x S. EDITION April 25c 1924
in 1922
How to Build a ~eledyne-Neutroflex-Supe ex- Three Tube Neutrodyne- Radio for Banana ~oute-Interference ------¥-~ ~ --'" + ~ ~.-¥- -c- - _« &11 _J"-~~""'T : -»!liTe, 11 !l ~i~ :11 ~I 1 ," ;;;;':,' - 'I ~,--~r .=-- ~ ...... :=.--~ I Cabinet Console Model Model $190.00 $350.00 Complete Complete
5 Vital Improvements plus a beautiful set
The console TELEDYNE gives all you can ask ot a receiver:
J, Extreme sensitil'itl'. de,'eloping weakest sign3k 2. l-Jig hl y selectil'c . tunes local stations Oll t , 3, G reater l'olulllc- a rea l LOUD-speaker set. -1-- No radiation- no regeneration howls to ann O,l' neigh bars, 5, Easy to tune- no log necessary- a step ahead of neutrodYll e.
Compare- antenna indoors or out- then choose. • Don't bu y a circuit-buy a set-buy performance- buy
The new Cutting and Washington ELEDY E TELE means distance - DYNE means power
SEE A CUTTING and WASHINGTON DEALER TODAY
WESTERN RADIO, INC.
EXCLUSIVE DISTRIBUTORS 637 South Hope Street Metropolitan Los Ang'eles, Calif. 8297
~~~~\:::::i'i:::l~)=v=lj;:=i);;;~~)::::~)::'l~~;::::''\::;;t'~~~~j;=,)::;;rH'':::'~i)::::i'):~~~::::j)::::ii)::::i'):~~~~ April, 1924 Page 157 Matches the Tones of the Nightingale By w. P. SHAW
HE Nightin gale! 3. SENSITIVITY-Operating on What a thrill the thought! average voltage the C a Ii for n i a T H ow it paints for us pictures NIGHTINGALE UNIT will carry - pictures of rapturous, balmy the delicate notes of birds or the nights-wondrous nights, Mediterran thunderous, massive pipe organ, It ean nights. will withstand amplification with Only Italy can fumish the setting. out distortion. It will reproduce The lagoons, a gliding, soft-moving perfectly the harmonics of the gondola, lapping waters, wafted per saxophone-conceded by experts to fume of blossoms, then the Night be the hardest of all musical in ingale-the perfect sin ger- bu rsts into struments to reproduce. By revers its song of love! 'Tis melody from nig the polarity of the cords, the th e s!~1'. tone pitch can be raise or lowered. vVhat a tone! There is none like the NigJlt Can Be Attached to Your ingale's lovely song. Phonograph What 1t masterly hope A rubber adaptor may be supplied that man for the Stentor California N ightin might catch gale Unit, which will tha t won make it fit any stand- drous note ard make of phono- -so hi gh, With graph - thereby en so clear, so abl ing you to make sweet that Volume a lo ud s pea k e r of all Nature your pho turns its car to listen. To do that Cldleity nograph man has striven long-almos t suc if yo u so ceeded-but each time falling short of desire. perfect reproduction. The note is so CCUltlCY! The e).- high and clear that it is a most diffi perience cult thing to catch. of phono The Night of the Great graph ma facturers has shown that a rubber Test insul ator should be used between the All was sil ent in the shop as the sound box and tone-arm. This prin· interested spectators waited for one ciple is used in our rubber adaptor, more great test of man's mechanical wh ich increases the volume and guar skill in reproducing over the radio antees a perfect, airtight joint. the tones of the Nighti ngale. The A Final Type Loud tone experts were li stening intently. Super~Speakfr Speaker "I almost hear it. You nearly have it- " F or use in the home-where a The tones may be even those of the pic moderate amount of volume is de "N 0 , not quite I" colo with its shrill 4200 vibrations-the same sired, and for dancing and outdoor "That's almost the tone." as the Nightingale. Human voices may sing speaking-where a big volume is ne- "Now! Do lliat adj-rtstment again! Do that cessary. That is why a critical comparison or instruments may play- it is the same. of all louci speakers in variably results in again! Man, that's it! That's the tone. T he tone is clear, sonorous and strikingly favor of the Stentor Cali fornia Nightingale Exactly like the N ightingale's-clear, dis recreated. Su pel'-S pea /.'e r. tinct, unwavering, sweet! It is the tone California Nightingale Super Stentor, of the Nightingale itself! It is a success." Simplified for You Mechanically complete .. _...... _..... _.. ~ ...... _..... __ ..... $22.50 Points to Be Considered in the Califomia Nightingale Unitype, which And So We Christened This Purchase of a Loud Speaker is a Unit only ...... __ ...... $10.00 Trilf,mph "The California This peaker is simplified for you. There Rubber Adaptor for Phonograph Nightingale" Unit is no adj ustment screw. This is done at the Attachment __ ...... __ . __ ...... 50 It is a super-tone spe al~eT 1111it that will factory and sealed, and as long as it remains reproduce even the song from the throats sealed, carries our guarantee. of birds- the most difficult In purchasing a loud speaker you expect of all r a d i 0 accomplish · the three following points which are suc ments. Because of the full cessfully co-ordinated in the Stentor with carrying qua Ii ty California N ightin gale Unit: of this new Cali . 1. SUBSTANTIAL QUALITY-A real fornia Nightin addition to the musical instruments of gale Unit and the home, with beautiful polished base, completed cabinet and gracefully low built trombone horn. and h 0 r n, it is '2. AUDIBILITY-When you think of called the Stentor the California Nightingale Unit you Super-Speaker - think of round, full tones made possible Stentor for volume and Nightingale for by the elimination of many factors that melody. have made radio objectionable. For Sale by Leading Dealers Page 158 April, 1924
"THE AIR IS FULL OF THINGS YOU SHOULDN'T MISS"
Why Big Cells Count in Radio "B" Batteries HIS handsome metal case Everea,;dy world's foremost electro-chemical T "B" Battery No. 766 costs only two laboratories. We think that No. 766is the thirds more than the smallest Eveready . handsomest battery ever made. But that "B" Battery, but it contains seven times is a matter of opinion. It is a matter of the electricity! This makes the No. 766 engineering record, however, that this over four times as economical as its baby great standard "B" Battery has proved brother. That is why most people buy it. itself as perfect in performance as we are convinced it is superfine in appearance. Its fifteen large cells give 22~ volts of strong, steady energy day after day. The 45,volt Eveready No. 767 contains Cells that pour out power the moment the same large powerful cells as the No. you turn on your tubes. 766. For maximum "B" Cells that rest well when Battery economy, there idle, renewing their vigor fore, buy the 22~ -volt for your next demands. Eveready No. 766 or the No cells have a bluer 45-volt Eveready No. 767, blooded ancestry than . as you prefer. Here is the "B" Battery at its best. these. They are the prod Eveready "B" Battery No. 766 2:! Yz volts. Six Fahnestock Spring Clip uct of thirty years of dry Terminals. giving variable voltage from NATIONAL CARDON COMPANY, I NC. H,adquarfus JOT RadIO Barrcry Informa tion 16 Yz to 2'2 Yz volts, in 1 J;i·voit steps. battery r esearch and Length, 6 3.4 in.; width, 4 Ys in .; heigbt, New York San Francisco l l/16 in. Weight,5Ibs. Canadi,ln National C :1rbon Company, Limited development of the Factory and Offices: Torontu. UUt.l[lO
If you have any radio battery problem, write to G. C. Furness, M anager, Radio Division, National Carben Company. Inc., 212'2T4 Orton Street. Long Island City. N. Y. In(orm ' ative and money' s.1.ving booklets on "A," "B" and "C" Batteries sent free on request.
Eveready 6-vol t Storage Battery Evereadv Radio "A" Dry Cell Speciall y manufactured for use with dry cel l fNEREADt; tubes No. 764 The Space Saver Vertica l 'Radio Batteries z:lYz-volt "B" Battery -they lil_st longer No. 771 "e" Battery Clarifi es tone and increases "B" Battery life • April, 1924 ~_ Radto - ]OUtnat~ "" Page 159
Volume.Four APRIL, 1924 Number Four
Radio Jouma! CONTENTS is published monthly by Radio Journal Publishing Company, 113 Stimson Building, Los Angeles, EDITORIAL COMMENT 160 California. Telephone £ 77-7 2 6. HOW TO BUILD THE TELEDYNE ______H. S. WILLIAMS 161 EDITORIAL BOARD ANTIPODES GET ACROSS ____ .... _...... __ ...... _.. ___ . ___ ... __ .. _. _____ ._ ...... ______162 Ed,itol· .. ___ ...... __ __ ...... __ K. P. FREDERI CK BRITISH HEAR SIXTH DISTRICT _.... ______. __ . ______.. ___ _ 164 A ssociate EditOl· ______DR. D. N. CLARK Cenel'at }\ifanager. ______HuGH HARLAN BUILDING THE NEUTROPLEX .. ______. ______. ____ M. S. ADAMS 165 A d .t· · SA. W. MAJORS vel lsmg ...... _ ...... l THOMAS ELLIS ELECTRICAL UNITS AND FUNDAMENTALS __ . ______. ______. __ __ . ______._ . ______PROF. H. LA V. TWINING 167 SUBSCRIPTION RATES HOW TO BUILD THE SUPER-REFLEX ___ . ____ EDMARD J. W.IGGI NS 169 6 months ...... $1.50 THE HOOVER CUP MOVES WESTWARD ___ .. _. ___ . ______. _____ ._ . __ 170 1 year ...... 2.50 LONG RANGE CRYSTAL SET_. __ . ______.. ____ . ____ ._... _. ______. ___ ._. ______.. _. ___ _ 2 year s ...... 4.00 170 Single Copy, Foreign, ...... 35c WHAT MAKES THAT SET NOISY ___ ... __. __ . ______._. __._. ____ J. T ROFFY 171 Canadian or Mexican- 1 year ...... 3.00 RADIO AMATEURS RESCUE SHIPS . ___ .. __ . __ ._. ___ . ______.. _._ . ______.. __ . __ 172 Foreign, 1 year ...... 3.50 Single Copy ...... 25c RADIO FOR.. THE BANANA ROUTE. _____ ... ____ ._. ______.. ______I. M. P EEL 173 SET AILMENTS AND REMEDIES_. _____ . ______. __ . ____ .. __ D. A. RU NYARD 174 ChalJ.ge of Address-Notify us of any change in your address. TUNING YOUR SET AND SELECTIVITY _____ ._. ______M. C. BATSEL 175 Be sure to give both your old and CAT WHISKERS ______. ___ __ .. ______.. __ _. ______._. __ _.______176 new address. NOTES ON 100-METER TRANSMISSION ______... BEN ]. CI-IROMY 177 . Beca~se .of the fact that intense interest In ~adlO 15 sweeping the entire country caUSIng a flood of inventive and research I NTERFERENCE, WHAT, WHY, WHERE. ______. ______T . E . NIKIRK 178 ~vor k. much of which will be duplicated, it IS necessary to state that in the event of SOMETHING ABOUT DEAD KINGS ___. ___ .. __ . ____ . _____ .. ____ ] . T . ROFFY 179 expressio1ls of opinion and various state. ments from contri butors and corres")onri . OH BOY, HEART THROBS ._._. __ ...... _...... _.. ___ ...... ___ ._ ...... __ . 180 ents appearing in Radio Journal 'from n: ~nt h , to ,month becoming the 3ubject of Ilt,lgat.lO.n I~ courts, or of co:!t!"oversy in COMBINED CRYSTAL SET HOOKUP. __ _. ______...... W.H. H. K NOX 180 sC l e n~lfl C clrc1es, and which may involve questIOns of priority of invention and a HOW TO BUILD AND TUNE 3-TUBE NEUTRODYNE comparison of merit of apparatus. the own e.r s and publi shers of Radio Journal posi ____ ...... ______... __ .. __ ...... _...... ___ ...... __ ..... __ ...... _____ ...... C. H. STOUP 181 t1vel)'. ?1!d uncquivocal1y. disc1aim any re sp-::m.slb dlty fo~ any such expressions of QUESTIONS AND ANSWERS ______...... ____ ...... _____ ._.. ... ______._._ .. __ ._._ .. ___ .. _ 183 opInion or partIsan statements,
LISTENING IN .... __ __ _. ______. __ . ___ ... ______.... ______. ___ .... __ ._ .... _. ____ .... _. __ 184 "Entered as second-class matter ~1ay 19 1922, at the post office at Los Angeles' WITH THE RADIO CLUBS . ___ .... _..... _... .. _...... _...... _.. ... 185 f81;~. ~,rnia, under the Act of March 3: WITH THE WESTERN AMATEURS ... _____ ._. ______.. . __ ...... ______. __ _. _.. ___ . 187 The entire contents of Radio Journal, TRADE TALKS .. ______. __...... _._ ._ .. __ ._. ___ . _____ . __ . ______._. ______._. __ .... _._ ...... _.. . 188 including arti cles, stories, pictures, dia grams, etc. (unless otherwise credited), WITH THE EDITOR __ .. ______... _. ______. ___ __ . ___ .... __ ._ .. _.. ___ ...... _. ____ _... . 204 copyright, 1923, by Radio Journal Publish ing Company, which reserves all rights. Chi cago Representati ve, Franklin E. Wales 17 N. La Salle Street Printed in U. S . A . such as the R epublican and Democratic conventions, elec Up an' at 'em tions, big public figures of stage, music and platform turn ing to the microphone-the public will buy radio and keep Next to taking a gentle but firm seat on a batch of well on buying radio. Vlfe knew a man, a real business man sharpened carpet tacks we can think of nothing more un with lots of credit for insight and vision and far sighted ness and all that line which is usually applied to the suc pleasant for a member of congress than actively support cessful business man; and he told us several years ago ing a tax on radio. Yet there are members of congress who to stay away from radio because it was onl y a temporary are doing just that thing. Maybe they haven't felt the tacks fad and couldn't hold popular favor. He meant it for our yet, but we feel certain that s.hould .they succe~d in puttir:g own good and all that. Well, we hunted him up behind over this more or less nefarious bit of taxatIOn they will hi s plate glass door the other day, and he began to ask us feel them-and the radio public at large should make it what he could do to clear up the tone of his super-but a business to see that such members of congress feel not blamed if he hadn't forgotten all about what he told us a only the tacks but the axe. A good many homes would feel couple of years ago. Forgetting all about the improve such a tax as a crushing blight on what has proven one elf ment in radio sets and broadcasting since a year ago, for the o- reatest sen'ices ever rendered mankind. The country getting all about loss in range due to warm weather and neecf., revenue-to be sure. But striking at a very vital all that, on the mere fact that radio is making a thousand bit of family li fe, a vital sen'ice rendered to the halt, the converts a day to a dozen a year ago we 'will wager a 'pink lame and the blind, to the sick and infirm, to the needy rabbit against a pair of ear muffs- which we don't need in and the aO'ed, a service which promises to make us all more California-that it is going to be a good radio summer. nearly br~thers than we have b e~ n sin ce the day C~in killed Abel-such a blow would be lIke unto the stnklJ1g of a friend because one needed bread, like the slaying of a Troub les that Pass brother beC<'luse one needed raiment. But has this Union become so impoverished that it must reach into the pockets These glowing days remind us-what about the m of this class, must throttle and restrict a vital and growing eri can Society of Composers, A uthors and Publishers. service to mankind for the sake of revenue? Hardly. We One judge has ruled in favor of freedom in broadcasting do not know what the verdict will be as this is written, while another as solemnly rules that the Ameri can Societv but whatever it is we shall make it one of our aims in li fe is right in its attempt to throttle free broadcasting. Meat{ to see that those who supported such a tax have an un while congress is bein g asked to give relief to the broad comfortable time of it when that judgment day of every casters in one fo rm or another by amendments to the congressman roll around election day. copyright act. Meanwhile the country at large has had one The appropriation for radio inspection for the coming thing demonstrated-it can get along without the Amer year was increased two thousand dollars. Ye Gods! There ican Society or its music so far as radio broadcast is con are that many new receivers within a few blocks of our cerned and not know the difference. Any time any organ residence since ij" ew Year's day. Some day an enterprising izati on thinks it has all the talent or all the art in America radio salesman is going to invade the hall s of co ngress and. co rnered it is letting itself in for a tumble through the bed sell a few sets-after which even congress will wake up, slats. A fter all it's a very healthy sign that America and a consummation devoutly to be wished. its broadcast stations can get along without the American Society--'-and the thousands and millions go on listening Sulphur and Molasses in to great programs just the same. Summer is with us once more. vVe know it by the most familiar sign in radio-we met a merchant who dispenses Problem for Jobbers radio the other day and he asked us about the summer New York, Boston and Kansas City electrical dealers slump. By quite a coincidence we had letters the same day have adopted firm resolutions against trade discounts. Re from two large manufacturers of radio equipment who cently we have heard mutterings from the radio trade said that their April business had been double that for anent stich practices which, if carried far lead to much March and that they confidently expected their May busi abuse. The problem is one for the radio trade to work out ness to exceed April. So we told our dealer friend about conscientiously and seri ously, keeping in mind the definite the letters and suggested that instead of broadcasting that fact that such discounts may, in time, be extended to such summer slump stuff he try to double his business for April a wide circle as to seri ously impair the legitimate retail -and forget it. Of course there are firms who will feel market. a slackening in the business pulse; and there will be others who will saw wood and get the business. Broadcasting is better than it ever was. Big events are crowding close on Penny Radio one another's heels these days on the air. Every day adds Drop a nickel in the slot and listen to the radio. It's a new listener-in to the ranks of radio, in every dealers in operation in the east as an adjunct to the penny ar territory. Every day sees a new program announced some cade. We question, however, whether this form of where that is of vital interest to the community served by commerciali zing free broadcasting wi ll hold interest for that broadcasting station. T hen the big national events anyone for very long. April, 192( Page '161 How to Build the Teledyne Receiver By H. S. WILLIAMS
The Teledyne, non-re-radiating super-rege11erative radio circuit was designed by Dr. Bowden Washington, chief engineer of the Cutting and Washington Radio Corporation. "Tele" mea11S d'istance and "dyne" power. This article by Mr. Wil liams, radio enginee'r, deals with the general features and also explains in detail how to build it. All of the constructional data here given has been approved by Dr. Washington.
HE "teledyne" was designed which was at fault, but, rather, the way give coast to coast loudspeaker volume with two primary objects in in which it was used. It is a force, a under average conditions. view. The first was to produce very potent force, which, when intelli There is just sufficient regeneration gently utilized, opens up infinite pos intended in the antenna circuit to min Ta powerful and simple regener sibilities in the field of broadcast re imize to a marked extent ill-construct ative receiver that would not "trans ception. No vacuum tube receiver, ed antennae. The minimizing of an mit" or "re-radiflte." The second was even with radio frequency amplifica tenna resistance aids ,",olume and selec to increase the 'range, volume, clear tion, can ever reach any great degree tivity. ne.ss and selectivity of four-tube re of sensibility unless regeneration is The tuned radio frequency stage, ceIvers. employed. The .problem in regenerat in being coupled in a peculiar manner Both of these objectives were ob ing radio frequency amplifiers is the to the grid of the detector, with tained. By a series of engineering ex tendency to spill over into oscillation. both tuning and regeneration, gives periments it was found by Dr. Bowden Neutrodyning prevents the tubes from enormous amplification with greater Washington that it was possible to eliminate "re-radiation" from regener ation. This accomplishment, in itself, will appeal to the radio fan who is con tinually annoyed by squeals and cat calls from neighboring receivers as one of extreme importance. The average fan may ask why is regeneration necessary? The discovery of regeneration was a great step for ward in radio reception. It made a vacuum tube almost a thousand-fold more efficient, bringing about consider able economy in tubes coupled with greatly increased sensitivity and selec tivity. When radio-phone broadcasting swept over the country, regenerative L------____~~.z~& receivers fairly "rained down upon the Complete hookup f or the already famotls T eledyne 1·ecezv er. listening public.". Unfortunately, in sufficient thought and foresight used oscillating, but with a great sacrifice selectivity. Under ordinary conditions in the beginning and the radio-fan was in sensitivity, for it also prevents the the radio frequency stage amplifies the presented with what has turned out to tubes from regenerating. very weak incoming signals ten times. be the course of the ether- the single The problem of utilizing regeneration This amplified oscillation is then im circuit regenerative receiver. It was with the unquestionable advantages pressed upon the grid of the detector this type of receiver with its many without danger of self-oscillation was where through means of controlled re solved by Bowden Washington by tak generation it is again amplified as much as one hundred times. I..--.- 3J:'-r-- __ Zi"'" I ing the principle that when a resonant ~ >l '~ 26-'- circuit, consisting of an inductance and The amplification in the detector cir r7i' '"-' -1 capacity in parallel, is placed in series cuit is a material aid to ease in tuning. • i The detector circuit can be made to ,I " with the plate circuit of a vacuum tube, ~ the grid circuit of which is also reson oscillate without antenna "re-radia ated to the same frequency, the reson tion" and therefore pick up distance ant plate circuit will produce oscilla carriers through the conventional boat ----"------<,; tions, and just off this resonant point, or whistle method without the neces .t5 o.a l ZJ·Jl). :ttJj"or T()1U'(/CA O>f BA~I. J.l rc Tvdlk/, /fJlIl.fA.II negative resistance or regeneration. sary of hunting for the stations . fiG. 1. The research finally was simplified Once this carrier is located, all that down to the point where the coupling is necessary to bring in distance signals drawbacks that brought regeneration was made at a certain critical value, is to tune the antenna control until the into such disrepute. The demand for thus preventing oscillation. signal or boat is loudest. The regener complete neutralization of the forces ative control may be tuned back of regeneration has mounted to such Highly Selective slightly if necessary and the signals an extent that many people are under The Teledyne comprises four tubes, left clear and loud. The set therefore the impression that regeneration is namely, tuned radio frequency, regen has only two major controls, compris practically dead as far as broadcast re erative detector and two stages of !ng the secret of easy and simple tun ceivers go. audio frequency, the circuit being so mg. It was not regeneration, however, developed as to be very selective and The Teledyne also uses a four and Page i62 ~Radio Joutnat~ April, 1924
step by step, in proper order of assem WiND INC, TO 'f.NTRALY 1.00TeD ~ I05TuR~~ -:::1 Off TV/JE. bly and wi:ing:. If ~t is followed closely r5T.~Tl the work IS sImpltfied considerably. Primary Coil A~ accurately as possible layout the locatIOn of the holes for the beginning a~d end of the primary winding as per FIg. 1. A No. 55 drill is commonly srA~T used to drill these holes but other sizes COli.. HE.II.! are permissible, depending on what is handy. Too large a hole is not to be recommended however. Referring to ~FAo ovr WIl{£56. rAP Fig. 2, 105 turns of the No. 26 double ro (J/i 6" £01(4 silk covered wire are to be wound on #;2.613& 5. 4 11. 4/fUIf D.5.C. CoPPell, WlR.t: this coil. Starting at the left end of one-half volt HC" battery which is in tion coil will be left to the builder's the coil as in Figure No. 2 and turn tended to give battery economy along discretion. They may be of anything ing the coil in the direction indicated with loudspeaker volume. preferably brass or bronze and may be by the arrow wind on, as close as pos sible, 65 turns. Loop the wire at this How to Build It shaped to suit the particular style of layout that the buider contemplates. turn and take off a tap leaving about The following- l.ist of materials should Either hard or soft wire may be used six inches for conne£ting to the switch be followed as closely as possible and fo r connecting the various units up. point. Continue in the same direction where any alterations or substitutions E leven binding posts will be required until 40 more turns are wound on. An are necessary, equally as good parts one each for the antenna, ground, chor this as indicated, leaving as be must be secured. negative A, positive A, negative B, de fore about six inches for connecting. Primary Coil Tube: One bakelite tector B positive, amplifier B positive, A diluted solution of collodion, pro tube two and seven-eighths outside dia negative C, positive C, and two for the curable at a drug store, may then be meter; one-sixteenth inch wall and used to coat the wiring so that there three and one-half inch long. /"'£~~;'Aofi ( ~" :;S/f~ ~",,,,""':~ ,,(lt~,, "/:. " ------c:.,.:--:;;a=?=_. will be no possibility of the wire com Secondary Coil Tube: One bakelite ing loose or sliding off the coil. tube four inch outside diameter, one sixteenth inch wall and two and one S econdary Coil eighth inch long. c Figure No. 3 shows a complete Regeneration Coil Tube: One bake sketch of a Teledyne Secondary. There lite tube three and one-fourth inch are two windings on this coil, the low outside diameter; one-sixteenth inch er one being the detector grid coil, or wall and three-fourths inch long. the secondary, while the small four 1 plain U V 199 tube socket. turn coil wound over this is the plate 3 U V 199 tube sockets shock ab horn. If flexible leads are used as in delivery coil of the radio frequency sorbed. the Cutting and Washington teledyne tube. The latter is especially critical 1 Dubliier Grid condenser type 601G all but the first and last two may be dis and should be wound and placed ex capacity .00025 mfd. carded, and soldering lugs used in their actly as in the drawing. Separating 1 Dubilier phone condenser type 601 place to which the flexible leads are these two coils is a thin piece of bake T capacity .002 mfd. soldered. lite or impregnated cardboard. I f the 2 Dubilier by-pass condenser capa One switch contact arm of conv'en latter is used, it should be thoroughly city .1 mfd. tional design with two switch contact dried and then impregnated in a dilute 1 spool No. 26 double silk covered points. solution of collodion. This prevents ab magnet wire ~ lb. Painstaking care in assembling is sorbtion of moisture and assures bet 1 variable condenser capacity .00025 most important thing in building a Te ter operating conditions. The strip mfd. ledyne for results. The winding of the should not be more than a thirty-sec I variable Vernier condenser capacity coils is probably the most difficult op ond of an inch thick and about ~ inch .0003 mfd. eration of the process, but even that wide. A strip 12 ~ " long will just go 2 All American amplifying trans should not be alarming if instructions around the secondary coil around the formers high impedance ratio 5 are followed carefully. secondary coil over the other winding. to 1. The following formula is intended 2 Carter switching rheostats resist to take the builder through the work, J:L=: ~~' -j . ance 30 ohms. ( ~e ---ri 1 Carter plain rheostat resistance 20 ohms. 1 Carter two spring jack. I bakelite panel approximately 8x18 inches. (Depending on space avail able.) 1 shield plate slightly smaller than J panel or at least large enough to cover the condensers and coils. The transformers and rheostats need not be shielded. 5 or' more dials, depending on whe ther or not separate verniers are used. Miscellaneous brackets for the coils and tubesockets, transformers, etc., fiG. 4. 4' o.s. DIA'X-/i wALL I3L~K BA~r.LITE'TUBU and a suitable shaft for the regenera- April, 1924 Page 163
Layout the holes for the secondary is mounted directly between these coils. tube according to Figure No.4. The This makes short and direct leads pos three holes marked 13-64" drill may sible. To the right of the secondary
be omitted if the circular bracket as 4 7,,11 regeneration coil assembly is mounted used in the Cutting and Washington ." the secondary tuning condenser. This set is not used. A different form of is the one having a capacity of .0003 mounting will of course require a dif mfd. The vernier in this case is separ ferent bracket and hence different ate and actuated by a separate control holes. To those who have not had ex to the right of the main control. This perience in reading blue prints Figure is not essential as any type of vernier No. 3 will probably suffice. The anchor condenser is suitable. holes may be drilled approximately With the aid of a few shafts and In the rear on a special shock ab correct or as near as can be judged. bolts the secondary and regeneration sorbed mount are mounted the grid The only two holes which are at all coils may then be assembled somewhat condenser and leak to the left while accurate are the two holes thru which as in Figure No.7. The inside of the the detector and two audio frequency the regeneration coil shafts run. These, regeneration coil should be that side amplifier tube sockets are to the right. of course, should be quite accurate having the winding on it. If this is A patented switching condenser used otherwise the dials will probably wob true and all the winding directions are in place of the ordinary primary con ble when attached to the shaft. as given in the prints, the rear con denser make the use of a switch lever Winding the secondary is next. Start nection or that one marked "P" will go and points unnecessary. These are not at the left at Figure No.3. Wind in to the plate of the detector tube while the direction shown in the drawing and the remaining one or that one marked continue until 45 turns of the No. 26 "B" will go to the outside winding of double silk covered wire are closely the audio transformer primary and wound. Anchor as before, leaving sev thence to. the detector "B" battery. The eral inches for connecting. Coat the experimenter wi11 undoubtedly have coil with col!odion as was the primary. many ideas as to how to assemble the Procure the bakelite or cardboard strip. regeneration and secondary coils so Fasten close to the right hand end of that part wil! be left entirely to the builder's discretion. All that must be remembered is that the regeneration Front view of completed set. coil must be swung inside the second ary coil at the end opposite to the one procurable on the market so it becomes carrying the plate delivery coil of the necessary to use the switch lever and radio frequency tube. The assemblv points instead. These should be mount of this complete assembly in turn wiiI ed at the left of the panel so as to make depend upon the particular style of short leads from the primary coil pos panel layout that the builder is using. sible. The rheostats may conveniently Panel Layout be mounted to the right since this is secondary coil with col!odion or a rub the audio side. Likewise it might be \Vhile the assembly and panel layout ber band. This is illustrated in the advisable to mount the audio frequency of the Teledyne will depend upon the sketch. Once the wire is wound in amplifying transformers to the right particular kind, and quantity of appa place over this strip, it wil! hold itself. close to the tube sockets. This also ratus on hand, still there are certain In the meantime, if the rubber band makes for short leads. fundamental principals which must be ' or collodion is not sufficient to hold the The mounting of the separate units borne in mind while this work is going strip, a drop of glue may be used on is also left to the builder's ideas. It on. A general idea of this can be gain- the ends. As shown in the drawing may be welJ to use a base board to this delivery coil, as it is called, is which the front panel can be mounted comprised of four turns of the same so as to alJow the units to be mounted size wire as used before. It is wound directly on the primary condenser. The in the same direction and very care radio frequency tube socket can then fully placed so that the last turn of be mounted on the base along side of the delivery coil is over the last turn it, making short leads possible. The of the secondary winding. This is secondary regeneration coil assembly quite important. To aid in holding the next to this either to the base or to the wire smal! pieces of cloth tape must be panel but at right angles. to it an~ w:ith inserted under the windings, the ends fiG. Z · the center line of the pnmary wmdmg of the coils slipped thru the loops and exactly on a line with the center of the - + .B - END Of the loops pul!ed tight. The coil is then T lc K1-E.R, secondary. This is important. In other coated with collodion as before and words, the two coils should. be exactly allowed to dry. in line both ways but at nght angles to each other. The secondary variable R epeneration Coil ed by glancing at the accompanying condenser can then be mounted to the Reference to Figure No.5 will show photograph of the Cutting and Wash right of this assembly with both the ington Teledyne. Here you will note how the coil is to be prepared before amplifying transformers and tube winding. The two No. 17 holes are that the primary condenser is mounted for the shaft. Figure No.6 will show at the left with the primary coil fast sockets nearby. The jack is conveni the method of winding. The same size ened directly to it. The coil is exactly ently mounted at the extreme right of wire is used as on the other three coils. vertical. This is important. To the the panel. Care should be exercised here as be right of this is the secondary and re A word of caution here. Care should fore to see that the windings are close together and properly placed. It like generation coil assembly with the re be taken when arranging the apparatus wise should be coated with collodion generation coil by means of a train of to see that all connecting wires will be and allowed to dry before handling. gears. The radio frequency tube socket as short as possible, and at the same Page 164 ~ . RadioJoumat~ April, 1924 time not come too close to one another. ing as shown in the accompanying dia the aerial. H owever, I hope to raise This applies especially to the radio fre gram. the aerial soon and then I may work quency leads. When the binding posts Next month the author will describe you o. m. At present I can't use any and other odds and ends are connected the antenna to use with the Teledyne more power as we have no mains here and assembled the set is ready for wir- and how to tune it. and I have to rely on dry batts or spark-coil C. W . Regarding results with the receiver o. m. I have now logged 400 U. S. and Can. hams. Not Antipodes Get Across bad for detector and one step. This is all this season since December 2, PPAR ENTLY 4AA, New gcles, Calif., reports 4AA, beli eved to 1n 3. List include 12 of the 6's and 4 Zealand, and 30K, A u tralian , be A ustrali an, at 3 :20 a.m. March 30. of the 7's. made the grade to the states Recepti on was while Mr. McCreery was on a special trip to Balboa. H e A during the two way tests just stretched an aerial from fence posts Important Discovery concluded. Myron H exter, 6CN L, re and reports wonderful reception con DIS COVER Y of prime ported first picking up A ustralian 30r-::: diti ons excel t fo r commercial and nav sci entifi c interest has just at 8 :25 p. m. April 15, and continued al station interfence. T he Atl antic getting this stati on, despite interfer coast came rolling in . been announced by Mr. Dan ence and fading, until 8 :59 p.m. P acif A iel Nelson Clark, LL.B., ic Standard Time. It was calling U6- 6LJ was reported in E ngland, re ception being in daylight 9 a.lll. G.M.T. author of "The U niversal Law of AAO. By wavemeter it checked at Organi c P rogress". and "The Constant 182 meters. T oward the last it was there, or 1 a.m Sunday morning, here. Reception was reported on January 6. of O rganic E nergy." This discovery QSA. 6ZC was with 6CNL at the time is an evolvemei1t from the numerical and checked the reception. T hey Check returned by Canadian and expression of the constant of organic phoned 6AAO who immediately tuned American 4.AA likewise fails to re energy of 178,275 ,065423786200 plus in and got the last end of the reception, veal either station on, though check (deri ved as a product of the orbital making a third check. T he time of re has not been returned from New Zea velocity and the square-root of the dis ception and remarkably clarity of the land. It is known however that Z4AA tance of any planet of the Solar Sys call, which was repeated over and over was on consistently. tem from the Sun). T hus, by the use again, cast some doubt on its authen And last but not least C. D. Mac of the o-ravitational constant, of any ticity, but a check of American and lurcan, on board ship in San Francisco planet, its peri odic time and its velo Canadian stations fails to reveal any harbor, positively reports reception of city, and equation for the true and in du plication. The check has not been Australian 2CM, his own station at fa lli ble relati on of the perimeter of the returned from ew Zealand or Aus home in Australia operating with his circle to the diameter thereo f has thus tl-ali a as yet. ship on special test. been discovered. 6CNL was using a modified Rein Lawrence Mott, 6XAD, on March H eretofore the perimeter of the artz at the time, ingle 90 foot aerial. 18, reports reception of station call ing circl e has been a proce s of repeated 6 AAO who reported A ustrali an 30K for "Any Ameri can Station" but inter attempts to approximate the circle by very. clea r was using the 9ZN low loss fel-ence and fading may have killed dividing it into the greatest number of recel\·er. the call-for he failed to get any sign straight li nes of a regul ar polygon. M. E. McCreery, 6LJ, of Los An- of a signature. T he true mathematical formula for Pi. a. it is commonly called after the Greek letter, has been sought fo r more British I-Iear Sixth District than 2700 years. The laws of motion and of gravitation are the direct source O ME i!ltensely interesti ng in single wire. Transmitter, one 15 -watt of this evolvemen t. formation regarding the type of tube, in put about 8 or 10 watts (not M r. Clark announces the rule, or kilowatts o. m. Hi!) Reversed feed- fo rmula, narratively as follows: receiver used by a British Ama· S back. Radiation maximum 6 amps. "The prod uct of one-half the per teur to receive signals from Cali I know this is not good for 8 or 10 iodic time, of any orbi tal body of the foniia is contain ed in a letter from S. watt, but I have not been able to Solar System, and its velocity, when K . Lewer, 32 Gascony Avenue, \Vest spend much time on the set as I am divided by the square of the quotient Hempstead, London, N . W. 6, E ng very QR W with school work. ( S.ay o. derived by a division of this Constant land. M r. Lewer, on the night of J a m. I am onl y 15 years old ) U ntil the of O rganic E nergy by such velocity, nuary 6, heard 6LJ, stati on operated other day my bes t D. X. was to South is the infallible perimeter of a circle." by M. E. McCreery of Los Angeles, _ ------..--11--.-----;:-;::;-<:+ In mathematical formula it may be Calif., a remarkable feat in itself. In stated thus : a letter to Mr. McCreery he writes : lO'} IS" ..... B [ Peri odi c time ] -~-< J in seconds X velocity in l11.iles per "That night, January 6th, was one fic conds of ti me. of the best I have had, OM. Logged - ' 2 ___ 40 U . S. and Canadian hams there. Conditions were good for the 6's as I LJf'----oi---L--,r - A ( I i 8,2i5.0G5423786200 ) 2 logged also 6AWT , 6XAD and 6BR." V elocity Lewer describes his set as follows : = T rue Perimeter or P i It's only a detector and one step o.m. of P aris 250 miles where I worked but it is the thing for D . X. Aerial is French 8AQ. That is with 3a 1. C. w. Lawrence Mott, 6XAD, Catalina Island, very badly screened by houses, trees, Have worked g 2JF, g 2FNM, g 5HA, and Ernest H obbs, 2ADM, Schenectady, etc. There are four metal roofs with all about 200 mi . with 15 amps C. W. N ew York succeeded recently in establishing a total area of about 500 sq. ft. All The other day I received a report from daylight communication across the continent. this is within 20 ft. of the aerial. Hi! Glasgow, Scotland, 350 mi. That is 2ADM operated on 195 meters and 6XAD Hi! Two other aerials run 10 ft. be my best D . X. Radn then amp 1. on 230 meters. Tests supervised by the 0 A.R RL. indicate that transmitting con low mine! Hite 30 ft. above ground, C. W . I expect this small range is due ditions are often excellent until 90 minutes 10 ft, above metal roofs, length 70 ft., to the presence of so much metal near after sunrise. April, 1924 Page 165 Building the N eutroBex By M. S. ADAMS
H arkness fa ils step forward. We present f o?' y o~t: ins p e~ti o n a lineal descendant of the H arlwess set yet one which handles ether-Jzggles h/~e a N eutrodyne. S O1'ne day a lot of us will get together and give our college yell-"H m'k ! Ha 'rl~ ! H arlmess)).
LOGICAL development of a and eliminated one by one. First, in fact that the factory-built sets are often operated on plate voltages up to logical set is the N eutroflex. the Harkness end it was soon discover ed that coils Tl and T2 would have to 175 without any signs of blocking, No set, not even excepting be completely re-designed with a view ringing or injury to the filament. A the terrific "blooper" single The R. F. now being satisfactory, towards increasing detector circuit ab circuit has had popular approval like sorption, and minimizing both induc- attention was again given to the re- the tuned reflex designed by Kenneth Harkness. Thousands have been home built, thousands sold for what they are, and still ¥reater thousands dis guised under fancy trade names. How ever, di stance, especially loudspeaker distance is dependent upon a good aerial, a fortunate location, and free - .+ optJonal dom from powerful local broadcasting. T Immediately a howl will go to the ]3Q.t. heavens, long lists of stations received will be presented, and authentic reports of marvelous reception under adverse conditions shown. For every set doing this, though, there is another that has never received out of town; so the average performance is about as above stated. Upon finding the possibilities and + B - limitations of the set the same thought This is the ci,'wit diagram of the Nentroflex. I t do es the trick 100. struck every real radio bug at once: a step of radio frequency! All spare tive and capacitative feedback to the fl exed tube. The added volume pro couplers, neutroformers, Tl's, and con R. F . tube. The Harkness tamed fairly vided by the first tube permitted, or densers were collected, and work start well, attention was centered on the rather compelled a reduction in the ed upon a beautiful example of a straight radio frequency tube. An an turn ratio of the audio transformer hay-wire set. Then, trouble, howls, tenna coupling coil of the N eutrodyne in the reflex stage. This has the effect squeals, and trouble. The Harkness is type was tried and proven satisfactory. of even bettering the tone quality of dependent upon absorption into the de T he still present oscillation was attack the original Harkness. tector circuit for control of oscillation, ed by both the counter E. M. F. and This added signal strength also al and apparently U'pon antenna absorp capacity methods, but now such a min lows the use of a fixed mineral detec- . tion as well. When a new ne.atly wired ute amount of either was needed that tor with scarcely any loss of volume layout failed to work, the average fan the simpler potentiometer grid biasing or distance. gave up in disgust. was made possible. A very slight re The layout and wiring is not at all Not so, however, with C. D. T anner, duction of the inherent negative bias difficult, but of course requires more of 528 W . W ashington, Los Angeles. completely stabilizes the set. That there care and thought than a crystal set. The difficulties were taken up in order is a true negative bias is proven by the A 7x 18 panel is recommended, with a 3x7 sub-panel for tqe last two sockets . and the audio transformers, which are mounted on the bottom side of the panel. T he three .0005 variable con densers are mounted 7" apart, with the potentiometer between 1 and 2, and the rheostat between 2 and 3. The first radio frequency tube uses a panel mounting socket preferably a Federal, as the undercut feature gives extra room for mounting the potentiometer. The rheostat should be of the semi circular type to permit the sub-panel being raised enough for the under neath mounting of , the audio trans formers. Sockets and audio transform ers are mounted by machine screws in tapped holes in ,the panel, care being taken that the screws do not come Showing arrangement of N elitroflex pa'rls, from ab ove. clear through to the opposite side: The Page 166 April, 1924
.T ohn Hays Hammond, Jr., vicc president of the Radio E ngineel;.in g Corporation, sai led f rom New York for Italy, where he said he would carry out a commi ssion fo r the Italian Gov ernment involvin g a new system of radio broadcasting, where.by the radio "fan" would pay fo r hi s concerts. l\Ir. Hammond said that receiving sets, mechanicall y devised to tune in on the station, would be rented to the public. A ll other sets would be unable to " li sten in ," he explain ed. "The Italian Government is organ izing broadcasting on a different basis from that in the U nited States where Showin g arrall ge1llellt of Nell troflex parts. frolll below. Note fixed crystal the broadcasting is done generall y for mOlllltcd OJ! co ndenser. pUbli city or advertissing purposes," M r. I-Iammond said. "The develop SUb-panel itself is mounted to the main lugs, etc. ments which I wi ll introduce will be panel by a brass angle plate. The fixed The fin ished result is a three tube superior to the broadcasting methods crystal, visible hetween the two jacks set closely approximating the Neutro here." in the bottom view, is mounted directly dyne in distance and selectivity, yet on the last variable condenser by means one possessing a clearness and fidelity Bishop T homas Nicholson of the of the regular projecting screw from of tone almost unbelievable to a person Methodist Episcopal Church, with the stationary plates. The special ra unfamiliar with· ·the original Harkness. headC]uarters in Chicago, Ill., issued a dio frequency transformers are sup Volume on local stations using max statement urging the establishing of plied with brackets for mounting di imum amplificati on is literally so great church radio stations. Bishop N ichol .rectly on the condensers. that it is necessary to shout to be heard son says that radio has unbounded pos With a correct lay-out wiring is :very above the still clear, clean reproduc sibilities for gooel. He mai ntains the simple. "A" and "B" battery leads may tion; while KGO, KFKX, KGW, radio will not keep people away from be bunched, but special care must be KPO, WDAF, WSB WFAA WBAP church, as is sometimes said, but "will taken to keep plate and grid leads se CFCN, KYW, WJAZ, WKY WDAL enable thousands to hear reli gious mes parate. Of course the usual precau and many others are had with good sages who could never otherwise hear tions about strong mechanical and good loud speaker volume. them. " Continuing, the Bishop says: electrical joints must be observed. The "Radio would even be a money saver, onl y difficulty likely to be encountered although I am not advocating its es is in the selection of a crystal. O ne In the next issue .Mr. A. L. tablishment for that purpose; it would with a comparatively low resistance M unzig, whose work in radio is be cheaper for persons li \'ing in inac and requiring a fairly heavy contact already well 'mown to l'eaders of cessible sections to own recei\'ing in is needed, but after it is installed will this magazille, will launch all ex struments than to pay home mi ssion give no trouble. The audio transform ten.ded series of articles 0 11 the aries to hunt them out." er next to the main panel is in the snpcr-hetrrodYlle. This method of refl ex stage, as is the socket directly receptioll, in which Radio Jonrnal An improved system of relaying will above. The "c" battery of from 3 to piolleered the fifld in publishi1lg be installed near London, to faci li tate 9 volts is connected in by fl exible leads. articles far ill adva'llce of allY the reception of concerts broadcast Minor details .of assembly are de other pnblicatioll, is s tea d i l Y f rom the United States on a low wa\'e pendent upon the make of apparatus gl'o'willg ill vallI e alld illterest. In length. Once every two weeks British used, but it is strongly urged that the fact Mr. MUII::;ig, i ll accord wdh broadcast li steners will be a fforded the general layout shown in the pictures 11IallY olher radio ellgill eers. be opportunity of "hearing A merica" on be followed. The complete list of ma lieves that th e sl.£p er-heterodY1Ie their regular recei\'ing sets-e\'en with terials given below may be purchased w ill pro'uc the greatest advance in one-bulb outfits. for about 50 dollars. radio for sOlli e years. l\ir ..Mu7I It is interested that the broadcasting 1 7x18 panel. zig has been developi11g some l'a vvi ll take place between 11 and 12 1 set N eutroflex trans formers. dically 7I ew ideas on the sltper o'cl ock at night. whtch corres poncls to 3 .0005 variable condensers. w hich 'will be divulged to Radio between 6 and 7 o'clock in the U nited 2 single sockets. J ourllal readers in this series of State. 1 panel mounting socket. articles. The experimenters 0 f the British 1 fix ed crystal. Broadcasting Company ha\'e been lis 2 30 to 1 audio transformers. tening for A merican signals every 1 sub-panel and bracket. Radio was prominent in the di scus night of late, but the results have va 1 lO-ohm rheostat. sions o f the A merican Newspaper Pub ri ed. Success fu l transmi ssion and re 1 400-ohm potentiometer. lishers Association recently at the ception depend very much on the dark· 3 3-inch dials. Hotel Waldorf-Astoria, New York ness. 6 binding posts. Citv. 2 2 inch dials. Y
Electrical Units and Fundamentals By PROF. H. La V. TWINING
Professor Tz lining, in this artie/e, begins th c l'cal discussion of 1'adio capacities and th eir relationships. The serirs, <('hen colllplete. "ielill havc carried the reader through the entirc radio eq lfip1lLe11t list.
N the last issue it was shown that second and hence (28) 10-B volts are Perpendiculars are erected at the one watt second is equal to 107 dyne produced. I f the conductor be placed equal distances N. Q. T, etc. Lines in the position DB making an angle from F, G and H are drawn parallel centimeter seconds; see formula r with the lines of force shown in the to OE. The intersections of these pa I (15); that one volt is lOB times figure, and if it be moved parallel to rallels with the perpendiculars at M. one absolute electro-magnetic unit of itself to the position GH in one second, P.c., etc., are points in what is known potential, see formula (16); and that then it cuts only 16 lines per second as a sine curve and this curve is form 8 the ratio between the electro-static and the voltage generated is (16) 10- • ed by connecting these points. system is (3) ( 10)'°. In the figure it is seen that the coI11- The voltage generated at each in There are two other ratios in which ponent BO of the conductor DB cuts stant in the face conductors of an arm we are vitally interested in radio, i. e., the lines perpendicularly while the ature rotating in a uhiform magnetic the ratio between capacity in centime ters and farads and the ratio between centimeters and henrys in the case of inductance. In the case of an alternating current free from inductance and capacity the voltage and current rise and fall re gularly and together. They are then £ said to be in phase with each other, or in other words they are in tune, speaking from the standpoint of radio. When the current is zero, the volt age is zero. When the current reverses the voltage reverses and when the cur rent is at a maximum the voltage is at a maximum. The reasons for this and Fjgm'e 1 the relationships are explained as fol lows (see F igure No.1). component DO does no cutting since field is thus proportional to the sine of Let Nand S be the north and south it is parallel to its line of motion. This the cutting angle and it is found as poles of a
r=wt and Ek WLkIk in the static system. Where r is the total angle covered Dividing one by the other in the time t and w is the angle covered A Ek WLkIk per second. Substituting this in (a) --=--- or and (b) we have E WLI E =Em Sin wt 1 Lk 1 I 1=Im Sin wt 300=- or The angular velocity w is related to L (3) (10)9 the frequency as follows: Lk Since one revolution per second is 11 one cycle per second assuming the ra -=9.10 dius to be unity; the angular velocity L expressed in cycles is also EU=WLUlm w=217' radians for one cycle per second. E = WLI Fig. 3 w=217'2 radians for two cycles per E WLI second. to Figure No.1, this is seen to repre Eu WLmIm w=217'3 radians for e cycles per sent a 90 degree relationship since the second. current is zero at A and at a max Ell etc, to--' imum 90 degrees from A at N. --=108 ~n d w=217'n radians for n cycles per That physical property of the cur E m 1m 10 second. rent which enables it to produce this counter-electromotive force is known L 108 = ___ But the cycles per second and the as the inductarlce of the circuit. It is frequency are one and the same thing, represented by L and since the counter LmlO hence : voltage is produced by a rate of cut w=217'8. L ting or __=10 9 Where f stands for the frequel)cy in dIl Lm cycles per second. -E1=-L- (e) In a purely inductive circuit the rise dt and fall of the current produced a Where - E1 is the instantaneous rising and falling magnetic field which counter voltage, L the inductance and cuts the conductors of the circuit pro ducing a counter-electro-motive force dI1 which is constantly equal and opposite to the impressed electro-motive force ; dt the instantaneous rate this causes the current to lag 90 de of change of the current. This is grees behind the voltage. Ohm's law for an inductive circuit. In figure 4, A, the rising current is but I1= Im Sin wt shown moving perpendicularly down dI 1 ~Imd (Sin wt) ward into the paper. By the right hand rule the so-called positive current pro or dIl=Im Cos wt d (wt) duces a right hand field which moves dIl~wIm Cos wt dt out and cuts B. . since w is a constant By the induc.;tion rule a current is dI l Fig. 5 induced in B with a field having the or --=wIm Cos wt ( f) A 0 same direction as the field of at dt in the side of contact. When the cur rent in A is at a maximum the current .substitute (f) in (e) then Radio is rapidly becoming a part of in B is zero because the field of A is -E,=-wLIm Cos wt passenger ship entertainment. Some then stationary and there is no cutting. weeks ago the Llewellyn Electric Com - E is at a maximum at r wt =O~ pany of Los Angeles installed a hand When the current in A is passing 180 degrees or 360 degrees, but through the values near zero the cur some set on the steamer "H arvard" rent induced in B is a maximum be Coswt= 1 at 180 degrees or 360 of the Los Angeles Steamship Com cause the lines of force are rising out degrees hence pan and now the same company se wardly the most rapidly, hence the -Elm=- WLIm cured the contract to install similar maximum current flows in B. The hence broadcast recei\res on the sister ship same remarks apply to the voltage. - E=- WLI Yale. Both vessels ply between San This is called mutual induction. Diego and San Francisco. The same thing occurs in the case of a current rising in the conductor The Lincoln Radio Company, ma itself. nufacturers of the well-known Lincoln In Figure No. 5 the same descrip 8) Fixed Adjustable Crystal will move tion applies as in Figure No.4, but all A Fig. I into their new building, Twelfth and within the conductor itself. A counter Santee Streets, Los Angeles, Calif., pressure is formed at all such points Since the ratios between Elm and E within a few weeks. J. R. Skaletar, as B, due to a rising current at all such and 1m and I are equal, it cancels from general manager, states the new struc points as A which is exactly equal and the equation. This will be shown later. ture, in which the company will have opposite to the impressed pressure. This is Ohm's law in a purely in 1250 square feet of floor space, will Thus the current I lags E by 90 ductive circuit. enable the Lincoln to increase its ma degrees because one is zero when the Leaving off the negative signs, nufacturing output as well as its rap other is a maximum and on reference E WLI in the volt ampere system idly growing wholesale business. April, 1924 ~ _ Radto Joul:nal~ Page 169 How to Build the Super-Reflex By EDWARD ]. WIGGINS
The set des c1'ibed in this article was originally constructed under the personal supervision of M ,'. Wiggins, who is chief engineer for the E lectrical R esea1'ch L aboratories. The reflex, tempomn:ly eclipsed by other types, is coming bacll, and the newer type reflexes Q1'e of growing interest to all 01t1' l'ea ders.
NEW receiving circuit with full a coupling as if the total inductive In addition to this novel tuning de coast-to-coast range on the coupling were maximum. The induc vice, the new circuit contains one stage tive and capacitive coupling between of straight tuned radio and one stage loud speaker and with only the primary and secondary circuits is of reflexed radio and audio frequency A two adjustments, has just been always fixed at a very low value by and one stage of straight audio fre perfected by the E lectrical Research -the selectoformer. With other couplers, quency amplification. A crystal detector Laboratories and is given out to those who "roll their own". It is not a manu factured set. This circuit can be accur ately logged on its two adjustments and its selectivity is as good or better than any other circuit yet devised, with the possible exception of the superheter odyne. The circuit is a development and re finement of the E rla three tube duo re fl ex and the secret of its unusual selec tivity and volume is the selectoformer, a new device perfected by the Labora torie , which takes the place of a var iocoupler, switches, taps, etc., which have always complicated tuning to a greater or lesser degree, depending on S howill g peculiar m Oll nting of trallsfon17CY and coluJ enser. the ability of the person operating the set. reducing the coupling reduces the vol of the fixed Erla type takes the place The selectoformer requires no ad- ume of signals. The selectoformer due of a detector tube, giving clearer re ception and, when used in this circuit, @·G more sensitiveness than a tube detec tor and without the latter's well known inberent defects. In selecting the fixed condensers be sure they are marked "tested capacity" not "tested mica", or "tested copper". The guarantee of capacity is necessary to get the proper value. Tests show that for this circuit, as well as all efficient amplifying circuits, the UV201A and the C301A tubes are the best and these will require 25 ohm rheostats. Of lower efficiency are the UV199 and C?99 tubes, which require Wiring diag1"G'III of the new Erla S llpel' R efle.'!: with selec tof om ier. 30 ohm rheostats. ' The WD-ll and ]ustment and has for its main object to its peculiar design, reduces the ap WD-12 tubes are not recommended, the coupling of the antenna to the re parent resistance of the secondary cir but if used will require 6 or 8 ohm rhe ceiver without broadening of signals. cuit and therefore increases the signal ostats. In this circuit the first and third The antenna circuit is never tuned to volume . . (C01ltillued Oll Page 189) resonance with any particular incoming signal, and the coupling of the antenna to tp.e receiver is only sufficient to ex cite the receiver at the wave length to which it is tuned, without adding the resistance of the antenna circuit to the secondary circuit, which always causes a broadening and reduction of signals. Cuts Inductive Coupling With the usual variocoupler it is pos sible to reduce the inductive coupling between the primary and the secondary to a fairly low value, but capacitive coupling still exists, which allows as Page 170 ~Radlo JouHlal~ April, 1924 Hoover Cup Moves Westward
HE Hoover Cup moves west ward- this time being won by 9ZT, Don C. Wallace of Min T neapoli s, Minn., one of the best known radio amateurs of the country. Mr. \i\Tallace has accompli hed much, not on ly for amateur radio but for radio in general, through experimental work which he has been conducting fo r many years. Be it known . moreover, that 1\1r. \ i\T allace is in no way inter ested commercially in rad io, but all of his work has been done for pure love of the science. Photographs of his sta tion are publi hed in this issue. 1\I r. \ Vallace has just receiyed a re que t from Chi le a king him to send special signals for them, using his call 9XAX. In a letter to Radio J ournal he expresses the wi sh that west coast X At left- 9ZT-9.YA.Y filter s\'stnll . electrol"tic rectifier calls would get down on 105 to 110 a~,d trallslllittl'J": "'ate. stor meters. " \ i\T e are working everywhere age battery ill II />Pl'r left 0 11 those wayes," he \.vrites, "and the halld shelf. slls/>em/cd frolll Sixth District is only represented by ceilillg to 1I1ake lcads short . to sct illllllcdiatel" abo,'e. At thr to/>. ill circll'. is the alltclllla. 7 'ood lIIast 85 fcet. three or four stations down there. Five iron 1I1(1St 60 feci. s/>read 60 fret six illches clla lll rlll'd No. 14. COHlltcr/>oisl' spread watts will be enough if it is on 105 in all directioll s for 100 fcrt Hlldrr alltelllla . ]]clmc'. (It right is the set itself. w illll er meters-tell them to keep about 105 of th e H oO"cr CIt/>. as \ VGY, KDKA and local harmonics j am below that." to our most recent query with the state excepti onall y interesting situation this Mr. Wallace conducted a series of men t that apparently isothermal lines summer, and a nationwide survey dis experiments which linked isothermal are unimportant on 11 0 meters or be closes the fact that at no time has the lin es with radio reception and transmis low, but that they seem to mean most industry been geared to rrive a higher sion, and the results of which we pub on other wave-length in the summer standard of service to the radio puQlic. li shed from time to time. He replies time. C ol1ventiollS Broadcast "In th ~ first place," said Mr. Mal lory, "the Democratic National Con Long Range Crystal Set vention in New York in June and the Republican National Convention in Your paper and its contents are very interference. KDKA was an induction Clevelancl during the same month, will good, but there is NO circuit made leak to my line.- JOSEPH GROSS, Chicago, III. place the radio 'fan' right in the thick which does not interfere with some of the pre-electi on campaign. For the body else. I have never traveled 'W est' first time in the history of the United or 'East', but the City of · Chicago is States virtually millions of people will composed of everything national, me 'attend' the national conventions. They chanical and electrical, and the last wi ll be able to fo llow each issue as it is word in radiophone intereference. Our t:o.pr ~d e"fOrt I () ~ t u rf\. debated on the convention fl oor; they neighbor can cut us off entirely, at will, will hear the nomination speeches of which makes our set useless. That is ' favorite sons' ; the thunder of applause one way, of a thousand and one, of for popular candidates-the music, making the many varieties of radio t .:J.f'f'e.J :J the clamor and excitement of the im every -tUM . sets a nuisance instead of pleasure! I promptu parades which will spring up have had KDKA, East Pittsburgs, Pa., f rom time to time on the convention on a crystal set, in Chicago, (a simple floors. Elaborate arrangements are now set ) and, again, I could not even get being made so that the greatest possible WMAO, WDAP, and WJAZ faintly, With th is silllple cr)Istal sel f. A. Gross, radio audience may be able to listen in and KYW (Keep Your Wife) with a 7803 Bishop St., Chicago, picks II·P KDKA, on these conventions. terrible lot of cutting off and general while his OWII very H ear statioll WAAF is orl. "Immediately after the conventions will come the Presidential election campaigns. There again radio will play Big Radio Summer in Sight an epoch-making part, for it is clear that every candidate is preparing to LANS and programs just com This is the announcement made by broadcast through the air his appeal to leted by the larger broadcasting E. B. Mallory, Chairman of the Radio the electorate. stations in the United States, Section of the Associated Manufactur ers of Electrical Supplies, which in Reception I mproved P as well as by the leading manu cludes in its membership all of the "The fact that there are more Class facturers of radio apparatus, will make leading factors in the radio industry. B high-powered broadcasting stations _ the summer of 1924 the greatest radio Extraordinary circumstances have in operation this year than last year, is summer since broadcasting was begun. combined, he declared, to create an assurance to the radio audience that April, 1924 Page 171
reception during the hottest summer said: one of the results of the many change and thermo eff ects at the joints months will be vastly better. T he new notable improvements made in receiv while the graphite or carbon rheostats allocation of wave lengths, particularly ina sets is that day-time reception this are subject to microphonic and other among the higher powered stations, it s u~mer will be better than night-time effects. T he above statement applies is generally agreed, will eliminate much reception in previous years. T his in to all sets. In the writer's pet circuit of the interference that resul ted from sures that the splendid program of the R3 Hook-up a Bradleystat is used. conflicting wave lengths. sports, music speeches and entertain This is written without any prejudice ment planned fo r this summer from to the makers of this excellent li ttle I11L p?'oved R eceivers many broadcasting centers will be re article that, while they are the best so "Another factor that will make for ceived with great satisfaction by the far, they are not all alike, and the ex good reception this summer is the strik millions of radio listeners in the United perimenter is advised to carefully ing impro\'ement noted by our tech States." check this item for supposed tube or nical committee in the new receiving Preliminary reports from radio dis static noises. apparatus now on the market. It is im tributors and dealers, Mr. Mallory con possible of course, to measure math cluded indicate the expectation 0 f re ematically the advances made by the Big New Station radio manufacturing industry in the cord-breaking summertime sales of LARGE experimental radio course of one year. But this may be radio apparatus this year. station will shortly be built by the General Electric Com A pany for a more complete in W hat Makes that Set Noisy vesti aation 0 f radio phenomena and b • By ]. T. ROFFY broadcasting. It is understood .that t~e cost of the experimental statIOn will OME 0 f the best constructed sulators and leading in wires should be approximately $150,000, and that sets possess a continuous crack not be wrapped around insulating it will be located on land recently ec li ng noise which is generally posts. They should be kept at least qui red by the company in Schenectady. eighteen inches from the eaves and Smisnamed as s t at i c or tube Vv'hile no plans have been drawn for walls of the building. Further the the new station, it is understood t h ~t noises, while as a matter of fact it may ground wire should be straight and the Central Electric Company WI ll be anyone of the following causes, direct to the ground and the piping ~1 build a power house capable of deli subj ect to a quick remedy. It is as a building is often insuffic ient as a vering a high power at various f r ~ sumed that the reader knows that all ground. quencies, and antenna structures WIll plate and grid leads in a set should be Now if your A and B batteries pos be erected for a wide range of wave as short as possible. T hat such units sess the required charge and short lengths so that systematic investigation as radio and audio frequency trans and large cross section wires are se can be made of the advantages of vari fo rmers should be placed at an angle curely fastened to the contacts then, ous wavelengths in solving the many to each other and at least three to four and onl y then, can you attribute the problems with which radio now has inches apart ; that the stationary plates c r~c kli n g sounds to static or tube to deal. of condensers without exception should nOIses. T he requirements of the present-day be connected to the grid side of the In enumerating the above possible broadcasting program, including stock circuits and that the rotating plates causes there has been one item left reports at noon, an afternoon program should be connected to the battery or open for further discussion and that is for those at home, evening stock and ground leads. Wires running to and that in all sets it is necessary to use market quotations, weather reports, from. all condensers whether they be some form of a rheostat. W henever musical programs, plays and religious of the fixed or variable type should a wire wound rheostat is used the slid services, have fill ed up the available be o f short length, large cross section ing contacts should be firm and clean time. It has also been found that the securely solderecI..a nd without bends or and even then the resistance wire used space available in the power house and turns and that before assembling any in some is subj ect to temperature operating section of the big broadcast- set, tube sockets should be securely tightened on their individual contacts before starting the wiring and further , that in wiri ng a set soldering com pounds or pastes should be used spar ingly and wherever two wires are to be joined a mechanical contact should be established, that is clinching one wire upon the other before soldering. If after these precautions the set still posssses a crackling noise it is still not always tube or static fault. The next thing to examine is the insulation of· the aerial and its lead-in. Nine tenths 0 f the aerials examined by the writer lack sufficient insulation and ninety-nine out of everyone hundred omit the insulating knobs on the guide wires supporting the aerial posts. It is absolutely necessary that guide wires shall have at least two insulators to . break up any radio frequency current . that may be gathered by the guide Cha1'les K. Field, editar of Sunset Ma.ga::iJle, {left}, and Stlla-rt Edward White, wires, that between aerial post and novelist and big game hunte-I' , stagillg a "radioview" 0 '1' broadcast 1:'Ilterv iew before the m icrophone at KPO, Ha.le Brothers, San Francisco. In th-is "?·adioview". Mr. aerial proper there should be at least White discHssed a f?rth-cmn:ing art-icle on the" come-bacle" of the bow and arrow eighteen inches and one or more in- as a ?'eal weapon f or hUlIte-rs who want to be ?'eal spo-rts1l1en. Page 172 _------,z-- Radto 'Joumat ~ April, 192! ing station is not sufficient to permit for re-broadcasting. On several occa of the shaft, which caused g round ca experimental work without interfering sions during the early spring, WGY's pacity and distorted signals. with the regular programs. On this programs have been rebroadcast by Another set up was tried about a account a new station was considered the British Broadcasting Company in quarter of a mile nearer the entrance. necessary for intensive experimental London and thus made available to the This time station K YW, Chicago ; work. British Isles as well as to France and W DAR, Philadelphia; W} AZ, Chica The broadcasting station now known other continental countries. This is go, as well as station W T AM came in the world over as WGY was originally only one of the experimental develop with fair audibility. built, several years ago, for experi ments to which WGY has contributed. mental purposes. Operating under the Noone believes that radio and radio experimental license 2-XI it has con broadcasting will remain stationary. Radio Forbidden ducted various radio experiments and The remarkable advances which have Some months ago the Revolutionary added materially to the fund of avail been made in the last few years indi Governmen t forbade by legal decree' able knowledge. It is well known by cate a continued rapid development. the operating of private wireless ap advanced radio fans and those fami The General Electric Company aims paratus in Greece. T his measure was liar with the workings of the station to perfect broadcasting so that it may taken largely to prevent the Greek pub that the regular programs have been become even more reliable and satis lic from being reached with propagan broadcast fo r many months at two factory. The service which radio now da unfavorable to the revolution, it is. wavelengths-the regular wavelength renders to the farmer and to all that reported. The Ministers of Finance and Ma of 380 meters available to those using large proportion of the population in standard receiving outfi ts and also a rine of the present government have lower wavelength of 107 meters which outlying districts is invaluable, but it prepared a law to b~ submitted to the has been found part icularly well a can be made an even greater factor National Assembly for ratification, by dapted to long distance transmission by further perfecting. which the operation of private radio sets belongi ng to Greek individuals will be permitted under certain restrictions and subject to the payment of a license Radio Amateurs Rescu~ Ships tax . By LOUIS GROMBERG while the transmitters on the ship sta No matter what type of sets you 'With the old coast station that used tions were tuned to' 600 meters. The have, be it a fi ve-tube neutrodyne or a crystal do-hicl<)r, if you use an out to operate at this city out of commis ships' receiving sets were crys tals for spark and phone reception only and, side antenna and want to get the best sion, due to a storm which completely therefore, the amateurs were compelled efficiency out of it, take the antenna demolished one mast of the antenna, to swi tch from CW to phone in order and insul ators down at least once a radio amateurs came to the rescue of a to be heard by the ship operators. year, replace the wire with new, and number of lake steamers. For a num clean the insulators with gasoline. ber of weeks the Duluth-Superior en W hen replacing it, see that the con tries to Lake Superior were tied up Radio's Penetration nection to the lead in is either firmly with huge blocks of ice, which extend An interesting experiment was car clamped by means of a regulation an ed seven miles out from the Twin ried on recently by ten radio enthusi tenna clamp, or else firmly soldered. Ports. As shipping from the lower asts, incl uding engineers and news T he reason for this is that the wire be lakes had already started, approximate paper men to test the penetrating pow comes oxidi zed, or black, thereby offer ly forty ships were on their way to the er of radio waves. The test was made ing a high resistance to the radio Duluth-Superior harbors. in a newly cut tunnel, more than 200 waves. This is not true, however, when When the boats encountered the ice, feet underground, at Lakewood, Ohio. insulated wire is used fo r the antenna. they found that the obstacle was too The shaft connects the river valley big to overcomt;., so the only thing to wi th Lake Erie and when complete will Many builders of sets a re only part do was to lie in wait until the wind provide an outlet fo r a service disposal ly satisfied with the results of their blew the ice away. A bout fen of these pl ant now under construction. receivers and are ever looking for hints ships were equipped with radio trans All the apparatus had to be carried as to their improvement. mitters and receivers and their oper down a fli ght of steps leading to the A potentiometer included in the fila ators endeavored to communicate with mouth of the shaft. It was estimated n~ e nt. grid circuit of most of the single their head offices in Cleveland by work that this fli ght was about fi ve degrees CIrcUI t radIO f requency amplifiers, and ing some land station. However, their out of perpendicular. T o add to the even triple circuits, will give control of efforts were fruitless for they found di fficulty of their progress they were the regeneration and volume of sound one kw spark too weak to work the wi thout any hand rail or any safeguard to such an extent that the builder will necessary distance , from falling, T he trip down was start actuall y be surprised. It is easy to Amateur radi o stations 9ADF, ed at 8 :30 p. m. with only small pocket install a potentiometer in the circuit 9DOE and 9DFN worked these ship flash lamps to light the way, and the and wherever it is possibl e it should stations, handled traffi c for them, and temperature was 20 degrees below the be used, especially with the U V199 and sent weather reports in order to facilit freezing point. A pronounced breeze the other dry cell tubes. . ate more immediate release from the bl ew from the lake through the tunnel, ice field s. A Bergtold , operating station the lake being only a mile and a half Scotland Yard's wireless equipment 9DOE, took three messages from three away. includes a motor radio patrol. This different ships and immediately for A fter having penetrated to the ap stati on can keep in continuous com warded them to Cleveland by wire tele proximate centre of the shaft, the re municati on with Police H eadquarters graph. Station 9ADF took a number ceiver was set up with the aid of spot even when the car is travelling at 40 of press reports and turned them over lights operated by storage batteries. miles an hour. Four more of a similar to local newspapers in addition to giv After much twisting of di als and pattern are shortly to be commissioned. ing several of the ice-locked boats straining of ears the signal of station r.che aerial win be placed on the roof weather reports. W T AM Cleveland, about 20 miles of each car and will be mounted on The receivers used by the amateurs away, came in, the poor results ob collapsible frames, so that they can be were only short wave sets, primarily tained being due to the fact that the lowered when passing under low built for work from 80 to 300 meters, aerial was erected too close to the walls bridges or over-hanging tree branches. April, 1924 Page 173 Radio for the Banana Route By 1. M. PEEL
Things move so swiftly that we had almost forgotten to wonder what had happened to the shortage in bananas, w iz en we discover that the United Fruit Company is putting in a batch of statiOJls, the most powerful on the American continent, for the handlillg of thi~ ba'llG1w business. So we have to sing about s01nething else.
IX radio transmitters, to be the the United States. It was shortly Since 191 L the radio actIvIties of the most powerful on the Ameri after the International Yacht races off Company in all its branches have been can continent, operating from Sandy Hook had been reported by under the immediate direction of radio that the first radio sending and Svacuum tubes and first to make receiving sets were purchased and in use of the General Electric 20 kilowatt stalled at Port Limon, Costa Rica, and are beillg installed by the radiotron, Bocas del Toro, Panama. This was United Fruit Company and the Tropi in 1904 and service was inaugurated cal Radio Telegraph Company at the following year. The operation of points in Central America and the these stations convinced the directors U nited States for the purpose of com of the United Fruit Company that pleting the links of an adequate com radio was practical and valuable in a m~ni cation s system between the Am- business which .handled such a highly encas. perishable product as the banana. So The e transmitters will be located at the year following, or 1906, stations New Orleans, La., Miami, Fla., Puerto were opened at Bluefields and Rama, Barrios, Guatemala, Tegucigalpa, Nicaragua. All these stations, because Honduras, Managua, Nicaragua, AI of the lack of land communications, mirante, Panama. The Tropical Radio Company op erate the stations at New Orleans, Miami, Tegucigalpa and Managua while the stations at Puerto Barrios and Almirante are operated by the United Fruit Company. The sets are being completed and shipped at the rate of one a month and as about two months will be required to install each set it is expected all six will be in operation by the middJe MASTER OSCILLATOR FOR THE BIG of this year. STATIONS. The United Fruit company estab lished the first radio stati ons in Cen George S. Davis, who is general tral America and was the first to manager of their Radio Telegraph establish commertcal radio communi department. He is also president and a director of the Wireless Specialty cation between Central Am~rica and HERE'S THE VARIOMETER WE ARE GOING TO GET WHEN WE BUILD OUR FINAL SET. Apparatus Company, general manager THIS I S A SIDE SLANT AT THE INTER· of the Tropical Radio Telegraph Com MEDIATE CIRCUIT VARIOMETER OF ONE pany and a director of the Radio OF THOSE 20 KW BANANA ROUTE OUT· Co rporation of America. FITS. IT MIGHT DO FOR A BATH TUB IF IT WERE FITTED WITH A BOTTOM. In the operation of these transmit ters, in some cases where stations are handled in addition to the Company's located in remote places, the primary business a Jarge share of the telegraph power is generated at the station by husiness of the general public between gas or oil engine driven alternators these places and the United States and supplying 220 volts. In other stations E urope. Other stations have followed the power is obtained from the dis sin ce then until now, with the six new tribution system of the local power tube transmitter stations, there will company. This power first goes to be a total of nineteen, comprising what the service panel where complete ap is known as the United F ruit Com paratus for control, protection and pany's radio system. All stations of metering is installed. Then it goes to the United Fruit Company's system, the rectifier which consists of a bank including all their ships of the "Great of transformers and six, twelve and White Fleet" are to be equipped with one-half kilowatt kenetrons. Here the tube transmitters of a similar type. voltage is stepped up and rectified, to The United Fruit Company has become 15,000 volts direct current. spent more than $3,000,000 in the This high voltage is then used for development of its radio system and plate power on the pliotron oscillators. upon the completion of new stations The frequency is controlled by KENETRON RECTIFIER UNIT FOR THE under construction its investment in means of a master oscillator employing 20 KW SET. radio will probably exceed $4,000,000. (Continued on Page 171) · Page 174 -~Radio Joutnal~ April, 1924
tery as well as an "A" or "B" battery. "Fading" and "fuzzy" reception can Set Ailmerlts and Remedies be minimized by cleaning the tube and socket contacts with a fine file or emery By D. A. RUNYARD cloth. Corrosion takes place on tube and sockets contacts and causes a CCASIONALLY, when you batteries. It is difficult to blame queer great deal of trouble. Fuzzy reception have invited your friends in noises to anyone thing. For instance, when you turn down your detector to hear the Radio, it refuses rheostat and the radio squeals, it is O to respond to your desires. well to believe that the voltage of your The reason for this phenomena will "A" or "B" batteri es has dropped not be attempted here. However, it '''' ';he~;L~{Ji~~E:£;;::fi;'~''''I served in th e radio branch of ====_~===_' below norma l. A test on both batteries is well to be prepared for any emer will probably reveal that either the the service, instructed classes gencies and forestall any grief that "A" or "B" battery's voltage has drop and built several stations. Of late may develop when the apparatus does ped. It is well to have a small volt not receive the care that is necessary . meter reading up to 25 volts with helarg hase radio been manufacturingcanected with s eenter-veral 1======to insure good results. which to make your tests. prises. He will help a lot of folks In the following paragraphs it is It does not follow that old batteries who have been having "operating my desire to call your attention to should be used. Great care should be difficulties." common symptoms of the radio recei v exercised in the care of the "A" bat 1111I !1 1mUIIIIIIIIII11111111111.IIIIUUlltIIIIIIIlUllllllllt1rt1mIlUlllllltilitlllil1111111111111111111111111111111111111. ~ er and suggestt a . remedy in each case. tery. To obtain uniform results and Contrary to general 'oe1ief, most of the quiet operation, a reliable battery may be caused by too high plate volt trouble is caused, not in the receiving should be selected. When having the age; this, of course, can be remedied set, but by the batteries and con by the operator by test. On some nections. wotozamati('r? sets, a difference of 1.S volts will make When the receiving set refuses to a decided change in reception; there function properly it is well, before fore, it is well to test on numerous doing anything to the set, to inspect voltages in order to secure the best the voltage of both the "A" and "B" results. There are numerous people who say they have purchased a loud speaker (Continued from Page 173) and can not get good results with it. one, one kilowatt pliotron. The master It is very true that all loud speakers oscillator provides a lower power radio HIS SILENT NIGHT. wil not work with all sets; however, frequency supply which is then am if you are bothered on that score it plified to twenty kilowatts of power battery re-charged it is well to see might be well to try adding capacity by means of one of the new water that it is charged at a slow rate; that to either one side or the other of your cooled twenty kilowatt tubes. The is between four to six amperes. If loud speaker binding posts. I f you find amplified power is passed through a you own a re-charging outfit it is well by testing that you see no betterment, tank circuit which eliminates harmon- to recharge, as near as possible, to the then try shunting a small fixed con rate of discharge, and allow one-third denser across the terminals of your more time; that is to say, if you op loud speaker, from .002 to .005 Mfd. erate for 20 hours at the rate of' 3 The resistance of all loud speakers, amperes, you should recharge at 3 of course, varies slightly and it is well amperes for 30 hours. to remember that you should try dif Battery connections give endless ferent "B" battery voltages as well as trouble unless they are soldered or capacity tests in order to get good clamped. Spring clips are used to a results. great extent and are certainly not Pure tone should be the goal, rather dependable. The clip corrodes and a than volume. vVhen you are bringing voltage leak develops on the battery in a station as loud as your set will binding post; this robs you of the respond, you are straining your tubes much needed voltage. A clamp is the and also taxing your expensive "B" most satisfactory arrangement; this in batteries. sures perfect contact to the battery The detector is not efficient when binding post. turned on full, hence the "hissing" and "B" batteries will, if given fair care, "crashing" you hear. Turn the rheo last over a year. However, that does stat back and give the set a chance to not mean that all "B" batteries will give you pure tone. The foregoing last that length of time. When using speaks for the radio and audio fre a high plate voltage, necessitating a quency as well as the detector circuit. large battery, it is well to buy small Any queer sounds which develop in units of 22.5 volts, then when your the set can, as a rule, be traced to the voltage 'drops down, you can remove batteries or their connections. It is THE WATER COOLED TUBE UNIT FOR the low test battery, replacing it with well, therefore, to keep the lid on the ONE OF THOSE 20 KW RADIOTRON UV·207 SETS. another, thus saving the expense of a set closed and look for trouble outside whole new battery. the set. If, however, you find that ics and is then fed into the multiple "C" batteries which are employed in everything seems normal outside the tuned antenna. the grid circuit of the audio frequency set and the tube contacts are free from Keying is accomplished by means in some sets will cause trouble when corrosion, then it is well to call on of a relay on the master oscillator unit. they run down. "C"· batteries should your radio dealer or one who under This relay may be controlled from any be tested along with the "A" and "B" stands the inner workings of radio to desired distance and is adapted to key batteries, for a voltage drop. "Squeal aid you. In this way it may save you ing speeds of sixty words per minute. ing" may be blamed to a low "C" bat- considerable grief and expense. April, 1924 Page 175 Tuning Y our Set and Selectivity By M. C. BA TSEL
Some of the principles underl:ying mdio set operation a're here outlined by Mr. Bats~l, r~dio el1ginee1' of the Westillghouse Electric and Manufacturing Company. Tumng IS a problem, until it is understood thoroughly, and Mr. Batsel has here attempted to 11lake some of the factors which govern tuning understood so the novice can see why he gets certain results when he do es certain things.
H ERE are between five and note heard, due to the interfering complicated circuits requires consider six hundred broadca ting sta waves, will be tuned out. Therefore able time even when performed by an tions in the United States. In it is evident that the only remedy f01: expert operator. T this condition is an assignment of wave There is no doubt that the nearest every locality it is po sible to lengths that will prevent two or more choose from several stations operating high powered broadcasting station can stations from transmitting at the same render better service than can the sta· at the same time. In order to do this time on wave lengths that will produce tion at a great distance, because of we should kno,~ some of the prin such interference. fading and atmospheric disturbance. If ciples underlying selectivity, or the If there are two powerful broad the reception of very weak stations is power of choice, which permits us to casting stations . in the vicinity and not attempted while the more powerful neither can be received without inter tune out the stations operating on wave or near-by stations are operating, the ference from the other one, it is advis small antenna and regenerative receiv lengths differing from the wave length able to use a small antenna. Very er will be found to meet all require of the station we wish to hear. often an indoor antenna or small wire ments. An electric curren t is caused to flow concealed by a picture moulding will be entirely satisfactory and does not If the small antenna with the single in a receiver by the waves from the require lightning protection, as it is tuned circuit regenerative receiver is transmitting stati on. If the receiver is indoors. If this very small antenna not preferred for eliminating interfer tuned to the same wave length as the is not sufficient, an antenna may be ence, a receiver with coupled tuned circuits may be used for reducing the transmitter this current is of maximum used consisting of a single wire struno in the attic. If the small antenna and interference from a very powerful sta strength and the sounds received are tion. This type of receiver may be therefore, loudest. Currents due to th ~ a single circuit regenerative receiver are used, the sensitivity of the system made by adding an additional tuner for waves of other frequency or wave the antenna circuit and placing it near length aloe relatively much weaker. T he' is in general only slightly less than the regenerative tuner. This additional relative strength of the currents re when using a large antenna, and the strength of the interference is reduced tuner consists of an adjustable circuit ceived from two stations of equal made up of a variable inductance and power and at eq ual distances from the in proportion to the effective height of the antenna. a variable condenser. The antenna and receiver, when the receive r is tuned to ground connections on the regenera one of the transmitting stations, de When using a small antenna the ad tive tuner are connected together to pends on the difference in the wave j ustments for tuning and regeneration ' form a closed circuit. The coupling is !engths, the design of the receiving must be made more accurately in order controlled by relative positions of the ll1struments, and .the receiving an to bring in weak stations. A very satis coils in the tuners. tenna. factory and convenient arrangement By properly proportioning -the in of antennae is to install a small indoor A more convenient method of re ductanc.e and the capacity of a circuit, antenna and another outdoor antenna ducing interference from one station the ratIO of the current received on consisting of a single wire fr0111 50 is to connect a circuit tuned to the in the wave length for which it is tuned to 125 feet long with the horizontal terfering station between the antenna to that of other wave lengths may be span from 25 to 40 feet from the and ground terminals of the receiver. made very great. The use of reo-ener- earth. The outdoor antenna should be This circuit will pass the current due . . b atlon stIll further increases this ratio. clear of wires and the metal frame to the interfering station to ground The principles just stated govern the work of buildings. When there is in and if the circuit has considerable in design of practically all receiving sets. terference from a nearby station, the ductance and a small capacity the de If there is no powerful station in the small antenna can be used to advant sired signals are not noticeably weak immediate vicinity a properly desio-ned age. When .there is no interference the ened. The operation of the tuner is single circuit regenerati ve r eceiver~l sed large antenna will make it possible to not complicated so much as it is when with an efficient aerial will select the tune in weak stations more quickly and -two circuits must be adjusted to tune desired station and tune out all other without such critical adjustments of to a station_ When the tuned by-pass stati?ns that can be tuned out by any the tuning and regeneration. The very circuit has been adjusted to eliminate receIver capable of receiving music small antenna is practical only when the interference, it requires no further without destroying its quality. Two regeneration is employed or when sev attention. stations that are so nearly on the same eral additional tubes are used for ra These coupled tuned and by-pass wave length that a sustained note or dio frequency amplification. circuits will assist in receiving distant howl is heard cannot be separated by More complicated receivers can be stations when the local stations are any known method of tuning so that used with large antennae to obtain a operating ; but the simplest arrange the satis factory reception of music and greater degree of freedom from inter ment and a very satisfactory one for speech is possible. If the tuning is ference by near-by stations, but the receiving one of several local broad made so sharp that one of the stations adjustments become troublesome and casting stations or one of the more can be selected, all notes in the music annoying to the unskilled operator. powerful distant stations is the small of a pitch equal to or higher than the The proper adjustment of the more indoor antenna. Page 176 ~ _ Radto ' Joumat~ April, 1924
By A TICKLER
Canine Verse All Shot Up How We Do It Today This is the story of a ham By Cha1-les F. Filstead, 6CU 'vVe are all noodled up, as the expert \i\Tho had a "5" watt lamp, The following verse was printed in tape slinger said to the waitress. Le?ll He raised the rated voltage up A. Morgan has broken loose agal11. So he could get an amp. the March, 1900, issue of "Science Without further incriminating testI- and Industry." It is so clever and mony let us present: . Few thousand volts upon the plate, so pregnant with the changes that Editor Radio Journal, Dear SIl-: Too quickly it got hot. have taken place since the advent of With your Radio family I would con- He raised the filament to eight, electricity that it is reprinted here, fer- W hich helped him quite a lot. About a simple little hook-up, twenty-three years later, and it is as Just a little Crystal PUP. full of meaning today as it was when \ i\T hile 1istening in one winter nite, first printed. How little they dreamed He heard a "I" come in, then that in a few years the same And calling same for fifty times, (,l!LS ;.:.)') rT [·K!" " lightning bolt" would be whispering "J o . 22 £N-\M£L Switched off, to listen in. their children's voices through the sky! He turned his eyes upon his set, "In olden times we took a car And there his glad (?) gaze fell. Drawn by a horse, if going far" The plate was melted to the base, And felt that we were blest; ;;::LJ\' " I, , ~~ J~ And the filament shot to Oski-Wow! N ow the conductor takes the fare 1-- -1'L _- -_____ And sticks a broom tick in the air Wow! By 6CFL. And lightning does the rest. THIS IS THE HOT DOGLET DESCRIBED BY MR. MORGAN IN THE ACCOMPANYING "In other clays, along the street, BLANK VERSE FOR BLANK PEOPLE. EACH Earwigs Attention! COIL IS MADE FROM 200 FEET OF NO. 22 A glimmering lantern led the feet ENAMEL WIRE. When on a midnight stroll; But now we catch, when night is \ i\T ith me, he is some PUP 'to hear nigh, But a bit wild I fear, A piece of lightning from the sky His bark is sure loud- And stick i't on a pole. For which I am proud- If vou could keep him out of th,~ "Time was when one must hold cl~owd. his car You see, I- keep him down town Close to a whispenng voice to But he thinks its fumlY, acts lIke a hear, clown, . Like deaf men - nigh ancl So folks-will you help tame h1111 f,Ve'll bet a horsehair watch chcin nigher; down. agai11st a floc l~ of pink earwigs that But now from town to tow n he Wish you would help with this PUP Shakespeare lmew about mdio. Why talks Cause, I hate to give him up, else, tell us, would he have Lady Mac And puts his nose into a box Got so used to him now- beth say, "Out, Damned Spot!" unless And whispers through a wire." And hi s loud Bow-\ i\T ow, she had been foolin' with a cr'}/-,:fal And it's a shame and a sin- set? Put up your earwigs. Not to have more patience with him, An Eternal Bit And help him while he is a PUP, By B en Field BROADCASTER TO HIS LOVE To be a better clog when grown ti p. But yesterday was given birth Now GIRLS you can help with this My mind becomes a vacuum tube The super-conquest of the race Help his tail to twist, \i\Thene'er I think of you ; A subtle voice around the earth. Pet him ni ce until each note, My heart gets quite ec-static, That vibrates through the realms of Comes separate from his throat, My headband goes askew. space. But, keep it loud- Your eyes that fl ash like unquenched Ancl out of the crowd. sparks, Its magic power draws each to each, The Editor says-send'm in Folks, Your hair li ke copper wire, Man to his brother, near or far, It's real serious and no joke, Break down my high resistance Its slender wires receive men's speech- Just address then RADIO JOUR Like a transformed amplifier. While yonder shines a waiting star. NAL PUP, I really think we're both in tune, 11 3 Stimson Bldg., one flight up, And ere through life we roam, Earth's spiral rises round on round, Try now FOLKS and tame this PUP. Suppose you hook up now with me, N or crushed nor crucified it be Sincerely, A nd share my humble ohm! Life's secrets shall amaze, astound L EON A. MORGAN. -A. C. M. A. 111 Life . . The while we grasp eternity. April, 1924 ~Radlo Joutnai~ P age 177 Notes on loa-Meter Transmission By BEN ]. CHROMY, gC]O
This paper is the result of a lot of research worl?, and should provoke thought and discussion wherever there are amateurs, which is eve1'ywhere. I t was read before the Milwaukee Radio Amateur's Clu b, January IO, I294, through whose courtesy it is given a wider reading pubhc in th ese columlls.
DRING the spring of 1923 gives details of the circuit and the con The antenna current given out by experiments with 100 meter stants. a set which is oscillating on 100 meters transmission were conducted The receiver used during the short is usually a little over one-half of the wave tests was a two circuit regenera Dat 9CJO. Since there was not current that this same set would give tive type. The coils L t and L2 in fig off on 200 meters. However, the an very much literature obtainable on this ure 2 should be wound with 6 and 12 tenna is a more efficient radiator of phase of short wave communication it turns respectively of number 16 double energy on 100 meters than it is on 200 was not possible to predict any results, cotton covered wire doubly spaced. meters. This may be proved as fol either theo retical or practical. There The wire must be doubly spaced in or lows: fore, everything had to be determined der that the distributed capacity of the Radiation is inver'sely proportional winding may be reduced to a minimum. to the square of the wavelength. by experiment. However, previolls to The coils should be wound upon 3 inch 1923 the common conception among paper tubing in. such a way that they amateurs and radio men in general was • (Rad& )":2). Therefore, Rad used at 9CJO had an arc take place low resistance of the tube to this fre the same as a transformer which is on in it near the glass seal. A voltage of quency. a given wave length. five volts ac., was then applied to the The value of the 100 meter wave has It may be heard very sharply at one filament ; some time elapsed before the already been established. Its reliabi wave, and twenty or thirty meters filament got red, after it became red lity in the recent Trans-Atlantic two either side no interference is noted. it immediately burned out. The reason way tests cannot be disputed .. Anyone A nother type which has created much for arcs taking place in the tube near listening in 100 meters can judge bet interference for broadcast receivers the sealed stem is because excessive ter than words can express the future has been the case of what appears to plate voltages are used. The sparking of these short waves. Try it by tun· be a swinging wire, which swings ir is also due to the high frequency of the ing your transmitter down to at least : egular intervals, often times swinging 100 meter wave and the comparatively 150 meters. mto a tree or some other grounded con~ection and. s?unds like a telegraph statIO n transmlttmg at a rate of from one to two words per minute, in fact Interference-What, Why, Where so slowly that the dots and dashes can be counted very readily. By T. E. NIKIRK Amateur transmitters, are often blamed for this type of interference NTERFE RENCE is a subject that P oo r connections m power trans and are not guilty. every person interested in radio is formers on the high voltage side some One of the commonest methods of acquainted. wjth in some fo rm or times cause serious interference. People locating these various sources of inter I other. In Southern California I living in localities where arc lights of fe rence is by locating sparks shooting over or through insulators or wires have had the opportunity of investigat the older type which fli cker badly are swinging into some grounded object ing many cases of complaints on inter in use often hear various kinds of such as tree etc., causing smoke and ference. At the present time it seems noises due to ·the opening and closing sometimes even a flame or sparks. that about seventy-five percent of inter of the arc light circuit, which makes Other types are often not detectable ference in this locali ty is due to high various sputtering and frying noises. by the eye but a strong hissing can be voltage high line leaks. T his is due Another peculiar type of high line buzz heard from what appears to be certain oftentimes to a cracked insulator or is due to a guy wi re being energized insulators. Again other types of leaks dirt accumulating on the insulator and from a high voltage wire through a are of such a nature that the only true then moistened by fog or some other leaky insulator or exciting the guy wire method of locating them is by the use precipitation, which often occurs in the in the same manner in which an anten of a very sensitive receiving set, using evemng. na is e nergized. T his type often acts a loop antenna. W ith this loop and sen sitive receiver, generally located in an automobile, lines which are suspected of having the leak or causing the inter ference have to be trailed from the substation or from the home where the interference was first noted, until a point is reached where the interference seems to come in louder on the re ceiver than at any other point. Who Will Pay? Five hundred dollars in gold is the cash prize announced by the American Radio Association for the best answer to the question "Who is to pay for broadcasting", according to an an nouncement made by Alfred M. Cad dell, secretary of the American Radio Association, with headquarters at SO Union Square, New York City. T he terms of the contest require that all answers shall have been placed in the mail addressed to the American Radi o Association on or before July 20, 1924. 'T he contest is open to any res ident of the U nited States without regard to sex or affiliation with the radio industry. Contestants are re quested not to exceed fi fteen hundred words in their statement of any one plan, which should be typewritten and double spaced. In addition to the plan itself a brief summary should also be included. In the possible event of the same plan being received from two different sources , the board of judges will be requested to award the prize to A LOS ANGELES RADIO FAN BUILT THIS SET ACCORDING TO THE ARTICLE BY T . E. the fi rst one received according to the NIKIRK IN THE JANUARY ISSUE AND, MAN HOW SHE DOES WORK. S01l1E MORE OF YOU SET BUILDERS SEND 'EM IN AND LET US SEE WHAT THEY LOOK LIKE. postmark on the envelope. . " April, 1924 ~Radio JOUtnal~ Page 17S Something About Dead Kings By ]. T. ROFFY Deceased Kings, and Ki-ngs 'who succee d th e 11'~ have been favorites of history. Mr. Roffy here gives Radio ] mm~al readers his idea of why certain Kings of radio will amble into the am,btl/ance and others trip on the plush rug at the foot of the throne, HE King is dead, long live the and plate circuits closely coupled and or what is the method of diminishing King. You no doubt figure its transformer turns so deployed so grid current flow to maintain control that I will elect one 0 f my pet as to possess minimum capacity, can of that finely balanced state of border T circuits as king. I hasten to be sharply tuned from its minimum to line between self sustained oscillations inform you that I shall only make it maximum range with a straight line and extreme radio frequency ampli a prince. amplification constant. That is it will fication. The reader's attention is called respond to the incoming broadcast sig to the vernier rheostat in the circuit In radio frequency amplification em nal without having a predominant peak which accomplishes this function and ploying air core transformers the sec or preference to any particular wave permits the operat9r to control the ondaries of wHich are tuned by means length, other than 'that at which its electron emission of the oscillator of variable condensers, a condition own condenser will bring the combina through the inter range of the conden arises where the cascaded circuits fall tion circuit into resonance. It is appar ser setting and maintain that trigger into mutual resonance, re-amplifying ent then that in· a circuit of this nature position at an even sensitive point a received wave to the point of oscil there will be a plate current with a throughout the entire broadcast range. lations and completely blocking the cyclic change a true counterpart of the For the experimentor whose fancy further functioning of the set. The incoming broadcast frequency and runs to complicated circuits, this circuit immediate remedy for this suggests super-imposed modulation with a tube lends itself to limitless elaboration, but the potentiometer control of the grid amplified magnitude. If we carry this for the portable set, for consistent per- circuit or inverse feedback a' la neu trodyne through small balanced capaci ties and thus you are introduced to the demised king and now for the manner of his death. The idea of the balancing capacities is or was beautiful except that it bal anced through but a narrow band of wave lengths. In widening the broad cast wave lengths the neutrodyne would not "neut" effectively and the locating of new stations was tiresome. So discarding neutrodyne which just CirCll it R 3 means that it is less than a dyne we go to the other extreme and elect hetero current through a comparatively few formance, four 99 tubes, two R-3 dyne which in ordinary words means turns and closely coupled to this pri transformers, two audio .transformers, many dynes as tJ1e new king. We are mary, a secondary winding that is sub two condensers, a vernier rheostat, and now accustomed to the support and sequently employed with a tuning con A and B batteries constitute a great maintenance of five tubes ahd without denser, grid leak and grid condenser as set. Peer of all circuits. fear we enter into the maintenance of a grid circuit of a plane detector; we six or more tubes. If our fancy lies have a similarity to the famous Cock W ithOllt Carrier Wave in the direction of complexities we can aday Circuit where a tuned aerial in ductance is coupled to a detector; the Radio transmission without carrier receive the incoming signal at short waves has been successfully demon radio frequency, pass it through an difference is that we have a highly ef ficient frequency amplifier before the strated by station WRM, it is anounc oscillator, super-impose itself upon it ed, by the University of Illinois. Fur detector. The use of two large conden self on one of its harmonics, re-detect ther experiments are to be carried on it and then reflex it once more upon sers and two grid circuits at the first and broadcasting may be materially af itself at audio frequency and we have blush would compare the R3 Circuit to fected. By means of the new invel1tion the most beautiful thought of a man the neutrodyne, missing, however, the only the modulated frequencies of carrying himself by his boot straps. aggravati'on of the third condenser to voice or music are broadcast, and these The question arises can it be done? be brought in resonance with two al are devoid of the carrier wave ten The answer is yes. ready minutely variant tuning con dency to pick up extraneous frequen "Sometimes." Now since we have densers. The perusal of the R3 Circuit cies. Thus the new method of broad shows a further change in comparison introduced the royal family of long casting, if it becomes successful COlD distance circuits let us have a word or to the neutrodyne that whereas in the mercially, would tend to eliminate all so for the prince. It has long been old circuit the plate passes its ampli manner of sounds, etc., now accom understood that a short wave radio fication to the next tube, the plate in panying broadcast . reception at times. frequency amplifier is most sensitive the R3 Circuit returns upon its own to external signals when its plate and grid circuit as a paramount issue to The new high powered broadcasting grid circuits are in resonance and at bring about a state adjacent to self sus station, WTAM, in Cleveland, Ohio, the border of self sustained oscilla tained oscillations and therefore the is rapidly gaining a reputation for long tions. Therefore a well known oscilla greatest sensitiveness to the external distance transmission. the latest evi tor circuit which requires but a single wave impulses. The question now a dence coming in the form of a letter condenser for tuning having its grid rises "What is the method of "neuting" from a listener in Eng-Iand. Page 180 April, 1924 word as to selectivity and you will also notice that this feature is included in Oh Brother-Heart Throbs! the submitted diagram. No. '3 hookup,. you will perceive, is simply a single cir o demonstrate the extreme just above the heart of the subject. The cuit with a tapped variometer, with the sensitivity of the glow-dis heart beats sent out are said to be the stator between the aerial and the de charge microphone perfected faintest sounds ever picked up by a tector, instead of the detector being radio microphone but they intensified T by Dr. Phillips Thomas, station connected direct to the aerial, as is cus so clearly that they were audible to all tomary, and, in my opinion, the only KDKA of the Westinghouse Electric listeners. and Manufacturing Company recently real feature of this particular circuit broadcasted a program of heart throbs. To those who heard the heart beats, is the second switch,-that makes a The test of heart beats was heard from the sound was most unusual. One radio sort of vernier for the coarser tuning Maine to California and from Canada fan who called up the station said that of the first switch. to Me:cico, according to reports that This feature, you will also notice, is came In. taken care of in the hookup enclosed, Because of the fact that heart beats by the use of a 15 turn coil connected have a much lower period of frequency in such a way as to buck the windings than the voice or a musical instrument of the taped inductance coi1., and kill it. is exceediI1:gly difficult to find an~ the current down to' the right wave"' pickup that Will properly register them. length in the same manner as a vario After a long series of tests with the meter. This acts as sort of a vernier Thomas micr6phone, it was decided for the main inductance coil, and takes t~~t ~he instrument had the proper sen the place of the numerous taps, without sItivity to record the heart beats. The the danger of dead-end losses. This apparatus necessary for the experi also helps to adapt the finished set to ment, which was installed in Dr. different aerials, which naturally vary Thomas laboratory in the Westing in length. In the case of taps being house research laboratory, consisted of used, the set would work efficiently the amplifying apparatus, such as is only on a certain length aerial. I shall used with all microphone pickups", the be very glad to answer any questions microphone itself, and a telephone line regarding this hookup, and will· wel to the broadcasting station in E. Pitts come any improvements that any of my. burgh. The amplifying apparatus was co-experimenters may chance to work all arranged by Dr. Thomas and con out. I put this hookup on a Modesto sisted of a number of vacuum tubes horn with Baldwin unit and, while it balanced with other tubes. In the ar was not as loud as a phonograph, it rangement the apparatus was so hook We have applied for this job. This broad was plenty loud enough for a room caster is registering the young lady's heart ten by ten feet, and by using the switch ed up that high frequencies were elimi beats on the microphone.-Oh, Boy! nated and thus the heart beats could and slightly adjusting the movable coil register more clearly. the beats sounded something like the any of the four stations here in Los In the actual broadcasting of the telephone when the operator is ringing heart beats, the microphone was placed a busy signal. Combined. Crystal Hookup By W. H. H. KNOX HE writer was one of the en ation of the outstanding features of tl~e trants in your January crystal the 1st, 2nd and 3rd prize winnina GeOl·ge L. M o.rley sll.b1llils Ihis crystal hook contest, my hookup being 7th circuits, and with no intention of crit i~ up to S11.pplelllellt his hookup of last issue. cizing the editor of this department, I T on the list. I have been exper must say that the answer to his ques Angeles could be entirely tuned in or imenting on crystals for over a year tion, with the diagram, was most dis out at will. My aerial is eighty feet, for my own amusement, one of the appointing to me, and can only feel single length, stranded or braided wire, most fascinating hobbies I ever in that i.t was the same to th~ inquirer, as with about thirty-five foot lead in and fifteen foot ground to water pipe, and dulged in. In your February number I practically none of the Ideas of the mentioned hookup were incorporated a counterpoise of two strands, seven noticed an inquiry from K. R. Morgan, feet from ground. The aerial is twenty Long Beach, regarding the incorpor- in the diagram. However, there are two very good principles involved in feet high and points directly toward this circuit, viz; "the link", an old the Times Building, about five miles standly for securing selectivity, and out. Please address' inquiries to W. H. the variometer in the secondary circuit. KNOX, in care of Radio Journal. Please note that both of these are in the hookup submitted. Hookup No.2, The crossed coil radio beacon devel you will see by redrawing it, is simply a single circuit with a condenser be oped at the Bureau of Standards has tween the stator and rotor windings, been suggested as a means of guiding and with the return connected at the ferry boats across San Francisco Bay center of the variometer, instead of to in foggy weather, and the Bureau be the ground, after the rotor winding, as lieves it will prove very useful for This is the Knox Perplex crystal circHit is usually customary. This is the last that purpose. April, 1924 ~Radlo Joutnal~ Page 181 How to Build and Tune 3-T u6e N eutrodyne By c. H. STOUP Nope! We G1'e 110t through with the N eutrodyne-not by an old-time jugful. H ere~s a three tube N eutrodYl1e, built by a P en11sylvanian, 'which do es the stuff on dista11 ce as well as local. A11d it is as sharp as the liV. K. razor. HE N eutrodyne Receiver is not has first been given a thin coat of schel of the first two variable condensers are nearly as difficult to construct lac to prevent absorbtion of moisture. wired to the -A lead, the third one is as many believe. When pro Attach binding posts temporarily connected with the plus A lead. and rheostats permanently, then attach Place the grid leak and grid conden T perly constructed, with the ex Neutroformers at about a 60 degre ser as near as possible to the grid ter ception of the Super-Heterodyne, in angle temporarily so as to see about minal on detector socket. Complete all the writer's opinion nothing else is where you will have to run your wires neutroformer connections also wire more satisfactory. in the order to clear neutroformers. fixed condensers before attaching the The following instructions combine Now locate the radio frequency tube neutrodrons. After attaching each wire two stages of raGlio frequency with de sockets between the transformer coils you should check with' the diagram and tector and is for the use of phones and the detector socqet to the right of if correct solder the connections. only unless you live very near a broad the ri ght hand neutroformer. R emove You can make a good soldering job cast station. If you wish to use a loud the neutroformers and SC rew the sock by having your iron well tinned and speaker it will be necessary to add two in order to clear neutroformers. Now hot enough to melt solder quickly, and stages of audio frequency to the set. locate the radio frequency tube sockets then holding iron with a drop of solder Some of the features of the circuit between the transformer coils and the against the connection to be soldered are: no howls and squeals; no body long enough to heat the connection as capacity effect; no re-radiation; auto 1-----_._-,.. ' .' . hot as the iron itself. A great many matic tuning; fine selectivity; ability make the mistake of not heating the to bring in stations over two thousand connection enough, which makes a miles away. The following parts are poor appearance, a bad mechanical job required: and a worse electrical connection. 1 panel hard rubber of bakelite When you have completed the wir 7x21x3-16" or 3 small panels ing, being sure that at least enough of 7x3x3-16". the connections are insulated to pre 1 base board 21x6xX " . vent short circuits check again with the 3 neutroformers. diagram. Be sure your connections are 2 neutrodons. all correct for this is absolutely neces 3 single sockets (not metal base). sary in order to have your set function 3-3 Yz or 4" dials. properly; and then, too, 90 volts of B 1 20-ohm rheostat. Th~ three-tube N eulro assembled. battery is very unhealthy for the tube 1 6-ohm detector vernier rheostat filaments. preferably of the carbon pile detector socket to the right of the right, The aerial should be fairly high and resistance type. hand neutroformer. Remove the neu about 100 feet long A longer aerial 9 binding posts. torformers and screw the sockets in makes the set less selective and does ....,------' places. not noticeably increase the volume. The Begin wiring by first attaching tin ground wire should,be as short as pos ned wire to the ground post after leav sible and run as direct as you can from ing the end over long enough to attach the instruments to the nearest water to the primary of first neutroformer. pipe at a point nearest where the pipe A fter insulating with tubing attach the enters the ground. The water pipe other end to -A battery binding post, should be well cleaned and the con and then to - B battery binding post. nection well soldered. - Back panel 1I70ltntilt,q and unnn,q of thru tub~ N wtro with amplifiers. Connect one filament terminal of The instruments should be located as each socket to -A wire, after cutting near as possible to where the lead-in 20 ft. insulated tubing. away enough insulation in order to enters the house. 20 ft. round tinned copper wire. make a good contact, then wire plus Connect aerial and ground to set; 2 .006 mica fixed condensers. A battery circuit through rheostats as also A and B batteries and phones. 1 .00025 mica fixed grid condenser per diagram. With rheostats all turned on try one with 2 megohm grid leak. Replace neutroformers in position amplifier bulb in the first socket, then 2 20IA or 30IA amplifier tubes. being very careful to set them at the remove bulb and place in the second 1 200 or 300 detector tube. proper angle. This is very important, socket and after that in the detector 2 45 volt B batteries. a 55 to 60 degree angle is O .K.; how socket and if your bulb is yet O.K. you 1 storage battery (80 ampere-hour ever the angle should be the same for are safe in placing all bulbs in their or more). each neutroformer. Wire neutroform sockets. It is advisable to test out the The circuit is really simple to wire if ers as instructed finishing one at a time circuits first with one bulb only so in you go after it intelligently. before going to the next. case you do not have the set properly The panel should be drilled for Neu Be sure the fixed side of the variable wired, you will only burn out one bulb troformer condenser shafts, binding condensers plates are attached nearest instead of two or three. posts, rheostats and base screws as per the grids, otherwise you will get con N ow connect the neutrodrons. Ad diagram and then screwed to the base siderable body capacity effect. Take just variable condensers for full ca with round head screws after the base notice that while the rotary plate side pacity or with rotary plates all in, then Page 182 April, 1924 lengths and not on the long wave lengths or vice versa. Don't give up the ship until you have her in "Port Neut" and you will be well paid for the time spent for, as said before, the circuit is either all right or all wrong; there is no half way How to Tune Set all dials at zero and then move each one and all together two degrees at a time until you hear a station which you should tune in to loudest point by L-______~ ____~ ______o ~A adjusting each dial separately. If you now mark down the dial settings for Three-tube N cutrodyne mounted on a board 20%6%% inches. N -Ne utrodon. this particular station you will know exactly where to find him the next attach all dials with the 100 setting at place tube and if your paper has n?t time. slipped out of position the tube WIll the ·top. There should be a scratch or After logging quite a few stations in mark pIaced on panel at edge of dials NOT light. Before removing tube to place paper on the socket filament te: this manner you can pick up distant directly above the center of dials. T une stations by first knowing their wave minal you should have first tuned 111 in your local or 'nearest broadcast sta your local station and after installing lengths and operating time and hunting tion by first setting all dials at zero the paper and replacing the tube you for them on settings which you will be will find you can still hear the station. able to approximately determine from and then moving each dial and all three your log. For instance when I first went dials together, two degrees at a time You should now readjust the dials slightly for the best signal strength after KHJ Los Angeles Times on 395 until you locate your station. Then ad and then adjust the first neutrodon un meters from my home in Pennsylvania just each dial separately to the loudest til you cut the station entirely out or I tuned slightly over WTAM Cleve point. In all probability your dial set as near out as possible. land who is on 390 meters. WT AM tings will now be slightly different and was on dial settings 1st dial 460, 2nd if so, carefully loosen set screw on first Before the tube is neutralized and dial 47, 3rd dial 47, and KHJ I found dial and without moving shaft in the with the piece of paper under the tube on 1st dial 470, 2nd dial 48, 3rd dial least place dial setting the same as sec filament contact you are able to hear 48. ond dial and then perform the same the station louder on account of the If your chief aim in radio life is operation on the third dial, setting it capacity of the tube and a~ you n~u picking up the distant stations you to the second dial reading. Your dial tralize you balance out thIS capacIty should provide yourself with up-to settings you will find will now be ap and therefore eliminate or nearly elim date schedules, preferably obtained proximately the same on each dial for inate the signal. After adjusting the from the broadcast stations themselves, the different stations. neutrodon to this point remove tube and then sort them out as per above from the socket and also remove the instructions, for no matter how well Neutralizing the S et paper and then replace tube in socket. your set is perking you are working at In an ordinary three circuit regener The directions fo r neutralizing the first a disadvantage without a correct sched ative receiver, regeneration is obtained tube are now followed for balancing ule. For instance, if you tuned all Fri by feeding back the radio frequency out the capacity of the second tube and day night for PWX, Havana, you adjacent circuits, the adjusting being currents through the capacity existing would not be able to tune him in for he done of course with the second neutro is only on the air Wednesday and Sat between the plate and grid of the de don. tector tube. urday nights. After removing paper from the sec It is this condenser effect or capac The following list of dial settings ond radio frequency tube you are ready may be of some assistance. Your own ity that we now wish to neutralize in for business, provided you have made order to keep the radio frequency cur settings will of course be somewhat a job of neutralizing and this you will different. These were reached from rents from being fed back to preceding very readily determine as you tune in circuits. By adjusting the capacity of Valencia, Pa. : short and long wave length stations. Sta. Location Wave 1st 2nd 3rd the neutrodon to the capacity of the Lngt. Dial Dial Dial tube, the feed back currents are forced The neutrodyne circuit is a ringer KDKA Pittsbur gh 326 32 32 31 when neutralized properly and all 6KW Tuinucu, Cuba 332 37 37% 3 7~ to take two paths instead of one, one WKAQ San Juan PR 360 39 40 39 wrong when not fully neutralized. KHJ Los Angeles 395 47% 48 48 path through the bulb and one through PWX Havana, Cuba 400 51 51 51 the neutrodon. This causes them to WDAF Kansas City 411 53 53 53 After making sure that you under KPO San Francisco 423 56 56 56 buck or neutralize each other and stand how to neutralize and then find CKAC Montreal. Can. 430 59 59 59 therefore no current flows. Ten or fi f WOS Jefferson City 441 62 62 62 you are unable to do so you may have KFI Los Angeles 469 68 % 67 % 67 % teen minutes will tell you if your set is to change some of your wiring in order WEAF New Yor\( 492 81 80 80 going to neutralize properly. to keep high frequency leads that are Tuning out Static You are now ready to neutralize the not at or near ground potential se On local stations when static is real set but before attempting this you parated well from each other and from should interchange the. two radio f re the ground potential leads. Leads that bad you can eliminate almost all of it, quency tubes and if this br!ngs in the run parallel should be well separated by detuning your first dial to the left signals louder, leave them thIS way, and as they form a beautiful condenser several degrees and the second dial if the signal strength is decreased re leak if too close together. All leads several degrees to the right. You will turn them to their original positions. that cross should be at right angles. be surprised at the results. Quite often there is one way they will Care should also be taken to see that Study your set. The better acquaint work best. leads are well separated from the rot Remove first radio frequency tube ary plates of the variable con?ensers ed you become with it the better oper and place a small piece of paper on one when the plates are out, otherWIse your ator you will be and the more pleasure of the filament contacts of socket. Re- set may be neutralized on short wave you will get out of it. April, 1924 Page 183 Q.- I am very much interested in your variometer in series with the tickler coil. article mentioned. I am wrttmg for inform "Reflex Regenerative" Hookup described in Tickler coil should have about 15 turns of ation, if you are kind enough to set me on the F ebruary number of Radio J ournal. I large wire, say No. 20 DCC. If you have the road to success. In the Radio Journal should like to build this in a three-tube set, this variometer suggest that you use it by all diagram the coil is continuous with the rest if I could use a Sod ion detector tube in place means. Regenerati on is obtained by adjust of the set while in another diagram there ii .of the 0300, if that is not possible, a low ment of both variometer and tickler. Ampli a dead end. I have hooked up according to voltage tube of some kind, that would give fication can be added with no trouble at aU to both diagrams. In the Radio Journal diagram good long distance work. The 300 tube uses this circuit. there is nothing to show the polarity of the quite a bit of A-Battery, and some of us in Q.-Am looking for information in regard batteries, and no rheostat is shown. I am the country are rather hard put to keep up to a receiver which will operate successfully only an amateur in radio, though I have built our A-Batteries. The Sod ion tube seems to with one or two steps radio frequency and quite a number of sets which gave good re be quite a wondj::rful detector tube but, I two audio. H ow about the Reinartz,-is R F sults. I have lately built an Erla three-tube understand, has to nave a different type of adapted to this circuit ? If so, is it depend set, and get with a lou'd speaker, Hastings, tuning element than the Radiotron detector. abl e,a good receiver for D X, and is it selec Neb. However, I made a slight change in the I should like to use, as you do. one of the tive? Also quiet ? I now have a receiver us set from their blue print, and improved the Ray Dee Artcraft's Transformers, as an in ing a Lemco tuner, which I believe is similar strength of the signals fifty percent.-E. W. ductance element. Can you tell me where I to the one used iIi·the Radiola IV. Am using EVANS, San Diego. Calif. can get a blue print working drawing of this two steps audio and it seems to be quite A.-In respect to this circuit it has been set, that would give relative siz e of panel, noisy most of the time. However, I have found that using a small tube results are not etc?-}. E. J OHNSON, Alhambra, Calif. anything to compare with the results obtain A.-I am sorry to disappoint you in regard ed with a standard 6volt tube. I believe if to the use of a Sodion tube in the pl ace of you shunt a variable leak between the plate 6-volt type detector tube. The Sodiol1 ' tube and grid. that your set will then perform. will not regenerate and is not the type of tube that can be used in this circuit. In this Q.-I am writing you in regard to reflex circuit it is absolutely essential to use the circuit on page 25, January issue Radio Jour type 300 or 200 soft tube detector tubes, since nal, Figure No. 2. Would you please tell me the various transformers used are designed the make of transformers to use to get the to be used exclusively with this type detector. best results from the UV 199 tubes ?-A. C. The Ray-Dee-Former Type M-33 must be OLlVER, Reeding, Okla. used with the large tubes for bes t results. A.--Most any Harkness coil can be u!ed For use with the 199 tubes, we have our in this circuit. Type M-66 Ray-Dee-Former which is de signed to be used with smaller tubes thm Q.-I read with interest the article on the bei ng adaptable to portable sets, T hi s new Hookup for D avid C. T aylor. Mum:ig circuit in the February issue of type M-66 is a new development, because of Radio Journal. The article, however, doesn't the pressing demand for a Ray-Dee-Former received over seventy stations since January ~ay anything about the selectivity of the set, designed express ly for the small tubes, fir st, but am not satisfied with its selectivity. and this is what I am most interested in. Is Q.-I received your letter of the 1st in st. , I believe it is as selective as a Radiola IV the 2-tube set equal to a !ingle circuit !et in which you kindly answered the questions (but not as qui et) after having' heard several using two steps of audio frequency? I am I asked relating to the Reinartz Receiver and Radiolas in operation. I mention this so you now using a single circuit of the type de! your opini on tends to strengthen what I had will have some insight as to what I desire in cribed by 6ZJ in the various magazines, and already begun to think, that it is very un selectivity. I have the fo llowing parts on have obtained wonderful results with only stable, So I am go"{ng to take advantage of hand,-2UV 712 Trans., 4 Reml er UV199 one tube, but am looking for a more selective your kindness and ask you if you wi ll send sockets, 4UV199 tubes, 1 Kilbourne and set, as there are five broadcasting stations in me either in the envelope enclosed or refer Clark 11 pl a.te condenser, with vernier, Denver and the General Electric is going to me to a copy of Radio J ournal, a hookup 3-30 ohm rheostats, Freshman variable grid build a thousand watt station here soon. with clear instructions (as I am just a nov leak, double ci rcuit jack, 1-200 ohm poten H ow does the Munzig circuit compare to a ice) of a one- tube set using dry batteries, tiometer, and miscellaneous. I have tried four 3-circuit set as to selectivity?-OSBORNE and which you deem to be of a stable nature different circuits in the past five months and HUCKEBY, Denver, Colorado. and which you think w ill get consid erable am sti ll looking for my pet. Perhaps I am A.-About the selectivity of the Munzig di stances ( I am 600 miles from nearest sta becoming a crank, but am having a good circuit, I have completely eliminated KFSG tion), The qualifications of this set sound time becoming one. I thought the Reinartz from interfering with KFKX while both like the perfect receiver we are all looking would probably fill the bill , as I have seen it were transmitting. Tl1is is before KFKX for. But I know you have just such a set in well recommended in several publications. changed her wavelength. This speaks very mind and I will allow myself to be thorough Can same batteries be used through out this well for the circuit and in fact it is absolu ly guided by your advice. I am enclosing a receiver, with R F? If you have a better tely the most selective circuit that I have hookup which I would like you to pass judg ci rcuit pl ease advise me.-LOREN BARNES, ever listened to, the super-heterodyne ex ment on and tell me if, in your opinion, it Armona, California. cepted of course. This circuit gives only would answer the above requirements, I real A.- Your interesting letter received. The one stage of audio amplification using two ize. Mr. Munzig, that a set might get 1000 ci rcuit that you are looking for appears in the tubes, but with a third tube a second stage miles in New York or California. and mi ght February issue of Radio Journal. This circuit of audio is added. which brings the volu receive but 100 miles wi th conditions around is the most sensitive receiver that I have ever up enormously. The loud speaker on D. X. here. and I just want your advice, for which used. I highly recommend it. It will give you stations operate eff ectuall y. I take occasion to thank YOll right now and both volume and di stance. The circuit refer also for prev ious advice, whi ch has been red to is called the Munzig Q.-I have a five tube Neutrodyne set built kindly and ob ligingly given. I would like to from the Fada hazeltine blue print. This build a set to which amplification may be Q.-For the last two weeks I have tried to machine wants to squeal and whistle and I added.-DA VID C. TAYLOR, Warren, build a hookup according to instructions I cannot get over five hundred miles with it Arizona. found in a late copy of Ii magazine. I have and even on close stations it is hard to keep A.- The ci rcuit that you enclose will an utterly failed to get any results, although I it from whistling. I have it adjusted accord swer the requirements you desi re in every have taken it to pieces and tried to rebuild ing to instructions. I am using a C-301 -A way, since you are located away from every more according to heart's desire-re~ults al tube for detector and also for amplifiers. one. This type of receiver is considered very ways the same, nothing doing. In lookin~ I have Jefferson type 45 amplifying trans simple in operation, and will give you a great over myoid copies of the Radio Journal, I formers. Work-rite transformers and neu voltage impress on the grid of detector tube. came across a similar hookup, written, I am tralizing condensers, capacity .0004 M.F.D. It can further be improved by in serting ' a sure, by the same person who wrote the first variable condensers. I would be pleased to Page 184 ~Radio Joul:nal~ April, 1924 have you tell me what my trouble is.-K. W. J AMES, Prescott, Iowa. A.-Your trouble is evidently in your Listening In neutralizing condensers. Construct larger ones by using a three inch length of ~" copper tubing with a flexible sliding lead. 6PL and 6MG From 6EA Q.-Last Summer I built a radiophone Calls heard at 6PL and 6MG, Hollywood, The recent rains and winds have delayed receiver. as described in Radio Journal for California. Month of March, 1924. 6EA and 6EB in putting up their new 100 ft. June, 1923. I have hooked up several other pole, so they have decided to wait until 1AIl, 1BEL, lUW, 1KC, 1CPN, 1AUR, summer and build new stations also, to be sets since then, but have found none that I 1ER, 2PD 2CUK, 2IW, 2BLP, 2BY, 2RK, liked as well as your hookup. I have some ready for next winter. With only 40 ft. of trouble with squealin g on the low wave 2AWF, 2CXL, 2GK, 3VW, 3AV, 3BVA, it up, they are getting out fine, working lengths and the signals are not as loud as 3BGJ, 3BUY, 3BO, 3HG 3]], 3AB, 4BS, every di strict and being heard in new places. they are around 400 meters. What is the Heard by 6EB: 2ABD, 2BRB, 3QV, 4IO, 4XC, 4HS, 4MB, 4RH 4DV, 40B, 4IK, 4MY, SADB, SADO. SAGN, SAH, SAIC, cause of this and i there any remedy for it? 40A, 4FS, 4FZ, 4GZ, 4FT, 4GH, 4CR, 4EB, I am u ing 'vV. D. 12 tubes. Thanking you SAIU, (SAMO), SAZ, SBE, SDW, (SLG), for my reply, DEWITT SWIGART, Rt. 2, 4KZ, SOG, SVM, SNT, SNA, sALV, SZAV, sLR, sNW, sPH, sQD, sQH, (sRG), sSK. Box 606, Pasadena, Cali f. sEH, sSD, SSP, sIG, sAJB, sDU, STJ, sXD, sZA, sZAV, 7ABB, 7ABY, 7ACI, SVC, sAIR, sEK SQH SRG, sRB, SBE, 7ADP, 7AEL. 7AFO, 7AHS, 7AIV, 7AJD, A.-YOlll· trouble is in the tube used. Since 7AJQ, (7AJY) , 7AKH, 7AKK, 7ALD. the VvD 12 has such low internal capacity it SQD, sAKN, 5LR, SADB, SXD, sKR, SKA, 7ALI<. 7ALL, 7AOD, 7BR, 7CG, 7CO, 7DI is hard to make it oscillate and regenerate at sKC, sBM, sNW, SMO, sAGH, SUX, sQL, 7DR, 7EI. 7EJ, 7EM, 7FQ, 7FR, 7FS, 7GQ high frequencies or in other words on low 7GR, 7HW, no, nw, 7JU, 7KE. 7LH, wavelengths. SALR, sALM, sEI, SSP, sEF, sZA, sMN, sGG, sLG, sADO, sSD, SXV SAIC, SAU, 70B, 70M, 7PW, (7QD), 7RY, 7SF, 7SH, A C 300 detector tube will give greater 7SY, 7TQ, 7TT. 7VN, 7WS, 7XB, 7ZU, volume as well as ' greater distance. 5 I, sAMF, SAl], sFJ, sVF, sAZ, SAIU, 7ZZ, 8ATC, 8CEK, 8CGT, 8CJD, 8CMY, If you do not care to invest in a larger SALX, SAW, SFV, sWH, SAMW, sJD, 8FJ. 8IN, 8KC, 8QY, 8VY, 8XE, 8YN, 8ZK tueb you can shunt a hi gh Tesistance pencil sAMU, sAMA, SAC, 6 EU, 6ADO, 8FM, 9AB, 9ABC, 9ACM, (9AEC), (9AHZ). marks between grid and plate. This will al 6FU, 8BXX, 8AJS, 8PL, 8ART, 8RN, 9AMB, 9AMP, 9AOJ. 9APF, 9AQC. 9AVC low the tube to oscillate on all frequencies. 9AWY , 9AZG, 9BCW, 9BEU, 9BEZ 9BKF 8COM, '8BNZ, SCMU, 8ALW, 8JY, 8AOZ, 9BLY, 9BQY. 9BTO, 9CAA, 9CAJ, 9CCS, Q.-Just got hold of a copy of the Feb 8DDC, 8BCH, 8VQ, 8BKN, 8DED, 8APT, 9CDQ, 9CDV, 9CJU, 9CJY, 9CLD, 9CLY, ruary iss ue of your magazine and was great 8CFQ, 8DDC, 8FN, 8CZZ, 8DKS, 8ZZ, 9CTV, 9CVC. 9CVO. 9CZG. 9CZQ, 9DA W ly interested in' the "Questions and Answers" 8ZT, 8CUG, 8BFH, 8BGZ, 8ARO, 8CPD, 9DKQ, 9DPP, 9DSW, 9DTE, 9DYI 9DXX columns, as it related la rgely to a neutrodyne 8BLB, 80A, 8CZY, 8BQS, 8CGX, 8BDA, 9EAE, 9EAK, 9EAM. 9EEA. 9EIQ, 9ELB outfit, one of which I built this winter, a 8ADA, 8APN, 8DN, 8DO, SZY, 8AFG, 9HM, 9MC, 9SS. 9XAX. 9XBA. 9XBE, five tube set using Fada Kit and a good as 8IB, 8WY, 9BSP, 9BLY, 9BWF, 9AFM, 9YAU, 9ZT, W NP, KFZ, KDEF; Can.: semblage of parts. I used All American 9BXQ, 9CEH, 9CCM, 9CCV, 9AAO, 9AIM, (4DQ) 4CB, 4FZ, (4SH). sCN, sG O. SHG transformers, one 3-1 and one 5-1, and 9CZM, 9CKM, 9BQJ, 9ATO, 9A VG, 9CZG, (9BX). The above list of calls heard were good rheostats, jacks etc. The set has good 9DJB, 9CLD, 9COS, 9AUU, 9HK, 9APF, received on a Seefred EA-6 which needs range as I have covered the country from 9AMB, 9BAK, 9BIK, 90 X, 9BEY, 9BSY, no antenna, just a ground connection. Just coast to coast and brought in the stations on 9BUN, 9FM, 9YY, 9BKB, 9AAU, 9VK, had 500 cards printed and if any of the loud speaker. 9BEZ, 9VE, 9CHO, 9EAK, 9ASN, 9CIU, calls li sted here have not received one, please The only trouble I have had is to neutral 9ARU, 9EHJ, 9CSC, 9ENW, 9DAY, write me and also don't forget to let me ize the set and don't seem to be ab le to g: t 9EER, 9ER, 9CJX, 9BMH, 9BJK, 9BSZ, know if you have heard 6EB, regardless of this done properl y. Have tried the paper 9VZ, 9BLT, 9AUW, 9AEM, 9DHG, 9DHB, distance. I am always glad to know and over one of the filament contacts of the 9BSB, 9DKQ, 9DKB, 9VM, 9CFF, 9CGL, answer all cards. One stage of amplifica radio frequency tubes, in fact both of them, 9ADY, 9CFI, 9FV, 9DUG, 9DUN, 9CGA, tion was used but will have three stage soon. and also by using a buzzer, but I can't seem 9AHQ, 9APS, 9ZT, 9BOF, 9BXA, 9DKY, February "Radio J oumal" has some more to get it right. Have the Fada Neutrodons 9MC, 9ZG, 9 YW, 9ARY, 9AAU, 9DRY, calls heard by 6EB. and they ought to be properly built, but 9BPV, 9BRK, 9CAA, 9DGA, 9CKA, 9CDO, whether they are or not I don't know. as 9EM, 9CIC, 9RK, 9AUM, 9DTN, 9APE, my knowledge of radio is extremely limited. 9AP, 9CNY, 9WA, 9DTE 9CTE, 9RC, From6BQR I thought possibly it mi IY ht be something in 90CZ, 9VD, 9CJT, 9UZ, 9CVO, 9CEA, DX Calls Heard by 6BQR, 1422 Allison the construction of the set. A party here in (9XW fone 100 meters), 9EK, 9AWV, Ave., Los Angeles, Calif. Kindly notice the the city who assumes to know something of 9CHT, 9FM, 9BGH, 9AA, 9CKM, 9BKF, new qra 1422 Allison Ave., when u qsl. radio apparatus !lnd the assemblage of sets 9DID, 9DWN, 9AKZ, 9DPX, 9GZ, 9BSI, U. S .CW: 1ABF, 1AJP, lAKL, lECR, told me that I made a mi stake in the mount 9BHW, 9DLR, 9ABF, 9BJY, 9DRK, 1BQ, lCI, lCMP, IFD, IGV, lKC, 1XAK, ing of the variable condensel's and neutro 9CRA, 9BUW, 9CLX, 9CZX, 9CKZ, 9ADZ. 1XAM, 1XW, 2AGB, 2BQHH, 2CQZ, 2GK, formers. He said that the proper spacing 9AOL, 9DA Y, 9AGB, 9CZW, 9CJY, 9EHJ. 2RK, 2XAC, 3BG, 3BJ. 3GK 3HH, 3LG, between the center of the rotary shafts of 9EZC, 9EAK;, 9DRI 9DUI 9DSW, WNP, 3MB, 3PZ, 3XAQ. 4AI. 4BQ, 4CS. 4FT, the variable cond nsel's should be six inches KDEF. KFZ. 4IO. 40A, 4QY, 4XC. 4XE, 4XU, 8ACY, and with same spaced thusly the neutroform 8AGP, 8AMM, BAOL, 8AOQ, 8APN, ers should be set at the published angle of 6EA and 6EB 8APT, 8ATC, 8BDA. 8BDU, 8BFM, 8BLY. 57.4 degrees, and that inasmuch as I spaced 8BXH, 8BZC, 8BZY, 8CDZ. 8CFD, 8CGJ, these instruments seven inches in my set Log from 6EA, Los Angeles: 117D, IF , 8CHY, 8CPK, 8CUD, 8CWU, 8DAT. the angle should be increased to perhaps 60 ( IABF), (lARE) , (lAWE) , lESD, 8DHS, 8FM, 8FU,. 8GZ, 8HV. 8]]. 8JY, degrees or thereabouts. The set is constructed (2CLA), (2CWO), (3BVA), (3XAQ) , 80A, 8PL. 8QK, 8TV, 8WX, 8XBA. 8XBH, 8XBP, 8XC, 8XS, 8YN, 8YV, 8ZC, on a 28 inch panel 0 there is no crowding of 4BZ. (4IO), (4XC), sBX sEK SLG SOQ, the parts and is ve l'y carefully wired with 8ZZ. Other Dists. too numerous. (sPH), (sQL), SRG, SV 1: , sZA, sADO, Canadian CW: 3AA. 3BP. 3BQ. 3CO, bus wire uncovered and great care was taken sAIC, SAIU, (SAMO), SAMW, SANF. to keep all plate and grid leads as short as 3KG. 3XN, 4CO, 4CW, sCN, sGO, 9BP, sZA V,7BJ, 7EM. 7EY 7FD, 7FQ, 717R 9BX. possible consistent with keeping all leads at 717S, (7GQ), (7GP), (7GR), 7II-I, no. least three fourths of an inch apart, and also North Pole: WNP. np, nw, 7JE 7KE. (7LH), 7LN, 7MI, Broadcasting:: KDKA, KYW, KFKX. not running any wires in close parallel re 7NO, 70M, 7QC, 7QD, 7TQ, 7V , 7WM, lation with each other. I really did a very WBAP, WHB. WGY. 7WS, 7ZU 7ABB 7ACM, 7ADG, 7ADQ, Mexican : CYL. good job of wiring and used a lot of care 7ADS, 7AEL, 7A17N, 7AGE, 7AGR. and the set works as a result but not as good 6BQR is rebuilding and will soon be on 7AHV, 7AJQ. 7AKK. 7ALD, 8ER 8VY, with SO Watter. as it should and would if I could neutralize (8ZK), (8ABS), 8ACM, 8ANM, (8BDA) , it properl y. Do you think it would help to 8BFM, (BXX), 8CTP, 9EQ. 9GK. (9MC). make up a small set of neutrodons with wire 9RY, 9VK 9ZK. 9AMB. 9APF. 9A VU. Railway clerks, barbers, accountants, and tubing and put them in, or do you think 9AZG, 9AZR. 9BEU, 9BJI<. 9BL Y, 9BMU, farmers, machinists, artists. electri it would be better to connect to the Fada 9BPY, 9BTL (9BUN) 9BVN. 9BXQ, neutrodons at one end terminal and connect cians, lawyers, school boys and univer 9CAA, 9CJY, 9CLD. 9CZG, 9DA Y, 9DCW, sity students are among the many who at the center terminal with the other lead 9DDP, 9DFH, 9DTE, 9DTJ, 9DUG, 9DYI, wire. Would'n't this latter plan aggravate 9DYR, 9EAE 9EAK, 9EKF. 9XBA, 9XAX. are taking the course in "Radio Com rather than alleviate my troubles in neutral KFZ, KDEF buzzer and CWo munication" now being broadcast from izing? I have thought of buying two Sham- . Canadian 4CB, sGO, 9BX. Above DX Station WBZ operated by the Westing rock neutrodons and trying them as I like worked on five watts and heard on low qrh the looks of these but know nothing of their three circuit regenerative receiver.-H. C. house Electric & Manu facturing Com (Continued on Page 186) SEEFRED, 343 South Fremont Ave. pany, Springfield, Mass April, 1924 Page 185 Milwaukee Club cisco. Rarely doe.s the amateur gain admis Twin City Club sion to the high powered government arc The Twin City Radio Club, at its last A ··Broadcast Listener's Night" at which stations, so this talk was doubly interesting, meeting, May 1, heard a most enjoyable some of the country's foremost radio ex for Mr. Drew's remarkable memory brought perts spoke was the big feature on the last speaker,-Professor J. C. Saunderson. Pro back even the dimensions of the antenna month's program of the Milwaukee Radio insulators. fessor Saunderson is an ardent student of Amateurs' Club, Inc. At a regular Thurs The experience of a Radio Editor is a Esperanto, and is working towards the fur day evening meeting in the Trustees' Room subj ect that is bound to attract attention, so therance of this international languages. He of the Milwaukee P ublic Museum WIth an when Robert E. Knoff, Radio Editor of the audience overflowing the hall, E . T . F lewel secured many new members to the Esper Milwaukee Journal, rose to address the club, lin g, Chicago, of fliver super-regenerative he found a capacity crowd expectantly wait anto system at the meeting, and practically circuit fame, David Grimes, New York and ing fo r his talk. Nor were they di sappointed, everyone in the \·00m has now enough know Minneapolis, known for his inverse dupl ex for Mr. Knoff raised tlie roof with his tales ledge of Esperanto to be able to handle it and reflex circuits, H. J . Marx, Tech1l1cal of incidents that were as true as they were over the air in a more or less effiCIent man Editor of '·Radio D igest," Chicago, Milo humorous. The head of the radio department ner, depending upon ho~v much education Guerney, the "mystery man," and F . D. of newspaper whi is bitten by the "ham was had before the meetll1g. Pearne chief electrical instructor of Lane bug" is a sorry individual, and the various Techni~al High School, Chicago. but better stages in the education of such a person af The meeting place of the Twin City Radio known as technical editor of "Radio Age" Club is now at the auditorium of the main ford many a good laugh, as well as much and technical radio editor of the Chicago serious consideration. En Shepherd's Bush, where the mica !s split, broadcast, but to broadcast the whole of the Super-Heterodyne will require a separate gauged, sorted and te:;ted for dlelectnc proceedings would be sheer waste of power, undertaking. Unl ess you wish I don't be strength. The assembly of the small conden since nobody could afford the time to wear lieve I would wreck your present set. Try sers used in wi reless receivers, and the manu the headphones all day long and far into the to di spose of it to some one so that you may facture of grid leaks and anode resistances ni ght. get your money back anyway. Then con were followed step by step, special mention After the moti on had been fully discussed struct the Super-which indeed is a separate being made of the very thorough tests to by the Society a di vision was taken, as a undertaking. which every condenser and resistance IS sub result of which the motion was lost by 17 jected before leaving the works. The manu votes to 9. The British Standard List of Terms facture of various types of large condensers On February 29, a Question Night was was then dealt with, and it was stated that and Definitions Used in Radio Com held, when a very interesting exchange of munication, just off the press, is really the efficiency of these condensers exceeds ideas took pl ace. One member raised a 99.99%. Mr. Coursley concluded his most a vocabulary of radio. The list of interesting and in structive lectures by show discussion on F rame Aerials and Power Am ing a few slides of the experimental trans plifiers, and Mr. Stanley gave an account of terms and definitions numbers about mitting station 6XX. t.he. statlOn of the RadlO his recent visit to the 2LO Studio. T he 170 in general use. technical di fficu lties involved in the use of Society of Great Bntam. long wave-lengths for telephonic transmis Owing to the rapid growth of the The hundredth meeting of the Radio So sion was di scussed, and some useful inform subj ect it is not possible to include ciety of Highgate, E ngland, was h ~ ld on Fri ation was given concerning the position of every term used in connection with day, February 7, when a most mteres tl11 g the grid-leak and filament rheostat. radio science, and such new terms as lecture was given by Mr. G. G. Blake, F. The Society has pi easure in reporting that survive will be incorporated in future Inst. P., M. 1. E. E . on "The Modern View the H on. Secretary, Mr. J. F. Stanley, A C. of Electricity and Its Relation to Matter." G. 1., B. Sc., F. R. A, has been elected H on. revisions of the li st. Where the same Mr. Blake began by di scussing in a simple Secretary to the General Committee of Af definition applies to more than one manner the theory of Relativity, and some filiated Societies, which Committee is com term, the term re.commended for gen analogies wer.e ~iven to convey some con posed of representatives of Societies all over eral use is printed in bold type, the ception of the smallness of electrons .. W e Great Britain. shall never be able to see electrons, said the other terms being given in li ghter lecturer, but existence was conclusively prov type as synonyms of the preferred ed by Sir William Crookes and others. The (Continued from Page 181) term. In this way the committee res constitution of solids, liquids and gases was efficiency. One party here says the cambric ponsible for drawing up the li st hope dealt with and a striking exp riment was and wire, home constructed affair has done shown to illustrate the motion of the part the trick for him. Those who profess to to encourage uniformity in the matter icles in a liquid. The uses of X-Rays to !mow here in Fargo say that everything has of nomenclature, a step which is spe study the constitution of molecules was very been done for my set that can be done, but ciall y desirable in the case of such a clearly explained by means of lanter!1 sl!des in this I feel differently, and their state rapidly developing science as radio and experiments, and the existence and pro ments to the contrary rather induce me to the perties of ultra-violet li ght were also de bel ief that they don't know as much about communication. monstrated by means of experiments. Lan radio construction details as they would like Copies of this publication are ob tern slides and experiments were also shown to have the public believe. If the spacing tainable from the B. E. S. A. Publica illustrating the properties of waves and the of my neutroformers to seven inches apart tions Department, 28, Victoria Street, action of the thennionic valve. On February hasn't made any material difference, then IS a lecture on "Analogies" was given by there is nothing wrong with the set and it London S. W. 1. Mr. E . S. Anderson, F. R. A A simple can be neutralized if the proper apparatus is electrical ci rcuit was explained by means of used and it is properly adjusted, but in this water system and its pipes. The properties I am at sea as to what to do and do it right, From calliope to chariot races, from of inductance, capacity and osci llatory cir hence am writing you and will thank you spectacular opening to the ballyhoo of cuits were al so clearly explained by means for a response setting forth such suggestions of mechanical and hydraulic analogies. An as you think might serve to correct the side show "talkers", the circus has ingenious analogy was given to explain the troubles designated. gone over the radio. Westinghouse flatness of tuning of waves radiated f rom I was also interested in the Neutrodyne Station KYW recently broadcast fo r an open aeri al, and the modulation of a tele Super H eterodyne hook-up as it is called by the first time in radio history the Met phony carrier-wave was compared to the Mr. Ludlow of Monroe, Wis., and read the ropolitan opening of a big show-the corrugating on a gramophone record diSC article by Mr. Munzig, but having a ·very Full particulars of the Society wi ll be gladly limited knowledge of radio don't exactly un fifth annual premiere of Sells-Floto supplied on application to the H on. Secre derstand it. Am I to understand that the circus in Chicago's Coliseum. With a tary, Mr. J. F. S tanley, B. Ss., A C; . G. 1., construction data as outlined is for the build three-way switch, KYW presented the F. R. A, 49 Gholmeley Park, Highgate, ding of a set in addition to the Neutrodyne big show performance far beyond N.6. to be later connected with the Neutrodyne, or does it contemplate the wrecking of the both coasts, sending forth side show An interesti ng debate took piace on Friday, Neutrodyne and rebuilding same. Am inter and menagerie "High Lights" to give F ebruary 22, on the motion that "In the ested in something better than I now have, the typical big top atmosphere to the opinion of this Society the whole of the and was greatly interested in a Super Hetero interesting achievement. proceedings of Parliament should be broad dyne hook-up as outlined in the March issue cast." of the Radi o in the H ome written by W. H. McFarland, dean of " kid" Mr. D . H. Earle and Mr. J. D. Steele pro Neeley, supplemented by full details by one show managers, toured the circle of posed the motion, which was opposed by Morgan and also by one Clark. If this ma freaks and curioos peoples with the Messrs. J. F. Stanley and G. A Y. Lowter. chine will do what they say it will, it is fans. Each platform was visited, and, The main point in the argument of the pro quite some set and should please the most after a rattling old-time introduction fastidious radio fan. posers was that there are at present no reli by the veteran impresario, the freaks able sources of information on parliamentary However, my N eutrodyne is working. has proceedings readily available to the general worked and will work again and as I get greeted the fans. The wild man grow public. Newspaper reports are abbreviated to both 'coasts now, can probably get up led, the fat lady gave her weight and and biased. Further, the proposers main and down the Mississippi Valley country the colored minstrels strutted their bits. tained that broadcasting would tend to raise during the summer, and it has done quite A darky quartet broke in at intervals the level of the debates, since all M. P 's as well as anything I have yet heard in this would realize that their words were being city, range, volume, selectivity, etc., con with racing lilts of syncopated mammy heard by thousands of people. T he opposers sidered, and if I could get it neutralized as stuff, and Captain Jacobs, "fearless of the motion sugg-ested that M. P's would I ff!el should be done, would be as good a lion fi ghter" fought the good fight for be so anxious to make themselves heard that machine of its kind as there is out I believe. the sixteenth time that day. they would get up and speak without really -L. H . AMIDON, Fargo, N. D . having anything to say. a proceeding which A.- The spacing of your Neutrofromers is not conducive to the transaction of busi is O. K. I personally believe that you can A. G.Farquhar on, secretary of the ness. In the case of ordinary broadcasting remedy your trouble by constructing N eutro Los Angeles Music Trades Association the broadcasters are specially trained to con dons as follows: Cut a three inch length of vey their personality to the broadcasters copper tubing ~ inch in diameter. In this and of the Radio Trades Association through the voice alone, whereas M. P 's slide a 4Yz length of flexible lamp cord. This section of that organization is installed have not had such a training, and a long capacity will be much greater than the FADA in new quarters, 612 Commercial Ex parliamentary debate would not make very N eutrodons and as evident in your set, it will change Building, E ighth and Olive Sts. interesting li stening. It is admitted, of course, be necessary to have more capacity for pro that special events in parliament should be per neutralization. The construction of the Los Angeles, California. April, 1924 _-_.e-"'"""1.L-,RadIo -Joumal ~ Page 187 With the Western Amateurs A Department Conducted by A. L. Munzig New A.R.R.L. Chiefs Dope from 9ZT-9XAX Tests With Paris The names of the new directors of the Here is some real dope from D. C. Wal Radio amateurs of the U nited States and American Radio Relay League have been Canada are li stening for test signals from announced by the executive committee at lace, ADM, A.R.R.L, 92T, 9XAX, 1923 the A.R.R.L. headquarters following official Hoover Cup winner : the Eiffel Tower in Paris through special count of the ballots from all divisions Practically all of the amateur stati ons in request to the American Radio Relay League throughout North America. Because of its the vicinity of the Twin Cities who are able from General Ferrie, director of telegraphs position as a non commercial association and for the French government. the democratic nature of its constitution, to tune to 150 meters and are allowed to do peculiar to an organization of the kind it i. so on their license, have found that this wave A special short wave radio transmitter required that the directors be selected by the length enables them to communicate with has been installed at the tower for this pur membership. pose and reports of reception by amateurs of many stations and many districts that were North America under varying weather con Between 15,000 and 16,000 ballots were out of the qu estion heretofore. Several of ditions are to be sent to the A.R.R.L. and distributed and in several divisions rather the stations have reported that on 150 meters forwarded to the French government. strenuous campaigns were waged by the sup porters of the candidates. After a complete they find conditions as satisfactOl-y as are DurinlS his recent visit to Paris. where the survey of the vo,tes cast by the League's the conditions on 110 or 120 meters. InternatIOnal Amateur Radio Union was membership in the United States and Canada formed. Hiram Percy Maxim. president of It seems that if the station transmitter is the A.R.R.L. learned from General Ferrie the following men were declared officially tuned be low the fundamental. it makes very elected: that his government was desirous of obtain little difference where it is tuned, and Atlantic Division, George L. Bidwell, ing the co-operati on of American amateun. Washington, D. C. whether the wave. length will be 200, I SO, Central Division, Clyde E. Darr, Detroit, or 100 meters. In other words, if the an- Radio Legion Michigan. The recently formed Radio Legion Dakota Division, Cyril M. Jansky, Min neapolis, Minn. of America, whose ambitious goal is Delta Division, Benjamin F . Painter, to bring all factions in the field of ra Chattanooga, Tenn. dio activities into one vast organiza East Gulf Division, Harry F. Dobbs, At lanta, Ga. tion with a membership that will total Midwest Division, L. Boyd Laizure, Kans a million, came into existence through as City, Mo. the efforts of a small group of enthu New England Division, George H. Pinney, South Manchester, Conn. siastic broadcast listeners in Chicago. Northwestern Division, Karl W. Wein It is the wish of the legion that the garten, Tacoma, Washington. public generally know that no officer Pacific Division, Allen H . Babcock, San This is 6AVA nor anyone else connected with it has Francisco, California. the least affiliation with any commer Rocky Mountain Division, Paul M. Segal, cial activity in the radio field. Denver, Colorado. . tenna has a natural period of around 175 Roanoke Division, W. Treadway Cravely, meters, the best working wave would be be John J. Funk, president, is a devoted Danville, Va. low that and not above it. T his of course, electrical experimenter, and earns his West Gulf Division, Frank M. Corlett. means rather low antenna current, but we living as a motion picture operator; M. A. H. Keith Russell becomes a director through his election as Canadian general have long been familiar with the saying that Herschman, vice-president and treas manager of the A.R.R.L. Although Canada antenna current does not determine range. urer, is a cigar manufacturer and re is divided into sever~ operating divisions, it In the vicinity of 200 meters, communi tailer; M. E . Donegan, secretary, is in is represented on the board by this office cation is being carried on as usual, but under the business of renting high grade fur created in the League's new constitution. greatly improved conditions, as the interfer The election of the foregoing candidates ence that has heretofore prevailed on 200 nished apartments; Hill Bernstein, or becomes effective July I, 1924. meters has reduced down to the point where ganizer, is an advertising expert and The annual meeting will be convened by practically no interference exists. Stations in is employed by theatrical interests. the president, Hiram Percy Maxim of Hart the Dakota division have been endeavoring to ford, Conn., the latter part of July. improve the pureness of the emitted wave, Officers are not on salary nor are and now it is rare that we hear spark or they compensated in any other way. New Station 6COS ICW, and pure CW seems to be the rule. The Radio Legion operates on a strict W e are rapidly approaching the day of the ly cost basis and pays out money only Editor, Radio Journal : I am writing this "silent transmitter" and we hope that some letter to let you know that I have just re day we will be able to have several hundred for work actually done, and other ne ceived my station license and call letters. I communications going on simultaneously cessary expenses such as printing, am also going to describe my transmitter and from every large community in the Dakota mailing, etc. . receiver. Division. My transmitter is a 5-watt set, using one Anyone interested may secure full S-watt tube with 135 volts on the plate. It is information by addressing the Legion a portable set and the panel measures From 6ARB national headquarters in the Garrick 7"x5Y.". It consists of a plate and grid coil, Report April 1 to April 30, by 6ARB, Theatre Building, Chicago, III. honeycomb used as a radio frequency choke C. E. Duncan, 3029 Acton St., Berkeley, coil, radiation meter reading from 0-250 mil Calif.: (lKA) (lBCR) (lBSD) (lCPN) liamperes, .0015 Micadon Condenser, and a French Concert 5-watt tube. I am going to use a michrophone IXAS, 2GK, 2ADK, (2BRB), 2XAB, and a key with this set. (2XNA), 3ME, (3YO), 3ZL, 3AEC, The first radio concert h~ard in My receiver is just an ordinary single cir (3BVA) 4EB (4XC) 5KC, 50V, (5AFH) America transmitted from the Eiffel cuit C.R.5 receiver. SAIC, (SAJH), (SA]]), (SAPH), SZAV, Tower, Paris, France, was intercepted My aerial is an inverted L type 50ft. long (6BUO) , 7ABB, (2ABS), 8APT, (8ZK), and 50ft. high with four wires.-WM. M. 8CTP, 8XBH, (8XBL), (9AMB), 9BTL, Saturday night, March 29th, by Bert SEELEY, 6COS, Los Angeles, Calif. (9CAA), (9CIP), (9CJY), 9CLQ, 9DWN, Moulton, Chatham, Mass. Moulton is (9DYZ), 9DXY, Can.: IBQ, (3BQ), 3CN, employed at the Radio Corporation of The QRA of 6XBQ is: L. Picker, San 3PZ, 4CB, (4CR), 4DQ, 4HH, (4IO) , America coastal station at Chatham, Ysidro, Calif. Any reports on CW and (SSG) , 9A V. All districts worked in one phone signals will be greatly appreciated. morning twice during April, using a 250 Mass., besides operating his own ex Picker also has call 6ZH. watt bottle and a Grebe 13. perimental station. Page 188 .. ~Radto Joutna1 ~ April, 1924 tuYers Coast on One Tube immediately and it is to fill this need quires the minimum of space for instal for trained men that the new institu lation. This new vertical type battery Getting Los Angeles with a single tion has been launched. The address of takes less than half the table space of tube dry cell receiving set powered the school is 625 South Hope Street, the horizontal type of 45-volt battery. by two Nationai Carbon Company dry Los Angeles, Calif. It fits perfecctly in the battery space compartment of the new Radiola batteries is the record set by Allen T . New Bradleyohm Super- Heterodyne, and any cabinet of Haas, of Magnolia,. N. .J. Mr. Haas, other makes which take the large sized who has been. a DX radIO fan for only The Allen-Bradley Co., 286 Green 45-volt "B" batteries. Many multi-tube two months, has a single tube (WDll) field Ave., Milwaukee, Wis., has added receiving sets uses a hard detector tube Westinghouse Aeriola Sr., and uses a another item to their increasing li st of which does not call fo r a tapped "B" battery, so the No. 772 has three Columbia dry cell for his A battery radio produ ~ ts known as the Bradley plainly marked terminals, - negative, and an Eveready for his B battery. ohm. The Bradleyohm is an adjust plus 220 , and plus 45-volts. Con able resistor which is similar in opera His outside aerial is 100 feet long, nections are made to regular large size seven strand copper wire, running from tion to other Allen-Bradley graphite disc rheostats such as the Bradleystat Fahnestock sprin g clip connectors. It the house (30 feet) to a tree · twenty has the same service capacity and is feet high. Aerial runs east and west and Bradleyleak. The resistance of the Bradleyohm is varied over a wide of the general electrical characteristics -pointing due west. and construction as the No. 767 Eve Magnolia is about ten miles from re~dy, and will ell at the same list Philadelphia, far enough away so that pnce. the powerful Philadelphia stations do not interfere too greatly. In a period of two months Mr. Haas has tuned in Sixteen Battery Stations 56 distant stations, including Tuinucu and Havana, Cuba; Montreal and Ot "Events move quickly in the radio tawa, Canada; Miami, Fla. ; Atlanta, world," said Guy Owen of the West Ga. ;Kansas City, Mo. and Hastings, ern Auto Electric Co., distributor of Nebraska. The latter station comes in Willard Batteries. "Radio Broadcast over his set more distinctly than any ing Station WT AM, at Cleveland, 0., thing else over 1000 miles distant. ?oasted last fall, when it opened, that Mr. Haas was looking for a Texas It was the only station without a gen- . station to add to his string and when erator hum and. the only station using around 395 m'hers, tuned in KHJ at storage batterIes for transmission 11 :40 P. M. Eastern Standard time. range by applying or removing pres power exclusively. There are now six He heard a speaker, singing, and mu teen stations scattered throughout the sic. The announcement and call let sure on the two columns of treated discs by means of an adjusting knob. country that have installed Willard ters came in quite distinctly. He retain broadcasting batteries as their only ed the station for fifteen minutes. A The Bradleyohm is suited for such purposes as : providing an adjustable source of power. This was on the description of the program was imme strength of WTAM 's success with diately sent to this station which is resistance across the audio-frequency transformers to reduce distortion; pro these batteries. - Besides the sixteen operated by the Times at Los Angeles, stations there are over one hundred California, and verification of the re viding resistors to be used in coupling radio frequency or audio-frequency re more using Willard broadcasting bat ception was received from their radio teries in connection with their gener department. sistance amplifi ers ; adj usting push pull amplifiers. ator or rectified A. C. power for voice modulation and other purposes. The New Radio School radio staff at WT AM has been read New "B" Battery ing the handwriting on the wall and The Western Radio Institute has in order to maintain the reputation for opened a radio school in Los Angeles A vertical type 45-voIt "B" battery excellence of transmission, gained under the direction of E. S. Farns has just been announced by the Nation: when WT AM was the only battery worth. The school will give courses in al Carbon Company, manufacturers of powered station, have turned their at all branches of radio. Mr. Farnsworth Eveready batteries, as the latest ad tention to improving other features of is an experienc·ed radio operator and dition to their radio battery line. Their the station. If you hear a strong sta was in charge of the Y.M.C.A. radio vertical type 220 volt battery No. 754 tion broadcasting under the call letters school prior to assuming leadership of has become so popular, that it logically 8XG, it is WTAM trying out some the new institute. The demand for led to the development of a big brother new broadcasting stunt to improve radio operators, according to Mr. to this space-saver, and there was felt transmission. The experimental call Farnsworth, is such that any really a well-defined demand for a compact, letters of the Willard Storage Battery qualified student can secure a position long-life 45-volt batttery, which re- Company are 8XG." April, 1924 ·~Radio JouHlat~ Page 189 (Continued from Page 169) Line Radio cording to Assistant Engineer J. J. Jakosky, of the Interior Department, . rheostats need scarcely be touched dur Experiments with line radio and ing the period of operation, but the by the develo-pment of the "wired wire carrier currents in mines indicate that second rheostat is more critical. less" telephone, utilizing existing "car this method is feasible for two-way riers", such as trolley wires, mine From 90 to volts of plate battery 135 conversations between miners below tracks, water and compressed air pipes, are needed to get the best results. This the surface and the mouths of mines, and cables . In tests, which he super is due largely to the characteristics of both for every-day use and in emer vised at the Pittsburgh experimental the low amperage tubes' used. gencies, according to the BUl'eau of mine, no difficulty was experienced on Antemla Specifications Mines. the surface in receiving the messages The antenna should be from 60 to The difficult problem of communi from a transmitting set on a mine loco cating with underground workers and motive, feet below the surface, as 100 feet, single wire, well insulated at surface stations of mines, especially af 400 its ends. If you have too much antenna ter severe disturbances or accidents long as the apparatus was near any and do not wish to go to the trouble have taken place, will be so lved, ac- metall ic carriers. of cutting it down, you can reduce it by placing a fixed condenser of .00035, .00025 or .0001 in your lead-in wire. Tests will show which will give you the best results. Here are the parts used by the Laboratories in ~ blliiding this set: 1 selectoformer 2 bakelite dials 3 rheostats 1 23 plate variable condenser (.0005 mfd.) 1 11 plate variable condenser (.00025 m feL) 1 single circuit jack 1 double circuit jack 3 sockets 1 Erla reflex transformer No. 1 1 Erla reflex transformer No. 2 1 E rla 6 to 1 audio transformer 1 Erla 30 to 1 audio transformer 1 crystal rectifier 3 fixed condensers of .001 , .002 and "The Loveliest Thing I've Ever Heard .00025 mfd. respectively Over the Radio" - Mary Garden 3 1 panel 18x7 / 16 6 binding posts Only the most flawless reproduction. free from 25 feet tinned copper bus wIre distortion and parasitic noises, could earn a tribute This set is easy to assemble and even so unreserved from America's queen of song. more easy to operate, there being an The exqui~ite tone quality and purity of Duo entire absence of body capacity and, Reflex reception that appealed so i(resistibly to for the benefit or your neighbors, no Miss Garden is finding equally enthusiastic appre re-radiation. After a station is once ciation in the homes of super-critical radio lovers logged and the numbers from the two everywhere. dials jotted on your chart, you can re Not only in sheer tonal perfection. but in range turn to this station practically at will. and volume. have Erla Duo-Reflex receivers demonstrated dpcisive superiority. Tube for tube, How to Tune Increased range and volume. as well as elimination of dis they are the most powerful receivers known. Tuning is done by adjusting the two tortio n, follow installation of Erla transformers. Re Complete Erla parts, including celebrated syn variable condensers. The 23 plate tunes flex and Cascade types. $5 chronizing radio and audio transformers that the selectoformer and input circuit enable vacuum tubes to do triple duty, guarantee while the 11 plate tunes the radio fre success to the amateur who "rolls his own." Easily quency amplifier. These two adjust understood blueprints guide every step of con ments should be about the same on the struction and assembly. dial positions and care should be exer Ask your dealer for free Erla bulletin No. 20, giv cised to keep them somewhat in step ing latest Erla one, two and three-tube diagrams; when tuning. They must also be turned or write .direct, mentioning your dealer's name. slowly or stations will be missed. A little practice will make perfect on Exclusive ability of Erla Electrical Research Laboratories tuning. audio transformers to ampli fy three stages without dis Dept. U 2515 Michigan Ave., Chicago If a howl is encountered it may be tortion assures improvement due to low A or B batteries, rheostats in any receiving set. List, $5 Vealers and lobbers-Erla turned too low, or the use of too large products turn over rapidly. reducing capital invested a by-pass condenser where the .00025 and increasing profit. Send mfd condenser is indicated in the cir for liberal scale of discounts cuit. Changing to a .0001 or a .00015 fRiA will improve this condition, but too low a value will lessen distant signals. Page 190 ~Radio Joutnal~ April, 1924 ]\,Ir. VI!. S. Percy, the well-known Are You in Doubt? . stage comedian and etcher, who was lately in Au trali a as a member of a THEN BUY CROSLEY SETS J. C. IVilliamson comecly company re BETTER - COST LESS! cently broadcasted from London a spe ciall y written play entitl ed, "The Man \ Ve hm'e nine different models.-List P ri ce Who \ Vould Sing in His Bath." T o $17.60 to $132.00 add realism to the piece, a thousand guinea bath-room, situated in the Sa COOK .. NICHOLS CO. Yoy Hotel, was commissioned, and it 411 So. San Pedro Street, Los Angeles. Cali f.-Trinity 1350 was from there that the splashing of Pasadena Branch: 482 So. Fair Oaks- Phone Fair Oaks 1578 water was hea rd o\,er the countrv_ In WHOLESALE ONLY an in terview with the London repre sentati\-e of the Sydney Sun, Mr. Percy said: "I took the opportunity of "I rehearsals to go into training and so !" I shouted into the microphone. The Get DISTANCE with COAST COILS engin eers were alarmed and rushed in COAST REFLEX COAST COUPLER and said I wou le! burst the machine unless I was more careful. I thereupon 'Coils, adaptable to one tube re A wonder for distance and select spoke fr0111 eiglJt feet away_ I have flex sets, 'or two tubes for select ivity. Nothing like it. vVe make hea rd of a man breaking a camera I ivity, give remarkable results. it, guarantee it and sell it with a when he was photographed, but I did Factory guaranteed. Mailed any- "real hookup." Mailed anywhere. not think it possible to burst a broad where. $3.00 per. ~ 00 perr caster with a ,"oice." Patr $5. Coupler South of l\TLillich, Bm-aria, is the mountain Herzohstancl, on the sum ICAST: IDUPLE~ !OMPANf m it of which i being erected a huge MANUFACTURERS and DEALERS wireless station, which wi ll li ft its an 245 East Seventh Street Long Beach, California tennas higher than those upon the •••••• a •• __ ••••••••••••••• ;.. Pari s E iHel Tower. On the other side of the valley, from the 6,000 feet high peak, is another Distance, Volume, Selectivity eminence almost as high. From these two peaks is swung a long wire cable, 5 .. Tube Tuned R. F. Set R .. 305 by whi ch means the costly construc tion of steel towers is avoided" while Dealers Write U s for Discounts the stupendous electrical energy re quired to work a stati on of this nature Excell Radio Mfg. Co. is developed from water power. On account of the great weight and 4615 Moneta A venue, Los Angeles, Cal· length of the cable, together with the strength of the wind-pressure, an in LOS ANGELES DEA LERS: genious system of counter-weights is Parmelee"Dohrmann C o. H ome Electr ical Specialty Co. M elody Shoppe used to compensate this. T he sides of the peaks away from the valley are gently inclined, and easy to climb, but those which form its inner walls are almost in accessible, and make the lo OUR 5-TUBE RADIO FREQUENCY SET cality an ideal one for radio purposes. Is bringing pleasure and entertainment to hundreds of passengers E. IV. Vogel. a marine wi reless o on the palatial steamshi p ', the "Yale" and the "Harvard", plying be perator, recently picked up and took tween San F rancisco and San Diego. down in full a radio telegraphy mes We feel a pardonable prid e in the fact that a two months test of our 'age transmitted from France while Radio F requency set on the "Harvard" brought us the order fo r iden hi s ship was omewhere in the 180th tical eq uipment on the "Yale." YOU may own a dupli cate of these sets. meridian in the Pacific. This meant that the sending station was over 12,000 miles away-half-way round INSTALLED IN YOUR OWN HOME the earth. The feat is thought to be Complete, with tubes, A and B Batteries, Loudspeaker and pair of a worlel 's record fo r long-distance re head phones for ception. $176.50 T here are some 290 radio stations in Russia, Moscow being the center with Llewellyn's Electric Appliance Shop three very powerful broadcasting and telegraphic sets. O ne is Shabalovs k, 613 South Spring St. Phone TUcker 4884 Los Angeles, Calif. (RAJ) callecl Mossoviet; with a power The Most Central Location in the City of 150 kw.; the central radiophone station of Kodinsk ( RAr) now called October. Page 191 April, 1924 -~~Radio Joutnal~ A new method of determining dis according to Stephen B. Davis, Soli tances at sea was descri bed by George citor of the Department of Commerce, Lewis, assistant to Powel Crosley, Jr., who discussed the subject at a meeting :C'fhe Complete Ejjicie:d of the Federal Club of the Bureau of in a talk before the Ohio Academy of Standards. lAnd Economiml Jlerial Science at Columbus. Mr. Lewi s was 1\1 r. Davis stated that while common a li eutenant in the United States Navy law was based almost wholl y on pre and holds the first li cense issued to ra cedent, it often was modi fied by court ANTENEllA dio operators. For several years he decision to meet new conditions, such No Aerial or Antenna Needed as have been created by rad io and air had charge 0 f experimental work for craft. VI" n y pay the nayy. " :\ specially designed radio $10.JO or more transmitter sends out a series of clots, ,to h a v e an one second apart, \'Ich ich, used in con The Bureau of Standards is trans aerial spoil the nection with the sound 0 [ a bell thru mitting special signals of standard fre appear ance of your home? the water, enables the observers on a quency about twice a month. The last ship automaticall y to determine their AnleneJJa elim previously announced schedule was linates all un- distance from a giyen object, such as published in the March, 1924, issue of 125 sightly wiring, a shi p or shore." $ 1 i g h tning ar the Radio Service Bulletion. T he next resters. etc., and precludes the Does it terference with radio waves schedule is announced below. T he sign p o ~ sib i iity of dan g e r 0 us grounding on a power line. It carrying a senuon constitute a yiola al can be heard and utilized in general also stops "canary bird" re ti on of the Kansas law prohibiting in east of the Mississippi River. These radiation from nearby asciI· terference with rel igious worship. special signals of standard frequency lating sets interfering. That is the question that has been are of use to testing laboratories t rans submitted to Attorney General Griffith mitting stations operators, and others ANTENELLA by the congregation of a little church in standardizing wave meters and ad is not only a real distance getter at Norway in Republic County. T his justing transmitting and receiving ap but also successfully overcomes church is without a pastor at present, paratus. The t ransmissions on June 5 static annoyances, but the tru tees of the church ci eterm will be of special interest to ship oper A l } 0 01:'- c.I~i11er. otherw ise ined to continue the regul ar sen ·ices ators, those on July 7 to amateurs. All Sf! n t fJu 'l"ch.t."'e p..-ice ~"\",d you every Sunday, so they installed a radio transmissions are by unmodulated con W l { be supp lied postpaid. rec.eiving set and have been getting the tinuous-wave telegraphy. A complete f~t1S" ~reshmcm 10. Inc. services f r0111 O maha. frequency transmission in cl u d es a \f..caolo! Condenser ~oducts "general call", a "standard frequency 10n Seventh Ave. New York Legal questions ari sing out of in ter signal" , and "announcements" at eight ference between users of radio could minute intervals from 11 p.m. to 12 :32 probably be settled by common law, a.m. eastern standard time. I'atI·onjze Radio JOlll'nal Adve l'tisCl·s, A $200,000,00 COMPANY '5 ,STANDS SQUARELY BACK [ial=~" !!I" EVERY , PHONE wORLDs ~~ GREATEST 95 HEADSET VALUE , ?; 1f.@~ 0: , • Five-Day Money-Back Guarantee If Not Fully Satisfied . We Guar 9lus u/euJ cents postage antee the Scientific to be 1. One of the finest phones on the market r egardless of price. 2. The most comfortable--weight SEND No MONEY only 8 oz. 3. Perfect tone mates. Order by mail if your dealer cannot supply you and we will ship 4. Made of standa rd double pole immediately. Written 5-day money back Guarantee with each set. construction (no single pole Our next year's production schedule of two million phones UN· nonsense to save expense.) 5. Made of the best materiah DOUBTEDL Y places us as the money can buy. Powerful m agn ets, genuine tinsel cords, aluminum cases. WORLDS LARGEST HEADSET MAKERS 6 . Manufactured under ideal working conditions. THE TOWER MFG.CO. 98-M BROOKLINE AVE., BOSTON, MASS. '0 Page 192 . _------zt-.Rad.to Joutnal ~ April, 1924 SPARK TRANSMITTERS New interest in radio in Canada is 75 ,",V utt, Portable. revealed in figures issued by the D o~ Made for U. S. Army Aer opl a n es minion Department of Marine at Ot Government Cost $45.00 each Our Price $5.00 E:teil tawa. Since December last eleven li A 1U EIU CAN SALES AGENCY censes for broadcasting stations have' 3S Park Row New York City T e l. Cortland 5181-2 been isued by the department, making a total of forty-five broadcasting sta ti ons in Canada. T he new stations are, Patronize R a dio Jout'nal Advertisers. by provinces: Ontario,S; Nova Scotia, 1 ; Quebec, 1 ; British Columbia, 2, and . Alberta, 2. STOP INTERFERENCE With the double wound ske1eton coil that is u sed in three popular wave tt-aps. Nolte wave Station CYL, at Mexico City, has trap inductance. Your dealer or postpaid $1.25. been heard in many sections of the NOLTE MFG. CO. 63 Gautier Ave. Jersey City, N . J . U nited States. The station has been on the air every night· since December. It is rated wi th a power of 500 watts. ONE TUBE-ONE CONTROL All broadcasting is done on a wave AUTOMATIC REGENERATION 150,25,000 Meters length of 500 meters, and the programs AND AN AUDION , ULTRA-AUDION coqsist of news bulletins and music. I • HOOKUP R h eostat, Storage Battery, Varlo coupler, Variomete r, 3-coil Mount NO ing Va riable Inductan ce, T aps. HORN: Dead End Losses or Radio Frequency. Has cl ea r, natural lone and an excep tionally COmPlete Hookup, cuts, instn.lctions, fin e appeara nce . Yo ur re- everythin g . Nothing left for you to guess ceiver fil s in busf.. Ma il a $1 about. No stamps or checks. Budd your This is DO·t~ C. Wallace, 54 .Penn Avenue doll ar bill for horn li ke pic- 00 own r eceiver and save 50% or more and N ., JlIlinll capolis, Minn., olle of the best ture. knocked dow n. prepa id . = get b etter r esults. RADIO EXPERI Imown 1'adio alllotC1lrs in th e Unitcd States Ell sily assem bl ed by anyone. M.ENTAL LABORATORY, Box 194 H, Berkeley. Cal. alld winner of the Hoover wp. His calls are FOX MFG. COMPANY, DEPT.M 9ZT and 9XAX. 247 So. Broadway Los A ngeles, Cal. The San Francisco studio of KGO in 10 INITIALED BINDING POSTS $1 "RADI O" "RADIO" Beauties-Sent anywhere by mail on receipt of the Hotel St. Francis was to be fo rm price. Fine panel design and 100 Station LOIr BOB HERNANDEZ ally opened on Wednesday evening, Free. P anels driUed. Wood for beautiful cob· inets cut to size, with instructions for assem Special Sets Made to Ot'der May 28, at eight o'clock. Ralph Mc Let me quote you on any circuit. bling and finisbin!( like rosewood or maholrany. Laren, acting Mayor of San Francisco, Will secure any thin&" you ..ant 10 the Radio 2034 Sunset Blvd. P hone, Drexel 1142 Line and sbip by parcel post, C.O.D. Send u. Los Angeles, Calif. was to speak. The KGO Grand Opera your orders. Satisfaction ruaranteed. Company, under the direction of Carl MAITLAND AND SPENCER ROACH New Words! New Words! Anderson, with Florence Ringo, Blan 2905 Columbia Avenue. Philadelphia, Pa. che Hamilton Fox, Gregorio A rtieda, thousands of them spelled, Marion Vecki, and Elsie Hilton Cross pronounced, and defined in in the cast were to produce "Cavalleria WEBSTER'S Rusticana" with Augusto Serantoni New INTERNATIONAL conducting. Radiola Ground wires under San Francisco Dealers DICTIONARY Bay connect the San Francisco studio and The "Supre11l; Authority" Get the Best! with the control room and power house Distributors of KGO, located about ten miles away on East 14th Street and 56th Ave., CALIFORNIA Here are a few samples: Oakland. With this arrangement, it is abreaction agrimotor soviet possible to produce a number on a pro Paul Franklin Johnson hot pursuit cyper rotogravure gram in San Francisco, and so quickly Air Council askari capital ship switch to the Oakland studio that lis 560 E. Colorado St. mud gun sippio mystery ship teners will not be aware of the change. PASABENA, CALIF. Ruthene sterol irredenta Complete programs will be given by "Everything W orth While in Radio" megabar Red Star Esthonia San Francisco talent from time to shoneen Flag Day paravane time, and prominent people stopping in NEW JERSEY S. P . boat overhead Blue Cross San Francisco will be asked to speak aerial cascadc to the KGO audience. camp-fire girl Tri-City Electric Co. Is this The West Indies, Bermuda, Cuba, 52-56 Lafayette Street Storehouse of Haiti, Canada. All in one day's mail. IlIfor11latioll Although the Chicago Tribune-Zenith NEWARK, N. J. Serving You? Broadcasting Station \~ . G . N . located on the Edgewater Beach, Chicago, is MINNE SOTA used to distance communications since 2700 Pages. 6000 Illustrations 407,000 Words and P hrases its establishment of a world's record by Gazetteer and Biographical Dictionary confirmed reception in several Austra STERLING ELECTRIC WRITE for a sample page of the N ew lian cities, the studio staff experienced COMPANY W 01'(j.s, specimen of Regul ar and India quite a thrill when from one morning's Papers, FREE. mail delivery letters were extracted MINNEAPOLIS, MINN. G. & C. Merriam Co., bearing postmarks from the five coun Springfield, Mass., U.S.A. tries named above. April, 1924 . Page 193 ---....-----z--Radio JOll'tnal ~ Radio fans have discovered that it is fi rst successful re-broadcasting Df a E nthusiasm for radio telephony con s tatic of the mind-not static of the air concert from an American city. CKY tinues to grow throughout Great Bri - that has given credence to the myth also claims possession of the greatest tain, according to Acting Commercial 1n past summers, that radio was largely number of wire connections with Attache Hugh A. Butler. Up to March a seasonal feature. This was the key churches. theatres. skating rinks, dance 1, 1924, over 600,000 licenses for re note of a recent conference held by a halls, etc. ceiving sets had been issued. group of prominent radio men in New England, with Elmer E. Bucher, Chair man of the merchandising committee of the radio section of the Associated Manufacturers of E lectrical Supplies which includes in its membership all TRIMM PHONES the leading elements in the radio in dustry of the U nited States. ,Vere selected by MacMillan on his trip "Statistics and reports discussed at to the N orth Pole. A safe and sure i 11- this con ference developed many start strument to use at all times for clear re ling facts concerning radio", declared ception and to bring in faint distant sig Mr. Bucher. "Did the average Ameri nals . can, who has kept abreast through the . . . . $5.00 newspapers of the latest developments in the radio art, expect to forego the "Professional" Headsets . ______$7.65 pleasure and profit of radio reception "Dependable" ______!_ 5.00 whenever there happened to be a stray "Giant" Phono Attachm ent ______10.00 interloper in the air ? He did not, it was "Little ' '\To nder'' Phono Attachment 4.50 agreed. " ~ ~'S tandal-d" Loud Speaker ______22 .50 "Home Talker" ______. ___ 12.50 Among Canadian records claimed by the Manitoba Telephone System's sta For Sale at All Good Dealers tion CKY are the following :Broad· casting of the first service from a church; the greatest number of church Carl A. Stone Company "LITTLE Pacific Coast Distributors WONDER" services to date; the first regular series UNIT $4.50 of Agricultural College talks and the 644 New C all DIdg-. greatest number to date; the first 1113 S. ' V all St. San Franeiseo, 1116 lUinor Ave., broadcasting of speech received over a Los Angeles, Cal. California Seattle, ' Vasil. long distance telephone line. and the Portable Roffy Circuit No.3 with Power Amplifier ,., w+-,------.------, ., +--1'------t------, I, ROFFY '" Circuit No. 3 B The fundamental diagram of Roffy Circuit No. 3 was pub lished in the February issue of the ,., Radio Journal and as in all cir - Build Set Reading Right to Left cuits the professional fine touch makes the Circuit keener, more fle xible and s h a r per. T he fl ood of inquiries on the 111 a s t e r set prompts the publication of the Circuit in detail. The experi No.3 menter is cautioned against imita Transformers tion Roffy T ransformers. Prefer $ 8.50 U . S. Tool Condenser, Amer Tran Audio, K ing Sockets and a t All Dealers Bradleystat for best results. Roffy Circuit No.3 J. T. ROFFY 725 State Street P. O. Box 94 Huntington Park, Calif. ~IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111 111111 11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111 IIIIIIIII IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIE Page 194 ~R.adlo Joutnal~ April, 1924 wire connecting the extra stage of radio to the aerial post of the set. Further Helps on Moise Re~ex Sth-\ iV hen tuning with the extra By Alfred H. MOISE, R.E. stage of radio amplification set the Moise U nit No.2 for verv weak os RACTICALLY all of those properly connected these currents are cillation and you can pi ~ k up the from whom I have heard who in phase and working together make whistle of stations as you cross their the second tube a more powerful am carrier waves. Of course keep unit Phave tried out Moise Reflex cir plifi er than the usual refl ex second tube. No. 1 set for regeneration just short cuits as described in the last is 3rd-Follow the accompanying dia of oscillation if very best results are sue of Radio Journal find the straight HR I ~I- Moise Reflex by far the best with 199 or 299 tubes, and there seems to be a feeling that the Moise Harkness hook 1-.------r_+J3 QO v up is better for A tubes. T hi s is reall y due to the fact that A tubes are more easily set into oscillation than 199's, thus making the regenerati on control or A T ubes more critical than in 199's -.B in the straight Moise reflex. ----~~----~~----_J--~==~~+ A ~~~V 199 tubes n e~d the extra tendency ~------~------~~------~------4 -A L-______~ ______-e ~~4R~ 9y toward oscillation found iil the Moise '----+-'---.:r-...-~ctRO\JN)J reflex and it is due to this, with the refl ex units control that 199's practic ~)J } r1 015(> Reflex U",fs all y do the work of A tubes. First I 0 1 will answer questions ' which seem to S.v dclt to rJ'1lrf Whl'l1 I/Sltfy e ){trc, s t4je of rc.q', o bother some 0 f the experimenters. 1st-Most audio transformers of 4 gram and have an extra stage of radio wanted, and a fter you have tuned in or 5 to 1 ratios function well in this which can be kept connected though your station adjust unit No.2 slightly circuit. A mong the particularly' 'satis not necessarily in use. to make the refl exed tube just stop os factory ones of medium price which I By taking the aerial wire off the cillating. have used are Modern and Hegehog. extra stage and connecting it to the 6th-The set will sometimes work 2nd-The second audio transformer aerial post on the reflex set, and throw better with the primary of the first in the Moise reflex circuit has two sets ing the switch to the left the set func audio transformer reversed from the of audio frequency currents in its pri tions as a two tube refl ex. It is advis connections as shown in the accom mary. Of course when everything is able but not essential to disconnect the panying diagram. TONE TRUTH At last...... a set that doesn't tell you that a violin is a flute ...... that a piano is a harp and that a] 1 announcers have a bad cold. Neutroflex III THE NEUTROFLEX " ;,1 t '!\':, never draw r: ------I C. D. TANNER CO. 528 \ \T . W ashi ngton S t. C. D. Tanner Co. I Los Ano:olc5. Calif. I P lease ship me C. O. D. 1 set -i\cutroflcx Transformers $]2.5 1 ~ I ] Com plete Knockdown ki L ...... 50.00 I 5 28 West Washington (Cross out order not wanted) I Kame ...... D ealers write for A ddress...... I p roposition NEUTROFLEX TRANSFORMER ;m; I Mounted on Kilbourne and ClarkCondenser L.C :. ... =.... ~ ~ _... := ... =... --1 il~mmmHHmmHmmmmHm~ ~ ~!~mmmHm~~~~~m~~mmmm~~~immmnmnmiH~i~n~ mmmmm~i~nmmnmmi~mnm ~ ,n~ m~i~imm~~~~HmmimmmJj:: 1 April, 1924 Page 195 7th-Accompanying sketch shows winding off the Harkness T2. The Catalogs and price lists for Amer how to mount the Moise Reflex unit. Moise reflex unit can be mounted at ican receiving sets and parts for ama It is better to have the coil up dose to either end of coil L1 but the grid con teurs assembling are wanted by radio the unit. nection should go to the same end as enthusiasts in India. Firms interested 8th-I do not know of any circuit the result. are l'equested to send such literature T he following parts are recommend to the A meri can T rade Commissioner, ed for building this refl ex thirty ohm James E . Miller, Esq., Room 29, Gros rheostat, 2 sockets, 2 seventeen or vernor I-louse, 21 Old Court House twenty-three plate variable condensers, Street, Calcutta, India, who will be 1 Moise reflex unit, 1 Moise To. 1 an glad to make it available to those in tenna coupling co il , 1 Moise No.2 re terested. jector coil, 1 7 x 12 panel, 2 three-inch dials, 1 crystal detector with high grade crystal,S binding posts, 2 4-1 or 40-1 audio transformers, Modern or other MA JONG other high grade, 90 volts B battery, The great and fascinating game that 2 UV199, UV201A or C391A tubes, everybody is now playing. The talk of the country. A battery to suit tubes, loud speaker, At last a compl ete set including 144 cabinet, C battery 4 0 volts, aerial and tiles, 4 wi nd s, 11 6 counters. 2 dice. 8 paper ground. racks and in struction book, all in a pretty colored box. I am always glad to answer questions Contain s everything necessary to play accompanied by a stamped self-ad the game. A II of the above d ressed envelope. F R E E with your new or renewal subscription to O n April 2 Tamaki Miura, Japanese opera singer, actuated the mi crophone RADIO JOURNAL of stati on KYVV, Chicago. Her voice or send SO cents 'for the was heard as far west as Hawaii. She Ma j ong set alone. promi sed every li stener who acknow Send stamps, coin or checks to Radio j ournal. 11 3 Stim son Bldg., Los Angeles, better than this fo r con!) istent combinea' ledged reception of the program that Cali fomia. quality of reception, vo lume, di stance she would send an autographed photo on two tubes and selectivity. g raph, and up to the present time Name ...... Harkness co il s can be used though 10,000 letters have been received. they are not as efficient in this parti Street ...... cular circuit as Moise coils, nor quite Radio receiving sets in Denmark City ...... as selecti ve. For L2 strip the primary now number 3,109. The New Improved Advance Unit Charger A NECESSITY FOR EVERY OWNER OF AN AUTO OR RADIO SET SIMPLE - EFFICIENT - ECONOMICAL \\Then your hattery needs charging the Acl\'ance 'Cnit Charger may be connected to the ordinary alternating lamp socket and your battery wil1 be charged O\'er night. Radio owners find this charger adds to the pleasure of operating set. It is not necessary to move the battery when Ll snig the Ac1\'CL llce U nit Charger. Most efficiellt, rigid and simjJle constru.ction. Will stancl rough use without damage to parts. Very compact. Size live inches square. ONLY ONE WORKING PART. Self polarizing, which mealls that the battery muy be con1lectecl to churger either way, or polarity. "';'ill not injure the battery, if left on too lOllg. GUARANTEED for ONE YEAR AGAINST DEFECTS. Price $18.50 "Ask Your Dealer." Manufactured by ADVANCE ELECTRIC COMPANY 1260 West Second Street MetrojJolitan 5990 Los Angeles, California Page 196 ~RadIo Joutnal~ April, 1924 Classi ied Follow these advertisem e nts every month. Reliable advertisers from all over the country offer their most attractive specials in these eolumn8. Objectionable or misleading advertisements not accepted. Advertisements r eceived too late for current issue will be accepted for the IMue following . Name and address must be include d at the above rate. Cash should accompany all classified advertisements unless placed by an ac oredited advertising agency. No adve rtisement accepte d for less than 4 lines. Classified Advertising Rates, 5c per word. Time discounts for consecutive insertions; 3 times, 5%; 6 times 10%; 9 times, 15%; 12 times, 20%. Minimum charge, $1.00. PERSONAL IF YOUR NEUTRODYNE won't "Neut"o.k., send 10c for details of Kladag Coast To Coast OPERATE A TIRE REPAIR SHOPI-Bi, Pro INVENTORS: PROTECT YOUR INVENTION Circuit, bill of materials, etc., to change over fitsl Oldham made $2,200 in 4 month.. Evan. through A. M . Wilson, Inc., W ashington, D . C. your Neut into a set that will bring them all in averages $1000 week. We teach you and fur Over 25 years of efficient, expert, confidential from l\1exico City to TUIlUCU, Cuba, on a loud nish full equipment for $100 up. Write quiek. service. Skilled in Radio·Electrical, Chemical speaker. Or send $5.00 for all extra parts, blue Haywood's 1331 South Oakley Ave., Chicago. and Mechanical fields. Our new illustrated Pat· print, etc., you need to do this. Uses same panel ent Book, givin" much necessary and very useful layout. Stamps accepted. Radio List for stamp. SCHOOLS information which every inventor should know, Kladag Radio Laboratories, Kent, Ohio. will be sent free upon r equest. Prompt and TELEGRAPHY-BOTH MORSE AND WIRE careful attention. Highest references. Moderate EDISON ELEMENTS for storage "B" batteries, LESS taught thoroughly and quickJ.y. Trem",,· fees. Send sketch or model for our careful six to ten cents per pair postpaid, dependinl" dous demand. Big salaries. Wonderful oppor opinion and preliminary advice. Write today to entirely upon quantity ordered. I handle ong tunities. Expenses low; chance to earn part. A . M. Wilsol1, Inc., (Radio 3ARH), 325 Victor strictly first grade full capacity elements. A. J. School established fifty ,.ean. Catalog free. Bldg., Washington, D . C. Hanks, 107 Highland Ave., Jersey City, N. J. Dodge'. Institute, Caur St., Valparai.. , Ind. A WONDERFUL CRYSTAL SET-Can hear all RADIO FANS AND PROFESSIONALS-How PRINTING over Philadelphia, and sometimes outside Phila many of you know the correct CODIFICATION delphia. PTlce with phones $10.00, w;thout of all characters, punctuations and siena (such AI RUBBER STAMP with large call letters SOc; phones $4.00. ". Receiving sets $25.00 to $200.00. $, per cent, etc). We dare say that nine out Radiogram and Relay Radioli'ram blank. 25c Guaranteed of money back. Send money order, of ten don't know them correctly lOur in.truct per hundred, Post Card 60c hundred. Send us Williams Radio, 2339 W . 8th St., Philadelphia, or who has had 3S years' experience, ei~ht yearl 1_our order.. Carolina Printing & Stamp Co., Pa. of which were with Uncle Sam as MORSE and RADIO TELEGRAPHER, h". just J;>ublished Wilmington, North Carolina. FOR SALE-Crocker Wheeler motor generator rewound ISO watt., 1000 volts speed 3600 $75.00. ;hetr~~st a~dd c~~~~ctC~t~jF~CATI6l-/':t lill CALLS HEARD POSTAL CARDS for DX re Esco 500 watt, 1000 volts speed 1750 new characters used in both codes. This CHART i. port.. Station call letters in color. P.rinted on I~O.OO . Travis Radio Laboratory, 102 Diaz St., indi.pensable to all up to·date beginners and yet· !!overnment or plain postals. 80c hundred up. Antonio, Texas. erans alike. Fifty cent. (money order pre ·Used Everywhere--Go Everywhere." Write ferred) will bring CHART, also much in for samples. Radio Print Shop, Box 582, Ko GUARANTEED U P -TO-DATE, Radio Repairing, formation extremely i"tereBting to BOYS and komo, Indiana. Rewiriljg and Rebuilding. Send us that set which GIRLS; because, with this Inl'>rmation and a is out of order or will not work. Prices reason.. little PEP on your part, you can qualify shortly able.-RADIO SERVICE SHOP, Atwood, Kans. (as scores of our graduates have done) and .e- RADIO EQUIPMENT cure positions paying $1,500 to $3,000 yearly. FOR SALE (See Civil Service Bulletins 21 5, 357 and 54.) C.W. AND RADIOPHONISTS:-One hundred We are registered with the U. S. C. S. Com. at Ohio and Wagner 110V. sixty cycle A.C. syn A. B . C . of Radio by Waldemar Kaempffert Washington, and can help you. AMERICAN chronous motors built in ~ A .P . frames with over 500,000 copies sold at 25c. a copy. One TELEGRAPHIC STUDIO, BOX 793, WOR· ~ " shafts are yours for $18.00 each F.O.B.., of best beginne rs' r adio books on market. CESTER, MASS. lluffalo, N. Y. Original selling price $28.50. Special price 16c. each, postpaid. Western We also have the parts to attach to these motoTi Radio Supply Co., 418 Stimson Bldg., Los AGENTS to make synchronous rectifiers which will handle A ngeles. 2000 volts. Kimley Electric Co., Inc., 2665 Main AGENTS quit your worrying-make $50 daily seil St., Buffalo, N . Y. ing 4-in-1 Auto Direction Light, one that every MISCELLANEOUS body buys. Glover Mfg. Co., 659 Canton, De COUPLERS, 80 turn $2.00, 90 turn $2.25, 110 t roit, Mich. turn $2.75; variometers $1.50; complete tuners ONE MILLION GERMAN MARKS either hund $10.00. We make all kinds of coil. to order. r ed thousand of fifty thousand denomination. Special prices on sets. Stiles-Perry, Deposit, Genuine guaranteed currency. Fifty cents. Agents N. Y. wanted. Write or wire wholesale price.-Di Foti, RADIO BOOKS 561 Washington St., Akron, Ohio. E ngineering, Indlistrinl, Technical and WIRE TERMINALS-ISO assorted $1.00, 20 two Scientific Books foot lengths No. 14 square tinned busbar $1.00, FOR SALE-C.W. and Phone Transmitter , 10 10 two foot lengths No. 10 special round bu. TECHNICAL BOOK CO~IPANY watts. E lectric Specialty 100 w., 500 volt gen 1tlills Buil(ling, S:tn Francisco, Cal. bar $1.00. Sellfl for sample.. Immediate ship. erator, 110 volt 50 cycle motor; $100 complete ment postpaid on receipt of remittance. Radlo with tubes, microphone, key, buzzer, etc. Addresl Representing Engineering Co., 55 Halsey ~t .. Newark, N. J . Box B·42, Radio Journal. D. Van Nostrand Co., John Wiley & Sons, Inc. J. B. Lippincott Co., Longmans, Green & Co. RADIO BARGAINS-Any $6.50 Tube $5.75 ; Homespun T obacco-Chewlng-5 Ibs, $1.25; Erla Reflex Transformers, any type $4.50. Bur· 10 Ibs., $2.60; 20 le8., $4.50. Smoking, 5 gess 2156 Batteries $2.50; Brandes SuperioTi Ibs., $1.25 ; 10 lbs., $2.00; 20 lbs., $3.50; 5.25; Signal 23 Plate Condenser $1.75. Every Farmers' Union, Mayfield, Ky. At Last! A Practical Aut.horitive thing Guaranteed Perfect. Write for list. Ed ward Bromley, Jr., Whitewater, Wis. BOOK on MAIL ORDER METHODS-$50 WEEK, RADIO IVORY RADIO PANEL: White pyralin ivory evenin gs, I made it; mail order business. 562 pages. Price only $1. Compiled by make. the 1D06t beautiful set of all. Guaranteed Booklet for stamp tells how. Sample and HARRY F. DART, B.S., E.E. Formerly satisfactory. AI1+' size 3·16 inch thick. Three plain, 25' cents. Free 12 articles worth $3. with the Western. Electric Co.. and U. S . cents per square inch. Sample sent. E. P. Hal Alraj S cott, Cohoes, N. Y. Army InstructO&' of Radio. Technically edit tom, 614 Main, Dept. J., Fort Worth, Texas. ed by F. H. DOANK. WE SHOW YOU HOW TO EARN BIG MO The most complete boGIe of its kind ever FOR SALE-Omnigraph, IS dial, new $20. Trans NEY easily with our casting forms making published. \\'ri tten , compiled and edited by formers, Audio UV712, Radio UVI714, $3.50 Whistling Birds, Wild Animals, Crowing Roost- practical radio expert! of national reputa each. Paragon sockets and type UR542, SO cents ers, Automobiles, Baseball Players, Statue of tion. Packed with concise, sound informa.tion each. Paragon rheostats, 7S cents each. Ellison Liberty, Indians, Toy Soldiers, Cowboy., Bark useful to every radio fan-from beginner Thompson, 1301 Findlay Ave., New York. ing Dogs, Wag Tail Pups, Miniature casting of to veteran hard-boiled owl. Hundreds of Capitol, Bathing Girl Souveniers and others. illustrations and diagrams to make every GREATEST RADIO VALUE.-Fully Guaranteed No experience necessary. We furnish you with point clear. Crystal Sets complete, SOc. Free with "Little molds and necessary outfit from $3.50 up. We Tattler" head phones at $4.00 postpaid. Mail Order buy large quanti tie. of finished goods at highest Send $1 today and get this 562-paire I.C.S. De.oartment, Electric Novelty Co., Lincoln, Nebr. prices. Spot cash. Send for catalogue and Radio Handbook before you spend another information free. The Improved Metal Castine cent on parts. Money back if not satisfied. SET OF THREE LATEST TYPE Ancore R F Co., 342 East 145th Street, New York. Transformers for experimenters' information serv· ice Super-Heterodyne. Price $25 for set of three. TEAR OUT HERE AND MAIL TO Address: Box 4, Radio J oumal. LEARN CHEMISTRY AT HOME.-Dr. T . INTERNATIONAL CORRESPONDENCE O'Connor Sloane, noted educator and scientific SCHOOLS-714 SO. HILL ST .. SUITE PACIFIC COAST STATIONS are heard in authority, will teach you. Our home study cor· 410, LOS ANGELES, CALIF. Pittsburgh with vario·coupler and two Rogers respondence course fits you to take a position as Receiving Radiometers (Condensite molded vario chemist. See our full page ad on page 295 of I enclose one dollar. Please send me post meters). Radiometers $4.00 each. Postage pre this issue. Chemical Institute of New York, paid-The I .C.S . Radio Handbook. paid. Rogers Radio Company, No. 5133 Wood 66 W est Broadway, New York City. worth St., Pittsburgh, Pa. Name __. ______. __.. _. ___ . ___._._ .. ___0 _____ •• __ •• ______._. ______• __ W ANTED-lnvestor with $5,000 cash for one of FOR SALE- 1500 mile guaranteed Tube set, $10. the most meritorious business propositions on the L. Young, 910 Strand, Hermosa Beach, Calif. Pacific Coast. Paying now,-increasing every Street ...... month, with an unlimited future. Investor may FOUR CIRCUIT COCKADA Y, COMPLETE, be silent or active, man or woman. Glad to answer City for sale, $105. Tubes, speaker, all batteries. all inquiries. Address : BUSINESS, P . O. Box Address, DX 1200, care ot Radio Journal. 1056, Los Angeles, California. Page 198 ---~-Radlo Joutnal ~ April, 1924 This $10 Stentor Speaker FREE with FREE with 5 Subscriptions 5 Subscriptions to Radio Journal to Radio Journal , . Bring in the wonderful things of r a d i 0 1 and as you have never brought them in before. We are giving away t"his wonderful Stentor Advance Fixed Anything You Want Supe1'-S peaker unit, which for tone Crystal We have dials, sockets, quality, audibili ty and sensitivity is jacks, plugs, variometers, unexcelled, and we want to give one variocouplers, variable coti~ to you. It is making a big hit with densers, crystals, grid leaks, by-pass condensers, audio broadcast listeners everywhere. transformers, radio trans How to Get it Free formers, reflex transform ers, reflex coils, neutrodyne This Super-Speaker embodies a condensers, - in fact any new and novel application of the thing you want to complete C antileve1' principle. Handsomely Actual Size your set. And we are giving finished in nickel, it is just the them away with subscrip speaker unit you have been longing This $1.50 Advance fixed tions to Radio Jo urna!. crystal, molded bakelite base for. It sells for $ 10. We will send nickeled binding posts, spe Write for what you want it to you free) if you will make up and we will see that you get cial tested crystal with an it. It will cost you nothing a club of five ( 5) yearly subscrip i8-K gold poir~t ,-guaran but a little spare time. tions to Radio J ournal, at $2.50 teed, - free w~ th one sub each. Send us $12.50 with the scriptJ:o lt new or re/l ewal. names of five subscribers, new or renewal, and the speaker is yours. Your own subscription will count. Yes We Are Giving Away Phones Also You can get the best phones made by devoting a few moments to getting sub scriptions for Radio Journa!. Let us fit A radio concert in any room in you out with Baldwins, Western Electrics the house-think of it. Just or any other. We will send you a set of screw this Antmella into an electric socket anywhere, - no the wonderful Trimm Dependable phones aerial, no bother. Renew your for three subscriptions) or Trimm Pro subscription now, or send us a fessional phones for four subscr'iptio1!s. friend's subscription, and we Any others you want, write for list. will send you an Antenella free. If there is anything you want and are willing to do a little work for, write us and we will get it for you. RADIO JOURNAL PUBLISHING COMP ANY 113 Stimson Building Los Angeles, California April, 1924 Page 199 KGO, the new Oakland station of ·i-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:.. :-:-:-:-:-:-:-:-:-:-:-:-:-: .. :-:-: .. : .. : .. ~ the General E lectric company, has al V V ready established a place fo r itself in :!: The Pair Which Makes D. X. Stations Easy:!: the sisterhood of broadcasting sta V v tions. From vessels in the Atlantic :i: Phipps Super Coil :i: to Honolulu and vessels in the Pacific v v 't' $1.00 per pair 't' have come reports of the station's re t ~y V ~ v ception, as well as from all over North : N y V ~ V America. T he new station is the most V ~ v powerful 0 11 the Pacific slope and is a :i: For All Reflex ~ ~ :i: bit unique, as broadcasting stations go. :i: Circuits ~ ~ :i: Using power of 1,000 watts, the sta .:. ~ (It) .:• • :. Coo.: 't' tion is situated far away from any V V masses of absorbing structural steel V v and the like. T he structure in which ::: SPECIALS ::: it is all housed is built specially for 't'f Mounted Crystals ...... 10 3 T ube Re fl ex, complete ...... 48. 00 't'f KGO, and the appointments through 't' 23 Plate Condensers ...... 1.25 4 T ube Reflex, complete ...... 54.00 't' out are handsome. :::, AFSocketsT ...... f... :...... 225.25 2 Tube Re" flex, comp I et e...... 45 .00 :::, 't' . < . rans ormers ...... 1 T b R fl I 39 00 't' The antenna system is supported by 't' P hones ...... 2.98 u e "e ex, comp ete ...... 't' two steel towers, each 150 feet high :i: H orns ...... 8.50 2 T ube H arkness ...... 58.00 :i: and 260 feet apart, and is located half 't' "A" T ubes ...... 3.75 2 T ube Portable (without tubes) .... 9.95 't' a mile from the studio building. Under ::: Plus 25c for Postage. ::: ~ ~ the antenna p roper is the power ,t, WORK BENCH and ADVICE FREE. ,t, house, housing the mechanical equip f f ment, which is similar in design to the :i: D. C. PHI P P S :i: v Distributor 't' radio broadcasting station W GY at V V Schenectady, the big brother of KGO . 't' WING RADIO PRODUCTS 't' ::: Phone TRinity 6434 Los Angeles, California 726 S. Spring Street :!: T rans-Atlantic broadcasting tests .:.. :-:-: .. : .. :-:-:-: .. : .. : .. : .. : .. :-: .. : .. : .. : .. : .. : .. : .. : .. : .. :-: .. : .. : .. : .. : .. : .. : .. : .. : .. : .. :-: .. : .. : .. :-: .. :-: .. : .. :-:-:-:-:-:-:-:-:-: .. :-:-:-: .. :. conducted during the week of N ovem ber 27, demonstrated the extraordin ary transmitting radius of WGY, the Schenectady, N. · Y., station of the General E lectric Company. According RADIO SUPPLIES to the 'Wireless World and Radio Re WHOLESALE ONLY view, an English radio magazine, WGY was the most generally received Dealers Write for Bulletins of the American stations participating in the tests. Some of the E nglish fans reported their reception of W GY as WALTER W. BIDDICK, Inc. 1316 South Grand 116 East Fifth perfect and one wrote that reception Los Angeles, Calif. Santa Ana, Calif. was "perfect on loud speaker." "The weather conditions," states the E nglish magazine, " were by no means ideal and a number of corres To Be SURE - Patronize' Radio Journal Advertisers ' pondents state that their aerials and .~.. :-: .. : .. : .. : .. : .. : .. :-:-:-: ... :-: .. :-:-: •• :-:-:.*: .. :.*: .. : .. :*.: .. : .. : .. : .. : .. :-:-:-:-:-: •• : .. :-:-:-:-:-: .. : .. : .. :-: •• : .. : .. :-:-: .. :-:-:-: .. : .. :. in sulators were eTlveloped in hoar A A ,t, Mounted 50c Unmounted 25c ,I, frost. According to many reports at f f mospherics were prevalent, and in not :::A [Work in Reflex? Yes! It sure will) :::) a few cases fading was very pro A l nounced. The chief ground for com A A plaint, however, appears to be the in "CATWHISKER" terference caused by the use of ex *v *V treme reaction by many listeners, who :~: RADIO CRYSTALS :i: thus drowned the American signals." ; ::: 'i' Our standard is set higher than was V +V 't' thought possible, and that is making 't' Get One of the *:. P,.,'" .... PP ll[O FOR .,. :i: RADIO CRYSTALS better Radio reception for all. :~: FAMOUS ::: [L PIC~~H~~~~~~v~ Co.lnc. Let them all meet our standard, and :t: :i: the day of bum radio crystals is gone! :~: A A POATES ~ ~ f To make BETTER crystals for you, we are going to MOUNT AND TEST .;- RADIOI MAPS 't' THEM AT THE MINE! Out in the desert, beyond Death Valley. where the 't' 't'V static is the worst on earth, EVERY CATWHISKER CRYSTAL W ILL BE 't'V FREE ::: TESTED ON LONG DISTANCE CONCERT S. Does that mean anything to :t: All the broadcast a nd commer :i: you ? Our nearest station is 400 miles. Our farthest-wel1, WE HAVE PICKED * cial stations list ed. Send us your ,I,A UP CHICAGO AND FORT WORTH ON A CATWHISKER CRYSTAL I ..A tria l subscription to R adio Jour +Think that over. f n al for 6 months and $1. 5 0 a nd V V we will ma il you the ma p. V V Address- :i: EI Picacho Mining Company :i: A A RADIO JOURNAL ,I, LAS VEGAS, NEVADA ,t, i i 113 Stimson Bldg., Los Angeles, Cal ..:-:-: .. :-:-: .. : .. : .. :-: .. : .. :-:-: .. : .. :-:-:-: .. :-:-: .. :-:-:-:-:-:-:-:-:-: .. :-: .. :-: .. : .. : .. : .. : .. : .. : .. :-: .. :-:-: .. : .. : .. : .. : .. :-:-:-: .. : .. :-:. Page 200 ~Radio lout-nal ~-- April, 1924 A novel method has just been adopted by the Australian common wealth wireless authorities for protect ing broadcasting stations, says a re port to the Department 0 f Commerce from Assistant Trade Commissioner Elmer G. Pauly, Melbourne. The regulations recently promulgated re quire that every prospective purchaser of a receiving set must present to the radio goods dealer a certificate of license showing that he has subscribed to the service of the station operating on the wave length to which the in strument being purchased is adjusted. To Be SURE - Patronize Radio Journal Advertisers If a radio enthusiast desires to "listen in" on additional programs he can have his receiving set so adjusted, but only on the production of certificates showing that he has made separate SPECIAL OFFER subscriptions to each. What next? STATEMENT OF THE OWNERSHIP, MAN· AGEMENT, C I R C U L A T ION, ETC., REQUIRED BY THE ACT OF CONGRESS OF AUGUST 24, 1912 Of Radio Journal, published monthly at Los An geles, California, for April I, 1924. State of California, 1 ss. County of Los Angeles f Before me, a Notary Public in and for the State and county aforesaid, personally appeared Hugh Harlan, who. having been duly sworn according to law, deposes and says that he is the Business Man ager of the Radio Journal and tnat the following is, to the best of his knowledge and belief, a true state ment of the owner ship, management (and if a daily paper, the circulation), etc., of the aforesaid publi. cation for the date shown in the above caption, reo quired by the Act of August 24, 19 12, embodied in section 443, Postal Laws and Reg-uialions, printed on the r everse of this form. to-wit: 1. That the names and addresses of the pub· lisher, editor, managing editor, and business man ager are: Publisher, Hadio Journal Publishing- Co. (Inc.). Los Angeles, Calif. Editor, K. P. Frederick, Los Angeles, Calif. Business ~lan ager, Hugh I-Iarlan, Los AngeIe!, Calif. 2. That the owner is: (If the publication i. owned by an individual his name and address. or if owned by more than one individual the name and address of each, should be given below; if the pub lication is owned by a corporation the name of the corporation and the names and addresses of the stockholders owning or holding one pcr cent or more of the total amount of stock should be given.) Radio J ournal Publishing Co. (Inc.), Los An- lIeles , Calif. Hugh Harlan, Los Angeles, Calif. Anna E. Harlan, Los Angeles, Calif. A. C. Humphry, Los Angeles, Calif. K. P. Frederick, Los Angeles, Calif. 3. That the known bondholders. mortgagees, and other security holders owning OJ" holding] per cent or morc of total amount of bonds. mortl!'ages, or other securities are: (If there are none, to state.) None. 4. That the two paragraphs next above, giving the names of the owners, stockholders and securit)r holders, if any, contain not only the li st of stock holders and security holders as they appear upon the books of the company but also, in cases where the .tockholder or security holder appears upon the hooks of the company as trustee or in any other fiduciary relation. the name of the per!on or cor poration for whom !uch tru!tce is acting, is given; also that the !aid two paragraphs contain state This 9-Tube Super-Heterodyne, built for a Radio Engineer, ments embracing affiant's full knowledge and belief 85 to the circumstances and conditions under which complete with loop, batteries, charger and horn, as shown. stockholders and security holders who do not appear upon th~ books of the company as tru.tec., hold stock and secllrities in a capacity other than that of a bonafide owner; and thi. affiant has no reason to beJieve that any other person, association, or Best Cash Offer Gets It corporation has any interest direct or indirect in the said stock, bonds, or other securities than as 60 stated by him. 5. That the average number of copies of each issue of this publication sold or distributed, through the mails or otherwise. to pa;tf subscribers during Radio Lab. & Mfg. Co. the six months preceding the date shown above i! (This information is required from daily publica tions only.) 215 Court St., Los Angeles, Calif. HUGH HARLAN, Business ~Ianage r . Sworn to and subscribed before me this 4th day of April, 1924. (SEAL) JOHN VINCENT MORRIS, Notary Public in and for said County and State. To Be SURE - Patronize Radio Journal Advertisers (My commission expires Oct. 19, 1927.) April, 1924 Page 201 Step Forward \ iVGN has succeeded in broadcasting of a new method of recording broad- . phonograph records of its opening pro cast reception, tuned in at his labor The Radio Association of South gram which were recorded in New atories in New York and recorded his ern California has taken a big stride in York. The broadcast of them was suf reception of the program, on aluminum engaging the interest of the Broadcast ficiently clear to make it possible to re disks. . He succeeded in recording vir listeners and dividing the organization cord the disks. When WGN went on tually all of the program, which con the air with its inaugural program into two sections, one of which is de tinued from six p.m. Saturday evening March .29, Mr. Frank Hoyt, inventor to six a.m. Sunday morning. voted entirely to the interest of the seeker after broadcast. The two sec ~:-:-:-:.. :-:-:-:-: .. :_ :_:_:.. : .. :_:_:+o:_: •• : .. :_:_:_:_:_: .. :_:_:_:_:_: •• :_:_: .. :_:_:_:_:_:_:_:_:_:_:_:_:_: .. :_:_: .. :_:_: .. :_:_:. tions, ham and broadcast, meet on al t t ternate Mondays, and any member is privileged to attend both, but in actual ~~~ Guaranteed Improvement ~~ practi ce it has been found that the plan .;. In + V V divides the organization pretty well 0 11 VOLUME, the lines of interest. The club has de :i: :i: finite plans for assisting the broadcast ::: DISTANCE and ::: listener as well as the amateur. Among * SELECTIVITY * 't' by use of 't' other things it will install, with the V Y cooperation of active broadcast li sten ers,a special set to locate trouble and :~: MOISE REFLEX UNITS :~: V V interference for ,members. It will like 't' in Harkness circuit. 't' wise plan special constructional helps v V meetings and the like. N. E. Brown is ~ X ,t, Moise Circuit Better Still ,t, p resident of the organization. .;. + 't' o ' Through economies in manu- 't' A. H . Grebe & Co ., Inc., haye just V V 't' facture and increased output 't' placed on the market a separate stage +:+ . cl d .:+ of tuned radio frequency amplification, y pnce re uce to 't' known as the Grebe clarifier or Type V V 't'V 't'V RORQ. It is claimed for this unit that V $2.50 V it effectively prevents radiation yet. V V V V increases signal intensity, as well as 't' Free diagrams showinbO" best reflex circuit, on request. 't' V V increases distance range, selectivity V V and quality. It operates on either 99 o r A tubes. The western branch of the :~: Glendale Radio Service :!: company is located at 4S 1 East 3rd St., VX 211 E. B road way Ph. one 341 7 GI endIe a e, a l'fI ornia :t:'f' Los Angeles, Calif. ..: •• : -:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:... : .. :-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:- :-:-:-:-:-:-:-:-:-:-!+(>:. Use the Ray-Dee-Artcmft RAY ",. DEE FORMER In the Super-Go-Getter MUNZIG CIRCUIT NOTICE RAY-DEE-FORMER Watch for the RAY-DEE-DYNE TYPE M-33 RECEIVER, the receiver that really reproduces perfectly, No illustrated with blueprint and squeals-no howls. - 1000 mile instructions for assembling. range guaranteed under average conditions. Ask your dealer for a demonstration as soon as pos Price ...... $5.00 sible, Order your RAY-DEE-FORMER direct if your dealer can't supply you USE THIS COUPON Ray-Dee-Arcraft Inst. Co., Redlands, California. I Gentlemen ;_ Enclosed find $...... for which please send me ...... , ...... RAY-DEE-FORMERS for use in the MUNZIG CIRCUIT. I will hold you good to your guarantee that ever~ R~Y-D EE-.FC?RMER is electrically and mechanically perfect and reserve the right to return the RAY-DEE-FORMER If not satisfied. Name ...... _...... _...... _...... _... _ ...... _...... -...... _...... _...... Address ...... _. _.... __ ...... - ...... _.. . __ ...... - .. _...... ---- _. _._ .... __ ._----_ ...... _... -...... _...... _...... Dealer's Name and Address ...... :...... . ······.·.· ..... ·.·_· ·· ... ___. _.... ····.······· . .. u.·_ ...... ("i;;i~t -- pi~i;;iy.. ~.;.. -T.yp~~;it~.j- .. _-_.--.. -- ... _-- ...... -...... -.- -.-....- ... --.-.. .. -..- ....- .... -.. -. ---.... . ------.1 Page 202 ~Radio Joutnal~ ApriI, 1924 New Detector The well known navy type variable detector is again growing in favor with LEARN RADIO! the radio public, accordi ng to D. C. P hi pps, 726 South Spring Street, Los "The Radio Industry N eeds T rained Men of Ambition" Angeles, distributor fo r the enti re line of the Wing Radio P roducts. Greater Complete Pract~cal Courses- given erficiency, he says, brings a steadily in creasing demand. Likewise its sim by practical men plicity and beauty add to the appear ance of refl ex sets. New crystals· can Commercial Operating be installed in quick time, thus giving Radio Salesmanship a choice of any preferred make of Amateur Operating t: rystal. T hi s, he adds, is the only sure Radio T heory for the Broadcast Listener way to get distance on a reflex set. Call or write The Chicago T ribune-Zenith Broad casting station and the Prest-O-Lite E. S. FARNSWORTH, Director Co., Inc., of Indianapoli s, have just completed arments whereby the inter national 500 mile atHomobile race at Indianapolis Memorial Day, May 30, Western Radio Institute will be broadcast from WGN. T he Schools and College Building 625 SO\lth Hope Street running story of the motor classic will Los Angeles, Califor nia TUcker 2406 be detailed through a microphone placed in a specially constructed booth directly over the start-finish line and, carried by an American Telephone and Telegraph circuit to the station in Chifago. Other mi crophones placed about the speedway will carry the Need Help on Your Set? sound of the exhaust from the motors, We Call Give You a Lift in Plan'lli ll g and Building Your Set the cheering of the crowds and other incidental noises to the ears of millions We car ry everything. Complete lines of Gilfi ll an Bros., K ilbourne & Clark, A jax and many other standard makes of parts and accessories. We can give you the of li steners. straight dope on what alld how to b1!'ild. Call, phone or w rite. 01' we will sell you a Ken nedy W hen ail press and commercial telegraph wires connecting Chicago P REST & DEAN RADIO ELECTRIC CO. with the res t of the world, except those 742 E . FOUl'th Street L ong Bea ch, California leading to the north through Canada, were put out of commiss ion by the most terrifi c sleet storm of the win To Be SURE - Patronize Radio Journal Adver tisers ter, representatives of two press as sociations depencled on radio and the American Radio Relay League to get press th ro u g ~ the world's largest news relay pO l11t. O ne of the several THERE'S A LURE TO important stories handled was a bul letin on the mine disaster at Croshy, THE OCEAN THESE DAYS Minn., giving a li st of the dead , which the newspaper co rrespondent acl dress T he balmy days of Spring have come and mankind feels ed to an office in New York City. D. the urge to travel- just somewhere. H. H iebert, operator of amat eu ' ~ st;,t tion 9BQ Q at Mimi.eapolis, who hand T he Seashore Sands of the Southland's many attractive led this message, stuck by his set with Beaches are especially alluring these days. only three hours sleep in as manv nights transmitting both news and pri T his railway reaches all of them very quickly, comfort vate messages. ably and economically. Travel the Electric Way-the Big Red Trains are al Radio School ways ready to serve you. COMPLET E course in constr uction and diagram build ing, t rouble shooting. No books. Actual buil d ing, 7 to 9 p. m. except Satur· days, Class starts Monday night. B ig de· Ask Our Nearest Agent for Information mand for mechan ics. B ig money. Open to all. LESTER'S Pacific Electric Railway RADIO SHOP o. A. SMITH, Passenger Traffi c Manager, Los Angeles 140 S. Sp ring Street Metro 4832 L os Angeles, Cal. April, 1924 ~Radto Joutnal~ Page 203 The kind fhooks that -Lincoln-· longed for Ridpath Historyof the World Ridpath's History Now Includes a Full Account of the World War America's Greatest Historian Ridpath Endorsed by Thousands JUST about the time when Abraham Lincoln In the opinion of statesmen, college presidents, became the nation's chief executive, a little professional and business men of all classes and Indiana boy wrote o~e day to the President of conditions, Ridpath's History of the World stands alone. There is no set of books about which opinion is so entirely unanimous. Harvard. He was a boy of the Lincoln type Ridpat h's History is praised by all for its wealth of learning, it s brilliant style, and its educative value to old and young. It is already in over a thirsting for knowledge. He wanted to know if third of a million American homes and should be in every home. there was a world's history, trustworthy, not too bulky or expensive. The reply was that no man 46-Page History Booklet Free had yet appeared with sufficient ambition, judgment, cour age, patience and literary skill to write a practical, useful, We will mail you our beautiful forty-six reliable history of the world. "I'll be that man," said the page free booklet of specimen pages from the boy to himself. For 22 years he prepared himself thoroughly History without any obligation on your for this task. For 17 years he toiled and brought it to com part to buy. Tear off the Coupon, write pletion. The boy was John Clark Ridpath and his History name and address plainly, and mail to us now be of the World is, in the opinion of every student and scholar, fore you forget it. We will name our special a masterpiece for all time. low price and easy terms of payment only in direct letters, We do not publish our Ridpath's 6000 Years of History special low price because to print our Ridpath takes you back to the dawn of History, low price broadcast would cause great injury to the sale of future Please mail, without cost long before the Pyramids of Egypt were built; editions. Hundreds who read to tne, sample pages of down through the romantic troubled times of Chaldea's this have thought that some Ridpath's History of the grandeur and Assyria's magnificence; of Babylonia's wealth time they would buy a History World, containing photogravures and luxury; of Greek and Roman splendor, of Mohammedan of the World and inform them of TheSurrender at Sedan, Napoleon. selves on aU the great events and other great characters in history. culture and refinement to the dawn of yesterday, including a that have made and un full authentic account of the World War. He covers every made nations. Don't you Also write me full particular. of your race, every nation, every time, and holds you spellbound by think it would be worth special nffer to readers of R adio Journal. while to at least send his wonderful eloquence. the coupon and find out all about our New Edition now ready--right down to date remarkable offer? ..______THE RIDPATH CINCINNATI, HISTORICAL O. ______SOCIETY DRESS...... •...... •...... ••.______Page 204 April, 1924 the rapid reCelVlt1g, and it is to the 'Wolverine, Mich.-My first copy of receiving end that Mr. Belin has re Radio Journal was fine. Am quite a cently been devoting his attention. Mr. radio bug and have used my set often ~ ~" . soon when anyone can sit in hi s home -DROP US A or at a movie show and witness what at the start of the Church Services LINE is going on anywhere in the world and for social events. With a four where camera man with a sending de tube radio frequency set we have list ened to services in Schenectady; Pitts~ vice is busy. Thus we all may witness burg, Boston and Kansas City, using a anything f rom shipwrecks to battles With CThe Editor non-power Magnavox and 75 volts of while they are actually OCCll rring B battery. This is a small town with some of these days. nothing doing during the long winter Television, or seeing by wireless, and the set has been quite an enter will become accomplished fact this Hot Mon! Here's the letters we like taining feature, though ' now I wish to open: summer, but probably in a crude form, mine was a neutrodyne. That's the' way "I'm for you every time. Radio J our it goes, first a according to an eminent physicist E. crystal, then a one tube, nal is getting better and better. Keep next two step or audio in a single cir Fournier d' A lbee. The scientist based it up.-LEE ROY POTTER, 6AKW, cuit, then radio frequency, and still his prediction upon remarkable prog Lancaster, California. wishing for something better and dif ress made by M. Belin, the French in ferent. Have heard Los Angeles, San ventor, in perfecting the reCelVlt1g T he H. L. Dodge Music Company Francisco and Portland, Oregon, three times each-but can't make the grade side of the il1v.ention. Mr. Belin has of Long Beach, California, has instal led a radio department, with John B. now.-REV. T. H. JONES. calculated that to transmit a movlt1 g Hughes in charge. Mr. Hughes intends image satisfactorily it will be neces to specialize in the installation of com T he experiments with direct wire sarv to send 30,000 signals a second . plete sets in phonographs. The store is less communication between England T h~ rapid sending is far simpler than located at 228 East Broadway. and Australia, with the new beam sys tem of short wave lengths is completely success fu!. The government will abondon the proposed large station and build a sta tion adaptable to the new system, thereby saving fo ur-fi fth of the cost. The tests to obtain secrecy which is a feature of the new system gave every sati s faction. RADIO well-established corporation 111 a All standard makes of Radio A P arts, Radio Sets from $75.00 profitable phase of the Radio business to $825.00. Demonstration at has reached the threshold of a large your convenience at home. EQUIPMENT SALES CO. expansion which will greatly increase Phone 641-79 its usefulness and profits. I have a small 402 B Street San Diego, Cal. block of the Common Stock of this Cor poration which I am offering subject to ENTERTAINMENT On picnics, outings. in the camp. a ll the yacht. prior sale. The proposition is sound and in the car, for t he trayell er. as well as in the home. That is what OUf portable sets do. No aerial the possibility of large profits attractive. to install. All batteries and loud sneaker en closed in a neat, compact and very attractive Your inquiry will bring the complete cabinet. just like a suit case. "Ve have a set for every purse. CALL AND SEE US FIRST or write for further in £ol"l1' story by mail and, of course, will obli tion. We also carry a complete line of assem· gate you in no way. blies and parts. HOLL YWOOD'S RADIO STUDIO 709 No. W estern Ave. Hollywood. Calif. Phone Hempstead 0195 Fayette Marsh OPEN EVEN INGS 611 Pacific Finance Bldg. .--...... _----, Los Angeles California IBOYS!! : II W rite for our special ! , premium offers. I I Circulation Department i ' R~~i~9BldI.~~!~tL I I • I •• __ • • • • • • • • • __ MAKE YOURSELF A PRESENT OF THIS efax an Boo With One Year's Subscription to Radio Journal for $5.00 Or with a two-year subscription to Radio Journal for $6.00. Lefax Radio Handbook will be sent you, postp~id, with one subscription to Radio Journal, new or re newal, your own subscription or that of your friend, for $5.00. Keep Up-to-the-minute In Radio Lefax Radio Handbook keeps abreast of developments. It is loose-leaf ...'~ and every month additional pages are sent out covering new developments. All pages are numbered and properly classified and may be inserted in the J handbook, thus keeping it perpetually up-to-date. This supplement has just been greatly enlarged. RADIO 11""09001( Ifm These additional pages are the most reliable source of supplementary reference in the field of radio literature. ~ Additional loose-leaf pages are mailed to you as they are issued-free of charge for one year. Every Radio experimenter needs this book. Fill lEFA)C I , ill tir e coupon below today and get your copy. RadiO' Joumal 11 3 Stim son .Bldg .. The Whole Story of Radio Los Angeles. Calif. Enclosed find ...... _. ___ .... for which please is told in this loose leaf book. Note the rings send Radio Journal for (one) (two) years they unsnap easily and leaves can be taken out or to added as they come in . The material is prepared by the two chiefs of the Radio Department of the Name Bureau of Standards at Washington. Dr. Dellin ger and L. E . Whittemore. Keeping abreast and City. ______..... __ __ .. ___ _.. ______State ______ahead of radio development is their sole business. Street No. ______•. ______. __ __ These men are two 0 f the foremost radio ex perts in the world. You have the opportunity to A lso send L efax Rad io H a n dbook. have these eminent radio experts guide you, too; postpaid. to to point out to you step by step what to do. Name ______Radio Journal, which is included in this re markable o ffer, keeps you up to the minute on Ci ty ______Sta te ______every phase of radio, amateur, broadcast and Street No. ______._. commercial. 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Manu factu rers of Tune Sharp Brand Radio Products 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.