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Vol. 9 No. 23 Illustrated

A 36" Cone Speaker

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Art's Great Inventions

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RADIO WORLD August 28, 1926

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A weekly Paper Published by Hen-nessy Radio Publications Corporationfrom Publication Office, 145 W. 45th

Street, N. Y., N. Y.Phones: BRYant 0558 and 0558.

[Entered as second-class matter, March, 1922, at the post office at New York, N. Y., under Act of March 3, 1879]

Rolls His Own 36" Cone

FIGS. 1 AND 2The cone itself, independent of unit, is shown at left, after the pasting process has been completed. The glue is allowedto dry thoroughly. At right is the previous process, the description of the 19" outer circle. T le cord must be kept taut.

Author Gets Bass NotesVery Satisfactorily fromReproducer That HasUnit With Ample Driv-ing Power.

By James H. Carroll(Photographs by the Author)

THE orchestra, the player or theI- speaker in the room with full volume

and perfect reproduction is the goal nowsought by the radio researcher. Probablyno radically new circuit will be developedthis Fall, so that most efforts are beingbent toward refinements of existing cir-cuits, development of power amplificationand the reproducing means, namely, theloud speaker. And this season really seesthe passing of the horn-the cone hascome into its own.

In order to get the most out 'of a conewe need power and this leads. us to thepower amplifier as the newest and mostperfect development in the form of aseparate audio amplifier coupled with Bpower supply, all in one unit ready toplug in on the power line. The inputplugs in on the detector stage of thereceiver and may be used in many ways.The set may be installed in the den withthe power unit in the cellar while theauditors sit in the parlor listening*to theprogram exactly as it sounds at thetransmitting end, whether that be stage,auditorium or studio. Another speakermay be mounted in the dining room forthe dinner music so that your guests mayenjoy music while dining and thenadjourn to the parlor for an evening'senjoyment of concert, opera, lecture andvaudeville.

Uses 36" ConeINS brings' us to the consideration of

the best type of speaker to he used forthis ultimate in reception and all signsindicate that the 36" cone will be afavorite among advanced fans who haverealized that the coming set will bemerely a detector unit with the rowerpack plugged in. Many leading experi-

menters are working on TRF and othercircuits along this line.

Working along my own lines end finish-ing up my own idea of a power amplifierto use with my Victoreen, I entered intoexperimentation on the three-foot cone.There will be several of this type on themarket this Fall, and good ones, too, ata list price of about $35 to $85. Afterlong research and experiment I found Icould make an excellent 36" cone withlittle trouble. Taking fine's time andusing due care in every operation payswell in this work.

The driving unit must be scientificallyconstructed of the best materials to becapable of fully actuating this largesurface. Cheap units will not give satis-faction. The paper must be the best

FIG. 3The unit that is used must have suffi-cient driving power. "A" representsthe adjustment screw, for establish-ing the correct air gap. Once prop-erly set, this adjustment need not bevaried, unless battery voltages arechanged. "B" is the driver or pinthat is inserted on the cone centerand secured with thumb -nut. "C" isthe speaker windings or bobbin, while"D" and "E" are the leads of the

speaker cords.

Works Fine From GoodAudio Channel and IsHighly Suitable for Con-nection to Power Arnfier.

procurable. Faced Alhambra was whatI used. This is parchment of the finestquality, used by the manufacturers ofquality cones. Failure to use the bestwill result in a mighty poor product.

Some excellent kits are procurable formaking such a speaker as mine. I usedthe kit put out by Engineer's ServiceCompany, which includes blueprint sonovices will meet no mysteries.

All you need now is a small bottle ofliquid glue, a large flat surface and alittle patience. The sheet of Alhambrapaper is 38" square and comes carefullyrolled up in a long box. Open it out,roll it in reverse, being careful to avoidcreasing, then smooth it out on a table.Now we are ready to proceed.

The ProcedureIt is advisable first to study the blue-

print thoroughly and we are now readyto go ahead. You may thumbtack thepaper to 'your table, although we did notfind it necessary to do so. First we makea 19" circle, using a pencil and string asshown in the illustration. Then we makean 183,V circle, which allows us a marginof %." which is afterwards folded outtoward the apex of the completed cone.Next we score our inner circle with ablunt point, being careful not to cutthrough our paper. Now we proceed todraw a smaller 3" circle for which thereis room up in one corner of our paper.This is for fastening our metal washerand screw on the anex of the cone,

Now, on the bottom of our 19" circlewe measure off 61/4". From the right ofthis space to the center of the circle werule a heavy line. On the top of thisfrom the center of the circle to the leftend of our 61/4" we rule a dotted line.And hi" in from this we rule a heavy line.This is for pasting our flap. Now we pro-ceed and cut out our two circles, thelarge and small, being sure to cut outside

4 RADIO WORLD August 28, 1926

Where to Place a Speaker

FIG 4

The 36" cone in action. The unit happens to be tied to the pillar for security,but the support is furnished by the cord at top.

our 19" circle. We cut into our largecircle along the heavy lines, making thesame kind of an incision in our smallcircle only our segment Is but 9/16"in the latter. We now stir our glue withthe spatula and if it is too thick we warmit up a little and proceed with our pasting.This must be carefully done. Just enoughglue must be evenly spread and no excessgobs or smears should be allowed to getoutside the fold:

We now leave the cone to dry, asshown, while we paste our little conewhich is a simpler operation. When bothare thoroughly dry we take our metalwasher, applying glue on the under side,placing it firmly on the apex of our coneand securing it tightly by glueing oursmall cone over it, making sure that thelittle set screw is free. The creased outeredge is now folded back toward the apexof the cone and we insert the driving rodof the unit into the metal washer securelyfastening it by tightening the screw. Ourcone is now ready for operation and theresult is a revelation in tone quality.

Hung From Wall.You note that this cone is designed on

a new principle in that the cone hangsfrom the unit on the convex side and thatthe unit is not fitted into the concave side,as in the usual speaker of this -type. Thismakes a big difference in the quality ofsound and every frequency is reproducedfrom the highest to the lowest, from theapex out to the very edge. The bass notescan be felt with the fingers at the edge ;the high tones at the apex. On a pianotest, using a "mike" on the receiver withthe cone several rooms away, every noteon the keyboard came through clearly

and at natural pitch. It will stand anypower and will work nicely on 90 volts.

Our cone may now be hung from a wallbracket, from a bridge lamp or suspendedfrom the ceiling. It will fill the roombeautifully if hung in a corner of theroom. An angle iron may be used for thispurpose. It is well, if it is hung perpen-dicularly to support the upper end by astout thread so that the driving rod willnot be bent. If hung horizontally, nosupport will be needed. The photos showhow mine has been mounted for thepresent. A beautiful cabinet may be madeby those handy with- tools, at small ex-pense with a silk curtain to cover thecone and which also may serve as a standfor the set. The batteries are hiddenin back. We have not space here to gointo constructional details on this and maytreat on it in a later article.

Needs Good AudioWe have tried this cone on several sets

besides the Victoreen and the resultshave been wonderful. However, do notexpect good results on a poor audio out-fit, for the better the speaker the more itemphasizes the poor quality given bycheap parts in audio hookups. One ofthese speakers mounted in the roomwhere reproduction is desired will giveample volume for any purpose. Withpower behind it, the modulator will haveto be used. For restaurants, one speakerhidden behind a screen will serve thepurpose of an orchestra and may betuned to a pleasing murmur, with themusic perfectly clear, or worked at fullvolume. For large dance halls, two atthe most, mounted in diametrically on-posite corners of the room, work well.

Trinidad ListenerGets WBZ Nightly

BOSTON.That the waves of WBZ are penetrating

to distant lands in spite of Summer may beattested by a recent letter received at thestation from Port of Spain, Trinidad, Brit-ish West Indies. The letter reads, "Iam sure it will interest you to know thatfrom July '16 until last night (July 21) I

have been listening to the concert broad-cast from WBZ. This time of the yearstatic is worse than ever here and I wasgreatly surprised to bring your station inwith as much volume as the Caracas sta-tion which is only 300 'miles away. Themusic comes in fine but the static almostprevents my hearing your announcer andmany times I am unable to hear clearlythe name of the artist presenting the con-cert. I would like to know if WBZ hasincreased its power as to date it is theonly American broadcasting station I canhear."

Invalid Claims1 -Tube DX Record

A world's record for reception on a 1 -tube set is claimed for Miss Jennie R.Miller, a bedridden invalid of 139 W. Sen-eca Street, Oswego, N. Y. She reportedshe heard LOW, Buenos Aires, Argentine.Her record came to light in the annualMiss Radio contest conducted by theRadio World's Fair to determine thechampion feminine radio fan.

Hearing long distance stations is noth-ing new to Miss Miller, whose log in-cludes 316 broadcasters. She listens induring the late hours of the night, herroom in total darkness. She has heard5NO, Newcastle, England, and gets thePacific Coast quite frequently, includingstations in Seattle rarely heard in theEast. She has won several prizes in DXcontests.

Canadian ProgramHeard 3,558 Miles

VANCOUVER, B. C.

Fanning Island, a cable outpost in theSouth Pacific Ocean, 3,558 miles distantfrom the origin of the broadcast, recordedreception of the Anniversary Program ofCNRV, the Canadian National stationhere, noting in particular a Wagner selec-tion by a quartet. This is regarded as agreat feat in Summer broadcasting, thecable station being more than 1,000 milesbeyond Honolulu on the route to Aus-tralia.

Among thousands of complimentarymessages received by CNRV on the pro-gram which marked its first anniversarywere a large number from Alaska andYukon territory. One enthusiast in thelatter district declared that despite theNorthern lights and old man static thetransmission from CNRV successfullyreached his set.

Public Jazz -Sick,Says KDKA Expert

PITTSBURGH.The Pittsburgh Municipal Orchestra,

under the direction of Victor Saudek,Musical Director of KDKA and conductorof the Little Symphony Orchestra, hasbegun a series of Sunday evening con-certs from the bandstand in SchenleyPark.

The orchestra programs formulated byDirector Saudek steer clear of jazz. Com-menting on this phase of the concertsDirector Saudek said:

"We are not to furnish the people withjazz music. "Instead, we will furnish op-eratic selections and some lighter num-bers, such as the works of Victor Her-bert. We believe that the public is sick-ened of common jazz and shall endeavorto give them something that will pleasethem."

STEIN IS APPOINTEDHarold Stein, known as 'the radio

photographer," has been appointed officialcameraman for the Radio World's Fairto be held at Madison Square Garden,New York City.

_August 28, 1926 NADI (1 O R I, I) 5

Trouble Cures For SetscRs

6(Photo ,y Gad,. cdr., 630 F.Tth A; enue, V. Y. City)SOME POINTS suggested by the authors as likely places to locate trouble. (A), scratchy noises may be due to variablecondenser rotor plates touching stator plates. They say variable condensers are the most frequent trouble causes. (B),inspect the grid lead for continuity if a "sound like a motor boat" is heard, unaccompanied by signals. (C), remove tubesto test voltage at filament terminals as test for short circuit or other cause of incorrect voltage, like accidental high resist-ance. (D) Aerial and ground input and total continuity should be tested. (E), remove plate and B plus leads to trans-former or other part and substitute a pair of phones, to hear a click that shows B voltage is being supplied. (F), the bat-tery strip should be tested to see that there is no short and B minus disconnected to confirm this. (G), the jack springsrequire careful inspection for security of contact, if the audio amplifier fails to work though the detector output functionsproperly. (H), the A battery switch should have cleanly wiped soldered joints. (I), the rheostats cause scratchy sounds if

the slider contacts poorly. (J), vernier controls sometimes cause trouble wrongly blamed on loose wiring.

Problems Considered From the Service Man's View-point, But Presentation of Them Is Equally

Useful to Fans Who Build or RepairTheir Own Sets

[In a paper presented before the Institute of Radio Engineers in New York City, LeeManley and W. E. Garity, of the Radio Corporation of America, comprehensively coveredtrouble shooting in a manner that makes their treatise the masterpiece in this branch of radioliterature. It will be published in full, Part I being printed herewith. Part II, the conclusion,will appear next week.]

By Lee Manley and W. E. GarityReprinted by permission of the Institute of Radio Engineers

MUCH has been said and much hasbeen written on the many troubles

that arise in radio broadcast receivers asto what causes their failure and how tocorrect troubles when they occur. Theradio sections of our daily papers andradio publications have devoted columnsand pages in answering individual prob-lems. These have been of invaluable as-sistance to the individual, but in nearlyall cases have referred to specific condi-tions.

In this paper we will endeavor to groupservice problems under general classifica-tions, prescribe methods of diagnosingthem followed by a prescription for cor-recting them.

We believe that general methods maybe applied in spite of the fact that thereare so many different types of sets on themarket, each one claiming individual dis-tinction all- its own. All radio sets, no

matter what type, which fail to give sat-isfaction do so for a number of reasonsthat are fundamental.

The Four CircuitsIn general, there are four basic pick-up

circuits in use today: the so-called regen-erative detector, the untuned radio fre-quency, the tuned radio frequency andthe Super -Heterodyne. Any set on themarket may be classified as using one ofthe foregoing types or possibly a com-bination of one or more. There are twoadditional types of pick-up circuits whichhave fallen more or less into oblivion andwill not be found in general use in thebroadcast receivers of today. They arethe crystal detector and the straightaudion detector which employs no form ofregeneration whatsoever.

Receiving sets consist of a pick-up cir-cuit, a detector circuit and an audio fre-

quency amplifying circuit. In the pick-upcircuit radio frequency amplification maybe incorporated. The detector may beeither a tube or a crystal. In the audiofrequency circuit from one to three tubesare generally used. In multi -tube setsemploying radio frequency amplifiers,some arrangement of circuit is made tosuppress or control the tendency of thetubes to oscillate, when the circuits aretuned to resonance.

Any set on the market today may begrouped under one of the foregoingclasses as to the circuit employed.

Troubles ClassifiedIn much the same way that receivers

may be grouped under circuit classifica-tions, their failure to operate may begrouped under certain general classes,namely:

Lack of operating experience on thepart of the user.

Location.Defective accessories.Open circuit.Short circuit.High resistance connection.Lack of operating experience may be

the result of not following out instruc-tions carefully enough, or, as is some-times the case, the instructions are notcomplete enough and are not entirely clearto the novice. It may be the result ofinsufficient instruction on the part of theservice man who made the installation.Then, too, it may be the result of im-patience on the part of the customer. Itis a peculiar condition, but a fact never-theless, that the first night a customerhas a set, he feels that he should be able


Where to Place a Speaker

FIG. 4The 36" cone in action. The unit happens to be tied to the pillar for security,

but the support is furnished by the cord at top.our 19" circle. We cut into our largecircle along the heavy lines, making thesame kind of an incision in our smallcircle only our segment :is but 9/16"i the latter. We now stir our glue withthe spatula and if it is too thick we warmit up a little and proceed with our pasting.This must be carefully done. Just enoughglue must be evenly spread and no excessgobs or smears should be allowed to getoutside the fold:

We now leave the cone to dry, asshown, while we paste our little conewhich is a simpler operation. When bothare thoroughly dry we take our metalwasher, applying glue on the under side,placing it firmly on the apex of our coneand securing it tightly by glueing oursmall cone over it, making sure that thelittle set screw is free. The creased outeredge is now folded back toward the apexof the cone and we insert the driving rodof the unit into the metal washer securelyfastening it by tightening the screw. Ourcone is 11 OW ready for operation and theresult is a revelation in tone quality.

Hung From Wall.You note that this cone is designed on

a new principle in that the cone hangsfrom the unit on the convex side and thatthe unit is not fitted into the concave side,as in the usual speaker of this .type. Thismakes a big difference in the quality ofsound and every frequency is reproducedfrom the highest to the lowest, from theapex out to the very edge. The bass notescan be felt with the fingers at the edge;the high tones at the apex. On a pianotest, using a "mike" on the receiver withthe cone several rooms away, every noteon the keyboard came through clearly

and at natural pitch. It will stand anypower and will work nicely on 90 volts.

Our cone may now be hung from a wallbracket, from a bridge lamp or suspendedfrom the ceiling. It will fill the roombeautifully if hung in a corner of theroom. An angle iron may be used for thispurpose. It is well, if it is hung perpen-dicularly to support the upper end by astout thread so that the driving rod willnot be bent. If hung horizontally, nosupport will be needed. The photos showhow mine has been mounted for thepresent. A beautiful cabinet may be madeby those handy with -tools, at small ex=pense with a silk curtain to cover thecone and which also may serve as a standfor the set. The batteries are hiddenin back. We have not space here to gointo constructional details on this and maytreat on it in a later article.

Needs Good AudioWe have tried this cone on several sets

besides the Victoreen and the resultshave been wonderful. However, do notexpect good results on a poor ,audio out-fit, for the better the speaker the more itemphasizes the poor quality given bycheap parts in audio hookups. One ofthese speakers mounted in the roomwhere reproduction is desired will giveample volume for any purpose. Withpower behind it, the modulator will haveto be used. For restaurants, one speakerhidden behind a screen will serve thepurpose of an orchestra and may betuned to a pleasing murmur, with themusic perfectly clear, or worked at fullvolume. For large dance halls, two atthe most, mounted in diametrically on-posite corners of the room, work well.

Trinidad ListenerGets WBZ Nightly

BOSTON.That the waves of WBZ are penetrating

to distant lands in spite of Summer may beattested by a recent letter received at thestation from Port of Spain, Trinidad, Brit-ish West Indies. The letter reads, "Iam sure it will interest you to know thatfrom July '16 until last night (July 21) I

have been listening to the concert broad-cast from WBZ. This time of the yearstatic is worse than ever here and I wasgreatly surprised to bring your station inwith as much volume as the Caracas sta-tion which is only 300 affiles away. Themusic conies in fine but the static almostprevents my hearing your announcer andmany times I am unable to hear clearlythe name of the artist presenting the con-cert. I would like to know if WBZ hasincreased its power as to date it is theonly American broadcasting station I canhear."

Invalid Claims1 -Tube DX Record

A world's record for reception on a 1 -tube set is claimed for Miss Jennie R.Miller, a bedridden invalid of 139 W. Sen-eca Street, Oswego, N. Y. She reportedshe heard LOW, Buenos Aires, Argentine.Her record came to light in the annualMiss Radio contest conducted by theRadio World's Fair to determine thechampion feminine radio fan.

Hearing long distance stations is noth-ing new to Miss Miller, whose log in-cludes 316 broadcasters. She listens induring the late hours of the night, herroom in total darkness. She has heardSNO, Newcastle, England, and gets thePacific Coast quite frequently, includingstations in Seattle rarely heard in theEast. She has won several prizes in DXcontests.

Canadian ProgramHeard 3,558 Miles

VANCOUVER, B. C.Fanning Island, a cable outpost in the

South Pacific Ocean, 3,558 miles distantfrom the origin of the broadcast, recordedreception of the Anniversary Program ofCNRV, the Canadian National stationhere, noting in particular a Wagner selec-

great feat in Summer broadcasting, thecable station being more than 1,000 milesbeyond Honolulu on the route to Aus-tralia.

Among thousands of complimentarymessages received by CNRV on the pro-gram which marked its first anniversarywere a large number from Alaska andYukon territory. One enthusiast in thelatter district declared that despite theNorthern lights and old man static thetransmission from CNRV successfullyreached his set.

Public Jazz -Sick,Says KDKA Expert

PITTSBURGH.The Pittsburgh Municipal Orchestra,

under the direction of Victor Saudek,Musical Director of KDKA and conductorof the Little Symphony Orchestra, hasbegun a series of Sunday evening con-certs from the bandstand in SchenleyPark.

The orchestra programs formulated byDirector Saudek steer clear of jazz. Com-menting on this phase of the concertsDirector Saudek said:

"We are not to furnish the people withjazz music. "Instead, we will furnish op-eratic selections and 'some lighter num-bers, such as the works of Victor Her-bert. We believe that the public is sick-ened of common jazz and shall endeavorto give them something that will pleasethem."

STEIN IS APPOINTEDHarold Stein, known as "the radio

photographer," has been appointed officialcameraman for the Radio World's Fairto be held at Madison Square Garden,New York City.

5 i rAugust 28, 1926 P 1)10 \V () I) 5

Trouble Cures For SetscR

6(Phoro by Garb., Ed,. 630 FIrch d. cu.', N. I. City)SOME POINTS suggested by the authors as likely places to locate trouble. (A), scratchy noises may be due to variablecondenser rotor plates touching stator plates. They say variable condensers are the most frequent trouble causes. (B),inspect the grid lead for continuity if a "sound like a motor boat" is heard, unaccompanied by signals. (C), remove tubesto test voltage at filament terminals as test for or other cause of incorrect voltage, like accidental high resist-ance. (D) Aerial and ground input and total continuity should be tested. (E), remove plate and B plus leads to trans-former or other part and substitute a pair of phones, to hear a click that shows B voltage is being supplied. (F), the bat-tery strip should be tested to see that there is no short and B minus disconnected to confirm this. (G), the jack springsrequire careful inspection for security of contact, if the audio amplifier fails to work though the detector output functionsproperly. (H), the A battery switch should have cleanly wiped soldered joints. (I), the rheostats cause scratchy sounds if

the slider contacts poorly. (J), vernier controls sometimes cause trouble wrongly blamed on loose wiring.

Problems Considered From the Service Man's View-point, But Presentation of Them Is Equally

Useful to Fans Who Build or RepairTheir Own Sets

[In a paper presented before the Institute of Radio Engineers in New York City, LeeManley and W. E. Garity, of the Radio Corporation of America, comprehensively coveredtrouble shooting in a manner that makes their treatise the masterpiece in this branch of radioliterature. It will be published in full, Part I being printed herewith. Part II, the conclusion,will appear next week.]

By Lee Manley and W E GarityReprinted by permission of the Institute of Radio Engineers

MUCH has been said and much hasbeets written on the many troubles

that arise in radio broadcast receivers asto what causes their failure and how tocorrect troubles when they occur. Theradio sections of our daily papers andradio publications have devoted columnsand pages in answering individual prob-lems. These have been of invaluable as-sistance to the individual, but in nearlyall cases have referred to specific condi-tions.

In this paper we will endeavor to groupservice problems under general classifica-tions, prescribe methods of diagnosingthem followed by a prescription for cor-recting them.

We believe that general methods maybe applied in spite of the fact that thereare so many different types of sets on themarket, each one claiming individual dis-tinction all its own. All radio sets, no

matter what type, which fail to give sat-isfaction do so for a number of reasonsthat are fundamental.

The Four CircuitsIn general, there are four basic pick-up

circuits in use today: the so-called regen-erative detector, the untuned radio fre-quency, the tuned radio frequency andthe Super -Heterodyne. Any set on themarket may be classified as using one ofthe foregoing types or possibly a com-bination of one or more. There are twoadditional types of pick-up circuits whichhave fallen more or less into oblivion andwill not be found in general use in thebroadcast receivers of today. They arethe crystal detector and the straightaudion detector which employs no form ofregeneration whatsoever.

Receiving sets consist of a pick-up cir-cuit, a detector circuit and an audio fre-

quency amplifying circuit. In the pick-upcircuit radio frequency amplification maybe incorporated. The detector may beeither a tube or a crystal. In the audiofrequency circuit from one to three tubesare generally used. In multi -tube setsemploying radio frequency amplifiers,some arrangement of circuit is made tosuppress or control the tendency of thetubes to oscillate, when the circuits aretuned to resonance.

Any set on the market today may begrouped under one of the foregoingclasses as to the circuit employed.

Troubles ClassifiedIn much the same way that receivers

may be grouped under circuit classifica-tions, their failure to operate may begrouped tinder certain general classes,namely :

Lack of operating experience on thepart of the user.

Location.Defective accessories.Open circuit.Short circuit.High resistance connection.Lack of operating experience may be

the result of not following out instruc-tions carefully enough, or, as is some-times the case, the instructions are notcomplete enough and are not entirely clearto the novice. It may be the result ofinsufficient instruction on the part of theservice man who made the installation.Then, too, it may be the result of im-patience on the part of the customer. Itis a peculiar condition, but a fact never-theless, that the first night a customerhas a set, he feels that he should be able


A Radio Doctor's Manualto get Chicago and points west fromNew York City. The responsibility forthis condition rests with either the sales-man who sold the set or the service manwho failed to correct this fallacy in thecustomer's mind, or with the manufacturerof the set for over -advertising his pro-duct, and being a little too optimistic asto the possibilities of reception.

A manufacturer who in New York Cityreceives the Pacific Coast stations on hisproduct is not justified in making a gen-eral statement that this can be repeatedat will, giving the impression to the readerof the advertisement that that particularreceiver will perform likewise in everyother locality. That is incomplete adver-tising and should be discouraged as it hasa detrimental effect on the industry as awhole, and results in unnecessary servicecosts.

The Dead AreaUnder the caption of location many

factors must be considered. The type ofbuilding in which the installation is made,the proximity to steel buildings, powerlines, trolley and railway lines, and thegeological and topographical conditionssurrounding the installation are all im-portant factors. Certain areas appear tobe "dead" to certain stations, while atthe same time particularly good forothers. We believe that this is due notto the area being "dead," but to a dis-tortion of the wave front from the trans-mitting station, causing it to be deflectedin such a manner as to render receptionof signals from that station very difficultor impossible in that particular location.

Under defective accessories we may in-clude defective tubes, batteries, loudspeakers, antenna and ground installa-tions, also improper battery connections.Many sets fail or are returned to thedealer as unsatisfactory because of poorantenna and ground installations. Manya set of good quality and capable of de-livering satisfactory results fails -becausethe loud speaker that is used with it doesnot have the proper electrical character-istics to operate satisfactorily in conjunc-tion with the receiver. Tubes will alsocause trouble as they are subject to cer-tain defects incidental to fragility.

Open Circuit PointsOpen circuits are generally found in

the movable connections of the set suchas a condenser pigtail, loop leads loudspeaker leads, and any other connectionthat is subject to movement or vibrationin the normal operation of the set. Opencircuits may also result from burned -outtransformers or from mechanical failuresin telephone jacks, rheostats, andswitches.

If a set has been once tested and foundto be 0. K., short circuits rarely occur.When they do it is the result of -a me-chanical failure of the moving parts orof tinkering with the mechanism of theset. It will sometimes happen that thepigtail of a moving element of the re-ceiver will break and fall in such a wayas to cause a short circuit of that ele-ment. This is particularly true of thepigtails of variable condensers.

The principal cause of short circuitsthat occur in the normal operation of aset is in the tubes. If the filament of thetube should break there is a possibilityof its falling in such a way as to causea short circuit between itself and the plateand grid elements of the tube. Whensuch a fracture of the filament occurs thevoltage of the B or C battery, as the casemay be, is short circuited through theconductors involved. This type of short

(Herbert Photos, Inc.)"IN loudspeakers of the adjustabletype, adjustment of the air gap willsometimes eliminate howling." Arrow

points to the adjustment post.

circuit is generally of very brief dura-tion as the filament will generally burnout as soon as the short circuit occurs.A contact between the grid and plateelement of a tube is a more serious typeof short circuit, resulting in the rapiddeterioration of the B and C batteries andmay possibly cause a burn -out of thetransformer windings in the circuits in-volved.

High Resistance TroubleThe foregoing troubles are relatively

easy to check up as they are immediatelyapparent or can easily be located by acontinuity of circuit test.

The most difficult type of failure tolocate is that caused by a high -resistanceconnection. It is not only difficult tolocate, but it is difficult to determine.This condition will cause the set to oper-ate indifferently with rather unsatisfactoryresults. This condition is sometimes mis-taken as location trouble. A high resis-tance is possible at any connection in thereceiver. Soldered connections that aresoldered with a corrosive flux that hasnot been properly treated after the sold-ering operation are probably the worstoffenders. Weak mechanical springs intelephone jacks and switches may alsointroduce high resistance connections.

Radio sets, like individuals, are verymuch the same the world over. They failor succeed according to a few fundamen-tal laws. They are subject, as it were,to the same ills, The doctor can diag-nose the trouble in a man's system whe-ther he be well dressed or poorly dressed,whether his name be Smith or Jones, be-cause he knows the fundamental lawsgoverning the human system and is notconfused by size or shape or a differencein physical dimensions.

One doesn't have to be a radio engineeror a radio expert to be able to service aradio set, but one does need experience tobecome adept, and some knowledge ofthe fundamentals is valuable. One mustbe, of course, familiar with the variousparts that are commonly used in radioreceivers such as rheostats, jacks, etc.,and must know, in a general way, thefunction of each.

Like a Doctor's WorkGiven a first -aid manual, the man in

the street with an ordinary amount of

common sense and an ability to read,might go out and administer first -aidtreatment and, if he followed the direc-tions properly, might effect a recovery.A doctor could do no differently. Hisexperience would permit him to handlethe case more skilfully and his intimateknowledge of the workings of the humansystem would permit him to diagnose thecase more quickly from the apparentsymptoms, but the man with the first -aidmanual would produce the same results ina little longer time and yet he knowsnothing of the medical science.

For instance, what does a doctor dowhen he is called in to treat a sick per-son? The first thing he generally doesis to feel the pulse and while doing thathe starts a series of questions as to thelength of time the person has been ill,where the pains are, etc., and he may evengo as far as to inquire into the familyhistory. Let that be the practice of theradio service man.

Do not immediately get out the toolbag and start pulling the set apart, buttry to find out what the difficulty is byquestioning the customer.

What would one think of a doctor if atthe first sight of every patient, he startedto operate, and yet you will see a serviceman start in immediately to pull the setout of the cabinet and look for trouble,and the trouble may be in a battery con-nection.

What we will attempt in this paper isto outline a first -aid manual for the treat-ment of "sick" radio sets; that will en-able the man who is not a radio engineerand who has only a slight knowledge ofthe art, to recognize trouble and makethe necessary repairs. We have avoided,therefore, all theoretical considerationsso far as possible and will treat the sub-ject from a practical viewpoint and referonly to theoretical discussions when ab-solutely necessary. We have prepared alist of complaints that are most frequent-ly heard, and we will analyze each com-plaint as to the possible reason for it.

Tip to the DealerLet us start with a suggestion to the

dealer or, for that matter, to anyone whosells a radio receiver. Test all sets be-fore sale. This takes but a very fewminutes and will surely pay well in avoid-ing dissatisfaction as well as time that issome times necessary to service a defec-tive set that has been shipped to a cus-tomer. A radio receiver that is workingproperly today does not as a rule go badtomorrow, and if such an installation doesfail, the dealer may feel that the troubleis due to a defective accessory ratherthan the set itself. When the serviceman is called on to service such a set hehas the confidence that the set is 0. K.and he will immediately be able to con-centrate on the real probability' of failurerather than imaginery ones.

Then, too, if the dealer would acquaintthe customer with the limitations of radioreception, what to expect and what notto expect, service problems would beminimized. Acquaint the customer as tothe probable length of time his batterieswill last. This is quite important, and iffollowed out, will avoid some very dis-agreeable service jobs.

For example, when a man purchases aradio set he becomes quite enthusiasticand will read all available literature onthe subject, and at the end of a month hehas absorbed just enough informationthat may prove dangerous. About thistime the signals on his set will start todecrease and he will remember havingread somewhere that this might be caused

-August 28. 1026 R A 1)1 0 \V ( I I)

How to Remedy Distortionby a defective transformer, and he im-mediately gets out the tools to make therepair, and then the dealer has a regularservice job on his hands. Had the dealerin the first place acquainted the customerwith the facts concerning the life of thebatteries, the customer would be morethan likely to recall such information and-take the proper steps to renew them.

The Service Kit- The question has been asked at times,"What should the service man's equip-ment consist of ?"

He should carry the necessary toolsand apparatus to be able to run a com-plete test on the set to be serviced andbe able to make any minor repair nec-essary. We would suggest the followingitems:

Set of tested tubes.Multi -scale voltmeter of good quality.Pair of head phones.Large and small screwdrivers.Small soldering iron.Solder and non -corrosive flux.Spare wire and tape.Test -leads with clips.Pipe cleaners.Large piece of cloth.Set of B and C batteries (small).When a service man goes into a cus-

tomer's home he is usually going there asa representative of a commercial estab-lishment. He should be instructed to becourteous and considerate. If he musttake a set out of the cabinet for adjust-ment he should use the piece of clothprovided in his kit to protect the surfaceof the table he works on. He shouldanswer all questions asked him no matterhow absurd they may appear to him.

The customer generally has one ques-tion that he would like to have answered,and in his mind the service man must bean expert, -in order -to be able to do suchwork, and so he unburdens his mind. Theservice man should respect this attitudeon the part of the customer and shoulddo his best to point out the fallacies tact-fully and set the customer right in hisideas about radio. The service man shouldmake the customer enjoy his visit andif this is done the service man becomesa valuable asset to a business and is apotential salesman.

The service man, before he starts tosnake any adjustments other than turn-ing on the set and trying the various con-trols, should question the customer as tohow it happened, the time, place, andconditions surrounding the failure. Suchquestions as the following:

How long has the set been in opera-tion?

Was the set operating satisfactorily upto the time of failure?

Were you tuning the set when thefailure occurred?

If so, what control were you moving?Did you make any change in the con-

nection of the batteries, if so, what warethey?

Did it suddenly stop operating?Was there any squeal or howling sound

just prior to failure?Were you moving the loop?Did the loud speaker fall?Is the antenna OK?In short, have the customer re-enact

the conditions at the time of failure. Getall the symptoms and an astonishingamount of time may be saved in runningdown the difficulty.

Customer Can HelpIf sufficient questions are asked, the

customer will generally give you the real

LISTENING carefully to the detectoroutput, quietly running a speaker, ascompared with no reception from finalaudio output, locates one's trouble in

the audio amplifier.

cause of trouble or he will suggest some-thing to you in the course of inquiry thatwill out just what the Cause of fail-ure was. Sets as a rule do not go badof themselves. The failure usually occurswhile some operation is taking place, suchas plugging in the loud speaker, turningthe condensers or making a change in thebattery connections.

The length of time that a set has beenin operation will be an indication of vari-ous types of trouble. A set that has re-cently been installed is subject to a cer-tain type of failure, while a set that hasbeen in operation for a year or more, issubject to other types of failure.

If a set has been installed for a periodof two weeks or less, outside of the in-ability of the customer to procure thedesired results, there are only a few rea-sons why the set should fail. They are:

A defective tube.Defective battery or battery connection.Loud speaker connection loose in tele-

phone plug.Burn -out of transformer.Of course, there may be other reasons,

but these are the.most common and aregiven in the order of their probability ofoccurrence.

If the set has been in operation for amonth or six weeks and has been -givingsatisfactory service for that period, thecause of failure is generally due to theweakening of the batteries.

If the set has been in operation for aperiod of six months or a year, the pos-sibilities of trouble will increase. If thefailure in this type of installation hasbeen gradual, the first thought would bethat the tubes were becoming deactivatedthrough continual use.

The Sudden BreakdownIf the breakdown was sudden, a me-

chanical failure might be expected in oneof the movable connections or pigtails. Aburned -out transformer could be expectedin difficulties of this sort. If the troubleis due to a noise conditions, the failure

might be ascribed to dust or dirt accumu-lations on the condenser plates or otherimportant parts of the receiver. The de-fect night also be due to a soldered con-nection. It will require, as a rule, a ratherlong period of time for a soldered con-nection to corrode to such a degree as tocause this conditions. The local atmos-pheric conditions under which the set hasbeen operating may have some bearingon the cause of failure. If the set hasbeen operating neat- the seashore and hashe en subjected to the action of salt atom -There it may have caused sufficient cor-rosion of the connections or other metal-lic parts to introduce high resistance orleakage path. Moisture may saturate thecheaper grades of insulating material tosuch an extent as to cause high -frequencyshort circuits.

If a set has been operating for a longperiod of time and has given satisfactoryresults and then develops noises andscratching sounds, one should not lookfor a loose connection in the wiring ofthe set, but rather look for an open cir-cuit in the moving parts. Worn mechan-ical parts are often mistaken for looseconnections in the wiring. The wiring isabsolutely stationary and it is not at alllikely that it will be disturbed in theordinary use of the set so as to cause afailure due to a loose connection.

Vernier drive shafts and vernier plateswill wear loose and while apparently theyare making perfect contact to the metalsurfaces of the condenser when the set isbrought into a critical condition, as is thecase when receiving distant stations, willcause noises that might be thought dueto a loose connection in the wiring.

"Set Just Stopped"Another item to be considered in the

servicing of radio sets is the cost of theoriginal apparatus. Radio, like any othermerchandise, is a matter of price. As arule, the more you pay for a set, the bet-ter should be the quality of the equipmentyou. get and you may reasonably expectlonger and more satisfactory service fromit. In a high-grade receiver the mechan-ical failures are less frequent than in thecheaper grades of sets. The same is trueof electrical failures. The cheaper gradesof sets are much more subject to clima-tic conditions than are the better grades.

We have compiled a series of com-plaints in such terms as they are receivedby the dealer, and we Will take each up inturn as to what it suggests as the pos-sible cause of failure.

"The set just stopped operating. Itwas giving excellent results, but it sud-denly stopped." This complaint is quiteunsatisfactory from a service man's pointof view. It does not suggest anythingdefinite and it may be the result of manyfactors. Trouble generally occurs whensome operation is taking place, whetherit he tuning or making adjustments orplugging in the loud speaker, or revolv-ing the loop. The service man should in-quire just how the failure took place, justwhat the customer was doing when theset failed.

If the failure occurred when some ad-justment was being made, he should lookfor a broken connection or a mechanicalbreakdown in the control being used atthe time. There are several causes of aset failing completely and suddenly,namely, a burned -out tube, a burned -outtransformer, a broken connection, or ashort circuit. A broken loop connectionwill also cause complete failure as wellas a burned -out loud speaker. Of course,there are many reasons why a set mayfail to function, but the list just given


Rules Forrepresents the principal causes for acomplete and sudden failure.

A burned -out tube will be immediatelyobvious and should be replaced. A brokenbattery connection or pigtail may be lo-cated by inspection and necessary repairsmade. A defective loud speaker may bedetermined by replacing the loud speakerwith a pair of head phones and notingwhether the head phones operate satisfac-torily.

Listen For the ClickIn making all checks on defective sets,

the first thing that the service manshould do is to light the tubes to theirproper brilliancy and then plug the loudspeaker in and out of the jack. If theB battery is properly supplying the tubesin the amplifying circuit, a loud clickwill be heard in the loud speaker. Ifthere is a jack provided on the detectortube, repeat this, using the head phones.In other words, see that there is a Bbattery voltage at the plate contact ofeach tube.

In the radio frequency tubes, if used,measure the voltage across the tube con-tact springs in the socket. This may beaccomplished by removing the tubes fromthe sockets and making direct contactwith the springs. There is another pos-sibility of failure in sets that employ alarge by-pass condenser which is con-nected across the B battery supply. Inevent of this condenser becoming short-.circuited, it will cause the B batteries todrop in voltage very rapidly and if theshort-circuit is complete enough, the bat-teries will heat up. This can be veryquickly determined by breaking the con-nection through the negative B battery.

If a heavy spark occurs, it is an indica-tion that there is a short circuit in the Bbattery supply which may be due to thiscondenser.

In testing this condenser should. bychance, the tubes be lit when the B bat-tery connection is broken, a small sparkwill be present. The small spark is dueto the normal drain on the B batteriesand represents the total plate currentof the tubes in the set. If the tubes arenot lit, no sparking should occur when thebattery connection is broken, but if thereshould be, this is an indication of a shortcircuit within the set. Of course thereis the possibility of a wire breaking freein the set itself and falling in such a wayas to cause a short circuit, but this isimmediately apparent on inspection.There is also a possibility of a short cir-cuit of the elements in the tubes.

"Can't Get Distance""I cannot get distance," is a general

criticism that is met with radio receiversof all types.

The most general cause for this com-plaint is the inability of the customer totune the set properly so as to get themost out of it. The obvious remedy forthis is to instruct him, further in the op-eration of the set. The service manshould spend an evening with him andshow him just how to do it, and once thecustomer knows that the set is capable ofreceiving distance, he will never admitthat he cannot get it.

A defective tube will sometimes preventdistant reception. Perhaps one of thetubes used in the radio frequency circuitis not particularly adapted for that pur-pose, but will make an ideal detector oraudio freqttency amplifier. Try inter-changing tubes so as to get the bestpossible combination. Do not make apractice of interchanging tubes after themost satisfactory combination has oncebeen, determined. This is particularly

mining Volumeapplicable to dry -cell tubes. Because oftheir delicate structure, it is not well tosubject them to excessive handling.

Location and local conditions materiallyaffect the ability of a set to receive dis-tant stations. Antenna construction andground conditions are important factors.If a loop is used, the shielding of nearbymetallic bodies will affect the results. Ina case of loop sets it is advisable to installthe set near a window. This is particu-larly true in the latest types of homesand apartment houses which employ intheir construction metal lathing whichacts as an electro-static shield to the in-coming signals.

"Loud and Out"In the case of sets employing antennas,

it will be necessary to experiment withantennas of different length and in dif-ferent directions. However, before theservice man blames the location for thefailure, he should take a set of similarmake which he knows operates satisfac-torily in another location, and check theresults in the doubtful location, compar-ing results received on the new set withthose of the standard set. In some in-stances, the service man is prone to uselocation as the cause of failure to receivedistant signals, whereas it may be due toa defective part in the radio set.

The signal comes in loudly and then diesout." This is generally due to the pheno-menon of fading.

However, should this condition exist onthe local stations, as well as the distantstations, we would be inclined to suspecteither a defective A battery connectionor a defective A battery. A soldered con-nection in the filament circuit that hasbecome corroded or broken for some un-known reason while not completely openso as to cause the tube's failure to light,but just making contact, will cause thiscondition. This defective connection, attimes, will become highly resistant; suf-ficiently so to cause a decrease in the fila-ment brilliancy. This condition is rarelymet, but it is extremely difficult to locatethe defective connection- and requirescareful inspection of every connection.

Battery TroublesThis condition may be brought about

by a defective dry -cell type A battery.In this case, it is due to a local actionwithin the dry -cell. The internal resist-ance of the cell will vary, due to this localaction, and cause effects similar to thatcaused by the defective connection justdescribed. In the case of dry cells, it issometimes necessary to readjust the fila-ment rheostats slightly in order to re-store the set to its normal operating con-dition, and at times, the set will recoveritself.

In a storage type A battery this con-dition may be brought about by a so-called" "treeing" effect. This conditionis generally present only in old storagebatteries and is the result of a leadtree building up on plates in such away as to penetrate the separator. Thislead tree builds up until it touches theopposite plate and causes a momentaryshort circuit of the plates involved. Theshort circuit burns off the lead tree andimmediately the building process is startedagain. When the short circuit occursthere will be a slight decrease in the totalvoltage of the battery, which will cause aslight decrease in the filament brilliancyresulting in a fading effect. in cases ofthis type, the fading periods are onlymomentary and recur at fairly uniformtime intervals and are present on all posi-tions of the tuning scale.

A. similar condition may be caused on

sets employing an antenna, by swingingof the antenna or lead-in. This conditionshould not be confused with the fadingphenomenon and may be identified by thefact that the volume of the signal willnot change, but will swing in and out.The particular danger to be encounteredis when the antenna is close to a metal-lic or other conducting body and inswinging, touches the same, causing amomentary short circuit. This is recog-nized by a click in the loud speaker whenthe ground occurs. '

"No Volume""I don't get any volume; the signals are

weak." If this condition is persistent andinvestigation shows that good resultswere never had on the receiver, and the,location has been carefully checked by asimilar type set, the difficulty would seemto be due to one of the following causes:

Inferior grade of set, not capable ofproducing good results.

Inexperience, lack of knowledge of tun-ing.

Defective tubes.Defective batteries.Reversed A battery connection.Poor antenna location or installation.Defective ground connection.Defective loud speaker.These are listed in their order of im-

portance and occurrence. If the receiveris of an inferior quality some advantagemay be had by replacing the grid con-densers and audio -frequency transformerswith similar instruments of better qual-ity. If it is due to lack of knowledge,it is the duty of the service man to in-struct the customer more fully. Defectivetubes should be replaced. This conditionmay be checked by replacing the entireset of tubes in the defective set withtubes that are known to be O.K.

A defective battery may be located bychecking the voltage. It is generallyconceded that a B battery whose voltagehas dropped 25 per cent. from the normalrating of the battery, should be discarded.If the A battery connections are reversedon receivers employing audio frequencyamplification, little or no amplificationwill be had. This is easily checked byreversing the battery leads.

Antenna DifficultiesJust when an antenna is defective is

very difficult to say, as there are so manylocal conditions which play importantparts in the success or failure of an an-tenna installation. In general, the an-tenna should be removed as far as pos-sible from all objects, such as trees andbuildings, and metal objects in particular.In general, the higher the antenna, thebetter will be the results obtained. If theantenna is erected in the vicinity of ahigh-tension transmission line, it shouldbe erected so that the line of the antenna

' is at right angles to the transmission line.The antenna should be carefully insulatedat all points throughout its length includ-ing the lead-in. It will sometimes happenthat a set employing an antenna operatesquite satisfactorily during periods of dryweather, but during, and after rainstorms, the operation of theset becomesrather indifferent. This condition is gen-erally due to a defective insulator whichbreaks down during periods of wet wea-ther, causing high losses. An oppositecondition may be had where the set oper-ated more successfully during periods ofwet weather than it did in dry weather.This would indicate that the moisture inthe ground enhanced the value of theground connection by reducing the groundresistance of the circuit.

Some care should be exercised in the

August 28, 1926A 1) 1 0 \ R D 9

Pepping Up the AF Circuitselection of a ground and the service menshould not necessarily use the first groundavailable. Several ground connectionsshould be tried and an effort made to de-termine the one giving maximum results,and this one used. In the present dayequipment it seems to. be customary touse an aperiodic circuit in the antenna,and for that reason defective grounds donot manifest themselves quickly. In an-tenna sets employing a series antennacondenser, a defective ground will causethe antenna condenser to tune verybroadly.

Speaker PolarityA loud speaker that has been connected

into a receiver with a polarity reversedwill, after a time, become demagnetizedand result in very poor volume andquality.

"1 he volume was great for a short time.but suddenly started to weaken." Thiscondition o'enera.ly results from using anexcess voltage on the tubes. It is par-ticularly true in.the case of sets employ-ing dry cell tubes. The customer some-times has a peculiar psychology and be-lieves that by turning the rheostats of thetubes on full that he is getting better

'results. With the tubes used today, em-ploying thoriated tungsten filaments, thisis a fa.lacy Operating tubes using thistype of filament at a greater than normalvoltage deactivates the filament veryrapidly and decreases its useful life. Underno consideration should a thoriated tung-sten tube be operated at a voltage higherthan the rated voltage as indicated by themanufacturer. A defective battery thathas deteriorated abnormally will alsocause this condition.

"I get one station well, but another sta-tion is weak and they are both about thesame distance away." It is the generalbelief that this condition is caused- bymetallic obstructions, such as steel build-ings, high-tension systems, railroads, etc.,or possibly mineral deposits near on theearth's surface. It is believed that theseobstructions cause either an absorption ora deflection of the radio waves whichrenders certain areas incapable of receiv-ing signals from certain stations.

You have probably all heard of the re-cent investigation carried on by the Am-erican Telephone and Telegraph Com-pany, in which it plotted the signalstrength of its New York station in dif-ferent sections of the metropolitan area,and of the peculiar results noted. Certainareas in Central Park were practicallydead to signals from this station.

Set Not at FaultThere is perhaps no remedy for this

condition and it is not the fault of anyparticular set, as this condition would betrue whether a crystal detector or asuper -heterodyne be used in such a lo-cation. Of course, the super -heterodynecircuit, because of its sensitivity, wouldrespond to an extremely weak signal thatwould be inaudible in a crystal detectorset, but for practical considerations, re-ception in such an area would not be sat-isfactory, while at the same time, excel-lent results might be obtained from othernearby stations.

"The volume used to be O.K.. but hasbeen getting weaker and weaker." Thiscondition is generally caused by the nor-mal decrease in voltage of the batteries.It may also be caused by the use of aslight excess vo'tage on the tubes whichwill cause a slower deactivation of thefilament than described previously.

In the case of a recent installation, de-fective batteries should be looked for.Should the installation have been made a

(Herbert Photos, (nc.)"FAULTY JACKS are the cause ofa large percentage of the failure ofamplifiers to operate properly. Tocheck these, plug the telephones inand out of the jack very slowly."

year previously, the difficulty might bedue to the normal depreciation of the use-ful life of the tube.

"It works O.K. for a while, but sud-denly a howl starts which sounds like asiren or a fog horn which can only bestopped by shutting off the set or cut-ting down the volume." This effect isdue to a vibrating air column which isset up between the loud speaker and, usu-ally, the detector tube of the set. Theaction is similar to that which resultswhen a receiver of a telephone instru-ment is placed in front of the mouthpieceof the transmitter. This condition is gen-erally caused by a microphonic tube inthe detector socket. It may be due alsoto a lose element in some part of thecircuit. A loose transformer laminationor condenser plate might cause the samecondition. A popular theory of this con-dition is that the vibrating air columnfrom the loud speaker causes a vibrationof the filament in the detector tube. Thevibration of the filament causes a varia-tion of the tube characteristics whichcauses in turn a variation of the platecurrent, and an acoustic feed -back re-sults.

Speaker AdjustmentIn loud speakers of the adjustable type,

adjustment of the air -gap will sometimeseliminate this howl. In the case of non-adjustable loud speaker units it will benecessary to try interchanging the tubesin the sets in order to eliminate this con-dition. If interchanging the tubes doesnot correct it, place the loud speaker sothat the bell points away from the setand place either the loud speaker or theset or both on pads of soft felt or spongerubber. It is because of this effect thatit is not advisable to place the loudspeaker on the top of the cabinet, unlessthe tube sockets are sufficiently cushioned.

This condition, however, usually oc-curs only when the set is operating atmaximum output and the radio -frequencyamplifiers are set in an extremely sensi-tive condition. Reduction of the volumewill invariably eliminate the howling ef-fect.

"The quality is terrible, we cannotunderstand a thing that is said." This

conifil ion is known as distortion and isdue to many factors. As a general rule,distortion occurs only in the audio -fre-quency circuits. Distortion may be causedby a defective tube, a defective battery,a defective loud speaker, a broken-downby-pass condenser across the output or,what is the most common cause of dis-tortion, overloading of the tubes. A softor gassy tube will cause distortion, butthis defect in a tube is rarely encounteredin standard makes of tubes.

In the Audio Channel

A weak or defective C battery is alsoa very common cause of distortion andwill be evidenced by a tendency of theanip,ifiers to squeal. A 13 battery whosevoltage has dropped 25 per cent. willoften cause distortion and may be accom-panied by a continuous high pitchedsqueal.

Audio -frequency transformers of poorquality and design will cause distortion,This is generally indicated by the inabilityof the amplifiers to reproduce the ex-tremely high and low musical tones. Atransformer in which the leads have beensoldered with a corrosive flux will causedistortion a short time prior to the timewhen the corrosive action of the fluxcauses the winding to open.

Overloading of the amplifier tubes isevidenced by a blasting of the loud tonesof the program. This is particularly trueon local reception. The customer shouldbe instructed to watch the overloadingof the tubes and if the blasting does oc-cur, he should detune his set slight.y so asto reduce the volume to the Point wherethe tubes wdl function properly. It isquite possible with the multi -tube setsused today, when installed in the vicinityof a powerful broadcasting station, to im-press on the grid of the last tube in aseries, sufficient voltage to swing the gridvoltage beyond the limits of the straightline -portion of the characteristic curve.

Increasing the C battery potential orvoltage on the amplifier tubes will tendto reduce this blasting. But this is notrecommended as good practice becauseof the possibility of increasing the nega-tive potential to such a point as to causedistortion when the tube is operating withnormal volume. A great many amplifiersin receiving sets use a fixed condenser,ranging from the values of 0 002 to 0.006,connected across the loud speaker term-inals. This condenser is known as a by-pass condenser and is subjected in thispart of the circuit to considerable peakvoltages. Should this condenser fail, adistorted signal will result. If. on servic-ing, this condition is met and all the fore-going items have been checked with noresults, replace this by-pass condenser, asa potential breakdown in this condenseris rather difficult to test for unless labor-atory equipment is available. Both theseconditions call for the replacement of thetransformers.

"Loud Enough; Very Noisy""It is loud enough, but very noisy.

There is a continuous, cackling, rasping orscratching sound in the loud speaker."This may be the result of any one ofmany causes. Interference from eitheratmospheric or local sources is the mostcommon cause of this defect. By localsources we refer to such apparatus as X-ray machines, violet -ray machines, elec-tric railway systems, elevator controls,leaky power lines or transformers. auto-matic telephone switching lines, telegraphlines. and local telegraph stations in thevicinity of the receiver.

(Part IT. the conclusion of this greatarticle, will be published next week.]


The Constant Coupling1 S.

F G . I 4 .

2 B

T

[Part I of this article was published in the August 21

A CHOKE COIL in theconstant coupling cir-cuit (Fig. 14) providesthe auxiliary plate ener-gizing path. C is notcommon to two circuits

(Fig. 15).

slue. The final instalment follows.]

By Edward H. Loftin and S. Young WhitePART II

(Copyright, 1926, by the Authors)

A s an example of the seriousness ofPI. this phase of the set, a Neutro-dyne licensee was catering to the tradein the far West when a well-knownmanufacturer of tubes decided to modifytube bases from metallic to insulatingmaterial. The Western jobber suddenlygot numerous complaints from his dealersthat the set owners were getting nothingbut squeals from their sets, so the mattercame back to the manufacturer who al-ready knew only too well the effect ofthis seemingly innocent change in tubebases. He couldn't make good with ex-planations-his set had to work underthe new conditions-so at a cost of $25,-000 he organized a readjusting party andcorrected every set he could locate inhis chosen territory.

How New Idea WorksOf course it would be easy to make the

neutralizing condensers Ci variable sothat the ultimate purchaser could adjustit to take care of any tubes he shouldpurchase, but then it would become thesame as an ordinary regenerative controland return radio to the early days ofbroadcasting and squealing regenerativesets. This was tried by one manufac-turer, but it landed him out of businessthrough a court decree under a regener-ative patent.

Now we can come back to combinedelectromagnetic and electrostatic couplingand point out how we make use of it toeliminate the detects pointed out in theregenerative multiple tube radio receiverand neutralized radio receiver, and by sodoing avoid regenerative patents andneutralizer patents.

Starting by using the combined coup-ling of Fig. 5 in the input side of thefirst tube we are enabled to get uniformenergy transfer throughout the broadcastband from the antenna, or any form oftransfer desired, such as stronger on thelong wavelengths or vice versa. It is aflexible coupling that will satisfy any de-mand along the lines shown graphicallyin Fig. 6. Of course, the combined coup-ling can be made tight or loose to anydegree desired, all being a matter of se-lecting the relative values throughout.

Mr. R. P. Clarkson, the well-knownradio technical writer for "The New YorkSun," stated as to the constant couplingfeature alone in the Sun Radio Sectionfor July 17, 1926:

"It is one of the most interestingdevelopments of recent years and fromcasual study appears to be the nearestapproach to exact engineering applied toradio:"

Uses Small PrimariesA feature of manufacturing importance

is that we need fewer turns in our pri-mary coil of the inductive coupling in

getting as much overall coupling as iscontained in the ordinary receiver be-cause part of the coupling is capacitive.

There thus results less distributedcapacity in the coil system which permitsa given modified coil system and tuningcondenser to reach a lower wavelength,it being quite obvious that when thetuning condenser is at its minimum set-ting the distributed capacity is quite afactor in the residual capacity of the cir-cuit. For instance, we have convertedcommercial receivers which could notreach below 230 meters and brought themdown below 200 meters without sacrificingany overall coupling. We find no diffi-culty in constructing a tuning systemusing commercial condensers that rangesfrom 150 meters to 600 meters, and havebeen unable to accomplish the same resultwith a normally effective inductive coup-ling alone.

We also find it unnecessary to arrangetwo connections to take care of long andshort antennae. The coupling has the ef-fect of eliminating the so-called "absorp-tion hump" that occurs when the antennanatural period falls within the broadcastband.

Examining the combined coupling be-tween the plate circuit and the tunablecircuit 2 in Fig. 14, it is obvious that thecoupling condenser interrupts the con-tinuity of the plate circuit to prevent theplate being energized through this path,so we have to provide the auxiliary plateenergizing path shown which includes achoke coil suitable to make the couplingpath the effective path of the plate cir-cuit for the broadcast band of frequen-cies.

Keeps Two ApartIt is seen that the location of the tun-

ing condenser of circuit 2 is proper toprevent impressing the plate potential onthe grid of the succeeding tube.

Taking up for consideration the platecircuit reactions through varying the cir-cuit 2, we find its tuning will create thesame cycle of reactions heretofore pointedout for plain inductive coupling, but theimportant feature of the new system isthat we can control in most definite man-ner how these reactions will vary withfrequency.

By comparison,- the plain inductivecoupling causes the troublesome pre-dominating inductive reaction to increasemost substantially with frequency, so thatif we construct an inductive coupling thatwill be sufficiently loose not to createoscillations at the shortest wave, then atthe longest wave regeneration is gone tosuch an extent that the receiver is ex-tremely poor in this region. It is for thisreason that the commercial receivers de-pending upon regeneration do not designto go below about 230 meters. If such

riG35.a receiver were designed not to oscillateat 200 meters it would be practically use-less at 550 meters.

On the other hand, with the new coup-ling we can so select the relative valuesof the elements and adjust them that weobtain just the reverse condition, that isoscillations or near oscillations on the longwaves and falling off on the short waves;or any other result such as just belowoscillations throughout, and thereforemaximum regeneration throughout, andwe have done it from 150 to 600 meters,or just in oscillations throughout the samerange. So here is a most important re-generation control, offering the possibilityof a regenerative type of set than canbe set as the regenerative user likes it,namely just below' oscillations, withoutproducing squeals for his neighborhoodas he tunes, and we will point later a stillsimpler form of regenerative detector set.

Adds a CondenserWe have constructed the arrangement

as a regeneratively reactive one stageradio frequency and detector (with twostages of audio), adjusted just below os-cillations, and got results in both select-ivity and intensity which we have not en-countered 4 -tube set, butwhen we tried to add another stage like-wise critically adjusted for regenerationwe ran into difficulties due to the criticalconditions brought in by the excessiveregeneration, so from our experience donot recommend more than one stage. Webuilt such a 4 -tube receiver, adjusted itin selectivity under New York conditions,and gave it to an experienced engineerwho took it down the Jersey Coast fortrial. When he brought it back _his onlycriticism was that he found it too selectivefor inexperienced operators on distantwork.

Coming to the final step that permitsof constructing a true tuned radio fre-quency amplifier of any desired numberOf stages that is entirely free from tubecapacity regeneration, and includes thedecidedly new feature of being independ-ent of tube capacity, tube construction,and therefore tube manufacturers, andalso embodying the entirely new featureof constant energy transfer, or uniformresults throughout the broadcast band,or further if desired, refer to Fig. 15,where we examine the effect of puttinga condenser C in the plate circuit justas we did with the condenser Ci thecase of Armstrong, Fig. 13.

The first thing obvious is that we donot make the condenset' C, Fig. 15, coin -111011 to the two circuits as is the con-denser C,,, Fig. 13, and therefore have toconsider only the plate circuit reaction itcreates and not any inter -circuit coupling.Of course the condenser C of itself wouldtend to produce a plate circuit reactionto send amplified current through the in-herent tube capacity out of phase, asshown vectorally in Fig. 8 in connectionwith Fig. 7, but the magnitude of thiscapacitive reaction will vary with fre-quency.

Two OpposeNow if we can introduce in series with

condenser C an arrangement that will(Continued on page 28)

August 28, 1926 RADIO \V (1 R. 1, D 11

Sets Should Be BalancedFailure to Include Means

of Suppressing Over -Oscillation Causes Re-ceiver to Be Poor inPerformance-Effect ofRegeneration on Un-desired Reaction.

By Capt. P. V. O'RourkeQUITE a few_ circuits are advocated

and constructed without regard tothe important consideration of stabiliza-tion. Various forms of balancing are inuse, and some form should be used, par-ticularly in a tuned radio frequency re-ceiver. All too often the coil, condenserand other connections are shown for a5 -tube set, and nothing said about thevice inherent in tubes, whereby they flopinto over -oscillation at some low wave-length, or even at an intermediate wave,like 431 meters, and misbehave on allwavelengths below that.

One form of attempting to avoid theconsequences is to resort to tletuning, forit is at resonance, or trivially off reson-ance, that over -oscillation is most likely.But the energy transfer is greatly reduced,the amplification suffers badly and effi-ciency is flung to the four winds whendetuned radio frequency amplification isused. Distortion is inevitable.

Hazeltine Paved WayThe first popular form of stabilization

was that developed by Professor Louis A.Hazeltine, then of the Stevens Instituteof Technology, and it resulted in the nowfamous Neutrodyne. It is a good method.It is something like the Hartley and Ricemethods, except that in application thesewere not introduced for the non -squealingeffect Hazeltine set out to accomplish. Infact, or rather, in law, it has been estab-lished that the Hazeltine method does notinfringe the Rice and Hartley patents ofthe radio trust.

As regenerative sets are popular, it iswell to keep in mind that they are stabil-izable, if one may coin that word. Theyare not stabilized, yet they do not abso-lutely require any neutralization of tubecapacity or other form of balancing outover -oscillatory vice, unless several stagesof RF are used. For instance, in the mostpopular form of the day, this circuit con-_sists of a stage of tuned RF, a regenera-tive detector and suitable audio forspeaker operation.

Rider's Important Invention

It is well to neutralize the RF tube witha small balancing capacity, say from apoint on the interstage secondary to gridof the RF tube, the reverse current flowbeing through the neutralizing capacity.Yet it is not absolutely imperative becausethe plate of the detector tube is con-nected, although not with keen premedi-tation, to the batteries common to theplate of the RF tube, and also and moreimportantly because the coil in the platecircuit of the RF tube transfers energyto the secondary of the 3 -circuit coil, andthe third coil therein is the tickler, in in-ductive relationship to the secondary andhence in the same relationship to theprimary or coil in the RF plate circuit.The adjustment of the tickler to belowthe saturation point therefore has a

a8

aa80oT

n-aa 211 I

g )

00", "-On'

FIG. 1The fundamental idea of the new neutralization method invented by John F. Rider.

stabilizing effect on the RF tube as wellas on the detector tube.

The subject of neutralization wastreated very thorougoly in last week'sissue of RADIO Vv-otttn, in the first instal-ment of the article by Edwin H. Loftinand S. Young White, which is concludedin this week's issue. That article advo-cates a particular method of balancingthat enables uniform energy transferthroughout the wave band, and which isindependent of tube capacity. It is a newmethod, as is the one illustrated in Fig. 1herewith, known as the Rider method,invented by John F. Rider, noted radioengineer. The Rider method (patentpending; serial number 124, 182), may beemployed in tuned radio frequency re-ceivers, even if three stages of tuned RFare used (normally four controls), andwithout recourse to shielding. A resistoris connected from the plate of a tube toB plus amplifier. A fixed condenser isconnected from the plate to one terminalof the primary of a radio frequency trans-former, the other primary terminal beingtied to B plus amplifier. The input to thenext tube is along conventional lines. Theresistor is R in Fig. 1, the condenser isC and the primary of the tunable RFtransformer is L.

This neutralization method, which Mr.Rider announced in his weekly full -pagetechnical department, The LaboratoryScrap Book, in "The New York Sun RadioSection," absolutely squelches over -oscil-lation, yet maintains high amplification.The explanation, as given in the patent

Rider Develops a New andEffective NeutralizationMethod, Based on Du-plication of AntennaConstants and the Ab-sorption Effect.

application, is that absorption takes place,due to resistance, capacity 'and induc-tance (R, C and L in Fig. 1), that approxi-mate these constants as they exist in thenormal antenna circuit.

Has Designed a SetDepending on the electrical character-

istics of the transformer and other items,the values of R and C especially wouldhave to be determined experimentally. Asa test one may try .00075 infd. for C, 400ohms for R, with an 8 -turn primary on a3" diameter for L. These arc merely sug-gestions.

In the design of a receiver using thissystem Mr. Rider has worked out thevalues with scientific accuracy for theparts used, and the set will be describedfor public benefit in weeks to come. Mr.Rider has made an important contributionto the science. Readers of RADIO WORLD,familiar with his contributions publishedin this magazine know the height of hisscientific radio knowledge.

McNamee In Movies; He Waxes ArtisticFinds It Hard Work With a 10c Whistle

Graham McNamee, the well-knownWEAF announcer, is almost daily addingto his varied list of accomplishments.During the past week the outcome of hisdebut as a movie actor has .been shownupon the screen. The familiar "This isGraham McNamee announcing fromWEAF" is thrown upon the screen andthe picture then depicts the announcer atthe broadcasting of a prize fight.

He enjoyed the thrill of appearing inthe movies but learned that his belief thatmovie actors had a "snap" was hardlyfounded on fact. After the intricate tricksof make-up had been explained and triedout, after the many rehearsals, the timeconsumed in placing the lights and theirheat on a hot day, he was still enthusiasticbut not one bit envious of the actors'lot. He lost four pounds during his moviedebut.

SPRINGFIELD, MASS.Felix Livingston, "America's Tin Whis-

tle Virtuoso," presented a novelty radioconcert from WBZ. One of the few flageo-lettists on the vaudeville stage, he createda sensation in his recent theatrical tourof the South and Middle West. He hasbeen heard over the radio in the West, buthis concert from WBZ marked his firstappearance on the wave of any broadcast-ting station in the East.

A 10 -cent whistle was the only instru-ment used by Mr. Livingston in his novel-ty program from WBZ but listeners wereastonished by the quality of the music ob-tained from such a cheap instrument.Classical selections as well as the latestdance numbers and song hits were offeredby Mr. Livingston and the tests made onthe WBZ wave showed that the cheapwhistle is well adapted to broadcasting.

ON ITSWAY

BERNARDA 6 -Tube Set Destined to Win Great Popularity

12 RADIO WORLD August 28, 192b

How to Operate the Improved

BROWNING -DRAKE

(photo Topics) FIG. 6The rear view of the Improved Browning -Drake, as designed by Arthur H. Lynch,noted radio editor and author. The input is at right as you look at this photo-graph, hence Cl is located there, CZ being at left. This of course is the oppositeto the relative positions when you are actually tuning, with the front panel nearer

you.

[The theory of the Improved Browning -Drake was expounded in the August 14issue, while the construction was detailedstep by step in the August 21 issue. Fol-lowing are the tuning and operating direc-tions. Other phases of the circuit and itscare will be discussed in subsequent issues.]

By Herman BernardAssociate, Institute of Radio EngineersTAKING it for granted that batteries

I are properly connected and that thetubes light as they should, and as theywill, if the diagrams are followed and thetubes are good, we will now proceed to adiscussion of the tuning and operatingfeatures of the Improved Browning -Drake. This receiver was designed byArthur H. Lynch along lines consistentwith the laboratory perfections achievedby Glenn H. Browning and Frederick H.Drake in coil design, and in consultationwith Laurence M. Cockaday, technicaleditor of "Popular Radio."

The whole circuit is built along qualitylines, and that presupposes a due regardfor the side bands, or inflections on thecarrier wave caused by impregnating itwith the audible frequencies. Thus theinput circuit, C1L2 in Fig. 1, page 3, issueof August 14, will not tune exceedinglysharp, for it should not do so. There is atuned radio frequency stage after it, rep-resented by the detector input, and thisdetector stage is regenerated, so that thefeedback here gives one a high degree ofselectivity indeed. Any design that wouldheap that high selectivity factor upon anultra -selective tuned input preceding itwould be a foible.

Going After DXIn searching for distance stations one

may rely upon somewhat greater leewaywith the dial tuning Cl, unless the signalstrength is very feeble, when distance canbe tuned in only by accurate setting ofthis dial, too. So, to get distance, youshould know at about what point on Cl,judged by its dial, the station shouldcome in, and the setting should be madethere and C2 should be tuned with thetickler just at the oscillation point. Whenresonance is established in the receivercircuit, and this tuning is pitted againstthe incoming signal frequency, an audiblefrequency results, due to the differencebetween the two frequencies. Now wehave the familiar beat note or squeal,

which may be heard from the speaker,but which does not get into the air out-side to annoy neighbors who are listen-ing in, for the radio frequency tube per-forms some slight blocking duty and moreimportant by far it is neutralized, so thatthe heterodyne wave generated in the re-ceiver does not get far outside of the set.

Now, with the beat note established,slightly retard the tickler that is, loosenthe coupling, and turn the dial of C2ever so slightly one way and another, andthen back to the original position, so thatno squealing results when this is done.

Easiest Operating PointIf you do hear a whistle you have too

much plate reinforcement of the gridcircuit, so loosen the tickler coupling justa trifle until the goal is reached. One ofthe panel knobs, the one to the left ofthe C2 dial, actuates the tickler.

Your set is now tuned so that thetickler coil enables the detector tube tofunction just below the saturation point,and this is where most generally satis-factory reception is received on distantsignals. Somewhat tighter coupling,known as critical coupling, gives greateramplification but blurs the signal.

Leave C2 set as it is and slightly varythe setting of Cl on both sides of itsoriginal setting until maximum volume isobtained. Then retune the C2 dial justa bit and finally try tightening the ticklercoupling by the barest fraction of a dialdivision. This last-named precaution istaken to be sure that not even slightestdetuning of the secondary IA has beenoccasioned by any tickler setting, or ifdetuning has resulted, then you are tak-ing proper steps to tune to resonance.

Freaks of DXDistant stations perform freakishly at

times. Fading is one nuisance and swing-ing is another. These considerations areindependent of the receiver. Unaccount-able factors cause the carrier frequencyto change perhaps only a trifle, and oncein a while you may have to retune tocatch up with it. This swinging phenom-enon is often ascribed to changed coursestaken by the radio wave, whereby inter-vening objects trivially affect the fre-quency. At best this sounds like a weakexplanation, but the problem is there.and an occasional touch of the dial willstraighten matters out satisfactorily.

Of course one must know somethingabout the location of different wave-

lengths in respect to the Cl and C2 dialsto be able to tune in distance with any de-gree of certainty. It is assumed that anyone can tune in locals, hence has done so,and has made a log or chart which en-ables him to know with a certainty whatthe Cl position is for any wave, and ap-proximately what it is on C2. As for thetickler, that can not be calibrated withscientific precision, due to changing fac-tors, such as altered A battery conditionaffecting the filament temperature andelectron emission, and the similarlychanged feed to the plate from the B bat-tery.

Another MethodFor instance, in tuning in a station far

away that has a wavelength near that ofsome- local, you may use the system oftuning to the local's wavelength, and ifthe DX station is of slightly lower wave-length, then turn the dial slightly tocome somewhere near the necessary fre-quency, and await the beatnote which atightened tickler setting affords.

Particularly in the reception of distantstations, and in large cities in receivinglow wavelength locals too, a steady whistlemay be heard, its pitch not being variedthough the dials are turned a little. Ofcourse the total volume declines, both ofthe signal and of the whistle or moan, butthe pitch never varies. This is an audiblenote caused by the wave of one stationbeating against that of another, or againstthe second harmonic of another, and noreceiver can offer any cure for that. It'sin the air, is the best you can say aboutthat and forget it until Congress meetsagain.

Tickler On LocalsIn tuning in local stations it is never

necessary to use tight tickler coupling, in-deed the looser it is, consistent with de-sired volume, the better, for the qualityis most easily upheld and the B batteryconsumption is kept down. Over -oscilla-tion or anything like it causes the platedrain to rise very pronouncedly.

It is obvious, therefore, that for quitea stretch of the wavelength spectrum itis possible to tune in locals satisfactorilywithout much attention to the tickler.It is set for good regenerative effect atsome medium or low wave, and the higherwaves will require no tighter coupling.unless great volume is required, as whenthere is dancing at home, or in cases ofscreened location, where the incomingwave is partly dissipated, and the extraamplification afforded by greater feedbackis desirable.

No sign of distortion is to be tolerated.The tickler always should be set so thatthe detector tube is under the saturationpoint. When there is over -oscillationthere is bad distortion, but that simplymeans the set is being abused, for if it istuned and operated correctly you haveno distortion, as that term is commonlyapplied, with the single exception that apoor speaker will spoil Lnuch of the merit.

Louder DXYet if you want to tolerate a little dis-

tortion on distant signals, to make themas loud as locals, you have this choice inthe tickler setting, since some fans liketo do this just to test the maximumvolume possible consistent with discern-ment of what is being said, sung orplayed at the station.

The set will reach out into the far dis-tance, if conditions arc suitable, yet it isa quality set in every sense of the word.

A ')Q 1926 RAnrn woRT n 13

Radio UniversityAFREE Question and Ans-

wer Department con-ducted by RADIO WORLDfor its yearly subscribersonly. by its staff of Experts.Address Radio University,RADIO WORLD, 145 West45th St-. N. Y. City.

When writing for information give your Radio University subscription number.

I WOULD like to have a wiring des-cription of the Federal Type 102 receiver.Please give the constants of the parts.-Thomas Vurt, Spring Valley, N. Y.

The receiver employs a tuned stage ofradio frequency amplification, a non -re-generative detector, coupled with a un-tuned air or iron core RFT and twostages of transformer coupled audio fre-quency amplification. A single windingantenna inductance is used. This con-sists of 55 turns of No. 22 double cottoncovered wire wound on a tubing 3" indiameter. Taps are taken from the 4thand 8th turns front the beginning of thecoil. The antenna post is brought toeither of the tapped portions of the coil,depending upon the length of the antenna.The beginning of the coil is brought tothe rotary plate post of a .00025 mfd.variable condenser, to the arm of a 400ohm potentiometer, to a terminal of a.00025 mfd.-fixed condenser and to a ter-minal of a .01 mfd. fixed condenser. Theother terminal of the .00025 mfd. fixedcondenser is brought to the ground post.The other terminal of the .01 mfd. fixedcondenser is brought to a resistance postterminal on the potentiometer and to theF minus post on the RF tube socket. Theother resistance terminal of the potenti-ometer is brought to the F plus post onthis same socket. The F minus posts ofthe two AF tubes are connected to theF minus post of the first RF tube. Thisconnection is then brought to the re-sistance terminal of a 10 ohm rheostat.The arm of this rheostat is brought to theA minus post. It is also brought to thearm of a 20 ohm rheostat. The resistancepost of this rheostat is connected to theF minus post on the detector tube socket.The F plus posts are all connected to-gether and thence to a terminal of aswitch. The other terminal of the switchis brought to the A plus post. This samepost is also connected to the minus postof the B battery. The end of the an-tenna winding is brought to the station-ary plate post of the .00025 mfd. variablecondenser and to the grid post on theRF tube socket. The P post on the un-tuned RFT is connected to the P post onthe RF tube socket. The B post is broughtto the 13 plus 45 volt post. The G post onthis RFT is connected to one terminal ofa .00025 mfd. grid condenser and a 2megolun grid leak combination. Theother terminal of this combination isbrought to the grid post on the socket.The plate post on this socket is broughtto the P post on the first AFT and to oneterminal of a .003 mfd. fixed condenser.The F post on the fixed RFT is broughtto the F plus post on the detector tubesocket, The B posts of both AFT arcconnected together and thence to 'die Bplus 90 volt post. The G posts on thefirst AFT is brought to the G posts on thefirst AF tube socket. The other 'terminalof the .003 mfd. fixed condenser is broughtto the F Post on the first AFT and to theF minus post On the socket. The P poston the first AF tube socket is brought tothe bottom terminal of a single circuitclosed jack. The second terminal frontthe hot torn of this jack is brought to theP post on the second AFT. The B poston the second AFT is also brought to thetop of Ihis jack. The G post on thesecond A FT is brought to the G post onthe last A F tube socket, The plate post

on this socket is brought to the topterminal of a single circuit open jack.The bottom terminal of this jack is con-nected to the B plus 90 volt post. The

filaments of the RF and the AF tubesare controlled by a single rheostat. The-01A tubes work best in this receiver.

* * *

I WOULD like to have the circuit dia-gram of the set using a carborundumcrystal with a potentiometer to control thebattery flow which was described in theRadio University col -inns of the August21 issue of Radio World. Please des-ignate each part.-Gerald Sharten, EastPittsburgh, Pa.

Fig. 417 shows the wiring diagram ofthis receiver. LI is the tapped Primary,while L2 is the secondary, which is shunt-ed by a .0005 mfd. variable condenser Cl.P is the potentiometer. C2 is the .002mfd. fixed condenser. SCJ indicates theplace where the phones are to be inserted.These may be substituted by phone tipjacks. A minus and plus indicate the PAvolt battery. The switch arm and taps areshown at S.

* * *

- I HAVE a 1 -tube reflex as shown inthe diagram, which I would like to changeinto a 2 -tube reflex, using a tube as adetector, instead of the crystal. Thechanges made on the original diagram,will be appreciated. I am using standardRFT, with .0005 mfd. variable condensertuning the secondaries. The primariesconsist of 10 turns, while the secondariesconsist of 45 turns. These are wound on

L/),

tubings 3" in diameter, using No. 22double cotton covered wire. There is noseparation between the windings. Therheostat that controls the filament of theRF tube is of the 30 ohm type. The AFTused is of the high ratio type. A fixedcrystal detector is used.-Bernard Smith,Haines Falls, N. Y.

In Fig. 418 you have the circuit diagramof your receiver, with the necessarychanges to be made, show in dotted lines.R3 and C3 are the grid leak and condenser(2 megohm-.00025 mfd.) combination. R2is a 20 ohm rheostat, which controls thefilament temperature of the new detectortube. The stationary plate post of thesecond condenser C2 is connected to oneterminal of the condenser -leak combina-tion. The other terminal of this combin-ation is brought to the grid post on thenew socket. The rotary plate post of thecondenser C2 is brought to the F pluspost on the new socket and to the begin-ning of the secondary winding. The crys-tal detector is disconnected. The platepost on this socket is brought to the Ppost on the AFT. The B post on thisAFT is brought to the B plus 45 voltpost. The connection from the B post ofthe AFT to the beginning of the second-ary winding of the second RFT is brokenalso. B plus detector indicates the use of45 volts, while B plus amplifier indicatesthe use of 67% to 90 volts.

* * *

I AM citing the new UX200A detectortube in the Diamond of the Air, insteadof the -01A and at times hear a continu-ous whistle or noise, which I cannot con-trol, unless I force the tubes. A reductionin the plate voltage does not help either;

S C ,/

FIG. 417The electrical diagram of a receiver using a crystal with a battery.

IR3

ryci

7

/1F-RF TUBE

B -/-/impOfl-0 fi+a-

.

FIG. 418The electrical diagram of the 1 -tube reflex, using a crystal detector, changed to a

2 -tube reflex, using a tube detector.


INI

ww 0

FIG. 419

The circuit diagram of the 3 -tube regenerative set using variometers to tune theplate and grid circuits.

installing the -01A however clears up thenoise. What can I do to remedy this ?-Max Rosacker, 26 South 10th St., Read-ing, Pa.

Evidently you did not change the gridreturn to minus. The -01A tube requiresa positive grid return, while the 200Aworks better with a negative grid return.The 200A will stand a high plate voltage,e.g., about 45. Try decreasing the gridleak resistance.

* * *

WHERE DOES the grid return of thedetector tube in the Diamond go, to theminus or to the plus of the filament?-Henry Lee, 904 West College St., Austin,Minn.

If the -0IA or -99 tube is used, it isbrought to the plus.

* * *

IS IT possible to add a stage of re-sistance coupled audio frequency ampli-fication after two stages of transfornfercoupled audio frequency amplification andget satisfactory reception? If so, pleasedescribe how to hook it up, giving theconstants of the resistors and the con-denser, etc.-J. Welsh, 903 West 8th St.,Cincinnati, 0.

Yes. The signals will be very loud. Apower tube should be used in the last stagewith a high plate and grid voltage. Theplate resistors, which should be connectedin the output of the last amplifier stage,should be of the 100,000 ohm type. Theresistor in the grid circuit of the newtube should be of the .1 megohm type.The stopping condenser should be of the.25 mfd. fixed type. One terminal of thefixed condenser should be connected tothe plate of the 2nd AF tube. The otherterminal of the condenser is connected toone terminal of the 1 megohm resistor andto the grid post of the new socket. Theother terminal of this resistor is connectedto the minus post of a C battery. Theplus post of this battery is connected to

the minus post of the A battery. Theplate post of this tube is connected to thetop terminal of a single circuit jack orsouse terminal which will make contactwith a terminal of the speaker. The otherjack terminal, or otherwise, should beconnected to the B plus post. The fila-ment of this tube should be controlledby a ballast resistor. Both the 120 andthe 171 require a Vz ampere ballast re-sistor. The 210 draws 1.25 amperes at 7.5volts, while at 6 volts, it draws 1.1 amperes.For further information regarding gridand plate voltages of these tubes, see thechart which appeared in the July 10 issueof Radio World.

* * *

I HAVE the following parts, which Iwould like to use in the construction ofa 3 -tube receiver: two Cardwell .0005 mfd.variable condensers; two variometers(150 to 600 meters); one coupler (10 turnprimary, 45 turn secondary, 3,1 diameter);two All-American audio frequency trans-formers, one having a 10 to 1 ratio andone having a 3 to 1 ratio; one 30 ohm,three 20 ohm and one 6 ohm rheostats;four 1-A type Amperites; one 112 Amper-ite; one 6 volt storage battery.-ArthurZalloff, Cleveland, 0.

The circuit diagram of a receiver usingthese parts is shown in Fig. 419. P in-dicates the primary of the coupler whileS indicates the secondary of the couplerLl is the variometer; which is used in thegrid circuit, while L2 is the other variom-eter, which is used in the plate circuit forobtaining regeneration. Cl is the .0005mfd. variable condenser used to tune thesecondary. S is a switch, used to cut inor out the variometer, for long and shortwave reception. C2 and R1 are the gridleak and condenser combination, e.g., 2megohm and .00025 mfd. C3 is a .001 mfd.fixed condenser used for bypassing RFcurrents. AFTI is the 10 to 1 ratio trans -

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Name

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City and State

former. AFT2 is the 3 to 1 ratio trans-former. R3 and R4 are the Yt ampere(1-A Amperites) ballast resistors. The-01A tubes are used. A 112 may be usedin the last stage. However when doingthis, it will be necessary to install the 112Amperite. SCJ is a single circuit jack.B plus 1 equals about 45 volts, while Bplus 2 equals about 90 volts. All thefilament controls are placed in the nega-tive leg. The two AF tubes have a minusgrid return, while the pet. tube has aplus return.

* * *

PLEASE GIVE a description of theaction of the Tungar or Rectagon tube asa rectifier-George Wells, Tacoma, Wash.

A coiled tungsten filament is heated bycurrent delivered from the secondary ofan auto -transformer. During the halfcycle, when the filament is negative, theelectrons emitted from it ionize argongas in the tube. A current of a fewamperes is carried by the ions in thedirection from a graphite anode to thefilament. Upon the reversal of the al-ternating supply voltage, the newly emit-ted electrons are driven back into thefilament. Thus no electrons are availablefor starting the ionization of the gas andconsequently no conduction of currenttakes place.

* * *

PLEASE ADVISE use whether the Bminus is connected to the A plus or tothe A minus in the Set With a 1 -TurnPrimary described in the July 3 issue ofRADIO WORLD.-R. L. Byrd, Winter Gar-den, Fla.

The A plus is connected to the B minus.

PLEASE GIVE the electrical character-istics of the first and second stage Amer-tran DeLuxe audio frequency amplifyingtransformers.-Max Lenton, Bear Moun-tain, N. Y.

The primary inductance at 200 cyclesof the first stage type, is 168 henrys. Theapproximate resistance of the primary(direct current) of this AFT is 1,470 ohms.The approximate resistance of the second-ary (direct current) is 6,000 ohms. Theplate current limit of this AFT is about 3milliamperes. This current is at DC whenapplied to the plate. The primary in-ductance at 200 cycles of the second stageAFT is 110 henrys. The approximate re-sistance of the primary (direct current) is1,090 ohms. The approximate resistanceof the secondary of this AFT (direct cur-rent) is 6,150 ohms. The plate currentlimit of this AFT is 7 milliamperes.

RESULTSResults Editor:

I have recently had the pleasure of con-structing the Bernard 1 -Tube DX set,which was described in the Oct. 24 issueof Radio World, with the addition of astage of audion frequency amplification.The set worked right off the bat and ina few nights I have logged over 30 sta-tions. I got the surprise of my life whenI tuned in the following stations all onthe loudspeaker: WREO, WBBM, KDKA,WBAL, WWJ and WPG. WREO couldbe heard all through the four rooms, theother stations coming . in with enoughvolume to fill the room. Although thissounds more like fiction, it is an honest -to -goodness fact and I think it is quiteremarkable for only two tubes.

HAROLD KING, Olivet, Mich.* * *

Results Editor:My Diamond of the Air works great.

I have had no trouble in tuning in DX.Havana and Dallas, Texas, came in withgreat volume.

DANIEL PIZZICA,1163 Grant St.,

Indiana, Pa.

veerxr-ire-,w-r- w

RADIO WORLD 15

Hookups for the FastidiousTo

*I*

Pvah-Pull TransforymerFOR LOW audio frequencies, 50 to200 cycles, the unit diagrammed abovemay be used as an audio oscillator.The transformer used is of the push-pull type. The value of the variablecondenser across the secondary is de-pendent upon the frequency output

that is desired.

ocpwo

---0.0144-_

A 5 -TUBE receiver, employing two RF, a non -regenerative detector and twostages of transformer coupled AF tubes. Rheostats are used for RF and detectorfilament control, while a ballast resistor is resorted to in controlling the filaments

of the last two AF tubes.

yr'

OB

0 B+

O A'

O k-A POPULAR 2 -tube circuit diagram, wherein a regenerative RF tube, a crystaldetector and a stage of transformer coupled AF coupling are used. The RF tube

also acts as an AF amplifier.

HOW A vacuum tube voltmeter ap-pears in a circuit diagram. V indi-cates a volt meter, used for ascertain-ing the exact grid bias required to ob-tain a plate drain of known value, pre-

viously calibrated.

0

UV -/99 UV -/99 UX 120

IN THE diagram shown above thefilaments of the first two tubes areconnected in series, the next two areconnected in parallel and this parallelcombination in series with the fila-ment of the 120 tube. The 120 draws120 'milliamperes, but only 3 volts.The -99 type tube requires the samevoltage, but only half as much cur-rent. Therefore two of the -99 tubesconnected in parallel, will require thesame current as the 120. The voltageacross the three tubes is then 6. Theytherefore may be connected across a6 volt battery and operated economic-ally. The total drain when using thetubes in the combination is only 180milliamperes. This is low enough fora single series of four No. 6 dry cellsto supply the filament for a long time.

IF YOU are using a resistance coupled AF amp ifier, in conjunction with a Beliminator and are troubled with a "steamboat" effect, the installation of the

variable resistor R7 will cure that ill.

A VERY successful way of adding three stages of transformer coupled AFamplification is shown above. The Centralab 500,000 -ohm variable resistance in

third audio grid prevents distortion. Low ratio AFT should be used.

A GOOD way to kill external powerline noises is to place two resistors,having a fixed resistance of about 3megohms in series and grounding themiddle tap. The generator above pre-sents the incoming line. These re-sistors may be substituted by fixedcondensers of a rather large size, e.g.,2 mfd. These should be able to standat least 750 to 1,000 volts. The groundmay be the same as used for the re-

ceiver, e.g., the waterpipe.


Television Nearer,ut Road Is Rough

No Practical Solution Yet Offered, But the ModulationMethod Appears to Have Better Chance Than

the Physical Means Final Solution MayBe Compromise

By Leon L. AdelmanThe Chas. Freshman Co., Inc.

The radio age is upon us. The elec-trical age, acknowledged by authoritiesto be still in its infancy, has been sur-passed by the meteoric progress of theart of radio. This progress has in itsscope the perfection of one most impor-tant invention to humanity-the art oftelevision.

Like the development of the moving,pictures, television will follow the perfecttransmission of photographs. Just whencan be only a matter of time.

At present there are several means oftransmitting photographs from one pointto another by wire, cable or radio. Thevarious systems of themselves offer nosolution to the problem cf transmittingmoving pictures. Nor has any one as yetproposed what appears to be a commer-cially feasible and practical solution.From a logical viewpoint just what is the

impossible barrier? Let usconsider the systems.

Caselli's 1856 MethodThe outstanding advantages of the

Belin system, the Bartlane, Hanson,A. T. & T., Leishman, Korn, R. C. A. orJenkins system as compared to one an-other, are evident from a brief resumeof their characteristics.

As early as 1856 Caselli sent variousdesigns by telegraphy, using for thetransmitter a tinfoil -covered cylinder onwhich the designs were drawn in insulat-ing compound. A needle acting verymuch like the stylus of a phonographserved the purpose of a contact pin,traveling spirally over the surface of therevolving cylinder. Thus the circuit wasmade and broken as the lines passedunder the contact pin, while at the re-ceiving end, by an electro-chemical ac-tion, a similar cylinder synchronized withthe transmitter reproduced the designsdirectly.

Effect on SeleniumThe discovery of the effect of light on

the electrical resistance of selenium be-came known in 1873 and shortly after-wards various schemes to substitute sele-nium for Caselli's process were attempted.The most noteworthy were those of Sem-locq and Perosino in 1878. After quitea lengthy interval Korn (in 1904) em-ploying Semlocq's plan with severalmodifications, succeeded in transmittingphotographs a few hundred miles. Themethod now in use by the R. C. A. is toplace a negative of the photo on a glasscylinder. On this is focused a very nar-row beam of light used as a stylus. Byreflecting the varying intensity of thelight passing through the cylinder theregistry is effected and then followsan amplifier system which then allowsthe photo to be reproduced in several

ways : either by a tape recorder whichrecords the photo as a continuous line ofdots and dashes; by means of a relaywhich operates a special pen and re-produces a pen and ink sketch, or bymeans of photographic reproduction, alight shutter being controlled by the cur-rent variations and controlling the lightfrom a lamp focused on a sensitized ro-tating cylinder.

Betio Full of OriginalityWith such a system successful photo

transmission has been accomplished byradio transmission from London to NewYork.

The first photo which was transmittedover the Atlantic was sent by a systembased upon the half -tone method ofscreening. The photo was automaticallydivided into a predetermined number ofdots per square inch. A photo -electriccell then determined into which of eight-een groups a dot belonged, each groupbeing given a distinguishing letter. By

of special relays, the letter wasautomatically transmitted and at the re-ceiving station, the letter was convertedinto a dot and placed into its properPosition in the photograph. Even thoughthe photo was converted into 12,000squares, much of its detail was lost. Amore pearly perfect system is the Leish-man process which employs a similar butmodified principle and operates on trans-atlantic cables.

Perhaps the most original scheme isthat developed by Belin. His process re-solves itself upon the fact that bichrom-ated gelatin becomes insoluble understrong light-his own discovery. Thus heplaces a film of wet gelatin under anegative, whereupon the portions of thefilm swell up more or less in proportionto the intensity of exposure. This formsa sort of relief map of the negative andis wound on a cylinder over which astylus traces its path. A microphone at-tached to the stylus varies the resistanceof a local circuit which is coupled. to atransmitter. At the receiving station anoscillograph has its mirror deflected, al-tering the projection of a beam of lightfocused on a synchronized rotating cylin-der having a sensitive photographic filmon it.

How Jenkins Does ItThe Jenkins method of analyzing is

based on aberration by means of pris-matic rings. These rings are of glass,the edges ground in such a manner thata beam of light passing through is givenan oscillating motion. By means of twosuch rings geared at a predeterminedratio, a negative is explored in minutestrips. and a photo -electric cell employedto convert light into electrical values.

The Bartlane system is a coding processwhich operates by a printing telegraph.Holes are punched into a tape and repro-duced at the receiving end by passing the

GLOBE-TROTTING

1-letbcnt Photos, Inc.)CAPTAIN PLUGGE, noted English glLondon to Constantinople in a car thattion. It has a 9 -tube receiving set anabout six weeks; he will visit 15 COI/enroute, while he picks up programs fr,

Best Radio Voi(Who has America's perfect radio voiceIs it a statesman, an announcer, a bar,

tone, a whispering pianist, or even a seprano, whose high notes are supposed t,register worst of all over the ether?

The Radio World's Fair will only revognize the possessor of the perfect voice

Manager G. Clayton Irwin, Jr., an-nounced the competition in these words

"We would be delighted to conducttest along this line and will welcome stm -gestions as to the best means of makina proper decision. It may be .that thebroadcast listeners are pretty wellagreed as to the finest radio voice and J;therefore they may vote by sending inletters to our office at 1475 Broadway.New York City, up to September 10. Itis quite probable we will be able, also, toarrange an actual test before the micro- I

phone, with a board of acoustical experts ylas judges, and the voices of the contest- 1,ants appearing in person will be projectedto hundreds of thousands of people whomay send in their opinions by special de-livery letter or telegram. Such broadcast- -ing will take place on Sept. 16, the fourth rt

tape in front of a beam of light. Syn-chronism is maintained by holes punchedinto the tape alongside the coding group.

By this time you may have noticed thatthere are two distinct classes into whichwe can place photo-transmission-thepurely physical transmission, such as theBartlane, Leishman and Korn systems,and the purely modulated electrical orradio transmission, such as the R. C. A.,Jenkins, Belin and A. T. & T. systems.

Chances Favor OneOf these the modulated systems stand

the better chance of development intopractical television. It is, however, verydoubtful that any one system will not beradically changed so this may be realized.Near perfection has been achieved insingle photographic transmission. Theaverage time it requires to transmit agood picture is about ten minutes. Sinceall the systems require that the photo

t.

iar

.\ tt..,:ust 2e". 1026 RADIO WORLD 17

WELL EQUIPPED

-trotter and radio expert, started fromcompletely fitted for radio communica-

a,o0-watt- transmitter. His trip will taketes and will broadcast his experiencesall over the world on his receiving set.

Sought In Test, night of the exposition, which takes placein New Madison Square Garden.

"Those who would like to appear inthis public test are asked to advise us atonce or fans may recommend favorites to

"Our only object is to ascertain, as faras we are able, the finest radio voice."

POWER AMPLIFIERS ROUSE FEARSThe power amplifier may cut down

radio sales in modern apartments, say, some dealers.I- With the advent of B eliminators andpower amplifiers the delivery of volume

; from sets nowadays is tremendous.With an outfit like this turned on full

blast in an up-to-date apartment (onewhere 2" walls prevail) the radiation ofvolume is sufficient to supply entertain-ment to four neighbors (two above andbelow and two at sides). So, why shouldall buy a radio set? is the worried ques-tion.

Tim Turkey was interviewed regardingthis, but refused to confirm or deny any-thing.

be analyzed into minute strips-about1/100" wide, this precludes the possibilityof resolving the same procedure into apractical solution of the problem.

For motion pictures we need sixteenpictures per second. Our nearest ap-proach to television is one picture everyten minutes, unless recent claims fromLondon of ten every second are correct.There is such a wide gap that all methodsproposed UP until the present time havefailed to offer a practical solution.

However, with' such marvelous inven-tions as the photo -electric cell, the Thalo-fide cell (one converting the light energyinto electrical energy, the other acting asa varying resistance controlling the cur-rent in the circuit), the Moore lamp cap-able of responding to very high fre-quencies and which may play an impor-tant part in future development work.and the prismatic rings of Jenkins, wemay expect a swifter solution.

Mother Gives SonPronunciation Lesson

Hears Him roadcast, ecords His Talk and Provesto Him That His Articulation Is at Fault -

Cites "Inquiry," "Lamentable"and "Acoustics"

By Myer L. LernerEdgar Wrenp, a radio author, went

about his preparations to deliver hisweekly talk from a New York broadcast-ing station with the fullest confidence inhis manuscript and his own ability to putover some high-sounding words which hehad incorporated.

After a very eulogistic announcementby the chief announcer, Mr. Wrenp wenton the air. During the talk he maintainedthe bearing of a diplomat and propoundedhis theories in the way that only a diplo-mat can. His enthusiasm waxed high onthe ability of an electron performing asit does, and one almost expected him tonominate A. Vacuum Tube for president.Truly it:was a talk fit for the ears of thehighest trained technicians.

Finally, though one must not say for-tunately, the talk was over, and Mr.Wrenp, feeling happy with the world ingeneral, wended his way homeward.

It must be remembered that the man-ager of the station himself had person-ally congratulated him on his "wonderfuldelivery."

So far so good.Always Listens In

Mr. Wrenp's mother always listens into her son's talks on Friday evenings, andno doubt sits back, with a glow of prideon her brow, to think that thousands ofpeople, perhaps millions (for mothers arethus generous) are listening to her ownson impart the almost confidential knowl-edge of an expert to a listening layworld.

That evening he was met with thesame maternal greeting. After diningand seating himself in a nice comfortablechair, his cigar lighted, he started tomuse over the furore that his oratorywould create in the best domiciles overhis speech.

When we're happy we like to thinkaloud. So thinks Mr. Wrenp. But hewas soon interrupted by his mother.

"Ed," she said, "I don't think thatmany will give much thought to yourtalk for the way you pronounced certainWords would lead only a newly arrivedimmigrant to agree with you."

He was startled. His mother had neverspoken thus to him before. Puzzled, hesaid she must be mistaken on that point.However, she insisted that she was right,and started to prove it.

While her son was "on the air" thatnight she had obtained a length of rub-ber tubing and inserted it over the pro-jection of the loudspeaker unit. Thenshe took down an old style dictaphoneoutfit, but still in good use by her dic-tatorial son, and had slipped the tubingover the mouthpiece of the dictaphone.

Offers ProofThis concentrated the volume output of

the loudspeaker directly to the dictaphone

input. Thus she recorded her son'sbroadcast on the wax cylinder.

So, with this much up her sleeve, shesaid:

"To prove my case, let me have youprove it for me. Close your eyes andkeep them closed until I tell you to openthem. Do you promise?"

"Yes, mother, I do," replied theastounded author.

She clamped on his head what felt likean earphone, on the top, but in one carit seemed there was a stethoscope.

So greatly was he nonplussed that hedid not mentally connect the sensationwith his dictaphone, especial.), as he washabitually at the talking end, never at thelistening post, of that instrument.

Hears Own Voice"* * * the electronic flow is governed

by the filament temperature, while otherfactors help determine it, too, such as thegrid bias * * logarithmic decrement,where the damping effect is uniform * * *All these matters have been subjected tolong inquiry, yet it is lamentable that'even experts can't -agree * * * We findalso that distortion may be caused by theloudspeaker or cone. Synchronizing theradio and audio circuits and the speakeris inherently a problem in acoustics * "Well, good night, my friends. I will bewith you again next Friday night."

Thus he heard himself talk. Beforemore than a dozen words entered his earhe knew he was listening to his dicta -phone.

"Well?" he asked, opening his eyes."Remember your promise," said his

mother, and he closed them.Several Words Wrong

"You mispronounced several words,"she said emphatically. "For instance, yousaid in'-oneer-y, with the accent on thefirst sy'lable. Open your eyes now."

He did so and his mother pointed to thedictionary, which she had opened to page407, where in-leztir'-i was the only pro-nunciation given, the second i beingsounded like the one in mite. He kepthis eyes open as she turned to him.

Conclusive Proof"You said lam-en'-to-bl, but see, the

dictionary gives only lant'-en-ta-bl. Andyou said (140os-tiles, but the dictionary'spreferred pronunciation is 'a -cod -stilts,'with the o pronounced as in not. So, myson, how can cultured people have faithin your facts, if your pronunciation is sobad?"

"Well, mother dear," he apologized, "Iappreciate the error of my ways andwords, but when I talk radio to technicalfolk I must use the language as theyunderstand it, or they'll all be at sea andwill accuse me of having a dialect.Nevertheless I'll buy a pronouncing dic-tionary and promise to do better nexttime."


Television Nearer,But Road Is Rough

No Practical Solution Yet Offered, But the ModulationMethod Appears to Have Better Chance Than

the Physical Means-Final Solution MayBe Compromise

By Leon L. AdelmanThe Chas. Freshman Co., Inc.

The radio age is upon us. The elec-trical age, acknowledged by authoritiesto be still in its infancy, has been sur-passed by the meteoric progress of theart of radio. This progress has in itsscope the perfection of one most impor-tant invention to humanity-the art oftelevision.

Like the development of the movingpictures, television will follow the perfecttransmission of photographs. Just whencan be only a matter of time.

At present there are several means oftransmitting photographs from one pointto another by wire, cable or radio. Thevarious systems of themselves offer nosolution to the problem cf transmittingmoving pictures. Nor has any one as yetproposed what appears to be a commer-cially feasible and practical solution.From a logical viewpoint just what is theseemingly barrier? Let usconsider the systems.

Caselli's 1856 MethodThe outstanding advantages of the

Belin system, the Bartlane, Hanson,A. T. & T., Leishman, Korn, R. C. A. orJenkins system as compared to one an-other, are evident from a brief resumeof their characteristics.

As early as 1856 Caselli sent variousdesigns by telegraphy, using for thetransmitter a tinfoil -covered cylinder onwhich the designs were drawn in insulat-ing compound. A needle acting verymuch like the stylus of a phonographserved the purpose of a contact pin,traveling spirally over the surface of therevolving cylinder. Thus the circuit wasmade and broken as the lines passedunder the contact pin, while at the re-ceiving end, by an electro-chemical ac-tion, a similar cylinder synchronized withthe transmitter reproduced the designsdirectly.

Effect on SeleniumThe discovery of the effect of light on

the electrical resistance of selenium be-cause known in 1873 and shortly after-wards various schemes to substitute sele-nium for Caselli's process were attempted.The most noteworthy were those of Sem-locq and Perosino in 1878. After quitea lengthy interval Korn (in 1904) em-ploying Semlocq's plan with severalmodifications, succeeded in transmittingphotographs a few hundred miles. Themethod now in use by the R. C. A. is toplace a negative of the photo on a glasscylinder. On this is focused a very nar-row beam of light used as a stylus. Byreflecting the varying intensity of thelight passing through the cylinder theregistry is effected and then followsan amplifier system which then allowsthe photo to be reproduced in several

ways : either by a tape recorder whichrecords the photo as a continuous line ofdots and dashes; by means of a relaywhich operates a special pen and re-produces a pen and ink sketch, or bymeans of photographic reproduction, alight shutter being controlled by the cur-rent variations and controlling the lightfrom a lamp focused on a sensitized ro-tating cylinder.

Belin Full of OriginalityWith such a system successful photo

transmission has been accomplished byradio transmission from London to NewYork.

The first photo which was transmittedover the Atlantic was sent by a systembased upon the half -tone method ofscreening. The photo was automaticallydivided into a predetermined number ofdots per square inch. A photo -electriccell then determined into which of eight-een groups a dot belonged, each groupbeing given a distinguishing letter. By

special relays, the letter wasautomatically transmitted and at the re-ceiving station, the letter was convertedinto a dot and placed into its properposition in the photograph. Even thoughthe photo was converted into 12,000squares, much of its detail was lost. Amore nearly perfect system is the Leish-man process which employs a similar butmodified principle and operates on trans-atlantic cables.

Perhaps the most original scheme isthat developed by Belin. His process re-solves itself upon the fact that bichrom-ated gelatin becomes insoluble understrong light-his own discovery. Thus heplaces a film of wet gelatin under anegative, whereupon the portions of thefilm swell up more or less in proportionto the intensity of exposure. This formsa sort of relief map of the negative andis wound on a cylinder over which astylus traces its path. A microphone at-tached to the stylus varies the resistanceof a local circuit which is coupled to atransmitter. At the receiving station anoscillograph has its mirror deflected, al-tering the projection of a beam of lightfocused on a synchronized rotating cylin-der having a sensitive photographic filmon it.

How Jenkins Does ItThe Jenkins method of analyzing is

based on aberration by means of pris-matic rings. These rings are of glass,the edges ground in such a manner thata beam of light passing through is givenan oscillating motion. By means of twosuch rings geared at a predeterminedratio, a negative is explored in minutestrips. and a photo -electric cell employedto convert light into electrical values.

The Bartlane system is a coding processwhich operates by a printing telegraph.Holes are punched into a tape and repro-duced at the receiving end by passing the

GLOBE-TROTTING C

II, bet t Photos, Inc.)CAPTAIN PLUGGE, noted English glLondon to Constantinople in a car thattion. It has a 9 -tube receiving set an,.about six weeks; he will visit 15 eons,enroute, while he picks up programs frd

Best Radio Voic.Who has America's perfect radio voice?is it a statesman, an announcer, a bari-

tone, a whispering pianist, or even a so-prano, whose high notes are supposed toregister worst of all over the ether?

World's Fair will onlyognize the possessor of the perfect voice.

Manager G. Clayton Irwin, Jr., an-nounced the competition in these words :

"We would be delighted to conduct atest along this line and will welcome sug-gestions as to the best means of making 1:a proper decision. It may be .that thebroadcast listeners are pretty wellagreed as to the finest radio voice and c:therefore they may vote by sending in .;letters to our office at 1475 Broadway,New York City, up to September 10. Itis quite probable we will be able, also, toarrange an actual test before the micro-phone, with a board of acoustical expertsas judges, and the voices of the contest-ants appearing in person will be projectedto hundreds of thousands of people whomay send in their opinions by special de-livery letter or telegram. Such broadcast-ing will take place on Sept. 16, the fourth

tape in front of a beam of light. Syn-chronism is maintained by holes punchedinto the tape alongside the coding group.

By this time you may have noticed thatthere are two distinct classes into whichwe can place photo-transmission-thepurely physical transmission, such as theBartlane, Leishman and Korn systems, I,

and the purely modulated electrical orradio transmission, such as the R. C. A.,Jenkins, Belin and A. T. & T. systems.

Chances Favor One'Of these the modulated systems stand

the better chance of development intopractical television. It is, however, verydoubtful that any one system will not beradically changed so this may be realized.Near perfection has been achieved insingle photographic transmission. Theaverage time it requires to transmit agood picture is about ten minutes. Sinceall the systems require that the photo

al;

RADIO WORLDAugust 28, 1920 711/

WELL EQUIPPED

trotter and radio expert, started fromcompletely fitted for radio communica-

nctiO-watt transmitter. His trip will takeivies and will broadcast his experiencesa.11 over the world on his receiving set.

Sought In Testnight of the exposition, which takes placein New Madison Square Garden.

"Those who would like to appear inthis public test are asked to advise us atonce or fans may recommend favorites tous.

"Our only object is to ascertain, as faras we are able, the finest radio voice."

POWER AMPLIFIERS ROUSE FEARSThe power amplifier may cut down

radio sales in modern apartments, saysome dealers.

With the advent of B eliminators and.power amplifiers the delivery of volumefrom sets nowadays is tremendous.

With an outfit like this turned on fullblast in an up-to-date apartment (onewhere 2" walls prevail) the radiation ofvolume is sufficient to supply entertain-ment to four neighbors (two above andbelow and two at sides). So, why shouldall buy a radio set? is the worried ques-tion.

Tim Turkey was interviewed regardingthis, but refused to confirm or deny any-thing.

be analyzed into minute strips-about1/100" wide, this precludes the possibilityof resolving the same procedure into apractical solution of the problem.

For motion pictures we need sixteenpictures per second. Our nearest ap-proach to television is one picture everyten minutes, unless recent claims fromLondon of ten every second are correct.There is such a wide gap, that all methodsproposed up until the present time havefailed to offer a practical solution.

However, with such marvelous inven-tions as the photo -electric cell, the Thalo-fide cell (one converting the light energyinto electrical energy, the other acting asa varying resistance controlling the cur-rent in the circuit), the Moore lamp cap-able of responding to very high fre-quencies and which may play an impor-tant part in future development work.and the prismatic rings of Jenkins, wemay expect a swifter solution.

Mother Gives SonPronunciation Lesson

Hears Him Broadcast, Records His Talk and Provesto Him That His Articulation Is at Fault-

Cites "Inquiry," "Lamentable"and "Acoustics"

By Myer L. LernerEdgar Wrenp, a radio author, went

about his preparations to deliver hisweekly talk from a New York broadcast-ing station with the fullest confidence inhis manuscript and his own ability to putover some high-sounding words which hehad incorporated.

After a very eulogistic announcementby the chief announcer, Mr. Wrenp wenton the air. During the talk he maintainedthe bearing of a diplomat and propoundedhis theories in the way that only a diplo-mat can. His enthusiasm waxed high onthe ability of an electron performing asit does, and one almost expected him tonominate A. Vacuum Tube for president.Truly itwas a talk fit for the ears of thehighest trained technicians.

Finally, though one must not say for-tunately, the talk was over, and Mr.Wrenp, feeling happy with the world ingeneral, wended his way homeward.

It must be remembered that the man-ager of the station himself had person-ally congratulated him on his "wonderfuldelivery."

So far so good.Always Listens In

Mr. Wrenp's mother always listens into her son's talks on Friday evenings, andno doubt sits back, with a glow of prideon her brow, to think that thousands ofpeople, perhaps millions (for mothers arethus generous) are listening to her ownson impart the almost confidential knowl-edge of an expert to a listening layworld.

That evening he was met with thesame maternal greeting. After diningand seating himself in a nice comfortablechair, his cigar lighted, he started tomuse over the furore that his oratorywould create in the best domiciles overhis speech.

When we're happy we like to thinkaloud. So thinks Mr. Wrenp. But hewas soon interrupted by his mother.

"Ed," she said, "I don't think thatmany will give much thought to yourtalk for the way you pronounced certainwords would lead only a newly arrivedimmigrant to agree with you."

He was startled. His mother had neverspoken thus to him before. Puzzled, hesaid she must he mistaken on that point.However, she insisted that she was right,and started to prove it.

While her son was "on the air" thatnight she had obtained a length of rub-ber tubing and inserted it over the pro-jection of the loudspeaker unit. Thenshe took down an old style dictaphoneoutfit, but still in good use by her dic-tatorial son, and had slipped the tubingover the mouthpiece of the dictaphone.

Offers ProofThis concentrated the volume output of

the loudspeaker directly to the dictaphone

input. Thus she recorded her son'sbroadcast on the wax cylinder.

So, with this much up her sleeve, shesaid:

"To prove my case, let me have youprove it for me. Close your eyes andkeep them closed until I tell you to openthem. Do you promise?"

"Yes, mother, I do," replied theastounded author.

She clamped on his head what felt likean earphone, on the top, but in one earit seemed there was a stethoscope.

So greatly was he nonplussed that hedid not mentally connect the sensationwith his dictaphone, especial.y as he washabitually at the talking end, never at thelistening post, of that instrument.

Hears Own Voice"5 * * the electronic flow is governed

by the filament temperature, while otherfactors help determine it, too, such as thegrid bias * * * logarithmic decrement,where the damping effect is uniform * * *All these matters have been subjected tolong inquiry, yet it is lamentable thateven experts can't agree " * We findalso that distortion may be caused by theloudspeaker or cone. Synchronizing theradio and audio circuits and the speakeris inherently a problem in acoustics * * *Well, good night, my friends. I will bewith you again next Friday night."

Thus he heard himself talk. Beforemore than a dozen words entered his earhe knew he was listening to his dicta -phone.

"Well?" he asked, opening his eyes."Remember your promise," said Isis

mother, and he closed them.Several Words Wrong

"You mispronounced several words,"she said emphatically. "For instance, yousaid in'-oneer-y, with the accent on thefirst sy'lable. Open your eyes now."

He did so and his mother pointed to thedktionarv, which she had onened to page407, where in-kwir'-i was the only pro-nunciation given, the second i beingsounded like the one in mite. He kepthis eyes open as she turned to him.

Conclusive Proof"You said (am -en' -to -b/, but see, the

dictionary gives only lam'-en-to-bl. Andyou said a-kons-tiles, but the dictionary'spreferred pronunciation is `a -cod -stills,'with the o pronounced as in not. So, myson, how can cultured people have faithin your facts, if your pronunciation is sobad?"

"Well, mother dear," he apologized, "Iappreciate the error of my ways andwords, but when I talk radio to technicalfolk I must use the language as theyunderstand it, or they'll all be at sea andwill accuse me of having a dialect.Nevertheless I'll buy a pronouncing dic-tionary and promise to do better nexttime."


Open Forum CreatedFor Debate on Waves

Broadcast Listeners' Association Wants All InterestsTo be Represented on Platform at National

Radio Exposition in Chicago"The threatened complete chaos of

radio, as predicted by Secretary of Com-merce Hoover and others when the claimwas made that the Department of Com-merce had no authority under existinglaws to control radio, has not as yetmaterialized but we are heading towardthat end," said Frank H. McDonald, pres-ident of the Broadcast Listeners' Associa-tion of America. "Stations are jumpingtheir wavelengths and increasing thepower allotted them by the Departmentof Commerce. Other stations are comingon the air, choosing the wavelengths andpower. There is no telling what thesituation will be by the time effectivelegislation is enacted. It is hoped thiswill be in the early Fall.

"The Broadcast Listeners' Associationof America has called a general strike,using the boycott as a means of bringingthe pirating stations to understand thatthe listeners' rights will be protected.This strike is now in full swing, thevolume of strike pledges increasing eachday, the listeners refusing to tune in onany pirate station at any time under anycircumstances.

"Realizing it would be dangerous torely on the pirate stations using commonsense or good business judgment in thematter, the Broadcast Listeners' Associa-tion, in an endeavor to obtain completedata from all the angles, asks all stationsto meet the Broadcast Listeners' Associa-tion in open debate and will hold an openfor urn.

"From September 27 to October 2, atthe National Radio Exposition, HotelSherman, Chicago, this forum will beheld. Satisfactory arrangements have

-been made with Milo E. Westbrooke,manager of the exposition.

"The Broadcast Listeners' Associationwill not wait and hope for the best, ordepend upon the radio strike to solve this

problem, although the strike will eventu-ally force the pirating stations to act ina manner that will prevent chaos. Evenwith this accomplished there remains thefuture of radio to be considered. There-fore, the officers of the association haveunanimously decided to use its entirepower, influence, and all its facilities tobring about a solution of this problem."

Those wishing to take part in the OpenForum should write the approximate datethey will be present, substance of theoriesand views for debate in duplicate manu-script form. The remarks will be readand recorded if it is impossible for theauthor to be present. Address Frank H.McDonald, 431 South Dearborn St., Chi-cago.

Public OpinionCalled Decisive

Commenting on the present changes inwavelength by broadcasters who are in-terested in obtaining better results forthemselves Frank Reichmann, presidentof the Reichmann Co., expressed regretthat the present radio law did not con-trol the assignment of wavelengths.

"There need be no worry about chaosof the air, however," Mr. Reichmann ex-plained. "The voice of the public wouldhe heard should any broadcaster trans-gress on the right of any other station al-ready transmitting.

"The public is the final judge of thevalue of a broadcasting station, and withthe only payment broadcasters get fromtheir listeners being in the form of goodwill, there is little doubt that no waveswill be used at any time that are not sat-isfactory to a large majority of the listen-ing public."

Trend Is TowardMuch Higher Power

Fourteen New Stations Listed in Six Weeks, But ManyMore Increase Their Output- 50 More

Licenses Prophesied

WASHINGTON.Changes in the alignment of stations

since June 30 indicate what the fan mayexpect when cold weather makes dis-tance reception possible.

On June 30 there was a total of 528stations. At present there are 542stations, an increase of 14. Furthermore,there has been a sharper increase inpower than in the number of stations.

At the time of adjournment of Con-gress there were 114 stations operatingbetween 545.1 and 280.2 meters inclusive,with 414 stations between 280.2 and 202.6meters inclusive. At the present time

there are 145 stations between 545.1 and280.2 meters and 397 stations between280.2 and 202.6 meters.

Most of the new stations which areoperating in the former class B band areworking simultaneously with one or moreother stations on the same wavelength.

Chief Radio Supervisor W. D. Terrelldoes not think the situation' particularlygrave at present, but he is not very op-timistic for this Winter. He expects thataround fifty more stations will be licensedand that there will be a big increase inpower on the part of a number of otherstations.

5 STATIONSINCREASEIN METERS

WASHINGTON.Four new stations were licensed by the

Department of Commerce, while fivestations changed their wavelengths.

NEW STATIONSKGBX, Julius B. Abercrombie, St.

Joseph, Mo., 347.8 meters, 862 kc.WKBS, H. L. Ansley, Birmingham,

Ala., 225 meters, 1,333 kc.WJBY, Electric Construction Co.,

Gadsden, Ala., 270.1 meters, 1,110 kc.WJBX, Henderson & Ross, Ostezville,

Mass., 280 meters, 1,071 kc.WAVE CHANGES

KTAB, Associated Broadcasters, Oak-land, Calif., from 240 to 302.8 meters.

KFPY, Symons Investment Co., Spo-kane, Washington, from 265.3 meters to275 meters.

KFQU, W. Riker, Holy City, Calif.,from 217.3 meters to 273 meters.

KMA, May Seed and Nursery Co..Shenandoah, Iowa, frOm 252 meters to461.3 meters.

KWKH, W. K. Henderson I. W. and S.Co., Shreveport, La., from 260.7 metersto 312.3 meters.

Freshman OpposesWavelength Grabs

Chas. Freshman said :"The present broadcast situation, though

far from being in a chaotic state, as someprolific newspaper accounts seem to bearout, is nevertheless undergoing a re-markable series of changes which willresult in a more dependable public serv-ice.

"Instead of having the effect of deter-ring people from purchasing radio re-ceivers, the very fact that our sales aresteadily climbing proves that the major-ity of the people have faith in Congressand that everything will be straightenedout to the best advantage.

"Those few stations which have jumpedtheir wavelengths will soon realize thatpublic sentiment is against any extrememeasures that they may undertake, and inone instance, already on record, a judgehas decreed that any change in wave-lenth is illegal.

"We must be thankful that the greatermajority of our broadcasters have goodcommon sense and that they use it."

Operatic SopranoIs a Hit at WSM

An artist of rare ability has been addedto American radio by WSM, Nashville,Tenn., with the advent of Mrs. Mr. H.Goldschedn, whose dramatic soprano voicehas interpreted many of the . airs fromopera for the radio audience.

Madame Goldschein received her train-ing from Paul Eisler, the conductor of theMetropolitan Opera Company of NewYork City and was being trained foropera when she transferred her residenceto Nashville.

Her voice has a sure, mellow tonewhich lends itself admirably to the ariasfrom Italian operas and her handling ofAmerican compositions meets the ap-proval of the sternest critics. She broad-casts regularly from the studio of WSM.

I August 28, 1926 RADIO WORLD

Inventions LightProgress of Radio

Forty-seven Years Ago First Dernonsiration of SendingAnd Receiving Signals Was Given-Rapid Advance

Followed-Great Inventions Cited

Within the past few years, the radio:field has been invaded by thotisands ofpersons who know nothing of its evo.utionand are many times unable to distinguishbetween what is new and what is old.As a consequence, they waste much timeand money in reinventing old devicesand in evolving others to circumventimagined patents on inventions long sincein the public domain.

Back in 1678 Huygens, a Dutch mathe-matician and physicist, propounded theundulatory theory of light. It was fromthis date that wave motion was concededto be connected with manifestation ofenergy such as heat, light and electricity.In 1843 Professor Joseph Henry, in anaddress before the American Society, an-nounced that he had been successful inmannetizing needles at a distanse of 220feet. Twenty-four years later, in 1867,

Ruhmkorff perfected the "Ruhmkorffcoil," later used almost exclusively in

wireless stations.Theory of Light

At about the same time James Clerk -Maxwell propounded the electromagnetictheory of light. This theory confirmedand extended that of Huygens and wassupported by mathematical proofs whichform the basis of radio engineering to-day. It was in 1879 that the first demon-stration of the transmission and receptionof radio signals up to a distance of sev-eral hundred yards was given by ProfessorD, E. Hughes and it was in 1888 thatRodolf Heinrich Hertz demonstrated ex-perimentally the possibility of creatingelectromagnetic waves in the ether.

And from this beginning other scien-tists and investigators have added theirwork to the end that the world mighthave a better means of intercommunica-tion.

The splendid work of Dolbear, Edison,Sir William Crooks, Elihu Thomson,Nikola Tesla, Lodge, Popoff, Marconi,Fessenden, Pickard, Dr. Rogers, andothers famous for their pioneer work inthe field, stand as shining examples ofcontributions to the art.

Important InventionsIt will be interesting to learn which

inventions are the most vital to an effi-

cient broadcasting station.In 1908 De Forest was granted a patent

on the three -element tube, the wonderfuldevice which makes broadcasting possible.

In this connection I might say that theso-called "Edison Effect," discovered in1883 by Edison, lies at the base of theoperation of a vacuum tube and it wasDe Forest's brilliant idea of conceiving agrid to control the electronic flow froman incandescent filament which is respon-sible for the very wonderful advancesmade in intercommunication.

The Heising modulation system andother refinements, such as speech controland speech amplifying devices, have

81e greatly added to 'the efficiency and de -anBI

,,, station. Thus, through the cooperativev

*,"", work of De Forest, Arnold, Logwood,Colpitts, Lowenstein, Heising, Farrington,and others, we have witnessed in therelatively short time a tremendous pro-gress which. will stand for all time in the

annals of history as having been the mostrapid and most benefitting to mankind.

Indirect AidsSome of the more important inventions

which do not find direct application tobroadcasting but . are indispensible (forcommercial and governmental uses arethe direction finder as conceived by Bel-lini and Tosi, the carborundum detectorby Dunwoody, the Fessenden beat methodof reception, the Duddell and the Paul-sen arcs, the Alexanderson high frequ-ency alternator, the decremeter as devisedby Colster, the Marconi beam transmit-ter, etc. There are also thousands ofminor inventions which find applicationand use in both a radio receiving andtransmitting station. The nature andpurpose of the countless various articlesof course determines their value.

The carbon type microphone, inventedby Edison, is one of the indispensabledevices finding unlimited application inboth telephony and radio. Without themicronhone we would be at a distinct lossin modulating the carrier wave as effi-ciently_as it is being done today.

Wireless at SeaAmong the other important dates which

stand as milestones in the progress ofradio, December 12, 1901, will be remem-bered as the date when the first success-ful trans -Atlantic communication was ac-complished. From then on until 1909events of relatively little importance tookplace and then on January 23, of that yearthe S. S. Republic, after collision withthe S. S. Florida, succeeded in callingassistance by wireless, with the resultthat all of her passengers and crew were

GIFTED VIOLINIST

PAULINE WATSON, violinist, en-joyed often by those who listen toleading New York stations. She wasmost recently heard from WGBS,where she played classically pieces

with superb technique.

saved before the vessel sank. This in-cident fanned men from all walks of lifeinto a greater interest in wireless andfrom that time on we have witnessed a'most rapid progress.

Following the Republic event on April15, 1912, the S. S. Titanic struck an ice-berg but owing to the promptwireless calls for assistance the lives ofmore than 700 of her passengers weresaved. The disaster aroused the worldto the need of better and more reliablewireless communication, and so in thefollowing June the International Radio-telegraphic Conference opened in London,where uniformity of practice in wirelesstelegraphic services was enacted into abinding legislation.-Leon L. Adelman.

Sentimental SongsLead the Requests

Lost Sweethearts, Mothers Who Have Passed Away'And Religious Compositions Predominate

As Themes in McQuhae's Mail

A national census of songs that live. isbeing made by Allen McQuhae, Irish tenorwho conducts the Sunday evening AtwaterKent radio concerts this Summer. Thesongs of the series are chosen from re-quests from radio listeners. The censusis expected to reveal not the "hits" ofthe day, which after a wave of popular-ity die out, but the songs that livethrough the years.

Mr. McQuhae's list of songs requestedalready runs far above 500. To sing allof them he estimates it would take himmore than six months in half hour weeklyconcerts. He selects those, however, forwhich he receives the greatest number ofrequests each week and places them onhis Sunday evening program.

For example, Mr. McQuhae says no one

has yet asked him to sing, "Yes, We HaveNo Bananas," while hundreds have re-quested such fine old favorites as "SilverThreads Among the Gold," "When Youand I Were Young, Maggie," "HolyCity," and "I Hear' You Calling Me."

Requests for the songs popular duringthe world war are not numerous and asyet only one man has asked Mr. Mc-Quhae to sing "The Star Spangled Ban-ner."

Mr. McQuhae's census is expected to bean excellent guide for ambitious songwriters as to theme and character. Senti-ment is shown to be the prevailing motivein the songs most called for, with thethemes of lost sweethearts, mothers whohave gone and inspiring songs of religiouscharacter predominating.


Per Agate Line

A THOUGHT FOR THE WEEKIT was never intended by radio officials

that broadcasting should be turned topropaganda purposes. But the word propa-ganda has been so 7vorn to a fra:;zle duringthe past few years that it non' means abouteverything from treason to a kind wordabout a new brand of chewing pion. Sowho shall say where interest ,,nds and dozen -right offense starts!

REG.US. PAT. OFF.

Radio World's Slogan: ' A radio est for ovary hams."

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AUGUST 28, 1926

A Matter of MoneyGRANTING that the De Forest Radio

Co. will hold its present position atlaw as the owner of the regenerationpatent, it may sue to enjoin infringers ofthese patents, with an accounting for backprofits and a refusal to permit the manu-facturers to obtain a license to continue,or it may adopt a more conciliatory andfinancially profitable method and seek allit can get by the previously mentionedmethod, vet offer the opportunity ofpurchasing a license.

Interest focuses on what attitude willbe adopted by the De Forest Co. in re-gard to the Radio Corporation of America.By announcement of counsel for the DeForest Co. the way is open for others toobtain licenses, but will this privilege beextended to the R. C. A.? Very likely itwill, because even the bad feeling betweenthe R. C. A. and the De Forest Co. willhardly deter the real owner of the patentsfrom gathering in all possible money,which could be put to good advantage.Stockholders are not particularly inter -

Tim Turkey Tells 'EmA Few About Patents

By Tim TurkeyTHE R. C. A. in 1924 was too busy mak-

ing patent suits to be able to make anymoney on selling its receivers. Maybe nowit can turn most of its attention to the busi-ness of the day.

How long does a patent have to be worth-less before you can prove it?

Whether you're a big manufacturer orjust on the outside looking in depends onwhether the judge writes "granted" or "de-nied" at the end of the long spiel that yourlawyer has handed him.

De Forest will protect his patents for allthey are worth and 10 per cent. extra. Buthe will grant licenses. That was more thanthe R. C. A. and Westinghouse were willingto do, unless for 10 per cent. or more ofthe gross. Lots of independents won't besuffering from abrasions, due to beingslapped on the left forearm with injunc-tion papers several times a day.

If it takes nine years to find out thatyou own a patent, how much am I bidfor the best radio patent on the market?

Two fellows were discussing their girls.One said that he was quite satisfied thatthey exchange girls, but that he reallydid consider his girl just a trifle. better.It was agreed the other fellow shouldrelinquish his girl and one patent.

No patent is any better than its lawyer.

Pride cometh before a fall, and greatdemands for royalties and other penaltiescometh before a discovery that the patentunder which they are 'demanded isn'tworth a burnt -out tube with the base re-moved and the glass envelope broken.

If you don't see any patent that youlike, ask for it. Or if you see one youlike, and you don't think you own it, suefor it, and check back on the otherfellow's sales for the last five years.

Every set manufacturer should keep twosets of books, one for his own busi-ness and the other for anybody whomay prove to him that his patent isn't hisbut the other fellow's. In the profit -and -loss column of the open -for -inspectionbook use red ink.

Build a business today, and lose it to apatent lawyer tomorrow.

ested in the satisfaction of grudges, andthe De Forest stockholders probablywould prefer to receive dividends thanpenniless revenge. Another point is that,even if the De Forest Co. now has thepower virtually to put the R. C. A. out ofthe set business, an assumption not com-pletely established, the R. C. A. must begiven due credit for the position it occu-pies in the radio industry as a whole, andin the set manufacturing business in par-ticular. It is really a sales organization,so far as sets go, the manufacturing beingdone for it, but the general public doesnot appreciate the distinction. The ideaof putting the R. C. A. out of business, orseriously crippling it, has been maintainedin spiteful quarters for quite a while, notonly by persons in the industry, but bysome politicians as well, and these baseaims of its enemies have cost the R. C. A.a pot of money, a fact over which no onewith a spark of fairness in his bosom needgloat.

But a patent is a patent and its ownerhas certain broad rights which it is hishigh privilege, indeed his duty, to enforce:Were the De Forest Co. to sleep on itsrecently confirmed right of ownership ofthe regenerative patents-two in number,in its case-it might well be deemed tohave waived its rights. But there is noneed to fear that pillows will be requiredin the offices of the De Forest patent as-serters and defenders, for they are hot onthe trail of gold, and if the courts areconsistently good to them, huge richeswill swell the coffers of the companywhose valiant struggle has won theadmiration of many.

A patent is a monopoly. In exchangefor the disclosure of what the inventionconsists of, and the reversion to the pub-lic of the patent after 17 years of its life,the inventor gets exclusive control overand ownership of his contribution to theimprovement of civilization. This smacksof lofty theory and socialized benevolence,when contrasted with the actuality-pro-cess servers secreting ,themselves in un-expected places, with summons and peti-tion in injunction suits in their inside coatpockets. The law has been generous tothe lawyer no less than to the inventor.

Counsel for the De Forest Co. pointsout that the R. C. A. can not drag out

the case interminably by appealing to theUnited States Supreme Court, since theDistrict Court of Appeals is the court offinal resort, and to that court the R. C. A.must be expected to appeal. This is nostage at which the R. C. A. will stop,after nine years of bitter struggle. Whatthe final outcome may be no one dares toprophesy, since the courts frown on deci-sion guessing, but the De Forest Co. wantsthe R. C. A. and all other alleged in-fringers enjoined or stayed from makingor selling regenerative sets, pendingappeal.

Tied up with the fight is a large num-ber of set and parts manufacturers oper-ating under the now exploded Armstrongpatent, as direct or indirect licensees. Thefight is an all-important one, indeed ismomentous, although it is viewed ev,ennow with almost disinterested eyes bypersons and concerns that should be alertto its great consequences.

As the upset of the Armstrong patentand the issue of two patents instead toDe Forest took place in 1924, and aspatents have 17 years to run, these twowill expire in 1941, whereas the Armstrongpatent would have run its course by 1931.The many who were impatiently awaitingthe day when they could make regenera-tive sets and assemble such kits withhookups enclosed in the carton, withoutfear of patent suits, must therefore checktheir feelings for ten years extra, or sufferinconceivable tortures over a most pro-tracted period.

FINER SETS POPULARTime was when any old kind of a set

that worked was plenty good enough, andpeople marveled at the phenomenon ofreception. Now the public wants efficientand handsome sets and manufacturers aremaking such.

FIRST ALASKAN BEACONWASHINGTON.

The first radio beacon established inAlaska was placed in commission accord-ing to the Lighthouse Service. Thissignal is located at Cape Spencer and itmarks the northerly entrance from thePacific Ocean into the channels of south-eastern Alaska.

I -E

August 28, 1926 RADIO WORLD 21

De Forest to Sell LicensesOffers Opportunity to

Westinghouse to BuyRight Under Regenera-tive Grant That Has 15Years Still to Run-Same Offer Likely toR. C. A. and Others-Rigorous Assertion ofPatent Rights Promised.

Samuel E. Darby, Jr., chief patent coun-sel for the De Forest Radio Co., in astatement announced the readiness of hisclient to grant to the WestinghouseElectric & Mfg. Co. a license, underproper financial terms, to use the regen-eration patents which the courts haveawarded to Dr. Lee De Forest, cancellingMajor Edwin H. Armstrong's patent.This declaration was taken to mean thatthe same opportunity would be extendedto other alleged infringers, including theRadio Corporation of America, rather thanattempting to stop infringement withoutalternative of the license purchase privi-lege.

Mr. Darby said the American Telephone& Telegraph Co. and the General Elec-tric Co. are authorized De Forest licenseesunder the patents, the arrangementshaving been made long ago. An allegedgrant by General Electric to the R. C. A.and to Westinghouse is void for illegality,Mr. Darby contends.

He pointed out the De Forest patentshave fifteen years to run, while the Arm-strong patent would have expired in fiveyears.

The decision of Federal Judge Thomp-son in Philadelphia, invalidating theArmstrong patent No. 1,113,149 and hold-ing that Dr. De Forest was the first andoriginal inventor of the feedback circuitand the oscillating audion, as covered byhis patents assigned to the De ForestRadio Company, Nos. 1,507,016 and 1,507,-017, may be far reaching in its effect uponthe present and future of the radioindustry, Mr. Darby intimated.

Darby's StatementMr. Darby's statement follows in full:"Those effected may be divided into

four groups : (1) the Westinghouse Elec-tric and Manufacturing Co., defendantsin the recent suit, owners of the Arm-strong patent and manufacturers of radioreceiving and transmitting sets embody-ing the regenerative or feedback circuitand employing the oscillating audion (2)the licensees under the Armstrong patent;(3) the independent radio manufacturers;(4) De Forest Radio Company.

"To more fully appreciate the effect ofthis litigation on the radio art and indus-try one must realize the scope of theDe Forest and Armstrong patents. First,this decision invalidates the Armstrongpatent and substitutes the patents of DeForest.

"The Armstrong patent has been adjudi-cated by various courts to cover not onlythe feedback circuit for regeneration andreception but also radio transmission.Likewise the Armstrong patent has beenheld by Federal courts to cover radio fre-quency amplification where regenerationis usually always present and is controlled.A great majority of the reception setsnow being manufactured or already in useemploy regeneration in one form or an-other. Therefore the De Forest patents

will largely dominate the entire radiomanufacturing industry as to both receiv-ing and transmitting equipment.

Peril to Westinghouse"The Westinghouse Electric and Manu-

facturing Co. is immediately affected bythe decision as it cannot continue to man-ufacture its present radio receiving andtransmitting equipment without infringe-ment of the De Forest patents, unless, ofcourse, it procures a license.

"The Westinghouse Co. has been receiving royalties from a large number 01licensees under the Armstrong patent.With this decision, these licenses are ter-minated with the Armstrong patent can-cellation, and the former licensees becomeindependent manufacturers whose productby reason of their statement that theyare operating under such Westinghouse -Armstrong licenses make them infringersof the De Forest patents who may beimmediately enjoined from further manu-facture of their regenerative equipment.

"The following are the original licenseesunder the Armstrong patent. Some ofthese licenses have been transferred orthe companies owning them have beenacquired by other manufacturers.

Radio Corporation of AmericaInternational Radio Telegraph CompanyA. H. Grebe & Company, Inc.Chicago Radio LaboratoryClapp-Eastlaarn CompanyCutting & Washington, Inc.Adams -Morgan CompanyPrecision Equipment CompanyJones Radio CompanyMignon Manufacturing Export Corp.Tri-City Electric Manufacturing Co.Klitzen Radio Manufacturing Co.Card Radio LaboratoriesPennsylvania Wireless Manufacturing

Co.Eastern Radio CompanyChelsea Radio CompanyRadio Craft CompanyThe C. D. Tuska CompanyThe Radio ShopThe Cohn B. Kennedy Company

Independents Warned"The position of the independent manu-

facturers is not changed. Their equip-ment previously infringing the Armstrongpatent now infringes those of De Forest.

"The De Forest Radio Company maynow hold every radio manufacturer in theUnited States employing the Armstrongpatent or whose equipment heretoforewas held to be an infringement of theArmstrong patent, such as regenerativereceivers, transmitters, and radio fre-quency amplifiers with regeneration, foran accounting of their profits from such

Pennsylvania Decision,Defeating ArmstrongPatent, Can't Be Ap-pealed to U. S. SupremeCourt, Only to DistrictAppeals Court, SaysDarby-Will Seek In-junctions Against In-fringers Pending Out-come.

manufacture made since September 2,1924, and may enjoin these corporationsagainst the continued manufacture of suchapparatus.

"Authorized licensees under the DeForest patents at the present time are theAmerican Telephone & Telegraph Co. andthe General Electric Co. The latter issaid to have granted a license to theRadio Corporation of America and theWestinghouse Electric & ManufacturingCo, the legality of which is now beinglitigated in the Federal courts.

Appeal Limited"Should the Westinghouse Co. elect to

appeal from this decision to the UnitedStates Court of Appeals for the ThirdCircuit and court of last resort, the DeForest Radio Co. retains the right to in-stitute injunction proceedings for infringe-ment until such an appeal is finally de-cided. The decision of Judge Thompsonwas based on the law laid down by theUnited States Supreme Court and hereto-fore consistently followed by the ThirdCircuit Court of Appeals. Since no newpoint of law is involved, no appeal may betaken from the Circuit Court to theSupreme Court."

The De Forest patents were applied forearly in 1914 but did not issue until Sep-tember 2, 1924, because the right of DeForest to these patents had been vigor-ously contested in the Patent Office andit was necessary for him to press litigationup to and including the United StatesCourt of Appeals for the District ofColumbia, the court of last resort onUnited States Patent Office cases. Dr.De Forest's right was also contested bythe United States Government, The Gen-eral Electric and the Westinghouse com-panies. His patents will not expire untilSeptember 2, 1941; that of Armstrongwould have expired in 1931.

25 Stations WinFrequency Honors

WASHINGTON.According to the Bureau of Standards

the broadcasting situation is being stab-ilized in part by the friendly rivalry ofstations for places on the Bureau's honorroll of those who maintain their frequencywith high accuracy. During the pastmonth, measurements revealed thattwenty-eight stations have given evidenceof holding their frequencies accurately onthe assigned values and are of value asfrequency standards.

The special devices for frequency regu-lation employed by the constant frequencystations include piezo oscillators, piezoresonators and frequency indicators. The

number of stations upon which measure-ments were made was necessarily limitedbecause of the practical difficulties in-volved in any measurements of thisnature.

The constant frequency stations follow:WOC, Davenport; WTIC, Hartford,Conn.' WMAQ, Chicago; WCCO, Min-neapolis -St. Paul; WWJ, Detroit; WLS,Chicago; KFAB, Lincoln, Neb.; WJJD,Mooseheart, Ill.; WEAO, Columbus, 0.;KFKA, Greeley, Colo.; KFH, Wichita,Kansas; WENR, Chicago; WCAD, Can-ton, N. WAAM, Newark, N. J.;WSKC, Bay City, Mich..' WOWO, Ft.Wayne, Ind.; KBBM. Chicago, WEBQ,Harrisburg, KFVS, Cape Girardeau,Mo.; WOK, Flonlewood, Ill.; WPDQ,Buffalo; NAA, Arlington; WEAF, NewYork; WRC, Washington; WJZ, NewYork; WGY. Schenectady; WBZ, Spring-field, and KDKA, Pittsburgh.

Freshman AnnouncesLine for New Season

Latest Developments Represented in ReceiversAccessories Power Plant Enables Complete

Operation From the Line

Tlut Fresktmana 6-1- -IV, is buried w...Inaut Laarra a* tilt

"RAMBLER -SIX"THE ONLY

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CM AM'S C*IALP A a EX, ROAD A FLA,-Hk k, SITED ,

and

SEE SEPTEMBER, 1926,-RADIO NEWS"

ON THE NEW"1927 DIAMOND

OF THE AIR".41 fa+ Saaletta 70$

B. C. L Radio Service, Inc.ft! I ON, T.T NEW 1r Oka CITY

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G'10August O, 1.72./ RA T-1 (1 AV (1 1, I r)

THE RADIO TRADESchott Promoted

To Chief of SalesAnnouncement has been made by the

National Carbon Company, Inc., manu-facturers of Eveready flashlights, radiobattgries, and dry cells, of the appoint-ment of Harry S. Schott as general salesmanager. Mr. Schott goes to his newoffice from the post of assistant generalsales manager, which he has occupied forthe past two years.

Mr. Schott is a widely known figure inthe electrical industry, with which he hasbeen identified in both the jobbing andmanufacturing ends of the business foralmost 25 years. During most of thisperiod he was actively engaged in sellingand sales direction in the Eastern Statesand Canada.

His first association with the line ofgoods made famous by the Evereadytrademark was in 1913 when he went withthe old American Eveready Works toassist in launching the first advertisingcampaign undertaken for Eveready flash-lights. Mr. Schott then entered the Can-adian territory for the American Ever-eady Works, whose Canadian branchwas established in 1914. When the Can-adian branch was taken over by the Can-adian National Carbon Company in 1918.he was named assistant sales manager.

Mr. Schott returned to New York in1920 as Eastern sales manager of theAmerican Eveready Works, and whenthey were absorbed by the National Car-bon Company in 1921 he became theEastern district manager for the latterconcern. He was appointed assistant gen-eral sales manager of the National CarbonCompany in 1924, and continued in thatcapacity until his recent appointment asgeneral sales manager.

Fiske Takes PostWith C. E. Mfg. Co.

Edward R. Fiske, formerly Eastern salesmanager for the Waage Electric Com-pany of Chicago, has joined the staff ofthe C. E. Manufacturing Co., Inc., at 702Eddy Street, Providence, R. I., as assist-ant director of sales.

Mr. Fiske has long been associated withradio sales work and activities, havingmanaged the Eastern field for the WaageElectric Company for the past two years.Prior to that he was buyer for the radiosection of the John -Wanamaker Store,New York City. From shortly after theWar up until his entering the WaageElectric Company he was identified withthat organization, and during the worldwar, Mr. Fiske was on active duty in theRadio Communication Department of theU. S. Navy.

The wide, varied and successful experi-ence in the radio field, makes the newsales executive of the C. E. Manufactur-ing Co. well capable of riding to successwith the "CeCo" tubes, which the con-cern manufactures.

Incidentally, the C. E. ManufacturingCo. are the largest exclusiVe tube manu-facturers in the United States, and aremaking an excellent product which canaccount for their rapid strides made inthe past few years.

Mr. Fiske feels that he will be able todo many a good turn to his old friendsby lining them up with his new employers.

WBBM IS ELECTEDThe Stewart -Warner Speedometer Cor

poration which cdriducts the Stewart -Warner Air Theatre through stationWBBM, has been made a member of theChicago Broadcaster Association.

Literature WantedTHE names of readers of RADIO WORLD

who desire literature from radio job-bers and dealers are published in RADIOWORLD on request of the reader. Theblank below may be used, or a post cardor letter will do instead.Trade Service Editor,RADIO WORLD,145 West 45th St., N. Y. City.

I desire to receive radio literatureNameAddressCity or town

State

William McCann, Irving, Mich.J. Southwick, Eastport, Maine.Jas. J. Burda, Garnon, Ia. (Dealer.)Joseph Kase, 9410 Nelson Ave., Cleveland, Ohio.Eugene L. Meadows, 312 South Ave., Wilkins -

burg, Pa.Wilbur Bardin, Wauchuta, Fla. (Dealer.)C. W. Poff, 249 S. Lincoln St., Denver, Colo.Louis Thomas, 524 Baldwin Ave., Hays, Pa.

(Dealer.)J. Ferguson, Kreps, 17 West Main, Madison,

Wisc.Franklin Shaffer, 861 -20th St., Merced, Calif.

Business OpportunitiesRadio and Electrical

Rates 10c per word; Minimum, $1.00; Cashwith order

WILLING INVESTOR with sales ability tomanage chain store; must have $5,000 to investin a well -established radio and hardware concernneeding capital to open a series of chain stores;no previous experience necessary; complete in-structions given; every prospect must be willingto submit to training in one of our stores beforetaking over complete management. Phone Cort-landt 0677 (N. Y. City) for appointment with Mr.Pering. Excellent opportunity for right party.

RADIO LOUD SPEAKER cries aloud for properrepresentatives; everywhere; 'exclusive territory;cheap for cash buyers, otherwise strictly com-mission. Brownie Products Corp., Ridgewood.N. J.

clin'ers ShowA .Claytonr

/Ao RADIO

WORLDS FAIRMadison Square Garden

,New York GtySept,13-1,8- 926 co"

0

anage-

Presents SS0

001 CHICAGORADIO SHOW

ColiseumChicago

Oct,11".'17-1926O

THE WORLD'S FOREMOST RADIO EXHIBITIONSWith new distance records being made daily, radio is At the New York and Chicago shows every represen-destined to link the world, bringing all nations into tative radio manufacturer will display his new products-one big family. a complete showing of everything new in radio.Whether or not you are a radio fan. you should keep There are all kinds of shows, but this is the show youabreast of the latest developments in this marvelous new can't afford to miss.industry.

"Go to the Radio Show"


Stoner & HeathTake a New Line

The English -Whitman line of productsis now ready for the trade. One is theEnglish -Whitman loop, known as the"Tun -A -Loop" which matches all tuningdial settings regardless of the size of thecondensers. Made of genuine Bakeliteand spider web wound with silk overphosphor bronze wire, it prevents dielec-tric losses and eliminates possible leak-age. It can be used on any set which hasradio frequency, gives amazing results onregenerative sets, works on Neutrodynesand all classes of Super -Heterodynes.The list price is very reasonable.

The English -Whitman speaker is ex-pected to create a sensation, as it uses anentirely new principle and is hornless andconeless. After much thought and con-sideration of the field, the English -Whit-man Company have placed their lines inthe hands of Stoner & Heath, 122 Green-wich Street, New York City. Full infor-mation may be had from this concern.Mention RADIO WORLD when writing.

Acme ApparatusAnnounces Models

The Acme Apparatus Company of Cam-bridge, Mass., known the world over fortheir famous slogan, "Acme for Amplifica-tion," announces the release of their 1927specialties. The K-1 and K-2 double free -edge cone speakers will be on the market

WORLD'S FINEST"7; \ LOUD- c

SPEAKERA three-foot tone speaker-unit developed by theInventor of the Tropadyne.Easily assembled, saving80% of the cost Cornp late I( It with blue yr' ntesold on rig id money -backguarantee - snipped pre-paid or C.O.D. 510.

Engineers'/

25 Church StreetService Co.

New York

in improved form, with the addition of anew K-3 single free edge cone 11" indiameter. All the faithfulness of repro-duction inherent in the two other modelsis maintained in this speaker. The K-3can also be adapted to wall mounting bya simple adjustment.

Three models of B power supply atreasonable prices are also part of the newAcme line, together with a model for Asupply and one for C supply. Eliminatorkits for those who prefer to build theirown may also he had, also a full line offilters, chokes and transformers. Audioamplification and miscellaneous parts tofill every need are also in the line. 'The"ham" is not neglected, for in the catalogappears everything to meet his heart'sdesire, all of the well-known Acme qual-ity. A beautifully illustrated catalog willbe sent to those interested upon applica-tion either to the Acme Apparatus Com-pany, Cambridge, Mass. or .Pearcy W.Mack, 1270 Broadway, New York City.Mention RADIO WORLD.

New De Jur CatalogThe De Jur Products Company, 199

Lafayette Street, New York City, hasjust issued a 12 -page catalog, illustratingdescribing and pricing their entire lineof radio products for 1927. Featuredtherein is the new De Jur ResistanceCoupled Amplifier which the company ismarketing under the trade name "Plano-fier." This company is the maker of thefamous De Jur rheostat and other ex-cellent parts. They will be glad to sendthe catalog free. Mention RADIO WORLD.

FERGUSON ENLARGESJ. B. Ferguson, Inc., manufacturers of

"The Gold Standard of Radio Receivers,"have been compelled to double their fac-tory space due to the increased volumeof business. The factory is located at 354241st Street, Long Island City, N. Y. Theoffice is at 225 W. 57th Street, N. Y. C.

Bring in Europe on a

Victoreen "SuperWrite for Layout and Parts ListTHE GEORGE W. WALKER CO.0515 Carnegie Avenue Cleveland, Ohio

Attention, Radio World Subscribers!Subscribers will note that the end of their subscriptions is indicated on the labels

on wrappers. If your wrapper shows a date earlier than the current issue, pleasesend payment for renewal. Changes in expiration dates on wrappers appear two weeksafter receipt of renewal.

RADIO WORLD, 145 West 45th St., New York City. (Phones: Bryant 0558-0559.)

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SUBSCRIPTION RATES:Single Copy $ .15Three Months 1.50Six Months 3.00One Year, 52 Issuce 6.00Add $1.00 a Year for ForeignPostage; 50c for Canadian Post-age.

Empire-trons LineFor 1927 Is Ready

The new line of Empire-trons, includ-ing the new gas -filled detector (EX200),high -mu and power amplifiers, is now on

on the market. These tubesare sturdily built for longservice and are built to themost rigid and exacting re-quirements. On recent labor-atory tests a line of Empire-Trons were kept in continu-ous operation over 1,200hours without showing signsof paralysis. The internalworkmanship, is novel andclean-cut, and each tube mustpass the most exhaustive testbefore being shipped fromthe factory. The three volttube is made both in regularand adaptor base while thesix -volt tube is made in both

standard and navy style. A fully descrip-tive circular will be sent to those inter-ested by the Empire Electrical ProductsCo., 132 Greene Street, New York City.Mention RADIO WORLD.

Pacific ShowTo Open Sept. 21

The second annual Pacific NorthwestRadio Exposition will open its doors atthe Public Auditorium, Portland, at noon,Tuesday, September 21, and will last fivedays.

The decoration scheme is accentuatedby the brilliant flood lights, Oregon scenicstrips and colorful stage sykes that hidebare wall spaces.

The exploitation cost runs well over$5,000. A very elaborate advertising cam-paign was prepared by Crossley & Fail-ing, Inc.

The entertainment is so varied and ofsuch quality as to encourage show goersto attend several nights. Stations KFJR,KFWV, KTBR, KGW, and KOIN willbroadcast every evening.

NEW CORPORATIONSCentury Radio Panel Corp., N. Y. C.; $20,003.Reid & Green, Inc., Newark, N. J., electricalaccessories; $50,000.

NAME CHANGESLuxor Radio and Sport Shop to Luxor Radio

Corp., N. Y. C.

SEE JAY POWER UNIT

A ..o.opmation alkaline element battery andtrickle charger all in one. Can he chargedwhile set is operating. Price complete shippeddry with solution, $16.00. with Chem-ical Charger. $12.00. 140.volt, $0.00.Write foe our illustrated 24 -page booklet and

Send No Money Pay Expressman.SEE JAY BATTERY COMPANY913 Brook Avenue New York City

BROADCASTING STATION, SUPERPOWER,5,000 watt, licensed A. T. and T., and departmentincludes Western Electric amplifiers and tubes,for sale, lease or hire; offers wanted immediately.Address Box 9V, San Antonio, Texas. Businessaddress 101 West Pecan St.

E I A ILS OF WIRING THE DC B ELIMIN-ATOR, Part II, by Lewis Winner. appeared inRADIO WORLD dated April 24. Sent on re-eipt of 15c, or start sub. with that issue. RADIOA ORLD. 145 W. 45th St., N. Y. C.


COMING EVENTSAug. 21-28. Pacific Radio Exposition, Civic

Auditorium, San Francisco. Pacific Radio TradeAssociation, 905 Mission St.,San Francisco, Cal.

Sept. 5-11. Los Angeles adio Exposition. Am-bassador Auditorium, Auspices Radio Trades Asso-ciation of Southern California. A. G. Faruharson,Secretary, 515 Commercial Exchange Building,Los Angeles, Cal.

Sept. 6-11. Omaha Radio Exposition. CityAuditorium. Auspices Omaha Radio Trade Asso-ciation, F. R. King, Secretary, Hotel Fontenelle,Omaha, Neb.

Sept 13-18. Third Annual Radio World's Fair,New Madison Square Garden, New York City.Radio Manufacturers' Show Association, 1800

Times Building, New York CitySept. 15-18. Akron Radio Show. Auspices Radio

Dealers Association and "Times -Press." GeorgeMissig, Secretary, "Times -Press," Akron, 0.

Sept. 20-25. Pacific Northwest Radio Deposi-tion. Public Auditorium. George J. Thompson,Jr., Secretary, 411 Journal Building, Portland, Ore.

Sept. 20-26. Cleveland Second Annual RadioExposition. Public Auditorium. G. B. Boden-hoff, Manager, 511 Guarantee Title Building,Cleveland, 0., Room 817.

Sept. 25-29. Fourth Wisconsin Radio Exposi-tion, Municipal Auditorium, Milwaukee, N. C.Beerend, Manager, Box 1005, Milwaukee, Wis.

Sept. 27 -Oct. 2. Second Allied Radio Congressand National Radio Exposition, Exposition Hall,Hotel Sherman, Chicago. Milo E. Westbrooke,Manager, 608 South Dearborn Street, Chicago, Ill.

Sept. 27 -Oct. 2. Boston Radio Exposition, Me-chanics Building. Shelden Fairbanks, Manager,209 Massachusetts Avenue, Boston, Mass.

Sept. 27 -Oct. 2. Northwest Radio Exposition,Kenwood Armory and Coliseum, Minneapolis.Harry H. Cory, Executive Secretary, 301 TribuneAnnex, Minneapolis, Minn.

Sept. 28 -Oct. 1. Utica Radio Show. StateArmory. Auspices Utica Radio Association. H.Benner, Manager, "Observer -Dispatch," Utica,N. Y.

Oct. 2.9. Salt Lake Radio Exposition. Manu-facturers Building, State Fair Grounds. AuspicesMountain States Radio Trades Association. H. S.Jennings, Secretary, 221 South West Temple, SaltLake City, Utah.

Oct. 4-9. Pittsburgh Radio Show. James A.Simpson. Managing Director, 420 Bessemer Build-ing, Pittsburgh, Pa.

Oct. 11-16. Rochester Radio Show. Conven-tion Hall. Auspices Rochester Radio DealersAssociation, Rochester, N. Y.

Oct. 11-17. Fifth Annual Chicago Radio Show,Coliseum. Radio Manufacturers Show Association,127 North Dearborn Street, Chicago. Ill.,

Oct. 15-23. Second Southwest National Radio

Show, New Coliseum, St. Louis, Auspices St.Louis Radio Trades Association. William P.Mackle, Executive Secretary, 1207 SyndicateTrust Building, St. Louis, Mo.

Oct. 25-30. Second Annual Indianapolis RadioExposition, State Fair Grounds. Auspices Broad-cast Listeners' Association. A. J. Allen, Secre-tary, 1406 Merchants' Bank, Indianapolis, Ind.

Oct. 25-31. Detroit Radio Slime, ConventionHall. Sponsored by the Radio Tradb Associationof Michigan. A. M. Edwards, Secretary, 4464Cass Avenue, Detroit, Mich.

Oct. 25-30. New Orleans Radio DrpositioittAuspices Radio Trade Association and "TheStates." P. K, Ewing, Manager, States Building,New Orleans, La.

Oct. 26-29. Sioux Falls Radio Show. Coliseum.Auspices Civic Club. Roger S. Brown, Secretary,care "Argus-Leader," Sioux Falls, S. D.

Oct. 30 -Nov. 6. Third annual Brooklyn RadioExposition, 23rd Regiment Armory. Stephen T.Rogers, Managing Director. Suite 513, AlbeeBuilding, Brooklyn, N. Y.

ConventionsSept. 21-22. Cleveland First Annual Radio Con-

vention. Hollenden Hotel, Jobbers and Dealers.Warren Cox, Chairman. Radio Apparatus Co.,Cleveland, 0.

Sept. 27-28. Wisconsin Radio Trade Convention.Auditorium. Milwaukee. N. C Beerend, Man-ager, Box 1005, Milwaukee, Wis.

Oct. 18-23. Jobbers and Dealers Convention.Southwestern states. Auspices St. Louis RadioTrades Association. William P. Hackle, Execu-tive Secretary, 1207 Syndicate Trust Building,St. Louis, Mo.

Oct. 25-31. State Radio Dealer Convention.Auspices Radio Trade Association of Michigan,Convention Hal, Detroit. A. M. Edwards, Secre-tary, 4464 Cass Avenue, Detroit, Mich.

Canadian Trade ShowsSept. 13-18. Winnipeg Radio Show, Royal Alex-

andria Hotel. Auspices Canadian Exhibition Co.,204 King Street, East Toronto, Canada.

Oct. 4-9. Mcc1real Radio Show, Windsor Hotel.Auspices Canadian Exhibition Co., 204 East KingStreet, Toronto, Canada.

Oct. 25-30, Toronto Radio Show, Coliseum,Canadian National Exhibition Grounds. AuspicesCanadian Exhil,..Cicn Co., 204 East King Street,Toronto, Canada.

Copyright bh, The Radio DealerRepublished by Special Permission

JUNE EXPORTS $441,396WASHINGTON.

Exports of radio apparatus from theUnited States during June totalled $441,-396, compared to $443,981 during May.

Canadian ProductsTotalled $5,548,660

WASHINGTON.The total Canadian production of radio

apparatus during 1925 amounted to $5,- .

548,660, according to a report to the De-partment of Commerce from Trade Com-missioner L. W. Meekins, at Ottawa. Thestatistics for the year show a steady de-velopment of the industry and a tendencytoward production of complete setsrather than parts. About 48,500 completesets valued at $2,196,000 were produced inCanada in 1925.

Imports of radio apparatus and partsinto Canada totalled $5,552,530, of whichthe United States supplied $3,358,200.

Royal Radio Corp., Jersey City, N. J., radioappliances, $100,000; Samuel Coccaro, Byron Pull,Sigmund Auerbach, Jersey City, N. J. (Attys.,Levitan & Levitan, Jersey City, N. J.)

HAGER FATHER OF TWINSTwin girls, weighing six and eight

pounds respectively, were born to Mrs.Kolin D. Hager. Her husband is studiomanager and chief announcer of WGY,the Schenectady station of the GeneralElectric Company.

The world's greatest variable grid leak,distributed by the North American Bret -wood Co., is selling enormously, and isgiving universal satisfaction. Get moreout of your set by using the BretwoodGrid Leak. Mailed for $1.50. GuarantyRadio Goods Co., 145 West 45th Street,New York City.

TO KEEP YOUR FILES COMPLETE. you caorder your newsdealer to put a copy aside foryou each week while on your vacation. Or, send$1.00 for RADIO WORLD from now until theend of August, and in this way you will notmiss any copies. SUBSCRIPTION DEPT..RADIO WORLD. 145 W. 45th St.. N. Y. C.

COMINGSPECIAL SHOW NUMBER

OF RADIO WORLD - DATED SEPTEMBER 11Last Red Form Closes Aug. 30 -Last Black Form Closes Aug. 31.

Last year's Show Number of RADIO WORLD was one of the outstanding issues of the year inthe radio publishing business. It gave splendid value to the shrewd advertisers in its pages. Weaim to beat it this year.

This Show Number will be issued at a time when radio sales start again, and, as RADIO WORLDis the only National Illustrated Weekly, it will carry the New York Show to radioists all over thecountry. Cash in on this great interest in the Show by taking advertising space in this Show Number.

All the news of the New York Show, complete list of exhibitors -what they will display -andservice features of value to the radio public.

Regular advertising rates in force as follows:GENERAL ADVERTISING -

1 Page, 71/4"x11", 462 lines $300.00Yz Page, 7Y4"x51,4", 231 lines 150.00Y4 Page, 4%8", D. C., 115 lines 75.00I Column, 2%"x11", 154 lines 100.001 inch 10.00

Per agate line .75

TIMES DISCOUNTS -52 consecutive issues 20%26 times consecutively or E. 0. W. one year 15%4 consecutive issues 10%

For space in this unusually valuable issue, communicate at once with

ADVERTISING MANAGER, RADIO WORLD, 145 W. 45th St., New York City


Steinmetz LivedQuaintly at Camp

Had Own Menagerie as Guests Enjoyed Canoeing,Was Quite Informal, Yet Always

Kept Eye on Work[Earlier chapters of the life of Charles P.

Steinmetz were published in the three pre -.ceding issues.]

By John W. HammondFew men of science were so surprisingly

informal, or so fond of knocking aroundwith a few chums, as was Steinmetz.

The friend who was closest to Stein -

1

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A(601411(FABoWaWrA

metz for ten years or more after theyboth came to Schenectady was Ernst J.Berg, who was a fellow -worker with himat Lynn, and who was also transferredwhen the calculating department wasmoved from that city to the present head-quarters of the company.

Steinmetz and Berg, one Sunday after-noon, were rowing on the Mohawk River,when their boat came to the mouth of asmall tributary, locally known as Viele'sCreek. The view at this point, as .,theylooked upstream, was so pleasant thatthey pointed their boat in that directioriand rowed as- far as they could in theshallow water. Before long they cameto a most attractive bluff which, theyfound upon landing, gave them a fineview of the landscape.

Picked a CampIt was a splendid place for a camp;

and within five years, Steinmetz built acamp on that very spot. It was a littleone -room shack at first, supported on therather steep slope of the bluff by slendertimbers, which hardly looked strongenough to bear very much weight. Laterit was enlarged until it was a rough, butpleasant group of structures, all joinedtogether and able to accommodate severalpersons overnight.

This camp became the one thing thatSteinmetz really wanted for himself; and

Sales

"Outsell, Because They Excel"

TUBES andLoud Speakers

All Types

Dealers and JobbersWrite for Priers and

Folder "W"

Lank for "EMPIRE"Booth at Rado Show

EMPIRE ELECTRICAL

PRODUCTS CO.

Laboratories and Factory: Kearney. N. J.Office: 132-134 Greene St., New York

it was the one thing which he took painsto secure as soon as he could afford to doSO.

Hardly any other person in Schenec-tady lived in such a simple style as Stein-metz did, nor had such curious hobbies,nor enjoyed life in such a picturesquemanner.

The Liberty Street place had a smallgreen house on the grounds. This littlebuilding, enclosed in glass, was immedi-ately made use of by Steinmetz to starta collection of cacti, ferns and especiallyorchids, of which latter he was alwaysfond. Out in the yard, and also in thestable which stood back of the house,Steinmetz and Ernst Berg constructedsome pens and cages for the numerouspets which they soon began to own.

Great Friend of kitimalsSteinmetz seemed to be able to make

friends with creatures such as men do notoften have about them. He managed totame two crows that were accustomed tofly about the yard. Steinmetz used tocall to them and offer them things toeat, until finally,, to the astonishment ofthe whole neighborhood, he got them sotame that they would perch on his wristand eat out of his hand.

They seemed to watch for him to comeout into the yard, and would sometimesalight on his shoulder. They would alsofly to the window -ledge of his bedroomand peer in at him when the window wasopen.

There were quite a few raccoons in the"menagerie": at Liberty Hall. One ofthese gave much trouble to tho cock.He was so much better behaved than theothers that the men allowed him to roamabout the house. After he had discoveredthe kitchen, however, he ate up so muchof the" food that he was finally put backin his cage. Several young eagles werepart of the collection of pets. Therewere also cranes and owls, squirrels anddogs, and a most intelligent monkey,known as Jenny.

Most remarkable of all was a youngalligator, three feet long. Steinmetz andthis alligator were great churns. It was afavorite pastime of his to try to teach thealligator tricks. He always told hisfriends that he could make the alligatordo anything he wanted it to do. Some-times this really appeared to be true.

Steinmetz insisted on having a little

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This is the way to-for the price of one:-Send $6.00 today for RADIO WORLD-for one year (regular price)-for 52 numbers)-and select any one of the other-nine publications for twelve months.

get two publications-Add 11.00 a year extra for-Canadian or Foreign Postage.-Present RADIO WORLD subscribers-can take advantage of this offer by-extending subscriptions one year-if they send renewals NOW!

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A tw14: 28, 1926 RADIO WORLD 27

laboratory in the house, and in tinkeringaround in the evenings or perhaps late atnight, making all sorts of experiments.Sometimes he would try an investigationin chemistry that would fill the house withunbearable odors and leave yellow stainson the window draperies. And sometimesit would he an electrical experiment,which to any one except an electrical en-gineer, might seem even more terrifyingbecause of the sputtering blue sparks andflashes that were produced.

Frequently during the time that he wasat Liberty Hall, he was visited by youngengineers of the General Electric Com-pany who admired his brilliant engineeringaccomplishments. About the beginning of1901, a young engineer named Chamber-lain, who had known Steinmetz a shorttime, called at Liberty Hall. He broughtanother young visitor with him, JosephLeRoy Hayden, whom he introduced toSteinmetz. A few days later they calledagain and gradually Hayden began to feelquite at home with Steinmetz, whose man-ner and conversation greatly interestedhint,

Adopts a SonFrom these purely ordinary little occa-

sions, growing out of a mere chance ac-quaintance, there developed a life-longintimacy between Steinmetz and Haydenthat finally provided Steinmetz with theonly family life he ever knew. It was anextremely pleasant domestic circle, withHayden as the adopted son of the famousengineer, and, as the years went on, Hay -den's children as the adopted grand-children.

The opportunity for Hayden to becomea special friend of Steinmetz's occurred(luring that summer of 1901, at the latter'scamp.

According to his regular custom,Steinmetz invited Hayden to spend aweek -end at the camp. It was the usualthing for a party of young men to goout there every Saturday afternoon andstay until Sunday night. As a rule,there was a most enjoyable social partyon Saturday night, and boating and bath-ing all (lay Sunday, with heal steak din-ner Sunday noon. That was Steinmetz'sfavorite Sunday dinner, which he cookedhimself. No one thought of wearing or-dinary clothes at the camp. They al-ways wore bathing suits. Steinmetzwore one constantly.

In 1900, Steinmetz abandoned Liberty11.111 for new and larger quarters on

ri t' which he had bought for the

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purpose. The General Electric built nima two story laboratory, which was fin,ished before his house, so he moved intotile laboratory.

He brought with him a number of ar-ticles of furniture which he had pur-chased while living on Liberty Street,and these were scattered about in thelaboratory wherever there happened tobe room for them. A bookcase, a horse-hair lounge, some parlor chairs, and sev-eral pieces of bric-a-brac seemed allmixed in with the laboratory and chemi-cal equipment. It looked very odd tothose who came to see Steinmetz; but it(lid not disturb Steinmetz in the least.

He felt exceedingly happy in his newsurroundings. He had a wonderfully fineplace for his ceaseless experiments. Hehad provided his rare plants with a shel-ter even before he had thought of lodg-ings for himself. And for the time being,he felt that he could live very comfort-ably ill his new laboratory; for he wasquite used to such an odd, half -disorderlykind of home as men often create whenthey live by themselves.

But the thing that made him mosthappy was his laboratory work. Only henever called it work. He liked electricalexperiments so much, especially when hehad to make use of mathematics, as heusually did, that it never seemed likework to him.

When he felt tired, or wanted to rest hismind, he Would go into his conservatoryand walk about among his plants. Allaround the conservatory, in hanging bas-kets, were many beautiful orchids, hisfavorite flower. And beyond them, in the

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larger part of the conservatory, were allsorts of queer, tall desert plants, espe-cially cacti. In these surroundings hespent the entire winter of 1901-1902, hav-ing moved out to his camp in the sum-mer, finding life altogether a delightful.experience.

Invents an Arc LampIn the very first year that Steinmetz

took possession of his new private labora-tory, he invented an arc lamp for streetlighting. This Was not by any meanshis only important invention. All his in-ventions together numbered nearly twohundred. But this one was the firstone to attract wide attention.

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24 RADIO WORLD

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August 28, 1c2.6

Stoner & HeathTake a New Line

The English -Whitman line of productsis now ready for the trade. One is theEnglish -Whitman loop, known as the"Tun -A -Loop" which matches all tuningdial settings regardless of the size of thecondensers. Made of genuine Bakeliteand spider web wound with silk overphosphor bronze wire, it prevents dielec-tric losses and eliminates possible leak-age. It can be used on any set which hasradio frequency, gives amazing results onregenerative sets, works on Neutrodynesand all classes of Super -Heterodynes.The list price is very reasonable.

The English -Whitman speaker is ex-pected to create a sensation, as it uses anentirely new principle and is hornless andtoneless. After much thought and con-sideration of the field, the English -Whit-man Company have placed their lines inthe hands of Stoner & Heath, 122 Green-wich Street, New York City. Full infor-mation may be had from this concern.Mention RADIO WORLD when writing.

Acme ApparatusAnnounces Models

The Acme Apparatus Company of Cam-bridge, Mass., known the world over fortheir famous slogan, -Acme for Amplifica-tion," announces the release of their 1927specialties. The K-i and K-2 double free -edge cone speakers will be on the market

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in improved form, with the addition of anew K-3 single free edge cone 11" indiameter. All the faithfulness of repro-duction inherent in the two other modelsis maintained in this speaker. The K-3can also be adapted to wall mounting bya simple adjustment.

Three models of B power supply atreasonable prices are also part of the newAcme line, together with a model for Asupply and one for C supply. Eliminatorkits for those who prefer to build theirown may also be had, also a full line offilters, chokes and transformers. Audioamplification and miscellaneous parts tofill every need are also in the line. The"ham" is not neglected, for in the catalogappears everything to meet his heart'sdesire, all of the well-known Acme qual-ity. A beautifully illustrated catalog willbe sent to those interested upon applica-tion either to the Acme Apparatus Com-pany, Cambridge, Mass. or .Pearcy W.Mack, 1270 Broadway, New York City.Mention RADIO WORLD.

New De Jur CatalogThe De Jur Products Company, 199

Lafayette Street, New York City, hasjust issued a 12 -page catalog, illustratingdescribing and pricing their entire lineof radio products for 1927. Featuredtherein is the new De Jur ResistanceCoupled Amplifier which the company ismarketing under the trade name "Plano-tier." This company is the maker of thefamous De Jur rheostat and other ex-cellent parts. They will be glad to sendthe catalog free. Mention RADIO WORLD.

FERGUSON ENLARGESJ. B. Ferguson, Inc., manufacturers of

"The Gold Standard of Radio Receivers,"have been compelled to double their fac-tor), space due to the increased volumeof business. The factory is located at 354241st Street, Long Island City, N. Y. Theoffice is at 225 W. 57th Street, N Y. C.

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THE GEORGE W. WALKER CO.ISIS Carnegie Avenue Cleveland, Ohio

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on wrappers. If your wrapper shows a date earlier than the current issue, pleasesend payment for renewal. Changes in expiration dates on wrappers appear two weeksafter receipt of renewal.

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Empire-trons LineFor 1927 Is Ready

The new line of Empire -trolls, includ-ing the new gas -filled detector kEX200),high -mu and power ;amplifiers, is now on

on the market. These tubesare sturdily built for long

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Pacific ShowTo Open Sept. 21

The second annual Pacific NorthwestRadio Exposition will open its doors atthe Public Auditorium, Portland, at noon,Tuesday, September 21, and will last fivedays.

The decoration scheme is accentuatedby the brilliant flood lights, Oregon scenicstrips and colorful stage sykes that hidebare wall spaces.

The exploitation cost runs well over$5,000. A very elaborate advertising cam-paign was prepared by Crossley & Fail-ing, Inc.

The entertainment is so varied and ofsuch quality as to encourage show goersto attend several nights. Stations KFjR,KFWV, KTBR, KGW, and KOIN willbroadcast every evening.

NEW CORPORATIONSCentury Radio Panel Corp., N. Y. C.; $20,000.Reid & Green. Inc., Newark, N. J., electricalaccessories; $50,000.

- NAME CHANGESLuxor Radio and Sport Shop to Luxor Radio

Corp., N. Y. C

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UE tAILS OF WIRING THE DC B CUMIN-4.TOR., Part II, by Lewis Winner. appeared inRADIO WORLD dated April 24. Sent on re-.eipt of 15c, or stall sub. with that issue. RADIOsh ORLD. 145 W. 45th St., N. Y. C.


COMING EVENTSAug. 21-28. Pacific Radio Exposition, Civic

Auditorium, San Francisco. Pacific Radio TradeAssociation, 905 Mission St., San Francisco, Cal,

Sept. 5-11. Los Angeles Radio Exposition, Am-bassador Auditorium, Auspices Radio Trades Asso-ciation of Southern California. A. G. Faruharson,Secretary, 515 Commercial Exchange Building,Los Angeles, Cal.

Sept. 6-11. Omaha Radio Exposition. CityAuditorium. Auspices Omaha Radio Trade Asso-ciation, F. R. King, Secretary, Hotel Fontenelle,Omaha, Neb.

Sept 13.18. Third Annual Radio World's Fair,New Madison Square Garden, New York City.Radio Manufacturers' Show Association, 1800Times Building, New York City

Sept. 15.18. Akron Radio Show. Auspices RadioDealers Association and "Times -Press." GeorgeMissig, Secretary, "Times -Press," Akron, 0.

Sept. 20-25. Pacific Northwest Radio Exposi-tion. Public Auditorium. George J. Thompson,Jr., Secretary, 411 Journal Building, Portland, Ore.

Sept. 20.26. Cleveland Second Annual RadioExposition. Public Auditorium. G. B. Boden-hoff, Manager, 511 Guarantee Title Building,Cleveland, 0., Room 817.

Sept. 25-29. Fourth Wisconsin Radio Exposi-tion, Municipal Auditorium, Milwaukee, N. C.Beerend, Manager, Box 1005, Milwaukee, Wis.

Sept. 27 -Oct. 2. Second Allied Radio Congressand National Radio Exposition, Exposition Hall,Hotel Sherman, Chicago. Milo E. Westbrooke,Manager. 608 South Dearborn Street, Chicago, Ill.

Sept. 27 -Oct. 2. Boston Radio Exposition, Me-chanics Building. Shelden Fairbanks, Manager,209 Massachusetts Avenue, Boston, Mass.

Sept. 27 -Oct. 2. Northwest Radio Exposition,Kenwood Armory and Coliseum, Minneapolis.Harry H. Cory, Executive Secretary, 301 TribuneAnnex, Minneapolis, Minn.

Sept. 28 -Oct. 1. Utica Radio Show. StateArmory. Auspices Utica Radio Association. H.Benner, Manager, "Observer -Dispatch," Utica,N. Y.

Oct. 2-9. Salt lake Radio Exposition. Manu-facturers Building, State Fair Grounds. AuspicesMountain States Radio Trades Association. H. S.Jennings, Secretary, 221 South West Temple, SaltLake City. Utah.

Oct. 4-9. Pittsburgh Radio Show. James A.Simpson, Managing Director, 420 Bessemer Build-ing, Pittsburgh, Pa.

Oct. 11-16. Rochester Radio Show. Conven-tion Hall. Auspices Rochester Radio DefilersAssociation, Rochester, N. Y.

Oct. 11-17. Fifth Annual Chicago Radio Show,Coliseum. Radio Manufacturers Show Association,127 North Dearborn Street, Chicago. Ill.,

Oct. 10-21 Second Southwest National Radio

Show, New Coliseum, St. Louis. Auspices St.Louis Radio Trades Assaciation. William P.Mackie, Executive Secretary, 1207 SyndicateTrust Building, St. Louis, Mo.

Oct. 25-30. Second Annual Indianapolis RadioExposition, State Fair Grounds. Auspices Broad-cast Listeners' Association. A, J. Allen, Secre-tary. 1406 Merchants' Bank, Indianapolis, Ind.

Oct. 25-31. Detroit Radio Show, ConventionHall. Sponsored by the Radio Trade Associationof Michigan. A. 114. Edwards, Secretary, 4464Cass Avenue, Detroit, Mich.

Oct. 25-30. New Orleans Radio Exposition.tAuspices Radio Trade Association and "TheStates." P. K. Ewing, Manager, States Building,New Orleans, La.

Oct. 26-29. Sioux Falls Radio Show. Coliseum.Auspices Civic Club. Roger S. Brown, Secretary,care "Argus-Leader," Sioux Falls, S. D.

Oct. 30 -Nov. 6. Third annual Brooklyn RadioExposition, 23rd Regiment Armory. Stephen T.Rogers, Managing Director. Suite 513, AlbeeBuilding, Brooklyn, N. Y.

ConventionsSept. 21-22. Cleveland First Annual Radio Con-

vention. Hollenden Hotel. Jobbers and Dealers.Warren Cox, Chairman. Radio Apparatus Co.,Cleveland, 0.

Sept. 27-28. Wisconsin Radio Trade Convention.Auditorium. Milwaukee. N. C. Beerend, Man-ager, Box 1005, Milwaukee, Wis.

Oct. 18-23. Jobbers and Dealers Convention.Southwestern states. Auspices St. Louis RadioTrades Association. William P. Mackie, Execu-tive Secretary, 1207 Syndicate Trust Building,St. Louis, Mo.

Oct. 25-31. State Radio Dealer Convention.Auspices Radii° Trade Association of Michigan,Convention Hal, Detroit. A. M. Edwards. Secre-tary, 4464 Cass Avenue, Detroit, Mich.

Canadian Trade ShowsSept. 13-18. Winnipeg Radio Show, Royal Alex-

andria Hotel. Auspices Canadian Wxhibition Co.,204 King Street, East Toronto, Canada.

Oct. 4-9. Mccireal Radio Show, Windsor Hotel.Auspices Canadian Exhibition Co., 204 East KingStreet, Toronto, Canada.

Oct. 25-30. Toronto Radio Show, Coliseum,Canadian National Exhibition Grounds. AuspicesCanadian Exhi"..,,,,,:cm Co., 204 East King Street,Toronto, Canada.

Copyright his The Radio DealerRepublished by Special Permission

JUNE EXPORTS $441,396WASHINGTON.

Exports of radio apparatus from theUnited States during June totalled $441,-396, compared to $443,981 during May.

Canadian ProductsTotalled $5,548,660

WASHINGTON.The total Canadian production of radio

apparatus during 1925 amounted to $5,-548,660, according to a report to the De-partment of Commerce from Trade Com-missioner L. W. Meekins, at Ottawa. Thestatistics for the year show a steady de-velopment of the industry and a tendencytoward production of complete setsrather than parts. About 48,500 completesets valued at $2,196,000 were produced inCanada in 1925.

Imports of radio apparatus and partsinto Canada totalled $5,552,530, of whichthe United States supplied $3,358,200.

Royal Radio Corp., Jersey City, N. J., radioappliances, $100,000; Samuel Coccaro, Byron Pull,Sigmund Auerbach, Jersey City, N. J. (Attys.,Levitan & Levitan, Jersey City, N. J.)

HAGER FATHER OF TWINSTwin girls, weighing six and eight

pounds respectively, were born to Mrs.Kolin D. Hager. Her husband is studiomanager and chief announcer of WGY,the Schenectady station of the GeneralElectric Company.

The world's ,,greatest variable grid leak,distributed by he North American Bret -wood Co., is selling enormously, and isgiving universal satisfaction. Get moreout of your set by using the BretwoodGrid Leak. Mailed for $1.50. GuarantyRadio Goods Co., 145 West 45th Street,New York City.

TO KEEP YOUR FILES COMPLETE, you caorder your newsdealer to put a copy aside foryou each week while on your vacation. Or, send$1.00 for RADIO WORLD from now until theend of August, and in this way you will notmiss any copies. SUBSCRIPTION DEPT.,RADIO WORLD. 145 W. 45th St., N. Y. C.

COMINGSPECIAL SHOW NUMBER

OF RADIO WORLD -DATED SEPTEMBER 11Last Red Form Closes Aug. 30 -Last Black Form Closes Aug. 31.

Last year's Show Number of RADIO WORLD was one of the outstanding issues of the year inthe radio publishing business. It gave splendid value to the shrewd advertisers in its pages. Weaim to beat it this year.

This Show Number will be issued at a time when radio sales start again, and, as RADIO WORLDis the only National Illustrated Weekly, it will carry the New York Show to radioists all over thecountry. Cash in on this great interest in the Show by taking advertising space in this Show Number.

All the news of the New York Show, complete list of exhibitors -what they will display -andservice features of value to the radio public.

Regular advertising rates in force as follows:GENERAL ADVERTISING -1 Page, 7N"x11", 462 lines $300.00

IA Page, 7,/4"x5%", 231 lines 150.005/4 Page, 4Y8", D. C., 115 lines 75.001 Column, 21/4"x11", 154 lines 100.001 inch 10.00

.75Per agate lineTIMES DISCOUNTS -52 consecutive issues 20%26 times consecutively or E. 0. W. one year 15%

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For space hi this unusually valuable issue, communicate at once with

ADVERTISING MANAGER, RADIO WORLD, 145 W. 45th St., New York City


Steinmetz LivedQuaintly at Camp

Had Own Menagerie as Guests, Enjoyed Canoeing,Was Quite Informal, Yet Always

Kept Eye on Work[Earlier chapters of the life of Charles P.

Steinmetz were published in the three pre-ceding issues.]

By John W. HammondFew men of science were so surprisingly

informal, or so fond of knocking aroundwith a few chums, as was Steinmetz.

The friend who was closest to Stein -

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metz for ten years or more after theyboth came to Schenectady was Ernst J.Berg, who was a fellow -worker with himat Lynn, and who was also transferredwhen the calculating department wasmoved from that city to the present head-quarters of the company.

Steinmetz and Berg, one Sunday after-noon, were rowing on the Mohawk River,when their boat came to the mouth of asmall tributary, locally known as Viele'sCreek. The view at this point, as theylooked upstream, was so pleasant thatthey pointed their boat in that directionand rowed as far as they could in theshallow water. Before long they cameto a most attractive bluff which, theyfound upon landing, gave them a fineview of the landscape.

Picked a CampIt was a splendid place for a camp;

and within five years, Steinmetz built acamp on that very spot. It was a littleone -room shack at first, supported on therather steep slope of the bluff by slendertimbers, which hardly looked strongenough to bear very much weight. Laterit was enlarged until it was a rough, butpleasant group of structures, all joinedtogether and able to accommodate severalpersons overnight.

This camp became the one thing thatSteinmetz really wanted for himself.; and

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it was the one thing which he took painsto secure as soon as he could afford to doSO.

Hardly any other person in Schenec-tady lived in such a simple style as Stein-metz did, nor had such curious hobbies,nor enjoyed life in such a picturesquemanner.

The Liberty Street place had a smallgreen house on the grounds. This littlebuilding, enclosed in glass, was immedi-ately made use of by Steinmetz to starta collection of cacti, ferns and especiallyorchids, of which latter he was alwaysfond. Out in the yard, and also in thestable which stood back of the house,Steinmetz and Ernst Berg constructedsome pens and cages for the numerouspets which they soon began to own.

Great Friend of -AnimalsSteinmetz seemed to be able to make

friends with creatures such as men do notoften have about them. He managed totame two crows that were accustomed tofly about the yard. Steinmetz used tocall to them and offer them things toeat, until finally, to the astonishment ofthe whole neighborhood, he got them sotame that they would perch on his wristand eat out of his hand.

They seemed to watch for him to comeout into the yard, and would sometimesalight on his shoulder. They would alsofly to the window -ledge of his bedroomand peer in at him when the window wasopen.

There were quite a few raccoons in the"menagerie": at Liberty Hall. One ofthese gave much trouble to the, cock.He was so much better behaved than theothers that the men allowed him to roamabout the house. After lie had discoveredthe kitchen, however, he ate up so muchof the food that he was finally put backin his cage. Several young eagles werepart of the collection of pets. Therewere also cranes and owls, squirrels anddogs, and a most intelligent monkey,known as Jenny.

Most remarkable of all was a youngalligator, three feet long. Steinmetz andthis alligator were great chums. It was afavorite pastime of his to try to teach thealligator tricks. He always told hisfriends that he could mace the alligatordo anything he wanted it to do. Some-times this really appeared to be true.

Steinmetz insisted on having a little

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August 28, 1926 R A I) I 0 \\I k I. I) 27

laboratory in the house, and in tinkeringaround in the evenings or perhaps late atnight, making all sorts of experiments.Sometimes he would try an investigationin chemistry that would fill the house withunbearable odors and leave yellow stainson the window draperies. And sometimesit would be an electrical experiment,which to any one except an electrical en-gineer, might seem even more terrifyingbecause of the sputtering blue sparks andflashes that were produced.

Frequently during the tune that he wasat Liberty Hall, he was visited by youngengineers of the General Electric Com-pany who admired his brilliant engineeringaccomplishments. About the beginning of1901, a young engineer named Chamber-lain, who had known Steinmetz a shorttime, called at Liberty Hall. He broughtanother young visitor with him, JosephLeRoy Hayden, whom he introduced toSteinmetz. A few days later they calledagain and gradually Hayden began to feelquite at home with Steinmetz, whose man-ner and conversation greatly interestedhim.

Adopts a SonFrom these purely ordinary little occa-

sions, growing out of a mere chance ac-quaintance, there developed a life-longintimacy between Steinmetz and Haydenthat finally provided Steinmetz with theonly family life he ever knew. It was anextremely pleasant domestic circle, withHayden as the adopted son of the famousengineer, and, as the years went on, Hay -den's children as the adopted grand-children.

The opportunity for Hayden to becomea special friend of Steinmetz's occurredduring that summer of 1901, at the latter'scamp.

According to his regular custom,Steinmetz invited Hayden to spend aweek -end at the camp. It was the usualthing for a party of young men to goout there every Saturday afternoon andstay until Sunday night. As a rule,there was a most enjoyable social partyon Saturday night, and boating and bath-ing all day Sunday, with beat steak din-ner Sunday noon. That was Steinmetz'sfavorite Sunday dinner, which he cookedhimself. No one thought of wearing or-dinary clothes at the camp. They al-ways wore bathing suits. Steinmetzwore one constantly.

In 1900, Steinmetz abandoned LibertyHall for new and larger quarters onproperty which he had bought for the

FREERADIO

CATALOGSpecial SummerBargain Bulletin

Parts, accessories, kitsand sets-all the best andthe latest. A $1,000,000.00Radio Stock to choosefrom. A copy of thisunusual catalog isyours for the asking.Just drop us a line-

now.

DEPT. R.W.

CHICAGO SALVAGESTOCK STORE

509 S. State St., CHICAGO, U.S. A.

purpose. The General Electric built ;tinta two story laboratory, Which was fin-ished before his house, 5o he woved intothe laboratory.

He brought with hint a number of ar-ticles of furniture which he had pur-chased while living on Liberty Street,find these were scattered about in thelaboratory wherever there happened tobe room for them. A bookcase, a horse-hair lounge, sonic parlor chairs, and sev-eral pieces of bric-a-brac scented allmixed in with the laboratory and chemi-cal equipment. It looked very odd tothose who came to see Steinmetz; but itdid not disturb Steinmetz in the least.

He felt exceedingly happy in his newsurroundings. FIe had a wonderfully fineplace for his ceaseless experiments. Hehad provided his rare plants with a shel-ter even before he had thought of lodg-ings for himself. And for the time being,he felt that .he could live very comfort-ably in his new laboratory; for he wasquite used to such an odd, half -disorderlykind of home as men often create whenthey live by themselves.

But the thing that made him mosthappy was his laboratory work. Only henever called it work. He liked electricalexperiments so much, especially when hehad to make use of mathematics, as heusually did, that it never seemed likework to him.

When he felt tired, or wanted to rest hismind, he would go into his conservatoryand walk about among his plants. Allaround the conservatory, in hanging bas-kets, were many beautiful orchids, hisfavorite flower. And beyond them, in the

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taker p:irt of the conservatory, were :ill,,f queer, bill desert plants, rape-

riallt In these surroundings hespew the entire winicr 1901-1902, hay-inc out 14, in the sum -

tinning life aliouellier a delightfulcS.periClice.

ItIV011t$ an Arc EnmpIn the very first year ticii Steinmetz

took possession of his new private labora-tory, he invented an arc lamp for streetlighting. This was not by any meanshis only important invention. All his in-ventions together numbered nearly twohundred. But this one was the firstone to attract wide attention.

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Opposing ReactionsBalance the Circuit

Degeneration May be Employed by Permitting Pre-ponderance of Capacity in the Plate Circuit

(Continued from page 10)supply an inductive reaction that variesin the same way with frequency, then thetwo reactions will oppose.

We have already pointed out how wecan control the magnitude of the induc-tive reaction, created as circuit 2 is variedin any desired manner, to produce or notproduce oscillations, and by the sametoken we can control it to neutralize thecapacitive reaction of the condenser C.By proper selection of elements we canmake the reaction neutralization complete

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to produce a non -reactive plate circuit,not only for one frequency but all fre-quencies, and therefore have neither re-generation nor degeneration, and all en-tirely independent of the inherent tubecapacity.

The energy in the plate circuit is there-fore solely the energy of natural amplifi-cation of the tube, and can be selectedout of the plate circuit at and with theefficiency of exact resonance, and withfurther efficiency of as tight a degree ofcoupling as the overall requirements ofthe receiver dictate.

We find that the adjustment that pro-duces a non -reactive plate circuit givessubstantially constant energy transferwith frequency, so that we term this newsystem the Loftin -White Constant Coup-ling Non -Reactive Plate Circuit System,or L -W Circuit for brevity.

Uses DegenerationA further advantage of the system isthat the plate circuit can be adjusted to

remain slightly capacitive throughout therange, thus producing degeneration whichmay be useful in a particular multipletube design of receiver where the overalllocation of parts leaves some regener-

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UX POWER TUBES installed in any setwithout rewiring by Na-Ald Adapters andConnectoralds. For full information writeAlden Manufacturing Co., Dept. S-20,Springfield, Mass.

ative or positive stray or distant stagefeedback. This, of course, cannot be hadin the neutralized type of set becausethe limit of adjustment is neutralizationand nothing on the side of degeneration.This feature makes it possible for us tobuild sets with three stages of radio fre-quency without the elaborate per stageshielding that is being practiced in themore -than -two stage commercial neutral-ized set.

We think a good practical example ofthe stabilizing characteristics of our sys-tem is illustrated in our experience withthe Atwater Kent "Compact." Its propor-tions and arrangement of parts offer un-usual factors toward stray feedback re-generation. We removed from one ofthese sets the grid resistances used tolimit regenerative effect, converted it toinclude our system, and thereafter oper-ated it with impunity with full filamentvoltages, 200 volts on the plates, and withany and all tubes with perfect stabilitythroughout.

As to our simplified regenerative de-tector see Fig. 16.

Here we use the grid circuit as the onlytuned circuit of the system and couplethe plate circuit to the tuned grid circuitwith a combined coupling. The antennamay be coupled to the tuned grid circuitin any suitable way, but a combinationConstant Coupling as shown is preferable.

Resistive TicklerThe ordinary connection of the grid

leak around the stopping -condenser can-not be made as the tuning condenser onone side and the coupling condenser onthe other effectively interrupt the gridcircuit against a grid bias, so that thegrid leak must be connected directly be-tween grid and filament.

By properly adjusting the combinedcoupling between the grid and plate cir-cuits, constant regeneration or "tickling"with frequency is had, and by includinga limited element such as the resistanceR, it is easy to hold the system withoutrepeated adjustment below oscillation forbroadcast or spark telegraphy recenfinn.or in oscillations for CW or heterodynereception.

It will he noted that the connectionacross the coupling condenser is in theopposite sense to that shown in previousfigures, but this is necessary as the feed-back must be such as to aid the current

RADIO WORLD'S QUICK -ACTION CLASSIFIED ADS.10 CENTS A WORD. 10 WORDS MINIMUM. CASH WITH ORDER.

HOW TO USE AERIALS IN GROUND ANDWATER, by Lewis Winner, appeared in RADIOWORLD, dated May 29. Sent on receipt of 15c,or start subscription with that number. RADIOWORLD. 145 W. 45th St., N. Y. C.

TABLE FOR CONVERSION OF FRE-QUENCIES AND METERS appeared in RADIOWORLD dated May 1, 1925. Sent on receipt of15c, or start your sub. with that number. RADIOWORLD. 145 W. 45th St., N. Y. C.

THE VACATION NUMBER OF RADIOWORLD DATED JUNE 12 contained many greatfeatures. The light 5.tube Portable, by HermanBernard. The Freshman Masterpiece, by AlbertW. Franklin, The Importance of C Batteries, byJohn F. Rider, etc. Sent on receipt of 15c, ofstart sub. with that number. RADIO WORLD145 W. 45th St., N. Y. C.

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BLUE PRINT FOR 1926 DIAMOND OF THEAIR sent on receipt of Ste. Guaranty Radio GoodsCo., 145 West 45th Street, New York City.

A BUILT-IN SPEAKER SET, by Herbert E.Hayden, POWERTONE IN OPERATION, byCapt. P. V. O'Rourke, THE NOVICE'S NOOK,byJames B. Scully, appeared in RADIO WORLDdated May 22. Sent on recipt of 15c, or startsub. with that number. RADIO WORLD. 145W. 45th St.. N. Y. C.

THE BRETWOOD GRID LEAK will aid youto get DX even in the summer. Sent on receiptof $1.50. North American Bretwood Co., 145 W.45th St.. N. Y. C.

A DISCUSSION ON SELECTIVITY, by J. E.Anderson, appeared in RADIO WORLD, datedJune 19. Sent on receipt of 15e, or start sub-scription with that number. RADIO WORLD,145 W. 45th St.. N. Y. C.

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HERMAN BERNARD. managing editor ofRADIO WORLD, broadcasts every Friday at 7p. in.. tram WGBS, Gimbel Bros., N. Y. City -315.6 meters. He discusses "What's Your Radio"rohlem?" Listen ini

GETTING MAXIMUM RESULTS with Super -Heterodynes by Herman Bernard appeared inRADIO WORLD dated May 15th. 15c per copy,or start your subscription with that issue. RADIOWORLD, 145 West 45th St. N. Y. City.

DESIGN DATA FOR RADIO TRANSMIT-TERS AND RECEIVERS, by M. B. Sleeper, senton receipt of 75c. Guaranty Radio Goods Co., 145West 45th Street, Nosy York City.

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August 1026 RADIO WORLD

POLARITY OF COILIMPORTANT ITEM

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FIG16in the grid circuit. Care must be takento so pole the inductive coupling that itwill aid this new arrangement of capac-itive coupling. This alternative capacityconnection permits of connecting the ro-tary side of the tuning condenser toground. Such a connection becomesnecessary in multiple tube receivers usingsingle dial control where all of the rotaryelements must be at the same potential,usually ground potential. There resultsa slight reduction in voltage applied tothe grid, since grid and filament are con-nected across the tuning condenser alone,which connection divides the overallavailable potential in the inverse ratio ofthe tuning and coupling condenser capac-ities.

While the matters outlined are basedon long and most intensive laboratorystudy and experiment combined withactual construction from the ground upof numerous receivers of different plansand numbers of tubes, and the conversionof some fifteen or more well-known com-mercial models, yet we think there canbe no more certain practical ratificationof their soundness than is contained inthe new ''Single Six" receiver of TheHartman Electrical Manufacturing Com-pany of Mansfield, Ohio, which receiverembodies the collaborative design of theengineers of that company and the writers conducted during the past winter toinclude the L -W Circuit in a radicallynew receiver.

The result is a 6 -tube set having threestages of radio frequency amplification,detector and two audio stages, with singledial control, the whole being housed inthe shortest space yet attempted for amultiple tube radio frequency system.

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Directional EffectOf Aerial Doubted

Author Says Tests of Receiver Pickup Agencies ShowsOther Factors Account for Difference in Results-

Points to Fundamental Wavelength as Caus-ing Deceptive Findings

By K. B. HumphreyThat there is a directional effect in

aerials when used in transmitting broad-cast. signals has been proven time andtime again by accurate measurements.That there is a directional effect in areceiving aerial of the outside wire typehas been proven, but not with the degreeof accuracy that gives the definite resultsobtained in the first case, I will not goas far as to say that there is no directionaleffect, but I will say that it has neverbeen proven to me conclusively that thereis an effect.

By that I do not mean that differentresults are not to be obtained by puttingup the aerial in different directions, butthat the difference in almost every casecan be traced directly to "other. thingsthan the mere fact that the aerial is facingwhere the experimenter was using twodifferent aerials to receive from differentdirections, the aerials themselves probablywere totally unlike in shape and size.

One Kind of "Teat"Take for instance the case of one man.

He had two aerials and in using the samereceiver one aerial would bring in Bostonat New York very loud while on the otherthe station could barely be heard at all.He attributed all to the directional effectsof the two aerials. However, the aerial

which hinnight in the best results fromBoston was lot.,r in height and quite afew feet shorter. In fast the other aerialwas by far the better aerial from all ofthe conventional ways of looking at anaerial. No measurements were taken at

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II

Loop Is DirectionalBut Within Limits

Incoming Wave Often Deflected, And In Some In-stances All Stations Come in Best at One Particular

Setting-Problem Arises in Big Cities

(Concluded from page 29)the time but in all probability the shorteraerial in conjunction with the set wasmore particularly suited to the wavelengthof the Boston station. This would causethe signal to come in with greater volumewithout taking into consideration anydirectional effects. It cannot be doubtedthat most of the cases where directionaleffects are attributed to the aerial thatthere are also other factors.

It is a well-known fact that to get thebest results, or the greatest pickup, from agiven station the aerial circuit must betuned, at least approximately, to the samewavelength as the station.

Needs Extra ControlThis, however, introduces another con-

trol on the panel, and as a rule is notnecessary. The fact that a tuned circuitin the aerial does bring better receptionexplains an otherwise unexplainable situ-ation which is often met in receiving.

For instance, one man in the neighbor-hood will get a certain distant stationwith great regularity and good volumewhile his next-door neighbor can not getthat station at 'all but can get some sta-tions that the other man can not get.The whole thing rests in the aerial andground installation. One happens to bebest receptive to one particular wave-length and the other to another wave-length. Nothing can be done about itexcept possibly to change the aerialaround. The experimenter, when he

Good Back Numbers of

RADIO WORLDThe following illustrated articles have ap-peared in recent issues of RADIO WORLD:1925:Sept. 19-The 1 -Dial, 2 -Tube Speaker Set, by

Percy Warren. Anderson's Theory of Fad-ing. The Way of the Frequency Dial, byCapt. P. V. O'Rourke.

Oct. 24-The 3-11)-1 Rif Receiver, by Sidney E.Finkelstein. A Phonograph Cabinet Set, byLewis Winner.

Nov. 7-A 3 -Tube Dry -Coll Circuit, by Capt.P. V. O'Rourke. One of the Best CrystalSets, by Herbert E. Hayden. I -Tube DXSet, by Hermon Bernard.

Nov. 28-The Zero Potential Loop. by FrankFreer. The 1 -Tube Headset Receiver, byJ. E. Anderson.

Dec. I2-A Self -Contained Receiver, by IL B.Hayden (Part 1). B Battery Eliminator, laoLewis Winner (Holiday Gifts No.).

Dec. 26-The Regenerative Wave Trap, by JohnF. Bider. The 5 -Tube Tuned RIP Bet, byCapt. P, V. O'Rourke.

1926:Jan. 2-The 2-C Sot for Simplicity, by Capt.

P. V. O'Rourke.Jan. 9-The 4 -Tube DX Symphony Set, by A.

Irving Wit. A Skillfully Made 1 -Dial Set,by Herman Bernard.

Jan. 16-Anderson's 5 -Tube Quality Receiver.The Raytheon B Eliminator, by Lewis Win-ner.

Jan. 30-An Individual Al Amplifier, by H. B,Hayden. Trapping Out Super -Power in NewJersey, by Capt. P. V. O'Rourke.

Feb. 20-The 8 -Tube Victoreen, by Herbert E.Hayden. Quality Stressed in 3 -Tube Sot, byBrainard Foote.

Feb. 27-The 4 -Tube DX Dandy, by Herbert B.Hayden. Umbrella Aerial for DX, by HugoGernsback. Part 2 of Tho Victoreen.

Mar. 6-The 1 -Tube Set, by Capt. O'Rourke.The Chemistry of Batteries, by A. It. Reid.The Victoreen Set (Part 3), by Herbert E.Hayden.

Any copy, 15c. Any 7 miss, g 1.90. Allthese 34 conies for 94.79, or start subscriptionwith any inane. RADIO WORLD, 145 West 45thStret, N./ York COY.

changes his aerial, usually changes theentire characteristics and possibly he getsthe results he wants. At least he getsdifferent results. Such experiments giveno definite results and lead the operatorto conclusions which have little, if any,foundation for making a statement inregard to the directional effects. This isparticularly true of experiments whichare made in the city.

Loop Is DirectionalSome time ago some experiments were

made with a loop aerial, which is direc-tional. Directional readings were taken indifferent parts of the city on various sta-tions. With loop fairly clear the direc-tions as indicated by the loop approxi-mated very closely the direction of thestation, but when the loop was used invarious positions inside of buildings andhomes the directional effects as indicatedby the loop were very erratic indeed.

In one house in Brooklyn the etherwaves apparently came through in thesame direction, as the maximum responsewas obtained by placing the loop in a cer-tain direction, no matter in what directionthe station was located. This conditiondid not seem to vary in the slightestwhether the station was at some distanceor a local station nearby and of the highpoWer class.

Located in a steel building in the up-town section of New York there was adirectional effect noticed but it variedconsiderably from the true directions inwhich the various stations were located.

When you see this trade -mark on a con-denser or res;aror, you know that all thequestions were taken out of it before it wasput on sale.

Used by The Browning -Drake Corporationand National CothPanies as standard.

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Cambridge, Mass.

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Another fact was noted: each room inwhich the receiver was placed seemed tohave a position in which the response wasgreater than in any other position in thatroom. This may be explained by theshielding effect of large masses of a metal-lic nature.

Loop LimitationsFrom these experiments it would seem

that even the loop is not a true directionfinder when located in the city, especiallyinside buildings. There is no doubt in mymind that the broadcast waves are bentout of their true path in many instances.This effect was also noticed at one placelocated at some distance from surround-ing objects and many miles from the city.It did not seem possible that a steel bridgelocated about two miles away could haveany effect, yet Schenectady, according tothe loop, was located in the direction ofChicago, rather than due north, as itshould be.

From the foregoing it does not seempossible that any aerial could have anytrue directional effect, as is often claimed.Granted an aerial may work better in oneposition than in another, but it seems al-most certain that the directional effectmay be entirely due to the effect ofscreening by metallic objects, the lengthof the aerial, the properties of the ground,and the location of the receiver.

Most of the accounts that have appearedon this question have given very littleauthentic information. In most cases thefact that an aerial should be directionalaccording to the way signals are sent outfrom an aerial is taken more or less forgranted. Remember, we are discussingonly the aerials commonly used for re-ceiving broadcast signals and not speciallydesigned aerials of highly complex charac-teristics.

Asks for InformationUnfortunately I have never had an op-

portunity to get any accurate results onthe subject of directional effects of aerialsand consequently the effect, if it is ofany consequence, is still an open questionto me. Some experiments were performedin an airplane in regard to the directionaleffects but the results seemed to vary tosuch an extent that no definite conclusionscould be reached whether there was anoticeable increase in signal strength dueto direction alone. In these experimentsthe aerial was stationary on the groundin one direction and the plane was send-ing front all directions in turn it beingflown in a wide circle. No particulardifference could be noted in signalstrength.

I would be interested in hearing fromany one who has given this matter somethought and actually has proven that thereis or is not a directional effect.

THE IMPROVED

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THEY ALL BR ETW OODPRAISE THEThe Bretwood Grid Leak came with today's mail. It is now exactly9.00 P.M. and the leak was installed about a half hour ago.This note is not only an expression of appreciation but also anattestation of the truth of your advertising. During the past halfhour I have tuned in stations "ALL OVER THE DIALS" atleisure, and can adjust reception with the leak almost equal to avariable condenser.I feel constrained to add that while waiting for reply and thenreceipt of leak front you, there has been on the set a fixed leak andcondenser of well known and thoroughly reliable make, and fairlygood reception has been enjoyed, but during this half -hour -only testthus far the results are inexpressibly beyond expectationHave been a radio fan only about four years, but feel I have suffi.nest knowledge and experience to recognize a good thing upon fairtrial. Your promptness and desire to satisfy your trade, in this casehas won for you another "BRETWOOD BOOSTER." Thank you.

The Rev. WALTER G. BARLOW,Bishopville, Md.

Very many thanks for your kind letter of the 21st ult. and for thegrid leak, which works perfectly. I have tried four different, makesof grid leaks. The Bretwood "has 'ens beat."

M. SAWYER,Box 238, Los Gatos, Calif.

Received your grid leak and wish to say that none can comparewith it when it comes to clearing up reception.

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Enclosed find P. 0. money -order for $3.00. Please send me two ofyour Variable Grid Leaks. I am using one and it works fine. Pleasemail them as soon as possible.

W. H. PERRY,119 Congress St., Buffalo, N. Y.

Received your grid leak and many thanks. It is the best $1.50 thatI have spent for radio equipment.

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Enclosed herewith find check for $1.50 for one Bretwood Grid Leak.I am using your leak and find it far superior to any others. Thisis my third Bretwood.

J. C. WHITE,422 W. Wooster St., Bowling Green, Ohio.

Will you please send me by return mail two Bretwood Variable GridLeaks. I enclose herewith check for $3.25, the 25c. being for aspecial handling stamp, airthese leaks are needed at once.The leaks are the only satisfactory instrument on the market. I findthem absolutely essential in the construction and operation of sensi-tive experimental receivers.

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Variable Grid LeakI want to thank you for your leak, it makes the set 100% better.I was going to have a Diamond of the Air built, but since I haveadded your leak to my set I am now doVen in the dining room ofthe first floor and the set is on the second floor. I can hear the setjust as plainly as if I were up there. I can hear every player inany band or music which is on air. The first night I gave the leaka very good test, and I got four stations in Chicago, one in Detroit,one in Canada, one in Atlanta, Ga., and several others without anynoise. All were good and clear. It is going to make me spend moremoney, as I will have to get a good loud speaker. The horn I havenow is a Manhattan Jr., and is good and clear, but as loon us yourleak is installed the howling present when using three tubes leimmediately stopped.

LEON E. COLE,5816 Tilbert St., Philadelphia, Pa.

Grid Leak received and tested out, and find it is the only variableleak I ever used that is really variable. Enclosed find $1.50, forwhich please send me another one.

F. E. STAYTON,Box 240, Ardmore, Okla.

Thank you for introducing me to the Bretwood Variable Grid Leak II have installed one in my Three.Circuit Tuner, according to yourinstructions, and find that it does all you said it would-and more.I am now recommending the Bretwood to all my friends, and thosewho have used this wonder grid leak have nothing but high praisefor it. The fact that it can be adapted for any hookup makes it In-valuable to the experimenter.Although I have only used the Bretwood leak for three weeks Ihave pulled in several of the weaker stations which were inaudiblebefore, and the microphonic noises which were decidedly pronouncedbefore have entirely disappeared.Please accept my best wishes for your continued success and alsofor the Bretwood Grid Leak.

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NAME

II

ADDRESS

CITY STATE

Inquiries Solicited froth the Trade

RADIO WORLD Augu,,,t 19)6

NOW you can afford the best in RADIOSold on the Clark Fifty -Fifty Plan

half cash - - half trust

BST -5

5 -Ply WalnutVernier PianoFinish Cabinet

SendOnly $20

New model cabinet base 21" long by 8" wide, height 9./z", top 21" by 6".

NEWMODEL

ShieldedReceiver

$40.00

T[ES highly sensitive, powerful and selective BST -5 radio receiver has all up-to-the-minute improvements. Heavy aluminum automobile type chassis, shielded against

stray currents and distortion. Flexible grip, Universal type sockets, eliminating micro-phonic noises. Has provision for battery eliminator and any power tube. Fahnestockclips on sub -panel for adjusting C battery, has voltages for power tube. Efficient on eitherlong or short aerial, including indoor aerial. This BST -5 sets a new standard for true tonevalues and selectivity. This BST -5 gives greater volume than many six -tube sets andconsumes less current.

28 Stations in 31/2 HoursMr. E. H. Thiery, Tax Collector, New Hartford, Conn., writes : "I am well pleased with my BST. In three hours anda half on Wednesday night I got the following stations: WTIC, WJZ, WGY, WBZ, WPG, WNAC, WMSG, WEEI,KDKA, WAAM, WEAN,,WSAR, WJBI, WMAC, WLWL, WJAR, WAHG, WBNY, WEAF, WNJ, WCSH, WSAN,

WHK, WMCA, WRVA, WHN, WHAR, WWJ.

Top inside view showing compact aluminum shieldedindestructible chassis.

Our Offer:-Send us your check or post officemoney order for $20.00, one-half its price, try outthe BST -5 in your own home for ten days, theneither send us the other $20.00, making $40.00 inall, or return the set and we will return your $20.00-no questions, no argument.

Bottom inside view showing improved foolproof curkoidcoils and rigid construction, with complete harness for

simple installation.

GUARANTY RADIO GOODS CO.,145 West 45th Street, New York City.Gentlemen:-Ship me one BST -5, $40.00 Radio Set, for which.'enclose $20.03 on account. I am to test it out for ten days in myown home and if satisfactory I will then send you the balance of20.00; but if not satisfactory to me I will return the set at the end

of the ten days' trial and you are to return my $20.00 immediatelyon receipt of the set without question.

OM& On OM M.

NAME

ADDRESS

rider neutralizing plan reg. u. s. pat. off. -0 · reg. u. s. pat. off. america's first and...

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