WA Jun 1924 .Pdf

25 CENTS

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5eatures in this Issue Newest Development The 'D -Coil 'Receiver wwwwiwww.w.w.www.w.w.www12'2w. w111111. By its designer, K. M. Macllvain The Cruise of the "eAra" W. K. Vanderbilt's Yacht 'Radio for 'Boatmen Motorists ô Hikers Construction of a Portable 'Receiver dummer Radio Described by M. B. Sleeper 1

www.americanradiohistory.com The Standard Tube for all makes of Radio Receiving Sets is the Vacuum Tube that has made possible the IT is and far -reaching application of radio telephony. and that plays the most important part in the operation of your receiving set. Radio messages from government' leaders -from the heads of the world's greatest educational insti- tutions or from those who stand foremost in the arts of the world will serve to bring the human race into closer contact. Cunningham Vacuum Tubes, standard for all makes of receiving sets-built by one of the world's largest manufacturers with unlimited resources - are the product of years of manufacturing experience and the creative genius of the engineers of that great scientific organization, the Research Labora- tory of the General Electric Company.

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The care and operation of each model of Receiving PRICES ON PATENT Tube is fully explained in our new 40-page "Radio NOTICE Tube Data Book." Copies my be obtained by CUNNINGHAM sending ten cents to our Sat Francisco othee. RADIO TUBES Cunninnhao n tu bes are covered by pat - Now in Effect ruts dated 2- 18 -08. (:- 301A -5 Volts 1 -4 Ampere a n d others isnted Iilament..03.00 1'-219 -3 Volts .00 amp. and pending. Li- Dry Battery Det. & censed for amateur, Amp. $1.00 experimental and en- C-300-3 Volts Cas Con- tent Detector $1.00 tertairunent tt se in C-11-1.I Volts. _lamp. radio communication.nication. Dq Battery Det. and Amp. ',SC veil! Home Office: Special Base. $5.00 Any other ('- 12- $Dollar to C -11 be an infringement. 182 Second Street 154 W. Lake Street 30 Church Street with standard base SAN FRANCISCO CHICAGO NEW YORK el 00

www.americanradiohistory.com NU.192-1 THE WIRELESS AGE 1

The Phones with the New Idea

N& K Head Sets mark a new era in radio repro - duction -an era of clearness and naturalness. Designed especially for the reception of musical tones, they record the entire range of the human voice and of musical instruments with extreme clearness and freedom from distortion. This is due to mechanical design different from that of any head set produced in America. And to an extremely careful quality of workmanship almost impossible to obtain in this country. Sold on a comparison basis NOK If, when you use N & K Phones on your own radio set, you do not find that they reproduce all the tones more clearly and naturally than any set you ever used before, and if they do not fit more comfortably, the store where you bought them will refund your Imported money, promptly and cheerfully. We protect dealers and replace any returned phones. N & K Head Set, Model D, 4000 ohms, has extra PHONES large diaphragms and ear caps, insuring better reproduction, better comfort and the exclusion of outside noises. Sanitary, leather -covered head hands. Six feet of stout cord. Retail price $8.50. DEALERS: N & K Phones provide Write for "The Phones the Fans Are Talking the high spot in the radio stocks of About," interesting new descriptive folder. dealers all over America. Racked by TH. GOLDSCHMIDT CORPORATION advertising and strong sales coopera- tion, they are proving attractive profit - Dept. W 6, 15 William St., NEW YORK in with Exclusive Distributors for United States, Canada and Mexico makers. Packed cartons of ten, display material and literature.

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www.americanradiohistory.com O 4 trete LJmencas 9dremos I Radiophone 4view - I' oI. ,XI -o. 9

1 June, 1924-Contents Tour eluthors

Editcrial Chat 14 A Radio Reverie of Summer - 17 U7 ALT. S. THOMPSON, JR. (Tele- phone Conversation by Radio) made Pictorial Section - - - - - 18, 19, 27, 32 his first radio set as a boy in 1914, and has studied and experimented with radio The Cruise of the "Ara," By William A. Hurd 20 ever since. During the war he was con- 24 nected with radio in the U. S. Naval Air Radio for Boatman, Motorist or Hiker, By W. F. Crosby Servize. Since leaving the service he has Radio on Mount Hall 28 been pursuing studies in electrical engi- Marcy, By E. Shepherd neering and doing advanced graduate Telephone Conversation by Radio, By Walt. S. Thompson, Jr. 33 work on radio communication at Lehigh University. He informs us that his prin- Selecting Loud Speakers, By Dr. Alfred N. Goldsmith 33 cipal hobby is fishing - not DX fishing either. but the old -fashioned piscatorial The D-Coil Receiver, By K. M. Macllvain 34 sort. Increasing the Range of the Super -Heterodyne, By William J. Smith 37 are pleased to note that Hall E. WEShepherd (Radio on Mount Marcy) The Boy Scouts of America, By Pierre Boucheron 38 who has been completing some research Wildemess,'By work at Yale University, has just been Radio in the Canadian Sinclair Arthur 40 admi-,ted to the practice of law. We wish The Right and Wrong of Receiver Tuning 42 for him the attainment of fresh mountain peaks in his chosen profession. Peeps Into Broadcasting Studios, By W. A. H. 44 CROSBY (Radio for Boatman, World Wide Wireless 48 WF.Motorist or Hiker) has been a radio amateur since 1407. He was in the Best Bets in Humor 52 marine business for twelve years, design- ing, testing and building motor-boats and Afloat and Ashore with the Operator, By William S. Fitzpatrick 53 yachts. He is now interested in the full A Set for expío Cation of radio in motor- boating. Radio the Summer, By M. B. Sleeper 54 Mr. Crosby was responsible for the be- 10,000 Boys Wanted ginning of the first New York radio 57 supplement-that of the Globe. He also Chasing Squeals, By R. A. Bradley 58 started the Amateur Modulator which he conducted for two years. Amplifiers, By Louis Frank - - - 6o le." M. Macllvain (D -Coil Receiver) Condensers, By Donald Gordon Ward 6z graduated from Tufts College. He then served in the Navy as an operator, Radio Frequency Circuits, By Henry Baron 64 stationed at London, England. Follow- ing the war, he entered the service of the Radio Engineering, By John R. Meagher 65 Radio Corporation of America in the Selected Radio Hook -Ups for the Home Builder bb traffic and engineering departments. He was transferred to Belmar. N. J., for en- Information Desk 68 gineering on marine transmission and reception. There he assisted in the Broadcasting Station Directory - 69 design and construction of marine trans- mitte -snow used in Marion, Mass., for High Lights in Radio Development 71 transmission to ships at sea. He is now engaged in the development work of New Appliances and Devices - - - - 72 Trans- Oceanic reception for the Radio Stations Worked and Heard Corporation. Mr. Macllvain reports 92 three children, all interested in radio. Amateur Radio Stations of the United States 95

PUBLISHED MONTHLY AT WIRELESS PRESS, INC., 326 BROADWAY, NEW YORK LOS ANGELES, CALIF.. 456 So. Spring St. CHICAGO. ILL.. 410 N. Michigan Ave. GREAT BRITAIN AUSTRALIA Coast Puhliehero l'o. Wheeler & Northrup 12 -13 Henrietta St., London 97 Clarence St.. Sydney C S W. Yearly subscription in U. S. A., $22.50- Outside U. S. A., $3.00; Single Copies. 25 cents. Entered as second class matter Oct. 9, 1913. Post Office. New York. N. Y., under the Art of March T. 1879. Copyright, 1924, Wireless Press. Inc. When subscription expires you will find a renewal blank enclosed. Return with remittance promptly.

James G. Ilarbord, l'res L. MacConnach, Sect. George S. DeSousa, Treas. H. L. Welker, Adv. Mgr. H. H. Reber, Bus. Mgr. Major Jerome W. Howe, Editor C. S. Anderson, Associate Editor

Because certai, statene its and expressions of opinion from correspondents and others appearing in these columns from time to time may be found to be the subject of controversy in scienr tic circles and in the courts. either now or in the future and to sometimes involve questions nr of invention and the comparative cf apparatus priority merits em toyed in wireless signaling, the ownersi and publishers of this magazine positively and emphatically disclaim any prlvitY or responsibility for any statements nfpinion or partisan expressions if such should at any time appear herein. Printed In U. S. A. THE WIRELESS AGE Is a member of the Audit Bureau of Circulations,

www.americanradiohistory.com In radio the Neutrodyne is the ultimate for selectivity and clear, true reproduction, as well as for power and ease of operation. THOMPSON NEUTRODYNE means the best radio principle plus the engineering skill of an organization that has been building radio and wireless apparatus for over fourteen years.

The THOMPSON is a factory- built -not an assembled -5 -tube Neutrodyne. What this means to you can be demonstrated by any good dealer. Price $150 without tubes or batteries. THOMPSON MAGNAPHONE is built upon an entirely new principle that gives purity of tone in any volume -yet no battery current is needed. The THOMPSON MAGNAPHONE is $35 ar all good dealers. R. E. THOMPSON MANUFACTURING CO. Manufacturers of Wireless Apparatus for the U.S. Army and Navy and numerous foreign governments l50 NASSAU STREET NEW YORK, N.Y. FACTORY- JERSEY CITY, N. J.

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www.americanradiohistory.com 4 THE WIRELESS AGE JUNE, 1924 ;,. Federal has done the experimenting for you Tite now famous Nn. 65 Audio Frequency is no Transformer is but THERE speculation about buying one of over 130 radio Federal Standard Radio Parts. You parts designed, manufactured and guaran- know beforehand just how complete, just teed by Federal. how mechanically perfect your set will be $7.00 according to the number of Federal parts 1;1 that are included. Federal has done all the experimenting for you -not hurriedly or superficially, but over a period of 25 years of intensive research. This, together with Federal's tremendous engineering facilities, makes it possible for Federal to protect you with feÙerxï an iron -clad guarantee on every Federal IIADIOPrcducts Standard Radio Part that you buy.

FEDERAL TELEPHONE & TELEGRAPH CO. Yeti eral. FACTORY: Buffalo, N. Y. RADIO P"d"' Boston New York Philadelphia Chicago San Francisco Pittsburgh Bridgeburg, Canada London, England The sign of Reliable Radio Dealers CONTINENTAL "NewYorks Leaaing-Raaio House"

TIE SYMBOL OF SERVICE Standards of Quality Receivers of real sales building merits are those which are nationally advertised and known to be "Standards of Quality." Your customers are buying "quality" not quantity. There is no better medium for an inexpensive portable radio receiver than the Crosley Model 51 or Radiola III. With either one of these two receivers the reception is exceptionally clear and loud enough to operate a loud speaker. They are selective and simple in operation. Continental Radio and Electric Corporation offer CROSLEY Model 51 you a- "Service for the Dealer." We can make immediate deliveries on these receivers. Send us your orders NOW! RADIOLA III 2076 -Q CONTINENTAL RADIO & ELECTRIC CORPN. 15 Warren Street New York, U. S. A.

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www.americanradiohistory.com TUNE,1924 THE WIRELESS AGE 5

:.I IIIIIIIIIINIIIII1111111IlllllilillüllllllaiiirlillllPJfJllllilllillllllllliilif Understand Radio E. An Introduction to Radio

For the Whole Family In Two Volumes -Handy Pocket Size FREE TO YOU

We want you to know "THE WIRELESS AGE" (America's oldest radio magazine) and 2 Volumes our laboratory tested text books. TO GET 3%x5 Inches Flexible ACQUAINTED we offer you this fine little Leather Cover set of books ABSOLUTELY FREE with one E Fully Illustrated 96 Pages In year's subscription to "THE WIRELESS Each Book rrlr,r_Lr_s'; rr.r_; :,... AGE." $2.50 A YEAR (Outside U. S., 50c l r- Y r. w (, r, l\ Price 2 Volumes ' 1_7 r extra). SAVE A DOLLAR. $1.00

ANSWERS YOUR QUESTIONS -Every novice in radio always asks the same questions: What is a radio wave? What's In Them? How is it made? How long does it take to get to me from the broadcasting station? Is there any difference VOLUME i between the dot and dash waves and the music waves? An Introduction to Radio What is a condenser for? What is a variometer? What Radio Telephony is the difference between a variocoupler and a loose The Various Instruments Used in Radio Trans- coupler? How are the ear phones made? What does the mitting and Receiving Outfits crystal detector do? How does a vacuum tube work? What is the grid leak for? Is there any danger that my VOLUME 2 antenna will be struck by lightning? How can I tune my Technical Terms Explained set to get the loudest signals? What is the difference How to Set up Receiving Outfits between radio frequency and audio frequency? What is a Primer of the Vacuum Tube potentiometer for and how does it differ from a rheostat? How to Set up Radio Transmitters And scores of other questions. All are answered in this International Morse Code and Conventional book. Signals Make no mistake. This is a non -technical book. All who can read English can understand it. Funny how hard it is for an expert to talk shop so everyone can understand -there are a number of good technical books, but this is the best book we have ever seen of the hardest 5 kind to do well. ORDER BLANK An introduction to Radio. That is just what it is. Mr. WIRELESS PRESS, INC., Date (Miss or Mrs.) Reader, we take great pleasure in intro- 326 Broadway, New York. . ducing Radio. After a few hours you can meet the other members of the family and talk radio with them as you can't now. I enclose $ Enter my subscription to "The Wireless Age" for one year and send me If you were sailing for France you would study an ele- free a set of "An Radio." I mentary text book on the French language -here is your Introduction to also book for your trip to radio land, the most fascinating want extra sets for some of my friends. country ever discovered by modern science. Explore it knowingly, as thousands are now doing, with a receiving Name set and "An Introduction to Radio." Street

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www.americanradiohistory.com 6 THE WIRELESS AGE JtNE,1924 Big Savings on Laboratory Tested Radio Books Pick out the books you want and Buy at these Rock Bottom Prices

Here is the greatest list of radio books ever pre- the weight per square foot. This gives you the sented. In this list are books that are known and chance to buy these books at a tremendous saving. used the world over. Take advantage of this opportunity to complete Our stock room is overcrowded-we must reduce your radio library.

Regular Class Regular Class BOOK AUTHOR Price No. BOOK AUTHOR Price No, Alternating Practical Wireless Telegraphy... E. E. Bucher $2.25 35 Current Work Shore $2.00 25 Magnetism for Home Study Penrose 2.25 30 Vacuum Tubes E. E. Bucher 2.25 35 Radio Directory and Call Book 1.00 12 Wireless Experimenter's Manual E. E. Bucher 2.25 35 1923 Year Book of Wireless Tel. How to Pass U. S. Government & Tel. (Paper) 3.00 20 Wireless Exams. E. E. Bucher .75 10 Lessons in Wireless Telegraphy Morgan .35 3 How to Conduct a Radio Club E. E. Bucher .75 10 Operation of Wireless Telegraph Apparatus Alexanderson System E. E. Bucher 125 18 Cole .35 3 Home Made Electrical Apparatus Practical Amateur Stations J A. White .75 10 Vol. 1 Powell .35 3 Acquiring the Code Gordon .50 6 Home Made Electrical Apparatus Vol. 2 Powell .35 3 Practical Aviation J A. White 2.25 30 Home Made Electrical Apparatus Prepared Radio Measurements .Batcher 2.00 30 Vol. 3 Powell .35 3

Modern Radio Operation J O. Smith 1.75 26 Home Made Toy Motors Morgan .35 3 Radio Inst. and Measurements Bureau of Standards 1.75 26 HOW TO ORDER The Oscillation Valve ...Bangay 2.75 40 Select the books you want. Add their class numbers by five that's the price The Elementary Principles of Wireless -Part 1 together -multiply -- you pay. Bangay 1.75 25 saving is evident at a glance. This is a real opportunity.

Standard Tables and Equations Hoyle 3.25 50 Include a year' subscription with your order, Wireless Telegraphy and Telephony. Dowsett 3.50 55 AND GET ANOTHER BARGAIN Fleming 5.00 80 Thermionic Valve THE WIRELESS AGE Wireless Transmission of Photos Martin 2.00 30 Regular Price $2.50 a year -Class No. 43 Postage outside U. S. 50 cents extra Selected Studies in Elementary Physics.. Blake 2.00 30

Operation of Vacuum Tubes in Radio Brown .35 4 Send all orders to Technical Instruction for Wireless Telegraphists ... Hawkshead and Dowsett 3.50 55 WIRELESS PRESS, Inc. Elgie's Weather Book Elgie 2.00 20 326 Broadway New York City

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www.americanradiohistory.com JUNE, 1924 THE WIRELESS AGE 7

_ - r 2( hRIRAIRARIRIRIRIAIRIRIRIRelb lbReRoRdlathAiRiRlRiR[1hRtRlAalloaRaReAt AaRtRiRIAARIna111A1RAIAlRtMAMAUI RiRINRiRIRell - á a á KELLOGG RADIO SI c - OFF/C /AL SCORE BOARD SI rPIsC 7 t PJIII CHICAGO O O O 2 1 at LOUIS I nl8, Ooccur ill a NEW YORK wo o o lUIIU C BD r- m BROOKLYN J© I I `Wei E IIC A f. II 9 CINCINNATI 00 O O ,.i..,¡1 a _ 316 PHILADELPHIA 1 O O 1 -, 1`,. w8® BOSTON O a ,C,L l., -' _' I I - , C ' F1V! PITTSBURG O (' A ' i è u d - á V, - a as

e Ss BASEBALL SC OÜES BYRADIO Ss 3 SAY THE RADIO BUGS m JASEBALL fans the country over will be counting on Radio this vs s L year more than ever before. Most Radio fans are baseball fans. a s SD Every one of them should see that his new set of Kellogg a s radio parts is ready in time for the baseball scores. S f: Get the Sport records and scores quickest by Radio -build your sr Sa set of Kellogg radio parts for dependability and economy. Si s There is a certainity of satisfaction with Kellogg as shown by á records of this equipment in use. Kellogg transformers rank among a s the best. To hear them in operation is to want them. Kellogg 9 4 tube sockets give the utmost of service, while Kellogg switch arms is s and knobs are in a class by themselves for quick assembly, low á s and satisfying operation. aSs s Kellogg variable and fixed condensers, variometers and vario- _a s couplers are all designed and built to give the satisfaction which the a s word Kellogg expresses in the electrical apparatus field. Kellogg á 5 rheostats have but one movable part. They come in six and twenty- á Ss s five ohm resistances, easilyY interchangeable.g TheyY are simple,P Yyet a Im vary in control on the half turn of the resistance element. Kellogg á á DX head sets are known wherever radio is in the air. They are á C built mechanically and electrically for long service, sensitiveness,

1 extreme lightness in wearing, and handling does not affect their á 4de tuning. They have Kellogg solid bakelite shells and are furnished Sa with the Kellogg famous receiver cords of which many hundreds or áSa s thousands are in use to dayY in the telephoneP field. Kellogggg radio parts are especially suitable in portable sets because of their strength and high a as C class manufacture. They will stand rough handling as will no other radio equip- á s= ment and yet have the range and afford the selectivity, in the limits of the circuits á Si used, surpassed by none. Sa sE If you don't want to bother to pick out the parts for your favorite hookup buy ÿ Q one of our Radio Kits which include all the necessary and suitable parts including 9 a two stages of audio amplification; you can select the tuning units, as you desire. its This summer as never before radio will be heard in every summer resort and a camp. See that your set is made of Kellogg radio parts. Ea s Specify Kellogg Radio- a A Ba Use -Is the Test 9

' á KELLOGG SWITCHBOARD Si 1 is SUPPLY COMPANY 9_á i 1066 West Adams St , CHICAGO, ILL. s Ea áa a I 111 a ó 4 tIPeitruim ruinivientuiviu. wwurowreleww luluwrwrururuwwwwleiwurutatuwww wwwewlnruruwruwluruwl0

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www.americanradiohistory.com 8 THE WIRELESS AGE JUNE, 1924

Founded 1892 Specialists HENRY M. SHAW in President Moulded FRANK H. SHAW Vice Pres. & General Mgr. BAKELITE and "Shawlac" The Guarantee of Quality A Message to Manufacturers of Radio Equipment Growing competition and rising manufacturing costs emphasize the advantage of dependable standards:- Quality Quantity Service The increasing demand for these advantages has induced many manufacturers of Radio equipment to STANDARDIZE WITH Guaranteed Quality MOULDED BAKELITE and SHAWLAC Insulation A Continuous

24 - HOUR PRODUCTION guarantees quantity with a minimum mold investment

rl staff of experienced research, production and sales engineers guarantees service We do not compete with you by selling wholesale or retail. We manufacture from your molds exclusively for you. Place your orders for molds and parts now and eliminate delayed production necessary for Fall and Holiday demands. SHAW INSULATOR COMPANY

Ö( 1 KQ Co;r Sir r Irvington -Newark, New Jersey Cleveland Office New York City Stuyvesant Bldg. Sales Representatives 154 Nassau Street Benj. Phillips Havekost & Simonds

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www.americanradiohistory.com JUNE, 1924 THE WIRELESS AGE 9 Fullest JVleasure of Undistorted `Volume

for the Most Critical Radio eAudience When you go to the theatre or to a con- Low loss steel used in its core construc- cert you expect to hear every word of the tion permits greater volume without dis- program. tortion. There is every reason to be Layer winding properly in- equally exacting in your de- sulated and impregnated pre- mands for clear and loud re- vents short circuiting of turns. production of radio broadcast Air gaps in core avoid dis- programs. tortion. To obtain the "fullest meas- Unbreakable feet with convenient mounting holes make ure of undistorted volume" it the transformer rugged and is tic sat y for your receiver easier to install. to deliver to the diaphragm of your loud speaker or ear Type 231 -A Heavy leads with soldered Audio F. A. Transformer connections eliminate losses phones audio frequencies "Best for All Stages" which will produce the max- Price $5.00 from poor contacts. imum volume and purest quality of tone. The 231 -A transformer has a high and flat curve which means that This depends directly upon the efficiency amplification amplification is nearly uniform through- of your audio amplifying transformers. out its entire audio range- making it best The General Radio Co. type 231 -A is for all stages. distinctly a quality transformer -of high Turns Ratio 3.7 to 1. Impedance 10 to 1. electrical and mechanical efficiency. Price, mounted, $5.00 Features contributing to its superior Write for instructive folder "Quality performance are:- Amplification" and Radio Bulletin 917 -W. GENERAL RADIO COMPANY Manufacturers of Radio and Electrical Laboratory Apparatus MASSACHUSETTS AVE. AND WINDSOR ST. CAMBRIDGE MASS "Products of Proven Merit" GENERAL RADIO C9

www.americanradiohistory.com THE WIRELESS AGE JUNE. 192-1-

THE PERFECT REPRODUCER

SUPER TRANSFORMER 312 -1 RATIO $4.00 Audio Frequency

6-1 RATIO $4.50

Did you ever think what a vital part of your phonograph is the little reproducer which rides on the record ? The most elaborate phonograph made, with a poor reproducer, would be worthless as a musical instrument.

The reproducer of your radio set is your amplifying transformer. The musical qualities of your set depend largely upon the ability of your transformer to exactly duplicate the incoming signals.

Many manufacturers of amplifying transformers have been devoting their entire efforts in developing great amplification regardless of tone quality.

Thordarson amplifying transformers are designed and built with one pri- mal aim,- perfect reproduction. The Thordarson super transformer is a product of the combined efforts of Thordarson engineers and nationally known tone experts and musicians, who were satisfied with only the best musical reproduction obtainable.

Thordarson amplification puts the finishing touches into your receiver, - that "breath of life" which you have so long sought. It actually brings the broadcast artist into your home.

Leading manufacturers of receiving sets, such as Kennedy, Zenith, Cutting & Washington, Radiodyne, and many others, use Thordarson transformers.

Ask to hear a set using the Super Transformer and you will be convinced.

Even Amplification over the entire musical range

THOIJ?RSONMFG.ca CHICAGO ILLINOIS

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www.americanradiohistory.com THE WIRELESS AGE 11 Radio Reception - more perfeci this summer/ Tremendous improvements in sending and receiving combine with better programs to provide the best of radio fun! This is indeed a radio summer! The vital interest of the presidential campaign - waged right in your own home. The glorious and inspiring church services. The important sporting events, market reports, home hints, intensely interesting talks, gay music -all these diversions are brought directly to you. Why Sending Why Reception Is Better Is Clearer Last summer many high power Setshave been vastly improved. broadcasting stations operated They are more keenly selec- on a single wave length. This tive, more sensitive, more sat- summer they are spread over isfactory generally. Vacuum a wave band. You may choose tubes have been re- designed, at your will. Sending stations new circuits have been devel- Table-Talker . . . $10.00 have greatly increased their ,Sor addiroonaf west of The Rothits oped. New loudspeakers, as- power and are spreading their In Canada . . S14.00 suring accurate anti true repro- programs over many more duction, have been put on the miles. Broadcasting from in- market. In fact, the combina- terconnected stations includes tion offiner programs,stronger many people who would form- sending and clearer reception Navy Type Headset . $ 8.00 erly have been deprived of the In Canada . . . . 11.00 now makes the marvels of radio unlimited pleasures of radio. an active part of every day life.

For sixteen years the Brandes name All Brandes Products are sold has consistently stood for service under a money -back guarantee for skill -and dependability. Superior Headwe . . $6.00 by reliable dealers everywhere. In Canada . . . . 7.00 Brandes ti.er .d.. 1-, 1s24 'The name to know in radio When writing to advertisers please mention THE WIRELESS AGE

www.americanradiohistory.com 12 THE WIRELESS AGE JUNE, 1924

M I CARTAREG. U. 5. PAT. OFF.

Ideal Material for Radio Construction

Micarta tubes, plates and other forms are appre- ciated by both amateur and professional builders of radio sets. Both know that Micarta affords that splendid insulation so vital to perfect receptivity They know Micarta is not a substitute, but a better material. Micarta is easily machined, drilled and punched. It takes a high polish. It does not expand or shrink due to contact with oil or moisture.

Get Booklet F 4566 entitled "A Material of Endless Possibilities."

Westinghouse Electric & Manufacturing Company East Pittsburgh Pennsylvania Sales Offices in All Principal Cities of the United States and Foreign Countries

Wesünghouse When writing to advertisers please mention THE WIRELESS AGE

www.americanradiohistory.com ir.i. 1 -4: THE WIRELESS AGE 13 nnounciny: --

A new Magnavox that will broadcast satisfaction to the radio world Wires big news "on the air" The supreme achievement of Magnavox engineers rep- M4 resented in a reproducer of truly exquisite tone quality. HE efficiency, the appearance and the price of this new 2500 instrument clearly reflect the research and production facilities of The Magnavox Company, largest builders of Requires radio reproducing equipment in the world. no Battery Its exquisite tone quality results from a further perfecting of the Magnavox semi -dynamic operating principle -magnetically balanced armature, improved diaphragm and extremely high resistance winding. Beautifully finished in dark enamel with gold high lighting, the graceful appearance of M4 suggests its use in the most dignified surroundings. The amazingly low price of this Magnavox Reproducer establishes an absolutely new standard of value in the radio industry. THE MAGNAVOX CO., OAKLAND, CALIF. New York Office: 350 West 31st Street Canadian Distributors- Perkins Electric Limited, Toronto, Montreal,Winnipeg C>R AGNAVOX Vhe eproducer Supreme \\ -hen writing to advertisers please mention THE WIRELESS AGE

www.americanradiohistory.com 14 THE WIRELESS AGE JUNE, 1924 kr FOUR new broadcasting stations this sum- THE radio vaudeville, unlike stage vaude- mer is the contribution of the British ville, cannot confine its audience within Broadcasting Company to the delight of four gilded walls and hold them there. If the DX hounds. British radio fans are as deter- other stations are likewise sending out variety mined as we on this side of the Atlantic to enjoy stuff which-so the listener thinks -may be better, broadcasting to the full this summer. While as a twirl of the dial will gather in the best from a for us-we are going ahead with the construction flock of stations. No, Mr. Program Man, your of seven new Class B stations and have as many variety stuff will hold us but for a brief half hour more planned. This summer will find nearly -or less. But, as suggested, there are other pos- every fan practically in the shadow of a powerful sibilities. Some day there will be less of the vaude- broadcasting station and getting clear and satisfy- ville performance, and more of the carefully ing programs without difficulty. planned radio evening, so unified and complete in * * * itself, yet so spiced with variety withal, that one HOW about Programs? It is natural to will never be tempted to tune in the other fellow. discover analogies between radio and the stage. Stage programs, of several varieties, have been the outgrowth of centuries of spectacles. HOW puffed up our There were spectacles in the Stone Age. The newspaper editor Roman populace jeered and cheered at spectacles tribe should be! in the arena where the program manager put on A prominent individual of hungry beasts and mixed in men and women to the radio industry has as- provide human -or inhuman -interest. The mys- serted his belief that every tery and miracle plays, the Elizabethan drama, the broadcasting station should wandering troupes of players -all had their pro- be associated with and grams. And radio broadcasting falls heir to them controlled by a large news- all. What an unlimited scope for the ingenuity of paper, for, says he, the radio program managers! corps of editors of a newspaper are well qualified * * * to know what the public wants. Probably so. And if so, why not put the moving picture busi- THE stage has always had its vaudeville pro- ness in charge of newspaper grams. But vaudeville is not the most sig- editors? (One newspaper editor has made a decided success as a nificant contribution of the stage to civiliza- movie director.) Also, why stop here? Let's put tion and human happiness. By the same token, newspaper editors in radio progress is going to be measured charge of our theaters; and, program if knowledge of what the public wants is to be by the steps it removes itself from the primitive the principal criterion-of our municipal govern- vaudeville. Admittedly, radio programs must ments, of our industries. Let's offer variety. The field of radio listeners is large put newspaper editors in charge of everything . . . Possibly and variegated. Programs must please all classes. it would numbers must be short. The be well to leave some lawyers functioning To hold listeners, in our legal system, and some financiers in our variety program, therefore, is the rule in broadcast banking, and some engineers in our construction studios. Will it always be so? development, and -when we get through with * * * connecting up specialists with specialties, we shall HAPPILY, some broadcasting stations are probably want to see newspaper editors editing, not content to follow the crowd, and are and broadcasters -broadcasting. If a newspaper producing real things often enough to in- editor should chance to develop proclivities of the dicate that it is not just happenstance. For in- radio broadcast order, the newer calling will wel- stance- Minstrelsy, Past and Present. What come him. But why close the door upon a lot of more appropriate framework could be imagined other talented chaps whc are not so fortunate as about which to entwine an evening's radio con- to be newspaper editors? Radio broadcasting cert! We congratulate the station manager who wants the biggest caliber men it can find to put in was blessed with this hap- its studios. ee py idea. And we hope that * d: * the variations on this mo- tif will be legion. Like a THE proposed Federal ten per cent. radio tax golden pageant from the failed of enactment, of course. Did anyone past! Early minstrelsy; learn of a single argument advanced in its the first minstrel, David in favor? the court of Saul; Min- strelsy at King Arthur's ee RADIO broadcasting is not -in the opinion ee Round Table; the trouba of Federal Judge Smith Hickenlooper -a dours; the Irish minstrels, public performance, as the framers of the Yankee Hill, the first American minstrel; finally copyright law understood the term. This decision modern minstrelsy otherwise known, we suppose, in favor of The Crosley Manufacturing Company a as Jazz! How's this for musical banquet! in preferred it by Remick & * the suit against Co., * * music publishers, becomes thus a noteworthy epi- MINSTRELSY, Past and Present, is repre- sode in the dispute between broadcasters and the sentative of only one possibility. There American Society of Composers, Authors and are many others. And it is pleasant to Publishers over the broadcasting of copyrighted note that some program directors are endeavoring music. This decision and its supporting reasoning to formulate programs that will possess the neces- tallies with the tenor of the argument and testi- sary variety, but will at the same time evolve and mony presented in the hearings on the Dill Bill, elaborate a central theme and be expressive of recently concluded, which were highly favorable something. The stations that succeed best in this to this bill designed to relieve radio broadcasting effort will capture the most listeners. of its present copyright handicap.

www.americanradiohistory.com JtmE, 1924 THE WIRELESS AGE 15

lnlSrrO)re S. Parent No. /, / /3.LM. MacMillan Listens toLicensed Honolulu under ff L', and New Zealand "Tunes In" California Using From a little ice - bound ThenewZenith3R Model 3R Long - Distance" schooner- eleven degrees from Receiver -Amplifier combines a speci- the North Pole -comes this ally designed distortionless three -stage message: amplifier with the new and different "Am very thankful that Arctic Ex- Zenith three -circuit regenerative tuner. ploring Ship Bowdoin is equipped Fine vernier adjustments - in with complete Zenith radio apparatus. connection with the unique Zenith Here at top of world, in darkness of aperiodic or non - resonant "selector" great Arctic night, we have already primary circuit - make possible ex- listened to stations practically all over treme selectivity. United States, from Europe, and even The new Zenith 3R has broken all from far away Honolulu. Zenith has records, even those set by its famous united the ends of the earth." predecessors of the Zenith line. Under -"MacMillan" favorable conditions, satisfactory reception over distances of 2,000 to Again, from far -off New 3,000 miles, and over, is often accom- Zealand comes a report of radio Long- Distance Radio plished in full volume, using any ordinarylaud- speaker. The Model 3R reception even more startling. is compact, graceful in "It may interest you to know that the writer last evening landed line, and built in a highly finished mahogany cabinet..... 16U KGO, Oakland, California, between 6:45 and 7:30 P. M. Heard his call four or five times distinctly, and jazz music. The music was The new Zenith 4R "Long- Distance" Receiver - not as clear as the voice, but one could pick up the tune all right. Model 4R Amplifier comprises a complete three -circuit As San Francisco is 6,300 miles from New Plymouth, and only regenerative receiver of the feed -back type. It employs the new one tube was used, we think this is a very fair performance." Zenith regenerative circuit in combination with an audion detector -(signed) H. Charles Collier. and three -stage audio-frequency amplifier, all in one cabinet. Because of the unique Zenith "selector," unusual selectivity is The sets used by Captain MacMillan and Mr. Collier accomplished without complication of adjustment. are earlier models -since improved by the addition of The Zenith 4R may be connected directly to any loud -speaker a third stage of audio frequency. These new models, without the use of other amplification for full phonograph volume, described at the right, represent an achievement in and reception may be accomplished over distances of $8 more than 2,000 miles CC77 radio construction not duplicated in any other set on the J market. A demonstration will convince you. Write today for full particulars and name of nearest ZENITH RADIO CORPORATION, dealer. Dept.l -L 328 South Michigan Avenue, Chicago, Illinois Gentlemen : Please send me illustrated literature on Zenith Radio. Zenith Radio Corporation Narre McCORMICK BUILDING, CHICAGO Address

When writing to advertisers please mention THE WIRELESS AGE

www.americanradiohistory.com 16 THE WIRELESS AGE TONE, 1924

" 1 I I E A I I S R F U L L O F T H I N G S Y O U S H O U L D N ' T M I S S"

No. 71tí Eveready Dry Cell The bat battery for use with dry cell tubes

No. 766 "B" Battery, as ,; volts More Power for Summer Radio WHEN you take radio away with you -take Eveready multiple for each WD -r t or WD -r2 tube-this gives Radio "A" and "B" Batteries, the batteries whose the economical "eighth" ampere drain per cell which great power lasts longer. Remember, summer's the insures maximum economy and longer life. For sets time when radio signals are weaker. employing one to three UV -199 tubes use three Batteries do get used up in time. The ones you've Eveready Dry Cell Radio "A" Batteries No. 7111 been using, though partly exhausted, may be satis- connected in series. factory for the strong winter signals, but are prob- The greatest electro- chemical laboratory known ably inadequate for the weaker summer signals. created these famous dry cell batteries on which radio For instance, use the familiar standard 22 i s -volt largely depends. The experience of thirty years in Eveready "B" Battery No. 766. It has variable taps battery making stands back of them. for "soft" detector tubes. Put two, three or four Eveready Radio "A" and "B" Batteries- lively, in series to provide sufficient power for amplifiers. peppy, long-lived producers of power. To light the filaments of your dry cell vacuum For your light -weight sets to take camping or on tubes for the longest time, use Eveready Dry Cell hikes, Eveready has suitable small batteries. Radio "A" Battery No. 7111. The Eveready "A" Manufactured and guaranteed by will you by its long-sustained vigor. It is NATIONAL CARBON COMPANY, INC., New York -San Francisco astonish Headquarters for Radio Battery Information advisable to use two Eveready "A's" connected in Canadian National Carbon Co., Limited, Toronto, Ontario

Informative and money-saving booklets on radio batterie sent free on request. If you have any questions regarding radio batteries, write to G. C. Fumen, Manager, Radio Division, National Carbon Company, Inc., aqS Orton Street, Long Island City, N.Y.

EVEREADY Radio Batteries -they last longer

When writing to advertisers please mention THE \VIRELESS AGE

www.americanradiohistory.com VOLUME vTI-I E WIRELESS AQ E NUMBER Il 9 "America's Foremost Radiophone Review"

oil Radio Reverie of Summer ROADCAST stations are planning elaborate The sky has become a clear azure, with but one pink summer programs. Programs that will be broad- streamer melting into the zenith as the last remnant of a with increased power. Programs of culture; glorius sunrise warns us that another day of activity has cast to explore; a of entertainment. begun. Hikes to be taken; long tortuous trails of education; a line cast into the icy water waves will be broadcast from picnic lunch on a rocky peak; The ocean of a trout brook; a dip in the lake; and back again under the Atlantic City. The swish and boom of the break- cool roof of pine boughs, to a supper of venison, and a dance ers will reach the bed -ridden folk in hospitals. in the evening. An evening of music that our radio provides. The Democratic and Republican National Conventions The fascination of a city's pleasure in the wild, untamed will be he d in New York and Cleveland during the month of realm of the mountains. June. While milling thousands swelter under auditorium roofs, radio millions will enjoy the Convention highlights under spruce boughs, on club verandas, in lake boats, and on front porches of an evening. only known to vacationists, will go In an out -of- the -way corner, Summer sports, baseball, tennis, and boat races we have found an inland lake. A modest summer hotel is on the air. The open air band concerts of the parks will be tucked away at one end. Around the bend, where the trees broadcast. edge, we find small screened -in cottages had for the tuning -in. overhang the water All to be sheltering a neighborly group of families, crowded and happy, released from the inhibitions of side -street society, the ruth- less tyranny of town existence. East or West is the seashore. We can spend a lazy, care -free afternoon on the porch, With the long rambling "Ls" and the wide, banistered reading a novel, or listening in on the radio. Or perhaps porches of the sea -side hotel come our memories of the gala - we'd rather fish. With a box of tackle, a pail of minnows day throngs leisurely strolling about on the spacious board and a portable receiver, we can row from shore, and to the walks. A group here, and a group there, discovering a gaudy strains of an orchestra troll for pike. array of souvenir booths with their baubles of canes and salt- In the evenings we have the best in news and entertain- water taffy temptingly arranged on tinseled shelves; gay little ment by radio. On a Sunday we gather in the old fashioned parties beneath red -striped awnings, scattered about on a parlor of the hotel for the religious services broadcast from green lawn; sober groups tucked away in the corners of the the temples of worship in the great cities. cool Palm Grotto; twos and threes, with tanned faces and We have the best of our civilization in the peace and sunburned arms, clad in vari- colored bathing suits lounging quiet of woods and lakes. under the umbrellas stuck in the white, glistening sand, or racing down the beach and out into the breakers; music and gay laughter floating across the water from yachts idling off shore. Glance again at the gay caparisoned seashore resort. The Those of us who are city- bound-shackled to a desk in radio is there, because it adds to the things we like best. the oven heat of an office building, grinding away under the irritating draft of an electric fan -those are the ones of us who will know the value of radio this summer. We can find surcease from the tense, vibrating grip of Early up and out on the porch to see a sunrise in the the day's business at our radio of an evening. mountains. We lean against the bark -log rail and strive to We can have a garden party, or a lawn fête, during the pierce the lavender shadows still hovering over the valley, longer daylight evenings. The best metropolitan hotel or- two thousand feet below. The clear, translucent surface of chestras will play for us. Mirror Lake, streaked with shades of crimson and blue, re- We can lounge on our front porch and listen to broad- flects the heightening color of the morning sky. The ever- cast talks on week -end motor trips; where to go, and how; greens and mountain ash on the distant shore carpet the when to go, and why. valley like a rolling, moss -covered tundra. And up the moun- On a Sunday we can drive to the neighboring woods for tain side they straggle out into squat bushes, then become a picnic lunch. And under the spreading branches of an oak, more distinct as they reach the timber line. A riot of bright listen in to religious services, mingled with the strains of an colored flowers cover a hillside that had been swept by a organ, the best of majestic cathedrals brought to us in the forest fire. sanctity of peace and' rest in the open air. 17

www.americanradiohistory.com THE WIRELESS AGE JUNE, 1924 Enjoying Summer Radio and

Radio dispelled the loneli- ness when getting the garden ready at this summer cottage before the family arrived

Radio has become indispensable in Boy Scout and Army summer camps. Excellent results were obtained with this equipment

A natural cave runs in to the left and cannot be approached other than down the rocks as shown. After the radio had been Through radio, the youngsters are receiving swimming installed the retreat was transformed into lessons broadcast from TFLW. These classes are under a homelike camp the auspices of the Y. M. C. A.

www.americanradiohistory.com lr I''' PICTORIAL SECTION

Woodland, Stream and Sea Shore

Radio on the beaches this A book of verses, a bit of summer will be a part of lunch and the radio under- summer vacationing and neath a bow -a pleasant sports. It can best be en- hike the more pleasant be- joyed beneath an umbrella cause of radio between times of Clips in the sea

nrn p.41 ... i..>;si7v:'á'

el log cabin vacation will have even more lure for radio fans this summer. This scene is in the dense woods along the Hudson River

This is an example of what can be done with a good The hours of fishing can be considerably lightened with portable set on the camping trip this summer. The aerial a good radio set. This is a six -tube set. The labor of is a single wire thrown over the limb of a nearby tree carrying the dry batteries was well worth the result

www.americanradiohistory.com The Story of a Millionaire's Yacht. What Radio Means to Mr. W. K. Vanderbilt Aboard the "Ara" By William A. Hurd SAILORS, ashore, enjoy the privi- thirty -foot motor cabin- launch for the be sound. And frequently in dupli- lege of using sea -going phrase- Commodore's private use, an eighteen - cate. ology to the confoundment and foot motor dinghy, a twenty -foot Out on the bridge an electrician is. envy of all landlubbers. Such is a motor launch, a twenty- six -foot life testing the electrically controlled mark of distinction. boat, and between them, on the Sperry searchlight, fastened above on But once a son of the soil climbs superstructure, waterproof lockers con- the foremast. This light is the most aboard ship -he is an object of pity, tain rigging, auxiliary storage batteries powerful built for ships, capable of a target for ridicule, a stranger to and jars of diluted formaldehyde in throwing a strong beam of light sev- Oceanic Jargon, and his criminal ig- which fish specimens are preserved. eral miles. norance is dealt with after the fashion Nothing to inspire romance there. Leaning over the rail, an increas- of the high -seas custom. He is ex- ing hustle and bustle is observed. A peditiously squashed, and flung into The Wireless Age is indebted to pungent odor of whale oil drifts up the scuppers. Mr. W. K. Vanderbilt's kindness in from below where it is being rubbed A floor's a deck, a kitchen's a gal- allowing the writer to go on board the on to metal parts that are exposed to "Ara" in order that a description of the salt spray. The davits creak and groan ley and a stairway's a ladder. Every yacht and particulars of the log might salt knows it, down to the last sea -dog be combined in a story. By way of as the provisions are swung aboard. who has roamed the highways and the enlivening the story, the writer has on tip forward one of the Boatswains byways of the seven seas. his own initiative added a touch of leans against a canvas -covered gun. So we'd better look sharp to our rig - romance. listlessly checking the supplies as they gin' -we're going on a cruise. The come over the bulwarks. An almost cruise of the Ara. Strolling up to the pilot house, signs imperceptible motion of the yacht is A trim little yacht, the Ara. 213 ft., of life become apparent as the wheel detected as she idly swings at her moor- fore and aft, with a water displacement and engine room signal controls are ing. of 850 tons, equipped with two 1,050 uncovered. The Mate bends over the Below, the crew's quarters occupy H. P. Diesel engines and run by a crew gyroscope compass checking its work- most of the forecastle. Just aft are of thirty-two men and officers. ing order. When asked, he explains the officers' quarters and the radio The Commodore, W. K. Vanderbilt, that unlike the magnetic compass, as station. railroad financier and scion of the well of old, this one operates electrically Steffen F. Nielssen. a World War known Vanderbilt family, purchased from a gyroscope located in the bot- veteran, is in charge of the radio sta- the Ara following the Great War, and tom of the ship. tion. Before the war he attended one refitted the yacht to suit his needs. Stepping into the chart room, we of the prominent universities in Ger- Since the total cost was approximately find a sailor putting the finishing many and is conversant with several $500,000, one might gather that yacht- touches to his brass polishing. The languages. His first schooling in ra- ing is, indeed, a luxury. And one is Second Mate is checking the chronom- dio was under the personal direction of correct-members of the crew consider eter and arranging the great number Poulsen, inventor of the Poulsen arc it a luxury to work on the Ara. of charts and maps. Here. every in- transmitter. Later he conducted the Four boats are swung on davits : a strument practicable to navigation may radio research work in the laboratories 20

www.americanradiohistory.com 21 J to N E, 192 -4 THE CRUISE OF THE "ARA"

tood is kept warm in an electric heater. of the University of Texas for a period STATEMENT FROM MR. W. K. of two years. VANDERBILT On the main deck is a large and Just now, he is wholly absorbed with "It is a pleasure to state that radio airy dining saloon which is connected the intricate circuits. looking for a has been a useful hobby as well as a with the pantry from which the food broken wire. a loose connection or any really worth while diversion. is served. The table is pivoted on gim- "At times I am several thousand bals so it remains on a level plane weak point that might cause trouble In that miles from home and the office. rolls pitches in at sea . the past I have been at a loss to know when the yacht and So we'll look around aft where the what might have happened during my high seas. steward's quarters are located. In these absence, and the knowledge that some- Going below again, we see the ice- thing might be wrong has frequently boxes. They resemble the finest in a quarters accommodations are provided been uncomfortable since I would not fo six stewards and chef. A laundry hear of it until many days later. But metropolitan hotel. is lalso provided below. now I am in constant touch with home Provisions are being stored away for Amidship is a large music room affairs, and possible business matters this cruise-chickens, meat, canned that might require immediate at- goods and an infinite variety of deli- luxuriously furnished with a gray plush tention. And this is possible through carpet, overstuffed lounge and chairs. the modern radio equipment on the cacies that make our mouths water. rare mahogany pieces, a grand player - Ara. merely to contemplate the good "feeds" piano, a console phonograph. floor "The reception of news has added ahead. much to the comfort of my crew, But our epicurean reveries are in- lamps, a large bookcase containing val- guests and myself. Through the uable editions. anti side -wall candle agency of radio we enjoy a daily terrupted by a shrill whistle from fixtures. Loud speakers can be newspaper on board the yacht, how- above. Having gleaned enough sea - "plugged in" at convenient outlets con- ever far from the land. etiquette and ship manners by this time "From a navigating standpoint radio to know that a whistle sounded por- nested by direct wire to the broadcast has proved invaluable. The Direction receiver which is located in the radio Finder has been a great aid in coast- tends something of significance, we operating room. wise sailing. We feel that when with- scramble up the ladders to investigate Stepping out of the music room, the in 50 miles of two stations our position the cause. leads of can be checked within a degree. has come passageway aft between cases "The time signals and the weather Commodore Vanderbilt sea and bird specimens, racks of fire- reports, and the fact that one may aboard. Brisk, orderly activity is evi- arms, some of a special sort, and lock- communicate with the outside world, dent at every turn. The Commodore, ers of nearly every conceivable kind have all added to the pleasure of a having been a Commander in the Navy, of fishing tackle. A sportsman's yacht, cruise." -W. K. Vanderbilt. always insists that precise conduct and no doubt about it. should be the mark of efficient man- Through this passage, entry is had fashion of a "club room" coziness. agement aboard the Ara. And so it is. toi the sleeping accommodations for Heavily cushioned benches surround a His first concern, before casting off, the guests. There are six suites, each table, and panels of matched grain form is about the navigation equipment. with private bath. The beds, dressing the walls or bulkheads. Then below to inspect the radio. tables, desks, cabinets and chairs in The galley (kitchen) is a model of The radio apparatus is a duplicate, each suite are of a uniform style. In spotlessness, where Commodore Van - throughout, of that on the Majestic of one, mahogany, another bird's-eye derbilt's private chef reigns supreme. the White Star Line. maple, and others, walnut, oak and The prepared meals are sent below, for Three transmitters are installed ; a various costly woods. the officers and crew, and above, for 1 % K.W. tube transmitter, a 1% K.W. Leading up the ladder, we may step the guests, on a dumb -waiter. Should spark transmitter of the quenched type into the card room appointed in the any of the company be delayed, the and a smaller spark transmitter, rated

Steffen F. Nielssen, the operator aboard the "Ara," at work. Left to right is the C. W. transmitter, the direction finder and gyroscopic compass, the two receiving sets and loud speaker (above) and the main spark transmitter (partly hidden by the operator's head). Above the main transmitter is the emergency spark transmitter and to the extreme right is the switchboard, and below, the motor -generator starter.

www.americanradiohistory.com 22 THE WIRELESS AGE it-xE. 1924 at / to / KW., intended for beacon lights, then following the boom no mishap and a record of fine weather_ emergency use, or for low power trans- of buoy horns; still out. around Sandy \lilk and fresh vegetables were mission. Hook, and at last, straightaway, due brought aboard. And then the crew A motor -generator supplies the pow- South! set to the task of scrubbing and paint- er for all three transmitters. The following day, the Ara pulled ing until the yacht, from topmast to The switchboard carries all the con- up in the sheltered water of Chesa- keel. was as ship -shape as a Bo's'n. trol switches for the main set and the peake Bay long enough to cast over could wish. emergency power. besides providing some lines. But fisherman's luck had The following day. the .Ira slipped means for charging the storage bat- stayed ashore. Other than three or into the harbor at \liami and dropped teries. four small sharks -disparagingly re- anchor to await the arrival of the Two receiving sets provide the ferred to by the natives as dog -fish- guests. traffic and broadcast reception. The the only catch that furnished any ex- On the way in, one of the sailors. broadcast receiver is connected to a citement was a sting -ray. This fish. who had been up in the rigging, stvunk three -step power amplifier. very much resembling a kite, its mouth out on a cable and waited. A few Mounted on the table is a radio di- about where the kite -string would be moments later a schooner hove along- rection finder that is often more ac- attached, spread itself out in such a side on the way out to sea. The sailor. curate than navigation instruments. manner that a three -foot board, hauled hanging in mid -air, let go. He soared Next to the direction finder is a broadside through the water, would out over the bridge, gripping the cable "repeater," part of the gyroscopic have offered less resistance. with his hands and one leg hooked compass system. The Commodore wished to send a over the top. He soared out over the Although atmos- pilot house and down ; down with in- pheric conditions. creasing velocity ; clown with a crash and many other fac- to the deck. tors. largely deter- The men aboard the schooner had mine the range of watched. spellbound. . \n old salt any radio equipment. rushed over to the rail. and with the apparatus aboard cupped hands to his mouth. yelled. the Ara consistently "Good work, sailor. Iletter ship over maintains a trans- on a square -rigger afore your sea - mission record of l'arnin' runs amuck !" 1.500 miles. The sailor grinned acknowledgment. Commodore Van- i le had been educated on a sailing ves- derbilt, well pleased sel, mid he knew that old timers. alone, after his inspection. would understand climbed up to the the urge that had bridge. questioned prompted his little the Staff Captain on display of vanity - some matters per- or perhaps it was taining to the general working order pride. He looked of the ship. and then gave orders to at his hands. The cast off. Most of palms were scorch- the guests ed by oakum. and * went a- shore to raw. He grinned A bell sounded - the engines visit the again. old his- throbbed - the water boiled and toric for- The Mate. who churned away from the stern -the Ara tress at Fort Jef- watched the epi- swung gracefully from the dock -her ferson. sode from the nose pointed seaward - long, black bridge. also grin- rolls breaking into swirling eddies ned. broadened out into a fan -like wake- Tw,, men aboard the topmasts like slender. artistic fin - the Ara liad known ger tips seemed to inscribe the words few radiograms, so a day was called. the wild thrill of hanging to a yard- ROMANCE and ADVENTURE on The yacht headed out to sea again. and arm. taking in a reef against a driving the moist mirror of the sky. Nielsen cut in the broadcast receiver storm. the canvas tearing the flesh The Ara slipped down the Hudson for the daily DX dozen. from clutching fingers, the topmast River, tooting her course through a In the music room. the Commodore slashing through the darkness in ter- maze of ferries and tug -boats; clown and his party enjoyed a concert from rifying arcs. between the batteries of wharves and New York. while the crew, below. The guests came aboard in the eve- clocks ; clown between sheer cliffs of listened in on another loud speaker. ning. Under the clear, Florida moon brick and steel buildings. The evening Four bells sounded on the bridge. the party Glanced on the quarter -deck settled into deepening twilight ; lights Simultaneously the time signals from to the strains of an orchestra broad- began to twinkle : red lights, green Arlington flashed the long dash for casting from New York. Around mid- lights and white lights drifted across 10:00 P. M. In the chart room, the night the music stopped. Stewards the water ; the New York skyline Mate checked the chronometer, and brought chairs and cool drinks, and the melted into a fairyland of gleaming then sent the Quartermaster below for guests gave themselves up to the lux- jewels and towers; the far -off, muffled the weather reports. Such was the ury of reclining beneath the high, star - roar of the great city drifted out as nightly ceremony that radio had dedi- clotted vault of a Southern sky. Re- from an enchanted world ; perhaps it cated to the precise art of navigation. freshing zephyrs skipped across the was the trumpeting of heralds from the It was a solemn affair because it was deck. The soothing trickle of water, turrets, proclaiming the freedom of important. A ship at sea must not be breaking against the bow. whispered souls from another day's toil. left to the caprice of human judgment. strange yarns of the sea. Delicate, Across the harbor, out into the ocean. * :: s phosphorus- streaked patterns of lace the Ara nosed along, pointing toward The Ara arrived at Jacksonville with spread over the surface. glowing and

www.americanradiohistory.com if NE. 1924 THE CRUISE OF THE "ARA" 23

ialing, the halt - formed pictures. ever salt in pockets full of brands ordinarily trade wind blew up from the \Vest el sire, always beyond the grasp of beyond their means. They found the Indies. Its velocity increased steadily, intrigued fancy. factories extremely cordial- almost followed by giant rollers that broke L\ steward came up to announce that grateful for such unprecedented con- into whitecaps. The yacht plunged, the operator had managed to tune in cern from two perfect strangers -but nose first, into a towering wave. She another orchestra. broadcasting on the courtesy in a Key \\ est cigar factory hesitated for a brief instant : a sheet Pacific Coast. : \nd did they wish to sloes not include the ritual of tucking of green water splashed up from the dance They (lid'. samples into comfortably receptive vest bow and swept across the bridge : the \n hour later, the party had to re- pockets. ship quivered, and then rose with a tr tt to the music room to continue While the guests aboard the Ara sickening sweep; up. and faster : she their dance because of the mist that sauntered about the town, oil was paused ; and then dropped like a meteor had settled over the harbor. And the pumped into the tanks, located in the into a yawning chasm : dropped like a dance continued until the last broad - sides of the yacht. thing gone mad. Head on into another cast station had closed for the night. A sponge boat had just returned mountain of water. The bridge was In the morning, the :lru left )lianii from an expedition in the sadly de- again swept with a (trenching wave. for key \Vest for fuel. pleted sponge fields of the Florida Cold, foam -flecked water washed over Key \Vest is south of : \merica- Revs. The boat reeked with the putrid. the deck. The air was filled with chill, 1.5110 miles south of New York-and nauseating odor of decayed animal sticky spray that foreboded "weather" yet it is indubitably a part of America. matter. during the night. It is, in fact, disappointing. The Ara left Ivey West for a run "I'retty mean out." the Captain The tote wooden honSCS have wide around to Fort Jefferson. Sonic of the mused. "Barometer's dropping like it verandas supported by pillars resembl- didn't know it had a ing- the u-opical abodes of a Latin bottom." Ile had pen plc. !tut they smack of our own addressed no one in familiar architecture. particular, hut the

I 'ere and there, a graceful palm tree Pilot laughed. rises from the curb, the delicate plume- "Don't worry, like branches drooping and swaying in Captain." the \late the constant sea breezes. For a mom- bantered, "there's a ent. one can picture the olden days bottoni to everything tt hen pirates took refuge in the losont --even the ocean.'. II- these coral islands. scarcely rising All afternoon and a Hoye the ultramarine blue of the (-ar- well into the evening, il bean. Then dis- the Conituodtre il tisionntent. The checked his bearings 5 ariti of autolno- on the radio direc- Illes clogging the tion finder, At 9:30 street corners are the storm broke with y ry nio(lern.. \uto- a fury approa:liing n obiles can even a typhoon. Rain poured down in solid destroy the tranquil sheets of water. twisted and lashed by t1 etnories jcal- and The chase the wind. (oflsly guarded tra- after the The telephone rang in the pilot queer "bal- ditions of a sleepy. loon" fish house. The Commodore grabbed the re- vll- resulted in New England the catch ceiver. listened. and then shouted the l4ge. of a large command to the ( )uarterniaster: jewfish Year - round "Tarn the searchlight on the loop prevalence of mos- aerial of the direction finder! It's quitoes and the broken! Nielsen calling!" acute lack of drink- Then turning to the \I ate : "The ing water irritate operator has to stay at the radio -any- the visitor from the States. The guests tv-cnt ashore to sec the old his- one aboard who can repair that loot}- - natives. however. accept the two evils toric fort of Civil \Var (lays. right'" with a resignation that surpasses the The few who remained on the yacht The Mate remembered the sai'or (x)ny)rehcnsion of restless. . \nierican- whiled away the time by fishing off who had risked his life in Miami mere- 1 orn citizens who are frequently guilty shore. Three small tish there caught. ly to prove his seamanship. "Aye, ( f acceptance tvithout reason, but never hardly worth saying, so they tyerc cast sir," he replied. then called the man resigned. out into the water. But one swelled up, curtly explained the trouble, and Innumerable cigar factories clutter like a balloon and floated away on the sent him out to do the job- right. t to island. Modern factories. well ven- title. :\ boat was launched to recapture Under the glare of the Sperry light, tilated by the steady breezes enjoyed in the strange specimen. the seaman worked fast. efficiently. .ey West. less pretentious structures \!though the balloon -fish could not Ile seemed to be hardly aware of the own the side streets, and small, single he found after a diligent search along raging elements. He had the wire. .A Shanties tucked away in stuffy corners the coarse it liad been last observed quick splice and it was fastened to the (¡f the town. all house the great indus- floating out to sea. a large jewfish insulator. He slipped to the deco: be- try of this natural focus point of ma- was caught on a troll -line. This was low, and was swallowed in the dark- terial. maker and consumer. brought back to the dock, cleaned and ness. Two sailors from the Ara went preserved for the Commodore's :\ moment later he reported in the ashore with a misconceived idea of Key museum. pilot house : "Done, sir."

\Vest generosity, and a goodly share of The following day. the Ara was The Commodore smiled. "Good ! We blissful ignorance. It occurred to them headed around and set on a course need that direction finder tonight. Bet- that a casual tour through the plants of for Nassau in the Bahama Islands. ter report in the galley fora bowl of better cigar manufacturers would re- Before lanci was sighted a strong Java.,,

www.americanradiohistory.com Radio for Boatman, Motorist or Hiker Practical Vacation Pointers The author is a practical boatman and has installed radio on boats of all kinds. He is a practical radio man and has used radio on automobile trips. He tells just how it was done; just what to avoid By W. F. Crosby

HE perpetual grouch. who goes article should have its particular ap- Consider the little UV -199 and what around broadcasting the fact that peal. it makes possible. Here is a tube which T radio is doomed for a terrific Broadcasting seasons change, just as draws such a small amount of energy "bump" during the coming summer, is in any other industry, and the leading from the "A" battery, that it is pos- going to have a rude awakening, one of broadcasters are planning some fine sible to run it from an ordinary flash- these fine mornings. He is going to things for the hot evenings. Dance light cell! With such a set as this. music will wake up and find that radio has taken predominate and what could employing several of these tubes, you be more enjoyable than to be anchored will be able have hold of the popular fancy more than to an outfit which will in some snug cove for the night with weigh next vacation are to nothing, when we stop ever and that radio and the old loud speaker pouring forth the to consider the more cumbersome bat- practically one and the same thing. strains of the latest dance hit. Or you teries required with the six -volt tubes. The forehanded radio fan is the fel- might be tucked away in a tent, some- Even the ordinary dry cell tubes, such low, who has made preparations far in where in the mountains, possibly during as the WD -11 and WD -12, require advance, who has spent about half the a rainy stretch. The morale of the larger and heavier batteries, for the winter in preparing and building a whole camp will be brightened up if simple reason that they draw a great good set which he can take along with only a good radio receiving set is on deal more current from the "A" bat- him on his vacation, or on his week hand, and. it might be added that good tery. end outings. whether they be on the music, under such circumstances, If you choose, you can make up a water, by car, or just plain "hikes." sounds about twice as good as it ever simple little one -tube set, using a 199, Such a man as this has had time to did before, or will again. and the whole thing may be enclosed study the situation and the circuits Oh, ves, it is quite possible to make in a space considerably smaller than and, by now, he is pretty well versed in up small portable sets which can easily the average haversack. If you want what is what in the way of summer- be transported on the back, and such to make use of what is known as a time radio; but there are always hun- little sets as this are frequently even mercury condenser or a compression dreds who have not looked so far more efficient than their larger broth- condenser in such a set as this, the ahead and it is to this class that this ers. total size of the panel need not exceed

An automobile trip will not be complete this summer without a radio set. Many a picnic lunch will be more enjoyable accompanied by radio music 24

www.americanradiohistory.com faNe, 1924 OUTDOOR RADIO 25 six inches square, by possibly six or aerial, and possibly the accompanying seven inches deep. There are plenty sketch will give an idea of what can of simple circuits to choose from, but be clone on a rather small cruiser of bear in mind that such a set will surely about thirty feet. require an aerial. This will necessitate In this particular case, the aerial is sonic form of reel or winding machine, started at the top of the awning, way where the wire may be kept when it is in the stern, and it is carried up to the not in use. Such a simple thing as this top of the mast and thence clown to will never feaze the average radio fan. the bow. where the lead-in wire is Then, if you wish, you may take ad- taken off and run in through the for- vantage of radio frequency amplifica- ward end of the cabin. There are many tion, because the 199 tube is a mighty variations of this, but for the par- good radio frequency amplifier, and ticular type of boat shown, such a rig you may rig up a set which will con- cannot be beaten. It will give the max- tain several stages of untuned radio imum over all length to the aerial. frequency. Of course there is no law something which is quite essential for against the use of tuned radio fre- good reception. quency, but it will make the set con- I f two wires are run in the same siderably more cumbersome and manner, it is advisable to use some heavier. Some radio fans think that form of spreader just as near the top reflex are the best circuits for this kind of the mast as possible. By keeping of work, and if such a set is properly Courtesy of Mullins Non -sinkable Steel Boat Co. the aerial high up in this manner, the designed and built, it is quite possible. A suggestion for campers overall length is slightly increased. with three tubes, to make outfit an Every inch counts, especially on small which will in with bring broadcasting on long distance stations, but if you boats. stifficient volume for a small loud happen to be camping within a fifty slieaker. Such a receiver may be com- mile radius of some broadcasting sta- Again referring to the sketch of the pletely enclosed within a cabinet fif- tion, you may rest assured that you boat, you will notice that we have a teen inches long, or even less, if you will at least hear that station, and if small insulator at the bow, two at the squeeze the parts up a little. The flash- circumstances are right, you may do masthead and one at the top of the light cells may still be used for the "A" even better. awning. The masthead rig is simply a bridle with an insulator on each end, battery. These little sets, of which there are through which the aerial wire is passed, In the reflex type of circuit, each many variations, will prove excellent and then hoisted up the mast by the vacuum tube is used over twice, once for hiking and canoe trips, where space regular halyard. Such a rig as this is at radio frequency and again audio is small and the weight must be kept at easily taken down at any time. frequency. Using a small loop aerial down, but when we come down to the is a practical proposition, if the set is motor boats, we find that the problem Now as for the ground, when you built right. Of course a regular aerial is considerably simpler. The main are on board boat, you have plenty of will give far better results, especially trouble seems to be in getting a suitable that all about you, despite the fact

An excellent aerial system on a small yacht or for the larger motor boats

www.americanradiohistory.com 26 THE WIRELESS AGE Jt:xE, 1924 that it takes the form of water. The close to the bronze propeller and shaft, extent, when we realize that great only thing that is necessary is to make because you will find that the plate has space is not always available. Of course some connection to that material. This been eaten completely away after a some of the larger motor boats and is sometimes accomplished by fastening month or two in the water. yachts will have plenty of room for a wire to the engine at some con- One more thing while on this sub- the most elaborate set, but this is far venient place, allowing the shaft and ject: try to avoid the use of solder, from true on the smaller cruisers. propeller to do the rest. This rig is especially soldering to copper or sol- Most of the present day motor boats sometimes satisfactory, but a far better dering a copper wire to a zinc plate. are equipped with electric lights and it way is to have a copper plate attached Such practice is extremely baci under- is not a difficult matter to arrange some to the outside of the hull, below the water workmanship and it will not be means of taking off a pair of wires %water line. There is only one difficulty long before you have no connection at from the storage battery. There is one here. and that is with the electrolytic all. poin= to look out for in this respect. action between the fastenings of the Instead of this, fasten the wire in This has to do with the voltage of the hull and the copper plate. place by means of screws, or by punch- l lttery. A combination of the two metals in ing holes in the plate before it is at- In a great many boats the system salt water will always make trouble tached and then threading the wire back calls for twenty -four volts and of unless well defined rtiles are followed. and forth through these holes until a course this will never do for a six -volt is I f your boat happens to be fastened solid contact made. vacuum tube. For this reason it will with brass screws or copper nails, then As for the set itself, we have a wide be far better to call in an experienced it will be all right to attach a copper variety to choose from. Of course the electrical man and have him arrange plate to the hull, but be sure to use old fashioned regenerative outfit will for a six -volt line. If you have a large copper tacks in doing this. On the work, after a fashion. and in some storage battery and are not sure as to other hand if the boat happens to be cases extremely well, but it is more or its correct voltage, count the vent caps. fastened with galvanized iron nails. less of a gamble as to just how it will If there are three of them, then you then it will be far better to use zinc perform. You will probably get a may be pretty sure that the voltage is in place of the copper plate. Galvanized much stronger signal by resorting to just six, because each cell in the bat- tacks should be used to hold the plate one of the newer circuits, tuned radio tery will give two volts and since there in place. It is also not advisable to al- frequency, neutrodyne, super- hetero- are three vents. there must be three low this kind of a plate to come too dyne, or reflex. Size governs to some cells. If you happen to have a battery with more than three vents in it. then Volt had better have it checked up carefully. The writer has seen some yacht installations where the radio set has been tucked away in a locker with the loud speaker arranged so that it can be plugged in at different positions on the boat. either inside the cabin or in the cockpit. This does not call for much radio knowledge and anyone who has been able to build a radio set can easily figure out such a scheme. In one rather elaborate outfit. the receiver bad been built into a bulkhead desk and was completely concealed when the desk was closed. The set in question consisted of an ordinary detector and two stage amplifier with a horn arranged in the corner of the cabin. way up under the deck beams where it would never get in the way of anyone's head. Of course, the large yachts are nearly all equipped with radio sets at the present time, many of them carrying regular licensed operators. These operators frequently have life rather easy and many of them have rigged up broadcast receivers for the yacht owners. Such installations are, of course, outside the scope of this article. Easily the most popular sport today is automobiling, but radio is running it a close second and the day will come when the two will be combined to give the vacationist the time of his life. Suppose you are about to start off on a trip to Niagara Falls, by automobile. of course, and you decide to take along a radio receiver. On the way you

On a hike, rie a rock on the end of flexible wire and throw it over the limb of a tree for an aerial (Continued on page 75)

www.americanradiohistory.com 1'i24 PICTORIAL SECTION

Ringling Bros. and Barnum &, Bailey Broadcast

These tigers told the lis- The elephants had a lot to

teners -in on 11'.12 just say. After they had broad- - what they thought about cast, the seals and the bears, this sort of a "daily the laughing hyena and rlu en." Th.e lions also many other animals of the broadcast their ideas on menagerie were allowed to circus life broadcast

This is the heart of any circus - - -the clown. If7iat would we care about the .sawdust rings if we couldn't have the merry/ antics of the acrobatic rlrercu.s.

/.ra///p iiyASe., ,,yr ' .6i//i,G.i,lí/

1:ew Graham, the veteran circus announcer who introduced The Pretty Lady of the circus parade. /While TUJZ broad- the various animals to the radio listeners. Lew is the "of- cast the circus from New York, Sells -Floto circus in Chi- fiéiator" (luring the performances of the Ringling Bros. and cago was broadcast from KYW. In both, everything from Barnum cS Bailey circus. Thousands know his "La-dee-es the Lally -Icon of the side -show announcers down to the and Gen -tle -men," heard again. over the radio. Calliope was included

www.americanradiohistory.com Up Above theWorld A Mile High And Radio

The first recorded ascent of Mt. Marcy. or Tahawus as it was known to the Indians, was made in 1837 by Professor Emmons and his party. There were no trails or guide posts to aid them in their endeavors. and they struggled through the virgin forests and dense alpine growth of pure s -rubby balsam. Today. however. one may motor to the font of the mountain. and the climb may he made over no less than five well marked trails which converge at or near the mountain's peak. Trails are marked and shelters have been provided. Now, more than a life's span after Professor Emmons' ascent, climb- ers have taken radio to the top, and any vigorous, am- bitious radin fan can do the same This story of how two hikers got radio reception on the top of Mount Marcy is told by Hall E. Shepherd Radio on Mount Marcy HERE were two reasons which construct a single condenser Flewelling which was a commercial product on led Sherwood Marvin and the receiver, a receiver which had given the market and which he had tested writer to climb Mount Marcy splendid results at White Gate Farm, and found to give excellent results. with a radio receiving set. The Madison, Conn., a few weeks before. Thus a non -oscillating receiver was first and outstanding one was that it had on the trip to the peak of Mount \lar- used, and such a receiver is highly never been done and thus by doing it cy, but after consulting a radio engi- recommended for the use of the camp- successfully we could add a little to neer who was with the Marine Corps er and traveler in the wilds who de- the short but brilliant history of radio for a year in the tropics, different plans sires to keep in touch with the events communication. The second reason were made in regard to the receiving of the world without overloading him- was that discoveries as to the effect of set to be used. The conditions found self with the heavy receivers now in altitude and climatic conditions might on Mount Marcy were such that it general use. be made on an antenna strung up over would probably have been impossible Now for the story of the actual as- a mile above the mean sea level. In to obtain any results whatever with cent of Mount Marcy. Marvin and the former we were successful, but in the Flewelling because of its very criti- the writer left Doctors Island, located the latter, due to unfavorable meteoro- cal grid -leak adjustment. The engi- in Upper Saranac Lake, early one logical conditions, we did nothing. neer told the writer of a very light morning and went by boat to Bartlets However, we successfully received a and compact non -oscillating receiver Carry on the eastern shore of the lake. part of the programs of several broad- Packs were carried containing blankets, casting stations and so consider that the necessary cooking equipment and the trip was a success. the radio receiver already mentioned Mount Marcy, or Tahawus, as it together with a hundred feet of was known to the Indians, is the high- stranded copper wire and the necessary est peak in New York State, rising to "A" and "B" batteries. After going a height of 5,344 feet above sea level. over the Carry we took the road and Tahawus, or the Cloud Splitter of the proceeded to Saranac Lake. From there Indians, was renamed after one of the we went to Lake Placid where we pur- leaders of the Empire State, Governor chased a few supplies and then pro- Marcy. The first recorded ascent was ceeded upon our way to Keene Valley made by Professor Emmons in 1837, Village. Many readers will remember who climbed with great difficulty to from their school days the interesting the top through the virgin forests cov- stories by Warner of the country ering the lower slopes and the dense around Keene Valley. It was in this alpine growth of scrubby balsam near same district that he came so very near the top. When the first ascent was to being eaten by a bear. Neither of made eighty -six years ago it was a us saw a bear on the trip, although feat so difficult that the interest of the we did see several deer. From the nation was aroused, but today, thanks main four corners in Keene Valley Vil- to the work of the Conservation Corn- lage we took the Johns Brook Trail mission of the State of New York, and headed for Marcy. This trail is there are no less than five well defined the oldest and best known one from trails, all plainly marked, leading to the east and was the one taken partly the top. because of that fact, and partly be- Preparing for a test in reception at a difficult It had been the writer's intention to point cause of the desire to see Keene Val- 28

www.americanradiohistory.com JUNE, 1924 RADIO ON MOUNT MARCY lev. The distance to the top of Mount was attached. We had expected to Marcy from Keene Valley Village is have difficulty in finding an efficient nine and one - fourth miles and the as- ground. but found that moist soil went cent 4,250 feet. After passing Bush- to the very peak of the mountain so nets Falls we branched off and took that it was only necessary to drive down a spike. l'pon checking with a compass we found that the antenna ran very nearly north and south. The lead -in was made from the southern end as there was more protection from the elements there. There was a very cold wind blowing and a driving rain fell at intervals during the day. Photo- graphs were taken, but because of the poor light none were as good as we had hoped for. In none of them did the antenna show up, although we liad hoped for a good one of the highest collector system in New York State. In the evening the receiving set was put into operation and three broadcasting stations heard. More could probably have been logged, but it was 'A precarious climb up the face of a rock cliff very cold a mile up in the air and we desired to reach a valley in which to the new trail from Johns Brook to make camp for the night. The first Marcy through the notch south of station heard was \VGY, located at Tabletop Mountain. This new trail Schenectady. It came in very clear was cut out by the Conservation Com- and we were greatly encouraged. After mission in 1920. We then proceeded getting this call the set was retuned Hanging Spear of East River Falls u t to a point just below the top of and station WRAF, located in New , o Man's Mountain where we made York City, was heard. The next sta- at the top of No Man's Mountain, and camp for the night. The next morning tion was more difficult to reach, proba- runs to Adirondack Lodge where we we reached an intersection with the bly because several changes were made found a road to North Elba. From Van Hoevenburg Trail. which we took in the hook -up, and it was nearly a there we went to Lake Placid and then to the top of Mount Marcy. From half hour before we found it to he back to Upper Saranac Lake over the this trail splendid views of the neigh - WMAF at Dartmouth, Mass. Be- same roads that we had used on the boring country were obtained. cause it was getting late no attempt upward trip. Upon our arrival at the top the an- was made to receive the long wave sta- Although much better results might tenna was strung between two boulders tions as we had at first intended. We have been obtained had the climatic op the very top of the mountain. Upon were very thankful that we had not conditions been better, we were very one of these boulders there is a map used a regenerative receiver because, well satisfied with the results obtained case erected in memory of a soldier with the rain and wind, fine adjust- and were very glad to have had the who gave his life in the World War ment of the circuit would have been opportunity of operating the first re- and one end of the hundred feet of impossible. ceiving set on Mount Marcy, the high- stranded copper wire was attached to On the return trip a much easier est point in New York State. a leg of this case. For the other end and shorter trail was used. It is known a length of rope was passed around as the Van Hoevenburg Trail, the same another boulder to which the antenna that we intersected on the upward trip You will find A Good Portable Receiver described on page 54 Make it and try Mount Marcy yourself!

Also,-if you are interested in Receivers- Examine the new D -Coil Receiver described by the designer on page 34

The open camp at the foot of Colden

www.americanradiohistory.com "Hello, Hello! Radio Exchange? Give me 2X9, please" L.L 3®®®EC:3 ,sPc Test Room 3®©®?' 71.71 r771 r, nary Telephone C/Wt

Wave Length 420Meyea =. 380ek 9,° Telephone

GRyt eoo 5aeo, ayReIlbenr9tr...... To, TnnvmWy Sylt, \ A Conversation by Radio Talking to Ships at Sea

By Walt. S. Thompson, Jr.

ships and shore, as well as one by mittirg stations, the construction of which three conversations with three buildings and antennas, the equipping different ships could be carried on from of stations with apparatus, the equip- one shore station, each conversation ping 3f ships. and the final operation being independent of the other. and tests of the completed system. 1-RO1;ABI.Y all the readers of this The engineers who designed this sys- In the completed system, two -way magazine are radio fans and have tem were confronted with both techni- conversation was obtained by using been enjoying the programs trans- cal and practical problems, a few of different frequencies or wavelengths mitted from the various broadcasting which may be mentioned as follows : for sending and receiving. Because of stations, but it is doubtful whether The perfection of a two -way radio tele- the highly selective receiving circuits. many of them have ever carried on a phone apparatus to meet the above - only a small frequency difference be- telephone conversation through the air. mentioned requirements, the perfection tween the two channels was necessary. Although the possibility of ever using of transmitting apparatus, the develop- In order that three conversations could a radio system as a means for convers- ment of a selective receiving system be held simultaneously and independ- ing with one's friends seems remote, which would allow the use of a narrow ently. three separate transmitting sets such service will no doubt eventually frequency band, the location of trans- and three separate antennas were used. be available to the majority of telephone subscribers. and will enable them to communicate by telephone with ships at sea. \Vhen this new telephone service goes into effect, the business man DEAL BEACH or any other telephone subscriber will TPANSM/TT NG be able call ± to pick up his receiver and Fr Sr a steamship just as he is now able to call some distant city. This service. however, will be limited to ships which are within a certain distance from shore. It is the purpose of this article to describe very briefly the development of this radio system and to give the reader sonic idea of the apparatus used. as well as its operation. This development began in 1919 when the engineers of the American Telephone and Telegraph Company and of the Western Electric Company started working on the problem of de- vising a means by which any telephone ELBERON subscriber could talk with those on RECE /v/NG board ships at sea. This, of course. Graphic illustration of the Deal Beach central station conducting two-way phone necessitated the development of a two - communication with a ship at sea way radio telephone system between 30

www.americanradiohistory.com 31 1 t r. 1924 DUPLEX RADIO TELEPHONY

I\ fter the apparatus had been developed in the laboratory, a model transmitting system of low power was set; up at (_'liflw-vood, New Jersey. With this: transmitting system and receiving sets located at a distance of about sixteen miles. a thorough operating test will.; made. This test showed that three cot yersations on carrier waves of 725, 75 and 775 kilocycles per second could lie separated at the receiving end with- ut any perceptible interference between them. and that interference from other continuous wave stations was negligiltle. While these experiments were being carried on at lliffwood, work was started un the permanent transmitting station at West Deal. New Jersey. The ]ari. cr building shown in the picture is the, permanent housing for the sets, and the smaller is used for experimental work. The three steel towers. each of which is 165 feet high. forni an equi- lateral triangle, 500 feet to a side. aau Three steel cables join the tops of these One of the transmitting units. In this figure can be seen the various shielded compartments towers, and three more inward which contain the master oscillator and various amplifiers, six radio frequency power amplifier extend tubes. six modulatnr Dower tubes. a few choke coils. circuit breakers. etc. and meet over the station. Four antennas are thus supported. one antenna cies. The four receiving sets with their ceived waves, coming from Elberon, going to the middle of each of the first loop antennas are located at re- from reaching the transmitter. mentioned cables and rising the one verti- ceiving station at Elberon, about a mile One operator seated at the switch- cally to the middle of the triangle. north of Deal Beach, and are connected board has complete control over all the The anal system as installed at Deal to Deal Beach by a twenty -wire tele- transmitting apparatus. The dials con- (leach makes use of these four anten- phone cable. trol amplification and, by means of nas and four transmitting sets. each The general principle of operation is jacks and cords, any New York long indicated in the figure showing the ship distance telephone circuit can be con- station using only one antenna for both nected to any one of the four radio transmitting and receiving, although circuits. two different carrier frequencies are In the final layout of the various used. The dotted lines in this figure stations, there are two operating shore indicate the three stations, that is. one stations, one at Deal Beach, New Jer- transmitter at Deal peach, one receiver sey. and the other at Green Harbor. at Elberon. and one transmitter and Massachusetts, and an experimental receiver on the ship. It will be evident station at Cliffwood, New Jersey. The that the speech waves coming in from ships on which the stations were in- the left over the land wires will be stalled operate between Boston and amplified by the speech amplifier and Philadelphia or Baltimore. The dia- will be impressed on the radiated radio grammatic picture shows how a con- frequency waves. The complete wave nection is set up between one of these sent out 1w the transmitter is desig- ships and a telephone subscriber. In nated as F, ± S, to indicate that the the instance illustrated here the Deal radio frequency wave with a frequency Beach transmitting station and the El- of P, has impressed upon it a speech beron receiving station are connected frequency Si. These waves are re- to New York by wire circuits, and are ceived at die ship which in turn sends in communication with the steamship out a radio wave designated as P, ± .1 nierica. S. This wave is picked up by the Probably the most interesting ex- loop antenna at Elberon and is de- periment carried on with this apparatus tected and amplified before it goes out was the instance in which a telephone on the telephone line to Deal Beach. conversation was carried on between At Deal Beach the received wave the S. S. Gloucester in the Atlantic passes out over the telephone line with- Ocean and an operator on Catalina out affecting the transmitter. The pur- Island in the Pacific. This circuit was pose of the hybrid coil and the bal- made through two radio links, between A transmitting unit such as installed on ancing network is to prevent any re- the S. S. Gloucester and Green Harbor. board ships Massachusetts, and between Long Beach, California, and Catalina Island. with a power output about equal to and one wire link between Green Har- that of our larger broadcasting sta- In an early future number will be bor and Long Beach. The quality of tions. One set and the vertical an- published an interesting European de- transmission in this case was sufficient tenna are tuned to 600 meters for velopment of a radio telephone service. to enable the operators to understand calling purposes and for emergen- each other perfectly.

www.americanradiohistory.com 32 PICTORIAL SECTION JUNE. 1924 The latest Shubert success,"Vogues," broadcast direct from the Shubert "Vogues" Broadcast Theatre by WJZ, has excellent music, good comedy and,fine dancing

Odette 3lrlrttl and Irene Del- ro y in a whim- sical number

Anna May Dennely in "rogues" 1

Betty Compton *O in one of her dances Jimmy ,Saro and Fred Allen, the "laugh manufacturers" 2 _2 .1 l, I e

www.americanradiohistory.com Selecting Loud Speakers

The right loud speaker is one that will reproduce perfectly for the broadcast listener the concert which is being given at some broadcast station studio

By Dr. Alfred N. Goldsmith r. I. R. i:., Director of Research, Radio Corporation of America

TO compress an entire orches- racy of quality in the concerts sent out tra into a tiny circular sheet from such stations. In fact, a great deal -this is the audacious demand of the distortion imputed by some lis- of the modern radio engineer when he teners to the station is really due to insists that the loud speaker shall re- their unsuitable loud speakers. The produce perfectly for the broadcast lis- experience is often repeated of listening tener the concert which is being given to an exquisitely rendered concert from at some broadcast station studio. The a definite station on one receiving set, problem is really a comparatively recent only to he amazed at its poor quality one. While telephone receivers have on a nearby receiving set. It is for this been, known for fifth years. they were reason that the listener should suspend generally adapted only to reproduce judgment on the quality of a concert the \nice feebly and with fair accuracy until he has proven beyond doubt that at best. It vas necessary to press them his receiving set is correctly designed to the ear to understand at all well. and and used, and that his loudspeaker is they failed to reproduce music with any a good example of a reliable product. rule, short horns emphasize the higher reasonable degree of satisfaction. 1 f it Loud speakers in general include a so notch de- was attempted to stake lottil speakers pitched notes. However, strong magnet, which is either a per - of them, they rattled and distorted the pends on the angle of the horn open- manent steel magnet or. in a few ing and on its method of attachment. music badly. \ new electric and cases. an electrically- excited magnet, acoustic technique together with the characteristics of the has had to be de- which requires battery current for its veloped to meet the requirements of telephone receiver portion of the loud an functioning. There is also a coil of effective loud speaker, that no general statements speaker. Only after con- wire, generally wound over the per- siderable research and development has manent magnets. through which flow can be here given as guides to what it become possible produce to such de- the electric currents. which carry the constitutes a suitable horn. vice which will accurately follow their music in the forni of regular or irreg- in the development of the new vocal masters at the broadcast studio. ular fluctuations of these currents. In Radiola loud speakers which have been A little consideration will indicate some loud speakers, an iron diaphragm designed as the result of much sys- why the construction of a satisfactory is set into motion by the variation of tematic laboratory experimentation lit- loud speaker is so difficult. It must magnetism caused by the incoming erally thousands of accurate measure- faithfully reproduce all sounds from electrical currents carrying the music. ments have been made to avoid the frequencies as low as fifty vibrations or In others, diaphragms of mica or other common faults of most loud speakers. cycles per second -corresponding to materials are set into motion by me- Unfortunately the testing procedure the deepest tones of the organ and chanical systems attached to them, and laboratory arrangements are too piano frequencies as high as which, in -to eight turn, arc controlled by the technical and complicated to be de- or ten thousand cycles per varying magnetic pulls second- on a steel or scribed here, but they represent most corresponding to the highest overtones iron movable part of the system. The a interesting modern development in of the violin or piccolo and certain of exact arrangement of the loud speaker the field of sound reproduction. the 'overtones of the spoken conso- is therefore not yet standardized, but nants "s" and "f." It must be capable what is required from the loud speak- The principal faults of sonic loud of producing soft pure notes and also er is well -known tit the experts ; and speakers. and the general listening extremely loud notes. so that the ex- elaborate electro- acoustic laboratories tests for them are pression and meaning of musical com- have been established by the leading 1. The loud speaker fails to repro- positions or oratorical efforts shall not radio companies for the continued de- duce high pitched notes. but does re- be lost. it must accurately reproduce. velopment and improvement of the spond to low pitched notes. Such loud in correct proportion, the voice and its device. speakers will sound well on piano piano accompaniment. or the various Practically all loud speakers are pieces in the lower register. and on instruments which blend into an or- provided with a horn of wood. fiber. bass voices. Tenors and sopranos will chestral ensemble. And, when finally papier- mâché, or some other material sound thin and weak, and the violin produced, it must be a sightly or even which is believed to be suitable. A will lack piquant quality. being "flat- ornahtental article since its place is gen- great deal of the quality and sensitive- tened out" into flute quality. Speech. erally in the home. ness of the loud speaker depends on and particularly feminine speech. will Great care is taken at high -grade the materials, shape. and mode of at- not be fully intelligible. Orchestral broadcasting stations to insure accu- tachment of the horn. As a general (Continued mt page 63) 33

www.americanradiohistory.com The D -Coil receiver is seen resting on the top of a console victrola. The output of the receiver is connected to a phonograph attachment which is attached to the vie - trola. The panel of the receiver is mahogany colored and all the dials are of the same color. The cabinet has a veneer of dark brown leather over the wood and since the victrola is mahogany, the whole setting blends in very nicely

The D-Coul Receiver A Wonderful Circuit -De- signed on a New Principle A New Type of Transformer Provides a Stable Non -Oscillating TH E limitation in a radio receiving Radio Frequency Amplifier- Covers a Wide Range of Wave- set employing several stages of lengths-- Outdoor or Indoor or No Antenna -Easy to radio frequency amplification is Construct Simple to Tune that the tubes in the radio frequency - stages tend to oscillate due to the back By K. M. MacIlvain coupling in the different radio- frequen- cy circuits. The greater the number circuits. Many circuits employ a re- neutrodyne receiver when placed at of tubes used for radio - frequency am- sistance in the circuit to damp out the just the right angle may be got into a plification the greater is the tendency oscillations and the loss thus intro- small space and at the same time have for these tubes to oscillate and there is duced is probably so great that it would zero coupling. That angle is a critical a definite limit to the number of tubes be possible to cut out one tube to angle and for the amateur building his that may be used in any of the stand- eliminate the damping resistance and own receiver it is a mighty hard one ard circuits published up to date. still get the same volume in the output to find. The following is the description of circuit. The D -Coil or astatic receiver is an the construction of a receiver that uses The neutrodyne receiver uses neu- advance over most modern circuits, as it special coils or transformers in the tralizing condensers to balance out the employs no neutralizing condensers and radio -frequency circuits which so stab- back coupling. due to the capacity feed no damping resistance, and principally ilize the circuits that, using the number back in the elements of the tubes. But it is better because the radio - frequency of tubes shown in the accompanying this does not neutralize the feed back amplification can be carried to a higher circuit diagram. there is not the slight- due to the coupling between the in- degree. In other words, more stages est tendency for self oscillations, and ductance coils in the different circuits, of radio- frequency amplification can be therefore the maximum amplification and many B. C. L.'s who have con- used and consequently greater distance possible with the number of tubes structed their own neutrodyne receiv- and more volume may be obtained. shown can be obtained, as each radio - ers find it exceedingly difficult to neu- This seems perfectly reasonable to ex- frequency circuit may be tuned right tralize their sets properly, due to the pect, since there is no tendency to os- on the peak of the incoming wave with - fact that these neutralizing condensers cillate with the number of tubes used out the usual howling and subsequent will not balance out the feed back due in the circuit that is herein described. loss of intensity experienced in the ma- to the coupling between the coils. The The amplification can be carried along jority- of radio- frequency amplifying radio experts say that the coils in the further to a point where oscillations 34

www.americanradiohistory.com \ l- 1921 THE D -COIL RECEIVER 35

ONO

90V+ 45V+ 222 +

oit diagram of the D -Coil Receiver, showing the astatic transformers and their connections. In connecting the transformer follow the directions carefully as given in the text. Reversing one connection will render the set inoperative

Will Ct,mnlcncc and When this point is through from one end to the other as reached. some neutralizing unit may he LIST OF PARTS the tubing would then be in two sec- employed and the amplification carried One 7 "x26" Box tions, therefore the Y1 -inch spacing is still ftttthcr. One 7 "x26" Radion Panel left at one end to make the tube sel f- The heart of the astatic receiver cir- One 7 "x25" Base board supporting. The windings consist of Five Paragon sockets cuit is in the radio -frequency trans - a primary and a secondary wound with One 30 -ohm rheostat mound in a special No. 24 double cotton -covered copper fornteri which are Two 6 -ohm rheostats 10 in manner'¡ so that the magnetic field Three 43 -plate Cardwell condensers wire. There are turns the pri- around ¡them is neutralized and there Two Acme audio frequency trans- mary winding and 40 turns in the is therefore no coupling from one coil formers secondary. Fou- binding posts for the to another. Due to the fact that these Three pieces of bakelite tubing 3" long terminal connections to the two wind- transformers have a neutralized held One filament switch ings are mounted at one end of the they tn(ty be located in the receiver Three 4" dials tube as shown in figures 2 and 3. Two assembl i n a vertical position, and it ACCESSORIES for the primary winding are mounter) is not n cessary to spend a lot of time Five UV -201A tubes at the bottom of section (A) and two in settit g them at some critical angle One 6 -volt, 100 -amp. hr. storage battery for the secondary at the bottom of as is ndcessary with the coils or neu- Four 22% -volt batteries section (B). For the purpose of dis- troformers used at the present time in One loud speaker cussion these are numbered 1, 2, 3 and the standard circuits. There will be One plug -l. respectively. Good serviceable bind- zero coupling between these trans- One pair of phones ing posts may be made from :,A-inch One aerial with formers when aligned in a vertical posi- accessories 8/32 round head brass machine screws tion. In the test circuit which the with nuts and washers to fit. author built these coils were set a dis- Now start the winding. Cut off a tance althrt just great enough to mount inches in diameter. With a hack saw. piece of No. 24 D. C. C. wire about 14 a tube socket between them. Since cut a / -inch slot down the side of feet long. This will be long enough these coils are the heart of the circuit each tube, starting at one end and cut- for the primary winding with a good it is essential, at this point, that their ting to within 3 of an inch of the surplus for connections to the binding construction be described in detail. other end. Also, on each tube, posts. Connect one end of this wire cut a similar slot on the oppo- to the binding post marked No. 2 in CONSTRUCTION OF TRANSFORMERS site side, diametrically opposite as figure (2), and connect the end of the First, procure three pieces of bake- shown in the diagrams. Obviously, it wire left on the spool to the binding lite tubing, three inches long and three wouldn't be advisable to cut straight post marked No. 3 in the figure. Since

This picture shows the proper arrangements of the various instruments. The layout provides short connecting leads and easy assembly. A 4!í -volt "C" battery is shown on top of the first audio frequency transformer (from right to left)

www.americanradiohistory.com 36 THE WIRELESS AGE JUNE, 1924 binding posts 1 and 2 are the primary section of the winding is in the oppo- winding is connected to the ground. ttinding terminals, and since binding site direction from that in which it The ground is tied through to the grid - posts 3 and 4 are the secondary wind- flows through the wire in section (A). return of the first three tubes and to ing terminals, we thus have the be- These magnetic fields will be equal the negative filament terminal of the ginning of both windings. with the since they are produced by the same first two tubes. two wires connected to terminals 2 and current flowing through the same num- The antenna circuit simply functions 3 as described above. Starting with ber of turns and they will be opposite as an untuned pick -up circuit for radio- the wire attached to terminal No. 2, and thus tend to neutralize. The re- frequency energy and this energy is wind in a counter -clockwise direction sultant field, then, if any, will be very gassed on to the grid circuit of the first until you come to the slot, marked (x) small. radio - frequency amplifier by means of ill figure 2. Pass the wire through TILE CIRCUIT the coupling between the 10 -turn pri- this slot and out through the slot on The schematic diagram of the astatic mary and 40-turn secondary of the first the other side of the tube. marked (y) receiver is shown in figure 1. The astatic transformer. The transformer in figure 2. Now continue in a clock- is so designed as to provide the trans- wise direction past binding loost 4. and fer of a great amount of energy be- when you come to binding post No. tween the antenna circuit and the first 3, pick up the beginning of the sec- amplifier circuit. The secondary of ondary winding and wind it in parallel Terminals Terminals this transformer is tuned by means of with the rrimary winding, both wires for for Primary secondary the 43 -plate variable condenser con- side by side. Continue the double winding w nected directly across the terminals of winding until you collie to the slot (x ), this winding. .\ variation of this con- pass the wires through this side and denser from minimum to maximum out the other side at (y). proceeding tunes in stations between 100 meters with the winding in a counter- clockwise and 650 meters in wavelength. Thus direction on this side. \\'hen ten turns everything from amateurs. through the have been around on. drill a small hole broadcast range and up to the com- in the tube at the tenth turn and in mercial ship and shore stations can be line with binding lost No. 1. Pass the tuned in on this combination. end of the wire being used for the The plate of the first radio-f requen- primary winding through this hole and cy amplifier tube is connected to the connect it to binding post No. 1. 45 -volt tap of the "B" battery through One complete turn, starting at ter- the primary winding of the second minal No. 2. for instance, is traced in astatic transformer. The secondary of a counter -clockwise direction to slot 2 3 this transformer is tuned in the same (x), through the center of the tube and Figure 2 way as the first and the amplified out at slot (y), in a clockwise direction energy applied to the grid of the sec- past terminals 4 and 3, through the ond tube. The plate circuit of the slot at (x), out at (y) and in a counter - second amplifier tube is a duplicate of clockwise, direction back to the starting the first. The secondary of the third point. The primary winding having astatic transformer is in the detector been thus completed. continue on with .circuit and is tuned in a similar man- the secondary winding until 40 turns ner to the first two and the energy have been wound on. Drill a small applied to the grid of the detector tube hole in the tube at the 40th turn and ? B through a .00025 mfd. condenser and in line with binding post No. 4 and Figure 3 figure 4 a 2- megohm grid leak. connect the end of the secondary wind- These sketches illustrate the method of wind - There is a double circuit jack in the ing to this terminal. One astatic trans- ine the D -coils described in the text plate circuit of the detector tube which former is thus completed and two more is wired up as shown in figure 1. If are wound in a similar fashion. Two first two tubes are radio- frequency am- the phones are plugged in here, the hundred feet of No. 24 double cotton - plifiers, the third is the detector and circuit to both sides of the primary covered copper wire will be enough the last two are the audio amplifiers. winding of the first audio frequency for all three transformers and there UV-201A tubes may be used through- transformer is opened and the plate will be a surplus. out, or they may be used only for am- circuit of the detector tube is com- just a few lines to explain why these plifiers and a UV -200 tube used as a pleted through the phones. When the transformers are so efficient in the cir- detector. The filaments of the radio - phone plug is removed, the primary cuit in which they are used. The fol- frequency amplifiers are controlled by winding of the audio frequency trans- lowing theory will explain why they means of the 6 -ohm rheostat shown in former is connected in series with the have a neutralized field and thus afford the figure and connected as shown. Six plate instead of the phones and the no chance for back coupling between ohms is sufficient to control these two audio frequency energy is passed on to the coils. Looking at figure 4 and tubes connected in parallel. The de- the grid of the first audio frequency assuming a current flowing in the sec- tector tube is controlled by a single amplifying tube. The plate circuit of ondary winding due to signal current rheostat and if a UV -200 is used for this tube is a duplicate of the detector flowing in the primary, as the current a detector the resistance of this rheo- tube plate circuit with the exception flows through that section of the wind- stat should be 6 ohms, but if a UV- that it is tied on to the 90 -volt tap of ing marked (A) it will produce a 201A is used this should be a 30 -ohm the "B" battery, whereas he detector magnetic field which will be in the rheostat. The two audio amplifiers are tube plate was tied on to the 22/ -volt direction as shown by the line and controlled by the single 6 -ohm rheostat tap. arrows on that side. The same current shown in the figure. The antenna cir- If a 201A tube is used as a detector flowing through the section marked cuit is untuned. One terminal of the the plate voltage may be increased to (B) will set up a magnetic field in the primary winding of the first astatic 40 volts. although there is little differ- opposite direction as shown by the transformer is connected to the an- ence in the volume obtained and there - arrows, since the current through this tenna and the other terminal of this (Continued on pupe 74)

www.americanradiohistory.com s- 50 TURN HONEYCOMB CO /L

.0005 Mr VAR /ABLE CONOEN5ER

GROUND Increasing the Range of Your Super- Heterodyne By William J. Smith

type of Radiula Super - tuned to resonance with one another volume %vill result. I recommend this Heterodyne tthìch is equipped and to the frequency of the incoming connection to those who have not had T,w,-wih a small self -contained loop signal. then a marked increase in sig- the opportunity to construct a larger provide. a greater range of reception nals will result; in fact, so much so loop for the Super -Heterodyne re- than anj type of radio receiver which that it is usually necessary to decrease ceiver. the writer has ever witnessed in opera- the sensitiveness of the Super- Hetero- I have not vet found it necessary to tion with a loop of such small dimen- dyne for quieter operation. It will be use a headphone with the Super - sions. 1In the Eastern part of the found that an increase in signals can be Heterodyne set to locate a far distant 1.uitccl States one is enabled with this obtained even though the honeycomb station, as the sensitiveness of this re- compact (outfit (often to secure loud coil is three or four feet ( listant from ceiver is such that it will invariably speaker operation from stations as far the loop of the Super set. overate the loud speaker satisfactorily. \Vest as I )saver, Colo., and further. In general. the process of tuning By the use of an enlarged external which I usually employ is the follow- loop. consisting of fifteen turns of wire ing. Distant stations are first logged spaced three- quarters of an inch apart on the Super -Heterodyne set in the and wound on a rectangular frame usual way but using the loud speaker.

1 14, 2 inches in width. 10"4 inches in The station desired is picked up on the depth and 25 inches in height I. it was Super set. being tuned to resonance on easily possible to obtain loud speaker the two tuning dials in the ordinary operation from the Pacific Coast with manner. Then the antenna is tuned quite some regularity. even when a to resonance with the Super set by local broadcasting station only three - means of a small variable condenser. quarters (of a mile away was in opera- and when resonance is located. a very tion. and with a difference in wave- marked increase in the loud speaker length of only 9 meters. In event that the owner of one of these splendid equipments is not in a position t(1 construct a loop of the dimensions which I have set down above. 50 TURNS- HONEYCOMB COIL the reccil ing range of the semi-portable Sup er -1 leterodyne can be materi- ally increased by the method shown in N\ Figure 1. where. a small honeycomb coil of approximately fifty turns and a AERIAL variable condenser are connected in series with the usual type of aerial. GROUND When the honeycomb coif is placed parallel with the loop inside of the Super- heterodyne Lox. and the antenna. as 0005' MFD. VARIABLE CONDENSER %yell as the Super- Ileterodvne set. are 37

www.americanradiohistory.com Boys! Gather 'round!

The Boy Scouts of America What Radio owes to them and what they owe to Radio By Pierre Boucheron A pioneer in the Radio Industry Tells how the Boy Scouts and Radio hit it off together

BOYHOOD LEADS TO RADIO The Beginning of a Career As told specially for Boy Scouts By Pierre Boucheron I will tell you how I entered the radio profession. First I learned the American Morse code jointly with a boy friend back in 1906. We strung a wire between our houses about two city blocks apart, then we made our own telegraph instruments, winding the electro magneto by hand. The line was the closed circuit method and worked quite well with bluestone batteries. Every morning and night we "spoke" to each other for a brief spell by means of dots and dashes. In three months we were proficient enough in telegraphy to be able to converse quite clearly and rapidly and three months later reached the speed of 25 words a minute. Frequently we spent some of our spare moments with the agent and operator of the nearby railroad station who permitted Members of the Boy Scouts of America made tests for "dead areas" in Central Park with a us to send and receive portable radio set, and acquired useful data for future experimenting occasionally a real telegraph message over the regular railway telegraph circuit. IT is a long way back to those days haps as no other art, of being especially Later I obtained a summer job in a man's As a a telegraph office during the school of Greece, in which the romantic boy's and young game. vacation period. I don't recall ever figure of the Marathon runner was matter of fact, the great progress that having spent a more enjoyable va- the sole means of communication be- radio has made during the past five cation while at the same time earn- tween the cities of this early democ- years can be directly attributed to the ing money which came in good imagination and of boys, who stead when school started again in racy. energy the Fall. The classic the runner began to experiment with radio shortly story of Then in 1907 came radio ama- Phidipides, who bore the news of the after Marconi's first successful tests teurism. There were about seven Greek victory of Marathon for a dis- back in 1920. amateurs in New York City then. tance of some twenty odd miles, then It was the after -school experimenta- How proud I was to be one of them! to drop dead from sheer exhaustion. tions of Edwin H. Armstrong that In August, 1912, I sailed away on is men a big freight ship as wireless oper- a story that stimulates boys and gave to radio that famous device we ator and in the succeeding four alike to an appreciation of the un- call the regenerative circuit -a circuit years I saw every important part of swerving purpose and tenacity of this that jointly with the vacuum tube has the world. But best of all was the man to perform the task given him done more to bring the broadcasting experience that thousands of others like myself obtained out of the though it cost him his life. art to its present state of usefulness War by enlisting as wireless opera- Great strides have been made in the than any other single invention. tor in either the Army or Navy. science of communication since that Of the men who are leaders in radio time. Today the boys of our Nation today, whether in the long distance are spared from such undertakings, radio telegraph, marine or broadcast- for electricity has become the standing fields, there is hardly one who did ard message bearer the world over. not start his career as a boy experi- With such a display of intense interest First, science gave to mankind the menter between the ages of 14 and 19. in the art. the future has surely many telegraph, then the telephone, and now Today there are in round numbers wonderful inventions and develop- radio is ready to serve every man, about 500,000 Boy Scouts in America. ments in store for us. With thousands woman and child. Probably three out of every four Boy of boys experimenting, playing and Radio enjoys the distinction, per- Scouts has made or owns a radio set. studying radio. -growing up with the

www.americanradiohistory.com Just:,1924 THE BOY SCOUTS OF AMERICA 39 business, as it were, -there is now wire work such as commercial teleg- day for at least an hour. After a short building up a reserve of talent that raphy, railroad, news and stock broker time he will be able. to understand the %yin make our present prophecies of communication ; the Continental Morse now meaningless dots and 'dashes, radio movies, radio vision, radio trans- for cable and radio communication. especially the messages exchanged be- mission of power, etc., pale into insig- While it is advisable to become adept tween amateur stations that usually nificant child's play. in the use of both codes. I rècòlmnend operate on 200 meters. Radio, of course, is not the special learning the Continental Morse Code, And now we come to what this ability plaything of any set or group of boys. as this is the code used exclusively in may lead to. When a Scout is older In point of cost it is easily within the radio work. One. should first_ memor- and has left school, he can take up any reach of every wide -awake boy in the ize the dots and dashes of The Contin- one of a number of well -paid profes- country. A resourceful boy of 14 tells ental Code so each character can be sions that require proficiency in send- me he has built himself a complete ticked off with a pencil or coin on a ing and receiving telegraph messages. crystal receiving set at a total cost of table or other hard surface. It takes A few of these positions, as they occur one dollar. Another boy of sixteen on an average an hour to memorize to me. are: (Continued on page 751 with more well -to -do parents has the characters. It is bought himself a complete vacuum much easier to attain r

www.americanradiohistory.com Radio in the Canadian Wilderness Our adventures over the portages and down the crest of White Water By Sinclair Arthur

HOBART and I decided to out into the lake they paddled, never take our vacation in the Can- faltering, never relaxing a stroke. DR.adian wilderness. The idea ap- Across the lake and down the Ship pealed to us. The wilderness, where shave we glided. The immenseness of men imagine they are men. country seemed to enfold us, gently We did think enough of our tame at first, then seeming to close behind civilization, however, to include a us, and finally we could feel the pull good, portable radio set in our equip- of the North. We could almost sense- ment. the fear that all natives of that wilder- On the way up to Chicoutimi we ness learn to know at an early age. learned that a trip into the interior of Every family out in that vast wil- Labrador, entailed something of an derness has lost a friend or relative exact science ; namely, the science of who has strayed too far from the economy. Our kindly adviser -who, trails -and never conk back. The by the way. happened to be the mayor little villages are clearings. Not a of Chicoutimi -told us that one simply tree within the forest line. The people doesn't carry excess baggage. He ex- are afraid of the forest. They do not plained in detail: want trees in their yards. in the streets. A canoe, of course. would be neces- or in the town. sary since travel of any extent during Doc suggested that we get out the the summer months could only be ef- radio. fected by water. One blanket for each "Be yourself. Doc." I chided. would be required. Cloth- individual Our guides. The Indian, Joe, on the left, the "Jacques made us leave the set in ing should consist of no more than French -Canadian, Jacques, on the right Chicoutimi." light felt boots. khaki trousers, heavy But Dr. Hobart had been a pro- flannel shirt. felt hat and heavy under- and jump over the tree stumps mil fessional man for a long time. "These wear. rocks. C'ana(ians.- he replied. "have recon- A rain coat would be superfluous The supplies and equipment were ciled themselves to the idea of visitors since one would undoubtedly perspire loaded in the canoe. Doc and I sat in from the States coming here to enjoy enough to warrant a soaking now and the middle. and the Indian. Joe. the freedom of the trails. and incident- then. kneeled in the prosy. Jacques occu- ally. to escape from a remarkable :\ not for tea and a pan for the pied the stern. amendment in the Constitution -the foods would suffice as cooking utensils. Everybody in the camp calve clown eighteenth. I believe." A tent for the guides and a tent for to the shore to wish us luck -and lots "Yes ?" I encouraged. us would serve as shelter. One gun. a of it. Jacques gave the word, and "So," he finished. "I put the radio in hatchet and a heavy jack -knife would with that, he and Joe swung the canoe a wooden box. marked ` iohnny Wal- complete the essentials. out into the water with short, power- ker.' " "Of course." the mayor concluded ful strokes. All woodsmen in Callada However. we had very poor results as he shrugged his shoulders. "you are proud of their paddling skill, and without an aerial. The guides sniffed. will probably carry liquid refresh- their strength. Jacques and Joe put Toward evening we landed, and ments, but you'll regret it on the por- their soul into that exhibition. Away prepared for a two -mile portage. Each tages." one of us had to carry a big Our guides. a French - load as it would not be prac- Canadian and an Indian, pro- ticable to return for any part tested vigorously when they of our equipment. learned that we contemplated The land rose up to a high the inclusion of our radio in ridge that we had to cross. the equipment. It was cer- Bending low under our bur- tainly apparent that every dens, which we held on our ounce would count. shoulders, a strap hooked to We had a thirty -five -mile the baggage and passing drive north of Chicoutimi to around our foreheads, we the head of Clear Lake. Most stumbled over rocks and of the road consisted of logs bushes. clutching at boulders. laid cross -wise in the trail. or saplings. or any object Large holes and occasional that might offer a means to stumps marked the course. pull us up the incline. The French- Canadian. Jac- Gnats and small, black flies ques, demonstrated his skill gathered around our heads in as a chauffeur by trying to black swarms. They flew leap over most of the pits The camp at the head of Clear Lake into our eyes. crept into our 40

www.americanradiohistory.com i i x t:, 1924 RADIO IN CANADIAN WILDERNESS 41

nostrils and ears and crawled down our necks. We began to realize the tortures of a portage. The need for economizing in equipment was obvious. Halfway up. Dr. IIobart's load caught oft a lots branch. pulling him hack on his heels. i le struggled for a moment. clutching at the air. \nd then he toppled over. "Be yourself, I)oc!' I yelled. "Shutt up! he growled. The lau4h froze within nie. The

radio was in his pact: ! Over the ridge. we stopped to rest. 'eloty us was a great clam under construction. The workmen's camp lay at the edge of a clearing that somehow reminded me of a circus. It certainly Dr. Hobart trying to cook a strip of bacon on the end of a forked stick. He couldn't accomplish seemed out of place. A great tvall of the feat satisfactorily. This is where we made camp at th: mouth of White Water concrete towered above - reached above the tree tops. At the furthest party was loaded into the canoe, and And again we tvottld plunge and leap end steel rods projected from wood our journey down the "White \Vater" clown the "White Water." palings. Derricks swung huge iron commenced. All clay we rode the crest, every mats over the heads of workmen and In Canada there are many unnamed minute a hair- raising experience. Long dro1ped them into place. A trei end - rivers called "White \Vater" because into the evening we kept on our course. ou, activity covered the ground for the water i1oms between nigh cliffs at A steady, high- pitched swishing .acres around. But the scene appeared a terrific rate, whipping the center into sound caught my attention. It grew to be a miniature puppet show. The foam. louder. The noise resembled escaping tiny figures appeared to be occupied sacques informed us that we would steam. I leaned back to ask Jacques with senseless. futile tasks. lost in the travel that day without stopping (it what it was. He nodded his head in- vast wilderness that seemed to smoth- luck was with us) until late at night. dicating that I should look forward. er the puny efforts of man. Not only that, but we would also travel I slid. The foreman told us that British in the exact center of "White \Vater" A solid mass of white loomed up. interests were building a dam that or lose our equipment as well as our The river ahead was seething foam, would require eight more years for precious persons. boiling over rocks, spurting up from completion. When finished, he in- The canoe was launched. The black, the cliffs at each side, rolling back over formed us, it would furnish enough swirling water caught the craft with itself in licking tongues of black water electric power for the North American a jerk. A few swift strokes of the flecked with white. Continent. The builders forbid any paddles projected us into the foam. I grabbed Dr. Hobart. The next publicity because they feared opposi- _\ sickening lurch threw us around. instant I was blinded with spray. . tion would result should the Canad- and head on into the spray we hurtled Water poured over my head. I gasped. ians learn of the extent to which the at a furious speed. The canoe keeled over, jerked to the (tam would inundate the surrounding We seemed to be riding higher than left, skidded, then swung to the right. country with water. the shore water. Conversation was A deafening roar lulled my senses. A 'l'hat evening we entertained the impossible most of the time. Occa- crash- water -more water- men of the camp with our radio. They sionally Joe, the Indian, would lean We glided along evenly. I opened offered to take up a collection for the forward, point his paddle, and then, my eyes. Joe was laughing. set if we would sell it. Upon refusal. with a yell, plunge it into the water. "All right, boys !" Jacques cried however. we were oath -bound to send elbow deep. The canoe would shoot from the stern. "We rode the rapids them a good one when we reached around a boulder. Jacques would pull and only lost a paddle." civilization again. our craft around into its course with The shore line sloped down to the By six the next morning, our little a cleft twist of his paddle in the stern. lake ahead. \Ve pulled over to the bank, fastened the canoe, and jumped ashore to stretch our cramped legs. While Dr. Hobart and I examined the radio, the guides put up camp. It was 10:00 P. M. by my watch. The sun had just set, and darkness had begun to settle over the still forest. Never in my life have I enjoyed a Looking across Pike radio set as I dici that night. The four Lake from the Indian of us lounging around the camp fire camp. Something of the listening in on immenseness of the Ca- the organ prelude, nadian Wilderness can "Adagio," from First Organ Sonata be detected here by Mendelsohn, broadcast from WGY. our silhouettes thrown out into the dark amphitheatre that lay below the interlocking branches of the trees, reminded me of many Arabian Nights' tales of magic boxes working their wonders in the enchanted forests. (Continued on page 78)

www.americanradiohistory.com The light and Wrong of Deceiver Tuning How to Prove That You Are Right and the Other Fellow's Wrong - L. O. Marsteller, Radio Engineer, Westinghouse Electric êI, Manufac- turing Co., Tells How Different Types of Receivers Should Be Tuned

ARADIO listener tuning in late cuts you dead, or slanders you! yond the point where the hissing on a program can be just as Yet it is so very easy to tune your sound is heard or you will hear a much of an annoyance to those receiver in a proper and entirely un- whistle or squeal, indicating that you around hint as if he were actually ar- objectionable manner. Here is the are sending out an interfering wave riving late at church or concert or way of it. which will interfere with your neigh- theater. making a noise and fuss about * * bor's reception. getting his seat. and obstructing the There are several types of receiving Ifa slight change of the tuner ad- view. sets which will act as transmitters, and justment causes a squeal or whistle to Do you tune by the hit -or -miss which will, if improperly tuned, annoy -3e heard, you should immediately method? But you would not play your neighbor with squeals and whis- remedy matters by decreasing the baseball that way, or tennis. You tles. One of these is the single circuit tickler until the whistle disappears. If would break other people's windows. receiver. There are two controls on a you do not decrease the tickler setting, You wouldn't play bridge that way, or single circuit receiver. One of these your set will continue to act as a trans- you would likely break your own controls is known as a tuner handle or mitter and radiate an interfering wave. pocketbook and your partner's heart. knob. This control makes it .possible This will cause your neighbors to re- A logical,, scientific method of doing to tune in one station and eliìninate ceive a whistle mixed in with the con- anything is always tobe preferred. It another. The other control. is a tickler cert music from the broadcasting sta- gives the best results, the greatest sat- or intensifier. Its purpose is to in- tion. Many times music of excellent isfaction and causes the least trouble. crease the signal strength. Both tuner quality is condemned because of the :Apia hävè. 'probably very little idea and tickler should be operated simul- interference caused by the wave sent 4 the amount of trouble you cause by taneously. Now let us consider the out from a neighbor's receiving set. t! uin yotir receiver .by a hit -or -miss proper operation of this set. With a very little practice the single Method. Every night you may -un- circuit receiving set can be operated known by yourself:----be causing a hor- TUNING THE SINGLE CIRCUIT night after night without causing any rible annoyance to the neighbors with RECEIVER interference. whom you most desire to keep on \With the tickler set near zero, bring Another type of receiver which often friendly terms. If your formerly so- the tuner control to approximately the finds a place in . the amateur's home ciable neighbor for some unaccount- setting where you would expect to find and sometimes is used for broadcast able reason avoids you, or frowns at the desiredsignal, and, with the other reception, has one more control than you or looks a frigid scorn at you - hand bring the tickler control up to the single circuit set, making a total just consider if you have possibly been the point where a slight hiss or rustle of three controls. This is known as tuning some of your unskilfulness and is heard and keep the tickler so adjust- the three -circuit regenerative receiver. thoughtlessness into his radio receiver ed as you more accurately tune in the night after night. What wonder he signal. Never increase the tickler be- THE THREE- CIRCUIT REGENERATIVE RECEIVER One control tunes the primary or antenna circuit and the other tunes the secondary or tube circuit. The third control is marked tickler or intensifier. This receiver is very selective but requires considerable skill and patièiice in order to tune in weak signals; this type of receiver has three confrgls, and, as the average person has but tito hands, it is rather difficult to keep. the tickler properly adjusted as the *i- lnary and secondary controls are *r- ated. The general tendency is to "'set the tickler to maximum and then tine the primary and secondary until the whistle-like note of a broadcasting station is heard. That means that the operation has probably interfered with your neighbor's reception of the concert. In this pleasing radio atmosphere in an exclusive Manhattan millinery shop it should be a joy For people who only have tko to select a hat; but the purpose of this picture is to show how NOT to tune your receiver. Two hands, there is only one way to operate controls demand the use of both hands. The radio receiver is like all good musical instruments in this respect such a set and not cause interference, 42

www.americanradiohistory.com JUNE, 1924 RECEIVER TUNING 43 that is, to calibrate the secondary circuit by marking the proper setting clown on a chart. Then to tune in a station it is only necessary to set the secondary control to the proper point as determined from the calibration chart and adjust the tickler to the point where a slight hiss or rustle is heard as the primary circuit is tuned to the desired signal. This type of receiver should be used only when it is at a sufficient distance from other sets to preclude the possibility of interference. 1.INTUNED RADIO FREQUENCY RECEIVERS SO far we have considered regenerative receivers which are thought by many to be the sole source of radiation. But this is not the case. In sets which introduce radio frequency amplifier stages oscillations may be set up which radiate as effectively and cause as much Correct Tuning. The Reverend John G. Gebhard of Mount Vernon, N. Y.. knows how to get the hest results from his set. And, being a divine, he practices the Golden Rule. With his annoyance as the regenerative receiv- left hand he controls regeneration while the right adjusts wavelength ers. The oscillation of the radio frequency amplifiers may be prevented by a receiving set oscillates, the antenna spot where the station is found. On means of the potentiometer or stabil- connected to that set radiates energy either side of the exact tune there may izer. which is picked up by neighboring sets be noticed a squeal rising in pitch as in the form of "birdies" and squeals. you leave the station. If this condi- Actually, of course, these "birdies" or tion is present, your set is oscillating beat notes are the audible frequency and the tickler should be turned back. difference between the inaudible high Do not be tempted to turn it forward frequency wave transmitted from the to get additional volume. broadcasting station and the inaudible In radio every listener -in should con- high frequency current produced by form to the Golden Rule. your oscillating detector tube. You can usually tell when your tube Broadcasting Station at Santi- is oscillating by a peculiar change that ago, Chile takes place at the beginning of oscil- I? of the best of the South Ameri- lations. There is often a slight swish can stations is or rustle as the tickler reaches the os- O broadcasting that of Santiago, Chile. This station has a cillation position and it should be power of 500 watts, and operates with backed slightly below this point. a wave -length of 460 meters. A dis- station Your search for a distant tinctive feature of its broadcasting is should always be made with the tube the use of an assortment of micro- near to, but always below, the oscillat- phones so that an appropriately de- be ing point and the tuning can then signed microphone may be employed done with no inconvenience to anyone. with each different class of instru- This picture shows Mayor George E. Leach One more caution : You must not of Minneapolis tuning his set properly. His ment- string. woodwind. voice, etc., right hand is adjusting the regeneration con- be satisfied that because you hear no thus enhancing the quality of trans- trol while his left hand manipulates the squeals in your own receiver you are wave-meter dial mission of musical programs, which causing no disturbance in that of your have been heard satisfactorily in neighbor. You may obtain quite clear The only practical way of Buenos Aires, Bahia, Blanca, Bolivia determin- music or speech from your own, yet ing the point on the potentiometer dial and Peru. your set may be oscillating and a few beyond which the tube will oscillate is meters from you your neighbor is re- experience in tuning this set. As the Brazilian Broadcast Stations ceiving your radiation and that from effect of tuning dial is to four this noted, one the station at the same time. At times PERMISSION establish should remember for the commonly radio broadcasting stations has add and double strength and used wavelengths the critical points on they give been granted by the Ministry of Public then they substract and cancel the un- the dial, at which the oscillating effect Works of Brazil to the Brazilian modulated carrier wave from the sta- becomes audible in the phones or loud- Radio- Telegraph Company for the tion. causing a doubling of pitch. So speaker-and thereafter be careful to purpose of broadcasting information, your neighbor's program is ruined to those points not lectures, concerts. etc. The four sta- adjust and a bit beat note, and beyond. without any apparent tions are to be located at Sao Paulo, is not at own will the trouble apparent your Bello Horizonte, and Pernam- How far any of these types of receiver. Bahia receivers transmit ? Any one will buco. cause interference over a distance of An effective method for determin- This past year the Radio Society has four city blocks and can under most ing if your set is oscillating is the fol- been active in Rio de Janeiro and now favorable conditions he heard six lowing: counts about 800 members. This so- blocks away, or even much farther. In tuning. when you come to the ciety has been operating a small 10- So every radio listener shòuld re- station you desire, turn the wavelength watt broadcasting station at 10 Avenue member : \ \'hen the detector tube of control dial back and forth over the Rio Branco.

www.americanradiohistory.com Peeps into Broadcast Stations Service and Song Together

alone were all artists, musicians, com- been reluctant to attend any ,ort of a posers. etc., in the world to go on a political caucus merely because they permanent strike. It is equally true felt that a lack of understanding would that such service warrants. and will hardly reward the effort expended. receive compensation of some sort: Through broadcasting we will learn that is to say, the service is so essen- American politics. We will learn the tial that it will be paid for if need be." fundamentals by radio. and then read * * * the embellishments with a well balanced perspective. all the artists, composers. * * * SHOULDand musicians go on a permanent strike, this world of ours would be a years ago. a convention of sad place. And one wonders. too, SOMEreligions was held in Chicago. whether the service of which Mr. Among others. were represented Mullen speaks would have gained a Christianity, Mohamedism. Brahmism, foothold had there been no entertain- and Budhism. The history of religion ment to encourage the building of was reviewed. Then notes were com- broadcast stations sufficiently power- pared. ful to reach a wide area. Many people were astonished to learn that some of our most valued axioms are in the Bible of Brahma faith ; "penny -wise and pound fool- Patrick Cardinal Hayes broadcasting from ish," W EAF and "do unto others as you would have others do unto \ ou. In fact. FRANK E. MULLEN, Radio the Golden Rule was found to be the MR. key religion. Editor of "The National Stock- -note of Hindu man and Farmer." writes us: The Mohamedans teach five points "The radio industry in discussing of which "give honest weight." and broadcasting has been concerned too "revere thy father and mother" are examples side of commonly thought to be much with the entertainment Christian tenets. radio, which is necessarily a changing The followers of Buddah believe in phase. and too little with the service brotherly love. That isn't a bad re- side radio, which is certain to en- of ligion. dure And the Christians discovered 144 "In April number, the music your different sects in this country alone. the future of radio. and controversy, \ little more knowledge of religion what is to be clone, was discussed. but with little or no mention macle of the service features of radio. The entertainment problem was emphasized Anita Brown. National Radio Chairman. League of American Pen Women, broadcast from WJY

NTERTAI'NMENT. up to April, An enduring broadcasting service in was paramount. The Press, over America must function as entertain- the entire country. has emphasized ment, or at least be closely allied with that phase of broadcasting. But a features that entertain. change is already upon us. Entertain- The American people study their ment has blazed the trail for the ser- political lessons by cartoons. The vice features of radio. From enter- "Congressional Record" with its gratis tainment and service combined, cul- circulation has probably little influence ture evolves. We may have national as compared with the Sunday news- service. with the improvement of papers carrying comic supplements. broadcasting. and perhaps, soon, have The churches employ organ recitals an intimate international relationship and choir singing. founded on international service. * * * * * * ENTERTAINMENT is essential in MULT EN continues: "Our radio broadcasting ; but broadcast- MR.experience has been with a par- ing has unquestionably progressed to- ticular radio audience that will inward greater service. evitably use radio primarily as a ser- The National Conventions this June vice and enjoy it as a blessing to life. will be attended by radio millions who We do not mean to minimize the im- could never before attend. Many will portance of music and other radio en- listen in who could not otherwise afford the time and expense to go direct. tertainment. They are essential, but Judge Ben B. Lindsey, famous juvenile court radio could and would live on service Many others will listen in who have judge of Denver. broadcast from KHJ 44

www.americanradiohistory.com .Fi. 1924 PEEPS INTO BROADCAST STUDIOS 4; ''0 R present system of broadcasting market reports." continues Mr. Mullen, "includes three reports daily and two weather reports from NDK. \. In the morning. the crop and market information, as released by the l'nited States Department of Agricul- ture. is broadcast after the live stock quotations have been given. At noon the weather forecast is given, the Pittsburgh livestock market repeated, a report on wholesale fruits and vegetables, and miscellaneous reports. Our evening broadcast includes a report on nine principal livestock markets: Chicago grain, New York Cot- ton and Sugar. Feeds at six primary markets. Baltimore and Philadelphia grain, Pittsburgh wholesale produce

Mrs. Minnie Maddern Fiske, the famous actress, broadcast from WJZ

Mildred Delma, colaturo soprano of Metro- and dairy products. Toledo Seeds and politan Studios, broadcast from WJZ Chicago butter and eggs. ''The reaction to the above broadcast and religions won't hurt any of us. has come from 47 states. Canada and Perhaps broadcasting will serve us in Cuba." this ¡way, too. Manifestly a fine record of a year's * * * splendid service! BROADCAS"l'IN(, will render a * * * profound service this summer. MR. CHARLES TITTM:\ N has Ilroitdcast stations have increased their appeared with New York programs of religious services. Those Symphony, Philadelphia Orchestra, who want it will have it. Those who Detroit "vnlphony, Baltimore Sym- are indifferent to church activities will phony, New York Oratorio So- profit in spite of themselves. ciety, Chicago Apollo Club. at Bach, For in broadcasting we may hear Cincinnati, Cornell and Spartanburg the best services, and of a divergent Festivals, at the New York Oratorio Above: Wendell Hall, the red -headed music character. We may listen in on de- maker, broadcasting from WEAF Society Festival of 1920, etc.. and in bates that have engaged theological recital at prominent colleges and for scholars for centuries. We will learn Below: Ernest Hare, Larry Briers and Billy leading music clubs. He is an Ameri- Jones. the Happiness Boys trio of phonograph some of the fundamentals of religion. fame, broadcasting from WEAF can, horn and trained in America. a unknown to us be- graduate of Prince-

fore i and then we ton and of the I lar- may be inspired to yard Law School. seek the history and and occupies a dis- philosophy of relig- tinguished position ion ;1 and imbibe a on the American little of the wisdom concert stage. He is of the ages. particularly well known through his man appearances at I( l' I.1) broad - the celebrated Bach SI tasting do little Festivals. and in con- more than pique our cert he has sung with temlieraunental curi- such distinguished osities it has trul artists as Matzen- become a service. alter. Garrison, Mary Politics concern Garden, Heifetz and our economic struc Casals. In festival he has ture. Religion has to appeared with do with our spiritual most of the great existence. Broadcast- stars of the flay, ing will surely open including Homer, our eyes to many Raisa and Martinelli. things in each that w i In recital he has been have not vet learned. particularly well re- Tune -in on both cei ved. this summer. He returned to the

www.americanradiohistory.com THE WIRELESS AGE JeNE, 1924

chestra, Coleman's Mont Martre Or- Keith McLeod (left) accompanist at WJZ. Mr. McLeod is a musician chestra, Vincent Lopez and his Or- worthy of the position to which his ambition is now leading him. (Be- Ace low) Edward A. Kaminsky, Paul Hyman and Mack Stock. This trio chestra, Paul Specht's Orchestra, accompanied by McLeod "put over" the last Wireless Age party from Brigode and his Ten Virginians, Ani - WJZ. Alfred Armand was the leading soloist bassador Orchestra, Garber -Davis Orchestra. Piron Orchestra. Interna - tional Novelty Orchestra, Keating's Ramblers Orchestra, California Ram - b:ers, Marion Harris, Van and Schenk. E. Ricard, Irving Kaufman, Colin (i'Moore. Brooke Johns. John Steele. Brox Sisters, Marcia Freer, and Eddie Cantor. All the performers are famous recording artists, and many of them are radio feature performers. Their pres- ence at the banquet and the broadcasting of the program was made possible by courtesy of Landas' Brothers Music House, and the Brunswick. Columbia. Edison, Okeh, Victor. and Vocalion Companies. * * *

invention has made possible ANEWthe recording of broadcast pro- concert platform in 1920, after service promptly enter the curriculum of grams on records which may be re- as First Lieutenant, Captain and Major teaching. Moving pictures and radio broadcast. and then again recorded. in the Army. Since, he has become a might well be combined for the teach- The all -star assemblage, broadcast- Victor artist of renown. ing of subjects that are now difficult to ing from WJZ, should have been re- And that is why his appearances learn. * * * corded. The records could then be before the microphone at \VRC have preserved for their historical value. been worthy events. It will be well PRESENTING the greatest assem- Two years from now we may have worth your while to listen in on Mr. blage of leading orchestras and occasion to study the evolution of Tittman at any time he may broadcast. famous recording artists which radio broadcasting. It would be interesting But don't let it go at that. Learn broadcasting has ever known. station to know in what direction we had ad- about your broadcast artists. Tune in \\-JZ of the Radio Corporation of vanced. on their performances. Your radio is America transmitted the entire pro- * * * a season ticket to the concert halls of gram of the annual Banquet and En- the country. tertainment of the Talking Men and THE enterprising State College of * * * Radio Men, Inc., direct from the grand Washington studied the broadcast ball room of the Hotel Pennsylvania. situation from a practicable point A POPULAR feature of CKY'S Through the courtesy of the American of view ; the service facilities. Satis- programs are the readings from Association of Authors, Composers fied that a broadctst station which the works of Rudyard Kipling and and Publishers, VV JZ was able to would devote itself primarily to in- Robert \V. Service. which are given by broadcast all numbers controlled by formation and high class entertain - D. R. P. Coats. Recently the an- the Association copyrights, insuring ment would be almost a necessity in a nouncer commenced a series of read- the listeners -in a continuous program public educational institution, the au- ings from the works of Charles Dick- of unequalled entertainment. thorities immediately proceeded to ens. Following "Sidney Carton's Among the orchestras and enter- raise the necessary funds. Support Farewell" made famous by Sir John tainers who were presented to the ra- was secured from the student body, Martin Harvey. a schoolmaster wrote dio audience in unbroken succession citizens of Pullman and nearby towns. to CKY congratulating the station and from nine o'clock until the end of the and the alumni was solicited. saying that the readings had proved of program was Paul Whiteman and his The Government gave the State special interest to the students of grade Orchestra, Selvin's Boardwalk Or- College of Washington an exclusive eleven who were reading "The Tale of Two Cities" as one of their texts for the year. The schoolmaster suggested that readings might also be given from Shakespeare and from other works in Mme. Tamaki Miura, the use in the schools. Accordingly, CICY "Madame Butterfly" of is taking the matter up with the edu- Japan, recently sang from cational authorities, and pupils in the KYW in Chicago while her mother listened in at Prairie Provinces are to have an op- Tokyo. Mme. Miura re- portunity of hearing extracts from ceived 10,000 requests for works, which they are studying, read her autographed photo over the radio. from the United States, Mexico and Canada. She Our educational system seems to autographed her name in follow in the wake of progress. It Japanese and English, re- has been hard to understand why mov- quiring 20,000 signatures ing pictures have not been exploited in the schools to a greater extent. Per- haps, however, broadcasting will

www.americanradiohistory.com JtNe,1924 PEEPS INTO BROA DCAST STUDIOS 47 wavelength, 330 meters, and christened tral America. During the season of the Station KFAE. 1914 -1915 he was the principal Italian The station then invited all listeners conductor at the Century Theater in to send in their preferences in pro- New York. He is the founder and di- gram material. KFAE now broad- rector of the Boston Conservatory of casts basket ball games, talks on agri- Music. * * * cultural engineering, the migration of SEE by is birds, chemistry and other educational « the Papers" the title of a by subjects, orchestral numbers, solos, I new radio series offered "f lollywood" McCosker and scheduled anti talks on books. to be broadcast weekly from WOR Thel programs developed are through [luring the summer months. the activities of the faculty and students management of 'l'he series is to be a humorous ré- under the Arthur sumé of outstanding news events pat- J. Nralowec, a senior student. terned after the style of Will Rogers' Tune in on Then decide KFAE. on known people and events whether von have definite ideas satire well any of national importance. Mr. McCos- on broadcast service. ker, who is a newspaper man and mo- * * * tion picture critic well known to the R \ I )IO fans all over the country radio audience, will offer the new series " w Il be fortunate this year in be- throughout the summer at which time ing ab e to hear the opening Pop con- there is a pronounced let -up in the re- cert at Symphony Hall, Boston, played lease of big movies. by mejnbers of the Boston Symphony "Hollywood" is of the opinion that t )rcheltra which will be broadcast by radio programs are lacking a humor- Station \\'I:7., Boston Herald -Traveler, ous vein and that thousands of the Mary Ellis, Arthur Hammerstein's new star, \Vestillghouse. These concerts are broadcast from WJY radio audience will welcome the un- conducted by Agide Jacchia, directing conventional. "In any event." he a symphony of 80 players which is ade- the Pops of this the 39th season follow writes, "my attempting to kid the quate for playing the most elaborate the original idea to sonic extent, the tyeek's news is a good joke to start modern score. idea has been enlarged to a great ex- with." * * * tent. In the first place, the orchestra has grown considerably -its full sym- phonic proportions are adequate and the music is taken somewhat more seriously, although light trifles for encores, waltzes, .operetta selections, remain an integral part of the Pops. This is Agide lacchia's eighth season as conductor of these concerts. :\ native of l'esaro, Italy. he becftne.a favorite pupil of Mascagni at an early age in the Conservatory -of that season, Mr. Jacchia made an immediate mark as a young man as a conductor in the principal opera houses of Italy. Since coning this country, Mr. Jacchia has conducted opera from coast to coast and from Canada to Cen-

H. V. Carpenter, Dean of Mechaniral Arts and Engineering, supervised installation of KFAE Charles Tittman. America's leading Oratorio Bass, broadcast from WRC These Pop concerts are so much a part of ,Boston as the Common or the ALTHOUGH the Chautauqua Cir- golden -domed state house and they cuit has eliminated "Jazz" and are unique in the fact that there is humor, particularly comedians, this nothing like them anywhere in this season, because those numbers have country. I n the summer of 1885 the not been requested, the radio audience project of a supplementary series of will probably welcome a smattering of concerts to the regular season of the something light with their summer Boston Symphony Orchestra, of popu- programs of politics and religion. lar char cter to suit the warmer season, B. C. L.'s now have greater advan- was inailgurated. After the example tages than Chautauqua audiences have of Bilse' concerts in Berlin, the formal enjoyed in the past. Cultural programs rows of I seats were removed, tables in- in broadcasting will show continual im- stalled And refreshments were served. provement. Also we shall have hu- The experiment was an instant suc- mor. We need sonic humor. Humor cess. The "Promenade Concerts" soon is a great educator. North Hudson Kiwanis Club Quartet broad- came called the "Pops." While cast from WJZ -\V. A. H,

www.americanradiohistory.com RADIO NEWS FROM ALL OVER THE WORLD

Leper Colony at Molokai, Ha- tainment from a central receiving sta- of radio, promoting and supporting the waii, Hears KDKA tion, janitors will have to be able to erection of well- organized stations. operate receiving sets and handle com- The society's activity is seriously 'T' HE great amount of enjoyment plaints. limited by the fact that. while a person has t hat radio broadcasting In Washington, several apartment or an organization may purchase a brought rest to those isolated from the owners object to numerous aerials of radio outfit, it is impossible to obtain of the world is dearly shown in a many different types, which they claim the Government's sanction to use it. communication just received at West- disfigure the roofs. Other landlords, inghouse Station KDKA, from the more thoughtful as to the comfort and Balloon Kalaupapa Leper Guided by Broadcast Settlement on the happiness of tenants, are installing one Island of Molokai. Hawaii. said to be Station aerial with a receiving set in the base- loneliest in in the upper air currents the place the world. ment and running wires to sockets in Recently under the personal super- ADRIFTfor nearly twenty -four hours, car- vision of R. L. Cooke, superintendent ried whither the winds blew them. two of the Wireless Department of the government officers had for their only Mutual Telephone Company of Hono- means of communication the radio. lulu. two radio receivers were installed They have completed several of the in the leper colony. The radio sets free balloon flights being made from consisted of a Radiola V, equipped Scott Field, Illinois, by the U. S. with an A. C. power amplifier and an Weather Bureau to establish the value R -3 Magnavox which was installed in of the forecasting theory. the amusement hall; while a Radiola II, A map of the country is carried in for ear phone reception was installed the balloon, and by information broad- in the superintendent's home. cast from different radio stations, they The very first time the sets were know their location and the weather replaced in operation, KFKX, Westing- ports and forecasts from Washington. house repeating station at Hastings. These tests are the first ever at- Neb., was received repeating KDKA's tempted, and fifteen are planned. Dr. program. Then a few minutes later C. LeRoy Heisinger, meteorologist KDKA was picked direct. from Washington, and Lieut. James T. Later KDKA was again received :Neely. of the army air service, who are with such good volume that the mu- manning the balloons, attribute the sic and other entertainment could be complete success of their flights so far heard about 100 yards outside of the to warnings of weather changes re- ball. ceived by radio from various stations. There are about 600 people in the Molokai leper British Interest in Radio settlement. About 400 LIFE BOATS EQUIPPED WITH RADIO were present for the first radio night. The newest Giant of the Seas, the steamship Increasing The leper colony is located on a "Columbus" of the North German Lloyd Line, which arrived recently in New York after her for radio telephony long narrow point of land surrounded maiden voyage, has the most up-to -date equip- ENTHUSIASMcontinues to grow throughout by ment in its radio installation. Passengers on on three sides the ocean and backed this vessel will feel greater safety when they Great Britain, according to Acting up by steep cliff's, 1300 feet high which observe the lifeboats equipped with radio. The boats have small receiving and sending sets, Commercial Attaché Hugh A. Butler. are practically unclimbable. with aerial as shown in the photograph Up to March 1, 1924, over 600,000 There are only two ways of en- licenses for receiving sets had been trance, by sea or over the steep moun- each apartment so that occupants who issued. And it doesn't stop here. THE tains, down a narrow trail that seems desire may plug in phones or loud \\TIRELESS AGE has just received word to drop right out from under the cliffs. speakers. from Mr. Arthur R. Burrows, Direc- The two radio receiving sets were tor of Programs of the British Broad- packed down this trail. "Listening In" in Lombardy casting Company, whose interesting In the future these afflicted people THE Italian society"Amici del'Arte" account of Broadcasting in the British outcast from the remainder of the has constituted a new branch of Isles was published in one of our re- human race will at least hear from the its activities, the "Radio Club Lom- cent numbers, that the official number outside world through the medium of bardo," with headquarters at Milan, of license holders in Great Britain is the radio wave. and with sections in other cities and now 750,000. He states further that towns of Lombardy. it is intended to tap four new populous Janitor Must Know Radio It is the intention of the organiza- centers by opening relay stations at builders throughout the country tion to encourage students and ama- Edinburgh (2EH), Liverpool (6LV), IFcontinue to erect apartment houses teurs of radio communication, to ad- Leeds- Bradford (2LS), and Hull and furnish tenants with radio enter- vance the adoption and improvement (2HU) this summer. 48

www.americanradiohistory.com l l \ r.. 1924 WORLD WIDE WIRELESS 49 Broadcasting in Switzerland \DIOTEI.EPHO\Y as a na- R tional pastime, such as it has become in the United States and Eng- land, appears to have no great future in Switzerland. It was originally intended to erect a central national broad - casting station. but this idea has been abandoned. and a system of decentral- zed stations is now prol>.ised. In view of the fact that there are only about 4,000.000 people in Switzerland, it is quite obvious that broadcasting- must be kept within modest bounds. It is reported that arrangements are being made for the erection within the near future of four broadcasting stations. They will be located. respectively. at Lausanne. Geneva. Zurich R. L. Luke, Chief Radio Electrician, U. S. Navy, is demonstrating here the Scotch Clariphone, and Basel. flans are now being pre- designed to modify the effect of atmospheric disturbances in radio reception pared for the station at Basel, and the installation work will begin at an early the Department of Commerce. Ap- Besides daily musical programs, he elate. The work of constructing the plications for radio concessions from said, farming instructions will be sent station at Zurich has been temporarily the German Telefunken Gesallschaft. to the natives in their own language. retarded pending certain financial ad- the E. Schrack Radio \ Werke, and justments, but the promoters hope to other companies had been pending, but Radio "Knife" for Major be able to complete the undertaking it was decided not to grant a concession Operations without much further delay. to any privately owned concern. A majority of the shares of stock of the A''l'I.ICATION of radio impulses The chief difficulty to be encoun- to a surgeon's knife which burns tered is the expense of providing pro- new company will be held by the Aus- trian State. its way through the tissues of the body, grams. The Swiss Federal Govern- cauterizing as it passes and thus pro- ment is giving its encouragement and duces nearly bloodless surgery, is assistance to the undertaking, and has African Natives to Learn claimed by Dr. L. E. Schmidt of the decided to place at the disposal of the Farming by Radio staff of the Alexian Brothers' Hos- f9ur stations part the larger of the NATIVES in the heart of Africa pital, Chicago. With the use of the revenue derived from the licenses is- will be able soon to perform their new instrument two operations for stied to amateurs. Industrial circles, ancient ceremonial dances to the cancer of the bladder have been per- ai hateurs, public corporations, and strains of jazz through a radio loud formed successfully, it is stated. bodies other interested are being urged speaker, and will be given instructions As explained by \V. H. Dodge, rep- subscribe scheme. to to the in modern agricultural methods in the resentative of the laboratory that per- Austrian same way under plans of British offi- fected the device, a low power radio Broadcasting Com- cials of Kenya Colony. transmitting set is used to generate the pany to Be Formed Trade Commissioner R. A. May at current. The "knife," which is about FI fl: \I. \TIO\ of a company called Alexandria, Egypt, has advised the half thebreadth of a lead pencil and " I broadcasting A. G." is being un- Commerce Department that plans al- resembles a knitting needle, forms one dertaken by the Austrian Government ready have been made to institute a terminal. The other is applied to the to carry on radiotelephone broadcast- radio set with loud speaker in every patient. The human tissue offers re- ing in that country, we are advised by village. sistance to the passage of the current

Chile is using radio extensively. Here is the wireless station north of Valparaiso. Chile, one of many stations built along the coast for the aid of shipping. Recently a fine broadcasting station has been opened in Santiago. the capital

www.americanradiohistory.com 511 THE WIRELESS AGE JUNE, 1924 tion during the life of the patents under which license is granted. 4. The present license is based on the operation of the station, with a maximum power of 500 watts de- livered to the antenna. but the telephone company agrees that it will at any time, upon request of the licensee, grant a license as far as its patents are concerned to operate with greater power upon terms commensurate with the present license fee. 5. The license is subject to revoca- tion by the telephone company upon violation by the licensee of any of the foregoing conditions.

Hoover on Radio Legislation H ERBERT HOOVER has become the Judge Landis, the Will H. 1 -lays; the Augustus Thomas of the air. He announced recently that he Here is how Paris enjoys radio in the summer -time. Concerts are broadcast from a band- stand in the Champs -Elysees would not attempt to set up a censor - ship and would never consent to any scheme when the knife is applied. The re- President Thayer issued his statement. by which radio listeners shall be charged a fee sistance causes heat. The knife burns position has is by law. Our been that there The itself through skin, fat and muscle nothing else for us to do but protect Government of the United quickly and without States will always control the ether pressure. the validity of our patents when we roads. The set is equipped with two 40- believe they are infringed and but it will not be drawn into put the saying what watt power tubes and condensers. The decision up to the courts. shall and what shall not be current oscillates at the rate of 40,000 " fed to the radio audience. \ \e have said all along that we were "There cycles a second. The tension is 800 perfectly willing to license any station are enough complaints volts at 450 milliamperes. The heat now," says Mr. Hoover, "against the which would respect our patents by individual developed is -great enough to fuse programs sent out by the applying for a license to operate under various brass. them. Our willingness to license Sta- broadcasting stations. If the " \Ve don't care to make any rash United States were to assume control tion WHN shows our intention to ad- of statements," said Dr. A. \Vochinski, here these programs, the kicks would be J. to this position. We believe that multiplied who assisted in the operations. "Radio other now with ap- by the tens of thousands stations operating and surgery has its limitations. It will not paratus that infringes on patents the first thing we knew we would our be having cure cancer, but can be used practically will for license and this sit- a Senatorial investigation apply that on our hands. wherever the knife can. uation will be straightened out." "There "The one the radio needle The will will be," he explains, "no advantage only difference that exist vested right has over the knife is that it prevents between Station WHN and the other in any one wave length. loss of blood, unless a large artery broadcasting units licensed by the should. be severed, in which case liga- American Telephone and Telegraph tures would have to be applied. The Company is that the WHN apparatus patient is thus saved the usual shock was not manufactured by the Western that follows major operations." Electric Company, which manufac- tures and sells the broadcasting sets installed under agreement with the tele- WHN Pays License Fee phone company. 'T`HE suit for infringement of patent The radio industry, which has brought by the American Tele- watched the progress of the WH phone and Telegraph Company against suit as a test case of broadcasting con- Station WHN has been dropped be- trol, was interested to learn the terms cause of an agreement reached be- of the license agreement. 'Its principal tween the parties whereby WHN takes conditions are given on good authority out a license from the telephone com- as follows : pany covering the use of the radio 1. The telephone company releases parts which were declared to be in- \ \'HN from all liability of claims for fringements. Henceforth WHN will past infringement arising out of previ- operate on the same basis as other ous operation of the broadcasting sta- stations licensed to broadcast by the tion. telephone company. The license fee 2. WHN is granted a "personal non- teas $2.000, which is understood to transferable" license to continue to ftse The Eiffel Tower radio broadcasting station hold for the life of the patents. the station for radio telephone broad- in Paris. Here are the tubes In discussing the settlement of the casting; including broadcasting for toll suit officials of the American Tele- or hire. There will be no monopoly of certain phone and Telegraph Company said : 3. The license fee is set at $2.000, roads in the ether. The Government "The action taken. means only that which is understood not to be an an- will see that the air is kept open to all this company meant what it said when nual fee but a sum covering opera- comers. The Government will do

www.americanradiohistory.com JuNE, 1924 WORLD WIDE WIRELESS 51 everything it can to encourage contin- uity of service from any one broadcasting station. Certain companies are soi tied up in the development of radio that there is reason to believe they will show great vision in handling the sub - je}t. In any event, while they may control radio instruments, the Govern - mnt vile never lose control of the air itself and will never permit the air routes to be run counter to the general public interest. "There has been no parallel to the development of the air as a means of communication since the invention of printing. The radio is the handmaiden of the printer. The Government will see that nothing happens in the ether to interfere with or hamper its future." Republican Convention by Radio MORE than one -tenth of the people of the United States, or about twelve million, can "tune in" on the Chess by radio. b'. E. Black, chief wireless officer of the S.S. "America." indulging in a game proceedings of the Republican Nation- of chess aboard ship Standard Radio Frequency SCHEDULE OF FREQUENCIES IX KILOCYCLES (Approximate Wave Lengths in Meters in Transmissions Parentheses ). THE Ilureau of Standards is trans- Eastern special signals of standard Standard Time June 5 June 20 July 7 mitting 11 :00 to 11 :08 PM 300 550 1363 frequency about twice a month. The (1000) (545) (220) signals can be heard and utilized in 11 :12 to 11 :20 PM 315 650 1430 general east of the Mississippi River. (952) (461) (210) These special signals of standard fre- 11 :24 to 11:32 Pli 345 750 1500 (869) (4001 (200) quency are of use to testing labora- 11 :30 to 11 :44 PM 375 833 1600 tories, transmitting station operators, (800) (360) (187) and others in standardizing wave 11 :48 to 11:56 PM 425 940 1700 meters and adjusting transmitting and (705) (316) (176) 12 :00 to 12 :08 AM 500 1050 1800 receiving apparatus. The transmis- (600) (285) (1671` sions on June 5 will be of special in- 12 :12 to 12:20 AM 600 1150 1900 terest to ship operators, those on July (500) (261) (158) 7 to amateurs, and those on Tune 20 to 12 :24 to 12 :32 AM 667 1250 2000 (450) (240) . (150) broadcasting station operators. The Radio in Mexico. A news reporter is here sending out messages from the powerful port- accuracy of these signals is better than Radio Expositions able set accompanying the forces of General of one per cent. Gonzalo Escobar in campaign three -tenths THE Pacific Radio Exposition is All transmissions are by unmodu- planned to be held in San Fran- al Convention when it starts at Cleve - lated continuous -wave telegraphy. _\ cisco from August 16 to 21 in the Civic lald, Ohio, on June 10. complete frequency transmission in- Auditorium. This exposition will be Every radio set owner in the coun- cludes a "general call," a "standard conducted by the Pacific Radio Trade tl- , whether he is on the Pacific or frequency signal" and "announce- Association. Atlantic Coast wave length, will be ments." The "general call" is given Chicago this year will be the scene able to hear the convention. Arrange- at the beginning of the eight -minute of the second of a series of three shows ments to broadcast the convention pro - period and continues for about two comprising the first annual Interna- cedings are being completed by the minutes. This includes a statement of tional Radio Exposition. The Chicago Radio Broadcasting Subcommittee of the frequency. The "standard fre- show will be conducted at the Coliseum th4 Cleveland Convention Committee. quency signal" is a series of very lung November 18 to 23 inclusive. headed by Charles L. Gehauer. clashes with the call letters \V\ \` \' in- The first show will be at Madison u`\Iore people will hear this conven- tervening. This signal continues for Square Garden. New York City, be- tion than ever heard any great political about four minutes. The "announce- ginning Monday. September 22, and event before." said Secretary James I.. ments" are on the sane frequency as closing Sunday night. September 28. E. Jappe, of the Cleveland Committee. the "standard frequency signal" just The third show will be held in a Pa- "First. there will be more than 13,000 transmitted. and contain a statement of cific coast city. soon to be selected, in in the public hall itself, either as par- the measured frequency. An an- January or February, 1925. ticipants or spectators. Then there nouncement of the next frequency to The exposition will be under aus- will he a loud speaker that will enable he transmitted is then given. There pices of the newly organized Radio forty to fifty thousand gathered out - is then a four -minute interval while Manufacturers' Show association, with side of the hall to hear. and finally the the transmitting set is adjusted for the a membership of sixty. U. J. Herr- proceedings will be broadcast over the next frequency. mann and James F. Kerr, who made land." The roll -call by States on The schedule of standard frequency a success of the annual Chicago show. President and Vice- President. will be signals from the Bureau of Standards twill be managing director and general broadcast. is as follows: manager respectively.

www.americanradiohistory.com Best Bets in Humor

MUSIC BY H. T. WEBSTER 1 went night after night. listening The New Control raptly to reports from all sections of the SEE that you don't know how to fi ¡ y w ,/ f country. "I tune this set." he observed, as he i ( . %' 1..roCae-eon I bought a set of my own. began adjusting the dials. "But don't e.., ::° ':: They can hardly tear me away from let that worry you. old man : we all " it. Now. r,b . :. ;M have to learn, you know. then," td'"*w'*' . I know what the weather was yester- ñ ' he continued, "did you notice the in- r. re.;:. ,..<.. day. is today and will be tomorrow in creased volume of sound as I turned . every important section of this great that last dial? Just put the finishing United States. touch on perfect reception, as it were. I don't know how I could live with- Of course. one cannot teach you the my out weather. whole game at one sitting. but I.11 say That's how I became a radio fan ! this much : you'd do well to pay par- Hoping we both enjoy the concert ticular attention to that dial if you Monday night. I remain, want good volume. That is one of Radiofanly yours, H. L. M. your most sensitive controls. Con- denser, I suppose ?" THAT LITTLE GAME-BY B. LINK "No, Bill," replied his host. "You see, it is like this. I bored one hole too many in the panel. and then put ...ne A 14.e 014e, 100 AIM1e: DCAEIC. N .10.3 Sa OP NA.F TAE NieNt P.AYINO S.AIOE MEF00-A A OH.Ñ Ne G OT14ent NA.F FORGett,NO WDoOT that dial on to hide the hole. It doesn't 6 t T14E RAO.o 14 FR,9,0 eATNER Awn A..ow T14e wAtER PIPES s,De.- control anything -except the imagina- _ . -+eï:asmrm:db2-áF.-- 11r To FReELE berme loon. veRY eYe3- NOt Se55 O A14D4TNE tion." -Geo. F. Noftsker. -.y. }', World RAD,O PROGRAM AN {l',.I,I yIl IY OPee.1 AIM H. L. M. Writes $ROAOCAST,GDDVD- FnorOAERt A STRAIN ON THE FAMILY TIE By Gaar Williams ONE night (his letter goes ) a friend asked me over to his house to "listen in on the radio. I went. During the course of the evening I heard a weather report broadcast from a Colorado station. The idea of hearing a Colorado weather report thrilled me. It seemed so -you know -impossible. That Colo- rado should have weather. ,aklrn Times I asked him if I might come over the next night. He said I might. That's Easy I told him I liked it. thought it was OKLAHOMA Radio Dealer (after great. I did not tell him about the lengthy explanations to Osage Colorado weather report. That was chief) : Now I've gone over this my secret. radio set thoroughly with you ; I've The next night I heard a weather shown you every coil and knob, and report from Chicago. It was wonder- I'd like to have your order. But is ful. "Cloudy in the southwestern por- there still anything you don't under- tions, with gradually increasing temper- stand; any questions you would like atures." I was ecstatic. I hardly slept to ask ? a wink that night. A weather report Chief : Ves, what makes it go?

! from Chicago -Oklahoma Whirlwind. -Clúra,; i Tribune BRINGING UP FATHER BY GEORGE McMANUS UMW THIS IS 44TAT1ON X.QD.INTEN itW '.yrv -TL1M ON1 SWEETIE INUTC}MISS'. NAPD OL THE FLAPPEfrj I TATe `n `;<. I ALL TE TUIY ( I I ; -TMET 4ET FRIVOLITY CO. WILL SING'wlv0 TNeT p)i 6` JINGLING w1TN ALLLET JINGLING ÿ Theme. FCET - WITNTNEIR RET-`./*l ¡ dy lJtr;:Ji1;I _ - t r. . 5 11111 CIENO. INr F.Ar,ere..... I+:. 4 II 1LñE. -The Washington Herald J9

www.americanradiohistory.com AFLO TAN \ASHORE WITH THE OPERATOR

By W. S. Fitzpatrick

WHEN the New fork office of During this period Alr. Guthrie tool: graph record of that singer. It is the United States Shipping part in the original radio experiments doubtful however, that he hung up hoard was opened a wise selec- of the Navy and right here might be stars over kiddies' homes. tion was oracle in the appointment of conferred the honor of his being the \\'hile still in the Navy \fr. Guthrie \Ir. Charles 1). Guthrie as radio super - original "Broadcast Listener." It was opened and assumed charge of the first visor. No one could have held this during the Jamestown exposition in wireless station to be built in Phila- position more creditably or mire effi- 1907 when it was his duty to listen in delphia. Following his discharge he ciently ; none could ha ve made a larger on an experiment made by the battle- became a commercial ship operator and number of friends and no one could ship Virginia. The experiment was five years later was made an inspector lay claim to greater ability or longer so successful that daily concerts were for the Marconi Company. radio experience. given for the benefit of the fleet. For two and a half years. which in-

I r. Guthrie started going to sea as :\ few years later while an inspector cluded the war period, Mr. Guthrie a boy and long before the advent of was chief government inspector of the radio. He was a cadet on the famous second district with headquarters at school ship Saratoga, five years after New York. He became Shipping the graduation of Captain Hartley. Board radio supervisor four and a half now commander of the Leviathan. years ago. who learned the fundamentals of sea- * * * manship on this same school ship. The radio personnel of the large The Saratoga was built in 1842 and American trans - .Atlantic passenger was in the fleet of Commodore Perry ships is often asked for and, no doubt, (luring the important historic event in will prove of general interest. opening negotiations with Japan in The Leviathan's radio equipment is 1853. The vessel. which carried 24 in charge of Elmo N. I'ickerill of New nine -inch smooth bore guns, was after - York and George E. Sinclair, also of ward used as a slave chaser and later New York, is first assistant. The commissioned as a school ship. other members of the crew Of eight : \fter leaving the Saratoga \1r. are: Henry F. Bollendonk of Nanuet, Guthrie joined the revenue cutter N. Y.; Oscar L. Goertz of Brooklyn ; service, now the all -important United Paul W. Karr of Skidmore, Mo. ; Earl States Coast Guard depending almost F. \Whitldon of Boston. Mass.; Leslie entirely upon radio. but which at that Weadcr of Madison. N. j., and Roy time had no knowledge of what radio Charles D. \ \. Jones of \'an Wert. Ohio. Guthrie, Radio might accomplish. It was only a little Supervisor, H. B. Von Thun is chief operator a November 15, United States on the George Washington; H. Young o4er year previous- S h i p p i n g ' 1$99, to be exact -when the American Board, as a is first assistant ; H. A. Herring, sec- navy operator liner St. Paul transmitted the first twenty years ond. and Ben N. Lazarus. third assis- ship ago and as he tant. wireless message ever sent from a looks today at sea. On the America. Frank E. Black is In 1904 he enlisted in the United for the Marconi company Mr. Guthrie in charge and is assisted 1w Arthur -States Navy and after a course at the alsd took part in broadcasting. Chu Cohen and J. C. Eddy. Brooklyn Navy Yard electrical school this occasion it was an effort to estab- The radio men on the new liner was made wireless operator on the lish wireless telephone service between Republic are Roy Butler. E. J. Girard battleship Kentucky. In use then was the two \ \'anamaker stores at New and N. Moore. On the President the coherer detector with no telephone York and Philadelphia in addition to Roosevelt are W. T.. Whitney. C. \V. headsets. the messages coming in on the wireless telegraph. So that the Butt and Louis Brown. The Presi- tape. The record distance was 115 listeners at Philadelphia might pick up dent Harding operators are George H. miles. Before the end of his naval the signals, Air. Guthrie would tall: Kolbe, C. Prevetti and Adolph enlistment head phones came into use until hoarse. then turn on several phon- * * * and distances of a thousand miles were ograph records. This experiment was Among the old time operators who common through the use of electro- conducted at certain times each day are still going to sea is Frank W. lytic detectors. and, while not meeting with the de- Rosenquist. now on E. F. Hutton s Mr. Guthrie suggested the use of sired success. still brought forth letters yacht Hussar. said to be one of the 10110 -ohm phones. but was informed and verbal continents from ship oper- most beautiful yachts afloat and on that none over 500 were manufactured ators who enjoyed the concerts con- which is installed the most modern of and that 500 ohms was the maximum siderable distances at sea. radio equipment. Rosequist started as for efficiency! It is not recalled what kind of an a commercial operator in 1912. but had Some time later the Schmitt- Wilkes announcer Mr. Guthrie macle. but he an amateur set as early as 1907. Dur- phones, forerunners of the Brandes, probably had his little jokes and most ing the war he was in the Radio Intel - were made with 1000 ohms resistance likely introduced John McCormack to ligence service of the United States and became the Navy standard. the audience before starting a phono- Army. (Continued on Dare 881 53

www.americanradiohistory.com A Radio Set for the Summer How to Build It Describing the construction of an outfit for automobile camping, the motor boat, or summer cottage which will do as well as sets made only for permanent installation By M. B. Sleeper Radio Designer and Technical Publisher

F you stop to think about it, you'll you want to work out. Consequently, as we sit around the room. New York I probably agree that, between sum- construction data will be given in this stations are, of course, quite loud. mer and winter, radio broadcasting article only on the radio set itself. While the volume is not as great as if really means more to us in the summer Figures 1 and 2 show the assembled regeneration were used, the clearness season than in the winter, not only be- instrument, consisting of a one -step of the reproduction more than makes cause some of the most interesting non- oscillating R. F. amplifier, detector, up for the lower volume. As a matter things, particularly sporting events, and two -step A. F. amplifier using of fact you might think, judging by come only with warm weather, but on UV -199 tubes, while figure 3 gives the your ear, that you were tuning an am- camping trips or at summer cottages, wiring diagram. You will see that the plified crystal set, because there is no news is not quickly available in the antenna circuit is untuned, with fixed carrier wave whistle nor the squeals form of late newspaper editions. More- coupling to the secondary which is ad- which come from an R. F. set requiring over, theatres and concert halls are justed by a .0005 mfd. condenser. 'In potentiometer control. either closed or at inaccessible dis- the plate circuit of the first tube -the One very important feature, and one tances. Actually, we need radio more, R. F. amplifier-is another fixed which is entirely new, is the pickle and it is more useful to us, during coupler, or fikit, which acts as a tuned bottle inductance. You'll understand, the summer months, and this year, too, R. F. transformer. when you read the instructions for we want radio to bring us the news of This is in no way a trick circuit. winding them, why they are called the political conventions. It is an accepted design which has been pickle bottle coils. Ït is enough to say Thanks to the L V -199 tubes, you in use long enough to prove entirely now that they are wound in a way can have a set wherever you go, not an satisfactory as to range, quality, and which makes them self -supporting. Of awkward, heavy affair, loaded with selectivity. At Darien, Connecticut, we all types of coils the single -layer wind- batteries, but a small outfit easily car- bring in the usual stations, Atlanta, ing is most efficient. The efficiency is ried. As to the general design of the Pittsburgh. Chicago, and Philadelphia further increased, or the R. F. resist- cabinet and the arrangement of the with sufficient volume on an inexpen- ance lowered, in the pickle bottle coil complete equipment you probably have sive loud speaker to hear the music because no insulating tube is required particular ideas of your own which and the words of the announcers easily to support the wire. With all the effort now being spent to reduce the losses in tuning condensers, this is the first improvement on small- inductance coils which has been brought out in several years. In this connection it is interesting to note that the R. F. resistance of a spider web or basket wound coil is greater, for a given inductance, than a single -layer winding on a bakelite tube. The only type of coil having any lower losses is the single layer winding without a tube. Information concerning the losses of spider web coils has been in possession of some of the commercial companies ever since 1917, when English army outfits, equipped with that type of inductance. were sent here to he repro- duced by American manufacturers. Experimenters, however, still cling to the mistaken notion that they have lower losses than the single -layer coil. But to get back to the set itself Figure 1 -The portable receiver assembled. Showing the tube panel and the reverse of the - front panel on which one of the R. F. pickle -bottle transformers is mounted the front panel is of 3 -16 in. bakelite. 54

www.americanradiohistory.com iCNF, 1924 A PORTABLE SUMMER SET 55

+ 6V. - -22V. ±90V+ Figure 2- Wiring diagram of the portable receiver mlasuring 7 "x14 ". :1t the rear, in diameter. of eight to fourteen sides. 20 wire, in the saute way, using four sulported on nickeled brass pillars 1f you can't get them of polygonal shorter strips of paper. Six turns are 3,8( x34;" long, is a vertical sub panel cross section, round ones will do. Cut required, wound on top and at the to ¡which a tube panel is secured. Both four lengths of the tape / " wide and center of the secondary. This coil com- measure 13 "x3% "x3/16 ". This is a 6" long. pleted, break the bottle and remove the very handy arrangement as it allows With someone to hold the spool of pieces of glass carefully so as not to the tubes and transformers to be No. 24 wire for you, clamp the bottle cut the insulation. You will then have m usted behind the variable condens- between your knees, fasten the end of a surprisingly strong, self- supporting erg, and permits them to be arranged the wire by several turns around the inductance unit. in ¡less space with shorter connections neck of the bottle and bring the wire To mount it, cut out two 3 -16" thin if a base panel were employed. up onto the straight part. Turn the bakelite strips 3'/4" long and %" wide. Figure 4 gives the dimensions of the bottle and wind the wire over the strips. Drill two holes in them at each end for three panels. Notice that all holes are placing them ninety degrees apart. screws to hold the strips together and made with a No. 18 drill except the Moisten the tape as you go. When you to act as primary and secondary ter- 15 -32" holes for the rheostats, con- have put on 70 turns, cut off the ends minals. In addition, drill two holes 1" densers, variohm and jacks. Four of the strips so that they stick out apart and countersink them, in one countersunk holes are made in the tube 1/" on each side of the coil, wet them. strip. They are to take screws threaded panel for the terminals of the Ark and bend them over on the wire. Thus into brass pillars 3" long by 5 -16" transformers. The countersinking is the tape will hold the turns securely in diameter which serve to mount the necessary because the terminal screws every ninety degrees. Cut the end of complete fikit under the tube panel. art a little short to go through a 3 -16" the wire. Put the coil between the bakelite strips pahel. Put on the primary winding, of No. and tighten the end screws with nuts. l f the drilling is changed slightly the parts from any of the reputable mann- ,facturers can be used, but if you want to 'reproduce this set exactly you will need two General Instrument .0005 nlfd. condensers, two 50 -ohm Amsco rheostats, two 3" and two 2" Kurz - Kasch dials for the condensers and rheostats, and open circuit filament control Carter jack, four General Radio UV-199 sockets, an Electrad Variohm, a .00025 mfd. Micadon, two Ark transformers, and nine Eby binding posts. The cost of all these parts, including the screws and fittings, comes to less than forty dollars. (n addition to the items mentioned. volt must have the two pickle bottle in- duétance units. Get a / -1b. spool of No. 24 S. S. C. and one of No. 20 D. C. C. wire, some gummed paper tape such as is used for fastening bundles. Figure 3 -The assembled receiver, showing under side of tube panel on which the A. F. trans- and two pickle or preserve bottles 2%" formers and one of the R. F. pickle -bottle transformers are mounted

www.americanradiohistory.com 56 THE WIRELESS AGE JeNE. 1924-

dition you must have a 4/ -volt flash - light battery or Eveready type 3 for the "C" battery. This is important for it improves the quality considerably and makes the "B" batteries last much longer. Since the primary circuit of the set is untuned you can use almost anything for an antenna. A wire fence is good. a tin roof, or the frame of an automobile. For portable use you can throw one end of a 100 -ft. length of bell wire tied to a weight up into a tree. On a motor boat use two wires three feet apart, run from the bow to the cross arm and down to the stern. (;round connection can be made to a tin can dropped into water, the pump pine. a nail driven into the roots of a Front panel, showing best arrangement of control dubs tree. or, on a boat, to a metal plate under water. Make another fikit to be used as the 1 f you are going to use telephones Once you have learned the approx- R. F. transformer in the same way, but a tapped 45 -volt "B" battery, prefer- imate settings for the condenser dials. put 12 turns on the primary. ably the large size, is enough, but 90 can tune in very quickly. set- You also need two angle brackets to you The volts will increase the volume greatly. tings will not change no matter what fasten the tube panel to the sub -panel. The small 22% -volt "B" batteries are kind of an antenna you use. Both dials They are 1" lengths of " angle brass, all right for a few weeks though the must be rotated slowly at the same one with a No. 18 hole in one leg " / hig ones stand up much better. In ad- time. to the right. and one 4 " to the left of a hole in the other leg. The brackets. I d" if /t' i' f' 1..._¡_..¡:. coil ¡-lt' f ' ' panel support pillars. and the Ì -r,-f i l-- - mounting pillars are stock items which f -c ro nr - er.+* you can buy it you do not want to f - make them up. + + \fount the instruments on the front - - 6ria leoA panel and do as much of the wiring as Socket Socket A.F..Tronst Socket A.FT'enst Socket you can. Then fasten the other parts + to the tube panel, and connect them as ` k 4 - $ far as possible. Notice that the socket connections must be changed. Take out 1 4 Yt' Tube F2nel the contact spring screw and put in its /3' place 1" R. a 6 -32 H. screw. with the -rt.. head on top of the socket base. Replace the spring. and clamp it with a nut. Repeat this process at each terminal. $1. 404*rt4*Z The sockets are held to the panel by For 0279._...... -- - nuts on these screws underneath. More- -- .'75:.pport ,"roa over, connections are in this way made under the panel as you will see from 4( the illustrations. Finally, mount the sub -panel and Vertical sub pane fasten the base panel to it ; then the tt' P} if last of the wiring can be done. Holes /3. marked X on the sub -panel drawing are to take wires connecting instruments on the front panel to those on eK the tube panel.

There is a wide choice of batteries MtvtllxiM NMlD l.t. available. The lower jack on the front panel is provided so that you can plug in a connection made in place of the OE, VIO. tuo tMt0. dash light on a motor car. Rheostats of 50 ohms are specified ro7 to take care . 1) r of a 6-volt "A" battery. Dry cells can 41s also be used for filament lighting. 0- for Pone 4) . -0tt- support pillars Three 6" dry cells, operated 2 to 4 hours a day, will run the filaments over ---' -----41, ..y r r 100 hours. Six cells in series parallel giving 4% volts, will last more than Ir J twice as long. If weight is an import- I-- rI . . t ant factor use four of the Eveready - t.? /Bail/ unless otherwise spec,fea.. type 3 batteries in parallel. They will Dimensioned drawings of the three panels. Note that .he tube and vertical sub- panels can be last about 25 hours. made by sawing a regular 7 -in,h panel in two

www.americanradiohistory.com 10,000 Boys Wanted A Job Open on The Wireless Age Staff for Every Youngster Who Wants a Radio Set or Parts to Add to the Set He Now Has

BACK in 1910, the writer. then a trill be well paid. And this is how you And this is what I will do for you youngster, borrowed some books join: I have 35.000 names of people who from the library in his midland Write a letter to the Boys' Editor. have bought radio sets. Each one of the home town, and set about to build a Tell nie whether you want a complete 35.000 will like to know more about r, dio set. At that time, however, very set; parts to go with a set you now TIlE WIRELESS AGE. Some of those little was known about radio. None of have; or just what you do want. people. in fact, have been taking the the dealers carried parts in stock. In Then tell me where you live and how magazine, but forgot to renew their fact. that youngster had a great many old you are. Tell me anything else subscriptions. Those 35,000 people live obstacles in his way -even the older about yourself that you think i would in every part of the country. Some of folks laughed good naturedly at his like to know. them live in YOUR town or city. "notion." When I have received your letter But the notion persisted. That telling nie what you want in radio, I yinutgster wanted a radio set. And will write to you and tell you how have it. he would. many subscriptions you must get in ( hie clay he found a catalogue, listing order to earn what you want. Even a great many parts. but parts that cost t )NE subscription wiil get you a radio too mach money for an allowance of part. fifty cents a week. There was but one And this is why you can get subscrip- thing to do -carry newspapers. And tions-I am going to teach you H( )\V that job brought in one dollar and fifty TO SELL. Then I am going to give cents each week. you, from the 35,000 navies I have, a "those of vott who are reading this list of those who live in your locality. story will know at once that on a In that way you become a salesman for small income of $2.00 a week a great TrrE WIRELESS AGE. with a calling de,sd of scheming and patience was list of people who own radio sets and, needed to accumulate enough money of course, will wallt a radio magazine.

f. r a full- fledged receiver. 1 have sent a letter to each one of the A fter the set had been completed 35,000 so that they will know about al tl used for some time, the youngster's THE \ \-IRELESS AGE even before you a bition turned to auction detectors call on them. at d other better parts. lle got joy out I now have a good many on the o every improvement made. And he magazine staff earning their radio sets. al ays wanted to improve his set still None have failed to make good ! And ft rther. the reason is that I have wanted to The difficulties once conquered, left make good myself and I now intend th t youngster with one resolution - to see all the others make good. th t some day he would make it easy Write to nie NOW. Address your for other young chaps to get the parts letter to the Boys' Editor. TILE WIRE- with which to build a radio set. LESS AGE, 326 Broadway. New York. nd resolution has been real - that Tell me just what you want most. iz d! Read the following -it tells you If you have a pal or two, write to- h Bobby Carmighael, Durham, North Caro- * * * lina. Bobby is an enterprising salesman gether. Sometimes team work is bet- on THE WIRELESS AGE staff, making alone. But write to me at want 10.000 young men to join the good under our careful guidance. He will ter than once. have his radio set earned in a very short st ff of THE WIRELESS AGE. Each one time -Bays' Editor.

A Steady Job for Enterprising Boys WRITE to me. I will teach you how to sell sub- and prize, and a N & K $8.50 Headset for third prize, to scriptions, supply you with samples, give you a those who secure the most subscriptions between JUNE calling list, and then send you out as a full- fledged 15th and SEPTEMBER 15th. The prizes will be given salesman. A credit account will then be established in in addition to what you receive for the subscriptions. YOUR name. You can draw CASH from that account If you win a prize your subscriptions will bring you or get what you want in radio parts at WHOLESALE cash or radio parts just the same. You are paid for your PRICES-just as you like. But in addition to this, I subscriptions even though you don't win a prize! That is will give a Paragon RB2 $135.00 Receiver for first prize, because you will be a paid member of The Wireless Age a Thompson (Magnaphone) $35.00 Loud Speaker for sec- Sales Staff! -Boys' Editor.

www.americanradiohistory.com Chasing Squeals How to Get Better Results From Your Receiver The first installment of this series of radio -trouble correctors was devoted to receiver noises; this month receiver -squeals are treated and next month the author will tell how to discover what's wrong with a "dead set" that gives no signal By R. A. Bradley

\ G the last year or two, the public has month's issue of THE WIRELESSIRELESS AGE we DL-RIundergone a stage of transformation or we might described receiver noises, analyzing them ; showing say reform in which time their sentiment toward how to connect up the noises with difficulties in the Radio has become in some cases enthusiastic, in receiver and in general how to eliminate them en- some cases tolerant and in other instances has be- tirely. This month we are turning our attentions come a radical dislike and opposition. Of this last to another source of discomfort and annoyance - class there seems to be two sub- divisions : those squeals. We defined noises as being anything in the that are waiting patiently for Radio "to perfect it- form of sound which come out of the loud speaker self." before partaking of any of its benefits -they or head phones which could not be classified as any acknowledge that there are benefits to be had from note on the musical scale. Thus, we have brought it -and then there are those who have had the misfor- about the definition of squeals as being sounds which tune to hear, in some friends home, a misguided were more or less musical even though they lacked radio set or in some radio shop where the sets are harmony and seemed far away from anything which tuned by guess work or left to suffer or work out could be called musical. their own salvation, which incidentiv they never can do. To these unfortunate people. radio has presented its worst side and they have been turned opera- against it, believing that the terrifying squeals and SQUEALS are almost invariably due to the noises issuing from the mouth of the loudspeaker tion of the set, rather than to any real fault in the constitute a normal and ever- present condition. This receiver itself. We can subdivide the squeals into is not true. To these we have dedicated this article three different classes. Probably the most common in the hope that they will be convinced partially or squeal is that due to a regenerative receiver in the totally that the foul and uncouth noises and whistles hands of an inexperienced or uninformed operator. which they have heard are remediable, and not On most regenerative receivers there are two main an features existing condition in a properly built and properly of adjustment, two dials which control the in operated receiving set. Also, this is written to aid tuning of a station. One of these is the wave length the man who has already delved into the subject and control which may be either a variable con- who has bought or built a receiver and who is dis- denser or variometer somewhere in the secondary appointed or is ready to give up in disgust.. circuit. The other is the means of obtaining regeneration which may be the rotor coil of a variocoupler or a variometer inserted in the plate circuit. Major Armstrong some time ago discovered that if the plate circuit of a vacuum tube was tuned and brought into approximate resonance with the secondary circuit, a peculiar phenomenon took place which greatly amplified the changes in the grid voltage brought about by an incoming signal.

you tune your set. you set the wave length WHENdial at approximately the position where a station should be received and then bring up the regeneration dial which as we said before may be the rotor of your variocoupler or a plate variometer until the signal is brought in loud and clear. We have said this is the way you do, but we should have said, this is the way you ought to do. In hunting for distant stations the inexperienced operator throws his set into a state of oscillation and then turns the wave length dial until he hits the squeal of a distant station. He then retracts his regeneration dial until the speech or music is cleared up. Much has been written on how annoying this is to neighbors who are listening in also, but the situation has not improved. When you pass over a station to which a neighbor is tuned, you set up in your neigh- Rev. Francis Duffy O'Laughlin, S.I.. Ph.D., is head of the Department bor's receiver a disagreeable squeal which varies in of Physics at Fordham University, which possesses the fine receiving equipment here shown. Father O'Laughlin teaches his classes how to pitch from very high to very low and then up again. tune properly to prevent squeals 58

www.americanradiohistory.com NE, 1924 RECEIVER TROUBLES 59

experience ill tuning or neutralizing condensers, they are cal condition. the same as a regenera- ALITTLEyour receiver will enable you to not correctly adjusted. I f your re- tive receiver. l'ast this point the am- turn both the wave length dial and the ceiver is a manufactured product it plifier breaks into oscillation and is r eneration dial at the sanie time keep- should be returned for complete neu- quite useless and likewise harmful.

] your regenerative dial at such tralization. If you have made it your- "l'he adjustment on this potentiometer p sitions that your set is at this sensi- self there are certain methods of pro- varies with the wave length control, ti e point. It is perhaps somewhat cedure which we will outline here. A and no set position can be predeter- h. rder to locate a (listant station by this signal should be tuned in as loud as mined. m thod at the start, but a little experi- possible, the filament turned out on thé Next we come to a different variety ence in tuning properly will not only first R. F. tube leaving the tube in the of squeal which can be more properly make your neighbors feel more kindly socket. The first neutralizing con- termed a howl. This howl does not toward you, but will likewise enable denser should then be adjusted, until vary in pitch and is somewhat of a yduu to hear more distant stations. the signal is disminished to its great- musical note. generally very. very high. Tjuere is another source of squeal in a est extent. This sane procedure shouid The cause of this is usually in the regenerative set and that is the grid - be followed with the second R. F. tube. audio frequency amplifier. There are leak. Experience has shown us that If the neutralizing condensers are the very few shielded audio frequency- the average man slams a two megohm proper size this will bring your set transformers on the market and those gridleak into his set and proceeds to to complete neutralization and no fur- that are not shielded have quite large forget it. Now in a good many cases ther difficulties should appear. If the magnetic fields surrounding them. tWo megohms is the right size grid - neutralizing condensers do not seem When two such transformers are letik for the average hard vacuum tube sufficient then attention most be paid placed close together or end to end detector on the market today, but in as there is a coupling formed between many instances or more, two megohms the magnetic fields and the result is an is not the right size for your particular audio frequency howl. This can be tube. For example, when a regenera- Don't clone away with by moving the trans- tive receiver goes into oscillation with formers farther apart or by placing a lop and bang over, you can be very one at right angles to the other. I f sure that your gridleak is of the wrong Shout this does not eliminate it the trouble side. Then, too, as your set goes into about your receiver troubles. It's may lie in the ratio of turns in the os4illation any way or in any fashion your own fault if you have them. transformer windings. You may have except smoothly and you can They can all be corrected. a low ratio in the first step and a high gradually This is the second of a series of he certain that your gridleak is wrong. articles designed to show our readers ratio in the second step which is the \ r v often receiving sets in a state of how every manner of radio receiver reverse of the way it should be. oscillation do not even squeal. but have trouble can be remedied. Last 1- however, we have used as many as month's article was a Steady devoted to three stages of audio frequency am- plop occurring at regular in- noises in your set -all kinds of tervals. noises, and told you how to get rid plification employing high ratio trans- This is another indication of an im- of them. Here you are informed formers in all three steps and placing proper gridleak. how to eliminate the annoying across the secondary terminals of each squeals. Next month you will learn Rules cannot be set down for the what to do when your receiver fails transformer a 1 -10th megohm leak. size gridleak to be used with your set, to give any signal at all. Make your This leak cuts out all "set noises" as conditions in different sets vary receiver give you full value! and squeals which were present when with each individual tube. For instance. the leak was not employed. It was till writer has used a UV -200 as a re- to the angular mounting of the trans- also found that by shunting the second- geaerative detector for about three formers and these transformers ad- ary of each transformer with an .001 it nifd. fixed condenser in of the years. He has never found neces- justed until complete neutralization is place sary to use any gridleak at all. The accomplished. 'If, however, you have gridleak the same result was brought leakage in the socket and in the mount - an untuned radio frequency receiver about. We do not advise. however. inns and in the various instruments such as the many types of reflex sets the use of more than two stages of frequency themselves proved sufficient for the now on the market, howls or squeals audio amplification. purpose. However, in the same re- in one of these means that the radio \Ve mentioned in a previous para- ceiver when using a UV -201A it was frequency amplifier is oscillating. graph how your set might be manipu- foúnd impossible to get satisfactory lated to the annoyance of your neigh- results except with a 1% megohm UxTCXED R. F. RECEIVERS bors, but we did not mention what to griclleak. It is well to have on hand There has been a harmful theory do in case your neighbor annoyed you values of /. 1. 1 %, 2, 3 and 5 meg- floating around that the placing of a for the very good reason that we don't ohpus so that the proper size may be stage of radio frequency in front of an know. The best thing that we can deNcrmined by experiment. If you ordinary regenerative receiver will offer in this instance is to locate the have a variable gridleak that is a good eliminate re- radiation. This is true offender and show him how to tune one. which is not subject to tempera- only when the radio frequency ampli- his set. There is one source of squeal ture changes, the need for this assort- fier is not oscillating. Radio frequency which may be in most any set and ment will be obviated. That finishes amplifiers in an oscillating condition which comes under none of the pre- up gridleaks and regenerative sets. can radiate just as powerfully and just vious headings and that is the one We will next take up the squeals as annoyingly as the worst regenera- which is due to too high filament cur- which are sometimes present in tuned tive receiver in existence. In most of rent. This is probably more noticeable and untuned radio frequency receivers. these receivers there is a potentiometer with dry cell than with storage battery in 'a tuned R. F. receiver squeals mean sometimes caller "stabilizer" across the tubes. We know of several owners of one thing and that is that the means "A" battery. This potentiometer con- radio sets who when they turn the set of neutralization of the stray capacities trols the negative and positive grid on whirl the rheostats clear over to the and of the interstage coupling. is out bias, on the radio frequency tubes. In limit in order to get more "noise" out of .adjustment. Whatever is the means turning this potentiometer from one of the set, and that is exactly what of neutralization -mounting the trans - extreme to the other a point is passed they get. formers at angles around 54 degrees. where the receiver is in its most criti- (Continued on page 82)

www.americanradiohistory.com Continuing a Summary of the Entire Subject of Amplifiers

plate battery from beiag impressed on the grids of the tubes through the plate resistances, thus avoiding dam- aging the tubes. Such a condenser is called an `'isolation" condenser, it iso- 1ers lates the grid from the plate battery mplf supply. Since these grid condensers are required it also becomes necessary to use grid leaks (r). For unless these With proper design great amplification can be obtained are used the negative charge accumu- in several ways without distortion lating on the grids will have no means of escape. and will thus reduce the By Louis Frank plate currents to zero and block the operation of the tubes. As soon as one PART II step or a multi -stage amplifier is Multi -Stage Amplifiers blocked the entire amplifier becomes in- Resistance Coupled: -Audio and radio frequency. operative. The grid leak functions in Impedance coupled amplifiers: --Choke Coils. discharging this negative potential, thus permitting the operation of the ampli- Part III will follow in next issue fier. The values of plate resistances re- IN the first part of this article pub - long distance reception, in order that quired in multi -stage amplifiers are de- fished in the May. 1924. issue of the very weak radio frequency signal termined by exactly the sane condi- T ii E Wilt ELESS .-GE we considered may be amplified sufficiently to actuate tions as for the single stage amplifier the cases where a single tube amplified the detector tube efficiently. On the described in the May issue. For prac- the energy input. When a number of other hand, audio frequency amplifica- tical results the plate resistances should tubes are placed in cascade. the ampli- tion will be found to be essential if be several times the internal impedance fied output being still further amplified loud speaker operation is to be secured. of the tube. Since the tubes used in by the succeeding tubes, we have a The limiting features of both these a multi -stage amplifier are usually alike multi -stage amplifier. Assuming prop- types of amplifiers will be described in the plate coupling resistances used for erly designed circuits, enormous ampli- the course of the article. the different stages are also the same. fications may be secured. For suppos- MULTI -STAGE RESISTANCE COUPLED plate impedance of ing each tube and its circuit gave an Inasmuch as the AmPLIFIERS -AUDIO FREQUENCY amplifying tubes as designed today is actual amplification of 10 times, the A two -stage resistance of 20,000 ohms, the plate received signal would be amplified 10 coupled au- the order of dio frequency amplifier is in resistances used should be times by the first tube. the second tube shown coupling would amplify this increased signal 10 times more. making an amplification of 100 and so on. The great possibilities of multi -stage amplifiers he- j comes apparent. Two stages of multi -stage amplifiers any of resistance cou- In the signal pled audio fre- the systems described for single stage quency amplification show- amplifiers may be used. Thus the may ing how the re- have resistance, inductance, sistances a r e multi -stage connected in transformer and tuned circuit ampli- the circuit. fiers. These in turn may be used for _ iIiI'IiF+ either radio or audio frequency am- B' bat. plification. and the design will depend upon which is used. In many cases it will be found that the radio frequency hgure 1. By adding more tubes in the about 60.000 ohms or over. These re- amplifier is more difficult to build for sanie way this may be made a three - sistances must satisfy certain condi- reasons which will appear later. But stage, or any numbered stage ampli- tions if good results are to be secured. f requcncy amplifier has some the radio fier. The audio frequency signal to In the first place, the the important advan- design of be amplified is applied to the grid of resis:ances must be such as to have a Radio Fre- tages. In the first the first tube. This audio voltage is minimum distributed capacity. For quency am- place it should be repeated in the plate circuit of the first since this distributed capacity is in observed that the tube and an amplified voltage appears parallel with the resistance itself. it plification detecting brings action of across the plate resistance R. This will result in reducing the impedance vacuum tubes is amplified voltage is then applied to the of the coupling resistance. and hence distance proportional to the grid of the second tube through the also in reducing the amplification. In square of the radio grid condenser Cl, and the voltage the second place the plate coupling re- frequency voltage applied to it. Hence amplified still further by the second sistance carries the entire plate cur- a radio frequency amplifier which will tube, and so on. rent. 'It must therefore be able to increase the magnitude of the radio In each case it will be observed that handle the amount of energy dissipated frequency voltage before it is applied a grid condenser is necessary even in it xvitltout overheating and changing to the detector tube will be of great though rectification and detection are its resistance. For the change in re- assistance in increasing signal intensity. not the objects of the tubes. The rea- sistance will again result in alteration Radio frequency amplification of one son for the grid condensers is to pre- of the amplification. Ilut worse than sort or another is quite essential for vent the high positive potential of the that. if the resistance alters regularly 60

www.americanradiohistory.com it- NE. 1924 AMPLIFICATION WITHOUT DISTORTION 61 with the passage of current through it, there will simultaneously result a ch nge in current through the rests- tat cc. with the bad feature that noises C A -stage choke wi 1 be heard in the phones. Crackling, two coil coupled audio hi -sing and irregular noises are often To loud frequency ampli- speoher fier. Compare this du to poor plate resistances which with the resist- va y in magnitude. The standard ance coupled amplifier. Note the tu &parr resistancc9 and lavite resis- similarity, in con- tal ces have proved to be satisfactory nections fo this wvnI:. 'he proper values for the grid con - nat. B" bat de sers and leaks are determined by de trite considerations. If figure 1 is ex mined it will he seen that the grid tir nit of the second tube is in paral- the first part of this article. The re- frequencies at the broadcast or amateur lel with the plate coupling resistance sistance coupled amplifier leas. however, wave lengths. one very great for broad- of the prey II tube between points advantage MULTI -STAGE IM I'EDAN('E 1, n'PLED cast purposes. It gives uniform am- .\ and I f. The impedance of the AMPLIFIERS -AUDIO FREOI('EN CV entire grid circuit must therefore plification over the entire audio :\ two -stage audio frequency ampli- be much greater than that of the frequency range, hence it is a distor- fier, inductance coupled. is illustrated plate resistance ill order that the tionless amplifier. It gives better in figure 2. It is similar in appearance amplification be not quality speech and music than most IIlfluence(I. any other type of amplifier. to the resistance coupled amplifier 'Resistance The previously described, the only differ- coupled impedance of the RADIO FREoUENCY ence being that iron cored inductances circuit is de - amplifiersa grid The sanie type of circuit and the are used in place of resistances to by ( 1 ) termined same considerations apply for radio couple the different stages together. the impedance of The grid isolation condenser and the !less frequency amplifiers as for audio fre- the internal grid- quency amplifiers. But there is one grid leak should have the sanie values filament path of the great difficulty with radio frequency as for the resistance coupled amplifier secinul tube. and (21 by the impedance resistance coupled amplifiers at low mentioned above. of the grid condenser and leak circuit. wave lengths. The impedance of the The amplification obtained with such The impedance of the grid -filament grill- filament path of the tube is so low a system depends upon a number of path inside the tube is determined by that it practically short circuits the factors. In the first place it depends its capacity anti resistance. In general, plate coupling resistance, and hence upon the value of the choke coil or as tubes are made today, its capacity destroys all amplification. To illus- inductance. Figure 3 is a curve which is so low as to make its reactance trate with a numerical example, sup- shows how the amplification depends greater than a million ohms at speech pose that the plate resistance R in upon the reactance of the inductance frequencies. and its resistance is of the figure 1 is 60,000 ohms. In present and it is seen that practically maximum order of a fete hundred thousand day tubes the tube capacity is of the amplification is secured when the re- ohms. Hence the impedance of the order of .000010 microfarad, and at actance is about three times the internal grid- filament path of the tube is seen 300 meters the reactance is about resistance of the tube. Hence the iron to be sufficiently great not to influence 16,000 ohms. These 16,000 ohms are core choke must be shade large enough the amplification at audio frequencies. in parallel with 60,000 ohms plate to give this value, when full amplifica- The impedance of the grid leak circuit coupling resistance. and therefore the tion is had. Now the reactance of the is cpendent on the leak mostly. This effective plate impedance is decreased inductance depends upon the fre- is isualiv of the order of a few nlil- to less than 16,000 ohms with the re- quency. Therefore, in the second hence have no liot opns, and will stilt that amplification is considerably place. the amplification depends upon on eff et the plate resistance and am- reduced. This effect is greater as the the frequency. The reactance of an pli cation. Since the voltage across iron core inductance increases with the plate resistance R is applied to the frequency. therefore at the lowest fre- gri 1 of the succeeding amplifier tube quencies it is possible that the reactance thr nigh the grid condenser C. the re- .to may be much lower than is required to acGtnce of this grid condenser mast give full amplification. At the higher be tie low compared to the plate resis- frequencies the reactance will be tanFe that it does not alter the voltage Reactance greater. hence full amplification will be app #lied to the grid, for any voltage Q Tube resistance secured at the higher frequencies. consumed by this condenser means that Thus the will have non -uniform ampli- much less to he amplified by the suc - fication of the low and high frequen- cee ling tube. Reasonable -aires for / 7 3 6 5 6 7 6 cies, which is had for it introduces thi. condenser are found in practice distortion. Graphic picture of the amplifying action of the )e about 0.1 to 1 microfaratl, the to vacuum tube This is largely the trouble with all lar er the better. Thus for a 1 micro - audio frequency choke coil amplifiers d condenser the reactance at 1,000 far wave length decreases. Thus resis- unless they are properly built they cyc es is about 160 ohms, which is seen tance coupled amplification at low wave readily distort. This may be avoided. to ',e negligible compared to the 60.000 lengths is not feasible. At the high however. by a consideration of the Mu us for the plate resistance R. and wave lengths it becomes more possible principles here outlined. 'If the in- the efore there will be no voltage lost because the reactance of the tube capac- ductance is made sufficiently great so in his condenser. ity is not so low. It is therefore that its reactance at the lowest audible he disadvantages of the resistance recommended that this type of ampli- frequency, say 50 cycles, is about three cot pled amplifier were explained in fication should not be used at radio (Continued on page 86)

www.americanradiohistory.com How to Choose the Right o n d e n s er s One for Your Circuit By Donald Gordon Ward Associate Member, Institute of Radio Engineers PART I

NU attempt will be made in this there are occasionally real bargains in both of the so- called 23 -plate variety series of two articles on the sub - radio parts. most generally if one pays and the capacity of one is almost ject of condensers to say that a small price for a piece of apparatus double the capacity of the other, yet any particular variable condenser is he gets something which is only worth according to the number of plates used any better than any other variable con- what he pays for it, and even some- they are exact duplicates. The root denser, but on the other hand the vari- times he does not even get as much of this trouble lies in the fact that a ous factors which enter into the con- as that, because even though to the great number of condensers are macle struction of a condenser will be pointed average broadcast fan a variable con- by concerns who have simply taken a out and it will be then left to the in- denser looks like a variable condenser, variable condenser and copied it with- dividual purchaser as to the make of mere looks does not enable the pur- out any regard to its electrical dimen- condenser which he will choose. chaser to judge as to the working qual- sions, probably for the very sufficient Any attempt to point out the very ities of his purchase. reason that they themselves do not best type of variable condenser on the know the meaning NOTE SOLID END PLATES of capacity and its market and then to say that only this effect in electrical circuits, NOTE HEAVY PLATES but of condenser should be used would law NO LIKELIHOOD OF course in time they will learn and grad- the one who had made the statement WARPING ually their products will improve in open to a great deal of ridicule, for as ft!Scn quality and then they will mark their there are all grades of condensers on au\tMalr condensers with their electrical values. the market at the time so present are x.7030 0 This will not come, however, in many there all types of construction in radio Jp ; cases until the public begins to demand receivers. We have variable condens- that the capacity of condensers be ers which are subject to many defects noted on the condenser as is the case not present in the best gracie of con- in the better grade of apparatus. densers and so there are many receiv- It is not an expensive procedure for ing sets which have defects not present the manufacturer to do this, and does in other receivers. It would be a fool- ACCURATELY not work any hardship upon him, while ish waste of money to put a variable MILLED SPACERS, on the other hand it does tell the con- condenser of best NOT MERELY STAMPED, the grade of con- BOTH ON ROTARY AND FIXED PLATES. structor definitely whether that partic- struction and having the smallest ular condenser will fulfill his demands amount of losses into a receiving set RANCE OF CAPACITY Is IMPORTANT or not. that had poorly constructed coils and One of the first determining factors was wired in a haphazard fashion and which concerns the home radio con- NUMBER OF PLATES MEANS LITTLE also it would be a senseless procedure structor is the capacity of a condenser. This matter of the public merely to burden a finely constructed receiver What is its maximum capacity and designating a variable condenser ac- with a variable condenser which has a what is its minimum capacity ? There cording to the number of plates it em- large number of losses of various are two elements which enter into the ploys may be exactly compared to the kinds. construction of the radio frequency man who, wishing to purchase a suit Therefore after the reader has de- circuit, and capacity is one of them. of clothes. walks into the nearest cloth- cided to construct a receiver let him Even if the amateur constructor does ing store and says that he wants a blue then decide just about how much not know how to calculate the wave- suit. The clerk hands him the first money he has to put into a receiver and length of his circuit from the induc- blue suit without looking at the size of then he will be better able to decide tance and capacity which it is going to the suit and the man merely says, just what he should purchase in the have, still he should know what the "Wrap it up." He would make a sorry line of condensers for his outfit. capacities of his condensers are sup- sight to say the least if he had pur- In this the first of the series of two posed to be. as it is the range of his chased a suit of clothes which was articles on condensers no attempt will capacities which determine the wave- made for a man of greater size than be macle to give any exact data on length range over which he will be able himself. but he would not look any condensers, but more attention will be to receive. The average diagram worse than would his radio set, if he given to pointing out the general con- which is to be followed by the one who should buy a variable condenser of any denser principles while the second ar- "builds his own" contains the maxi- old size, electrically speaking. It must ticle of the series will treat with some mum capacity values of the condensers be remembered that there is no rela- of the more exact condenser details to be used. tionship between the electrical and me- which must be taken into consideration A practice that has been followed in chanical dimensions of a variable con- when one wishes to be extremely pre- the past and is still being followed by denser. and that while two condensers cise and accurate in his receiver con- some manufacturers is to classify their may have the same number of plates struction in order to have. as a finished condensers according to the number and these plates may he of the same product. a receiving set which is as of plates in the condenser. but that is size. yet if the spacing between the fine a one as he can construct. One no indication of the electrical dimen- plates differs by even a slight amount. very excellent measure of the quality sions of the condenser, which is what such as a hundredth of an inch, the of a condenser lies in its price. for the one really wants to know. For ex- capacity will be radically affected. rule holds true in radio as well as in ample. there are two condensers lying Another dimension which is just as any other. that the purchaser gets just at the right hand of the author while necessary to have upon a variable con- about what he pays for, and while he is writing this article. They are denser as its maximum capacity. is its 62

www.americanradiohistory.com _lc xE, 1924 CONDENSER EFFICIENCY 63 minimum capacity, for it is the mini- denser of 20 per cent. minimum. The As will be seen from these figures mum capacity value of the condenser following table of three sets of values the first condenser with its very high which determines the minimum wave- was made of three condensers of dif- maximum of four times that of the length to which the circuit will tune. second condenser will be able to reach It is the usual practice for one who a lower wavelength than the second wants a circuit that will go down to the condenser if both condensers are em- lower wavelengths used in broadcast - ployed with the same coil of indu:- * to purchase a small sized variable tance. And in addition to this. the up- condenser. Suppose for example that per wavelength limit of the circuit will be tour times as high when using the tige maximum capacity is known to be .002 mid. condenser as compared to 0005 microfarad. \Vhat does this tell a circuit with the same value of induc- about the minimum wavelength to tance, but using the condenser which this circuit will tune Abso- which has a maximum capacity of lutely nothing. For the minimum .0005 mfd. wavelength is dependent upon its mini - mum capacity which should not be Therefore when about to purchase greater than 10 per cent. of its maxi- a variable condenser for the radio re- mum capacity in a properly con- ceiver, decide about how much, pm structed condenser, but which very are able to spend for your whole re- often will run as high as 20 per cent. ceiver and allot to condensers their proportionate part of the entire amount plate condenser \ ixl\nu \r AND MAXIMUM CAPACITY Grounded rotor, brass so that all of the apparatus will be of at least approximately the same grade RELATION makes and the different illustrates and so that nothing will seem out of .\ condenser with the 10 per cent. ference in electrical dimensions. place either mechanically or electri- minimum will permit the circuit to be Per Cent. Min. of cally. Then select your condensers Max. Cap. \lin. Cap. Max. (approx.) tuned down to approximately half the with a regard to their electrical dimen- wavelength .002 .00006 3 value which may he .0005 .0001 20 sions. about which more will be said reached by the circuit having a con- .00035 ,000018 in the second part of this article.

Selecting Loud Speakers Il,nlrllni,d from ,4ryh :.ì! selections will sound noisy and will be overloading his radiotrons by ex- test of a loud speaker under properly have a drumming quality. cessively loud signals. combined with controlled conditions. Conclusions in may be drawn 2. The loud speaker fails to repro- low plate voltage and incorrect grid badly error sometimes a single unsuitable listening test duce low pitched notes, but does res- bias. Unless the listener is sure the from being with the loud speaker fed from an un- pond to high pitched notes. Speech will radiotrons are not themselves or he reliable or from will be fairly intelligible on such loud "saturated" overloaded, should broadcasting station receiving speakers, but the piano will sound thin not blame the loud speaker for rattling an unsuitable set, yet the pre- noises. best way of up ceding suggestions do give a general and much like a harp or guitar. Bass The checking is re- idea of of some loud voices will be weak or else sound like on this point by trying a known the defects loud on in place speakers. thin baritones. The effect in the ren- liable speaker the set suspected It may be justly said that radio dition of orchestral selections will be of the one. 5. speakers occasionally are broadcast reception stands or falls in feéble and squeaky, and without Loud The insensitive ; that is, they fail to respond large part on the merits or defects of "Lindy" and roundness. accom- not paniment of the 'cellos and violins, and to weak signals at all. and do the loud speaker, since it is this device give response to reasonably loud which finally produces the desired en- other deep- voiced instruments will be a good The only test is by tertainment. It is regret- lost. The general effect will be that signals. compar- therefore ison with standard makes. The ob- table that so many inferior articles of of a cheap and poorly designed port- insensitive loud is have been able phonograph with a small horn. jection to speakers this type placed on the mar- the necessity for overloading the radio- ket 1w self -styled "experts" who were 3. The loud speaker may reproduce trons to get a loud signal. actually lamentably ignorant of the re- only notes in the middle register, drop - 6. Some loud speakers. while other- quirements of the problem. The in- pir ?g out high and low pitched notes. wise fairly satisfactory, reproduce fluence of such loud speakers on the This is unfortunately a fairly common combinations of instruments - voice reputation of radio reception has been fault. While speech is moderately in- and piano, or violin and piano -less undesirable. Fortunately quantitative telligible on some examples of this satisfactorily than solo efforts. This tests and exact design methods are now class of instruments, music is very fault requires for proof of its exis- available, and suitable loud speakers unmercifully treated, and the faults tence a careful listening test on a suit- can be obtained. Continued improve- found are a combination of those men- able selection from a broadcasting ment in these devices may also be con- tioned in 1 and 2 above. station of repeatedly proven high fidently expected until it will become 4. Loud speakers should not rattle quality. nearly impossible to distinguish be- on the loudest notes which are pro- It is not implied that the above tween loud speaker output and the duced ; but the user should be cautious rough listening tests are an effective original studio rendition of a musical in drawing conclusions since he may substitute for a precision laboratory selection.

www.americanradiohistory.com radio Frequency Circuits The Practical & Use of Honeycomb Coils and Regeneration in Radio Frequency Amplification There are several different arrange- writer has tried out quite a By Henry Baron THE ments this circuit which have been number of radio frequency am- of tried ; instance plifier circuits and has thought door antenna used with a .001 mfd. published and out for that possibly some of the results ob- variable condenser used in series with a variable condenser of the 23 or 43- tained from actual practice might be a 50 or 75 -turn honeycomb coil, as plate type may be used across the pri- of value to the radio man who builds shown. The coupling and regenera- mary coil, but this set works very well with a .0005 mfd. variable condenser A connected across the secondary. and a similar variable condenser connected across the tickler. The latter should 00/ %Iser of course be of the vernier type. as this control is very critical. If but one A.f. 0/170. stage of audio -frequency is used. as indicated at figure 1. then the audio frequency transformer utilized should have a fairly. high ratio. say 5 or 6 to 1, and it will be found the most satis- DL50 or factory to purchase a good sized trans- 751 H. C. former, and not a small one for this Pot. stage. or in fact for any successive stages. The large sized transformers, 11 V several of which are now available on the market, have a lower resistance -II[ 45V10 loo v.Bol. for one thing than the smaller transformers. and owing to the greater Figure 1- Hook -up of one step of radio frequency. detector and one step of audio frequency amplification quartity of large sized copper wire used in winding the primary and sec- his own apparatus. There are a num- tion are taken care of by three honey- ondary coils. together with the lower ber of peculiar things that happen in comb coils used in a regular three -coil flux density in the iron core. the oper- radio -frequency sets which are not met mom t provided with gears, or simply ating efficiency is improved all around. with in the ordinary detector and two - step or simple detector outfits.

RADIO- FREQUENCY \V ITII HONEY- COMB COILS Figure 1 shows a circuit which several friends of mine have been using for a year or more and which I have also tried out. This circuit provides one stage of inductively coupled radio- frequency amplification, and one stage of audio- frequency amplification. A second stage of audio - frequency can be added to operate the loudspeaker when desired. Referring to the dia- Figure 2 -Twin variometer regenerative set with 3 stages of radio frequency amplification gram, it will be seen that a loop shunted by a .001 mfd. variable condenser, with knobs. utilizing a 50-turn honey- and these large transformers selling preferably of the vernier type. may be comb coil for the primary. a 50-turn for $6.00 or $7.00 are certainly a fine shun ed across the grid and filament coil for the secondary, and a 35 or 50- investment and one that you will never circt it at A and B, or else an out- turn coil for the tickler. regret. There is a great deal of talk nowadays about using decreasing ratios Zslide tuning coil between the windings and the trans- /honeycomb, or / formers for the different ratios. that topped index/once 1 is, a higher ratio in the first stage and a lower ratio in the second stage. but some of the best commercial sets be- G ing turned out today utilize two of the large audio frequency transformers just mentioned, with identical ratios, and they certainly do deliver the goods. The writer at present is using two Schermatron transformers of the same ratio, and they leave nothing to be desired. A potentiometer of 200 to 300 Figure 3 -Radio frequency amplification added to a standard regenerative receiver (Continued on page 84) 64

www.americanradiohistory.com _TUNE. 1924 THE WIRELESS AGE 65 RADIO ENGINEERING An Experimental Home -Laboratory Course in Simple and Advanced Radio Design By John R. Meagher Vacuum Tubes AS the main purpose negative or positive volt- of this course is to age with respect to the summarize and to negative terminal of the wnie extent supplement the filament. A grid circuit textbook study and experi- voltmeter to show the volt- mental work of the stu- age difference between the dent, this and succeeding grid and the negative ter- chapters on vacuum tube minal of the filament, and operation should be read a plate current ammeter to only after the subject has register the current in the !wen studied in the text - plate circuit, are necessary books recommended at the to obtain the desired meas- beginning of the course. urements. In fact it would be well In using such a testing for the student to gather circuit, the filament and together a n d carefully plate battery voltages are study all available data on kept constant for any one tubes. If Professor Morecroft's Principles of Radio Communica- curve. The grid voltage is made negative to a value where tion can be secured read the section between pages 364 and 577. the plate current is zero and then, advancing the grid voltage ill steps toward zero and positive values, readings are noted Front our text books we should have found that a vacuum of the plate current values corresponding to each step in grid tube-or better termed-a triode -as used in radio communi- voltage. The upper limit of grid voltage is usually restricted cation has three elements : a filament, a metallic plate sur- to that value where further increase does not increase the rounding the filament and a grid or wire mesh interposed be- plate current. tween the filament and plate, Grid voltages and corresponding plate current values for an When the filament is heated -generally by an electric current assumed case of a small tube are given here: -it emits negative electrons which may be attracted to the plate if the latter is charged positively with respect to the (;rid Voltage Plate Current Grid Voltage Plate Current filament. The quantity of electrons emitted from the filament 0.00 3 1.50 depends mainly upon the temperature and structure of the -5 0.01 4 1.65 filament; secondarily upon the charge surrounding the filament. -4 0.10 5 1.90 The quantity of electrons reaching the plate depends upon the 0.20 6 2.10 difference in voltage between the plate and filament and up, nt -2 0.35 7 2.20 the space charge, or charge in the space between these elec- -1 0.55 8 228 trodes. If the space charge is negative -with respect to the 0 0.75 9 2.32 filament -the electrons from the filament will be repelled and 1 1.00 10 2.35 most of them will fall back upon the filament. If the space 2 1.25 11 2.37 charge is positive, the flow of electrons from the filament to the plate will be increased. The student may make up a curve from these figures. Secure Control of the space charge is the purpose of the grid; as a piece of cross -section or graph paper and along the left hand

its voltage varies, the space charge varies in exact accordance vertical line mark off units of plate current ; say one square to and the electronic flow and plate current change correspond- represent one -tenth of a milliampere. Then along the horizon- ingly. If the grid voltage varies at a radio frequency the plate tal bottom line mark units of grid voltage, say one volt to a current will vary at a radio frequency; if the grid voltage square, starting at the left with -6 and going as many squares %-arics at an audio frequency the plate current will vary at an to the right as necessary to number up to positive 11. Then on uaudio frequency. the minus 5 line make a dot up 1 /10 of the first .1 milliampere The relationship between the square to correspond to .01 mil- grid voltage and the plate cur - THIS Course of Instruction in Radio Engi- liampere; the value of plate rent is the most important fac- gineering commenced with the February issue current when the grid is -5. U r in vacuum tube operation. of The Wireless Age. In that issue the author Do the same with all the other This relationship is generally described a simple home laboratory layout of appa- grid voltage -plate current com- graphically represented with a ratus which students could make up at small cost. binations and after all the dots ,:did-plate characteristic curve. This apparatus was designed to enable the student have been plotted, connect them The measurements from which to experiment for himself along the lines suggested together with a smooth curve. by the author, so that by carefully following the This die curves may be drawn may course students may really learn Radio. In subse- should look similar to be secured experimentally for quent issues were presented first some elementary those shown in textbooks if any tube with a testing circuit instruction about circuits, then two chapters on drawn corrrcctly. similar to the diagram. inter -tube coupling, including the study of impe- Now that we have the grid Here a vacuum tube is ar- dance, grid -leaks, resistance coupling and transform- voltage -plate c u r r e n t curve, r ngcd with suitable A and it ers, which brings the student next to a study of the what are we going to do with

I lament and plate) batteries operation of vacuum tubes, the subject of the present it? For one thing we can see and a special C (grid) battery chapter. The author recommended the use of supple- how the vacuum tube operates mentary text books, particularly one by E. E. Bucher as an amplifier. tliat may he adjusted to main- entitled "Wireless Experimenter's Manual." tain the grid at ally de :irai To be continued.)

www.americanradiohistory.com Selected radio Hook -Ups

Ground binding post vario.meter on Receiver

6 turns .002 *70 0.CC .X75 1.00/ :3 yc.e 43 plate 3att. Hc-1500' ' IIIIIIIII 11.002 Separate A4 B 90-120 v. Batteries

the number of requests which we receive daily IN figure 2 is shown an external oscillator which can be 1FROM we gather that the one tube super is still popular as used with excellent results with most any radio fre- ever. Diagram of this set is shown in figure 1. The loop quency receiver. This oscillator consists of 40 turns of is tuned with a 23 plate variable condenser preferably with No. 24 double cotton covered wire wound on a three inch some means of vernier adjustment. A Hammarlund would in diameter cardboard tube. Three eighths of an inch from be particularly fitting here. The two honeycomb coils 1500 this coil another winding is placed consisting of six turns turns each are a necessary part of the circuit. of No. 20 double cotton covered wire.

.00/ 001

222 v. 45 '0 go r. "B - Illllllllilllill+ r -IIIIIIIIIIIIIIIII+ FIGURE 3 shows the ever popular Grimes Inverse stage audio is reflexed back in the second stage of radio and Duplex Receiver. The diagram is clear and explains it- the second stage of audio is reflexed back into the first stage self. This is a rather difficult set to get into operation and of radio. This arrangement provides for better balance in the satisfactory working conditions but is nevertheless an in- work of each tube and prevents overworking any one par- teresting one to experiment with. The set consists of three ticular tube. The main tuning unit consists of a variocoupler tubes two of which perform as radio and audio frequency whose secondary is tuned by a 23 plate variable condenser. amplifiers. It differs from ordinary reflex in that the first A 43 plate condenser is inserted in the antenna lead.

II JVvWW .00/

Rotor plates

IIIIIIIIIIIIIII+-

WE still have with us too many of the old standby. We IN figure 4 -B the Colpitts' oscillator circuit, one of the have shown how the single circuit tuner may be changed worst tuners in creation, is changed to an inductively to a three circuit arrangement which will greatly enhance coupled set. The antenna is tuned by means of a 35 turn its selectivity. In figure 4-A the antenna and ground are coil wound on to a three inch tube and tapped every 5 turns. disconnected from their original positions and connected to In winding this coil use large wire, preferably No. 20. This the two ends of six turns of windings placed directly over makes the tuner an inductively coupled circuit with a tuned the original windings on the stationary coil. primary.

www.americanradiohistory.com r' or the Home Builder

.00/

- -- Rotary plates to ground

AMAN came into our offices and told us that he had T N figure 6 we have shown an arrangement that will pro- heard Frisco on the set hooked up according to the f vide loud speaker connections for your receiver in each diagram in figure 5. We were skeptical as usual so we room of the house. The phone jacks are placed in the were invited out to hear it for ourselves. We didn't hear mounting similarly to the wall plugs carrying the house it but we heard nearly every other station this side of the lighting in the modern house and a single closed circuit for Rocky Mountains. It combines tickler and tuned plate feed jacks. By using this type jack any number of loud speakers ,back in obtaining regeneration. can be connected into the phone circuit.

-s.

ílIk' ,

T N figure 7 we have shown six ways of erminating inter- ceiver is located very close to one or two powerful broad- ference and sharpening your tuning. The first five are casting stations. The counterpoise consists of one to four developments of the wave trap and the sixth is the use of wires the same length as the aerial and insulated the same, a counterpoise instead of a ground. In each of the trap placed between the aerial and ground, from thirty to forty circuits the coil is a 50-turn honeycomb coil and the tuning feet below the antenna. condenser a 23 plate .0005 mfd. The counterpoise system A connection is then made from the counterpoise to shown in figure F is generally the last resort when a re- the ground binding post on your set.

/1C-35 uc

.0005

NC SO T .00i

WE STILL have requests for the popular old standby, the phones are plugged in the first or second step due to the three honeycomb coil detector and two step receiv- the difference in impedance which the phones offer with er. This is shown in figure 8. You will note that there is no respect to the primary winding of the first audio frequency jack provided for plugging in on the detector tube. The transformer. practice of omitting this jack is becoming more pronounced We ask our readers in requesting hook -ups and circuit as people realize that when a signal is tuned in with the diagrams for a particular type of receiver to look through phones in the detector jack it very often is not there when our back issues before writing us.

www.americanradiohistory.com INFORMATION DESK

CONDUCTED BY R. A. BRADLEY Due to the great volume of correspondence which this department entails we are forced to remind our readers on the following points: Be sure to enclose a self -addressed stamped envelope with your letter. Make your questions clear and concise. If you wish information on your set please enclose a rough sketch or hook -up if possible. Do not ask us to make comparisons between different makes of apparatus or sets.

The Wireless Age Reflex Loop Receiver resonance in this fashion. In figure 3 we Two -Tube Selective Reflex Set in Issue have an 180 degree variocoupler Described the April ordinary Mr. Anthony Gaffney of Rockville Cen- mounted on a 7 "x7" hard rubber panel with Judging from the requests we have re- ter, L. I., wishes a hook -up for a selective taps and tap switches, the whole placed in a ceived from our readers, it is evident that reflex set using two tubes. "One tube to be small left many persons who have built the reflex loop cabinet and placed near the end used for straight audio frequency amplifica- of the receiver. The four terminals of this receiver which was described in our April tion." The circuit for this is shown below. issue, wish to make this sensitive receiver instrument are brought out to four binding adaptable to use with an outside antenna. posts conveniently arranged on the front When such a set as this is used with an panel. Connections are made from the two outside antenna the results obtained gener- binding posts on the receiver, to which previously were connected the two leads from the loop antenna, now to the binding posts on the right hand end of the variocoupler panel. From these two posts two leads run to the secondary of the coupler. The wires from the two tap switches run to the two binding posts on the left of the coupler panel. To these are connected the aerial and ground leads. in operating this new device the coupling between the primary and secondary coils is set at maximum, that is, with their respective windings parallel Needs a Grid Condenser L. J. Meyers of Haver ford, Ill., encloses the circuit diagram for his receiver together ally resemble a boarding -house hash of all with a list of the parts which he uses. The stations at once regardless of the frantic set is home made and so far has refused manipulation of the wavelength dial. This to give forth any sound except a piercing is due to some extent to the sensitivity of howl despite the adjustment of the dials. the receiver and also to the resistance of Mr. Meyers, if you have given us the exact the tuning circuit which in this case hap- list of apparatus, you have neglected to pens to be the conventional single circuit include a very necessary grid condenser, shown in figure 1, and consists of a . fifty and a signal tuned in with the variable con- .00025 mfd. capacity which should be con- turn honeycomb coil or variometer tuned denser on the receiver. The tap switches nected across the grid leak terminals. by means of a series or shunt condenser. In are now adjusted for maximum intensity. figure 1, the antenna circuit is really the Now using one hand to vary the setting of only tuned circuit in the whole receiver, the condenser and the other to vary the while the grid circuit of the first radio fre- coupling dial gradually reduce the coupling quency tube which should be sharply tuned between the coils and at the same time re- Switching Arrangement for Charging frequency the is in reality fixed at the of adjust the setting of the condenser dial if "It is necessary for me to be away front coil. In figure 2, the antenna circuit and the necessary to make up for any change in house perhaps for a month or more at a grid circuit are both tuned simultaneously, wavelength brought about by the change in !ime and my storage battery in that time but can never be brought into absolute res- coupling. It will generally be found that frequently goes dead. I should like to have The wavelength to which the grid onance. as the coupling is reduced it is necessary are arrangement whereby throwing a switch circuit is tuned is determined by the ca- to increase the condenser setting. the other members of the family could put inductance pacity of the condenser and the the battery on charge or use it on the set, of the coil, while the frequency of the an- without connecting and disconnecting a lot of wires, etc.," writes S. G. Fisk of iV/tite Plains, Y. Generator Hum N C. W. Engelder of Norfolk, Va., is

troubled with a constant hum in the re- . s".u... ..;s unn ceivers whenever his set is turned on. He says : "Evidently this hum cannot be tuned out as I have tried in vain to do so." This trouble is often due to the receiving r- set being placed in close proximity with the sst house light wiring. your house happens J If HC to be wired with A.C. it is more noticeable. The placing of a stand lamp or desk lamp on the same table as the set is placed on This arrangement was shown in D. G. ten a circuit is dependent on these things will also produce this hum. To eliminate Ward's article on storage batteries in the and also the added inductance and capacity it, you must either change the position of April issue. However we are reprinting it in he antenna and ground systems. So it the set or the wiring itself keeping every here as its simplicity and handiness will ap- in will be readily seen that to have maximum part of the set, even the antenna and ground peal to many readers a similar circum- stance. selectivity it is necessary to tune these two wires, as far away as possible from the circuits independently and bring them into light wires. (Continued on page 74) 68

www.americanradiohistory.com 'o,/,JLILEID!/Jl?JJlVJll%JU.JJlI%Jll%J6V- WJ0.MMJJ6VJll%IXIMMl%IlMJLI%llNIALl%D7.l_JLl/JMPAl/Jl!/-1 IVJlJ J0.lJLl.l!lvJlI,l I BROADCASTING STATION DIRECTORY The Most Authentic, Up -to- the -Minute List of Stations Broadcasting in the United States, Canada, England, France and Cuba

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Wash. 258 KFIZ Daily Commonwealth and Oscar A. Huelsmsn, KGY St. Martins College Lacey. Fun -du -lac. Wis. 273 KN.! Timea- 3f1rror Co Los Angeles. Calif. 395 United States Stations Seattle. Wash. 360 KF1B Marshall Electric Co Marshalltown. Iowa 248 KHQ Louie Weenier Stockton, Calif. 273 K KA Westinghouse Elec. & Mfg. Co., E. Pittsburgh, Pa. 326 KF1C Seattle Past- Intelligenter Seattle, Wash 270 KA C. O. Gould Co Seattle. Wash. 283 K DP Westinghouse Elec. & Slig. Co., Cleveland. O. 270 K National Radio Mfg. Co-Oklahoma City, Okla. 252 K1R Northwest Radio Service K DP Southern Kim Calif. 244 Los Angeles. Los Angeles. Calif. 360 Electric Co Diego, K Liberty Theatre Astoria. Ore. 252 KJS Bible Inst. of 360 Supplies Co Oakland. Calif. 360 KDYL Neehouse 111.101 Salt, Lake City, Utah. K Delano Radio & Electric Co....Bristow, Okle. 233 KLS Warner Bros. Radio KDYM Savoy Theater San Diego. Calif. 280 Tribune Publishing Co Oakland, K FF 1 L Hanlsacg Manufacturing Co Ottumwa, Iowa. 242 KLX KDYQ Oregon of Technology Portland. Ore. 360 Co Coif. 360 Institute K University of North Dakota, Grand Forks, N. D. 280 KLI Reynolds Radio KDYW Smith Hughes & Co Phoenix. Arlx. 360 280 KMJ San Joaquin Light & ]'rarer Corp , Fresno. Electric Construction Co., Grand Forks. N. Dak. 360 K DY X Star Bulletin Ilonolulu. Hawaii 360 KMO ].ore Electric Co Tacoma, ash. KFIR Ashley C. Dixon & Son....Stevensvllle, Mont. 258 \Yeah. 263 K DZB Frank E. Siefert Bakersfield, Calif. 240 224 KNT Grays Harbor Radio Co Aberdeen, KF1V Thomas H. Warren Dexter. Iowa Calif. 256 K DZE Rhodes Co. Seattle, Wash. 270 226 KNV Radio Supply Co Is Angeles, KF1W Le Grand Radio Co Towanda, Kans. 360 K D2 Automobile Club of So. Calif., Tus Angeles. Calif. 278 Lighting Supply Co , Los Angeles. Cell[.. loon State Teachers College-Cedar Falls, Iowa 229 KNX Electric KDZI Electric Supply CO Wenatchee, Wash. 360 KFIX of Agriculture & Mechanic Fort Dodge, Iowa 246 KOB New Mexico College K DZQ Nichols Academy of Dancing Denver. Colo. 360 KF1Y 'Foresail Radio Co Arts, Slate College. R. 510x. 360 Wash. 261 K FIZ Texas Nat'l Guard. 112 Car , Fort Worth, Tex. 254 Mich. 286 K DZR Bellingham Publishing Co.. Bellingham. 248 KOP Detroit Police Department Detroit, K Co 380 KFKA Colorado State Teachers Collego..Greeley, Colo. Calif. 423 FAO McArthur Bros. Merrentlle Phoenix, Ariz. 286 KPO Hale Bros. San Francisco. K Wash. 330 KFKB Brinkley-Jones Hospital Assn., NI Wont. Kane. Ore. 360 FAE Stale College of \\'ashIngton ....Pullman, KQP Apple City Radio Club Iioal ]fiver. F 360 KFKQ Conway Radio Laboratories Conway. Ark. 224 K FA Western Radio Corp. Denier. Colo. KOV Doubleday -11I11 Electric Co SI'iPittsburgh. KFAI University of Colorado Boulder, Colo. 360 K FKV F. F. Gray Butte, Mont. 283 l.ala. 360 9d1 KQW Charles D. 'Jerrold K FAN The El.trlc Shol, Moscow. Idaho 360 KFKX Westinghouse Elec. & Mfg. Co., Ilestings, Nebr. Gazette e1erkeley, Calif. Springs, Colo. 234 KR E Berkeley Daily K FAR Studio Lighting Sen ice Un... HoRywnal, Calif. 280 K F KZ Nassour Bros. Radio Co.. Colorado Dispatch . 546 Butte. Mont. 283 KSD Post- K FA Boise High School Boise. Idaho. 270 K F LA Abner R. Wilson KSS l'rest & Dean Radio Co., and Radio Research K FA The Radio Den Santa Ana. Calif. 280 KFLB Signal Electric 51fg. Co Menominee. Mich. 248 Society of Lung Beach, Long Beach, Calif. 360 Seattle, 360 K FAY Virgin's Radio Service Medford. Ore. 283 KFLD Caul E. Greenlee. Frank] inton, La. 234 KTW First Presbyterian Church Wash. 360 KFB8 P. A. But trey & Co lierre. Mont. 360 KFLE National Education Service Denver, Colo. 268 KUO Examiner Printing Co...... San Francisco. Calif. KFBC W, K. Azdll San Diego. Calif. 278 KFLH Erickson Radio Co Salt Lake City. Utah 261 KUS City Dye Works & Laundry Co K FBE Reuben If Horn an Luis Obislm. Calif. 360 KFLP Everette M. Foster Cedar Rapids. Iowa 240 1.O3 Angeles. Calif. 360 Calif. 256 K FOG First Presbyterian Church Tarama, Wash. 360 KFLQ Bizzell Badin Shop Little Rock, Ark. 261 KUY Coast Radio Co FI Monte, Sacramento, Calif. 283 Calif. 360 KFBK Kloball -Upson Co KFLR University of New Meal...Albuquerque, N. 31ex. 254 KWG Portable Wireless Telephone Co.. Stockton, K Everett. Wash. 224 Calif. 360 FOL Leese Bros KFLU Rio Grande Itadlo Supply House, San Benito. Tex. 236 KWH Los Angeles Examiner Io.' Angeles, N Supply Co. and The 270 FBS Trinidad Gas & Electric K F LV A. T. Frykn,an Rockford, III. 229 The Electric Shop Honolulu. Hawaii Chronicle News. Trinidad, Colo. 360 KYQ KFLW Miasoula Electric Supply Co... Slissoula, Mont. 234 Westinghouse Electric & Mfg. KFBU The Cathedral Leromio, Wyo. 283 KYW 360 KFLX George R. Clough Galveston, Tex. 240 KIM Poston D. nn C ....ho aco.Calif. KFCB Nielsen Radio Supply Co Pho nix. Aria. 238 Salt City, Utah 268 KFLY Fargo Radio Supply Co Fargo. N. Dak. 231 Cane he Johnson Lake K FCF Frank A. Moore Walla Walla, Wash. 380 KIN 360 K F L2 Automobile Co Atlantic, Iowa 273 ]tat. & Motor Co., Wenatchee, Wash. K FCH Electric Station (Inc.) .. Billings, Mont. 360 Atlantic K2V Wenatchee Service of Little Rock. New Orleans. La. 268 K Richmond, Calif. 360 KFMB Christian Church., WAA3 Valdemar Jensen FCM Itiehm.nd Radio Shnn Little Rock. Ark. 254 New lit leans. 1.a. 360 KFCP Ralph W. Flygere Ogden, Utah. 360 WAAC 'l'ulane University Fayetteville, Ark. 263 Ohio 360 KFCV Fred Slehafey, .lr Houston. Tex. 360 KFMQ University of Arkansas WAAD Ohio Mechanics Institute Cincinnati, Sioux City. Iowa. ml Ill. 286 K FCY Western Union College Le Stars, Iowa 252 KFMR ]lorningside College WAAF Chicago Daily Drovers Journal....l'hieagu, Minn. 275 Newark. N. J. 263 KFCZ Omaha Central High School Omaha, Nebr. 258 KFMS Frei math Department Store __Duluth, WAAM I. It. Nelson Co Minn. 51o. 254 K FDA Adler's Music Store (taker, Ore. 360 KFMT George W. Voting Minneapolis, 231 WAAN University of Missouri Columbia. Nebr. 360 K FDD St. 31 'cheers Cathedral Boise. Idaho 252 W AAW Omaha Grata Exchange Omaha. Ill. 266 K FOB University of Arizona Tucson, Arlo. 360 WABA Lake Forest College Lake Forest. I( FDI Oregon Agricultural College Corvallis, Ore. 360 WA BB .John B. Lawrence Harrisburg. Ohio 283 K F DO II. Everett Cutting Roseman. Mont. 248 WA BD Parker High School D. C. 283 KFDR Bullock's lido. & Sporting Goals. York, Nebr. 360 W ABE Y. M. C. A Washington, Fla. 275 K FDV G llbretl,t & Stinson Fayetteville. Ark. 360 E 1 1REEE55 fIt1E. W ABG Arnold Edwards Piano Co Jacksonville, ppUS Sandusky, Ohio 240 K FD X First Baptist Chart, Shreveport. La. 360 W ABH lake Shore Tire Co Sle. 240 KFDY South Dakota State College ..Brook lugs. S. Dak. 360 YOU 01K1101 Of WA Bi Bangor Railway & Electric Co Bangor. K Q. Iverson \Iinneepo!is. 5flnn. 231 9 Conn. 283 FD2 Merry THE IjRITgh,FalnV, 5n0 WA BL Connecticut Agricultural College...Storrs, K F EC Meier & Frank l'o Portland, Ore. 248 Etguiiosr EUBafl STRTIOHS. IK THE lief WABM F. A. Doherty Automatise & Radio K EI fitly Greeson Tacoma, Wash. 360 Co.. Saginaw, h. 254 ISSUE IS SUM PInDnIER K FEL Winner Radio Corporation Denver. Co'o. 360 -- Crosse, Wis. 244 WABN Ott Radio (Inc. ) La .1. Srroggin O,k Nebr. 360 N. Y. 252 KFEQ L. EVIOESLt Of TOM hEEPiHi IIS WA BO Lake Avenue Baptist Church _Rochester, F Dodge. Iowa 231 K ER Auto Lleetric Servire Co.....Fort In(IIIfILO Dover. Ohio 266 Casper. 263 WELL WABP Robert F. W einig K FEV Felix Thomreon Radio Shop Wyo. Radio Club .. li Minn. 261 WABQ Haverford ('allege K FEK Augsburg Remirare %linpap011s. Ohl. 261 WABR Scott, High School Toledo.verfoni KFEY hunker 11I11 & Sullivan Slitting & Concentrating Newark. N. J. 244 Co.. Keltoga, Idaho 360 A .1eon nl W ABS Essex Mfg. Co 1nE Ol tlp, tI Washington. l'a. 252 K F EZ American Society of Mech. F:ngs., St. Toula Mo. 380 WA BT Holliday -hall I I Camden. N. J. 226 K FFB Jenkins Furniture Co. Raise, Idaho 240 W ABU Victor Talking Maritino l'o Nashville, Tenn. 263 K Eastern Oregon Radio Co Pendleton. Ore. 360 WABV John H. De Witt FFE Ohio 234 Smith Hillsboro, Ore. 229 W ABW College of Wooster Wooster, KFFO E. H. Mich. 270 KFFQ Slarksheflel Motor Co....Coloredo Springs, Colo. S60 WABX Henry B. .toy Mount Clemens. l'a. 242 KFFR Nevada State Journal sparks, Nev. 226 W A BY .John Magaldi, Jr l'hlmdcipbla, La. 263 KFFV Greecaul College Lemnni, Iowa 360 KFML Stevens pros an Marree. 'rev. 240 WA BI Coliseum Plant Baptist Church .New Orleans, KFMW M. G. Satern 'foughton, Stich. 266 WBAA Unlversit West Lafayette. Ind. 360 KFFX 5lrli raw Co . Omaha. Nebr. 278 Purdue \Iinneatwl is, Minn. 360 KFFY Pincus & Sfurithe Alexandria. Le. 275 KFMX Carleton College Northfield. Minn. 283 W BA D Sterling Electric CO NIinneatmll s, Minn. 417 K F FZ Al. G. Barnes Amusement Co Della. Tex. 226 KFMY Boy Scouts of America I ong Beach, Calif. 229 WBAH The Dayton Co N. .I. 244 K FGC Lmdsinne State University.. _Baton Rouge, Le. 254 KFMZ Roswell Broadcasting Club.. Roswell, N. Mex. 250 WBAN Wireless Phone Corporal ion Paterson. sil. 360 K FGD Phiekaslm Radio & Elea. Co.. Chickasha. Okla. 248 KFNC Mon. Monk, Jr. Corsicana, Tex. 234 WBAO Jams Millik in University Decatur, KFGH Leland Stanford T'nlverslty, Stanford Polo., Calif. 360 KFNF Henry Field Seed Co Shenandoah Iowa 266 W BAP Wortham- Carter Pub. Co. (Star Telegram). Foret Worth, Tex. 476 1< FGL Snell & Irby Arlington. Ore. 234 KFNG Wooten s Radio Shop Coldwater. Misa. 254 Coh,mbus. Ohio 390 KFGQ Crory lla nhva re Co Boone. low 226 KFNH State Teachers College Springfield, Mo. 236 W BA V Erner & Hopkins Co l'a. 360 K FGB Ileldbreder Radio Supply Co flora. Nebr. 224 KFN1 Warrensburg Electric Shop... Warrensburg. 510. 234 WBAX .John H. Stenger, Jr W'Iikes -Barre. New York. N. Y. 492 K FG X First l'resh,terinn (iorrh Orange. Tex. 250 KFNL Radio Broadcast Association ..Paso Robles. Calif. 240 WBAY Western Electric Co Ohio 240 K FGI En,maonel Missionary College, KFNV L. A. Drake Santa Rosa. Calif. 234 WBBA Newark Radio Laboratories Newark, Berrien Springs, Mich. 268 KFNX Peabody Radio Service Peabody, Kans. 240 WBBD Itarbey Battery Service heading. l'a. 234 KFHA Western StateCo1Mge of Colo.. Gunnison. Colo. 252 KFNY Montana Phonograph Co. Helena, SIonL 261 WBBE Alfred It. Slurry Syraeuse, N. Y. 246 Ga. 270 K F H B Rinito Theatre hood River, Ore. 280 KFNZ Royal Radio Co. Ilurlingam, Calif. 231 W BBF Georgia School of Technology Atlanta, K FHB 1112 Radio & Electric Co St. .Joseph, Mo. 226 KFOA Rhodes Co. Seattle. Wash. 455 WBBG Irving Verni lys Mattepolsett. Mass. 240 246 KFHF Central ('hrlstlali Church Shreveport, I.e. 266 KFOB Glenwood Technical Assn., Minneapolis. Minn. 224 W BB H .1. Irving tell Port huron. Mich. K F H H Ambon ' A. McCue Neal, Bey, {{'ash. 261 KFOC First Christian Church Whittier, Calif. 236 WBRI Indianapolis Radio Clui, Indianapolis. Ind. 234 K F H1 Fallon & Co. Sente Barbara, Calif. 360 KFOD The Radio Shop Wallace. Idaho 224 W BB1 Neel Electric Co West Point Beach, Fia. 258 K FHR Star Electric & Radio Co S. allie. Wash. 283 KFOF Rohrer Electric Co Marshfield, Ore. 240 WBBL (:rare Covenant Church Richmond, Va. 283 K F HS CI Wont J. Dow Mae. HawaIl 275 KFOh Radio Bungalow Portland, Ore. 283 WBBM Frank Allass Produce Co Lincoln. Ill. 226 KFHX Robert W. Nelson Ilutrhhnsnn, Kans. 229 KF01 Moberly High School Radio Club. Moberly, Mo. 246 W ISBN A. B. II eke Wilmington. N. C. 275 KFI Earle C. Anthony (Jar.) Los Angeles, Calif. 469 KFOL I.cslle 31. Srhatbuch \(arena°. Iowa 234 W BBO Michigan Limestone & ]'hem. Co.. Rogers, Mich. 250 K F 10 Ross Arbuckle's Garage Iola. Kans. 246 KFOh Eehophone Radio Shop Long Beach, Calif. 234 W B BP Petoskey High School Petoskey. Il ici. 246 K FIF ]tenson Polytechnic Institute Portland, Ore. 360 K FOP Willson Construction Co Dallas. Tex. 268 WBBQ Frank Cook Palucktt. It. I. 252 K FIL Windt-eh Elec. Farm Equip Co , KFPB Edwin J. Brown SeatI le, Wash. 224 W B BR ',moles Pulpit Aszochn ion;. Itossville. N. Y. 244 Louisburg, Kane. 234 KFSG Echo Park Evangelistic Assn., Los Angeles, Calif. 278 W BBS First Baptist Church New Orleans, La. 250 NF 10 North Central High SchooI....Slmknne. Wash...252 KGB Tacoma Daily Ledger Tacoma, Wash. 252 W BBT Lloyd Itroc. Philadelphia. l'a. 234 K FIQ Yakima Valley Radio Broadcasting Association. KGG Bullock Watson Radio Servico..Portland. Ore. 3601 W BB U .Jenks Motor Kies Co Wunmonl h. III. 224 Yakima, Wash. 242 KGN Northwestern Radio Mfg. Co Portland, Ore. 360 WBBV Johnnlnsvn ihadi. Cn lohnslo.. l'a. 248 KFIU Alaska Eger. Light & Power Co.. Juneau, Aln.dsa 226 KGB General Electric Co Oakland. Calif. 312 we BW (tun tier .lu,ior High School Norfolk, Va. 222 KFIX ilrorgnnI zed Church of .Irmo, Christ of Latter KGU Marion A. Moirons Honolulu. Hawaii 360 , WB BY Washington Light Infantry....t'barleston. S. C. 268 Day Saints, Independence, Mo. 240 K G W Portland Morning Oregonian....l'ortland. Ore. 492 WBBZ ',Sulk S, Watson Indianapolis, Ind. 227 69

www.americanradiohistory.com 70 THE WIRELESS AGE JUNE,1924

WBL T. & II. Radio Co Anthony, Kans. 261 WKAN United flattery Service Co Montgomery. Ala. 226 WTAM Willard Storage Battery Co Cleveland. O. 390 WSB I). W. May (Inc.) Newark, N. J. 360 WKAP noire W. Flint Cranston. It. I. 360 WTAP Cambridge Radio & Electric Co-Cambridge, Ill. 242 W BT Southern 'testis) Corporation-Charlotte. N. C. 360 W KAQ Radio Corporation of l'orto Rico, San Juan, P. R. 360 WTAQ S. H. Van Gorden & Son Osseo. Wis. 254 W BZ Westinghouse Eke. & Mfg. ('o.. WKAR Michigan Agri. College, East Lansing. Mich. 280 WTAR Reliance Electric Co Norfolk. Va. 280 Springfield, Mass. 337 WKAV Laconia Radio Club Laconia, N. H. 254 WTAS Charles E. Erbstein Elgin, III. 286 WCAD Y. Lawrence University Canton, N. Y. 280 WKY %VKY Radio Shop Oklahoma, Okla 360 WTAT Edison Electric Illuminating ('o..ltaston. Mass. 244 WCAE Kaufman & Baer Co Pittsburgh, Pa. 462 WLAG Cutting & Washington Radio Corporation, WTAU 'tue. Battery & Electric Co...Teemnseh, Nebr. 360 WCAG Clyde R. Randall New Orleans, La. 268 Minneapolis, Minn. 417 WTAW Agricultural and Mechanical College of Texas. WCAH Ems-elan E.ectric Co Columbus, Ohio 286 WLAH muel Woolworth Syracuse. N. Y. 234 College Station. Tex. 280 WCAJ Nebraska Wesleyan University W LA1 W'ano Electrical Supply Co Waco, Tex. 360 WTAX Williams Hardware Co Streator, 111. 231 University Place. Nebr. 360 WLAK Vermont Farm Machine Corp., Bellows Fails. Vt. 360 WTAY Imlar -Oak Leaves Broadcast. Sta., Oak Park. ill. 283 WCAK .Alfred P. Daniel Houston, Tex. 263 WLAL Naylor Electrical Co Tulsa, Okla. 360 WTAZ Thomas J. lief.uire Lambertville, N. .1. 283 WCAL st. Olaf College Northfield, Minn. 360 WLAP W. V. Jonlon Louisville, Ky. 360 WTG Kansas State Agri. Coll \lanhatlun, Kans. 360 WCAM Vlllamva College Vildanova, l'a. 360 WLAQ Arthur E. Schilling Kalamazoo, Mich. 283 WWAE Iloenig, Sworn & Co Trottin. N. .I. 226 WCAO S lem & Stayman Co Baltimore. Md. 360 WLAV Electric Shop Pensacola, Fla. 254 WWAC Sanger Bros. Waco, Tes. 360 WCAP Chesapeake Potomac Tel. Co WLAW Police Dept., City of N. Y., New York N. Y. 360 & WWAC Wright & Wright (Inc. ) .... Philadclphia, l'a. 360 aehlnslon, D. C. 469 WLAX Putnan, Electric Co Greencastle. Incl. 231 WWAE Lawrence J. Crowley .toilet. ill. 227 W CAR Southern Radio Corp. of Texas, San Antonio. Tex. 360 WLB University of Minnesota.. -Minneapolis, Minn. 360 WWAF Galvin Radio Supply Co Camden, N. .1. 236 W CAS William Bout Dunw'oody Industrial Institute, WLW Crosley ltfg. Co Cincinnati, Ohio 309 WWAO Michigan College of Mines Houghton, Mich. 244 :Minneapolis, Minn. 280 WMAB Radio Supply Co Oklahoma, Okla. 360 WWI Ford Motor Co Dearborn. 111ch. 273 W CAT Sotte Dakota State School of Mines. WMAC Cliva B. Meredith Cazenoria, N. Y. 261 WW1 Detroit News Detroit. Mirk. 517 RaplPhiladelp ilia. 240 WMAF Round Hills Radio Corp Dartmouth, Mass. 360 WWL Loyola University New Orleans, La. 280 WCAU Durham & Co 286 WMAH General Supply Co Ilnwhn, Nebr. 254 WCAV .1. C. Dice Electric Co Little Rork, Ark. 360 WMAJ Drovers Telegram Co Kansas City, Irlo. 275 W CA X University of Vermont Burlington, Vt. 360 WMAK Norton Laboratories Lockport, N. Y. 360 WCAY Kesselman O'Driscoll Co Milwaukee, Wis. 261iWMAL Trenton Hardware Co Trenton, N. .1. 256 WCAZ Cannage College Carthage, III. 246 WMAN First Baptist Church Columbus, Ohio 28 Canadian Stations WCBA Charles W. Ilehnbach Allentown. Pa. 280 WMAP Utility Battery Service Easton, Pa. 246 WCBC l'nivemity of Miehigan Ann Arbor. Mich. 280 WMAQ Chicago Dally News Chicago, III. 448 CFAC The Calgary herald Calgary. Alta. 430 WCBO %\Tibur G. Votive Zion, Ili. 345 WMAV Alabama Polytechnic Intitute....AUburn, Ala. 250 CFCA Star Publishing & Printing Co Toronto. Ont. 400 WCBE lirait Itadlo Co New Orleans. La. 263 WMAW ltalmemn Electric Co Wahpeton, N. Dak. 254 CFCF Marconi Wireless Telegraph of WCBG Bowan' S. Williams Pascagoula, Miss. 236 WMAY Kingshighway l'resby. Church. St. louis, flu. 280 QCanacCineda 440 WCBH I iiit vroity of StississippI Oxford. Miss. 242 WMAZ Mercer University Macon. Ga. 268 CFCH Abitibi l'nwer & Paper Co..Irutuots Falls, Ont. 400 W C K St Ix- Baer & Fuller Dry Goods Co., WMC Commercial Appeal Memphis, Tenn. 500 C FC1 La Cie de L'Evenement Quebec, P. Q. 410 St. Louis, Mo. 360 WMU Doubleday -Hill E:ectric Co..Waahington, D. C. 261 CFCK Radio Supply Co., Ltd Edmonton. Alta. 419 WC M University of Texas Austin, Tex. 360 WNAC Shepard Stores Boston, Mass. 278 CFCL Centennial Methodist Church Vkloria, B. C. 400 WCX Detroit Free Press Detroit. Mich. 517 WNAD University of Oklahoma Norman, Okla. 360 CFCN W. W. Grant Radio, Ltd Calgary. Alta. 440 WDAE Tampa Daily Times Tampa, Fia. 360¡ WNAL It. J. Rockwell Omaha, Nebr. 266 CFCO Semmelltaack- Dickson, Ltd Bellevue, Que. 450 WDAF Kansan City Star Kansas lily. Mo. 411 WNAN Syracuse hallo Telephone Co., Syracuse, N. Y. 286 CFCQ Radin Speeialtles, Ltd Vancouver. It. C. 450 WDAG J. Laurance Martin tmarillo, Tex. 263 WNAP Wittenberg College Springfield, Ohio 275 CFCR Laurent ide Air Service, Ltd Sudbury. Ont. 410 W DA H Trinity Methodist Church (South r El l'aso, Tex. 268 WNAQ Charleston Radio Elec. Co....Charleston. S. C. 360 CFCW The Radio Shop London. Ont. 420 W DA The Courant Hartford. Conn. T61 WNAR C. C. phonies Butler, Mo. 231 CF DC Sparks l'o. Nanalmo. It. C. 430 W D AO Automotive Electric Co Dallas, Tex. 360 WNAS Texas Radio Corp. and Austin Statesman, CF QC The Electric Shop, Ltd Saskatoon, Sask. 400 W DAP Board of Trade Chirago, Ill. 360 Austin. Tex. 360 CF RC Queens University Kingston, Ont. 450 W D A R Lit Brothers Philadelphia l'a. 395 WNAT Leaning Brothers Co Philadelphia. l'a. 360 CFUC University of ]lint real Montreal, Que. 400 WDAS Samuel A. White Worcester, Mass. 360 WNAV Peoples Tel. & Telg. Co Knoxville. Tenn. 236 CFXC Westminster Trust Co...New Westminster, IS. C. 440 WDAU Slocum & Kilburn New Bedford. Mass. 360 WNAW Henry Kunzman.,..lion 167. Fort Monroe. Va. 360 CH AC Radio Engineers Ilei itax, N. S. 400 WDAY Itadlo Equipment Corporation, Fargo. N. Dak. 244 WNAX Dakota Radio Apparatus Co. Yankton. S. Dak. 244 CH BC The Albertan Publishing Co Calgary, Alta. 410 WDBC Kirk, Johnson & l'o Lancaster. l'a. 258', WN1 Shatton Radio llfg. Co Albany. N. Y. 360 CHCB Marconi Wireless Telegraph Co. of Canada, Ltd., W D M Church of the Covenant Washington. I). C. 234 WOAC ''age Organ Co. III. P. Maus) Lima, Ohio 266 Toronto. Ont. 440 WDZ James L. hush Tuscola. Ill. 278 WOAD 1'riady Battery & Electric Corp., Slgourney, Iowa. 360 CHCD Canadian Wireless & E:ec. Co Quebec, flue. 410 W E A A Frank D. Fallahn Flirt, Mich. 250 WOAE Midland College Fremont, Neb. 360 CHCE M'estern Canada Radio Supply .. Victoria, B. C. 400 W EA F American Tel. & Tel. Co New York, N. Y. 492 WOAF Tyler Commercial College Tyler. Tex. 360 CH CL The Vancouver Merchants Exchange. Ltd.. W EA H Wichita Board of Trade Wichita, Kans. 280 WOAG Mgnollo Theatre ISelvWere, 111. 273 Vancouver. R. C. 440 W EAI I'ornell I adversity Ithaca, N. Y. 286 WOAH Palmetto Radio Corporation -Charleston. S. C. 360 Ltd Calgary, Alta. 440 283 Southern CHCM Riley & McCormack. W EM University of South Dakota .. Vermilion, S. Dak. WOAI Equipment Co....San Antonio, Tex. 385 CH CS The Band itoa Spectator Ilamilton. Ont. 410 W Al ! 1). Vaughn Tenn. 360 EA Borough of North Plainfield. WOAN James Lawn nreburg, C H YC Northern Electric CO., Ltd Montreal, Que. 341 Co \lisliawaka. Ind. 360 North Plainfield, N. J. 252 WOAO I.yradlon Mfg. C1 CA The Erimontnn Journal, Ltd Edmonton. Alba. 450 WEAN Shepard Co Providence. It. I. 273 WOAP Kaimazon College Kalamazoo. Mich. 283 J. Lande/ Monti Jolt, Que. 400 Wis. C.ICM L. Phillipe W EAO Ohio Stale Unis ersity Colutbus, Ohlo 360 WOAR Ilenry P. Lundskow Kenosha, 229 UGC London Free Press Printing Co....london, Out. 430 WEAP Mobile Radio Co Mobile, Ala. 360 WOAT Boyd M llamp Wilmington, Del. 360 T. Co.. Toronto. Ont. 410 Pennsylvania 112th l'a. 242 CJCD The Eaton Ltd WEAR Ilnit[more American and News Publishing Co., WOAV Nat. Guano LIf..Erie, Sprott Radio Co Vancouver, B. C. 420 Woodmen of the World Omaha, Neb. 526 CJCE -Shaw Baltimore. Md. 360 WOAW Cl CI Maritime Radio Corp., Ltd St. John. N. B. 400 W EA U Davidson WOAX .1. Trenton, N. J. 240 Itros. Co Sioux City. Inra 360 Franklyn Wolff CJCN Shamus Agnew & Co Toronto, Ont. 410 W EAT Iris Theater Houston. Tex. 360 WOC Palmer School of Chlropractie, Davenport, Iowa 484 W. Shackleton Olds, Alta. 400 W EB St. Iowa College \nies, Iowa CJCX Percival Itcnwoui Co Louis, Mo. 273 W01 State 360 The Evening Telegram Toronto, Ont. 430 W EV Co Tex. 360 Pine Co Bluff. Ark. 360 MC Ilurlhurt -Still Electrical Mouston. WOK Bluff fine CKAC La Presse Publishing Co., Ltd., Montreal. P. Q. 425 W EW St. Kt. 261 John \Vanamakor Philadelphia, l'a. Louis University Louis, Ito. WOO 509 CKCD Vancouver Daily Province Vancouver, B. C. 410 W FAA WOQ NS City. Dallas News ami Dallas Journal. .Dallas. Tex. 476 esicrn Radio Co Kansas Mo. 360 CKCE Canadian Indy. Telephone Co Toronto, Ont. 450 W FA Carl F. Worsese Syracuse. N. Y. 234 WOR 1,. Bamberger & Co Newark, N. J. 405 Railways Ottawa, Ord. 435 W FAM Times Publishing St. Minn. 273 WOS Missouri State Market'g Bu., Jefferson City. Mo. 441 C KCH Canadian National Co Cloud, Publishing Co.. Ltd Regina, Bask. 420 WVX 11. C. Sprat ley Radio Co...Poughkeepsie. N. Y. 360 WPAB Pennsylvania State College...State College, Pa. 283 CKCK Leader CKCO Dr. G. M. Geidcrt (For Ottawa Radio Assn.). W FAH Electric Supply Co fort Arthur, Tex. 236 WPAC Donaldson Radial Co Okmulgee, Okla. 330 Ottawa, Ont. 400 W FAl Ili -Grade Wireless Instrnni t Co., WPAJ Doolittle Radio Corp New Haven. Conn. 268 Calgary. Alta. 440 N. C. College. CKCX P. Muras & Co., Ltd Asheville, 360 WPAK North Dakota Agricultural Supply Co Hamilton, Ont. 410 W FAN Hutchinson Elec. Service Co., liutchinson, Minn. 360 Agricultural College. N. Dakota 360 CKOC Wentworth Radio CKY Manitoba Telephone System ....Winnipeg, Mar. 450 W FAQ Slissonri Wesleyan Collego Cameron, Mo. 360 WPAL Avery & Loeb Electric Co Columbus, 01110 286 Vancouver, B. C. 400 WFAT New Columbus College sioux Falls. S. Dak. 258 WPAM Auerbach & Guettes Topeka, Kans. 360 CFYC Y. W. Odium W F AV Unit coil ty of Nebraska Lincoln. Nebr. 275 WPAP Theodore D. Phillips Winchester, Ky. 360 W F I Strawbridge & Clothier Philadelphia, Pa. 395 WPM' General Sales & Engineering Co , Frostburg, Mil. 360 WGAL Lancaster Elec. Sup. & Coast. Co.. Lancaster, l'a. 248' WPAT St. Patrick's Cathedral El Paso, Tex. 360 W GA Cecil E. Lloyd Pensacola. Fla. 360 WPAU Cotuordia College tlourhead, Minn. 360 British Stations W G A Q Glenwood Radio Corporation.. _Shreveport, La. 252 WPAZ ,loin lt. Koch Charleston, W. Va. 273 W GAW Ernest C. 261 WQAA llorare A. Beale. Parkesburg, l'a. 360 Albright tltoona, Pa. Jr 21.0 London 365 WGAZ South Bend Tribune south Bend, Ind. 360 WQAC R. B. Gish Amarillo. Texas 234 Birmingham . 475 WO Anariranl Radio and Research Corporation. WQAD Whiten Electric Co Waterbury. Conn. 242 51T 5WA Cardiff . 350 Medford Hillside, Mass. 360 WQAE Moore Radio News Station ...Springfield. Vt. 275 6BM Bournemouth . 385 WCL Thomas F. J. Ilmdett Philadelphia. l'a. 360 WQAF Sandusky Register Sandusky. Ohio 210 375 2ZY Manchester . WGR Federal Tel. & Tel. Co üuffa!o, N. Y. 319 WQAL Poles County Tele. & Teleg. Co...Mattoon, III. 258 400 5N0 Newcastle . W G V Inters\ ate Electric Io New Orleans, La. 242 WQAM E:eetrlral Equipment Co Nilami Fla. 283 420 G Scranton, 5SC illosgow . W Y General Elect rie Co Schenectady. N. Y. 380 WQAN Scranton Tittles l'a. 280 495 W H A I'nBOnity of Wisconsin \ladison, Vis. 360 WQAO Calvary Baptist Church New Yore, N. Y. 360 28D Aberdeen Shell Lek( I station) 303 W H AA State University of Iowa latta City. lows 484 WQAQ W. Texas Radio Co. (Abilene Dairy Reporter) 6SL relay W HAB ('lark W. Thirst son Galveston. Tex. 360 Abilene, Texas 360 W H A O Nannette University MHwaukee. Wis. 280 WQAS Prince -\\'alter Co Lowell, Mass. 266 W H AG University of Cincinnati Cincinnati. Ohio 222 WQAW Catholic University Washington, D. i.'. 236 W H A H Hafer Supply Co bold hm. Mo. 283 WQAX Radio Dad pment l'o Peoria. III. 360 W M A K Roberts Hardware Po Clarksburg, W. Va. 258 WRAA Rice Institute Houston. Texas 360 French Stations School of The Club WHAM University of Rochester (Eastman WRAF Radio Lapone, Ind. 224 Lyon 740 Stanley Read Providence. It. I. 231 VN Music), Rochester. N. Y. 283 WRAH N. (Eiffel TostenI 2 600 WHAP Oita and Kuhns Decatur. 360 WRAC Northern States Power Co., St Croix Falls. Wis. 248 FL Paris Ill. 8A1 l'aris 1.780 W HA R Seaside (louse Atlantic City. N. J. 231 WRAM Lombard College Galesburg. III. 244 ESP l'arls 450 W H AS Copier- Journal mind Louisville Times. WRAN Black Hawk Electrical Co Waterloo. Infra 236 Louisville. KY. 400 WRAO St. Louis Radio Service Co St. Louis Mo. 360 W H AV Wilmington Med. Spec. Co., Wilmington. Del. 360 WRAV A ntiodr College Yellow Springs. Ohio 242 W H AZ Rensselaer Polytechnic Institute .... Troy. N. Y. 380 WRAW Avenue Redid Shop heading. Pa. 238 W M B Sweeney Sdiool Co Kairoas rit'. Mo. 411 WRAX f'ixon's Gange Gloucester City, N. J. 268 Cuban Stations W H K Ballotes I tleveland. Ohio 283 WRAY Radio Sales 1orporation Scranton, Pa. 280 W H N George Newark, Sehubel New York. N. Y. 360 WRAZ Radio Shop of Newark N. J. 233 PWX Cuban Telephone Co li onus 400 W IA B Joslyn Co 252 W RC C. 469 Automobile Rockford. Ill. Radio Corporation of America, Washington. D. 2D W Pedro Zasas Habana 300 W IAC Galveston Tes. R K Duran Bros. Co Ohio 360 Tribune l'alveston 360 W Electrical llanilton, 2AB Alberto S de Itustamant e I lalnum 240 W IA D 254 Union Schenectady. N. Y. 360 Howard lt. Miller Philadelphia. l'a. WRL College 20 K Mario Garcia Velez habana 360 W I AF (instar A. Delortin Nov Orleans, La. 234 WRM University of Illinois Urbana, Ill. 360 2BY Frederick V. Burton Ilab:na 260 W I AI (leer Stores Co Springfield. Mn. 252 WRR city of Dallas, Pollee and Fire Signal Dept. habana 320 WIs. Texas 2CX Frederick V. Horton W IAI Fux River Valley Radio Sup. Co., Neenah, 224 Dallas, 360 2EV Westinghouse Elec. Co habana 220 W IA K Journal-Stockman Co Omaha. Nebr. 278 W R W Tarrytown Radio Rei rch Lab., Tarrytown. N. Y. 273 2TW Roberto E. Ramirez Nahanni 230 W IAO School 360 Southeast Missouri Teachers College. of Eng'g of Milwaukee, Milwaukee, Wis. WSAB State 2HC Heraldo de Cuba Hab:uir 275 W I AQ Chronicle Publishing Co Marion. Ind. 226 Cape Girardeau, Mo. 360 'Lobuna 250 W IAS Home Co Burlington, Iowa Clemson Agricultural Col.. Clemson College. S. C. 360 2LC Lola Casas Electric 360 WSAC 2KD E. Sanchez de Fuentes Habana 350 W IA U Savings Bank, Le Mars, Iowa 360 1. A. Foster Co Providence, R. I. 261 American Trust WSAD 2MN Fausto Simon habana 270 W I K K. & L. Electric Co McKeesport. l'a. 234 WSAG Loren V. Davis and George Prestinan. Sr., 2M G Manuel (I. Salas Ilahana 280 W I L Continental Elee'I Supply Co., Washington. D. C. 360 St. Petersburg, Fla. 244 2.117 Raul l'érez Falcon habana 150 W I P WSAI United States Playing Card Co.. O. 309 Gimbel Bros Philadelphia, Pa. 509 Cincinnati. Alvaro Daza habano 200 WJ A D Jackson's Radio Eng'g Laboratories. Waco, Tex. 360 WSAI Grove City College Grove Pity, Pa. 360 2KP Pa. 2HS .Julio Power habana 180 WJA F Muncie Press and Smith Klee. Co.. Mincie, Ind. 360 WSAN Allentown Radio flub Allentown, 229 habana 290 AG Norfolk News Norfolk Nebr. 283 Dau_ht & Welch Elec. Co_ Fall ]liver, Mass. 254 20 L Oscar Copado W1 Dairy WSAR 2W W Saenr. Italians 210 WJA K L. Greentmtn, Ind. 254 WSAT Donohuo.W'are Hardware Co Plainview, Tex. 268 Anadeo CIlffoni White Leopoldo V. Figueroa Colon 360 M M. 268 John .1. Long. Jr Canandaigua, N. Y. 275 5EV WJA D. Perham Cedar Rapids, Iowa WSAW Frank Tulnucu 340 W1 A N Peoria Star Peoria. 280 WSAX Chicago Radio Laboratory Chicago. 111. 268 6KW Ii. Jones III. Jones Tulnucu 275 WLAQ rapper Publications Topeka, Kans. 360 WSAY l'ort Chester Chamber of Commerce, 6K1 Frank 11. WJAR The Outlet Co Providence, R. I. 360 Port Chester. N. T. 233 6CX Antonio T. Figueroa Cienfuegos 170 WIAS Pittsburgh Supply llouae. Pa. 250 WSAZ Chase Electric Shop Pomeroy. Ohio 258 6DW Eduardo Terry Cienfuegos 225 Radio l'Ittaburgli .losé Gandaxe Cienfuegos 300 W1 AT Kelley- Vawter Jewelry Co Marshall, Mo. 360 WSB Ai latta Journal Atlanta, Ga. 429 6BY 200 WJAX Union Trust Co Cleveland, Ohio 390 WSL .1. & M. Electrical Co Utica, N. Y. 273 6AZ Valentin Ulivarrl Cienfuegos W1 AZ Chicago Radio Laboratory Chicago. III. 448 WSY Alabama Power Co Birmingham. Ala. 360 6EV Josefa Alvarez Paibarlén 225 WJ D Denison University Granville. Ohio 229 WTAR Fail hiver Daily Herald Publishing Co.. 7AZ Pedro Nogueras Camaguey 225 WJX Deforest Radio Tel. & Tel. Co.. New York. N. Y. 360 Fall River. Mass. 248 7BY Salvador Blonde Camaguey 350 WJY Radio Corporation of Amerlea.New York. N. Y. 405 WTAC l'enn Traffic Co Johnstown. Pa. 360 8A2 Alfredo 'Smocks Wntlago de Cuba 240 WJZ Radio Corporation of America, New York, N. Y. 455 WTAF Louis .1. Gallo New Orleans. La. 268 8BY .Alberto Ravelo Santiago de Cuba 250 W KAA H. F. I'aar Cedar Rapids, Iowa 268 WTAG Kern Music Co Providence. R. I. 258 8FU Andrés Vlnnet Santiago de Cuba 225 W KAD Charles Looff (Crescent Park 1. WTAH carmen Ferro Belvidere. Ill. 236 8DW Pedro C. Andin Santiago de Cuba 275 E. Providence. R. I. 240 WTAZ Tire Radio Shop Portland, Me. 236 8EV Edurado Rateos Santiago de Cuba 180 WKAF W. B. Radio Supply Co Wichita Falls. Tex. 360 WTAL Toledo Radio & Electric Co Toledo. 0hio 252 8GT .luan F. Chi bas Santiago de Cuba 260

www.americanradiohistory.com Indtisirial Inklings High Lights in radio Development

THIS MONTH Announcing Trains - A New Storage Battery- A Ten -Year Lease - Matching Tone Quality- On a Canadian Trap Line Testin,, head so in the C. Brandes' laboratories

l': Interboro Railroad of Nev 'I`11E world's first annual interna- Coast early in 1925. The Board of T1lyuck has adopted the Callo- tional exposition will be held at Directors of the R. M. S.:\. has taken phune amplifying system for an- Madison Square Garden, New York an exclusive ten -year lease on Madison nouncing trains at the busy express City, September next. This radio show Square Garden for its annual and in- stations. Its premiere appearance took ttill open Monday. September 22nd, ternational radio show which will Le plact at Times Square station. the and continue until Sunday, September held there every Pall until 1934. The bttsiést station of the entire line, (und 28th. It will he held under the auspices . \ssociation has also taken over the prolptbly of any railroad system in the of the newly organized Radio Manu - Chicago Coliseum for a like period. and world. This is the culmination of many facturers' Slurry Association. composed another ten -year lease is being other installations in commercial houses of sixty of the most prominent Amer- negotiated on the Western exposition wIii h have given the Callop'.ume .I ican radio manufacturers. 1'. J. Herr- building. The new organization which great (leal of prestige. mann and lanes P. Kerr. the well - is heavily financed is indeed a perma- known theatrical managers, who made nent institution which nnises to be R ol..ERTs Radio Storage "II" Ilat- such a gigantic success of the annual of great benefit to radio in general. The tery Company and the Todd Chicago radio show. will be Managing outstanding feature next season will he I. leo t is Company, make an alka- Director and General Manager. re- the introduction of foreign exhibits. line) "II" Ilattery with a unique ar- spectively. There will also be an ad- There will also be a series of ultra- rangement of test tubes for cells. sonie visory board made up of E. B. Mal- important public experiments and dem- I:lisim elements, yards of heavy pure lory. Chairman of the Radio Division onstrations for the purpose of bring- nickel wire and a solution of i'otas- of the Associated Manufacturers of ing to light and testing out new radio situt¡I hydroxide ( Potash ). 'flic bat - Electrical Supplies. Paul R. Kiugh, inventions and theories. In addition to tery has a capacity of 1.500 milliam- Executive Secretary of the National awarding suitable prizes to all success- pertjs and it is estimated can he re- . \ssociation of Broadcasters, and Calvin ful inventors of the show management chal +ged for only 5 cents. The Roberts Harris, the pioneer radio publicity will also endeavor to assist them to "B "¡ battery has 2 switch levers which expert. The Radio Manufacturers' market their inventions to the best give, instant voltage changes upon a Show Association will hold three great possible advantage. gratis. Another in- seriès of taps, giving, a cottage range expositions next season which will teresting feature will be the Amateur of front 16, 22, 44 and 140. The Todd irrobably revolutionize the show end Builders' Contest which will surpass is alise tapped oil. The sets are portable of the business. The first will be held all former competitions of the kind. :oui are mounted in well -built niahOg- in New York, September 22 to 28, the The decorative equipment of the con- a n finished cabinets which tend to second will be held in Chicago at the ing exposition will be the most elabo- give; them an extremely neat appear- Coliseum, November 18 to 23, and the rate ever built for an American trade t ic(t. third will take place on the Pacific show of any sort. Manager Kerr has opened headquarters at the Hotel Prince George, 1.1 East 28th St., New York City, where he will remain with his personal staff tintil September 15th. 'T'11E manufacture of reliable radio head sets is marked by test after test, and the greatest possible accuracy must guide each succeeding operation from the time the receiver cut is fashioned until the completed headset is finally passed for shipment. Minute currents of the order of one -millionth of an ampere will make audible sounds in a really sensitive headset, and the fact that it is possible to hear them A five tube Neutrodyne in which Fil- Ko -Stats have replaced the usual wire rheostats for seems almost incredible. To produce filament control. This set, operating in Harrisburg, Pa., receives California stations nightly, mtcn while me Locals ate operaung ana always wutn they have shut down (Continued on page 88) 71

www.americanradiohistory.com NEW APPLIANCES AND DEVICES

Carter Inductance Switch Natann Battery Charger The Bradleyohm

TI I E Carter Inductance Switch made by HE N atann Charger, manufactured by Tl i E Allen-Bradley Co. has added another the Carter Radio Co., does away with T the Natann Mfg. Co., operates on the item to their increasing list of radio the difficult job of mounting and soldering vibrator principle, and rectifies a suitably products known as the Bradleyohm. The to switch points. It is only necessary to stepped -down voltage of alternating cur- Bradleyohm is an adjustable resistor which drill one hole in the panel. All contacts are rent by making and breaking the circuit at is varied over a wide range by applying or mounted back of the panel, only the knob the proper intervals, accepting only one side removing pressure on the two columns of and dial being exposed on the front of the of the alternating current wave. It has an treated discs by means of an adjusting knob. initial charging rate of 8 amperes, from an input current of 110 volts, 60 cycles. This rate tapers as the battery takes the charge. The case is of polished cast aluminum, mounted on rubber cushion feet. The interior working parts are mounted on a Celoron panel, and are made of sub- stantial, well -fitted and finished brass cast- ings. The springs are phosphor bronze. Beneath the panel is an oversize transformer, which operates with a minimum temperature

panel. It has a contact arm which fits into a depression in the combination contact and solder terminal. A slight "click" sound in- The Bradleyohm is admirably suited for dicates that a positive connection has been such purposes as providing an adjustable made with but one terminal instead of resistance across the audio -frequency trans- between two terminal contacts, as is usually formers reduce the case. to distortion; for providing resistors to be used in coupling radio fre- The terminals can be soldered and all quency or audio- frequency resistance am- connections made before the switch is plifiers; for adjusting filter couplers of mounted. This makes a much simpler in- super- heterodyne circuits, and for adjusting stallation, The contact arm is fitted with a push -pull amplifiers. clock spring type of pigtail which eliminates It is made in three sizes with the follow- the undesirable sliding contact. ing ranges : Bradleyohm 10- 10,000 to 100,- In place of the usual small knob and large 000 ohms; Bradleyohm 25- 25,000 to 250,000 dial, the Carter Inductance Switch is fur- ohms; Bradleyohm 50- 50,000 to 500,000 nished with a large tapered knob dial which ohms. shows at all times the exact position of the rise. The ammeter body is also placed un- contact arm. There are 15 contacts, but by der the panel, and the dial opens to the front "Red Seal" Phonograph means of an adjustable stop any number of side of the case. Attachment contacts up to 15 may be used and the balance left idle. THE Manhattan Electrical Supply Corn- Freshman Double- Adjustable patty is offering for sale a new phono- Crystal Detector graph attachment under their well -known mark "Red Seal." This consists of a CONSIDERABLE interest has been trade Durham Variable Resistance special Red Seal receiver attached to a aroused by the New Freshman Double - Omega Durham, the unique heavy non- resonant metal base air trade Adjustable Crystal Detector, which has been with ITTLEfigure which has helped to introduce diaphragm especially the found ideal for reflex and crystal circuits. chamber and designed Durham line of variable resistances is famil- The Freshman detector unit differs from iar to nearly every radio fan. other units in having a knob which can be brought through to the panel and, when turned, varies the crystal contact with the loop whisker, thus permitting the operator to find sensitive spots quickly without dis- turbing the tension on the whisker spring. It has an insulated housing for the crys- tál, and a lever at the base unit adjusts the contact tension of the whisker which operates in concentric revolutions about the face These grid leaks fit the standard grid leak of the crystal, thus covering every point to operate the large air column of a repro- condenser base and can be mounted so that on the crystal as it is adjusted by a little ducing horn. Attachment is made to the the plunger can be operated from the panel knob on the panel. tone arm of the phonograph by means of a and are adapted to all circuits. 'It is made in A special crystal of pure natural ore soft rubber tube. 3 values -1,000 to 100.000 ohms; 0.1 to 5 which will withstand voltages as high as The Red Seal Phonograph Attachment megohms, and 2.0 to 10 megohms. These 130 without burning out, is used. The is sensitive to faint signals and re-creates products are manufactured by Durham & crystals themselves are replaceable by fresh musical programs with the same fidelity as Co.. Philadelphia. units which are sold mounted. the well -known Red Seal Headset. 72

www.americanradiohistory.com icne,1924 NEW APPLIANCES AND DEVICES 73 Medium Frequency Radio Cabinet barrier to prevent oscillations generated by detector upon reaching the antenna. Bay the Transformer THE Radio- Spinet, designed by the The primary or antenna circuit of this View Furniture Co., in all essentials is THE design of a transformer for medium set is aperiodic or untuned, making it pos- the ideal radio cabinet because of its prac- 1 frequency amplification is quite differ - sible to calibrate the secondary circuit and tical features and its desirability as a beau- ent, from the usual amplifying transformer the tuned radio frequency amplifier in terms piece modern design. Audio frequency transformers must tiful of furniture. of wave -length, thereby enabling the re- The Spinet lias ample room in the ha c a considerable volume of iron while Radio- ceiver to be accurately adjusted to the sig- front compartment to nicely accommodate th 1 short wavelength radio frequency trans- nals of any broadcasting station from a cali- most receiving sets, and is of the popular bration table or curve sheet. by no means limited to any one kind. All batteries (both wet and dry), charger. and wires are contained in a rear compartment, concealed from view, but instantly accessible through a large size lid which CO. GENERAL RADIO opens up all the way and exposes the entire CAMBRIDGEMASS. interior. PRI Two large roomy drawers, one at each 311. 19116 end, provide for the accommodation of all The set is selective because it employs those miscellaneous items which accumulate tuned radio frequency, loose- coupled anten- around the radio- note -books, pencils, pro- na and a tuned secondary. It is possible to grams, clippings, extra tubes, head phones. receive the distant stations while local sta- etc. tions are transmitting. For example, in .forpners usually have no iron at all. As the The top measures 23 by 45 inches. The Cincinnati it is possible to tune in KDKA medium frequency transformer falls he- receiving set compartment measures 32 in- which is only seventeen meters higher in tw en both of these limits the natural tend - ches long, 10% inches wide and 7% inches wave length than WLW, while the latter en been has to make it merely a modilica- high. The rear battery compartment meas- station is in operation. tiot of one of these types. It is evident that It operates satisfactorily with a small in- .such a method does not produce a carefully door antenna with loudspeaker volume, and des gucd instrument. good results have been obtained using only The type 271 Transformer has been dc- a ground connection. It requires a detector sigtled by the General Radio Co. as an in- and two amplifier tubes of standard type and strument distinct in and itself particularly satisfactory results are obtained when dry adapted to the service required of it. is It cells are employed for lighting the filament, shiglded both electrostatically and electro- but the volume will be greater with 6-volt magnetically, thus reducing greatly reaction tubes. between stages and permitting the associated tubes to be operated at full capacity. Its Cruver Condenser peak frequency is 30 K.C. (10,000 meters). THE Craver Manufacturing Company have just put out a new condenser which cuts down the inefficient capacities by means Magnavox Electro-dynamic of mounting the stator plates on two rods Reproducer instead of the three usually used and there- '` E new model Magnavox Reproducers by have reduced the losses to a negligible 23 11 3 and R2 contain refinements making quantity. A -plate condenser showed the 290 for increased efficiency as well as economy same reading at maximum capacity and meters as the standard used, which was of operation. ures 32 inches long, 934 inches wide, and stated to have a loss of only seven one - Current consumption has been so reduced 11% inches deep. The top lid measures 32'/4 one per cent. at a capacity of that the new models can be operated at ally by 10 inches and opens up, on hinges, all thousandths of .001 ntld. point between .1 ampere and .6 ampere when the way. This condenser has two scales on one dial. supplied with six volts. The back panel has openings for insertion When the knob is turned either to the right The volume control is a true electrical of wires. Other openings can be drilled in or the left, the vernier plate lines up with switch which permits the user to control as needed. the rotor plates and the vernier index reads Made of combination mahogany with top zero. When the group plates are set for the and front of solid Honduras mahogany - coarse the shows on the the best obtainable. Finished in the popular adjustment reading dull -rubbed brown mahogany or in the large scale. The knob is then turned in the waxed antique old mahogany with its soft opposite direction and the fine adjustment highlights. is read en the inner scale, thus an accurate log can be obtained, which facilitates tuning Trirdyn Receiver in the required station. THE newest addition to the Crosley line, is the Trirdyn 3 -R -3 announced on the third anniversary of the corporation. Four important principles are accomplished in receiver design in the Trirdyn: tuned radio frequency amplification with the first tube: Armstrong regenerative detector action with the second tube; reflex amplification by employing the first, or radio frequency tube as an audio amplifier and one-stage of audio frequency with the third tube. These factors combined in the particular arrangement of this receiver, give signal strength of a current consumption as well as adapt the receiver utilizing five tubes. Perfect electrical connection between sta- reproduction to every possible time, place The Trirdyn will not re- radiate when re- tionary and movable plates is secured with- and condition. ceiving broadcasting station signals, due to out pigtail connections and body capacity Other improvements relate to the dia- the fact that the antenna is very loosely is eliminated entirely when the rotor plates phragm, the movable coil, and also the ex- coupled to the secondary circuit and a non - are grounded. It can be mounted by means ternal finish and appearance of the instru- oscillating radio- frequency amplifier is em- of one nut in a few seconds after the hole ment. ployed before the regenerative detector, as a for the shaft has been bored.

www.americanradiohistory.com THE WIRELESS AGE JUNE, 1924

The D -Coil Receiver of the most efficient receivers that can letters to us in this general form or a simi- one will receive priority in being an- (Continued front page 36) be built, being exceeded only by the lar super swered. fore if dry cell "13" used -heterodyne and Regenoflex re- batteries are ceivers. "1 am about to build the 5 -tube it is advantageous to keep the plate -\'cutrodvne Receiver shown in Fig. lIn this circuit the radio - frequency voltage as low as possible to prolong 9, p. 57, Wireless Age for April, amplification has not been carried to the life of the "13" batteries. The grid 1923. 1 have searched the lot and the maximum is possible, return of the two audio -frequency am- that and I no hook -up appeals to une as titis think it safe to assume plifier tubes is connected to the nega- that at least one une does: but there are a feto points or two more stages could in like 10 have cleared up. tive filament terminal through a 4.5 be put i would ahead of the first tube. I ('sing the attached envelope would "C" battery. This holds the grids 4.5 haven't tried it out, hot%ever. These you please set une right in the fol- volts negative and is another aid in additional stages of radio- frequency lowing: prolongation of "13" battery life, al- amplification would probably have to be untuned as If you were building this set and though its principal function is to hold had on hand a new Remler varioa- it would not be advisable to bring any au! two General Radio A, F. the grids at just such a negative value more eter that maximum amplification with mini- tuning elements into the circuit. transformers would you Three is enough. Regarding mum distortion will be produced from this cir- 1. Use the variometcr cuit that 1 have the audio amplifier. This value of "C" described, you will 2. Leave it out find that if you in 3. Use the General Radio trans- battery voltage is the proper one to bring KKX at Hastings, Nebraska, formers use when 90 volts is applied to the with the dials all set at 15 degrees, you will always find 4. ()sell rheostat for tdnc two A. F. plates and if the plate voltage is in- him at that point and therefore when tubes creased the "C" battery voltage should 1 rheostat for the two you have your dials calibrated in sta- 5. Use be increased. The plate circuit of the R. F. tubes tions it will always be an easy matter second audio frequency amplifier tube 6. Use 1 rheostat (or each tube to set the dials quickly for any station is connected to the 90-volt tap of the 7. Would a battery of dry cells that you wish to receive. "R" hatter) through a single or connected to furnish 6 Colts oper- open circuit jack. The only time yon ate. while they lus;', five 201A tubes as well as a storage battery.' will ever use this jack is when you Information Desk (continued from page 68) 8. Nearly as well \vish plug in The 11 to the loud speaker. Oscillator Circuit 9. Not nearly so well volume a' ailable here is much too E. F. Jones of Detroit, Mich., saps, "I great for the phones. Thus when the trou /fl like to have you give me a diagram DX Reception loud speaker is removed from the cir- for a good oscillator circuit that will cover j.. \. White of New York City. encloses a cuit and the phones arc plugged in on the broadcasting leave band. I have built diagram of his receiver and asks us how the detector or the first step, the plate myself a superheterodyne and have used he can get distance. Getting distant stations circuit of the second and last tube is up to the present time the Hartley oscil- dcp:nds on many things; your location, your open and therefore is not drawing plate lator circuit with a Cif %201-A tube. I have antenna, your ground, the condition of your current and this also helps to prolong had a great deal of trouble in trying to batteries, your familiarity with set and make the tube oscillate over the entire wave provably last of all, the set itself. Of these the li fe of the "B" batteries. band, having found it necessary to force mentioned items, familiarity with your par- No STAnILtz1xl; l'l slsTAxcl NEEDED the filament and use high plate voltages. ticular receiver is most important. This be gained by a week's It is to be noted that there is no SOeAC. experience cannot but months. \ \'e know of stabilizing resistance shown in the cir- listening -in. takes one type of set in particular that we have cuit Done is needed. and The circuit Pick operated on which we were able to get very is absolutely stable without the appli- up good results, yet in the hands of anyone else cation of stabilizing resistances or neu- the set might as well have been "dead." tralizing condensers and is therefore Learning the proper adjustments of the simpler in construction, easier to put dials. being ab'.c to "feel" for stations, and into operation and much more efficient sensing a resonant circuit, that is tuning. ill operation. sot. .001 j It is necessary to have a good KC "The Air Is Full of Things You ground. I would not say that a steam Below is shown an oscillator circuit which Shouldn't Miss" pipe ground was sufficient. It is neces- will oscillate with the same degree of effi- i7 EQUEETS coming in from radio sary to either have a water pipe ground ciency over the entire range of the variable " dealers for permission to make use of You or an electric light ground. Of course, condenser. The I lartley circuit is unsuit- the slogan, "The Air is Full of Things that theory applies to all receivers, but able for your use and is particularly hard Shcudn't Miss,' has led the National Car- to bon Company. creator of the slogan. to de- I have it adjust for maximum oscillation even at noticed more with this type with inquir- of receiver any Without one set frequency such as when used in fine the position taken all such than other. transmitting sets. ies. a good ground the receiver. will not The company says : "The National Car- give the results by a long ways that it How You Can Help Us to Help You Use bon Company has spent a large sum of is capable of giving. the Information Desk motley in popularizing the slogan, 'The Air Not Shouldn't as WILL OPERATE \VITUOrT ANTENNA long ago we received from one of is Full of Things You Miss' our readers, a letter asking several ques- applying everywhere and at all times to It will function very nicely without tions. This letter came so near to being Eveready Radio Batteries. As a result. the an antenna or loop. With a receiver our ideal that we are printing a copy of it slogan became distinctly associated in the of this type which I made up and here. You will note that the writer made minds of everybody interested in radio with which was located at 207th Street and his questions short and to the point: gave the line of Eveready Radio Batteries manu - Broadway, New York City, stations at what details were necessary to our under- fac:ured by the National Carbon Company. Chiçago, Cleveland, Cincinnati, Pitts- standing of his receiver; numbered his ques- "We have felt it necessary to refuse and burgh, Hastings, Nebraska, and many tions and left a space below each one where we will continue to decline permission to we could very easily jot down the answer dealers to use it except in advertising Ever - others in with a were brought only and send his original letter back to him cady Radio Batteries. For such purposes ground connection to the water pipe with both the questions and answers to- they are welcome to it in the public prints. and using no antenna connection what- gether. We hope our readers appreciate the in windows and in counter display. But it ever. I have tried this receiver out time and labor which this method saves in must at all times be associated with and am firmly convinced that it is one conducting this department. Hereafter all Eve ready Radio Batteries only."

www.americanradiohistory.com "' THE WIRELESS AGE 75 Radio for Boatman, Motorist or Hiker (Continued from page 26) would pass through many towns and engine. but the writer has never yet to be camping near a body of water, cities where small broadcasting stations seen a really successful demonstration. then weight a length of wire and throw are situated. We venture to predict Automobile reception will limit itself it out from the shore. that on a trip of this kind, you would to evenings spent in hotels and pos- A careful record kept of the weather probably hear a score of stations which sible noonday stops for lunches. The during last summer, proved beyond the Voo never had the opportunity to hear rest of the time the set will be of little shadow of a doubt that the nights when before, simply because they were too use, but it will certainly be enjoyed in really heavy static is heard, are far weak for you to bring in at home. Such a real automobile camping party, where below the usual idea of the subject. You a trip would not only give pleasure the nights are spent in the open. How- will find that the good nights average from its scenic side, bin also from the ever. there are some things to be re- about six out of seven. viewpoint of radio. membered. The automobile is consider- This summer is going to be radio t ti course in neither the motor boat ably shorter than the motor boat and from start to finish, and right now is nor the aut(m Tole is it possible to re- successful aerial installation on the car the time to start in your preparations. ceive while the engine is running. is seldom accomplished except for sta- Every time your spark plug fir , n tions c :1':y a few miles distant or with The Boy Scouts of America (Continued from paye 39) f! itlz the American _Worse Code: 1. Commercial telegraph operator. 2. Stock broker operator. 3. Telegraph and telephone en- ;ineer. 4. Railroad operator. 5. Train dispatcher.

frith the Continental Morse Code or Both:

A radiorquipped automobile 6. Ship radio operator. 7. Land station operator. have a miniature transmitting set in quite powerful receiving sets. 8. Broadcast station operator. action. and in a six or eight cy.inder Th -s makes it necessary to erect some 9. Cable operator. car, these explosions occur so often kind of temporary aerial at each camp that it would be almost impossible to Mg apace and again we will have to Boy amateurs played one of the receive anything else. t :n some of the resort to the spool of wire. For this most prominent parts in the World larger boats this might he avoided by purpose. nothing is better than what is \Var, which found them ready to give removing the set as far away as pos- known as a deep sea fishing reel. These their services to Uncle Sani. These sible, but in most cases trouble may cone in large sizes and it is possible boys, many of them. had but a few ensue. to wind considerable flexible wire on years previous been Boy Scouts. And, One enthusiastic radio fan used a one. The usual seven strand aerial wire moreover. this great radio we have device on his boat to overcome this will prove too bulky- and it is advisable today (I refer to broadcasting) is like- trouble. Ile got a fifty -foot length of to get some smaller size. wise directly the results 'of the vision, rubber covered copper wire and sealed If a rather heavy sinker is attached enthusiasm and imagination of former up the end with a test tube filed with to the end of this wire and it is then Boy Scouts. paraffin. When the boat was in mo- thrown over the limb of some nearby For when the boys came back they, tion, this wire was thrown over the tree, a suitable aerial will be the result. as well as the thousands who were st rn and broadcasting was actually Except in clamp weather, the fact that taught radio in the Army and Navy, reCeiyed, despite the fact that the no insulators are used will make but turned once more to amateur experi- aerial was under water. The rubber little difference in the strength of the mentation. They added radio tele- covering was. of course, waterproof. received signal. Of course it may make phony to their telegraph experiments while the test tube prevented leakage a little difference on long distance sta- and message exchange. They talked at the end of the wire. tions, but for all ordinary work it will back and forth. first only a few blocks. Such a device as this might work out prove to be quite satisfactory. then a few miles and finally from city quite well in some cases, but it is a By throwing the sinker over the tree to city. subject which is not to be counted branch and then walking off for fifty or It was the boys of the Nation that upon too much. so feet. to the set, a good stretch of helped largely to make this great art In the automobile this trailing wire wire will be secured. Of course the what it is today. And it goes without cannot be used, of course, and in most ground should be made in clamp earth. saying, of course, that many of these cases it will be found that the only if possible, and a short length of num- sanie boys are today leaders in the in- time radio listening can be indulged ber fourteen wire attached to a length dustry. I know two that are on the in will be when the engine is not of iron pipe will be sufficient. The pipe road to become millionaires. One of running. There may he some cases should be about two feet in length and them was once a Boy Scout. where reception has been accomplished driven into the earth for about three - Recently. while on a business trip, in close proximity to a running gasoline quarters of its length. If you happen I watched the farm houses as the

www.americanradiohistory.com 76 THE WIRELESS AGE JUNE, 1924

train whizzed past and there must have been an aerial on top of every fifth farm house I saw. Now I know enough about the fariner to know that they have not the time to install these sets. Who did it,- then ? Boys, of course, and many of them got their training in radio through Boy Scout activities. 0µß(G'' And now a few words about the meaning of radio to this great Boy Scout movement which today obtains in almost every big nation of the world. The call to rally has long been sounded by means of the Boy Scout "MINUTE MAN" whistle. Íts shrill blast has echoed throughout hundreds of camps, and hiking parties have been guided by its radio deceiving Set note. Yet its feeble signal scarcely reaches the extremities of the camp. INCORPORATING Reinforced by the tremendous amplifying ability of a powerful broadcast- Pathé Type "P" Phusiformers ing station, however, and the same signal will call a nation of listening Scouts to attention. Thus, through the agency of radio, Scouts in cities, villages and hamlets are welded together into a single group, and 500,000 Scouts may hear simultaneously the voice of their leader and Honorary President, the c President of the United States. I believe radio broadcasting will r Manufactured and Marketed Under Li- some day accomplish even more censed Agreement, Patent Pending than this. Already programs broacast from the United States reach out to PRICE foreign lands. Various refinements in $12500 transmission and reception coupled (tubes, batteries extra) with increased power will bring about reliable broadcasting between such THE new five -tube "Minute Man" was specially countries as America, France, Eng- constructed to meet the demand for a receiving land. When Baden Powell, speaking set embodying these features: from a London station, is plainly heard in all parts of America, and Dan Beard, No Squeals one of America's leading Scouts, re- Tune in either with a loud speaker or head turns a salute from the United States, phones without any squeals or rasping. At radij will prove a still more powerful any setting of the dials there is none of this unpleasantness so prominent in many other vehicle for promoting the Boy Scout sets. movement. Of course, there is only one ether, Pure Tone one vast highway, which must support The reproduction of broadcasting by the the burden of every conceivable mes- "Minute Man" is remarkable for its clarity sage hurled through space, whether it and sweetness of tone, increasing your enjoyment a hundredfold. be a broadcast concert or a radio telegraphic wave. We must use this ether Simplicity with the utmost respect for the rights The "Minute Man" is simplicity itself to of others. This great common high- operate. The dials can be adjusted by a way is divided into "lanes," which are child -and the set is "Fool- proof." The dial by settings are constant. A station once located policed the radio inspectors of the can always be brought in without preliminary Department of Commerce in the same searching. manner as our automobile and pedes- Genuine mahogany cabinet and panels. trian traffic on the streets. With the Gold engraved dials. rapid growth in the number of broadcasting stations in the United States, Free Booklet Dealers and Jobbers this broad highway had to be divided Booklet "How to Build o 5 -Tube Write Dept. A22 Receiver, into many narrow wavelength bands Using Three Fkusiform- For catalogueue an prices of ers," sent free on request. Address é p l to make a place for all until today few Dept. A22. Pathé line. additional divisions are possible. If thrcugh selfishness, lack of care or ig- PATHÉ PHONOGRAPH & RADIO CORP. , NEW norance, amateur operators violate the 20 GRAND AVENUE, BROOKLYN, YORK regulations governing the use of these wavelength roads, the foundation upon which the entire radio structure rests will collapse.

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WHOLESALE DISTRIBUTORS FOR Radiolas and Radiotrons Radio Corporation of America Sales Dept., Suite 2066: 233 Broadway, New York District Sales Offices: 10 South LaSalle St., Chicago, III. 433 California St., San Francisco, Cal.

ILLINOIS NEW JERSEY OHIO NATIONAL LIGHT AND RADIO SUPPLY THE MILNOR ELECTRIC TUSCOLA ELECTRIC COMPANY COMPANY STATION Co- operative Merchandisers Large Stocks -Quick Service Dependable Radio Apparatus 289 -291 MARKET STREET 129 GOVERNMENT SQUARE TUSCOLA ILLINOIS NEWARK, N. J. CINCINNATI, OHIO

MAINE PENNSYLVANIA CO., Inc. General Radio Special Service, to ATLANTIC RADIO RADIO DISTRIBUTING Dealers on Radio Cor- Corporation poration of America COMPANY Products, in Pennsyl- Guaranteed Radio for Every Purpose loth & Cherry Sts. vania, New Jersey Complete Service Philadelphia Delaware, Maryland, 8 PARK District of Columbia WEST STREET 8o6 Penn Ave. Virginia and West NEWARK, NEW JERSEY Pittsburgh Virginia. 2 t TEMPLE ST., PORTLAND, ME.

MARYLAND tUDWiG TRI -CITY ELECTRIC CO. VYIa10Y }'j! JOS. M. ZAMOISKI CO. > WHOLESALE EXCLUSIVELY 19 LIBERTY STREET 52-56 LAFAYETTE STREET NORTH Hommel's Illustrated Encyclopedia of Radio BALTIMORE, MARYLAND NEWARK, N. J. Apparatus 235 E will be sent free to dealers. We sell to no others.

MASSACHUSETTS NEW YORK ATLANTIC RADIO CO., Inc. CONTINENTAL RADIO PENN ELECTRICAL n AND ELECTRIC CORP'N ENGINEERING CO. Complete Service New York's Leading Radio House " Westinghouse Agent jobbers 15 WARREN STREET 727 Boylston St. Boston, Mass. NEW YORK SCRANTON, PA.

MINNESOTA "TIMES APPLIANCE CO., Inc. STERLING ELECTRIC THE PHILADELPHIA ELECTRIC COMPANY Approved Radio Merchandise COMPANY SUPPLY DEPT. Wholesale Only 130 -32 So. Eleventh St. MINNEAPOLIS, NIINN 145 WEST 45th ST. NEW YORK Philadelphia

MISSOURI WEST VIRGINIA WESTERN RADIO CO. LANDAY BROS. CHARLESTON Dependable Merchandise A Complete Stock of R. C. A. Merchan- ELECTRICAL SUPPLY CO. from dise Always on Hand America's Greatest Manufacturers Electrical Jobbers 31 1 Sixth Avenue, New York BALTIMORE AT FOURTEENTH CHARLESTON, WEST VIRGINIA KANSAS CITY, MO. Retailed at the 7 Landay Stores

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AlffirK Each listener, amateur and commer- SSNIllif cial operator has a definite responsibility which he must assume in order to preserve radio's usefulness. The Boy Scouts of America, an organization of 500.000 law- respecting young men, who daily demonstrate their regard for the rights of others and whose loyal devotion to the highest principles of citizenship have won for them the praise of the nation, have an important Announces a New Audio Frequency duty to perform to make radio of Transformer and New Variable greater use to everyone. They should impress upon others the importance of Condensers observing strictly radio laws in general ; they should instruct or warn those who, through ignorance or design, make trouble for their neighbors by sending amateur messages during the hours set aside for broadcasting. FADA and report cases of violation to their Audio local radio inspector ; their advice Frequency Transformer FADA guided by that of their Scout Masters No. 171 -A, $6.00 Variable should even extend into the home Condensers of No. 142 (15 plates the radio novice, who may not be en- .0003 mf), $3.00 tirely familiar with the operation of No. 144 (23 plates a .0005 mf), $3.50 receiver. The Boy Scouts of America may thus create another field for their endeavors, which should prove extremely helpful in maintaining a well- organ- ized radio system in America.

Radio in the Canadian Wilder- IN KEEPING with its established policy of ness producing only the finest of radio apparatus, (Continued front pare 41) F. A. D. Andrea, Inc., announces a new Audio As the fire burned out, the embers Frequency Transformer suitable for all circuits, formed into glowing patterns that and particularly adapted to the audio stages of seemed to illustrate the broadcast Neutrodyne receivers. music. Castles and forests. and Medi- A high average amplification over all audio aeval faces were pictured there. frequencies is the outstanding accomplishment Even the guides were won over to of this new FADA transformer. Encased in the radio. bakelite with nickeled binding posts, it looks * * * twice its worth. Try FADA Audio Transform- In the morning. we found two ers in your receiver and know what uniform and salmon and a lake trout spread on distortionless amplification really means. birchbark slabs that had been laici on the shore near our canoe. -and now, new variable condensers Jacques explained that the Indian family across the lake The name FADA on a condenser means just had left them as a neighborly greeting. one new He said that thing- condenser satisfaction. The custom forbade anyone going ashore FADA condenser is made in two capacities - at a camp until an invitation had been 15- plate, capacity .0003 micro -farads, and 23- given. plate, .0005 micro -farads; and each the exact Of course, I)r. Hobart and I wished capacity at which it is rated. Radio frequency to return the courtesy in some way. losses are reduced to a minimum by special rotor Jacques advised us that we should wiping contact brushes. A true "low- loss" use discretion because the Indians ap- condenser with an efficiency exceeding that of preciated a small gift ; in fact, respect- condensers selling at much higher prices. ed the White Men for their possession Dealers of that which the Indians would like are now ready to supply FADA trans- to have. and But should too much be given. formers condensers. the Indians would invariably demand more. and would very likely take it. F. A. D. ANDREA, INC. Doc suggested the radio. It was 1581 Jerome Avenue, New York the one thing we could give them in plenty without danger. The Indians couldn't use the set if they did capture o J Täó it. trinj.4' üÑr A trip to the Indian camp was when writing to adve tisers please mention THE WIRELESS AGE

www.americanradiohistory.com li\h:, 1924 THE WIRELESS AGE

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N E uS1 tHE AGYUSTICAL Aewurlra -; BEL CANTO z 3 O Ak

LOUD SPEAKER ; PRICE DELIVERSt FREE TO Item 45 YOUR DOOR1 A FEW GOOD COMBINATIONS. You can only bur '. Item Description Recommended for PI 2 350 V 40 Watt 2 -5 watt separate Fil, supply. - _ 7 500 V 100 " 1-5 " with separate Fil. supply. the BEL. CANTO - -w, 8 500 V 150 " 5 -5 2 mod. 1 mast. ose. -2 ose. sep. Fil. supply. Direct f romUs - * . 13 1000 V 300 dbl. comm. 2 -50 with separate Fil. supply. the Manufac- 15 1000 V 500 ' 3 -50 or 2 -50 watt and 4 -5 watt as speech amplifier and mast. ose. Sep. Fil. supply. turers-We 16 1000 V 650 " " 4 -50 ' with separate Fil. supply. 20 1500 V 600 " " " 2 to 3 -50 " with separate Fil. supply. PIIE 24 2000 V 500 " " 1 -250 " with separate Fil. supply. 26 2000 V 1000 ' " 2 -250 " with separate Fil. supply. you these three 31 500 V 100 " 10 V 60 Watt same as '.tens 7 but with Fit. supply. 35 1000 V 300 " 12 V 150 " " Profits- Distri butor- 41 2000 V 500 14 V 200 " " " Many other sets for various eon-thinntíet, of I .t be,. Special sets made to order. Jobber- and Dea]er. GUARANTEE TRADE // MARK "ESCO Money back any time within ten days it dissatisfied. We further guarantee to the MOTORS DYNAMOTORS -- GENERATORS - MOTOR - GENERATORS rublteation carrying this advertisement that Used by more than 150 Universities, Colleges, Research Labs., etc. Many Federal, and every speaker will be sold on the State, County and Municipal Depts. above terms and the Instrument will be ex o.th dv offered In this Issue. Write for Bulletins 237B and 242A Listing over 200 combinations. 7 Points of ELECTRIC SPECIALI Y CO. 267 South St., Stamford, Conn., U. S. A. BEL -CANTO SUPERIORITY Send us your problems-we'll help you solve them. (t) Fiber Horn, Crystalline finish. Pioneers in Developing and Perfecting High Voltage Wireless Apparatus. (2) Our own adjustable unit. (3) Heavy metal base, eliminating top heaviness. A/ All other metal parts heavy cat Al inum highly polished. (3) Height 22". Bell 10 ". (8) Guaranteed one year against mechanical defects of any kind. i 7) No extra battery required, Just ptug in on the phone circuit. Call at our factory, send us your LearntheCodeat Home with the Omnigraph check, money order, or pay the post- "Just Listen-The OUligraph nil/ do the teeel,,ag" THE OMNIGRAPH Automatic Transmitter will man $10.00. Prepaid to any part of Wireless teach you both the and Morse Codes - U. S. and Possessions. right in your own home -- quickly, easily and In- expensively. Connected with Buzzer. Buzzer and Phone or Sounder, It will send you unlimited messages, at any speed, from 5 to 50 words a minute. THE OMNIGRAPH Is not to experiment. For SENT FREE CHAP° -CET TONE more than 15 years It has been sold all over the world with a money back guarantee THE OMNI- GRAPH Is used by several Depts. of the U. S. Govt. -In fact, the Dept. of Commerce uses THE OMNIGRAPH to test all applicants applying for BEL -CANTO MFG. CO. a Radio license. THE OMNIGRAPH has been successfully adopted by the leading Universities. BENSEL -BONIS CO., INC. I' »liege, and Badto Schools. General s,ffiee & Factory, Dept. W. A. Send for FREE Catalog describing three models. DO IT TODAY. 417 -419 -421 E. 34th St., N. Y. C. ;rel. Vanderbilt 8958 THE OMNIGRAPH MFG. CO. 16B Hudson St. New York City If you own a Radio Phone set and don't know the Code -you are missing most of the fun

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planned for the afternoon so that we could tune in on some broadcast station. During the morning, Doc and I explored the lake shore while the guides baked a blueberry pie. JEFFERSON TRANSFORMERS incidently, baking in the Northern wilderness is quite an accomplishment. Jacques made a deep bed of live coals, placed the pan over them, raised two Pioneers logs over the pan, covered them with small rocks and then built a fire on the The trail blazers through their top. Was the pie good? untiring efforts are always the Juicy bacon on baked salmon with pioneers of Industry. steaming tea and flap- cakes, topped The present day perfection of with luscious blue -berry pie, the twang Radio Transformers is due in no of pine and spruce in our nostrils! small measure to the faithful and All day we heard the Loin -tort of the persistent efforts of Jefferson Indian Engineers who drums across the lake. It beat designed and ex- in my head. The monotony of it finally perimented with Audio Ampli- fiers aroused pent-up emotions within me long before Radio reached that I had never suspected were my its present day popularity. inheritance. We paddled over to the Indian TRANSFORMER SPECIALISTS camp and waited just off shore. The These extra years of experience are chief walked down, saluted, and lis- reflected in the quality and performance of Jefferson Transformers. tened to Joe's explanation. He immediately welcomed us to the bosom of his camp. Our Indian guide, Joe, acted as in- terpreter. The tribe we were visiting were, to say the least, incredulous of our "music box." These Indians travel in family The name Jefferson is associated by both groups of thirty or forty. They are professional and amateur Radioists as re- gards Radio, Intermediate and Audio small in stature and resemble Japanese frequency Amplification with extremely or Eskimos in feature. Tufts of hair high quality. protrude from unexpected points about The installation of Jefferson transform- their faces; from each corner of their ers in your set will assure you of a quality of Reception that is unparalleled. There's mouths, usually on the lower lips, or a Jefferson Transformer for every circuit. frequently from their cheeks. Their costumes consist of red to- Send for our latest Bulletin "Putting Quality Into Radio." The name Jefferson is known wherever Transfol mers are used. boggan hats, red -top socks, red sash, striped flannel shirts, and usually, ELECTRIC MANUFACTURING CO. khaki riding breeches. JEFFERSON The women are extremely shy. But 431 SO. GREEN ST. CHICAGO, ILLINOIS MANUFACTURERS OF the children, like all youngsters, stare RADIO TRANSFORMERS JUMP SPARK AND MAKE unabashed. BELL RINGING TRANS- AND BREAK COILS FORMERS TOY TRANSFORMERS The Chief had some Kodak pictures SIGN L I GH TING TRANS - rtttt[4Bre of the family a visitor had left. FORMERS FURNACEAANDILEBURN-OIL that AUTOMOBILE IGNITION l \ ER TRANSFORMERS He brought them for display much in COILS ¡off TESTING INSTRUMENTS the manner of country folk, showing the unfortunate visitor the family al- bum. The children learn to carry packs as soon as they can walk. They also have small, half -size canoes. Carrying the tons of supplies from the trading post into the wilderness requires the service of all who can be enlisted. While the women weave shirts, and YOUR FUTURE ASSURED prepare dried fish and meats, the men Radio is in its infancy. But it is a "mighty baby" and growing by leaps relay the supplies over the portages. and bounds! Now is the time for YOU to enter this profession with its They work hard on the portages -ter- unlimited possibilities. We train you in a short time for the positions of ribly hard. But they otherwise take Radio Operator or Radio Mechanic. New Radio Sales and Service life as it comes, leaving most of the Course. Radio Operators' correspondence course. State preference. responsibilities to the women. SEND TODAY FOR ILLUSTRATED BOOKLET When I managed to tune in CKAC, the Indians were delighted. Singing, Y. M. C. A. Radio Institute talking, orchestral music- inconceive- 149 East 86th Street New York able ! Late into the night we celebrated. When writing to advertisers please mention THE WIRELESS AGE

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rr . TOOL ^i;i.f_a\ CONDENSERS Up to the Progress of Radio laterial aiul workmanship equal to fy °I) he most exacting requirements of the latest circuits. ' - Superheterodyne Y.. FOR Superdyne Inverse Duplex; Four Circuit Tuner USEE Vernier Cap. .00057 Mfd. (24 Plate) J1: or Plain Cap. .00055 11Ifd. (23 Plate) Cgmlensers of recommended capacity for all known circuits are also carried in stork by lr ,ding radio retailers. End Plates of CELORON Ile Sure of Quality -Buy U. S. Tool Condensers 100% GUARANTEED 11 "rile for Booklet á e eutiodyne U. S. TOOU COMPANY, Inc. 113 Mechanic 't. I Newark, N. J., U. S. A. Balanced! RADIO RECEIVER

the EAGLE leads ! MU RAD Fine balance of tube capacities -per- .. fect as the balance of the experienced REC ERS structural iron worker. Quality, the THE ULTIMATE IN RADIO RECEPTION sum total of infinite skill and years of experience. Until others can suc- Licensed by Independent R a d io Manufacturers, cessfully duplicate the exceptional Inc., under Hazeltine Pat. ent No. 1,450,080, dated skill in balancing and testing of each (The Complete Efficient March 27th, 1923, and other patents pending. receiver, there can be no real rival of and Economical aerial the EAGLE. A product of "quality" rather than quantity production. Sta- ANTENELLA tions located instantly by turning dials so.* Aeovr No Aerial or Antenna Needed s i11.,,/ vs to the same points. Easy to Why pay $10.00 ,aya operate as a phonograph. Unreserv- RA or more to have h ó ;tt-- an aerial spoil the edly guaranteed. appearance of i your home? An- 24 Boyden Place Write for Literature tenella eliminates all unsightly wiring, lightning ar- resters, etc., and $1.25 precludes the possibility of dangerous grounding on a power line. It also stops "canary bird" re- radiation from nearby oscillating sets interfering. ANTENELLA THE SUNDAY is not only a real distance getter, but also overcomes troublesome RADIO ADDRESSES static. of the At your Dealer, otherwise sende purchase price and you will he supplied postpaid. REV. S. PARKES CADMAN Ask for circular A -16 are now being reprinted in the

(pas. Freshman o. Inc. t'ac4o Condenser Wookicts CHRISTIAN HERALD 106 Seventh Ave. New York Over 200,000 small town circulation of the highest type

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The Indians danced. Our guides told stories of the trail. And at the end we all sat down to a venison feast. A truly BRISTOL royal feast in the heart of a wild SINGLE CONTROL dominion. RADIO RECEIVER Using Grimes Inverse Duplex Chasing Squeals System (Continued ¡roui fay,. 591 Patents Pending Most Simple to Operate If you have a filament volt meter The set for those who want results with little ef- take a glance at the voltage which you fort. Anyone in the family can quickly learn to operate it because technicalities and guesswork are have ac. oss the terminals on the sock- eliminated Control Dial does it all. -One et. You %till note that with each tube Does Not Interfere with Your Neighbor there is -a specified voltage for the fila- Other close by reception is not disturbed when you tune in with this non -reradiating Receiving Set. It ment at which this tube works best. gives you a comfortable sensation of freedom to be In the case of \VD -11's and WD-12's ab'.e to change from one station to another knowing that you will not interfere with your neighbor's this voltage is 1 -10th, with UV -199's receiving. it is exactly three volts and. with Choice of Aerial or Loop 201 -A's it varies from 4/ to 5 volts. Where conditions make it difficult to install an outside aerial, as in congested sections of cities, Now in no case is the voltage of your good results can usually be had by using inside battery exactly that which is applied Loop. In fact, the directional feature of the Loop often brings in stations not possible with a sta- to the filament terminals, or rather we tionary aerial. should say that the voltage of your Mounted in solid mahogany case with walnut finish, the Bristol Single Control Radio Receiver is hand- battery never reaches the tube -intact. some in appearance. The price is $190.00. Bul- This is flue to poor connections. re- letin 3013 -V describing this set will be mailed on request. sistance of wires. etc.. which are beyond your control in most cases. Sii it becomes necessary to use a higher yoltaie battery than is necessary to BRISTOL feed the tubes at the socket terminals. 1 TRDE MARK For :he \VD -12 we use % or 2 volts AUDIOPHONE supply and cut it down by means of a REG V. S. PAT. OFFICE rheostat in series. For UV -199's we have four volts or 4% which we cut down to three and in the case of a Loud Speaker L' V -200 and 201A we have an initial This is known everywhere as the Loud Speaker voltage of six which we cut down to with the quality tone. Not only is the tone natural five. But the trouble is, we very and without mechanical distortion, but is sufficient- often ly big in volume to be easily heard in a large room do not cut it down to the proper volt- or all through the house. Comes to you ready to use -no auxiliary batteries are required. age but allow our eyes to tell us how bright the tube should light up. Made in three models: Unless you have had soute experience in this manner of telling the cor- Audiophone Senior Price $30.00 rect voltage we do not recommend it. Audiophone Junior Price 22.50 The hard tubes now on the market today are discolored such an Baby Audiophone Price 12.50 to extent that one is barely able to tell whether Ille tube is lit or not and at best. it is not a safe method. With a D. C. fila- nient volt meter reading from 0 to 5 or THE BRISTOL COMPANY, Waterbury, Conn. 0 to 7 volts you will be better able to regulate your tubes and their proper voltages and at the same time secure nttich better results and lengthen the lives of the tubes. Over- loading the filament of a vacuum tube decreases its life alarmingly. On one type of tube in particular an increase of- 3 per cent over the rated filament voltage cuts V E R N I E R the life of the tube one -half. A 3 per COTROL cent decrease below the rated filament CARTER RHENOSTAT voltage will more than double the life Eight exclusive Carter Features: Only Rheostat with Pigtail connections. of the tube. So you see it is quite Slight click indicates positive "off" position. worth the initial outlay of $7 or $8 for Iteavv phosphor -bronze contact spring. Positive Vernier Control from "on" to "off." a good reliable filament volt meter to Extra large tapered Knob and Pointer, one. know what are Heavy brass bearings -long life -n wobble. exactly voltage you Only one hole to drill in panel, mounts like jack. putting on your tubes. Wide spaced solder terminals for connections.

6 ohms - - - $1.50 Get on the subscription list of THE - 180z E UILDING . Any dealer can supply 20 or 30 ohms, 1.75 I AGO WIRELESS AGE and be sure of gettingjyour copy. \\ hen writing to advertisers please mention THE WIRELESS AGE

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Shell - I I s 6.a, .tudM 1!

Radio & Audio FreQuency TRANSFORMERS Police Sergeant Charles E. Pearce who erected and oiler.

fQa aced the first successful _ - "¡fie polite radio station in the ,,,,Re-,ahto world -a former student of G o t d RecI " the Radio Institute of America.

Vur dealer will tell you why Marl,: Transformers do not howl or distort. l'niform amplification up to as many as Radio - Performance 3.500 cvc1.. MARIE ENGINEERING CO. your chance plus Beauty ORANGE, NEW JERSEY From no knowledge of radio -to licensed operator. From operator Choose your panel for its insulating up the opportunity ladder to the value as well as for its appearance. big jobs at the top. And a life of fascinating interest, well paid. BE YOUR EARS The Radio Institute of America is MAHOGANITE KIND TO conducted under the auspices of the Radiophone Radio Corporation of America, the Radion Panels E a r Cushions greatest radio organization in the add a lot to world. This insures the most thor- give von both the supreme insulation your pleasure ough and up -to -date instruction, and and the beauty of polished mahogany. in DX work. therefore means preference for is not a surface finish They feel like positions when you earn your gov- For Mahoganite velvet -pre- ernment license. but a material which extends from one CD1/5 Actual vise vent pressure. The demand is side of the Radion Panel to the other. Exclude o u t - for trained men great noises. Fits make phone. -and growing. Write today! Get side any your start $1.00 per pair. Postpaid anywhere in U. S. 3 -and grow with radio! 21 Stock Sizes pars for $2.50. Remit with order. RUBBER SALES COMPANY lllaltogauilc and /duck FORT WAYNE INDIANA Home Study Course Conducted from New York City. Full 6x 7 7x14 8x26 instruction for those who cannot attend 6x10% 7x18 9x'4 the San Francisco resident school. 10x12 6x14 7x21 A. Complete Home Study Course. From 6x21 7x24 12x14 beginnings of magnetism through code 7x 9 7x26 12x21 and commercial practice. Prepares you "Kills Reflex for U. S. operator's license. 7x10 7x30 14x18 Troubles" 7x12 7x48 20x24 B. Advanced Home Study Course. For the ALL METAL COVED advanced radio student and exper- REEP sun ienced amateur. Specializes in C. W., CRYSIAL . 6 DUST OUT C. IS RENOVABLE \ I. W., telephone and radio measure- Look for this 6 REPLACE65LE, ments. staple on every a-- SOLID GOLD Send the coupon for full information genuine Radio', (AT WRiSnEa CUP TURNS Panel. Beware IS ADJUSTABLE of substitute, Radio Institute of America CAI WHISRED and incitations. TURNS61S (formerly Marconi Institute) RENOVABLE Established 1909

EASKr Western District Resident School OuNTED New Call Bldg., New Montgomery St., SPEC,ALLV ADAPTED San Francisco, Cal. FOP REFLEX WORK RADION HOME STUDY DIVISION The Supreme Insulation "LINCOLN" DETECTOR 326 Broadway New York City Creating tremendous sensation. En- Indicate by cross X the aune you are interested le: closed, fixed, adjustable. \cw. PANELS in loud and Radio Institute of America, Brings distant stations 326 Broadway, New York ! Dials, .Sockets, Knobs and Insulators: You need it. Price only clear. Please send me full information about At All Good Radio Shops $2.00. Absolutely guaranteed for radin nnnortunities today, and your or write to one year. COMPLETE RADIO COURSE O Jobbers, Dealers: Wire or write. ADVANCED RADIO COURSE American Hard Rubber Co. :Iention this ad. Name Address 11 Mercer Street New York LINCOLN MFG. CO. LOS ANGELES, CAL.

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www.americanradiohistory.com 84 THE WIRELESS AGE JUNE, 1924 Radio Frequency Circuits (Continued from page 64) ohms resistance is very imperative in B 41 most radio frequency circuits, and should by all means be used. The potentiometer is greatly needed to keep Krtuoa race aaa u a rsr, on. the set out of oscillation. ., ADDING RADIO -FREQUENCY TO \ REGENERATIVE SETS DeForest The diagram in figure 2 shows another experiment made in adding radio- ' acnd Bakelite frequency ahead of a twin variometer regenerative set of standard type. The \ Bakelite is standard insulation on aerial was coupled through a variable all DeForest Radiophones -from condenser and tuning coil or primary of a coupler, as shown, and this cir- panels to transformer covers. The \ cuit fed into the input of the radio - effective protection afforded by frequency set. The transformer lead Bakelite is a strong factor in the to the plate terminal on the third radio- o s success of these well known radio frequency stage was opened and a wire sets. secured to the socket plate terminal, and this then led to a variable con- -,.,., Good insulation must have me- denser shunted across the primary of chanical strength and rigidity, the variocoupler in the twin variometer regenerative set. It is advisable - chemical inertness, heat and water to also have a variable condenser of as well as electrical resistance and, the 23 or 43 -plate type (an 11 or 23- Send for our Radio Map last but not least, durability. plate is usually found sufficient, unless vario- Bakelite possesses all these char - the rotor of the coupler has Enclose Ioc and let us send you but a few turns of heavy wire on it) the Bakelite Radio Map. It lists acteristics in a very high degree. the call letters, wave length and connected across the secondary to give location of every broadcasting The fact that practically every sharper tuning. This circuit works station in the world. Address all right with one or two stages of Map Department. radio manufacturer uses Bakelite radio- frequency in use, but as will be is an excellent endorsement of its apparent, one of the main objections value for radio insulation. to it is that there are too many controls. One advantage which might be Write for a copy of imagined for this circuit would be that BAKELITE our Radio Booklet A along with the use of the radio -fre- Condensite quency, there would be a gain of IetDMAIV BAKELITE CORPORATION strength in signals, due to the re- Trade Marks for the generative action caused by the use Phenol Reds Products 247 Park Avenue, New York, N. Y. manufactured under of the variometers, etc., but as pointed patents owned by Chicago Office: 636 West 22d Street out by several radio engineers and as BAKELITE CORPORATION actual experience has proven, there is a suitable regenerative action, or the ---,..1 equivalent of it, through the use of several stages of transformer coupled THE MATERIAL OF A THOUSAND USES radio- frequency, and this is found to. be equivalent or nearly so to the effects produced by using a regenerative detector circuit, as shown in figure 2. One more thing to be mentioned in connection with figure 2 is that if a variable GHEGAN RADIO RELAY condenser B is used across the secondary of the variocoupler. the grid variometer may then be omitted. In figure 3 is shown one method of NEUTRODYNE* connecting one stage of radio -fre- without quency to a standard regenerative set. RAF $135 equipment A 23 or 43 -plate condenser may be Neutrodyne Registered U. S. Pat- ent Office; all rights reserved. Garod connected across the aerial or ground Neutrodyne Receiver licensed by In- posts and primary of the variocoupler dependent Radio Mfrs., Inc., under Hazeltine patents No. 1,450,080 and Taps permit tubes of various impedances to be used. in the set as shown, but some radio ex- patents pending. With Bunnell Register this Relay will tops telegraphic aignale at a speed of 60 to 90 words per minute. perimenters have found this to be un- With Siphon Recorder speeds up to 200 or per Made by minute have been obtained. Normal eventing current necessary, much depending upon the Is % to 2 milliamperes. Send stamp for catalogue THE GAROD CORP. Ne. 45 W. general design of the regenerative set Gbegaa Radio Relay $40.00 120 Pacific Street Special Price to Dealer, employed. The writer prefers the use NEWARK, N. J. I. N. BUNNELL & CO. 32 Park Place. New York City of a variable condenser across the primary of the vario-coupler ; in any case When writing to advertisers please mention THE WIRELESS AGE

www.americanradiohistory.com JUNE, 1924 THE WIRELESS AGE 85

ua .Il°, ..1...... :`: ...... - ... piiti . .. . } . '.T,:=. ... I; t . lp ...... -4.':s..» Results "On my set on which 1 u Filkostat there is no state I have not The of heard. The farthest filament infinite out of the U. S. A. is konfrol adjustment 5 S C Glasgow, Scot- land." W. H. Sul- livan, Macomb, Ill. A phone plus a "DX comes in fine, FI BERTONE I got Belfast, Me., makes a beauti ful musical in- on my single circuit." strument. J. D. Pattengcr, To- ¶NJSTAT peka, Kansas, "It cuts out all THE SCIENTIFICALLY CORRECT n of s c s experienced when a wire rheo- RHEOSTAT T h e Fibertone is stat is used. I have used by more Loud heard KHJ, Los An- Speaker Manufactur- geles, three times." /R`ADIO ers than any other one horn. I It follows that these manufacturers have Eugene Markley, made scientific tests and find Fiber Crellin, Md. Increases Reception In to be best for true tonal reproduction. This is a significant endorsement to "My greatest dis- Any Set In Any Circuit those who want the best reproduction tance has been 2,800 the least The base is The for investment. miles, with satisfac- last control you touch to designed to fit the phone from any head clear a distant station is your rheo- set. Use your own unit which you tion." G. E. Dill, you know is good. If your dearer can- Roston, Alass. stat. \Vhy? Because the most im- not pply you, write to direct. portant tuning unit in your set is FIBERe PRODUCTS COMPANY "I have tried nine -tour tube. 36 Orange Street Bloomfield, N. J. different makes of rheostats but up-to- What FIL -KO -STAT Does date there is none I 1. (Brings in OX stations you never heard before. can compare with 2. Makes tubes operate noiselessly, FIsERTorE Fil- Ko- Stat." John :1. Controls tulles at oscillating point. 4. Permits maximum Signal re,.en- RADIO HORN C. Nisser, Haskell, erat ion. N. J. 5. [teats Moments suddenly. pre- venting crystallizing. Write for G. Lengthens life of tubes. -. Operates tubes at mini- Free Booklet mum voltage. Reduces drain on about vacuum tube > "A" Battery, and how to con- FIL KO - STAT trol so assures inleromeler them as to control of elect sonic get volume. DX and 110N' and -all Its longer tube life. benefits. FOR Write Today! ALL. Addna Dept. \V :V;21/ TUBES

ioSafeóuaids MANUFACTURED f HARRISBURG Rad S AND INSTRUMENTO GUARANTEED BY PENNSYLVANIA STO R M j KING LIGHTNING ARRESTER Approved by. the National Board of Fire Underwriters VACUUM TUBES $1" at all dealers In Wireless Communication By ELMER E. BUCHER The best text book on the market devoted solely to the various applications of the Oscillation Valve 5oIJeraIISolders All Joints Per- Price, see page 6 manently. THE WIRELESS PRESS, INC. SOLDERALL CO. NEWARK,N.J. 326 Broadway New York

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it gives greater seleotivity and much sharper tuning in every respect. The aerial tuning inductance may be either PRECISION a tuning coil. a honeycomb coil of fifty a case of to seventy -five turns, or a tapped in- gear ratio ductance such as the primary of an old coupler. or else a coil wound with about seventy-five turns of No. 22 insulated maget wire with switch taps taken off about every ten turns.

Amplifiers (Continued from page 61) times as great as the tube resistance, then it will be more than that at all other frequencies above it. But from our chart in figure 3 we see that when this is the case we obtain full ampli- ficatit n at all frequencies above 50 cycles and thus have no distortion. Thus the trick is to make the induc- Geared 80 -1 Ratio tance L in figure 2 very great. A good value for L when used with such stan- The operating mechanism of the Accuratune Control is dard rubes as UV -201A or UV -199, is designed to give infinite tuning precision,-geared to develop about 50 henries or over. Now this is 80 to 1 ratio. This means the micrometer knob must be a very large inductance and not easily turned eighty times to secure the usual functioning revolu- built. It requires a great many turns ticn of an ordinary dial. on an iron core. For this purpose it This accounts for the unusual tuning efficiency of is therefore suggested that the secon- Accuratune Micrometer Controls and their ease of operation. Ten times more accurate than vernier condensers or any dary- of an audio frequency trans- tuning device. Stations you never heard before are tuned former be used for this purpose as it in clearly. has the necessary inductance. Designed for both coarse and precise tuning. Fit all stand- Such an amplifier, when it has choke ard condenser shafts. Guaranteed. coils of the high values given above, The tuning satisfaction and the results secured with will give as good quality of speech and Accuratunes repay for the slight additional cost over ordi- music as a resistance coupled amplifier. nary dials. Price each $3.50. At your dealers- otherwise send purchase price and you will be supplied postpaid. It is free from distortion. It has the AC CURATU NE added advantage that it requires less Phoaoiraph Attachment plate voltage, since the resis- Attaches Instantly to the MYDAR RADIO COMPANY battery reproducing a r and tance of the choke coil is much less converts lour [ phono 9 -A Campbell St. Newark, N. J. graph Into a loud speak - the resistances in resistance ,r. Permits nie wh.,le than used k .I '. Lid., llnni-r; al. Can Canadian Rehrr.ci ttfativ,s. coupled amplifiers. $10.00 RADIO FREQUENCY A radio frequency inductance ACCURATUNE coupled amplifier is a much more difficult proposition. The reason for this is that the inductance has distributed MICROMETER CONTROLS capacity, and this distributed capacity will by-pass the radio frequency. That is, the radio frequency currents will rather flow through the distributed capacity than through the inductance, and hence amplification will be sacri- ficed. Another difficulty is that multi- stage radio frequency inductance BURGESS A RADIO SENSATION coupled amplifiers are unstable ; that is, oscillate, RADIO BATTERIES Patent Applied For they have a tendency to A tuner that works without "B" bat- which results in poor quality speech teries. Something new. Reliable. and music and also decreased amplifi- Portable. Fool -proof and a hook -up cation. This type of radio frequency that will revolutionize the art. It is be- positively does not re- radiate and amplifier to be avoided. for it works with loop or aerial. Works comes very difficult to handle, and one loud speaker with one tube on local does not want to be under the necessity signals. of continually haying to be on watch Circulars two cents "A Laboratory Peodnu' and adjusting controls. especially when TRESCO SALES, INC. listening to concerts or speeches. This DAVENPORT IOWA is not recommended therefore and will Madison, Wisconsin i not be discussed. When writing to advertisers please mention THE WIRELESS AGE

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514 -Page RADIO An Expert Says: Handbook Only $1 .lust off the press. The greatest Resistance é 0° book on Radio ever written. 514 pages. Compiled by Harry F. Dart, E.E., formerly with the Western Coupled Electric Co., and U. S. Army Instruc- tor of Itatlio. Technically edited by F. H. Roane. Filled with sound, Amplification ! practical, tested information for For sending every radio fan, from beginner to hard- boiled owl. Send $1 to -day, and get this 514 -page I. C. S. Radio or receiving - Handbook before you spend another cent on parts. Money Back if not satisfied. 40,11011 already sold. Bakelite - Dilecto Panels Mail the Coupon To -day G. V. Allen, of the \Cestingli ii' are FAULTLESS Electric :ld Manufacturing International Correspondence Schools writes in the May Radii, Brow:, :,. P\xi.:1.N of Iltis rxcellrnt untieiial Box 6026, Scranton, Penna. are giving perfect service in many ue Dollar. Please semi Mr-post-Paid- have of the greatest broadcasting Stilton -. the 514 -page 1. C. S. ltadio Handbook. It to un- "True, great improvements derA,aal that if I an, not entirely s:nlsfed 1 teller. equipment lutist be unremitting- may cen made, but the fact remains return this book within fire days and you will re- ly satisfactory. And in Mimi:ands of fund my money. :hat fundamentally the trans - home, Bakelite- I)ilecto is oinking ioruler cannot ever give (lis- possible the highest achievements in !.irtionlcss amplification, For radio reception, through its ninny titl- urne... hose who demand quality at It:IbL. rn.li .- n,IvaIII.1, =,n' ,111:tlities. :ill cost, the resistance coupled nnplitier is unquestionably the _ ;mist desirable." bakelitem "RED- HEADS" Hta.:. wliiit uv ,., ..°;" 'Ited`ne.- is ri .... ost no longer a drawback! ihcy'rv the ie+t r'e: Ilaven specialized resistance dilecto ¡vivo, nt the mar- ostsCa ket Iodas. Superla- e inpled amplifier parts have cut k.I Laminated l'in i ii, tives are ra.y to say the price to less than $3.10 per Condensation Material) and hard to hark UP. stage. Ilere s lam. 5e hark up ours. \tNV.. ,::I'. \Ii float. r, Id. water, oil, solvents. ANTEK than m'll steam. gasoline. high voltage ozone and lllm `i . changing weather conditions do ma affect sup quality of Bakelite -Mile.: in any way. Panel gour radio set i,ar i. vit la Bakelite -IMileeto fur don't ail!, - supreme trial. satisfaction. Your radio dealer etul after Special inexpensive resistors fremi " lted - Heads- are get it eut for you. Identify genuine the lowest priced. ohms high -grade. aamnin - 5.000 up. Our RESIST(>- lin kid ite- !lileefo by its (cotir 1.441 , 1 receive, COl' I'LER, to hold resistor, leak and st ripe. condenser $1.50 THE CONTINENTAL FIBRE CO. MODEL "F" Factory: Newark, Delaware 1917; won hand: 'ulti ni'uini: Back Sn ,ce on Bakelite-Dilecto (also Conti- I,triaii r,,l ear efts: .null. I, nental-Bakelite. Co,rite, Conter and Val. exquisitely hitfre ' anal tatar dealer 19I ] Ask your -or let us cani,ed Fibre) from "RED-HEAD"1eRED- HEAD¡' Jr. $5.00 help yun .ut. Complete 211110 Dion set NEW i11RK CHICAGO 1915.] of new design: e re- Woolworth Building \Wrigley building nnalurtion mid Since 1915 s'ith the same workmanship guar- PITTSBURGH SAN FRANCISCO antee as on our standard Model 'F.'' DAVEN RADIO COMPANY Pwneen in 301 Fifth Ave. 75 Fremont St. R.aio-riwt THE GUARANTEE "Resistor Specialists" Slier year LOS ANGELES SEATTLE Money hark If after 7 days' trial you're te riot sutistled that -Red-Heads'. arc r. 307 S. St. 1041 Sixth Ave., Sn. schienta one '' Hill t II Campbell Street, Newark, N. J. purpose.- tlh:Sr :reefs-ors on the market at the Weer Offices and Agents Throughout the II'urld Meter The NEWMAN -STERN Co. w,.e.. Dept. W.A., E. 12th Street, Cleveland, 0,

Practical Wireless Telegraphy By ELMER E. BUCHER More than 90,000 copies of this book have been sold -your copy is ready to be shipped. Price, See page 6 WIRELESS PRESS 326 BROADWAY NEW YORK

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www.americanradiohistory.com NN THE WIRELESS AGE JUNE, 1924 Afloat and Ashore With the Which is the BEST Hook -up? Operator Which is the BEST receiving set? (Continued front page 53) Which is the BEST headphone? A recent issue of "Shipping Regis- ter," published in San Francisco, con- Which is the BEST rheostat? tained an interesting article about Which is the BEST variometer or coup- Arthur A. Isbell, now manager of the ler? Pacific division of the Radio Corpora- A. Malarin, Which is the BEST grid tion, and Lawrence now leak? district sales manager, in bridging the Etc., Etc., Etc. gap between Hawaii and the mainland of the United States when Mr. 'Isbell sent and Mr. Malarin received the first Which is the BEST Condenser? wireless message transmitted between While the claims of the various It is a significant fact that of all those two points, in the year 1908. manufacturers for the superiority the various kinds of radio apparatus of their products are interesting, it The article also gives Mr. Isbell on the market to -day the CARD - the of publishing the first wire- should be kept in mind that with WELL is credit exception there is no consen- CONDENSER the ONE ONLY unit which is recognized by less newspaper on the Pacific. This sus of authoritative opinion which was in 1907 while he was operator on single item really IS the best, -the engineers and technical Editors of acknowledged standard for com- National prominence as the ONE the President, since renamed the Dor- parison. best. othy Alexander. Hundreds of messages now pass ALLEN D. CARDWELL MANUFACTURING CORP. daily between San Francisco and Si PROSPECT STREET BROOKLYN, NEW YORK Hawaii with less thought and trouble than that one eventful communication hack r -I 1908.

"IT'S A FRAME UP'' High Lights in Radio Develop- NO MORE ment CABINETS CAST ALUMINUM FRAMES (Continued forni page 71) FOR YOUR RADIO SET an instrument capable of this indicates JUST APPLY MAKE IT RIGID and STRONG the supreme care necessary in manu- FLAT MAHOG- Nn SHORT CIRCUITS facture. ANY OR PLATE BROKEN WIRES GLASS COVERS To eliminate entirely the human TO THE NEW No WARPING SPRINGING equation in matching the tone of the receivers, the Brandes company has installed a battery of ingenious super- sensitive instruments to do this. These Quinby are so arranged that the receivers are tested both for volume and sensitivity, Radio Frames a needle on the dial giving the readings, and in addition indicates any grounds (PATENT APPLIED FOR) that may be present. The receiver is SIZE "A" for panels 7" high, each $1.00 made to produce a note the saine as that SIZE "B" for panels 5" high, each 1.00 produced by a receiving set, and this SIZE "C" for panels 7" high, each 1.00 (SIZE "K" for inclined panel sets, in- note is picked up and recorded visually quire) by a needle over the dial. The readings must be within certain limits, and those QUINBY RADIO FRAME CORP. receivers showing the same character- Subway Building istics are put in a box with others which registered similarly, later to be placed 587 West 181st Street New York in pairs in headsets. The illustration shows C. E. Brig- ham, chief research engineer of the Brandes Company, using the visual test machine. RADIO PIN -MAP EMPIRE of Unitd tats, and \Vest Indies 'lUi indexed booklet a broadcasting guide. A FRENCH -CANADIAN trapper, SPOT STATIONS YOU HAVE HEARD WITH ' Oiled Tubing COLORED MAP -PINS. Real Radio Sets of to- in with his winter's catch, was Map size. 22 c l l in., mounted on nap -pin board. EMPIRE Shows all broadcasting cities, distance stale. relay sf5555yh7^' day -the kind that last stocking up with the necessary sup- and time divisions. Guide gives all call signals, .awv. son; long and work best -are locations, stations. have lengths, etc. Price complete. insulated with genuine plies preparatory to returning to his 85c. yfappius. 10e per doz. Any color. Above book- Empire Oiled Tubing. let with folded parer map. 35c. At your dealer or beloved North country. At Edmonton direct. MICA INSULATOR CO. he became interested in a No. 110 Fed- AMERICAN MAP CO. eral Receiving Set. The instrument so MAP MAKERS PUBLISHERS 68 Church St. 542 So. Dearborn St. Maps of Every Description New York Chicago impressed him that he loaded a set on 7 WEST 42ND ST. Dept. M. NEW YORK Works Schenectady, N. Y. 2030 -F flra!ers and krp, esentatices Wanted his dog sled and took it north. Nothing was heard from him all When writing to advertisers please mention THE WIRELESS AGE

www.americanradiohistory.com I t N h., 1924 THE WIRELESS AGE 89

The Leading Jack Your search for quality ends here! The high quality of the Howard Radio Products is not a matter of "chance." Howard Radio merchandise is manufactured with extreme care and precision -by persistent efforts PACENT applied to the minutest details. And in order to keep it ahvay in the HOWARD lead, improvements are math, When you ask your radio man for a Howard from HOWAFVR.S time to time to increase its already Product you are getting the best. Your search well known durability and neat ap- for quality Radio Merchandise is ended, for 1 pearance. Howard Products carry the guarantee of satis- Some of the recent improvements factory performance. are listed below together with the STANDARD RHEOSTAT Discounts to Jobbing MULTI TERMINAI. PLUS now famous "Pacent Jack specifica- This Rheostat gives perfect satisfaction under constant ser- & Electrical Trades. A positive connection fer all tions." vice. Special heat resistant standard receiver terminals. base and knob. Fits all tuba A 2e stamp brings our booklet Acta Instantly. Does away with A new design of tapered springs 25 and $1.10 1 iii, all difficulties. Mechanically greatly improves its neat appearance Our new Rheostat with we- and electrically Ae- dial u new dy et- perfect and contour. mmmadates up te 8 Quires but ens hlhole for m out- pain of ing. e>,k, 25 and 40 ohm with phones in series, parallel. or Heavier nipple construction, avoids epode' dial $1.20 RADIO series- parallel connections. 2 any possibility of stripping threads Also made with micrometer CO. INC. 5I MU Terminal Receiver or breaking. attachment. 4248 N. Western Ave. Chicago Plug $2.00 A lock washer in addition to flat 3 washer under the head of assembly screw, increases sturdiness and pre. vents wear of insulation. 4 Finer NI Warta insulation. CATALOGGFREÉs C Entire frame satin nickel finished. auYEH- NafEHUUYNE -NEU T%UU Y NEI Radio needs New Complete Branston Kits, Includ- Parent Jack Specifications in addition to Here's your opportunity. ing Oscillator you. Win success in this fascinating field. Coupler, Antennae Coup- those listed above: ler, 3 Inter. R.F. Trans. and Special Trained men in demand at highest salaries. Transfer Coupler. Coin Silver contacts (riveted to springs). Learn at home. in your spare time. Complete Kit Lists. Genuine German silver springs. $36.50. Acme 30 Kilocycle R.F. Trans., Nickel plated brass frames (not iron). $5.00. All American 2,000 to 10,000 Extra booster springs. Meter Trans., $6.00. Hilco Antennae Be a Radio Expert Coupler. S8.00. Lugs fan tailed for convenient soldering. easily, to design, Oscillator Coupler. $7.00. I will train you, quickly and Gen. Fads Neut. Parts, 5 tube, $65.60: 4 Provided with three washers. construct, install, operate, repair. maintain, and rohe tee. no, Klt. $25.00 Fit s any sire panel iñ" to tbn all all forms of Radio apparatus. My new methods All details precisely accurate. ace the most successful in existence. Learn to earn Rugged construction throughout. $1,800 to $10,000 a Year There are 10 types of Pacent Jacks -a jack Wonderful, home- construction, tobe for every circuit. FREE receiving set, of latest design. Write for "Radio Poets" free Engineer Mohattpt. WHOLESALE Strict adherence to these specifications in RADIO ASSOCIATION OF AMERICA a DISTRIBUTORS coking Pacent Jacks has won for them the Dept. G -6 4513 Ravenswood Ave.. Chicago tspt. t distinction of being used as standard equip- 6WESTI4TNST. KANSASCITY,MO: ment by many of the leading set manu- Ltct tirers.

11 : it; for catalog 11'6 o PACENT ELECTRIC CO., INC. 110111®11I011101110111 II0IIIQIII0IIIF 4III011 22 Park Place New York Pacent Improve your set RADIO ESSENTIALS with an AmerTran And enjoy radio Send for Circular giving valuable this summer as information as never before to audio transformer design C _ ami use. "7be r rrdflic Cop the cAi r -..,

He oranges in orderly fashion the mans and TRADE MARKME1TRN REG.U.S. PAT.OF jumble of Broadcasting Stations that are seeking entrance to your set and brings 'ern i one at a time. so you can enjoy them! Never m- Ty1:e AF-6 has been ac- amplification -6 1st stage. inis., hut nearly always u-rease: volume. Add a (Turn ratio 5), long with AF for In this Veriu,ed Wave Trap to your wit and "Police" your knowledged the Standard of Excellence for use A F -7 decreases the tendency to overload reception. Regulate the Traffic! audio amplification. the last amplifying tube on loud signals. Price, b, tans not any interfering' station. The price Type AF -7 is now offered for 2nd or 3rd stage either type, $7, at your Dealers. i sÑcontendShin - ti. ads n .ei n,,,t P. , it win a (cisf,w r, ten. send cs,h in full with mÌ .. iim`If ° arenaiJ. Sr" u, , u.r, r,.eri today. American Transformer Company, 179 Emmet St., Newark, N. J. FERREND FERHEND F.LE(:1'ItIC Desiners and builders of radio transformers for over 23 )ears GT- coStP:tNY vccuc1%E.Southerige Water St. Chicago. Ill. II0111®11101110111®Illl-/II1®III0II1I-JIII®III01I

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during the cold, still. winter months. but when the warmer weather loosened up the ways and he again journeyed to the post with his furs, he immediately looked up the man from whom he purchased his radio outfit. The French- man was jubilant! He told of his little log cabin on the hill above the lake: how he would hurry from his toil among his traps to the now cheery little home where, during the long. (lark evenings. he and his wife (for he was the married now), could listen to beauti- UNIFORM CROSS SECTION Jjok For ful concerts broadcast from Montreal, OF THE NA -ALD DE LUXE and to news from outside SOCKET socket board the world. In radio st.lres will find the Na -al(l Socket leading vu STATEMENT OF THE OWNERSHIP. \1. \N- Board. displaying the live standard Na-add Sockets. . \GENIENT. CIRCULATION. ET('.. RE- For the 200 and 201 tubes, the De Luxe at 75c, and ¡H-1REI) BY THE AC'l' OF CONGRESS OE also the Small Space at 35c: For the CV -199, No. 499 !tI'GI'S'I' 24, 1912. 50c adapter at 75c: For \V. I). 11. No.411 at 75c. Of the Wireless Age. published monthly at New at and York, N. Y., for April I. 1')24.

Ask your dealer to show you the self -cleaning ar- State of New York 1 rangement of contacts in Na -add De Luxe, No. 400. County if New York f "' These dual -pressure contact strips cut into the sides Before me, a notary) public, in and for the State surface clean and and county aforesaid. personally appeared H. II. of tube terminals, keeping their Reber, who, having been duly sworn according to bright, and resulting in per fect contact. law, deposes and says that he is the Business These sockets have the highest dielectric properties, Manager of the Wireless Age and that the following is, to the best of his knowledge and belief, a true chtained by the thorough cure of the Bakelite used, and statement of the ownership, m;utagement (and if made possible by uniform cross -section. a daily taper, the circulation). etc., of the aforesaid Ault ication for the date shown in the above There can be no noisy circuits due to poor contact caption. required by the Act I f August 24. 1912. 'SPECIAL DIPPED BRIG with these sockets in use. embodied in section 443, Postal Laws and Regula- tions, printed on the reverse of this form, to wit: PHOSPHOR BRONZE CLIPS. erre,' rotogravure book!.; "What to Build" now packed the names and addresses the with each Na -add product. If your dealer's stock doesn't I. That of publisher, LAMINATED AND EXERTING editor. managing editor, and business managers hove this booklet 'send cover of Na -add carts n or I.rr for it. DUAL -WIPE PRESSURE o ALDEN MANUFACTURING COMPANY Publis'ner, \tireless Press. Inc., 326 Broadway. New York. N. Y. THIS ILLUSTRATION SNOWS NOW DEPT. A SPRINGFIELD. MASS. Editor. Jerome W. Howe, 326 Broadway, New THE CONTACT STRIPS CAN BE York. N. V. MADE TO CLEAN TUBE TERMINALS MNÌlilil;illni' ;IIIIIIIIEn, A_ ... :nlll \ laugt ing Editor, None. 'AUTOMATICALLY BI I1 L cllllllHniMn:llnIII :o R1100/1 ROTATING Business \tanager, 11. 11. Reber, 326 Broadway, TUBE SEVERAL TIMES, New York. N. Y. 2. That the owner is: (If the publication is owned I.y an individual his name and address, or if owned by more than one individual the name and add, ess of each. should be given below; if the Ilub!icat ion is owned by a corporation the name of the corp -,ration and the names and addresses of the stockholders owning or holding one per cent. or more of the total amount of stock should be given.) Wireless Press, Inc., 326 Broadway, New York. N. t. Radio Corporation of America (owning all the stuck of Wireless Press. Inc.), 233 Broadway, New York. N. Y. The names and addresses of stockholders of Radio Corporation of Annerita owning or holding 1 per tent. or more of the total amount of its .I...I.t/ stock are as follows: Cameron lit aikie & Co., 44 Broad St., N. Y. C.. General Electric Co., 120 Ati; Broadway, N. Y. C., International Radin Tel. & Tel. Co., 165 Broadway, N. Y. C., United Fruit Co., 131 State St.. Boston Mass. 3. Chat the known bondholders, mortgagees. and other security holders owning or holding 1 per tent. or more of total amount of ponds. mortgages, or other securities are: (If there are none, so state.) None. 4. That the two paragraphs next above, giving the names of the owners, stockholders, and security holders, if any, contain not only the list of stockholders and security holders as they appear upon the books of the company but also, in cases v.herc the stockholder or security holder appears upon the books of the company as trustee or in any other fiduciary relation. the name of the person or corporation for whom such trustee Quality Throughout! is acting, is git'ett: also that the said two paragraphs contain statements embracing affiant's full knowledge and belief as to the circumstances and The SOUTHWORTH Vernier Condenser conditions under which stockholders and security stands in the very front rank of precision holders who do not appear upon the books of the company as trustees, hold stock and securi- instruments. It is included in the Wire- Solid endplates of pine ties in a capacity other than that of a bona fide less Age list of "the four best "! Bakelite; heavy plates that twner: and this afant has no reason to believe that any other person, association, or corporation cannot warp: accurately has any interest direct or indirect in the said SOUTH WORTH Vernier Condensers milled spacers: velvet ac- stock, bonds. or other securities than as so should always be your choice -especially tion; handsome appear- stated by him. ance. 5. That the average number of copies of each in radio frequency circuits where every bit issue if this publication sold or distributed, of added efficiency makes all the differ- through the mails or otherwise, to paid sub- ence in the world. scribers during the six months preceding the date shown above is (This information is required from daily publications only.) SOUTHWORTH SPECIALTY CO. Ií. H. REBER, Business Manager. 91 Seventh Avenue N.Y.C. Sworn to and subscribed before me this 20th day of March, 1924. M. Ii. PAYNE. '.N'IANI. A'A'A'0L'A'. '/M'AY'I."./eAI.'A'Ilp'A'/K/M /p'/\'IM'A'A'II11'10M'I1'IVI(A I1 [ Sea'..] Notary Public. (My commission expires March 30th. 1924.) When writing to advertisers please mention THE WIRELESS AGE

www.americanradiohistory.com Pl-Ni. P)24 THE WIRELESS AGE 91 LEARN THE CODE BY THE Marconi -Victor Method WIRELESS AGE RECOMMENDS GENERAL INSTRUMENT CORPORATION You Just Listen and Learn GROUNDED ROTOR CONDENSERS

MARCONI VICTOR COURSE IN WIRELESS TELEGRAPHY SEE SEE It's just as interesting to read the dots and dashes PAGE as PAGE to listen to broadcasting. ROTOR COpNBfED These records will teach 0ND you quickly, under actual 54 54 operating conditions, to read code at a speedy rate. PArr L ersOmc GENERAL INSTRUMENT CORP. NEW YORK 111111111611/437

The LOW LOSS General Instrument GROUNDED ROTOR CONDENSER has practically no dielectric losses and hence you get 37; more DISTANCE and VOLUME than with the average variable condenser. ASK FOR IT AT YOUR DEALER OTHERWISE SEND PURCHASE PRICE DIRECT TO US AND YOU WILL BE SUPPLIED GENERAL INSTRUMENT CORPORATION 423 BROOME STREET NEW YORK CITY

INDISPENSABLE CRESCENT LAVITE RESISTANCES 12.000, 48.000, 50.0011, 100,000 Ohm:. Rubber Phone Cushions List $1.50 Each Six Double -Faced Marconi Victor r,r radio Ielcphoncs. lust .Ship OVel. Records, with instruction Manual $5.00 ., id note the added comfort. No outside i l no hard pressure against ears. 75e tile p r. WIRELESS PRESS, Inc. Gadget No. 1 . \11 Sets nerd it. Repi.ices jacks, plugs. switches. Room 405 retors. Just what you've been waiting to : Special Sizes to Order 326 BROADWAY :tnlonly 25e the pair. Full iirecti,ms. lust NEW YORK USED IN ALL CIRCUITS ROYAL RADIO CO. Dealers write for discount CRESCENT RADIO SUPPLY CO. 12 Osgood Place, Flushing, N.Y. 1 -3 -5 Liberty St. Jamaica, N. Y.

NEW COPIES for OLD PERFECT FILAMENT CONTROL

1 f you have the January, February, March, B April, August, October, 1923, copies of THE THE PERFECT GRID LEAK WIRELESS AGE send them to us and we will extend your subscription one month BrddleljOineter for each issue. THE PERFECT POTENTIOMETER

DEPT. "M"

PERFECT BATTERY SWITCH THE WIRELESS AGE 326 BROADWAY NEW YORK CITY 283GreenfieldAve., Milwaukee, Wis.

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www.americanradiohistory.com THE WIRELESS AGE JuNE,1924

Stations Worked Around the World ! A New Zealand amateur got Alabama (10,000 miles) on one and Heard Myers Tube -heard the signals and message perfectly. Certified by Radio News. This remarkable performance indicates that there is no limit to long -distance reception with Myers Tubes because their design is 9ASV -977 West Central Ave., St. Paul, Minn. right. labf, labt, (lare), (lavf), layt, lbbp, lbcr, (Ibel), lbgc, lbgo, lbie, (lbrl), lcit, lcmx, lga, lgv, lsk, 2aay, 2afp, 2a1, 2ate, 2axf, Myers 2cdp, 2cee, gybes (2bbn), (2be), 2bgo, 2bxd, 2cbg, 2cgq, 2cla, 2rk, 2sq, 2wr, 2xn, 2xq, (3abw), Practically Unbreakable 3am-, 3apy, 3aqr, 3bei, 3ccu, 3cej, (3cjn), add to the efficiency of any set by cutting out noise, tube hiss and 3cz, 3dt, 3hh, 31g, 31y, (3qt), 3qv, 3wx, 3xaq, interference. 4af, 4ag, 4ba, 4eb, 4jn, 4oh, 4xc, Saar, Saas, Two types: Dry Battery and Universal (for storage battery). 5adb, (5aiu), Saiy, 5ajj, Samo, (Scn), (5eit), Insist on Myers Tubes at reliable dealers- otherwise send pur- Sek, 5fv, Sjb, (5ka), 51r, Snw, (5ph), Sqd, chase price and be supplied postpaid. See the words "Made in 5sg, Ssz, Szav, 6aao, 6agk, 6aoc, 6arb, 6bql, Canada" burned on the glass. Others are not guaranteed. 6bui, 6buo, 6cdg, 6cef, 6cej, 6cka, 6cmr, Each, complete with (6cmu), 6cnf, 6fy. 6gq, 6ih, 6jj, 6m, 6zcd, clips ready to mount Myers Ltd. on your set; no sock- o. 7afe, 7agi, 7ajy, 7akk, (7co), 7dr, 7ej, lem, E.B.bath' 7 /c'ruum 7he5 ets or other equip- Tif, 7iw, 71k, (7no), $5 ment necessary. 240 Craig St. W. Montreal, Canada 7ew, ley, Ifs, 7gr, 7gw, 7nr, 8aaj. (8acm), (balm), (8alx), 8apt, 8atcj, 8avj, 8bce, (8bgw), 8bk, (8bqs), 8bwb, (8cci), 8ctz, (8cwr), (8dae), (8bgw), Entirely New (8dae), (8dgp), (8djd), (8gx), (8ig), Sqb, I]ISEMMANN RADIO EQUII'MIENT (8ry), 8sr, 8tj, 8uk, 8vn, (8xbc), 8xe, comprises D Principle (8yae), fone, 9ry, (9eeo). Can. 3co, 3pz, 4ba, Headsets. Variometers, Variocouplers, Premier Condensers. Potentiometers. Detector, 4cb, 4ch, 4dq, 4eo, 4fv, (4fz), (4ws). Resistance -Adapter. Radio and Audio Amplifier Units, A.F. AmplilyingTrans- MICROSTAT former, and ready drilled metal panels. Tia,le )tel; HERSCHEL SMITH, El Dorado, Kans. Also, the new R F2 Broadcast Receiver. Write for Prices and Descriptive Literature Super- Vernier Rheostat $3.00 T,,, \CDAP, KFI, KGO, WDAF, \\rBL, and worth it noiseless. luliuile ,tribut. handles KGW, KHJ, WCAL, KPO, CFCN, KFJW, tithe. l'an. :1 amp. Bakelite Inol.lel. Silver \VHB, WTAM, \VAA\V, WHAS, \VFAA,

SPECIFICATIONS

1. Operates without extra batteries. 2. Adjustable dial con- Brooklyn Hears trols volume. 3. Handsomely compact in construction. Great Britain on 4. Finished in a rich ebony; set off by a glistening silvered rim on the bell. the Dictogrand ! 5. Fully guaranteed. 51 Ilak Avenue Brooklyn, N. Y. pictograph Products Corporation Dear Sir: Kindly send me your large package of "Applause Ilse HOMMEL Cards. " I have a Dictogrand loud speaker and received station 21.0 and three other English stations all on the loud speaker on SERVICE $24so the last test. I have tried all makes and found yours to be the best. Respectfully yours, C. 1. LEAGUE. to build your radio ANOTHER record! night -right on the loud First, San Francisco speaker. heard Japan and Ncw And they have found that biustness ark on the Dictogrand. this marvelous mechanism. so Now, Brooklyn hears Great magically sensitive to faint By aligning yourself with the Rommel Britain on the Dictogrand. impulses from the other side Organization you have access to ample Amazing? Not owners to of of the world, is startlingly the lines this incomparable instrument. lifelike on local stations! stocks of leading of radio equip- For Dictogrand users in Ask your radio shop to ment at all times, and can serve your cus- every state are familiar with demonstrate the Dictogrand: tomers promptly without the necessity of the thrill of listening to far feat "Applause Cards " tying up your own capital. distant stations-night after FR'i.- at the same time.) working Cnprrtghted Write for Iiommel's illustrated Ency- clopedia No. 246E. DICTOGRAPH LUDWIG HOMMEL & CO. PRODUCTS CORPORATION Wholesale Jobbers Exclusively 929 Penn Avenue 220 West 42nd St., New York City Pittsburgh Penna.

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www.americanradiohistory.com (1 JUNE, 1924 THE WIRELESS AGE 3

INCREASES ELIMINATES RANGE and VOLUME INTERFERENCE

4 Pr d Make; Any Set Better 1. Lowest Losses (Too small to measure) 2. Micrometer Verniers 5. Adjustable Cone Bearings 3. Soldered Brass Plates 6. Double Wiping Contacts 4. Rotor i rounded to frame 7. Takes any size dial "Just be sure it'.c a Hammarlund" PATTERN No. 95 HAr/IMARLUND New Mode( VERNIER VARIABLE CONDENSER RADIO ¡('rite for Yew and Interesting Folder TEST SET HAMMARLUND MFG. CO., 144-146 West 18th Street. New York This radio set has been designed to meet the demands coming to us from serious experimenters, manufacturers and dealers in radio equipment and supplies, for a complete radio testing outfit. [AVM IIURglIIVJIA.VJM3,11,1JlVMMIMW _W-dWyMn nmeg,tN Q While the various ranges of OLEKIERIESMOIME readings permit making practically every test necessary in connection with radio receiving sets, Small Ads of Big Interest it has been particularly designed for the taking of characteristic Space in 'hishis departmentdepartment costs only 65 cents a lineTine curves on vacuum tubes, the only extra equipment required being Minimum space 7 lines Payable in advance the batteries. EilliMMEEIEUMEIREE tiiilriiYll%iYll1'íYlrrectrrareArMYI1rril1tíll /í1rf/íYrrtllrYílr.' ; ¶ The several instruments, any of which may be used independent- MAKE $100 WEEKLY In Spare Time. Sell ly, what the public wants-long cistance radio receiv- include an 0 -1.2 filament am- ing sets. Two sales weekly p Lys $100 profit. No RADIO GENERATORS-500V loo watt $28.50. meter, an O -6 filament voltmeter, big investment, no canvassin r. Sharpe of Colo- Battery Charging Generators $8.50. High Speed an 0 -120 plate voltmeter, an 0 -10 rado made $955 in one mot th. Representatives Motors, Motor Generator Sets, all sizes. MOTOR wanted at once. This plan is sweeping the coun- SPECIALTIES CO.. Crafton, Penna. plate milliammeter and an 10 -0 -10 try -write today before -oir county is gone. grid voltmeter. OL:\RK: \, INC.. S54 \Vastíir ono ailed., Chicago. Complete with instructions Price, $75.00 Send For Circular ORDER FROM DEALER COPPERWELD ANTENNA WIRE Jewell Electrical Instrument Co. IN CARTONS 1650 Walnut St. Chicago "The Ideal Radio Antenna" Strongest -Most Efficient -Best ?:.;.THE IDEAL RADIO AKTENN. -o-

/ fin L5 Sq'. 51 50\f.01 COPPERWELD LEAD -IN AND GROUND WIRE IN CARTONS

Rubber Insulated Brown Braid For inside and outside use

100, 150 & 200 It. per carton 25, 50 & 100 ft. per carton At dealers, or postpaid Durham SL Co.. 1936 Market St.. Phila. The construction direc ions and Underwriters' regulations on the carton answer all questions

Get on the ,AVE TIME - SELL IT IN CARTONS Subscription List of or THE WIRELESS AGE "COPPERWELD" and be sure of getting MADE EX ;LDSIVELY BY THE COPPERWELD STEEL COMPANY New York, N. Y. Ran tin, Pa. Pgh. Sub.) I Chicago, Illinois San Francisco, Calif. - your copy 30 Church Street B addock Post Office I 129 S. Jefferson Street 403 Rialto Building 'Mien writing to advertisers please 1i,:... TIIE \ \'IRELESS AGE

www.americanradiohistory.com 94 THE WIRELESS AGE JUNE, 1924 Advertisers' Index -0-

Alden Mfg. Co 90 Allen-Bradley Co. 91 American Hard Rubber Co 83 American Map Co. 88 American Radio Mfg. Co American Transformer Co a' Andrea. F. A. D 78

Bakelite Corporation 8.1 y7 Bel -l'alto . ARKAY ji Brandes. C.. Inc. II fi Bristol Company, The 89 Univer- Bunnell & Co., J. 11 S' yl Burgess Battery Company Se $ sal Con - trol Switch Cantwell Mfg. Corp.. Allen D 8+ Caner Radio Co. 82 `It SAVES TIME AND JACKS Christian Herald 81 Continental Fibre Co.. The 87 Luse uric in your new set and get inst.,- tLg Continental Itadlo & Eier. Corps ) taut cos and positive control of all circuit, so that it can 6, y7 ('nii..erwetd Steel Co. yj Adjustable in settings in way a I). P. switch with S or Crescent Radio Supply Co nt 1$ used any 1 less poles can be used. including a seni- $ nley Radio Corp., The Thini Cover Yf r'ceive switch for C. W. or phone. C111111 inghan. E. T. Second l'ors Complete with Knob Pointer and Screw Doren Radio Co a7 $ In Touch llietagralat Products l'e 112 Price $3.50 1J: Durham & Co.. Inc Ux Instrument Co. 8 1

with the World Eagle Radio Co. Si 180° Eby Mfg. l'o., II. If ill PALL Make your set portable with Eiseman. Magneto Corp. Vario- a Ray -O -Vac Dry Cell "A" Electric Specialty Co. F:rsey \Ifg. Co S I MALL Coupler Battery and take it on your $ camping trip or tour. Enjoy Federal Telephone & Telegraph Co I Eel Lend Electric ('o WI fft outdoor life at Fiber Products Co. .. The Coup er That Makes a Good Set Better and the same tL, French Batter' & Carbon Co nl time keep in touch with things. Designed after a thorough investgadot. 7t F'resh:nan ('o.. Inc.. f'has vi i the essentials of Coupler performance Our "Trouble Finder" gives Seven Taps -Easy to Solder. Carol Corp.. The si Range 150 to 600 Meters. valuable pointers on batteries Y7 I ;mend instrument Co. nl Y1 Accurate-Tunes Sharply. and other things in the use (tettertl Radin Co. n $i Nothing to work loose and break. $ Satisfaction Guaranteed. and care of radio sets. It's roldselnnidt Corp.. The Price $2.00 yours for the asking. Ilonunarlund Mfg. Co. . Death Radio & Elrrtrle Mfg. Co nl FRENCH BATTERY fa lbonnie] & l'o., Ludwig CARBON CO. P RY, Madison Wisconsin Bow'ard Radio Co., fue YI E S E A E Atlanta Dallas Denver Kansas City International Cnrresl:ondenee Schools 0 Chicago New York Minneapolis t R S 71 S L Jefferson Electric Mfg. t'n wi F U yf Y D Jewell Elec. Instruntent Po lie E L`ft E I:rllogg Switchboard & Supply Co $T C T 0 R T Sx Lincoln \ifg. Co. g4 x Mt(gmn-ne Co .. The TWIST BEND- -then STRAIGHTEN Marie Engineering Cf S $ x Lea Insulator Co. ss Essex SKWAREFLEX Bus Bar II -,caul Laboratories you a perfect job. (It din- Radio CO . $ And get to Fracture. ers. E. It.; Co., Ltd n^ $ Citable- Strong -Hart) yl I 'r.ro more-Worth the Difference. 5c for two foot length. \utinuai Carbon l'o. 1t'. New ratan - Stern ('n., The SC Buy These Products at Your Dealers. Postage extra on Mail Orders. Omtdgralat Mfg. Co.. The Jobbers, Dealers, Write for Discounts. Parent Elect rie Co.. Inc $ Patio( Phonograph and Radio Corp x Essex Manufacturing Co. RAY- O P: ender Electric ('o. x -VAC 117 Mulberry Street, Newark, N. J. tft Radio's 73est 73atteries Ma Inlitru' Radio Cmtat. l'o. xxxxxxxxxxxxxxxxxxxx tails Aston-lotion of America SO (olio Corporation of America Fourth Cover .aalo Corporation of America Distributors -' tail., Institute of America 8:1 (.nyal Radio Co 01 EQUIP YOUR SET WITH HEATH Radiant Condensers ribber Sales Co. 83 cEntt . ttortI :ee ..t I ttiug . PERMANENTLY FLAT Plates 'rhe Heath Shane Insulator Co. 8 process of stamping to absolute flatness and Small Ads of Big Interest ns their tempering to steel hardness protects you Solderait Co. Bí 00 from warping, buckling plates. The differ- . outhwordt Specialty Co. ence is worth the effort of insisting on Heath Condensers. Thompson Mfg. Co.. R. a Micrometer Geared Vernier 'l'Imrdarson Electric 111g. 10 Reducing gear gives hairline adjustment. 'Fresco Tri -City Radio E:ee, ,g,uPPIT Co x0 Separate tension adj usDnent. U. S. Tool Company. Inc St Write for LI I Jobbers and Dealer: Write lmmedloley for Propoeifion Westinghouse Elec. & Mfg. Co 12 HEATH RADIO & ELEC. MFG. CO. Wireless Press 5 n, 91 203 First Street Newark, N. J. DIFFERENCE SO AND NOTE THE Canadian Distributor: Marroni Wire- Y. M. C. A. School less Telegraph l'o., Montreal. Canada. Zenith Radio Corp 15 The H. H. Eby Mfg. Co., Phila., Pa.

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www.americanradiohistory.com JCNE, 1924 THE WIRELESS AGE 95 Amateur Radio Stations of the United States Supplementary List brought up -to -date from May WIRELESS AGE

1. s 111'.\ Call t 2a1a Coining .Ate., l'ietelaud, O. \\'illimn Schwartz _1621 ;slit S1, Itluikl}n. . F.1, :e.kt Burt Toegel Victoria Ave., New \larl:ei. . .1. Jluwurd S. Iy1e 12:7 \loulrlair .Asst., Detroit, Mich, First District David \1. Unger, 1277 E. Imh .. .11 DE Francis il. Bat ... Cornellus C. \'rrnmulc, Jr., 1::1 Imrris11n St.. Philae .I. Itla,7sclung, 1113 N. Edward St, El Itussell F. Smith, 210 Pleasant St.. Providence, It 1 ' }:fist Orange, N. .I. Kalamazoo, Mich. Edward T. Norton, S enru1111ia Terrace. Portland. Ste (:I \\'illian, 11. F.duads curt Slurunl, N. 11111 'l'op Y. \J. 1'. A Pittsburgh, Pa. GU Roger F. Connor \l.Vrlle SL, Ilillsborn, N. 1'. , Clt.l Henry .1. Stahlken, 353 Itroml ay. Wm. L. ltust....110 W. Senora St , (than, N. Y. S. Dart s pleasant Sl.. Bradford, \'t. IIA Frain Ilea Bright., N. 1. lao lace Gilman and W. Itnbertz, 14932 Ave.. P. 1'hnuq,son St.. Brunswick, Me. Quincy 110 I:dw.Od Acklry..tl 2 SIC \1'lllhun \\'aalrnw, N. Y. Vocational Srhod for Detroit, 11111. P. lö Smith St., \Inrblrbrnd, \Lus. Illt Itngrr Gut BONA, 1:6%1i1 St. and 5111 Awe., N. Y. I. Everett 1.. Knapp.. \tiO Phila. Ave., DelmB. Mich. IN Ceage It. Shaw....2211 'Ft emonl St.. Melrose. 3lasa. 2 1t \'1: .lohn V. l'rhultr, S31: I.e1TerLs 11e., and l'Ora .loam N. Patterson land .los. .Anderson, 1318 E. IQ :\rtl.ur C. StnnsOeld, 119 E. Haverhill St. 11101 St Lawrence. Mass. A' e., Rrooklyo, N. Y. Cleveland, O. 2 1\lnler A, l'nhb, I7S So. Main St., Orange. N. .1. Clyde \\'. Clalupness, 44:3:1 \\'. 40th St.. Cleveland, O. J. Edward M. llanunrr ....20 Salem SI., Lyn, Mass. l'll 2 1ynusl Sieiueeke. 2%:t7 itoulcvm Jersey N. J. S. F. Eloper....2:10 Second St., West. Newton. Pa. JK Thomas G. Ferretti, IS Trenlol St., Charlestown, \las. I)M A City. 1N 'l'hdurr I. Van Luan. :a Plot] vet Ave., T. I. I'renier..12:32 Rocky hiver Or., Cleveland. O. KI George F. Russell 11 Linden St., Exeter, N. It. , C. a S. Windham, Ale. Catskill. N. It. ]toy l'hal l l+s. 9 Grand View ('ark, KI I'hlllp L. Alms High St.. Canmulalgua, 11:1 N. ]lain St.. N. Y. KI Ilomer \larnun:dd, s I: It 11. C. Squires N. Nat irk, Muss. and A. 1'. Typer. 2065 E. 7911, St.. SIImPson. 1:1 11111 St.. Skouhrcan. Mc. Cleveland. O. IC1, ILA/rat 1). Third District W. NleShaiìrey, Hadley, 57 St.. Leominster. \Inss. lt. care of Star Theatre. KIt I. E. Orchard lfonessen. 105 Jdnn'ph II. .\ppel, Jr 621 Commonwealth :\v., \\' !twig!), \I. \\. ,IelTan.on Am.. Pa. Reston, \Iass. Ilud.loatlrid. N Gilbert E. Slems....910 Kirby W Detroit Mich. B. \I. 914 KY (tlady'9 l7. Hannah, 4s Lake \'iew Ate.. Baldwin. No. Union St.. Fostoria. O. Mass.. 4411. 1I. \I:nshall. 1199 Orchard (trove, laakewloll, O. Jon W. 95 K% Thrndore E. 09 Mottle St.. 100brid¢r.Cnoabridge, \lass. hilt Lida SL. Mansfield, O. Claret. Eighth District ,huos A. 1\'i ison..911 1.7. First Parish Seiulale, \Jass. Lay Blvd.. Kalamaurl, \I lch. Arthur I'. Sytvrstcq ltl., \.\II l::drl G. Bruediel.,..1:1 Nu, SI , Cuhlcsl:ill, N. Boy ,a Ralph l'amis. 503 Pleasant St., Grand (.edge, Mich. \IF' \1'Illi11n, M. F:udult, It. F. D. :, A.\11 John C. lll'iimlcr, 2$ Cmnherinl rl St.. Put 'tam, l'nia. Frank Gibbs New Hartford. N. Y. ItneLester, N. \1'. (1. Chandler NIT \Willlam, Bryan, Jr., 155 Huntington Ate. 6'ol2 Erie St.. Sylvania. O. \1:1' I.:Iliturr L. 1'L:u'miriq', 111211 MI . :tulunn Ave., Lester W. Kimtey..2.10 Winslow Buxton. Mla. Clrve:and Ave., Buffalo, N. Y. NI .tubo W. Dain. 6,1 \\'oR1111 i,le Si.. S. Iladlcy, 11.n- Wolcott It. Louis 1252 51011111 : .\ re. I.nkenunl, O. SPECIAL AMATEUR NN Grmge L. Itollhls. 1'5 Wells St.. S Mlauehester. AIS Warren It. Cox, 902 l'ierp1,nt Ave., Cleveland. O. .v %l1 Charles Gault 329 Maple St.. NS Donald A. MacNeill. 12.1 Jaques Sl.. Somerville, 310 - Ypsilanti, 'Mich. 113- MR 11Vderiek 11'. %laurel', Jr., Pit slurgh St.. Itl' flora r C. earltau, 17 l'ariund

~~www.americanradiohistory.com 96 THE WIRELESS AGE JUNE, 1924~~

DOA Howard Scheer Lyons. N. Y. 9 t'Ati Itirhard K. Sutherland, ARS William 1'. Lloyd, 209 S. Spaulding St.. DOB Anthony Raymond 648 Jay St.. Utica. N. Y. Shattuck School. Faribault Minn. Chicago, Ill. 9 CF:t: Wilfred James....213 S. Orange St , Cameron, Mo. ASO Theodore A. Giles, 125 N. Davis St., Ottumwa. Iowa DOC DeValne ' igart..901 Kenmore Blvd.. Kenmore, O. Wise. DOD Lawrence II. Wise, Jr 226 So. Cherry St.. 9 CV.I Evsln S. Milts. ATA Otto T. liasen, 117 S. Page St.. Stoughton, 2709 First Ave., S., Minneapolis, Minn. ATK Ed. T. Ross, 1331 Seventh Ave Antign. Wise Van Wert, Ohio St DOE Fred W. Albertson Fairgrove, Mich, 9 ('W'T William L. Cochrane. AXU Frank F. Compton, 775 Grove Glencoe. IIL DOF Karl V. Rettstatt, 613 Howard St 119 W. Wilson St, Carterville, Mo. BEG Harold L. Fouts. 656 N. Second Ave....Cantun, III. So Brownsville. Pa. 9 UL'/, George A. Starck BHT W. P. Ingersoll Canton. Ill. DOG Edgar A. Hike..1708 Charles Ave.. Kalamazoo, Mich, 2202 Lincoln Way, W., South Bend, Ind. BAIP William J. Hceckol, 321 N. Jackson St , DOH Ishmael B. Andcrson..1011 W. Pittsburgh, 9 UNII Melbourne Renken Cole Camp, Mo. Belleville. Ill. 9 IiEll Joe F. Milde, Jr.. BVZ Joseph T. Hood. 1314 W. 3411, St., Indianapolis. In& Scondale, Pa. St DOI Donald M. Swentzel, 1733 3rd St.. 311 E. First. South St.. Jackson, Mo. DAD Harry L. Pingel, 129 Union Neenah, Wisc. 909 N. Long Ave.. Chlea;;o, Ill. Huntington. W. Va. V EI O Diedrich J. Thies Arlington, Minn. DAV Francis N. Fitzgerald, 644 W. 61st St Chicago, Ill. DOJ Samuel D. Fralick. 4_ E. State St., u YAIV Board of Education, DCF Nathan C. Janctt 33d and Coming St., Omaha, Nebr. UDII Floyd Poetzinger, 1829 E. 51.11 Ave., Cedar Rapids. Cheboygan. Mich, Iowa DOK Gilbert Burrell. .420 S. Logan St., Lansing. Mich. IHZ Culver Military Academy Culver, Ind. 9 SIN 427 St., Louisville, KY. Paul J. Carmello. 3404 Lafayette Ave.,.Omaha, Nebr. DOM Fabian Stroh, 3349. Woodbridge Ave.. Cleveland, O. Robert C. Berry. W. Chestnut DFB 9 I'D Caul IL Lamoree 4kron, Ind. DER John Debevc. 1137 Twelfth St No. Chicago, Ill. DON Raymond Donaldson.. 11 ('ark St., Amsterdam, N. Y. Wisc. DOP Thomas D. Johnson..S. Main St.. Lake Odessa, Mich. 9 EEO Carl .1. Madsen 1329 "N" St., Lincoln, Nebr. Clare E. Newell Deforest, DOQ A. Weaver. So. 9 EE'r Peril R. Marger Masten, Iowa DOW Harry E. Hasbrouck Goldfield. Iowa Charles Penne, Ave., Huntington, Pa. 616 Walt, Ave., S. Dak. DOR Harry A. Hagler It F. D. 9, Xenia, Ohio o ERO Francis J. Fox. DIY Roswell Marsh. Jr., N. 3501 S. 11th Ave., Minneapolis. Minn. DKP Enos M. Kehler. 107 E. Glenn Stt., DOS Edward B. Damail..20 Fargo Ave Ashtabula. Ohio Peoria Heights, Ill. DOT Stanley McMlllan..3612 Carey Ave , Kenmore, Ohio 9 XBO Edmund T. Fiewelling, 2 836 S. St. John's Ave., Highland Park, Ill. DLD Walter L. McCarthy, Box 164 Stockton, Ill. IK Geo. Belprez 552 Newport Ave., Detroit. Mich. Elroy, Wise. TA Raymond E. Hawring. Gratiot DLS Lloyd L. Tripp. 1309 2d Main St. 6808 Ase.. DEL Arnold Gerlach. 1707 West Ave Burlington, Iowwa Detroit, Mich. CHANGES DOC Frank L. Brundage. 2637 W. 37th Ave., Denver, Colo. UI Albert E. Flemming, 2813 Brooklyn, Wayne, Ind. 703 Oakdale Ave., Chicago. Ill. DPJ Leo B. Wilcox, 1225 Spy Run Ave., Ft. Detroit, Mich. 9 BO Bernard P. Hansen, DPM Chas. S. Hotchkiss. Jr., Box No. 682. Stratford Hilla, WB West Penn Radio Club, Crawford Ave., 9 FS Edward E. Pippenger, 806 S. 7th St., Goshen, Ind. Elmhurst, Ill. Comrellsville, Pa. 'J LW Robert R. Spooner. DPU H. D. Rogers. 621 E. Euclid Ave Lewiston, /IL CHANGES OF ADDRESSES 2933 S. 28th Ave., Minneapolis, Minn. DQB Howard W. Siegel, 219 Adams Ave....Eveleth, Minn. 8 ACN Warren Root, J. Butternut Ridge, 9 TE Clifford Chilson...7425 S. Shore Drive. Chicago. Ill. DRH Frank R. Brown, 201 N. Main St...Waupaea, Wisc. Olmstead, Ohio 9 UU (toy W. Weisbach 6727 Yale Are., Chicago, Ill. DRI Hale T. Cottrell. 1301 Frederica St.. Ownesboro. Ky. 8 APO Eugene A. D. 3, Springville, Y. Fattey, R. F. N. 9 AAK Charles H. Atchisson, DSA Theodore H. Jacobsen, 7337 Indiana Ave Chicago. Ill. 8 BAH Harry A. Tummonds. 1478 Wager Ave.. 6839 Flyer Are., St. Louis. Mo. DSI Fred'k. F. Freytag, 3120 State St Omaha. Nebr. Lakewood. Ohio 9 AMW ]toward H. Smith. 204 W. Nevada St., Urbana, 111. DTR Malcolm A. Smith Lake James. Ind. 8 BFF Robt. J. Hunter, 6 Costello Park. No.. 9 AVA Griffith M. Morgan, William A. Ebert, 393 37th St.,.Milwaukee, Wise. Rochester. N. Y. 845 S. Saville St., Oak Park, Ill. DUC Roger D. Man. 120 Adams St Terre Haute, Ind. 8 BFFI Andrew Noaker 146.1 Western Ave.. Toledo. Ohio 9 AVit Floyd E. Philips. DUK Elmer J. Dean, 670 E. Jefferson St., Franklin, Ind. 8 BWN Richard L. Dyer 428 Peach Ave., 200 Jennings Ave.. Hot Springs, S. Dak. DUL Orville F. Hill. 3535 S. 25th Ave., Minneapolis. Minn. Point PAve Toledo, Ohio 9 .4ZC Charles R. Sheffer, Frank L. Uhrus. 4823 Huron St. Chicago, Ill. 8 CrI Joseph M. Hertzberg, 1376 Dewey l'. O. Box No. 46. Winona Lake, Ind. DUZ John A. Noll Faribau!t MInn. Rochester, N. Y. 9 IIBII Leo J. Hruska, 2619 Bever Ave.. Cedar Rapids, Ia. DVQ Basil D. Rauth, 1518 Spring St., Jeffersonville, Ind. 8 Wise. DEF John B. Allen 68 College St., Clinton, N. Y. 9 Erwin A. Rasmussen, 205 Parkway, Oshkosh, DVR Maurice Flint. 1603 La St Lawrence, Kans, 8 Bell Colo. OJ Norman Schlaack, 423 Ridgedale St., 9 C.11l James A. Lowe 675 Knox Court, Denver, DWL Fred'k. W. Bomberger. 394 Larch Ave.. Elmhurst Ill. Birmingham. Mich. 9 DGZ M. S. W114 165 and H. Jack, DWV William Atkins. 3723 E. 9th St.. Kansas CIO', Mo. 8 UDC K. Mawby 1000 Pitken Ave.. Akron, Ohio ve.,Ave., S.. Minneapolis. Minn. Robert S. Embry, 250 Rhodes Ave., Lexington, KY. Mo. EXPEItISÍENTAL 9 BOU Thomas L. Daly, 5109a Delmar Ave., St. Louis. DWZ Winfred C. Hilgedick, 2191 Knapp St., 8 X8U Dept. of Elec. Engineering, Michigan Agricultural 9 B(1O Clarence R. Shenberger, St. Paul, Minn. 117 W. Forrest St.. Marengo, Ili. ADO Milton Elrod. Jr.. 917 West Drive, College. East Lansing. Mich. Ill. o RNP Edward J. PosseR 5317 W. 25th St., Cicero, Woodruff Place, Indinarois, Ind SPECIAL AMATEUR Walter J. Cahill Oakland, Nebr. ASI Harold A. Scott, 509 N. Georgia 8 ZN Walter M. Volger, 117 Lafayette Blvd., 9 BEC 9 13%D Samuel M. and Charles C. Wens. Are..Mson CiO', Iowa Detroit Mich. 1607 Ainslee St., Chicago, Ill. DXQ Forrest Metcalf, 57 W. Chestnut St., Mo. 9 CPVV John E. Cook....1713 Arlington. Independence, Wauwatosa, Wise. St., Louisville, Ky. Albin 206 Second Ave V'irginia, Minn. Ninth District 9 CPR Albert B. Marshall, 318 Caldwell Ind. DXT Lofbak, N. 9 CXC Albert W. Brown, 315 N. Meridian St., Lebanon. DXW Arthur Schmitz Glyndoo. Minn. 9 HD Lake Formt Ind. University Lake Forest, Ill. 9 CYT Grover S. Dale, 779 First St.. N. E., Linton, DXX Aaron Herahire. 835 Tenth Are Clinton, Iowa 9 JL Iowa Stale Teachers College, Almon 782 Minn. William N. Smith, 1243 First St, Louisville, Ky. 21t1, Evanston, l. and College Sts., Cedar Falls. Iowa 9 GHQ Fred'k Wolcott, 281E Thayer St., DK Amos C. Dadesmn, 439 Minnesota Ave. 9 KQ David C. Smith....12108 Parnell Ave., Chicago, Ill. Wirth. Wichita, Kane. 9 LU Armory Radio Club.209 Ind, N. Main St., Fairmont, Minn. 9 I)I'E Lonnie t H. 3Ì Oxford St., Ìndiannapolis' TAU Carthage College. College Are Carthage, Ill. 9 Mit Gerard Mel, Cole..41 5 Greenvlew Ave.. Chicago. III. XAZ State University of Iowa Iowa City. Iowa 9 BEM Charles E. Wells, Wise. 9 NL Frank W. Arnoldus..2719 S. 10th St., Omaha, Nebr. East 81111 St., Richland Center. XBA Fred'k. J. Marco. 5723 Winthrop Ave. - Chicago. Ill. 9 Radio Electrical Exp. W Club. 9 SM Paul A. Perry XBB Iowa State College, Dept. of Elec. Eng., Ames, Iowa Third Ave., Baraboo. Wisc. 218 Washington Blvd., River Forest, Ill. XBC G. G. Shalkhauser, Institute Place Peoria, Ill. 9 TE Clifford Chilsn..7425 S. Shore Drive, Chicago, Ili. Robert Woolsey, Oleander St.. Chicago, XBD W. E. Schweitzer, 4264 Hazel St..., .Chicago, Ill. 9 TZ Harry Z. Wileon....1126 S. St. AIo. A. Benton W. C. Grover, 31st St., Omaha, Nebr. 9 ADE harles E. Gutke. 4115 Lafayette ouis, XBE Ben. Ott. Ed. & 'J WN James P. Boland. James E. Walden, 7359 Champlain Ave., Chicago, Ill. 1627 State St., La Crosse, Wise. let 3d 9 AGN R. F. D. No. 1, V'Irgil, Kans. Lt. F. A., Ft. Beni. Harrison. Ind. 9 AZX Hubert G. Tudor, AUA Howard T. Bonnett, 9 BLP Wilson Thomas 704 W. 511, St., Cameron, Mo. St., Ind. BFN Grant H. Woldum, 409 W. Main St., Decorah. Iowa 3720 S. Washington d. 9 CEP Herbert B. Settle, 462 E. Burkhart St., Moberly, Mo. CAT, Glendon A. Klein Earth, BFU Herrick J. Aldrich Balriew-, Minn. 9 Theodore 9 St , Concordia, Kane. Shenandoah, Imva CFO Lange. 9 CCV Ed. Barricklmv, 222 E. Sixth BKI Howard Grrenwalt, 730 Thomas St., , City, Ill. Wayne, 893 N. Division St., Appleton, Wisc. 9 CMC Homer A. Huber....2656 "I" St Granite BKJ George H. Graue. 824 Home Ave., Ft. Ind 9 CTA Elmer Box 75 Batavia, Iowa Lemke..892 Commercial St., Appleton. Wise. 9 DPW Warren D. Birkenhead, BPR Edward Schultz. P. O. 9 CVU Frank .1. Bruce 603 Pine St., Chisholm, Minn. Addison Ave., Elmhurst, III. BOX. Arthur M. McGregor, 815 Clark St Wareaw, Ill. 9 CW11 Louis E. Dechant 100 W. 251e Ave. B, Nebr. S. high St., Belleville. Ili. 9 DNV Daniel M. Pottgieser, BST Richard Albright, Kearney, 9 CXR Frank W. Jenkins 5666 Vernon Ave., St. Louis. Mo. 1160 E. Rose St., St. Paul, Minn. CEN Charles M. Conley eeihert. Cola, 9 DBL George W. Birdsall, Haysmer 29th St.. CVSI Jerome Kitterman Batavia, low's 121 Washington St.. Hampton, Iowa 1Ó3Bow1 Bowen St Independence. Mo. CXX Arthur A. Collins, 514 Fairview Drive. 9 FF ArthhuB. Church, Ill. 9 DOM Leonard Bolets Swisher, Iowa Zeta Beta Fan Fraternity. 5401 Ellis Ave., Chíago. Cedar Rapide, Iowa 9 9 BYB Nichols, DUO Kenneth C. Shirk, 2407 Evans St., Omaha, Nebr. 9 DAL' Drew D. MacDougal Ina CYA Leonard D. Kammeyer, 714 E. Fourth St., 9 Huron. S. Dak. DXO Ralph Allan 7421 Sheridan Rd., Chicago, Ill. 9 DBZ Maurel F. Ohman. 783 Iowa Ave., Waterloo, Imes 9 DYD Caul D. Cooley 321 Scott St.. Ripon. Wisc. Burt, Iowa CYSI Cuy D. Newkirk, 319 W. Main 51 . Carterrfl:e. Mo. 9 DCG Ray E. Ladendorn Hampton, Nebr. 9 EAJ Arthur Eseman....105 W. Oak St.. Red Oak, Iowa 9 DCL Ellery L. Pious 9 Kansas City, Mo. EAW Karl Everett It F. D., Cameron, Mo. 9 DEJ Lee E. Pedigo, 1830 Benton Blvd.. CHANGES 9 EAZ Lester Ill. Huron, S. Dak. Wagner....1408 E. Main St.. Belleville, 9 DGIt Dwight M. Pasek, 780 Illinois St., 9 4716 Colfax Ave.. S.. EBO Urban A. Weiler, 9 DGZ S. W. Williams & E. K. Jack, RB Harold J. Buckley. 4716 N. Campbell Ave., Box No. 12, R.F.D. No. 2, Burlington, Wisc. Minneapolis, Minn. 111. 9 1:191' Clair R. Ditto Seaton. Ill. 91)I1Y L. J. Bowers Mound, Minn. BO Paul R. Mangue, 805 Leland St., SouthChingo,Bend, lnd 9 E1111 Weir L. Strayer Wagner, S. Dak. Wildman, Nichols Ave. and High St.. Marco, Winthrop Ave Chicago. Ill. 9 DIR Thomas S. Iowa CD Fred'k. J. 5723 9 EBW John W. Blessing....\Vefel St., Fennimore, Wisc. Nichols, CH C. Haysmer Thompson, 1526 S. 29th St , Omaha. Nebr. 9 EIIX louis E. Ludke....158 N. 7th Ave., Ft. Dodge, Iowa R. Guth, 1326 S. 28th St., Omaha, Nebr. FC R. Hall, 7208 S. Shore Drive, Chicago. Ill. 9 DEN Arthur St.. Harland 9 ECK Maras C. Kronauer, 9 DIN George F. Grubb, 2706 S. Harrison FF Arthur B. Church. 103 Boren St., Independence. Ito 2521 White St., 'Marinette, Wisc. Ft. Wayne, Ind. F% Randall C. Ballard, 1202 W. Oregon St., Urbana, Ill 9 ECP Reniff F. Brown Ill. 9 DMQ Paul W. McCallum, 808 N. Front JE Philip S. Westeott 134 N. Mayfield Ave., 9 EUC Donald E. Powers, Marquette,St.p Mich. Chicago, Ill. 1516 Woodland Ave., Des Moines. Imva Lee Ave., Webster Groves, Mo. 9 DSI% Francis A. Smith, 550 Ill. OX Carl L. Peum, 1330 S. First St Louisville, Ky. 9 EUX Leonard H. Loufek, 9 1)NP Harry Merlin, R. F. D. No. 1 Rockford, VT Ralph W. Elliott, 502 N. Twelfth St. 1246 S. Fourth St., W., Cedar Rapids, Iowa Shovers, 280 W. Broadway, Shelbyville, Ind. Independence, Kans. 9 DER Joseph Iowa 9 FEY Mervyn A. Russell..103 E. 7th St.. Rushville, Ind. 9 DOI Kenneth O. Benzins, R. F. D. No. 1, McGregor, AAT Clarice L. Cohoon, 423 E. Seventh St., Mt, Carmel. Ill, 9 EFM Harold M. McNiff. Mountain Grove, Ma St., Ltd. 9 DRQ Earl Russell Peters Wisc. AHE Harry Gruazka. Tapper and 17th Hammond, 302 S. Manhattan Ave., Manhattan, Kans. 9 DNA Carl L. Wesley Athelstane, AID Graham L. Tarts, 5666' Vernon Ase., St. Louis, Mo. 9 EFIt A. 2212 S, 29th St., Omaha, Nebr. Laurence Dean. 9 DTI) Donal( K. Reed. Ill. AKI Charles A. and Earl L. Freese, 919 Milan Ave.. 104 N. Raymond S Marinette, Wisc. 9 UTZ Harold 31. Wallace, 604 E. 5th St., Mendota, Ravenna, Nebr. 9 EGY Gilbert D. Jackson Boa 147, Galatia. Ill. H. Smith, Franklin-Mill Barron, Wisc. A. Giles, 125 N. Davis St Ottumwa. Iowa 9 DXII Archie Wisc. ASO Theodore 9 EG% Robert W. Freitag Feeble, Ind. 9 I)Lh Orrin Nelson Osseo, AUO Francis M. Quinn, 1941 Morse Ave , Chicago. Ill. 9 EHE Francis P. Shirley, 1021 S. Harrison St., Sedalia, Mo. Saxton, 4644 Maryland Ave., St Louis, Mo. 421 Pine St Eureka, Kans. 9 D%Q John Nebr. AYP Robert B. Reed, 9 EIIU John S. Windt, 2520 Maple l'1., Ft. Wayne. Ind. 9 SIt C. Haysmer Thompson. 1526 S. 29th Bt., Omaha, ß1.F Harold R. Reiss, 406 Austin St Sparta, Wisc. 9 E1C Howard P. Dickover, 9 AQA Frank C. Weeks, 701 Randolph St., Champaign. Ill. BID Theodore Graffunder Marshall, Minn. 1706 E. 37th St., Kansas City. Mo. 9 George F. Messier. 203 S. Channing St., Elgin. Ill. Arthur T. Bailey. 217 S. Second St., Virginia, Minn. ATQ S. BTP 9 14.1.1 Ralph F. Haupt, 306 Sycamore St., Peabody, Kans. 9 AYW Edgar W. Freeman Elk Point, Dak. CUE Robert F. Genhart Franklin St Edinburg, Ind 9 EJO John 13. Llringer. 9 DAH William H. Gilchrist. 8223 Greenwood DCO Alfred D. Fowler, 4 S. 26th St., Lincoln. Nebr. 73a Meade Are., Ft. Leavenworth, Kans. Chicago, III. DDW Duke E. Reed, 30 West Are Riverside, III. 9 EKI Edwin Rinehart...411 E. Scott St., KinksVllle, Mo. 9 DAI Richard T. Carsten, 1900 E. 76th St., Chicago, Ill. DIP Fred'k. C. Crowell, Jr., 3519 University Ave., 9 AY Paul D. Meyer 2702 Prairie Ave., Evanston, Ill. 9 L. Beckley Sanborn, Iowa Des Moines, Iowa DITO Willis Mo. 9 Ull York Community High School Elmhurst Ill. 9 l)EU Adolph H. Will. 820 E. Vine St Macon, DJL Leslie M. Devoe, 234 Littleton 0 DZ Kcmpster W. l'yle. 9 DEG Paul O. Pearson, R. F. D. No. 1, Muscoda, Wisc. Stets Lafayette, Ind 25G Greenwich SL, Valparaiso, Ind. 9 TOGO Ilerbert G. Crome. 1659 Melrose St., Chicago, Iil. DLW Benny Mutsehlecner, 820 Home Ave., Ft. Wayne, Ind. 9 HE Lorenz D. Smith, U.lY Glenn E. Harman Plymouth, Iowa DSG Charles R. Young. 202 Livingston St Monticello, Ill. 5116 S. Harriett Ave., Minneapolis, Minn. 9 DKF William S. Grove, 4003 Third St...Des Moines, Iowa DSW Lance Wikkerink, 861 Twentieth St., 9 LK Clarence H. Powell. 915 S. Western Ave.. Mexico, Mo. 9 DET lester J. Wolf. 920 S. 28th St So. Bend, Ind. Milwaukee, Wisc. 9 MI Merman B. Manson, 340 Lincoln St., Longmont, Colo. 9 DLB Francis A. Fillmore, 42.22 Nebraska St., DTN Arthur V. Raught, Box 2SA, R. F. I). No. 4. 9 MK Chambers Island. Inc Fish Creek, Wisc. st. Louts, Mo. Berryville, Road, Racine, Wise. 9 MX Louis A. Woilaeger, 9 DLC Elmer E. Comstock Winnebago, Ill. ECZ Ernest Smith. 1510 Cleveland St.. care of Lakeside Hotel, Pewakee, Wisc. 9 DLE homer P. Stenersen Minot. N. Dak. Kansas City, Kans. 9 OP Francis J. MsGrail, 4031 Brighton Pl., Chicago, Ill. 9 DLX Cluster C. Jones, 1130 Tennessee St , EHO Verne Goldin. R. R. No. 2, Mollette S Dak - 9 PM James Schultz 511 W. Gale St., Angola. Ind. Lawrence, Kans. NS Joseph P. Snorke, 5113 S. Ada St., Chicago, III. 9 ACK Lee Wong 516 Front St.. Jamestown, N. Dak. 9 DNM Robert W. Johns Z20 Melrose Court. Clinton, Iowa ALI, Dale Fouts, 656 N. Second Are Canton, Ill. 9 ADO Clarence Hayward. 509 N. Henry St., Savannah, Mo. 9 DNO Lanson R. Romiu N. Rollins St., Macon, Mo. BNZ Leo B. Welch, 802 Gand Are Waukegan, III. 9 AFC Robert G. Starrett, 1009b E. Eighth St., Sheldon, la. 9 DOlt Allison V. Homer, _; F. D. No. 1, Mx 64. BWV Joseph E. Davidson, 101 N. Polk St., Albany. Mo. 9 AFB Vincent SI. Kerrigan, Jefferson City, Afo. EER Lowell S. firth Story City. Iowa 2500 Monticello Ave., Chicago, Ill. 9 DPL George W. Davis, 21A North St.. Ft. Sheridan, Ill. CPI' Lyradlon Mfg. Co., 9 AFG Everett E. Richardson, Jr., 9 HM Otterholm & Tyrrell, 1807 Selby Ave.. Slain and Front Sts Slishawaka, Ind. Walnut St.. Webster City, Iowa St. Paul, Minn. 944 Place. CPI Clifford Ilolge. 9 ACE East Sido High School, 9 QM Lawrence A. Middleton, 337 W. 37th 621 Fifth Ave., N., Jamestown, N. Dak. E. Washington St., Madison, Wise. Chicago, Ill. St., Muncie, Ind. CP31 William J. Mashek. 9 BILL Rudolph G. Dahl Bryant, S. Dak, 9 ARM Daniel IT. Cohn. 2224 S. Jefferson 5032 S. Ly'ndale St., Miuneapo'!s. Minn. 7. l'os. 2317 E. Grand Ave...Des Moines, Imva 9 BLK George It. Underwood. 9 ADD Alva CPS Alfred H. Kelly Box :107. Pro rate. Ill. View, Nebr. AJY . Charles B. Ewing, 403 L St College View. Nebr. 5'I North "L" St., College 9 C. Bees Harty -k, Iowa 9 AMT Edward D. havens Cicero. Ind. ('PX Fred 9 BUU Erwin E. Ricker, W Cooperstown. N. Dak. 110ó'r Third St., Bismarck, N. Dak. 9 ARD Clarence E. 7oonen, 915 George St.. DePere, Wisc. CItG (toss Phipps

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~~Approved by Over 200 Experts New Crosley Engineering Achievement~~

A three tube set with five tube efficiency -the greatest This new Crosley triumph is called the Trirdyn because selectivity with the minimum effort- positive calibration of its original combination of the three "R's" -Radio fre- to any wave length between 200 and 600 meters. These quency amplification, Regeneration and Reflex. The first are only a few of the many advantages offered in the re- tube incorporates non -oscillating, non -radiating tuned markable new Crosley Trirdyn Radio Receiver. radio frequency amplification ; the second tube, a regenerative detector is reflexed back on the first tube for one It was only after a year of constant experimenting. that stage of audio frequency amplification. Then it has our engineering department perfected this exceptional re- a third tube which acts as a straight audio frequency ceiVer. Thorough tests proved to us that it would out- amplifier. It uses the ultra selective aperiodic antenna perform any receiver ever before produced. But we were circuit and external selector coil, which adds to its no satisfied with our own opinion. So we shipped out wonderful selectivity. 200 of these sets to experts in every part of the United The Croslev Trirdyn in range, volume and selectivity is States. Their criticisms are one and the same -"tried the equal of any five tube receiver on the market. Greater out your new Trirdyn Receiver Saturday night and logged volume will. of course. be obtained through the use of 13 stations, among them Cuba, New York and Omaha. storage battery tubes. but it will function well with any between 9 and 10 o'clock. The set was very selective. type and can be used with either indoor or outdoor antenna. During the time this test was on. local station KSD was operating and we went through them without any diffi- The opinions of many experts have convinced us that the culty or interference whatever. The range of the local Trirdyn is the best receiver ever offered the public regard- station was not more than three points variation in the less of price. dial setting." Practically every radio dealer can furnish you Crosley Radio Sets, including not only the Trirdyn, but the Model "Tried one of these sets out and obtained wonderful re- 51, a two tube set for only $18.50; the Model V. a single sults. Were able to log all stations which we heard very tube receiver at $16.00: the Model VI at $24.00; the successfully. This set should go over big." "The set has Super Vi at $29.00; the Model X -J at $55.00 and the Iwónderful volume and is selective" -etc. Super X -J at $65.00.

AU Crosley regenerative sets aro Crosley Builds .11ore Radio Receiv- licensed under .Avnstrona t . S. ing Sets than any other Manufac- Patent .yo. 1.113.149. Getter -Cost Less turer i,, the World. Radio Products

See this new wonder at your dealers THE CROSLEY RADIO CORPORATION POWEL CROSLEY, JR., President Formerly The Precision Equipment Company and Crosley Manufacturing Company 628 Alfred Street Cincinnati, Ohio

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