which in the overcome all energy losses in the oscilla- possibility there has been no lack of simple circuit is between antenna and tory circuit. Analysis of the fundamental articles in the various publications ground, is here placed between the plate regenerative circuit will show the action describing circuits designed to "add a and B battery where it supplies amplified is very similar to that of the telephone. stage of radio." It is not my purpose to energy to the same detector tube. go beyond the average reader's technical Feedback Action knowledge, nevertheless it will be agreed Adding R. F. Stage By means of the tickler there is a a somewhat more adequate analysis of transfer of some of the amplified energy the theory of operation of the four tube THIS is simple and easy. All that has back to the input, where it is again circuit will enable the set builder to get to be done is to place a tube ahead amplified. However, if too much energy more out of his manufactured parts or of the original detector to amplify the is sent back the tube will oscillate and assist him in making his own. signal, and so give greater signal strength, prevent satisfactory reception of broad- but the results are true only if the action cast signals. It is apparent then, that as explained. Fundamental Circuit is as definite and efficient best results will be obtained when the Before we can assert that this action, and largest amount of energy possible is fed ANATURAL starting point from no other takes place, there are a few back but yet not enough to cause oscilla- which to proceed is from a funda- other considerations which must be taken tion. mental circuit, which, when properly into account. It is these other considera- constructed with good apparatus, has as tions which require a receiver of this BUT it will be found when an efficiently many desirable features as can be com- type to be designed, rather than imply designed stage of radio frequency bined in a steady -going reliable one -two- built. amplification is added in the manner just or three -tube set. The result of placing a telephone described there will be an excess of Unless some radically new and as yet receiver in front of the transmitter is energy fed back from the output of the unheard -of method of reception is familiar to many. A continuous whistling radio frequency tube to the input from 22 RADIO AGE for January, 1926 The Magazine of the Hour

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Fig. 2. The schematic diagram, by which the set should be wired is shown in Fig. 2. For placement of the parts the reader should refer to the photograph at the beginning of the article.

the very beginning. Instead of requiring When this condenser is set correctly pairing the efficiency of either circuit as a special tickler to secure oscillation, the the inter -action between the detector would have happened had we just added feedback due to coupling between coils and r.f. tube will be so slight that the on the extra tube, and the writer is and through the internal capacity of the tickler coil of the detector tube may be fully convinced the resulting circuit is one tube with a tuned plate circuit is set at its best point without having the that has no equal in a 4 -tube outfit sufficient to cause oscillation and prevent detector cause the r.f. tube to go into either for operating efficiency or smooth- satisfactory reception. oscillation. ness and simplicity of operation. Methods of preventing this will be You will note the absence of tnis But the advantages mentioned are by found in the telephone analogy. The condenser would create a condition where no means all. We have still another amplification may be decreased to a point the detector quite frequently could not improvement which is also in direct where it cannot overcome the losses in be operated at its best point, as the r.f. keeping with present demands. By the circuit, the feed back may be de- tube would be thrown into oscillation proper design of the two inductances and creased, or the losses in the circuit before that point had been reached in the use of a tandem condenser with a increased. the detector circuit. small "clean -up" adjustment on each To prevent such condition arising is unit it was found possible to bring both Defeat Our Purpose the advantage of_using the "Counter - stages to exact resonance by a single Altho the latter method is commonly phase" method of control of the radio adjustment. In other words, the de- used it will be seen at once that if we frequency stage. tector and r.f. units may be so balanced fixed losses into the it is possible to tune them both with but have to put back SINCE the B battery circuit is common circuit we are defeating our purpose, as one dial. to all tubes a choke coil and a 1 The regeneration and tuning controls we planned to combine the two parts in microfarad condenser are inserted to such way as to retain the full effects of are entirely independent of each other; prevent coupling between tubes thru the great advantage of which is im- both. the battery circuit. What we want is not a fixed reduction mediately apparent, as the tickler coil of By means of these changes we have the detector does not detune the detector of amplification, or a "damming" process 'added a stage of radio" without im- by insertion of resistance, but a means of input, and therefore it is not necessary to securing that balance which will keep the adjust the small "trimmer" condenser on circuit just below the point of oscillation. the tandem with every station as would When we test the final circuit as shown List of Parts otherwise be the case. in Fig. 2 we find a greater resultant 1 .00035 Mfd. tandem condenser. output than by any of the other methods, 1 .00025 Mfd. variable condenser HERE, then, is a highly practical and so the theory must be correct. 1 Four- Circuit coil. efficient four -tube set with really 1 Antenna Coupler. only one tuning control, yet with the THE method used is covered by the 3 1 Mfd. fixed condenser. "trimmer" adjustment available when- 2 R. F. choke coils. Bremer patents. A coil is coupled to ever the final touch is required on weak 1 Low ratio audio transformer. or the primary in such manner as to transfer 1 High ratio audio transformer. distant stations. "counter" potential; that is, energy in a 4 Sockets. The second condenser, as well as the reverse direction to that which would 1 Ballast resistance for four tubes in parallel. resistance across the audio transformer, cause oscillation, the action therefore 1 Set of binding posts or multiple plug con- are volume controls and do not in any being almost exactly opposite to the nector. way impair either selectivity or sensitivity. 1 Filament Switch. so called regenerative principle. The set is just about as good a com- The 1 Baseboard 10" z 17 ". proper amount of counter potential neces- 1 Panel 7" x 18 ". bination of desirable qualities as can be sary to balance out the objectionable 2 Vernier dials. combined in one instrument. The feedback is controlled by a small con- 1 Two circuit jack. sensitivity will please the distance hound, denser connected to T on the antenna 1 Grid leak (2 meg.) and condenser (.00025). while the ease of tuning and clarity and coil and so adjusted that the energy 1 Inductance switch (Four or eight points). range of tone unite to charm the less going in one direction (which would 1 Balancing condenser (about 30 MMF). expert manipulator. cause oscillation) is just equal to that 1 500,000 ohm variable resistance. The use of a variable tap on the antenna going in the other (to stop oscillation). coil makes it possible to balance the RADIO AGE for January, 1926 The Magazine of the Hour 23

required selectivity against the volume The condenser may be left in contact the proper apparatus has been used the desired and thereby obtain the best with the shield but it is necessary to radio tube should now be in an oscillating adjustment possible for any individual insulate the jack, selectivity switch and condition. antenna and receiving conditions. volume control. Shielding prevents the wiring in the set from picking up the TUNE in a weak signal at about 300 Use Good Parts signal and feeding it in direct before meters. When the tuning dial is GOOD apparatus should be used. To going through the tuned circuits. The rotated back and forth across this signal be sure perfect resonance may be advantage is less pronounced the further a beat note or possibly a whistle will be obtained on all wave lengths, it is neces- your location from the station. It will be heard. Increase the capacity of the sary to employ a tandem condenser with noticed no rheostat is used, a fixed Mikro -mike condenser until this beat a small clean -up capacity on each stage. resistance giving the proper filament disappears when the tuning dial is One of these capacities is variable and adjustment on all tubes. Many operators turned back and forth across the signal. controlled from the panel. It is doubtful use a rheostat as a volume control, which Watch carefully for the point where the whether it is possible to construct a set is wrong. When the volume is sufficient beat disappears and then turn the small that will tune to perfect resonance with to overload the tubes turning them down condenser from one -eighth to one -quarter the same capacity on both stages due to only overloads them more and although turn beyond this point. When making individual variation in tubes, wiring and the volume is decreased the clarity is this adjustment it is best to operate on other apparatus except by using a small impaired. a weak signal in order you may be sure clean -up capacity to compensate for this Volume Control both tuned circuits are in resonance. If variation. Properly constructed toroid necessary disconnect the antenna. If the A volume control is provided in the coils have the advantage of cutting down rear trimmer condenser is set at the right form of a variable resistance first coupling between stages and were used across the point, the front or panel trimmer will for this reason. They also may be audio transformer which has the advan- show best results at about its middle shielded with good effect as noted later. tage of actually increasing the clarity point, and no further adjustments are By carefully following the wiring as the volume is cut down. necessary. After the wiring is completed, -and it diagram in Fig. 2 and making all leads short and direct no assembly trouble is so simple that it needs no explanation, Use 201 -A Tubes all that remains is the adjustment of the should be experienced. IT IS generally best to use about 45 Connect leads to every other tap only balancing condenser. The batteries and antenna should be volts on the detector tube, although on the antenna switch. This avoids the a lower voltage may be more satisfactory possibility of the contact arm connecting connected to the set and some station on the lower wave lengths tuned in. with certain individual tubes. The two taps at once and short -circuiting the circuit is designed for the 201 -A type of turns between taps on the antenna coil. Finding the Stations tube throughout, but small or dry-cell tubes may be used if desired, with some Shield the Set zero, in Set the single condenser at sacrifice in volume. LOCATED within less than a mile order to prevent the detector tube from If your work has been well IFof a strong local station it is advisable oscillating, and turn the rear trimmer done and to completely shield any set. The cabinet condenser about three- fourths of the way the instructions carefully followed you and panel should be completely lined in. Adjust the small balancing condenser will be more than pleased with the ease with thin copper. Partial shielding is of to the minimum capacity (pointer at the of tuning and the smoothness of no particular value. highest point). If wiring is correct and operation.

tur* Ih tlti1. Ihr!

Fig. 3. Here is an isometric view of the set looking at it from the left rear. The three connection wires with clips are for B battery connections. 24 RADIO AGE for January, 1926 The Magazine of the Hour It won't be long before. YOU'LL SEE WITH YOUR RADIO TUBES Interesting developments on the therm ionic photo- electric cell detailed by Engineer

N LATE years photo -cells are taking being connected with the film. The a more and more important place in By V1 K1 Zworykn* blocking action will be reduced and part aboratories as most precise and sensi , or the whole available thermionic current five apparatus. With the increase in will flow to the anode, depending on the application of- photo -cells the methods of rate of discharge of film or intensity of using them are improving or, vice versa, the light. With such arrangement, the the improvement of methods increases output of the order of milliampere was the usefulness of cells. obtained, the cell being preferably of hard After the development of methods of type. When larger output is desire with- amplification of phot- electric impulses out going to the higher potentials and by means of thermionic tubes, the without sacrificing the sensitiveness, the application of cells extends far beyond other circuit is preferable. the laboratories. We know now, after The first grid is used as an anode with the works of G. de Prell (Ann. der low potential (order of 30 volts) due to Physik No. 3, 1923); G. Ferrie (Compes, the close spacing between this grid and Rendus November 5, 1923) and others filament. The second grid is connected how to amplify the photo- electric im- through the high resistance to a negative pulses as high as a million times by means potential with respect to the filament. of a single thermionic tube. These The cylinder can be connected to the methods are particularly adaptable for first grid directly or, preferably, have amplification of very weak impulses an re- possible potential in respect to it. quire careful) insulation and evenspecial thermionic tubes for best results. In order Can Block Current to simplify the installation and adapt The second grid is now working as out- the photo- electric cell for use of untrained side control electrode and with sufficient operators, the following device was de- negative potential can completely block veloped, having in view the output suffi- the current between filament and first cient to operate directly the average grid. If this potential will be adjustable mechanical relays. without light falling into the cell, no current will flow between the electrodes Photo -Sensitive Tube . and no voltage drop across the resistance. This device is the combination of While illuminated the film and second thermionic tube with a photo- sensitive grid will discharge the photo -electrons to control electrode. It consists of filmanent the cylinder and this current will produce of oxide coated type inside of open mesh the voltage drop across the resistance. grid enveloped completely by another The potential of the second grid will be grid of fine mesh. This second grid is in lowered and the current start to flow electrical contact with metallic coating from filament to the first grid. The of inside wall of glass container. The amount of current depends upon rate fourth electrode of cylindrical shape is of discharge of photo -electrons, i. e. around the second grid. These last illumination, and charge of second grid three electrodes are coaxial. The inside through the resistance. of the cell is coated with photo- emitting By proper choosing of spacing and substance, for instance alkali metal, mesh of second grid and adjusting the and treated in the usual way. Great resistance, it is possible to obtain good care should be taken to prevent the alkali relation between the intensity of the light metal from condensing appreciably on and the output within certain limits. insulatng parts of the cell. The cell in the arrangement, of course, In order to prevent the light from the has the time lag which is proportional filament falling on sensitive film, the part to the capacity of second grid and the of second grid is closed by metal shields value of the outside resistance. and the filament is operated at the tem- Ine one tube, made as described above, perature below visual emission. the time lag with this circuit was calculat- Several connections are possible with ed to be of the order of 1 -10000 of a this cell, depending on requirement of second and this has been verified experi- VDU can truly say now that vacuum tubes have the output. The simplest connection is eyes, at least electrically. The tube shown above mentally up to a frequency of 3,000 to let the second grid float and first grid is the thermionic photo -electric tube which is cycles. This value can be considerably adaptable to transmission of photos either by wire connected to plus side of the filament and or radio. Much experimental work is being done reduced by diminishing the capacity of positive potential applied to the cylinder on this phase of transmission and the story by Mr. the second grid and increasing its voltage Zworykn should be of interest to photo-transmis- in respect to the filament. sion fans. factor on the first grid. The continuous of the order of five How it is Used output obtained was milliamperes. This limit was due to the The cell is now operating as three The second grid acquies the negative heat developed inside of the cell, which electrode tubes, as the first grid acts only charge from the electronic flow and blocks distills the alkali metal on the transparent for reduction of impedance of the tube the current between the filament and and insulating parts. Of course by proper and can even be omitted. anode. If the light will fall now on the construction this also can be improved. ( *Research Department, Westinghouse Electric sensitive film, it will discharge by photo- For this connection the cell, of both soft and Manufacturing Co., East Pittsburgh, Pa.) electrons the second grid, the latter (Turn to page 54) RADIO AGE for January, 1926 The Magazine of the Hour 25 Hornless Wonder of Schenectady Uses New Diaphram Principle

Dr. C. W. Hewlett, inventor of the loud speaker bearing his name, which is described in the article below, is shown with a few of the models he has developed in the research laboratories of the General Electric at Schenectady. The largest one shown on the right is probably big enough to blow a person out of a medium sized room with the volume of tone emitted. Over a hundred and fifty thousand people who visited the Coliseum in Chicago during the recent radio show had an opportunity of seeing and hearing this loudspeaker which was connected up so as to amplify the broadcasts going on inside the model studio maintained by the show authorities.

UTOMOBILE tourists who visit the many different sizes, but the type used to pend on permanent magnets. No horn camping ground at Schenectady entertain tourists and residents of Schen- is necessary as is the case with the will be furnished radio entertain- ectady, measures forty -two inches in ordinary loud speaker. Sound is thrown ment by the municipality. diameter. The working diameter of the out equally from both sides. The dia- A giant, hornless loud speaker that diaphragm is thirty -six inches. The phragm is acted on at all points of its emits signals equally from both sides has device consists essentially of two large surface so it vibrates as a whole rather been installed near the camp ground, and flat coils of wire mounted close to one than being allowed to break up in partial listeners within 500 feet of the apparatus another in a frame which holds a thin vibrations. may enjoy music and speech of great aluminum diaphragm between the coils The large size of the diaphragm enables volume and free from distortion. It is These coils carry direct current which it to emit efficiently the low components known as induction loud speaker, and produces a radial field in the space occu- of the tones in speech and music. This was developed in the Research laboratory pied by the diaphragm and these same results in much more natural reproduction of the General Electric Company. coils carry the amplified voice currents that can be obtained from ordinary types Induction Principle and induce in the diaphragm corres- of loud speakers. This is particularly ponding currents which, by their interac- noticeable in the reproduction of piano The induction loud speaker is quite tion with the radial magnetic field, cause music. The induction loud speaker is different in every respect from the house- the diaphragm to vibrate and give off very substantial in construction. It is hold variety of loud speaker using a horn. sound waves. practically impossible to damage it or Dr. C. W. Hewlett, physicist, is the inven- When calls New get it out of order. occasion tor of the device, which until its installa- Features for it, a speaker may deliver large tion in the Schenectady park, has had Briefly the features of the new am- volumes of sound, as when addressing a only limited use in public. plifier are: large audience. The speech amplifier has been made in It has no iron in it and does not de- (Turn to page 56) 26 RADIO AGE for January, 1926 The Magazine of the Hour There is need for ACCURACYinRECE I VER Operation Antenna, inductances, capacities and all allied apparatus yield better results with fine control

IF a radio fan gets more than fifty per By working well. It stuttered and stam- cent of the efficiency that is in his mered. At times it seemed to need the receiver, he is getting more than a good ARMSTRONG PERRY stimulation of the stuff the boss kept hid many of us. We humans, in our "higher" under his desk. An expert was called development, seem to care more for ease receiver at the moment. But the knowl- in. The manager told him that the wet and convenience than for the opportunity so many users grow impatient batteries were charged regularly every edge that new to make our efforts completely effective. over the slightest extra effort keeps some night and that the dry batteries had One of the best radio devices ever in- been purchased only a few days before. manufacturers from using fine controls The vented was criticized on the ground it on even their best and highest priced expert picked up a voltmeter that required six full turns of the knob to sets. They leave it up to such users as are was lying beside the batteries, applied it cover the voltage range over which willing to try for maximum efficiency to to the "B" battery, and found that the filaments show their greatest efficiency. install knobs and dials that make fine latter was delivering about one -half of One turn was all the public would stand adjustment possible. its rated voltage. for. That is all a latch key requires, About Batteries and see what that lets you into -some- Condenser Control The date of purchase has no more times! The control of condensers is as import- Fish Are Efficient relation to the age of a battery than it ant as the control of inductances. The has to the age of a fish or an egg; a The electric light, which is generally connecting of two or more condensers to battery smells about the same regardless considered as a rather effective modern one controlling knob probably is due to of age, so it is easier to sell a rotten one, device, is said to be only from 6% to 8% the desire of the manufacturer to make that's all. Wet batteries can be tested efficient, dissipating most of its energy in his set appear more simple, rather than with a hydrometer. They can be charged the form of heat. Deep sea luminescent to any idea that the possible efficiency from the house lighting system, and fishes, on the other hand, are 100570 can be increased by that practice. It is closely controlled. Dry cells are not efficient, according to Beebe of the possible to pass stations without hearing wholly subject to the control of the users, Arcturus. He says, even while dying they them, even when condensers are separ- but the potential of the plate can be emit a light so strong a photographic ately controlled by knobs on the ends of regulated by keeping watch of the voltage plate exposed to it becomes overexposed the shafts of thé movable plates and available at the various taps and con- in a fraction of a second. He shows when the operator is listening with necting at the proper place or adding photographs to prove it. Since man- phones and exercising ordinary care. batteries. The test for wet operators made devices are so inefficient at best, the Inevitably, many stations are lost when and their control does not enter into this radio fan should try to bring out the efficiency is sacrificed to ease, and when discussion. most there is in them. In fact, it might the operator brags that he has no use The ground connection needs control- be well to emulate the polygamist, who for phones but gets 'em all on the loud ling also. High resistance there may tries to get more out of life than there speaker. affect or offset efficiency elsewhere. A is in it. There are experts who tell us the good -sized ground wire, making actual modern tubes are not critical as to fila- with wet begin work down- connection earth, and elec- TO at the top and ment voltage and, therefore, the rheostat connections are all ward, how many of us know just what trically tight that are made of coiled wire with a sliding tongue necessary for ordinary purposes. The there is in our aerials? The inductance that hops from turn to turn is accurate resistance can be measured. and capacity of an aerial can be calcu- enough in its control. Laymen should lated, roughly at least, by following not try to argue down experts, but any- NO severe criticism need be aimed at directions found in all well -regulated one who has used a filament control that careless radio users if they accept radio text -books. Most manufacturers provides smooth and continuous varia- the responsibility for the results of their and dealers are willing to divulge the tions of voltage knows, if the fine control own carelessness. None, unless they use secret if approached by a good customer. of the detector filament does not bring radiating receivers or turn on their loud The aerial can be adapted to the receiver, in the hard -to -get stations, something speakers and leave them yowling at the or the receiver to the aerial. No one else does it while he is working the whole .neighborhood. Close control of a who has noted even the effect of cleaning rheostat. receiver for a long period of time is tire- the insulators and brightening the con- some. The t.b.m. whose Maggie keeps nections can doubt that efficiency can WHAT we do not know about our him from the plumbers' ball or the front be increased to a remarkable degree if batteries would fill a large sheet row at the Follies is justified in plugging the characteristics of the aerial are from the memo. pad. Not long ago I in and letting the nearest, loudest station studied. visited a Broadway restaurant in New provide a soothing atmosphere while he The aerial connects, more or less York which had dismissed its orchestra enjoys his pipe and his paper. But when directly, with inductance coils. The and installed a radio set, and a loud the itch for distancé is active-the thirst variocoupler and variometer are forms of speaker more perfect than any I have for adventure and achievement -it is only variable inductance. Either of these ever heard except a later one invented just what we should avoid placing all the devices, properly designed, constructed by the same man. This radio outfit had responsibility upon the inventor, designer and installed, is capable of almost infinite become more popular than the orchestra. and manufacturer. We should use such accuracy of control. A hair's breadth It gave volume at least equal to that of intelligence as we possess in our efforts in the adjustment of the rotating coil the orchestra, and better quality and to produce something besides imaginary may make a difference of a thousand variety of programs. Business depended performances to brag about tomorrow at miles in the receiving range of the upon it. For two days it had not been the office. RADIO AGE for January, 1926 The Magazine of the Hour 27

Mutiny Aboard Pirate Ship WBCN

THE murderous ruffians pictured above are none other than the redoubt- " crew of the pirate ship WBCN which sails the ethereal sea every Tuesday from midnight until about 3 a. m. when even bold pirates should be abed. "Bloody Bill," the skipper, is William H. McDonnell, co -owner and director of the station; Edward H. Dougherty, the business manager of Foster and McDonnell, officiates as "Iron Knuckle," the first mate. "Terrible Terry" is Merle Yagle, musical director and chief accompanist. "One Eyed," the boatswain, has as many good eyes as any other person, despite the title. He is Harry A. Zook, Jr., chief announcer and assistant director. The Pirate Ship is Harry's brain child. Malicious McDonald is Frank H. McDonald, president of the Broadcast Listeners' Association of America, well known for his fight to secure a real silent night for Chicago fans. Altogether, this crew present an excellent nocturnal aerial feature; some of the scenes via radio are quite realistic, while the rollicking good humor quickly spreads to the listeners at distant points. Keep it up, Harry! 28 RADIO AGE for January, 1926 The Magazine of the Hour What the Broadcasters are Doing

Public's Taste For Looks Like Jazz Is Due Good Music Increases For a Fall Is musical taste and appreciation being uplifted King Jazz is slipping - and are radio listeners swinging Classical via loudspeakers and over to the classics? music, earphones, is favored by the masses "Yes!" JENNINGS PIERCE, who signs "JP" (maybe - is the emphatic answer of This trend, said to be completely con- Percy A. Scholes, widely known it's Jupiter Pluvius) is one of the announcing music staff at KGO, the General Electric's Pacific Coast trary to all expectations, was revealed by a critic of the British broadcasting station at Oakland, Calif. Many Broadcasting com- widely heralded poll which was conducted pany, with headquarters in who Eastern fans would give their right ear to hear London, him, but the Mid -Westerners are well acquainted by KOA, Denver station of is on a tour of America. with his voice. broadcasting "For the General Electric chain. Voting was example," he observed, "we read heavily in musical history Beethoven stimulated by a spectacular musi- that was cal competition between jazz and the born in 1770, but for thousands he was WCAD Makes Air Relay classical school, 'staged as a program only born in 1900 or 1910 when phono- of WGY Signals graphs or reproducing novelty by the Rocky Mountain broad- pianos came into Leading our homes. And for millions more, WCAD, "The Voice of the North casting station. artists and representative compositions of both fac- Beethoven was only born in 1923 Country" on 263 meters, operated by 1921, were featured. or perhaps as late as 1925 when many of students of St. Lawrence University, tions us first acquired radio receiving sets." has solved the problem of program fea- Broadcast listeners, representing all life virtually Substantiating the expericne of staff tures. WCAD gets them out of the air. walks of and sitting as an members at KOA, General Electric broad- By tuning to the 1560 meter wave of the international musical jury, voted three casting station of Denver, he pointed out developmental transmitter of the General to two that jazz is falling behind in popu- that marked changes in the public atti- Electric Company, near Schenectady, lar favor and therefore will never replace tude toward music of a higher standard, they get programs that originate in New the works of conventional composers. have taken place within recent months. York, Washington, Poughkeepsie, Albany As judges of this studio clash, listeners "Introduction of broadcasting was the and Schenectady. were invited to vote jazz, classical or greatest event in the history of the art of Canton, the home of St. Lawrence for a combination of both types of music. musk," he continued. "That America University, is the county seat of St. On the face of virtually complete returns should have developed such manifold Lawrence. It lies within sight of the from listeners, the classical camp won broadcasting activities is matter for northern foothills of the Adirondacks and three of every five votes cast in the congratulations. Our British experience only eighteen miles south of St. Lawrence race with jazz. Of the total votes cast, is sure to be the American experience- River. Its slogan, "The Voice of the more than 50 per cent favored the classi- give listeners plenty of fine music and North Country" is a tribute to a promi- cal school, the remainder being split they will learn to like it." nent St. Lawrence alumnus, Irving between proponents of jazz and those As music critic for the British broad- Bachelier, who immortalized this region who lean to a combination of both racy casting organization, Mr. Scholes' duties in fiction as "the North Country." tempos and conventional numbers. consist principally of a fortnightly re- WCAD grew from the need of the view of the leading musical events of inhabitants of Canton and vicinity for London. This is broadcast from the Lon- radio entertainment and for information don station, linked with all other stations on agricultural topics. The larger sta- Must Broadcast to of the country and requires approximately tions were available to those who had Hold Your Wave fifteen minutes. In addition, critics of selective sets, but not all who would With the radio public and, in, fact, books, dramas and films are heard at appreciate broadcast programs could most of the radio industry desirous of regular intervals. afford the type of set needed to pick up weeding out a large number of the 571 "distance." broadcasters now licensed, the Depart- WSUI to Have College Several weeks ago WCAD began ment of Commerce is seeing to it that experimenting with radio relay from every station licensed is actually operat- Scenes on the Air WGY at Schenectady. Efforts were ing. Wave lengths not being used Making use of radio to strengthen the made to rebroadcast the 41.88, 109, 379.5 regularly may be recalled and issued to allegiance of the alumni to their school, and 1560 meter waves, and of all these prospective stations awaiting air channels. and to interest outsiders in their institu- it was found that the 1560 was most Some owners are apparently of the tion, the Alumni Association of Cornell reliable and most generally free from fad- opinion that they can renew their broad- College, Mount Vernon, Iowa, is broad- ing or static. casting licenses once a month without casting a series of episodes typical of keeping on the air. This is far from the campus life from Station WSUI, Iowa fact. A license to operate a broadcasting City, Iowa. Resume Homemakers' Hour station is given with the understanding A rambling trip through the college - that the owners actually broadcast - glimpse of the chapel exercises; a few Homemakers' Hour, which experienced at least once a week -and may be recalled words from a professor's lecture, and a quite a vogue over WLS the Sears - if this requirement is not net. Just as glance at the more frivolous of campus Roebuck Agricultural Foundation Sta- with traction companies or public carriers, activities are being planned for this tion last winter, was resumed November radio broadcasting, as a public service, program by Prof. and Mrs. Clyde C. 18, conducted under the direction of must function, or the charters will be Tull. Both faculty and student talent Ellen Rose Dickey, Home Advisor of the revoked in broadcasting, a renewal of the will be utilized. Foundation, assisted by Martha Meier. license refused. Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 29 Union College Professor WFLA to be On Air by Here's Chance to Brush Makes Electron Sing January 1 Up on Spanish The possibility of creating a new The recent edict of Secretary Hoover From the icy sweeps of the Arctic circle musical instrument by utilizing the that there would be no new stations to Mexico and Central America, radio photo -electric effect was recently brought allowed to start, will not in any way listeners of all ages and nationalities are out by Dr. Peter I. \Vold, professor of affect the station the Mizner Develop- to be invited shortly to study Spanish physics at Union College. ment Corporation is building at Boca over KOA, Rocky Mountain broadcast- A photo -electric cell was connected to Raton, according to a recent statement. ing station of the General Electric com- \VGY's broadcast circuit and a disc with The company expects to have \VFLA pany at Denver. many rows of perforations was placed in full operation by the first of January. Manuals already have been obtained between the cell and a light source. The Lamdin Kay, \VSB's chief announcer, to accommodate a class of 5,000 persons, photo -electric cell is coated on its inside will open the new station at Boca Raton and it was predicted today that this surface with metal potassium which is it is stated. number would be increased materially very sensitive to light. At the center of before the expiration of the course, an the cell is a plate of tungsten. A battery all- winter feature. of 135 volts has its negative terminal Instruction, in charge of Prof. Benicia connected to the potassium coating and Batione, head of the Spanish departments its positive terminal to the tungsten at the University of Denver, will be based plate. When light falls on the potassium upon the Galeno natural method, as pre- coating electrons are given off and travel pared by Prof. Oscar Galeno, formerly of to the tungsten plate, thus constituting the University of Chili and more recently a current. By means of a motor the disc the University of California. with circular rows of holes was rotated KOA's classes will meet via loud- between the light and the cell. When the speakers and earphones regularly every disc was revolved slowly a low pitched Monday evening at 8 o'clock, commen- note was given off, rising gradually as the cing November 30 and will be in session speed of the disc increased. approximately one hour, it was said. In Prof. Wold's demonstration the disc contained four rows of holes, the outer row with 48 holes, the next row with 36, the third with 30 and the inside row with Cousin John Gets In On 24 holes. By covering one row or another Woman's Hour he secured different notes. STATION KY\V established a pre- Even a Scientist Has Sense cedent November 16, when a man appeared on the women's hour program of Humor in the morning from the Hearst studio. VEN a scientist with his head in the John C. Cutting, known as KYW's F4 clouds can show evidences of dry Little Miss Phyllis Stepler, of Chicago, "kitchen aid," was the lucky fellow. He is shown in the title of a recent twelve -year old dramatic artiste and gives a ten minute talk each Monday humor as danseuse who has just returned from a publication from the Government Print- three months' tour of the Pacific Coast and Friday morning at 11:15 o'clock. ing Office. during which time she appeared before Mr. Cutting, who has been broadcasting "The Vacuum -There's Something in the microphone of most of the western each week for the last six months from it," by Dr. W. R. Whitney, Director broadcasting stations, where her rare the Edison studio on KY \\"s program, Research Laboratory, General Electric charm and personality was vividly con- tells the ladies what to do with a stew, Co., is a brief description of the types veyed to the listeners. During the 1921- how to hemstitch hamburger, crochet of vacua known to science at present. It 1922 season Miss Stepler was the official steaks, etc. For more than two years child actress of the Chicago Grand Opera Mr. was is known as Publication 2799 from the company. Cutting the only man appearing Smithsonian Report for 1924, and may be She is the daughter of Mr. and Mrs. on the woman's program of Station secured from the Government Printing R. R. Stepler, 1125 Farwell Ave., Chi- \VJZ, the Radio Corporation of America. Office at Washington. cago. Mr. Cutting has discontinued his title of Prof. R. A. Millikan, winner of the "kitchen aid," because of the confusion $40,000 Nobel peace prize for the meas- in the minds of some women that he is urement of the electron, has an interest- to be classed with the pots and pans. ing report on "The Physicist's Conception His new title will be "Cousin John." of an Atom," known as Publication No. If They Can't Sing 2798 and obtainable from the same source as above. They Can Talk "The Electrical Structure of Matter" If the directors of the Chicago Civic Broadcast Service Area is covered in Publication No. 2797, by Opera will not permit the broadcast of is Mapped Out Sir Ernest Rutherford, F. R. S. opera performances, at least the public will have an opportunity to listen to a One of the interesting features disclosed number of its brightest stars discuss the by Secretary Hoover in his address before Good Relay Work intriguing background of grand opera the Fourth National Radio Conference L. G. Windom, owner and operator of from station WHT. at Washington, was the compilation of a amateur radio station 8GZ, of Columbus, Arrangements made with the opera service area chart made up by the Bureau Ohio, is making some excellent records company call for the appearance of an of Standards which tends to show the in speedy communication between this opera star before the WHT microphones average range of broadcasting stations for country and New Zealand. Acting as an eách Monday, Wednesday and Friday at crystal receivers. intermediate for East Coast stations, 11:15 A. M. during the current season. The radius of the circle served by a Windom has on several occasions taken These musical celebrities will tell the 500 watt station under adverse weather messages which are relayed to Ivan radio audience what goes on behind the conditions, day and night, throughout O'Meara of Gisbourne, New Zealand. scenes in a great opera house as well as the year, would about cover an area of Other New Zealand amateurs, to whom their own experiences. ten miles. A 5,000 watt station would these messages are consigned, are able Another feature of these special broad- cover an area of 30 miles while the 50,000 to answer through O'Meara's station, casts will be the establishment of a radio watt station would not exceed an area of z2AC. Windom has succeeded in getting question box on opera subjects, and 100 miles. Of course good weather replies to the originating stations in the inquiries will be answered on the micro- conditions and better receiving sets would course of a twenty -four hour period. phone as well as by mail. increase the individual ranges. Tell them you read it in Radio Age /30 RADIO AGE for January, 1926 The Magazine of the Hour Basis of Radio to be SERVICE to the AMERICAN PUBLIC Secretary Hoover outlines phases of situation and tells how problems were handled at Washington conference.

FOLLOWING is the text of Secre- Canada for Canadian stations, and ours tener. Certainly in radio I believe in

tary Hoover's recent radio address, , have come to be an integral part of a freedom for the listener. He has much delivered at the conclusion of ¡ single network. To speak in actual less option upon what he can reject, for the Fourth National Radio Conference, figures, for all the broadcasting in the the other fellow is occupying his receiving and broadcast from Washington. In it United States there are practically 88 set. The listener's only option is to

the fans may find interesting phases of Í wave lengths which can be used at th abandon his right to use his receiver. the broadcast situation touched upon by present development of the art, and w Freedom cannot mean a license to every Secretary Hoover. now have nearly 600 broadcasting station person or corporation who wishes to broad- clamoring for their use. cast his name or his wares and thus mo- WE HAVE just completed the Fourth "The air to -day is over crowded. And nopolize the listener's set. National Radio Conference in Wash- / even worse, we are faced with the de- "It was suggested that we might make ington. As chairman of that conference sires and demands of nearly 200 new room for more stations if we widen the I have been requested to report the re- broadcasters who wish to erect stations broadcasting band. Your instruments sults of the conference to the radio lis- and to force their way into the air. would not cover new stations outside the teners, for you are the people most vitally "This was the primary problem with present band, and if this suggestion were concerned in its conclusions. which the conference had to deal. It is adopted it would mean that we should "The conference included representa- the cause of major interference. It faced have to invade the band which has been tives of all phases of radio, both civilian it boldly. The conference declared the assigned to amateurs, of whom there are and governmental. thousands. The Conference agreed with me that radio has a useful contribution Interference to the fine development of the American "The major subject of this whole boy. None of us wish to minimize his three -day conference was interference. position in growing American life and In the practical terms of the listener, therefore the conferences confirmed here interference is the different howls, his province. noises, and whistles that come along with your programs. We know from the ex- Need Legislation perience of the last few years in this new "While the recommendations of the art that many of these noises can be conference should ultimately result in done away with, but the doing away with tremendous betterment to- broadcasting, them takes us into a dozen varied we must not expect radical improvement difficult fields. It involves questions of too soon. The conference was merely an legislation by Congress to further control advisory body. It had no final power. the traffic in the ether; treaties 'ith It expressed the views of every one in- foreign governments to eliminate inter- terested in radio. Before most of its ference of code signals from their ships at recommendations can become effective, sea and to coordinate the broadcasting in they must be enacted into law by the foreign countries with our own. It in- Congress of the United States. I hope volves many complicated and complex that this legislation will be given us by questions in the operation of broadcasting Congress at its next session. stations; cooperation from the electric "The problems of those radio listeners light and power companies, that electric isolated from the city communities were currents will not go astray. It involves HERBERT HOOVER especially considered in the conference. cooperation of the listeners themselves Methods were recommended by which that they shall keep their own receiving /public interest, as represented by service we can secure an extension and improve- sets so they do not occasionally turn to the listener, should be the basis for ment of the service to our farmers. them into sending sets and thereby dis- every broadcasting privilege. "The Navy must have wave lengths turb their neighbors. "I think therefore if I were asked what (by which they communicate with their "All radio listeners know that messages are the two outstanding results of the ships at sea. They must have wave over the radio are carried on a specific conference, I would say they lie first, lengths by which they communicate wave length. They also know there is in the recognition of the listeners' with their aeroplanes in the air. The only a certain band of these wave lengths dominant interests in radio, and second, Army must have wave lengths by which from about 200 to 550 meters which can as a correlary, in the determination that! they communicate with forces in the field be used for telephone broadcasting. the amount of interference must be and with their aeroplanes. We must Many of you perhaps do not realize the reduced. That means fewer stations and, have wave lengths assigned for interna- enormous amount of commercial and other better ones, or at least no increase in tional telegraph, for we are now in daily radio work that is carried on outside of numbers, and it must result in mord radio communication by code with every the broadcasting band. efficient service and better programs. important country in the world. One Limited Channels of the greatest services radio has per- Freedom of Air? formed is communication between ships "But in the broadcasting band there "It may be we shall hear a great deal and shore and between ships at sea. are only a certain number of paths over about freedom of the air from some of Radio has enormously reduced the loss which broadcast messages can travel the people who want to broadcast and who of human life at sea and we must provide from the station to the ears of the listener, will not be able to show that their desires full facilities for that at all times. There and only one of these paths can be used accord with your interests. But there has been a very wonderful invention called by one station at one time, unless they are two parties to freedom of the air, and "the radio compass" which takes the are a long ways apart. Some of these to freedom of speech for that matter. place of the old magnetic compass by ) paths are used by our neighbors in There is the speech maker and the lis- (Turn to Page 58) RADIO AGE for January, 1926 The Magazine of the Hour 3 1 Street Railway Company GOES on the AIR with WKBJ Employes of New York's Third Avenue Line Construct and Operate 500 -Watt Transmitter

THE first power - Westchester. In this fully equipped way the management radio broadcast- hopes to spread the ing station to be owned news about the new and operated by a station to more than a street railway company million street car pas- was opened on Sep- sengers daily. tember 9 in New York Mr. Bruno also and assigned the call stated that no paid ad- WEBJ. It is the sta- vertising talks would tion of the Third be broadcast from this Avenue Railway Sys- station. Later he tem of New York City, hoped to include talks operating on 500 watts of general interest to and on the air with a the public, instructing 273 meter wave length. them how to prevent An interesting thing accidents. about this new station It is interesting to is that it was entirely note WEBJ has already constructed by mem- drawn some of the bers of the company's best radio artists to electrical staff under its programs. In addi- the supervision of Wal- tion, the names of ter J. Quinn, chief several new artists also electrical engineer of appear in the weekly the railway system. It is located on the rf HE Executive Director of the station schedule. Some of the Broadway movie roof of the executive offices and trolley is Garrow T. Geer, who is also Secre- houses will co- operate in arranging the barns at 130th Street and Third Avenue, tary of the Third Avenue Railway Com- programs. Some of the artists who Manhattan. pany. The Program Director and Chief appear at these theatres go on the air at Radio engineers are agreed this is a for- Announcer is H. A. Bruno; the Assistant WEBJ between shows. They are rushed tunate location as the station is not sur- Director and Announcer is R. R. Blythe, by car to 130th Street and Third Avenue, rounded by tall steel buildings or other .and the Operator is F. O. Speicer. and returned in time to make their next structures which might tend to absorb the In a recent interview Mr. Bruno said: appearance on the stage. output. It is expected relatively long dis- "We intend to present the very best pro- S. \V. Huff, President of the Third Ave- tances will be reached, although this was grams obtainable, bearing in mind the ra- nue Railway System, is an enthusiastic not the purpose of the company in build- dio audience is always interested in hear- radio fan and listens in to each program ing a station of this size and power. On ing something new. In addition to the at his country home in Westchester. the contrary, the management intend to general public we are also reaching many present entertaining programs which will of our three thousand employees and their OPERATION of this station is being thus easily reach Greater New York and families. closely watched by officials of street other sections in which their street cars "The preliminary programs we have al- railway companies throughout the coun- operate. ready given have been a carefully balanced try. The fact it is the first and that its admixture of vocal and instrumental music programs have been well received, has The Antenna System and interesting talks. They were presented created considerable comment. The em- The construction of the station took two in an endeavor to determine just what our ployes of the company are also enthusi- months. The antenna towers are sixty feet particular radio audience wanted and from astic about their station and are quick above the roof and the antenna itself is of the letters received we seem to have struck to offer comment and suggestion. the T type and a counterpoise system is the right note. Aerial photographs of the station were used. There are 145 feet of phosphor "Our transmitter is tuned for a wave taken recently, and Mr. Bruno, who is an bronze wirein the flat top and the length of length of 273 meters, which is considera- aviator in his spare time, directed the tak- the lead is 48 feet. The direction of the bly lower than some of the other local sta- ing of these air views from an observation antenna is approximately north and south. tions. Consequently tuning is much shar- seat in an accompanying airplane. They The operating room is also on the roof per." are to be used to show the location of and is made of steel and hollow tile. A Has Some Innovations the station and will also be given to winding metal staircase leads below to the artists as souvenirs of their visit to "the fourth floor and the studio which is ap- Station WEBJ has already inaugurated car barns." proximately 50 feet from the operating one or two new features. A radio airplane During the winter months some of the room. The studio is 15x25 feet and the travelogue is presented every Tuesday and entertainment will be furnished by em -, walls, ceiling and floor are soundproof in Friday between the hours of seven and nine ployees of the company, and so we may accord with the most modern practice. The o'clock. The correct time is also announced soon expect to hear the Motormen's Quar- hangings on the walls and ceiling are made every fifteen minutes during the programs. tette and the Conductor's Band coming of lined druid cloth and the floor is heavi- There is also a review of the current pho- over the ether. Anyway, from the pro- ly carpeted on felt. It is furnished simply toplays at the first run Broadway houses grams WEBJ has been presenting up to but tastefully. Deeply upholstered maho- by Blybrun, and on Fridays he will also this time it seems as if a welcome addition gany furniture and a special system of review the week's new plays. has been made to the already large num- electric lighting together with a Duo-Art High spots of the weekly program are ber of broadcasting stations in Manhat- grand piano help to make this studio one to be posted on a bulletin which will be tan, and future programs will undoubted- of the most comfortable and efficient in placed in every street -car of the Third ly be watched with interest by the radio the city. AvenueSystemin Manhattan, Bronxand audience. 32 RADIO AGE for January, 1926 What the Broadcasters are Doing Here We Have I ugh Lights at RADIO CONFERENCE Service to Radio Public was keynote; cut down number of transmitters; bar advertising

WITH the conclusion of the Fourth might be assured of a wave length when National Radio Conference at By CARL. H. BUTMAN the station was complete... Washington the radio public well as in marine discouraged, as those Cut Number of Stations - heaved a sigh of relief at the action taken use, in an effort to further clear the air. and the recommendations made to Arc apparatus, it was held, might be HE Department of Commerce was Secretary of Commerce in their behalf further improved and the use of high - urged to decrease the number of and in the interest of the industry in oower only when necessary was advocated stations by refusing to grant any more general. wave lengths and likewise refusing .. any Ask Congress to Act more oper.ting permits until' such Radio time All Phases of WHILE no attempt to draw up a as the mortality of stations had created a No more broadcasting stations will go radio bill was made, a number of demand. This resolution was passed in on the air until such time as there are salient features were outlined and will be different forms by several of the corn - suitable channels released; no more presented to Congress through Chairman mittees and accepted unanimously by stations will be forced to divide time or White of the House radio sub -committee. the convention. wave lengths; the broadcasting band was These recommendations covered licensing Wavelength Speculation left as it has been between 202 and 545 of stations, opposed a monopoly in radio meters; and efforts to eliminate all forms communication, and suggested an appeal A blow was dealt the rebroadcasting of of interference were advocated -in res- over the Secretary of Commerce decisions, programs without the specific consent of olutions adopted, almost unanimously, although vesting in him the power of the originating station and a warning by a conference representing every phase administration in radio matters. Five sounded against the practice of specula- of the industry. years was proposed as the time of dura- tion in wave lengths. It was urged that This conference, cited as the largest and tion of stations' licenses, and established the Department scrutinize the sale of the most satisfactory of all, ended with fees ranging from $25. to $2,000.. per broadcasting stations in the future to the adoption of a resolution thanking station, were advocated. Any form of discourage any attempt to speculate in Secretary Hoover for his interest, and government censorship was objected to, wave lengths which are becoming more promising him the support and coopera- and, as radio broadcasting is not felt a and more valuable now that the number tion of all branches of radio and its allied public utility, the question of rates and of stations is to be limited. interests. In reply, Secretary Hoover fees was not considered a matter for In dealing with the marine radio thanked the conferees in turn for their legislation. situation it was recommended users of close cooperation, which, he said, showed Secretary Hoover registered himself as radio transmitters be encouraged to that this industry was the first to ad- opposed to the granting of so much power install transmitters of less broad emission. minister to its own needs through upon a secretary, or rather an official of This was assured by the steamship practically '`self government " -setting an the government, without having some authorities, who were replacing the spark example for other industries. form of appeal from his decisions, which equipment with apparatus having less Certain of the recommendations, when suggestion will undoubtedly be in- broad emission, it was explained. worked out into regulations by the De- corporated in any legislation. partment and laid down in legislation by Amateurs Unchanged Congress, it is believed, are indicative of No Band Changes far smoother sailing for the many radio MATTERS dealing with the amateurs the general opinion were not changed on the etherial seas in the future. Contrary to the to any extent. craft allocating committee accepted the present They were urged to observe the silent Salient Points broadcast bands without change but hours but were otherwise left to govern Among the salient points touched upon urged that special consideration be given themselves on their present wave as- -some of them felt to be drastic, are the the various government departments in signments. following: the dissemination of their particular news. It was felt the matter of interference If, in the opinion of the Secretary, there In dealing with the complicated prob- from radiating receiving sets should take be no public need for additional broad- lem of advertising by radio the conference the form of persuasion rather than casting stations on the air, he will not expressed itself as unqualifiedly opposed coercion and that such interference could license any more, even if stations are now to direct methods of advertising and better be eliminated by giving publicity complete and awaiting a channel. This called upon the members themselves to to methods of operating these receivers in position may be taken pending action of keep radio as free from this practice in such a manner that they would not Congress. It will be considered a hard- the future as it had in the past. It was radiate. Publicity of this kind had ship by some desirous of entering broad- decided that the burden of keeping the accomplished much during the past year casting but is held a benefit to listeners. air free of direct advertising should fall but this, it was felt must now be more Throughout the whole conference the upon the broadcasters rather than upon emphatic to accomplish the desired result. key note was "service to the radio public ". the government and that no legislation This objectionable feature to radio had The manufacture and sale of radiating was necessary at this time. been greatly reduced in Canada, the receivers was opposed by the Conference, It was recommended that inasmuch as committee pointed out, by the circulation it being pointed out, that although the distinction between class A and B of pamphlets to all the receiving set control of some types of oscillating re- stations is purely artificial that this owners. The committee urged the press ceivers was possible and that education terminology should be discontinued. The to publish such articles as would help to was needed, the committee on inter- licensing and classification committee educate the public in the use of radiating ference was anxious at some early date also suggested that a permit for the receivers and the proper manipulation of to prevent the further manufacture and construction of a station should be sets which through changes made in use of this type of listening device. necessary before the building operation factory -made equipment might be made Spark sets, partly used by amateurs were was commenced in order that the owner to radiate. (Turn to page 60) RADIO AGE for January, 1926 The Magazine of the Hour 33 You'll probably ask

What Does a Radio Supe ry iso r D ream About?

Department of Com- merce's Chicago representative leads a hectic life compared to the old days

Edwin A. Beane, Radio supervisor for the Ninth Radio District with headquarters in Chicago, who is the man responsible for holding all broadcasting stations in this zone in line.

HILE there has been a great deal commercial traffic on 600 meters was receiving and sending, save government written about the marvelous occasioned. Those were the days of the transmitters were squelched and the W changes wrought in the radio open spark, the carborunduin detector, Navy department took over control of industry since its inception in 1898 or and the straight coupled antenna which the air. With the cessation of hostilities so, little has been told of the development had possibilities for a wonderfully dis- the ban on transmission and reception of the Department of Commerce in turbing fracture of the ether. was lifted. Then the radio supervisors' general from an organization with govern- With the 1912 law in effect regulations difficulties began to accumulate. mental powers over wireless on shipping were passed to bring about inductive With the experience gained in the war vessels in United States waters to the coupling for spark transmitters and the in using telephone transmitters it was highly specialized and trained corps of use of a decrement which would prevent not long before Frank Conrad, now engineers and administrators who today undue interference in communication assistant chief engineer of the Westing- handle from Washington and nine in- between stations. Vessels' transmitters house company at Pittsburgh, fostered spection regions in the United States and those of the amateurs were regularly in part by H. P. Davis, vice -president of the destinies of the vessels, the amateurs inspected and licensed. At that time the same organization, began broadcast- and the broadcasting stations. the worries of the radio inspector, as he ing phonograph music from his amateur Perhaps a few words about the super- was then called, were not so bad, for there experimental transmitter, radio 8XK, visor of radio for the ninth district would was a limit to these shipping in the then his personal transmitter but now not be amiss at this time when the fourth United States and even the amateurs assigned to the \Vestinghouse experi- national radio conference at Washington had not reached into the thousands. mental station at Pittsburgh. Then has passed into history with a vast num- Today the Ninth district over which modulation was atrocious and the music ber of suggestions made to Mr. Hoover E. A. Beane presides as radio supervisor of the canned variety, but the scheme for the proper regulation of the industry. of the Department of Commerce, com- took a strong grip on American imagina- Broad Waves prises the upper Michigan peninsula and tion. About the same time the Western the states of Wisconsin, Illinois, Indiana, Electric conducted some tests with their the 1912 law authorizing the UNDER Kentucky, Kansas, Colorado, Missouri, experimental station at Deal Beach; also Department of Commerce to admin- Iowa, Minnesota North Grebe, of Richmond Hill, Long Island, ister wireless and South regulations covering Amer- Dakota and Nebraska. Headquarters used a transmitter, followed by the ican shipping, there were a number of are located in the Federal building at General Electric interests. inspection districts designed to make a Chicago. complete blanket of the country. At that Fever Grips U. S. time the amateurs were working with The War Ban jW ITH the radio fever thoroughly wave lengths anywhere from zero to DURING the war by presidential 0 v enmeshing the American public infinity and considerable interference with edict all wireless stations, both (Turn to page 62) 34 RADIO AGE for January, 1926 The Magazine of the Hour rrangement for RADIO a STUDIO

B y B o b E l l s w o r t h

WHEN the first section of the new but the size can be best estimated by $40,000,000 Palmer House, Chicago, telling you the larger studio is twenty - was formally opened in the latter part of two feet square. The advantage of two December, what is claimed to be the Eight room suite studios has been proven at other stations ideal radio studio arrangement was put and is obvious. A trio, small orchestra, into operation. in new Palmer or even a band can be placed in one This hotel, when the second section is studio, and while they are performing on completed next year, will be the world's House devoted to the air, a soloist and his accompanist largest hotel with 3,000 guest rooms. It can be in the other engaging in a brief stands on the site of the historic old activities of rehearsal so that the accompanist is Palmer House, which has been so promi- accustomed to the piano and the tempo nent in the history of Chicago. Mooseheart desired by the singer, who can warm up a bit and get into the swing of the song Up In the Air broadcasting before actually broadcasting. It also The eight room radio suite located on saves all the confusion of removing music the twenty- fourth floor (the highest station. stands, changing accompanists, arranging studio in Chicago) is the first radio studio music, while the announcer is talking or to be incorporated in the original plans while he waits for the number to be of a large building so all modern arrange- started. Thus the biggest advantage of ments and conveniences were put into some cases it has been necessary to run two studios is that there are no waits the plans and nothing was overlooked to heavy wires from the basement of the between numbers and a smooth running make it ideal in all respects. hotel up to the studio. This means a program on the air results. It is the Chicago Studio of WJJD, lot of inconvenience to the guests of the So that both studios will be under the the Moose Station at Mooseheart, Ill., hotel as well as being a great bother to control of the operator, an elaborate yet the station named in honor of Secretary the people in the studio and the hotel practical signal light system is installed. of Labor James J. Davis, the Director - electricians. So in our movie booth we The volume of singer and accompanist, General of the Loyal Order of Moose and will have direct leads from the main and the soloist's distance from the micro- the Founder of Mooseheart, the City of switchboard of the hotel in the basement phone are controlled by signs which light Childhood, which now has over 1,200 heavy enough to carry the load for the up electrically actuated by the pressing boys and girls from all over the country. lights. In the movie booth also, we will of a pushbutton on the control operator's It is maintained in cooperation with the store the lights and camera so when we desk in his room between the two studios. Garod Corporation and the Palmer want movies, all we need to do is call These are in addition to the signal lights House. in our camera nun from Dloosehart, who required by government regulation. will be available at all times. The movie Has Movie Booth booth is so located that, except for the Well Furnished BECAUSE it was included in the lights, a guest will hardly know a reel FOR the comfort of artists and guests, original plans, it has been possible is being taken because the door will be not only is the studio parlor furnished to include in the layout of this radio a divided one enabling the camera man in excellent taste to remind one of a suite all the conveniences for artists and to actually shoot from the booth. It is living room, but a rest room for the guests and at the same time to include true, of course, this will only be used ladies and a smoking room for men are all the latest improvements for better occasionally, but when it is, it will be a part of the suite. In fact, nothing has programs. great convenience to us." been spared for the comfort of those who Some of the features of this ideal are in the radio suite. For instance, over radio suite are as follows: Twin Studios $10,000 alone was spent for proper venti- It is the first radio studio to have a ALTHOUGH the studio has eight lation of all the rooms. movie booth. The floor plan reproduced rooms, it is the equivalent in floor To avoid the inconvenience of mike herewith will show it is located adjoining space of twelve guest rooms. No dimen- stands or pedestals, the microphones are and almost a part of the larger studio sions are given on the plan printed here suspended in each studio at the end of (No. 1) with a door entering into that an eight foot arm, w!i: -h can be adjusted studio. Jack Nelson, the director of to any height or position. Microphone WJJD, who with the architects, Holabird wires from the mike stand to a wall socket and Roche, is responsible for the plans, in the ordinary studio are a bother and explains this feature by saying: "There a source of trouble. Unless they are have been many occasions when motion securely anchored, somebody is con- pictures have been taken in studios in stantly but unwittingly kicking the cable which I have been working. Many of the and pulling the plug from the wall motion picture News Weeklies have socket. Then, too, the cable lying requested permission to take movies of loosely on the floor is not decorative to celebrities who have come to the studio say the least, and there is always the to broadcast talks and entertainment. bother of moving a microphone stand to If the celebrity is willing, of course, we get the proper distance for each artist. are, and then enters the problem of The above diagram il ustrates the manner in This can seldom be done without a noise getting the proper electric current to which the studios, parlors and offices are ar- on the air, but with the suspended micro- ranged in the new studio of WJJD, located on operate the powerful Klieg lights. In the twenty-fourth flaor of the Palmer House. phone on the adjustable wrought iron RADIO AGE for January, 1926 The Magazine of the Hour 35

,,,--, -;;c:' .

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VT V` f-i Ahlf-." 11,'...4.-,-----, - -,,,., ! ...- - 72-'1 rOd. .,, v I ,.e.... t -, ;F., -.X ;-< 411- .0. .7_ ;14_2)r;,, '',5 ...r i: r, r ..t., 1,.. - r _ s- ., r r. 0, , r .. r .,..r... .. x. r 1 p---7" --r1 . . - - F. . r g '

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New Palmer House and Jack Nelson ( inset) Director of WED arm in the new WJ JD suite, all this is Loud speakers have been placed in the Performers Like It eliminated. The arm itself harmonizes studio parlor, each of the rest rooms and IT was mentioned above the studio with the furnishings of the studio, it in the director's office so the program on parlor has been furnished in the style can be moved with no trouble or noise, the air can be followed from any place and comfort of a home parlor or living and the microphone cord is hidden at in the suite. room. Roomy chairs, divans, sofas and all times. (Turn to page 59) 36 RADIO AGE for January, 1926 The Magazine of the Hour

ANNO U The 1926 Radio Age Annual Will Be Ready Early in January TO MOST RADIO FANS the Radio Age Annual needs no introduction. Thousands of fans from all over the world have been waiting for this announcement of our 1926 ANNUAL, and we have a great treat in store for them. Many pages of blueprints of the most successful hook -ups of the year, along with complete descriptions of these sets. Technical articles on every phase of radio written by unbiased radio experts. Photographs and illustrations by the score. A complete list of broadcasting stations with a log you can easily fill. These are just a few of the things that will make the RADIO AGE AN- NUAL for 1926 the most talked of and widely read book about radio. The price of this book will be $1.00. If after receiving your copy you are not completely satisfied, return the Annual and we will refund your dollar. For the past two years our Annuals have been sold on a money- back -if- not -satisfied guarantee. Out of the many thousands of copies sold only one came back! (You can't please everyone.) The number of copies available is limited. Use the coupon below and be sure of getting the 1926 RADIO AGE ANNUAL as soon as it is off the press! To those fans who have never before been the proud owners of a RADIO AGE ANNUAL we are making a special offer. For only $2.50 we will send the 1926 ANNUAL, and include also a copy of the 1925 ANNUAL and a copy of the 1924 ANNUAL. A complete library of three years activity in set building and technical writing. Don't miss this opportunity to add to your knowledge of radio. Use the Coupon below.

Everything from the smallest to the largest Radio Age, Inc. 500 N. Dearborn St. the simplest to the most complex circuits known Chicago, Ill. to radio. A technical library; a how -to -make I want to be one of the first to receive a copy of the 1926 book that has no equal; a book you will be proud RADIO AGE ANNUAL. Enclosed find my check (cash or money order) for 1926 to own. The RADIO AGE ANNUAL for $1.00 for the 1926 ANNUAL $2.50 for one each of the 1924, 1925 and 1926 RADIO AGE, Inc. ANNUALS. Name 500 North Dearborn Street CHICAGO Address._ City. State 1 -26

Tell them you read it in Radio Arge RADIO AGE for January, 1926 The Magazine of the Hour 37

How To MAKE A Simple Power Supply Device By JOHN B. RATHBUN USING the electric light socket as a Copyright: 1925 There is always a rapid and regular source of high voltage plate current variation in D. C. current due to the has always proved a very attractive commutator used on the generator, and proposition, particularly with radio re- Plentiful B Battery while this is a very small percentage of ceiving sets employing four or more tubes Power in Your Home the total voltage generated, yet it is suf- at loud speaker volume. Properly de- ficient to cause a disagreeable humming signed, such devices supply an unfailing Electric Light Socket noise known as "commutator hum" un- current at a constant potential indefinitely less it is properly filtered out by the without attention or replacement regard - eliminator. If it were not for this minute vibration, the D.C. voltage be used less of the number of hours in operation tion of placing a device on the market could of tube without or the condition of the receiving set. It is is properly perfected. On the directly on the plates the before it further as the set is simply a matter of turning on the switch other hand, there are a number of well treatment just connected to a As a matter of when the receiver is started and turning designed units that maintain a constant "B" battery. fact it is usually more difficult elimin- it off when through with the set. voltage at above 60 milliamperes and in to Loud speaker operation makes a heavy which system ate the commutator hum than to filter out a perfected filter entirely rectified wave. demand for current on the ordinary type eliminates all hum even on the headset. a alternating current of "B" batteries with the accompaniment devices, the improvement Rectification of the alternating current With the latter is of trouble due to exhausted batteries such in reception is remarkable. The set has supply accomplished by electron tubes or by an electrolytic rectifier. In as reduced volume and battery noises, to a much greater "kick" owing to the con- either say nothing of the trouble and expense case, these devices permit the current to stant high voltage on the plate, and there receiver caused by replacements of the dry cell no rasping diminishing vol- flow through the circuit in only are crackles, one direction by entirely stopping or re- type or the recharging of the storage type ume or irregularities in reproduction due versing the alternate waves, and after the "B." Further, the voltage of a battery to the resistance of dried -up cells. drops off when there is a heavy demand waves are made unidirectional a filter for current so that there is always a cer- Principles of the Eliminator system of inductances and capacities tain amount of distortion taking place on In general, all "B" battery eliminators smooths out the gaps by providing suffi- crescendos when music is being received are divided broadly into the alternating cient electrical inertia to maintain a flow or a blurring of speech when the speak- current (A.C.) or the direct current (D.- of direct current to the set at the time er's voice exceeds a certain pitch. These C.) type according to the nature of the when the A.C. waves are zero. In many troubles increase rapidly when the bat- lighting current to which they are to be respects, the filter is like the flywheel of teries approach exhaustion because of the connected. For use on a D. C. current an engine for in both cases a uniform flow rapidly increasing internal resistance of supply, only a filtering system is necessary of power is maintained when the impelling the cells. For a five tube set, the source by which current variations are smoothed forces are above, below or are at zero in of plate current should be capable of out together with the noises they cause. regard to the output. The engine fly- supplying at least 25 milliamperes without When used on an A.C. current circuit the wheel carries the load at the time when drop of voltage or 50 milliamperes with eliminator must be supplied with a trans- the piston is on dead center. The filter the eight and ten tube receivers. former and rectifier by which the alter- system continues to supply current when True, there are certain "B" eliminators nating current is converted into a uni- the supply momentarily ceases. new on the market which will not main- directional current. After rectification, A. C. Rectification tain a constant voltage when a current in the usual filter system is connected to excess of 20 milliamperes is drawn, and smooth out the current ripples and fluc- An alternating current, such as taken which produce a strong 60 cycle hum, tuations in voltage. The employment of from an alternating current lighting sys- but this is a question of incorrect design a rectifier marks the difference between tem, is a current which periodically re- and by no means proves that the prin- eliminators used for A. C. and D. C. verses its direction of flow, first in one ciple is at fault. It is the old, old proposi- currents (Turn to Page 39) Tell them you read it in Radio Age X

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.00))0 $41* Fia 4 A. G SUPPLY FiG. 5 FiG 6 COPYRIGHT /906 R40/0 AGE; INC. cJ, B. iPATHBUN CH/C460, /L C. BE-2GbL"' RADIO AGE for January, 1926 The Magazine of the Hour 39 direction and then in the other without areas, the mean or average D.C. voltage for use as a rectifying medium in a "B" intermission. In Fig. 1 is a graphical is increased to (m2) which means a greater eliminator. For proper operation, a spe- representation of an alternating current effect than with the half -wave system, cial rectifying tube should be used from showing the violent periodic changes that and the rectified voltage (a2 -a2) is more which 50 to 60 milliamperes can be drawn take place. All of the loops (P) above nearly equal to the input voltage. For without over -taxing the t ube. Such tubes the reference line (X -X) are considered maximum results, full -wave rectification are now on the market but they have a "positive" in direction, while the loops must be employed. filament which is subject to deterioration. Further, the shown of (N) below the line are "negative" and Classes of Rectifiers tube types are the flow oppositely to the loops (P). The half -wave type and for full rectification height (VP) above the reference line Probably the simplest form of rectifier two tubes must be connected together. (X -X) indicates the maximum voltage or is the electrolytic cell rectifier shown in By the use of two independent filaments "amplitude" of the positive waves and Fig. 4. This consists of a lead rod or in one bulb full rectification can be ob- (VN) is the voltage of the negative sys- negative electrode (Pb) and a positive tained but there is only one tube of this tem, both sets of waves being equal, but electrode (Al) consisting of an aluminum type now on the market and that tube is occurring at different times. As the posi- rod. Both rods are immersed in a solu- difficult to obtain. tive and negative waves are equal and tion of borax or similar solution which The Raytheon tube, a full -wave rec- opposite it is evident that their sum is will maintain a film of oxide on the surface tifier, is one of the most interesting and zero. of the aluminum rod. When the alumi- efficient rectifying devices yet devised, In "single wave" rectification all waves num plate is formed, current will pass and while it has the external appearance of a given polarity or direction are entire- througn the cell in only one direction as of an ordinary tube, yet it has no filament ly suppressed leaving only half the waves indicated. The single cell performs half- and takes no heating current in the ordi- effective. Thus, in Fig. 2 the negative way rectification but when two cells, or nary sense of the word. Owing to the waves (N) are stopped with only the cells in multiples of two are connected up, absence of a filament, the life of the positive waves (P) remaining. These are full wave rectification can be had. This Raytheon is indefinite, thousands of hours spaced widely apart by the full width (n) is identical with the rectifier used in of operation being recorded during which of the missing negative waves so that the charging storage "B" batteries. there was no appreciable drop in the impulses are intermittent and jerky. The An electron tube, a common example output. The action is rather peculiar and average voltage is now only equal to the of which is the Tungar bulb, is very rather difficult to describe within this height (n) which is far below the value of commonly used as a rectifier. In this limited space so that our readers must be the A.C. current, with the line (a -a) device a heated filament throws off elec- content for the time being with a descrip- indicating the average D.C. output. The trons within an exhausted vessel and cur- tion of its practical workings and appli- shaded portions between the waves (P) rent is conveyed only in one direction in cation to the "B" eliminator. indicate the energy that must be supplied the electron stream. In Fig. .5 is a two A general view of the Raytheon assem- by the electrical inertia of the filter to element rectifying tube similar to a Tun - bly is shown by Fig. 7. The elements are maintain the voltage over the spaces (n) gar bulb. The filament (F) is heated to enclosed in the usual type of pear shaped at which the supply voltage is zero. If it the point where electrons are freely emit- glass tube which contains a highly ex- were not for the flywheel effect of the ted and the electrons form a path from hausted atmosphere of helium gas, and at filter, the line (a -a) would also drop to the filament to the plate (P). A trans- the bottom is the usual four prong socket zero at every point (n) and then cause a former (T) connected to the 110 volt A.- which fits into a standard tube socket. periodic humming in the receiver. C. lighting circuit supplies current for On closer examination we see the elements Full -wave or "Two wave" rectification heating the filament and the two connec- are very different from those in a filament is shown in Fig. 3. In this case the positions (A) and (B) are the terminals from heated tube. There are two very small tive waves (P) are allowed to pass freely which the half -wave rectified current is anode wires (el) and (e2) which are im- through the rectifier as before, but instead drawn. bedded in the lava block (L) so only the of suppresing the negative waves they An ordinary three element radio receiv- ends are exposed, and above the anodes is are turned up by an independent rectifier ing tube, such as a 201A, can also be used the cap shaped cathode (C) which forms and made positive waves. The converted as a rectifier tube by connecting it ac- the abutting element. We therefore have negative waves (n -n -n) are then inserted cording to the diagram in Fig. 6. The the three elements necessary for full -wave between the positive waves so that we grid and plate are connected together to rectification, the two anodes and the now have twice the energy that we had in form a single electrode while the remain- cathode, and these are connected to the the half-wave system, and further, the ing connection is brought out from the prongs in the base of the tube. application of the energy is more uniform filament transformer as before. Such an The discharge takes place between the with correspondingly less demand on the arrangement also functions as a half -wave anodes and the cathodes by a process of filter system. With an equal amount of rectifier, but its output is limited to a few ionization of the residual helium gas, and filter inertia, indicated by the shaded milliamperes and hence is not desirable (Turn to Page 42)

Figure 1. The completed power supply device, looking from the rear. - 'BUI:B. Eryo"

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COPYRIGHT 1926 RADIOAGE,ING. J.B. RAT HBUN CHICAGO, LLL, BE-200E - "Y = 42 RADIO AGE for January, 1926 The Magazine of the Hour because of the extremely small end area ed into circuit with the coils. It is the and should be rated at 30 henries. The of the wires (el) and (e2) exposed to the inductances or "chokes" that provide the iron core chokes have only two binding gas, there is very little "back current" or necessary electrical inertia, retarding the posts instead of four and in this way may reverse flow in the circuit. Flow reversal flow of current until the voltage or poten- be easily distinguished. takes place to some extent at certain tial is established. The condensers have This arrangement gives us a potential portions of the cycle with all filament and the reverse effect and are for the purpose of 135 volts across the main lines (M) and electrolytic rectifiers, this action making of modifying the action of the chokes, the (N) with the proper transformer ratio, a filtration a difficult problem, but with the condensers being connected across the voltage suitable only for the audio am- Raytheon this trouble is reduced to a output of the tube while the inductances plifying stages. A considerably lower minimum with practically no reversal in are in series with the circuit. This ma- voltage is desirable for both the detector the output. terially smooths out the rectified current, tube and the radio frequency stages (45 When placed in a standard tube socket, and while not new in transmitting cir- volts), so we must be able to draw both as in. Fig. 8, the grid post (G) and the cuits has only recently been applied to 135 and 45 volts from our "B" eliminator plate post (P) are connected together to broacast receivers. for the usual type of radio frequency re- form the terminal (1) while the filament A detail of the filter circuit is shown by ceiver. posts are the two anode posts running Fig. 10, the outline of the Raytheon tube This is accomplished by a sort of special from the filament (F) posts of the socket. being shown at (T) on the left so the potentiometer arrangement connected This completes the connections for full - relation of the tube to the filter circuit across the main lines (M) and (N). One wave rectification. can be more easily followed. The anode element is a high fixed resistance (R2) and A schematic diagram, Fig. 9, shows the of the tube is the (+B) source of D.C. a high variable resistance (R1) by which connections to .the tube up to the filter. current so the plate of the tube is con- the value of the detector voltage can be Alternating house current at 110 volts is nected directly to the choke coils (L1) and varied to suit conditions. Thus the (+45) supplied to the terminals (A) and (B) of (L2) and thence straight through to the post corresponds to the sliding arm of a the transformer primary (T), and by the +135B output post which goes to the potentiometer, the resistance of which is required turn ratio twice the required audio amplifying circuit of the receiving connected across the main line. Instead plate voltage is established at the ends of set. Very large fixed condensers are con- of sliding this connection back and forth the secondary coil (a -a). The ends of the nected between the chokes and the ( B) to obtain varying voltages, the resistance transformer then lead to the tube anodes line as shown so that a condenser comes (Rl ) is varied. A smaller condenser (0.5 (el) and (e2) so alternate half-waves are before and after each choke. When the to 1.0 microfarad) is a bypass to the fixed impressed on the cathode (C). By the current is being dammed back at the left resistance (R2). This completes the ele- use of two anodes each half -wave is recti- of choke (L1), for example, a portion of ments of the rectifier and filter system and fied and passed on to line (t) giving a total this stored energy or reserve energy is we will now pass on to a description of the or full wave rectification at the output. dissipated by allowing it to escape to the complete practicable instrument. By a mid -tap (r) in the transformer opposite side of the line through the con- Conventional Circuit Diagram secondary and by the two fixed balancing - denser (K1). In the same way, current condensers (K), half the transformer volt- that is held back at the left of choke (L2) Fig. 11 is the complete conventional age, or 135 volts in this case is established escapes (partly) to the oposite side of the diagram of the "B" eliminator circuit in the output line (u) so the rectified line. which is actually an assembly of the ele- output has a potential of 135 volts across The A. C. current going from the posi- ments already described together with a (t -u). The primary tap (n) permits of a tive side of the line through the condens- few additional controls which are of still higher voltage when desired by in- ers is opposite in phase to the current in assistance in handling the device. The creasing the ratio between the turns in the negative lead, hence these oscillations completed circuit is suitable for connect- the primary and secondary coils. This is oppose each other and damp out the ing to a 110 volt circuit and delivers direct a special transformer now easily available vibrations that tend to cause humming. current up to 180 volts for the audio on the open market and no doubt will The condensers are very much larger than amplifier with a tap for the lower detector soon be made by a number of firms as those used in radio receivers for the con- and radio frequency amplifier tubes. It well as by the pioneers-the Acme Radio densers (Kl -K2) have a capacity of 2.0 should be particularly noted that this "B" Apparatus Company. microfarads and condensers (K3 -I(4) are eliminator in its present state is suitable Intermediate voltage as may be requir- the 4.0 microfarad size. The chokes (L2) only for use on 110 volt alternating cured for the detector tube and radio fre- consist of thousands of turns of very fine rent circuits, and that it will be injured quency amplifying tubes are attained by insulated wire wound around a laminated if connected to a direct current main. a resistance balance system connected to iron core, much like the core of the com- Special provision must be made for direct the filter output and has no direct connec- mon audio transformer. The total in- currents which are not given here as tion with the rectifier. ductance of the windings, however, is alternating current is the prevailing sys- Filtering systems consist of iron core considerably greater than that of either tem for the distribution of light and power inductances and fixed capacities connect- the transformer primary or secondary, (Turn to page 44)

Figure 2. Looking down upon the finished power supply device vi

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in the vast majority of installations. 4.0 m. f. The casings of these condensers A "picture" diagram of the completed At the left of the diagram we have the are also grounded to (-B). All of the "B" elminator is shown by Fig. 12. Here special Acme Type B -4 transformer suited fixed condensers shown must withstand a all of the parts are shown as they actually for this sort of service, and this transform- considerable voltage without breaking appear and this is of great assistance to er was used in the experimental elimina- (K4) and (K5), each with a capacity of the novice in wiring and laying out the tor with excellent results. It consists of down, much higher than ordinarily met parts. The upper view is a rear view of the primary coil (PRI) and the secondary with in a receiving set bypass and should the panel which is connected to the lower (SEC) wound on the same iron core, and be tested to at least 1,000 volts before plan view by the wiring so that the con- the lettering of the transformer terminals they are accepted. The Tobe Deutsch- nection between the baseboard parts and is the same as that marked on the Acme mann condensers used in the experimental panel parts can be clearly followed. The transformer. Alternating current at 110 set are well adapted for this purpose. parts bear the same reference letter in volts enters the circuit at the terminals At (R1) is the variableiresistance used both Figs. 11 and 12 so it will be an easy (X) and (Y), this being first connected to for the control of the detector tube volt- matter to trace back and forth between the single pole double throw switch (SW) age, the movable member of which is the two diagrams. by which the output voltage can be connected to the (+45) post. The varia- A standard 7 "x18'x %" Dilecto panel varied. Throwing the switch to the upper ble resistance actually used at this point forms a support for the instruments and contact connects the current to the pri- was a "Bradleyohm" which gave a very resistances. This is fastened in the usual mary tap and gives the "high" voltage. smooth and continuous variation of from way to a wood baseboard measuring Throwing the switch over to the lower 25,000 to 250,000 ohms and excellent con- 7'x173x3", although the board may contact includes all of the primary turns trol of the plate voltage. This is known be deeper if the cabinet will permit. In and thereby reduces the voltage. as the No. 25 Bradleyohm. At (R2) we these dimensions the eliminator can be From the secondary posts (O -C -O), the can use a 10,000 ohm fixed resistance such installed very nicely without undue secondary coil is connected to the Ray- as the Bradleyunit, but for our purpose it crowding and yet with a compactness not theon tube (T) already described, and it was found the use of a No. 10 Variable often noted in apparatus of this sort. will be seen from the extension arrow Bradleyohm was a better lead as it per- Before starting out on a description of above this part of the circuit that this is mitted advantageous adjustment. Once the arrangement, it will be well to list the known as the "input." A dotted line adjusted, it requires little further atten- materials used in the test set and which around the parts of the transformer in- tion. are highly recommended. We warn the dicates the outer shell or casing which At (K6) is a 1.0 m. f. Tobe bypass beginner against the use of audio fre- must be invariably "grounded" by con- condenser connected across the resistance quency transformers in the place of the necting it to the (-B) line marked (N). (R2), for the purpose of cutting down the iron core chokes, for this is often recom- By this we do not mean that the shell is last ripples on the detector tap. It is of mended by those who have not had actual actually to be connected to earth, but that particular importance that the Current is experience in the construction. it must be connected to the (-B) line so steady in the detector circuit and the Connection with the electric light cur- that it will not transmit humming to the combination of (K6) and (R2) assures rent is made through the receptacle (U) output through capacity transference. If maximum damping at this point. into which a plug on the end of the flexible the casings of the chokes, transformers A 0 -100 scale milliammeter (MA) is lamp cord is screwed. When the elimi- and filter connections are not connected very convenient but is not absolutely nator is to be moved, the plug can be to (-B) there will certainly be a hum no essential. The milliameter used in the unscrewed without fussing with any high matter what other provisions we may experimental set was a Jewell instrument tension wires. In the upper right hand make in the circuit. which proved its value on many occasions. corner of the plan view will be seen the The Tobe Deutsch mann condensers and were we to build another "B" elimi- terminal connection strip (F) with its (K1) connected across the tube have a nator it is certain that a similar meter three binding posts used for the connec - capacity of 0.1 m. f. and as shown, their would be installed. It is an index to the tion between the eliminator and the re- casings are also thoroughly grounded to condition of the tubes, the volume, modu- ceiving set. The three wire cable is used (-B). A tap taken to the mid -point (C) lation, and many other similar factors. A at this point and three separate wires of the transformer secondary forms the small panel controlled switch (S) is for the must not be used in place of it. Twisting line (N) or the (-B). Anode connection purpose of short -circuiting the meter the three wires in the cable very material- (a): now goes to the first iron core choke when not in use. It is not desirable to ly cuts down the remaining ripples be- coil (L1), and is bypassed by the 2.0 m. f. leave it in circuit continuously. cause of the close proximity of the wires fixed condenser (K2). Choke (L2) is in In general, that portion of the circuit and this effect would not be obtained series with the first choke (L2) and is marked "input" should be kept well away with wires widely spaced. bypassed by the 2.0 m. f. fixed condenser from the "output" portion to avoid in- It is not a good idea to place the (K3). The casings of both condensers ductive disturbances and possible hum- eliminator very close to the receiver. It (K2) and (K3) are grounded to (-B). The ming through capacity coupling. While should be at least two feet away or in the capacity of the chokes is 30 henries. the casings are all grounded together, yet lower battery compartment of the console After the last Thordarson choke coil is it always safest to separate the input if a console is used. The:e is practically comes the final output fixed condensers and output sections. (Turn to page 48)

Figure 3. Front panel view of the B battery eliminator RADIO AGE for January, 1926 The Magazine of the Hour 45 \""\,, Piek.e laps crnd -- Ilookoemps s le6- C:g our 1 eaders

Conducted by Fred Hill ROBERT S. Smith, of Bangor, Pa., CONTRIBUTORS favors us with the following sketch A. P. Secor 228 Laurel Ave. Bridgeport, Conn. as the result of divers experiences in elim- Robert S. Smith Bangor, Pa. inating interference, which might be of Geo. H. Holtham_ 1716 Nicollet Ave. ______Minneapolis, Minn. interest to many of the radio fans who G. L. Luers 122 East Capital St Washington, D. C. have labored along similar lines: - "Static eliminators are the bunk! DIAL TWISTERS "When high frequency waves are Donald C. Smith _7 Erskine St. Dartmouth, N. S., slipping from the aerial to the set to the Canada loud speaker and upon being transformed into sound waves, manifest themselves Joseph O'Brien 2625 Harway Ave. ______Brooklyn, N. Y. by a continuous squak -squak of a leaky Felix Fredericksen Delmar, Iowa insulator or a vibrator charger or an Harold Young 400 North Harold St. Ft. William, Ont., electric refrigerator in company with Can. some perfectly good music - Owen E. McGillicudy 4 Algonquin Ave. Toronto, Canada "Well, don't buy a static eliminator. Jack T. Parr 861 Post St San Francisco, Calif. Both the music and noise are high W. W. McCune 728 Porter St. Glendale, Calif. frequency waves and, being of the same nature, one cannot be obliterated without destroying the other. Nine times out of ten the noise (or more frequently, noises) proposition but it is an end to work for. remember when the pencil mark was the which we hear are high frequency electric It would really save thousands and grid leak and the mark had to be rubbed waves and cannot be gotten rid of by use thousands of dollars for the electric off and reapplied several times before the of chokes and filter coils in the radio set. company both in repair and leakage. proper value was reached. Then came The tenth time, you migth have an Wherever there is a spark in a power line carbon paper -like substances on which a induced AC low cycle hum you can there is a loss and that loss does two coating of graphite had been applied. eliminate and still hold your music. things: It costs the electric company The unions at the ends of the resistance "Not so many years ago, all automobile money and causes us great annoyance. material generally loosened so we had a manufacturers were vying with each "Let's work for better roads for radio." noisy grid leak and immediately blamed other trying to eliminate the bumps in it on static or the house cat.. Then small the road by fixing the springs on their A contribution on the subject of var- coated rods began appearing, each en- machines. But even today, with balloon iable condensers is received, this time closed in a glass tube. Each six months tires and practically perfect springs, the from G. L. Luers, 122 East Capitol or year has seen advances in design in real, honest -to- goodness country road St., Washington, D. C. In the sketch which the manufacturer tries his level with lots of ruts and bumps defy any sent in by Mr. Luers is shown the rotor best to put out a quality product that man -made machine to run over it without plates of a condenser, especially the will stand the gaff of radio usage. Today feeling the bumps. Finally the people vernier plate, with holes bored in it we have a fairly uniform set of resistances came to their senses and, instead of trying so as to give it somewhat of the s.l.f. for our grid condensers. to conquer the bumps in the road by tendency. The holes should be bored in The same thing applies in the resistors working on the machine, they fixed the the rotor near the point where the rotor for filament control. First the rheostat road. meshes with the stator, which would be that used to burn up when handling the "Why not come to our senses and really the point where the lower bands are ampere of current on the old type tubes. get to work on the source of the trouble? found. The holes may be bored on one Later a better model. Then the quarter We know that most of our noise is due to or more plates depending upon the amount ampere tube; still better rheostats. Then man made machinery. It isn't in the of capacity reduction that is desired. the ballast resistance to eliminate the radio set. Why not start a general Do not drill both rotor and stator. Either rheostat control, and now we have the house -cleaning campaign by getting some drill the rotor or the stator. The sketch tube made with sufficient resistance in dope on filters and chokes and putting sent in by Mr. Luers shows the manner its filament to float on the six volt "A" them where they do good -not in the of doing the work. While this department battery line without external resistances. radio set, but across the armatures of the is always in favor of showing as many Probably the next step will be the 110 vibrator chargers, motors, generators, etc. kinks as possible yet it believes for those volt tube in which the heating element Get the trouble at its source. We could who can afford it the best practice is to will be separated from the electron eliminate at least ninety -five per cent of get a good s.l.f condenser and use a emitting surface, and after that -we can't our noises by vernier dial which combination will repay even guess. "1. Putting all electric wires under- the investment. ground. "2. Having generators and motors Some of the little things in radio sets We note with amusement the Weagant in our local power plant properly efficient are being improved constantly, and no variant, born somewhere around 1916- and by using a couple of filters and chokes. one better realizes this fact than the chap 1917, is again being discovered and de- "3. Putting condensers and chokes who is forever building sets and tearing veloped by some of our latter day radio across the armatures of noisy .vibrator them apart, as many of the readers of experts and doubtless Mr. Weagant feels chargers, electric refrigerators and other_ this column are in the habit of doing. quite elated over the recent original re- sparking electric equipment. Take, for instance, the matter of search; if we believed all we read King "The first of these is an expensive resistors for the grid circuits. We all Tut is running for President. Tell them you read it in Radio Age 46 RADIO AGE for January, 1926 The Magazine of the Hour Between power line troubles and lake of audio amplification without distortion have informal discussions of various boat interference Harold Young, 400 and howling. The last stage is biased as problems. The idea is good and should North Harold St., Ft. William, Ont., usual either through the negative return be applied all over the country. Canada, is making the best of it and or a separate C battery. Lack of space sends in a good list of DX. The chap prevents showing this in a sketch. who sticks to it despite the interference W. W. McCune, 728 Porter St., is certainly most deserving of the button. How would you like to have a loud Glendale, Calif., reports good luck with a single speaker whose diaphragm was 42 inches tube set made from descriptions in Radio Age, in diameter? appearing the Pittsburgh, Frederick Fredericksen, Delmar, Iowa, The General Electric people who have Calgary and Cincinnati are his best Eastern stations through the local bar- favors us with a sketch of a Danish been doing a good deal of research on the rage. 5 tube tuned r.f. receiver which lack of cone speaker have developed what is space at this time prevens our repro- known as the Hewlett loud speaker. We ducing. The set utilizes the well known do not believe it is on the market and honeycomb coils for the r.f.t.'s. To One of the most popular methods of may not be for some time, but it is controlling regeneration in a tuned r. f. stop oscillations the grid returns of the interestingly described in Publication No. r.f.t.'s are connected to the center arm set nowadays seems to be the 200,000 2799, obtainable from the Government ohm variable resistance in series of a potentiometer, one of the many with the Printing Office at Washington. plate circuit of frequency methods of preventing oscillations. the radio tubes. No horn is used on account of the large We believe there are about twenty or size of the diaphragm. The absence of the thirty manufacturers making use of this horn and the distributed exciting coil George H. Holtham, 1716 Nicollet device in their factory built sets. It make reproduction possible with a high works on the voltage loss principle. Ave., Minneapolis, Minn., sends in his degree of faithfulness. We understand conception of a three tube 199 set making In addition many set makers are using one of these loud speakers is a part of the the variable resistance, something about use of a crystal detector. The wiring is equipment of KOA at Denver. made up of No. .18 bell wire which 500,000 ohms, across the grid and filament probably helps considerable compared of the second r. f. tube to control its to some of the much smaller sizes. Mr. tendency to oscillate. These are two Holtham says he is not bothered by the ROTOR BLADES OF CONDENSER of the thirty two methods of presenting locals in his home town. DRILLED AT ENTER/N6- PO /NT oscillation, all of which has been pre - viously detailed in the pages of Radio Age. Try and find a new one! Joseph O'Brien, 2626 Harway Ave., Ave., Brooklyn, N. Y. must spend his young life bent over a radio set judging Judging from appearances, although from the list of stations he recently the super het is still the king pin on weak forwarded this magazine. We don't see and distant signals, the tuned r. f. sets how the world can situp all night with using tandem control of capacities and a set and still work the next day. How restricted field inductances, is going to be do you do it? represented in a large number of the sets made for the coming year. The plug - in type of inductances meet with some Youth is no protection against the bite favor under certain circumstances but of the radio bug. Here we have Donald /ER OF CONDENSER for the general public this method of C. Smith, 14 year old radio fan, of 7 VERN BLADE IS MADE MORE CR/TICAL OR covering more than one band seems a Erskine St., Dartmouth, N. S., Canada, little involved. For waves who, has been it for two pro- the amateur at years, SELECTIVE BY DRILLING system is gressing from the crystal to the tube set the plug -in aboùt the only means of hopping around in search of the hanging a good list of stations on and rip signals on various which Uncle single single tuber he is now the bands the circuit Sam has pounders. using. assigned the brass

George Wistow, 95 Leslie St., Toronto, We would be very glad to hear from Ont., Canada, who has already been the readers of this department as to their initiated into the DT fraternity, writes opinions, favorable or otherwise, on the us asking that we extend the honor to Model Receiver appearing in the Decem- Mr. McGillicudy, 4 Algonquin, Ave., ber Radio Age and also the one in this Toronto, Canada, who conducts a listening number. post on radio for the Toronto Daily Star. It seems that Mr. Wistow recently had Mr. McGillicudy over to the Wistow homestead and as a result the Star YOU'RE RIGHT! reporter had a column and a half of good "Leaving out the usual apple- dope heard on Mr. Wistow's set. The .sketch shown above explains pictor- sauce about your having the best ially the manner in which Mr. Luers magazine, etc., I will say instead makes capacity changes in his condensers that it is different enough to get Despite KPO about ten blocks away so as to get the s. 1. f. characteristic without the monthly quarter . . . One from him and using 1,000 watts, buying condenser type. you thing I notice is the reference to the Jack T. a of that If Weagant variant appearing more Parr, 861 Post St., San Francisco, Calif., contemplate drilling the rotor, do not drill frequently than in other magazines 1 manages to break down the barrier and the stator. n other words only one of the . . I hooked up this circuit some get the Eastern stations uniformly, elements should be drilled, either the stator time back and found it a wow for although it entails staying up late at or the rotor. volume, selectivity and a full, rich, night to do it. round tone." Radio fans in Wilmington, N. C., have The above from a N. S. G. W. progressed to the stage where they find it named William J. MacKenzie, 220 A. P. Secor, 228 Laurel Ave., Bridge- beneficial to have a radio club and as a Pierce St., San Francisco, Calif., port, Conn., uses a three megohm grid consequence such an organization has who in addition to rooting for the leak in series with the grid terminal of been formed. The president is Raymond Golden West includes Radio Agein the third audio transformer to improve Hunt, Vice -president, A. B. Blake, and his cheers. quality and allow the use of three stages Secretary, H. H. Hunt. The members Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 47 Recently in the lab. we stumbled upon Definite Hour Is Set For a great combination for making inductance tests without having to tear up International Tests everything in sight every time we wanted Final arrangements have been made to swap inductances. The Kurz -Kasch for the International broadcasting tests people sent us which one of their demonstrator take place during the week of "/1/////,'-' panels on which are mounted three January 24. USL condensers geared together with a All American broadcasting stations Dealers -if you want the best pro- rack and set of gears. The center dial, will remain silent between the hours of ducts, the fastest shipments and the most liberal discounts, write on which is the master, controls the left and ten and eleven o'clock, at night, Central your letterhead for our catalog right hand condensers. Each of the con- standard time. L1003. % densers has an E -Z Toon vernier by means This will mean that radio fans will ,,,/,/, , of which capacity discrepancies may be have sixty minutes in which to angle for ï i !!°/////%%%/ ///'// % compensated in connection with the European signals on waves which ex- use of inductances which tend from 300 2600 i/ % J / yí are not exactly to meters. ZS of the same period. This panel we mount- European stations will broadcast their / on a special i,i// ed baseboard with sockets and every- programs for the listeners on the /// thing made fast permanently. To further North American continent from 4 to 5 conserve time and energy we made use a. m., G. M. T., which means anything of the Allan- Bradley resistance coupled from a five to an eight hour differential Biggest dollar's amplifier unit which we also attached to for residents of various sections of the the baseboard. Thus we had the con- United States. worth in densers, sockets and the audio amplify- The table below will give you an idea ing sections fixed up in permanent form. as to the proper time for your particular Then to compare different sets of induc- geographical section of the United RADIO tances all we had to do was to remove States: - one type and substitute the other, with- The European program runs from 4 out in any way disturbing the balance to 5 a. m., January 25. of the test set. All of which saves a great New Yorkers on Eastern Standard deal of wear and tear on the nerves. time will find their time 11 to 12 o'clock the night of January 24. Chicagoans and Middle Westerners on Central Standard time will start up their otse D- 4 trans -Atlantic signal quest from 10 71I-GOT FOREIGNERS' to VV LS, XMQ WHY DON'T 11 o'clock, the night of January 24. VXM. CHXY THEY STAY LAS' NIGHT, ON TH51 Residents of the Mountain Standard TRIeD BY OWN ,IOE.' WpAN AÑ time should twirl their dials between XOYß. 9 and 10 o'clock the night of January 24. Californians and residents of the Pacific Standard time region will be on the alert for 8 9 their European signals from to Compiled by HARRY F. DART, E.E. p. m., on January 24. Formerly with the Western Electric Co., and In reckoning time the fan may make U. S. Army Instructor of Radio use of the fact that Greenwich mean time Technically edited by F. H. DOANE (generally abbreviated G. M. T.), is considered the starting time; every fifteen 514 PAGES -ONLY $1 degrees of longitude west counts one ONE of the most complete books of its hour earlier, while every fifteen degrees kind ever published. Written, corn- of longitude east counts one hour later. piled and edited by practical radio experts Packed Thus New York is in the 75th meridian of national reputation. with con- sound information useful to so five hours subtracted from cise, every are the radio fan -from beginner to* veteran hard - G. M. T. time; Chicago is in the 90th so boiled owl. Contents its time interval is six hours earlier; - Denver Electrical terms and circuits. antennas, CATCH CRIMINALS BY in the 105th and its time differ- batteries, generators and motors, elec- RADIO ential is seven hours while San Francisco tron (vacuum) tubes, most receiving By M. L. Jenkins hook -ups, radio and audio frequency is in the 120th meridian and its time amplification, broadcast and commercial The radio is beginning to take its place as a difference is eight hours. transmitters and receivers, wave meters, factor in the prevention of crime. The results In this week of international tests the super -regeneration, codes, license rules. of a message broadcast by a Nebraska sheriff Many other features. recently no doubt caused Nebraska and Kansas owner of a tuned r. f. set will still be at Just mail the coupon printed below with a dollar criminals to wonder just where they would be the mercy of the gentleman who owns a bill and your name and address, and we will send able to you this 514 -page I. C. S. Radio Handbook or any hide. regenerative set and has not learned to of the other I. C. S. Handbooks that you want by When the Hastings, Nebr., sheriff broadcast properly handle it. Despite this fact, return mail. Money back if not satisfied. the description of a stolen car, a Bird City, however, it is confidently Kans., radio fan thought it was a car he had expected the International Correspondence Schools bought from J. B. Freeman of Hebron. It was. tuned r. f. group of receivers (together Box 8782 -E Scranton, Penna. Investigation resulted with I enclose , which send me. post -pald. in the recovery of four- the super) will carry off the laurels. the Handbooka marked X. at $1 each. It Is under - teen stolen Nebraska and Kansas cars, and the The straight 1 stood that It I am not entirely satisfied I may regenerative in the hands of return them within five days and you will refund arrest and conviction of three Nebraska men. my money. Radio possibilities an experienced operator will give a in the detection of crime RADIO HANDBOOK, $1 are good account of itself. unbounded. It is probable that every Automobile Handbook $1 county seat town and all cities will soon have Location of the receiver, surrounding p Electrical Handbook S1 I D Chemistry Handbook - S_1 broadcasting stations and that when a crime is structures, power wires, trolleys and other Pharmacy Handbook committed, details will be sent out in every Traffic Handbook I direction. absorbing structures will make their Building Trades Handbook S1 Machine Shop Handbook S 1 Not so long influence felt when the listener is strain- Salesman's Handbook S1 ago the automobile was reckoned Advertising Handbook as a big factor ing for every millivolt sl in the increase of crime. It from a distant Bookkeeper's Handbook 1 provided a quick getaway and so many transmitter's signals. Civil Engineer's Handbook cars The fans located in Steam Engineer's Handbook 11 look alike, it provided a superior method of the wide open spaces will have concealment. But the ad- now the radio. It more vantage of their city Name than offsets the auto, and may be developed cousins, but the very effectively in dealing city dweller may outdo his competitor at with crime. 'Addrees least in the number of :tubes in operation. L -----___--1 Tell them you read it in Radio Age 48 RADIO AGE for January, 1926 The Magazine of the Hour

( Continued from page 44) Now, at the heighth no limit to the distance between the two of their first season. ''00-page the POWER-PLUS parts and it is often very convenient to Fieldless Coils are be- in a Reference ing accepted nation- put the eliminator cabinet and install ally as the outstanding it in the basement where it will be out of successes of the year. Book Radio experts from the way. When run in a damp place it coast to coast have indorsed and recom- will be a good idea to use a three wire mended POWER - PLUS Coils and Con- cable with an outer rubber cover in addi- densers. tion to the braid so that internal leakage will not develope. As previously explained, it is advisable co keep the apparatus in the output cir- POWER - cuit, such as the chokes and large fixed On Their Merit PLUS, the condensers, at the opposite end of the Mailiñ: - new, superior, POWER-PLUS Coils and Con- Fieldless Coil. baseboard from the input portion of the densers have won thousands of en- List thusiastic boosters on their merit circuit as shown. If the parts are rearranged If you are building a new set-or improving the old one you will only so the condensers come close to the trans- Catalo'q be fair to yourself if you send former you may be almost of a for the free folder recently pub- sure No.55 lished by the manufacturers of persistent hum which will be im- POWER-PLUS Products, and almost the seven copyrighted hook- possible to eradicate. For the same POLK'S REFERENCE BOOK up blueprints which they are FOR DIRECT distributing to interacted reason, do not locate the eliminator so MAIL ADVERTISERS individuate free of charge. Shows how to Increase your business by Simply clip and mail your that the three wire cable passes close to the use of Direct Mail Advertising. 60 pages request coupon below to full of vital business facts and figures. Who, the A. F. Benninger the transformer end on its way to the where and how many prospects you have. Corporation, 4507 receiver. If it does, it is almost certain Over 8,000 lines of business covered. Ravenswood Ave- Write for your copy. nue, Chicago, Ill. to pick up-some hum. FREE In Fig. 12 the outlines of the apparatus R. L. POLK & CO., Detroit, Mich. 599 POLK DIRECTORY BUILDING are shown in light continuous lines, the Branches In principal cities of U. S. A unit of the main wires by heavy full lines and the POWER PLUS Kit - Set, Fieldleas Coil "ground wires" to the case by dotted - and S. L. F. Con- denser. lines. All of the wires electrically connected to the ( -B) post are considered as being ground wires although not neces- A. F. Henninger Corp. 1. sarily connected to earth, while the wires 4507 R wood Ave., Chicago, IR. eoing to the positive amplifier and detec- Five Tube Gentlemen: ril.-01r.-o.,o1111110.,.1....11o.1on11..1nInI..v Which Kindly send me your folder and 7 Copyrighted I Set book -up blueprints. I understand they are absolutely FREE -and I am not obligated in any way. Bill of Materials startled Name No. of Index Pieces Name the World Address K1.__ 2 0.1 m.f. Tobe Deutschmann Fixed Condensers. K2- K3.... 2 2.0 m.f. Tobe Deutschmann Town State. Fixed Condensers. K4 -K5... 2 4.0 m.f. Tobe Deutschmann FRESHMAN Fixed Condensers. K6...... 1 1.0 m.f. Tobe Deutschmann Fixed Condensers. AASTERPIEct L1 -L2. 2 30 Henry Thordarson Iron Core Choke Coils. MA. 1 0-100 Scale, Jewell Milliam- The Greatest Value LOW meter. R1._ 1 No. 25, 25,000 to 250,000 gi-e10e ohm. Bradley ohm. Ever Offered in A R2.__.._ 1 No. 10, 10,000 Fixed Brad - Interference Eliminator leyunit Resistance, or No. Receiving Set No Radio Set Complete Without It 10, 10,000 to 100.000 ohm. Radio Bradleyohm. The latter Now you can select stations at will, cutout is shown and is best. At Authorized Dealers interference and undesired stations -tune S...... 1 Small Panel Switch, Nickled in loud and clear. Wonderful results with any Knife Type. like or crystal set using any kind of aerial ex- 1 Cutler- Hammer T o g g l e cept loop antenna. Partially absorbs static. Switch. Amazing Re- SW ..... 1 D. S. P. S. T. Baby Knife Switch, Porcelain Base $ sults, Better Type. Reception T 1 Raytheon Tube. Guaranteed or TRANS 1 Acme B -4 ' B" Eliminator Transformer. We Refund Your TS.__ 1 Standard Tube Socket. Post- Dollar. Send Standard Molded Recepta- paid. Order Today cle used in electric lighting work. Select Stations At Will A. -- 1 7 "x18 "x3/16" Dilecto Panel. Try this Interference Eliminator on your set - B....._._ 1 7 "x17! s "x ii" Wood Base- no tools -nothing to add-attached in 2 minntea board. to aerial. Doesn't disturb present log. Direc- Standard Flexible Lamp tions easy to follow. Two big banks testify to our reliability. Order today -dollar bill will do-. Cord, No. 18. Length de- we take the risk -money back if yon say so. pends on distance of eliminator from lighting socket STEINITE LABORATORIES D._ 8' Three Conductor Belden The Indoor Aerial that 302 Radio Building. ATCHISON, KANSAS Cable with three rubber - Write for complete Steinite Radio literature - covered conductors in a is more selective and it'a FREE. Most beantiful and least expensive heavy braid. i radio sets in America. E. 2 Electric Light Socket Plugs. more efficient than any outside F 1 1 % "x3 W "x3 /16" Dilecto Ter- minal Connection Strip. antenna. This device has estab- G.___.._ 3 Eby Binding Posts. H-_ 2 Brass Corner Brackets for lished an enviable D -X record in stiffening panel. i I...._ 60 Solder Lugs. the congested district J..__.... - 15' Rubber covered Flexible Wire. Strand used for of Chicago for the wiring sets. Radio's biggest season is here. Get our Busbar, Tinned Copper. past two years. new catalog showing huge stocks of radio Roll of Solder. i Seni prepaid on remps of money order parts, sets, kits at lowest rock- bottom M -... 60 Assorted Wood Screws. prices. Quick service. Wonderful spe- AERION AERIAL CO. cial offer on best sets, tubes, batter- 7253 CORNELL AVE ies. Write for free copy. ir- CHICAGO. ILL WiC.Bratur Co, 36-Se SCGnto. St, Mean, U.S.A. (Turn to page 55) J Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 49 Plenty of WGY Waves For Fans to Pick Up ANTED! $158 -$225 a Month ? U. S. RAI LwAY Those who grope among the air chan- ALL POSTAL SALARIES JUST RAISED nels at night have found an increasing -MAIL MAIL COUPON BEFORE YOU LOSE IT number of radio stations signing "General Franklin Institute, Dept. M331, Rochester, N. Y. Electric Company, Schenectady." There Sirs: Rush to me, without charge, (1) Sample Jr Railway Postal Clerk Examination questions; are now nine transmitters applying elec- (2) tell me how to get a U. S. Government job; trical impulses on nine different wave- (3) send list of positions open to me. lengths from Schenectady, and during Steady Work - No Layoffs -Paid Vacations Travel-See Your Country Name some periods seven transmitters may be Common Education Sufficient on the air at the same time. Not all BOYS, MEN, 17, up. ACT IMMEDIATELY Address however broadcasting, some are transmitting code -but each is on its own wavelength and each is applied to its apportioned task. Schenectady, in the past eight months, has become the great world center of 4-17PMIllirieriiiiry step radio transmitter experimentation. With- in three miles of the city the General Electric Company has constructed a gigantic transmitter developmental station. On the plot of many acres eight , transmitters have been erected. Each filrevard transmitter has its independent antenna system and these systems, as well as the i` transmitters, are constantly undergoing changes as information on operation and .: reception accumulates. All transmitters are constructed on wooden frames and may be quickly dismantled or altered as defects are discovered and new methods are devised. The men at the transmitters are doing Complete, nothing only part of the work, for development else to buy. would be impossible without reports on Operates at maxi- reception of the output of these stations. mum efficiency at all times on either di- The entire country, as a result, becomes rect or alternating a laboratory and the interested radio current, any fre- experimenter is invited to become a quency. Noiseless - no hum. volunteer co- worker. The General Elec- Delivers unlimited tric Company is greatly indebted to current to any re- these listeners who have thus far reported on the various tests, notably the 50 kilowatt broadcast tests and the programs FERBEND "B" ELIMINATOR broadcast alternately from vertical and ceiving set, regard- horizontal antennas on super -power. Now you can supply plate voltage to your Radio Set at a less of number of Reports from volunteer listeners are price scarcely higher than new "B "Batteries! Your electric tubes. supplemented light socket and new Ferbend furnish Delivers 100 volts by observations made by the "B" Eliminator the to any set. a corps of field engineers who are detailed permanent means of efficient "B" current supply for any set. Cost of operation to various parts of the country. For No need for you to pay more than $9.75 for a "B" battery less than 50c a year. example engineers are traveling about eliminator for Ferbend guarantees theirs to be equal or supe- It lasts indefi- rior to any on the market regardless of price. Our price was nitely. with trucks equipped with measuring All parts are spe- fixed with the interests of the radio buying public in mind. instruments by means of which the cially designed and The result is efficient and permanent "B" current now placed manufactured by us characteristics of the radiated energy for this purpose only. may be accurately set forth. FERBEND Within Reach of All Unconditionally Investigations at the South Schenec- The price of this remarkable new unit Guaranteed tady station include the short and long CR/'e giY3' is spectacular in more ways than one. to be equal or supe- wavelengths, code and broadcast sig- This company also manufac- Besides saving you from $15 to $50 it rior to any elimina- tures the famous Ferbend tor on the market, nals, with various degrees of power input WAVE TRAP-the ¡ ostro. is amazingly low considering the qual- ment which has been widely regardless of price. and a side variety of antenna structures. imitated but never equalled. ity and superiority. Surely it marks It is the only original and in Engineers are painstakingly recording genuine. See advertiement a revolutionary step forward radio data on transmission during daylight on page 64. Equip your set NOW with this mar- instrument, and be c and dark, in rain, snow or fog, during velous the daylight and at dark. your dealer, or send direct r =- At the present time the following Ask FERBEND ELECTRIC CO. distribution is completed it 431 West Superior St, stations may be heard on the air with Until nation -wide Chicago is possible that your dealer hasn't stocked the t] Send at once. I am enclosing $9.76. broadcast programs from the studio of Ferbend "B" Battery Eliminator as yet. So you send C. 0. D. \VGY: 2XAG, 379.5 meters, 2XK, 109 will not have to wait, we will make shipment O Send Literature. meters; 2XAF, 41.88 meters. Tele- direct to you upon receipt of $9.75, or C.O.D., Name__...... -- are guar - ----..... graph or continuous wave if desired. Remember, superior results signals are teed or your money back. Be one of the first to own and put out from: 2XAZ, 214 meters; use the Ferbend Maxmin "B" Battery Eliminator. Use the 2XAC, City 80 meters; 2XAD, 21 meters; coupon NOW ! 2XAW, CO. 15 meters. 2XAH operation on 1560 FERBEND ELECTRIC 431 Superior St. - Chicago, Illinois meters is now undergoing changes in W. design, but has been on the air for weeks and will be hear adgain in a short time. Let Our Hook -ups be Your Guide Tell them you read it-in Radio Age 50 RADIO AGE for January, 1926 The Magazine of the Hour

Electricity and Music Unite Radio Trade Meeting Bureau of Standards Does in Panatrope Set for New York Not O. K. Claims Before a distinguished audience of The fifth annual convention of the The attention of the Bureau of Stand- scientists, musicians, and men and women National Radio Trade Association will ards has again been called to the frequent prominent in society, the Panatrope, a be held at the Hotel Ambassador, misuse of its name in connection with the new musical reproducing instrument Atlantic City, the week of May 10, sale of dry batteries for radio receiving which for the first time utilizes the 1926, according to announcement by sets. Claims have been made by some electrical principle for the reproduction F. E. Potter, Chicago radio manufac- dealers and factory representatives, that of sound, was presented at Aeolian Hall turer, chairman of the committee on the superiority of their particular brands recently. annual meetings. of dry batteries has been shown by tests The panatrope has been perfected by Retailers, jobbers and manufacturers made at the Bureau of Standards. Tests scientists of the Radio Corporation of will attend from every section of the of batteries, including the dry -cell "A" America, the General Electric Company, United States, according to early reports and "B" batteries for radio use, are made the Westinghouse Electric and Manu- from the membership of this organiza- at the Bureau in accordance with govern- facturing Company and the Brunswick - tion which is the largest exclusively ment specifications. Balke- Collender Company. radio trade body in the country. These tests are made to aid the depart- The program consisted of introductory ments of the government in the purchase remarks by P. L. Deutsch, Vice President of batteries and to help each manufac- of the Brunswick -Balke -Collender Com- turer to improve his product. The pany, selections by the assisting artists,. Bureau does not publish the results of Mario Chamlee of the Metropolitan its tests, nor does it inform any manu- Opera Company and the Elshuco Trio, facturer of the results of its tests on other a speech by Dr. Alfred N. Goldsmith, manufacturers' batteries. Therefore, Chief Broadcast Engineer of the Radio statements that any make or brand of bat- Corporation of America, who talked over tery is superior as shown by tests made at the radio from Washington through the the Bureau of Standards are unwarranted. panatrope, and selections on the panatrope itself. China Radio Reproducer The panatrope is a new musical reproducing instrument involving new inven- Attracts Attention tions and entirely new principles. The One of the points of interest at Cleve- recent Radio Show was the "Kirk" phonograph cannot faithfully reproduce NEW COIL FORMER land's all the delicate vibrations of the elec- A DEVICE which will help materially in the vitreous china radio reproducer manu- recorded records. It remained winding of spiderweb, low loss and other types factured by the Cambridge Sanitary trically of coils, has been put on the market by the Franklin for the panatrope, based as it is on Coil Winder Co., and is shown in the accompanying Manufacturing Company. electrical recording and electrical repro- picture. This product represents quite a devia- Although the device would be more appropriately in duction, to complete that union of called a "coil former" it will help many an experi- tion from former reproducers both with music which has marked menter to make clean -cut and business-like coils. material and construction. The design electricity, It consists of a set of spokes and metal blocks a milestone in scientific and musical which may be fitted together into a variety of is patterned after the sound shells of patterns covering the construction of many types famous orchestras, having many import- fields. of inductances. Through the panatrope it is possible ant advantages, principally the large, to take an original sound, cause it to be vibrationless base and the rim construc- changed to light waves and electrical Taper Thickness of Plates tion, in which the rim forms a part of waves and finally reproduce it again In New Condenser the base, eliminating vibration at both with a loss and distortion which is points infinitesimal. ANEW variable condenser of the grounded rotor type in which s. 1. f. Moves Offices tuning is accomplished not by the eccen- Ernest Walker Sawyer has moved his Zenith Dividend tric shape of the rotor or stator, but by offices from the Chapman Building to a tapering thickness of rotor and stator 1915 Santa Fe Avenue, Los Angeles. At a meeting of the Board of Directors plates, is announced by the Allan D. Mr. Sawyer represents the Silver - of the Zenith Radio Corporation held Cardwell Co. Marshall, Amsco, Radiotive and several November 4, the regular annual dividend This condenser secures straight line other well known lines in the West. of six per cent was declared, plus an extra tuning by using plates whose thickness of four per cent, payable January 2, 1926, is tapered so as the plates are revolved to stockholders of record December 1, they tend to dovetail more closely due Company Incorported 1925. to the variable thickness of both stator R. C. Blume Company, with offices at The above action is the result of the and rotor. 1650 Monadnock Bldg., Chicago, has report of operations for the year just The new type, known as the type E, been recently incorporated for the pur- closed. Net profits for the year exceeded are said to be more rugged than the pose of handling a complete line of those of the preceding year by 175%, it original Cardwell on account of the extra electrical and radio specialties on a dis- is stated. thickness of the plates. tributors basis. Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 51 Radio Game Grows into Group Control for Gold Watch Prize for a Lusty Infant Neutro dyne Receivers Most Miles Per Watt As evidence of the tremendous hold Neutrodyne owners and those who A 21 jewel watch with solid white which radio has taken upon the public, are constantly trying out different cir- gold hand engraved case and a Lord the Chas. Freshman Company, Inc., of cuits will welcome a recent product Elgin movement has been selected as New York and Chicago, manufacturers marketed by the Kurz -Kasch Co., which the 1926 prize offered by the Jewell of the line of Freshman Masterpiece consists of a gear rack and a set of gear Electrical Instrument Co., in their Receiving Sets, announced the following which may be attached to any three "most miles per watt" contest which is figures of business done during the past condensers so as to secure group tuning open to all American and Canadian few months: control. licensed transmitting amateurs. The net sales of the Company for The center condenser is the master The contest closes on June 1, 1926. September, 1925, were $676,442.69, as control and has in addition an E -Z The winner will be the one who has against net sales for September, 1924, of Toon vernier, as have the left and right submitted documentary proof of havnig $161,583.73; an increase of more than hand condensers pictured in the illus- transmitted by wireless telegraphy the 300% -and yet -one month later, the tration herewith. With the center most miles per watt over a distance of net sales were almost twice those of knob the operator moves all variables three hundred or more miles. September. For October, 1925, net sales simultaneously over the wave band. The input wattage in the contest were $1,290,174.65, as against $366,417.83 Slight discrepancies In the different shall be taken as the sum of the watts for the same month in 1924. As a matter sized antennas and the inductances in the filament and plate circuits of of comparison, the sales for the entire may be ironed out by means of the the tube. In order to simplify matters year of 1924 were $2,122,315.92, showing verniers attached to the group control. the watts will be taken as the product conclusively that sales for the one month of volts and amperes. of October, 1925, approximated 60% of The contest is attracting considerable the entire amount of business done in attention among members of the brass - the year of 1924. pounding fraternity in this country Other companies report excellent vol- as well as Canada. ume of business.

Inventor of Tirrill Voltage Pole Piece Winder Runs at What appealed to the Radio Age Regulator Is Dead 10,000 r.p.m. staff mostly was the fact this unit Allen A. Tirrill, 52 years old, an inven- An automatic coil winding machine for which the Kurz -Kasch Co. supplied tor and consulting engineer of the winding pole pieces on telephone and loud us mounted up in a demonstrator panel, Westinghouse Electric and Manufactur- speaker units has been announced by t he can be attached to a baseboard and ing Company died recently. Mr. Tirrill Radio Production Machinery Co. used as a means of testing any number was the inventor of a voltage regulator The winding machine turns the spools of different inductances without having bearing his name. at a rate of 10,000 r.p.m., the wire to tear down the test set every time. For many years he was associated with traveling at 60 miles an hour. Wire up The condensers used in the group con- the General Electric Company. Schenec- to No. 44 enamel may be run. The trol demonstrator were made by the tady, N. Y., and in 1910 became an device is also made in multiple spindle U. S. Laboratories. The device may engineer at the Westinghouse Company. to take care of different types of jobs. be readily attached to any set using He left the company in 1916, since that three dials. time being one of its consulting engineers. As a means for simplifying the neutrodyne control the E -Z Toon group con- Charges Your B Battery trol should be especially acceptable From Your A to all. In our laboratory tests on a Battery set of three inductances it was a very A novel B battery which can be charged simple matter to compensate with the from the A battery by the simple expe- verniers so when the center master dial dient of placing all of the cells in parallel is revolved station after station comes in for charging and series for discharging, Only a slight variation on one of the has been placed on the market by the verniers was necessary to build up Orotone Battery Co. This unit was a signal to maximum, -after that the exhibited at the Radio Show held at control was' operated from the center the Furnite Mart in Chicago and attracted knob. considerable attention.

Self- Aligning Bearings A set of bearings, for use with vario- meters, variocouplers and other tuning devices requiring a variable inductive relation, has been made by Edward Board, a designer of special machinery. The new flat cell "B" battery re- The bearings are self -aligning and assure cently announced by the National positive electrical contact. Carbon Company makers of Eveready The battery, which is a 96 volt one, is batteries, utilizes the new principle cut up into 24 four volt sections which of patented battery construction by are charged in parallel by placing of a substitution of flat cells for cylindri- conducting bar into a line of unit switches. Pressure Ground Clamp cal cells. The battery may be charged in fifteen Under the name of "Snap -tite" the There is about 30 per cent more minutes with enough current to last Snap -Tite Clamp Co., is marketing a active electricity -producing material the evening, while the charge for an ex- ground clamp which requires no soldering than in the Heavy Duty Battery hausted battery is about four hours. and which holds the wire tight against No. 770 of identical external dimen- The scheme outlined above does away the pipe or other metallic rod used. The sions. About fifty per cent longer with the necessity for a special charger clamp is made in three sizes to take care life is given by use of the layer con- for the 96 volt type. of various types of metallic conductors. struction. Tell them you read it in Radio Age 52 RADIO AGE for January, 1926 The Magazine of the Hour Pioneer Announcer Leaves EFFICIENCY KDKA's Microphone ' One of the best known voices in the That Meets the Require- world will become silent, as far as the ments of Eminent radio audience is concerned, this month Radio Engineers when Harold W. Arlin, pioneer announcer of the world and chief announcer of Apex Vernier Dials are more Westinghouse Station KDKA since its than mere "knobs." In reality beginning, severs his connection with they are instruments endowed the station to take a position in the com- with an ultra degree of efficiency. Their rich elegance of mercial world that will necessitate end- finish lends a touch of striking ing his residence in Pittsburgh. attractiveness to any set. Pre- Mr. Arlin remains with the Westing- cision of production and of house Company, however, as he has " l'm a MASTER operation makes a good set a been appointed manager of personnel better set -providing greater for the Westinghouse Electric Products OPERATOR" range of AMPERITE never distinguishes between selectivity- positive- Company, at Mansfield, Ohio, and with a novice and an experienced operator for ness of control -and utmost his removal to the Ohio city has resigned the wonderful clarity and full, rich tones simplicity of tuning in most his position as Chief Announcer of KDKA. it makes possible. Just pull the switch difficult stations. Ratio 12 to 1. and each individual tube does its utmost Clockwise and counter clock- to outdo the other tubes. The "Self -Ad- wise. No back lash. Royal justing" rheostat that takes theguessout Brass finish 4 -inch $1.50-31/4 - of tube control. Used in all popular con- inch $1.25. Satin Silver Finish struction sets. Price, $1.10. 4 -inch $1.75 -31/4 -inch $1.50. There is an AMPERITE for every tube DeLuxe Gold (24K) Finish fl- _tta Write For free hook.ups inch $2.50 -31/4 -inch $1.85. .2* l mpasny Your dealer has them. If not, adiall ê order direct. Dept. R.A.-1 SO Franklin St., N. Y. City APEX Rheostat Dials PERITE are as essential to successful operation and pleasing appearance as are Apex Jhe "SELF ADJUSTING "Rhautat Vernier Dials. Royal Brass Finish -60c. Satan Silver Finish -70c. DeLuxe Gold (24K) -80c. APEX ELECRTIC MFG. CO. FOR CLEAR, QUIET tB" POWER Dept. 111 1410 W. 59th Street CHICAGO

RADIO H. W. ARLIN Storage "B" Battery 24 Volts Lasts Indefinitely -Pays for Itself Economy and performance unheard of before. Recharged at a negli- cost. Delivers unfailing power that Is clear, and quiet. Mr. Arlin was connected with the Agiblepproved anri listed as Standard by leading Radio Authorities, including P D. Radl Laboratories, Pop. Sci. Inst. Standards Radio News Westinghouse organization when the com- ab Lefax, Inc.. and oh important institutions. Equipped with Solid Rubber Case an Insurance against acid and leakage. Extra pany instituted broadcasting by estab- heavy glass jars. Heavy rugged plates. Order yours today) lishing the world's pioneer station in SEND NO MONEY wtáJost wbilewshá ship der 's received. Extra offer: 4 batteries in eeries (96 volte), 210.00. P ay exp- essman after examining batteries. 5 percent discount for cash 1920, and became an announcer. No with order. Mail your order now! one in those days had any very clear idea WORLD BATTERY COMPANY 1219 So. Wabash Ave., Dept. 81 Chicago, I11. of the qualifications of radio announcer, Makers of Me Famous World Radio "A" Storage Battery Prices: 6.014 100 Amp. $11.25; IRO Amp. S 11.26; 140dmp. but it quickly became apparent that AU equipped with Solid Rubber Case.

Mr. Arlin had qualifications that made Set your Radio Dials at 210 meters for the new 1000 him a valuable asset to the station; his watt Storage Battery virile, resonant voice, his exceedingly òrld Watch for announcements. STORAGE BATTERIES clear enunciation, his tact in handling 6DEFOEAFsW6NsWJ5sK sK Ot F s people under the peculiar nervous strain MD1O CATALOG of broadcasting, his coolness and good judgment under trying circumstances, u-::;..:;... :::<:..,:::...... :ï.. :. his wide knowledge of music, sports and :..?`'`;:s3;":s:h; also LO other matters most commonly broad- on all the latest stand* and radio merchandise! cast, his amiable disposition reflected Save No exceptions. in his voice, soon endeared him to the Our 1926 Beautifully Illustrated Caalog JUST OFF THE PRESS!! rapidly growing radio audience. Everything new in Radio at SLA SIZED PRICES. °;.: tr Buescher Saxophone Write for it today, before you buy Thousands of Letters anything. Delay meane losing excep- You can do it -easy. 3 lessons free with each tional chance to participate in thin new instrument give you a quick start. Prac- great BARGAIN-SALE. Rush your The hold Mr. Arlin has on the radio ticing is fun because you learn so fast. And it name and address at once and get al.o audience is evidenced by the thousands will make you popular, in demand, the center a LOG BOOK FREE. of attraction everywhere you go. Always a hit. ECONOMY RADIO SALES COMPANY of letters he has received from every Even if you have failed with some other instru. 288 6th Ave. Dept. C New York section of the United States and from ment, you can learn the simplified Buescher DEAL DIRECT AND SAVE REAL MONEY civilized in Saxophone. Don't delay. Get into the big fun. (No Dealers) nearly every country the Any instrument sent for 6 days' free trial. Easy world, friendly personal letters from terms if you decide to buy. Write now for people who have never seen him, in most beautiful, free literature. Address: Buescher Band Instrument Co. t'' Let out Hookups be Your Guide (Continued on page 53) 1214 Buaacher Block Elkhart, Indiana Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 53 Pioneer Announcer Leaves KDKA's Microphone .ß. (Continued from page 52) cases, but who write to him as they would to a warm and highly esteemed personal friend of long standing. The best known American voice in Europe, the London Times editorially calls him. "Young 'Arry W.' ", Johannesburg, South Africa, affectionately dubs him. Among the radio fans in Australia, Soath The Heart Africa and the British Isles, especially, of the his name is almost a household word and his photograph is familiar. In the out- Bradley- side world, as well as among the officials Amplifier of the company itself, his work as an- The Bradley-Amplifier is equipped with sockets nouncer has received commendation. that will accommodate the new UX tubesas well as the old tubes. No adapters are required for Marshall Foch and Lloyd George are using any type of UX tube. among the international celebreties Mr. Arlin has introduced to the radio audience. Other notables whose appearance away within ;n the air he has announced are Theodore TUCKEDthe polished Roosevelt, Jr., Governor Pinchot, Fritz bakelite base of Kreisler, Manager "Bill" McKechnie the Bradley -Am- plifier are six in- of the world's champion Pittsburgh conspicuous, Pirates; Babe Ruth, Hughey Jennings, Surprise Your Friends solid molded re- Lillian Gish, Priscilla Dean, and a host sistance units of other stage and movie stars. With The Improved Tone known as Brad - Mr. Arlin is one of the incorporators Quality of Your Radio Set leyunits. They and the first vice president of the Na- are permanently tional Association, Radio Announcers T IS that a good radio soldered into NOT ENOUGH place and can of America. He has made addresses receiver is selective or is able to bring Exchange clubs in never work loose before Rotary and I in distant stations. Quality of reproduc- or guest cause trouble. various cities, and has appeared as tion is now considered as important as announcer from stations in Chicago, The Bradleyunit New York, Boston, Providence, Roches- selectivity and sensitivity. is the heart of the ter, Syracuse and other cities. Fortunately, of your radio Bradley-Amplifi- the tone quality er because it Handling Concerts set can be quickly improved an i perfected alone can amplify One of the highlights of Mr. Arlin's without disturbing the existir.g wiring of the incoming radio activities was the handling of the the set. All that is necessary is to replace tone frequencies concerts from Wanamakers in New York your present audio -transformer amplifier without distortion. It replaces and Philadelphia which were transmitted with a Bradley -Amplifier. This compact to England by Westinghouse Interna- the ordinary unit employs no transformers and amplifies -fre- tional Short Wave Relay System. bulky audio all quency trans - his position Mr. Arlin will be in tone frequencies with faithfulness and In clarity, and without distortion. former and elim- charge of employment, the educational inates the most activities, relief, safety, and all factors It is a mark of distinction to have a radio frequent cause pertaining to the personnel of the Mans- receiver of fine tone quality and you will of distortion in a field works. surprise your friends with the remarkable radio receiver_ "Radio announcing has been a fas- The Bradleyunit cinating thing for me, with its oppor- improvement in your set that follows the cannot deterio- for studying character and use of a Bradley -Amplifier. It is as easy to rate or change tunities the with age. eccentricities of people and its peculiar install as a B- Battery and usually can be possibilities for making friends," Mr. installed within the receiver cabinet. Arlin said. Due to my position as KDKA Be sure to try one, tonight. announcer, I have been able to make friends and acquaintances in numbers cask Your Nearest Radio Dealer for a exceeded by few people, including poli- ticians who are supposed to know every- body. I can go into any city and feel Mail that I am among friends, instead of in a strange land, and hosts of people will B the instantly connect me with the station upon hearing my name." Resistance - Coupled Coupon Enormous Amplification PERFECT AUDIO AMPLIFIER Needed (Continued from page 20) ALLEN -BRADLEY COMPANY fication, all of which will require six tubes, 289 Greenfield Avenue, Milwaukee, Wisconsin this weak little signal from the distant station has been amplified three million, Please send me, by return mail, literature on the two hundred seventy -six thousand, eight new Bradley-Amplifier. hundred times by the time it reaches the loud speaker. Here then, is the secret Name which makes it possible to take these in- finitely weak signals which are so far out Address of the range of the human senses and bring them out with enormous volume. Tell them you read it in Radio Age 54 RADIO AGE for January, 1926 The Magazine of the Hour You'll See with Your Build the Set That Radio Tubes Holds 4 World's Records (Continued from page 24) and hard type, can be used. If the reverse order of action of the cell is desired, i. e. if it is desirable to have the current flow while the cell is not illuminated, the circuit can be changed as follows: The second grid is left floating Same device winds both spider web or and the cylinder is made negative with solenoid coils in different sizes. Coils respect to the filament. The first grid easily removed in perfect shape. All will again be main metal brass and aluminum. the anode. The re- Approved by Popular Radio. sults with this arrangement are almost as For sale only by good as obtained with the second circuit. FRANKLIN COIL WINDER 81 Irving Place, By means of this cell it was possible to New York City. operate from reflected daylight or small You canwind. Coils forali Circuits lamp, 150 The receiver that brought in sta- the ordinary ohms. telegraph tions 6,000 to 8,000 miles distant relay which in turn operated the circuit . .t Price with loud speaker volume night after of power line with several amperes. Its PATtNTEÓ ( , , uses more OCi,13:- __ " OO night. All records fully verified. are and more appreciated by 1925-.. Holds World's Records For the radio and electrical worlds. trrt= _---J-"dollars (1) Longest distance ever received on a loop aerial -8,375 miles (2) Most consistent reception of stations Radio Production to be Heard 6,000 to 8,000 miles distant -117 programs in three months. From WHT (3) Brought in 6 different stations in 2y hours -all over 6,000 miles The establishment of a radio produc- PRICE tion department with a theatrical per- Complete Set of Parts $89.00 sonnel directed by John Clark, nationally (Includes all parts necessary to make an known scenario writer, is a departure by exact duplicate of this wonderful receivr together with book of instructions and complete station WHT to influence a new type of blue prints.) radio program. Story of development and proofs of records sent on receipt of stamped and addressed The WHT production department will envelope. Circular free upon request. prepare a series of radio novelty presenta- Scott Radio Laboratories tions with all star casts scheduled twice 35 S. Dearborn St., Chicago weekly. The members of the production Dealers and Set Builders write for discounts company are on the payroll of the station and subject to rehearsal call. All re- hearsals are supervised by George Junkin, Chicago manager of the Drama League op Send foe of America. To lend theatrical atmos- iC phere to the presentations all casts will h this 84 Add a Ferbend Wave Trap f +^ U, S. Post Office, N Page be costumed. to your Radio Set and "Police Book Radio novelties written and produced your reception. Regulate traf- Billings. Mont. over WHT by Production Manager Clark fic! Guaranteed to tune out any "Ferbend Electric Co. This interfering station. Widely im- Gentlemen: are "The Listeners," Kipling's "Road To itated but never equalled. Not With mr Fada Neu. Book a "toy'- quality. material. Mandalay," "West Of The Golden WaveTrap I received Has workmanship equal to that of the address of Pres. Gate," "North Of Montreal," "In The the finest receiving sets. The Coolidge from W OA W Shown Omaha on a epecial Of original and only successful wave length. Many 3187 Men Land Cotton," "A Trip To The Far WAVE TRAP. Now in its fan. tried to get It hut failed. Also the base - East.' fourth year. Sent postpaid up- bauworld Series from on receipt of $8.50 or C. O. D. WOAW and H M A. Shenand,ah I ws. plus postage. Send for Free Had wSAF, New How to Make More Money Booklet. York, loud enough to carry cross the Sell radio,spare time -evenings. A demon- KDKA Singer street. Will of my Ferbend Electric Co. Set and Wave Trap up stration means sure sale. Whip any compe- 431 W. Superior St.. Chicago against any in the city longest distance lowest regardless of pnce. tition- possible- See the new Fed:end "B" (Signed) prices -big commissions. No selling or rad io Eliminator announcement J. A. Thompson, experience necessary. 12 sales lessons and 10 on page 19 Sont. of Malls," RaENt71y/ radio service lessons FREE. Local ads, at- f tractive booklets and letterheads with your own name. Exclusive territory to proven men. Start right now to build a permanent business of your own. $100 Weekly in Spare Time Big Money in Radio Many representatives making from $50 to $100 week - Demand for high pay radio men is so great that a ly, working evenings -you can do the same. Our 84 concern fitting page Ozarka plan will prove it-FREE copy for those big Kansas City wholesale is now who ask for Book No. 100. Better write today -ter- men free to get into the radio business for them- ritory going fast -only plan of its kind-a proven selves and make $60 to $200 a week without any success for four years. Don't fail to give name of capital invested. Select territory open. Send to- your county. day for free catalog and amazing offer. Write direct 122Austta AvenueA, to Mr. H. J. Saizow, Standard Radio Co., 1424 OZARKA, Inc. Chicago, Iltiaois Walnut St.. Kansas City. Mo.

$35° Ladoratory FLINT Distortionless Produci SC WINIFRED PERRY, contralto, is a graduate oç f (es" . V1 Audio Transformer of the Overlin Conservatory of Music and has CIES Sold on Money Back Guarantee studied with Oscar Sanger and William S. Brady, in New For DistortionleasAmpli&cations Write for Free Literature York City. Mrs. Perry's accomplishments on the American Used by chief radio experimenters and stage and her appearance at KDKA as soloist of amateurs in America. All crpacitìes 12.000ohm; *FLINT RADIOCO. the Dutch Master Half Hour of Music programs, and up. Speoial sizes made to order. Write today for ,4 1862 Wilson Ave. CHICAGO have won for her a place in the hearts of music full information. Liberal discounts to dealers. lovers. Crescent Radio Supply Co,, 5 L betty St., Jamaica, N.Y. Tell them you read it in Radio Age RADIO AGE for January, 1926 The Hagazine of the Hour 55 (Continued from page 48) tor are the high tension wires and are all of a positive polarity. The ( B) ground wires for the most part can be plain tinned square section copper busbar such as used in wiring sets, but the high tension wiring should be rubber covered flexible wire to avoid the possibility of short circuits and shocks. At certain points the difference of potential between wires may reach 280 volts or more, and at all points except one, the potential is 135 volts. With this voltage one can get a very good healthy shock, and the power behind the apparatus makes good wire insulation imperative if we are to avoid TYPE BM burn outs and similar troubles. Where ground connections are made to the cases of the instruments, the paint You wouldn't have an auto without should be carefully scraped off around the a self starter. point of contact so a bright metal surface Then why a radio set without a Multi -plug? shows. The wood screws used for attach- BUY ing the parts to the baseboard are then -BUILD -EQUIP YOUR RADIO run through soldering lugs so that the WITH A lugs are brought down forceably in contact with the cleaned contact surfaces, MULTI -PLUG and the ground wires are then soldered Affording a plug and socket connection between the radio to the lugs. Good strong soldered joints set and all outside connections, Jones Multi -Plug is as es- and rigidity in the general construction sential to the radio as a cord and socket to the electric iron. are important points that must be Type BM-For Set Build ing- $4.50. observed. Weak connections, loose and Type BP- Adaptable to any set -$5.00. jangling parts cause noise which must be avoided. HOWARD B. JONES, CHICAGO, ILL. When thrown in one position, the main 618 S. Canal Street two -way switch (SW) gives the highest voltage, and the switch is shown in this position. In the other position of the switch blade the voltage is reduced. With the blade in the center so that it does not make contact with the other side, the power is cut off. As a rule, this switch need not be touched frequently and when through with the receiver the line current is cut off by the Cutler- Hammer snap panel switch (SL). Either switch can be used however. At (R1) and (R2) on the panel are the high resistance Bradleyohms. The variable resistance (R1) is used for controlling Jt.1te the detector plate voltage which in some receiving sets may be a fairly critical quantity. The other variable resistance :1- (R2) generally requires adjustment only once, but re- adjustment PLUG may be necessary at long intervals in special cases. THE STANDARDSET' CONNECTOR Some detectors and radio frequency stage tubes work better on from 22.5 to 30 volts than others while in other receivers it may be necessary to use 45 volts or even 67.5 volts to get the best results. Boselli One Dial Control Attachments This is the purpose of (R1). tPATENT APPLIED FOR) Careful attention should be paid to the markings on the transformer and the Any three dial set can be made into a one dial control within wires that run to these posts, and the fifteen minutes. transformer should be placed so the pri- All the parts necessary including one dial with vernier adjusters mary binding post strip is at the left and all assembled and ready for the condensers shafts. the secondary posts at the right of the transformer where these posts feed into Price, $4.80. We pay Postage the Raytheon tube. Also note the Ray- Put one on your set and enjoy the pleasure of bringing in the stations loud theon tube is mounted in a standard tube and clear without even looking at the dial, just listen for the loudest point of socket, and the grid and plate posts (G) each station as you turn the Boselli one dial control. and (P) of this socket are connected together to form one terminal of the tube The Henry G. Boselli Mfg. Co. output. This is entirely different than the connections made to the socket for a 41 Mill St., 120 East Second St., receiving tube. Paterson, N. J. Clifton, N. J. This rectifier and filter will carry a continuous load of 65 milliamperes without materially reducing the voltage or volume. Let Our Hookups Be Your Guide Tell them you read it in Radio Age 56 RADIO AGE for January, 1926 The Magazine of the Hour Hornless Wonder of Schenec- tady Uses New Diaphram Get the New (Continued from page 25) The amplifier on Schenectady's tamp- MATCHED DON'T WAIT! PEP UP THAT SET NOW WITH ing ground is erected in a small building which may be thrown open on both sides. AERO COILS T. R. F. Klt X -L VARIO DENSERS In a neighboring building is a motor Matched Coils ENDORSED BY ALL LEADING RADIO AUTHORI generator set which supplies three kilo - s12 °° TIES FOR USE IN THE LATEST AND BEST CIRCUITS. watts of direct current power to polarize MODEL N -Capacity range 1.8 to 20 micro-micro- the loud speaker. The amplifier for farads, for balanco in Roberts two tube. Browning - Drake. McMurdo Silver's Knockout, Neutrodyne and supplying the voice current is divided tuned radio frequency circuits. Price. $1.00 into two parts, a voltage amplifier and a MODEL G-Two capacity ranges. .00016 to .00055 and .0003 to .001 Microfarads, for the Cockaday circuit, power amplifier. The voltage amplifier titter and intermediate frequency tuning in superhetero- dyne and positive grid bias in all sets. Price $1.50 consists of two stages of 201 A Pliotrons and one 210 Pliotron coupled in cascade X -L RADIO LABORATORIES, 2424 Lincoln Ave. N. CHICAGO by resistance and capacity. The power amplifier consists of a one kilowatt low For SELECTIVITY and DISTANCE Regardless of how good your set seems to be. you can impedance Pliotron. The plate current make it many times more selective and much more powerful by replacing your T.R.F.transformers with for all these tubes is supplied by a 2,000 Aero Coils. Get Aero Coils now -and tune through Ain ín tbe gebn pear!! volt, -wave kenetron which strong locals and bring in DX with tremendous loud full rectifier speaker volume! Listen to the clear tinkling bells on the is operated from the alternating current 95% AIR DIELECTRIC frosty midnight air-at the stroke of 12. lighting mains. Filament current for the The secret of Aero Coils' markedly superior performance is its patented constructionwhich makes possible tubes is furnished by transformers. the correct use of 95% air dielectric and dopeless, air - Why Not Use the spaced windings with the consequent advantages of The radio programs of WGY, the lower high frequency resistance and distributed "B" Rectifier? General Electric Station which is located capacity. only four miles from the park, are picked AT YOUR DEALERS OR DIRECT "B" Rectifier T. R. F. Regenerative Kit $11.00 Rhamstine* up by means of a loop about fifteen inches 3 Circuit Tuner...... 8.00 Only in diameter. Wave Trap Coll...... 4.00 Write tor the Aero Booklet U. S. Tool Moves Into AERO PRODUCTS, Inc. $25 Larger Quarters 217 N. Desplaines Street, CHICAGO (Tube The U. S. Tool Company, Inc., whose not factory is located on the edge of the resi- included) dential part of that section of Newark, New Jersey, known as Ampere, has *Asterisks* made extensive additions and improve- placed in advertising space ments in its plant. The present company d en o t es manufacturers A Rhamstine * "B" Rectifier eliminates "B" was formed in 1919 and started with Battery troubles, converts alternating current (110 about 2000 square feet on one floor of have submitted samples volts) into direct current, and assures a continuous flow of power through Radio receiving set at a con- 51 Lawrence Street. As the business grew, of their products to Radio stant voltage. The B" Rectifier gives you better larger quarters were taken at 117 Me- reception and reproduces the original sound in all its Age Institute and ¡these natural fullness. Its efficiency will amaze you. chanic Street with additional space at Endorsed by Radio Manufacturers and Dealers. 78 and 117 Mechanic Street, where they products have passed the Why not get one? Sold on assured satisfaction -you floors. can depend upon Rhamstine* quality and perform - used two In December, 1924, Institute test. cnce. Send no money. Just check the coupon. the present buildings were purchased Why Buy New Tuber? from the General Electric Company, which had erected it with a view to using A Rhamstine* it as a tube testing laboratory. Tube Booster will Rham- From its inception the company has re- energize the fil- stine * ament and repro- prospered and its officers are: E. M. duce the clear Tube Squarey, president and treasurer; Fred tones, and give Booster Koch, A. E. Borton, A. B. Bergen, vice 116 better volume and presidents: W. P. Powers, secretary, NONEI! reception; A few Only P. A. Prior, chairman board of directors. minutes, once a The engineers are W. P. Powers, who is a $3,000440,000 a year month, will re- graduate of the University of Pittsburgh, create the energy 6 Pa., and was assistant to Professor Want to make big, easy money? Learn in the old tubes how to instal 1, operate. repair. construct and make them Hazeltine at the Stevens Institute and and sell Radios. Write now for facts Ernest Ross, formerly of the General about the amazing opportunities for just like new. Radio experts. and our special offer of a Works on any A.C. Electric Company Laboratory at Sche- FREE 1000 -mile receiving set. and how 110 -120 volts, 50- nectady, N. Y. you can quickly train at borne by mail. 133 cycles-201A Be a Radio Expert or 199 type tubes. No previous experience necessary. Anyone with ordinary education can now learn Radio gnat, borne -study plan. MAIL THE COUPON TODAY We need men right now to represent our Association. Be the Radio expert fu your J. THOS. RHAMSTINE* (1) P big 616FREE copper etched neighborhood. Get your share of the 504 E. Woodbridge, Detroit, Mich. beautiful American, profits. Hundreds aboutyou want Radios and Please send me Canadian, and European stamps, advice how to operate. You can earneuough each with the call letters of a sta- money right from the start to pay for course. Rhamstine * Tube Booster at $6. tion, FREE with Ideal 48 -page Nothing difficult about it, Radio Stamp Album and Log. Low cost and easy terms. Rhamstine* "B" Rectifier at $25. . Also contains complete list of sta- T. . fii by express C. O. D., subject to inspection. I tions both alphabetically and by If am call letters. As you hear new sta- Pi' :,. not entirely satisfied with the 'B" Rectifier I will re- tions. Just put the proper stamps in hlllf turn it to you in five days and receive a refund of your album. Album and stamps be- the full purchase price. come a permanent and Interesting II FREE record of the stations you receive. Name You and your children will enjoy ` 1,000 -MILE it. Complete album, 8."x11 ", heavy Receiving Set Address board covers. $1 plus postage. Don't mies this big special offer to supply FREE all parts necessary to coustruct a City high-grade 1000 -mile receiving set. You can SendNoMow sell this set alone for practically the entire lust pay postman after album and stamps cost of the course. Send for the facts now. J. THOS. RHAMSTINE* arrive. We prepay postage if you prefer to pay out all about this big -pay field Address with order Find Radio and Electrical Products MONEY REFUNDED if not DE- Radio Association of America 504 E. Woodbridge Detroit,Mich. LIGHTED. Send order today -NOW. Postal will do. IDEAL CO., Dept. 2021, 366 Wrigley Bldg. Chicago 451$ RevoaswoodAve.. Dept. 21 . Mono. Ill. Tell them you read it in Radio Ape RADIO AGE for January, 1926 The Magazine of the Hour 57 Set Winner

PATENTED-

-On Feb. 24, 1925, we were granted our patent on a Self Contained Switch mounted through the flange of instrument. This feature is very valuable in Radio combining two in-- struments in one without an external switch. We use this Switch on our new No. 140 -2 -inch- shown herewith. Send for special No 776 Circular 15 Miss Jean Waggett, 7753 Saginaw Ave., Chicago, No. 140 and -B Radio III., who won the December Model H radio set Actual Size Catalog. given away by the Radio Age at the Fourth Annual Chicago Radio Show held in November. Runners -up in the contest were: Bert Fisher, 310 Order from Dealer Burlington Ave., La Grange, Ill., and George Nik- dem, 2547 South Harding Ave., Chicago, Ill. Jewell Electrical Instrument Co. 1650 Walnut St., - Chicago Important New Metal Useful in Radio "26 YEARS MAKING GOOD INSTRUMENTS" As a result of a search by chemists over a period of one hundred years all over the world, a new metal of immediate value and vast possibilities has been added to the world's technical resources, in the form of pure metallic ductile thorium which has been prepared for the first time by the research laboratories of the Westinghouse Lamp Company, according to a statement by Dr. H. C. Rentschler, head of the research depart- TH OR O L A Islodyne Receivers, Thorola Islodyne $85 to $225 ment, and Dr. J. W. Marden. Thorola Loud Speakers and Thor - Thorola Speakers $25 and $15 Thorola Coils $4 ea., $12 set Thorium is of particular interest to the ola Low -Loss Doughnut Coils -the radio enthusiasts because it is the active trinity that brings finest radio today. constituent of practically all radio tube Isolated Power, made possible only filaments. The present method of mak- by Thorola coils, brings positive se- ing radio tube filaments consists of com- lectivity to the Islodyne. The wanted pounding thorium oxide in the tungsten signal only, gets the benefit of all the wire, as thorium has the ability to throw power. Fading and distortion are off electrons with great ease and at a barred. The clear, undistorted signals very low temperature. As the tube is are faithfully reproduced by the cele- heated, the thorium oxide comes to the brated Thorola Loud Speaker which surface of the wire in the form of minute outsells every other make by far. quantities of thorium metal, which Hear a Thorola demonstration and gradually oxide off through the emmission know what radio should be! of electrons. As the thorium on the surface of the tungsten is used up, more REICHMANN COMPANY of the thorium oxide in the filament 1725 -39 West 74th Street comes to the surface, the life of the tube ending when the thorium is all used up. CHICAGO Through the use of the new method, thorium can now be produced commercially in filamentary form as contrasted with the minute admixture with tungsten Mailing Lists used at present. Will help you increase sales send for FREE catalog givingcomb and prices on thousand. of el._+eifad In addition to its use in radio tubes, names of yourbest proseppeecettive custom - CONDENSERS ers -N.tl oo ai, s rate s o local- -Indlvid- this metal is of extreme importance nab. Professions, Busineas Concerns. to V ERNIERS O/ the medical profession as a target material RHEOSTATS Guarantee d 9 by refund of each for X -Ray tubes, being much more jMSCO DAO DUCTS, Inc. New York City efficient than the tungsten now in use. Tell them you read it in Radio Age 58 RADIO AGE for January, 1926 The Magazine of the Hour Service to the American Public (Continued from page 30) which ships have been navigated for centuries. We must provide wave lengths ,SavER for use on the ships. Agency Established "We must bear in mind that radio SIX broadcasting is the birth of the last five years and that our previous conferences have been largely concerned with trying to get the service established; to create an effective service that could reach every home. The agency is now established. When I called the first conference only 30 people were present. There WINS FIRST PRIZE were then only 2 or 3 broadcasting sta- A Silver 'Six," built by Mr. C. Wood Tatham won First Prize in the "Home - tions and only a few hundred thousands Built Set Contest" at the Radio Show held listeners. Today there are nearly 600 in the Coliseum, Chicago, November 17 -22. stations and about 25,000,000 listeners. The problems of the present conference SECOND PRIZE were to perfect that service. in the same event was awarded to a Silver "In general the Conference, represent- Super built by Mr. Hartley. ing every phase of this question, was un- animous that there must be new legislation AND SECOND PRIZE in the "MISS RADIO CONTEST" was to give more control in the protection of won by another Silver Super operated by public interest and in the perfection of Miss Dorothy Goedecke. the service." Every circuit designed by McMurdo Silver, Assoc. I. R. E. has been a prize winner Inexpensive Tube Tester several times over. Silver Circuits are always in advance of their time, always up- Issued by Jewell to-date- always in a class by themselves prize winners over years. - Individual set owners may now secure Mr. Silver's last receiver -"THE SILVER an inexpensive tube tester which will SIX," has everything that makes for perfect reception -marvelous selectivity, ease of determine the worth of their tubes, control, sensitivity that makes DX work through the recent issue by the Jewell facinating and tremendous volume. It is a lbeKODEL receiver beyond compare, and can be built Electrical Instrument Co., of a Junior by anyone. tube tester known as No. 108. Write for Mr. Silver's own description Checking tubes is a simple process of the "Six" since the tester is supplied with a plug TYPE 600 KIT Includes all parts MICROPHONE and cord. Readings are shown on a necessary to build the Complete milliameter. Six" $53.00 You can't tell the KODEL MICROPHONE TYPE 610 KIT Essentials only, in- LOUD SPEAKER from the microphone Another of the Jewell issues is the cluding 3 condensers, 3 inductances the broadcasting stations use -they are portable voltmeter de luxe, furnished in a and 3 inductance sockets $27.75 exactly alike in size and appearance. mounting somewhat similar to clock Complete Building Instructions 50c. The efficient Kodel Sound Unit, with a ingenious new snail-shell horn, mounted mountings and which adds a decorative AND HERE'S THE inside the microphone case, produces a effect to the radio set. The meter will remarkably clear, full -toned volume. Non. vibrating tone chamber absolutely elimi- read either A or B batteries. Many of nates distortion. the newer model sets are having provision $15 model incorpo- rates Kodel, Jr. unit; made for plug in method of reading A equipped with large T and B voltage. Kodel unit $20 Radio dealers every - Music To Go With where have them. Technical Talks THE KODEL RADIO CORP. "Something New in Radio," is the title E. Pearl St. Cincinnati, O. of a novelty talk to be broadcast every RECEIVERS :: SPEAKERS Sunday night from Station \YMCA HOMCHARGERS (Hotel McAlpin), New York City, by Bernays Johnson, who has just returned from an extensive tour of the leading Owners of Kodel Broadcasting radio stations of the European nations. Station WKRC. Send for program Mr. Johnson is sponsored in these IMPROVED talks and enabled to make them through Raytheon -Thordarson B- Eliminator the courtesy of the Daven Radio Corpora- NO MORE LOOSE CONNECTIONS S -M Type 650 Kit X -L PUSH POSTS tion and is assisted by the Daven Or- This eliminator will deliver from 20 to 200 A binding post that really does excel, chestra at these various demonstrations. volts at three different, adjustable voltages looks, action, service, and convenience. and maximum current of 50 milliamperes - Push it down -Insert wire-cannot jar This is the first time radio technical more than enough for the largest receiver. loose from vibration. No screwing or danger of shearing off wires. talks with the ail of an orchestra have . Includes Thordarson transformer, Furnished attractively plated with been used in this country and this half choke, Tube condensers, genuine soldering lug and necessary markings. Raytheon Tube, Bradleyohms, and Price Each._ ..._. -.15 Cents hour period, 10:30 to 11:00 o'clock, all necessary parts- $34.00 X -L RADIO LABORATORIES, 2424 Uneoln Avenue N. Chicago Sunday nights, should prove an interest- Assembly Instructions by McMurdo Silver, ing innovation on the air. 1Oc. See at Your Dealers Set Builders Save Spare With Goes to 25 Kilowatts SM Products DUPLEX CONDENSERS Station HDO, Hilversum, Holland is Specially designed shaped -out stators make these straight -line frequency condensers as small ae to try out 25 kilowatts soon according to Sulver-Isfarsltali ordinary condensers. power Writ, fer literature. reports from Europe. Its present 114 S. WABASH AVE. DUPLEX CONDENSER dc RADIO CORP. is 1000 watts and it operates on 1050 42 Flatbush Ave. Extension, CHICAGO Brooklyn, N. Y. meters. Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 59 WJJD's Ideal Studio Arrangement (Continued from page 35) lounges are scattered about with tables, lamps, etc., so that it will be homey in appearance and comfort. This, it is claimed, is a step forward in so- called audience rooms, which have been put into some of the latest studios. The reason for this is that benches which resemble pews are not satisfactory from the guest's standpoint, and with a crowd of people staring through a plate glass window at him, certainly not from the artist's standpoint. Performers have said that such arrangements resemble aquari- ums and are distracting. In the Palmer House radio suite by means of drapes and lights it is possible for all the guests in studio in their comfortable chairs the Illustration shows parlor to see and hear the artists, but the Model 7-5 tubes - cur- "B" Battery com- artists cannot see through the gauze partment under- tains into the studio parlor and thus be neath. distracted because after all, the effect on the air is the important thing. ORTOL E The Most Amazing Performer Public Address System 1 L You've Ever "Tuned In" What is called a public address system has been installed in the hotel, which Oriole radio receivers step right out and make astounding records means that music or speeches can be on distant stations -they give exceptional volume-unequaled for broadcast through WJJD no matter clarity and sweetness of tone. The most selective, sharpest tuning whether they originate in the hotel, or set you ever played with- you'll be "sold" on the ORIOLE the the radio program upstairs or any outside minute you turn its dials. be loudspeakers station can received by Model 7 Tubes, with "B" battery compartment. The many -5 in all parts of the hotel. Model 7 -B -5 Tubes. orchestras now playing in the Palmer Model 7C-5 Tubes -Console. House, both concert and dance orches- Model 8 -4 Tubes. tras, almost continuous from noon until Write for folder illustrating and describing all models. one A. M., will be broadcast by WJ JD, Dealers: There is some exclusive territory open- and the public address system makes it ask for details. not only possible but convenient to pick the music from these orchestras from any W -K ELECTRIC CO. part of any of the big dining rooms and KENOSHA WISCONSIN banquet halls, or even from any of the private dining rooms, the hotel lobby, or the hotel foyer. Atwater Kent Booklet "A trip through a modern radio Irelan's Latest factory" is the title of a little booklet issued by the Atwater Kent Mfg. Co., "Wonder" and sent to radio fans who write in their comments on the series of Atwater Kent Coil Sunday evening broadcasts. line sei DISTANCE VOLUME builders SELECTIVITY Hydrometer Receptacle use The Elwood 1Ifg. and Specialty Co., 7;; ^M1i \\ are now putting on the market a holder \1;1t; for hydrometers known as the Ecloid hydrometer receptacle. It solves the '?' 1a111}il,, question as to where to put the hydro- IIORDAsuper meter after testing the specific gravity TRANSFORMERS l0)MITI of a storage battery. The receptacle hangs on the wall Follow the like a thermometer »;Jf/01,tJ and is provided with a glass drip cup. lead of the Leaders More Canadian Licenses Because leading set Price $6.50 Canadian fans numbering 64,682 builders require the se- finest tone quality Manufactured by the Inventor cured receiver's licenses during the first and absolute uniform- A. E. IRELAN, 9 months of 1925, an increase of 7,823 ity in transformers, Sharon Hill, Pa. they use more Thordarsons than all com- over the corresponding period of 1924, petitive makes combined. Follow theirlead Distributed by Consul Hickerson, reports to the Depart- -build or replace with Thordarsons. Un- RADIO SERVICE CO. conditionally guaranteed. Recommended 3704 N. 6th St., Phila., Pa. ment of Commerce. Licenses issued by best dealers. Audio frequency : 2-1. $5 during this period to fans in Ontario 354- 1.$4:6 -1,$4.50. PowerA mplifs ingpair,$13. Dealers Write for Our Proposition Interstage $8. totaled 32,833; Quebec, Power Amp. Autoformers, $5. in 9,062; and THORDARSON ELECTRIC MFG. CO., Saskatchewan 7,729, followed by Mani CHICAGO toba, British Columbia, Alberta and Nova Scotia in order. Let Our Hookups Be Your Guide Tell them you read it in Radio Age 60 RADIO AGE for January, 1926 The Magazine of the Hour Here We Have High Lights at Radio Conference (Continued from page 32) J Stick to Wave The Committee on Interference also endeavored to help the listener by urging the broadcasters to adhere strictly to their wave lengths, stating those who had not equipped themselves with machinery to constantly check their frequency, should immediately do so. The committee pointed out that harmonics, so objectionable to the listener -in, might be avoided partly by having the operators refrain from using more power than was necessary. This fault should be removed by management- through a closer supervision it was pointed out. Power Interference You Can Build This Efficient THE interference committee expressed the hope that cooperation between the broadcasting stations and the power companies would continue to the end that Receiver for $27.27 the interference caused by these companies would be eliminated. Some of these cases were possible of detection Built Around the locally without the assistance of the department and the broadcasters were HEATH VARIABLE CONDENSER urged to assist the inspectors in those instances. It was also believed by the By Book committee that many of the interference the Citizens Radio Call problems could be solved by the forma- tion of listeners clubs throughout the country and it was urged that these be THE remarkable performance of the Heath .0025 Variable formed and encouraged. This committee Condenser caused The Citizens Radio Call Book Labor - also opposed the further issuance of tory to design this remarkable high -power, low -cost radio set. licenses at this time when the congestion Is so acute. Go to your nearest dealer and get your set of plans -they are The legislative committee pointed out with each purchase of a Heath Condenser. Start right now to that the existing federal statutes are not get the parts to build this super -efficient receiver. You'll have adequate to permit proper administration of radio communication activities and a radio that all your friends will envy. If your dealer doesn't urged Congress to pass the necessary carry Heath Consensers, write us direct. legislation as quickly as possible, which it is understood the Commerce Department plans to do. In the three -day discussions of the copyright committee headed by Repre- sentative Wallace White, Maine, which Heath Radio and Electric Mfg. Co. attempted to reach an agreement between 206 -210 First St. Newark, N. J. the Society of Authors, Publishers and Composers Manufacturers of and the broadcasters, the members were unable to dispose of this HEATH CONDENSERS HEATH SOCKETS HEATH DIALS vexatious problem. After the committee HEATH RESISTANCE COUPLED AMPLIFIERS had recommended to the conference that legislation be enacted to settle the question, Secretary Hoover advised that the matter be left as it now stood until a further effort has been made at concilia- tion. The recommendation of the Secre- 'I 1 MASTERTONE e 00 tary was accepted, and the report RADIO TUBES y tabled. ALL TYPES GUARANTEED Free, big Radio Catalog The copyright sessions were hectic and I fj Dealers' Proposition íir and Guide brimful of new - revealed the inside features of a long Dextron Radio Lab. estldeas over 100 specIal hook- Ups and illustrations. You save fight which may still continue. 74 Sterling, Dept. R. A. as much as 50% on sets and East Orange, N. J. parts. Se sure to get this thrifty book before you buy. It puts money In your pocket. Shows Nut's Headquarters standard radio parts, sets, -Radio -Parts only, no kits, au reliable, guaranteed A Human "S. O. S." sets. $20,000 stock. Most comprehensive. If goods. Please include name you can't find it, ask us. Weekly latest of radio fan to whom we may When New York officials recently "dope "-10 wks. 50c. "Change your Neut" send copy also, Write letter Kit $5 prepaid. Particulars-10e. 48 page or postai now. apprehended a foreign vagrant whose parts catalog -10c. Knock Down Loop Kit - speech they could not understand, de- $7.50. 150 v., 55 milamp B Eliminator, off 110 v. a. c., knock down kit including 2000 spite the aid of several linguists, they hr. Z 50 tube -$36.55. Assembled, ready to located some of his countrymen by per- use --$40. Data -10c. Kladag Radio Labora- tories. Kent, Ohio. mitting him to broadcast a personal "SOS ". Several of his native brethren, who proved to be Laplanders, came to his Let Our Hookups Be Your Guide rescue and he was released. Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 61 Carrier Telephony Used On Railroad Train Further reports on applications of ANNOUNCING radio and wired wireless to railroading by the American Railway Association, A complete new line of reveal that a new carrier current, or wired -radio, system has been developed ADJUSTABLE for communication between the front and rear cars of long freight trains on electrified roads. Either code signals or Consoles, Tables and Enclosures voice may be used satisfactorily: the latter however, only when the train is Many new designs and (patent pdg) features. A standing still. Wave lengths of 100 to standardized size. Panels adjustable, to length, 140 meters were used in recent tests with depth, width, location, tilted or upright. Panels about 50 watts power, over a line three are deeply bevel enclosed, etc. All in each model, miles in length. beautiful inlaid woodcraft, decorative effects, built The most interesting tests was made in loop and indoor antenna with other new (Pat. on the electrified section of the Norfolk & Western Railroad. Duplicate sets Pdg.) features. At LARGE PRODUCTION fac- were mounted in two locomotives, one tory to you prices. Watch for them! (January pulling and one pushing a train which issues.) Wait for them. was fully half a mile long. By means of Setter still-write for literature carrier- current signal in the rails the To FACTORY and SALES DEPARTMENT train was started and stopped most satisfactorily, THE Detroit Woodcraft Corp. THE both engineers working ORIGINAL 4611 Woodward Ave., Convention Hall ADJUSTABLE together. The train was started up and DETROIT, MICHIGAN its speed increased to 14 miles per hour "MAKES ANY RADIO LOOK LIKE A RADIO" in less than a minute, whereas it usually required a longer time to start a long, two -engined train. Stopping was readily accomplished without the accustomed jarring and bumping. Voice transmis- THE RADIO MASTER sion from cab to cab was found clear and easily understood when the train was not in motion. LOUD SPEAKER Further demonstrations indicated that this system would operate satisfactorily An Excellent Gift when the two engines were separated a distance of six miles. This equipment ONLY $16.50 is to be tried out by a large southwestern Speaks for Itself road before representatives of the Rail- way Association's radio committee. Folks value radio for the entertainment it brings into their homes. To them, the Radio Tube's Light Not a Guide to Master will be a most important step in radio Sensitivity development, for it re- Many radio fans are under the impres- produces the music of the broadcast studio sion that the amount of light a radio faithfully and without tube gives off is an indication of its distortion. You have sensitiveness or general condition, and never heard such tonel some are even inclined to regard with You have never heard suspicion tubes that appear glow such volume ! Absolutely to only free from rasping dimly. The fallacy of this idea is ex- and blasting that usually Design plained by Clifford M. Norberg, a re- accompanies big volume. Patented search engineer. The fact a radio bulb does emit light Scientifically is entirely an incidental feature of its Correct operation, says Mr. Norberg. What is desired in a tube is a flow of little particles The loud speaker is made entirely of resonant wood such as used of electricity called "electrons," and the for sounding devices as exemplified in the delicate If your dealer cannot supply, order easiest way to obtain is construction of a violin. The Radio Master is it to burn certain equipped with a Burns unit which throws the sound direct from factory. kinds of wires in glass bulbs from which from the back of the horn into a wooden bowl, -SEND NO MONEY scientifically designed with a series ofcurves to bring American Wood Turning Company, Mfrs. the air has been exhausted. The tem- the sound to the audience with clear, natural tones. Representatives perature must be quite high in The speaker stands 14 inches high and has a 9 -inch Sidney Gelb Fred Bert order to bell, well proportioned throughout. 514 W. Van Buren St., Chicago. make the flow copious, and most wires The most beautiful finish will harmonize with any radio set Please send me a Radio Master by express, must be heated white hot by the current on the market. C. O. D. If I am not entirely satisfied with the loud speaker, I may return it within 10 from the "A" battery for proper opera- days and receive a prompt refund of my Fully Guaranteed money. tion. Of course the incandescent wire, Name or "filament ", as it is correctly called, Buy a Radio Master and use it for 10 days. I. it is not everything we claim, just return it to us Address. emits considerable light, but this pheno- and your money will be cheerfully refunded. menom has absolutely no connection City State with the functioning of the tube from the radio standpoint. Watch the Radio Age Model Sets Tell them you read it in Radio Age 62 RADIO AGE for January, 1926 The Magazine of the Hour What Does a Radio Super- visor Dream About? (Continued from page 33) there began a scramble for apparatus. Tubes were scarce, tuners hard to find and loud speakers unknown. Little by little manufacturers began making stuff a new S -Tube Set with all the power with which the public could hear music. and none of the grief of the Super." Thus far the radio inspectors had only -so wrote Henry when M. Neely, Editor of a few problems to conquer, but Radio in the home, actual broadcast transmitters began Philadelphia cropping out over night with a demand 12 -Cell - 24 -Volt for wave bands it seemed while life was Storage'B'Battery hard it was still livable because there given free with each was space on the air for a number of purchase of a WORLD A" Get This Book Storage Battery. You must stations. send this ad with your order. WORLD Batteries are famous But when the demand for stations Write today for this big fascinating for their guaranteed quality and service. Backed by years reached the point where five or six 32 -page booklet which tells how you of successful manufacture and can build the truly amazing new thousands of satisfied users. hundred broadcasters desired stations on Equipped with Solid Rulder Case. QUADRAFORMER receiver an muranee eg.lnrt acid end leak- a band which probably does not accom- age. You rave 60 per cent end gets Based on a new radio principle, 2 -Year Guarantee modate more than ninety channels, the five tubes give remarkable results. Bond in Writing woRLD BaA Approved problems loomed larger and larger. tell their friends. That's our bent r,roOf Listed Enclose l0c and you'll have it by return mail of performance. Send your order in today. and Much trouble was saved by the institu- Solid Rubber Case Radio Batteries as Standard tion of the radio conferences called by 6-Volt, 100 -Amperes . . $11.25 by Leading Gearhart -Schlueter Radio Corp'n 6-Volt. 120 -Amperes. 13.25 &Volt. 140 -Amperes. 14.00 Authorties Mr. Hoover, but still it has not entirely 713 Voorman Avenue, Fresno, California Solid Rubber Case Auto Batteries Including Radio relieved the radio supervisors of a good &Volt, 11 -Plate $11.25 News Labora- & It, 13 -Plats 13.25 tories. Popular 12-Volt. 7 -Plate 16.00 deal of trouble. tute of Stand - Send No Money iérr ° ;d;t ardy Popular Today the most popular song in the we will ship_ order ù received,W by Ea. Radio tag°ra- preea C. O. subject to ur examination t ilea, Radio Department of Commerce is, "Yes, we on arrival. .FREE B" Broadcast Lab. Bettery included. orator Radt° Extra Offers 5 per cent discount for cash have no frequencies." To list the multi- In frill with order. Buy now and get -W Iu the Home, guar and Lott, Inc. anteed battery at 60 per cent saving to yon. tudinous duties of Supervisor Beane at WORLD BATTERY COMPANY 1219 So. Wabash Ave., Dept.35 CHICAGO. ILL. Chicago would entail considerably more Bet r°m Radio Dial. at 210 space than we have at our command in mters tor the 1000 watt World storage Ratsar, this issue, but you can rest assured he tation WSBC. Chicago. o rl Watehlorennouneemenrx. has little time for rest. The chap TORAA; BATTERIES who vows a station is off its frequency (despite the fact the station's frequency meter shows it is on frequency) has to be placated. The individual who believes there is serious heterodyning going on because a regenerative set next door is operated as a transmitter instead of a = All receiver, also has to be told the matter t'i Standard $2.5U will be looked into and things straight- Types _ iP2/yy9,3+'terl:l.MrD7sssataetaprneryrw.ysrpbsroors wse ened out. The party that rails at an ,aUi+-.vrrntP.- '.ryirJlfeel4aw/taAw:rliG%lCalfGea - ow amateur in the next block on account of /íll /a1 1i1a-ri-4/i.11\11 shown CM f UM interference, has to be the cause MO NM of his is power lines in his INN trouble leaky P.Vbsac.:wweaes.v .rplslw0alteranarealleit alley. art wrraraear,rr.snmaser OM ma MO The Famous Truly Portable Another form of trouble is that * GUARANTEED RADIO TUBES TELMACO P -1 Receiver reported by Radio Supervisor Beane, constituting interference in the broad- NM Four Tubes Do the Work of Seven Ing ease of tuning, casting band and which may require a , The peer of portables in size, weight, Flawless reception -full enjoyment of MI selectivity. distance, volume, workmanship and price. radio is impossible without perfect tubes. and batteries contained. reallocation of channels. When two I Aerial, loud 1125.00 Use cleartrons and be sure of noiseless sm $125 high -powered broadcasting stations, using reception, more volume and long distance. 5141.50. Receiver only . either modulated or unmodulated waves, Perfect service or instant replacement P-1 Kit Sam You Money! guaranteed. e Oarofer of the Telmaco P-1 Receiver lu kit form has are operated simultaneously on widely NIN met with enthusiastic reception. This contains all At all reliable dealers parts, as built by us, luclodrngg ease, drilled and en- separated frequencies, they produce a Write for free six page tube folder CT- graved panel, and illustrated instructions. $80.00 third frequency in the air, which is quite 101A -The original Hi -Mu tube for 00 Complete kit Resistance $ 3 ° Ask your dealeror write us. Descriptive folder free. sharply defined. They actually hetero- -Coupled Amplifiers 'Radio Division: dyne each other, Mr. Beane points out. mob CLEARTRON VACUUM TUBE CO. Telephone Maintenance Co. This, of course, interferes with- any 28 West 44th Street New York City So. Wells St. Dept. C Chleago, fil. stations on the wave produced and Factories = broadcast by the two operating stations. West New York, N. J. Birmingham, Eng. - Qolity Radio Exclusively b+ Established 1918 Produces Third Frequency FOR BETTEIkRECEPTION Explaining the phenomena to the Im11111lUUun1111111IiiulhIuuilhIiil Interference Committee at the confer-' ence, Mr. Beane said: "The principle of DIO RENCH heterodynation is quite well known, of r,. nonne Mole wrncho course. For instance, an oscillator func- PATENTS oo your rm.& Ad hold tioning on a given frequency can 'beat' Z.t1 POLACIIEK togoihyr OMPTLY PROCURED ND A SKETCH OP ppTENT ATTORNEY W; with another oscillator, located in close OUR INVENTION á it, which produces a third CONSULTING FNCINEE' la ra Metal proximity to EECOROING BHLANK WALL 5T. Cerpwattea frequency. This frequency is the differ- NEW YORK r.a.. ME t. leu400 ls ence between the frequencies at which the two oscillators are functioning. ADDRESS RE (Turn to page 64) MAIL TO -DAY L / Tell them you read it in Radio Age r RADIO AGE for January, 1926 The Magazine of the Flour 63

MAGNATRONS in your set will give sweet purity of tone - clear and complete rendition of all the wealth of overtones. Music and speech come from the loudspeaker of the Magnatron equipped set with rich fidelity and generous volume, recreating in your home the actual performance itself, whether it be ten or a thousand miles away. Magnatrons are the product of the oldest exclusive makers of vacuum tubes. That. in a large measure, explains their excellence. There's a Magnatron for every purpose. The Dc-2o1 A, the D e -199 [large or small base), the DC -120 [for now we'll super volume), and the Rex [for B Eliminators]. All list for only $2.50 each. Write for your FREE copy of "Pox Pouxiu "--a snappy review of mirth and music to Department A . -) have clear CONNEWEY ELECTRIC LABS. Magnatron Building musics Hoboken, N. J. 1-,

Complete factory stock for Pacific Coast carried at Pacific Radio Labs., 256 So. Los Angeles St., Los Angeles, Cal.

Suit to Stop Radio Livestock Quotations YOUR MODEL, RECEIVER A court action of national interest to YAxLEY broadcasters which may establish a IS NOT COMPLETE legal ruling effecting the manner and method of dissentenating information UNLESS YOU HAVE by radio has been instituted in the A Circuit Court at Chicago by John P. Bowles, cattle broker, against the Chicago RADIO JACKS Live Stock Exchange which seeks to Sachs to fill every need in the finest radio sets. One nut mounting in 7 -la In. panel hole. Gen- prevent the broker from broadcasting uine phosphor bronze springs, with pure silver cELl:O-METErt contact rivets and terminals tinned for solder- live stock quotations over \\'HT. ing. The Chicago Live Stock Exchange Merely press the button and it tells the No. 1 Open Circuit Jack 50c passed a resolution effective December exact condition of the storage "A" battery -whether low, half charged or full. At the best radio dealers first which prohibits any member of the It keeps the battery at its most efficient YAXLEY MFG. CO., Dept. L exchange from broadcasting live stock point, removing all uncertainty and guess- 217 E. Desplaines St., Chicago, Ill. quotations and information or furnishing work, eliminating the messsy hydrometer. such information to broadcasting sta- It is very easily connected with the re- tions. The John P. Bowles Company, ceiver. Price $7.50. one of the largest commission houses at New Perpetual Log the Chicago Stock Yards, has for the CELLOKAY MFG. CORP. for -Radio Loose Leaf Revisions Map FREE past six months been broadcasting the Sales Office 1707 Flatiron Building, New York City New 64 page log. Corrected sheets may be secured as changes iin calls, wave lengths, owners addresses, sic., occur. Holds 504 stations current market quotations by remote 4 dial settings, remarks, etc. Tuning sugges Dons. Station hats by wave lengths in meters control direct from the yards through kilocycles -by states, etc. Repair hints, Tandrouble aids. Dictionary of Radio Terms. Other station WHT. valuable information. Beautiful cover. So con - t. Worth many times small costs. Only Si on NO Pay . The court action is predicated the SEND MONEY. postman after log a d FREE map arrives.iv Postpaid if pay with order. Money refunded it not delighted. toda -now. right of the plaintiff to use radio as an Radio Printers, Dept. 2021, Marengo, Ill. advertising medium in the same manner Earn 100 a We e and for the same intent and purpose as A regular $25 loud speaker for he would employ newspapers or maga- Profits iz Advance $16. Loud, clear, mellow tone. zines. Sell Gibson extra fine men's made-to -order Bell 13J/ in. diameter, horn all -wool suits at $31.50, direct to wearer. 22 in. high, equipped with Regular $55 values. Biggest commis- Lakeside Adjustable Unit sions paid in advance. We deliver Agents wanted, write for par- *ASTERISKS* placed in ticulars. advertis- and collect. 6x9 cloth samples (over 100 ing space denotes manufacturers styles - all one price) and complete outfit in handsome carrying case. fur- Lakeside Supply Co. have submitted samples of their products nished to ambitious men who want to 73 W. Van Buren St., Chicago to Radio Age Institute and these pro- earn $100 weekly. Write today. ducts have passed the Institute tests. W.I. GIBSON, Inc., 161 W. HarrisonSt.. Dept. N62oChicago Tell them you read it in Radio Age 64 RADIO AGE for January, 1926 The Magazine of the Hour What Does a Radio Super- for visor Dream About? (Continued from page 62) Another frequency equal to their sum is for-Real Enjoyment Long Distance also created. Similarly, a radio station with operating on 560 kilocycles and another station operating on a frequency of 1200 kilocycles will actually heterodyne at Big Volume radio frequencies and produce a third and frequency of 640 kilocycles in the air. As this third frequency created by the two stations, may already be assigned to Keen Musical a third, or a continuous wave broadcaster, modulated or unmodulated, a so- called Quality `beat note' is produced ruining transmission of a third station operating on 640 kilocycles." The reassignment of new waves or frequencies should be so arranged, according to Mr. Beane, that this phenomena will not take place. It is actually taking place he has ascertained, between broadcasting stations. Fortunately, he states, the field strength of the third wave or frequency created by the two stations on their proper frequencies, is considerably less than the strengths of the original frequencies, so the use of frequencies which may cause such interference need only be considered within a small radius of two stations which may produce a third frequency. The third frequency created by two 500 watt transmitters is 33AAJL/1105r Install a pair of KARAS reported as only objectionable for a dis- LOUD SPEAKER of five miles. Two Harmonik Transformers tance about 5000 watt Assures utmost in volume and clarity of stations, however, cause this difficulty tone -reaches full range of musical scale, giv- in radio set ing a faithfulness of reproduction that equals your over a radius of approximately 20 miles. hearing the original. If practical and logical assignment of Flare in several handsome finishes. GRAS Harmonik Transformers de- frequencies in the future is to be made, liver perfect music with loads of Prices $22.50 - $ 25.00 - $30.00 it is believed absolutely necessary that volume from stations one to two Manufacturers thousand miles away. Distant reception the results of radio frequencies heterodyn- worth listening to! With Karas Harmon - ing each other must be considered. iks in your set, you can truly enjoy radio ,,merrcan 6lecfric The Navy's Scheme COMPANY broadcast music from near or from State and 64th Streets far. You can get in all the volume de- Officers of the Navy point out they CHICAGO, U. S. A. sired without crowding your receiver to have taken this phenomena into con- the distorting point. You can sit back in your easy chair and listen with keenest sideration for some time and use fre pleasure. quencies ending in 5; any new frequency NEW BIC POWERFUL created by beat notes, is therefore, not "Fishing" for distant stations becomes a É RADIO matter of finding programs you want to an assigned frequency and cannot inter- MIRA s fere with regular channels; since their " 4111 hear -not straining to catch only the s O a bare announcement, and compiling a sum or difference would necessarily be -, .;: list of call letters. frequency ending in zero. A reassign - j s9 There's power and to spare in Karas Har- ment by the Department of Commerce IlVluullll ... moniks. Power that brings the biggest to prevent this form of interference, may ú7á5PoiAi Factory pr ere 90ve ou 1.3 to 20 Úmÿ big, everYwhere report Ultra 5 gets ro. volume without distortion. You hear be undertaken on this basis -that is, and coast. \clear on speaker; UUtperlOtrmsSIbOo to full, round, sonorous tones because you increasing all assignments by five kilo- $250 sets Many hear Europe. Marvelous get the complete musical tone. All the value -let estlmony of users convince you. cycles, or reducing them that much. sets $13.75 uo. W vital harmonics and rich overtones are Drama MIDWEST RADIO CORPORATION Mr. Beane's tests in Chicago included of Sofa there in all their naturalness. Lew notes, Write! 523.1) E. nth St., Cincinnati, Ohio middle notes and high notes all are am- several stations, among them KYW on plified to the same degree -a rare achieve- 560 kilocycles, and WGY and WOR on ment for audio frequency transformers. 1200 kilocycles; they produced a frequency of 640 kilocycles, which was The true characteristics of all musical tones are re. unassigned, yet Chicago listeners got the HEATH created in your speaker. Piano music pours forth with the rich beauty of the concert hall. The pure, beat note created. Tuning below and CONDENSERS liquid tones of a violin played a thousand miles away above this frequency showed the adjacent For Real Radio Reception cannot be detected from those of a violin played in Write for Litera tare the same room. The inflections of the human voice stations in the band were on their proper are all retained -the very breathing at the micro- HEATH RADIO & ELECTRIC MFG. CO., phone-the soft, elusive sounds of S and Z. assignments and were not involved in 206 First St. Newark, N. J. the interference reported. If this is the kind of reception you want -whether distant or local, you must have Karas Harmoniks in Your set. It's the only way you can get it over the radio. Don't wait to build a new set. Take the old transformers out of Your present set and install a ZI LT TZM R,12 I E TZ, pair of Karas Harmoniks. The sooner you do, the -VS sooner you enjoy the highest quality radio reception New Italian Station TUNING' CONTROL The projected station at Milan, Italy A VERNIER DIAL ON WHICH YOU CAN will be to London, I Karas Electric Co. similar 2L0 at equipp- RECORD THE STATIONS GEARED O ed with 12 kilowatts on 384 FINISH' 52 50- -GOLD FINISH 53 e.3 4059 N. Rockwell Street Chicago, Ill. to broadcast meters. It is owned and erected by the N.1. L For or.-r, SO years makers of Precision Electrical Apparatus Union Radiofinica Italiana. PHENIX RADIO CORP., 116.F East 25 St., Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 65

Lis Just Hear A $27.50 QUAM RADIOVOX With the Silver Drumhead Diaphragm T is far superior to any other loudspeaker in tone quality, volume and enunciation, due to an entirely new principle of diaphragmatic construction -the Silver Drumhead. I This Silver Diaphragm is only three one -thousandths of an inch in thickness, stretched tightly over a brass ring and adjusted to a sensitivity that responds to the slightest impulse. A small silicon steel disc is welded to its center to receive the impulses from the magnets. The extreme thinness of the silver, coupled with its well known musical qualities and tuning to the proper pitch, permits it to vibrate so fast that its reproduction of speech and music is perfect and sets an entirely new standard in radio reproduction. Non - vibrating, semi - hard rubber horn, finished in mahogany and cast aluminum tone throat in russet crackle, make for a beautiful appearance as well as perfect reproduction of sound. Manufacturers -Write us for our special proposition on Quam Radiovox Dealers and Jobbers They will improve Let us send you a Quam Units. your receiv- Radiovox on Approval. ing sets 100%. Wire or Write. The Quam Condenser -with the Pyrex end plate, is the world's lowest loss and highest quality condenser. Straight line frequency and wave length. QUAM RADIO CORPORATION List Price, $6.00 and up. Transformers, $5.00. 1925 So. Western Ave., Chicago, Ill. Also Quam Audio

DeForest Cuts Price AJAX,71-, on Receiving Tubes Retail price reductions on all lines of the DeForest radio receiving tubes, as a A marvelous, new aerial that is guaranteed to give greater distance, easier tuning, more result of specialized manufacturing pro- perfect selectivity. Consists of pure copper ribbon, heavily enameled, wound around cesses, increased production, and greater sturdy, weather -proof rope. Try this new sales, were announced on December 1. aerial for better reception. 50 ft. $3.00 100 ft. $5.00 The lines affected are the newly stand- 75 ft. 3.85 150 ft. 7.00 ardized DV -2 detector, the specialized DV -5 for radio and audio frequency Acorn Window The New Loop Lead In amplification, and the DV -3 and DV -3A for dry cell battery circuits. The Ajax patented screw Fits into as attachment pictured above sash pictured. H. L. Lanphear, an executive of the keeps the wiring always taut Made of pure copper ....extended. the loop is 15 ribbon Winch wide, heavi- DeForest Company, in announcing the inches wide and 33 inches ly enameled by special new schedule made high and may be folded into process. Triply insulated public the following a box just 14 inches long. with waterproofed fabric. statement: "Our recently inaugurated The construction of the Thousands Ajax is of the finest of users recom- policy of developing and producing a new solid wal- mend them for sat'sfactory service. Each 35c. all woodwork of line of nut and all metal parts (Unenameled -25c.) and complete highly specialized heavily nickel-plated. Easily receiving tubes has resulted in such connected to the receiver -all Acorn Master Switch leads supplied. Extra terminal Instantly connects your battery to charger or increased sales throughout the country provided for centre tap. battery to receiver. that we are now in the fortunate position Endorsed by the leading Radio Single socket type - - $5.00. Authorities as the most efficient Double socket type - - - - - $6.25. of being able to announce forthwith a loop on the market. (for use with B- eliminator) $12.50 If your dealer cannot supply sweeping price reduction on all lines of you orderdirect. Send for circulars on Acorn Products. our receiving tubes. Write for circulars describing the Aj ax in detail. JOBBERS -Write for discounts-DEALERS DEALERS Write for Discounts JOBBERS the of DV -5 "With addition the the Sole Distributors Acorn Radio Prod. Co. Company has at last realized the ambi- CO. tion long held by the DeForest tube THOR RADIO 712 W. Madison St., Chicago Dept. 718 35 So. Dearborn St. Chicago, Ill. engineering staff, namely, to supply Manufacturers -Ajax Radio Co. Chicago specialist tubes for each step in radio YOU CAN GET C O I L S reception. Greater reflex or crystal set_ Radio Frequency Transformers "This tube development by DeForest reception if You use the= Low Loss Freshman or Pfanstiehl Type Engineers has resulted in several points BROWNLIE 3 of tube superiority, one the use of an VERNIER Each $0.65 - Set of $1.50 isolantite base by which the electrical DETECTOR Guaranteed Satisfaction or Money Refunded $2.00 At your dealer or Direct. 2215 Archer Ave. losses have been reduced from one -eighth ROLAND BROWNLIE & CO. Kissel- Carman Chicago, Ill. to one- fiftieth. 21 Sander. St. Medford Mess. Tell them you read 'it in Radio Age The Magazine of the Hour 66 RADIO AGE for January, 1926 Correct List of Broadcast Stations Jr...... _ Chico, Calif. 254 Pa. 309 KFWH F. Wellington Morse, - Calif. 226 Electric & Mtg. CO...... __.._...... _._...East Pittsburgh, Radio Entertainments, Inc South San Francisco. KDKA Westinghouse -. Devils Lake, N. D. 231 KFW1 Oakland, Calif. 207 KOLR Radio Elect rio Co ..._.__...... 250 I(FWM Oakland Educational Society 211 _ ...... __.._...... _.Cleveland. Ohio ...... _...._.._. Avalon, Calif. KOPM Westinghouse Electric & Mfg. Cb -.- Utah 246 KFWOLawrence Mott. _.._...._....._ Texas 214 IloteL.._.._...... _.._...._.._ - ,_,_._.._...- Salt Lake City, Rio Grande Radio Supply House. Brownsville, KDYL Newhouse .__....- ....Bakersfield. Calif. 210 KFWP Pineville, La. 236 KOZB Frank E. Seifert -.- »_ _.._-- .--- KFWU Louisiana College - .. »_..- Portland, Oreg. 213 Electric Supply Co.._..._...-....--....- ...... _...... --- Wenatchee, KFWV Wilbur Jarman. K OZI _..._...... _...._. Nash. 360 .Big Bear KFAB Nebraska Buick Auto Co _.- 273 KFXB Bertram O. Heller Calif. 203 Co... »...... _...- _.-Phoenix, Aria Valley Railroad CO._ Marke, KFAD McArthur Bros, Mercantile Jose, Calif. 217 I(FXC Santa Maria Logan, Utah 205 ...... _..__. -- ..... _...._._..._.._....5 n Strong - _.._..._.._..-- _r...... _.._ I(FA F A. E. Fowler_..._...._...... _ Boulder, kif. 2 KFXO L. li. -._.» Waterloo, Iowa 236 University of Colorado KFXE Electrical Research & Mfg. Co _...__ Colo. 250 KFAI ...... Idaho 261 Co Colorado Springs. K FA U Independent School Dist ._...... _._ -._ 275 KFXF Pike's Peak Broadcasting .EL Paso, Texas 242 ... __ _._...._...... Havre. Mont. Radio Company KFBB F. A. Buttrey & Co Diego, Calif. 224 K F X H Bledsoe sta. I....Denver, Colo. 216 ..... ». San 1(FXl Mountain States Radio Distributors. Inc. Wort. KFBC W. K. Azbi1L ...... Tacoma, Wash. 250 _ Beaumont, Texas 227 Presbyterian Chinch .._...... »..__...... _ K F X M Neches Electrio Co.._.._ Okla. 214 I(FBG First _Sacramento, Calif. 248 Film Finishing Co ...... _.._._..._._ Oklahoma City. KFBI( Kimball -Upson Co.._.._. Wash. 224 I(FXR Classer ._...._.._.Flagstaff Ariz. 205 _.. _.. Everett. F XV Mary M. Costigan _...._...._...__.__..__- K F B L Leese Bros...... __.._. --- Trinidad, Colo. 238 I( Oxnard, Calif. 205 School District No. One._.._...._..___... »_-. _...... _._._ I(FYF Carl's Radio Den._.._ .... ._ __.._.....__.+- .------Texas 238 KFBS .Laramie, Wyo. 270 ....._.. »_._.__ Houston, N. S. Thomas K FYJ Chronicle Publishing Co - 248 I(FBU Bishop Ariz. 238 - - -. Bismarck, N. Dak. Co,._..__ ...._ - ..Phoenix, KFYR Hoskens- Meyer, Inc ...... _...._....___..._...... - KFCB Nielson Radio Supply Walla. Wash. 256 _._ Tacoma, Wash. 250 Frank A. Moore.»...... __..._ _...-- .... --- .....Walls 1(GB Tacoma Daily Ledger._.. -..._ Calif. 361 KFCF Boise, Idaho 278 CO ...... - Oakland, St. Michaels Cathedral __.._.._...._..._.._ KGO General Electric ...... _.... _*-- Calif. 234 I(FOD Corvallis. reg. 280 Tabernacle. San Francisco. KFOJ Oregon Agricultural College - - -- Texas 316 I(GTT Glad Tidings Hawaii. Waikiki Beach 270 »._ ._..... _...__...Beaumont. Mulrony Ilonoluhi, K F D M Magnolia. Petroleum Co _ KGU Marion A. Oreg. 491 Shreveport, La. 250 ...... - -- Church ______...... KGW Portland Morning Oregonian.__-_--_- ...... - -Portland, 246 I(FXX First Baptist S. Dak. 273 »...__.._..___ ------Lacy, Wash. Dakota State College..._....._...._ _.._...._.....Brookings Martins College _...... 405 I(FOY South Minneapolis. Minn. 231 KGYSt. .._...._ ...... _.._.-_.._-- -.Dos Angeles, Calif. O. Iverson._...._._- . - - - -- KH1Times -Mirror Co...... _ Wash. 273 KFOZ Harry Portland. Oreg. 243 Seattle. Co. .- ..- . -» K H Q Louis Wasmer...... _...._ __ - 220 I(FEC Meier & Frank ..- Minn. 261 ...... San Francisco, Calif. .Minneapolis. .113S J. Brunton & Sons - ...__...._...._ ...... _ K F E I( Augsbury Seminary - -_ -_ Colo. 254 I( _..._... Seattle, Wash. 384 Denver. KJR Northwest Radio Service Co..___-...... _....__ ...... KFEL Winner Radio Corp ------Oak, Nebr. 268 Los Angeles, Calif. 293 ...... _..__...... _ KJS Bible Institute of Los Angeles. Inc. KFEQ J. L. Scroagin Moberly, Mo. 242 of Jesus Christ of Latter Day Saints...._...._... Baptist Church 235 KLDS Reorganized Church Mo. 441 K F F P First and Concentrating Co-Kellogg. Idaho Independence, I(FEY Bunker I1111 & Sullivan Mining eb. 224 Oakland, Calif. 250 Radio Supply Co.. _..._ ...... -....._..__..__.. I(LS Warner Brothers Radio Supplies Co Calif. 508 KFGB Heldbieder Rouas, Nib. 224 Publishing Co...... __ ...... _.._.._.._.._..___...._ Oakland, Louisiana State liniversltY ------°- KLX Tribune Denver, Colo. 266 I(FGC ..._...... __..__...Chickasha. Okla. 248 Radio Co KFGO Chickasha Radio & Electric Co.._.._.__. Calif. I(LZ Reynolds _..... Shenandoah, Iowa 252 Stanford University..._...._ ...... - ...... _Stanford University, 1(MA May Seed & Nursery Co...... _....._...- Calif. 234 KFGH Leland . a 270 Bee Fresno. KFGQ Crary Ilardware Co "w "'_ "'" Wichita, Kans. 268 KM1 Fresno Clay Center, Nebr. 229 Lassen_.._...... __.._.._ ...... 1(MMJ M. M. Johnson Co Wash. 250 KF H Hotel Gunnison. Colo. 252 Co Tacoma, Western State College of Colorado_ 261 KMO Love Electric Los Angeles, Calif. 208 KFHA Neah Bay, Wash. RC C. H H Ambrose A. McCue.- .._--- .__.. -,. 240 K B. Juneau _Los Angeles, Calif. 337 1(F Oskaloosa, Iowa Los Angeles Evening Depress _...- ...... - - - - K F H L Penn College _.- --- Calif. 469 KNX Denver, Colo. 322 Inc.._..__.._...... »...._ Los Angels. KOA General Electric Co Mex. 349 K FI E. C. Anthony, Oreg. 248 of Ag. & Mechanic.Arta...State CollmaN. Polytechnic Institute..... _....___.. _....____..._...... Portland, 266 ROB New Mexico College 258 KF I F Benson -._ Spokane. Wash. School - °° I(FIO North Central High School._ .- _...._...... _..__.._ Wash. 256 KOCH Central High - - Chickasha,-" Okla, 252 Yakima. KOCW Oklahoma College for Women - . -...- 278 IC F I Q First Methodist Church Alaska 226 _....Council Bluffs. Iowa Co. .Juneau, I(01 L Monarch Manufacturing CO _.... -. -- w.._ 428 I(FIU Alaska Electric Light & Power Fond du Lac, Wis. 273 -- San Francisco, Calif. . _. KPO Hale Bros. Calif. 229 KFIZ Daily Commonwealth Iowa 248 . Pasadena, Co ._ M,irshalltown. KPPC Pasadena Presbyterian Church 297 KFJB Marshall Eleotrical ...... Junction City Kans. 219 Ilouston. Texas R. B. Fegan (Episcopal Church) K PRC Ilouston Post-Dispatch ...._....Pasadena, Calif. 316 I(FJC ..._ Oklahoma City. Okla. Publishing Co K F1 F National Radio banufacturing Co. 261 KPSN Star-News -- Portland. Oreg. 213 Marsh) I(QP II, B. head. 27$ KFil Liberty Theatre (E. E. Iowa 242 . Pittsburgh, I'a. Co OAstria. I(QV Doubleday -Hill Electric Co ...... _...._.._._...___.._ Calif. 231 1< Fi L Ilardsaeg Manufacturing Forks. N. Dak. 278 San Jose, North Dakota Grand KQW Charles D. Ilerroid Berkeley, Calif. 256 KFJM University of ».._...... Portland. Oreg. 263 C. Dixon & Son -- 258 K RE Berkeley Daily Gazette Manhattan, Hans. 341 KFJR Ashley ..._.-...... Cedar Falls. Iowa State College. _.._...._..._._ KFJX Iowa State Teachers' College....._...._..._..- Dodge. Iowa 246 KSAC Kansas Agricultural St. Louis. Mo. 545 Co _ Fort KSO Pulitzer Printing Co City. Utah 300 I( FJ Y Tietwall Radio Fort GW rtteh... of Uralt. Salt Iake Southwest Baptist Theological Seminary._._ axas 254 A. A...... _. _.Clarinda, Iowa 242 I(FJZ I(SO Berry SeedCo. 333 KFKA Colorado State Teachers College._...... _...... _ Lawrence. Kona 275 Oakland. Calif. of Kansas I(TAB Tenth Ave. Baptist Church Angeles. Calif. 294 KFKU The University Co...... partings. Nehr. 288 Los Westinghouse Electric & Manufacturing Mo. 226 KTBI Bible Institute. Portland, Ore. 263 KFKX Kirkville, I(TBR Brown's Radio Shop Wash. 306 I(FKZ P. Henry .Franklinton, La. 234 Co., Inc Seattle, KTCL American Radio Telephone Springs, Ark. 275 I(FLP EverPaul t -- -- Cedar Rapids. la. 256 Arlington Hotel Co Hot F LP Everett bí.M. Foster New Mexico 254 KT HS New Muscatine, Iowa 256 Mexico .- 1.Ibuquer(lue. 236 KTNT N. Baker Wash. 454 I(FLU University of New San Benito. Texas Church Seattle, San Benito Radio l'Cb Rockford. Ill. 229 KTW First Presbyterian San Francisco, Calif. 250 Church. KUO Examiner Printing Co Mont. 244 K F LV Evangelical Galveston, Texas 240 of Montana- Missoula, KFLX AtorgeGeorge Roy Cough .Anita, la. 273 KUOM State University Vermillion. S. D. 278 Co USO University of South 'Dakota.._ Texas 231 KFM Atlantic Automobile Rock, A. 254 I( ._...... _...._...... _.._.....- ...._ _Austin, Churches _ Little KUT University of Texas ...... »- Bristow, Okla. 375 KFMQ sit Fayetteville, Ark. 300 Oklahoma University of .legs. s Iowa 261 I(V00 The Voice of Stockton. Calif. 248 KFMR Sioux City, Wireless Telephone Co 236 K F M R M. Sate College. Mich. 263 If WG Portable Kansas City, Mo. Houghton Studios 261 M W G. $stereo Minn. 337 KWKC Wilson Duncan 1(ennonwood. La. F Northfield, W. G. Patterson Wash. 349 KFNF Carleton College Shenandoah, Iowa 266 KWKH ...... _.._...__..._. Pullman. Seed op I( W SC State College LeMars, Iowa 252 KFNF WrHenry te Field Coldwater. Miss. 254 Union College. KFNA Rhodes's Radio Shop Seattle, Wash. KWUC Western Brownsville, Texas 278 KFOB chore ._.._ Burlingame, Calif. 226 KWWG City of Brownsville. Honolulu. Hawaii 270 Chamber Mo. 242 KYO Electric Shop. Chicago, Ill. 535 KFOB Moberly, Electric & Mfg. Co. _ 240 KFOJ Echophv Schooliohool Long Beach, Calif. 233 1< Y W Westinghouse Oakland, Calif. RRadio sin Shop 236 KZM Preston D. Allen.---- New Orleans, La. 268 KFON Later Salt Lake City, Utah Jensen. 258 I( FOP Latter Day Saints' University Marshfield. Ore. 240 WAAB Valdemar Cincinnati, Ohio Rohrer Elec. Co City. Nebr. WAAO Ohio Mechanics Institute....._...._. Chicago, Ill. 278 I( David Daily Drovers Journal . 263 R David City Tire Electric Co 230 WAAF Chicago Newark. N. J. K FO Wichita, Hans. Co...... _ ...._...... _.. -... 278 K F OT College I Radio 248 WAAM I. R. Nelson Omaha, Nebr. Technical High 8chooL...... Omaha Grain Exchange N. C. 254 KFOX Board of Education. OPaul. Minn.r 252 Co.. Inc Asheville, KFPG Beacon Radio Sernne Angeles, Calif. 238 W A BC Asheville Battery Bangor. Me. _Los WABI Universalist Church ..... __...... __ Conn. 283 KFPG On and Dennis -- Dublin. Texas 252 ,st College._..__,._.., -._ - - -_ Sores. i._...._...._ ...... _.._... -..__ WABL Connecticut Agrimiltural _Rochester. N. Y. 278 KFPL T. C. woxur... Greenville. Texas 242 Baptist. Churc The New FurnitureCounty Co Calif. 231 W ABO Lake Avenue Ifaverford, l'a. 261 KFPM Dept - lets Angeles. College. Radio Club 263 KFPT Cas Angeles County Forestry - Salt Lake City. Utah 286 WABQ Toledo. Ohio Cape & Johnson Mn. 258 WABR 6ve ÌÌíd Wooster, Ohio 207 I(FPT _..... Carterville. 246 I(FPW St. Johns M. E. Crch..... _....- Spokane. Wash. 266 W AB College of Wooster Mt. Clemens. Mich. I(FPY Symons Investment Co ...... _ --.. at Louis, Mo. 261 WABX Henry R. Joy Philadelphia, Pa-a 242 Principia Texas 263 WA BY John Magaldi Jr __._. _.New Orleans, 275 KFQA The Co Fort Worth, Place Baptist Church._._...._ ...... 238 KFQB The Searchlight Publishing Burlingame Calif.a 263 WA BY Coliseum ,Oh. T. Simmons (Allen Theatre) 275 . Iowa C{iy. 224 WA OC Allen port Duren, Mihi KFOP G. ._...... _...... ta. Co.-...... - G. S. Carson, Jr.»..._ ...... _...---. City, Calif. 217 WA F 0 Albert B. Parfet - .Ricunond 11111. N. Y. KFQP Holy A. H. Grob e & Co Mass. 229 KFOU Riker .. -.. .,...... North Bend. Wash. 216 WANG _....._ ...... _.- .._._...._..._ -.' Taunton, ucts Calif. 226 WAIT A. H. White Co Ohio 294 KFQW Hollywood, Insurance Union 244 KFQZ Taft Products CoCo- Beeville, Texas 248 WAIU American ,Minneapolis, Minn. & Co . Ala. 248 KFRC Hall Brea..._. ,San Francisco, Calif. 268 WAMO Ilubbard Institute ...... _...._. Auburn. Bo Dry Goods Co - 242 WA PI Alabama Polytechnic Medford. Mass. 261 KFRC Cam of -- Ft. Sill. Okla. Radio Research (Coro KFRU James P. Boland_ Columbia. Mn. 500 WARC American W, Lafayette, Ind. 273 »--» Wash. 219 W B A A Purdue University ,Clemson College, S. C. 331 I(FRU of Olympia, Clemson Collige--.._...... _..._...... _...._.... 417 F R W UnitedCoped Churches N. Mex. 266 W B AC _- MinneaPOlfs. Minn. I( Arts. State College. Dayton CoC _....-_.- ....------Pa. 275 College of Aft &MscnanicMechanic Arts Angeles, Calif. 275 WBAH The ..- ...._...._.._...IIarrisburg, KFSG Assn Los Pennsylvania State Police Ill. 270 I(FU.1 Echo Park Evan. Breckenridge, Minn. 242 WBAI( lacy Decatur. Plumbing and Music Co 258 WBAO James Millikan U&tn Baltimore, Md. 375 KFU1 Topmast Co Galveston. Texas ishin Co T. Das oroagan & Bros. Music Springs. Colo. 242 WBAL Consolidated Gas Telegram) Fort Worth, Texas 476 I(FUL Colorado Publishing (Star Columbus, Ohio 292 KFUM D. Corley .St. Louis. Mo. 545 WBAP Co Seminary Colo. 234 WBAV Errer & liopkinaHopkins Wilkes -Barre. l'a. 256 KFUO Denver. II. Stenger, Jr »- Y. 492 I(FUQ Fitzsimmons ons Co... ,....,..,,.,San Francisco, Calif. 234 WBAX John - _.._...-- ....._..,._...._...... Now- York. N. and Sons Co. ...._..._.._...._ ...... WBAY Western Co.O..._....Chu.c Newark, Ohio 226 I(FUR Julius BldgwnBrunton Ogden. Utah 224 Congregational Church- _ _..__...... _.._.._...... KFUS Lours S. Co Oakland. Calif. 256 WBBA Plymouth Church...._._..._..._...._.._ Richmond, Grace Covenant Presbyterian ..._...... Chicago, Ill. 226 KFUT Louve L. Sherman Salt Lake City. Utah 261 WBBL Co...... -,..,_,.._...... _ »- »-- - of Utah 224 WBBM Atlass Investment -- N. C. 275 KFUT University San Leandro. Calif. A. B ..- .,..------_.... Wilmington, KFUU Aorfan Radio San Diego. Calif. 246 WBBN Blake. -__ Corporp I'etoskey High School. _.._ - ..- .- _- ._ Petnellló, Nit 273 KFV0 Radio San Pedro, Calif. 205 WBBP _.. - ..- ._...... _.._...... Co R Pulpit Assoc Orleans, La. 252 K F V F Et ..St. Iglus, Mo. 240 W B B I'eoPle's Corporation of America. 208 WBBS First Baptist Churoh._ - - Norfolk. Va. 222 KFVE CllrFilm Hollywood. Calif. nigh School - B. Juneau - ans. 236 WBB Ruffner Junior Inf...._ ..... Charleston, SIC. K F V G Clarence - - -- .._...._.....Inmhtt. Light Infantry Co. "B" 118th 266 VG First M. E. Church. Kans.Kens. 219 W BB Washington Manhattan. & McDonnell Mich, 256 K F V H Whan Radio Shop Houston. Texas 240 W BCN Foster Grand Rapids. Cavalry . Laundry ._ Md. 222 1(FVI Headquarters Troop. 5Gth 226 WBES Baxter _,_.._.._...... _...._. Takoma Park, Bagley._ _.._....._ ...... _.._...._.._.WIetckme. WBGA Bliss Electrical School _Baltimore,_ Y KFVN Carl E. _.._..._...... _.._...... _.._. -. Munn. 226 Radio Mfg. CA .r...__..._.- ...... »._.... -_.. 210 F. M. Henry._.... Colo. 244 WBNY Jones Elea. & K F V 0 Route 6. Denver. Shirley N. Y. 236 R Moonlight Ranch Mo. 224 WBOY Katz .Richmond HIL K FV Station ...Cape Girardeau. H. Co., Inc - °- Pa.. 286 Battery A. - -- _...... ßutler, KFVS Cape Girardeau Eureka, Calif. 210 W BO Police._....».. - -_...... __.... Publishing Co 246 WBR Bell Slate Birmingham. Ala. 248 I(FVU Standard San Diego. Calif. adii ikon...... __...... __._..- 231 Radio Radio Corp M. 250 WBRE Bell RadioRodeo tiara Wilkes- Barre, Pa. KFVW ..._....._....- Albuquerque, N. Baltimore Radio Ftehangn ('harlotte, N. C. 275 K F V Y Radio EMMA.), San Francisco, Calif. 234 WBRE Commerce. TaCernacle. 261 Charlotte Chamber of Suringfleld. Mass. 333 I(FW Brod Tidings Ogden. Utah WBT Electricctrie & Mfg. CO Bros.osas. Co Calif. 252 WBZ Westinghouse ]Boston Mass. 242 I(KFWB Browning -Hollywood. Westinghouse Electric & Mfg. Co Conn. 275 F W C Warner Bros.._.._ ..... - -- -- Upland. Calif. 211 WBZA Mansfield, K Cen...._...__.....- Connecticut Agricultural College 1( F W C D. Wall. St. Louis, Mo. 215 WCAC F W F St. Loura Truth Center -..._ I< Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 67 Finishing Your Radio Cabinet (Continued from page 13) pumice of a fine grade, on the surface of the cabinet, a light back and forth i motion may be attempted. Do not make the downward pressure any thing but light as you will find that you have Patented Noc. 16', 1924 rubbed through the varnish if you are not careful. Do not make any circular motion or go across the grain as we found .kuipealza in sandpapering, scratches will result Corro% that will show up later.. Examine the progress of the rubbing frequently by wiping the surface clean and where the varnish appears to be rough or still For EVERY retains its gloss, the rubbing operation should be centered more than where it seems to be finished. Look out for Centralab Radio Set rubbing the edges and the corners through A stunning piece of furniture that white. It is about the easiest thing to Radiohm restores room do. If that condition does present itself, order in the where a little of the original stain applied with for Oscillation Control you have your Radio! No more a small pointed brush will restore the cluttered table -tops, nor litter of color. Get full efficiency from your set by Keep the felt wet. installing a Centralab Radiohm. Pro- equipment un- When you think that the surface is vides perfect plate circuit control of der-foot. rubbed about enough, wash off with oscillation. No water and thoroughly dry. Now it By controlling oscillation with this unsightly will take several coats, applied just this little unit, you can hold that sensitive horn in evidence, same way, and each one rubbed down, regenerative position which immediately either! This - precedes the oscillation point, without con before a good surface can be had. I distortion or loss of selectivity. Think sole has its own suggest that at least three coats be used what a boon to clear, true -tone reception loudspeaker, in- and more if you want the best job. When this is! built. It's out of you consider that a piano with its fine Provides smooth variation of re- polished finish often has fifteen or twenty sistance from zero to 200,000 ohms. sight, but with Used as a Non- Vibrant Ceramic coats of varnish, you can better under- standard unit in several very apparent leading sets. Price: 52.00 -at your Horn stand why. A good deal of success in dealer's or mailed tonal superiori- The clearest tone pro- direct. ties. ducer on the market. rubbing is generally due to a fine grade For it has Made of special com- of varnish, the good patience of the the highest position which defeats Centralab Modulator -de- vibration. worker, allowing the varnish to be very veloped type of dry before rubbing, and the degree of for Volume Control unit. With horn built of special skill attained by the worker as he goes non -vibrating, This improved type of potentiometer extra -hard material. along. Some shops use a semi -flat or takes the "rough spots" out of volume Produces clear non -vibrant tone. velvet finish varnish, as they call it. smooths out powerful "locals" as well- There's This drys with a surface that resembles as difficult "DX." It provides noiseless ample room for everything; control of volume from a whisper to space for A and B wet batteries a rubbed one. A little rubbing to smooth maximum. Used in audio circuits with -or battery eliminator and for a off the lumps and specks that accumulate any transformers or with Thordarson charging outfit, too. somehow while the work is drying, will "Autoformer." Price: $2.00 at your dealer's-or mailed direct. Finished in mahogany, or walnut produce a job that looks as well as the color. Dainty one using the regular varnish. Some say Write for literature describing these design of parqueterie and other Centralab Radio Controls. on two front panels. Top, 38 in.x18 in. it is not as durable as the other, but claim is. Additional the makers it Central Radio pattern No. 128 (Special When finishing up on the rubbing it Laboratories for Radiola 24 Keefe No. 125) in two -tone fin- is wash Ave., Milwaukee, Wis. ish. Top, 21 in.x31 a good plan to the felt off and in. Fitted with surface with wet doors for access to control switches of rub the just the felt, combination eliminator- charger. as this will remove the tiny scratches and leave a better looking finish. Be sure The price, forty dollars, is for the complete console and includes to get all the pumice off between coats, the loudspeaker horn washing, or and unit. Thousands of dealers are show- by thoroughly the next coat ing this artistic addition to home radio will appear lumpy. equipment. It is after the last touch has been done Rear View -Set Modred UP that the care or carelessness of your early work shows up. If you left any dents or rough places in the surface of the wood, they will remind you of it. The felt will not go down to the rubbing RAULF'°c°°MFG. CO.562 VEDDER ST. bottom of these places and a shiny unfinished not will remain. CHICAGO. WRITE FOR CIRCULAR Much time spent on the preparation of the wood is time well spent, if you want a perfect job.

Price, $40 West of Rocky Mts., 812.50 *Asterisks* placed in advertising space denotes manufacturers have submitted Doslers, FR£E Windsor Furniture sat u< bie Co. samples of their products to Radio 'Zags cArqLo 1428 Carroll Ave. you buy. C Age Institute and these products toas of standard SEr. Chicago, Ill. Lilo parta, seta, kits t rock- p4grt have passed the Institute Special KS tests. offer ñeeá, çubenbñtteries. B.O. Braun Co.3e-50 9.etlatou St.. Chleseo,II. S. Á. Tell them you read it in Radio Age The Magazine of the Hour 68 RADIO AGE for January, 1926 N. Y. 263 WHBA C. C. Shaffer... ..,. _, . _Oil City, Pa. 250 WCAD St. Lawrence University._ --Canton, WHBB The Copps Co Stevens Point, Wis. 240 Co. and The Pittsburgh Presti..,_.. ,Pittsburgb, Pa. 461 WCAE Kaufmann & Baer Columbus, Ohio 266 W H BC Rev. E. P. Graham._ Canton, Ohio 254 W CA H Entrekin Electric Co .... Howard_ ». _Bellfontafne, Ohio 222 Place. Nebr. 254 WHBD Chas. W. - -- WCAJ Nebraska Wesleyan University ..University Beardsley SPeclalfy Company. ..- Bask Island, 111. 222 _ -----.Northfield, Minn. 337 WHBF WCAL St. Olaf College- Md. 275 John S. Skane _.Harrisburg, Pa. 231 WCAO A A. and A. S. Brager -Baltimore. WHBG Culver Military Academy_. ...__,_._...... _...._.Culver, Ind. 222 Co Washington, D. C. 468 WCAP Chesapeake & Potomac Telephone -- Texas 263 HBJ Lauer Auto Co.._ t. Wayne. Ind. 234 Southern Radio Corp. of Texas. _._...San Antomo, .Ellsworth, Me. 231 WCAR Institute ____Minneapolis, Minn. 280 Franklin St. Garage, Inc... WCAS W. H. Dunwoody Industrial S. Dak. 240 WHBL James IL Slusser .Logansport, Ind. 216 WCAT State College of Mines...._.__ _._.._ ...... -_ - .._.._.._.Rapid City, Portable Statua_. Chicago, Ili 233 .....__. »- Philadelphia, Pa. 278 WHBM C. L. Carrell, WCAU Universal Broadcasting Ca...___,_.____ --. Vt. 250 WHBN First Ave. Methodist Church _ St. Petersburg. Fla. 238 WCAX University of Vermont______.._....-__.Burllngton, M. E. Church ,..._,..» _...._..._...Memphis, Tenn. 233 ..,,. _Allentown, Pa. 254 WHBQ St. John's South_.._ -_- WCBA Charles W. Heimbach._.. Zion, Ill. 345 WHBP Johnstown Automobile C0.._.__...._... .__....__.._.r.__....Jobaste wn, Pa, 256 WCBD Wilbur C. Valve_ ..... ______._ Scientific Electric & Mfg. Co.. 3664 Vine St. _ _ _.Cincinnati, Ohio 216 ...... _..__..._._...._._._.._New Orleans. La. 263 WHBR WCBE Uhalt Radio Co...... ------..Pittsburgh. Pa. 236 W H BU Riviera Theatre and Bing's Clothing....._..... »...._...... _.._.Anderson, Ind. 219 W CB F Paul J. Miller._..__._ .__._ ---.....Pittsburgh. D. R. Kienzle...... _ .._.. Philadelphia, l'a. 216 (Portable).... Pascagoula, Miss. 268 WHBW WCBG Howard S. Williams Oxford. Miss. 242 WHBY St Norbert's Colleen_ West De Pere, Wis. 250 WCBH University of Mississippi .- __.... -..._ W. H. Dunwoody Ind, Institute. -Minneapolis, Minn. 278 __,,. ._, __Baltimore, Md. 229 WHDI WCBM Charles Swart . BenJ. Harrison, Ind. 266 WHEC Hickson Electric Co., Inc . ._.Rochester, N. Y. 258 WCBN James P. Boland _,_,Ft The Radio Air Service Corp Cleveland, Ohio 273 Cburrlt_.. __ _._..__.__..__..__.__._...- Nashville, Tem. 236 WHK WCBQ First Baptist _._..___Providence, R. I. 205 WHN George SohubmL...... _ .._ .New York, N. Y. 361 WCBR C. H. Messtor .Newark. N. J. 233 WHO Bankers' Life Co.._._._... - Des Moines, Ia. 526 WCBX Radio Shop of Newark (Herman Lubinsky)- WHT Radiophone Broadcasting Cori _Deerfield. Ill. 238 -Crosby Co..._._ _ _ __. Anoka, Minn. 416 WCCO Washburn , Ill. 275 WHT Radiophone Broadcasting Corp...... -...... Deerfield. W. 400 WCEE Liberty Weekly.- ...... --- _____ R. Millen...,__.._.___..__ ...... Philadelphia, Pa. 250 ...,- .....- -.._-._._.Camp Lake. Wise. 231 WIAD Howard WCLOC. E. Whitmore.... _, Ill. 214 WIAD Chronicle Publishing Co,. Marion, Ind. 226 H. M. Couch.._+..__ ....._.._-.._...... »_.. -_.- ___.._Joliet, WCLS ..- .- _.,,_.._...... Portland. Maine 256 WIAS Hove Electric Ca._..___..- _.,- ..... _...... __..__.._...._..Burlington, Iowa 254 WCSH Henry P. Rines. - _ - Springfield, Ohio 248 WIBA The Capital Times Stuilo__._ .Madison, Wie. 236 WCSO Wittenberg College_..._ L. M. Tate Post, No. 29, Vet. of Foreign Wars. St. Petersburg, Fla. 222 . -..._. .._ Worcester, Mass. 238 WIBC WCUW Clark University..._.... _..Providence R. I. 210 WIBC St. Paul's Protestant Episcopal Church.. Elkins Park. Pa, 222 WCWS Chas. W. Selene (Portable) WIBH Elite-Radio Stores._._ ...... ______. .New Bedford. Mass. 210 Press and Jewett Radio & Phonograph Co -__..Detroit, Mich. 517 WCX Free _._ _,...... Nashville, Tenn. 226 WIBI Frederick B. Zitteii, Jr .FIushing, N. Y. 219 WDAD Dad's Auto Accessories, Inc 273 WIBI C. L. Carrell (Portable).....__._...... _.Chicago, Ill. 216 . .._.Tampa, Fla. WDAE Tampa Daily Times. W I BM Billy Maine Cbicago, 216 » »_...- _..__- .Kansas City. Mo. 366 (Portable)____.. Ill W DA F Kansas City Star._ ... W I BO Nelson Brothers....._...._._ .Chicago. Ill. 226 Martin _...... :_._ _...,_..,, ....._ Amarillo, Texas 263 WDAG L Laurence -__ El Paso. Texas 268 W I B R Thurman A. Owings Werton W. Va. 246 W DA H Trinity Methodist Church. Philadelphia, Pa. 393 WIBS New Jersey Nat'I Guard Hdgs. Co.___..._. . ..._.Elizabeth, N. J. 203 WDAR Brothers-. ._..._ ____.__... 222 Lit _..._..__».. -.- Fargo. N. Dak. 261 WIBU The Electric Farm...... _ .Poynette. Wis. Equipment Corp- I WDAY Radio .__._,.....Newark, Ohio 226 W B W Dr. L. L. Dill.._.__..__._...... _,_- . ... _. __ . - Logansport. Ind. 220 W D BA Plymouth Cong. Church - 229 WIBX Grid-Leak, Inc »-_ ..Utica.. N. Y. 205 Co.. Inc._ _ _ _...... _._Taunton, Mass. WDBB A. H. Waite & .Lancaster, Pa. 258 W I BZ Powell Electric Company. Montgomery. Ala. 231 W D BC Kirk, Johnson & Co. _._ W. Va. 268 WIL Benson Radio te The Star.___...._...._ __ .St. Louis, Mo. 273 WDBD Herman Edwin Burns...-....-.._._. _..._...._...___...MartJnsburg. Bros. 508 _... Atlanta. Ga. 270 W I P Gimbel ...._.Philadelphia, I'a. W D B E Gilham- Schoen Elec. Co -_ American Electric Co _.._..__...Lincoln, Nebr. 229 Corp. ... Roanoke, Va. 229 WJAB WDBD Richardson Wayland Electric .- -._ 227 WJAD Jackson's Radio Engineering Laboratories Waco, Texas 353 - - Cleveland. Ohio WDBK M. F. Bros __ _.Bangor, Me. 252 Norfolk Daily News Norfolk, Nebr. 270 WDBN Electric Light & Power Co.._ - 240 WJAG Clifford L. Wh Greentown, Iowa 254 College. Inc _- ._-- ._....,.,..._._.winter Park, Fla. WDBD Rollins Boston. Mass. 261 WJAM D. M. Perham. Cedar Rapids Iowa 268 WDBR Tremont Temple Baptist Church. 258 The Outlet Co. (J. Samuels & Bro. )._.._...... _..__.._ _Í rovidence. R. I. 306 . ..__ Fort Wayne, Ind. WJAS WDBV The Strand Theatre... _.Kingston, N. Y. 233 Pittsburgh Radio Supply Houses Pittsburgh, Pa. 275 WDBZ Boy Scouts. City Hall. .- ...._...._..__...... WJAX City of Jacksonville_ ,._.._.....Jacksonville. Fla. 337 College ...... _ ,_ _ Hanover, N. H. 256 WDCH Dartmouth ...- ...... __...-Chattsnooga, Tenn. 256 Zenith Radio Co._..._...._..___..__ _...._..,.._ .Mt. Prospect. Ill. 322 WOOD Chattanooga Radio Co.. Inc,_..._»_.»_ New Haven. Conn. 268 WJBA D. H. Lents, ...... _.._._...._...._...... Joliet. Ill. 207 WDRC Doolittle Radio Corp... WJBB L. W. McClung----- »...._ _...._.....SL Petersburg, Fla. 254 , CraTuolaR.I _._...._ W D W F Dutee Wilcox Flint, Inc...... _»...... _.-._..- »._- I. 441 Hummer Furniture-Co...... » _..._.._...._...._.LaSalle. Ill. 234 WDZ J. L. Bush ....._._.__...... - ...... » - WJBG Interstate Radio, Inc...... _.._.._..__.. _...- ._.__.._.Charlotte, N. C. 224 Co.. _ -... -- New York. N. Y. 491 ....- WEAF American Telephone & Telegraph __Ithaca N. Y. 254 WJBI Robert S. Johnsaa_.._...._....._.._-.._.._...... _ »....._- ...._.._.Red Bank, N. J. 219 WEAI Cornell University - E. F. Goodwin._..__...... _...... _..._...._.._.._ »_..__...._.....Ypsilanti. Mich. 233 Gibson Buttfleld)_.North Plainfield, N. J. 261 WJBK WEAM Bor. of N. Plainfield (W. Providence. R. I. 270 WJBL Wm. Gushard Dry Goods Co...... __...... Ill. 270 WEAN Shepard Co St. Johns Ev. Lutb. Cburoh._.__ _. Sycamore, Ill. 256 --_.._ Columbus, Ohio 294 WJBN WEAO Ohio State University WJBP Seneca Vocational School.-...._.._ _.._.._..- Buffalo, N. Y. 218 and Rubber Co. ». . ._._ Cleveland. Obits. 389 WEAR Goodyear Tire _.__..._..»».,,..._Sioux City, Iowa 275 WJBQ Bucknell University .». »...Lewisburg. Pa. 211 WEAU Davidson Bros. Co ...... _ St. Louis, Mo. 273 WJD Denison University._..__ -...... _.._ Ora..-ville, Ohio 217 Co.._...._...... __._.,,..._.._ ..... - _ ...... __..__.._ Supreme Lodge, Loyal of Moose Moosebeart WEBBenwood .- .__.....- ,._ »._.._._..»_. -Superior, Wis. 242 WJJD Order Ill. 303 WEBC Walter Cecil Bridges_..._...... Anderson, Ind. 246 WJR Jewett Radio & Phonograph Co. and Detroit Free Press.Pontiao, Mich. 517 WEBD Equipment and Service Co.. _..__ ...... _..____ America .New York, N. Y. 405 Electrical .» ...... __....Cambridge. Ohio 234 WJY Radio Corp. of WEBE Roy W. Waller .....____...... Chicago. Ill. 370 WJZ Radio Corp. of America ....._...._...- .._...._ »_._. New York. N. Y. 4M WEBH Edgewater Beech Hotel and Herald Examiner WKA A H. F. Paar ._..__ . -.... ._ Cedar Rapids, Iowa 278 Railway Co .,_,..._ ---- ...New York, N. Y. 273 W EBl Third Avenue ...... _Grand Rapids, Mich. 242 WKA D Chas. Looff (Cresoent Park).-.-----_--..-.East Providence, R. I. 240 WEBK Grand Rapids Radio Co .. N. Y. 226 WKA F WKAF Broadcasting Co...... __.._._.__.._....__.._. _.._...._.Milwaukee, Wis. 261 Corp. of America (Portable) New York. WEBL Radio _ New York. N. Y. 226 WKA Q Radio Corp. of Porto Rica San Juan, P. It. 34) WEBM Radio Corp. of America (Portable).. WKA R Michigan State College_-. - East Lansing. Mich. 285 ...... » New Orleans, La. 280 W E B P E, B. Pedicord ..- . ».. --.._.- Harnsburg. Ill. 226 WKA Laconia Radio Club' _._....._._...... _.._...._.._..__.._.Laconia, N. H. 224 Corp.... -_ . .._..- ..._... WEBQ Tate Radio ...___...._.Buffalo. N. Y. 244 WKB B Sanders Bros. _ __._.._ ... ._.._..__...... Joliet, Ill. 214 W EB R H. H. Howell _ Dayton, Ohio E K. & B. Electric Co...... _.__..__._....._.. ..__._....__..__..._._.Webster. Mass. 23) Dayton Coop. Industrial High School G ( ..... _..__._....._ ...... _.._.Chicago, Ill. 216 WEBT The » Beloit. Wis. 2682 WKB C. L. Carrell Portable )_.._. _._...... W E B W Beloit College. ...._.______Savannah.Bal Ga. 263 W K B K Was Sbirley ...... _.._....New York. N. Y. 210 Savannah Radio Cop C Kodel Radio ._ _..._._..._.....Cincinnati, Ohio 326 W EBZ Ca______-- »_ ston. Mass. Corp.._..._..._....._.._.._. WEE( The Edison Electric Illuminating 476 WKR C Kodel Radio Corp.-.------Cincinnati, Ohio 422 W EH S Robert E. Hughes. -- - --...Bernen Sprnga.¢o,Mich. Wiry Radio Shop _....._..- _...._._.Oklahoma City, Okla. 275 WEMC Emanuel Missionary College....._ Chicago, h. 285 WLA G Cutting & Washington Radio Corp._..__...... Minneapolis, Min. 4)7 W EN R All -Amerioan Radio Corporation.-._ St. Ill. 248 WLA L First Christian Church..... __.._...... _ ...... _...... _.__._._.._.._ Tulsa. Okla. 250. W E W St. Louis University -- °- Dallas. Teo. 476 WLA P \Vm. V. Jordan...... Louisville. Ky. 275 W FAA Dallas News & Dallas Journal- .._ 273 WLALA Q Arthur E. Shilling. ... Kalamazoo. Mich. 283 Co...... _...... SL ....._...... _.._..._.___ Greenvastle, Ind. 231 W FA M Times Publishing .Lincoln,. Minn. 275 X Community Broadcasting Statio University of Nebraska Knoxville, Tenn. 250 WLB University of Minnesota._.. Minneapolis. Minn. 278 W FBC First Baptist Church ------234 B Liberty Magazine.. Chicago, Ill. 303 Baptist Church.. »...... Philadelphia, 394 WFBD Gethsemane -- - ...... PhlIa moere. Ind. W LIT Lit Bros...... _.._...... _._.._..__..__.. Pa. WFBE John Van De Walla ------WLS Sears Roebuck & Co... .Crete. Ill. 345 ..._.... _ » 'Altoona. Pa. 278 ...... WFBG The Wm. F. Gable Co...... _. Y. 273 WLT S Lane Technical High School_ Chicago. Ill. 258 Radio Corporation ---New York, N. - Cincinnati. Ohio 422 WFBH Concourse - ... Crosley Mfg. Co Galvin Radio Supply Co.». ... ._.__ .- L Missionary Society of St. Paul the Aiso,tla...._.._ New York, N. Y. 288 WFBI - , Minn.N. L 236 W LW .... Card WFBJ St. John's University --__--.: ._.._.__.-...._.Syracuse, N. Y. 252 W M A C C. B. Meredith Casenovia. N. Y. 275 W FB L Onondaga Hotel Co.._...... »....._.._...____.._.._..__.. WM A F Round Hills Radio Corp Dartmouth, Mass. 441 Co...._...... _ ...... _...._ ».._Indlaapo WFBM Merchants Heat & Light 265 W M A K Norton Laboratories. Lockport. N. Y. 266 Co _..._...... _...__.._..._..__ s *Ind. WF BQ Wynne Radio _Baltimore. Md. 254 WMAL M. A. Lesse Optical Co.. »___..__..._..._...... _...._...... Washington. D. C. 213 WFBR Fifth. Inf. Md. Nat'l Guard....._...... _.._ W MAN Church. Columbus, Ohio 278 Co...... _._ ...... Cincinnatl Ohio 309 First Baptist WFBW Ainsworth -Gates Radio _.__._...-_ Galesburg. Ill. 254 WMAQ Chicago Daily News Chicago, ill. 447 WFBZ Knox College ------_ -... Y Kingsiilghway Presbyterian Church .... St. Louis. Mo. 248 ...... _..------._ .... ._.. -.. »...._..Flint. Mich. 234 WFDF F. D. Fallain ,philadelphia. Pa. 394 W M A Z Mercer University Macon, Ga. 261 and Clothier +.._- .._...... ».__.._._..._ Chicago, ill. 250 W FI Strawbridge .» Chicago. Ill. 217 WMB B American Bond & Mortgage Ca_..._....._ WFKB F. K. Bridgman N. Y. 205 WMB C Michigan Broadcasting Co- ...._...._.._..._...._ ...... _..__..Detroit, Mich. 256 Robert Morrisson Lacey -__-__....-Brooklyn. _....._..._._ ____Miami Beach. Fla. 384 WFRL -- _ Springfield. Mo. 252 W M B F Miami Beach Hotel. W F U V G. Pearson Ward __ _. - Moberly. Mo. 233 W M C Commercial Appeal._..__ Memphis, Ten. 500 W FU W Earl William Lewis A (Greenley Square Hotel Co.)._ ,_ _ New York City 341 Supply & Construction Co.. _ Lancaster, Pa. Hotel McAlpin W GA L Lancaster Electric 248 W M C Ainsworth -Gates Radio Co. __ Cincinnati, Ohio 32) WGAQ South Hotel WNA B Shepard Stores. _ __.._...._ ...... Boston. Mass. 250 Tribune - South Bend. Ind. 360 _____Boston, Mass. 280 WGAZ South Bend -- --' ._...FreeWrt, N. Y. 244 WNA C Shepard Stores. _..._...._ _ FrstY H. Carman ---- -_.... _. Norman, Okla. 254 WGBB .. :._.__....D[emPhis, Tenn. 278 WNA D University of Oklahoma WGBC First Baptist Church Y. L High School ..... Omaha. Nebr. 258 ...... __.._._.._ »- .._...-...Evansville, lnd. 236 WNA Omaha Central WGBF Fink Furniture Co ...... _...__... _ Pa. 240 WNA T Lennie Brothers Co. (Frederick Lennie) Philadelphia, Pa. 250 S. Megargee._...... _ ...... __....__._.__._.._,.» -. Scranton. Co...... __._..._..._ -_ Yankton, S. Dak. 244 WGBIFrank .»._.. »_..._.. - - -- Johnstown Pa. 248 WNA X Dakota Radio Apparatus WGBK Lawrence Campbell.. _.._Providence, R. I. 234 W N B H New Bedford HoteL _._.._. -...._ New Bedford, Mass. 248 WGBM Theodore N. Beaty _...._...._....Menominee, Wis. 234 WWI Radio Shop _...__...... _». _ Newark, N. J. 252 W G BQ Stout Institute 229 WNO X Peoples Tel. & Tel. Co Knoxville. Ten. 268 S. Ives. Marshfield, Wis. _.New York. N. Y. 526. W G B R George N. Y. 3 C Dept. of Plant and Structures_____. WGBS Gimbel Brothers _.... New York, Lima, Ohio 261 Co.._..._. _..__...FulIOrd By -The -Sea. Florida 278 WDA C l'ac WGBU Florida Cities Finance 252 WDA E Midland College Fremont Nebr. 280 of Maine _...... -. .»...__ Orono, Me. 274 WGBX University J. 252 WDA G Apollo Theatre (Belvidere Amusement Co.) Belvidere, Ill. D. W. May. Inc _.- . ».- .....- ._ »..__----Newark, N. San Antonio. Texas 394 WGCP W I Southern Equipment Co .... »_..__.._....._».... »_.... »...Clearwater, Fla. 266 OA 283 WGH B G. H. Bowles Developments 270 WDA N Vaughn Con. of Muslo (Jantes D. Vaughn) Lawrenceburg. Ten. H. Phelps _..._.... ._._..._...... _.._...Detroit. Mich. Mishawaka. Ind. 369 WGHP G. Oak Park. El. 250 WOA D Lyradion Mtg. Co -- -_- G Coyne Electrical School ...... ».»_..... »_._._...- -._.._ .- »...... _.l:enoeha. Wis. 225 W ES Mass. 261 WOA RLsuidskerw, lienry P._.. .._...._.._._...... _....__...._.. WGI American R. & R. Co - .--....Medford Hillside...... _..._ \Silmingtnn, Del. 360 _ .Richmond Hill N. Y. 236 WOA T Boyd M. Hump._ ...... W GM U A. H. Grebe & Co.. Inc.. Portable.....__._. Nat. Gua...._...... __.._...... rd, 2d Bat., 112th lnf Erie. Pa. 242 _ V Pennsylvania 526 WGN The Tribune. N. Y. 319 WOA W Woodman of the World. Omaha. Nebr. WGR Federal T. and T. Co .- ___., ....- .._Buffalo ....._ Trenton. N. J. 240 School Technology Atlanta. Ga, 270 WOA X Franklyn J. Wolff 484 WGST Georgia - N. Y. 379 WOC I'aimer School of Chiropractie._.. _...__.___Davenport. Iowa WGYGeneral Elec. Co --- . »...._,,..__. ».._..__.Schenectady, Station .._.._ » Sycamore. Ill. 205 Wisconsin..- --...Madison, Wis. 535 WDC G Triple Alliance Radio WHA University of L Inc M.. -_ -- __.._.._Jamestown. N. Y. 275 Marquette University and Milwaukee Journal »._ ...... Milwaukee, Wie. 275 WDC Hotel Jamestown. - WHAD Ohio 233 W O D A W H AG University cf Cincinnati __.._.._.Cincinnati. _ Iowa 270 ... Joplin. Mo. 283 W01 Iowa State Collega - ....» » » - -- »_....Anse.. W H A H Hater Supply CO WDK Neutrowound Radio Mfg' Co.....___..____. _,.. Homewood. Ill. 217 WHAM University of Rochester (Eastman School of Mudo) »,... Rochester, N. Y. 278 _....New York. N. Y. 233 _ Brooklyn, N. Y. 240 WDK D Otto Bn r...__.._...._..._...__.... ».. .._..» - ..._.._ WHAP W. H. Taylor Finance Corp Vanaiitaker ..»_...... _.._...... Philadelphia, Pa.. 508 WHAR Seaside Flouse._..._.._ _ ...... -Atlantic City. N. J. 275 WOO John ._..-Kansas City, Mo. 278 Times Louisville. ILy. 400 WDQ Unity School of Christianity_.._ WHAS Courier- Journal & Louisville - and Co._ ....._.._._.._..__. _...»...__..._._...._.._Newark, N. 7. 405 George W. Young Minneapolis, Minn. 263 WO R I. Bamberger Bacarla. Ill. 275 WHAT Dr. Wilmington. Del. 266 WD RD People's Pulpit Aga. _._.- _._..._.. ... Wilmington Electrical Specialty ('o . _ City, Mo. 441 WHAV Troy. N. Y. 379 WD S State Marketing Buren....._...._ _..»_...._...... Jefferson WHAZ Rensselaer Polyteehnic Institute.- WL Owl Battery Company ___. -..._ ..New Orleans. La. 270 WHB Sweeney School Co...... _ ...... __.______Kansas City. Mo. 366 WO Tell them, you read it in Radio Age Guide for Fans Who Want Free Radio Books Folder listing types of radio tubes, Cleartron Vacuum Tube Co., 28 West 44th St., New York, N. Y. Data on resistances, Crescent Radio Supply Co., 5 Liberty St., Jamaica, N. Y. General catalog of parts, sets, broadcasting stations, Randolph Radio Corpo- 0 ration, Dept. 224, 159 N. Union St., Chicago, Ill. Literature on consoles, tables and enclosures, Detroit Woodcraft Corp., 2262- 4 Hendrie St., Detroit, Mich. Sind General catalog and log, Economy Radio Sales Co., Dept. C, 288 6th Ave., (for New York, N. Y. Literature on audio transformers, Flint Radio Co., 1862 Wilson Ave., Chicago, Ill. Circular covering development of set, Scott Radio Laboratories, 35 South Dearborn St., Chicago, Ill. The Book To Go By -When You Go To BUY! radio products, Acorn Radio Data on The Products Co., 712 W. Madison St., Biggest and most complete radio guide book published. Compiled by experts- 96 pages crammed full of exceptional Chicago, Ill. radio values and interesting data for radio enthusiasts. Folder describing sets, W. K. Electric From first to last page, it's an illustrated review of the newest Co., Kenosha, Wis. and finest in radio. Everything included: Sets, parts, equip- Literature on resistance coupled am- ment, apparatus, cabinets of every description: 1 tube set plifier, Allen- Bradley Co., 289 Green- to the finest, multitube outfits. Your radio library is not field Ave., Milwaukee, Wis. complete until you have this book. Write for your copy Special circular No. 776 and 15 -B today -NOW. It's FREE! A postal brings it. catalog covering indicating instruments, Jewell Electrical Instrument Co., 1650 Walnut St., Chicago, Ill. An entire page in our catalog is devoted exclusively to a Literature on condensers, Heath Radio complete and detailed descrip- and Electric Co., 206 First St., Newark, tion of this famous circuit. N. J. Write for your copy now! Book describing radio courses and Radio opportunities, National Institute, ALL PARTS IN STOCK EXACTLY Dept. AU3, Washington, D. C. AS SPECIFIED Rauland Lyric Transformers Radio hookups, Radiall Co., Dept. Hammarlund Midget Condenser .0006 mfd. Straight Line frequency Con - RA -1, 50 Franklin St., New York, N. Y. Hdenmrhsnd Set Hammarlund Roberts Con Descriptive folder covering kits and Alden Sockets Alden DLux Sockets sets, Telephone Maintenance Co., Dept. Alden K-3843 1 3-4 inch Dial Amperites No. 1 -A C, 20 Pre. Union Phone tip jacks South Wells St., Chicago, Ill. Carter 25 ohm "Imp' Rheostat Carter Single cirent No. 101 "Hold. tite" Jack! Catalog of radio products, Daven Carter "Imp' Battery Switch Radio Corporation, 157 Summit St., Dubilier Type 640-G .00026 mfd Grid Condenser Duhilier Type 640 .006 mfd. Condenser Newark, N. J. Durham Resistor Booklet describing inductances, Aero Hammarlund- Roberte Foundation Unit Products Inc., 217 N. Desplaines St., Chicago, Ill. Circular describing consoles, Raulf Radio Console Mfg. Co., 562 Vedder St., We Are Chicago, Ill. Headquarters For All STANDARD Fans Like Minstrel Shows Over Radio KITS Officials at KOA recently expressed belief they had found the champion New Silver -Marshal program for radio broadcasting -Nine- Factory teenth century minstrel shows. This de- B T Counterphase RCA O R 0j luction was made following three min - DNNI NGHAM Built 3trel performances which were arranged Browning Drake TUBE by experts as a test feature. and guaran- Following Raytheon teed to conform in EVERY detail to each program, a spectacular Plate Supply Unit Mr. increase was noted, it was said, in the Cockoday's plan. Every part used in its construction is exactly as specified by the number of responses from the audience. Described and Illustrated page orginator. Our customary guarantee accom- A check of these communications pointed rradiolctalog andguide. panies this receiver. to growing popularity for negro melodies, for Write for a copy NOW.r this new LC -26 circuit ready for IM- jokes and impersonations. O MEDIATE DELIVERY. Fully described Asserting and all parts listed in the catolog.Write for jazz has defeated itself, a KITS copy today? North Dakota fan insists "the time is ripe for an early revival of minstrels." From the standpoint of studio directors, minstrel shows, it was explained, are easily suited to broadcasting because of an absence of stage settings 6 Church St. New York including effects and also, because a wide variety of musical numbers and humor- ous sketches may , 4. :; .. .. - be used. ..:::;.;'.ixv::. ?t..: :: ?},.:. .. ..:ì{:: ..,, 70 RADIO AGE for January, 1926 The Magazine of the Hour wowo Main Auto Supply Co._..______....___..._...Fort Wayne. Ind. 227 WSA R Haughty & Welcb Electrical Co.._..._._....._...._...__Fall River, Mass. 254 WPAC Donaldson Radio Co. ._..__..__.__»_.. ._..N...... _...._.....Okmulgee, Okla. 360 WSAX Zenith Radio Corp. (Portable).___.._- Chicago. Ill. 268 W PA1 Doolittle Radio Corp ._ .New Haven, Conn. 268 WSAZ Chase Electric Shop ------..---_.._. _...... _.._...-___..Pomeroy. Ohio 244 WPAK North Dakota Agricultural Cofege_..._..Agricultural College, N. Dak. 275 WSB Atlanta Journal_..._...._ _ _..._Atlanta, Ga. 428 W PA L Superior Radio & Telephone Equipment Co...... __._..Columbus Ohio 286 WSBC World Battery Co.._.__.._...... _...._...I219 S. Wabash Ave., Chicago, Ill. 210 W PCC Nortb Shore Cons. Church. ...Chicago, Ill. 258 WSBF Stix- Baer -Fuller D. G. Co.._...... _...... __ St. Louis, Mo. 273 Ii. L, Turner._.__. .___.._..__.._...._...._ ...... __...... _ __._Buffalo. N. Y. 205 W SBT South Bend Tribun e._..._ _. ..._...._...._..__._South Bend. Ind. 275 WPGQ The Municipality of Atlantic Pity ._.._____.._. .... _ Atlantic City. N. J. 300 WSOA Seventh Day Adventist Church _.__._.._.._..__..._.._New York. N. Y. 263 WPRC Wilson Printing & Radio Ca. .._____..- __.._...._-..-_- ....Harrisburg. Pa. 216 WSKC World's Star Knitting Co.._.._ ....______..._.._.__._._....Bay City, Mich. 261 Pennsylvania State College _.....__...._.__._...... _.State College, Pa. 261 WSM Nashville Life and Accident Ins. Co..____...... __. _.._Nashville. Tenn. 283 W QAA Horace A. Beale, Jr Parkersburg, Pa. 220 WSMB Saenger Amusement Co. & Maison Blancbe CO.__._New Orleans. La. 319 WQAE Moore Radio News, Station__ Springfield, Vt. 246 WSMH Shattuck Musio House_ - __Owosso, Mich. 240 WQAM Electrical Equipment Co Miami, Fla. 263 WSMK S. M. K. Radio Corp _....._.._...-.._ ....._...___....._.....Dayton. Ohio 275 WQAN Scranton Times.. ran ton, Pa. 250 WSOE School of Engineering- _...... _._._. ..____.._....__.T_..Jíilwaukee. 246 WQAO Calvary Baptist Churcà_- _._____._._._._..___ -_.New York, N. Y. 361 WSRO 252 W Q1 Calumet Rainbo Broadcasting Ca ._ .____._._.__...__.._...Chicago, Ill. 447 W STA Camp l larienfeld._..__...._ _...... _._» »__...._...... _ »_....Chesham. N. IL 229 WRAF The Radio Club (Inc.)_ ..__. _._____.._..___.__._._ LaPorte, Ind. 224 WSUI State University of Iowa .._._._.._._._ Iowa City, Iowa 484 WRAK Economy Light Co.. _Escanaba, Mich. 256 WTAB Fall River Daily Herald Publishing Ce._..___..._..Fall River. Mass. 266 WRAM Lombard College -___-.____.. .._..._....__...... _.....___ °-_.Galesburg, Ill 244 WTAC Penn Traffic Co..-.-_..--_.... _..._.__._ ...... _.__.._ »._.._-...Johnstown, Pa. 268 WRAQ SL Louis Radio Service Co. .St. Louis, Mo. 263 WTAD Root. E. ...._.Carthage. Ill 236 W RAV Antioch College._.._...._...._..___ Yellow Springs, Ohio 263 WTAG Telegram Pub. Co...... _ ..-...._.....__..._.__....--- .._Worcester. Mass. 268 WRAW Horace D. Good_.._...._ _ ._ _._.Reading, Pa. 238 W T A L Toledo Radio & Electric Co.._.._._- - _._.Toledo, Ohio 252 WRAX Fla:on's Garage....._ ...... _._.._...___._._....Gloucester City. N. J. 268 WTAM Williard Storage Battery Co.._.._ ».__..__.___.» _._._.Cleveland, Chic 389 Immanuel Lutheran Church._._...... _...._...... »..._...... Valparaiso, Ind. 278 WTAP Cambridge Radio & Electrio Co.. .Cambridge. Ill 242 WRCC Radio Corp. of America- Washington. D. C. 468 WTAQ S. H. Van Gordon & Son. - Osseo, Wis. 254 WRCO Wynne Radio Co.._._..._...._....._.._.. .__.___._..._.____ _.Raleigh. N. C. 252 W TA R Reliance Electric Co ...... __._...._....- Norfolk, Va. 261 WREC Wooten's Radio & Electric Co ....._ _..____.Coldwater. Miss. 254 W TAT Edison Electrio Illuminating Co.._._._._ Boston. Mass. 244 WREO Reo Motor Car Co. _.Lansing, Mich. 285 WTAW Agricultural & Mechanical College of Texas. College Station. Texas 270 WRHM Rosedale Hospital, Inc. Minneapolis. Minn. 252 WTAX Williams Hardware CO...... _...... ,,._ Streator, Ill 231 WRK Doron Bros.. Hamilton, Ohio 270 W TAZ Thomas J. McGuire ._...._.__...... _..._.._.._._ Lambertville. N. J. 261 WRL Union College... .Schenectady. N. Y. 270 WTG Kansas State Agricultural College___._ ._...... _.....__...Manhattan, Kans. 273 University of Illinois...... _..._...._ ._.__ Urbana. Ill. 273 WTIC Travelers Insurance Co.____..____.____.._ _ Hartford, Conn. 349 WRMU A H. Grebe & Co.. Inc., Motor Yacht "MU -I"_.._..New York, N. Y. 236 WTX H. G. Saal Co.. _..._.._._..___.-__..._..._..._ Chicago, Ill. 268 WRNY Experimenter Publishing Co .__..r.___...... _...._...New York, N. Y. 258 WWAO Wright & Wright (Inc.).- Philadelphia. Pa. 250 W RST Radiotel Mfg. Co.. Inc. _._._...... _..__..Bay Shore. N. Y. 216 WWAE Electric Park. Plainfield, Ill. 242 WRVA Lares & Brother Co., Inc _..___._.._ .Richmond. Va. 256 WWAO Michigan College of Mixes. Houghton. Mich. 263 WRW Tarrytown Radio Res. Labs. -_._....__._..._._Tarrytown, N .Y. 273 WWGL Radio Engineering Corp. _.____..._._...... _..._Richmond Hill. N. Y. 213 WSAI United States Playing Card Co.. .Cincinnati, Ohio 326 WWI Ford Motor Co.._.._...... _....__.__._.._..._...... Dearborn, Mich. 266 W SA1 Grove City College. Grove City. Pa. 229 WW1 Detroit News. Detroit. Mieb. 353 WSA N Allentown Call Publishing Co.__._..._. ...__., Allentown, Pa. 229 WWL Loyola University.- ...... _..__. _....._.__...._._.._.__....New Orleans, La. 275 Dominion of Canada CFAC Calgary Herald...... _.._.._...._....__.. .-..- ..._.._ _._ _Calgary. Alta. 434 CJCA Edmonton Jourenal..._...... __ _.___ -._..__..._..._.....Edmonton, Alta 511 CFCA Toronto Star Pub. & Prtg. Co ...... _...._...____._.- ._ - -. Toronto, Ont. 356 CJCL A. Couture __..___....__.._ Montreal. Que. 279 C FC F Marconi Wireless Teleg. Co.. ILtd.) Canada ...-____.-__Montreal. Que. 411 C1 GC London Free Press. ...._....._.__.____..._..._._._ London, Ont. 321 CFCH Abitibi Power & Paper Co., (Ltd)._..__... .._..____Iroquois Falls. Ont. 500 CKAC La. Presse...__..._..._...._...... _ » »...... M..a._... »_.__ .Montreal, Que. 411 CFCK Radio Supply Co.._....- ..__.___...__._ _...... _._....____Edmonton. Alta. 517 CKCO Vancouver Daily Province....._...._.._.._...... _ Vancouver. B. C. 397 CFCN w. W. Grant (Ltd. l._.._..._...._.._..._ ...... _.___.,.._...Calgary, Alta 434 CKCK Leader Pub. Co,_._ ...... _...... __....__ .Regina, Sask. 476 CFCR Laurentide Air Service. _..__._.___»...._._.._...___ .._...Sudbury. Ont. 410 CKCO Ottawa Radio Association.___.._._._._ .Ottawa. Ont. 434 C FCT Victoria City Temple ._ Victoria, B. C. 329 CKCX P. Burns & Co., (Ltd) Calgary. Alta, 434 CFCU The Jack Elliott (Ltd.) _Hamilton, Ont. 341 CKFC First Congregational Church Vancouver. B. C. 411 CFHC Henry Birks & Sons._.___.....__. _...__..._...... _...... Calgary. Alta. 434 CKLC Wilkinson Electrio Co., (Ltd.)._...._.._. »_ Calgary, Alta. 434 CFKC Thorold Radio Supply.. _Thorold. Ont. 248 CKNC Canadian National Carbon Co. Toronto. Ont. 357 CFQC The Electric Shoo ( Ltd.)._ .Saskatoon. Sask. 329 CKOC Wentworth Radio Supply Co._ Hamilton. Ont. 341 CFRC Queens University_____._------_ --- _ _Kingston. Ont. 450 C K Y Manitoba Tel. System___.__.. Y.._.._..»._...... _...... -.Winnipeg. Man. 384 CFXC Westminster Trust Co _Westminster. B. C. 291 CNRA Canadian National Railways.- Moncton, N. B. 312 CFYC Commercial Radio (Ltd I. Vancouver, B. C. 411 CNRC Canadian National Railways_ .-_. _...... _.._...... Calgary, Alta 434 CHBC The Calgary Albertan- ..._..---- ._____._._....-. _ ^_.Calgary. Alta. 434 CNRE Canadian National Railways ...... ___..»... ».._...... _...... _Edmonton. Alta.. 517 CHCM Riley & McCormack (Ltd).__ ___.....r._.._.._.__ Calgary. Alta 434 CNRM Canadian National Railways...._...__.._ ..- ....._____..._....Dfontreal Que. 411 CHCS The Hamilton Spectator_ ...__...__..._. ._._.__.___.._.._._.._.Hamilton. Ont. 341 CNRO Canadian National Railways-- .Ottawa. Ont. 435 CHIC Northern Electric Co.._.__..._ ____.__. __ ._.Toronto. Ont. 357 CNRR Canadian National Railways ._.__..r ...... ___...._..__ Regina, Sask. 476 CNNC Toronto Radio Research Society---.___..._____- Toronto, Ont. 357 CNRS Canadian National Railways_._.. ..._..._ Saskatoon, Sask. 329 CHUC International Bible Assn _..__...... _...... _.._.__.._.Saskatoon. Sask. 329 CNRT Canadian National Railways. Toronto, Ont. 356 Ont. 434 RV Canadian National Railways...__.._._.... _...Vancouver. B. 41 CHXC R. Booth, Jr. - __.._..-.- . -- - -_ _.___..__._.._...._._...Ottawa. CN C. CHYC Northern Electric Co....._.._.....-- .- ._ ...... ___.._.__..__..Montreal. Que. 411 CN RW Canadian National Railways. Winnipeg. Man. 384 Republic of Mexico CYB Mexico City 360 CYL Mexico City. 510 CZE Mexico City ._..____.._._._.____»___ 345 Republic of Cuba PWX Cuban Telephone 400 2KU E. Sanchez de Fuentes_._.__._....Habana 350 6DW Eduardo Terry .... _.._.._.._.....,....Cienflegos 225 2BY Frederick W. Baton.....- °.__ Habana 260 2LC Luis Casas Habana 250 6K1 Frank H. Jones ._._...._..__.._..__.._.Tuinucu 275 2CX Frederick W. Borten._ Habana 320 2M G Manuel G. Salas .....__.__._._..___.. habana 280 6KW Frank H. Jones ....__.._...._..._.._.Tuinucu 338 20W Pedro Zayas _.._._._.....__._._ Habana 300 2M N Fausto Simon._..Y.._._.._.___.Habana 270 8BY Alberto Ravelo Stgo. de Cuba 250 Westinghouse Elec. Co...._ ...... __Habana 20L Oscar Collado _..._._._..._...__.._.1labana 290 80W Pedro C. Anduz Stgo. de Cuba 275 2HC Heraldo de Cuba._._..___..._.....__»Habana 275 Roberto E. Ramires _.Fa liana 230 8FU Andres Vinnet Stgo. de Cuba Julio Power... _-_.____Habana 180 2WW Amadeo Saenz._..__.._....._.- _.._.._.._.Habana 210 12AB Alberto S. de Bustamante .Habana 225 210 Raul Parez Falcon_._.._.._._._.._.Hahaaa 105 Leopoldo E. Figueroa.. colon 360 I6AZ Valentin Ullivarri ._.._...._...... _.._.Cienfiegos 200 2K Airara Dave- _Habana 200 68 Jose Ganduxe _._.._...... tienfegos 300 20K Mario Garcia Velez _.._...... __.._.habana 360 6CX Antonio T. Figueroa .._._...__.._.('ienlegos 170 Great Britain -....._ 365 63M Bournemouth .... _- __._...__- ...._..._...... -- ._.385 5SC Glasgow 420 2L0 London _....__._...__ _...____...__._... 2B0 Aberdeen 492 51T Birmingham . »..._.__...____.._._ 475 2ZY Manchester .._..._...._ __._._..._.__.__._.._._..._.375 5WA Carded ..._ »_ ._...____._ ._...._ 350 5N0 Newcastle _.400 6SL Sheffield (relay station)_. _303 France

. 8AJ Paris . 1.870 YN Lyons .. __..740 es n FL Paris (Eitlle P___

the Model Sets are list might also be used. Further if the easily see how the various parts may be Why experimenter desired to wind his -own utilized. At the same time readers may Being Built inductances he would be able to do so witness the process of simplified set - For some time past Radio Age has been and make use of them in the same hook- building described in a step -by -step deluged with correspondence from readers up. For example, honeycomb coils may manner, all of which makes very interest- asking why we do not show a number of be used for inductances in either the ing reading for those who have a genuine sets made up of commercially manu- December or January models; in fact any interest in the art. factured and easily secured material, the kind of inductance may be used by the idea being that perhaps a number of fans builder. Our technical staff on account have on hand radio parts of good quality of the greater convenience and the fact BECOME AMMO EXPERT Our . am, ..m var practical which they might utilize in a standard 17 TKS CIO npn..Ingnaa. . a ., commercial apparatus is generally more .Va Ton devote rpar.hn..ra of T3 YXD01YY m.gl°glkl. of «iep p W é circuit without having to buy all parts a.. Yoe to get tale accurate than the home made, grouped e eñ: :aá á floor."' atXOME furnl.hMnroañ Ino.lncud ei t»T.In niñ . the same general type. Our le r ter learn . mR maeo together a number of representative from Iba run. LEA6Ñ íÌÌÌa COV9ga IaEt The Radio Age model series was begun Our o.u.u.l pln .I,o..;op he. you n pe lho rnurm free. wen good prod{. d.. Whether knew rn410 not.... e ah Ie,. units and made them into a receiver. tallo. If n «d hl: W imÉy our easy. anal*. iIW«r.wf in December with a list of parts easily 1a,abg ad at aedlplom. Or Indio .ngln r Tho,l.nda of poMt.op will u lab Ib g ` pon . you. tl.r 4 eh á.i4 teal m The sane policy will be adhered to in the f s.p É Oat our beat. -Million. Dnlou.hoi" `Ìe I. IM1w. secured from any good radio dealer. Any learn ISO parts of equal merit to those shown in the future so the interested experimenter may AiËEÌCÁt daÁD10 iN0[NEEEd. De t 5Be aduni. rfNwgo.aÚJ~ Tell them you read it in Radio Age RADIO AGE for January, 1926 The Magazine of the Hour 71 CLASSIFIED ADVERTISEMENTS If you hpve anything to buy or sell, don't overlook the value of RADIO AGE'S classified advertisements. Many such messages have paved the way to independent incomes. The classified advertising rates are but ten cents per word for a single insertion. Liberal discounts are allowed on three, six and twelve -time insertions, of five, fifteen and thirty per cent respectively. Unless placed through an accredited advertising agency, cash should accompany all orders. Name and address must be included at foregoing rates and no advertisement of less than ten words will be accepted. All classified ads for the February issue must be sent in by January 1.

ADVERTISING SERVICE DOGS RADIO CIRCUITS

QUEX Sales Lettere Get More Business. Write him BEAUTIFUL REGISTERED BULL PUPS $15. Bulldogs, SPECIAL FOR JANUARY Ave., 501 Rockwood, today. Quez, 4418 Michigan Chicago. Dallas, Texas. The Reinert. Radio Booklet, by Frank D. Pearne, fully illustrated, and RADIO AGE, for $2.50. Price of Book- let alone is 50e. Send check, currency or money order to RADIO AGE. 500 N. Dearborn Street, Chicago. AGENTS WANTED HELP WANTED FORDS. 60 miles on one gallon of Gas. It has been RADIO DEALERS proven such mileage can be made. AIRLOCK guar- RADIO SALESMEN and SET BUILDERS -We need DEALERS -Write for our illustrated catalog of reliable antees to increase gas mileage; also prevents radiator you and you need us. If you are reliable and well Radio Merchandise. Rossiter- Manning Corporation, boiling in summer or freezing in winter. Cools, Fuels, known in your community, we will appoint you our Dept. D, 1830 Wilson Ave., Chicago, Ill. Decarbonizes the Ford motor. Splendid territory re resentative and furnish you with standard well open. AIRLOCK PRODUCTS, Box 703G, Willow Street, advertised seta and parts at prices that will enable you Long Beach, Calif. to sell at a handsome profit. Write at once for cata- RADIO SUPPLIES log and sales plan. Waveland Radio Co., Div. 53, 1027 HAVE YOU SEEN THE NEW N. State St., Chicago, DIALITE, THE UNIQUE RADIO -Join our sales organization and make big Ill. lamp that lights up your panel and adds a decorative money. We want a man in every county to sell well touch to any radio set? Retails at $2.75, complete. advertised sets and parts made by the leading manu- MEN wanting forest ranger, railway clerk and other Send for folder and dealer's proposition on this fast facturers. Widener of Kansas City makes $150.00 government positions, write for free particulars of moving article. Also. we are distributors for the famous weekly. You can do as well or better. Write today exams. Mokane, Dept. B-33. Denver, Colo. Knurled Walnut Cabinets, the most beautiful cabi- for catalog, and discounts. Name your county. Wave- nets made. American- Universal Radio Co., 6255 land Radio Company. Div. 52, 1027 No. State St., Chi- Broadway, Chicago, III.. Box 11. cago, Ill. MEN WISHING TO ENTER DINING, SLEEPING CAR SERVICE AS CONDUCTORS, PORTERS, WAITERS, SALESMEN MANUFACTURER'S AGENT calling on Radio-Elec- WRITE 123 RAILWAY EXCHANGE, KANSAS CITY. WANTED trical Jobbers, Chicago and vicinity, has opening for 3 additional line. carrying volume business, as we cater Make $100 WEEKLY in spare time. Sell what the to large jobbers. Edelstein, 1804 McCormick Bid., public wants-long distance radio receiving sets. Two Chicago. sales weekly pays $100 profit. No big investment. INVENTIONS no canvassing. Sharpe of Colorado made $955 in one month. Representatives wanted at once. This plan Man wanted for this territory to sell wonderful NEW IDEAS WANTED -Well known Radio Manufac- sweeping the country -write today before your value men's, women's, Children's shoes direct, sav- turer whose products are nationally advertised and sold county is gone. ULARKA, IL' C., 126 F Austin Ave.,. ing consumer over 40 %. Experience unnecessary. everywhere wants new Radio device to sell. Will pay Chicago. Samples supplied. Big weekly perm income. outright or royalty for idea or invention which is really Write today Tanners Mfg. Co., 1334C. St.. Boston, Mass. and saleable. Address, Mr. R. F. Devine, Room 66 MILES ON 1 GALLON -SCIENTIFIC GAS SAVER. 1101, 116 West 32nd St., New York, N. Y. All autos. 1 free to introduce. Critchlow, A -90, Whea- ton, Illinois. RADIO SALESMEN and SET BUILDERS in every county write Grenzer Radio. 1479 Hodiamont, St. Louis. Mo. MANUFACTURERS OF NEW AND IMPROVED STA- PATENTS tion finder and vernier tuning -dial want live salesmen to call on radio trade. Excellent side-line: good commission. exclusive territories. Westerland Corpora- FOR SALE: U. S. and Canadian Patent on an Attach- tion, Dobbs Ferry, New York. AGENTS ment for Phonographs; is the most beautiful invention of the age. Address Chas. F. Smith, Huff, N. Dak. AGENTS: 100% PROFIT; WONDERFUL LITTLE article. Something new; sells like wildfire. Carry in STAMPS pocket. Write at once for free sample offer. ALBERT STAMPS, 50 varieties, Africa, MILLS, Manager, 5794 American Bldg., Cincinnati, Brazil, Peru, Cuba. Thin. RADIO Mexico, etc., 10e. e 50 different U. S., 25c; 1,000 mixed, 40.; 1,000 hinges, 10c. List free. C. Stegman, 5950 Cote Brilliant., St. Louis, Missouri. Sixty cents monthly subscribes four Radio magazines "B" BATTERIES List Free. Spencer -Shields Agencies, West Los Angeles California. WANTED 100 VOLT EDISON TYPE "B" BATTERY knocked WANTED -To complete my set RADIO AGE need down. Parts and plan- complete, $12.50. Lana Mfg. A PRACTICAL TUBE RECEIVING SET FOR 2937 W. Lake, Chicago. $10, August, September, October, November, 1923, Issuer, Postpaid, less phones and tube. Complete with bound or unbound. Advise price. Lloyd C. Henning, phones, tube and battery, $18.00. J. B. RATHBUN, Hollbrook. Arizona. 1067 Winona St., Chicago, III. BATTERIES FOR SALE -Four 24 -volt "Main" Storage "B" Batteries, never used, shipped and ready to wire WIRELESS for $38.00. First order gets the batteries. Address Standard solderless radio Jacks. Binding post attach- Box B, Radio Age, 500 N. Dearborn St., Chicago, Ill. ments. Double circuit. One dollar bill. Postpaid. WANT TO MEMORIZE THE WIRELESS CODE? The Clinton Seward. Jr., New Peitz, New York, N. Y. Corydon Snyder Code Method, Patented, is quickest. Send 50c coin, stamp or M. O. to C. G. Snyder, 1423. Elmdale Ave.. Chicago, Ill. BUSINESS OPPORTUNITIES Three Cosmopolitan Phusiformers, each $5.50, book of Instructions included. F. A. Mall, Triopli, Iowa. TELEGRAPHY -Morse and Wireless-taught at home: $100 weekly up. We want experienced Radio men to in half usual time and at trifling cost. Omnigraph operate branch assembling plants. Part or whole Automatic Transmitter will send, on Sounder or Buz- time. Barfield Radio Co., 13 Tillery Street, Dept. A R, 15 to 25 per cent discount on nationally advertised sets , unlimited messages any speed, just as expert Brooklyn, New York. and parts. Every item guaranteed. Tell u your needs. operator would. Adopted by U. S. Govt. and used by IMPERIAL RADIO COMPANY, Delaware, Ohio. leading Universities, Colleges. Technical and Telegraph Schools throughout U. S. Catalog free. Omnigraph Mfg. Co., 13 F Hudson St., New York. CRYSTALS RADIO SETS. Our prices save you money. Lists free. The Radio Shoppe, Box 645, East Liverpool, Ohio. Supersensitive Galena Crystals: Pound 75c prepaid. ALKEMITE. All sensitive Crystals 50c. Burkett, PERSONAL Geologist, Joplin, Missouri. AT LAST I The Radco Static Eliminator. Eliminates 50 to 90% Static. Many satisfied users. Write for LONELY HEARTS: Exchange letters; make Interesting particulars. Radio Specialties Company, Sioux Falls, new friends in our jolly club. Eva Moore, Box 908, South Dakota. Jacksonville, Florida. Enclose stamp. Classified ad. copy for the Febru- $1.00 For Your Old Tubes Look! You Radio Rugs! Join Radio Correspondence. ary RADIO AGE must regardless of make or condition towards the purchase Club. Entirely new. Broaden your acquaintance, be sent in of each new Standard $2.50 tube. Positively guaranteed. exchange ideas. Membership open to LADY BUGS - We do not sell rebuilt or bootleg tubes. Order today. also. Dime stamp brings pamphlet and Radio Novelty by January 1, 1925. Luzern & Davis Mfg. Co., 6229 Broadway, Chicago, Ill. Cards. Radio Rose, Box 662, Cleveland, Ohio.

Radio Age Classified Ads Bring Results

Tell them you read it in Radio Age 72 RADIO AGE for January, 1926 The Maazine of the Hour Radio Dianas Pat. April rí,1925 Other U.S. and Foreign Patents Pending

HE ACCURATUNE is ideal for coarse or extremely fine tuning, segre- gating even those stations . now so closely grouped on the lower wave lengths; it A Six Tube brings them in with ab- IN CONSOLE solute precision. Volume and clarity are matters of course to the Accuratune. Mayor William E. Dever of Chicago officially (With Loud Speaker) Quickly with- welcomed Miss Rena Jane Frew of Beaver, Pa., substituted America's Radio Diana, (left) and Flossie E. out alteration of your set. Erickson of Bloomington, Ill., Miss Radio of the Middle West, to the fourth annual Chicago Radio DIANA "SIX" Show, Nov. 17 to 22. The Mayor also spoke at MYDAR RADIO CO. the formal opening of the show. A perfect in a 17 CAMPBELL ST., NEWARK, N. J. set beautiful cabinet. A real six tube set. Two models. CabinetGrand $100 list. CCURATUNE Elect Officers for National Console as shown above with aaa,.rraca ea ART Orr Radio Trade Association loud speaker, $125 list. A long Henry M. Shaw, president of the Shaw distance set. Easy to tune. Insulator Company of Newark, N. J., and prominent radio figure was re- elected Exclusive Territory Open head of the National Radio Trade Asso- Write for Liberal Discount and splendid ciation for the coming year, according to Sales Proposition. Booklet R -A upon announcement by George Lewis, teller request. at the recent election. Battery Prices Other officers elected were: C. B. DIANA RADIO COMPANY SMASHED! Cooper, New York, treasurer; L. A. 1429 So. Michigan Ave., Chicago To Consumers Only Nixon, secretary; and Walter A. Schilling, Here is a real battery quality. members of the board of directors at guaranteed to you at . prices tbatwil I astound the entire hat - large. Eight vice presidents were elected tery bnying public. Order Di- rect From Factory. Put the as heads of various committees directing Dealer's Profit in your own pock- the activities of the organization, includ- et. You actually save much more than half, and so that you can he ing Powel Crosley, Jr., H. B. Richmond, convinced of true quality and performance wegivea Written 2-Year Guaran- Geo. C. Furness, Frank Reichman, tee. Here is your protection! No need to take a chance. Our battery is right -and Lawrence Mott, D. MacGregor, R. W. the price is lowest ever made. Convince To the Man with an Idea yourself. Read the prices! DeMott, and Burt B. Barsook. Auto Batteries Radio Batteries Directors elected to represent specific I offer a comprehensive, experienced efficient service for his P ia e.1 1 5O 6Voit1Amp.115,26rs.Volt13 0 sections of the were as follows: 12Volt.6, 7Plate.13.00 6Volt.i40 Amp.13.00 country prompt, legal protection and the Buy Direct -Send No Money Paul B. Lamius, Denver; Arthur Hallo- development of his proposition. We ask no deposit. Simply eend name and ad- Send sketch of model and de- dress and style wanted. Battery will be shipped ran, San Francisco; C. J. Zamoiski, scription, for advice as to cost, same day we receive our order Express C.U.D subject to your examination Baltimore; J. L. Willinbrink, Louisville; search through prior United States on arrival; Our guarantee patents, etc. Preliminary advice accompanies C. P. Belden, Chicago; Royal Stemm, Vt xoun gladly furnished without charge. for cash in full with or- My experience and familiarity der. You cannot loeel Chicago; Chas. G. Taylor, Newport, order today with various arts frequently en- Ñd 9 ur Vt.; A. Ullman, Boston; Alex Eiseman, able me to accurately advise clients ARROW BATTERY CO. Brooklyn; O. B. Carson, New York; as to probable patentability before Dept.12 . 1215 5o. they go to any expense. Wabash Ave..Chicate M. W. Kunkel, Pittsburgh; A. R. Wild - auer, Detroit; Herman Rose, Newark Booklet of valuable information and form for properly disclosing your and F. M. Rosenfeld, Newark, N. J. idea free on request. Write today. These officers will serve until after the fifth annual convention of the association RICHARD B. OWEN, Patent Lawyer 81 Owen Bldg., Washington, D. C. to be held in May at Atlantic City, their 2278 -M Woolworth Bldg., N. Y. City BAK ELITE PANELS successors being elected shortly after the convention and taking office in the sum- used by 95% of all set manufact- mer of 1926. The membership of this urers. Write for Booklet 31. organization, according to announcement, BAKELITE CORPORATION makes it the largest in the Radio industry, *Asterisks* denotdestmanufactuierrs have 247 Park Avenue, New York, N. Y. taking in every branch of the trade and submitted samples of their products to Radio Age Chicago Office: 636 West 22d Street Institute and these products have passed the In- art. stitute tests. Tell them you read it in Radio Age Associate THE unusual simplicity in design of the Hammarlund- Manufacturers Roberts is one of the many stirring features that have All-American Radio Corp. made this receiver the talk of the country. Alden Mfg. Co. Radials Company (:\mperites) The creative genius that conceived the idea of this masterly five - Carter Radio Co. idea to Union Radio Corp. tube receiver, and the engineering skill that brought the International Resist- reality, kept always in mind the limited mechanical ability of the ance Co.. Inc. (Durham Resistors) inexperienced builder. The result is a plan of assembly so com- Westinghouse Micarta Hammarlund Mfg. Co., plete, so detailed, that anyone, following the step -by -step direc- Inc. Send For tions in the instruction book may construct the Hammarlund- This Book Roberts in the course of an evening. Contains step -by -step instructions on the as- And, to the proud owner, his completed work becomes at once the sembly, wiring and operation of the Ham - measure of efficient receiver design. At a fraction of the cost of a marlund- Roberts. Ful- -made receiver of nearly efficiency, he has an "engineer- I y Ilustrated; most ready equal complete "How to Build ed" radio set scientifically perfect mechanism in which every It" radio book ever -a published. part synchronizes with the others. 25c The masterpiece of ten leading engineers -equal in performance to a standard eight -tube set -backed by the best known parts manufacturers in the radio field -this is the Hammarlund- Roberts. To- day it is the one radio receiver desired above all others. Parts Complete, less Cabinet, $62.30

HAMMARLUND- ROBERTS, 1182 -D Broadway, New York City

A -taLQ ami Dials, Sockets AVt,- {1MER /CqA, TRANSFORMER Thisfamous instrument and other parts shown are some of t he qual- `4 DURHAM ( llr4es' ity units used in the /IiMPEfMTE .3, Switches and Hammarlund- Roberts. UNION ammarlund Rheostats

* Tested and Approved by RADIO AGE Ten Tubes! in De Luxe Art Model Cabinets from $500 to $2,000. Zenith Super -Zeniths Super. DeLuxe priced from English $240 to $355 Model Other Zenith Sets $100 and $175 Zenith Super- DeLuxe Colonial Model

Ten Tubes with but a Single Dial! If you would really know the wonder of Super -Zenith fine radio reception- listen to the ten - Model VIII Same as V I l except - tube Zenith Super -DeLuxe! built with mahogany legs of well propor- Imagine a tone, for example, so tioned, appropriate clear and mellow design, converting that each instrument in a big orchestra can be model into console readily identified. type. Imagine a control so perfectly synchronized that the turning of a single dial gives you a complete procession of programs, each coming in the instant the dial touches its proper mark, each vanishing less than two points beyond. To make the statement that one has discovered "the best in radio" without having listened to the ten -tube Zenith Super - DeLuxe is like calling a violinist the greatest in the world without ever having listened to Kreisler. Super -Zenith VII Six tubes-2 stages tuned frequency am- See Zenith in your own home to the in- plification- detector and 3 stages audio -listen frequency amplification. Installed in a strument which MacMillan chose exclusively for beautifully finished cabinet of solid ma- all hogany -44ió inches long, 16. inches his Arctic Expeditions. Then -hear the other wide. 10.'4 inches high. Compartments sets you like. We will abide by your decision. at either end for dry batteries. Your nearest Zenith dealer will be glad to demonstrate a Zenith Super -DeLuxe, any night you say. Write for his name, together with complete de- Why did Commander MacMillan scriptive literature. take Zenith to the Arctic? Because -on his previous expedition, ZENITH RADIO CORPORATION Zenith kept him in touch with civil- Straus Bldg., 310 S. Michigan Ave., Chicago, Ill. ization. Naturally he again chose it because of first hand knowledge of iu absolute dependability.

* Tested and Approvea oy IGAU1U A(j