FACTS BOO'MERANG CRITICISM THE "WHY OF THE SIX" The Silver Six is at once the most satisfactory and the most unusual as described in Radio Broadcast 01 No~ernber and De~t,"ber broadcast receiver ever devised. It is the first practical receiver with Sensitivity, Selectivity and Tonal Quality which cannot be surpassed. SELECTIVITY is such that out of town stations may be brought to Chicago through twelve powerful This can only be understood by a careful study of the receiver's charac­ local stat ions. S electivity can be regulated at will, t eristics as analyzed under" FACTS." from a degree satisfactory for ordinal y reception, up ~o the surprising limit where side· bands arc cu! , The Silver Six was put through its paces for a prominent Editor, SENSITIV1TY is so great that nothing w ill sur· pass the • Six" except special laboratory· build an Engineer and an Executive just after it was perfected. How super· heterodynes. E ither coast may be brought did they react? The Editor asked to have the tuning broadened into Chicago during the summer months on a small antenna - 1n many cases on a loopa The Engineer was astonished at the uncanny ability to bring in DX FLEXIBILITY permits the use of antenna or Stations in daylight The Executive objected to the intensity loop with either detector, one or beth stages of with 'which notes low on the musical scale were reproduced. Why radio freq uency amplification. In tcrchangeable R. F. Transformers, with adjustable a ntenna coup· did these men react this way? Simply because t he Silver Six was not ler, permit operation on all waves from 50 to 550- .. just another receiver" of merit easily recognized in comparison with or h igher if desired. existing standards But because it was an accomplishment VOLUME is so great as to paralyZe any but the best loud ·speaker.. Yet it may be adJusted to any so far in advance of the commonplace that these three authorities had degree by a single knob. to revise their standards in order to appreciate ideal performance-­ QUALITY cannot be excdled due \0 resistance coupled amplification. It is the only receiver that not merely in theory- but when the" Six" actually demonstrated it to wtll bring real appreciation of"cone" speakels. their amazed senses. CIRCUIT consists of two stages of R . F . amplifi· cal ion with special oscillation control uniformly These men were unable to demand and the" six" fail to produce. Se­ effective at all wavdengths, grid. biased detector and three stage resistance coupled audio amplifier. lectivity was at t heir command--ease of control t heirs for the ask­ EASE OF CONTROL allows use of one, two or ing- one, t wo or three dials as preferred- vOlume adjustable by a three dials at w ill . single knob from a whisper to a roar without a discordant note-­ TUBES may be either dry cell Or storage batterY, rather with a perfect harmony that enthralled the listeners. with UV201·A's recommended. "B" Battery Consumption at 13S volts is below 10 miliamperes­ less than once· third that of other six·tube rece ivers. What Was Their Verdict? Unqualified Approval! Why? Because ASSEMBL Y requires but a few hours, using only Seeing Is Believing. parts supplied in kit. ------I Type 600 Kit including all parts necessary to build the complete "Six" ... _ ...... _ $53.00 Mail this Coupon Type 610 Kit, essentials only, including 3 condensers, Silver· Marshall, Inc., Chicago, 111. Gentlemen: Please send me 3 inductances and 3 inductance sockets ...... $27.75 A- Complete building data on the Silver "Six," See S-M Products at Your Dealers. for which 1 am enclosing SOc. B - Descriptive circulars on S· M Products. Name_ ...... ___ ..._ .._ _ ...... _ ...... Silver,.,MarshaIlttinc. 114 South Wabash Avenue CHICAGO

¥- Tested aml Approved by RADIO AGE ¥- RADIO AGEJor November, 1925 The Maga::;ine of the Hour 1

This Catalogue represents the world's greatest radio store

Ward's New Radio Catalogue Is Yours Free

Where you buy Radio is equally as im­ one station after another by turning a portant as the set you buy. single dial! Send to Radio Headquarters for the Every price quoted means a big saving to most c~mplete Catalogue of the season. you. Everything offered is tested by our own See for yourself what is neW in Radio and Radio Experts; in fact, the best experts com. what has been actually tested and ap­ piled this Catalogue for you. proved. Write for this free S2 Page Book. It is yOW"S Free. See for yourself what low prices can be -made on Radio when it is sold without Our 53 Year Old Policy the usual "Radio profits." For S3 years we h~ve sold only quality mer­ chandise under a Golden Rule Policy. You A Complete Radio Manual can rely absolutely upon the quality of every­ thing shown in this Radio Catalogue. This new S2 page Radio Catalogue shows , everything in parts, batteries, cabinets, ...... contains a list of stations, a radio log for To Montgomery Ward & Co. Dept. 18-R recon;:ling stations. It shows the best of Baltimore Chicago Kansas City SI. Paal the new sets. One tube sets that give Portland, Ore. Oakland, Calil. Fort Worth amazing results. Five tube sets with a (Mail this coupon to our house nearest you.) single dial to turn. Think of tuning in Please mail my free copy of Montgomery Ward's New Radio Catalogue. MontgomeiYWard &Co NlUne ....•...... ••.. , ... • Local address ...... • ...... The Oldest Mail OYder House is Today rhe Most Progressive Post Office ...... •...... Baltimore Chicag() Kansas City St. Paul Portland, Ore. Oakland, Calif. Ft. Worth State ...... •...... ••.. . . ,. ~ Tested and Approved by RADIO AGE ~ 2 RADIO AGE f or November, 1925 The 1l fagazine of the Hour

A Chat With the Editor The Magazine of the Hour EstablisMd .,,/arch. 19ZZ DITORS, engineers and manu­ WITH WHICH IS COMBINED RADIO TOPICS facturers have combined their E efforts toward making "The Volume 4 N (Y'"ember, 1925 Number 11 Radio Age Model ReceiYer" a truly valuable aid to the home set-maker. The description of the circuit, with drawings, photographs and blue­ CONTENTS prints, will be published in the December issue. \Ve are giving Cover Design by Anker P. l\Iehlum the circuit a name which clearly shmvs that back of this outfit is the A Super·Het without Intermediate Stages __.. ___...... _ .. 7 indorsement of our engineers and By Roscoe Bundy editors. \Ve do not claim this Riding the Short \Va\·es. ____ .... ______.. ______.. ______11 circuit is a departure from present By Armstrong Perry approved lines of design and con­ Directing the Air l\Iail By Radio ______...... _.. __ .. ______13 struction. \Ve do not claim that By S_ R. Win ters it im'olves any radical improve­ A Windless, Pipeless Pipe Organ .. __.. _.. _.... ______.. ___ _... 15 ments. \\'e merely assert our con­ By J- C. Jensen fident belief that this December A New Low Loss Receiver.._.. __ .... ___ .. ______.. _.. 17 feature will be the best illustrated By H. Frank Hopkins how-to-make article this magazine Magnetic Theory of Radio Transmission __.. ______.. __ ___21 has ever published. By Beecher I. Sheridan All parts used in the construc­ On Inductive Radio Interference_ _.. ___ .. ______22 tion of this set will be listed under Bow to Make an Efficient Low-"'ave Transmitter.. 23 their trade names. This, in itself, By Brainard Foote is a departure for Radio Age. Our RADIO AGE "\Vhat the Broadcasters are Doing" policy heretofore has been to let Studio-Land Feature Section ___ .. ______25-32 the reader make his own selections RADIO AGE BLUEPRINT Section- Adding of apparatus and accessories. In Radio Freq uency Stages ______,H--!O this feature article, hmvever, we By John B_ Rathbun are going to try to make the lfi­ Late Models at the Chicago Radio Sho\\" ______,42 structions so complete that no Pickups and HookUps by our Readers __ __ .. __ .... _.. __ ___ ,43 reader will have to ask a single question further after he has read Corrected List of Broadcasting Stations ___ _6 6-68-70 the directions. Realizing that in choosing good parts for a five-tube-tuned radio 1,======1 frequency receiver, such as this set, it will be impossible to include , Radio Age is published monthly by RADIO AGE, Inc. Member: Audit Bureau of Circulations_ all the really good parts which would gi \'e satisfaction for a given I Publication Office, Mount Morris, Ill. purpose, it is our purpose to follow Address all communications to RADIO AGE, INC_ the original article with others, one Executi\-e, Editorial and AdYertising Offices 500 N. Dearborn Street, Chicago, 111. each month, in which there will be changes lfi various details of FREDERICK A. SMITH ~ Editor the circuit and in which the list of FRANK D_ PEARSE, Technical EditDr parts again will contain trade M . B. S~llTH, Business ,Manager names, probably quite a different Adt.erti sillg Di rector list in a majority of its items from HARRY A. ACKERBURG the December suggestions. 500 N . Dearborn St •• Chicago. IU. Tuned radio frequency is popu­ lar no\\'. \Ve suggest that set­ I Eastern Representative makers make sure of getting the DAVIDSON & HEVEY, 17 West 42nd St_, New York City December issue and follow the Pacific Coast Representative series carefully. V. M. DEPUTY & ASSOCIATES, 515 F. W. Braun Bldg., Los Angeles, Cal.

- Final Advertising forms close On the 20th of the 2nd month A preceding date of Issue ~ , ii,- Vol • • , No. 11. Issued monthly. Subscription price 82.50 a year. Nov~mbe r. 1925_ ~f'r~ Entered as second-class matter at post office at Mount Morris. lUinois. under the Act of March 3. 1879_ I Editor of RADIO AGE Co"I!ri#ht. 1~1I . h RADIO A(}B. I.... . RADIO AGE for November, 1925 The Magazille of the Hour 3

* ALWAYS RELIABLE Eadc", Standard Tt'me For rea) radio enjoyment, tune In the "Eveready Group." Broadca!t througb stationr- EVEREADY Radio Batteries are WEAF WJAR WEEI always uniform and reliable! WFI WGR woe Evereadys perform the same, everywhere, for everybody, need­ ing no skill, calling for no ex­ perimentation, wasting no time, saving you money. Trouble­ proof, wonderful Evereadys. There is an Eveready dealer nearby. Jlanu/actured and guarantad by NATIONAL CARBO~ COMPANY, INC. New York San Francisco Canadian National CarlJon Co., Limited, Toronto, Ontario £VEREADl Radio Batteries -they last longer

¥ Tested and Approved by RADIO AGE ¥ 4 RADIO AGE for November, 1925 The .Magazine of the llour

HICAGO'S experience with silent l\Ionday nights only goes to prove the ancient impression that a good is one which supplies plenty of evidence that the listener is about as great an institution as a good C radio public is really the boss of broadcasting· broadcaster. During the recent summer a dozen Chicago stations were on the air on Monday nights, in spite of the fact HARLES E. ERBSTEIN , owner of stations that that night was theoretically silent. The mayor's C \VT AS and \VCEE on the hill top near Elgin, radio commission and the broadcasters had attempted Ill., is the stormy petrel of radio broadcasting. He is to get together on a plan which would make Monday unique. There have been reports that his stations night silent in fact as well as in theory. But scyeral were to be taken O\'er by the owners of the· Chicag0 Tribune and negotiations may be completed before of the broadcasters refu~cd to abandon thcir place at the microphone on those nights and a s a result other this gets into type. If the sale of his stations m eans broadcasters announced that they also would broad­ that Charlie Erbstein is not to continue regularly as an cast on Monday nights. announcer the news will cause a pang of regret in the hearts of literally millions of listening fans. \Ve do not know that a si!cnt night for Chicago Erbstein is an extremely successful lawyer. He is stations is an unmixed blessing. \Ve su:-; pect that a gifted pleader before juries. He is quick witted; there are thousands of listeners in the great middle he is a satirist of parts; he is a master of repartee. west city who would prefer to have Chicago stations He has courage to say what he chooses to say. He broadcast seven nights the w2ek. This is true chiefly follows no rule of ethics or conduct in a station studio because there are many fans who do not aspire to unless he thinks that rule should arply. get distance for its own sake. Ma:1Y others have The lawyer-announcer-broadcaster picked up his receiving equipment that is not de s i~ned for distance vast enthu-; iasm for radio several years ago, before work. broadcasting was born, He found that experimenting However, there are tens of thousands of fans in the with radio transmission and reception devices was a Chicago district who prefer to have Monday nights for fascinating relaxation for him and he spent much of travelling from state to state and from station to his time during long winter evenings making his own sta tion. It was not realized how numerous these fans stuff, winding coils, testing resistances, measuring were until they became a rticulate through the Broad­ ca pacities and soldering joints. Soon after broadcast­ cast Listeners' Association of America. ing arri,'ed Mr, Erbstein spent a small fortune on The B. L. A., which announces it has branches in broadcasting equipment and erected a station that is twenty-two states, organized a listeners' strike. l\Iem­ easily one of the best in the United States. bers of the association were urged to write to the E ver since he started Mr. Erbstein has been making broadcasters who did not observe silence on Monday the country listen. Fans ha"e called him eccentric, nights and tell the station owners that the individual but he is not. He is simply natural. He recites signing the letter would not listen in on the offending "The Face on the Barroom Floor" and "The Shooting station at any time unless the station became silent on of Dan 1\lcGrew." He quotes James \Vhitcomb Riley Monday nights. How many of these protests were while "The Boss' Own Orchestra" plays creepy, weepy received by broadcasters is not knO\vn. There must mu-;ic. He calls for contributions for a relief fund for have been an impressive number judging from the the victims of a devastating tornado and with tears immediate results. One after another the stations gli:;tening in hi s eyes and emotion choking his voice he shut off their generators on Monday nights, put a acknowledges the checks that pour in. He talks dust cloth over the microphones and turned out the politics, religion, international economy. He sings lights in the studios. Charles E . Erbstein, owner of "You Can't Fool an Old Horse Fly" and forgets that \VTAS, Elgin, 111., was the latest to announce that he he is working fifteen hours out of twenty-four. In will be silent on Monday nights. That leaves only one distant parts of the country they have acquired the station on the air in the Chicago district during the habit of listening in for Charlie. He pays the bills forbidden period. himself and they are large bills, frequent and contin­ It really appears that the fans accomplisned an UOlL-; bills. object which the mayor of Chicago, several of his I f broadcasting loses the Erbstein drollery and aldennen and representatives of stations had failed to philosophy it loses a studio character whose like is not do. Truly the radio fan is a power in the land. It to be found. RADIO AGE for November, 1925 T he Magazine of the IIolir 5

~ ,

Bennington Tube Socket Radio tested all insulations~ and adopted Baltelite Mason Z & T Jr. Detector In all the laboratories of radio manufacturers, in actual use in all climates and under adverse conditions, Bake­ lite has proven its superiority for radio insulation. The reason for this dominance of Bakelite in radio is easily understood. Its high insulation value, so essen­ tial to tonal quality, is unimpaired by time, tempera­ tUre variations or by service.

Saal Bakelite is generally used for exposed radio parts, Soft Speaker dials, knobs, panels and accessories, because its color . and high finish are permanent, undimmed by exposure or handling. The use of Bakelite in the set you buy or build, will Pacent Knob insure you against inferior reception through defective inSUlation. It will pay you to make sure that Bakelite is used in the radio set or parts that you buy. Write for Booklet 31 BAKELITE CORPORATION Pathe Dial * 247 Park Avenue, New York, N. Y. Chicago Office: 636 West 22d St.

Bakelite is an czcJusivc tn

¥- Tes ted Gild Approved by RADIO AGE ¥- 6 RADIQ AGE for No ember, 1925 The Magazine of the Hour

$125°0 Complete with all Accessories 10% Additional West of Rockies.

Unlike Some Music OZARKA SERVICE Satisfies Every Owner- N radio, when one selection does not please, you simply tune it I out and pick up another broadcasting station. If it is a matter A Few More of unsatisfactory volume or tone in your instrument then it becomes an entirely different matter. Men areNeeded In a great many counties we have the You have certain very definite ideas you sometimes little things may go man we want. He is rapidly building up a in mind as to what you want your wrong. The best radio salesman often permanent and profitable business of his radio to do. Will you allow us to make knows nothing of correcting radio own because he has an instrument that will a few suggestions regarding a plan troubles-sa tisfy yourself. more than meet all competition. More than whereby you can settle the radio this. he is trained to back up his sales with Our Ozarka representative in your the kind of service that counts. question? community will gladly put an Ozarka Many well established Ozarka representa. Select the instruments which you in your home for such a test. More tives started by giving us only their spare think might answer. Have a demon· than tl:is, you will find that he is a time--their evenings. If your county is open stratin3 instrument brought to your thoroughly trained mechanic on our you can do the same. . home. Let each salesman, in turn, instrument. He has gone through a The investment in cash is very small. make the necessary battery connec­ complete course of study under Ozar· The investment in time necessary for study tions. Let him tell you how to operate ka Engineers, the men who designed is considerable. I t requires patience. but: the results have enabled many men to get it but do all tlie tuning yourself. and perfected the Ozarka. out of the salary and time clock class. You'll buy the instrument then, 3187 such men today can correct Any previous sales experience is helpful based on your own operation. You'Jl any trouble which may ever occur on but not necessary. We can and will teach size up each one for any Ozarka instrument-more men you how to sell. -ease of tuning are being factory trained daily. You -distance received wouldn't buy an instrument blindly­ Send for 64 Page Book­ -volume then don't buy service the same way. "The Ozarka Plan" -tone Any radio instrument is only as P:;~pi!. ~. ~~ Thi. book. i. entirely to,? expen­ -sel.ectivity O%AAld\ sive to be 3entout on pOstal card satisfactory as the quality of service rcqucsts. I t will be .cot FREE to -price. behind it. any maD who mails the coupoo bdow and who i. really anxious There still remains one very impor­ Our Book No. 200 shows the full to impo"ove big conditiOD. Tell u. tant question to settle-the matter of Ozarka line from $75.00 to $197.50, about yourself-ask. for Darka. Plan No. IOOanddon·t fail to give service. No matter what anyone tells complete with all accessories. • tbe name of your county. INCORPORl\1tl) 122 Austin Avenue A 122 Austin Ave Due A Chicago. Illinois Chic,'lI:o.lIIinois Gentlemen: Without obligation send book "Ozarka Instru· Gentlemen: I am greatly interested in the FREE book "The ments No. 200" and Dame of Ozarka representative. Ozarka Plan" No.lOO. whereby I can sell your radio instruments. Name ...... Name ...... ···· ... . Address ...... City ...... Address ...... City ...... Ask ,be Man Who ~ unty ...... St"te, ...... Wears rhi. ButtOn County ...... State ...... :(. Tested and Approved by RADIO AGE :(. © C18670347 RADIO AGE for November, 1925 The Magazille of the Hour i

A New Super~Het Design that BANISHES Intermediate Stages

~E of the most interesting and TH I RD, but no less important original types of superheterodynes By ROSCOE BUNDY A Copyri«bt 1925 feature of the circuit IS the ability O recen tly developed takes full ad­ to heterodyne to a very low wavelength, vantage of the regenerative principle in much lower than commonly used in the both the radio frequency and detector intermediate stages of other super-hets. stages, and the great amplification thus No Loop or Matched This reduces the number of "repeat attained is further augmented by a stations" on the dials to a point where cascade coupling between the two re­ Parts Required in "repeating" is at an absolute minimum generative elements which imparts ex­ with a corresponding gain in effective· traordinary sensitivity and selective prop­ This Unusual Super tuning, and simplicity in operation for erties to the circuit without the neces­ the novice. sity for the conventional intermediate One of the principal objections to radio stages. As with the standard radio could be tuned in perfectly through the standard type of superheterodyne frequency circuits, the radio frequency strong local stations, differing in wave­ has been the repeating of the same stage precedes the detector. The radio length by only a few meters, and that station at t\\·o or more dial positions, stage is heterodyned by an oscillator such stations came in without the slight­ and complete rectification is performed est suggestion of interference. The and in the elimination of this objec­ by the single [(,generative detector tube. added complication of manipulating the tionable feature the new circuit stands This is all there is to the proposition loop during tuning no longer exists so unique. Even strong locals rarely repeat, except for the three succeeding audio that the two dials are really the only while the duplicat ion of distant stations frequency stages. wa"'elength adjustments necessary. is practically unknown. By employing The Circuit regeneration in the Explained r a d i 0 frequency tube and detector, Because of t he and by the use of many functions a "flat-top" or out­ performed by each door antenna in of thetubes and the RFT-I 62 relations existing place of the usual ~--~~--~ ,---~~ loop aerial, the in­ between the vari­ termediate trans­ T-I ous stages, it will formers and tubes probably be easier are done away to explain each with, and the dif­ stage by itself and then show them ficulties experien­ CI "','___ .... Ka ced in properly completely assem­ matching thes~ .0000S., bled in their pro­ parts is also elimi­ per relative posi­ nated. Selectivity tions. In Fig. 1 we is now purely a -A have isolated the function of the first or radio f re­ tuning units com­ quencyamplifying bined with the os­ stage from the bal­ cillator, with no ance of the circuit dependence upon LI in order to show the directional pro­ o-_~p how the regener­ perties of a loop ative feature is at­ aerial or other si­ tained and how the milar external aux­ -1111 -hllllllllllll ' oscillator coupling iliary to tuning. is effected. By actual test on j~ A B In many ways, the r a d i 0 f r e­ the circuit, it was -====- found that really A6.! quency stage is distan t stations - very similar to the 8 RADIO AGEJor November, 1925 The Magazine oj the Hour

\Veagent regenera- Co mplete As­ tIve circuit when sem bled Circuit the feedback is All of the ele- considered. \Ve mentary circuits have the aperiodic are shown com­ primary (Ll) in AFT-I ,,-.-.,G... pletely assembled the antenna cir­ INPU in the proper rela­ cuit and the secon­ tion by Fig. 4, dary coil (L2) tun­ where they will be ed to wavelength T2 recognized b y a by the 0.0005 mf. close examination. variable condenser Indentification is ( 1). At (tl) is a - .0005 simplified by using tap which goes to the same letters in (-A) so that the Fig. 4 as in the first portion of the coil three small dia­ (TICK) below, the grams, so that it tap point is really wZ should not be dif­ the tickler coil for ficult for the obtaining regener­ novice to under­ ation. A \\' ire stand the func­ (wI) connected to L4 tioning of the cir­ the plate of the -A cuit. The ,three r ad i 0 frequency au d i 0 frequency tube (Tl) feeds stages are shown back the plate cur- behind the detec- rent to the tickler tor c i r cui t, by coil through the -A +A -rB45 which the volume three-plate vari- is brought up to able regenerative HG,Z lou d s p ea k e r control condenser requirements. (K 1). This is not Impulses from a very critical con- the antenna are trol and is used for clearing up the signals regenerath'e similar to the first stage, led to tube (TI) and amplified at radio and for controlling the volume. except for the addition of the grid con­ freq uency with further amplication by Below the coil (L2), and inductively denser and leak. With the t,\'O circuits the regenerative feature already ex­ coupled with it, is the single turn pick­ coupled together, we have a cascade re­ plained. These waves are then hetero­ up coil (L3) connected to the oscillator generative circuit \\ ith its output con­ dyned by the oscillations of tube (T3) circuit. All coils (Ll), (L2) and (L3) nected to the first audio frequency coupled to the radio frequency circuit are in inducti ,'e relation to one another transformer (AFT-O. Following the through the l\Iarconi type link (M), and and are wound solenoid fashion on an detector are three audio stages of the the output of the radio frequency tube is insulating tube, It is through (L3) that usual type for increasing the audio then coupled to the detector tube (T2). the heterodyr.e effect is obtained by volume of the detector. The detector rectifies the currents re­ impressing the oscillations of the ex­ A 0.0005 fixed condenser (KT5) is ceived from the first stage and develops ternal oscillator tube upon the in­ connected across the coil section (90 the audio frequency phase so that the coming waves. At (L4) is the primary turns) marked (L5) for sharpening the signals become audible. Regeneration coil of the radio frequency transformer tuning. in the detector stage still amplifies the or fi:ter (RFT-l) through which the put­ signal so that the total amplification at Oscillator Circuit put of the tube (Tl) is coupled to the the output of (T2) is unusually great,. following detector tube. This completes o W comes the third and last ele­ although only t wo tubes are employed. the radio frequency circuit. Primary N ment of the radio frequency cir­ . Only two wavelength controls are coil (Ll)='lO turns of r\o. 22 wire, sec­ cuit, the oscillator circuit, which super­ needed, condensers (C1) and (C2), ondary (L2) =46 turns of No. 22 wire, poses the oscillations of an external Condenser (Kl) is not concerned in the and (L3) = 1 turn of Xo. 22. oscillator tube upon the secondary wavelength adjustment, but is used for Following the radio frequency cir­ circuit of the radio f req uency stage. controlling the volume and for clearing cuit is the detector circuit of Fig. 2, This is shown in detail by Fig. 3, where up the signals when excessive regenera­ coupled by means of the air-core radio the oscillator tube (T 3) is connected to tion tends to make them mushy. Con J frequency transformer or filter (RFT). the grid coil (L6) a nd the plate coil denser (K2) is seldom touched after The primary (L4) carries the put put (L i ) in the usual manner. The fre­ the set is once adj usted. Tuning is of tube (Tl) as previously explained and q uency of the oscillations is controlled surprisingly sharp, but with the coils acts inductil'ely on the seconda ry (L5) . by the second variable tuning condenser properly adjusted, the two condensers As before, the secondary is t apped at (C2) which has a capacity of 0.00025 can be so carefully logged and matched (t2) with a connection to the (-A) line, mf. At (K3) is a 1.0 mf. fixed bypass that little difficulty is experienced in and the lower portion of the coil (TIC K) condenser. picking up e,'en the weakest of stations. again acts as the tickler coil for securing A rather unusual link coupling (:'II) Locals go in and out completely with one regeneration. At (GC) and (GL) are is ma de between the oscillator circuit division of dial mo\'ement, and further, the usual grid condenser and leak used and the ra dio frequency secondary by the set is not only sharp but is also per­ with a detector circuit, but now variable coils (L3) and (L8). As before ex­ fectly selective with no "fringe" or condenser is used for tuning the system plained, C()i1 (L3) forms a portion of the hangovers" after the given wavelength to wavelength. Coil (L-l) =330 turns of antenna tuning unit as shown in Fig. I, has been passed. Ko. 26, coil (LS) =90 turns, and (TICK) but the coil (LS) consists of two turns Some contribution is made to the = 330 turns of same wire. of wire wound bet,,'een the grid and plate sensitilrity of the circuit by the oscilla­ By means of the wire (w2) connected coils (L6) and (L7) of the oscillator tor tube and circuit, but its principle to the plate circuit, plate feedback is circuit. This arrangement gives the function is added selectivity and stabil­ led to the tickler coil through the variable necessary loose coupling between the ity to the regenerative circuits. By the regenerative control condenser (K2). two circuits, and at the same time is ~wo condenser controls the range is The latter is a very small condenser of mechanically advantageous in assem­ from slightly below 200 meters to 555 the "midget" type, and when once ad­ bling' the c'oils in the receiver. Coils meters with properly designed coils, and justed seldom needs attentiqn, It is (L6) and (L i) = 28 t urns of No. 22 wire, throughout this range the dials seldom e"ident that this is a Weagent type (L8) =2 turns of No, 22. if e,'er "repeat" a station owing to the RADIO AGE for Ko ember, 1925 The Magazine of the Hour

low wavelength of the heterodyned cores at (g-g-g) indicate that the trans­ tance across the plate (P) and grid waves, made possible by this particular former casings are grounded by a connec­ (G) post of the last tube (T6), and thus arrangement. Impressing the oscillator tion running t o the ground binding post deliberately short-circuit the energy wa ves upon the first stage permits so that the transformers are etTcctiyely output. On locals, tremendous volume regeneration to be carried to a higher shielded from stray radio frequency is secured and some means is generally degree than with the ordinary type of fields. This is of the greatest impor­ necessary for relieving the load on the regenerative circuit, so that the oscilla­ tance tot he proper operation of the re­ tube. tor tube indirectly adds further amplifi­ ceiver and the grounds should be care­ Filament Control System cation and is not to be considered as an fully made to avoid distortion and noises. idle tube as in the majority of super­ In some cases, improYement can be ha d r-1"'VO rheostats are employed for the heterodynes. It is possible that this by connecting a 0.00025 mf. fixed con­ control of the filament Current. A stabilizing influence may be some­ denser between (-.'\) and the ground, rheostat (Rl) controls the emission of what after the nature of the system em­ but in the majority of sets a still better the radio frequency tube (Tl) and the ployed in the old time super-regenerative plan is to ground the (-A) line directly detector tulle (T2). A second rheostat circuit, where the amplifier is intermit­ through a wire indicated by the dot t ed (R2) controls the audio frequency tube~, tently opened and closed by t he oscilla­ lined (Q) in the diagram. for the latter are not critical and can tor tube so that tube "flopping" and I n order to bypass t he radio f req lIency be worked nicely with a single rheostat. squealing did not take place with the currents around the primary coil of the Experiment has demonstrated the advi­ usual degree met with in feed-back first audio frequency transformer (AFT­ sability of separate control of the first coupling. I), a fixed condenser (K4) will sometimes two tuhes according to the degree of be found advisable, while in other cases amplification required and the regenera­ Audio Amplification it may have no appreciable effect on the tive effect. Regeneration in this cir­ CONNECTED to the output of the operation of the set. The exact size cuit is directly influenced by the fila­ detector tube are the three cascade required can be best found uy experi­ ment emission. and therefore filament audio frequency stages employing the ment bllt usually a 0.001 mf. or a 0.002 control is essential. The Oscillator audio tubes (T4- T 5- T6). These stages mf. fixed condenser will be found correct. tube is provided with an amperite con­ are coupled together by the usual iron­ This bypass is not critical. Bypassing trol (R3). core audio frequency transformers (AFT- various parts of the circuit by means of A full 90 volts of " H" battery is used 1), (AFT-2) and (AFT-J) which must fixed condell~ers is largely a matter of ·on the oscillator, radio frequency and be perfectly matched to avoid howling experiment "'ith the individual circuit, audio frequency tubes, but the battery and other troubles incident to the use and yaries wit h different types and is tapped at the 45 volt post for connec­ of three audio stages. This audio am­ makes of apparatus. What will be tion to the detector tube plate. This plification insures more than ample proper for One set of transformers may assumes the use of the 201A storage volume with the weakest stations passed pro\'e inadequate for another set, and battery tubes, which are normally used by the detector tube and all broadcasting the only way is to tryout the effects of with this circuit and which give the best stations can be heard on the loud speaker different bypass capacities. all around results. The "199" tubes with volume to spare. '\'hen the overloading of the audio can be used, but with a considerable Low ratio audio transformer are used fre

regenerative control· condensers and the audio resistance (r) are not sO sharp and almost any low loss condenser will be satisfactory at these points. Rheostat adj ustments are not critical but shOl!ld be turned on far enough to insure that the tubes are sensitive, say about % on for the detector rheostat and nearly full on for the audio and oscil­ lator tubes. The position of the rheostat knobs varies with the condition of the storab"e battery, as well as the tubes, and with a partly charged battery it will be necessary to turn the rheostats father than when the battery is fully charged. It is not necessary to use the rheostats in tuning, nor is it desirable. Condenser (K2), used to control re­ generation in the detector tube (T2) is set slightly below the point where it causes excessi\'e regeneration or howling. The closer this is brought to the howling point, after the set is tuned in by the main condensers (Cl) and (C2), the greater will be the amplification and volume. It is not necessary to handle this control frequently, except when special con­ ditions of selectivity and sensitivity make such adjustments necessary. With the plates fully meshed and at full capacity, the detector tube (T2) is in an oscillating condition, and in turning the condenser dial of (C2), a series of clicks will be heard. Stopping at any of these clicks will show them to be whis­ tles due to the oscillations produced by the heterodyne oscillator, and when in this condition, signals cannot be heard. The condenser must be adjusted so that the tube is just belo\v this oscillating point by moving the adjustment toward minimum position gradually until the whistles have all disappeared. \\'ith the condenser (K2) adjusted as abo\'e, the tuning is performed by means of the dials attached to (C1), (C2) and (K 1), the latter being the regenerative control for the radio frequency tube (T1) and is used for volume control. The control (K 1) shows no effect until -'__ ~N __ i!J~fl.;.:..J...:..1 _____.... ~~I------~I I , wa\'e of the station will be heard as a [> muffled whistle. On hearing the whistle, (Turn to page 61) RADIO AGE Jor Noyemoer, 1925 Tile Jlagazi1le oj the Holtr 11 Riding the SHORT WA YES BY ARMSTRONG PERRY

Amateur Radio Station 9CXX, owned by Arthur A. Col. lins of Cejar Rap i ds, la. Note the effici­ ent equipment and "call~ heard" on the waU.

~. J 1

Work of Young Anlateurs 1S Responsible for Renlarkable Developnlent in Short Wave Work; Many Records Made by U. S. Boys 0:-'IE TIl\lE ago it was disco\'crcd short-wave apparatus. On the last cates that amateurs of allY age have a that extremely short radio waves, previous Arctic expedition conducted most attractive field for in \'estigation 8 from fivc to forty metcrs in length, by Mac)'l illan, which sailed in the sum­ in short-wave work. A visit to the sta­ would cover distances far grcater than mer of 1923 and spent the winter within tion of Arthur Collins, at Cedar Rapios, those in common use. Thcir rangc was eleven degrees of the North Pole, a showed me that his apparatus is simpler discovered -to be practically as grcat in prominent amateur named Donald l\[ix and less expensive than the avcrage daylight as in darkness and static did represented the American Radio Relay radio Lug would think possible. Con­ not matcrially interfere with thcir recep­ League and kept the expedition in touch "incing proof of its efticlC ncy IS sho,,- n by tion_ with the world most of the time. He hundreds of reports from brother hams Radio amateurs were prompt in follow­ was out of communication for two months who have received his signals in all ing up this discovery, as they have been at one t ime, when a fifteen-year-old boy, parts of the United States and in :\lexico, in developing many ne\\' things in radio. Everett Sutton, of Port Angeles, \rash­ Hawaii, Cuba, Porto Rico, Scotland, One of the best known members of the ington, picked up his signals a nd took England, Belgium, Chile, Guam, Tahiti, American Radio Relay League, which SCOres of messages, which we re deli vered India, New Zea land a nd Australi a. includes most of the amateur experi­ per instructions, to friends and relatives \ hile broadcast listeners are using menters, ,,'ent as a Naval Reserve officer of the officers and crew, to the press and receivers with fi ve to nine tubes, Collins on the Seattle, during the recent cruise organizations interested in the expedition. hears signa ls from distant countries of our Pacific fleet. This was F, II. Again in the Summer of 1925 it was a with three tubes. He made his receiver. Schnell, traffic manager. A ~avy officer fifteen-year-old boy, Arthur A. Collins The i nductance coils ha\'e ea ch a few reported, after Schnell and his short of Cedar Rapids, Iowa, who succeeded turns of rather large wire, insulated by wave set had established communication in keeping in touch with the Arctic double cotton covering. The ends go with amateurs in many countries, that expedition, using the shorter wave­ directly to binding posts on the panel. all Schnell had to do was to press the lengths, when older and more experienced There is no mounting, knob, dial or key of his short-wa,'e transmitter and radio men were unable to keep up com­ other device for changing the coupling. he would be heard in any part of the munication. If Collins wants to put the primary world. nearer the secondary, or the tickler Then John L. Reinartz, known to all A~e Is No Barrier nearer either, he hends the m over with amateurs as well as in professional radio HE fact that in two successive years his fingers. The coils were wound on a circles, went with the M acMillan Arctic T mere boys should ha\'c been able to square box. \"hen taken ofT, the wire expedition in the summer of 1925, taking render such noteworthy sen-ice, inoi- had a tennency to uncoil. It was per- 12 RADIO AGE jar November, 1925 The Magazine of the Hour

~,~,A.rw~JtirT-"'?""'9' Collins became the only connecting link between the explorers and the fol ks back home. For twenty-two days he was the only operator in communication with the expedition. He worked from S a. m. to 5 p. m. daily and handled a great volume of traffic, including persunal and official messages and artic:cs for the newspapers, The National Geographic Society, which sponsored the expediti

WINO SLOWING .32I<.M(20MILES) PER ' HOVR . "'rHE value of direction-indicating beacons for use of airplane pilots cannot be over-estimated. The in­ creasing air travel, together with the frequent low visibility during storms J or other atmospheric disturbances, makes 1 it almost imperative that some definite, safe and constant means be adopted to guide the air traveler on his way. 1------It-I KM (100 MII-(5)------I The navigators of old were practically helpless without beacons, although the radio compass has now practically made navigation error-proof. The adaptation of the radio compass to air work, with particular emphasis laid on the beacon scheme, should do a great deal to iron out difficulties which aviators have had to encounter in their flights. Naturally, the radio compass aboard an air machine is too bulky a proposi­ tion to be considered, so the beacon after all seems to be the most feasible project yet developed. GUiding Steamships

A NT£NNF\ 1'11\0'0 Old timers will probably compare the aEACON aerial method of holding to a course to the buried cable in New York Harbor some years ago when underwater oscil­ 2 lators, one located on the port and the Fig. other on the starboard, were used to keep track of a signal being emitted by the cable laying on the floor of the harbor. METHOD OF ELlMINAnNG EFfEC,T OF WINI) DRIFT ON AN f\IRPLANE:: By noting the intensity of the signal StiOV(IN~ C.OURSE fL-OWN I3Y f\IR9LfH,£ fiT I("IKWI (100MIL£S) PER received in the port and starboard re­ HOUR IN E'QIJ I-SI"'NAL. Z.O!(E. ceivers the pilot (the skipper) Was en­ abled to hold the vessel to a true course. the airplane was installed in the rear or crossed-coil radio beacon, an airplane This was exceptionally valuable in foggy gunner's cockpit. This consisted of may maintain a straight course regard­ or heavy weather When there was a antenna reel and wire, inducti\ ely­ less of cross winds and visibility condi­ possibili ty of a collision if the vessel coupled tuner, 7-tube Signal Corps tions. " strayed far from her beaten path. amplifier, and batteries. The fair lead projected through the flooring of the WIND ' BLOWING .32K"l(2.0Mu..es) PER HOuR cockpit, thus permitting a wire to trail on the left side of the fuselage looking .. forward. In addition to the trailing wire, a coil of t'l\'O turns of insulated wire extending from the trailing edge of the upper wing and landing gear to the rudder post could be connected to the radio amplifying unit and coupler by a double­ pole-double-throw switch. 1------'''' KM (100MIL(S) ------~ "One of the great advantages of this system," reports Francis \\'. Dunmore of the Radio Laboratory of the 13ureau of Standards, "over the method of em­ TRUE COURSE. ploying a radio direction finder on the airplane or on shipboard is that the eff ect of side drift may be immediately noticed and corrected by heading the airplane at the correct angle in to the wind, th us NON t>IRECTlONI'\L ena bling a pilot to maintain a straight RRDIO SLAtoN - course along the line of direction to the t ransmitting-coil beacons. " In aerial na\'igation this is much more important than in ma rine naviga­ t ion, as the effect of side drift due to crosswinds is often ,"ery ma rked. The effcct of cross winds on an airplane navigating by means of magnetic or ordinary radio direction finder bea rings Fig. 3 is illustrated in one of the diagrams repro­ duced with this article. It will be seen E.FF£CT OF WiND DRIFT ON AIR P1.A N£ SHOWING. COORS£. TAKEN that under these conditions the airplane B'f FlIRP1.RNE WHEN 0 FLYII'IG AT 161 KM (100 MILES) PER HOUR may deviate considerably from its true AND NRY,IGFITING 6'1' MEANS OF DIRECTIOf\! FINDER BfARI NG-S course. By means of an equi-signal aN L Y. RADIO AGE for November, 1925 Tile Magazine of the liour 15 A New Use for 3,Element Tubes A WINDLESS, PIPELESS, PIPE ORGAN :\ THE twenty years since the inven­ The primary coil consists of 3000 turns tion of the audion by DeForest, By J. C. JENSEN of ~o. 26 enameled wire insulated from 1 the three-element vacuum tube has DePt. of Physics. Nebr3.5L.1I \\'e:UeYIln UDh"eniity the core and between layers with empire been put to a large variety of uses and cloth. new applications are constantly being core transformer, T. The core is built A tap is taken out at thf' 1800th turn made. Besides its well-known functions up of laminated steel with outside dimen­ for the filament connection , and if the as a detector and amplifier, it is used to sions 4x5 inches and 1 inch deep. The transformer is intended for general drive oscillators of every description from width of each piece of steel is 1 inch, experimental purposes, it is a good plan the small experimental units of the radio which lea\"es a rectangular hole, 2x3 to take out a tap for each 300 turns, laboratory to the large powerful types inches in the center. To facilitate wind­ beginning with the 120{)th. The secon­ which furnish the carrier-wa ve for broad­ ing, the steel plates, taken from a burnt­ dary is wound in a similar way with 300 casting purposes. out power transformer, were cut into the turns of wire. Any hard amplifier tube The pitch of a musical instrument shape of an L, 5x3x 1 inches, and piled will serve in that position. The UV201A depends on certain properties of the for each half so that alternate layers gives very good results, while for ma xi· substances whose vibrations produce the extend in the directions a and b as shown mum volume the UV202 may be used. in .the drawing. various notes. I n the piano it varies Only One Octave with the length, tension and weight of the After the coils have been wound on the string. In the pipe-organ it depends resulting U shaped forms, the laminations I ~ THE experimental outfit here chiefly on the length of the pipe and on at the ends are slipped over each other described, one octa ve on ly was pro­ whether one end is open or closed. In so as to form a solid mass of steel, and vided for. The condenser, C, is a 43· the case of an oscillating electrical circuit pushed into place by the use of a bench plate variable in a metal case, the latter the controlling factors are the capacity vise. Holes were then drilled in each being filled with transformer oil so as to and inductance as given by the equation, end of the core and bolts through these increase the maximum capacity to ahout holes held the entire structure together. 1 .003 Mfds. The fixed condensers Ch n Cz, C J , etc. were made out of an old where n is the hi gh-voltage paper number of oscilla­ condenser. Trials tions per second, with small labora­ L the inductance tory units showed of the circuit in that the value of 'henries and C its C1 should be about' capacity in farads. Fig. I .01 Mfd. to gi\"e a Since this equa­ pitch of C - 256 The w iring diagram jor the pipcless pipe vi brations per sec­ tion holds for all organ, an outgrowt h oj much experiment values of Land C, by Proj. Jensen. Although other cirCllits ond. A paper it follows that if could be used to advantage, Hartley's was condenser of that their "\'alues arc wed as being best suited. magnitude was properly chosen a connected in and vacuum-tube cir­ the pitch tested may be made to against a tuning oscillate with fre­ fork. Approximate quences within adjustment was the range of the lIlade by trimming human car. the tinfoil between layers of paper, A Vacuum Tube c and final tuning to Oscillator the exact note was HE vacuum obtained by the T tube oscillator use of the variable described herein is condenser. the outgrowth of To keep C1 Con­ considerable labo­ stant, the paper ratory experimen­ and tinfoil parts t at ion 0 n 10 \\"­ were tightly freqllency circuits. clamped between As will be noted two pieces of bake­ from Fib' 1, the b lite. Cz, C 3, etc., Hart Icy circuit is Tr- a, n 5. were constructed used, although in a si milar man­ sorr,e of the others ner. With all the could also be made key-switches open, to sen'e the ·pur­ the a p par a t u s pose. The most would still gi ve out difficult part of the a h i g h - pitched apparatus to con­ note due to the struct is the iron- variable conden- 16 RADIO AGE for Noveml>er, 1925 The Magazine of the Hour

Establishing Octaves COKDENSER C l, of approximately .01 mfd. capacity gave a pitch of C, or -256 vibrations per second, th . lowest note of the particular acta ve fO li which this device was made. The re­ maining condensers, C2, C3, etc., wil naturally have to be of a smaller capacit}\ than .01 mfd. The capacities of these condensers can be altered until the result­ ant pitch is obtained. This can be accom­ plished by altering the capacity of eacn of the condensers, C2 arid C3 until the note produced is similar to that given when the corresponding keys of the piano are sounded. By employing the method of establish· ing the octave, described above, several other octaves can be included by provid. ing additional keys and corresponding condensers and adjusting them by com· parison with the piano or by ear until the desired notes are produced. . There has been quite an insistent demand on the part of a certain type of radio experimenters for an article on an Fig. Z. A close-up of the remarkable key-board for the orgall def/iscd by Prof. Jensen. The transformer and oscillator tube are also shown in this photo. audio oscillator. The scheme outlined by Prof. Jensen seems to cover the subject quite well and we believe his article will ser. This can be obviated in either of The cone type of speaker will also give enable many of our readers so inclined two ways. Instead of the permanent better satisfaction if a wide range of to go ahead with their own work on an connection from C to the condenser­ frequencies is to be made use of. There is audio oscillator. The range of frequencies transformer leads, a separate wire can practically no limit as to the qualit}' of the can of ' course be determined at will by be run from its upper side to the contact tones which a device of this kind can be the selection of different sized condensen points of the s'\\'itches CI, C2, C l , so that called upon to produce, since a .resis­ as outlined by Prof. Jensen and with thE the variable condenser is in circuit only tance or impedance coupled amplifier trimming process employed one may gel when a key is struck. and cone type speaker can be connected the various capacities down to a nicety. Another plan is to connect a 1 Mfd. to the output circuit of the oscillator condenser to the upper side of a bar, tube. This form of amplifier and speaker joining all the keys in such a way' that will faithfully reprociuce all the tones this large condenser is in circuit only generated without the slightest distor­ when all keys are up, its capacity being tion. Don't miss the December num­ sufficient to make the note of the oscil­ It may be found that while operating ber of RADIO AGE. Chock lator too low to be audible. this tube organ that a slight disturbance full of inspiration and topped The output of the transformer is put occurs in the radio receh·ing set when off with the "Radio Age into an amplifier of two or three stages. both are operated at the same time. If Fig. 2 shows a close-up Yiew of the key­ this interference of disturbance is trouble­ Model Receiver." On the board, transformer and oscillator tube, some, it can be eliminated by completely stands November 15. while Fig. 3 illustrates the entire appar­ shielding the oscillator-circuit, (Fig. 1) atus including a two-stage power am- ' with a copper or tin foil cOYer box. plifier. With a little care in adjusting, the notes produced may be made true to pitch and of good quality. The volume of sound depends wholly on the amount of amplification applied, and it is obvious that greater ranges in pitch can be added at will.

Similar to Pipe Or~an HE action of the keys in this device T is the same as that of any electrically controlled pipe organ, except that each key has a set of contacts which opens a nd closes its respective condenser circuits, instead of a relay circuit, as is the case with the usual electrically cop.trolled pipe orga n. The keyboard of this radio organ is nothing more than a number of hinged pieces of wood, each haying a set of con­ tacts and a spring to hold the key switch open. In the event that the experimenter desires to work with the lower notes of the piano or organ scale, it may be necessary to use one of the newly develop­ ed cone type loud speakers in the output switch, as it is often the case that the usual type of horn speaker will not Fig. 3. The entire apparatus, including the two stage power amplifier. Fans who build respond to the lower notes 'of the scale. this novel organ are asked to write in concernin~ the re.~ults obtained. RADIO AGE for November, 1925 The Afagazine oj the Hour 17

I. FIGURE' 1

3CT PH

1) (ZS"')

F+ ..

SCHEI?IIT/C CIRCUIT PIIICRIIM (IF THe .. SPECIAL rOVR" R£l'£IVEtfP. A New LOW LOSS "Special Four" s THE cold weather lhc yariable condenser as approaches, all of An Efficient Long~Distance Set RC. A the DX hounds start polishing up the old solder­ Combining Regeneration and a The Two-Circuit Coil ing iron and looking for new y AX a(ljustable stage ideas in receiving circuits, RF B of tuned radio fre­ and here is one right off the Stage of Adjustable Tuned quency, we mean a two fire. A combination of the circuit coil with the .... ariable old reliable DX regenera- By H. FRANK HOPKINS condenser as described tive set, less the trouble- abo\"e, with the windings some howls and squeals, with a stage let us analyze the circuit. \Ve will start mounted so that they can be moved to of "adjustable" tuned radio frequency at the incoming or radio frequenc), end various distances from one another, as amplification that will reach out and and see \I'hat takes place. By radio shown in Figure 2. This feature enables bring home the distant stations to your frequency amplification, the incoming one to increase or decrease the antenna heart's content, and two stages of audio signal is amplified at radio frequency, coupling as desired. When this is once frequency amplification to rattle the or at a frequency abo\'e audibility, set, it need not be changed, unless the \\'indow panes. depending on the wavelength of the operator desires to sharpen the tuning This circuit has shown surpnslng incoming signal. By tuned radio fre­ so as to cut out some nearby station. selectivity while being worked within quency, we mean that the radio frequency This is accomplished by reducing the a mile and a half of two l$OO-watt broad­ transformer is capable of being tun('d to coupling or moying the coils farther casting stations and one-half of a city filter signals of various frequencies and apart, or he may increase .... olume and block from station \\'IBO, which is block all other signals of different fre­ distance by c1osel' coupling, "'hich is sending out 1000 watts. During the quencies. The most commOn tuned obtained by moYing the coils closer first part of September, it reached out radio frequency circuits have a two­ together. This, however, reduces the almost two thousand miles and brought circuit, air core transformer, one winding selectidty of the set and it is suggested in signals On the loud speaker-and acting as an aperiodic primary. This that when once a good setting has been that is going some for that time of the winding usually has from eight to fifteen obtained, the coils be locked in that year. In fact, for distance on a se .... enty turns of insulated copper magnet wire, position, or that position marked so as foot antenna, it beat an eight tube about Ko. 22 gauge, and the other wind­ to be able to go back to it as desired. super-heterodyne using a loop and being ing as a tuned secondary usually COn­ In this circuit, we ha\'e all of the above operated at the same time. sisting of from forty-five to sixty turns features, with the addition of a brass of the same size wire, when a .00035 shield between the primary and seCOn­ Cost Is Not Great Mf. variable condenser is shunted across dary coils of the transformer VRF. HE cost of building this set is com­ its winding. By changing the capacity This shield was fo und to reduce most of Tparatively small when One considers of this condenser, the circuit is tuned the strong induced currents that were that the popular trend is for five, six to filter various frequencies or to pass responsible for considerable foreign noises and even eight tube sets, and it will signals of a given wavelength to the in the recei\'er. This shield is grounded stand up and bring them in alongside grid of the radio freque ncy tube, where to the negati ....e side of the filament, or of the best of them. they are amplified, or strengthened. "An battery, and is kept in about the I n selecting a receh'er, it is always a This coil is shown in the schematic center of the air gap between the two good plan to find out how it works, so circuit diagram, Figure 1, as VRF. and coils. (Turn the page) 18 RADIO AGE for No\'ember, 1925 The J.1Iagazine of the Hour

The pla te element or ourput terminal to produce an audible vibration of the Three--4/1 composition dials (for of the radio frequency tuhe RF in this diaphragm in the receh'ers of the loud JCT, RC and DC). circuit is then connected to the primary speaker. By adding stages of audio Two-3 to I audio frequency trans­ side of a three circuit tuner, desig nated frequency amplification, we increase the formers (Tl and T2). 3eT in Figure 1. A three-circuit tuner output strength of the set and conse­ One-.00025 l\Hd. grid leak con­ is a set of three coils, t\vo stationary quently get more \"olume. denser (GL). and One mo,'able. The first coil is known Two such stages of audio frequency One- 2 megohm, tubular grid leak as the primary and has about twelve amplificatio n are usually employed, and resistance (GL). turns of ~o. 22 insulated copper magnet sometimes three, but more than three Four-UV tube sockets (RF, D, wire; the second coil is known as the stages tend to distort the signal and AFt and AF2). secondary and has alJout fifty,five turns are therefore not desirable, One-6 1-2 ohm rheostat (R). of the same size wire. A yariable con­ :\11 that remains to be described are One-25 ohm rheostat (D). denser is shu nted across this secondary the batteries and the ground and an­ One-Two circuit phone jack,wit:l coil and the comlJination \Yorks the tenna connections. The filament or filament cut off (UP). sa me as the radio frequency unit just "An battery, as we all know, is used One--Single circuit phone jack described. The third coil is movable to heat the filament of the tubes, causing (LS). and is located inside of the other wind­ an emission of electrons to take place Seven-Binding posts (A, G, B amp ings, It is known as a tickler coil and has within the tube, the flow of which is B det, BR. F+, and F-). a bout twenty-five turn s of the same regulated by the grid element of the One-A battery switch (SW). size wire; this coil is what produces tube. The plate or n battery is con­ One--Composition panel, 7 "x2'x regeneration and is a \"olume control. nected to the plate element of the tube 3-16 ". through the receivers or the secondary One--Base board, 7"x23"xt;2". The Secondary Connection of a transformer. The battery furnishes t he high voltage necessary 'to pass a XXX-Miscellaneous mounting ilE secondary side of this three screws, wire, solder, etc. T circuit tuner is connected to the grid current from the filament to the plate of the detector tube D, through a gri(\ element of the tu\w, making a completed leak resistance and small fixed con,\enser circuit through the phones or loud The first step in the assembly of the GL. This grid leak and condenser is speaker so that the current will flow and set will be to layout and drill the panel used to insure an even grid bias poten tial the variations will be reproduced by and shelf. This is usually done by placing or grid voltage. The plate of the de­ sound. the parts around until a satisfactory tector tube is connected to One side of The ~Iaterials arrangement has been found. Starting the tickler coil; the other side of the O\\' that we have analyzed the cir- with the shelf, the holes for mounting tickler coil is connected to the positive 1N cuit, let us go about getting the each piece are then marked with a sharp si,\e of a forty-fi,'e volt plate Or B ba ttery materials ready to build the set. E very­ instru ment, the parts removed and the through a set of head phones or the thing that will be required is listed holes drilled. It \\'ould be well to ,drill primary coil of an audio frequency lJe\o" , E ach part bears a designation. the holes that pass the movable shafts transformer, thus producing regenera­ The same designat ion is sho\\'11 On the through the panel at least one-half of tion, or strengthening the output of the circuit diagram and is used throughout an inch in diameter, to prevent them rletN'ror tube, which has rectified the the a rticle so as to ena ble the reader to from binrling against the panel and incoming signal from the inaudible mOre easily distinguish each part and turning hard. Oftentimes it saves a radio frequency to an audible frequency, to properly place it in the circuit. The great deal of time in fitting. or a frequency that will pro(iuce sound parts are as follows: \\'hen the holes for moun ting the in the head phones or louri speakt'r. One--Adjustable radio frequency parts ha,-e all been located and drilled, This output is usually connected 10 transformer (VRF). Described later it would be well to give the panel a velv et the primary winding of an au,iio fre­ in this article, finish, by rubbing it lengthwise with a quency transformer. By audio fre­ One--Three circuit tuner (3CT). piece of fine sand paper that has been quency amplification, we mean amplifica­ Two-.00035 ~Ifd. variable, straight dipped in oil. All of the marks and tion of the signal which has been rectified , line-wavelength condensers (RC and scratches ,,'ill disappear and the panel or change,i to a frequency low enough DCl. will ha' e a soft, dull finish that will not

/

BRSI' 60RRD UIY()VT.

~ @ 5W LS G> PE7R/i.5 FOR MOVNTII\/~ YKF CO/I.:>. FRONT PI9NEi. LA'YOVT. ~ l1('rVfl/. ~/zF.

nr;URE 2 /9J".fEMBL Y RNO J)ET/ULS FOR "SPECI/IL FOVK" REC£I V£~. RADIO AGE for NO"ember, 1925 The 11Iaga~i1te of the Hour it)

mark up as easily as the highly polished and antenna leads. All other connections to the negative fila men t lead of the set surface. are considered power or low frequency at the binding post F-. A great deal could be written about leads and are not as liable to interference The tuning of this set is comparatively the placing of the parts in relation to as are the others. Solder all connections simple. The condensers RC and DC each other, but there are only a few and see that the terminal nuts are turned control the wa ,relength and the tickler pointers necessar5', and they are: Keep down as tight as possible. A loose con­ coil of the three circuit tuner (3CT) the radio frequency transformer as far nection is often a hard thing to find anrl control the \'olume. T he filament cur­ away from the t hree circuit tuner as is is the cause of much noise in the receiver. re~t for the detector tube is controlled by con...-enient. In nO case let it come within For those who like t o wind t heir Own the rheostat D and the rheosta t R con­ five inches of the tuner; also, keep the coils, the construction of the adjustable trols the filaments of the radio frequcncy three circuit tuner as far a way from any radio frequency transformer is explainecl. and audio frequency tubes (RF, AFt and unshielded audio f rcquency transformer The construction of a good three circuit AFl). as possible, and at least five inches. ' tuner has been described often and hv If the set rloes not tunc sharply enough If the audio frequency transformers arc referring to a back number of RADIO at the start, move the coils of the trans­ not shielded, that is, if they are not AGE, or to the RADIO AGE AN:\UAL, former (\' RF) farther apart, un til the encased in a metal shell, they will have a suitable unit can be found very easily. desired select i ity is ohtained. When to be separated and mounted at right The material required for making this the distance results do not scem to be all angles to one an- that shOUld be ex'­ other. All of the pected, move the above points coils of this same should be followed transformer closer out, as if these together, until parts fall within maximum coup ­ - cur r~O/"1 1#20 the inductive or ling is obtained. C'I9Vt>£ .fN~£r ePRJ,S magnetic fields of ""22 COPP£1t -I" ¢ This 'will make the one another, howls MIN;Ncr 1V11t£. set tune mOre and squeals will broadh', but will result and the set bring i~ the distant will be practically signals loud and worthless. clear. The set may be Wiring the Set logged, if the coils HEN all of of the radio fre­ W the parts have quency transform­ been mounted and er are set; that is, the shelf fastened if a good average to' the panel, t he setting is obtained, set will be ready I and thecoils locked to be wired, but in this position. before we start to TW" C'dN.S - (J/o/~ HI9Y/N~ /-Z TURN's By moving thcse wire the set, it ,liND (JIVE HI9V/Ntf SO rVIPN~ RR£ OIVC .fN/Ct.D RCt;>VIRED coils, the setting may be well to R'£

Cotning In• Our Decetnber Issue-"The Radio Age Model Receiver"

EADERS who make their own sets will HIS superior how-to-make feature will not R welcome this most complete how-to-m~ke T only have the imprint of the skill of our own article this magazine has ever published. technical staff-one of the very best in the radio field-but the editor of Radio Age has enlisted The receiver will be a five-tube tuned radio manufacturers of quality apparatus to assist frequency outfit. Every part will be listed under us in making this receiver what its name implies the name of the manufacturer or the trade name - a model outfit. so that you will not have to ask a question as to what apparatus to select. John B. Rathbun, whose blueprints and arti­ cles in each issue of RADIO AGE are followed The article will be illustrated with line drawings, by fans all over the world, will write the descrip­ a wiring diagram and several full page size blue­ tion of this model receiver and he will cover the prints. story down to the very last detail. Even the accessories, such as loud speaker, bat­ Frank D. Pearne, technical editor of Radio teries, etc., will be suggested. Age .and chief instructor in electricity at Lane Technical High School, Chicago, will assist in If you are planning to build another set this the tests that will be made before any part or Winter you will make no mistake in investing accessory is included in the apparatus recom­ your time and money in this" Radio Age Model mended to the set-makers. Receiver. " Fred Hill, veteran radio amateur, writer, tech­ The complete working model of this beautiful nical editor and accomplished engineer, now con­ set will be on exhibition in the Radio Age booth ducting several important departments in the at the Fourth Annual Chicago Radio Show, technical sections of this magazine, will work Coliseum Building, whch opens on Nov. 23. with Mr. Rathbun and Mr. Pearne in produc­ See it there! This de luxe set will be given away ing the best construction article we have ever to one of the lucky fans who visit our Qooth. published.

Why The ""Radio Age Receiver" Was Designed

HE reason for thus announcing the description of a new receiver, down to the last detail, is our desire to impress upon you that this feature in the December issue will set a new Tmark in the presentation of "how-to-make" information. We publish blueprints and many other helpful illustrations in each issue of Radio Age. In the "Model Receiver" we go a step farther and offer instructions and advice in selecting parts, and we place behind this receiver the name of our magazine as evidence that it has our unqualified approval and indorsement.

To Insure Getting the December Issue, Order FroITl Your Newsdealer or Subscribe Now! RADIO AGE, Inc. 510 N. Dearborn Street Chicago, Illinois

~~~I======I~~ ~ RADIO AGE for No\"ember, 192 i 21

Some Interesting Speculation on The MAGNETIC THEORY of Radio -----_ 1.. ,.. T ranslllission

ADIO, since its hirth, has been somewhat of a mystery to the By world. Even our best ra(lio engineersR cannot accoun t for, nor explain, BEECHER many of the results obtained in radio transmission. Ther ha "e learned that under certain conditIons, or arrangement 1. of apparatus, certain results arc obtained. \Vhy or how still remains a mystery. SHERIDAN Many of the theories and laws of radIO engineering which a year or two ago were considered up-to-date and practical ha\'e been proven false or obsolete. Rad:o is making rapid strides in spite of the mystery surrounding it s trans­ mission. How are we able to transmit messages or music half wax round our globe? \\ hat pre­ vents them from being Cast into space and lost? The Heaviside theory seems to h e rather generally ac­ cepted, but at its best a great deal is left to to the i magin a tion. There is no means of proving the theory. It IS not the inten tion here to disprove tha t which is now accepted, ( but to present to the radio interested public what may he called "the magnetic theory J n the set abol'e is shou'n the prot,er arrangement of coils tl) prevent inductive coupling. Engineers of radio transmission." have made a study of the effect of the magnetic fields of adjacent coils upon each other, and efforts have been made to so place th e coils in the receiver that the effect is redlKed to a m in imum. Radio ex~ How ImpUlses Travel perience also has shown that better results are obtained in reception if th e aerial is pointing toward or HE Magnetic away from the sending station sought. This is especially true of th e loop aerial. TTheory of Radio Transmission is just what the name im­ around the coil ,'ery similar to the earth's knowinJ?ly at least, except as an aid in plies. The magnetic field surrounding magnetic field and which attracted the navigatIon or direction finding. The our earth is the medium through which compass needle in the same way within earth's magnetic field has the same our radio impulses arc transmitted. a small area surrounding the coil. Any characteristic as the field surrounding a Several hurtdrerl years ago the magnetism magnetic field constructed by man is simple coil, the north pole of which is of the earth was known, studied, and very small when compared with the ncar the north pole of t he earth and the used. Columbus, in his voyage of discov­ magnetic field of the earth, the extent south pole nearly opposite in the region ery, used a magnetic compass as an aid in of which nO One knows. \Ve do know, of the southern axis of the earth. salling his three small shiRS. In recent however, that it extends into the earth Since the advent of radio, engineers years, since the discovery of electricity, it and into the air beyond any point pene­ have made quite a studr of the effect of was learned that a current through a trated or reached hy man. This giant the magnetic fields 0 adjacent coils coil of wire created a magnetic field force has never heen used hy man, (TUn! 10 page 50) 22 RADIO AGE for November, 1925 Tile lIIaga:;ine of the Holtr On Inductit'e Radio Interference- CLEARING UP THE ETHER

Man~Made Interference a Bi g Problem in Establishing Good Radio Reception; How Sonle Scientists are Classifying Radio Bug~Bears

:\ .,\DURESS was delinred I)y comlllunication, it might seem at first the a nadian Radio Service has inter­ Prof. C. 1'1. Jansky, Jr., before thought that the operation of other ference squads continually at work. In _A the ~orth Central Electric Asso­ electric equipment could not possibly our own country, some attention has ciat ion at Duluth, recently. Prof. produce wa\"e1 engths \\ ithin the broad­ been paid to the elimination of inter­ Ja nsky, \\ ho is in charge of radio instruc­ casting ra nge. This would be true were ference by our Radio Supen"isors. How­ tion at the University of Minnesota, it not for the production of other fre­ e,'er, the Department of Commerce has is Cha irman of the Technical Committee Quencies in electrical systems by the been criticized by some for the small of the N"orthwest Radio Trade Associa­ interruption or disturbance of those amount of work which they ha,"e done t ion a nd Consulting Engineer of t he systems from one cause or another. Such on this problem, on the grounds that the Gold J\ledal Station WC CO. About interruptions or disturbances may cause Radio Act of 1912 under which Radio 300 electrical engineers attended the the generation of high frequencies, which communication is regulated docs not annual convent ion of the 1\ orth Centra l may be radiated as electro-magnetic pro,"ide for the licensing of reeeh"ing sets, Electric Association which is the N'orth­ waves at the point of genera tion, or may and therefore, the Department should west Branch of the K . E . L. A. in i\Iinne­ be ca rrie,l as electric currents along the not concern itself with anything whicJ1 sota and the Dakotas. adjacent wiring an cl radiated from other docs not directly affect transmitting sets. His address follows: points on the system. Someti mes the "It is an interesting fact, worthy of " \\"ithin the pa st ten years the public effect of the disturbance may be ac­ special emphasis, that more study of the has become tremenduously interested centuated by the fa ct that the distributed problem of inductive radio interference in a compa ratively new field of electricity capacitance and inductance of the wiring and its elimination has been done by the - ra dio communication, more particu­ may be such tha t oscilla.tory currents pri\"ately o,\'ned Electrical Public Utili­ larly radio telep hone broadcasting. This ha,"ing natural frequencies within the ties, inclh;dually and collectively, than interest has in the past a nd will continue broa dcasting bnnd exist and damped sine by any other agency. This fact is greatly t o de" elop problems affecting those wa,·es may be pror!uced at these fre­ to the credit of our public utilities and interested in the other elect rical sciences quencies. The difference het wcen radia­ is added proof of their desire to gi"e in common wit h t hose interested in ra dio tion and induction, or the question satisfactory, efficient sen'ice to the pub­ communication. Not the least of these whether or not there is a difference be­ lic. Ho\yel"er , the public utilities can­ problems is the problem of inductive t ween them will not be discussed here. not· and should not assume the entire radio interference. Incluctive radio inter­ The efiect in t he recel\'ing set is the burden of eliminating interference. ference may be defined as interference same. "I firmly belie,·e that satisfactory to radio reception resulting from the "Many assume that if electrical de­ results cannot be obtained without the operation by man of other devices, using vices or systems produce interference co-operati,"e aid of all those involved. or attended hy electrical phenomena. to ra ilio reception such devices or systems This problem concerns the power com­ "Radio communication is carried on 'arc not operating properly. \\'h.ile this panies, telephone and telegraph com­ by the aid of electro-magnetic wa ,·es. may be true in many cases there are in panies, electric rail,,·ay companies, elec­ Electro-magnetic waves arc generated common use today many electrical de­ trical and radio dealers and jobbers. by high frequency alternating Currents. ,·ices the normal operation of which will transmitting radio amateurs, and last but For the purposes of radio transmission ca use tremendous inducti,"e radio inter­ not least, broadcast listeners themselves. high frequency alternating Currents are ference. An excellent example is the I can best describe what I mean by co­ produced in the familiar antenna system sy nchronous motor driven high voltage operati,·e effort, by gi,·ing a brief des­ seen at any broadcasting sta tion. A rectifier used "\\'ith X -ray tubes. The cription of radio interference now being fixed relationship exists bet ween the sparking discharge produced in this de,"ice organized in St. Paul and l\linneapolis" frequencies of the a lternating current s will interfere ,,·ith radio reception at points "The Northwest Radio Trade Associa­ in the radiating syst em, and the wa, ·e within a radius of s e ~ · eral miles although tion is an organization of radio dealers, lengths o-f the elect ro-magnetic disturb­ the operation of the rectifier may be jobbers, manufacturers and others in­ ance prod ucecl. Since electro-magnetic entirely satisfactory from an electrical terested in radio, which has been in \\"a,·es arc identical with light waves, and a nd medica l standpoint. The a bO\'e , is existence for only t\\'o years; but in this therefore travel with the velocity of of course, an extreme example. time has grown to a point where its mem­ light, this relationship is-wavelength "Time is too short and the subject bership includes practically e,"ery radio in meters equals 299,000,000 divided by too complex to permit a more detailed dealer and jobber of importance in the the frequency in cycles per second. discussion of the sources of inducth·e North,\·est. A full time paid secreta ry "The wa"elengths used for radio radio interference. The immediate prob­ is employed to loo k: after the interests broadcasting ranged approximately from lem is the co-ordination of effort in the of its members and to help impro,"e radio 200 to 600 meters, that is; the frequencies dctermination of what in specific cases conditions generally. used to produce these \\"a,·cs range from is causing interference and its elimina­ A 'itep Forward 1,500,000 cycles per second down to tion or minimization after t he source has "TAST spring the Association under- 500,000 cycles per second. been found. In Canada every recei\'ing L took to foster "the organization of a How Frequencies Are Made set owner must pay a license fee of $2.00 Twin City Radio I nterference Com­ "SINCE the frequencies used by elec­ per year. Because of this fact, the mittee for the purpose of co-ordinating tric po""er companies and by elec­ Canadian Goyernment feels under obli­ work on radio interferences. The mem­ t rical communication companies are gation to study and eliminate radio inter­ bership ind udes representatives from much lower than those used for radio ference where,"er possible. Accordingly (Tum to pageS3) RADIO AGEfor l\ovember, 1925 The ,Magazine oj the Hour 23

Spanning the U. S. with Low,.Power 'T ransrnission A Low,Pofver Station that Anyone Can Build and \'Vhich By BRAINARD Provides Maximum Interest FOOTE

N THE days when radio amateurs longer Wines between 150 and 2UO meters ning a spark coil or in obtaining voltage used a wavelength of 200 meters are superior. through transformers from house current I the spark transmitter was the most The writer is go ing to give a brief would be much Icss effective in distance popular and almost the only t ype ·of description of a low power station he work, for the simple reason that a pure equipment. Communication over a few has set up at a Sumnler bungalow, located continuous wave, as results when bat­ miles was established with an ordinary at Stanhope, Kew Jersey. The trans­ teries are employed, consists of a steady 1 inch spark coil, and with a huge and mitting tube used is a single C 301A, strcam of impulscs at radio frequency noisy outfit comprising a 1 kilowatt lighted from a storage battery and sup­ while in A. C. use the radio frequency transformer and a rotary gap, distances plied with plate voltage by ordinary impUlses rcach a maximum periodically up to a thousand or more miles \I·ere "Heavy-Duty" "B" batteries. F ive and then decline to a low point. A pure occasionally co,·ered. such " B oo batteries were obtaincd fQr D. C. "notc" will carry much farther The application of the tube to the thc plate sourcc, making 225 volts in than an A. C. note of eYen more power sending set greatly simplified the appar­ all, but in most of thc cxperiments and on this account. All ·the stations report­ atus and reduced the power necessary communications, only three of these ing on the signals gaye a good account for a given distance. With a fi ve watt werc used, making 135 volts. Thc of the signals, stating reception as "R5 tube, the continent was spanned Once radiatcd energy is extremcly minute, to R6," meaning signals moderately in a while and the amateur had a fairly of course, but reports from stations strong or strong. .\11 seemed astonished reliable outfit for night-time DX work. within an 800 mile radius indicate that when informed that a single " :\" tube "Vith the use of short waves nowadays, such slight energy gets " out" just the on " B" batteries was being used at the down to 20 and 40 meters, low power same. At the present writing only a writer's station 3 :'.IT. tubes "cat up" thc milcs with startling single day's work is included, but the Antenna System ability, and five watt transmitters today few stations "workcd" listed bclow in­ frequently are heard one-half way round dicate that a single "A" tube ruffles THE aerial in usc is absurdly simple. the earth. the ether to an appreciable extent. .\ COun terpoise four feet above ground The five watt sending set is usually 1UE Wollaston, c3X I Sarnia, Can. consists of about 35 feet of solid wire, operated from the 110 yolt alternating Mass. 2A8.\ Kew York 1\0. 12, running between the house and current mains, obtaining both its fila­ 8DRL Reliance, City a low tree. A mast only 4 feet high ment and plate voltage from this source Ohio 8AFQ Brockport, supports one end of the antenna, while through transformers. The plate voltage 3AFT Schwenks- X. Y. the other end runs to the roof, 20 feet is best rectified to approximate a direct ville, Pa. 8 ~T Buffalo, t\. Y. away. The lead-in runs to the mast current, to improve the transmitted tOne 2CY J Hartsdale, 8CSR Portable and measures approxImately 25 feet to the and make the signals easier to "copy." ~ . Y. Station, Alliance, apparatus, making the aeriaL 45 feet 8DPL Buffalo, Ohio long in all-a single K o. 12 wire. Results Still Less Power X.Y. probably would be better Were the aerial 0 WEVER, On short wavelengths, In contemplating the use of " B" entirely vertical, running to a higher pole, 11 po"·cr Icss than that of a fh·c watt batteries for plate voltage supply, One This will be tried. tube is surprisingly successful. The might inquire as to the life of the bat­ The entire receiving and sending peeuliar thing about 20 and 40 meter teries in such use . \\·hen more than 90 hook-up is gi ven in the circuit , showing work is that waves sent out on the earth's volts is applied to the plate, the plate how the same " A" and "B" batteries surface don't get very far, being absorbed current is naturally somewhat higher serve for both purposes. The antenna by metal objects, hills, houses, wires and than in ordinary a mplifier use. How­ ~s employed with ground for reception, the like. But wa\:es which are sent ever, in C . \V. transmission, the current but with the counterpoise for trans­ upward at the proper angle are reflected IS not drawn continuouslY from the mitting. This particular outfit is oper­ by the Heaviside layer or refracted by battery, but only while the key is de­ ated on 40 meters, and the description the upper limit of the earth's atmosphere, pressed. The eiTecth·e drain On the is gh·en for this wavelength. It can as diiTerent theories haye it, and come batteries is therefore probably a good easily be applied to 20 meters or to the down to earth at distant points with

_," ,, ____ ------;o-" I ~- ANT

L- S

RFC-l

R-l

LOW POWER C.w. SYJT£H RADIO AGE for November, 1925 What the Broadcasters are Doing 25

Radio's "Prettiest Announcer"

UNE MARLOWE, a distinguished actress and dramatic reader, has been won over to radio, because, as she expresses it, "It is so vast and awe­ J inspiring." She puts such a feeling of interest in her radio presentations that her listeners acclaimed her from the start. Recently she acted as an· nouncer for an entire evening at Station KFWB. (c. Ueilthtoa :\toaroe Phot.o.) 26 RADIO AGE for Noyember. 1925 What the Broadcasters are Doing What the il Broadcasters are Doing /~

Story of KWKH an Example ( ~~) "Merry Old Chief" Fitzpatrick of Perseverance Joins WJR 0\\"~ in Shreyeport, Louisiana, in o THE "~Ierry Old Chief" is packing D the extreme Northwestern corner his bag and good cheer and moving of the State, where Texas, Arkansas and A radio editor and announcer-combi.u d. is Corley Eastward. He is leaving the Kansas Louisiana meet, there is a city called W. Kirby, of WWJ. Detroil. W,lh such a fund of City Star's station where as one of the "Shreveport. " knou·ledge. Mr. Kirby "krwws his stuff" as far as being up.to.dale j" radio matters is con cerned. Added to real pioneers he helped to put broad­ The community having for its assets that. he has an unllsually ell ar ro iu for announcing. casting on the map and during October three yery important industries, yiz ; he will join the staff of the new Jewett Oil, lumber and cotton, it is seldom con­ WRR, New Station, Opens station, \\'JR, of Detroit and Pontiac, tinued prosperity is not felt in this city Mich. for, as a rule, one commodity is ah\'ays in Dallas, Oct. 1 The "~[erry Old Chief," or Leo Fitz­ good, even if the other t \Yo are suffering ~ T RR is the municipal station of the patrick as he is known outside the radio a slight depression. . \I city of Dallas. It was first es­ Y world, has personality that has endeared Doubtless a great many of our readers tablished in 1920 and i's the second oldest itself to millions of listeners-in. To him throughout the country have heard at broadcasting station in the world and the is due the amazing growth of tha t popular various times programs from K\\'KH­ first in Texas. It was closed down by radio organization known as the r\ight­ The W. K. Henderson Iron Works & order of the Government in 1925 because hawks. There are now 250,000 of them Supply Company, Shreveport, Louisi'ana. of the obsolete equipment. and the membership keeps on growing. This station is probably the only one Thc City appropriated S6,OOO toward He organized the Nighthawks and his in the United States of America owned new equipment, while contributions from merry good nature has been the food on and operated by a concern enga ged in citizens brought t he fund up to S15,OOO. which the membership grew. the iron and steel and manufacturing ::'IIodern SOO-watt, 101 B broadcasting ~[r. Fitzpatrick is a graduate of Kan­ trade and the history of the acquisition equipment is being installed in Fair Park of this station by the W. K. Henderson in a special built building for the new sas University, a newspaperman of many years experience, and one of the best Iron Works & Supply Company provides station and two 150·foot steel towers an interesting story. are being built for the station. known radio announcers in the world. l\[r. W. K. Henderson, president of He organized the radio department of this Company-a man of large interests the K ansas City Star and has been in in his community, in addition to his con tin uous charge of the station there other acth'ities, is President of the from the time it was started four years Chamber of Commerce and, visualizing ago. He is president of the Central the great benefit in an advertising way r- States Announcers' Association. His ~ ~ ~- radio popularity is easily understood that could come to the community, be­ If ~ .. came interested in the local station 't:- when you read the following description when it was very small, of low wave­ '-.; f of the" Merry Old Chief." He wrote it length, poorly powered and under­ " himself: financed. "To begin with, I was born in Kansas The credit for the origin of radio broad­ So ,\'ere many others-Carrie Nation. casting in Shreveport must be gi"en to 'Bill' White. Henry Allen, Sockless \V. G. Patterson, \\ ho operated the sta­ Jerry Simpson and sunflowers and grass­ tion first of all with a very small set and hoppers. had for his call letters \\'GAQ. When "Early in life I became a broadcaster. this station was about to be discontinued My mother claims the distinction of for lack of proper finance, Mr. Henderson being the first Nighthawk that I kept intervened and ha"ing interested the awake until da,,'n with my howling. Hotel Youree and the Shreveport Times, "I survived the first eighteen years together with himself and Mr. Patterson, and decided that I should write the great reorganized, refinanced the station and American nO\'el or try for the O'Henry started it off on a bctter (ooting. In prize. So I took up journalism by en­ time, howe\'er, Mr. Henderson became rolling in the engineering school of the so much interested in this station and Kansas University. Finally I landed its possibilities, he decided to purchase on The Star. When I started, the Star the interest of the Hotel Youree and the had a circulation of 200,000. It has now Shreveport Times. changing the call Urbine J. Herrmann, managing direc­ more than 250,000, in spite of my being It'tters, with the authorization of the tor, and Clayton Irwin, general manager, here all the time. proper authorities, to KWKII, increas­ of the New York Radio World's Fair alld ":\Iy ambition is to get eight hours ing the wa"elength to 273 meters and lite FOllrth Annual Chicago Radio Show, sleep all at one time. Aversions-alarm increasing the power to something over to be held in November, are shown ill a clocks and hook.up fanatics. Descrip­ friendly pose above before broadcasting 500 watts and is now contemplating greetings to the radio public at the Fair i,l tion-five feet eight and one-half inches increasing the power to a great,cr I'X­ New York, .llonday, September 1-1. perpendicular; thirty-six inches circular; tent. ( P. and A. Photo ) thirty years old." RADIO AGE/or i\o\cmLer, 1925 What the Broadcasters are Doing 17 Why do They Call Him -. RADIO'S Luckiest Devil?

Luck Played No Part in Banks Kennedy's Meteoric R.ise to Fanle in the Studio World

The years w ay pass, but Ba ll k s K ell nedy still re la ~ lls th e YO/trhjttl gl o..J and dY1LU1IZic personality. OJ course, lu!l's ollly 27, but he's a "vet" as far as broadcasthrg goes. Abot'e he is shoum al the console of the mighty By HARRY ALD Il"E WOK orgall, where he officiates daily from the Terrace Garden of tire HOlel Morrisol1 , ClIicago. .

E 11.\S been dubbed "Radio's lad\', an"ious to please her youngest called upon him at the Terrace Garden Luckiest Devil," but that is son',s slightest "'him, conceded his re­ of the l-Iorrison Hotel, Chicago, where H truly a misnomer for Ranks fluest, and before he reached t he mature the glass studio of \VOK is located, Kennedy, radio staff organist at Station age of six, Hanks har! composed a song, Banks was holding true t o his hoyhood \VOK, Chicago. For if ' anyone e\'er which he .!ubhed "Et hel." by surrounding a chic ken dinner. worked to de~erye fame, it was Hanks Either the name was a handica p be­ of the silken locks. cause of its impression of tameness, or Ranks Objects Readers of R ,\DIO AGE, and espe­ Banks couldn't \\'ork up enough ent hus, DOX'T like this stuff ahout being call­ cially those who listen in on Chicago iasm, for the initial masterpiece died stations, are all fa milia r with Banks aborning and Ba nks decided to COn tent I ed • Radio's Luckiest Deyil' ," Ranks Kennedy's music, his pianologues, an.! himself with learning to play, rather than protested. "Here I\'e told the natives of his foolish monologues. He has appeare,1 learning to compose. At that time he Tuskaloosa that my success is the result over nearly eyery station of importa nce was working his way t hrough grammar of years of ha rd labor, and no\\' the news­ in Chicago, and vicinity, anfl also at a school by deli\'ering groceries at the paper writers say I'm lucky." few unimportant ones. Hut the real enormous sum of four dollars (8-1) per "I t's prohahly because )' ou work so story of his career-the story that will week, which, howe\'er, was not enough little, accomplish so much, and get paid so prove he is not lucky-but just perse\'er­ to prO\ ide for his modest needs. highly," we interjected. Hanks accepted ing, has rarely been brought to light, So Banks made it a custom to furnish a the e:l.planation and attacked another It is because Banks' admirers are so busy musical rendition with each delinry of laver of fruit cake. listening to his dynamic songs and organ groceries. The idea fun tioned better 'So, after a victorious career at the organs recitals that they neyer find the time to than he expected, and he picke.! up of the Th-oli and Capitol theaters, Banks inquire into his spotless past, consioerable small change. The reaction is no\,' back in radio's arms again, broad­ on the grocer, howeyer, was more or less casting from the organ ano the piano A Small Beginning disastrous, for the musically incline.! three times a day, ano in general spread­ Al':KS was born in Tuskaloosa, customers refused to buy groceries unless ing good cheer and apple sauce, B Alabama, where he obtained his Ban ks delh'ered them and hesita ted Once he wrote a song called" If I Can southern drawl and his love of mint long enough to play ");" arcissus" Once Arrange It," and the best explanation of juleps, It was at the age of fi,"e that he more. his phenomenal success as a song writer persuaded his mother not to throwaway With such a background of groceries, and general good fello\\' can best lIe the old grand piano, but to put it in the it is small wonder Banks never lost his expressed in one phrase-"He arrangeo basement for him to play ,,·ith. The dear lo,'e for food. "'hen our correspondent it, somehow." 28 RADIO AGEJor November, 1925 What the Broa4casters are Doing Getting the Farmer to Buy a Radio Set Only One Farmer in Forty Has a Receiver, According to Census 0/ Big Territory By A. O. PROCTOR

disclose that there are approximately When presellt set owners will buy five sets for every 200 farmers, which, another set-More than one-fourth of if it may be taken as an average, for the set owners answering this question the entire country, shows the farmer said they \\'ould buy another set soon. market is but one-fortieth saturated. The same number reported they would The report also discloses that, in the buy within less than a year, the same area surveyed, there are 1.3 dealers in one or two years, and the balance in per 1,000 families and that each dealer's four years. Evidently the replacement average sales per 1,000 families were of sets, if this data can be depended on, 18.1. is going to be a substantial business. Volume of radio businesS' done by Since iO\'estigators reported that some types of dealer~The exclusive radio dealers were already giving )'trade-in" dealer is evidently by far the most values on old sets, this factor must be successful in building up a volume of operating quite strongly now in rural business, his sales averaging very much districts. The maximum price which higher than any other class as a whole. present set owners would pay if they In towns over 10,000, hardware dealers were to buy a new set, ranged between achieve the second largest volume, but S153 and S190, complete. in towns of less than 10,000, electric Status of expos lire to radi~f the appliance dealers are substantially more 408 non-radio owning farm families successful. Practically all types of interviewed, 29 per cent had never dealers in all sizes of to\\'ns carry parts, listened in. The balance had listened accessories and tubes. Between 67 in one or more times. Twenty-three per cent and 85 per cent of their total per cent had listened in frequently. sales were in complete sets, 3 per cent Forty-six per cent reported they had to 13 per cent in parts, and 5 per cent listened in on radio sets in their own to 11 per cent in accessories. It is very or neighbors' homes. Fifty-four per interesting to note that at least 75 per cent reported they had been interviewed The American Farmer is one of the greatest cent or more of dealers in all sizes of by salesmen or had priced sets them­ -if not THE greatest factor in our national towns reported the business profitable. selves. Thirty-three per cent reported life. And yet the radio has not reached him as it should. This article tells what Guaranteed service as an aid to sales-­ that radio salesmen had visited them an e;ctensil'e surVey rel'ealed in the farmer Definite guarantees ' and assurances on in their homes. market. the part of the dealer, of sen;ce, is Wizen non-oW/lers expect . to blty­ apparently necessary and is used as a Xearly one-half. 49 per centl to be sales argument in 91 per cent of the exact. report that they anticipate buy­ ALl"ABLE information of interest sales. Forty-nine per cent of sales ing a set within the next twelve months. to radio dealers, listeners and manu­ required follow-up sen·ice. Dealers who Texas led by far in this figure, 82 per V facturers alike, h as ),een brought are most generous in making installa­ cent expressing a determination to buy to light by the recent survey of the tions and giving sen'ice ha\'e achieved this season. Ohio was lowest, about farm market for radio. made by the the largest sales volume to farm families. (Turn to page 52) Capper . Farm Publica tions. of Chicago, Ill. The area covered by the suney includes a 50-mile radius of these four towns: Lima, Ohio; ::'IIason City, Ia.; Salina, Kansas, and \Vichita Falls, Texas. What Kind of Radio Sets Do Farm Customers Demand? The most outstanding point in the PRICE REQUIREMENTS AERIAL REQUIREMENTS report of the s urvey is the discovery Per Cent Per Cent that no particular t ype of store is the Under $50...... 4.9 Outdoor...... _ ...... _ .. 82.2 leader in selling radio to the farmer. $ 50 100...... 17.8 Indoor...... 5.5 " It is difficult to determine the desir­ $100 150._ ...... : ...... 41.1 Loop...... 6.8 ability of any special type of stOre $150 200 ...... 25.2 Enclosed...... 5.5 from the standpoint of de\'eloping farm $200 250...... 6.1 KIND OF A BATTERY trade," the report say s. "On the COn ­ $250 300 ...... _ ...... _...... 4.4 Over $300...... 2.6 Per Cent trary, it seems evident that the develop­ Dry ceIL._...... 38.3 ment of farm as compared with to\,'n TUBE REQUIREMENTS Storage...... 61.7 trade depends entirely upon the dealer Per Cent PLACE OF LOUD SPEAKER himself, regardless of whether he is a 1 tube...... 2.4 music, automobile, special radio Or Per Cent 2 tubes ...... :...... 5.0 Want enclosed in set.___ ...... 29.4 hardware dealer. In other words, allY 3 tubes ...... 16.4 I y.ood dealer making an effort to sell, has 4 tubes ...... _ ...... 26.4 PLACE OF BATTERIES been about as successful in developing 5 tubes ...... : .. _ ...... 42.2 Per Cent farm trade as any other type of dealer." 6 or over...... 7.6 Want enclosed in cabinet. __ ...... 49.2 Statistics taken from the survey RADIO __-\GEfor ~o\"ember, 1925 What the Broadcasters are Doing 29 Out Where the Newsboys Sing.t

It's hardly ne"essary to teU you, but the above gleaming vi,ages belong to the newsboys' radio quartet, which is one of KNX's surprise features for the impo:nding radio season. Don't they look as though they "ould wield a lusty lung? KNX Adds "N etv s boy s' Q uar tet" As Latest Radio FeatHre; ,Ralph L. Power GilLIes Impressions of California Radiodom

ADIO fans who tune in on ~Iexican and Spanish loye songs has won been particularly applauded by fan Southern California broadcast sta­ instant applause in radio fields, and she mail and personal telephone calls, R tions wi th any degree of frequency has appeared at KHJ, Los Angeles, many Then there is Louise Santschi Katzen­ know that they can expect al most times. Special programs for the !\lexican berger, Swiss yodeler, who brings to anything from stations in and around Day of Independence and separate receiving sets everywhere the plainth'e Los Angeles. Of course, they ha ve their programs of Spanish folk songs have melodies of the Alps region. She has set musical menus via the ether wa ves, been a favorite at KF\\,B, Hollywood, in but they are always offering something solo work as well as with the Tvroler new to listeners. Zither Club, whose soft, sweet ~usic For instance, KFI has just put on a has brought as many as .J,SOO applause series of talks by Dr. William E . Bal­ cards for a single concert. The organiza­ singer, famous plastic surgeon who ma in­ tion has gathered together a unique tains offices in Chicago and Holly\\-ood. library of original melodies from their Dr- Balsinger, who was a major in the nath'e land and each program is a gem reserve during war days, is the surgeon in artistic and musical setting, who re-made Dempsey's nasal appendage :'\Irs, Katzenherger, in nat ive costume, and he told listeners-in all about the takes great delight in singing the quaint new nose, F ans had heard lectures on yodel songs and the soft lullabies brought topics ranging from dandruff to birth to us from the land across the sea, control, but ne\-er anything about how The poet laureate of the Los Angeles to acquire a new nose as fashions in police department is Sergeant Cyrus facial expressions change, Johnson, of the Hollywood station, and he is a frequent orator at K~X. As a The Newsboy Warblers pun'eyor of romantic sonnets and tales of lI E~ there is the Ne"'sboys' Quartet romance, Officer Johnson has made an Toften heard from K:;X in Holly­ en\;able record and, while he remains a wood, The yout hful vendors of news­ guardia n of the law by necessity he is a print have warbled their way into the poet at heart and radioland gains thereby. homes of thousands of radio families Duane Thompson Enters Radio everywhere and their graduation from the barber shop group to the newsboys' ~D of course you can hear any quartet could never ha\'e been accom­ A number of film and stage stars talk plished without the magic of radio. or present SOme kind of musical talent From singing on the street corner to from Southern California , transmitting their present engagements at banquets stations. and c1u hs, made possible through radio, Duane Thompson, One of filmland's was a big forward step in their lives. celebrities. has entertained from \"arious Senora Alma Real is an old time Los Angeles stations. Others who have favorite in the grand opera field and she entertained from the film colony include has made numerous personal appear­ Lew Cody, \Valter Hiers, Creighton Hale, ances in California this year, notably in Renee Adoree, Lewis Stone. l\!onte the Hollywood Bowl Concerts and at Blue, Percy Marmont, l\!arie Prevost the Theatre of the Stars at Big Bear After seeIng Duane Thompson, film star, John Bowers, Marguerite de 1a Motte. Lake, where radio KFXD is located at in this pose. we don't care whether she can Johnny Fox, Jr., Baby Peggy. Carmel an elevation of more than a mile. sing over radio or not. She appears consis­ Myers, Katherine McGuire and scores of Senora Real, '\\'ith her repertoire of lenlly at KFI-but-what were we saYing? others equally as well known,

• 30 K.. \DIO AGEjor November, 1925 What the Broadcasters are Doing The Only "Mammy" Writer Born in Dixie!

Jumping from LAW to JAZZ

It's a Long Jump, According to Charlie Garland

Charlie Garlalld appears staid and dig." ified only when posing for Plloto­ graphs like lite abot'e. You ought to see- alld hear-him when he directs ifTBB 111' s famous" Nut Club" et'ery Stmday at m idnight.

IJAI{LJE GARLA ~ D, writer of FTER graduating from high school at with WBB.i\1 in 1925 and remained there blues Clnd popular songs, radio 17 , Garland entered the Uni,'ersity since. He was appointed studio director C..A musical comedy producer, moyie of l'\'lississippi and studied law for two at \VB B l-I in June, this yeqr, and has organist, baritone and pianist . and pro­ years. He fail ed, however, to find just been made program director, gram and studio director of radio statio n romance in musty briefs, citations and In addition to his other variated \ BB~I - fife began to 100111 in his mind as an actidtiCfS, 1\lr. Garland has left a trail of That's the best introduction we can endless path of subpoenas and amended popular song hits behind him. Some of think of regarding the roung ma n in the petitions to make mOre definite and his latest are "Sweet l\lother l\Jine," horn rimmed specs and " soup and fish " certain. "'Vant a Little Love?" and "r\'lississippi \,'ho controls the goings On o,'er \\TBn:\1 's He left t he legal profession flat and Blues," the latter being the twenti.eth microphone, Tn cidentally . howel"er, it became lea der· of an orchestra known as that he ha s pu blished. may be of interest that Cha rlie is the the ' Grunwald s yncopators, indirectly The ability to sing in rich baritone, only known writer of sO'lthern melodies st arling his tlek north. After the orches­ and the nil'!lbleness of his fingers over the that ever came froOl the P ixie country , tra nlade quite a na me for itself in the piano keys, has made Charlie better Cha rlie, in fact, was born in ' Va ter south, Charlie joined the regular army known to the radio fans of the country Valier, l\liss., wh('re ma mmies are iu 1!)16, and wa s assigned to the rank of than the a verage studio or program direc­ mammies, front porches are galleries and the 155 t h Infant ry. tor. lIe docs his oll'n stuff as lI'ell as ordinary sweet potatoes are yams. In 191i he was commissioned a second directi ng others, This ,,'as in 1894 and he sta ved there lieutena nt , and after a rather e,'entful Radio Comedies, Too! until he grew up a nd was lure( i up no'th army ca reer he was discharged, and de­ IS latest C{Jntribution to radio is a by a jazz band. cided to give the business world another If it hadn't he en for the jazz hanel, whirl. This time he tried selling life H series of radio musical comedies howel"er, he might have been a lawyer. insu rance. The "whirl" was short. "'hich he is writing to be put on the air o ver ' VBBM. The productions--each Despite the fact that he could read Tn 1919 he married j\liss Lela 1Ilercier, 45 minutes long-will be adapted espe­ music before he knell' his ABC's, and of \-rcComh, i\ liss., and came to Chicago cially to microphone effects and be "pro­ could play thro piano when he sta rted to where he took up moyie organ work. duced" O,'er ' VBBl\!. school at the age of eight, in what, e,'en He gained considerable reputation at this Garland, incidentally, is the instigator the neighbors admitted, was an entertain­ and in 1921 heard the call of the radio. of an interesting experiment being carried ing way, the fu ture that was plan ncd for After appearing over KY \V and several out o\-er WB B M - a newly inaugurated him called for Blackstone and a lot of hi m. other local stations he became connected rule that the program must be 95 per­ cent musical and entertainment. "The rule means just what it says," DO VOU WANT SPEECHES OR MUSIC? said Charlie. "Basing our actions on the RADIO AGE wants to know whether its readers agree with Charlie requests and written desires of fans we Garland, Program Director of WBBM, in his contention that radio programs are barring all lengthy "educational" should be at least 9S per cent musical. talks and addresses. Anything in the If you agree with Mr. Garland, or take exception to his views, you can line of talks that go on over Our "mike" use the pag~s of RADIO AGE to air your ideas. Just send us your viewpoint must be short and snappy, in the nature and we'll pnnt the best arguments--pro and con-in an early issue. of 'spot' information or authoritative Which shall it be-Music or Speeches-jazz or farm talks--edueational opinions voiced by nationally aes:epted or amusing discourses? Take your pen in hand NOW and start the sparks a-f1yingl authorities. " Garland's hobbies are golf and swim­ ming and a young son. RADIO AGE for Kovember, 1925 Whut the Broadcasters are Doing 31 Are Y ou Temperamental?

Radio Stars~ More Than Any Other Class of Public Entertainer s~ Are The Hardest to Handle

SAYS GEORGE GRAHAM Of all radio stars, Raque{ Nieto, coloratura radio soprano, has a right to be temperamental,for it is her temperament that makes her performance un­ usual-different, and refreshing,

E~IPERAl\IEKT! It is the bug­ bear of the stage-the movies­ T business-and e\'ery\\"here that high happening nightly in radio studios \\'here excuse for ha ving a fiery, passionate strung personalities can be found. But tact does not prevail. :\nnounce rs and expression in her musical renditions. nowhere is it more evident, mOre harder directors are known to he among the \ \'ithout tempera men t, her songs " 'ould to cope with, as Willis Arnold used to "transient" class of employment, for be listless, uninteresting and mechanical. say-than in this intricate game of radio they possess an uncanny ability to lose And directors and announcers cater to broadcasting. their positions with amazing rapidity; her whims-for she is really a great David Belasco can dismiss the tem­ chiefly because,of their untimely remarks artist-by giving her soft lights, soft peramental actress who refuses to put to the tender feelings of artists who music-an absence of spectators, and a the proper fire in the soul-kiss bestowed think they are good and will never be general atmosphere of refinement and On the Barrymore playing opposite her; convinced that they aren't. quiet. It takes very little elIort o n the or Griffith can always get another cinema One of the best examples of handling part of the station-and it makes performer to take the place of the sulking temperament can be seen in the case of ~l1Ie. i'ieto feel at home. Valentino. And even in the best adver­ l'.liss Raquel l\ieto, coloratura soprano "If a few more announcers would tising agencies, those outstanding exam­ with the Chicago Opera Company, the adopt the policy of broad-mindedness in ples of business efficiency, the long-haired San Carlos Opera Company, and others. handling artists, there ","ould be less copy writers find themselves perusing She appears over nearly all the ,,'estern flareups and broken-up programs," ac­ the want-ad columns following an un,,'ise radiophones, such as KFI, KGO, KXX, cording to Pat Barnes,announcer-director burst of temperamental disagreement. KOA, WBAP and others too numerous of WHT. "These artists are furnishing Radio Stars Can't Be Bossed to mention. And because the facts of free programs, so the best the station her temperament have heen broadcast can do is to cater to their temperaments." ADIO entertainers, however, can do far and wide, directors of the stations Pat Barnes, more than any other an­ R as they please. There are enough where she appears are forewarned of her nouncer, perhaps, has known what it is of them to sink a good Sized ship, and coming and treat her accordinglY-"'hich to be temperamental, and it is this yet each is so confident of finding a is successfully. common bond of feeling that causes him place to broadcast his or her wares, that Miss :-\ieto is not purposely tempera­ to sympathize with temperamental artists the slightest provocation on the part of mental, such as the majority of self­ and treat them as they should he treated. the studio director causes a sudden styled radio stars. She gained her "Temperament is usually inborn or flareup and an equally sudden departure temperament by birth, as you will unconsciously assumed," Pat explained. on the part of the "hurt" artist. As a discern by her French-Italian name. and it should be handled as a malady and result, a studio director, careless with his Unusual as it may seem, she considers her not as a disgusting condition. I have comment, might find himself atthe begin­ temperament as a valuable asset, for, tried to follow that policy in arranging ning of a three-hours' program with noth­ as she pu 's it, she "really means" the my artists, and I am proud to say that ing but the staff acc~mpanist on hand. words of a song when she aims them at temperamental outbursts are a thing of It has been known to happen, and it is the microphone. Temperament is her the past at our station." 32 RADIO AGE/or November, 1925 What the Broadcasters are Doill :~ A Real T ask Confronts Mr. Hoover

Annual ,Radio Confab to be Called this W in- ter Must Over ... ride Industry's Obstacles BY CARL H. BUTMAN

HE remarkal.lc growth 01 radio who gi,-es u" l,ctLer prograllls and bet ler broadcasters, and e,'en the staff of thl during the past fiv e years was ql1ality of transmission, and is the ob­ Department of Commerce deserve somt T eulogized by Secretary of Com­ ject eff the manufacturers of receiving credit. merce Herbert Hooyer last month, sets tha t t hey SllO lil d give more reliable But whether the listener pays directl~ when he spoke through Stations \YRC, and more perfect reception. I t is the or indirectly or not at all, it is the listenel \ JZand \YGY, in conjunction with the object of the Department of ComDlerce, in the American home who is the founda· :'Il'ational Radio Exposition in 1\ew York. which has t he very difficult job of keep­ tion and furnishes the support for th« During the course of his talk Secretary ing the traffic la nes clear so that the whole industry. For if he relaxes or hi! Hooyer announced he would probably "oice over the radio may reach the lis­ interest fails, the whole radio structun call the Fourth Annual Radio Confer­ tener. It is, therefore, the listener in "viII fall as quickly as it has grown. ence some time during November. He whom "e a re primarily interested, not In the course of another month I admitted he ,,-as fully aware of the im­ only as a n industry bllt as a I,ublic serv­ am summoning the Fourth Annual portance of the problems confronting ice. There is no industry so dependent Radio Conference in Washington, t he Conference, and urged the American upon pu.hlic good will and interest. I in which all elements-the listeners, radio public to pay a patriotic interest tak~ it that it is in realization of the fact the manufacturer, the broadcasters, in the outcome of t he Conference. and the '\'ish to demonstrate the efficiency the radio press, the distributor and The high-lights of Mr. I1oover's ad­ of the service, both prescnt and to come. the government-wi)] come around ,Irf':ss follow : Kow, it is often said that the' listener in a common table for the fourth time Radio-Its Influence and Growth the United States recei ves an e;'(traor­ to discuss t he mutual problems of dinar), sen-ice without pay ing for it. this industry. This is the only in­ Radio has already hecome so imhedded This is not entirely true, for he pays in­ dustry where everybody agrees that in American life that we forget that the directly for some of it. Rut in t he fash­ there must be regulation. Without developm ent o f this. great scientific ion we have ueyeloped the org-a nization regulation we should have complete discovery is but fi "e years 0 Id. Five of radio in t he lTnited States the listener chaos in the air. And as every word years ago we had not a single broadcast­ is f rec fro nt any direct charge for pro­ by radio is an interstate performance ing station. Toua)r ,vc have o yer 572 grams- And in this we uifier fWIll the we cannot avoid Federal regulation. stations and probably 6,000,000 homes methods of foreign countries who seek to Attempt to regulate rigidly by law with receidng sets. Five ears ago the support broadcasting by tax on the without the cooperation of the indus­ total expenditure in the industry was listener. A few rears ago llluch anxiety try and the public would, I believe, less than a million dollars for the year. was expressed that we could not main­ stifle progress. And thiS m~nner of It will prohably exceed $400,000,000 tain goo!1 programs of entertainment and regulation by which all parties sit in this year. the delivery of puhlic information wit 11- for solution of problems is unique I do not I,elieye any other generation in Ollt de" ising some s),stem of tax upon the in our relations of government and history has had the privilege of witness­ listeners. l.t has heen Illy a spilat ion that industry. ing t he progress from birth to adoles­ we should keep the hOllle free from con­ U. S. Leads Them All 'cence of a discovery so profoundly stant annoyance of any attempt to assess affecting the social and economic life the cost of broadcasting upon each re­ ,\'11E are far in advance of all other of the peoples of the world. You who ceiving instrument. And I have believed ,, \ countries and I feel it has been ill attended your first radio expositions that the industry would de\-elop far large nleasure due to the cooperation four years ago, and who have the privi­ more rapidly in this llIatter than if we worked out in these conferences. But lege of being present again tonight, can pursued the Ellfopean pla n. But be­ with the fine cooperation which we haye see marvelous advances in t he art. 1\0 yond this, support by taxation means a developed we have done something new other im'ention in all time inyadeu tile limited number of government controlled in the whole development of relations home so rapidly and intrenched itself broaocast ing slat ions, and therefore nluch between the industry a t large and the so securely as radio, and though it is less variety of program, much lcss com­ public. still far from mat Hrity, we see g-reat pet iti ve en dea vor to please t he listener We still haye plent y of unsol "ed advances every year. E,'ery year brings and above all constant dangers of Cen­ problems. The numLer of radio channels additional scientific discovery, and there sorship. is limited. They are already so oyer­ follows uIJo n it new invention and new crowded that there is little room for the application to sen'ice. Your annual I am today confident in the annOunCe­ ment t hat our policy, that there shall be new comers. They jostle each other a expositions serve as milestones to dis­ good deal. More legislat ion for solution close these advances. on the air evel-Y broadcasting stat ion for which there is an available channel and of our. difficulties is ,being frequently Service is the Keynote that the cost shall be borne indirectly ' suggested ' !lnd we must SOOner or lat~r VERY radio activity exists finally or by puhlic .service institutions, has determine the major. issue whether we-WIll E.:..A and lastly to serve the listening proved far. and away the most successful. continue to a1lO\~ eyery new broadcasting public. The keystone of the industry is and has finally settled our policies for all station access to radio paths or whether to maintain their interest ' by service. time. It is a great accomplishment and ei,'ery applicant entering must firs t show That is the motive of the hroadcastel' one for which the manufacturers. the' {turn /(1 page 52) R.-\DIO .-\GEfor No ven~her, 1925 The JIIL ,!!uzhle of th e Hour 33

More Selecrivity, Less Losses, by Adding Radio Frequency Stages By JOHN B. RATHBUN

HERE are a number of advantages Copyright: 1925 the amplifier is at the plate connection obtained in adding one Or two steps (P) which goes t'O the succeeding portions T of radio frequency amplification to a of the circuit. detector tube outside of simply increasing R. F. Addz'tz'on Wz'll With short aerials a loading coil the sensitivity and distance gett ing (LC) will be necessary to bring the q ualities of the set. In the first place, H l S S l system up to broadcasting wavelengths. t he addition of one or two stages of R. F . e p uppress quea s Generally about 20 turns of wire on a amplification increases the selectivity of a three·inch tube will be sufficient. This receiver without introducing additional causes no losses as there can be no leak- losses as is the case with the average age to ground through the distributed wave-trap or auxiliary tuner. Secondly, magnify the weak antenna impulses capacity. the radio frequency stages act like check before they reach the detector tube so The principal advantage of this sort valves and prevent the detector tube that the detector can more effectively of radio freq uency amplification lies in oscillations from passing out to the aerial, rectify the incoming impulses. In other the fact that all of the energy collected thus suppressing the emission of annoy- words, the output of the radio frequency by the antenna is led directly to the grid ing waves and squeals in a neighboring tube forms a second aerial in which the of the tube where it is amplified without receiving set. Thirdly, the great degree radio waves are much stronger than in loss, and this is of the greatest importance of amplification attained by the radio the true antenna, and with the detector when working very weak distant stations. stages permits the use of a loop aerial ~ onnected to the radio frequency output The customary losses due to the tuning or else a very short indoor aerial In place it is evident that stronger signals can be inductances, tuning condensers, etc., are of the more common outdoor "Hat top" obtained at the detector, that is, up to eliminated with the result that radio type. the saturation point of the tuLe. Radio frequency amplification is at a maximum. Radio frequency amplification can be frequency amplification very greatly 1\ considerable amount of radio fre- applied to any sort of a detectqr, a cryst al increases the signal strength of weak dis- quency energy is dissipated' by leakage, detector or vacuum tube detector of either istant stations, but has very much .less losses th rough the distributed capacity of the regenerative or non-regenerative effect in amplifying strong signals from the coil winding, and by other paths order, and to each of these detector types local stations for the reason that the when a tuning unit is used between the it imparts the virtues of sensitiVIty, R. F. tubes reach their saturation point antenna and t he tube, hence by the selectivity, and reduced radiation from very quickly with even moderately strong aperiodic stage we conserve every bit the antenna. It should be noted, how- incoming waves, and therefore, any of the precious energy for amplification. ever, that the del'lree of selectivity varies further increase of the antenna impulse The output of the tube is tuned·. to 'Wave­ with the properties of the detector cir- strength will have no effect on the detec- length, and the undesired waves are re- cuit, the selectivity being the least with a tor output. jected after this amplification takes crystal detector and at a maximum with a A PeriodiC R. F. Stage place, hence with less loss and better regenerative detector just as with the distance than can be attained in any detectors themselves when used direct ONE of the simplest radio frequency' other way. connected to the antenna in the usual stages employed is· the .. Aperiodic ' By means of the coupler or air-core way. With a crystal detector, very loose or "Untuned" type of stal'le shown in transformer (CPLR) in Fig. 2, the first coupling is req uired to obtain satisfactory Fig. 1 of the Bl ueprint SectIOn. In this radio frequency stage can be tuned to selectivity, and the same is true of the case, the radio frequency tube (RFl), is the desired wavelength in the usual non-oscillating type sodion tubes and connected directly to the antenna and manner , thus attaining selectivity from diode tubes. Regeneration in either the ground with the grid (G) going to the the start. The primary c('il (P) is con­ detector or the radio frequency tubes antenna without any attempt at tuning. connected to the antenna (ANT) at very greatly increases the selective When connected in this way, all wave- One end and to the ground at the other, properties of the circuit, and when more len~ths are amplified indiscriminently only a few turns of wire being employed than one radio frequency stage is em- within the range of the circuit' constants in this coil so that the lower wavelengths ployed, it may cause excessively sharp and the selectivity of the stage of course will pass through as easily as the long tuning and so critical adjustment that is zero. All tuning controls must be waves. By placing (P) in inductive the set is difficult to handle. included in the following radio stages, relation to the secondary coil (S), radio In regard to 'sensitivity, the effect of if any, or in the detector circuit which frequency currents are induced in the the ra~ io frequency tubes is to amplify or follows the tube (RF1). The output of (Turn to page 36) .~~.;, . Original Blueprints on Radio Frequency Stages on Pages 34, 35, 38 and 39

.,. 36 RAD IO AGE for November, 1925 The Magazil1e of the Hour ( Con tinued from page 33) (P2) is electrically independent of the secondary ci rcuit which correspond ex­ secondary coil (S2). If the primary is act ly to t hose in the antenna and primary THE RADIO AGE connected with the secondary in any way, coil , a nd from the coupler the impulses RECEIVER then there is likely to be a short circuit are led to the grid of the tube (G) where through the "B" batteries and this means t hey are amplified and then pass out The surprise of the seasonl trouble. Carefully examine the tuner­ through the plate (P) to the following coupler of the regenerative circuit that After months of research, RADIO you intend to use for the detector to see circuit. AGE is offering its own set-any­ whether the primary coil is isolated from A variable condenser (C) is connected one can built it, and it will positive­ the rest of the circuit, for in many cases across the secondary (S) to tune the radio ly give you the results it claims. you will find a short connection between circuit to the required wavelength. The the primary (P2) and secondary (S2) selectivity or sharpness of this adjust­ Fully illustrated by additional blue­ prints by John B . RathbUn-All as at (X) which must be removed before ment depends largely upon the degree of going further. "Coupling" existing between the two Parts specified by trade names- At (GC ) is the grid condenser and at coils (P) and (S); that is, the distance in between the coils and the percentage of (GL) is the ~ rid leak which need not be inductive effect resulting from this DECEMBER RADIO AGE tampered WIth as a rule, although in­ separation. With the coils close together, creasing the value of the leak (GL) is the tuning is "broader" and the set is not ON THE STANDS sometimes advisable in order to secure so selective as when the coils are separat­ stronger signals. Leaks having a re­ ed by a greater distance. For example, NOVEMBER 15 sistance higher than 1.0 megohm are with coil (P) within 1-8 inch of coil (S) seldom used in straight regenerative it may require 20 dial divisions or more to circuits alone, as higher values increase tune out a station, but when the coils are the tendency toward antenna radiations, separated by 1-2 inch or more, the same handling the variable condenser and but when a stage of radio is added in station can be completely and sharply usually increases the amplification. front of the detector, this can be increased tuned out by turning the dial through to 2.0 megohms with improved si~nal By connecting the output (0) to the strength and with no danger of radiatIon. only a small fraction of a dial division. (ANT) ,Post of a detector set, in which This adjustment must be made care­ I ndependent filament rheostats for the a t"'o-clrcuit coupler is employed, and radio freqtJency stage at (Rl) and for fully so that the set \\"ill he sufficiently connecting in the "B" battery to the selective and yet· not unfiuly sharp or the detector at (R2) must be used as the ground post of the detector circuit as in­ detector rheostat adjustment is much critical. dicated by the dotted lines, the stage of Primary coil (P) may consist of from more critical than that of the R. F . tube, radio frequency can be added to a regen­ particularly when a fixed tickler coil is six to ten turns of No. 24 D. C . C. copper erative set with good results. The wire wound on a three inch cardboard used. The old rheostat used in the coupler of the detector set must be of the detector circuit should not be changed. or bakelite tube. The secondary coil two-circuit type with a primary coil (S) has about 55 turns of the same size electrically separated from t he secondary. Plate voltages depend upon conditions. wire, and is separated approximately 1-2 Special arrangements will be required For the radio' frequency tube (RF1) a inch or 5-8 inch from the end of the with single circuit detectors as we must "B" battery voltage o f 45, 67.5 or 90 primary coil. This coil is tuned through avoid making any connections likely to volts can be used, but with ordinary the range of broadcasting wavelengths cause circuits in the "B" battery line. apparatus 45 volts on the R. F. tube is by a 0.00035 mf. variable condenser (C) This amplification cannot be used with generally best for bringing in distance. connected across the secondary coil as ultra-audions in the form shown nor with "B" battery potentials of 67.5 and 90 shown. There are other and more similar circuits of the single circuit type. volts may give stronger signals on local efficient coils than this on the market, stations or stations at a moderate dis­ but the dimensions aho"ve will give data With One Stage of Radio tance but this does not necessarily indi­ for a home built coil that will give fair THE application of one stage of radio cate that these voltages are best for results. ' frequency amplifications to an exist- distance. Further, high voltages make A potentiometer (PO) is shown con- iog regenerative receiver is shown more the set more critical, more difficult to nected across the " A" battery circuit clearly in the completed diagram of Fig. tune and noisier, so that we should use with its sliding member or contactor (s) 3. In order to make a more prominent the lowest possible voltage that will connected to the lower end of the coil distinction between the radio frequency "bring in the stuff." and variable condenser, but this is not circuit and the regenerative detector Usually, the detector tube (DET) always includ'ed in all radio frequency circuit to which the radio stage has been works best on 22.5 volts of " B" battery, amplifiers. Its ' purpose is to vary the added, the radio frequency amplifier the voltage being obtained by tapping the potential or voltage on t he grid of the circuit is drawn in heavy full lines while "B" battery as at (t). Convenient tube so that regeneration can" be con- the original detector circuit is drawn in taps are provided on most ~' B tt batteries trolled in the first tube and hence forms a dotted lines. The radio frequency circuit so that this voltage control can be easily means of eliminating howling or mushed- is as before with its plate output post at made. In any event, the detector volt­ up indistinct reception when the regenera- (0), the "B" battery connection posts at age should not be higher than 45 volts. tion is excessive. l\loving (s) upwards ( +B), and the " A" battery leads at A full 90 volts will be required for the toward (-A) causesanincreasing negative. (-A) and (+A). There are now two audio frequency stages, if any, so that potential on the grid of the tuhe which wavelength tuni!lg controls, the radio almost any combination of voltages for t ends to reduce regeneration and to sup- frequency condenser (CI) and the origin­ the R. F. and detector tubes can be press free oscillations and howling. al detector condenser (C 2) which of carried out experimentally up to 90 volts :\loving (s) toward (+A) givesan increas- course adds greatly to the selectivity of without purchasing unnecessary equip­ ing positive potential on the grid and the circuits. Audio amplifying stages ment. increases the sensitivity by allowing in- can be added at the detector output It will be noted that the tuner unit of creased regeneration. There are other marked "Phones" but they are not the regenerative detector circuit now methods of control but this has the virtue shown as they would add needlessly to becomes a radio frequency transformer of slmplicity and ease of operation and the complication in describing the radio having a primary coil (P2) and a second­ installation. frequency end of the circuit. ary (52). A radio frequency transformer A fixed condenser (K) varying from As will be seen, this regenerative detec- of the air-core type can be substituted 0.0005 mf. to 0.006 mf. is connected tor circuit at the right is of the two for the tuner unit if provision is al5.o between the slider and the ( -A) wire of cIrcuit coupled type with the addition made for the ticler coil. Some form of the potentiometer to reduce the inductive of a third coil (TICK) known as the coupling must always exist between the effect of a wire wound potentiometer. "Tickler" used for regeneration in the output of the R. F . tube and the detector It bypasses the radio frequency current detector stage. The primary coil is at which will prevent the plate current (0) across the windings of the potentiometer (P2) and the. secondary at (S2), all three from being directly connected to the so that the potentiometer does not upset coils being coupled inductively in the grid of the following detector tube. the tuning adjustments every time tha~ usual .. manner. In some receivers, the If the " B" hlittery potential is applied it is moved. This is not necessary wh.h tickler coil (TIC K) is adjustable from to the detector tube in any way, It will carbon-pile potentiometers or similar the. front of the panel so that the plate give such a strong positive bias that the types where coil windings are not used. ' t oupJing can be varied by turning a dial, tube will be inoperative or paralyzed as A ground connection (G) running from while in other receivers the tickler coil long as the voltage continues. In the the (-A) line to ground is always an ad- is wound in fixed relation to the other case of single circuit regeneratives, it is vantage and is: sometimes an absolute coils. However, this makes no differ­ usually necessary to use a 0.0005 stopping necessity. It greatly red uces any ten.- ence in the connection of the radio fre­ condenser between the plate of the dency toward body capacity effect in quency stage as long as the primary coil R. F. ann the detector tubes, or in other RADIO AGE for No\,emuer, 1925 The lvlagazine of the Hour 37 cases to connect the outer end of the in the old location in fron t of the detector grid leak to the (+A) line instead of tube. Phones or an audio amplifier can leaving it in the position shown by Fig. SOMETHING TO BE be connected at the output of the detec­ 3. However, nothing of this sort is re­ PROUD OF! tor and the "B" battery is shown tapped quired in Fig. 2 where the plate and at t he point (t) to obtain 22.5 volts for 'grid circuits are effectually separated by the detector tube although the full 45 -is the Radio Age Receiver, to volts can aillo he ulled lluccessfully with the air space between coils. be described in detail for our In cases where a potentiometer is not the majority of tubes nOw on the market. readers in the December issue, out The output is cleaner and the set is more desirable, and when other means of con­ November 15. Illustrated with trolling self-oscillations have been em­ stable when 22.5 is employed on the clear blueprints by John B. Rath­ detector plate, but the vol ume is greater ployed, the wiring in the diagram can bun. be altered so that the (-A) line at (a) on weak signals with 45 volts. For the is connected directly to the grid-return A tuned r. f. receiver with all the radio frequency tube (RFl) a p!ate line at (b). This places a negative bias latest improvements in the radio potential of 45 volts generally gIves on the first tube which tends to suppress art. better distance reception while 67.5 to self-oscillations but which may interfere 90 volts givcs better volume on locals and THE LAST WORD in Radio Engi­ modera tc distances. with the sensitivity to some extent by neering- a set that will last for the reduction of regeneration. By adding two radio frequency. stagcs years. instead of one, much better dIstance Re~enerative Radio Frequency Further particulars on page 20, getting qualities are obtained and the set Circuit this issue. is made more selective because of the greater number of tuning c0!ltrols. By applying the regenerative principle This is the arrangement adopted In the to the radio freq uency circuit, a very popular five tube radio frequency receiv­ much greater amplification can be ob­ ers having two radio frequency stages, Extended Detector Re~eneration tained with correspondingly greater sen­ detector, and two audio frequency stages, sitivity and distance getting qualities. OTH radio frequency and audio fre­ the latter being for the purpose of gain­ There is as much difference between a B quency currents exist in the plate ing loud speaker volume. Adding radio regenerative and non-regenerative radio circuit of the detector tube, and on pass­ frequency stages does not greatly increase frequency circuit as there is hetween a ing through the tube the radio frequency the sound :volume and audio amplifica­ regenerative and non-regenerative detec­ currents are highly amplified. In one tion is usually necessary with any num~er tor. The radio wave from the antenna' very effective radio frequency circuit of radio frequency tubes except WIth receives amplification by the manner the plate current from the detector tube rather strong locals. already explained, and the amplifier out­ is led to a tickler located in the first Fig. 7 shows two stages of radio fre­ put of the tube is then returned to the stage coupler so that radio frequency quency added to a non-regenerative grid circuit where the strengthened im­ regeneration is obtained together with detector circuit, the coupling point of the pulse is again impressed on the tube some audio frequency feed-back. The radio and 'detector circuits being at the resulting in a second and greater ampli­ radio frequency tube is not regenerative line (X - X) and indicated by the small fication . The radio frequency waves are within itself as shown by the two pre­ circles representing binding posts be­ greatly intensified before they pass to ceding diagrams. tween the additional stages and the old the detector for rectification. A typical circuit of this sort is shown set. At (1) and (2) are the two radio A straight tickler (inductive) feed­ by Fig. 6 where the radio frequency tube freq uency tubes con trolled by One rheo­ back can be applied to the radio stages is located at (RF1) and the detector at stat (R1). The detector tube is shown al as in Fig. 4, where (P1) is the primary (DET). Plate current from the detector (DET) with the usual grid condenser of the antenna coupler, (51) is the second­ is led foward to the tickler (TICK) (GC ) of 0.00025 mr. capacity and the 2 ary coil of the coupler and (TICK) is above the secondary (51) of the coupler megohm grid leak (GL). This tube is the tickler coil feeding plate current back and is arranged so that regeneration is controlled by the rheostat (R2), acting to the seeondary. Plate current also controlled by turning the tickler in rela­ independently of the R. F . tube rheostat passes through the transformer primary tion to the other coils. This circuit is and also independently of the rheostat (P2) through which the radio stage is very efficient and is highly recommended used for the audio frequency tubes when inductively coupled to the succeeding where one stage of radio freq uency is an audio stage is used. (Not shown in Fig. detector or to a second stage of radio to be added to a regenerative set or for a 7.) frequency. When the tickler coil (TICK) new regenerative set. A single circuit coupler (CPLR) is is adjustable in regard to the other coils A radio frequency transformer (RFT) used for tuning the antenna circuit to a very close control of the regeneration couples the radio frequency circuit to the wavelength instead of the more usual can be had, an d when it is excessi ve detector with the primary (P2) in the two circuit coupler shown up to this through any means, the direction of the plate circuit of (RF1) and the secondary point. I t consists of a single coil of wire coil can be suppressed so that opposing (52) connected to the detector. ThIS connected at the grid (G) and (F) ends, or "negati ve feed-back" is had which transformer can be of the fixed self­ tapped at (a) and (b) for the connection suppresses the free oscillations in the tuned type or else the typical tuned air­ to the antenna. By connecting at (b) circuit. With an adjustable tickler, the core type can be employed with the as shown, a very selective condition is potentiometer (PO) is omitted, and variable condenser (C2) shown in dotted had while connection further up the coil direct connection is made between the lines. An iron-core (untuned) radio near the grid end at (a) broadens the (-A) line at (a) and the grid return frequency transformer is desirable at tuning for locations where there is not line at (b). this point and avoids the use of a second much local interference. A single circuit With a fixed tickler coil wound directty tuning control when a high degree of coupler in the first stage has a n umber of on the same tube with the other two coils, selectivity is not required. Where there advantages when three tuning controls no such feed-back control is possible, is a great deal of local interference, a are used. hence some other means of. oscillation tuned transformer with the condenser (1) The circuit is more stable and is less control is employed-generallY by the (C Z) may become necessary. likely to break into self-oscillations combined adjustments of the rheostat A potentiometer (PO) with the fixed than with a two circuit coupler. (R) and the potentiometer (PO). bypass condenser (K) affords a means of (2) When very selective tratuformers are oscillation cont rol, and it will be noted used, tlte use of the single ci rcuit Much closer control of the oscillations that both tubes are provided with inde­ coupler eliminates the split-hair is had by the revamped "\\'eagent" re­ pendent rheostats (Rl) and (R2) for di al adjustments and the sharp generative circuit of Fig. 5 where a tap the individual 'control of the tubes. peaking of resonance that so greatly (t) divides the secondary coil (51) into The conventional 0.00025 mr. grid COn­ interferes with tlte receptioll of dis­ a tuner and a tickler coil. Plate current denser (GC) and the 2 meg. leak (GL) tant statioll s. is fed back into the lower end of (51) are employed as before, care being taken (3) There is less loss with the singl~ cir­ through the small variable condenser to connect the filament end of the second­ cuit type, since the gri d Of the tube (C2) while the variable 'condenser (Cl) ary (52) to the (+A) line so that there is directly con Ilected to the antelllla, tunes the system to wavelength as before. is a positive bias on the grid of the detec­ and di stallce is obtailled more con­ Regeneration is very accurately con­ tor. sistently. In adapting this circuit to an existing A 0.00035 mr. variable condenser is trolled by condenser (C2) which regulates regenerative set, it will of course be neces­ connected across the coupler as with the the feed-back 1:0 the grid circuit. Tap sary to mOve the coupler and tickler of secondary of the two circuit coil, and a (t) COnnects with the ( -A) line so that a the regenerative circuit to its new position potentiometer (PO) provides the grid negative grid potential is impressed at all in front of the radio frequency tube potential variation necessary for the times, and in effect this IS the grid return (RF1). The radio frequency transformer control of self-oscillations and the regen- circuit as well . (RFT) is then substituted for the coupler (Tum to paKe 40)

I

40 RADIO AGE f or NO\'emIJer, Ins The Magazine of the Hour

( Continued from pa~ e 37) distance of the station is increased so that antenna, the adjustment is fixed for that eration. Across t he slider of the poten­ the s?eaker is not practical without audio particular locality and no further change tiometer a nd t he ( -A) line is a 0.005 m£. amplification at distances much greater IS needed at this point. The tubes are 3 fixed bypass condenser and from the than 50 miles. It seems hardly necessary inches in diameter. inner end of this condenser is the ground to describe the audio stages in detail at Straight-line-wa ve-length or straight­ li ne (g) which connects the (-A~ line this point for they have been published line-frequency condensers add much to to ground. This first stage is coupled to time and time again in the blueprint the ease of tuning, especially in bringing the second radio frequency stage by section of Radio Age as well as in other in stations in the 200 meter band of wa ve­ means of the radio frequency transformer portions of the book. lengths. There is more space between . (R FT 1) with the primary coil (P1) in the While the detector tube (DET) is such stations when measured on the cir­ plate circuit of the first tube and the shown connected up as a non-regenerative cumference of the dials, and their is . seconda ry (S1 ) going to the grid circuit yet no changes are introduced into the more opportunity of tuning stations out of the second radio tube (2). The circuit if it is supplied with a tickler coil that lie within a few meters of each other. secondary may be tuned by the 0.00035 mounted in inductive relation to the Vernier type dials capable of very close mf. variable condenser (C2) when the secondary coil (S2), as shown in the adjustments are now almost a necessity. transformer is of the tuned air-core right hand dotted portion of Fig. 3. Either the 20lA type of tube Or the t ype, or this condenser can be omitted This introduces another control, but if a "199" can be used successfully, but the with the self-tuned air-core or iron core fixed untuned transformer is used at storage battery tube 201A gives the transformers often used with radio (RFT2) in place of a tuned transformer, maximum results. Being used for radio frequency additions in this sOrt. Iron we will still have three controls and the frequency amplification they are not · core transformers reduce the number of set can be easily tuned in and operated. particularly critical to filament· current controls and only slightly reduce the With a movable tickler coil, the detector and can be used with fixed resistances of efficiency of the stages. tube will no longer he so critical to fila­ the amperite type in. place of the rheo­ When two stages of radio frequency ment current control which will simplify stats. a mplification are added to an existing matters by allowing the use of fixed regenerative circuit, the number of tuning resistances at all points in place of the Twenty Grand Opera Stars controls is likely to be inconveniently rheostats. Three Amperites (one at large unless the iron-core untuned radio each tube) will entirely eliminate rheo­ On the Air frequency transformers are used in at static control, and in this way.the.intro­ Radio fans throughout the United least one stage, and this is particularly duction of the tickler adjustment V:'ill States are now able to tune in regularly the case where the detector circuit is of effect an actual saving in the number of on some twenty grand opera stars and the regenerative type with a tickler con­ controls. orchestras of international note through trol and t wo variable condensers. Furth­ Complete Two Stage R . F. Unit arrangements made by A. Atwater Kent er, the small fixed untuned transformers with a New York mUSical bureau con­ take up less room and the radio frequency ~ FIG. 8 is a picture diagram of a trolling these artists and the American cabinet can be of smaller dimensions than I complete two stage radio frequency Telephone and Telegraph Co. when tuned air-core transformers with amplifier adapted for use with a d etector Starting on Sunday night, October 4th, t heir variahle condensers are mounted unit. This is the same circuit as that in WEAF and a chain of the affiliated on the panel. With a good iron-core Fig. 7 with the exception that the detector stations put the first of this series of high­ transformer there is not much less in tube is omitted, and for the convenience class concerts on the air at 9':15 p.m. a mplification, but the circuit must have of the reader, both drawings are lettered Eastern Standard Time. The appearance at least three tuning controls (including and numbered the same so that the rela­ of these concert artists, all well known those in the detector circuit); for the tion of the parts can be easily followed. internationally, will continue every Sun­ necessary selectivit y. It is arranged in a separate cabinet ready day night from WEAF, New York during The output of the second radio fre­ for connection to an existing circuit by the present radio season. It is also hoped q uency tube (2 ) is coupled to the detector means of output and battery posts that many will sing and play from other tube ' (DET) through the second radio marked at the left of the set. These stations located farther west and south, frequency transformer (RFT2) which posts correspond to the posts in Fig. 7 a little later in the year. may be either a tuned or untuned type. shown along the line (X - X). It is Mr. Kent's idea to demonstrate If tuned, then the secondary (S2) is Both the coupler (CPLR) and the for the radio fans what can be done t uned by the 0.00035 mf. variable con­ first radio frequency transfo'rmer (RFT1) toward better radio programs, being the denser (C3), and if untuned, this variable are tuned by the two variable condensers first step of the general movement toward condenser 'is omitted. Note that the (C1) and (Cl), both condensers having a a greater radio season, and perhaps con­ grid leak a nd grid condenser are con­ capacity of 0.00035 mf. The se<:ond tinuous radio service for the listeners nected into circuit just as with the fore- : transformer (RFT2) is an untuned type, throughout the country. ~oing circuits, and that the detector tube iron core preferred. which couples to the The list of artists already signed up, IS fed with 22.5 "olt " B" battery current detector tube in the following unit. No many of whom will appear on early as before explained . From 45 to 67.5 condenser is ' used with this transformer. Sunday night programs, is as follows: volts is preferable for the radio tubes While the potentiometer (PO) is used for Louise Homer, contralto; Mabel GarriSOJl, ' (1 ) and (2) rather than 90 volts. the control of the oscillations in .the radio Soprano; Frieda Hempel, Soprano; Maria Great stability can be added to this frequency stages and as shown on the Kurenko, Soprano of Russia; Florence circuit when all tra nsformers are of the drawing, it will be possible to use one -Austral. soprano of Covent Garden, air-core tuned t ype by the use of grid neutralizing condenser con nected to the London ; Julda Lashanska, soprano; Anna neutralizing condensers shown in dotted first tube (1) in place of the potentio­ Case, soprano of the Metropolitan Opera lines at (NC), and the circuit is also meter. l\ly advice is, to use the poten­ Company; Reinald Werrenrath, baritone; much q uieter when t he tubes are neutral­ tiometer at least for a while, unless you Edward Johnson, tenor of the Metropoli­ ized in t his manner. As will be seen from are rather skilled in adj usting neutralized tan Opera Company; Albert Spalding, Fig. 7, the neutralizing condensers are circuits. violinist; Alexander Brailowsky, pianist; connected hetween the grids of the radio There are many ready-made com­ the London String Quartet, England; the ~re qu e n cy tubes a nd suitable taps (N) mercial coils' more suitable for use than State Symphony Orchestra of New York, In t he transformer secondaries. When the solenoid types shown at (C PLR) and and Paul Althouse and Arthur Middleton the grids are neutralized , the potentio­ (RFTl) but these low-loss coils cannot of the Metropolitan Opera Company. meter (PO) is no longer necessary and be easily made at home. E xamples of Other artists who will be heard on the after it is removed, t he grid ret urn line these coils will be found in the advertise­ air provided permission for broadcasting is closed b y c o n nec t in~ the (-A) at (e) ments of the makers. However, for the can be secured include the following: to the ground line at (d). Owing to the benefit of those that prefer to "roll their Subject to permission from the Victor high resistance of unt uned radio fre­ own," the dimensions of the coils are Talking MachIne Company; Mme. Ernes­ quency tra nsformers a nd t he d amping shown in Fig. 8. They are wound with tine Schumann-Heink, Cecilia Hansen, influence of the resistance on self-oscilla­ No. 26 D. C. C. or No. H D. C. c., with Margaret l\fatzenauer, Olga Samaroff, tions, it is not necessary to use neutraliz­ eight t urns on the primary and 55 turns Emilio de Gorgoza, Kathryn Meisle, ·of ing condensers when these transformers On the secondary of transformer (RFTl). the Chicago Civic Opera Company and are in the circuit. The coupler (C PLR) is a continuous coil Giannini, of Europe. The output of the detector tube ca n tapped at the 16th turn (b) and also at Those subject to the Brunswick go to the phones, or else to t he input of a the 30th turn (a). These tapping points Company, are Joseph Hofmann, world's two stage audio frequency amplifier will generally give a sufficient range of greatest pianist; Allen McQuhae and "'hen loud speaker operation is desired selectivity under ordinary conditions, Mario Chamlee. on distant stations. Connecting a loud but there is no reason why more taps Subject to permission of the Metropoli­ speaker to the output of the circuit shown cannot be provided-say at every tenth tan Opera Company are Lucrezia Bori, will give soft low volumes with local turn or so. When once the proper tap Merle Alcock, Joan Ruth, and) Marion stations but this soon falls off as the point is found for the connection of the Telva. RADIO AGE for NO\'emuer, 1925 The Magazine of the Hour 41

The World's Largest Exclusive Radio Mail Order House WiD Send You This Wonderful Book FREE 64 illustrated pages containing thousands of bargains in radio sets. semi-finished sets and radio kits of all styles. sizes and approved cir· cuits. 5 tube complete sets as low as $29.50. Beautiful models of the very latest designs and types. Elaborate console models with loud speakers built right into cabi. nets of genuine mahogany and walnut. ALL SETS GUARANTEED. Coast to coast receiving range. Catalogue also contains everything in radio supplies, including batteries, chargers, loud speakers, transformers, condensers, rheostats and any other parts you may want for improving your 6et or building a new one. Guaranteed saving to you of YJ to lh. The Biggest 5-Tube Value on the Market Positively the world's greatest 5 tube radio bargain. REGULAR $75.00 VALUE. Our large Quantity production enables us to sell this set for ONLY $29.50, fully built and wired in beautiful mahogany cabinet of latest design with 910ping Bakelite panel of Satin finish, handsomely etched and engraved as iIIus. trated. Constructed of the finest low·losscondensprs. coils and IIOCkets. bakelite baseboard. panel and dials. PRICE FOR $29 50 SET ONLY. . . . • . • . • . • • - Transportation charges extra. shipping weight 25 pounds. This Set with All Accessories, Including The Famous American BeU Loud Speaker with adjustable unit, 2-45 volt "B" batteries. one guaranteed 100 Ampere Hou r storage "A" baltery, cable for battery connection, 5-20lA tubes. Aerial and ground equipment. and everything comy!ete ready to set up and operate. Nothing else to buy. PRICE '5915 Transportation charges extra. Shipping weigbt 100 pounds. - Complete instructions with set. • • • • • , •

·rect From This Page' Sa~e Y3 to Yz. Our guarantee protects YO!!. Money cheerfully refunded if you are not Order D. • ~atlsfied Wrtte your order and pnces plamly. Send post offlc\. money order or bank draft for full amount to insure safety. Refer to any bank or c.>mmerclal agency regarding our reliability. RADIO FREQUENCY Semi-Finished 5-Tube RECEIVING SET Semi -Finished 8 -Tube Super - Heterodyne

World's famous 8·tu['e Complete Parts for Best's 4S This special offer is aSloulldillg the radio world. Coast to coa,st re­ Super- Heterodyne Kilocycle S u pe r- Heterodyne ce ptioll 011 loud s peaker. ~w los! cOlldensers a!,~ sockets. HI ghest Fully mounted on panel and base- Genuine Remler Parts Quali tv transfonners. Bakelite rhe o st at ~ . All wmll" conc .. aled under board. These pictures show inte. basc b~a.rd. 7,.18 panel fits into .mr standard "'18 cabinet. Complete in· rior set and how it looks wben $4950 struction! for operating. G UA RANTE ED SAVING TO enclosed in cabinet. Comes com· _ YOU OF 560.00. Price of eet all mounted. Not wired, SI8 15 pletely assembled ready to wire Cabinet of same model as American Radynola - and operate. We have testimonials pictured above $S.6S extra - • • - • from thousands of builders of thi9 Yon moat have our catalog nO matter what l et or kit you want. Our line ia eom-­ set. Some Have Received Foreign Station!! on Loop Aerial. pleteand inclDdes all popular sets. 8u~b all S"perhet.rod~ne. Neutrodyne, Ultra- Unsurpassed' in "olume and tone Quality. L",,··loss strah"ht Jihe frequency couden:.. effl. ver nier dl1ih. finest qualih' rbOO''1 tut... . AIAtcher! Columbia. lOll!; wave :rbne~·)~:!~aC~~ J~~atG~la:!~:·a~~~:;~'!.~~lac~~;dnbnyg~r~~~ ~~~ ~~~ traosfonntrs, ReqUlrM ODI )' t hree s crew. for atta ching PADCl and ha..~flboArd ft. od eet faerorers a~b all Fro.t, Howard, Baldwin, Brllndes, Weatern Electric, Co- is relldy t.o operllte. 7,.30 panel. Price of eet only. Reaui,ea following aceesaories to complete tbia set. 7 .. S0 'um8~~ =j~~ia~d Bets come witb all parts 1Il0DDted on panel and b..... boanl ready cabinet, 8·201A tubes for storage battery operation or 199tubea $43 forwiriDg. Do not f aJI tOBendfor onrcatalo~ . Remember-we are tbe largeBt.excln· 15 Biveradio maHorder dealers in tbe world and carry tbe beetofeverytbin.g in radiO. WB ~~l~rl.B~l'b!t~!!~~ioigos :er:re~ ~eO:t~;ti::~db~~r~e;~5. -- save YOU 1-3 to 1-2 OD tb. followlDg" kIts. D.tailed descrlptloD appear IDour catalo.r. Ali tbeae ltemg are hated inourcataIog at. tremendous Baving. NEUTRODYNE COCKADAY BROWNING AMBASSADOR Gennine LieenBed NentrodYDe ULTRA·AUDION OUR CATALOG kIt of P"",, come fnlly a.. _ · 3-tube Cockaday kit of DRAKE bled on the panel and ba.'tt­ parts. fully assembled W:~~~b"of ~.z:~AU~~ry 3-tube Liu wire receiv- includes complete list of board witb complelA> IDstraeo onpanel and baseboard. 4-tube complete low. as.sembled and reali, to er-<:omplete parts broadcasting stations and ' t10na r eady to wire ready to wire loss parts wIre. witb laatractioDO general infonnation and $29.75 $15.85 $32.40 $6.35 $19.95 facts about our free ser· vice division. Our radio OUR GUARANTEE engineers will help you solve ' Every article exactly as rep­ resented. Every article is tes­ RANDOLPH RADIO CORPORATION a II your radio problems. ted befDre shipping. Com· Send your name and address plete satisfaction or money on a card or in a letter. cheerfully refunded. 159 N. Union Ave. Dept. 94 Chicago, Illinois We will send catalog FREL 42 RADIO AGE f or November, 1925 The Magazine of the Hour Latest Models Displayed at Chicago Radio Show

HE radio industry has offered an abundance of new receivers and other apparatus for the season 1925- T 26. Many of these have been displayed at the National Radio Expositions in Chicago and New York, during the past month, and at the Radio H'o';';'.:. Fatr in New York. Now comes another show to be held during the month of November at thp. Coli~eum in Chicago. Even more developments and improve­ ments will be shoum at this show, and a few of the latest to be introduced to the radio public are shown on this page.

HE 1JeW "Apex" Super­ T Five, with built-in loud speaker, is attracting allention at recent shows. It is tll6 product oj the A pex Electric Company oj Chicago and is but one oj their many interest­ ing models Jor this season.

or lIE "Miraco" Ultra-5 Re­ or HE LogudYlle Big Five, i ceiver, a product oj the 1 made by the Kodel Radio Midwest Radio Corporation oj Corporation Of Cincinnati, is Cillcillnati, Ohio, combines the a high type tUlled radio fre­ latest innovation Of engraving quency receiver, ell closed in an tire dial readillgs 011 the panel. Adam Brown mahogany cabinet With "man-size" dials and of massive proportions. The attractil'e general appeara nce, stations are already logged, this receiver presents an idea and the panel is of tire sloping of the new trend in rereiver l'ariety, l'1If,!TflI'ed in gold on design. Form ir.a.

ilE Diana "Big TSix" com e s in many shapes and sizes, but the console model .\' response to show" at the right, I rea d e r s' re­ llJith its attractive cab- . quests, further pic­ inet for bal/eries, elc. , tures and descrip~ Iras proven the most tions oj new re­ popular. Wlren closed ceivers 10 be intro­ the enlire receiver has duced at the Chi­ lire aspect of a dig­ cago Radio Show nified piece Of fllr­ will be published niture, and wlren open, in the Show Section as shown in t/ze photo, of the December il harmollizes with any Radio Age, Ollt No­ surroulldings. l'ember 15. RADIO AGEfoT November, 1925 The 11lagazi l1e of th e 110llr .J.3

THE material appearing under tbe title "Pickup. and Hookup. by OW' Readen" in RADIO AGE, i. contributed by our readen. It i. a department wherein oW' readers e",change vieW!! on various cir· cuit. and the con.truction and operation thereof. Many times our readen disagree on technical point., and it should be understood that RADIO AGE i. not re.pon.ible for the view. pre.ented berein by con· tributors, but publi.bes the letters aDd drawing. merely a. a mean. of permitting the faD. to know wba t the other fellow i. doing and thinking.

Conducted by Fred Hill. F one were to judge from a casual perusal of the radio and trade CONTRIBUTORS I magazines, it would appear that the doughnut coil, the form of winding old C. M. Thomas ...... Freight Traffic Dept. Nand W. as the hills in the telephone game, but Ry ...... Roanoke, Va. its radio application. fairly new, is at­ tracting quite a bit of attention from a W. G. Bailey...... 1315 Davenport Road ...... Toronto, Can. host of manufacturers. Quite a number Robt. A. DeVries ...... 1l4 8th Ave ...... New York City of the sets advertised for the 1925-1926 market are announced as being equipped H. J. Hughes ...... 2082 East Grand Blvd ...... Detroit, Mich. with the doughnut coils, although travel­ ing under many different names. A. W. SmalL...... 1210 12th St., N. W ...... Washington, D. C. The single or double control also seems to be getting some attention and efforts Paul M. Hayes ...... _. __ ...... Pasadena, Calif. are made by the manufacturers to ar­ range the tuni ng units so that single DIAL TWISTERS control will work out smoothly and accurately along the waveband covered Floyd E. Morris...... Fort Saskatchewan...... Alberta, Canada by the different type of receivers. All of which seems to indicate that radio fans Wm. F. Lauritzen ...... 275 Highland Ave...... Somerville, Mass. cannot be far from wrong in following Frank Scudello...... 83 Bay 44 St...... Brooklyn, N. Y. out this general plan, at least for the sake of greater simplicity in tuning and George B. Jones, Jr. 75 Maiden Lane ...... New York City the greater selectivity afforded by the inductances with enclosed fields. In our August Pickups and Hookups we de­ tailed the description given by George This can be done with a hacksaw by secondary all the way around the dough­ B. Hostetter, Box 325, Freewater, Ore., placing the tube on a board and nailing nut and give coupling. The process of a simple means of making the toroid a strip at both ends that passes through related above may be repeated as often coil. the length of the tube, to hold it down on as necessary to give the number of dough­ Now comes H. J. Hughes, of 2082 the bench while cutting and also prevents nuts required. East Grand Blvd., Detroit, Mich., who the tube frolll binding on the saw. elsewhere in these pages, presents a sketch After slotting the tube, drill and tap Another r. f. unit to be added ahead of and a description of the method in which two 6-32 holes in it to hold the wire. a standard receiver (providing the pri­ he makes his doughnut coils. A reading Tie one end of the wire to the screw and mary and secondary coils of the old set of Mr. Hughes' description and that of start winding your coil clockwise, fasten­ are thoroughly isolated) may be made Mr. Hostetter will probably prove very ing the other end to the other screw. from the diagram shown in this depart­ enlightening to the radio fan who wants Before winding, take the clips C and CC, ment, Fig. 1, and submitted by Robert to take a fling at the doughnut coil shown in Fig. 3, and solder them at A. DeVries, 114 8th Ave., New York construction. either end of the tube over the slot, City, N. Y. L 1 consists of 45 turns of Readers of this department might find keeping the slot three-eighths of an inch 22 DCC spaced 5-8 inch from L 2 and interesting dope in the September blue­ apart. wound on a three inch tube. L 1 con­ print section where Mr. Rathbun gives After winding the seconda ry, which sists of 15 turns of the same sized wire. audio amplifying circuits, both trans­ consists of about 225 turns of 1'\0. 22 L 3 is made up of 60 turns of 22 DCC, former and resistance coupled. Then DSC or DCC wire,and the primary, which tapped at the fifteenth, thirtieth and 45th in the October number he shows the ismadeof20turnsof the same wire wound turn, on a three inch tube. The variable single and double controlling of doughnut over the secondary, unsolder the clips, across Ll is a .0005 mfd., Rl is 30 ohms. tuning units. Taking a composite of take out the screws and press in at both R2 is a variable resistance. The two the September and October numbers of ends of the tu be to release the coil. posts at the extreme right of Fig. 1 RADIO AGE, the reader should be able Take a piece of adhesive tape 5-16 inch should go to the aerial and ground posts to fix up a dandy receiver that will follow wide and bind it over the coil through the of the old set. (Be sure the primary of more or less the latest practice in radio slot. Then bring the coil around, fasten the old set is not in any way connected manufact ure. the ends and the job is finished. The coil to the secondary.) The A battery con­ Il!ay be treated with a little airplane nections may be carried over to the old The data given by H. J. Hughes, varnish, although untreated will do set so the two units function off the referred to above, for winding doughnut just as well. same A and R batteries. coils, follows: Procure a piece of one In winding the primary it should be and an eighth inch brass tubing ten wound in four groups of five turns, as W. G. Bailey, 1315 Davenport Road, inches long. Cut a slot its full length, shown as the places marked X in Fig. 3. Toronto, Canada, who smashed his slot to measure three-eighths of an inch. This is so the primary will follow the collar· bone and has been laid up all 4-1 RA DIO XGE for :\m·ember. 192:' Tlte Magazine of the Hour neighbors say things entirely un-holy. \\'ould suggest YOll publish these con­ tribution diagrams as to the changing 1 ~3 sets so they won't radiate. There are 1.- \ many such plans now published." {~O!} Mr. Thomas then tells of adding 0 a r. f. unit to his receiver with an in­ C 1 crease of a bout 25 per cent in efficiency. ~ The department this month has a scheme 0 A for making your own r. f. unit; we have also published these ideas from time to time, but it is a Herculean task to con­ vert the ..... orld from a single to a loosely coupled circuit. If you don't believe it, o 6- tr~ it on your friends.

Radio fans who are troubled with e maciated signals in the last stage of their amplifier, or else who are bothered - A +- with an overloaded last stage, might do well to tryout the Radio Corporation's Fig. 1. , n this r. J. IlIIit. co go ahead of a regular u t. submitted by Robert A . De\ ries. latest tube, known as the UX-112 which 11-1 8th Ave., N ew York City. N . Y .. readers may fin d a solution to their lI~orri es about is designed for use in the last stage of the lack of signals. T he variable resistance in ser ies with a tal!ped plate. cot! allows th e audio and which will probably be equiva­ control of the plate potential and helps prevent undue regeneratIVe effects ITl the first tube. lent, in results secured. to two of the The description is given elsewhere in this department . 201-A type. The tube has an oxide fila merit , dull emitter type, and cer­ Summer as a result, sends in the dope of any of our radio family has eyer juggled tainly does pep up your signals wonder­ shown in Fig. 2 which is a loosely coupled the fil a ments of a I,urned out tul,e fully. We ha ,'e noted that the Daven regenerative set, using the \Veagant around while same was hooked to a 110 Radio Corp., has also placed a tube de­ variant for control of regeneration and vol t line. \Ve'll sa y we did, sometimes signed for last stage work on the market, oscillation. The primary coil consists disastrously and sometimes ot herwise. being known as the l\IU6. The use of a of 10 turns of No. 24 DSC. The secon­ Best way is to hook it to your battery good power tube in the last stage gener­ dary is a straight winding of 60 turns of and then lightly tap the burned out allY recompenses the owner for his t he same sized wire, with a center ta p tube agai nst your pa lm. If you are trOll hie, in increased Yoillme. at the 30th turn, which goes to the lucky YOll might have a new' tube; fi lament. The wavelength control is the otherwise t rot down to the store and Several fans ha \'e written t his depart­ capacity from end to end of the coil plunk down your hard earned kale for ment lately for a good soldering flux to and is a .0005 variable. The regeneration anot her glass hau hie. he used with rosin core solder. Our control which runs from the lower e nd method is to ta ke aJ,out a half glass of of the secondary to the plate of the tube, Wow-listen to this one. Its fronl C. grain alcohol and dissolve into it enough is a three plate vernier condenser. The 1\1. Thomas, Freight Traftic IJepartment, powdered rosin to make a watery paste. tube used is a \VD-ll. The entire set N . and W. Ry., Roanoke, Va., who Use this paste 011 join ts to be soldered, may be made up into porta hie form and relates as follows: "Read your magazine just a little dot of the stuff being enough. furnishes good results under normal regularly and must say it is the best It will clean the joint well, and when ,the conditions. The grid condenser is .00025 monthly on the m arket wi t h .no excep­ iron is well tinned and ho t, the soldering and the leak, 3 megohms. tions. It has mOre in it than all the rot job can be made a thing of beauty in­ of its class nOw sold. I've been reading stead of an awkward lump. Use wire Pardon us, gentle readers, but we li ke your pages regularly and notic.c most of rosin core solder. For the meticulous to see letters like the following. and to t he hookups a re single circuit rr the li ke solderer. a wet rag will help to wipe off thin k we have deserved them; " Desire t hat squea l fearful1 ~ ' a nd make the (Turn to page 4fi) to t hank you for back numbers sent me due to various changes of address. You have without a doubt the finest puhlica ­ tion in the radio field and I am part icu­ larly pleased not to ha"e missed any of the numbers." The ,niter was George B. Jones, Jr., 7S l\Iaiden Lane, New York City, N. Y. I"' · . Using the one lunger known as a single control, single tube set Frank Scudello, 83 Ba y 44 St., Brooklyn, N. Y., manages to pull in 'the signals de~pite the Summer­ time and the high power nest in New York.

Rosary-like, " The hours I spent with thee" is applied uy William F. Lauritzen, Somen·ilIe, io. lass., to the pursuit of the wily DX ·with the result that his one tuber has kept him hopping from ethereal pillar to post. His list is a staggering one and would entitled him to the button even if for no other reason than the amount of energy spent in compiling it. F ig. 2. Another variant of the \\"eagant sent in by W'. C. Bailey, 1315 Davenport Road, Toronto. Canada, who uses \¥'D-11 tubes and gets good results. Many of the Albert W. Small. 12111 12th St., !\. Canadians use th e dry cell type of tube on account of their economy and the portability W. Washington, D. C . rises to· inquire of the set. T he description of the CirCllit is found in these pages. RADIO AGE for November, 1925 The jlagazille of Ihe flour 45

Ilr=-1J ~e lInitedJ/chievement o./:Jen Radio engineers

HE DIFFERENCE in this receiver is no mere superficial T difference. It is a distinction that you yourself and thousands of others made in discussing the "ideal Receiver." The Hammar­ lund-Roberts is a "composite receiver," the individual achieve­ ments of ten leading radio engineers, Every unit in the Hammarlund-Roberts Receiver represents the highest attainment of a leading engineer. The transformers were selected by a transformer engineer familiar with every reliable make, after months of experiment and trial. The condensers were similarly determined on by an engineer whose special study has been condenser characteristics, functions and construction. A man whose whole effort has been on resistance research and perfection selected the resistance units. Even the smallest, usually neglected units, were made the object of scrutinizing study. Never before * has so much extraordinary thought been given to every detail of a receiver. This combination of these harmonizing units in the most desirable circuit is a receiver that is truly the ultimate of five-tube reception, a composite of the higher ideals in radio. }.MPERlr£ And now- you can obtain this remarkable Hammarlund-Roberts Receiver Ml'rl by Rarliall Co. for LESS than the price of any factory made 5·tube receiver on the market of anywhere near equal quality. WIite for descriptive folder. Hammar/und Roberts, 1182-D Broadway. N , Y. RHOa~arIUnd) /~~~~~ Interna!ional K 0 e rts /~, ,:.~~~~ Re!istance Co. "Durham Resistors" ~======L ~'1. = Alden Manufacturin~ Co. IFOUNDATION UNIT CONSTRUCTION BOOK ~~ Hammarlund Mfg . Co. The skeleton or foundation for your HAMMAR-. .:::y Carter Radio Co. LUND.ROBERTS RECEIVER- bakelite panel, Write for this most complete book Westinghouse Micarta engraved: drilled bakelite . sub·panel, brackets giving complete details on assembling, wiring and wiring. The other spcclfied parts are stand· and operating the Hammarlund· 2Sc ard and can be purchased from any $9 40 reliable radio dealer -- -- . • Roberts Receiver -- - - ?

:(. Tested and Approved bfl RADIO AGE :(. 46 RADIO AGE jur ~o\'cmber, 1925 The Magazine oj the H()UT

• ~C ,I.. :I:::::,., I Ce .... , I I t • 1::::.: 1 l , Slot " ~ "III ,.' ~ .. ~ 'I'ltll,' .. t t

~ /f/-

F ig. 3. Th~ sk~tch sh"wn ub"w IS jurnlsh~.l by 11. J. Ilughes and shows th~ manner oj winding a doughnut coil. H 'is the end IMW. Full .lata is given in the text in this department. This data and that published in the August number should enable any oj our readers to go into the subject thoroughly.

the joints after being soldered so no 1-2 meg and 1-4 meg for the grid biasing. no longer entitled to protection so t'he traces of rosin will remain. Generally the experimenter wiII arrive at invention may be used by all. The his own conclusions regarding the values patent situation is one of the most com­ Resistance coupled enthusiasts will to be used. The use of a C battery in the plex ones in existence and the fact the find a world of opportunity for experi­ last stage is generally advisable in order radio game has gone into the billions mentation in the use of various values of to bring the plate curren t val ue down to merely makes the situation more intri­ leak resistances for the first, second and a reasonable figure. The biasing of the cate, involving vast sums of money to third stages of their resistance coupled first and second stages is not absolutely determine the worth of a contested amplifier. For this purpose a handy necessary. though it may be done. The patent. But we still need a good static clip scheme may be employed, the clips use of a small milliammeter in series with eliminator or suppressor, so there is hope being secured in sets from radio dealers. each plate as you advance across the in the hearts of the experimenters re­ The clip idea may be used for the coup­ amplifier will readily tell you the B gardless of the trials and tribulations of ling condenser between the plate of one battery current being used by each tube. the inventor in search for adequate and tube and the grid of the next, the value This milliammeter may be rigged up with complete protection generally used being .006 mfd. Almost clips on a couple of wires so it may be any of the square condensers will slip clipped into any of the plate dircuits of IVlusically inclined fans might like to firmly into the clips. Then for the re­ the amplifier and you readily tell what make a windless. pipeless, pipe organ. sistances there are clips into which you your plates are pulling. Too great a such as is described in this issue by J. C. can put any desired value of resistor. battery drain in the plate circuit is Jensen. \Ve have had several requests The use of a bypass across the first 100,- neither desirable nor economical. from readers for an audio oscillator .and 000 ohm plate resistor is advisable and t he article by Mr. Jensen fills the bill for this purpose another clip may be After looking over patent papers completely, we believe. used. Thus the. whole affair can be granted by the U. S. Patent Office during changed in value at will and wit.hout the the past few months we are convinced Work on short waves proves more and necessity of unscrewing binding posts or more than ever that the large companies more the fact that eventually radio unsoldering lugs. The scheme is a handy in the radio combine are busy getting communication will be governed by one and should prove of real benefit to protection on everything that human wavelength for the various purposes de­ the insatiable radio tinkerer. We ob­ ingenuity can devise. Judging from past sired. For example a 5 meter set is hard serve that Daven specifies 100,000 ohms performances there will be a number of to hear across a city, or even a limited for each of the plate resistors in the resis­ battles-royal to finally determine the distance, yet it will put an awful signal tance coupled amplifier. while the grid priority of certain ones, especially some into the ears of a listener a thousand biasing resistors are one megohm. 1-.2 and of the patent applications made to cover miles away. So you may expect to see 1-4 meg for the grids. Others have found schemes that have been in use for years the longer waves used for the local or that one megohm in the first. a half in but not actually protected by the inven­ short distance communication and the the second and a quarter megohm in tor. In these cases it seems the judges shorter waves to drop your message into the third tube will work well.- Rathbun, take the attitude that if the original the lap of a listener at a distance without in his' recent contribution on resistance patentee has neglected to protect himself local interference. The study of short coupled amplifiers. showed the. 1 meg, for any length of time in the past, he is waves is quite interesting. RADIO AGE for November, 1925 The J[agazine of the Holtr 47

7henewAMSCO ALLOCATING CONDENSER (STRAIGHT LINE FREQUENCY)

PREADS tbe stations evenly S around the dial according to their frequency in kilo-cycles. Eliminates the crowding on low waves and simplifies tuning_ And unlike previous S. L. F. de.­ signs, its "half·a-heart" rotor plates save space in the cabinet. Three sizes-single or Siamese. 1henewAMSCO VERNIER DIAL

AS easily installed as an ordi­ n nary dial-and as easily ma­ nipulated. But-each turn of the dial is translated to 1/13th the motion-giving finesse to your fingers. A precision instrument, without momentum or back-lash. There is no vernier like it for dis. tance-getting. Low in price. 7lielllwAMSCO RHEOSTATS AND POTENTIO:METERS OTHING saves tubes and N batteries like correctly de­ signed, electrically efficient resist· ance instruments in the radio circuit. Stromberg-Carlson, Freed· Eise­ mann, Priess Radio and other builders of the highest type re.­ ceivers have selected AMSCO. It will pay to investigate. Ask your dealer or write to the makers:

AMSCO PRODUCTS,Inc.Dept. P Broome and Lafayette Sts., N. Y. City Makns of the Me/co S"",.eme Radio Rec:ei"e1'

• T ..t.cl aM Appro".cl bll RADIO AGE #10 48 RADIO AGE Jor l\ovember, 1925 The Magazine oj the Hour Reducing Electrical Interference RADIO recepti'on in some localities is seriously disturbed by interference arising from electrical apparatus in the Save vicinity. The only general remedy for electrical interference is cooperative effort, on the part of users of radio and owners Your of the electrical source's disturbance, to reduce or eliminate the causes of trouble, the Bureau of Standards points out. Tubes :VI uch of the work in reducing electrical interference also results in an improve­ ment in the operation of the electrical Don't bum them higher than devices or supply lines and is thus a the manufacturer's rated volt­ double gain. There are, however, some electrical devices which, even when in age: If you bum them too perfect working order, cause disturbances low you lose volumn. resulting in interference with radio reception. But in many cases it is Use a Jewell High Resist­ possible to provide filters, shields, chokes, etc., either at the source of disturbance ance Volt Meter on Panel of or at the receiving set, which do much to your set and be safe. If you relieve the difficulties. own a Radiola Portable Su­ A frequent cause of interference IS the presence of alternating-current power per-Heterodyne get our No, lines near the antenna or receiving set. 109 Voltmeter Panel. Low-frequency voltages (usually 60 cycles are induced and the resultant current (Ask for our 15-B Radio flowing in the receiving circuit causes a Catalog) "Humming" sound in the telephone receivers. A method of eliminating or at least reducing this interference is to place Jewell Electrical Instrument Co. the antenna as far as possible from the 1650 Walnut St. Chicago lines and at right angles to them. When the interference can not be eliminated by "26 Years Making Good Instruments" such means, the choice of a receiVing set may help. An inductively-coupled (two­ circuit) receiving ..set may help. An inductively-coupled (two-circuit) receiv­ with the exclusive ing set is less susceptive to such inter­ Straight Line Frequency conDerlible feature ference than a single-circuit set. The use of one or more stages of radio-frequency The Crest is the only AdaptBble amplification should also help to filter out to ANY condenser which is Circuit the audio-frequency interference. It has convertible from 23 been suggested tnat audio-frequency plates down to 2 interference might be shunted Clround a * receiving set having a series antenna plates; which is adap­ condenser by connecting between the table to any circuit; antenna and ground terminals of the set and which assists ex­ a high resistance, which wiII offer lower perimentation with impedance to the audio frequency than short wave tuners i iui will the receivirig set itself. transmitters. Sparks are produced in the normal operation of many types of electrical apparatus such as motors, doorbells, Crest Convertible Condenser buzzers, gasoline engines, x-ray app;Lratus, Th. following Usls w"e made alld a Ppro\,td and the Quality and precision of workmanship violet-ray machines, some forms of by the Armour ]"st;lule and Popular Radio is guaranteed. battery charges, rural telephone ringers, Laboralory. If dealer cannot supply rou. send your order Maximum capacity (with 23 plates) .0005 direct to us with hIS namE'. Mcney refunded heating pad thermostats. They are also Minimum capacity (with 13 plates) .O()(lOO6 if not satisfactory. sometimes produced at defective insula­ Set manufacturers who wish to improve their Ohmic resistance .18 ohm above laboratory sets should write for details and special proposi­ tors, transformers etc., of electric wire standard.; due to special construction. t ion. Dealers and jobbers who have not The Crest is made of solid brass throughout. lines. investigated are im'ited to do so. One remedy for such types of inter­ 23 PLATE $5.00 ference is to eliminate the spark. This is Nickel Silver Finish will ?Iel'er corrode , pOSSIble if the spark is an electrical leak and not necessary to the operation of the CREST RADIO CORPORATION SN. ~'1c~COAVE. I machine in which it occurs. Many very useful electrical machines, however, re­ quire for their operation the making and Your Set w ill be on all the latest breaking of electrical circuits while they Standard RadIO Loud and Clear SAVE M erchandise are carrying current and whenever this with Our 1926 Beautifully happens a spark is produced. It is im­ Illustrated Catalog­ FLINT TRAN~~8A~ERS JUST OFF THE PRESS possible to eliminate these machines, so Ruah 70ur Game aDd ad.. it is necessary to make the spark of such From Jour Deal., or direct dre~ aad tet I:'I.J~D ·FLINT RADIO CO. LOC BOOK FREE nature or so arrange the circuits that the 1872 WilBon Ave. Chicago £CONOMY RADIO SALES COMPANY radio-frequency current is reduced or 288 61h Are., OtPI. C. Nt" York. N. Y. prevented from radiating, :to Tut.a a.a A"prolled by RADIO AGE THE·. P H R F E C T. ~ U N ION .• 0 F ART AND SCIENCE

. &;; ~.. . ,~'\.: DE fOREST AUDION Is tbe world otandard In tubes. De For",,! rrcalro tbe lI",t ouooesslul radio tubr.. Dnd hi. invention mBde broadcasl1ng possIble. The De }o'orest 1l0ilOY 01 /'. slledllo type tube (or eBoh .oeket ID9ur~ tlner recePtion and """"'... r distance. Prlet!.S3.

DE FOREST F-5 A W A oompact. I>Owerlu loet In I>OUshed walnut that will bring JOY to II\l1ny a bousehold. Gives rlcb ,"olume. Rnd bas tbe capa<'lty to 8eparateotatlons /MlBltlvely 90 that you Oa n pick tbe brolUl oast gems without In""r!rr­ ence. Extremely easy to opt'ra t.... PrJoe (",Inus tubes. loud speaker and batteries) ~90.

DE FOREST F.5 M A-superllne 5-tube o.. t In two color mabo/':­ any cabinet with bullt,-In loud spt'aker and concealed comll:ll'tmenlS tor "A" ar.d "B' bRtt<'l'les. A great distance-getter. wltb un­ ca.nny pow.. r to tune In and out 8~tlOM at will, and gtrlro with splendid tonal quall­ lies. Extremely 81mPI~ to opemte. No howllng or b1slling In tuning In. An unsur­ pass('(\ vaJue I1t 5110.

De Fore ~a" be bought at pricl'J 7'a"gi1lC from $85 to $450. De Forest Genius now Humanizes Radio! ~C"'7VrARVELOUS new circuit, just dance, ripple aud sparkle ... clearly, dis­ But Tonal Supremacy;s Not AII­

DEAI.ERSFOREST IN AI.I. CITIES AND RADIO COMMUNITIES DE _s..~ HE EPOCH-MAKING ACHIEVEMENT WHICH MAKES ORDINARY RADIO RECEPTION A THING OF YESTERDAT~

:(.. Tested and Approved by RADIO AGE :(.. so RADIO AGE for Noyember, 1925 The Magazine of tlte Holtr Some Facts on the Magnetic or- Theory (Continued from page 21) Real Enjoyment upon each other, and efforts have been f made to so place the coils in the modern receiving set that the effect is reduced to a minimum. Various tests have proven that in two adjacent magnetic fields, the field of each is distorted, either pushed apart or dra wn more closely together by the action of the other, depending on the polarity. An alternat­ ing current or varying current creates a vibration in the field. In radio transmission the high fre­ quency vibrations carried out by the transmitting aerial, located anywhere within the great magnetic field of the earth, tend to distort the field as in two small adjacent coils. This disturbance or vibration is carried out in all direc· tions similar to the wa"es sent out from a disturbance on the quiet surface of a pond, or more nearly like sound waves radiating in all directions, even upward and downward through the magnetic lines of force. These vibrations cause a A Six Tube change in intensity of the earth's mag­ IN CONSOLE netic field in somewhat the same manner that sound waves cause a change in intensity of the air, each crest or wave $125 LIST being followed by a low or thin area. (With Loud Speaker) The magnetic field, like any other body, tends to remain at rest or Ifi balance. As the wave progresses across any conductor, DIANA ""SIX"* a small current is generated which tends d3AUVnH to balance or overcome the effect of the A perfect set in a beautiful cab­ waves, consequently the current generat­ LOUD SPEAKER ed is an exact duplicate of the originat­ inet. A real six tube set. Two Assures utmost in volume and clarity of ing current which started the disturbance. tone-r~chcs full range of musical scale. giv­ models. Cabinet Grand $100 list. ing a faithfulness of reproduction that equals The aerial being a conductor is therefore hearing the origmal charged with a current which tends to Console as shown above with Flare in several handsome finishes. keep in balance the magnetic field sur­ loud speaker, $125 list. A long rounding it. This is the current detected Prices $22.50 - $25.00 - $30.00 by the receiving set and transformed distance set. Easy to tune. Manufa.,turers into audible signals. Exclusive Territory Open ~6kcttic To Generate Electricity Write for Liberal Discount and splendid COMPANY 1\ generating electricity, engineers Sales Proposition. Booklet R-A upon State and 64th Streets request. CHICAGO, U. S A. 1 have learned that the coils in the generator must cut across or through the magnetic field of the generator in order DIANA RADIO COl\fi>ANY to generate a current in t he service lines. 1429 So. Michigan Ave., Chicago Radio experience has taught us that bettcr results are obtained in reccption if the aerial is strung pointing toward or away from the sending station sought. ¥o This is decidedly true of the loop aerial which must be in such a position that Tube the oncoming wave or magnetic disturb. The FIVe ance cuts directly into the plane of the aerial. If the loop were placed broadside I Set WhiCh! to -the oncoming wave, the change in intensity of the magnetic field surround­ startled ing -the loop would be the same at all points around the loop; in other words, the World t he magnetic field in the plane of the loop would at no time be out of balance; therefore no current would be generated. A study of the earth's magnetic field discloses the fact that it is a constantly C~nRPlM changing field due to outside influences, the principle one of which seems to be the sun. During the daylight hours we The Gr~ Value have the greatest changes. During any one hour between 8 :00 a. m., and 5 :00 Ever Offered in p. m., there is a greater change in inten­ sity and direction of the earth's magnetic Radio Receivin9 Set field than during the whole of the night from 9:00 p. m., to 4:00 a. m. Every At Authorized Dealers day there is a magnetic tide, or magnetic "wind" blowing, if it may be called such, RADIO PARTS FREE! which upon the setting of the sun calms down and almost ceases during the hours Announcement in this of darkness, only to rise again at dawn. We know by observation that sound is Read the Classified ads on page issue of RADIO AGE. transmitted much easier and clearer on a 79 for some real BARGAINSI (Turn to page 6Z) 'f. Tested and Approved by RADIO AGE 'f. RADIO AGE for November, 1925 The }'fagazille of the Hour 51 "Socket of Future" Claimed by Pacent One of the interesting improvements in the development of radio reception is embodied in the new universal base tha t has been adopted for Radiotron vacuum tubes. It permits interchangeability, lowers the total capacity of any 'circuit, and increases the efficiency of the elec­ trical contacting arrangement with the tube prongs. The tube socket of the future wiII be a small bridge shaped ar~icle supporting a disc with four holes, similar to that which has been designed by the Pacent engineers. The contacts will be com­ pletely out of sight, but so arranged that they grip the sides of the tube prongs with firm side contact. The new socket designed by the Pacent engineers is constructed of lsolantite. This material has been found practically ideal at radio frequencies with n e ~ligible dielectric loss, which, coupled wIth the small amount of metal required in the contactin~ devices of the socket, reduces 1 the capacIty effect between grid and plate thus making the radio frequency cir­ cuits far more stable in operation than has been the case with the older type of tubcs. Probably the most important advan­ HETHER you build your own radio re­ tage of the new type tube base is that it permits the design of a socket ...... ith a one W ceiver or buy a factory-built set, you will piece contact in such manner that when improve your set by installing Allen-Bradley Perfect the connecting wire is soldered, a contin­ Radio Devices. Not only are Allen-Bradley Radio uous circuit connection throughout is Devices strikingly beautiful in finish and design, established. This alone is a great ad· vance in efficiency. but their marvelously silent, selective control never fails to amaze and delight you. The eight salient, The Humble Rheostat is unrivaled Allen-Bradley features are: Worthy of Praise 1 Terminals are readily Intemalswitcn openS Little and much can be said about the accessible. Designed 5 battery circuit, if de­ humble rheostat t hat hides behind the sired, by turning knob front panel of our receiving sets. Seldom Brsdleystat- Perfect for bus bar wire or Filament Control to the left. seen, and soon forgotten, this important lor aU Tube. terminal lugs. piece of apparatus 'opposes the flow of 6 Highly polished bake­ electricity to the filaments of the vacuum 2 Metal parts are heav­ lite knob is removable tubes ...... hile the set is in operation. ily nickeled and if you prefer to match \\'ithout a rheostat the filaments would soon become damaged beyond buffed toa high polish. other dials. repair, due to too much current passing 3 Container is made of One-hole mounting throu~h and causing the thorium coating 7 makes installation to dismtegrate and flake off. This is an glazed porcelain that every day occurrence where the rheo­ excludes moisture. simple and easy on all stats are turned on too far and is the sets. principal reason for sO many tubes going 4 Speciall y - treated 8 Can be used with any "dead." I graphite discs give panel thickness. Back In t he struggle to oppose the flow of I current, the wire becomes warm, even amazingly wide and panel extension is ex- hot if the tube requires considerable Bradloylea k-Pcrlcct noiseless control. tremely small. Grid Leak ~ to ID "juice." As the temperature of the Megohm. rheostat rises it causes the wire to expand. Mail the Coupon fOT Booklet If the ...... ire becomes hot e nough to char the insulation on which it is wound, it becomes loose, the wires touch each other, and the rheostat loses its smooth ~-BRl' ~Co. operation and trouble begins. fLECTRIC [DNTRDLLlNG APPARATUS I t is for these reasons that the new Frost rheostat has extra heavy wire on 289 Gr~enfield ~ .. Milwa~ee, a strip ·of insulating material, the whole Ave. _ WIS being in a moulded bakelite frame. Heat Bradleyometer-Pcrlecl will not ruin t he rheostat by changing Mfrs. of Graphite Disc Rheostats Porenttometcr the shape of the insulating strir of the for over 20 Years frame, and one can be assured 0 faithful service from this part of a radio set. Brsdleyohm-Pcrlect Adjust.ble Resistor USE WHO GETS IT? ALLEN·BRADLEY The Radio Age Receiver--the PERFECf most talked-of set of the year, RADIO will be given away at the Chicago DEVICES Bradl"yunit-Pcrfcct Radio Show in November. Who Fixe d Resisto r will get it? You have a chancel See page 20!

'!- Teste.d and A vm'ovcd , bu RADIO AGE :f. 52 RADIO AGE for :'\O\'cmuer, 1925 The Magazine of the Hour Secretary Hoover Faces His Big Task (Continued/rom page 32) a legitimate and a valua'ble purpose to MEETING POPULAR DEMAND the listener before we allow him to further congest the overcrowded lanes. But. above all we must not crystallize things into law which will impede the development of the art. Any day may see discoveries which may simplify the whole of our problems of congestion. And in any event the undoubted improvement in our sending and receiving sets every year contributes to widen the paths through the air. We have gre.at unsolved problems in the amount of power neces­ sary to give real service to listeners even against opposition of static and summer conditions and without adding still further congestion and interference. We have all watched ~his industry gro\\' from the curiosity of a scientific toy to a communication system . now well nigh universal. It is better ·and greater than it was a year ago. So great has it become in service that I The new five ampere Tungar-at the belie\ ~ e it would be almost possible in a same price as the old-means a quick great emergency for the President of the United States to address an audience of charge of all kinds of storage batteries. forty or fifty millions of our people.· It is bringing a vast amount of educational and -It is more silent than ever. informative material into the household; - It cannot bum out Radiotrons. it is bringing about a better understanding amongst all of our people of the many - It cannotcreate radio interference. problems which confront us; it is improv­ - It is ideal for auto batteries-and ing the public taste for music and enter­ * tainment; it is bringing contentment into charges 2 to 6 volt radio "A" bat­ the home. \Ve are at the threshhold of teries, or 24 to 96 volt liB" batteries, international exchange of ideas by direct in series - all without attachments. speech, and it will bring us better under­ standing of mutual world problems. Only oyer-optimistic prophets would The Tunga r is a G·E attempt to predict radio advance. One product• developed in 'the thing we are sure of-that the radio great Research Labora­ torIes of Gen era IElectrlc. industry is only i' n its youth, that it will continue to grow with increasing strength. Two ampere Tunga~ TunREG. u.s. arPAT. OFF. . (East of the RockIes ). r------~ If it will succeed it must continue as in the $18.00 BATT'ERY CHARGER past to devote itself to actual public ser­ FIve ampere Tun gar vice to which it is already dedicated. (Ea st of the Rockles). TUNGAR-a re/fist" red tradem ark-is found only $28.00 oJn the genuine. Look for it On the name plllte. Getting the Farmer to Buy 60 CYCles-ll0 volts Merchandise Division a Radio General Electric Company, Bridgeport, Conn. (Continued/rom page 28) 25 per cent being willing to buy. How owners make use 0/ sets--83.97 per cent reported they make use of GENERAL ELECTRIC radio weather reports; 80.98 per cent use the market reports; 70.92 per cent said they did not object to advertising over the air, 9-1.96 per cent declared they were satisfied with local programs. What kind 0/ programs does the farm NO MORE LOOSE CONNECTIONS X-L PUSH POSTS family like?-::-'larket reports was voted A bin,Uol:' post thal reaUy does neel. for by 143 farmers out of 427 as the look." actmn , Sl"rTlee. and cont'en1e-nce. RadJo'e biggest B..... uQ I~ b~rc . G et U W: Push it .Jown- iDMrt Wlre--<"annot iar most popular program for the man of new catalog ehowing hUl'e BlOCks of radJo l oo s~ from vibration. ~o screwing ~ parts. Bets. kits at lowest rock-bottom danger r1 shearin!: ofT wires. the house, and 114 voted for the crop rrices. Quick eernce. Wonderful epe- / .....A' ... Ji'O / FUTnlsh, 34· SO S.Cli.oI ... SL.Cbica(O.U.S.A.--~-'" 1"'=!liT~~ 242~·'un~~~I~..,~~:O:'ATO Rbt~ago fifth and religious services sixth. Classical and operatic music are not in the run­ ning, so far as the man of the farm is Big Money in Radio TO THE MAN WITH AN IDEA concerned. Popular songs were voted Demand for high pay rad,o men Is so great that a I offer a comprehensive service. I f you big Kansas City wholesale concern is now titting first by the majority of farm women, men fr.:e to get Into the rad.o bus iness for them­ have a new invention, I will assist you in with religious music second, informative selves and make $00 to $200 a week without any obtaining a patent. Write for further in­ capital invested. Select tel ritory open. Send ta­ formation: RICHARD N. OWEN, PAT­ talks third, religious services fourth, day for free catalog and amazin!: offer. Wrote direct jazz orchestras fifth and classical music to Mr. H . J Sa;%ow . Standard Radio Co. • 1424 ENT ATTORNEY, OWEN BUILD­ Walnut St .• Kansas City. Mo. . . ING, WASHINGTON, D. C. sixth. (Copyright by MtGraw-Ht'U Co.) J(. Te sted and ApP"o1)cd by RADIO AGE J(. RADIO AGE for November, 1925 The :Magazine of the Hour 53 Spanning the U. S. with Low Power (Continued from page 24) the transmitter. Rheostat R-2 has 10 ohms resistance, for the two "A" tubes emJ..loyed in the receiver. Both tubes are supplied with voltage from the 4S volt tap on the" B" battery. Sl:ch an outfit might well be laid out on a fairly large table, with plenty of separation between transmitter and re­ ceiver but with short leads to a.ntenna and counterpoise. The batteries could be placed on the floor underneath the set. The "B" battery used for the send­ ing outfit ought not to exceed five "heavy duties" and can well get along with three of them. The constructional data is given in rather sketchy manner, but is sufficient for the man who has had some experience with amateur apparatus and who knows, for instance, which side to connect the rotor plates of the variables, that the tickler and primary go at the filament .. DET~CTO end of the receiver secondary coil, etc. '-- Other transmitting circuits may be used, of course. In getting results, most ~-- of the work must be done in daytime, as it is then that fewest stations are on The Bridge to Amplication Without Distortion * the air. Patience is also necessary, but once the "ham" gets into communica­ Daven engineers were pioneers. They blazed the way for others to follow. They tion with a few stations, more follow designed and built the first Resistance Coupled Amplifier offered the public. They rapidly. It is best to answer "CQ" found resistance coupling in an experimental stage. They perfected it. calls that are given on about the same Daveo ResistaBce Units, Amplifier Kits and SU[>er-.\mplifierli nrc accepted by the foremost authorities wave as the transmitter, as it is in that in Radio as standard. The Daveo SUp<'J'-Amplifier, for use io any ILDo.,..n set or circuit, is priced at $l5.00. wavelength vicinity that the distant r ------fellow is going to listen first for a reply. A NEW TUBE BY DAVE~ H·ll-25 To meet the exactiog requirements of Resis­ CLIP TillS tance-Coupled Amplificatioo the Daveo Radio COUPO:-l Clearing Up the Ether Corporatioo has creat.. d a new product, the Daven Radio Corporation DA \,EN HIGH :\W \'ACUU:\f TUBE, 158-160 Summit Strpel Started at Last Type 1\1 U 20. It is desigo.-d for oDe spcdfic Newark, New Jerse)' 22) purpose only-to iocrease ti,e amplificatioo PIl".asc sen 1 me the follow­ (Colltinued from page ing 00 Resistance Cuu· of the Daveo Resistance COllpled Amplifi"r the ~t. Paul Gas Light Company, the pled Amphficatiun:- so as to e.<:red that of ordinary audio fre­ Check one Northern States Power Company, the quency coupliog. is The Da.rn lIigh Mil. o Resi~tor i\f "oual. JOe Twin City Rapid Transit Company, the a 6 volt, 1-4 amp<>rc tuhe with aD amplifiea­ is enclosed. Northwestern Bell Telephone Company, tioo constaot of 20. The price is $1.00. Daren I D Complete Cat"log (froo) Pou:u Tu.be Type Jl fu. 6 is recolQIDeodcd for the Tri-State Telephone Company, the RESISTOH !\I'\ .... UAL I Twin City Radio Cillb of Amateurs, last or output stal:e. Price $5.00. I Name...... _ ... Manufacturers of high the Chit:f Engineer of the Gold l\ledal Daten products are sold only I grade sets are turning to by good ,u,,/ers I Address ...... Radio Station and the President and ResislaDce Coupled Ampli­ I Secretary of the Korthwest Trade Asso­ ·9'..G.JIM yKN'iC· I fication. The authority is I ._._-.. -._--.. - ..... - .. . ciation. This committee has held six TIu! Resistor .\1anual. At ~~M~f\gr,t\~'i'!f'{, {j8PQ~&1\!;5lf I For DUll ...... &nd ~"'" 1...... - )'our dealer's, 2:ic; or by meetings. The speaker has acted as 9>", ...10," sp"C'ia/utJ I :ead.:lL~~· =/~~'d°~t~~ Chairman. So far, our effort has been I mail,30c. NEWARK a.... U.s. I'.t. Off. NEW JERSEY I utO'J" C4nJ\J"I'tuni(:(lk W1th " ou.. concentrated on securing a classification of the various types of interference. THE BIG LITTLE THINGS OF RADIO This has been quite a task. In addition, the ~orthwest Radio Trade Association h~c~c~a~db~nbamongitsmembe~ 1 r------~ which may be used by broadcast listeners for reporting cases of interference. These I RADIO AGE SUBSCRIPTION BLANK blanks have been drawn up in such a Radio Age, Inc. way as to discourage indefinite, vague 500 North Dearborn Street, $2.50 A YEAR complaints, but to adequately take care Chicago of intelligent ones. "Having taken steps to classify induc­ Gentlem.. n: Please enter my subscription Cor RADIO AGE, the Magazine of the Hour. for One th'e interference, and to determine just year. beiinmng with your next issue. for which I e~lose $2.50. what types of interference exist, the Twin City Inteference Committee is now Name confronted with the task of finding means whereby interference can be minimized. Strut Addr''''es~< ______Complete information giving location of specific cause of in terference, ca used by uty,______defective equipment, will of course be acted upon immediately by those owning State-.___ . ______._ · __.. _____. ___ and operating- such equipment. How- Send cash. money order or draCt. (Turn to page 55) ¥o Tested and ApP.I"olled by RAmO-AGE ¥o 54 RADIO AGE for November, 1925 The .Magazine of the Hour

Developed for Those Standard Radio Receivers \Vho Demand theBest Some time ago RADIO A .GE inaugurated a new department calUd"Know Before You Buy," to serve as a guide to the prospective radio purchaser in APEX deciding on the receiver best suited to his individual needs. Fans 'hroughout VERNIER DIALS the country have shown a keen interest in this new feature, and acccrdingly it are constructed on exhaustively tested is being made a feature of all numbers of RADIO AGE. Readers are invited and truly scientific principles and are to write us concerning the sets in which they are interested, and manufacturerl engineered to meet the precise re­ also are asked to send us maUrial describing their sets. quirements of experts-consequently they .more than meet the expectations of the average radio user. They bring in distant stations with alacrity and The "Why" of The Audiola Receiver positiveness seldom encountered and provide control and accuracy essen­ tial to full radio enjoyment. They Proper Balance of impart a degree of elegance that cre­ ates a marked improvement in the Parts a Feature appearance of any set. Clockwise and counter clockwise. Royal Bra •• Fioish. 4 in. $2.00: 3% io. $1.65 Satio Silver Fini.h. 4 in. 250: 31ft io. 1.90 DeLuse Gold (24K) 4 in.. 3.50: 31/. io. 2.50 APEX RHEOSTAT DIALS are little brothers to Apex Vernier Dials. Accurate.handsome--a neces­ sity to satisfactory operation and beauty of appearance. Royal Brass Fini.h ...... ••••• ,$ .75 Satio SLiver Fini.h ...... •••••• , .85 DeLuxe Gold (24K) ...... 1.00

o GIVE the best results, a radio set Coils--spider web, low-loss, of Audiola T must be built of parts designed manufacture. especially for use with each other, so that Condensers-dust-proof, low-loss. of If your dCQle. i. uDable to aupply you.D.de. there will be a balance between them. Audiola manufacture. direct from U:'I. This relationship between coils and con­ Sockets-low-loss, of Audiola manu­ densers is especIally important. Audiola facture. A pex Electric Mfg. Co. manufactur:es their own low-loss, dust­ Wiring-first made mechanically self­ 1410 W. 59th St., Dept. 1111, CHICAGO proof condensers and low-loss coils, so sustaining and then soldered. that there will be a perfect balance be­ Circuit-standard tuned radio fre­ tween the two. quency type, with addition of power They a lso manufacture low-loss sock­ amplification. ets which are used in all Audiola Radio Receiving Sets. "Sealed Five" An efficient circuit, such as is used in Five tube tuned radio frequency set. the Audiola "Big Six" and the Audiola Panel--eighteen by seven inches, vVal­ " Sealed Fi"e," high grade balanced parts, nut finish. skilled, conscientious workmanship, and Sub- Panel-Walnut finish covering careful inspection ine"itably results in practically entire interior of set. high grade radio receiving sets. Cabinet-beautiful Walnut finish. Specifica tions Rheostats-(2) one for detector tube, and one for radio and audio tubes. "Big Six" Transformer9--two of three-to-one Six lube tuned radio f requency set with ratio of All American make or equal. pou'er amplification. Coils-spider web, low-loss, of our own . Panel--scven by twenty-one inches, manufacture. Walnut finish. Condensers-dust-proof, low-loss, of L.======Suh Panel-Walnut finish covering our own man ufacture. practically entire interior of set. Socket9--low-Ioss, of our own manu­ Cabinet-genuine Walnut, beautifully facture. _ finished. \\,iring----first made mechanically self­ Rheostats-(3) one each for radio fre­ sustaining and then soldered. quency tubes, detector tube and audio Circuit-standard tuned radio fre­ tubes. quency type, revamped to eliminate Transformers-three of Thordarson oscillation or howls and to give more Free. big Radio Catalog make or equal, onp. stage of audio plus "pep" than the usual five tuhe set, ulJd Guide brimful of new. power amplification. (Turn to page 56) ~1~~Iu°~~;8~.:eci~I~~~ as mucb as 60% on eelS and G Parts. Beeure to get thla tbrltty book be/ore you buy. It PUIS money In your JlOCket. Sliowa t~~U'riir,.bfe. Pl<~~d goode. PleJl36 InClude nam.. of radlo fan to Whom w. may .....~ il®:: eendcopyalso. Write letter I , or postal now. l - Inaure Diatortionle.. Arnpli6ca­ tion and.a clariwoftonenotobtain­ eel through any otber resistances. All ",paci ties 12,000 Ohms 1l!'d up. Lis~ price $1:50. Special sizes to order. Wnte for full.nforDlaQon. Crescent Rld'tO Supply Co~ 5 l.t1tert, St. hmaiu, L I. :(. Te8ted and Approved by RADIO AGjJ., :to RADIO AGE for November, 1925 What the Broadcasters are Doing 55

(Continued from page 53) ever, the task of locating the exact source is often a long and tedious one. The public utilities of the Twin Cities h ave already individually devoted much t ime and money to this problem in spite of the fact that many times after extensive search, they find that the interfering de­ vice is neither owned nor controlled by them. The Northwest Radio Trade Association contemplates the establish­ ment of trou ble shooting service to assist in the 'work already so ably initiated by the public utilities. It is only by such whole-hearted co-operation as I ha \'e outlined that we can arrive at the ulti­ mate solution of our problems in induc­ tive radio in terference. "Neglecting radio interference, there are three factors which determine whether or not reception from a given radio broad­ casting station can be made satisfactory at a given location. These factors are : 'Where is the difference The intensity of the received signal, the intensity of static. or atmospherics, and the intensity of inductive interference. in radio transformers? In discussing these factors, the terms 'signal level,' 'static level' and 'inter­ HE audio frequency tranS' ference level' may be applied to the T formers in your radio perform average conditions existing at a given a most important duty. They aid location during a given period of time. in increasing the volume of sound With modern efficient amplifying receiv­ ";,., /'. ,_I .. ing equipment, it is not the actualle,-e1s •.. in building it up to the desired of these three factors which are impor­ strength. BUT- tant, but their relative values. A signal When sound is increased, the from a broadcasting station can easily tendency is toward distortion. be amplified to satisfactory intensity, That's where the difference comes providing the ratio of the signal le\'el to in transformers. Inefficient trans, the static and interference levels is formers give distorted recep' sufficiently high. If this ratio is not will sufficiently high, satisfactory reception tion, just as a defective mirror will cannot 'be obtained. show a distorted image. "During the summer months, the stat­ Whether you are building a set, ic level is usually much higher than the or buying one, be sure about the inductive interference le,-el. and conse­ transformers. No radio, remem, quently it is sta tic which limits d.e recep­ ber, can be better than its trans, tion of distant stations. l\I a n has not formers. A safe guide to follow is yet found a satisfactory method of con­ the Jefferson trade mark. You can trolling the static level. During the win­ depend on quality in perform' ter months, the sta tic level drops almost ance when the name "Jefferson" to zero and consequently it is the inter­ Tube Rejuvenator is on the product. ference level which limits reception. It Keep ,our radio rubes like is therefore but natural that we should Jefferson Transformers are made by new! Rejuvenate them regu... hear more about inductive interference transformer specialists-the world's larly, AT HOME, justasyou largest manufacturers of small tranS, rechar~e Your storage bat­ in the 'winter than in the summer time. tery. Jelferson Home Re;uve. formers. There is a very definite reason nator double s and trebles "The time is not far dista nt when we why leading radio engineers specify rube life, quiclcly pays for it· must determine just how much right to "Jefferson." You'll find it in the clear, self. Raises lou r set'sefficien­ cy to 100%. a nd k.>eps it therel protection from inducti ve interference the sweet, life-like amplification whic h Completely te.tores para­ user of an ultra sensiti"e recei ving set is Jefferson Tr:msformers give. Sold by lY:ed Ot exhausted tubes. the better dealers, used by leading set Takes large or small rubes­ entitled to. If, in any community, we rypes 20 1-A, 301·A, UY· I99, succeed in lowering the interference le,-el manufacturers. C!99. SoYA. Don't be with­ Out this long-awaited rad io to a gi"en point the users of sensith-e necessiry. S7.S0 at leading receivers immediately in crease the amount JEF~ERSON ELECTRIC dealers_ of amplification in use until the same in­ MANUFACTURING CO. terference level exists in his mind, as 501 So. Green St., Chicago, 1lI. before, and the same problem arises Makcts of lefkrson RadiO, Bell R i ng i n~ and again. Toy Transformers: Jelferson Spark Coils for AutomobIle. Station.ry and Manne Engines; ")'ly experience in the radio communi­ JelfetSon 011 Burnet Ignition Transformer._ cation field has led me to the conclusion that there is no other field, where the need of co-operative effort directed towards the sol ution of common problems is greater. It is only by bearing con­ stantly i~ mind the necessity for co-opera­ JEFFERSON tion with our fellow men, that we can RADIO TRANSFORMERS arrive at satisfactory solutions of all of the problems which today confront the radio industry and those associated with it."

Tested n,nd A~rn1},.d bll RADIO AGE ~ 56 R;\DIO AGEjor November, 1925 The Ma.gazine oj the H01lr The New Model L-3 Ultradyne By The Experimen ter (Continued from page 54)

Worlel RadIo ·'A • uelAueD Rau.r'' ••• r. famODI t.r t be' r lltUannteed ~tl:!! t~d ::=~:; llUeee•• tut manafaetDl•• Old tbCM.LI&D.:'. or ..ti.a.d oeen. EQ01Pped wi tb Solid R-ub"'" tA..• • an ta.a.ra.DU ...-,in.t .. c:id a.od jeakq • • You aa .... in percent... Rad;oSutlon a.Year Gu_aatee had W S Bela WritlaIJ WOltLD I\attf"r"J" o'tl'1'\er. "t.loll their f riend • . II Tb t o. our but proof or per· rof"IZLADce . Send ,our orelar l a t0d.7. hlld R.bber C: ... R.dll a_H,rl.. ~ftlc. 100 Ampere. " .. .. 511.25 $.V'olt. 12[) Ampcn...... 13. 25 ~.ult. UO Amperellt ...... 14.00 $ond Rub"" c... Auto BaH.,.I... 6-"\llt. It-Plet. • .. • • $11 a5 ~.olt. la.PLal. .. • ... 13 25 tz,...,olt. "Z-Plate ...... la,oo HAVE had before me a cabinet of lhe volume. When turned full to the nllD JIO MOMEY I pleasing appearance. I t looks well left it cuts off the current to the filaments Ja.t .tawb_U..... wantadafld •• wmahlpd., orcJ.r from all sides but it is the front that holds of the vaCuum tubes and this is all that b rec. i .. ecI. by EJ[ o r~ ... C. O. D •••ubj~t to ,.our .';I.miaation aD .rrb.l. IE.u. OH.r: 6 per unt di ... the eye. Besides being a thing of beauty, is necessary to do to "turn things off." coaDt for cub ia fuJI it is different. It might or might not be A small jack at the lower left on the ""ith order. taken for a radio set: at least it does not cabinet front balances up with the Bu,nowud ••t • cu-,... resemble the sets one is used to seeing. volume control and is there should you ant~d b.t· t.f7 at 60 I took it for a cabinet type loud speaker care to use head-phones. . until I was told that it was a full fledged This set, being knobless, is also dial· radio set with a built-in loud speaker and less, though there is a large but un­ everything. obtrusive scale bordering the circular T his was the new Model L-3 Ultradyne grill, in the center. This scale is the and R. E . Lacault is the man who de­ determining factor for all stations one veloped it. I thought back to the time wishes to receive. There are no wave­ he first introduced the original Ultradyne length, frequency or station markings ~lie Receiver to the radio public, who ac­ on this scale whatsoever. Who would cepted it with confidence and who now desire to mark a fine piece of furniture ./la/co remain to praise it. And I have thought or a phonograph with n umbers.or letters, since that wha tever fame Mr. Lacault done free-hand, excepting for the mo­ 4!fp , has gained in the p ast will be small COm­ ment that there was some reason for :.: .,{i pared to that he will gather in the future. doing so, when the manufacturer could ..... I couldn't help but form a contrast have provided other and simpler means at the time for it came to me that the in the first place? In other words, why new Ultradyne no mOre resembles the make it necessary for the owner to detract old type than the original Edison Talk­ from the beauty of a radio set made to * ing l\lachine resembles the present day be beautiful when a simple chart can be Victrola. This contrast entered my provided to do the trick just as well and mind fi rst, I belie,·e, because the me­ Just as rapidly? That is the system chanical appearance of the usual type worked out for the new U1 tradyne. of radio set has been entirely removed There are two levers, which are out of from the new Ultradyne. It is mOre sight, but whose ends terminate in con­ like a nice piece of furniture than an venient gra sping handles. Adjustable to any position electrical instrument a nd from its beauty Their path is along the large scale. Wiring always taut of t y pe and broa d adaptability to design, They are the station selectors and it's I would say that one could put it where as SImple as falling off a log to handle GUARANTEED FOR A one plea sed without the slightest worry them. There is no "cramping" of sta­ of its clashing in an y way with the scheme tions within a few degrees on the scale, LIFETIME of a room. nor any of the usual critical adjustments The Aalo<>-the lowrst resis"""'" loop 1Ua.d~ as.' u..... maximum seJ""t.,1" 8Jl <1 raniif'. IUJd found necessary in the common type of perfect dIal matchlns: modo I\oss,ble by variable General Refinements receiver. All you have to do is to grasp inductance Constructed t>f lhe h,~h ••t J:r1Ide materials m a new and m.. . I.. rly de",",,- L<-Dgtb. The front view photograph of the new the lever ends and move them down Z4 in - Normal I H :1 0 1 n .- "'&~e1t·n e' th f&nJ:'8 1 ~ O·6 0 0 m.te.... LA non \TOIlY TE!>T RE., Ultradyne sho\\ n herewith reveals ·more slowly until you have the station you SUJ.TS UPON REQUEST. than words possibly could, still t here is want. much that cannot be seen well and quite Another feature of the new set is the Price $15.00 a bit that cannot be seen at all, so a position of the loud speaker. It's right description is required if I am to do the In front of your nose so to speak, or to AALCO RADIO LABS. set justice. be more specific, directly behind the 6350 Cottage Grove Avenue, CHICAGO First of all, let me say that the set is circular grill. This grilling, by the way, as near to being automatic in operation is given a statuary bronze finish and is as is possible to make one under present backed by a screening of dull ~old. The limited circumstances. I believe this whole blends well with the cabmet which to be true under the consideration that is made of five ply mahogany veneer there are three stages of radio frequency with a two tone lme cutting. amplification to contend with. And doesn't it look automatic if we judge by Technical Specifications the absence of knobs and.dials? There is The new Ultradyne employs six tubes a small knob, placed at the lower ri~ht of the storage battery type, three oi of the cabinet front, but it h~s nothmg them, as mentioned before, functioning to do with tuning. Rather, it controls (Turn to next page) ¥o Te8ted and Approved by RADIO AGE ¥o RADIO AGE for November, 1925 The ~Magazille of the Hour 57 a9 radio frequency amplifiers, the fourth as the detector and t he last two as the audio t:requency amplifiers. Two of t~ c radio frequency stages are tuned, while the third stage is fixed. In connection with the radio frequency amplifier unit cA'Olll! * Mr. Lacault has killed two birds with one stone. The "stone" amounts to two resistances inel uded in two of the grid for Tu'Jted.RadioFrefllency~ or input circuits of the radio frequency tubes. They prevent these circuits from oscillating or "spilling over" at reSOnance points and at th.e. same time .actual~y increase the selectl vlty of the entire radio . e4 frequency amplifier. Then, t here is the matter of the con· densers employed in the new Ultradyne that have made the improved tuning system possible. They are the now well known Ultra·Lowloss variable condens­ Kit of which the secon~ary unit ers with a "straight line wavelength 95% is of exact and equal induct­ curve." \Vith such a type condenser, Air Dielectric ance value. the wavelength is distributed evenly . Dopeless over the entire scale reading; that" is to Air-Spaced say, one hundred meters or so are not Wlndln~s Use AERO COILS ~rammed in a relatively small space on he scale. Thus, crampin~ of. sta.ti~ns In Any Circuit within a small degree reading IS ellmm· The only Air Dielectric COliS] Having Variable Prhnarles ated. [ lin Antennae Circuits In the new Ultradyne the loud speaker unit is electrically matched with the 3 Circuit Tuner audio frequency amplifier so that th.e impedance of both IS the same. ThiS I does ~onders yet there is no~hing so complicated about the system.; It co~es to me, in fact, that there IS nothing complicated about any of the little schemes l\Ir. Lacault works out. He OW you can build a set and have aU three tU.ning seems to have the faculty of solving an I N dials tune exactly the same-or, you can bUild a abstruse problem in a very simple way. one control set using a gang condenser and know that adapt;,Hon of the pat. pro­ The volume is as much as any normal it's going to work right. AERO Coils are matched! I construction,.$8.00 soul would ask for. The set will not I entertain the people on the next block, But-the matched feature of Aero Coils is not their Rad:'o Frequency perhaps, but then it is not built to be a only exclusive feature. public address system. Aero Coils are, by electrical measurement and by use I think I have mentioned that the tests, the most powerful, l!lost selective ~nd most sen­ ~~.en.ra3 new Ultradyne is self contained. The sitive inductances ever deSigned. They Will enable your "B" batteries fit in the cabinet to the set to sharply cut through powerful locals an~ will bring • • .

Fans-Here's the Amsco Describing Eagle Radio Co. 's Saturn Co. Puts Out Extension The Amsco Compensating Condenst:r Latest Neutrodyne Cord Connector is a three electrode Condenser and is so designed that it will not detune the The Eagle Radio Company's new Radio, havin~ passed the experimental radio-frequency transformers while ad­ neutrodyne receiver is twenty-two inches stage, progressive firms like the Saturn j usting to eliminate the feedback or re­ long, eight and three-quarters inches Mfg. & ~ales Co., of 48 Beekman Street, generation. high. The black Bakelite panel is finished N. Y. City, are concentrating on equip­ The Amsco Compensating Condenser with gold trimmings and lettering. The ment t<;' eliminate the unsightliness of is mainly constructed for the purpose of battery switch and phone jack are also connectIOns and are producing parts of. gOld. The set is designed to operate, that are good to look at as well as useful. ~alancing the grid charge on the Amplify­ Ing Tubes. It stops all local oscillations With five 201 A Or 301 A tubes, or with One of the latest products of this firm without detuning the amplifier. It is four 201 A or 301 A tubes and one power is The Saturn Extension Cord Connector shielded against hand capacity disturb­ tube. with which owners of receivers may move ances. It makes it easy for the operator Other striking points of improvement their ear phones or loud speakers to to find the correct capacity because of in the new Eagle model F, are, first· different parts of the house or rooms. the circuits always being tu ned. I t is radio freq uency coils. . In case of illness, the chap who must the third electrode in the Amsco Com­ These coils are a radical departure stay in bed for a time, need not be de­ pensating Condenser that makes this a from the conventional type. The w;re prived of the pleasure to be derived from clean-cut and straightforward adjust­ on both primary and secondary is space t~e air progrll:ms; also, the family at ment. wound on very thin cylinders of cellulose dinner can bnn~ the metropolitan or­ The compensating condenser for the acetate. The high frequency resistance chestra music nght up to the table. last stage in particular may be varied and distributed capacity is lower by There are numberless ways in which this so that the receiver can be used efficiently a~tual measurement than on any other latest addition to radio will be a help for C. W. reception, or it may be only t~e of commercially adaptable coils. and advantage to the fan. slightly unbalanced so as to give sharper This means a greater ability to receive The Saturn Connector is of hard tuning characteristics to each stage in stations on the lower wa ve lengths than rubber, neatly constructed, with the the set. ~e have hitherto been able to accomplish positive and negative cords in different The ideal set using tuned radio-fre­ In any neutrodyne receiver. co.lors, easily differentiated, and ter­ quency transformer amplification must Second is volume control. minals that fit snugly into place. With' Instead of a switch which changes this connector, and as many extra feet have a variable compensatin~ con­ denser in order to eliminate the regenera­ from first st~ge to second stage, the Eagle ?f cord as. are desired, a very neat look­ tion due to tube capacity. model F resistance is across the second­ Ing extensIOn can be made. The " V. T.-1" or "1" tubes have ary to the second audio frequency trans­ nearly three times the capacity between f?rmer. This T!ermits a gradual regula­ the grid and plate that the Radiotron tlO~ of .volum~ Instea.d of the two jumps Connewey N ow Located m tubes have so that a greater variation is wh~ch IS obtained With a switch. This Magnatron Bldg. necessary. resistance also acts as a protection to the quality. The Connewey Electric Laboratories In the model F the rheostats are have taken possession of their mammoth changed so that one controls the radio new fireproof and sanitary plant at 406- Radio Battery Cable Made frequency tubes and the other the audio 408 Jefferson Street, Hoboken New by Belden frequency tubes. The detector has been Jersey. The structure will be kn~wn as The Beluen :\Ianufacturing Company. placeu on an automatic filament control the :\Iagnatron Building. The building 2300 South \\' estern A yen ue Chicago, \\,it~ this chan!,?e the sensitivity and has been ent irely reconstructed to fit Illinois, has recently placed' a battery clanty can be ~uJusted to the best point every detail in the manufacture of :\'Iag­ cable on the market that is very similar much more easily than previous rheostat natron Tubes and will vastly increase to the well known and uni "ersally used systems. production. Belden Radio Battery Cord. It is sup­ The dials, which are of Bakelite, have The New :\Iagnatron Plant has been plied in 100 foot lengths on spools, or been changed to the concealed type and almost entirely refitted. New machinery 200-foot lengths in coils, and can thus be geared dO\\'n to a 5 to 1 ratio making was installed in every department and cut to any special length that the oc­ fine tuning very easy. the latest appliances necessary for the casion req uires. Th~ company h~s an exceptionally manufacture of their product were pur­ The cable consists of 2 !\'o. 16 B. & S. fine line of cO!lsoles. In either mahogany chased. Everything was done to make 6tranded and 3 No. 20 n. & S. stranded ·or walnut finish With battery compart­ the structure one of the most modern copper conductors, each ruhber covered ments, and built-in loud speaker horns. of its kind. Clean, wholesome working and insulated with indiyidually colored conditions and plenty of room to do cotton braid, coded in accordance with efficien t work has been provided for the the standard of the A. :\1. E. S. The J. L. Polk Designs a employes. entire unit is then encased in a heavy T o the Connewey Electric Labora~ black, glazed cotton braid cover. ' Binding Post tories goes the honor of being the first to The cable is used when it is desirable . So.mewhat .on the order of a spring develop a vacuum tube especially for or necessary to isolate the batteries from binding post IS the latest product turned B Battery eliminators. This new tube the set, by placing them in the basement out by J. L. Polk, 443 South ~Iadison known as the "REX," has proved mor~ than successful in a series of exhausting o~ tn a similarly remote location. The A v~., La Grange, III. The binding post difficulty usually encountered in tracing which Was submitted has been tested ~ests c~nducted at the new factory and a maze of tangled, unsightly wires from and approved by the R,\DIO AGE Institute. In outSide laboratories. battery to set is thus eliminated. The The "REX" is manufactured with a colored tracers simplify the checking of standard bakelite base, so that it will connections and insure absolute ac­ THE LEADER OF THEM ALL! fit all present standard sockets. The curacy in the hook-up. Blown-out b.ulb itself is round in shape and of such tubes, crossed wires, short circuits and The New Radio Age Receiver­ size as to quickly dissipate the heat generated during operation. The base wrong connections are entirely disposed in December of by the use of this cable. . carries the usual four prongs, althou/?h only three of them are used in the CirCUit. RADIO AGE for November, 1925 The l1fagazi1ze of the Hour Official Show of Radio Manufacturers' Association

U. J. Hernnann, Managing Director G. Clayton Irwin, Jr., General Manager

Business Office: 127 No. Dearorn Street RADIO MANUNACTURERS' 611 Times Bldg. Chicago, Illinois SHOW ASSOCIATION New York City

Positively,..--' * More Stations if you use a BARRETT "Be PADEN Micrometer Condenser I (For an)' type of Sel) Incl"ding Dial ECEIVER cannot bring in a speaker volume 1 The micrometer station unless it is tuned into action of the Barrett &"Paden when .0002S f{ resonance with that station. applied to its broad capacity range, .0003S There are many stations which you enables you to find the exact reSQ# .OOOS .0002S have not been able to receive bc# nance points of many stations which Straight Line: Wave: Le:n~th cause the condensers in your set did with other condensers areso close to not have a sufficiently wide range of interfering stations that separation minute capacity variations to enable is impossible. you to tune enough separate . and You will be amazed at the tremen­ distinct resonance points. No matter dous immediate difference these how finely you try to tune with your condensers will make in the pcrfor­ present condensers you skip these mance of your set. They not only Signals-because their tuning range will give you more stations, by rea# is limited. son of their micrometer action, but Install Barrett &. Paden Microm# because of their lower loss will eter Type Condensers and bring appreciably increase the strength in the weak distantstationswith loud with which signals are reproduced. At )'our dealers or direct BARRETT~ PADEN 1314 Sedgwick Street Chicago, Illinois Prepurd b, KlrlJaod.~el Ad ... Co .• Chlul'Q

:(. Tested and Avproved by RADIO AGE :(. Tuned and Untuned R. F . Linked For the first time in 'radio history, tuned and untuned radio frequency have been successfully lin ked. I t has been done by Willia m H. Priess and the engi­ necrs assisting him. When the experiments leading to this result were begun, they were with the thought of commercial application in mind. Pure research at no time entered the minds of the experimenters. How successfully the resu lt worked out was shown 'lin the demonstration of the re­ ceiving set at the Radio World's Fai·r in New York last week. Radio scientists have long desired to combine tuned with untuned radio frequency, but the difficulties that had to be faced narrowed the experimenta­ tion almost to a minimum. Priess has POLK'S REFERENCE BOOK done it and as a result achieves an ampli­ FOR DIRECT MAIL ADVERTISERS fication that is simply enormous. Show, bow 10 Intruse your busln." b7 As is generally known, the distance ~~fl ~r· .~[.ID~~~'i~.~·J!t~~~~IA~~~O ~~~ reception property of any set is depend­ where and how many prospect. yoU Ute. ent upon the voltage amplification that it Over 8,000 IIn_ or bustn.... to ••red. - delivers at radio frequency prior to the Write tor your FREE ClDPJ'. detector tu be. The average five tu be R. L POLK &: CO., Detroit, Mich­ _ .. POLK DIRECTORY BUILDING set rarely delivers in excess of 400. By In rille. of U. s. combining tuned and unt uned radio n pt Into the ~ r, so ACT QUICKI time, this new product is being purchased NATIONAL RADIO INSTITUTE, widely both by car owners and radio Dept. SJNB, Washington. D. C. enthusiasts. l'rtmitt* Radio Advertisers' Data Issued 5TUBE' by Rosen berg The 1925-1926 Radio Advertisers' National Radio Institutt, Data Book, a volume of rates and other Dept, S3NB, Washington, D. C. Serore yOU dtcidt on a radio of any kind at any information for national advertisers, prict, see the ntw Premier 5. Tube E.r.semblt. \'I1thoul oblll:alln~ me In any wa)' , "I.a"u has just been issued by its publishers, A complete En.emble of genulnt PremIer part. ' ''1Id me you r Cree hook , "ltIch Rcwazda In (not a kit) already attachtd to panel9 of genuine lta.ilio:· also eomhlete In ronna-tion OIl your Arthur Rosenberg Co. Inc., New York. ,,,actical. horne,slo dy Radio co ur ..._ black walnut grained S.ktlitt. Seltctivityl D i.· SC\'eral features which were not in the tancel Suptrb reception I Dot. anything any 1924 issue have been included in thc set at three or four time. its Price@ Na me _ ___. ..__ _ " ... __., __ .,_ .. . _._ ... current edition. The contents include Can do. It i. today'. unmatchtd radio valut. See your dtaler at • advertising rates, circulation and other OnCe. Find out why a bundrN Addr""" .. ... _. .. _ ... _. _ _._. ___ . _ _ _...... data regarding Radio Consumer and thou. and Ensemble. will be .oId in Trade publications, as well as of all the tht ntxt few month.. See your dealt!". A.k him. Thert i. a gen. on TO\fIl. __. .___ _. . ___: ..,...... __ .. State... _ _...... _ . periodicals of the allied trades, including uint .urpriSt waiting you. :\utomo.tive, Ele~trical, Hardware, Mus­ Premier Elec:lric Co.. DepL M·21, 3813 Ravenswood Ave. IC. Talkufg Machme and Sporting Goods. CHICACO ILLINOIS -¥: Telted and Approved by RADIO AGE -¥: RADIO AGE for November, 1925 The J.rfagazi1le of the Hour 61 A Super Without the 1. F. Stages! Rhamstine* (Continued from page 10) TUBE BOOSTER readjust dials (CI-C2) for maximum Your r:Jdio en­ results and then re-adjust (KI) for the joyment depends required volume and to clear up any largely on the distortion or mush that may be present. tubes. They must The radio frequency transformer function properly. They can be made (RFT), also known as the "filter coil," "just like new"­ is adjustable by sliding the primary Rhamstine* Tube coil back and forth on a brass rod in re­ Booster gi ves lation to the secondary coil. In effect, them new pep, Tone Clarity this adj ustment is similar to the adjust­ freshness-a true. ment of a vario-coupler, for it controls full. round tone Beyond Expectation the degree of coupling between the pri­ which carries the mary and secondiry circuits and hence message as ,. clear Just pull tbe awitch and note the as a bell." claz:ity an~ richness of tone any Am­ determines the selectivity. With the pen.te-equlppedsetgivesyou.Amper_ primary close to the secondary, the tun­ Works on any alter­ Ita IS the automatic rheostat which Rhamstine* nating current 110-120 does away with hand rheostats and ing will be broader and the set will be Tu be Boos ter volts, 50-In cyclc.s- filam~nt meters. No guessing. No un­ less selective than when the coils are 20 I-Aor 199 Type T ubcs certainty as to correct tube current. farther apart, therefore the adjustment Send no money--chcck $6 the coupon below-pay Tubes last longer. Makes any novice On Iy ~ master operator. Insist Upon Am per­ affords a means of varying the selectivity on deilvery. Itewbenyou buyor build. Price $1.10. in accordance with local interference, and after the adjustment is made after ~ R;;~~'C~;;~:::Vy an installation, the coil is locked in place "8" Reeb -f- ler (EI""B::n~~::::y ) Dtpr. R. A, 11,50 F ... nklia St., N.Y. Cit,. and no further adjustment is necessary until the set is moved or changes are made in the antenna construction. ~rp~RlTE \Vith strong signals which cause over­ Price loading of the last audio tube, and there­ "SELF-ADJUSTING" RJU:OJfat Only ':Ihe fore produce howling, adjusting the resistance knob (r) will stop the howl. If a carbon disc type of resistance is used, $25 screwing down the knob will reduce the resistance and the overloading. Unscrew­ ing the knob increases the resistance and also the volume on weak stations. This adjustment is not critical, and needs no Rhamstine* " B" Rectifier ­ To Coaeamen Onl~ adjustment over a wide range of volumes, Here Is a real battery qooJity, but when a strong local is tuned in, it a quality product furnishing a de­ tr.r-..'iIT~~u~d i~: e:~~;~ pe~d~ble s~~r~~ of "B" power. terY .. buying public. Order DI. may be necessary to unload the tube. rect From ract0l")'. Put tbe Eliminates B Battery troubles Deale.·s Pr08t in YOQrown pock­ The grid condenser for a 20lA tUDe it et. You actually save mncb more normally 0.00025 mf. capacity, while the such as chemical action, dead cells thaD balf. and 80 that you caD be <:oov!uced of true Quality ....d perform- leak value will range from 1.0 to 2.0 recharging, and gives a continuou~ ::.~e H~~~~:a'!"~~~~o~faN:::::~ megohms. Experiment will show the I and uniform current, reproducing take 8 cbance. Our battery is right- and tbe price i9 lowe.st ever made. (.;.onvinC8 proper leak value to use, but in any case perfectly the original sound. The you,,,.II. Read tbe price.r it is not critical. Auto Batteriea Radio Batter'•• cost is nominal compared to servfce. 6Volt.t! Platf'!,S9. 50 eVolt, 100 Amp_59.50 The usual length of antenna, from 60 6Volt,IS tfl.te, 11.50 6Volt.120Amp. ll.50 Send no money--just check the coupon 12Volt• ., Plate.ll.00 6Tolt.HOAmP.13.00 to 75 feet long, is used with this super­ Buy DIrect-Send No Money heterodyne. Longer aerials are not MAIL THE COUPO~ TODAY :::!d~:!l:O':~ted~~~~;dwliit>!:ht ;!t ------aam. day w. re eelve ,OUl' order E%pre.s C.~ . D. recommended. .ub,iedto yourexamtnaboD J . THOS. RHAMSTINE* (11) OIl arrival. Our ~arantee 504E. Woodbridge W~°!Jro-.n15~=·dl!:~tl'J'· Detroit, Mich. ' for cub to luU with or. Please send me du. You cannot loeel "Roxy" on Way Back to His * :!."~~~r"" ...... /IMM -- your Tube Booster at $6. ARROW IlATnRY CO. Admirers -- your "8" Rectifier at $25. • Oept. U .. 1215 So. by .express C . o. D .• subject to inspection. If not Wabash JlMe.,Ch'cago s. L. Rothafel, famous "Roxy" of ~ntlTdy satisfied with the "8" Rectifier I wilt retum radio, will soon return from a European It to you In fIVe d ays and receive a refund of full trip and early next season make his en­ purchase price. trance as a director of his own Theatre in Name ...... New York City. :'Ilr. Rothafel is not only a great Address ...... '. , ... •••• •. • • announcer of radio concerts-gifted with the power of injecting his personality ------J. THOS. RHA~lSTI!-.~'" Over the ethe~but there is no more Radio and Electrical Products enthusiastic listener on the radio than 504 E. Woodbridge Detroit, Mich. "Roxy." He takes great pride in the wonderful . log of stations that he has recei... ·ed on several receiving sets. \Vhen he went to Europe on the "Le­ viathan" he took with him a Freed­ Eisemann 5-tube radio frequency portable receiver and used this on his tra"els on the continent. THE BEST RADIO APPARATUS On the trip home he will "listen in" to obtainable is being given away with 'the "Gang" from the Capital on' the new subscriptions to RADIO AGE. same receiver. The Magazine with Blueprints. Full announcement in this issue. Get your share of these valuable parts by a little .I . spare time work. Read' Radio Age :t- Tested Ilnd App-roved by RADIO AGE :t- 62 RADIO AGEJor November, 1925 The Alagazine oj the Hour The Magnetic Theory of Now you can Transmission (Conli nmdfrom page 50) UNDERSTAND quiet day than on a windy day when the air is in violent motion. Why would not * RADIO! the same be true of radio transmission? The magnetic field of the earth is con­ 514 PAGES stantly changing during daylight and is comparatively calm at night. 100,000 Recent experiments have shown that * short wave, or high frequency transmis­ SOLD sion, gi'-es much better results than long C.... pi/.I b, wave or low frequency transmission for HARRY F. HART daylight work. 1t is possibly that the E.E. high frequency waves are so rapid that A Real Long Range F."".,I, will. they are not affected so much by the lhe W.. hrD natural daylight OScill,tions in the earth's Crosley Receiving Electric Co., magnetic field. aDd U. S. The magnetic field of the earth has Arm, ID. been found to be strongest and most Set, $9.75 Iincl.r or Radio. T«b. unifor m during the months from October Do not aSSume from its very interesting DiuJl, .dil.d to l\larch, during which time the earth is price that this very unusual Crosley b,F.H.Oc>aD'. two million miles or more nearer the sun set is a toy. 1ts impressi ve performance More than 100.000 radiO fans relY on tbis than in June. During these months our alone entitles it to serious consideration. I. C. S . Radio Handbook to take tbe mystery radio reception is at its best. \\'hat is Heretofore. the $1 0 radio was designed only out of radio. Why e"periment in tbe dark the nature of the reception during these wben you can quickly learn- the tbings that for local reception. Now the Crosley insure success 7 Hundreds of illustrations months in the Southern Hemisphere? Pup extends the entertainment radius and dialrrams explain everytbing so you can An answer to this question would be to 1500 miles under ordinary condi.t ions. get tbe most out of wbatever recei.-er you interesting. build or buy. Place it beside some costly multiple­ A comparison of radio transmission tube set and operate the dials, Both Contents: EleclYiw terms and cir. conditions with conditions of the mag­ cuits, ant·ennu, batteries, genera­ tune through local stations sharply. netic field of the earth during its daily and Both get the same programs with equal tors and motors, eleclYon (vacuum) annual cha nses gives us very strange tubes, most receiving hook-ups, ease and clarity. Both let you tap the radio and audio frequency a mplifi­ coincidences If radio does 1I0t depend on infinite enjoyment coming through the cation, broadcast and commercial the magnetic field of the earth as the air. There is only one difference-the transmitters and receivers, wave means of its transmission. Pup operates with head phones instead meters, super-regeneration, codes. The observations of the earth's mag­ of a loud speaker. ' license rules. Many otber feat .... es. netic field, upon which the a bove state­ Almost overnight the Pup has become A practical book. Written by experienced ments are based, were ma de about six ty radio engineers. in plain language. Some­ years ago, the results of which were the most popular Crosley set ever offered. tbing useful on every one of its 514 pages. published, in part at least, in 1870 by I t is being bought for youngsters whose A book tbat will save you mallY t imes its George B. Airy, Professor of Astronomy curious fi ngers cannot resist the lure small cost. of d ials and switcheS; for the cook, the Just mail tbe coupon .... itb a dollar bill at Cambridge Uniwrsit y. snd Your name and address. a nd tbis 514- maid, the old folks back home, and for page I. C. S. Radio Handbook will be sent shut-ins. Traveling men are selecting to You by return mail. Note tbe ot ber good it because of its easy portability. and books listed below at low prices. STATEMENT OF THE OWNERSHIP. MANAGEMENT. radio enthusiasts to have an inexpensive r - ~T:R:A-;'O-:-A-;:- C~R-;;-E~O-:-D;N;E - -1 CIRCULATION. ETC. • REQUIRED BY THE ACT OF check on their larger sets. Hear it once­ l SCHOOLS I CONGRESS OF AUGUST 24. 1912. and you will own one too! I Box 878I·E. Scranton. Penna.. I Of RAD IO AGE. Pl1blished ;\! ODtb4'. t ) loUDt M orris. DliDoi.•• lor October. 1925. I Cro sley manufacturers receiving sets which are licensed under Armstrong U. S . I th~ :J~~I3b~Js·iiiark.13rx~~!tc h~ Is e~a~b~eit ~s t~~~~ I State of Illinois. } Co....a.1Y of Cook sa. patent No. 1.113. 149 and priced from l ~~~n t ~b !lllif\T lth r: 11~~t d~~ir~~ ~O~s~\~th ~e[~~ I D~f ore me, ~ Sotary Public iD a.nd for tbe StIlte and countY $9.75 to $00.00 without accessories. Add I my Illoeey. I afof'8H o:.id. J)er.;oDal.ly appearf'd F rederick A . Smith. who. 10% to all prices west of the Rocky o RADIO HANDBOOK. 514 PAGES. $1 b:l.rin« ~u dlJly s worn ,"ccording to b.w, de~s and s.'\Y'S M ountains. S ee your Crosley dealer or I ~ .\utolllobile Handbook. 354 page. -- - $1 I tbt be is the Presi":e"t of the RADIO AGE and th.. t the a e fo1.lowin« is, to tbe best of hi3 l..no.le:!~e aDd bellef . .. true write Department 63 for catalogue 'of ;a;.; I ~~~c~rf~~~~ ~~~Jbg~k . 4§U = : : ~ I I s tat eDlel1t o f the ownc:rshiP. D1AD:UtUDent (and if :I. chily complete Crosley Line. I'haem.e, Handbook. 324 page. - - - $ 1 I I):lpeI. the circulation) .et c• • of the a. (ol"e..'i 3id publkatioD for the I o Tr.ffic H ao d boo ~. 3 S G pal:" - S I date s hown in tbe a bove caption, reQuired by tb Act of Cuilding T rades Handhook. 409 pal:e, - - $1 I Machioe Sho!> H andbook. 83S p'l:e. - - ~ I August 2-1. 1912. embodied in .eetion 411, P o ,,; u.l La:ws and I S Regulations. Pr'i.oted on tbe reverse of1h.U form. , to wit: I ~"J;:~I~'I~~ Ill3n,.~~~okk. 34 ls Pp~~~'. : : : i I I 1. That t he name3 :lad addresses of t be pu blisher. editor, SITTER COSTS LESS Bookkeeper's Handbook, 3 02 page. -- ~ I ma.a.aqinl:' e6ltor. aDd busbe.5.! m.:t.D3ger-s ILre: PUblisher. I Ch·n Engleeer'. H andbook. H I pages - - u I I Stealll Eegleeer's Haedbooli. 298 pages - U I RADIO AGE. Inc .• F. A. Smitb. Prtl>i';eGt, 500 N . De.lrborn THE CROSLEY RADIO CORPORATION ~ 8t .. Chieaeo. Ill.: Editor. Fred.rick A . Smith. 500 N. Durbom St .• Chir:!lCo. Ill.: l\lan.o.G'ing EUitor. Frederick A. Smitb. Cincinnati, Ohio.

SOO N I De.:.rbom St. • Chic:t,gO. Ill. ; Bwin~ A1 !l.nat;ers. 1\1 . D. Nalll ...... _...... Owning and operaling- \VLW. first remole conlrol I I Smitb. 500 ~. D""rborn 81• • Chicar.o. Ill. Super power Broadcasting- sta lion. I [ 2 . Tb.. tth.owu .... . re: RADIOAGE.lnc •. ~OON. Dear· AddN!3 .••. ,...... , ...... _...... I born St.. Cbi"""". I U. : Fredericlo: A. Smith. 500 N . O""rbo", I St• . Cblcid binding. All of ab..,. 3 . Tbat the knOW'll bondholder.<. mortcacee:s, sod other I ~~:~d~co~'1 b:.r~:D~.~idi~~n '¥;:dee:~1:}nJt~o l.raffic I security boJrler'8 owuin.c: or boldiru: 1 per cent or mo~ of tot.:U L----______J a mount. of bonds, mort~ll~es, or otber securities IUc: (If there An Announcement are none. 50 state.) None. 4. T hat t he two J)8racraJ)h5 next "bo\·e. givi.nc the names of Importance of t he ownen>•. stockholder5, and security bolden, i f BuY. CODt-Ua Dot only the lut 0 f ~ tod.hold~nl and security holde n; to Every Atnerican t.S theY &PJ)bf upon the bOOb of the ~omPft.Jly but a lso. lD Real Radio Apparatus c.a.ses wb~ l" e tbe s tockholder o r .lt e ~ uri.ty bolder p,p:>C-l.J"S u pon tbe books o f tbe comIJaaY a.s tru..~ tee Or in an}· other fi ducbry Radio Fan! for Subscriptions to rebtioD. tbe Dame of tbe 'Person or corpou tion for w hom 1!I ueh tfU.!.t~ is QCtinc. ht Given; al!l.o that t he aaid t wo xm ra... Turn to page 20 of this · Radio Age! gr~pb s COD.t:LiD o:t::Ltement..:t embr:aei.nc affi.tt,.nt'. full k:nowled&:e a.nd belief IL4 to tbe Cl:'cumstsnces aDd conditiol13 UDde r 'W hicb atockho\ders Bnd security hol.!e11ll who do DOt AD()ClLr upon tbe issue of Something New in Prizes book... of t b~ COmp& DY &a t~U'e9, bold stock and securitie s in a el'UJ6citY o t b&r than t hat o f a bon$. fide owne rj and t his for Readers! affiunt bn..q no re3.S0 n to believe that anY other person, ~ o<:: io.... tion~ or corporAtion h~ any inte:-est di:-ect o r indi:-e-d i n t he RADIO See Announcement said !Itock. bonds. o r other ::t.ecu ritie3 than lLJiJ .B4? B~te d b y him. FREDE RICK A. ~nTB. AGE I Sworn to Bnd . ubecribed before ",e i.bi. Z(l th day of s..~"'1D- in this Issue ber.1925. I lSo"!.l '. HARRIET DILLON. ~------~ KARAS MONIK

AUDIO FREQUENCY AMPLIFYING TRANSFORMER * For aver 30 years makers 0/ PRECISION Elect:ical Apparatus.

UST one year ago the Karas Harmonik Audio delightful pleasure of real, true radio music in Frequency Transformer took the radio their homes. Set manufacturers were prevented Jworld by storm. by price from adopting Karas Harmoniks for Nothing like it had ever been known before. their sets. So the ready-made set-buyer, unless For the first time, scientific study had been de­ he undertook to switch transformers, had to voted to perfecting an audio transformer for the do without Karas Harmoniks. Today there are in use, hundreds of thousands of sets-good reception of broadcast music. The problem of sets-which could be vastly improved in musical quality by amplifying high, low and medium frequencies the simple operation of replacing the old transformers with to equal degree was finally solved. Bass notes Karas Harmoniks. Perhaps you own one of these sets. It were poured from the sQeaker in full strength may be all you desire from the standpoint of selectivity, of range, and other tuning qualities. But, if it is not equipped and rich tone quality. The vital harmonics in with Karas Harmonik Audio Frequency rich overtones, formerly lost, Transformers, you are NOT getting were brought out in their full The Distinctive Qualities that nearly the musical quality you can just as beauty by this marvel of audio Elevate Karas Barmonik Trans­ well enjoy. Are you going to be content transformers. formers to the Highest Pinnacle with anything short of the best? of Success in the Radio World. You can install Karas Harmoniks your­ Music critics, who had always self. It's a short, easy job. Or, any radio 1. Many thousands of turns of wire condemned radio music as false 2. Low ratio of turDS repair man can do it for you. Make up and distorted. approved the re­ 3. Estra large quantity of apecial your mind to do it now-at once. Get a formula iroa i.o core pair of Karas Harmoniks TODAYl sults of Karas Harmonik ampli­ 4. CODtroUed air gap S. No core saturatiOD ID large cities. most I/oad dealers carry Karu fication with great enthusiasm. 6. MiDi mum of Reluctance Hannoniks-aDd in maDY smllU towns. If your 7. Least Hysteruis ....d Eddy CurreDt dealer i .. out of them. order direct hom .... Prominent radio engineers sub­ Lo .. SeDd DO moDey. Just use the COUPOD below I jected Karas Harmoniks to ex­ 8. Low Distributed Capacity K EI . C haustive laboratory tests-and preYeDtinll iDtercoupJiDg of elec. 4065 N. RoekweU St., 9. trostatic: and electromallDetic Chic:al:o, J1l. __ pronounced ita technical ScieDtificall~~;ci~rCU~;lair~.~hi~.e~ld~iD:eJ:..;~ar~a:S~Ee:c:t~rl:C:~O~'~1fields -~=~ masterpiece. Technical editors 10. Very Hieb who promoted the season's most 11. Extremely Higb 12. Higb aDd eyeD ...~c CO.. _1_..n,11\. ". .. udio ¥te""\UO AmplificatiOD ':lee~· St. '"' ...... ~- nu> n ~ ~ successful hook - ups specified of all ADdio ~ar.S .,. lloc:k~e\l' raS ~a[tllO $' a~iec:e'ed to Karas Harmoniks in their cir­ F",~ueDciO$o I\Qb5 N· p airS ot ~~e p

~ Teeted and Approved btl RADIO AGE ~ 64 RADIO AGE/or No\'cmbcr, 1925 The Magazine of the Hour $110,000 Super-Station Plan­ Pat. Build the Set That ned for St. Louis April The primary plans of organization 11, I~S Holds 4 World' s Records were completed recently for the establish­ Other ment in St. Louis of one of the largest U . s. and and most eleborate radio broadcasting Foreign i'atenU stations in the United States. The pro· Pendiog ject, which is being undertaken by nine representative business organizations of St. Louis. including the Globe-Democrat, involves the erection of a $110,000 super­ d station, which is expected to be ready for operation shortly before C hristmas. It will be announced as St. Louis' Christ· mas gift to the nation. Contracts for the apparatus have been placed with the \\'estern Electric Company. I t is proposed that this mammoth stations, operated at a cost of approxi· mately $135,000 a year, will typify the The receiver that brought in sta­ "voice of St. Louis," identifying the city HE ACCURATUNE tions 6,000 to 8.000 miles distant with superpower and super-programs is ideal for coarse orex# with loud speaker volume night T of exceptional merit. Application will tremely fine tuning, segr~ after night. be made for a charter for a corporation, Holds World's Records For membership in which will be held by the gating even those stations (I) Longest d istance e ver received On 8 following original organizers: St. Louis now so closely grouped on loop 8erial-8.375 miles Globe-Democrat, The Merchants' Ex­ the lower wave lengths; it (2) Most consist ent reception of s tations change of St. Louis, The Brown Shoe brings them in with ab# 6.000 to 8,000 miles d istant-1I7 pro­ Company, Skouras Brothers Enter­ g rams in three months. solute precision. Volume (3) Brought in 6 d ifferent stations in 2 ~ prises, C. F . Blanke Tea and Coffee hours-all over 6.000 miles Company, Colin B. Kennedy Corpora­ and clarity are matters of Full sized blue prints with com­ tion, Wagner Electric Corporation, St. course to the Accuratune. plete instructions showing how to Louis Radio Trade Association and Quickly substituted with# make exact duplicate of this George Kilgen & Son, Inc. out alteration of your set. marvelous receiver. To Include Sixteen Firms PRICE $5 The plan calls for a total member­ MYDAR RADIO CO. Story of development and p roofs of records ship of sixteen firms and several other 17 CAMPBELL ST., NEWARK. N.J. sent on receipt of slamped and a ddressed concerns, besides the present members, envelope. are considering the plan wi th a view to Scott Radio Laboratories joining the organization. 35 S . Dearborn St., Chicago The Board of Trustees of the organiza- Dealers and Jobbers Write tion is composed of E. Lansing Ray, president of the Globe-Democrat, chairman; ElectricW. A. Layman, Company, president and C.of theF. WagnerBlanke, I ~~~;;~~~~~~~~~~~~~~~~ president of the C. F. R1anke Tea and Coffee Company. The entire en terprise has been inspired by the civic interest among the organi­ zers, who expect the project to prove an WRS 96-PAGE important factor in fostering the de\'elop- RADIO GUIDE BOOK ment of the city and community. Profu"C'ly illuAtJ'at~d . " rhocldul*' of data. for tbe W. Palmer Clarkson, president of the redio fO[l:,. Chamber of Commerce, has been pres­ T .ouLl. Shoolin~ Chrt. ent at several of the meetings, which Complfle New List 01 Broadc~3inl Stations have heen held during recent weeks to Log Chart perfect the organization, and has mani­ _Dd detaila of D_eot fested enthusiasm onr the possibilities I ~~~~~=:~a pPtlr"t UB fl Qd hundreds of which the plan offers for advertising the The Famous ~ruly POTtable ~ Exceptional * Radio Values g~r city. TELMACO P-1 Receiver .. Capital of 49th State" MONEY BACK GUARANTEE Four Tubes Do the Work of Seren FrOtD bu. bu to the ft nest mu l ti.tQb. aet. 1111"0 C3l'T7 oDe q aatity­ The programs, which will take rank THE FINEST! 1c\fERY article h pr el'lenta 100 ('4."nta _o tt~ of with the outstanding radio-casting pro­ ~!:~~:.f!;:!:~~~v~~~::=;~::i; :~:u;~~~: C:~~J1rs·I~r~i!.r:uy :~e~~o~~::JJr6t~ K,,::~r~~ grams of the world, will be designated as Aerial. lond opeaker and batteries a.1f eontaln.d. liB J'oo aro tboro1lBb17 aatiafied ID OVIIIZ7 wa,. ~4'r.~te~~ti~e~.!'~ ILD~ b~tte~lae: $125.00 WRS IS HEADQUARTERS !'OR KITS AND SETS coming from "St. Louis, the Capital of the 49th St ate." and while the call letters P-I Kit Sayu Tou M_e,.i ~~~S: ~~~r ~~~!~c:::~. Ourolrer of the Telmaco P-I Reoeiver 10 kit form bu UHI'Odyne pressley Supel' have not yet been assigned, it is probable Roberts· Knock-Out Rasia met witb entbosilMJtlc reeeptioo. Ttue contalDII all that their arrangement will suggest parllII. as built h1 ""Ilnelodint.:""". d,,11. d and en- FREE :o.~:;':~ :~~f:.r~o~ri~ t~:ttT~t;A. rd. book. "The 49th State," ~':~~e~T~' ~ iJ •.,..~ted. ~O~DS . $80.00 Business offices have already been AIIk )'oordealoror write us. D.ocr!ptlvo 'oldar tree. WHOLESALE RADIO SERVICE CO. "1{tfdio CJ)itlision: 6 Churrh St. CaL R. A. 10, New York City estahlished at 737 Frisco Building, under the management of Thomas P. Convey, Telepbone Malntenance Co. general manager of the St. Louis Radio so So. Well. St. Dept. C Cblc.ao,1JJ. Trades Association. A committee, com­ posed of Colin B. Kennedy, Melville B. ~ NO QUESTIONS ASKED! II all, treasurer Brown & Hall S upply ~lit,. "1{tfdio c"cllUitI~l,. ~ c.l4blis1r~d 1918 You won't have a thing left Company, and W. A. Layman, president to ask about when you build \\'ajl:ner Electric Compa ny, wlil select a site for the broadcasting towers and the RADIO AGE Model Re­ building, which will be located about ceiver to be described in the sixteen miles from the heart of the city. l1LTRZf-VSI{nIBR. Decetnber issue. Every part, This committee is also negotiating for TUNING CONT~OL dpwn to the last binding post, temporary quarters for the central studio, where the programs will be produced " YER~If..R OIA\,.. ON "N'''UC:1 v OU C"'N ~E'C I I. will be specified by its trade ~ECORO 't"t£ STATIONS C£A~£O 20 -('1 ' ~1 L.. V ~f? pending completion of the new Ambassa~ -"\'fPS~ 3250 - COLO FINrS.H S3 50 name. ORDER YOUR COPY dor Building. Permanent studios will NOW I eventually be located On the top floor (Continued on page 65) PHENIX RADIO CORP. 116.F Ea.t 25 St.. N.Y. C. 'f. Tested and Approved by RADIO AGE ~ RADIO AGE for NO\-ember, 1925 The Alagaz£ne of the Hour of that building, adjoining·the miniature rehearsal theater of the Skouras Bros'. en terprises. Engineers on Way Engineers are now on the way to St. Louis, having been sent by the Western E lectric Company to survey the ground here and supply the technical informa­ tion necessary for immediate installation. T he reason for the location of the broad­ casting towers at a point removed from the city, according to members of the Qq;anization, is that programs trans­ mitted from such a station will offer n , minimum of interference with the less powerful broadcasting from other St. Louis stations. "The radio receiving public is becom­ in!? more and more discriminating." said \V. A. nutler, manager of radio I apparatus sales of the Western Electric Company, in discussing the project. "Radio enthusia!:' ts want better pro­ grams and better broadcasting. For this reason, our company, in recommending the apparatus and the location for this super-station, has urged the selection of an outlying site, which will enable listen­ ers to tune out selectively, without, however, monopolizing the air. THE KODEL MICRO­ Effective Throughout Nation PHONE LOUD SPEAKER is an exact replica or. the "St. Louis, in its geographical loca­ transmitting microphone tion, is exceptionally well adapted to the used in broadcasting_ establishment of a super-station like the The effecient Kodel reproducing one planned. This station, with its unit, with 8n ingenious new 5000-watt capacity, will be ten times as snail. shell horn. mounted inside the microphone case. produce~ powerful as any within 'The 49th a remarkably clear, full-toned State.' It will have a dominant range volume. Non-vibratinf!; tone throughout 'The 49th State,' and, ac­ chamber eliminates distortion. cording to the experience of similar The $15 model incorporate. the new Kodel. Jr. unit\ WIth the stations, an effective range throughout Jara:e Kodel unit. $ZO the entire nation." While the plans for the programs have Ra

KDKA KFVY Rndio Supply Co...... Albuquerque. N. M . 250 KDLR ~i~n~:c~~~c E&~~ : i.c . ': ~ ~ ~~ ' , ~o:. " .... "· . :D:vr~t~~k;~~ ,Pn: ~~ KFVZ Glo.d TidinC'5 Ta.bernade ...... San Fl'&Jlciaco. Calif. 234 KDPM K FW A Bro.. nin~ Bros. Co _ ...... Ogden. U tab 214 KDYL ~;:~~~~:t~~~~~r.i ~ .~ . ~(. f~: .~ .: . . .':: :&li ' ~k~etit~: B~h i~~ KFWB Wa.rner Bros ...... , ...... Hollywood. Calif. 252 KDZB Fro.nk. E. Siefert ...... Bakersfield, Calif. 240 KFWC L . E . Wall ...... Upland. C ..lil. 211 KDZI Electric Supoly Co...... ' . , .. . W~n.t.cher.. 'Vash. 360 KFWV " 'ilbur Jerman .,...... • . , ...... 385 68th St. 8., Portl&D.d, Oro. 212 KFAB NebtA.t:>ka Bukk Auto Co.. 13th &;: UueSt.'i...... • Lincoln. Nebr. 3-41 KFXB nertrnm O. Hell.r ...... •...... Bi" Bear Lako. Calif. 203 KFAD "[cArthUr Bt03. ~I creaDtile Co. . . . . , . Phoenix. Arix.. 273 KFWD Arkaru;aa LiKIIt & Power Co . ' .... '" .... , .. ' ...... , Arkad~lohia. ArbDSILS 266 KFAE State CollC!~e of ",VD.;i.binRton . . •. .. , . • . Pullman. \Yuh . J ... 214 KFAF ~· e." tflrn Radi~CorpO ra tion ...... , 'i:eoldflr • ~oto. i~~ ~~~~ ~~.,t:u~~C'~~~t~fC:::.eJ~ :::::::::::::::::::::::::::::, . : : ~~Ch~':,~c~hf: 254 KFAJ KFWI R&.dio ED tertaiDment.s. Inc ...... , ...... 80utb So.a Franciaco. Calif. 220 KFAN KFWM Oa.kland Edur&tional So~iety ...... •. . • ...... , OakJand, Ca.lif. 224 KFAU KFWO l.a'Wr~D~e !\iott ...... , . . Av .. lon. Calif. 211 KFAW KFWP RlO Crande H&dioSuOOly HOWie ...... •.. Browu::;villc, TeX&3 214 KFBB KFWU Loui:.iana Colle~~ • . • ...... •...... •...... , .. . . PineviU~, La. 238 KFBC KFXC Santa ~Io.ria Va lley Railroad Co, .... .• •...... Santa 1\[aria. Calif. 210 f~~~~:;~:H+ i .iii· . (£t~.~ ~! KFXDT L. II. Stron~ ...... Lol<&n. Utah KFBG 205 KFBK KFXE ElectriCAl Research & Mfg. Co ...... • .... . 'Vat4:"rloO, Iowa 236 KFBL 250 KFBS ~~~~ :~~:~e PR:~i~C:~C=~i~~.. ~ ~ :.' .- ::.':.-:.-.': :.-.'.-.': ~~I~~~~~. :r~:::~ T~~I:'; 242 KFBU KFXJ 1\[ountain Sta tu Ro.dio Distri.butors. Inc. (PortD.blo .tation) ...... Cclorac.io 216 KFCB ~~1t:~~' : ·:: t~~1~~ ill KFXM NMhr's Electric Co ...... •...... Beaumont. Te100ll 227 KFCC The F intt Conl:reJ:lltioaal Church ...... ••.. , " ...... HelenD.. ~(ODt. 2.8 252 KFCF Frank A. ~Ioor o ...... W ..II. W.U". '\\·... h. 256 ~g~ ~:~~~ ~:~i~C!~e.r .-.- .' : .-.-:.' .':.':.' :.'.'.'.'.-.-:.-::::.'::.'.'.'.-.- ~:~:=d .\b:i?i . 361 KFCZ Omaha Central U ich SchooL ... .•...... •...... Omaha. N.hr. 258 KGU Mnrion A. ~lulrooY ...... Honolulu. Baw.. i.i. Waikiki Be.>ct. 370 KFDD St. MichaeLR Cathedral ...... " ...... , • Boi.... e. Idaho 252 KCW Portland l\.[orning Ore¢ooian ...... , .. .. . Portlaod. Ore~. 491 KFDII Univelbity of Arizona _ .. . . . _ . ..• .. • . . • ...... • Tut' on, Aru. 361 KG Y Ih. ~artin . CoII."e (ltcb. S.1> ...t;"n Ruth) ...... • Lacy. W ...h. 253 KFDJ Orel;'oD Agrirultur ..l College ...... •..•. .. • ...... COrvaUi... . Ore. 254 K HJ Timc.,-l\lirroT Co . . ' ...... •.. . •.. Loe Anc-eles. Calif. 405 KFDM ~(acnoli& Petroleum Co...... Beaumont. Te~ 31S KHQ Louis ~'aamer . . . • ...... •. . . •.•.. . , .. .. . Seattle. Wub. 273 KFDX Fir5t Baptist Ch urcb . . . .. , , . .•. . • • , •• . •. .. r ••• •••• • •• 8hrevcDort. La. 360 KJR Northwest Radio Sen' lco Co . .• ...... •.• ...... Seattle •. W&ab. 384 KFDY Soutb Dakota 8uto College ...... • ..•.. . ..•. , . ... . BrookinCS. S. D&k. 360 KJS Bihlc lQ.5tituteof Lo!'l Aol:elM. InC . .. , ...... Loll An~elea . Calif. 293 KFDZ lIarn' O. I,-ers on ...... •. • ...... ~[innearJOli". ~liD.D . 231 KLDS Iborl:o.nizeo Church or J e...u .. Christ of Latter DAY 8&inta. Indepeadence. 1\.[0. 441 KFEC !\(eier &. Fa-auk Co ...... __ . . •.•.• ...•...... •...... Portland. Ore&'. 248 KLS "'arner Broth~r.. Radio 8uPtlliC.!l Co ...... , ... , ...• Oakland. Calif. 242 KFEK Aunbury SemlDarY...... MiDneaooliR. ~linn. 261 508 ~t~ it~~~l. P:~~~~iDd'o .C~,. : : . . , . . ::: : :: : : :: .... : .. : .. : ...... : .. '. ?&~~;. ~~I~ : KFEL r.·'L~8~r~. ~~r~.. :. :::. :.-:. " ...... : ': .. ,'. ::::::::::: ... ~~o..i:: ~~~~: ~~ 283 ~~~~ Bunker Hill&: 8ulli\'tLQ 1\.lining and Concentrating 0...... Kelloa:. Idaho 233 ~~~ &;" j~~;'i'; '1:"l.-lich . 286 KFGS Crary H a rd"'are <::0.' • •. . .. .•.. •• , . • ••...... • , ... , . Boone. Iowa 22 6 KPO lIal~ Bros ., ...... • .... . Sao Francisco. Cnlir. 428 KFHA Western Sts.tP Collei!O of <::Olotado .• .. " .•• .• .. .• • .• . , . . .. Gunnison, Colo. 25Z KPPC PMailfina. Pre.;,bY1.crJan Chureh ...•...•...... •. , . . Pa.sa.den_, C.lir. 229 KFHH Ambros. A. McCUe ...... N~nh Bay. W""h . 261 KPRC HOU l ton POSt--Dl::iDlI.tm • ...... ••..•...... Houston. Te1U 270 KFIlL l'>f'nn Colleh ...... •...... •. •...... Oskaloosa. 101\'n 240 KQP Appl.C;tY. llamoCluh ...... 11 000 Rivor.O • .•...... • ,., , •• . , . . ... • St. Louis. ?>olo . 545 KFIZ DailY C.ommonwcalth ...... , ...... •• . . "...... F o nd du Lnc. Wis. 273 KSL Radio s.,,,·.c. Corp.ofUu.b .. ' " ... , ...... S< Lr.k.CitY. Ut&b 299 KFJB Mflr8baU Electrical Co...... •• ...... ~I af': h n. llto",·n . J01\'a 241 KTAB T(lntb A\'e . .Baptist Churcu ...... •...... • ...... Oakland. C&1ir. 216 KFJC R. B . FAPO (E~('ogal Church) . . . .. • .••...... ' Junction CitY. Kan.'I&.S 2U KTBR Br01\·n's Radio Shop ...... • ••.. .. , .. , ...... Portland. Orecoll 263 KFJF Nati:onnl Ihdio M li.nUracturillC Co...... Oklahoma City. Okla. 25Z KTCL Am(>riean Radio Telephone C o .• Inc • . • ...... , ...... Seattle. W .... b. 306 KFJI Lb('rtY Thcstre (E. E . ~Inr .... b) ...... Astori:l.. Ore«. 252 375 KFJL Hardso.cJ: Ma.nubc turinc Co...... •...... Ottumwa, lo~& 242 ~~S ~i~~ 1!~~~:,I!:t~~r~ h · .- . .- . ·:.·.':.. ..: ....:::: .. : ..: ... ·.. : __ :.~~~~~~:~W~~: 455 KFJl\f Uni\'en, tY of North D a kota ...... •. , ..• ,., ... . CTa nd Forb. N . D.IIk, 280 KUO Exnminf'r PTintillC ("0 . .. • • • • •• ••• , •• , • • ••. • . • S ZLO Francisco, Calif. 2.46 KFJR .A3bteY C. Dixon & Son .. . , ... .. , .. , . ' " Portland. O re&:'. 258 KUOM Sta te UniH.>rsitY of I\-l0Dtanli...... •.• , .•. , .. ' ..... l\.lissoula. 1\lollt3.DA 244 KFJX Iowa State Tf'&chcr'., Collel:e...... , .Cedar Falls. 10",, 8. 280 KUPR Union P:l("ific Railroad Co . . • . .. . ••. • •..•.. •. .. " . . , . . Omaha. Neh. 270 KFJY TUllwllll Radio Co...... Fort Dodge. 10'\\'a 246 KWC Porta ble \\' iteJess Telcphone Co ...... •.•.. •...... Stockton, Calif. 248 KFJZ W. E , Brllnch .. , ...... , ...... • Fort 'Vorth. TfI'-&8 25. 236 KFKA Colorado Sts te Teachers C-oLleP:e ...... • Crecley. Colo. 271 278 ConwllY Ih.dio Lahor.!ltories (Den H. ''"oodrulO •....•.. , •. . ('..on'lT Il.)". Ark.. 250 ~~cf~ ~i!~~r;~ ~;~o~~~~.~. : 7·:·::.. :. ..:: :... .::: :..... ::.. :.:.:: .. :.:: ...... ·:~~~:'::i~~:~~? 270 ~~~8 The Unl" erutY of Ka~ . .. , ...... ' , ...... , .• . L &lVrence. K allA. 275 KYW 'Vestin&hnU5e l-lectrio'& ~lfl:. Co . . •...... •.. . . Chicago. In. 535 KFKX We:-;tingbo~ . 8 Electric &. ~( a lluflLC lu ri ng Co. . ,...... H AS tincs ~ Nellr. 288 KZM Preo;on O. Allen...... •...... Oaklanci. Calif. 242 KFLO Paul E . Greenlaw ...... • . Fralnk.Unton. 1.011 . 2 3-1 263 KFLP Everett ~1 . I ~o. .; t~r ...... , .... . • u rches. ,. . .•. . , .•• ..• .. . • ••. . • ...... l.ittle Hock, Arl. 254 ~!=~ ~~i:"~~ts~~~~·:: i ~~d. Co ·. ·.·,·.·.·.. : ...... ''-:.'. ':.', ':.'...... tI:rri!'b~~~ ' ~~: 266 KFMQ Univen.itY of Ark a1lJl (W • . . •• . . .• . •• . •• • • . • • . . . FaYettevillr, Ark. 299 WABC A.b.villo BatterY Co .• IbC ...... A.heviU~. 1'. C. 254 KFMR MorninltMide Colles:...... •...... S)ou:t: City. lo-n.a 261 WABI Ban C- or Railw.!lY &: Elef"tric Co . , •. ..•...... , .•... . , ..•.. . . BanKOr . l\le. 240 KFMW ~I. C. 8a.terrn ...... •...... nou.:hton. :Mic: h. 266 WABL Connectirut A~ricultura1 COllpl:"e .• ...... •. .• . . , . .•... . Sorr". ConDo 283 KFMX C ..I~ton Coli"""... .. " ...... North6~hI. I\Unn. 336 WABO l.ake Av ~nue B n.-ptist Church . , ...... •• . •.. • . • ••••. .. Rocbuter. N. Y. 283 KFNF Jlenr ~' Field Seed Co...... •.... . Shena ndoah. lown 266 WABQ Haverford CoHeeE'. R . dio Cluh ...... ••.• .•.••..... Haverford. PD.. 261 KFNG Wooten's HntlioRho'P ...... ' ...... CoJclw.t.er. :M is.'f. 254 WABR Scott W"h School. !'. W. B . ~· oley ...... Toledo. Ohio 270 KFNV L . A. Drake BatterY and Radio SublllY Shop. . Sant!l 1t00'ia. enhf. 234 234 KFOA Rhod.. O.partmont Sto~ . .. . lSe a ttl~. W ..h. 454 ~~:~ ~~~eB~fJ!~~.t~~ :::: . ~: : ::::: . ::::: ::::::::::::: : ~ii : c1!~~s:~.~~~~~ 270 KFOL Ledie M. Sch.a.fhush ...... ~l areQl:"o.lowt\. 234 WABY John ~1.Cllldi. Jr • ...... , . . .. ••..•..•. , .....•...•.. . Philadelohi ... Pn. . 242 KFON Hcho-phono Jladio ~IOI ). • • • •• ••• •• • • • LoI1£ Bench. Calif. 234 WABZ Coliseum Plllcc Baptbt Church • ...... •...... •• • . New Orl.ns. La.. 263 KFOO Latter DaY S:l.intl.· Univorl' it y . . • ...... Salt Lake City. t:u.b 261 WADe Allen T . S immOl\Jl (Allf'n Theu.tre) .....•...•...•. . •...... • • Arkon. Ohio 258 KFOP nohr~r EI••. Co...... Ma r bfi.ld. Oro. 240 WAFD Albert B, Pllrfet Co...... Port Buroo. l\ticb. 233 KFOR Da v idCitYTir.&'EI~ctr i cCo .. .. , ...... David City. Nebt'R.I:>b 226 WAlle A. II. Crob. '" Co...... Richmond Bill. N. Y. 315 KFOT CoU.".lIill Hadio Club...... Wi.h,u.. Ka...... 231 WAPI AlAbama. PolYtechnio lnatitute • •...... •.••...... , ., ...... Auburn. AI ... 248 KFOX Board of Education.T~~hn ic n.1 DigbSchool. ..•...... • • , . Omab.a. Kebr ~ kll 248 244 KFOY BM<'on Radio Ser\'i('e...... •• •.• .. •• • . . . St. Paul. ~Iinn. 226 ~~r'!> :;:~~ll:t~i\~tY ~: ~ .. ::::: : ...... ::: '.:: ::::::: ~ ~: ~ : ·. ~~W~~:le~ll:~: 283 KFPC C a.r ret.-on a nd Denni.,...... • ..• • . , • . Los AnC'elf!~ . Calif. 238 WBAC C1olDOon Agric. Coli""• ...... • ...... Cl8111110n Coli"" •• 8 . C. 331 KFPL WBAft The Dal"ton Co...... , .. .•.•..•..... 1\[innea.poli.s. Minn. 417 KFPM ~b~N~wX 'F~ ~ ~ it~~~ 'c;,: : ~ ~ : ~ ~: ...... ~ : ::: : :: : : ~ : : . Cr!:'!i~i: : i:= ~:i 275 KFPR Loa Anr.t'lft'l County Fore!'ltry D~Pt . . . . . • . . . •• . . • . • . . . Lo.q AnJt'ele.• • C.lif. 231 ~C~~ ~:~:YI;I~~flSnULttnfv~::~~;:.· . · ',' ...... : ... .. '~ '...... : ..... ·. ~D=~~~~: 1:: 360 KFPT Ca",,&JohlW>n ...... Salt Lake City.l tah 286 WBAP " 'ortham-Carter Puhlishing (Sta.r Teleoam) ...... , Fort 'Vorth. Teu,s 476 KFPW 8t. Johns It-I . E. Church...... • • • ••• •.. , ..•. • . . Carterville. ~10. 268 \\'BAV Erner &; Hookina Co . .. .. ' ...... " '" . Columbu.,. Ohio 292 KFPY Symons Investment Co ...... , ...... • ...... Spokane. W fU; b . 283 WBAX John ll. Sten". r. Jr...... Wilk6S-Barre. Pa. 254 KFQA WBAY 'Veit.ernl;; lectrioCo . . . . . •. • ...... , New York. N . Y. 492 KFQR i~: S~~~~~W!ht 'liui)ib h i nC'~ : :' ...... ' .'.': .. : :.' : : :::::: :: · F~ttw~:b~T!.~~ ~~ WBBC In' in~ "~rmilya .. • , . , ...... • .... .• .. • Mattaooisett. ~1&ll5. 248 IGdd Bruthers Radio Shop ...... Taft, C alif. 258 WB8L C ra~. Co\'eDa nt Pre.... bytcrian Chtll'ch ...... Richmond. Va. 253 y,,'BBM AtlA.l:l:s Inve."i tmeot Co ...... , ... .. icago. IU. 226 KF~~~~ P WBBN Bh , ).;~. A. B .. • . . . . • ...... •. • ...... Wilrninonon. N . C. 275 KF T ~!{;:1;.~t~ ~~ : : : :: . :::' .. '. :::: :: :::::.:.:: :. ::: :: ~~1=~!:i~aE~ m WB8P Peto~ keY ni~h School ...... P~tos keY. 1w1i~h . 246 KF W. Hiker ...... I10lYCiW. Calif. 253 273 KF W C . F . Knierim ...... , . . , . . •. . •.. " North Bend, "pash. 248 tt:::~ ~~I~!:'l:.I."~~'!.c:.: . :::: : .' .. :::: .' : N~~ssOr~:~·L~: 252 Tnlt Prolrini:hou:;e E1C!Ctric &: ~Ifi:. Co ...... Hotel Bnm.s-n·ick. Bo.ston. 1\-[-.u. 242 KFUS WCAD St. UlwT~n ce University ...... , Canton. N. Y...... •.• ...•.....•.• :::: '•..•• ::::::: '.:: 280 KFlJT ~lil~~r~tt~~rU::;.·.·. · ·.&ii ~~~la~y ~l~~ ~~~ WCAE Kaufmann « Ba~r Co. and Tile PittAburi:b Press ...... • ... . Pittsburgb. Pa. 461 KFUU Colburn Radio Lnh:t .•.... , . . ... , • ..•. • ••. •.•.•• , . . . Sao LM,odro:CaJif. 2Jt WCAU Entrekin ElectriC! Co ...... ColumbWi. Ohio 286 KFUZ WCAJ N.brB-Ak, \\'e..leYAll Uni~'e nii tY .. , .. . . •...... Unh · r:r ,. itYPla('~.Nebr. 283 KFVO WCAL St. Olaf Celle" o...... Northfield. Minn. 336 KFVE WCAO Sand... '" Staym.... Co ...... " ...... •... . Baltimoro. Md. 275 KFVF WCAP Che.-.;.aoe&ke &. Potomae Tclf.!phone Co ...... , ..... , Waahi.ngion. D , C. 468 KFVC i!~;~fi~~~:~~~7~:~ ~ ·:":~·:i ·:: ·::·~ ·:~~·:·:·:·~·~:·~i"::~·: ·~~L~~?~~=;E~ ,~ WCAR Alamo Radio }~lectric Co. " . . ." ., ...... • ..•...... San Antonio. Texas 263 "FVI! \Vbao Rtldio Shop (Herhel' t \\,h~n )...... •...• ...... l\[l1nhattan. K.Q.n~&8 218 WCAS W. 11. Dunwoody ImhL~ trlal In.'ititute . ..••. ••••.••• . ••. Minneapoli..'I. MiDD. 280 KFVI neadQuB.rt~nt Troo-p, 56th C"vAlry • .•••••.....•...... Hou 1i ton. TetA.'J 248 WCAT State CoII."eol ~Iin...... , ... , ...... Rapid City. S. Oak. 240 KFVN •...•. •. : •.•••..••••• ::'••• •.•• :: ..•. : •. ::: .. .. :: .. 278 KFVO ~~r~{~·B~~;.~ ·.· , · . · .·.·.· ·. ~;il l!~i~~~I~~~: ~~~ ~~~~ 8~i~\:r:it: ~v~;~~~'t: ...... :., ...... :. ...: ...... ' . ~~~i!I~~., ~~ 250 KFVR "Z4G KFVS ~a=~~~:r~t=:\~it~~ y · SU:t·i~ ·.: :: : ::·. '. :'. ~ '. : '. : ~:: ~C:~~ 1::~::d~~u.

lesk~Ak-charles Stuart, Lincoln, Neb. Power-Plus Straight.L.ne Straight Lin~ Frequency. The Rotor and KFIX-Arthur B. Church, Independence, Mo. Frequency Condenser Stntor plates of tbe new Power-Plus conden­ KFW A-Rohert Nevins, Ogden, Utah. ser are designed to give straight fr!'quency KLX-J. R. Knowland. Oakland, Cal. line and perfect contact. PIgtail aesign KPo--R. B. Hale. San Francisco, Cal. eliminates contact resist ~ ncc and auto­ WCCo--Prof. C. M. Jansky, Jr., Mmneapolis. matic Wf'ar comprns-, tor prc,'ents frequency ~.h"nge. Numerous f",turt's of design render St.~~_~~E. Harkness, New York C ity. ..ffecth enf'~s nf'-vcr before nppro:Lched "ith WFBG-Walter S. Greevy, Altoona, Pat straight line Or any othf'r type of condenser. WGHP--y RADIO AGE 'to 68 RADIO AGE for No\'embcr, 1925 The -Magamtle-oj the Hour

~~:~ ~J:lb~:."i'i: . DI\~~-:~~~ ::: :: : ~~:;-::: : :.::::::::::::::::: ~~ . ~~fo;;~IiJli: ' lI!O • . • WHBV- Rivi.r.Th~treaDd Biwr's CIot.h.i04~ ...... _...... ADd.,"".n. Ind. :ua WCBE Uhalt R&dio Co ...... Ne .. Orl...... La. iY §!r:~~~~~~~i~~t~~ ;:.. :·:·:·:·:·:·:··:·:·:·:·:·:.. : ·:·:.·:.. :· :·:":·:· :.·: · ~ :·:·~fk~ft~f i~

. •. .. ..;b ...; l... ..; . :: ...... •. :. ..: . • ..: •.. .. .: .:: •...... : :. :: .. .. . : :: :::::: ::: : :::: : :: : : ': : : m ~wWCC~B~R Uc~.fnf.~.;r~"¥"'~':.. _, ' :'~'~" :.~:b~ ~O .;:.~ ~ ~ ~ :.:~ ~ \.~ ~ ~ ~ ~~. ~: : B. · . ~. :p:[roiv~,~d~~.fD~C~.~.;R·~'{;I ';· ~~~~: ~:tg~E~ ~.:''::;i~!t·t,!~li.'hi;';:~J~~~11rr!~. : t~ :i~~~c.;::::::::.'.' .'.' :.':::.'::::: .'::::: : :~~{!!.~i~I~:~:: ~~i~~~l::.ia~d·. m WCBT Clark Uni\'er:-. ity.Col1f'Ntfi D.nt ...... •....• •.. " . . . WOrCf!";fcr. fI,[JI.l/.S . 238 WIAS Home Electric CIi .Mer.dith) ...... C ...DOvh .N. Y. 261 ~~~~ 6'.:i'::.::~:~jJ.~~~r~~k~: i>~j,·~·N;,;e ,;i~i EI~ ctr; ~i En.ti;'.~ri!~·L9!~~~,;. ~~~~ : m ~~!f ¥~;~~'13~::r~~~:~ ·: ·:·:·.·:· : ·:·:·:·: ·:·:·:·:·:·: ·:·: .:.:.: .: .:-:.:.:.:.:.: .:·: ~~:ll::~1: m ~~l~ ~U!.~=~~tB~ti~~hC~~r; h ::· · : : :: : :::::::: ::: : : :::.: : ~hi~:J!r;h~c~~: 234 W~[AN FifStBapti'ihCburcb ...... • ...... •. . Colu mbus. Ohio 286 WFBE V3n De "'alle :\[u."l icAnd Ra.dioCo ...... SeYmour. loci. 226 WMAQ Cbic ~o Daily Ne:ws ...... , ...... • . ••• ...... OiicB&'o. (11 . 447 WFBC Tb., WID . F. Cable Co ...... , ...... •..•...... A!tOOD3. p$. 261 WMA Y Kin&:fhighwaY Presbyt.crian Cburcb • ...... •. . . , ...... St.. Louie. ~Io. 280 WFBH COD coursoJtadioCnrporatiOll .. . , ...... New York.N. Y . 273 WMAZ hfercer UDh·erl\itY• • ...... • • ...... Mo.con. Ga. 261

WwWFFF BBBJRQ ~,. ,YuotbJOI~DDr~.· .' Ur'd·:'. · N~Dt· ~·lwG: U·.: ,:d· .: 5: t:b: 'R' ';'. .' A: ''r 'm' :o: r'y: :.: .. :.:.:.:.:.:.:.:.... ~.. 0. 1. ~I!~I'.~,.~bo·'.e~.II\~ICdn... i~~ ~~:~ I{l~~D8!!~ l:~ci:: :: .. : : :::.-:::: . .. ::: ::: : :::::: . ~:::~{i~~ C:~~~~~. rl~ ~ ~~ r ~, ...... ••• 452 WMC Commercial ApheaJ ...... ll .. mphie. T enn. 503 WFBW Alnswonh-Gates Radio Co...... • Cin eian ~ ti Obio 309 WMCA lIotel McAIDin (Greenley Square HOI.J Co.) .. . •• • • • . .•..•• . N ... York City 341 ~W~FrKZB ;F~r::D~b18' ;~.~cel!.n,·,ddg· cm· l~aini• .i ·e. ·r. '. ". ". ".:.:. ". ". ". ". ". ". :. :.:.:.:. :• •:.:.:.:.:.:.:.:.: . :. :. :. ~. ·h. G.il.!~~. bc i"'i!'!~.JII~I.: 254 W~lH A1DAWortb·Gat~.'1 Radio Co . •...... •...... •.. .. • Cincionati. O . J21 ~ _ ... .. ___ m ~~t~ t~~!~it~t~iOi.i';b;' ;,;~ : : : : : : : : : :::: : : :: : ::::: : :: ::: ::.' : ~:~:~. tglli: m WFRL Roboort I\IOrT;',OD Lacey ...... •...•....•..•... Brooklyn. New York 205 WNAL Omaha C.DtrDII!i~h Behool ...... •... .•. . . . Omab ... N.br. 255

~GWAWL ~La·' ~nr~~t·.i~r~m.WI _'ttrr~,·.·' h.S·u:p· p· ;~: · ~ ~ :Co·· D •• t·' "UC··t"O·D·':C ·o··.·.:.:.:.: ....: ... ·.·.:.: .: ..'. ~. ~~~~,~.,· .~I~O.o ... ~~ ~~t: ~;:!ieCt;:rr:t ~bb~; ~ h ~ : .. ~ :: :: : :: : : : :: : ::::::: : : : : : : : ~~~:if:tl~~: ~~~~ §~~ W ... ~ .,. """ '-J Q;. '" ...... ,....- ...a 248 WNA T LeD.nig Brotbera Co. (Frederick !..eClQig) .. •. • ...... '. . . . Pbiladelphia.. P... 254 WGA~ Youree Hot.4!ol ...... •...... • ...... Shr~ve port. I~a. 252 WNAX Dakota Radio Aw&r&tu.s Co...... •. . •• ...... • . Y4Dkton. B. Dak. 248 ~g~B fra~~ ~~n~a~.::::~~i7 · B ~d~ iI · St . ' . .'.':: : :: :::: .':: ::: : : ~.o~:~c!cr~~N~n.g:~: ~~~~ b':':'~";r~~~ ;nd ·S .. ~·ct.; ~~ : :.' .. .' .. : ::::::.. .. : ::::: : .' ::::~::~~!t rr~: ~~ ~gg~ ~:~ ~~~!~~~bC~~~ ·.·. ·. ·.·...... •...... • .•...... ~~:~ ~ie:i~d : i~; ~g~~ ~if:,~:~~:c~ .- :: ::::: ~ : ... .:: .: : : : ::::: ::: ::: :::: : '.: : F'r ~;;~:~NC:t~~ ~~ WGBG BricteDhaeh'8 ltaclio Shop ...... • ... .• • . .•.•...•..• . Thrift.on. Va. 226 WOAG Apollo Tbf'lltre (Bclvirle:ro Amu .... (! IQCDt.Co J . ' " .. . . .• ...... Bel videre. IU . 27. ~g~k L":r~D~~ ~:;:;g:u .: ' .. :'.' .: ...... :" ~ .,. ....'...... :.... :.... :' .... .~ ~t':t!!~n:: r,: : ~:: ~g!~ ~~:h~C~~i~~~~~ ·~lu.~io '(j~ ~;" i:>: v~~~i;~ ) · :.'''. L~':~o~~~·.f:~ ~~ ~g~r th:;::r~ii~~~';: (Aib.ri if: i~';'·t . :: :::: : :: ::::::'. :: . P~~tl~:: ~i.f~ i~~ ~gt~ ~~\:,:.;~I~~~r"Y Ii:. :::.'. :::: .' .:.'::: ..:: .::::: .. :: : : :: : ~.. ~~::.i.~.~~.' ~~~ ~g~~ ~:::~~I~t~':'o;'d"~~nsi A.~ ;' : :: ::: ::: : : :: : : :: : ::::: :"::.W:~~:~: ~~t : m ~g!~ ~~~.;i~~':::'PN ·a·ti.;~ ~· 'c;,;;d: 'Zd ' B~t i~i i;';' : ' iiith · i,;i~~::.~~~::~~: m ~g~ ~~~:!rut~i~;~'ii y : .:.: .'::~ ::::: : : :::::: : : :::':::.' : cir::n~l~~"~: 6: ~~ ~g~~ ~~~J~ri~:H~~~~I~ :: ::: : : : .. ::::: . .'. : : : :::::: :: : :::.~~e~~;.brN~~~ ~~~ ~g:~ ~~i~~~if~ti:; ~[~i~:' . ~O: :.:: :: ::::::::: ::: ~:~ ~ ~ .~~~T~.~cho~~o~r!.~ i~~ ~8~G ~::J::;:rft~:=~eo:~ii~o:::~~~ : :: :: : : : :::: :: :::: .. ::::: .. : s~:'~~~.'ii~~:~ ~~: ~gfS £"':cri:~·[f.,t''tt~C~~~I: ...... : .... ·.. : .. : : : ...... ::: ...... M.;U~~d · ~~ti ~:.r~i~! : m ~g~~ ~'::. JK~OI>:'~· . ~~~ ·:: : : ::.': :: : : ::: : : : : : : .':::: :: : p~j},~,:~:'N::,.J~;.;y i~~ ~GGG R~U J~~;~.o.n&d. ~•. ~.;n..c .:: ~.~.~ .tah.... ~...... ::.: : .:•. ••.••...: •. •.: ...... : ...... Rl .. ·..e .!'.. rn.' .~B~CbUdlIlia1~a.o:ol1·oN~.· IY~.·. U~ ~gk t':.~r!:~ndC~':t~;]\ii.. : c;.'...... : ::::... '::.':. ':::.: '::::. '. H~~~~orill~ m 319 WOO Jobn \\'&03"'"cr ...... PbUadelpbio.. Pa. 509 WGY G"!'.rnl.Elee.Co . . .: .. , '" ...... Sch."oct.ad,;. N. Y. 379 WOR L . Ba mbo,ltcr and Co ...... Newark. N. J . 405 WHA Umv.talty 01 ''I'\.'c."..oo...... :'( ~di.. on. ''>is. 535 WORD Peoplc', Puloit AAAo ...... B.",";". Ill. 275 WHAD l\ 1~ rll ue:tto UDive r ~i t ~ and !\ l il\" ll ukee J OUfQa1. . t ••••••••• l\.lil"'Dukee. WL~. 280 WOS State ~lnrlr:etiD~ Bureau ...... • ... • " . .. . • . . . .. JeBenon Cit.Y. 1\10. 440 WHAC University of CinclDDati ...... OnciDDat.i. Obio 222 WOWL O~l BAtterY CompoDY New Orlea.as I a 270 ~~!~[ U:f:~!::~~rR~h~~te~ · <'~t.~flD ·S ~ h~~ I · ~i:r\i~i~ ; ::.:::: .: R~t::~~irn.J:~: 283 WOWO ~[ainAutoBuplltyCo ::'" ·,·: : .'::::::::.::::: ::::: ::::: .Fort Wayne. in;"': 227 WHAP II. Alvin himmons. 2!,0 Flalt bWlh Ave...... • BrooklYn ·N. Y. ~~ ~~~~ b~D~~:~~~~tC~~~l~~~ . : :: : ::::.' :: ::: :: :::: .. : .'::: : : ~6kt~~~!:~t>~:: ~~ WHAR Se 8.t..i~e HOttl'l e ...... : ...... : ...... Atlantic City: N . J. 275 WPAJ Doolit.tle Radio CorP ...... • ...... New Baven. CODn. 268 WHAS Cou r.~r ~ Journ aJ k Loutqvllie Tlm e-~ ...... , ...... Lou i ~ vil1e. Ky. 399 WPAK North Dakota A~';cultur.1 College ... . ' ...... \gticult.ural Collece. N. D. 283 ~~~~ {{·iir5~rt~D ~e!:ri~ ' Sh~i~ ity Co .. : .. : : : : : : : : : : : : : : : ~~\\~i:r:!~dn~{i>e~: ;:~ ~~~ L ~h~;;C:;nli~!~i~~~11~aOo~!c ~~~ . ~~~~ .~~ : : : : : : .. : : : ~ : : Aii~~~:~~ : ~~~ i:: ~~~z 1l::D~;esc~:!rc~~Dic ~~" tit ut.e ...... K~!rC~tYN i?c:' 33:5O~ W~QPQRA:i.C WEH.~~B:.~~f.hi). :.:~.n.• "' . J.~.. ..R&.• .••. ~. ~o..•.. ~ ..~ .:. :.:.:. :.:.. ... :.:.:.:. :.:.:.:.:.:.:.:.:.:.:.:. :. :.:. .'. ~A~~erL:s~,lbl;O~. ~~'.~. ;~ ~2~14~ 2 ~EI~ ~~~"li~~~~;~~~ ~ ;; : .: :' ~ ~ ~.: .: ~;:. ~:: ~: .:.: : .: ; : .: ~.:.: .:: .: ~i~~ ~;~t i\~ 240 WQAE l\Ioor.JL.dio Nc ... St.ation (Edmund B. Moo,.) .. . • . . •. ' .. • S;;incfic\I. Vt. 275 ~~~~ ~~~y J:~ci:'~ c.;.;.~;.~ .. ::: .'::::.':,,::::::::.' .. ::~;~I~:r::~neil1~~il! ~~ ~8~~ ~~~:~;~~~~~:;'r:h~'~ :':':':':' :' :.:.:.:.:.:. :.:.:.:.:.:.:.:. :.:.:. :.:.:.:. : · : ·:· ~~~~!:r';N?J: m ~H!~ E:~~~~,!I~E ~~ . ·~~~~~';;': :':':' :' :'."." :':' :':':' :: :' :':':' :' :':':' :':':' :':' :':':' :' ;:~ ~~~':;i m ~~f' f:~u~:~i~~iu'b (t~~)~":":"~ .~ : : :: : :: :: : :: : : :: : :: : :: : : :: i3:.";"~~I!!I: ~~! - ~Ei~ f~~£!~~:~~~n~ ·~~ii~·: ·:·:·:·:·:·:·.'·:·:·.. ·:·:·:·:·:·.'· :·:·:·:·:·:·:·:·.: ~~~~S~~~: i* ~~~ [ii~ll~lN;~;~ :~~ ~ . : ~.; .;.; ~ .;.; ~ .; ~:.;: ~ .;: ~ ~ ~: ~ :: :~~t~~i~~]~ i~ :~:~ f~~~v:~ l\~~~~~~i?ebc:. : '.: :: :: : ~ : : :: :: :::: j~b~'t~!:,h~~~~ ~i!~~ ~~ ~:~~ ~:~':,~~. J~::c~~~ . ~1.1~~~~~ .~ : ~~~ : : : : :::::::: : : cI~~~~ie~~~~~N:j : ~~ W"'SQ St •. Joh.n·II M.E .. ChurehSouth • .... ~ .... • • . . .•• ...... ]\fcrnphis.Tcnn. 233 WRBC Imm huel Luthe &Il Church '. . ·V&~o lnd 278 WHBR Sc)tloh6cJ<;]ectr-1C& Mf8'. CO .• 30r. ... ' ille St •...... Cincinnati.Ohio 216 WRC ltadi: Corp. or America ...... ·. ·: : ::: ::: : :::::: : : ::: .... :··Vri~hin~t.on. D. C~ 468 RADIO AGE for November, 1925 The 1v!agazi!te of the Holtr ( 9

Broadcasters Elect (Continued from page 67) tion of Censorship. Thcre have been rumors of bills to be introduced in Congress which will require a broadcasting sta tion to lah~l. through announcement, whether a program is an ad .... ertisement or not. Discussion on the * subject covered much data on the present state of broadcasting for profit. The filial result was the adoption of the following resolu­ tion : " The question having come up in some quar­ ters as to whether a program paid for hy others than Ule owner of a broadcasting sta tion should he lahE-lIed 'Advertising' or not. BE IT RESOLVED that inasmuch as it is Complete, noth* necessary that the name of IIscr of the station ing else to buy. be connected, by suitable announcement Operates at max­ \\'ith the program in order to derivc good \\'iJI, and fUrthermore, inasmuch as any such an­ No-w-,..,Plate Voltage imum efficiency at nouncement or program if imllroperly pre, ali times on either s ~ nt('d ,,'ill create ill will, there seems no direct or alternat­ necessity for any spccific regulat.ion in regard for any Set,--J and ing current, any to form of announcement in ('onnection with frequency. such paid, or any other program." I Dis('ussion of Censorship developed the You can afford it! Delivrrs unlim­ First Cost Ecol/omy now makes it possible for EVERYO)lE to ited current to any following resolution. " 'hich \Va >! unanimously obtain effi cient "B" · current supply right from their electric light adopted. socket. Now onc of the biggest improvements in modern,day radio receiving set re­ "WHE REAS it is universally agreed that reception is placed within the reach of all. Think of itl A perfect, gardless of number the success of Radio Broadcast.ing is founded . always efficient source of plate voltage for allY set for $9.75 I It of tubes. marks a revolutionary step forward and will be welcomed by mil­ upon the maintenance of \lUblic goodwill Dclivcrs 100volts and that no broadcasting station can ollNate lions of radio enthusiasts. successfully without an appreciative audience, to A~Ysct. and Ferbend Costof operation WHEREAS the puhlic is quil.'k to eXpTPBB less than 50c a year. its approval or disapproval of broa

WREO 286 WSOE Scboul of EDc1neeri n« . , .. " ...... •• ...... • •• t.1il.-aukee. Wis. 246 WRHF ~-=~~:~~ 'i:~d~ii~pji,;j 'F~~d: :::::::: :::: : :: :~: : w~=::: ~~ie~ : 256 WSRF H.rdrm S:.1Ic.s and. Service ...... Broadlande, W . 213 WRHM 252 WSTA 229 WRNY ~~~~!:e!~:~i,t~~!bf~~ ' ~ : ',',: :: ', : ',::',:', ',::::: :',:',. ... ~~:::~o~~k.~~D.:: 258 WSUI ~~-:-:U~av~~i~~~' r' i~~~ ::::::::::: : :::::: :: ::: :::::: : : : fo~tc~;,.~;.~.: 498 WRK 360 WTAB Fall ruver Daily Herald Pu bl.bine Co, ... • .•....• . • .. •• Falllti "er • t.1asa. 248 WRL 270 WTAC POD .. Traffio Co .. _ • ...•••... . .• . ....•..•..•.. •.. . .. •• JOhne. Wi> . 22( WSAI Unltcd St.lt.eS l'1a>'ioc (~a rd Co ...... •.. ..•...... CincinnAt.i. Obio 325 WTAR Reliance Elflctric Co ...... •.. •...... ••.•••••• . •• •. • •• . No rfolk. Va. 28J WSAJ Grove City Cul1ece ...... •...... •. .. .•. .••.• . .. . • •.. Cro\'fj Cih' . P •• 258 WTAT Ed~on Electric Illuminating Co (portable) •.•• . . •• ••...... Bot.too. Maee. 24( WSAN Al1onto~·D C.U Pubti.hinlr Co ...... ••... •• .•...... •.. . Allento..·D. Pa. 229 WTAW A~rj c ultural '" t.1ecb&nic.. 1 College of Te:ma ... . . College Bladon. Teu.a 2l1li WSAP SeveDtb DBY Ad,,·entid. Church ...... • ...... • . . , • .. .. . New York, N. Y. 263 WTAX " 'Ullams H .. rd ..... re Co ...... , .• , ...... Stroator. Ill. 231 WSAR Daui:bt.Y & W'fIolcb Electncal Co ...... F .. II Rh·er. Mas... . 254 WTAZ TboPlAH J . 1.1cGwre ...... •..• •• ... . •.. . • • Lambertville. N. J. 28J WSAU Camp hln.rif"nli~It1· ...... ' ...... ••• , .. . .•. •• Cb,,-, bam. N~w H.ro~bir& 229 WTC Kanau St3te A~rloultralCol1f'ce . •.. . . •. •• . • ••.• • .• • .. Manbattan. K.&ns. 273 WSAV C. '''. Virk Radio Cow.ttuoc:ion Co...... • ...... • • • HO\.1b tOD, Teus 360 WTHS Flint Senior lli"h Srhool .. .. . • . •...... •... .• .. • Flint. Micb ... 211 WSAY In'inlt Au:.tin (Port Cb~tcr Chamber or Cornmercd •. • Port Cheater, N . Y. 233 WTIC Travelert Io.,uraoce Co...... I ~ ••• • • ••••••••••••• Hartford, Coon. 32:! WSAZ Chaa. Electric ~hop . ... • ...... PomeroY. Obio 25a WTX II. (~. S:l.lll Co ...... , ...... Cbicaco. UI . 261 WSB Atlanta Journal ...... • . . •.•...... , .. , . . Atlanla. C ... 428 WWAD Wri"ht'" WriEht Und ...... • ....•.•• . .. ' ...... Pbiladolpbia. Pa. 36( WS~C World B.tl.y Co . ... •...... •.••.••.. 1219 8 . W.b.. b Avo .• Chic&co. Itt. 210 WWAE Tbc Abmo B" II Room ...... • ...... • .. . •...... , . . .. JoUet. lU. 24l WSBF f::tix-Baer-· Jo"' ullfilr D . O. Co ...... , .. . . . St. Louie. ~lo. 275 WWCL It.dio Encineel ing Corp . . ...• ...... RicbmoDd Bill. N. Y. 21, WSKC '\'orld'" Ntar Knittioc Co ...... •...... Bay City. ,M icb . 261 WWCS Itadio ErutiueerinC CorP ...... R icbmond Hill. N. Y . 211 WSM N~bvillH Life In.~. Co. .. • . . , . . .. • ...... • •.. ..•. • , • . . NB8bville. Tenn. WWI Ford Motor Co ...... • . . .• . , ••.. . .• .. • . " • . Dearborn. Mich. 27, WSMB S:'I.f"n&:er Amusement Co .•• bod M.i.son Blancbe Co ...•. ..• "e'~.. O deAOf'. La. 319 WWJ Detroit New. dio Corp ... . .•. ... ' •...... •. DaytoD. Ohio 275 Canadian Stations CFAC C.lCa.foY Herald ...... ••. . • ...... •..•. •....••.•.•... .. Catgary. Alt •. 434 CJCA Edmonton JournaL ...... ••• , . , ...... ••.....• . Edmonton, Alta. 511 CFCA Toron(.o Star Pub. & P'rte. Co .. • .• ..••.. . . •....•...•...... Toronto. I.nt. 357 CJCL A: Cuuture ...... • . . , . •...... •. ...••...... • ..•.. . Montreal. Que. 27l CFCF ~larcon.i " 'lrrleo.", Telef:. ('..0., (LtdJ Canada .. , ..•••.•.•..• . MontT~.t. Que. 411 CJC C L.ondun . 'rr'" Pfe!J\ . •. .. .• . .•. .•. ..•...... •. .•...... • . • • l.ondon, Oat. 321 CFCH Abit ibi Pov.er &: Pal)tlr ('0. • (Ltd.) ...... , . Iroquois Falls. Onto 500 CKAC I..a Pre.o;!'e. , ••.•..•. . , .. ••...... • , .. ..•...... ••. . l\toDtrul. Que. 411 CFCK 517 CKCD Van~ouveT UBily ProviDce • •. . .•....•.•..•. . ••.• • •..•.• Vancouver, B. C . 39i CFCN 434 CKCK 471 CFCR :~:~:i~~~r~!~L :· :.::: :-:.:::::. :-:.:::< ::.: ::: ::.::: :: ·: ~~~1i~?;.~1;: 410 CKCO 1>i::!~ ' ~U:dioC& !'~~i : ~ii~~ : ·,·.·•.• .•.. :: ...• : .•.. : .•.... : .. .. : :: .• : '. '...... ~~!~a.:. BOo~: 43' CFCT '''icto''ia <"~itv Temple ...... \ 'ictoria.. B . C . 329 CKCX P. BUrOJil & Co.. (Ltd ,} . .... , ••••...... •. •••...... •. ClllcarY. Alta. 43' CFCU The Jack Elliott (LtdJ ., •.• •• .•• • ••.••..•.••.. •...... • HamiltoD. Ont o 341 CKFC First Concrel: ,tional Church • •• . •.•• .• ••.• ..•...• ... , . • Vancouver. B. C. 411 CFHC HenrY Uirks k Sone ....••• • ... •• ...... •.••....•• . .... Calcar.)". Alta. 43~ CKLC 'V-Ukin .o; OQ Elecl ria Co .• (Ltc.l .) ...... , • • C.lcaroY, Alta. 43. CFKC Thorold U:ulio Sup"ly ...... ThoTold. Onto 248 CKNC Canadian l'at ioaal CarhoD Co . ... •. . .••.•...... • TOTonto. ODt. 35i CFOC Th. Eloct· .c ShOll (I.Id.l ...... _ ...... 8 ...ka'OOD. Suk. 329 CKOC " ·ont ..:orth Hl\rl io SUpplY Co ...... •.•• • .•. . . . , .. . . . nam.Htoh. Oat. 341 CFRC ()uceD8 U lli\ · e ~i ty ...... , •...... KinptoD. Onr. 450 CKY Manltoba Tf'L SY!Jtem ...... •...• ...... • .• ...... • WiDDil)eC'. M.An. 3~ CFXC " ·.tmin.ter Trust Co . . , .•...•.•.. ••...... •.. . • Westmin;,teT. B. C. 291 C NRA C.na'ti!l n NatioDll1 R.il"',.)...... ,Moncton. N ,'S. 31l CFYC 411 C NRC Canatlinn Nation. I R ailway,: .•...... •••.. . " ..••. . .•. CalcaroY, Canada 43< CHBC ~h~'C~~rly '~alr:rt!~ t~ ..).: . ::::::::::.':: ·~·: .. ::::: .. : .~~ ~C.k:;y.BAI~: 434 CNRE CUlatliaD NatioDnl n.ihra)"fl ...... • .•.• . • • .• ••. ••• EdmonwD. Alto. 511 CHCM H IIt'lY (\0: 1\leCorm&t'k ( Ltr' .) . .. • . • ' •• . •• •...•...•• , .• , •. CalcaTY . Alta. 434 CNRM Canadb .n Nationsl Rail""'o.Ys •.....•... ..•.•• , •••• • ... ••• Montreal. P . Q . 411 CIiCS 341 CNRO Caoaduln National Raihrays ...... Ottawa, Ont.. 43. CHIC ~~~t~!~:U~i':ct~~ecCot~~ :. : : •. ::: : ::: :.'~:: ::.' ~ :.'::: :.'.' : : ~";::~l!~~ , ' 8:!: 357 CNRR 411 CHNC Toronto Ranio lwr,urch Society ...... •.•...... •.... Toronto.Ont. 357 CNRS g:~:.1i:: ~: :i~::I' ~P:a~~: .·.·.·. ·. ·.:.·. · .· . · . ·.·.·. · .·.·.·:. ·. · .·:.·: . ·.B·~~=fo:: g::~: 32~ CHUC Internation&1 Bihle A8.~D ...... •...... Saskatoon. S h ~ k , 329 CNRT Can_diaD Notiunal n'\il,,·.)·,...... • _ ...... •...... •.. . • Toronto. Ont.. 351 CH>"C R. Booth. Jr...... ,.. ... , ...... • Ottawa. Onto 434 CNRV CanadiAD Klltio n41 Rail~· ,, )'W ...... • ...•. . ...•...... V.ncou,·rr. B. C. 411 CHYC JII."ortbern Electri C) C o , .. , ...... , ...• . , . ....•...... fl.1oDt re&1 . Que. 411 CNRW CaD4di&n Natlonal n.ilways ...... , ..•....•...•..•...... WiDnipri:. Man. 3~

R. M. A. Names Official Radio Shows Official announcement has just been made by Herbert H. Frost, President 01 the Radio Manufacturers' Association, that the Show Committee of the asso­ ciation has designated the official sho w~ of the manufacturers for 1926. These will be the Third Annual Radio World'5 Fair in New York and the Fifth Annual C hic~.,:o Radio Show in the latter city. These two sho ws will be under the ViIgilance direction of U . J. Herrmann and G. Cli!Yton Irwin> Jr. T he Radio World's Fair next year Constant vigilance wiJI be held in the new Madison Square Garden, and the tentative date approved for the openirig is September 13. is the price 01"""" The Chicago show next year will be moved forward about fiye weeks, October uni#ormitq""''''' 11 having bee n designated for its open­ and constant vigil­ ing. It will be held in the Coliseum. ance is maintained NEW SELECTIVE CIRCUIT This spccialo((cr includes genuine FULL SOc over Magnatrons. SIZE blue print with illustrations and full instructions, together with large size That is why Magna­ printof circuit diagram. all for only .• SWDp> or COiD trons are uniform.and uniformly good.""" "'AGI1ArnOtll~ The "latina/ron DC-20J /I, nC-J9!J, and I R£)( DC.I!J9 (larp~ /oan) 110"' f'JI for on(v th~ new t:!.JO Mell. ,ta.abe ror Connewey Electric Laboratories B.bclttct : MagnMron flltlg . Hoboken. N. J. An ideal circuit for selective "DISTANCE GET­ Wcst coast sUI>plie I from complete slocks carried TER·· with fine tone. requires no outside wire. d'~;la Operates on a loop by PAC IFIC RADIO LA l:S., Werner R.dio and Audio Frequene,... Tr.nJormera 256 So. Los Angeles St .• Los Angeles, Calli_ are used in the above circuit which consists of I stage of tun ~ d radio freguency amplification for selectivity and ··P~p··-followcd by two powerful untuned stages-a VaCUum tube detector and two stages of Quality audio frequency amplification. ~ Send for free ducripI;ve Ulera/uTe Wornor R.dio MI,. Co •• 204·206 NiJolh St.. Bro01.lyn. N.Y.

~ Tested and Apnroved bll RADIO AGE ~ RADIO AGE for November, 1925 The .Magazine of the Hour 71 Fourth Conference Called HE Fourth National Radio Confer­ r ence in the interest of public sen'ice had been called by Secretary of Commerce Hoover to meet in \Vashington on November 9th. Representatives of all radio interests are invited to participate, A REAL RADIO SET and should consider t his notice an invi­ tation to be present. For the first time the members of the for $27.27 ~ Press are called in to represent the public especially in matters affecting broadcasting. Special letters to some Built Around 400 magazines and newspapers having radio departments are going out asking THE HEATH CONDENSER that each publication send a delegate to represent the public at the national Designed by Citizen's Radio Call Book Laboratory sessions, which will carryon for about a week. This method of selecting dele­ ow you can build a super-efficient radio set at an extremely gates, it is belieyed, will guarantee to the low cost_ The well known performance of the Heath fans the best possible representation. N Condenser caused the Citizen's Radio Call Book Labora­ The conference, Secretary Hoover tory to design a radio set featuring this remarkable Condenser. points out is called for the general discus­ There are two points of vital interest about the HEATH CON­ sion and consideration of matters affect­ DENSER- ing. radio communication in the United States_ The delegates called in will 1. Permanent Flat Plates-stamped under huge presses represent the following groups: broad­ to absolute flatness and tempered to prevent warping. casters, press associations, radio maga­ 2. A micrometer geared vernier that reduces ordinary ad­ zines and newspapers, radio set manufac­ justments to hair breadth distinction. turers, organized broadcast listeners, amateur organizations, commercial land To each purchaser of a Heath .0025 Variable Condenser we and marine interests, radio trade asso­ are giving a complete set of plans, and instructions on how to ciations, Governmental departments, en­ build this high quality, low cost radio set. See your dealer and gineers, electric light and farm organiza­ get yours today, or if your dealer cannot supply you, order tions interested in radio. - direct, giving your dealer's name. The heads of the above organizations and groups should communicate with Secretary Hoo\'er before October 26, Hea th Radio and Electric Mfg. Co. ad'dsing him who their representatives will be. No persons will be recognized 206-210 First St. Newark, N. J. as a delegate whose name is not filed I'v!anufacturers o} with t he Commerce Department before HEATH CONDENSERS HEATH SOCKETS HEATH DIALS the above date. HEATH RESISTANCE COUPLED AMPLIFIERS The major problems scheduled for dis­ cussion include: interests of the listening public in broadcasting; saturation in broadcasting channels a nd necessity for limitation of stations on basis of pur.lic service; requirement of construction permits prior to building of broadcasting stations; wavelengths or frequencies for the se\'eral radio communication groups; use of high power in broadcast­ ing; location of stations outside congested centers to prevent interference; alloca­ tion of channels with regard to t ime and geographical distribution; use of broad­ casting for publicity; amateur activities; and rebroadcasting.

Bakelite Used in Loud Speaker Horns The first loud speakers for radio were patterned after the morning-glory type of horn used in the early phonographs. Radio fans quickly began to realize that the resultant sounds were not R:\ :A~A:I:ft~ AGENTS all that they should be, and the loud Hear What YOU Like A ·W. ~JI. WANTED speaker came in for its share of the ¥o SEND NO MONEY 5 Tube'Dt-mOnStratorFREE! Stat!on. are ~l:\(j to put 0 .. numbers at Your request. blame. Earn ~Z 5 to SJ 00 a week. part or fill! lim", Everyone Tin, thin sheet iron and other metals r';T~~~\6~~T~l a~~s~~I;'Tt'~~~:ite~O(;'et c~~:e ~l!~S ~~ .1. prospect.. C;'1J)plete line standard set s and accea­ that have a definite rate of vibration, rrom your radio. All the RAGE. Good grade-cardlL sones. $5 to $90. Write lou, y ror Illustrated .alalog Quallt1 prlntlni:. Satisfaction Kuaranteed. You U bo and ~:rcl u fli:\'e sellin/: plan for hve dealers and rOm­ have a metallic or harsh sound when delighted. munity o;.ols. 2flTl1 CF,:-;TURY RADIO CO.. 1021 used in the construction of amplifying Coca Cola BId!: .. .Kansas CitY. Mo. horns. It has been found that inert materials, such as paper, wood pulp and mineral compositions, and other substances that are neutral as far as vibration is concerned are best for loud MASTERTONE speaker horns. The best materials from RADIO TUBES an accoustical standpoint, however, are AlL TYPES GUARANTEED usually very fragile. Dealers' Proposition Bakelite, a substance formed by a Dextron Radio Lab. composition of phenol and formaldehyde 74 Sterliol, De~L R. A. under heat and pressure, has been found East Oranle, H. J. ideal for loud speaker horns, 72 RADIO AGE for ~o\"e mber, 1925 The Magazine of the Hour Iir"'" "'"'' ,,,,,,,mEl""'" """'''''''''''''''''''''''''''''''''''''''''''''''''''' "",.'" ",;om """EO";;;"" '" ""'''''''''' """""'''''''' "",,,,,,,,, "'''''''''''''''''''' ""''''''''''''''''''''''r:1 They're Nearly-All Gone! Get Your ~~Annual" Now! , W h I THE edition of RADIO AGE ANNUALS that It sort t: was first introduced to the radio public last THE RADIO AGE Spring is a1m.ost exhausted! Month after month, ANNUAL for 1925 is orders have come in from enthusiastic fans, worth every cent of until at this writing only a few hundred of these valuable books remain unsold! the dollar you pay Now that the radio season is in full sway, for it. The leading you cannot afford to be without this authori- engineers and set- builders of America tative guide and first-aid for all radio troubles! have acclaimed it the If you have not yet built your set, here is the book most complete, au- that will tell you which one to make-and how! ... thoritative and clear Or, if you already have made or purchased '" ~I ~~~~~.l'n';:ne ~v:~ i:.~rp~:e~o~/~~~ RADI(/AGE~uitf~f~~~= I!I '" understand its many stant reference, to solve -the many problems :.: m pages of construc- that arise in connection with the operation of 1~! ill m~~;~~~t~f:; ;;~~f4tl:i~~:;~~~~;!i~~~i!!~~:~~ II m' never before been but has several articles dealing with construc- m ::: duplicated-in any tion and operation of loud speakers, battery m hookup book or radio chargers, aerials, wave tra ps, amplifiers, etc.

~.li.\I. . E:~~f~~::~u:!;~ ~~%:~:ri~~~p~{~~~!~tt~~~l::r~ ::;: your radio library gone! No more will be printed. One dollar a copy, ,! for years to co I ad your f d f d' kId' 1 till II ~l~Og; me~D;OF~~;191i;;u:~e ge IS r:~i; ",

Ii ~rr.~:~;:~~r::!r;~,;,::- Some of t~7~~~~~~k:!h;:"" hooku~. Boby H .. No How to .elect the right receiver. How to make an amplifying unit. iii Substituting a tube (or a crystal-buildina the fint tube .et. How to recogni%e and deal with every kind o( tube trouble. ::: How to amplify any kind o( set. Another super-heterodyne (or the SUpd" erperintentd"s. m ~ta_~,:,g a refler.:etR . Hints on tracing troubles in super-heterodyne circuits.

¥,! I ~~ii~~S?a~~ia~;;:~~~~~~"'BabY Het. ~ ~~~~~~ ~';.~~ ~~!~~c:e~~r:;:e~g'o on the lOUd .peaker How to make a battery charger. (rom Ohio. How to make a loud speaker. Improving the ever popular Reinart:. RADIO AGE ANNUAL BLUEPRINT SECTION with .uch AND MANY OTHER UP-TO-THE-MINUTE HOOKUPS AND popular hookups as the aperiodic: Yariorneter, loop ..,ts, ARTICLES. ------~ ------RADIO AGE ANNUAL COUPON ::: RADIO AGE. INC., Hi SOO North Dearborn St. • Chicago, 111. ~g Gentlemen: I want to be a proud owner of the RADIO AGE ANNUAL FOR 1925'. Enclosed find ~i ~i;~~_I;~~;~~~~~,~~:;t~~~~~;~L~~~e':~~~~~~~~~; v:e~":~~~n~u=~':~~~:u:;~:;~== iii- jl~ I ff~r5-·················· · ·-··········· ·· · ·····~·· ····· ...... -...... ---.--.. -.. ------.----.-.-.--.-.-- State .. _...... _... __ .. _ ... _.... _ ...... _ .. _...... ::~::l.:.j HI ... t~ 1: :::::::::::::::::::::i!ni:::::i::::::::::: : :: :: :::: ::: ::::::: : ::: : :::::::::::::::::::::::::::::: : :::::::::::: :: ::::::::::: : ::::::::::::::::::::::::::::::::::::::::::iii::: : ::::::::::::::::::::::: : :::!: : :: ::: ::::::::::::: ~:!::::::::::::::i}l RADIO AGEJor November, 1925 The Magazine oj th.e Hou r Mar-Co Vernier Dial Is Unique . All radio apparatus requires a sens}tive indicating device for the careful calIbra­ tion of a particular setting of the instru­ ments. Such an indicator must be care­ fully designed in order to include in its operation all the good points that are required. In building the ~Iar-co Vernier Di~I, the greatest care has been taken to In­ clude desirable features. I n the first place, the hair line indicator in combin!!-­ tion with the double scale graduated 10 half points gives a sight reading compara­ hie to the indicators on the highest types of engineering instruments. The fact that the hair line is close to and extends across it destroys the error c;lue to parallax which is the most common defect in radio dials using an indicator engra\'ed on the panel at some distance from the dial scale. The fact that the indicator Mfd. und .. Lowenstein is built into the Mar-co Dial also elimin­ Patents, Mmch S, '9'8. ates the necessity for prodding a sepa­ rate indicator. The Mar-co Vernier Dial has no 'back lash, and is non-microphonic. It does ~i Space Gives Ideal not use worm or spur gearing which is rough in action and extremelv hard to assemble without play or shake, nor TlIIIing at allWavelengths does it use rubher or cork friction washers which quickly wear out and cause trou­ ble. Tn this dial a special split metal Spreads low wavelength stations without crowding those pinion is prm;ided as a part of a friction 0 0 bevel ~ear train which will last indefinite­ from 50 to 100 • Lightweight and compact in style. ly_ The resultant operation is noiseless, extremely smooth and extraordinarily ERE is a new con­ sensitive. Equi Space is small and The Mar-co Vernier DiaL is housed in a H denser that surpasses compact, requiring little black bakelite base carefully designed to all present-day types. The Special Erla Features space. Very·light but hav­ harmonize with anv panel arrangement. conventional straight line MmimumcapacityonlylOm.m.f. ing extreme rigidity be­ Mounting requires the drilling of but one I fr e quency condenscr Ratio of tnaxlmum to minimum cause of four riveted cross spreads stations on the capacity 35 to I. members. hole to prod de for the panel stud. A Toeal resistance of only 3 ohms special template is pro\'ided with the low wavelength propor­ at 1000 cycles. tions on the dial but it also Go to any radio store instrument for this purpose. Fourrntct~d crOM member! ~ up­ and see this amazing con­ A new ano, IlL I the dial to insure the best results. Tun­ Tell m e what' s new In radIo. I vices, including earphones for the deaf, ingis made far sharper. Sensitivity is I the Vactuphone, a vacuum tube device g reatly increased. reducing losses to an Nam& .... _ ...... I for the hard of hearing, auditorium unprecedented minimum. Plates of spe­ Address ...... : ...... ' ...... _...... I phones, and earth stethoscopes, now cial spring brass are scientifically spaced I announce the de\"elopment of a new and give maximum conductivity. Scien­ City _ ...... _ ...... _ ... _._ ...... I Globe Loud Speaker. tifi c tests show a resistance far lower I __c ~~n~: . :. :. .::. ___:::: ___ .~~~::-.:..: . :.:::; . ::: ::; ..:. J Built on an entirely new principle even than costly laboratory types. . the Globe Loud Speaker has a Silicon steel diaphragm, extra large drop-forged magnet with carefully balanced coils mounted On a sound bridge with a special tone pocket beneath. This gh'es a sur­ HTHE BEST RADIO MAGAZINE PRINTED" prising smoothness of tone and faithfull y -is the verdict of thousands of broadcast enthusiasts who reproduces ml'sic Or the spoken word in have voluntarily written to RADIO AGE of their apprecia­ full, deep, mellow tones throughout the entire acoust ical range. tion. Every month come additional praises for the newsy, A vibration less horn is used and it is interesting material to be found in our pages. claimed that all unpleasant overtones Are you a regular subscriber? $2.50 a year, postpaid any­ are eliminated and that the speaker is where. Subscribe NOW if you want to be sure of getting excellent for distant reception . the big December issue, with its eight page section devoted Careful, accurate and expert factory entirely to the adjustment assures maximum volume regardless of the type of receiving set t'RADIO A(;P vn!:, !:: ~ -:: -:C.C"t!: \- ER." used. ,------. 74 RADIO AGE for November, 1925 The .Magazine of the Hour New Mu-Rad Receiver Has One Dial Control HE ~ factory of the Ivl u· Rad Radio , TCorporation is ideally located, so it is small wonder its engineers have been ORIOLE • able to turn out a receiver that· is a help to the industry. The new 1\I u-Rad is a One dial tuning control and there are no other tuning ad­ The Most Amazing Performer justments of any kind. The circuit and You've Ever ~~Tuned In" control system were completed last January, and all through the Spring and Summer have been subjected to the most careful tests under various conditions. There are two stages of tuned radio frequency amplification, detector, and two stages of audio frequency ampli­ fication with a new type of fieldless R. F. transformer coil and a new method of tuning through One manual control. There are nO verniers or t1,lning com­ pensation devices. The tuning is ex­ tremely sharp On all wavelengths and the receiver can be used on any antenna in any location. A very slight turn of the knob shuts out powerful local stations Oriole radio receivers step right out and make astounding and brings in the distant s.tations with records on distant stations-they give exceptio rial volume good volume. -unequaled for clarity and sweetness of tone-the most The cabinet is two toned mahogany of finest furniture construction and selective, sharpest tuning set you ever played with­ finish. It is 33 1-2 inches long, 12 1-2 you'll be "sold" on the ORIOLE the minute you turn its high, and 14: wide. It contains com­ partments for A, Band C batteries and dials. may be operated on an inside or outside Model 7-5 Tubes. Model 8-4 Tubes. antenna. The single control simplifies Write for illustrated folder. the tuning so that the most un mechanical Dealers: There is some exclusive territory open­ person can bring in stations. ask for details. YOU CAN GET

W-K Electric Co. BROWNLIE IER DETECTOR KENOSHA, WISCONSIN $2.00 At your dealer or Direct. ROLAND BROWNLIE & co. Sander. St. Me

Januer,.. 1924 Septentber. 1924 April,1925 ---TUD.iDR Out IDterlerlP1ee--Wave 'Tr-aor-Elbnillaton -now carllfuJ Mount:iDtt WUl Improve ~ilt.ion . - A 3-Tube Portable Sot. - Flltere -ODe Tumnc Control '-uHair·, Brftadth Seler.tivib. _··B IO Voltace from ,be A. C. Boeket. -It. .JuDior Super-ReterodYDe. -Four Pu_ of Rw BluepriDle of a New BabY" Heterodne -Ao Amplifier lor tb 3-Cireuit Tumer. aAd e.o Ape..riocbo Variomet.er Set. -BluepriDtc of • Fiv... Tube Radio FreQue.nol' Receiver. =~.;.~!~c:~~t!~: -Data Sheeta. Mal'. 1925. M.rc),.1924 October. 1924 -A ··Qule'" n..cener~tor . - A n Eaaily Made &per-He'. - A Power Supply Receiver. -AD. Eicbt-Tub. Super· Beterocl,yne. - How to M.ke a Tub... T_ter . -A .imple.JOllJ 'uner. -Two Radio ADd Two AudiO for Clear TOIM. loe.tI -A Simple RUec!lrative Set. - A Unique Super-Bet aDd aD Improved ReUI.Ar"t4. -A Tuned Radio FrequencY ApJifier. - The tntradYlJe tor Re&.I DX. -A Si.:I: Tube Portable Rec';'er lUustrat.ed with Btu.priDe. -6impl. RdOll S.t. -Real Blueprinle of It. 3-Tube NeutrodYD!l &lid a Mld.et June, 1925. April. 1924 RaIIOlI Bet. -ReduClDC Static: Diaturba.oeel -AD. Ef5.cie.n' Supoer--HeterodYlJe (fully illus\roted). Novrntber. 192. -A Sevlln-Tube Buper--HeterodYUe. -A Ten Dollar ~ceiver . - BluepriDte of. Sinet., Tube J.6akor at • Small Co.t. - A Simphfied Portable Super-Bet. JUhe, 192. -Bluepri.llita of Conven'iooaJ Radio. JAnuary, 1925 -ImPOrtan' F .. C!to~ In CoaavuetiDc a Super-He'erOffJlne. --8y'mbob and Crystal Detector Circuit.. -A Ubi"...... Ampl~er. - A R.eSes:ed Neutrodyne. Aul(U.t, 1925--SOc prr cop,. -A Sure Fi.re ReBes: Bet... -A Sis: Tube Super-Bet". -How to Att&in Smooth Tuni.ne. -AddlnlZ Radio and AudIo to Baby Heterodyne. -An Rftielent Porta hie Set. -AJt4r1latlDtt Current Tu ..... -R&d.lo Ace Data fib ..... -A Tuned PIDte Reir:enerator -Decit. C, 114 S . Wabash Ave., Bureau of Standards and the majority of the broad­ Chicago, Illinois. casting stations of the world. The Pyrex end plate is one Rich Rewards in Radio. Nat'l Radio Institute, Washington, D . c., Dept., of the features that makes the Quam the lowest loss and 531\'B. highest quality condenser built- showing even less re­ Better Tuning (lOc). Bremer-Tully, Dept. 53KB, 532 S. Canal St., Chicago, sistance than the laboratory standard. As a matter of Illinois. actual fact the Quam is used as a laboratory standard Millions Untouched. American Radio Engrs., Hearst Square, Dept. 15, Chicago, in many experimental and testing laboratories, not only Illinois. in America, but in all parts of the world. Catalog. Standard Radio Company, 1424 'Walnut St., Kansas City, 1\10. Furnished in straight line frequency and straight line Descriptive Folder. Allen-Bradley , wavelength design. Prices .00025, $6.00 ; .00035, $6.50; 289 Green field Ave., l\IiI'\\'aukee, Wis­ 0 consin. .0005, $7.00 (with a 4-inch Bakelite 360 Dial, add $1.00) Catalog. Pacent Electric, 91 Seventh Ave ., New York. QUAM Audio Transformers $5.00 Catalog. Crosley Radio, Cincinnati, Ohio., Dept. 63 . 15-B Radio Catalog. Jewell Electrical, QUAM RADIO CORPORATION 1650 Walnut St., Chicago, Illinois. Catalog. Randolph Radio Corpora­ 1925 S. Western Ave. tion., 159 K. Union Ave., Chicago, IlL, Dept 94. Chicago, U. S. A. Free Hook-Up. Radiall Company, 50 Franklin St., Dept. R. A., Kew York, N. Y. 11-50. Catalog. W. C. Braunn, 34-50 S. Clinton St., Chicago, Illinois. Catalog. Barawik Company, 103-126 S. Canal St., Chicago, Ill. WHO GETS THE RADIO AGE MODEL Ozarka Instructions No. 200 Ozarka, Inc., 122A Austin Ayc., Chicago, Illinois. RECEIVER? Ozarka Plan No. 100, Ozarka, Inc. 122A Austin Ave., ChicaiP Illinois. Catalog. Montgomery Ward & Co., It will be on display at the November RADIO SHOW Chicago, IlL, Dept. 18-R in Chicago, and will be GIVEN AWAY to some radio fan at the conclusion of the exposition. Who will get this remarkable set-the receiver that is attracting the atten­ Set Builders Save Space With DUPLEX CONDENSERS tion of the entire country? SpeciallY designed shaperl-out stators make these straightrline frequency condellRers as small as ordinary condensers. Writa for Further details in the December RADIO AGE. Out litera lure. * DUl>LEX CONDENSER & RADIO CORP. November 15~ 4Z Fl •• bum Ave. &.enalon. Brooklyn, N. Y.

:.to Tested and Approved by RADIO AGE :.to 76 RADIO AGE for November, 1925 The .Magazine of the Hour

Investigate' lI Before Investing

E very advertiser-whether national or local-owes it to the best interests he represents to fully inves­ tigate every publication's claim for circulation, etc., before he invests in "white space" advertising.

It is . the advertiser's right to denland facts, not theory. Superficial infornlation is not the kind on which to build a successful advertising canlpaign, and unless each copy is delivered and read, the ad­ vertiser is paying for waste circulation and his ad­ vertising dollars are not producing proper results.

By our nlenlbership in the Audit Bureau of Circu­ lations we safeguard the advertiser's money, for we want it known that we nlake no claims of any nature that are not fully substantiated with A. B. C. verified reports.

Get our last report. l

500 N. Dearborn St., Chicago ·RADIO AGE for· November, 1925 The ~lIaga:siJle of the HoltY 77 NEW Operate Your Radio With 64-PAGE One Switch LOG "Whenever you make radio so easy Revisions to operate that I can turn it 'on' and 'off' like an electric light, with nO batter­ ies to recharge or replace, you can send me the finest set you t urn out," wrote a Congressman recently to a manufac­ turer. Pau II"d NOfJ . 18,19U This-has been the challenge to radio of thousands of persons who have held off buying sets by reason of rea l and imaginary difficulties in their opera­ tion. The Congressman referred to above has received his set. It was equipped with a new power unit that plugs right For EVERY into a 'Iamp or wall socket and trans­ forms ordina ry electric light current into Radio Set Send NO Money the smooth, h urn-free current necessary Lo~ YO l 'R radio. ThIs new perpetual 101: with loose for radio. leaves can be kept UP-IO-d&te ReTlsed sheets ran be A stunning piece of furniture that secured as cll" fIg '" octUr. Holds 500 stations. SbOl\'S One switch on this new power unit restores order in the room where calls (a.JphabctICltI(YI. cIties. WOY< irn ' lbs. 4 dI al set­ UnGs. re",arks. clC. Station 11St by "ave leru:lhs. controls e,'erything-"A" power, "B" you have your Radio! N o more StaUons alphabe!lcaUy by states nnd c!tirs. Valuable power, even the radio set itself. Snap tuninll Suggestions. Station. o\mers. Trouble a ids. cluttered table-tops, nor litter of Chock full of other ••luable Information. So eon ••n1mt . it "OX" and you get a strong, uniform Get clearer pro""ams. Iliu minat. 10ur troubl<>s. Worth cquipment un­ many Umes small CGSL Only $1.00. Order Now. flow of both " _\" and " B" power. Snap Radio Map FREE 1Di;:'J:.;st it "OFF" and your po\ver is shut off and der-foot. your radio is silent. Don't send a. eent. Pay postman after log and No unsightly map urn'c. If yOU P&J wi th order we pay postat:e. This new radio power unit was de­ Money refunded if not dell. hr.d. You I

ADVERTISING SERVICE CRYSTALS RADIO CIRCUITS

QUEX Salce Lcttcri eel More Buelncee. Write him Supenen .itive Calena Cr,..ta f.: Pound $1 .00, "repaid. SPECIAL FOR NOVEMBER today. Quu, ••18 Michi•• n A.e., Chica.ro. ALKEMITE. AJI.en.itive Cryetal, SOc. Bu.lr.ett. T1u R.inart. R.d.o Boo klet. b.,. Frank D . Pearne. full,. CeoloslIt. Joplin. Mia.ouri. llh.. trated, and RADIO AGE. for S2050. Price of Boo ..- let alone il SOc. Send eheclr:, currency or mone.,. ordar 1 AM AN EXPERIENCED RADIO ENGINEER and am to RADIO AGE. 50(; N. Oe.rborn Str... t. Chi~"o . ~:~e~~:IlCic·~tl:c~r~~.i~~r re,.':1ton~:e,,~;:!~:;~~~~ ·lfr;:~ HELP WANTED are enterin .. an .dvcrtieinl'carnpailfn with any technical RADIO DEALERS product you mUet have authority b.ehind your etator­ p RADIO SALESMEN .nd SET BUILDERS-W. need DEALERS-Writ. fOT OUT illultrated caU.lolr of reliabl. rnents to make your .dvert~ainl: command rca pctct. you .nd .,.ou need u.. If yoU aTe r e liable and well R.dlo MeTchandi.e. Rouiter-Mannin. Corpor.tion, I will make ncceeaary e " perimente on any technic al known in ,.our communitY, wa will appoint you OUr Dapt. D, 1&30 Wlla.on A ••. • Chica .. o, 111. product in radio or electrical ft~ld, and write dominat_ Tepre.entativ•• nd furniah You w ith .t.ndard w@11 inll te-chnieal or non_t.echnical copy. Send for liet of ad.erti.ed .et. and part41 at price. that will enable you ref.rence . and . '1( ~J.n.torY booklet. No ohlll'lIItioh. to leU at • h.nd.ome profit. W,..lte.t once for cat __ RADIO SUPPLIES Harvey T . Kelley, Not inc., Suite 301,210 £,a.t Ohio St .• Chical'o. III. ~.I[S~:~. S:~,'C~~~';I'O~n'i~I.nd Radio Co., Di •• 53, 1027 MAKE BIG MONEY BY REPRESENTING u, In your territorY If You live We.t of tho Miaa.a.ippi. where MEN wantln .. forolt ran ..er, railw • .,. clerk .nd otheT R.dio il ..etting more .nd more popul.r, why not go.ernment polilion•• writ. for fr .. parlfcul.n of repre.ent Radiolrraph Laboratoriel and malr:e • aplendid uaml. Mokane, Dept. B-31. Dcn.cT. Colo. income for youree)( by handlin .. our linel or acting a. AGENTS WANTED our _aent? We have Bever.) e1(duatve .,ropoaitlona that will intere.t you. Send for i ntere.t'hg folder de.crib'nlr OUT ptvducta, which include the ~.t aeU FORDS. 60 mile. on one .. allon of Ca.. It ha. been MEN WISHING TO ENTER DINING. SLEEPING CAR acceallOri ••, tube., etc. Cat.l0lr of p.rt. w ith di •• pro ..... n .ueh lD.iJ~al'. c..n be made. AIRLOCK guar­ SERVICE AS CONDUCTORS. PORTERS. WAITERS. count. on requeat. Specify whe theT yOU are dealer 0- .ntee. to inerea.e .... mile-."oi al.o pr.... ent. T.diatoT WRITE 123 RAILWAY EXCHANGE, KANSAS CITY. fan. RADIOCRAPH Labor.torie., 1234 Ros emont av.­ boOin. in .ummer or fT~2:in .. In w i nter. Cooh. Fuell, Bos llA. Chica"o. III. Decarbonbe. the Ford motoT. Splendid territoI'.,. open. AIRLOCK PRODUCTS. 80s 703G, Willow Str_t. HAVE YOU SEEN THE NEW DIALITE. THE UNIQUE Lon .. Beach. Calif. ·INVENTIONS lamp that Jig-ht. up your panel and add. a decor.tive toueh to any radio .et? Ret.a •• t $2.75, complet~. RADIO--Join our ..Ie. ol"l'ani.z.ation and make b.g NEW IDEAS WANTED-Well known Radio Manufac­ Send for folder and dealer'. propoaition on thi. f •• t money. W. want. m.n in eYer,. count,. to .eU well turer whoee product. are nation all.,. ad.ertiecd and IOld movinlr.rticle. Al.o. we aTe diltrihutora for the f.mou. adyeui.ed .et. and part. made by the I_din .. manu­ ...eTFWh ... e wantl new Radio device to eel). Will ~y Knurle-d W.lnut C.hineu. the moat beautiful cahi­ facturer.. Widener of Kan.a. City make. $ISO. OO outril'ht or rD.,.alt.,. for idea or in.,.ntion which i. reen.,. net. made. Americ.n-Univer.al Radio Co. . 6255 weekly. You can do a. well or ~tter. Write toda.,. new .nd ..Ieable .. AddTe... MI'. R. F. D ... lna. Room BroadwaY. Chicago, 111., Box 11. for catalo •• and diacount• . Name .,.our count,.. W ••e­ 1101. 116 We.t 32nd St•• New York. N. Y. I.nd R.dio Com~n.,., D i ..... 52. 1027 No. State St., Chi­ e ... o. Ill. SALESMEN WANTED PATENTS MANUFACTURER'S ACENT c.allinc On Radio-Elec­ Make $100 WEEKLY in .pare tim.e. Sell wh.t the trical Jobbera. Chical'o and .lcmlt,.. h .. open'nl' for 3 pu.hlic wanta-Ion. di.lance radio receivin... et •• Two addition.1 line. carrying .... olume bu.lne... a. we cater FOR SALE: U. S • • nd Canadi.a P.tent on an Att.ch­ •• Iea weekly pay. $100 pTofit. No bi.. inve.tment. to tar .. e jobber.. Edel.tein, 1804 McCormick Bid., ment for Phonogra.,h • • i. the molt beautiful in .. en­ no c.anva•• inll. Sharpe of Co 101'. do m.de $955 in one Chlc.aco• tlon of the ..... Addre .. Ch••. F. Smith. Hull'. N. Dak. month. Repre.entative. wanted at once. This plan i ••weep ' n .. the country-write today before your county i. I'one. ULARKA, INC., .26 V We.t Au.tin "'''an ••nt~ for thi. territo'l to ••11 wonderful Ave .• C hical'o. .... alue hun' •• women' •• ChildTen • .hoe. dire<:t.... - Inl' con.umer o.er 4:0% . E.perience unne<:e ...ry . PERSONAL M~3!.~~t~. • ~Oc~ar~:i.iUJe~:~~catJ. ~~~~:t ; ~~~O ';~~ '. iirit:lt~:;'¥~~~. ~lf.. Co~.k:r:uCr~~&,~o!~M~':: LONEL Y HEARTS. uch.nl1'"elatteni maae interenin.. 4Oc; 1.000 hinl'c a. lOc. Lilt fre e. C. Stelflnan, 5950 new friend. in our joll.,. club. E •• Moore. 80. 90s. Cot. Brilliante. St. Loui •• Miuouri. J.cluonYiIl•• Florida. Enelo .. .tamp. RADIO SALESMEN .nd SET BUI LDERS in eoery count7 writ. Crenz:er R.dio. 1479 Hodiamont. St. Loui• • Mo. Loold You Radio Bug., Join R.dio Corre.pondence VOCATIONS Club. Entirel.,. neW. Broe.den your .cquaint.nce. Make Bil' Mone.,.. Safe and Lock E:ipert. Wayne ACENTS WANTED to .d.... erti.e OUT ..ooda and dis­ :i!o~.nrf:'rni~:::~p ~~r:!~r;!'~ph~n.~d ~d~;N~:!~~ Suon... 3800 Lan Fr.nco St.• Lo. An ...l ••• Calli. tribute .ample. eiven to con.umere. 90c an hour; write C.rd.. R.dio Ro ••• BOK 662. Cle.el.nd, Ohio. for full p.rticula~ . Americ.n Product. Co .• 4201 American Bid • . , Cincinnati, Ohio. WANTED WANTED-To complete m7 oet RADIO ACE neod PRINTING Auaull. s..,tember, October, No ••mber, 1923, l ••u". hound or unbound. Ad.i.e pTice. Uoycl C. H.nnin •• UB" BATTERIES WE .,Tint Stationery, Booklet •• Cat.lo.... Circul.n. Hollbrook. ATizon • . S.m.,le.. Comm.rci.l Pre ... Bata.i •• Ohio. 100 VOLT EDISON TYPE ··B·· BATrERY. "nocllta. 249 Tran• ...,ltt.r. 70 Detector •• 6.ed cr7et.a1 l~ ;:~:\.:u~IT.dn~~~lI~n:- zSO Tubo •• 'f'accuum-peanut a city that is erect ing a broadcasting 71 Dial. adiu.ten drilled 2S1 Tube ••••cuu...,-two al_ 72 Di.... compo.ltion a" Pan.l., fib .. m.nt station as a project of the city govern ment 7J DI.I•• h.rd rubbar ISS P.n.l•• h.rd. rubber 252 Tube•••• cuu...,--thr... 1 ... 14 DI.I •• rheoot.t 166 P.rt. rnent to enterta:in, amuse and educate its own 75 Di.... ""etal 167 P •• t., .old.rln.. tSJ Tun .... 76 Dial •.• ernier 168 Pat.nt .ttorne" 2>4 Variocoupler., h.rd I"Ubber people and those within hearing of the n DI ... with "'nob. 169 Phon. conn.clot'., mult~ ZS5 V.rlocoupl ...... olded 78 DI .. station. 79 DrUh, .Iectrlc 170 ~~onol'l'.ph .d.pt.... ~~; ~:~::c.:~t~re::h:r~~bbe, Of course Jacksonville expects this 80 D..,. cell. 171 PI.te•• conden .... 258 V.rlomet..... molded 81 Earth lfI"Dund. In Plug • • coil 259 V.riom.t .... , wood an radio station to help advertise Jackson­ 8Z Eloetrolyte 173 Plu .... telephon. 260 V.rni.h. In.ulaUn. 83 Enamell. batt.r,. 174 Point.... , daal .nd bob 261 Voltm.t .... ville. As a matter of fact it expects the 84 Enam.". m.tal 175 Pol••••• ri.1 262 W ••h .... 85 End dop. 176 Pot.ntiom.t.en 263 Waye m.t.... station to playa very substantial part in 86 Ey.I.t. 177 Punchin.. m.ch'n.. 264 Wa.. a traIN the program of telling the world things it 87 F...l\o8rlm.nt.1 worle 178 Reinart. ..t p.rt. 265 Wir., aari.1 SA Flbn .heet, ..ulc.nl_" 179 Rel'enerati.... t parll 266 Wire.'bralded and .tranded \\.iI\ be pleased to know about Jacksonville 89 Fik.r re.cto"'i 180 RIK.lver "PI 267 Wir•• coPper 90 FiKture' 181 R.el i6.... . battery 268 Wir •• In.ula t.d and her opportunities and advantages a~ 91 Fuee cut oull 182 R •• i ••nee leak. 269 Wire, Lib 92 Fu.e•. tube 183 R •• ill.nee unit. 270 Wir•• ma .. n.t a port, an industrial center, a distributing 93 C.ner.tot'.,hl.. h f.-.qu.nc,. 184 Rheo.tat ba... 271 W i .... pl.tinu .. 94 Cdd choppe.... rot.ry 185 Rhecutet .trlJMI 272 Wire. tuna-.taD point in one of the most rapidly growinl! consuming centers of the country, th{ center of a famous agricultural territor} ~---.------.------~• RADIO AGE BUYERS' SERVICE, 500 N. Dearbonl Sl.. Cbicaa-o, JU. I and a resort city of unusual advantages I PIGrule see thnt I am s!lpnlied wilh buyilllt 8peelfieatloll8 and pdces on tho articles numbered herewith: • and facilities. But the methods by which ~ .the municipal radio broadcasting station • I will accomplish its part of the program 01 • [ am a- 0 Daater 0 Jobber 0 I4fiTa.' ReP. 0 KallnfaetulW • advertising Jacksonville to the outside I • world will be the most improved, the • Firm [If identified with Radio Industry] .....•....•....•..•...... •...... _•.. _ ..•. ____•••.• __ I most 'up-to-date methods. It win be I I • 147 OoclIPatloll _ ....•. -_.. _ .••••• __._._ .•• _ .•. __...... _ .• _ .•_ ,•. _.-----_.. - I painless. Nay, more, it will be really • 147 N..- __...• _ ..... __.. ___ .. . __..... __. ___. . __ ..•... _ ... _...... • pleasurable. For Jacksonville is de­ termined that her municipal radio broad­ I • • A.ddra .. ---.•- • ._ .•.•- •• _ ...... -._.• _._•• _ .. _ ... _.-••..... (.11:25) . casting venture shall reap for her a harvest of friencls. visitors, and new • City •..•.•.••.••.. _ ... ______: __ •.•..•.. _...... State ._._•. _ ... _.____ .. _ ._____ • citizens . •... ------.------~¥o TeRted and AvvTo1'''fl hu RADIO AGE ¥o Howling and distortion in radio .ets is fr~uently cau.ed by running transformer lead. too close to· gether. The ca.e and bracket. on B-T Euphonic Tran.­ former. are so designed that the tram former may be mounted in any position,-base-board, sub panel, Or sidet- with terminals always in position for most convenient and efficient wiring. This is exclusively a feature of the B·T Euphonic Transformer.

""Pleasing to the Ear" More and more is popular judgment of radio directed toward quality. idelity to speech or music as given in the studio is the requirement of today. Convinced that better audio transformers were necessary to secure the full benefit of B-T circuits and apparatus, B-T engineers tackled the transformer problem. The result of their long effort is the 13-T Euphonic, a superior transformer. As its name im­ plies, it is "Pleasing to the Ear." \\T e believe it the best audio transformer available today. Ratio 2.2 to 1 Price $5.00 Ratio 4.7 to 1 Price $5.75

B -T Straight Line Frequency B- T Torostyle Transformer Condenser Built properl y the toroid in­ All the solid dependability of ductance is a big improvement. the famous B-T "Lifetime" Con­ Poorly designed, a toroid makes denser,-the same electrical ef­ oscillation control difficult and fic iency, the same superior bea ring tuning broad. construction,-now a\'ailable in B-T Torostyle Transformers are stra ight line frequency plate the result of inductance experience design, For those who prefer this that be~an before broadcasting, type. The Torostyle is built right. Send for circulars. Send for complete information. Two Condensers, but One Dial Used in New Circuits Control New circuits require potentio­ The famous B-T Type L Con­ meters and varia hie high re­ denser nOw a \'adahle in tandem. sista nces. Tone is often improved A t ypically sensible "trimming" by using a modulator. B-T Re­ device enables accurate balance sista nces are stepless, non i nduc­ between units. tive, smooth in operation and are Literature on request. una ffected by continued service. Tuning is Easier Literature on request . Distance and tone are often The B-T Universal Socket onl y a matter of accurate adjust­ ,\ socket t hat takes the N a vy ment. B-T Tuning Controls Rase Tubes all the i':ew UX permit hairline adjustment easily tubes without an adaptor. Poor and quickly. contact an impossibility. Less I mprove the appearance of your capacity due to small area anJ set as well. wide separation of contact s prings. Circula rs on request. Send for circulars. The Latest Thing in Radio The la test best Circuits, the newest apparatus are always in "Better Tuning." Helpful hints to set owners make it worth ten times the pricc. Send 10 cents for your copy. BREMER- TULLY* MFG. Co. 532 S. Canal Street, Chicago, Illinois

¥- Tested and APP1'ovcd by RADIO AGE ¥- Z enith was created for the home LL one needs to get the fin .. est radio results from Super.. Zenith is good musical taste and a feeling for exquisite tonal values. So far as technical ability is con.. cerned, the Super.. Zenith is so easily controlled that a child can bring in just as many stations­ just as quickly-each with the same clear quality of tone-as a radio engineer. ",- Only a demonstration can make completely evident the ;l~ ·mark.. Super.Zeniths are Priced at from $240 ably selective chara~ter:9tf.1)eSu .. to $ 2,000. Each instTU~nt is sold under a quality guarantee. Ab~e per.. Zenith-its clt;ar ~S\v~~~i§ri'e is -sho wn the De Luxe Spanish modeL -its thorough depe n~a~i:Ilt'y . t·'·· ..... Such a demonstration is ... ·,yours fot the---a§king;-in your ,/~C?w u. Super.. Zenith VII . $240 home, .if you"?o'desire. Simply Super.. Zenith VIII . . 260 telephone your /'nearest dealer.' Super-:-Zenith IX ..... 355 A\lso Zenith rcgenerative sets (non­ )0:''' '" '" radiating) licensed under Armstrong Again Com~nder Donald B. MacMillan. oosee U. S. Patent No. 1,113,149 Zenith for his Arctic Expedition. When h uman lives may depend upon thc reliabnttY . "~f r acU o per:fO'rm­ Zenith 4R $100 ancc, only one rcas{)nC'i"n cxplain his choice: Zenith has proved to be thc 9.cst obtainable a,t an'( price. ¥- Zenith 3R ...... 175

Zenith Radio Corporation, Straus Bui'ldin-g, Chicago, Ill.

o

:.j. T ested and Approved bll RADIO AGE :{. This file including all text and images are from scans of a private personal collection and have been scanned for archival and research purposes. This file may be freely distributed, but not sold on ebay or on any commercial sites, catalogs, booths or kiosks , either as reprints or by electronic methods. This file may be downloaded without charge from the Radio Researchers Group website at http://www.otrr.org/

Please help in the preservation of old time radio by supporting legitimate organizations who strive to preserve and restore the programs and related information.