REG-U.S. PAT. OFF AN AC POWER AMPLIFIER AND 400-v B ... · THE SUITCASE SIX FOR OUTINGS (Hayden)...

JUNE 11 VACATION NUMBER 15c

REG-U.S. PAT. OFF

PUSH-PULL RESISTANCE AFSHOWN FOR FIRST TIME

LIST OF STATIONS; NEW WAVES

AN AC POWER AMPLIFIERAND 400-v B ELIMINATOR

THE SUITCASE SIX FOR OUTINGS

(Hoyden)

PORTABLE SET That Fits Into A Suitcase Is An Attractive Vacation Asset. See Article onPage 5 on How to Build the Suitcase Six

VFJYNeutr lization of SetsVastly -xnpipriant

S

HOW To Use B J atteries MostEconomically

11111111111=111.159....

RADIO WORLD June 11, 1927

B.S.T. DE LUXEA NEW AND IMPROVED MODEL

Simply Beautiful-Beautifully Simple

The B. S. T. De Luxe, a 5 -Tube Receiver,with Concentrated, Simplified Tuning, andUsing Resistance Coupled Audio. Price ofset, in genuine walnut cabinet, and includ-ing built-in eliminator of all "C" batteries

GUARANTY RADIO GOODS CO.,145 West 95th Street,New York City.Gentlemen:-Enclosed please find check (or money order) for $.60.03,for which kindly ship by express at once one B. S. T. De Luxe5 -Tube Set, in genuine walnut cabinet, less accessories, but withbuilt-in eliminator of all "C" batteries, on five-day money backguarantee.

NAME

STREET ADDRESS

CITY STATF B.W.

$60."The Set That All AdmireThe B. S. T. De Luxe is one of the most beautiful setsmade. Beautiful to eye and ear alike. Thrilling fidelityof tone and fine volume assured. Uses any type tubes.May be used with B eliminators without "motorboating."Awarded Certificate of Special Merit by Radio Worldafter exhaustive tests.A Switch, a Volume Control and a Tuning Unit-These

are the Only Parts on the Bakelite Front Panel.Simplicity and Beauty in the Extreme.

GUARANTY RADIO GOODS CO.145 WEST 45th STREET NEW YORK CITY

SIXTH 1 t'

Vol.. XINo. 13

Whole No. 272

June 11, 1927

1Se Per Copy. $6.50 Per Year

lk?PILL ItYott 9355 uw l 0529

[Entered as second-class meter, March, 1923, at the post oilier at New Ymlc, N, 1 Ad of NI...eh. 10?91

Push -Pull Resistance AFNo Filter, Yet No Hum and No Motorboating

[The push-pull resistance eoupw audio circuit developed byniarks'a departure in audio amplifier design. It oilers the only practical preven-tion of motorboating, as a part of the resistance audio design, .vo far fir, ugh t topublic attention, by stiking at the cause, the common impedance. .Al startlinfact brought out in the article that follows is that the plate supply used wasunfiltered DC from the house line! No choke coils, no filter condensers! Andstill no hum! And no motorboating! All radio experimenters will 'welcwiteAnderson's important contribution.-EDIT*

By J. E. AndersonContributing Editor; Consulting Engineer

THE great advantage of push-pull am-plification is that it eliminates the even

harmonics. Since most of the frequencydistortion lies in the second harmonic itis evident that this type of amplificationis relatively free from distortion.

Heretofore push-pull amplification hasonly been used in connection with trans-former coupling, and then only in a stageor two. But the system is equally ap-plicable to resistance coupling, and in thisform other advantages become apparent.Two of these are the freedom from self -oscillation when all the tubes are servedby the same B battery eliminator and theabsence of hum even when no filter isused. These, of course, follow from thefact that the system eliminates the evenharmonics.

A circuit of this type was first set upby me for eliminating motorboating. Togive the system a thorough test the cir-cuit was made odd, that is, in each half ofthe circuit an odd number of tubes wasused. Such a resistance coupled amplifier,when one-sided, will motorboat violently.

No Filter, Still No HumThe plate voltage was obtained mostly

from a DC lighting line without the useof any filter whatsoever. There wasneither motorboating nor hum. If, how-ever, one side of the circuit was renderedinoperative by lifting out a tube or other-wise, both hum and motorboating becameintense. Motorboating difficulties, how-ever, were encountered when a high.im-pedance filter was put in the B voltagesupply line. The reason for this failureof the circuit to operate as expected willbe taken up later.

It is not difficult to understand why thepush-pull resistance coupled circuit shouldbe relatively humless even when the Bvoltage contains considerable hum. Forthe purpose of explanation we might takethe four stage amplifier shown in Fig. 1.

In this circuit Z is the impedance of theeliminator which is common to all theplate circuits. It is drawn in four differentplaces for ocular convenience only. Thecorresponding plate and grid resistors andgrid condensers are supposed to be identi-cal in value, and the corresponding tubesare supposed to be identical in their char-acteristics. The audio frequency input tothe circuit is impressed across the termi-nals ab and the loudspeaker is connectedacross the terminals AB.

Suppose now that the line voltage

FIG. IFour stage push-pull, resistance coupled amplifier in which the tendency to motor -

boating and other oscillation is reduced to a minimum, and in which there is no audiblehum even when the voltage supply contains considerable. Accurate balance of the twohalves of the amplifier is essential to gain these advantages. Final balance is obtained

by dividing input at RI and equalizing the output at R2.

changes. The plate current to any onetube will change, but the changes in theplate currents in any two opposing pairswill be the same since by supposition thecircuit is balanced, stage for stage.

Out -phased CurrentsHence there will be no change in the

numerical difference between the voltagedrops in two corresponding coupling re-sistors, or there will be no change in thepotential between the points (1) and (2)).Hence the change in the plate voltage willnot give rise to audible signal, that is, thehum will not be transmitted by the ampli-fier to the speaker.

The reason for the absence of motor -boating also is plain. Suppose a signalcurrent is sent through the potentiometerresistor RI. Divide the voltage betweenthe two sides equally and accurately. Thetwo halves of the amplifier therefore willbe in opposite phase at all times. Whenthe plate current to one tube increases,the plate current to the opposing tubedecreases in exactly the same proportion.Hence in the common impedance Z therewill be no change in the plate current. Inother words, the signal is perfectly bal-anced out of the common impedance. Thisholds for every pair of tubes. Since thereis no signal current present in the commonimpedance there can be no regenerationthrough it, and consequently 'all tendencyto motorboat will be eliminated. It makesno difference whether the number of

stag,. ll1C eirvOit i; odd or even Longa, every stage is bala ccoi,

Discussion of DifficultiesTheoretically this circuit ''orbs perfectly.

It ''ill not motorboat or oscillate at anyfrequency, even when there is a high com-mon impedance. It will not hum even ifthe ripple in the It voltage has not beenfiltered out. It will keep the even har-monics out of the signal, provided theyare not a part of the signal. But in pr.ac-tice some difficulties arise. Sonic of thesewere expected, others were not.

The circuit works by virtue of balance,and the better the balance the more nearlyit works in accordance with theory. Butthe practical difficulties in attaining ade-quate balance are very great. No twothings can be found alike, and this isespecially true of radio parts. Any twothings having the same designation arethe same by courtesy only. Of course,moderate deviations from rated values areof small importance so long as the crux ofthe matter is not that of identity of values.That it is, in this circuit. The couplingresistors in any one stage must have thesame values. The same applies to thestopping condensers and to the grid leaks.It is of course possible to select pairs ofthese units which will have the same valueswithin narrow limits when they are work-ing tinder the same conditions.

And that takes us to the main difficulty,(Continued on next page)


DancingVolumeBut No Extra Tubes!

liii111110S.=

The NewDe Luxe Model

Bretwood

When you're dancing to radio music you often wish yourset were just a bit louder. Compliments to partners, shuffleof feet, distance from the speaker all put on the set a demandfor extra volume.

Use a De Luxe Model Bretwood Variable Grid Leak. Turn it toMaximum Resistance and thus increase the volume up to 25 per cent.-the dancing volume you desire.

Also, you thus have a handy combination volume control and sensitivity con-trol.

The De Luxe Model may be mounted on front panel or baseboard.

TO DEALERS: If your wholesaler cannot fillyourorders we will supply you direct.

The De Luxe Model Bret-wood Variable Grid Leakis specified by HermanBernard for Radio World'sfour -tube Universal re-ceiver.

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North American Bretwood Co., 145 West 45th St., N. Y. City.Gentlemen: Enclosed find $1.75. Send me at

De Luxe Model Bretwood Variable Grid Leakmoney -back guarantee. (Or $2.25 for leak withdenser attached.)NAME

ADDRESS

CITY STATEInquiries Solicited from the Trade

No. 3

once oneon 5 -daygrid con-

JUNE 11 VACATION NUMBER 15c

REG- U.S. PAT. OFF:

PUSH-PULL RESISTANCE AFSHOWN FOR FIRST TIME

LIST OF STATIONS; NEW WAVES

AN AC POWER AMPLIFIERAND 400-v B ELIMINATOR

THE SUITCASE SIX FOR OUTINGS

(Hayden)

PORTABLE SET That Fits Into A Suitcase Is An Attractive Vacation Asset. See Article on on How to Build the Suitcase Six

Ailly Neutralization of Sets IsVastly Important

How To Use B batteries MostEc nornically

RADIO WORLD

NM/

B.S.T. DE LUXEA NEW AND IMPROVED MODEL

Simply Beautiful-Beautifully Simple

The B. S. T. De Luxe, a 5 -Tube Receiver,with Concentrated, Simplified Tuning, andUsing Resistance Coupled Audio. Price ofset, in genuine walnut cabinet, and includ-ing built-in eliminator of all "C" batteries

111 11111 IIMIMIN

GUARANTY RADIO GOODS CO.,145 West 45th Street,New York City.Gentlemen:-Enclosed please find check (c4- money order) for $60.03,

5 -Tube Set, in genuine walnut cabinet, less accessories, but withfor which kindly ship by express at once one B. S. T. De Luxebuilt-in eliminator of all "C" batteries, on five-day money backguarantee.

NAME

STREET ADDRESS

CITY STATE R.W. I

$60."

June 11, 1927

The Set That All AdmireThe B. S. T. De Luxe is one of the most beautiful setsmade. Beautiful to eye and ear alike. Thrilling fidelityof tone and fine volume assured. Uses any type tubes.May be used with B eliminators without "motorboating."Awarded Certificate of Special Merit by Radio Worldafter exhaustive tests.A Switch, a Volume Control and a Tuning Unit-These

are the Only Parts on the Bakelite Front Panel.Simplicity and Beauty in the Extreme.

GUARANTY RADIO GOODS CO.145 WEST 45th STREE NEW YORK CITY

SIXTH YEAR

Vol. XINo. 12

Whole No. 272

June 11, 1927

15c Per Copy. $6.00 Per Year

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

Street, New York, N. Y.Phones: BRYant 0558 and 0559

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

Push -Pull Resistance AFNo Filter, Yet No Hum and No Motorboating

[The push-pull resistance coupled audio circuit developed by J. E. Andersonmarks' a departure in audio amplifier design. It offers the only practical preven-tion of motorboating, as a part of the resistance audio design, so far brought topublic attention, by stiking at the cause, the common impedance. A startlingfact brought out in the article that follozos is that the plate supply used was'unfiltered DC from the house line! No choke coils, no filter condensers! Andstill no hum! And no motorboating! All radio experimenters will welcoliie Mr.Anderson's important contribution.-EDITOR]

THE great advantage of push-pull am-plification is that it eliminates the even

harmonics. Since most of the frequencydistortion lies in the second harmonic itis evident that this type of amplificationis relatively free from distortion.

Heretofore push-pull amplification hasonly been used in connection with trans-former coupling, and then only in a stageor two. But the system is equally ap-plicable to resistance coupling, and in thisform other advantages become apparent.Two of these are the freedom from self -oscillation when all the tubes are servedby the same B battery eliminator and theabsence of hum even when no filter isused. These, of course, follow from thefact that the system eliminates the evenharmonics.

A circuit of this type was first set upby me for eliminating motorboating. Togive the system a thorough test the cir-cuit was made odd, that is, in each half ofthe circuit an odd number of tubes wasused. Such a resistance coupled amplifier,when one-sided, will motorboat violently.

No Filter, Still No HumThe plate voltage was obtained mostly

from a DC lighting line without the useof any filter whatsoever. There wasneither motorboating nor hum. If, how-ever, one side of the circuit was renderedinoperative by lifting out a tube or other-wise, both hum and motorboating becameintense. Motorboating difficulties, how-ever, were encountered when a high, im-pedance filter was put in the B voltagesupply line. The reason for this failureof the circuit to operate as expected willbe taken up later.

It is not difficult to understand why thepush-pull resistance coupled circuit shouldbe relatively humless even when the Bvoltage contains considerable hum. Forthe purpose of explanation we might takethe four stage amplifier shown in Fig. 1.In this circuit Z is the impedance of theeliminator which is common to all theplate circuits. It is drawn in four differentplaces for ocular convenience only. Thecorresponding plate and grid resistors andgrid condensers are supposed to be identi-cal in value, and the corresponding tubesare supposed to be identical in their char-acteristics. The audio frequency input tothe circuit is impressed across the termi-nals ab and the loudspeaker is connectedacross the terminals AB.

Suppose now that the line voltage

By J. E. AndersonContributing Editor; Consulting Engineer

FIG. IFour stage push-pull, resistance coupled amplifier in which the tendency to motor -

boating and other oscillation is reduced to a minimum, and in which there is no audiblehum even when the voltage supply contains considerable. Accurate balance of the twohalves of the amplifier is essential to gain these advantages. Final balance is obtained

by dividing input at RI and equalizing the output at R2.

changes. The plate current to any onetube will change, but the changes in theplate currents in any two opposing pairswill be the same since by supposition thecircuit is balanced, stage for stage.

Out -phased CurrentsHence there will be no change in the

numerical difference between the voltagedrops in two corresponding coupling re-sistors, or there will be no change in thepotential between the points (I) and (2)).Hence the change in the plate voltage willnot give rise to audible signal, that is, thehum will not be transmitted by the ampli-fier to the speaker.

The reason for the absence of motor -boating also is plain. Suppose a signalcurrent is sent through the potentiometerresistor RI. Divide the voltage betweenthe two sides equally and accurately. Thetwo halves of the amplifier therefore willbe in opposite phase at all times. Whenthe plate current to one tube increases,the plate current to the opposing tubedecreases in exactly the same proportion.Hence in the common impedance Z therewill be no change in the plate current. Inother words, the signal is perfectly bal-anced out of the common impedance. Thisholds for every pair of tubes. Since thereis no signal current present in the commonimpedance there can be no regenerationthrough it, and consequently 'all tendencyto motorboat will be eliminated. It makesno difference whether the number of

stages in the circuit is odd or even so longas every stage is balanced.

Discussion of DifficultiesTheoretically this circuit works perfectly.

It will not motorboat or oscillate at anyfrequency, even when there is a high com-mon impedance. It will not hum even ifthe ripple in the B voltage has not beenfiltered out. It will keep the even har-monics out of the signal, provided theyare not a part of the signal. But in prac-tice some difficulties arise. Some of thesewere expected, others were not.

The circuit works by virtue of balance,and the better the balance the more nearlyit works in accordance with theory. Butthe practical difficulties in attaining ade-quate balance are very great. No twothings can be found alike, and this isespecially true of radio parts. Any twothings having the same designation arethe same by courtesy only. Of course,moderate deviations from rated values areof small importance so long as the crux ofthe matter is not that of identity of values.That it is, in this circuit. The couplingresistors in any one stage must have thesame values. The same applies to thestopping condensers and to the grid leaks.It is of course possible to select pairs ofthese units which will have the same valueswithin narrow limits when they are work-ing under the same conditions.

And that takes us to the main difficulty,(Continued On next page)

4 RADIO WORLD June 11, 1927

FIGS. 2 AND 3.Circuit showing how the detected signal can be put into the balanced amplifier. (Fig.

a left). The voltage applied at B must be filtered, otherwise the signal, which entersthe push-pull amplifier, will contain hum as a signal. Fig. 3 (right) is a circuit showinganother way in which the detected signal can be put into the balanced amplifier with-out the use of a transformer. This method requires a separate A and B battery for thedetector tube, as shown above. Othewise one grid is grounded and the amplifier is dead.

(Continued from preceding page)that of obtaining identical tubes. Thecharacteristics of any two of a pair oftubes must be identical. They must havethe same amplification constant, the sameplate output resistance, the same filamentrequirements, the same inter -electrode ca-pacities. Tubes differ widely, and to selecta set of pairs of identical tubes wouldnecessitate an almost unlimited supply oftubes. No experimenter has that good for-tune. It is, however, possible with a lim-ited supply to arrange the tubes, providedtheir actual characteristics are known, insuch a way that differences will be partlyneutralized.

At first thought it might appear that asmall unbalance would not make muchdifference. But that is not so, particularlywhen there is a considerable common im-pedance. If there is any slight unbalancethere will be an alternating current in thecommon impedance, because one side of

more than theNow if the common impedance is consid-erable there will be an appreciable voltagedrop in it because of this current. Thisvoltage drop will increase the amplificationin the stronger side and it will decreaseit in the weaker side by the same amount.Thus the circuit is in a sort of unstableequilibrium. A small unbalance in the ad-justment will cause a great unbalance inthe effective amplification in the two sides.The primary effect of the unbalance ishum and motorboating.

Equalization ProblemsWhen a circuit of this type has been

built and balanced as nearly as possiblewith fixed units, the balance can still beimproved by a judicious application ofvariables. Instead of fixed resistors, po-tentiometers could be used both in the plateand grid circuits for dividing the outputof one pair of tubes and the input to thenext.

But it is neither practical nor desirableto use a large number of these variables.One at the beginning and one at the endof the amplifier should be enough to effecta good balance, if reasonable care has beenexercised in selecting the fixed parts. Thusthe input potentiometer R will serve todivide the voltage equally between thetwo sides, or in such proportion as willbe required to maintain the same signallevel in both sides of the circuit. Againa voltage divider can be used to equalizethe input to the last two tubes, or ratherto vary the input so as to equalize theoutput currents. It is of great importanceto equalize the AC plate currents in thelast two tubes, because they are muchgreater than those in any of the others,and therefore their difference is likely tobe large. It makes little difference wherethe equalization takes place, in the firstpair of tubes or in the last.

Another method of equalization that canbe resorted to is variation of the filamentcurrent. This is not applicable to the cir-cuit in Fig. 1, but the filament wiring can

easily be changed so that the two halvesof the amplifier are independent in thisrespect and so that one master rheostatcould be put in each half. This methodis not recommended except as a minoradjustment.

Note that no condenser is used in theoutput of the amplifier. None is needed.The speaker is connected directly betweenthe points A and B. No direct current willflow through the windings of the loud-speaker because the points (1) and (2) areat the same potential with respect to di-rect current. But AC current will flowas soon as there is an AC signal im-pressed on the amplifier. It is, of course,necessary that the output chokes Ch havea high inductance and a low DC resist-ance and that the two chokes be equal. Apush-pull output transformer can be sub-stituted for the two chokes, if desired.This is desirable if high impedance tubesand a low impedance speaker are used. It

that the plate impedance ofthe two tubes are in series and that forthis reason not much volume can be ob-tained from the circuit unless a load im-pendance of twice the ordinary value beconnected across the line.

Detector Coupling

Instead of using an output transformerfor matching impedances two speakers canbe connected in series across the pointsA & B. If only one speaker is availableit can still be connected directly across theline without the intervention of a trans-former provided that such low impedanceoutput tubes as 71 type be used. The out-put impedance of each of these is about2,100 ohms, so that the impedance in serieswith the speaker would be 4,200 ohms,which is about right for a good matchwith the better speakers available.

There are other practical difficultieswhich must be taken care of before thiscircuit can be operated. One is that ofcoupling it to the detector. Suppose anattempt be made to operate the first twotubes in Fig. 1 as detectors in push-pullrelation and putting a tuner across thepoints a and b. Nothing but queer gruntswill be emitted from the reproducer. The

(Anderson)

effective audio component in the plate ofthe detector is the second harmonic, andthis as well as all the other even harmonicsthe system effectively balances out. Ifwe attempt to use one of the first tubesonly as detector, one side of the circuitbecomes a useless appendage as far as theamplification is concerned. It is still ef-fective in keeping a certain amount ofhum out of the signal, as well as subduingthe tendency to oscillate, but there is nogain in the amplification. The first twotubes are ruled out as detectors, singly orin any combination.

One way out of this difficulty is to usea crystal detector. This can be connectedin series with the (a) lead and then con-nected to the tuner in th'e usual way.When a crystal detector is used the resist-ance of the potentiometer R can have anyvalue from 2,000 ohms upwards. The vol-ume increases as the resistance increases.For very high values of this resistance thecircuit is likely to oscillate at a very highfrequency unless the output and all itsleads are carefully shielded electro-static-ally from the input. This squeal is not aquestion of common impedance.

When a crystal detector is used select-ivity must be gained in the radio frequencystages.

AF Input OptionsAnother way out of the difficulty of input

is to employ the method shown in Fig. 2.This is satisfactory if a good transformris used. However, it is necessary to elim-inate thoroughly all ripple from the Bvoltage supply of the detector tube. Alsothe use of this method requires more com-plete balancing of the push-pull amplifierand removal of signal current from thecommon impedance, because if there isany residual current it will affect the platecurrent in the detector and either causeoscillation or damping of the amplification.

The use of a push-pull input transformerdoes not differ in any essential detail fromthe use of a single transformer and apotentiometer. But in the case of thepush-pull transformer there is not a chanceof suitably dividing the input between thetwo halves of the double amplifier.

If it is desired to avoid transformercoupling and still retain the tube detector,it can be done as shown in Fig. 3. SeparateA and B batteries for the detector tubeare required. If an, attempt be made touse the same batteries for the detectoras for the balanced amplifier it will befound that one side of the amplifier isdead. It has no input because the firstgrid on that side is grounded.

Separate TunersThere may be a possibility of using the

first two tubes in the push-pull amplifieras detectors, provided that two separatetuners be used. These must be entirely in-dependent so that the phase of the outputcurrent can be chosen at will. This choicethen has to be made in connecting theradio frequency transformer. It shouldalways be possible to find a connectionso that the audio frequency outputs ofthe two detectors add up across the grids

(Concluded on page 6)

FIG 4.The receiver constructed by the author consisted of a stage of tuned RF, a tuned

detector input and three stages of push-pull audio.

June 11, 1927 RADIO WORLD 5

The Suitcase SixA Sensitive Portable Easy to Operate

By James H. CarrollContributing Editor

FIG. ICircuit diagram of the Suitcase Six, a portable set consisting of one tuned stage of RF amplification, two untuned stages of RF

amplification, a tuned regenerative detector, and two stages of transformer coupled audio amplification.THIS Summer the portable radio set

will be an almost indispensable partof every camping outfit, and every oneplanning to go on an extended trip shouldprovide himself with a good portable re-ceiver now. When a good radio set isgoing in camp or other country or seasideresort, enjoyment of one's vacation ismultiplied a thousand fold.

A rather sensitive receiver is requiredfor woodland use, because many locationswill be remote from any broadcasting sta-tions, and many will be in semi -shieldedareas, too, due to trees and mountains.A sensitive receiver insures reception inevery place.

Since sensitivity is very largely a matterof radio frequency amplification, the de-sign of the receiver must emphasize thisend of the circuit. Yet for practical rea-sons more than two tunings controlsshould be avoided, even when localizedtuning is employed. The only practicalway of insuring sensitivity without mul-tiplying wavelength tuning controls is toemploy untuned radio frequency trans-former to couple some of the RF stages,and embody regeneration. This has beendone in this portable receiver.

Tracing of CircuitLet us start at the beginning and trace

the design of the Suitcase Six (Fig. 1) tothe final binding posts. Provision hasbeen made for use of either open circuitor loop antenna, and to change from oneto the other it is only necessary to plugthe loop in to the double circuit jack J1.Binding posts "Ant" and "Gnd" terminat-ing the antenna input coil Ll have beenprovided in case it is desired to use anantenna. The antenna coupling trans-former 1,11.2 is a Bruno RF coupler on2 inch diameter tubing, to fit .0005 mfd.condenser, Cl.

The next two RF tubes are coupled bymeans of Acme R3 and R4 radio fre-quency transformers T1 and T2.

Volume and oscillation in the circuitare controlled with a single rheostat R1placed in the filament circuit of the firstthree radio frequency tubes. A twenty -ohm instrument is used. Since there arethree -99 type tubes on this rheostat andsince the filament battery has a maximumvoltage of 4% volts, the current in eachof the three tubes can be cut down to 40milliamperes. This gives adequate volumecontrol at all times.

The next cottpler, L3L4L5, is a smallBruno three -circuit tuner of the same elec-trical and mechanical dimensions as theantenna coupler. The tickler coil L5 con-tains 16 turns of fine wire and it is woundon a specially moulded bakelite form 1%

inches in diameter. This tickler, of course,serves to increase the selectivity and thesensitivity of the receiver to a very highdegree. The secondary L4 of the three -circuit tuner is tuned with a .0005 mfd.condenser, C4. The grid condenser C3has a capacity of .00025 mfd. and the gridleak R3 a resistance of 2 megohms. Theby-pass condenser C5, which serves tofacilitate regeneration and detection, hasa capacity of .001 mfd.

LISTS OF PARTSLIU-One Bruno antenna coupler, for

.0005 mfd. condenser.L3L4L5-One Bruno three -circuit tuner,

wound for .0005 mfd.Cl, C4-Two Bruno straight line fre-

quency condensers, .0005 mfd., arrangedfor drum type localized control.

C2-One Dubilier by-pass condenser, .01mfd. or larger.

C3-One Dubilier grid condenser, .00025mfd. with clips.

CS-One Dubilier by-pass condenser,.001 mfd.

R1-One Bruno 20 -ohm rheostat.R2, R4, R5-Three Amperites, No. 4V-

199.R3-One grid leak, 2 megohms.TI-One Acme R-3 radio frequency

transformer.T2-One Acme R4 radio frequency

transformer.T3, T4-Two Bruno Trutone audio fre-

quency transformers.J1-One Electrad single closed circuit

jack.SP-Two Yaxley tip jacks for loud

speaker.S-One Bruno pilot light switch (lamp

La omitted when set is used away fromhome).

Two XL binding posts (ant., grid).Six Benjamin sockets.Two bakelite knobs, one for rheostat

and one for tickler.One Birnbach battery cable.Six No. 6 dry cells for A battery.Two 45 -volt B battery blocks.One 7% -volt C battery.Six CeCo type BX tubes.One speaker unit and Radion horn.One loop.One Formica panel, 12x13 inches.One suitcase, 7,4x13x24 inches.Twelve 3 -inch flathead 6-32 machine

screws.Ten feet of insulated connecting wire.Three partition boards.Two dozen half -inch roundhead ma-

chine screws 6-32.

If the set will not oscillate properlywhen the tickler is turned on maximum,this condition can be remedied either bydoubling the capacity of condenser C5.However, before this change is made anew tube should be tried as detector. Itmay be that the tube is defective for de-tection, though it may serve nicely foraudio amplification.

The audio frequency amplifier is stand-ard in construction in that it employs twoaudio frequency transformers. T3 andT4. These have been selected becausetransformers give maximum amplificationper tube.

The filament current in each of thelast three tubes is controlled by amper-ites R2, R4 and R5, all of which are No.4V-99.

The plates voltage on the first fourtubes is 45 volts and that on the two au-dio frequency amplifiers 90 volts. Thisvoltage is enough on the small dry celltubes employed to give good speakeroutput. A by-pass condenser C2 is con-nected across the portion of the platebattery which serves the radio frequencytubes and the detector. Its capacityshould be .01 or greater.

A grid bias of 4% to 7 volts should beemployed on the two audio frequencyamplifiers. A lead in the battery cableis provided for this purpose so that theC battery can be placed in the compart-ment with the rest of the batteries.

The tuning condensers are of the Bruno,straight line frequency, drum controlledtype, in which the control is localized atone point.

The panel arrangement can be seenfrom Fig. 2. The drum control is locatedin the center of the 12 x 13 inch panel.

Placement of PartsThe tubes are arranged in a crescent

shaped formation, two at the left, two atthe right, and two at the rear. Thetickler knob is placed in the left frontcorner and the master rheostat in thecorresponding right corner. The inputbinding posts and the loop jack are placedat the left rear corner, and the two tipjacks for the speaker are placed at theright rear corner. The panel, of course,is placed horizontally. The filamentswitch is placed directly in front of thetuning control, midway between the rheo-stat and tickler.

The six sockets are suspended from thepanel by means of 3 -inch flathead ma-chine screws, two being required for eachsocket. In fact all the parts are attachedto the panel. The arrangement is such

(Concluded on next page)

6 RADIO WORLD June 11, 1927(Concluded from preceding page)

as to simplify wiring and to take fulladvantage of the space available.

The receiver has been built to fit intoa 71/2x13x24-inch suitcase. These can bebought in fabricoid for a few dollars. Thiscase has been divided into four compart-ments. The largest of these, occupyingabout half of the available space, is for thereceiver proper and the smaller compart-ments are for A, B and C batteries,speaker and collapsible loop.

Data on LoopA loop may be built into the top of the

suitcase, wound on four notched woodencleats glued diagonally in the corners ofthe lid. It contains 14 turns of flexibleinsulated wire. The loop is concealedbehind the lining of the case so that itcannot be seen when the set is in opera-tion. The terminals are brought out nearthe binding posts provided for the antennainput. When using the ,loop it is neces-sary to provide a plug for inserting injack 31.

Attention should be called to the factthat no metal frame should be used in theconstruction of the suitcase, or the loopcannot be placed in the manner used inthis set. The metal frame would form acomplete electric circuit and it would bevery closely coupled to the loop. Thusthe frame would absorb most of theenergy the loop picks up. If a metalframe suitcase is used the loop shouldbe detachable so that it can be taken outwhen used, or else a cut should be madein the frame so that the circuit thusformed is open. This cut need not neces-sarily weaken the structure to any con-siderable extent.

Cable and TubesA battery cable is provided instead of

binding posts. Each conductor in thiscable is colored and marked appropriatelyto make correct connections simple. Thiscable makes it very easy to change thebatteries when that becomes necessary.

All the tubes used in the set are of the-99 type and are CeCo type BX. Theserequire a filament voltage of 41/2 volts,which is supplied by three or six No. 6dry cells. When light weight is a primeconsideration three cells can be used,otherwise six of them should be used inseries parallel as this combination is moreeconomical in operation than the use ofmerely three cells in series. In otherwords, six cells will not last more thantwice as long as three cells of the same

FIGS. 2 AND 3One-half of the suitcase houses the re-

ceiver, the other half the accessories.The lower photograph (Fig. 3) shows anunderneath view of the parts and wiring.The antenna coil is at upper right, the

tickler coil at lower left.

size. The total current drain on the cellswhen no pilot light is used will be .36ampere.

Two medium sized 45 -volt B batteryblocks should be employed, and one Cbattery having a maximum voltage of 71/2

Experts Debate ReasonDX Is Harder to Get

By KarlDistant stations are not so easily re-

ceived now as they were two or threeyears ago, and radio engineers often dis-cuss this subject heatedly. Some say thatthe great growth in the number of an-tennas has had an absorption effect onthe transmitted wave.

Others say that interference is themain cause of making DX a harder to"catch." The drowning effect of strongstations, particularly locals, on frequen-cies near the desired station, is the formof intereference meant.

The absorption theory was under-mined somewhat by recent measurementsmade by a leading radio engineering con-cern, when the field strength at a givendistance was measured when no other orintervening sets were tuned to that wave,and when hundreds of sets were thus

L. Kohltuned. That there was absorption seemedclear, but it was of such tiny magnitudeas to be almost negligible. In some ofthe tests the meters and circuits werenot sensitive enough to disclose anydifference.

That interest in DX is still high isproven by several facts discussion ofDX by fans, enthusiasm of set -buildersfor receivers that possess distance -gettingability, and the demand for verificationstamps or letters sent out by stations.However, the Radio Commission doesnot regard the protection of DX condi-tions as a public service, holding thatwavelength accommodation for all sta-tions, with minimum interference, comesfirst.

This plan is worked out in the new listof assigned waves. See page 16.

Resistance Audio,Using Push -Pull

(Concluded from page 4)of the next two tubes. This is more of apossibility than a practical solution.

The two most practical ways of input-ting this double amplifier are the use of acrystal detector in series with a high re-sistance potentiometer and a transformercoupled tube detector as shown in Fig. 2.

The most practical way of putting theamplifier to work is to use two tubes ofvery low output impedance in series withthe reproducer and supply the plate cur-rent to these two tubes through high in-ductance choke coils of equal value.

Substitution of ResistorsResistors of equal value can be sub-

stituted for the choke coils with faireffect, particularly when the available volt-age for the plate is higher than otherwisenecessary. The resistance of these unitsshould be several times larger than theplate impedance of the tubes. If 71 typeof tubes are used the values can be about5,000 ohms each. If two speakers are usedin connection with smaller output tubes,one speaker can be connected directly inthe plate circuit in each side of the am-plifier, without the use of chokes. If thespeakers are identical the hum will notbe noticeable, even if it is not balanced outuntil it gets into the air.

It is not to be expected that this willbe a popular circuit. It takes too manytubes and too much filament current forthat. But as a special purpose amplifierand for elaborate installations the advan-tages of this system should well repay theextra equipment and the care required inbalancing the circuit.

The four stage, eight tube circuit ismuch easier to stabilize than a three stagecircuit, provided that the output is shieldedcarefully from the input electrostatisically.The amplification will most likely be toogreat in the four stage circuit. Hence inorder to limit the amplification controllablemagnitudes as well as to limit the numberof tubes used in the amplifier, it is desir-able to use only three stages, even if morecare is required in balancing.

Values of ResistorsThe following are suitable values for the

various parts. The six -plate coupling re-sistors used were El-Menco 250,000 ohms:the six intermediate grid resistors El-Menco 2.5 megohms; the six coupling con-densers .01 mfd. The insulation in the con-densers should be mica. It is better touse small coupling condensers with micadielectric than large condensers with leakydielectric. The coupling and grid resistorscan be made larger if desired. But to in-sure success of a resistance coupled am-plifier of this type it is essential that thegrids be properly biased and that thereis no leakage from the plate to the grid.The total resistance of the potentiometerR should be about 200,000 ohms. A similarpotentiometer can be placed in series withthe last two grid resistors and returningthe grid battery lead to the sliding arm.By this means the voltage on the last twotubes can be equalized.

Dellinger Will StudyState of Art Abroad

Washington.Dr. J. H. Dellinger, chief of the Radio

Laboratory, of the Bureau of Standards,will visit England, France, Germany,Switzerland, Holland and Czechoslovakia tostudy the application of radio beacons toaviation in those countries.

Dr. Dellinger will also make a generalstudy in order to have first-hand knowledgeof condition of radio conditions at the in-ternational radio conference, which is tobe held in Washington this Fall.


A 400 -Volt Power SourceA Quality B Eliminator and AF Stage

FIG.is the diagram of anr easy -to -

construct, yet efficient combination Beliminator and power ampilfier. The half -wave filament rectifier, 316B or 216B isused in conjunction with the ThordarsonPower Compact Unit, R210, Igrad con-densers, and Kroblak fixed wire -woundresistors in the B eliminator portion. Inthe amplifier section, the 310 or 210power tube, Thordarson, R76 outputchoke and R200 audio transformer areused. To regulate the voltage at the90 -volt tap, a voltage -regulator tube,374 or 274, is used.

Placement of PartsThe proper placement of the parts when

constructing this eliminator is as essen-tial to the successful operation as isfollowing the diagram and using goodparts. Therefore Fig. 2, which showsthe layout, should be followed carefully.

Instead of placing the rectifier, voltageregulator and power amplifier tubes ina line and close to one another the ampli-fier tube is placed at right. With thetubes in line the familiar drone was heard.This was due to the vibration of bothtubes, the beat frequency produced be-ing audible.

Where the amplifier tube would beordinarily, the 4 mfd. condenser C4 wasput. To reduce the length of leads fromthe audio transformer to the audio tubesocket, as well as reduce electromagneticinteraction between the power trans-former and the audio transformer, theaudio transformer was placed at the op-posite end and next to the audio tube.Next to it is the output choke. Betweenthe power transformer unit, PTU, whichalso carries the choke coils, the remain-ing condensers, e.g., Cl, C2, C3 eachhaving a capacity of 2 mfd., and C5, of1 mfd. capacity, are placed. Stock sizebrass lengths, aided by corner braces,hold these condensers down.

The Chimney EffectThe special way of mounting of the

resistors is unique. A chimney stackeffect of preventing the resistors frombecoming hot is obtained by placing themupright, instead of horizontal. Smallsquare pieces of asbestos, about l/t-inchthink, arc used to hold them in place. Inthe center of these asbestos pieces por-tions are cut out, to fit the resistors. '1 ohold these asbestos pieces to the board,

(Hayden) FIG, 3

The metal case in which the completeeliminator is placed. The ground post, -towhich one side of the A battery must beconnected to filter out the hum, is placedon the same hard rubber strip as are the

other posts,

By Leonard Upham

7'4, 7'MO*

q® C5

,,AiAFT

s -

FIG. 1The circuit diagram of the combination B eliminator and power amplifier.

R2 is from +B Max. to +B90.

(Hayden) FIG. 2How the parts should be placed, to obtain fine results. Note the distance betweenthe rectifier tube (upper left) and the amplifier tube (right), which prevents theannoying drone, many times laid to the rectifier tube or the circuit. The other tube

is the voltage regulator.

screws arc used. Washers are placed be.:tween asbestos and the board to keepthe asbestos off the board, The hole inthe asbestos helps keep the resistor firm.The three resistors R2 (8,000 ohms), R4and RI (10,000 ohms apiece), are placedin triangular form, between the 4 mfd.condenser and the two, 2 mfd. condensers,The fixed resistor, RI which has a re.

sistance of 1,000 ohms, with which thegrid bias for the power amplifier tube isobtained, is placed near the amplifier tube.Flexible insulated wires connect the out-put leads from the eliminator to thebinding posts on the B eliminator caseshown in Fig. 3.

The maximum output voltage of this de-vice is 400 volts at 65 mils.

Balsa Wood for SpeakersThe New Sounding Board That Affords Realism

FIG. IThe completed Late Balsa wood

spealser. The three wide pieces thatoccupy the interior of the frame, theseven radiating arms or fins, and the littlesquare under the unit, to which the coup-ling rod is fastened, are Balsa wood. The

rest of the pieces are hardwood.

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FIGS. 2 AND 3How Balsa wood looks under the MiCrO4C-Opt. At left i5 a transverse section, at

right tangential section.


logs for rafts to float heavy woods downthe rivers from the interior to the sea-coast.

Balsa is the lightest wood that grows.The commercial product averages from6 to 7 lbs. per cubic foot. This is approxi-mately one-half the weight of good cork.This lightness results from its peculiarcellular structure, which differs from thatof nearly every other wood. In ordinarywood the thickness of the cell walls gen-erally forms a considerable part of theirdiameter while in Balsa, the cell walls areextremely thin and there is practicallyno lignification. This structural arrange-ment confines within its large, barrel -shaped cells a considerable quantity ofdead air, that is, non -circulatory air,which represents 92 per cent. of the totalvolume.

A radial section of Balsa shows, evenbetter than the transverse, the thin par-titions dividing the cells into microscopicair spaces so small that heat passage isreduced to a minimum, thus making Balsawood efficient for reproducers withouttemperature causing response variation.

The. use of Balsa wood for radio repro-duction is something new, but its usefor other purposes is of long standing. Itis used for stream lining of airplanes,hydroplane pontoons, swimming floats,shock absorption, shipping containers andscores of other purposes, for some ofwhich is is specially treated and is anexcellent insulation material in itself.But for radio purposes do not add any-thing to the Balsa wood. Do not paint,shellac, varnish or otherwise treat it. Ifdecorative instincts are strong, light tapes-try may be employed very handsomely.Decorators' material, such as cretonnes,chintzes, etc., for this purpose are com-mercially available.

An Enlightening ExperienceAnd what does this wood accomplish?It furnishes us with a ready, inexpensive

and astonishingly effective means ofbringing out those low notes, about whichwe are so anxious. It still gives us goodresponse in the middle and higher audiofrequency brackets. It enables us to hearlow notes we possibly never heard beforeon the radio. It opens a new vista andchallenges the constructional side of ournature, indeed, defies us to ignore theexistence of Lata Balsa wood. Listen tohow an orchestra sounds in a Balsa woodspeaker, listen to a piano solo, and notethe startling realism. Never judge anyspeaker by a violin solo, for even on apoor speaker this will sound well.

I connected a Balsa wood speaker toa set consisting of a TRF radio channeland three resistance -coupled audio stages.The constants of the AF circuit were:.25 mfd. stopping condensers, .1 meg.plate resistors and 2 meg. grid leaks. Theoutput was filtered through a 100 -henrychoke and a 14 mfd. condenser. I citethese constants only to show that thesuppression at 20 cycles was not morethan 10 per cent., hence neglible.

I heard low notes that I had-neverheard before on that set and was ableto distinguish between the bassoon andthe tuba, the tuba and the bass drum, andthe tuba and the bass viol. The speakerwas a large one, hence low pitched, butit handled the higher frequencies withcredit. The speaker I had been previouslyusing was just as good on high notes,or perhaps brought these out with justa little more volume, but on low notes itsimply did a filtering action. "On lesaura!" The air was Paris just after thefirst Battle of the .Marne. The low notesnever got to Paris!

But with the Lata Balsa wood speakerthere was an energetic response at even14 cycles! This pitch had to be generatedfrom an audio beat note oscillator, be-cause no organ was on the air, and onlythe organ among musical instrumentsnormally goes as low as that.

It was interesting to compare the onespeaker with the other. This was done

FIGS. 4 AND 5The unit's coupling pin is secured to the small square piece of Balsa wood by

insertion in the anchor screw and tightening down the thumb nut. The square issecurely glued to the horizontal fin, which is one piece. The diagonal fins are in twosections, each. Notice three of them in foreground, glued to the square, too. Place thethumb nut on the anchor screw BEFORE you mount the unit. At right (Fig. 5), four

screws that secure the unit to the crossarm.

by connecting together one tip of eachspeaker cord at the filter output con-denser, and alternately touching the freetips to the ground post of the set (Aminus being grounded). It simply did notsound like the same orchestra. Whenthe Balsa speaker was cut in the zoom-zoom was there, full-grown. Could youdance enjoyably to the music as it camefrom this speaker? Could you avoiddancing to it, would be a more logicalquestion. Cut out Balsa and cut in theother-fine, strong high notes, but noth-ing much below 100 cycles, hence no char-acter, personality, vivacity or f etching-ness to the music. Reconnect the Balsaand you wondered what Thomas A.Edison possibly could have meant whenhe said that radio music wasn't worthlistening to, it was so badly distorted.Maybe he referred to speakers with ahigh audio frequency cutoff or suppres-sion hollow, attached to an audio ampli-fier suffering from core saturation andsecond harmonic distortion. But Mr.Edison had never heard a Balsa woodspeaker when he made his famous re-mark. Perhaps he would be surprised tolearn that the combination of set andspeaker that I used-with a CX371 powertube in the last stage-was as good asthe best in phonograph reproduction-Orthophonic or Panatrope or, indeed,Edison-and with electrically recordedrecords. The finest quality is on a par, inphonograph or radio. It must not be for-gotten that when the record is reproducedon a radio speaker, as is common practice,speaker limitations affecting reproductionfrom a set apply to the phonograph.

A good speaker is simply a good sound-ing board and a good unit. If eithercomponent is poor, the speaker is poor.Therefore when you build a Balsa woodspeaker be sure to use a ggod unit.

Care In ConstructionThe Balsa speaker may be most con-

veniently constructed in either or bothof two popular sizes. The constructionmethod is the same in both.

The speaker consists of an oblong hardwood frame with a hardwood crosspiecejust below center, three pieces of Balsawood, side by side, but not touching,occupying the space within the frame andglued to it; seven radiating Balsa woodribs, a small Balsa wood square withcoupling rod screw anchor and thumb-screw, and a unit mounted on the cross-arm so that the coupling rod touches thecenter of the speaker at the point where

the anchor is located. That's all there

is to it -18 pieces of wood, a unit, athumb -nut and screw anchor for theunit's rod and something with which tofasten the unit to the crossarm, e.g., fourDA" woods crews.

But the speaker can not be slappedtogether and be expected to live up toexpectations. It must be made pains-takingly. The gluing must be done withextreme care, so that, for instance, thesquare Balsa seat for the coupling rodhousing is tau: at all points, and proofagainst unseating on exertion of moderatefinger pressure. Any play at this pointmeans a rattle in the speaker, even atlow volume reproduction. This is theonly critical point of the speaker and!oust be given close and careful attention.

Do The Gluing WellThe gluing at all places should be firm

and continuous. Especial care should beexercised at the ends of the fins, for thecurling tendency may require a secondapplication of glue to insure keeping theends down.

These ribs, by the way, unite the -re-spective sheets of wood with one anotherand the small driving square, and if evenone of the seven ribs is omitted the lownotes suffer, while if all the ribs areomitted you are working on virtually onlyone Balsa woocl sheet, and you don't re-produce the low notes. So, follow style,and be careful in gluing, so that everyglued piece adheres firmly throughout thelength of intended contact.

Constructional DataThe eighteen pieces of wood are con-

situted as follows : (a) three wide stripsof Balsa wood to be cut to desired widthand length; (b), seven thin ribs or finsof Balsa wood, to be cut to desiredlength ; (c), four pieces of hardwood forframe; (d), one piece of hardwood to beused as crossarm for mounting unit; alsotwo small pieces of hardwood to elevatethe crossarm suitably; (e), one smallsquare piece of wood, Balsa or other-wise, for accommodation of bushing.

The accessories are one bushing, con-sisting of anchor screw and thumb -nutfor holding stylus (or driving rod or coupling pin) of unit; brads, screws and atube of glue.

The hardwood frame is made first.Glue the corners and also nail them withbrads. The 3/32 -inch recesses at thecorners must make an even fit. This isimportant.

Next cut the ends of the wide strips(Concluded on page 18)


The Need of NeutralizationThree Different Balancing Devices Analyzed

By Lester Harrison

cn Co

0

FIGS. 1 AND 2The bridge method of neutralization (Fig. 1, at left) in which the effect of the

inter -electrode capacity Co is neutralized by the condenser Cn which feeds energy togrid A in reverse phase. Fig. 2 shows how the neutralization takes place. The variousinductances and capacities are indified by the same symbols as in Fig. 1. R in thetwo figures represents the resistance of the parallel tuned circuit in the input of thetube. The value of this resistance is LrC, where L is the inductance of the tuning coil,

R its resistance and C the capacity of the condenser when the circuit is tuned.ONE of the greatest steps forward inthe design of radio receivers was the

introduction of neutralization for stop-ping radio frequency oscillation. Thatstep was taken several years ago, andsince then many different devices havebeen brought out with the same objectin view.

Although all schemes for stopping radiofrequency oscillations are called neu-tralizers, some of them do not neutralizeanything but the power of the set toamplify. They are devices that introducepower losses to such an extent that os-cillation is impossible. In true systems ofneutralization the cause of oscillation isremoved by preventing any power in theoutput of a tube from reaching the inputcircuit of the tube or any preceding tube.This is usually done by arranging aWheatstone bridge network and balanc-ing it so that there is no effective feed-back. There will be some feedbackthrough stray capacity and mutual in-ductance but this is offset by feeding backexactly the same amount in oppositephase.

The system of neutralization introducedby Hazeltine, and upon which the Neu-trodyne is based, is shown in Fig. 1.There is between the grid and the plateof any tube, or between the parts onthe plate side and the parts on the gridside, a certain capacity. This is repre-sented by Co. in Fig. 1. Through thiscapacity energy will flow from the platecircuit to the grid circuit and it will be insuch phase, provided that there is a largeinductance in the plate circuit, that os-cillation will result. Now if an equalamount of energy be sent back to gridA from the plate circuit in exactlyopposite phase, the effect of either partof the fed -back energy will be nil in sofar as oscillation is concerned. This neu-tralizing energy is supplied through thesmall variable condenser Cn and the coilLn. The capacity of Cn is varied until theenergy fed back by the two routes is thesame.

Tice four reactances that form thebridge circuit are Cn, Ln, Co and Lo.These can be arranged as shown in Fig.2, in which R represents the resistanceof the parallel tuned circuit in the inputof the tube. If the plate circuit shouldsend any current through R in phase withthe current sent through by the incomingsignal, regeneration results and oscilla-tion is likely. The phase of the incomingsignal is indicated by arrow A. Now, itis evident that Io is in phase with this in

the circuit RCoLo. If the circuitLnCnbe added and coupled to the output ofthe tube in a suitable manner it is clearthat a current In can be established inRLnCn. By suitably connecting the coilLn the direction of In can be madeopposite in phase to Io or so that thesetwo currents buck in resistance R. Alsoby suitably selecting the capacity of Cothe two bucking currents can be madeexactly equal. When they are equal nocurrent flows through R as a result offeedback and then there is no tendencyto oscillate. However, this balancingdoes not affect the incoming current. Itflows through R just as it did beforeneutralization.

Since the four branches of the bridgeare reactances, it is possible to effect com-plete neutralization at one frequency andstill have unbalance at all other frequen-cies. This is not a desirable condition.The circuit should be neutralized for allfrequencies within the tuning range ofthe receiver. This can be brought aboutby making the two coils Lo and Ln equal.This will also require that the two con-densers Co and Cn be equal. When neu-tralization has been effected under theseconditions it will function over the wholetuning range

Another non -oscillating type of circuitis exemplified in the Loftin and Whitesystem, shown in Fig. 3. As stated above,a tube will not oscillate unless there is ahigh inductance load on it. If the loadcan be made capacitive or resistive therecan be no oscillation as a result ofcapacitive coupling between plate and

grid. This fact is made use of in theLoftin -White circuit. The values of thechoke coil Lo, the coupling condenser Co,the coupling coil Ll and the coupling con-denser C3 can be chosen so that the loadon the tube is purely resistive for onefrequency and slightly capacitive for therest of the band. The circuit will notoscillate at any frequency with this ad-justment.

The object of the dual type of coup-ling in the Loftin -White circuit is not toprevent radio frequency oscillation but toequalize coupling over the entire tuningrange. The coupling between the primarycoil LI and the secondary 1_2 is greatestfor the higher frequency end of the spec-trum and therefore this will cause greateramplification and these frequencies thanat the low. The low frequency amplifica-tion is built up by capacitive coupling be-tween the primary and the secondary cir-cuits. The primary current flows throughC3, which is also a part of the tunedsecondary circuit. More energy is fedinto the tuned circuit by this means atthe lower end of the tuning range thanat the higher. The combined coupling ofLi and C3 is nearly constant throughoutthe tuning range.

Another method of preventing radiofrequency oscillations is exemplified in thePhasatrol, invented by John F. Rider.This device changes the phase of theenergy fed back in to the preceding tubeso that it does not aid the incoming sig-nal. In the Phasatrol device the platereceives its voltage through a high resist-ance potentiometer R. This high re-sistance itself changes the phase of thecurrent forced through, the inter -electrodecapacity to grid A so that it does not aidthe incoming signal. The phase controlis still further aided by connecting theprimary LI through a condenser C tothe sliding arm of the potentiometer andthen adjusting the position of the armuntil the tendency to oscillation disap-pears.

It will be noted that the phase of thefed -back energy is largely controlled bymeans of resistance variation. Conse-quently the degree of neutralization isnot greatly dependent on frequency. Oneadjustment will serve for the entire tuningrange, and there will be no appreciabledifference in the amplification for thevarious frequencies. The control is alsoaided by the presence of condenser C,provided that it is not made too large.The correct size depends on the value ofthe inductance of the primary coil, andto some extent on the coupling between


FIGS. 3 AND 4The Loftin -White circuit (Fig. 3 at left) in which oscillation is prevented bymaking the load on the tube resistive or slightly capacitive. At right (Fig. 4) is thePhasatrol method of preventing oscillation in the radio frequency tubes. The phaseof the energy is changed so that it is out of step with the input when it gets to thegrid A. The load in this tube is also resistive or capacitive.

June 11, 1927 RADIO WORLD

B Battery ConservationHigher Efficiency Gained At Reduced Cost

THE A battery must be kept "up." Inother words, do not let this battery

become discharged below its efficientoperating range. If dry cells are used forA power, do not use these cells after ameter test shows them to be below seven-ty-five percent of their efficiency whennew. A new dry cell should read from30 to 35 amperes when shorted with a highresistance ammeter. Never use a low -resistance meter to test batteries. Thecell should not be used after it reads be-low 15 amperes.

Where a storage battery is used for Apower be sure to- keep this battery wellcharged. A trickle charger is handy asnothing has to be touched except that youadd water. Distilled water should beadded to the battery as often as is neces-sary to keep the water line above thelead plates in the battery.

The reason for so much concern aboutthe A battery is simple enough. If yourun your set when the A battery isdown it is necessary to use more B bat-tery current to gain the same volume asyou obtained with your A battery in goodcondition. It is cheaper to buy new Acells or take ocasional care of your stor-age A battery than it is to buy new Bbatteries.

Get the Right SizeOne of the first things to consider in

the use of B batteries is the size of bat-tery to empoy in a given set. For setsup to three tubes the small size batteryis correct. An example is the type 772Eveready. For sets using from three tofive tubes the large size battery should beemployed and sets using over five tubesshould employ the extra large battery.The use of too small a battery meansthat a new battery must be purchasedwithin a short time.

When purchasing B batteries do notbuy them at a sale where you can obtain

By Thomas L. McKayMcKay Instrument Co.

B- Jetbindinsi

post

FIG. 3

them "cheap." Such "bargain" batteriesare likely to be seconds or have stood onthe shelves for a long time. It does notpay to take the risk. It is well to re-member that you usually get what youpay for.

Using the correct size of battery in yourset, you will get six or more monthsservice, depending on how much you useyour set each day, what means you em-ploy for conserving these batteries, andhow efficiently you handle your set. Forthe average case the life of a B batteryis probably eight to ten months.

Worn Out One a DragWhere two or more B batteries are

connected together do not connect an oldworn-out battery with new batteries.This is, of course, always permissiblewhere the old battery reads over 37 volts.The old battery should be tested fre-quently and should be replaced as afterit drops below its efficient point. Not allB batteries should be discarded when theyread under 37 volts, but satisfactory oper-ation should be the test.

The use of poor tubes is costly. Have

FIG. 1 (bottom) and FIG. 2 (top).

11

your tubes tested occasionally and discardany that do not come up to the averagestandard. The use of old tubes simplymeans greater B consumption for thesame signal strength.

Using the proper value of C battery isan important method of conserving theB batteries. Fig. 1 shows how this Cbattery should be connected to the set.If the set does not now employ a C bat-tery it is an easy matter to rewire forthe use of one.

Where 90 volts are used on two audioplates a 4% -volt C battery should be em-ployed. For 67% volts B use 3 volts Cand for 45 volts B use 1% volts C. Inresistance or impedance coupling threetubes are usually employed with 135 voltson the plates. But the plate resistors dropvoltage, so the actual voltage applied tothe plate is less than 135. The drop onthe speaker is smaller. Hence 4% voltsof C for the first two AF tubes will suf-fice. For the last tube, as this may bea power tube, conditions vary.

Case of Power TubesFig. 2 shows the system necessary where

a 112, 120 or 71 power tube is used. Theusual 4i volt C battery is employed onthe first stage of audio for it uses 90volts on the plate. The 112 power tuberequires a special 9 -volt C battery. Ifthe 120 power tube be employed, a 22,4 -volt C battery must be used. This bat-tery can be an ordinary small size 221/,volt B battery. Due to the voltage dropin the speaker windings it may be advisa-ble to use 16V2 -volt post on the C batteryfor the 120.

The proper use of C batteries cutsdown B battery consumption at least onethird. This means a worthwhile saving.It is also true that the drain on a Cbattery is so small that this battery willlast from nine months to well over a year.Be careful not to use an old C battery.This again impairs the efficiency of your"saving system." Do not use a C batterythat is below seventy-five percent of itsrated voltage, is a good rate, but notinviolable.

The efficiency with which a set isoperated is very important. It has beensaid that the human ear cannot detecta change in sound volume that is lessthan one-fourth of the original volume.It is, therefor, impossible to depend onthe ear to tell whether you have your setadjusted properly.

Fig. 3 shows a simple system that tellsyou whether or not your set is adjustedproperly. This method helps save B



$17,500 for New VoicesOffered by Atwater Kent

Philadelphia.Very extensive plans for a "National

Radio Audition" for young men and wo-men for the purpose of finding by test thebest undiscovered voices in the UnitedStates were announced by the AtwaterKent Foundation, an institution estab-lished for scientific and educational pur-poses.

Every community in the United Stateswill be given an opportunity, first to se-lect by popular vote the best voices, ofyoung women and young men ; and thento enter these singers in a test of state,sectional and national auditions to bebroacast.

Awards aggregating $17,500, with oneand two years' tuition in an Americanconservatory for certain winners, will beoffered as an incentive to young peopleto enter the tests, which will be heldin each of the forty-eight states.

Kent's StatementA. Atwater Kent, president of the Foun-

dation, said:"The discovery of one of these rare

voices, of which each generation producesa very few, seems to me an event of pro-found national importance. Even whensuch a voice could give pleasure to onlya few thousand people in a year it was anational treasure. Now that millions mayenjoy it on the same evening through themedium of radio, such a voice has becomepriceless.

"The National Radio Audition, sup-ported by the Atwater Kent Foundation,is an undertaking to search the entirecountry for beautiful voices and to offerthese singers an opportunity for fulldevelopment, recognition and reward.

"In Europe, when a singer of promiseappears, the entire family will gladlymake any necessary sacrifice to providemeans for a proper cultivation of thatvoice and the support of the singer untilfame is achieved. It is in this spirit thatwe hope each community in the countrywill receive this Audition idea and devotewhatever effort is required to discover andpresent its candidates for state and na-tional honors."

Opportunity for YouthThe primary purpose of the Audition

is to provide opportunity for recognitionto every young man or woman in everycommunity, no matter how isolated, andto give to the world of music throughradio the best voices thus discovered.

After a series of state and district au-ditions, five young men and five youngwomen will be brought to New York fora final audition, which will be broadcastover a nation-wide network of stations.

In the finals-the National Audition-five awards for merit will be given towomen and five to men. The two whoget first place in the National Audition-a man and a woman-will each receivea gold decoration, $5,000 in cash and twoyears' tuition in a leading conservatory.

Winners of second awards will eachreceive $2,000 in cash and one year'stuition.

Winners of third awards will each re-ceive $1,000 and one year's tuition.

Winners of fourth awards will each re-ceive $500.

Winners of fifth awards will each re-ceive $250.

Musical, civic and women's clubs in eachcommunity in each state will be invited

to hold local tests to select the bestyoung man and best young woman singerof their towns. These winners will thenbe certified to a state audition, which willbe broadcast by a radio station in eachstate. A state winner of each sex willbe chosen and wiJl receive a silver medal.

The next step is a district audition.The young men and women who havewon state honors will be taken to a cen-tral broadcasting station in one of fivedistricts, where an audition will be broad-cast to select the two winners-a youngman and a young woman-from that dis-trict.

The two winners in each district willreceive gold medals and the ten finaliststhus selected will be brought to NewYork for the final National Audition.

Each national winner will also be wellstarted on the road to fame as a radioconcert artist, with a successful musicalcareer ahead. All expenses of contest-ants the district and final auditions,including railroad fare, hotel bills, enter-tainments, etc., will be paid by the At-water Kent Foundation.

Judging of contestants will be by voteof radio listeners and juries made up ofthe musical authorities of each commun-ity, state or district. Listeners -in willparticipate in the state and district audi-tions, their votes counting sixty per centand the vote of the jury forty per cent.For the final National Audition in NewYork, a jury of great figures in the musi-cal world, is being created. Its decisionswill be made without participation by theradio public and will be announced imme-diately after the broadcasting of thefinals.

Qualifications for TestsThe principal qualifications for -con-

testants are as follows :They must not be more than twenty-

five years old; must never have beenassociated with a professional theatricalor operatic company; must never havebeen a paid principal in any concert heldoutside their own states; must declarean intention to follow a musical careerand must be free from theatrical or musi-cal contracts.

This limitation permits choir singers toenter the auditions, even though theymay have received financial compensationfor singing in churches. It is expectedthat many of the contestants will be theleading young choir singers of their com-munities. Other groups from which en-tries are anticipated are students in mu-sical schools and locally prominent singersin high schools and colleges. Musicalorganizations in each state are also af-forded an opportunity to put forwardtheir best talent and to assist in holdinglocal auditions.

Preliminary organization for holdingthe auditions will start soon under thedirection of the Atwater Kent Founda-tion. It is expected that the first stateauditions will get under way early thisFall, followed by the district auditionsin November, with the finals in New Yorkearly in December.

CROSLEY CONVENTION HELDThe annual convention of the Crosley

Radio Corporation's distributors was heldin Cincinnati June 8 and 9. Announce-ments of new developments in the Cros-ley line were made and plans for thecoming year will he discussed.

SIGNALLY HONORED S

LORETTA LEE, first vocal graduatefrom the Peabody Conservatory of Musicsince Mabel Garrison, who obtained heridiploma in 1911. Miss Lee was the third'sone to receive the diploma in the Con.t,servatory's existence of 57 years. She re..cently gave a song recital from WEAL

Baltimore.

VARIATION OF C BIASIf in doubt as to the proper ohmag0

fixed resistance to be used for providinii.C bias from a B eliminator, a variabbi t

resistance of about 2,000 ohms maximuniresistance, with a carrying capacity of 5watts may be substituted.

MisleadingOver Air 13

Washington.Federal punishment for stations whici

misrepresent articles over the radioplanned in a bill that probably will be in-troduced during the next session of Congress by Senator C. C. Dill or Representstive Wallace White.

Numerous complaints have reached thr.Federal Radio Commission against statiowhich through direct advertising overair have offered articles for sale and whichaccording to the complainants, have not entirely lived up to the promises. The cot*plaints have been most vigorous aboutfew stations in the Middle West.

According to one letter received by thy'Radio Commission, a station broadcasted 0announcement about radio tubes. The an-,nouncement was that a special price had bee4fixed for the tubes and anyone who sent in,the money for the tubes was guaranteedsatisfaction or else the money would bdrefunded.

He Buys the TubesA listener -in in another state heard tbef

announcement and sent in the money foii,four tubes. In the letter containing tmoney was a description of the kind otubes desired. In about two weeks tubewere forthcoming, but they were not of th,kind ordered nor were they suitable foruse.

The tubes were returned to the station'with a request that the proper kind oftubes be sent or the money refunded. Upto the time of writing to the Commission,.the listener had received neither the moneynor the tubes.

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SET MADE OF MATCHES

PAUL R. WOTTON, of Friendship,Maine, made this model of the RadiolaNo. 20 entirely from matches. It tookMr. Wotton's spare time for four months.More than 2,200 matches were used. Thedrum dial and volume control knobs turnand the switch pulls and pushes, as on theRadiola. The loop also was made ofmatches, but wound with thread to givethe appearance of metal. No nails or pinswere used. Every match was glued. Theset is perfectly proportioned to the

original.

dvertisingUnder Fire

There is said to be no Federal statute bywhich action could be taken against thestation.

It is not believed that the station was at-tempting to defraud. The opinion is that arush of orders was responsible for thedelay.

The Legal ViewCommissioner Eugene 0. Sykes, the legal

member of the Federal Radio Commis-sion, believes that a law extending the PostalAct to cover attempts to defraud over theradio would be a very good thing.

"The Federal Radio Commission has notthe authority to exercise censorship pro-grams," says he. "It therefore follows thatwe cannot attempt to say what a stationshall or shall not broadcast, whether it isdirect or indirect advertising or somethingelse.

"It is up to the listeners entirely and ifthey think the station is rendering a publicservice, it is up to us to keep our handsoff.

"Of course, if conclusive evidence of in-tent to defraud by any station were pre-sented to the Federal Radio Commission,an effort would be made to deprive thestation of its license. But it does seem thata law covering the subject might help toclarify matters."

BANQUET BOARD TO MEETThe organization meeting of the com-

mittee for the Fourth Annual Radio In-dustries Banquet wil be held at theStevens Hotel on Wednesday, June 15.

Highest Type ProgramsPredicted for Daytime

Hot Springs, Va.The inauguration of a daytime broad-

casting schedule on a nationwide scale,comparable to the best features nowtransmitted between 8 P. M. and mid-night, was forecast in an addreses byGeorge F. McClelland, vice-president andgeneral manager of the National Broad-casting Company, at the annual meetingof the National Electrical ManufacturersAssociation here. Probably 10,000,000listeners would be added to the radioaudience of the United States if a six-teen -hour day broadcasting service wereregularly established, he said. Mr. Mc-Clelland added:

"There is a good reason, of course,why radio should have settled first at theAmerican fireside. It was brought intothe home by the boy and finally em-braced by the man of the house. Then,too, the predominantly entertainmentfeatures of radio made it natural thatthe best program features be concen-trated during the hours when the familyusually seeks entertainment.

Too Big for Small Clothes"But broadcasting has outgrown the

narrow limits of its early experimentaldays. It has a greater destiny to fulfillthan mere entertainment. Is mission to,the home is to carry to it every form cAcultural influence and service which thissystem of mass communication is pre-eminently equipped to do.

"Broadcasting, theoretically at least,already covers the outermost limits ofspace. But it has still far to go in timebefore we may be said to have estab-lished the best possible broadcasting serv-ice commensurate with the requirementsof a population of 117,000,000 people.

"Of the more than 30,000,000 womenin this country over 21 years of age, lessthan 9,000,000 are employed in duties out-side of the home. Radio broadcastinghas made a start, it is true, in bringinga daytime service of information andentertainment to the home. Yet muchremains to be done in order to providean adequate daytime program for 21,-000,000 women in the United ,States, mostof whom are anxious and eager to re-ceive the musical, educational and in-formative features which radio can bring.

The School Children Audience"There are 25,000,000 school children in

the United States, the vast majority ofwhom are still awaiting an organizedplan of service that will bring radio tothe classroom, as an established factor inmusical education. The decision reachedby Walter Damrosch, the distinguisheddean of musical education in this country,to broadcast a series of educational con-certs to the schools, is a very great stepin the right direction.

"It may seem an anachronism in thisday of super -radio programs when thegreatest stars of the opera and the con-cert stage, when the most distinguishedfigures in educational and public life, havebeen featured on the air, that hundredsof thousands of people whose homes areequipped with radio sets have never hadthe opportunity to hear an outstandingradio program. For we must rememberthat in many professions and manytrades there are millions who labor whilemost of us sleep. Daytime broadcastingof a primary character would prove agreat boon to this element of our popu-lation.

"The last but not the least factor thatwould call for the extension of daytimeradio programs is the need of the greatbuying public when it is in the marketfor radio sets. It is the unique positionof radio that it is an industry builtaround a broadcasting service. 1t canbe demonstrated only in connection withthat service. The best possible receptionof the poorest possible program is aninadequate recommendation for any set.A high class broadcasting program, there-fore, transmitted during the day hours,would be of inestimable value to the radioindustry. z z zz

"It is plain that any program whichadvances the radio manufacturing indus-try advances the interests of broadcastingand therefore the interests of the public."

Mr. McClelland in his address alsodetailed the great technical progress made

by engineers of the National Broadcast-ing Company in broadcast transmission.

Technical Achievements"A new science of electro-acoustics has

been created for broadcasting," he said."Remarkable progress has been made inthe technique of handling sound in theair.

"Microphone technique has been im-proved to the extent that not only themiddle register but the high notes ofmusic or the speaking voice can now behandled by the microphone.

"Modulation systems have been workedout by which distortion in radio trans-mission practically has been eliminated.

"Sound control systems have been de-veloped by which an invisible radio con-ductor mixes and controls the outputof the microphone, so that a concertmight be transmitted in perfect form bythe broadcasting station."

The greatest contributions thus far tothe development of broadcasting in theUnited States, Mr. McClelland declared,have been made by the communication,the electrical and radio manufacturingindustries of the country.

WLW Short WavesHeard World Over

Short wave broadcasts from WLW, Cin-cinnati, are being heard consistently incountries throughout the world. Threereports from three different individualsin London were received in a single dayand other reports have come in from Mex-ico, Trinidad, the Canal Zone and severalother foreign points.

The short wave transmitter, 52 meters,uses only 500 watts as compared with the5,000 watt power of the long wave Cros-ley station. The short wave transmis-sion, however, far outdistances the other.

WLW will put on a special program forAustralian listeners at 3 A. M. (E. D.S. T.) Sunday morning, June 29 (8:00P. M., Monday, in Australia).

AMERICA'S LEADERSHIPScientists of every nation are looking to

the United States in radio development,and the majority of the new wondersin tubes and devices for transmission andreception, to be shown at the next RadioWorld's Fair, in New Madison SquareGarden, New York City, will be theproduct of American inventive genius andresearch.-

14 RADIO WORLD June 11, 1927A THOUGHT FOR THE WEEK

J UST as millions of people a few yearsago declared there wasn't anything prac-

tical in radio, and then were shown to besilly unbelievers, so does that flying eagleof the West, Charlie Lindbergh, come alongand prove to a breathless but doubtfulworld that Paris is only across the way tothose who know how to make it; and thatsame world is still divided as to whetherintrepidity or modesty is the flyer's middlename.

SIXTH YEAR

The First and Only National Radio Weekly

Member, Radio Publishers Association

Radio World's Slogan: "A radio set for every here."

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HENNESSY RADIO PUBLICATIONS CORPORATION145 WEST 45th STREET. NEW YORK. N. Y.

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James

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"Ask Me Another" StuntIs Worked by WLW

"Now we'll ask one," is the answer ofWLW, the Crosley station at Cincinnati,for the current "Ask Me Another" craze.

Every night at 8 o'clock, Eastern Stand-ard Time, the announcer will ask five ques-tions, and every night he will give the an-swers to the questions of the night before.

The queries will be taken from all ofthe fields of knowledge entering into a lib-eral education-music, art, literature, his-tory, politics and current events. The mu-sical questions will be answered musicallyas well as verbally. For example, "Whatfamous composition did Schubert write in abeer garden?" The following night the an-nouncer gives the answer.

WJAZ Primes Its Gunsainst Law's Validity

Washington.Notice that the Zenith Radio Corpora-

tion of Chicago, owners of WJAZ, isprepared but has no present intention,to enter the courts to dispute the con-stitutionality of the Radio Act of 1927,was given to the Federal Radio Com-mission by Irvin Herriott, attorney forthe station, preliminary to the formalopening of a public hearing before theCommission so the station could enter aprotest to the wavelength assignment ofthe station.

Mr. Herriott asserted that the ZenithRadio Corporation does not at presentintend or expect to test the authority ofthe Commission, but that lie was enter-ing possible contentions "solely for thepurpose of preserving the record." Itwas his belief that WJAZ could prove itspublic service value fully enough to thesatisfaction of the Commission so that itwould be assigned a frequency otherthan the one allocated it, effective June15, namely 1,140 kilocycles (263 meters).

Prepared to DisputeHowever, Mr. Herriott continued, the

Zenith Radio Corporation proposes tobe the first organization on record asprepared to dispute the constitutionalityof the radio law passed by Congress lastFebruary.

If suit should he entered in the propercourt of jurisdiction, the Federal districtttourts, it will be on the followinggrounds, he said:

1. The Act permits of deprivation ofproperty without due process of law.

2. The regulatory power of Congressdoes not extend to a subject of thischaracter.

3. Orders of the Federal Radio Com-mission "undoubtedly" amount to con-fiscation.

Prefers 389.4 MetersRepresentatives of the Zenith Radio

Corporation, however, disavowed anydefinite intention of going to the courts.Required under the Commission's pro-cedure to name the frequency to whichthey feel they are better entitled, theynamed 770 kilocycles (389.4 meters).

E. F. McDonald, Jr., president of theZenith Radio Corporation, asserted onthe witness stand that the station waswilling to accept a frequency assignment

anywhere in the wave band between 300and 425 meters.

Mr. McDonald testified that Commis-sioner Bellows specifically promised himthat Station WJAZ would be assigned awavelength between 300 and 400 meterswhen the 60 -day license's were issued.to become effective June 15.

Cites Broken PromiseRelying upon this promise, the Zenith

Radio Corporation was surprised andconcerned, he said, when the 263 -meterallocation for Station WJAZ was madeknown.

Mr. McDonald said that the 263 -meterwavelength was not suitable for StationWJAZ's range of service, and that broad-casting upon it would largely disrupt itsvalue to its listeners. Station WJAZcannot be heard on 263 meters by thetype of receiving apparatus that wasmanufactured up to about the first ofthis year, he said, and under the Com-mission's plan of frequency separationwill not be heard suitably.

President McDonald said it was hisopinion that the majority of receivingsets now in use cannot catch programstransmitted on waves below 250 meters.He regarded the continued operation ofWJAZ as "essential and necessary" tocarry on the Zenith Radio Corporation'sbusiness, which is primarily the manu-facture and sale of radio apparatus.

Zenith Was the "Starter"It was when the Zenith Radio Cor-

poration won its suits in the Federal dis-trict court against the authority of theDepartment of Commerce to control andregulate radio, that Secretary Hooversought an opinion from the AttorneyGeneral regarding this authority. Theopinion, rendered last July, stated thatthe Department of Commerce had noauthority over radio under the Communi-cation Law of 1912.

Thereupon Federal control of broad-casting broke down. There was no regu-lation until February, 1927, Ystllen Con-gress enacted the law creating the Fed-eral Radio Commission and defining itsfunctions and powers.

Under the "public service" clause ofthis act, the Commission has reallocatedconditions of broadcasting within theprogram band. Station 1VI AZ is one ofthese required to shift its frequency.

Mathilde Harding Weds Radio OfficialMathilde Harding, hostess -accompanist

at WEAF, was married recently toDonald Withycomb. The romance beganat the formation of the National Broad-casting Company in November. 1926. Mr.Withycomb, is assistant secretary of theN. B. Co.

Miss Harding was born in Washington,Pa. She early planned a musical careerand after her graduation from the Wash-ington Seminary came to New York tostudy the piano.

Last season Miss Harding served asaccompanist for Ethel Hayden, who willbe remembered by WEAF's audience asthe soloist during the "Atwater KentRadio Hour," when the Oratorio Societyof New York was heard. In her tourwith Miss Hayden she went as far Westas St. Louis and toured extensivelythroughout New England and northernNew' York State.

Before her appearances at WEAF,Miss Harding had never played on theair, and in her first appearance beforeWEAF's microphone she accompanied"Silver Masked Tenor." On two occasions

she appeared as the soloist with the Rus-sian Symphony Orchestra in engagementsin Pennsylvania, and in 1923 gave her ownrecital in Aeolian Hall, New York City.To her many friends at WEAF she isknown as "Billie."

Donald Withycomb was born July 4.1896, in Montreal, Canada, and attendedhigh school and the Lower Canada Col-lege in that city. He entered the execu-tive offices of the Canadian Pacific Rail-way and later became a salesman for theInternational Equipment Company ofMontreal, in which capacity he traveledthroughout Canada.

He joined the British Royal Air Forcein 1915 and served overseas as a pilot dur-ing the World War, returning to Canadaafter the Armistice. Early in 1924, hecame to the United States to accept theposition of private secreary to Merlin H.Aylesworth, then managing director ofthe National Electric Light Association.With Mr. Aylesworth's appointment asPresident of the N. B. Co., Mr. Withy-comb became assistant secretary of thecompany.


is

NEW WAVES INEFFECT JUNE 15

Washington.Postponement until June 15 of the effec-

tive date of the new radio allocationsoriginally ordered to go into effect onJune 1, was ordered by the Federal RadioCommission so stations would have timeto adjust themselves to the new require-ments.

This was announced by the Commis-sion when it made public its GeneralOrder No. 13, continuing in force thetemporary operating permits under whichall of the 694 stations in the United Statesare now operating. Nearly all of thestations are affected by the reallocationplan whereby the Federal Radio Commis-sion granted 60 -day licenses to all appli-cant stations and prescribed new condi-tions of broadcasting.

Stations Need TimeThe postponement for two weeks of

the plan, which re -logs the whole programbroadcasting scheme, was also orderedin consideration of the fact that moretime is needed by stations to make tech-nical changes. The full text of the orderfollows:

"In consideration of the fact that acertain amount of time is required inmany cases for making the changes ofequipment required by changes of sta-tion frequency, and for securing suitablecontrol equipment to maintai frequencywithout serious variations, the FederalRadio Commission hereby amends GeneralOrder No. 11, dated May 21, 1927, to readas follows:

"'The Federal Radio Commission herebyorders that all temporary permits tooperate radio broadcasting stations underthe terms of the Radio Act of 1927, shallterminate at 3 o'clock, local standardtime, on the morning of Wednesday, June15, 1927, and that thereafter all radiobroadcasting stations subject to the pro-visions of the Radio Act of 1927, shallbe operated solely in accordance withthe provisions of the licenses issued as ofJune 1, 1927, by the Federal Radio Com-mission.'

Permits Continued"The Federal Radio Commission here-

by orders that all licenses for the periodof 60 days, issued as of June 1, 1927,shall not become effective until 3 o'clock,local standard time, on the morning ofWednesday, June 15, 1927, and shall con-tinue in effect, unless previously revokedor modified by order of the Commission.for a period of 60 days after June 15,1927."

Public hearings on disputed frequen-cies are being held continuously and allcases decided as quickly as possible, itwas stated by Commissioner Henry A.Bellows.

Less Interference,Bellows' Prediction

Washington.The new assignment of wavelengths

should result in a considerable reduction ininterference, in the opinion of Federal RadioCommissioner Henry A. Bellows.

"Of course there will continue to be someinterference," says Mr. Bellows. "The lawfortunately makes no provision for takingcare of thunderstorms and troubles insidethe set. But aside from those things, inter-ference should be greatly relieved."

Don'tchargercation.

VACATION ADVICEforget to disconnect the tricklewhen going away on your va-

Changes No Panacea,But Good, Says Bellows

Washington.Distance reception is not facilitated by

the new wavelength assignments of the Fed-eral Radio Commission, according to Com-missioner H. A. Bellows.

Proceeding on the theory that the lawdoes not authorize the Commission to re-quire anybody to get off the air, the Com-mission assigned wavelengths for approxi-mately 694 broadcasting stations.

Commissioner Bellows regards the newwavelength assignments as the very bestthat can possibly be done under the cir-cumstances. He says there will be an ade-quate separation between stations to preventtheir interfering with one another. Powerwas reduced to a point where three sta-tions can operate simultaneously in dif-ferent parts of the country without inter-fering with one another.

The Two TheoriesThe new arrangement of the Commission

is predicated on two theories. They are:(1) That the actual service area of a

broadcasting station does not exceed 200miles, and that distance hunting does notconstitute a service.

(2) That it would be unconstitutional todeprive existing stations of their licensesand therefore it is necessary to squeeze allstations into the picture.

Commissioner Bellows displayed confi-dence, but little pride, in discussing the newplan.

"There is going to be a tremendousamount of grief," said he. "It will taketime to relog sets We are asking thebroadcasting stations to ask their listenersto exercise patience in the new logging proc-ess."

Without creating a "languishing band,"the Commission has made wavelength as-signments to some stations so bad that thestations are not expected to remain longon the air. In fact Commissioner Bellowspredicted that within the next year thetotal number of stations will be reduced toaround 450.

Believe Board Has PowerBoth Senator C. C. Dill and Representative

Wallace White, co-authors of the RadioLaw, believe that the Commission has fullauthority to reduce the number of stations.

They said the wording of the law "pub-lic service, necessity or convenience" pro-vided ample authority for the Commissionto reduce stations, if such a step seemedbest in tangled condition of broadcasting.Senator Dill said that if the law were un-constitutional, it would be better for theCommission to test it out immediately sothat additional legislation might be pro-vided.

Commissioner Eugene 0. Sykes, the legalmember of the Commission, said:

"It is not the duty of the Commission topass upon the constitutionality of the law.It will assume that every part of the lawis constitutional, legal, valid and binding,and the Commission will enforce the law aswritten."

Without definitely committing themselves,the members of the Federal Radio Com-mission have indicated that they believe theonly satisfactory solution of the broadcast-ing problem is a reduction of the numberof stations.

The list of broadcasting stations, withthe new wavelengths, frequencies and power,is published in this issue. See next page.

Stations' Wave PleaTo Fans Boomerangs

Washington.Inspired propaganda by broadcasting

stations which have urged their listenersto write the Federal Radio Commissionin their behalf has had a boomerang ef-fect, according to Commissioner HenryA. Bellows, spokesman for his associates.

In the case of two middle western sta-tions, which asked their listeners to writein to the Commission beseeching a goodwavelength and plenty of power, morethan half of the letters reaching Washing-ton voiced dissatisfaction with the stationsand some of them even went as far asurging the Commission to put them offthe air altogether.

According to Commissioner Bellows, theCommission 'accepts such propaganda asevidence that the station is afraid it cannot stand on its own merit.

The stations about which there has beenthe least fan mail, Mr. Bellows says, arethose which are rendering the highestgrade of service.

He made a personal tally.

Flying Field AerialMasts Emblazoned

WASHINGTON.Increased safety in flying in the United

States is the aim of a standard programfor marking and lighting obstructions toair navigation just approved by the De-partment of Commerce, the Army AirCorps and the Bureau of Aeronautics,Navy Department.

According to provisions of the approvedreport, all obstruction towers, such asradio masts, transmission poles, flag poles,etc., in the vicinity of airports, interme-diate landing fields or civil airways, mustbe painted to insure maximum visibilityfrom the air. The method followed willbe to use alternate bands of white andchrome yellow, separated by black bandsrunning horizontally about the obstruc-tions.

At night the obstructions will be markedat the top with flashing red lights. Thesewill be lit from sunset to sunrise. Addi-tion fixed red light will be used on radiotowers, one-third and two-thirds of theheight from the ground.

Compass Station Quits, Due to Shore ErosionThe radio compass station maintained by

the Department of the Navy at Hog Island,Va., a little above the entrance of the Chesa-peake Bay, was abandoned, due to erosionof the shore line and consequent danger topersonnel and material, the Department an-nounced.

Immediate replacement of this station isnot contemplated, and in the interim theChesapeake Bay entrance group, which ad-vises both vessels and airplanes as to theirhearings, will comprise only the stations at

Virginia Beach and Poyners Hill.For the time being, therefore the Chesa-

peake Bay Entrance Group will only fur-nish two bearings; viz., Virginia Beach andPoyners Hill. If a third bearing is re-quired it can be obtained by calling theCape Henlopen Group. In addition, shipscarrying a radio compass can take a bear-ing on the Cape Henry radio beacon. Aradio beacon will be established on CapeCharles Light Vessel within a few weeks,it was announced.


$17,500 for New VoicesOffered by Atwater Kent

Philadelphia.Very extensive plans for a "National

Radio Audition" for young men and wo-men for the purpose of finding by test thebest undiscovered voices in the UnitedStates were announced by the AtwaterKent Foundation, an institution estab-lished for scientific and educational pur-poses.

Every community in the United Stateswill he given an opportunity, first to se-lect by popular vote the best voices,ofyoung women and young men; and thento enter these singers in a test of state,sectional and national auditions to bebroacast.

Awards aggregating $17,500, with oneand two years' tuition in an Americanconservatory for certain winners, will beoffered as an incentive to young peopleto enter the tests, which will be heldin each of the forty-eight states.

Kent's StatementA. Atwater Kent, president of the Foun-

dation, said:"The discovery of one of these rare

voices, of which each generation producesa very few, seems to me an event of pro-found national importance. Even whensuch a voice could give pleasure to onlya few thousand people in a year it was anational treasure. Now that millions mayenjoy it on the same evening through themedium of radio, such a voice has becomepriceless.

"The National Radio Audition, sup-ported by the Atwater Kent Foundation,is an undertaking to search the entirecountry for beautiful voices and to offerthese singers an opportunity for fulldevelopment, recognition and reward.

"In Europe, when a singer of promiseappears, the entire family will gladlymake any necessary sacrifice to providemeans for a proper cultivation of thatvoice and the support of the singer untilfame is achieved. It is in this spirit thatwe hope each community in the countrywill receive this Audition idea and devotewhatever effort is required to discover andpresent its candidates for state and na-tional honors."

Opportunity for YouthThe primary purpose of the Audition

is to provide opportunity for recognitionto every young man or woman in everycommunity, no matter how isolated, andto give to the world of music throughradio the best voices thus discovered.

After a series of state and district au-ditions, five young men and five youngwomen will be brought to New York fora final audition, which will be broadcastover a nation-wide network of stations.

In the finals-the National Audition-five awards for merit will be given towomen and five to men. The two whoget first place in the National Audition-a man and a woman-will each receivea gold decoration, $5,000 in cash and twoyears' tuition in a leading conservatory.

Winners of second awards will eachreceive $2,000 in cash and one year'stuition.

Winners of third awards will each re-ceive $1,000 and one year's tuition.

Winners of fourth awards will each re-ceive $500.

Winners of fifth awards will each re-ceive $250.

Musical, civic and women's clubs in eachcommunity in each state will be invited

to hold local tests to select the bestyoung man and best young woman singerof their towns. These winners will thenbe certified to a state audition, which willbe broadcast by a radio station in eachstate. A state winner of each sex willbe chosen and will receive a silver medal.

The next step is a district audition.The young men and women who havewon state honors will be taken to a cen-tral broadcasting station in one of fivedistricts, where an audition will be broad-cast to select the two winners-a youngman and a young woman-from that dis-trict.

The two winners in each district willreceive gold medals and the ten finaliststhus selected will be brought to NewYork for the final National Audition.

Each national winner will also be wellstarted on the road to fame as a radioconcert artist, with a successful musicalcareer ahead. All expenses of contest-ants the district and final auditions,including railroad fare, hotel bills, enter-tainments, etc., will be paid by the At-water Kent Foundation.

Judging of contestants will be by voteof radio listeners and juries made up ofthe musical authorities of each commun-ity, state or district. Listeners -in willparticipate in the state and district audi-tions, their votes counting sixty per centand the vote of the jury forty per cent.For the final National Audition in NewYork, a jury of great figures in the musi-cal world- is being created. Its decisionswill be made without participation by theradio public and will be announced imme-diately after the broadcasting of thefinals.

Qualifications for TestsThe principal qualifications for con-

testants are as follows :They must not be more than twenty-

five years old; must never have beenassociated with a professional theatricalor operatic company; must never havebeen a paid principal in any concert heldoutside their own states; must declarean intention to follow a musical careerand must be free from theatrical or musi-cal contracts.

This limitation permits choir singers toenter the auditions, even though theymay have received financial compensationfor singing in churches. It is expectedthat many of the contestants will be theleading young choir singers of their com-munities. Other groups from which en-tries are anticipated are students in mu-sical schools and locally prominent singersin high schools and colleges. Musicalorganizations in each state are also af-forded an opportunity to put forwardtheir best talent and to assist in holdinglocal auditions.

Preliminary organization for holdingthe auditions will start soon under thedirection of the Atwater Kent Founda-tion. It is expected that the first stateauditions will get under way early thisFall, followed by the district auditionsin November, with the finals in New Yorkearly in December.

CROSLEY CONVENTION HELDThe annual convention of the Crosley

Radio Corporation's distributors was heldin Cincinnati June 8 and 9. Announce-ments of new developments in the Cros-ley line were made and plans for thecoming year will he discussed.

SIGNALLY HONORED

LORETTA LEE, first vocal graduatefrom the Peabody Conservatory of Musicsince Mabel Garrison, who obtained herdiploma in 1911. Miss Lee was the thirdone to receive the diploma in the Con..,servatory's existence of 57 years. She recently gave a song recital from WBAL

Baltimore.

VARIATION OF C BIASIf in doubt as to the proper ohmag-

fixed resistance to be used for providiniC bias from a B eliminator, a variabl,resistance of about 2,000 ohms maximunresistance, with a carrying capacity ofwatts may be substituted.

Misleading I

Over AirWashington.

Federal punishment for stations whiclmisrepresent articles over the radioplanned in a bill that probably will be in-troduced during the next session of Con,'gress by Senator C. C. Dill or Representative Wallace White.

Numerous complaints have reached theFederal Radio Commission against station:which through direct advertising over thtair have offered articles for sale and whichaccording to the complainants, have not entirely lived up to the promises. The com-plaints have been most vigorous about a.few stations in the Middle West.

According to one letter received by tht.Radio Commission, a station broadcasted arannouncement about radio tubes. The an-nouncement was that a special price had beenfixed for the tubes and anyone who sent inthe money for the tubes was guaranteedsatisfaction or else the money would berefunded.

He Buys the TubesA listener -in in another state heard the

announcement and sent in the money forfour tubes. In the letter containing the,money was a description of the kind oftubes desired. In about two weeks tubeswere forthcoming, but they were not of thekind ordered nor were they suitable foruse.

The tubes were returned to the stationwith a request that the proper kind oftubes be sent or the money refunded. Upto the time of writing to the Commission,the listener had received neither the moneynor the tubes.


) SET MADE OF MATCHES

PAUL R. WOTTON, of Friendship,Maine, made this model of the RadiolaNo. 20 entirely from matches. It tookMr. Wotton's spare time for four months.More than 2,200 matches were used. Thedrum dial and volume control knobs turnand the switch pulls and pushes, as on theRadiola. The loop also was made ofmatches, but wound with thread to givethe appearance of metal. No nails or pinswere used. Every match was glued. Theset is perfectly proportioned to the

original.

dvertising!O Under Fire

There is said to be no Federal statute bywhich action could be taken against thestation.

It is not believed that the station was at-tempting to defraud. The opinion is that arush of orders was responsible for thedelay.

The Legal ViewCommissioner Eugene 0. Sykes, the legal

3;" member of the Federal Radio Commis -r mon, believes that a law extending the Postal' Act to cover attempts to defraud over the

radio would be a very good thing."The Federal Radio Commission has not

the authority to exercise censorship pro-grams," says he. "It therefore follows thatwe cannot attempt to say what a stationshall or shall not broadcast, whether it isdirect or indirect advertising or somethingelse.

"It is up to the listeners entirely and ifthey think the station is rendering a publicservice, it is up to us to keep our handsoff.

"Of course, if conclusive evidence of in-tent to defraud by any station were pre-sented to the Federal Radio Commission,an effort would be made to deprive thestation of its license. But it does seem thata law covering the subject might help toclarify matters."

BANQUET BOARD TO MEETThe organization meeting of the corn-

mittee for the Fourth Annual Radio In-dustries Banquet wil be held at theStevens Hotel on Wednesday, June 15.

Highest Type ProgramsPredicted for Daytime

Hot Springs, Va.The inauguration of a daytime broad-

casting schedule on a nationwide scale,comparable to the best features nowtransmitted between 8 P. M. and mid-night, was forecast in an addreses byGeorge F. McClelland, vice-president andgeneral manager of the National Broad-casting Company, at the annual meetingof the National Electrical ManufacturersAssociation here. Probably 10,000,000listeners would be added to the radioaudience of the United States if a six-teen -hour day broadcasting service wereregularly established, he said. Mr. Mc-Clelland added:

"There is a good reason, of course,why radio should have settled first at theAmerican fireside. It was brought intothe home by the boy and finally em-braced by the man of the house. Then,too, the predominantly entertainmentfeatures of radio made it natural thatthe best program features be concen-trated during the hours when the familyusually seeks entertainment.

Too Big for Small Clothes'But broadcasting has outgrown the

narrow limits of its early experimentaldays. It has a greater destiny to fulfillthan mere entertainment. Is mission to,the home is to carry to it every form (4cultural influence and service which thissystem of mass communication is pre-eminently equipped to do.

"Broadcasting, theoretically at least,already covers the outermost limits ofspace. But it has still far to go in timebefore we may be said to have estab-lished the best possible broadcasting serv-ice commensurate with the requirementsof a population of 117,000,000 people.

"Of the more than 30,000,000 womenin this country over 21 years of age, lessthan 9,000,000 are employed in duties out-side of the home. Radio broadcastinghas made a start, it is true, in bringinga daytime service of information andentertainment to the home. Yet muchremains to be done in order to providean adequate daytime program for 21,-000,000 women in the United .States, mostof whom are anxious and eager to re-ceive the musical, educational and in-formative features which radio can bring.

The School Children Audience"There are 25,000,000 school children in

the United States, the vast majority ofwhom are still awaiting an organizedplan of service that will bring radio tothe classroom, as an established factor inmusical education. The decision reachedby Walter Damrosch, the distinguisheddean of musical education in this country,to broadcast a series of educational con-certs to the schools, is a very great stepin the right direction.

"It may seem an anachronism in thisday of super -radio programs when thegreatest stars of the opera and the con-cert stage, when the most distinguishedfigures in educational and public life, havebeen featured on the air, that hundredsof thousands of people whose homes areequipped with radio sets have never hadthe opportunity to hear an outstandingradio program. For we must rememberthat in many professions and manytrades there are millions who labor whilemost of us sleep. Daytime broadcastingof a primary character would prove agreat boon to this element of our popu-lation.

"The last but not the least factor thatwould call for the extension of daytimeradio programs is the need of the greatbuying public when it is in the marketfor radio sets. It is the unique positionof radio that it is an industry builtaround a broadcasting service. It canbe demonstrated only in connection withthat service. The best possible receptionof the poorest possible program is aninadequate recommendation for any set.A high class broadcasting program, there-fore, transmitted during the day hours,would be of inestimable value to the radioindustry. z z zz

"It is plain that any program whichadvances the radio manufacturing indus-try advances the interests of broadcastingand therefore the interests of the public."

Mr. McClelland in his address alsodetailed the great technical progress madeby engineers of the National Broadcast-ing Company in broadcast transmission.

Technical Achievements"A new science of electro-acoustics has

been created for broadcasting," he said."Remarkable progress has been made inthe technique of handling sound in theair.

"Microphone technique has been im-proved to the extent that not only themiddle register but the high notes ofmusic or the speaking voice can now behandled by the microphone.

"Modulation systems have been workedout by which distortion in radio trans-mission practically has been eliminated.

"Sound control systems have been de-veloped by which an invisible radio con-ductor mixes and controls the outputof the microphone, so that a concertmight be transmitted in perfect form bythe broadcasting station."

The greatest contributions thus far tothe development of broadcasting in theUnited States, Mr. McClelland declared,have been .made by the communication,the electrical and radio manufacturingindustries of the country.

WLW Short WavesHeard World Over

Short wave broadcasts from WLW, Cin-cinnati, are being heard consistently incountries throughout the world. Threereports from three different individualsin London were received in a single dayand other reports have come in from Mex-ico, Trinidad, the Canal Zone and severalother foreign points.

The short wave transmitter, 52 meters,uses only 500 watts as compared with the5,000 watt power of the long wave Cros-ley station. The short wave transmis-sion, however, far outdistances the other.

WLW will put on a special program forAustralian listeners at 3 A. M. (E. D.S. T.) Sunday morning, June 29 (8:00P. M., Monday, in Australia).

AMERICA'S LEADERSHIPScientists of every nation are looking to

the United States in radio development,and the majority of the new wondersin tubes and devices for transmission andreception, to be shown at the next RadioWorld's Fair, in New Madison SquareGarden, New York City, will be theproduct of American inventive genius andresearch.

14 RADIO WORLD June 11, 1927A THOUGHT FOR THE WEEK

JUST as millions of people a few yearsago declared there wasn't anything prac-

tical in radio, and then were shown to besilly unbelievers, so does that flying eagleof the West, Charlie Lindbergh, come alongand prove to a breathless but doubtfulworld that Paris is only across the way tothose who know how to make it; and thatsaute world is still divided as to whetherintrepidity or modesty is the flyer's middlename.

The First and Only Nation 1 Radio Weekly

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"Ask Me Another" StuntIs Worked by WLW

"Now we'll ask one," is the answer ofWLW, the Crosley station at Cincinnati,for the current "Ask Me Another" craze.

Every night at 8 o'clock, Eastern Stand-ard Time, the announcer will ask five ques-tions, and every night he will give the an-swers to the questions of the night before.

The queries will be taken from all ofthe fields of knowledge entering into a lib-eral education-music, art, literature, his-tory, politics and current events. The mu-sical questions will be answered musicallyas well as verbally. For example, "Whatfamous composition did Schubert write in abeer garden?" The following night the an-nouncer gives the answer.

WJAZ Primes Its Gunsainst Law's Validity

Washington.Notice that the Zenith Radio Corpora-

tion of Chicago, owners of WJAZ, isprepared lout has too present intention,to enter the courts to dispute the con-stitutionality of the Radio Act of 1927,was given to the Federal Radio Com-mission by Irvin Herriott, attorney forthe station, preliminary to the formalopening of a public hearing before theCommission so the station could enter aprotest to the wavelength assignment ofthe station.

Mr. Herriott asserted that the ZenithRadio Corporation does not at presentintend or expect to test the authority ofthe Commission, but that he was enter-ing possible contentions "solely for thepurpose of preserving the record." Itwas his belief that WJAZ could prove itspublic service value fully enough to thesatisfaction of the Commission so that itwould be assigned a frequency otherthan the one allocated it, effective June15, namely 1,140 kilocycles (263 meters).

Prepared to DisputeHowever, Mr. Herriott continued. the

Zenith Radio Corporation proposes tobe the first organization on record asprepared to dispute the constitutionalityof the radio law passed by Congress lastFebruary.

If suit should be entered in the propercourt of jurisdiction, the Federal districtcourts, it will be on the followinggrounds, he said:

1. The Act permits of deprivation ofproperty without due process of law.

2. The regulatory power of Congressdoes not extend to a subject of thischaracter.

3. Orders of the Federal Radio Com-mission "undoubtedly" amount to con-

scation.Prefers 389.4 Meters

Representatives of the Zenith RadioCorporation, however, disavowed anydefinite intention of going to the courts.Required under the Commission's pro-cedure to name the frequency to whichthey feel they are better entitled, theyroamed 770 kilocycles (389.4 meters).

E. F. McDonald, Jr., president of theZenith Radio Corporation, asserted onthe witness stand that the station waswilling to accept a frequency assignment

anywhere in tloe wave band between 300and 425 meters.

Mr. McDonald testified that Commis-sioner Bellows specifically promised himthat Station WJAZ would be assigned awavelength between 300 and 400 meterswhen tlie 60 -day license's were issued,to become effective June 15.

Cites Broken PromiseRelying upon this promise, the Zenith

Radio Corporation was surprised andconcerned, he said, when the 263 -meterallocation for Station WJAZ was madeknown.

Mr. McDonald said that the 263 -meterwavelength was not suitable for StationWJAZ's range of service, and that broad-casting upon it would largely disrupt itsvalue to its listeners. Station WJAZcannot be heard on 263 meters by thetype of receiving apparatus that wasmanufactured up to about the first ofthis year, he said, and under the Com-mission's plan of frequency separationwill not be heard suitably.

President McDonald said it was hisopinion that the majority of receivingsets now in use cannot catch programstransmitted on waves below 250 meters.He regarded the continued operation ofWJAZ as "essential and necessary" tocarry on the Zenith Radio Corporation'sbusiness, which is primarily the manu-facture and sale of radio apparatus.

Zenith Was the "Starter"It was when the Zenith Radio Cor-

poration won its suits in the Federal dis-trict court against the authority of theDepartment of Commerce to control andregulate radio, that Secretary Hooversought an opinion from the AttorneyGeneral regarding this authority. Theopinion, rendered last July, stated thatthe Department of Commerce had noauthority over radio under sloe Communi-cation Law of 1912.

'thereupon Federal control of broad-casting broke down. There was no regu-lation until February, 1927, when Con-gress enacted the la,.v creating the Fed-eral Radio Commission and defining itsfunctions and powers.

Under the "public service" clause ofthis act, the Commission has reallocatedconditions of broadcasting within theprogram band. Station WJAZ is one ofthese required to shift its frequency.

Mathilde Harding Weds Radio OfficialMathilde Harding, hostess -accompanist

at WEAF, was married recently toDonald Withycomb. The romance beganat the formation of the National Broad-casting Company in November, 1926. Mr.Withycomb, is assistant secretary of theN. B. Co.

Miss Harding was born in Washington,Pa. She early planned a musical careerand after her graduation from the Wash-ington Seminary came to New York to,tudy the piano.

Last season Miss Harding served asaccompanist for Ethel Hayden, who willbe remembered by WEAF's audience asthe soloist during the "Atwater KentRadio Hour," when the Oratorio Societyof New York was heard. In her tourwith Miss Hayden she went as far Westas St. Louis and toured extensivelythroughout New England and northernNew York State.

Before her appearances at WEAF,Miss Harding had never played on theair, and in her first appearance beforeWEAF's microphone she accompanied"Silver Masked Tenor." On two occasions

sloe appeared as the soloist with the Rus-sian Symphony Orchestra in engagementsin Pennsylvania, and in 1923 gave her ownrecital in Aeolian Hall, New York City.To her many friends at WEAF she isknown as "Billie."

Donald Withycomb was born July 4,1896, in Montreal, Canada, and attendedhigh school and the Lower Canada Col-lege in that city. He entered the execu-tive offices of the Canadian Pacific Rail-way and later became a salesman for theInternational Equipment Company ofMontreal, in which capacity lie traveledthroughout Canada.

He joined the British Royal Air Forceits 1915 and served overseas as a pilot dur-ing the World War, returning to Canadaafter the Armistice. Early in 1924, hecame to the United States to accept theposition of private secreary to Merlin H.Aylesworth, then managing director ofthe National Electric Light Association.With Mr. Aylesworth's appointment asPresident of the N. B. Co., Mr. Withy-comb became assistant secretary of thecompany.


NEW WAVES IN Changes No Panacea,EFFECT JUNE 15 But Good, Says Bellows

Washington.Postponement until June 15 of the effec-

tive date of the new radio allocationsoriginally ordered to go into effect onJune 1, was ordered by the Federal RadioCommission so stations would have timeto adjust themselves to the new require-ments.

This was announced by the Commis-sion when it made public its GeneralOrder No. 13, continuing in force thetemporary operating permits under whichall of the 694 stations in the United Statesare now operating. Nearly all of thestations arc affected by the reallocationplan whereby the Federal Radio Commis-sion granted 60 -day licenses to all appli-cant stations and prescribed new condi-tions of broadcasting.

Stations Need TimeThe postponement for two weeks of

the plan, which re -logs the whole programbroadcasting scheme, was also orderedin consideration of the fact that moretime is needed by stations to make tech-nical changes. The full text of the orderfollows:

"In consideration of the fact that acertain amount of time is required inmany cases for making the changes ofequipment required by changes of sta-tion frequency, and for securing suitablecontrol equipment to maintain frequency

ithout serious variations, the FederalRadio Commission hereby amends GeneralOrder No. 11, dated May 21, 1927, to readas follows:

" 'The Federal Radio Commission herebyorders that all temporary permits tooperate radio broadcasting stations underthe terms of the Radio Act of 1927, shallterminate at 3 o'clock, local standardtime, on the morning of Wednesday, June15, 1927, and that thereafter all radiobroadcasting stations subject to the pro-visions of the Radio Act of 1927, shallbe operated solely in accordance withthe provisions of the licenses issued as ofJune 1, 1927, by the Federal Radio Com-mission.'

Permits Continued"The Federal Radio Commission here-

by orders that all licenses for the periodof 60 days, issued as of June 1, 1927,shall not become effective until 3 o'clock,local standard time, on the morning ofWednesday, June 15, 1927, and shall con-tinue in effect, unless previously revokedor modified by order of the Commission,for a period of 60 days after June 15,1927."

Public hearings on disputed frequen-cies arc being held continuously and allcases decided as quickly as possible, itInas stated by Commissioner Henry'A.Bellows.

- _Less Interference,

Bellows' PredictionWashington.

The new assignment of wavelengthsshould result in a considerable reduction ininterference, in the opinion of Federal RadioCommissioner Henry A. Bellows.

"Of course there will continue to be someinterference," says Mr. Bellows. "The lawfortunately makes no provision for takingcare of thunderstorms and troubles insidethe set. But aside from those things, inter-ference should be greatly relieved."

VACATION ADVICEDon't forget to disconnect the trickle

charger when going away on your va-cation.

Washington.Distance reception is not facilitated by

the new wavelength assignments of the Fed-eral Radio Commission, according to Com-missioner H. A. Bellows.

Proceeding on the theory that the lawdoes not authorize the Commission to re-quire anybody to get off the air, the Com-mission assigned wavelengths for approxi-mately 694 broadcasting stations.

Commissioner Bellows regards the newwavelength assignments as the very bestthat can possibly be done under the cir-cumstances. He says there will be an ade-quate separation between stations to preventtheir interfering with one another. Powerwas reduced to a point where three sta-tions can operate simultaneously in dif-ferent parts of the country without inter-fering with one another.

The Two TheoriesThe new arrangement of the Commission

is predicated on two theories. They are:(1) That the actual service area of a

broadcasting station does not exceed 200miles, and that distance hunting does notconstitute a service.

(2) That it would be unconstitutional todeprive existing stations of their licensesand therefore it is necessary to squeeze allstations into the picture.

Commissioner Bellows displayed confi-dence, but little pride, in discussing the newplan.

"There is going to be a tremendousamount of grief," said he. "It will taketime to relog sets. We are asking thebroadcasting stations to ask their listenersto exercise patience in the new logging proc-ess."

Without creating a "languishing band,"the Commission has made wavelength as-signments to some stations so bad that thestations are not expected to remain longon the air. In fact Commissioner Bellowspredicted that within the next year thetotal number of stations will be reduced toaround 450.

Believe Board Has PowerBoth Senator C. C. Dill and Representative

Wallace White, co-authors of the RadioLaw, believe that the Commission has fullauthority to reduce the number of stations.

They said the wording of the law "pub-lic service, necessity or convenience" pro-vided ample authority for the Commissionto reduce stations, if such a step seemedbest in tangled condition of broadcasting.Senator Dill said that if the law were un-constitutional, it would be better for theCommission to test it out immediately sothat additional legislation might be pro-vided.

Commissioner Eugene 0. Sykes, the legalmember of the Commission, said :

"It is not the duty of the Commission topass upon the constitutionality of the law.It will assume that every part of the lawis constitutional, legal, valid and binding,and the Commission will enforce the law aswritten."

Without definitely committing themselves,the members of the Federal Radio Com-mission have indicated that they believe theonly satisfactory solution of the broadcast-ing problem is a reduction of the numberof stations.

The list of broadcasting stations, withthe new wavelengths, frequencies and power,is Published in this issue. See next page.

Stations' Wave PleaTo Fans Boomerangs

Washington.Inspired propaganda by broadcasting

stations which have urged their listenersto write the Federal Radio Commissionin their behalf has had a boomerang ef-fect, according to Commissioner HenryA. Bellows, spokesman for his associates.

In the case of two middle western sta-tions, which asked their listeners to writein to the Commission beseeching a goodwavelength and plenty of power, morethan half of the letters reaching Washing-ton voiced dissatisfaction with the stationsand some of them even went as far asurging the Commission to put them offthe air altogether.

According to Commissioner Bellows, theCommission accepts such propaganda asevidence that the station is afraid it cannot stand on its own merit.

The stations about which there has beenthe least fan mail, Mr. Bellows says, arethose which are rendering the highestgrade of service.

He made a personal tally.

Flying Field AerialMasts Emblazoned

WASHINGTON.Increased safety in flying in the United

States is the aim of a standard programfor marking and lighting obstructions toair navigation just approved by the De-partment of Commerce, the Army AirCorps and the Bureau of Aeronautics,Navy Department.

According to provisions of the approvedreport, all obstruction towers, such asradio masts, transmission poles, flag poles,etc., in the vicinity of airports, interme-diate landing fields or civil airways, mustbe painted to insure maximum visibilityfrom the air. The method followed willbe to use alternate bands of white andchrome yellow, separated by black bandsrunning horizontally about the obstruc-tions.

At night the obstructions will be markedat the top with flashing red lights. Thesewill be lit from sunset to sunrise. Addi-tion fixed red light will be used on radiotowers, one-third and two-thirds of theheight from the ground.

Compass Station Quits, Due to Shore ErosionThe radio compass station maintained by

the Department of the Navy at Hog Island,Va., a little above the entrance of the Chesa-peake Bay, was abandoned, due to erosionof the shore line and consequent danger topersonnel and material, the Department an-nounced.

Immediate replacement of this station isnot contemplated, and in the interim theChesapeake Bay entrance group, which ad-vises both vessels and airplanes as to theirbearings, will comprise only the stations at

Virginia Beach and Poyners Hill.For the time being, therefore the Chesa-

peake Bay Entrance Group will only fur-nish two bearings; viz., Virginia Beach andPoyners Hill. If a third bearing is re-quired it can be obtained by calling theCape Henlopen Group. In addition, shipscarrying a radio compass can take a bear-ing on the Cape Henry radio beacon. Aradio beacon will be established on CapeCharles Light Vessel within a few weeks,it was announced.


LIST OF STATIONSWith new wavelengths, frequencies and

power, effective June 15. Time sharers inparenthises.

StationWAAD-Cincinnati, 0WAAF-Chicago, Ill. (WBBM,

WJBT) 770 389.4WAAM-Newark, N. J, (WGBS) 860 348.6WAAT-Jersey City, N. J ,WGBB),

WSOM) 1200 245.8WAAW-Omaha, Nebr. (Before 7 p

m. only) 800 374.8WABC-Richmond Hill, N. Y

(WI3OQ) 920 325.9WABF-Pringleboro, Pa. 1460 205.4WABI-Bangor, Me. (WGBX) 770 389.4WABO-Rochester, N. Y. (WHEC) 1290 232.4WABQ-Philadelphia, Pa. 1410 212.6WABR-Toledo, 0. (WTAL) 1070 280.2WABW-Woester, 0. 1210 247.8WABY-Philadelphia, Pa. 1210 247.8WABZ-New Orleans, La. 1210 247.8WADC-Akron, 0. 1250 239.9WAFD-Detroit, Mich. (WTHO) 1370 218.8WAGM-Royal Oak, Mich 1330 225.4WAGS -Somerville, Mass. .. ....... 1390 215.7WAIT -Taunton, Mass 1400 214.2WAIU-Columbus, 0. (WEAO) 1060 282.8WALK-Bethayres, Pa. Portable) 1490 201.6WAMD-Minneapolis, Minn. 1330 225.4WAPI-Auburn, Ala.; daytime only 610 491.5WARS -Brooklyn, N. Y. (WSDA,

WBBC) 1320 227.1WASH -Grand Rapids, Mich . 1170 256.3WASN-Boston, Mass. (daytime only;

WSSH) 1300 230.6WATT -Boston, Mass. 1490 ....WBAA-West Lafayette, Ind (WRA1) 1100 272.6WBAK-Harrisburgh, Pa. (WPSC) 1000 299.8WBAL-Baltimore, Md. 1050 285.5WBAO-Decatur, Ill 1120WBAP-Fort Worth, Tex. (WFFA) 600 499.7WBAW-Nashville, Tenn. 1210 247.8WBAX-Wilkes Barre, Pa. (WBRE). 1200 249.9WBBC-Brooklyn, N. Y. (WARS,

WSDA) 1320 227.7WBBL-Richmond, Va. 1210 247.8WBBM-Chicago, Ill. (WJBT, WAAF) 770 422.3WBBP-Petoskey, Mich. 1250 239.9WBBR-Rossv ille, N. Y. WGL) 1170 256.3WBBW-Norfolk, Va. 1270 236.1WBBY-Charleston. S. C 600 499.7WBBZ-Chicago, Ill. (Portable) 1470 204.0WBCN-Chicago, Ill. (WENR) 1040 283.3WBES-Takoma Park, Old 1010 296.9WBET-Boston, Mass. 1240 241.8WBKN-Brooklyn, N. Y. (WWRL,

WIBI, WBMS) 1120 267.7WBMH-Detroit, Mich. (WMBC) 1420 211.1WBMS-Union City, N. J. (WBKN,

WWRL, WIBI) 1120 267.7WBNY-New York, N. Y. (WKBQ,

WFRL, WKBO) 1,370 218.8WBOQ-Richmond Hill, N. Y. (WABC) 920 325.9WBRC-Birmingham, Ala. 1230 2,43.8WERE -Wilkes Barre, Pa. (WBAX) 1200 249.9WBRL-Tilton, N. H 1290 232.4WERS-Brooklyn, N. Y. WCDA,

WCGU, WRST) 1420 211.1WBSO-Wellesley Hills, Mass

(WDWF) 780 384.4WBT-Charlotte, N. C 1160 258.5WSMK-Dayton, Ohio 1010 296.9WBZ-Springfield, Mass. 900 333.1WBZA-Boston, Mass 900 333.1WCAC-Mansfield, Conn. (WDRC) 1090 275.1WCAD-Canton, N. Y 820 365.6WCAE-Pittsburgh, Pa. 580 516.9WC,AH-Columbus, Ohio 560 535.4WCAJ--Lincoln, Nehr. 860 348.6WCAL-Northfield, Minn. (KFMX) 1270 236.1WCAM-Camden, N. J. 1340 223.7WCAO-Baltimore, Md. (WCBM) 780 384.4WCAT-Rapid City, S. D 1210 247.8WCAU-Philadelphia, Pa. 1150 260.7WCAX-Burlington, Vermont 1180 254.1WCAZ-Carthage, III. 880 340.7WCBA-Allentown, Pa. (WSAN) 1350 222.1WCBD-Zion, 'Illinois (WLS) 870 344.6WCBE-New Orleans, La 1320 227.1WCBH-Oxford, Miss 1240 241,8WCBM-Baltimore, Md. (WCAO) 780 384.4WCBR-Providence, R. I. (Portable) 1490 201.6WCBS-Springfield, III. 1430 209.7WCCO-Minneapolis, Minn. 740 405.2WCDA-Brooklyn, N. Y. (WRST,

WBRS, WCGU) 1420 211.1WCFL-Chicago, Ill, WLTS) 620 493.6WCGU-Coney Island. N. Y. (WCDA,

WBRS, WRST) 1420 211.1WCLO-Camp Lake, Wisc 1320 227.1WCLS-Joliet, Ill. (WKBB) 1390 215.7WCMA-Culver, Ind. 1160 258.5WCOA-Pensacola, Fla. 1200 249.9WCOC-Columbus, Miss. 1300 230.6WCOM-Manchester, N. H 1260 238.0WCOT-Olneyville, R. I 1330 225.4WCRD-Chicago, Ill. (WFKB &

WPCC) 1340 223,7WCSH-Portland, Me 830 361.2WCSO-Springfield, Ohio 1170 206.3WCWK-Fort Wayne, Ind. (WOWO 1319 228.9WCWS-Bridgeport, Conn. (Portable) 1490 201.6WDAD-Nashville. Tenn. 1330 225.4WDAE-Tampa, Fla. 1120 267.7WDAF-Kansas City, Mo 810 370.2WDAG-Amarillo, Texas 1140 263.0WDAH-E1 Paso, Texas 1280 234.2WDAY-Fargo. N. Dak 830 361.2WDB,T-Roanoke, Va. 1300 230.6WDBK-Cleveland.. Ohio 1320 227.1WDRO-Winter Park Fla 1200 239.9WDBZ-K ngston, N. V. (WOKO) 1390 210.7WDELWilmington, Del. 1130 265.3WDGY-Minneapolis, Minn. (WRHM) 1150 260.7

Station Kc M WattsWDOD-Chattanooga, Tenn 1180 254.1 500WDRC-New Haven, Conn. WCAC) 1090 275.1 250WDWF-Cranston, R. I. (WBSO) 780 384.4 500WLSI-WDWM-Newark, N. J. (WHAP,

WMSG) 1270 236.1 500WDZ-Tuscola, Ill. (Daytime only) 1080 277.6 100WEAF-New York, N. Y 610 491.5 5000WEAI-Ithaca, N. Y. (WOAX) 620 483.6 250WEAM-North Plainfield, N. J 1250 239.9 250WEAN -Providence, R. I. (WNAC) 1130 265.3 500WEAO-Columbus, 0. (WAIU) 1060 282.8 750WEAR -Cleveland, O. (WTAM) 750 399.8 1000WEBC-Superior, Wisc. 1240 241.8 250

500 WEBE-Cambridge, Ohio 1210 247.8 10WEBH-Chicago, Ill. (WJJD) 820 365.6 2000

2500 WEBJ-New. York, N. Y. ,WMCA) 810 370.2 500250 WEBQ-Harrisburg, Ill. 1340 223.7 15100 WEBR-Buffalo N. Y 1240 241.8 200500 WEBW-Beloit, Wisc. 1160 258.5 500500 WEDC.-Chicago, Ill. WGES) 1240 241.8 50050 WEEI-Boston, Mass. 670 447.5 50050 WEHS-Evanston, III. 1390 215.7 100

WEMC-Berrien Springs, Mich 1260 238.0 1000WENR-Chicago, Ill. (WBCN) 1040 283.3 500WEPS-Gloucester, Mass. 1010 296.9 100WEW-St. Louis, Alo 850 352.7 1000WFAA-Dallas, Texas (WBAP) 600 475.9 500WFAM-St. Cloud, Minn 1190 252 10WFBC-Knoxville, Tenn. 1280 234.2 50

5000 WFBE-Cincinnati, Ohio 1220 245.8 25050 WFBG-Altoona, Pa. 1070 280.2 100

1100 272.6 1001160 282.8 7501330 225.4 2501330 225.4 1001210 247.8 50940 319.0 50860 348.6 100820 365.6 500740 405.2 500

245.8 500

Kc M Watts1120 267.7 25

500500

300

(51))

100025050

30

500 WFBJ-Collegeville, Minn.1000 WFBL-Syracuse, N. Y

WFBM-Indianapolis, Ind500 WFBR-Baltimore, Md,250 WFBZ-Galesburg, (WRAM).

WFCI-Pawtucket, R. I100 WFDF-Flint, Mich.100 WFHH-Clearwater, Fla.500 WFI-Philadelphia., Pa. (WLIT)500 WFIW-Hopkinsville, Ky. 1220

3000 WFKB-Chicago, Ill. (WCRW &100 WPCC) 1340

1500 WFKD-Philadelphia, Pa. 1460100 WFLA-Boca Raton, Fla 1410100 WFRL-Brooklyn, N. Y. (WKBQ,

WKBO, WBNY) 1370 218.8500 WGAL-Lancaster, Pa. (WKJC) 1190 252.0100 WGBG-Freeport, N. Y. (WAAT,

1000 WSOM)1221080100 WGBC-Memphis, Tenn.

1000 WGBF-Evansville, Ind. 127050 WGBI-Scranton, Pa. WQAN) 130075 WGBS-Astoria, L. I., N. Y. (WAAM) 860

100 WGBX-Orono, Me. (WABI) 770250 WGCP-Newark, N. J. (WNJ) 1070100 WGES-Chicago, Ill. (WEDC) 1240500 WGHP-Mt. Clemens, Mich 1230

WGL-New York, N. Y. (1,000 watts100 7 a.m. to 1 p.m.; WBBR) 1170100 WGM-Jeannette, Pa. 1440

WGMU-New York, N. Y., Portable100 (WRMU) 1490 201.6 100

WGN-Chicago, Ill. WLIB) 980 305.9 15000500 WGR-Buffalo, N. Y. 990 302.8 750500 WGST-Atlanta Ga. (WMAZ 1110 270.1 500250 WGWB-Milwaukee, Wisc. 1370100 WGY-Schenectady, N. Y. (WHAZ) 790800 WHA-Ma rb son, Wisc. (WLBL) 940

WHAD-Milwaukee, Wis. (WTMJ). 1020100 WHAM -Rochester, N. Y 1080

WHAP-New York, N. Y. (WDWM,100 WMSG) 1270 236.1500 WHAR-Atlantic City, N. J. (WPG) 1100 272.6200 WHAS-Louisville, Ky. 650 461.3

15000 WHAZ-Troy, N. Y. (WGY) 790 379.5500 WHB-Kansas City, Mo. (WOO) 890 336.9500 WHBA-Oil City, Pa 1150 260.7500 WHBC-Canton, Ohio 1270 236.1500 WHBD-Beliefontaine, Ohio 1350 222.1250 WHBF-Rockre) Island, 1350 222.1500 WHBL-Chicago, Ill. (Portable -Car -500 204.0 100500 WHBM-Chicago, Ill. Portable -Car250 rell) 1490 201.6 100100 WHBN-St. Petersburg, Fla 1010 296.9 10500 WHBP-Johnstown, Pa. 1310 228.9 250100 WHBQ-Memphis, Tenn. 1290 232.410050 WHBU-Anderson, Ind. 1360 220.4 15

100 WHBW-Philadelphia, Pa. (WIAD) 1360 220.4 505000 WHBY-West De Pere, Wisc 1200 249.9 50

5 WHDI-Minneapolis, Minn (WLB) 1220 245.8 500100 WHEC-Rochester, N. Y. (WABO) 1290 232.4 100100 WHFC-Chicago, III. 1390 215.7 200100 WHK-Cleveland, Ohio (WJAY) 1130 265.4 500250 WHN-New York, N. Y. (WQAO) 760 394.5 500

5000 WHO Des Moines, Iowa 560 535.4 5000WHPP-New York, N. Y 1450 206 8 10

500 WHT-Chicago, Ill. (WIBO) 730 416.4 50001500 WIAD-Philadelphia, Pa. (WI-I13W) 1360 220.4 50

WIAS-Burlington, Iowa 630 475.9 100

500 WIBA-Madison, Wisc. 12050 239.9 (00100 WIBG-Elkins Park, Pa. Sunday,150 day time only) 680 440.9 50

250 WIBI-Flushing. N. Y. (WBKN,500 WWRL, WBMS) 1120 267.7 100100 WIBJ-Chicago, Ill. (Portable -Carrell) 1490 201.6 100100 WIRM-Chicago, Ill. (Portable-Carrell)1490 201.6 10050 WIBO-Chicago, Ill. (WHT) 720 416.4 500

WIBR-Steubenville, Ohio. 1200 249.9 50

500 WIBS-Elizabeth, N. J. (WTRC,500 WLBX) 1470 202.6 150

500 WIBU-Polynette, Wise 1380 217.3 20

500 WIBW-Chicago, Ill. (Portable -Car -100 rell) 1470 204.0 100

500 WIBX-Utica, N. Y 1260 238.0 150

500 WIBZ-Montgomery, Ala. 1300 230.6 15

1000 WICC-Bridgeport, Conn. 1400 214.2 250250 WIL St. Louis, Mo. 1160 258.5 250100 WIOD-Miami Beach, Fla 1210 247.8 1000250 V/IP-Philadelphia, Pa. (WOO) 590 508.2 500250 WJAD-Waco, Texas 670 447.5 500

250 WJAG Norfolk, Nebr, 1350 222.1 250500 WJAK-Kokomo. Ind. 1280 234.2 5050 WJAM-Cedar Rapids, Ia. (KWCR) 780 384.4 100

100 WJAR-Providence, R. I. 620 483.6 500500 WJAS-Pittsburgh, Pa. (KQV) 1110 270.1 500

223.7205.4212.6

245.8277.6236.1230.6348.6389.4280.2241.8

243.8

256.3208.2

50010

1000

50015

40015

250100500500500500

1,500

50050

218.8 500378.5 30000319.0 750293.9 500277.6 500

1000750500500500

ig

Igg

Aber.)WMBI-Chicago, III. (WJAZ).., ..WMI31-Monesson, Pa.WMPL-Lakeland, Fla.WMBM Memphis. Tenn.WMBO-Auburn, N. YWMBQ-Brooklyn. N. Y. (WTRC,

WTBS, WLBX) 1470 204.0 100

WMPR Tamna, Fla. 1190 252.0 100

WMBS Harrisburg, B3 1280 234.2 250

WM.U-Pittsburgh, Pa. 1380 217.3 50

WMBW-Youngstown, 0. (WKBN) 1400 214,2 50

WMBY-Bloomington, Ill. (WNBL). 1500 199 9 15

W1VC-Alemnhis, Tenn. 580 516.9 500

WMCA-New York. N. Y. WEB) 810 370.2 500

WMPC-Lapeer, Mich. 1280 234.2 30

WMRJ-J7 m a ica. N. Y. (WTRL,WHPP) 1450 206.8 10

WSMG-New York, N. Y. (WDWM,WHAP) 1270 236.1 500

WNAB-Boston. Mass. (Changed toWASN).

WNAC-Boston, Mass. (WEAN) 1130 260.3 500

W.NAD-Norman, O'kla. 1250 239.9 500

WNAL-0'313a, Nebr. (KOCH,KFOX) 1160 78 0 250

WNAT-Philadelphia, Pa. (WRAX) 1040 261.0 100

WNAX-Yankton, S. D. 990 302.8 250

Station Kc M WattsWJAX-Jacksonville, Fla. 890 336.9 1000WJAY-C.eveland, Ohio (WLIK)..., 1130 265.3 500WJAZ-Mt. Prospect, Ill. (WMBI) 1140 263.0 5000WJBA-Joliet III. 322.4WJBB-St. Petersburg, Fla. 870 344.6 250WJBC LaSalle, Ill. 1320 227.1 100WJBI-Red Bank, N. J 1120 267.7 250WJBK Ypsilanti, Mich. 1360 220.4 15WJBL-Decatur, III. 1410 212.6 250WJBO-New Orelans, La. 1140 283.3 100WJBR-Omro, Wisc. 1320 227.1 100WJBT-Chicago, Ill. (WI3BM, WAAF) 770 389.4 100WJBU Lewisburg, Pa. 1400 214.2 100WJBW-New Orleans, La. 1250 238.0 30WJBY Gadsden, Ala. 1280 234.2 50WJBZ Chicago Heights, III. 1440 208.2 100WJJD-Mooseheart, Ill. (WEBH) 820 365.6 1000WJPW-Ashtabula, Ohio 1440 208.2 30WJR-WCX-Pontiac, Mich. 680 440.9 5000WJZ-Bound Brook, N. J. 660 454.3 30000WKAF-Changed to WTMJ Mil

waukee, Wis.WKAQ-San Juan, P. R. 880 340.7 500WEAR -East Lansing, Mich.

(WREO) 1300 230.6 1000WKAV-Laconia, N. H. 1340 223.7 50WKBB-Joliet, Ill. (WCLA) 1390 215.7 150WKBC-B irmingham, Ala. 1370 218.8 10WKBE-Webster, Mass. 1310 228.9 100WKBF-Indianapolis, Ind. 1190 252.0 250WKBG-Chicago, Ill. (Portable) 1490 201.6 100WKBH-La Crosse, Wis. 1360 220.4 500WKBI-Chicago, Ill. 930 322.4 50WKBL-Monroe, Mich. 1460 205.4 15WKBM-Newburgh, N. Y. 1440 208.2 100WKBN-Youngstown, 0. (WMBW) 1400 214.2 50WKBO-Jersey City, N. J. (WKBQ

WBNY WFRL) 1370 218.8 500WKBP Battle Creek, Mich. 1410 212.6 50WKBQ-New York, N. Y. (WKBO

WBNY WFRL) 1370 218.8 500WKBS-Galesburg, Ill. (WLBO) 1380 217.3 100WKBT-New Orleans, La. 1190 252 0 50WKBU-New Castle, Pa. (Portable) 1470 204.0 50WKBV Brookville, Ind. 1380 217.3 100WKBW-Buffalo, N. Y. 1380 217.3 500WKBZ Ludington, Mich. 1500 199.9 15

WKDR Kenosha, Ibis. 930 322.4 15

WKJC-Lancaster, Pa. WGAL) 1190 252.0 50WKRC-Cincinnati, Ohio 900 333.1 500WKY-Oklahorna City, Okla. 1040 283.3 150

WLAP-Louisville, Ky. 1120 267.7 30WLB-Minneapolis, Minn. (WHDI) 1220 245.8 500VVLF1C Muncie, Indiana 1430 209.7 50WLBF-Kansas City, Mo. 1430 209.7 50WLBG-Petersburg, Va. 1400 214.2 100WLBH-Farmingdale, N. Y. (Port-

able) 1490 201.6 30WLBI-East Wenona, Ill. 1260 238.0 250WLBL-Stevens Point, Wis. (WHA) 940 319.0 1000WLBM-Boston, Mass. 1420 211.1 50

WLBN-Chicago, Ill. (Portable) 1470 204.0 50WLBO-Galesburg, Ill. (WEBS) 1380 217.3 100

WLBP-Ashland, Ohio 1480 202.6 15

WLBT-Crown Point, Ind. 930 322.4 50

WLPR-BelviCiere, Ill. 930 377.4 15

WLBT-Crown Point, Ind 930 32.2.4 50

WLBV-Mansfield, Ohio 1450 205.8 50

WLBW-Oil City, Pa. 1020 267.7 500

WLBX-Long island City, N. Y(WIBS, WMBQ, WTRC and

WLB ) 1470 264.0 250

WLBY-Iron Mountain, Mich. 1430 209.7 50

WLBZ-Dover-Foxcroft, Me. 1440 208.2 250

WLCI-Ithaca, N. Y. 1210 247.8 50

WLIB Chicago, Ill. (WGN) 980 305.9 500

WLIT-Philadelphia, Pa. (WFI) 740 405.2 500

WLS Chicago, Ill. (WCBD) 870-384.4 5000

WLTS-Chicago, ill. (WCFL) 6,0 483.6 100

WLW-Cincinnati, Ohio 700 428.3 5000WLWL-New York, N. Y. (W(YDA) 1020 293.9 1000

WMAC-Cazenovia, N. Y. (WSYR) 1330 225.4 500

WMAF-South Dartsmouth, Mass.., 700 428.3 500

WMAK-Lockport, N. Y. 550 545.1 750

WMAL-Washingtcn. D. C 1310 2''89 100

wmA N -Columbus. Oh, . 1200 234 2 50

WMAO-Chicago, Ill. (WQJ) 670 447.5 1000

WMAY-St. Louis. Mo. 1210 247.8 100

WMAZ-Macon, Ga. WGST) 1110 270.1 500

WMBA-Newport, R. I. (Portable) 1470 204.0 100

WM1313 Chicago, Ill. (WOK) 1190 252.0 500

WMBC-Detroit, Mich. (WDMH) 1420 211.1 100

WMBD-Peoria Heights, Ill 1460 215.4 250

WM11E-St. Paul, Minn. 1440 208.2 10

WMBF-Miami Beach, Fla 7803384.4 50084.4 50

WMF1C, Richmond. Va. 1450 206.8 15

WMBH-Chicago, Ill. (Portable -E. D1470 204.0 1001140 263.0 5001290 2,2.4 501310 228.9 501430 209.7 101360 220.4 100

June 11, 19Z/ RADIO WORLDStation Kc

WNBA-Forest Park, Ill 1440WNBF-Endicott, N. -Y 1450WNBH-New Bedford, Mass 1150WNBJ-Knoxville, Tenn. 1450WNBL-Bloomington, 111. (WMBY) 1500WNBO-Washington, Pa. 1420WNBQ-Rochester, N. Y. 1480WNBR-Memphis, Tenn. 1310WNJ-Newark, N. J. (WGCP) 1070WNOX-Knoxville, Tenn. 1130WNRC-Greensboro, N. C 1340WNYC-New York N. Y 560WOAI-San Antonio, Texas ..... 990WORN -Lawrenceburg, Tenn. 1050WOAX-Trenton, N. J. (WEAM) 1250WOC-Davenport, Iowa 850WOCL-Jamestown, N. Y 1340WODA-Paterson, N. J. (WLWL) 1020WOI-Ames, Iowa; 5000, daytime, 6

to 6 (WSUI) 1130WOK -Chicago, Ill. (WMBB) 1190WOKO-Peekskill, N. Y. 1390WOKT-Rochester, N. Y. 1430WOMT-Manitowoc, Wis. 1350WOO -Philadelphia, Pa. (WIP) 590WOOD-Furnwood, Mich. 1150WOQ-Kansas City, Mo. (WHB) 890WOR-Newark, N. J 710WORD -Batavia, Ill. (WTAS) 1090WOS-Jefferson City, Mo 760WOW -Omaha, Nebr. 590WOWO-Ft. Wayne, Ind. (WCWK) 1310WPAB-Norfolk, Va. 1430WPCC-Chicago, Ill., (WFKB,

WCRW) 1340WPCH-New York, N. Y. (WRNY). 970WPDQ-Buffalo, N. Y. (WSVS) 1460WPEP-Waukegan, III. 1390

M Watts208.2 200206.8 50260./ 250206.8 50199.9 15

211.1 15202.6 15228 20256.3 500265.3 1000223.7 250535.4 500302.8 2000260.7 250239.9 500352.7 5000223.7 25293.9 1000

265.3 2500252.0 5900215.7 250209.7 500221.1 50508.2 500260.7 500336.9 250422.3 500275.1 5000394.5 500508.2 1000228.9 1000209.7 100

223.7 500309.1 500205.4 50215.7 250

Station KcKDL.R-Devils Lake, N. D. 1300KDYL-Salt Lake City, Utah 1160KELW-Burbank, Calif. (KPPC). 1310KEX-Portland, Ore. 1250KFAB-Lincoln, Nebr. (5000 before 7

m.) 970KFAD-Phoenix, Ariz. 1100KFAU-Boise, Idaho (4,000 watts day -

time) 1050KERB Havre, Mont. 1090KFBC-San Diego, Calif 1210KFBK-Sacramento, Calif. 560KFBL-Everett, Wash. 1340KFBS Trinidad, Col, 1260KFBU-Laramie, *Wyo. 700KFCB-Phoenix, Ariz. 1230KFCR-Santa Barbara, Calif 1420KFDM-Beaumont, Texas 800KFDX-Shreveport, La. 1270KFDY-Brookings, S. Dak. 760KFDZ-Minneapolis, Minn. 1300KFEC-Portland, Ore. (KFIF) 1400KFEL-Denver, Colo. 1210KFEQ-St. Joseph, Mo. 1300KFEY Kellogg, Idaho 1290KFEQ St. Joseph, Mo. 1300KFH-Wichita, Kansas 1220KFHA-Gunnison, Col, 1180KFHL Oskaloosa, Iowa. 1410KFI Los Angeles, Calif. 640KFIF Portland, Ore. (KFEC) 1400KFIO-Spokane, Wash. (KEPY) 1220KFIQ-Yakima, Wash. 1440KFIU-Juneau, Alaska 1330KFIZ-Fond du Lac, Wise 1120KFJB-Marshalltown, Iowa 1210KFJF-Oklahoma, Okla. 1100KFJI Astoria, Ore. 1200

M Watts230.6 15

258.5 100228.9 250239.9 2500

309.1 2000272.6 500

285.5 2000275.1 50247.8 100535.4 100223.7 50238.0 15428.3 500243.8 125211.1 50374.8 500236.1 250394.5 500215.7 10214.2 50247.8 250230.6 1000232.4 10230.6 1000245.8 500254.1 50212.6 10468.5 5000214.2 50245.8 100208.2 100225.4 10267.7 100247.8 15272.6 750249.9 15

WPG-Atlantic City, N. J. (WHAR) 1100WPRC-Harrisburg, Pa. 1430

272.6209.7

2500100

KFJM-Grand Forks, N. Dak 900KFJR Portland, Ore. (KTBR) 1060

333.1282.8

100100

WPSC-State College, Pa. (WBAK) 1000WPSW-Philadelphia, Pa. 1480

299.8202.6

50050

KFJY-Ft. Dodge, Iowa 1250KFJZ-Fort Worth, Texas 1200

239.9249.9

10050

WQAA-Parkersburg, Pa. 1390 215.7 500 KFKA Greeley, Colo. 750 399.8 200

WQAE-Springfield, Vt. 1210 249.9 50 KFKB-Milford, Kansas 12,40 241.8 1000

WQAM-Miami, Fla. 930 322.4 750 KFKU Lawrence, Kansas (WREN). 1180 254.1 500

WQAN-Scranton, Pa. (WGBI) 1300 230.6 100 KFKX-Hastings, Nebr. (KYW).... 570 526.0 2500

WQAO-WPAP-Cliffside, N. J. KF -Kirksville Mo. 1330 225.4 15

.5 500 KFLR Albuquerque, N. M 720 416.4 100

WQJ-Chicago, Ill. (WMAQ) 670 447.5 500 KFLU-San Benito, Texas 1270 236.1 15

WRAF -La Porte, Ind. 1440 208.2 100 KFLV-Rockford, Ill. 1120 267.7 100

WRAH-Providence, R. I. 1500 199.9 250 KFLX Galveston, Texas 1110 270.1 100

WRAK-Escabana, Mich. 1060 282.8 50 KFMR-Sioux City, Iowa 680 440.9 100

WRAM-Galesburg, Ill. (WFBZ).... 1210 247.8 50 KFMX-Northfield, Minn. (WCAL) 1270 236.1 500

WRAV-Yellow Springs, Ohio 880 340.7 100 KFNF Shenandoah, Iowa (KMA).. 1110 270.1 1000

WRAW-Reading, Pa. 1260 238.0 50 KFOA-Seattle, Wash. 670 447.5 1000

WRAX-Philadelphia, Pa. (WHAT). 1040 283.3 250 KFON-Long Beach, Calif. 1240 241.8 500

WRBC-Valparaiso, Ind. 1260 238.0 250 KFOR-Lincoln, Nebr. 1380 217.3 100

WRC-Washington, D. C. 640 468.5 500 KFOX-Omaha, Nebraska (KOCH,WRCO-Raleigh, N. C. 1380 217.3 250 WNAL) 1160 258.5 100

WREC-Memphis, Tenn. 1180 254.1 50 KFOY St. Paul, Minn. 1050 285.5 100

WREN -Lawrence, Kans. (KFKU).. 1180 254.1 750 KFPL-Dublin, Texas 1090 275.1 15

WREO-Lansing, Mich. (WKAR)... 1300 230.6 500 KFPM-Greenville, Texas 1300 230.6 15

WRES-Quincy. Mass: 1380 217.3 50 KFPR-Los Angeles, Calif. (KFQZ) 1290 232.4 250

WRHF-Washington, D. C. (Daytime KFPW-Carterville, Mo. 1140 263.0 50only) 940 319.0 50 KFPY-Spokane, Wash. (KFIO).... 1220 245.8 250

WRHM-Minneapolis, Minn. (WDGY) 1150 260.7 1000 KFQA-St. Louis, Mo 930 322.4 50

WRM-Urbana, Ill.; 1000 watts be- KFQB-Pt. Worth, Texas 1150 260.7 1000

fore 6 p.m. (WBAA) 1100 272.6 500 KFQD-Anchorage, Alaska 870 344.6 100

WRMU-New York, N. Y. (Portable) 1490 201.6 100 KFQU-Holy City, Calif. 1200 249.9 100

WRNY-New York, N. Y. (WPCH). 970 309.1 500 KFQW-Seattle, Wash. 1380 217.3 100WRPI-Terre Haute, Ind. 1440 208.2 100 KFQZ-Hollywood, Calif. (KFPR)... 1290 232.4 100

WRR -Dallas, Texas 850 352.7 500 KFRC San Francisco, Calif. 660 454.3 50

WRRS-Racine, Wis. 930 322.4 50 KFRU-Columbia, Mo. 1200 249.9 500WRSC-Chelsea, Mass. 1460 205.4 15 KFSD-San Diego, Calif 680 440.9 500WRST-Bay Shore, N. Y. (WCDA. KFSG-Los Angeles, Calif. 1090 275.1 500

WBRS, WCGU) 1420 211.1 250 KFUL-Galveston, Texas 1160 258.5 500

WRVA-R,z1 ,--ad Va. 1420 211.1 250 KFUM-Colorado Springs, Colo 1270 236.1 100

WSAI-Cincinnati, Om.., 830 361.2 5000 KFUO-St. Louis, Mo. (KSD) 550 545.1 500

WSAJ-Grove City, Pa. 250 KFUP-Denver, Colo. 1320 227.1 100WSAN-Allentown, Pa. (WCBA).... 1350WSAR-Fall River, Mass. 1190

222..252.0 100

KFUR-Ogden, Utah 1330KFUS-Oakland, Calif. (KRE) 1170

225.4256.3

5050

WSAX-Chicago Ill. 1470 204.0 100 KFUT-Salt Lake City, Utah 600 499.7 50WSAZ-Huntington, W. Va. 1240 241.8 100 KFVD Venice, Calif. (KGFJ) 1440 208.2 250WSB-At lanta, Ga. 630 475.9 1000 KFVE-St. Louis, Mo. 1280 234.2 1000WSBC-Chicago, Ill. (WWAE) 1290 232.4 500 KFVG-Independence, Kans. 1330 225.4 50WSBT-South Bend, Ind. 1350 222.1 250 KFVI Houston, Texas 1260 238.0 Si)WSDA-New York, N. Y. (WARS, KFVR-Denver, Colo. 630 475.9 250

WBBC) 1320 227.1 250 KFVS Cape Girardeau, Mo 1340 223.7 50WSEA-Virginia Beach, Va. 1370 218.8 250 KFWB-Los Angeles, Calif. 830 361.2 500WSIX-Springfield, Tenn. 1410 212.6 150 KFWC-San Bernardino, Calif 1350 222.1 100WSKC-Bay City, Mich. 610 491.5 250 KFWF-St. Louis, Mo. 1400 214.2 250WSM-Nashville, Tenn. 940 319.0 2000 KFWH-Eureka, Calif. 1180 254.1 100WSMB-New Orleans. La. 930 322.4 500 KFWI-San Francisco, Calif. 1120 267.7 500

WAAT) 1220 245.8 500 KFWM-Oakland, Calif. (1000 watWSMK-Dayton. Ohio 1010 256.9 e06 day time) 1270 236.1 500WSOE-Milwaukee, Wis. .1100 270.1 500 KFWO-Avalon, Calif. 1370 218.8 2550,

WSOM-New York, N. Y. (WGBB, KFWV-Portland, Ore. 1310 228.9WSRO-Hamilton, Ohio 730 384.4 100 KFXB-Los Angeles, Calif. 190 252.0 500WSSH-Boston, Mass. WASN).... 1300WSUI-Iowa City, Iowa (W01).... 1130

230.6265.3

100500

KFXF-Denver, Colo. 1060KFXH-El Paso, Texas 1240

500100

WSVS-Buffalo, N. Y. (WPDQ).... 1460 205.4 50 KFXJ-Near Edgewater, Colo 1390WSYR-Syracuse, N. Y. (WMAC). 1330 225.4 500 KFXR-Oklahoma City, Okla 1400 214.2 155

WTAD-Quincy, Ill. 1270 236.1 250 KFXY Flagstaff, Ariz. 1460 205.4 25WTAG-Worcester, Mass. 1040 283.3 SO() KFYF-Oxnard, Calif. 1260 238.0 25WTAL-Toledo, Ohio (WABR) 1070 280.2 100 KFYR Bismarck, N. Dab 1250 238:9 2:5-6

WTAM-Cleveland, Ohio (WEAR).. 750WTAQ-Eau Claire, Wise 1180WTAR-Norfolk, Va. 1090WTAS-Batavia, Ill. (WORD) 1090

399.8254.1275.1275.1

3500500500

3500

KGA-Spokane, Wash. 1150KGAR-Tuscon, Ariz. 1280KGBS-Seattle, Wash. 1480KGBU-Ketchikan, Alaska 1310

2607234.2202.6228.9

2000100100500WTAW-College Station, Texas 970

WTAX-Streator, Ill. 930WTAZ-Lambertville, N. J. 1360

309.1322.4220.4

5005015

KGBX-St. Joseph, Mo 1040KGBY-Shelby, Nebr. 1480KGBZ-York, Nebr. 1410 212.6

50050

100WTHO-Detroit, Mich. (WAFD).... 1370WT1C-Hartford, Conn. 650WTM.1-Miwatikee, Wisc. (WHAD) 1020WTRC-Brooklyn, N. Y. (WIBS,

WMBQ, WLBX) 1470WTRL-Midland Park, N. J.

WJBI, WIBI, WBMS) 1120WWAT-Chicago, Ill. (WSBC) ..1290

.WWJ-Detroit, Mich. 800WWL-New Orleans, La. 1090WWNC-A h '11 N. C. 1010WWRL-Woodside, N. Y. (WBKN,

WJBI, WIBI, WIIMS) 1120WWVA-Wheeling, W. Va 770KDKA-East Pittsburgh, Pa. 950

218.8461.3293.9

204

267.7232.43748275.1296.9

267.7389.4315.6

250500500

50

100500

1000100

1000

100100

30000

KGCA-Decorah, Iowa 1480KGCB Oklahoma City, Okla. (KGFG) 1390KGCG-Newark, Ark. 1340KGCH-Wayne, Nebr. 1020KGCI-San Antonio, Texas (KGDR) 1480KGCL-Seattle, Wash. KPCB) 1300KGCN-Concordia, Kansas 1440KGCR-Brookings, S. Dal, 1440KGCLI-Mandan, N. Dak 1440KGCX-Vida, Mont 1230KGDA-Dell Rapids, S. Dak. (Day

time only) 1280KGDE-Barrett, Minn 1460KGDJ-Cresco, Iowa 1480KGDM-Stockton, Calif. 1380

202.6

222153:7 7

293:9202.6230.6208.2208.2208.2243.8

234.2205.4202.6217.3

1050

500250

15

50

50

1510010

15501010

17

Station Kc M WattsKGDF-Pueblo, Colo. 1340 223.7 10

KGDR-San Antonio, Texas (KGCI) 1480 202.6 15

KGDX-Shreveport, La.1450 2068 100KGDW-Humboldt, Nebr.1410 212.6 250

KGDY-Oldham, S. Dak. 1450 206.8 15

KGEF-Los Angeles, Calif. 1140 263.0 500KGEH-Eugene, Ore. 1490 201.6 50KGEK-Yuma, Colo. 1470 204.0 10KGEN-El Centro, Calif. 1330 225.4 15

KGEO-Grand Island, Nebr. 1460 205.4 100KGEQ-Minneapolis, Minn. 1480 202 6 50KGER-Long Beach, Calif. (KRLO) 1390 215.7 100KGES-Central City, Nebr 1470 204.4 10KGEU-Lower Lake, Calif 1320 227.1 50KGEW-Fort Morgan, Colo 1370 218.8 10KGEY-Denver, Colo. 1490 201.6 15

KGEZ-Kalispell, Mont. 1460 205.4 100KGFB-Iowa City, Iowa 1340 223.7 10

KGFF-Ava, Okla. 1460 205.4 25KGFG-Oklahoma City, Okla.(KGCB) 1390 215.7 50KGFH-La Crescenta, Cal. (KMIC) 1340 223.7 100KGFI-Ft. Stockton, Tex 1360 220.4 15

KGFJ-Los Angeles, Calif, (KFVD) 1440 208.2 100KGFK-Hallock, Minn. 1340 223.7 50KGFL-Trinidad, Colo. 1350 222.1 50KGFM-Yuba City, Calif 1420 211.1 15

KGFN Aneta, N. Dak 1500 199.9 15

KGFO-Terra Haute, Ind 1470 204.0 100KGFP-Mitchell, So. Dak 1410 212.6 10KGO-Oakland, Calif. 780 384.6 5000KGRC-San Antonio, Texas 1360 220.4 50KGRS-Amarillo, Texas 1230 243.8 150KGTT-San Francisco, Calif 1450 206.8 50KGU-Honolulu, T. H 1110 270.1 600KGW-Portland, Ore. 610 491.5 1000KGY-Lacey, Wash. 1230 243.8 50KHJ-Los Angeles, Calif 740 405.2 500KHQ-Spokane, Wash. 810 370.2 1000KICK -Anita, Iowa 650 461.3 100KJBS-San Fra'ncisco, Calif 1360 220.4 50KIR-Seattle, Wash. 860 348.6 2500KKP-Seattle, 'A ash. 1130 265.3 15KLDS-Independence, Mo. 1260 238.0 1500KLIT-Portland, Oregon 1450 206.8 10KLS-Oakland, Calif. (KZM) 1220 245.8 250KLX-Oakland, Calif. 590 508.2 500KLZ-Denver, Colo. 1120 267.7 250KMA-Shenandoah, Iowa (KFNF) 1110 270.1 500KMED-Medford, Oregon 1120 267.7 50KMIC-Inglewood, Calif. (KGFH) 1340 223.7 250KMJ--Fresno, Calif. 820 50KMMJ-Clay Center, Nebr 1310 228365.6 500KMO-Tacoma, Wash. 1180 254.1 250KNIOX-St. Louis, Mo. 1000 299.8 5000KMTR-Los Angeles, Calif 570 526.0 500KNRC-Santa Monica, Calif 800 374.8 500KNX-Los Angeles, Calif 890 336.9 500KOA-Denver, Colo. (10,000 until 7 P.

m.) 920 325.9 5000KOAC-Corvalis, Ore. 1110 270.1 500KOB-State College, N. M. (KWSC,

KTW) 760 394.5 5000KOCH-Omaha, Nebr. (W NAL,

KFOX) 1160 258.5 250KOCW-Chickasha, Okla. 1190 252.0 250KOIL Council Bluffs, Iowa 1080 277.6 1500KOIN-Portland, Ore. 940 319.0 1000KOUT-Durango, Colo. 1500 199.9 5KOMO-Seattle, Wash. 980 305.9 1000KOWW-Walla Walla, Wash 1000 299.8 500KPCB-Seattle, Wash. (KGCL) 1300 230.6 50KPJM-Prescott, Ariz. 1400 214.2 15KPNP-Muscantme, Iowa 1420 211.1 100KPO-San Francisco, Calif 710 422.3 1000KPPC-Pasadena, Calif. (KELW) 1310 228.9 50KPRC-Houston, Texas 1020 293.9 500KPSN-Pasadena Calif. 950 315.6 1000KQV-Pittsburgh, Pa. WJAS) 1110 270.1 500KQW-San Jose, Calif 1010 296.9 500KRAC-Shreveport, La. 1360 220.4 50KRE-Berkeley, Calif. (KFUS) 1170 256.3 100KRLD-Dallas, Texas 1350 222.1 500KRLO--.Los Angeles, Calif. (KGER). 1390 215.7 250KROX-Seattle, Wash. (KRSC3 1420 211.2 50KRSC-Seattle, Wash (KROX) 1420 211.1 50KSAC-Manhattan, Kans. 900 333.1 500ICSBA-Shreveport, La. 1120 267.7 1000KSCJ-Sioux City, Ia(KWUC) 1230 243.8 500KSD-St. Louis, Mo. (KFUC) 550 545.1 500KSE1-Pocatello, Idaho 900 333.1 250KSL-Salt Lake City, Utah 990 302.8 1030KSMR Santa Maria, Calif 1100 272.6 100KSO-Clarinda, Iowa 1320 227.1 500ICSOO-Sioux Falls, S. D 1430 209.7 250KTAB-Oakland, Calif. 1070 280.2 500

KKTTBAr- LosSan Angeles,Antonio, Texascalif1040282.3 500

1310 228.9 10

KTBR-Portland, Ore. (KFJR) 1060 282.8 50KKTTCLs-Hat

Springs,Veattle,Na 1080 277.6 500Wash.

KTNT-Muscatine, Iowa 1018700 324056..73 37a0050

KTSA-SanwAcnAtzio, Tex. (formerly1130 265.3 2000

KTUE-Houston, Tex. 1410 212.6 5KTW-Seattle, Wash. KWSC, KOB) 760 394.5 1000KUJ-Seattle, Wash. 19.9KUOA-Fa yet tev tile, Ark. 1010 96.9 500KKUu0sDMTvMeimunloan, Mont.s..p 800 374.8 500

620 483.6 250KUT-Austin, Texas 12so 232.4 500KVI-Tacoma, Wash. 1280 232.4 50KV00--Bristow, Okla. 860 348.6 1000KVOS-Seattle, Wash. 1430 209.7 50KWBS-Portland, Ore. 1500 199.9 15KWCR-Cedar Rapids, Ia. (WJAM) 780 384.4 250KWG-Stockton, Calif. 870 344.6 50KWKC-Kansas City, Mo. 1350 222.1 100KWKH-Shreveport, La. 760 394.5 1000KWLC-Decorah, Iowa 1210 247.8 50KWSC-Pullman, Wash. 760 394.5 500KWTC-Santa Ana, CalifKWUC-LaMars, Iowa (KSCJ) 1230 243.8 1500KWWG-Brownsville, Texas 1080 277.6 500KXL-Portland, Ore. 1360 220.4 50KYA-San Francisco, Calif. 970 309.1 500KWY-Chicago, Ill. (KFKX) 570 526.0 2500KZM-Oakland, Calif. (KLS) 1220 245.8 100

18 RADIO WORLD. June 11, 1927

Freshman Power SpeakerThe Charles Freshman Company have

developed, and are now offering for salea combination high quality amplifier andloudspeaker, housed in a small mahoganytable. The combination, called the Fresh-man "Power Speaker," is designed for usewith any type of radio set, having onestage of audio frequency amplification orthe equivalent. The amplifier in the PowerSpeaker takes the place of the secondstage of audio freguency in the radio set,thus eliminating the source of 90 per cent.of the distortion. The amplifier requiresno batteries. It obtains its power directlyfrom the 110 volt 60 cycle house lightingsystem. As an amplifier tube the R. C. A,UX 210 is used, as a rectifier the R. C. A.UX 216. Full voltage for proper amplifica-tion is supplied the power tube, the resultbeing clear pure reproduction at anyvolume.

The cone speaker supplied with thePower Speaker is of the diaphragm type,the unit being one capable of properlyhandling the great volume and fine qual-ity available from the amplifier. The PowerSpeal,er is a complete audio frequencyamplifier unit and reproducer, capable ofthe best in quality reproduction at anyvolume.

Because of the self-contained feature of

the. Power Speaker it may be convenient-ly used with any radio set. Receiving setswhich have been condemned as no longeruseful because of their distorted reproduc-tion, can be made to equal and surpassthe best and latest designs on the market,says the manufacturer, adding:

"This statement may appear extrava-gant until it is considered that practicallythe only improvement in radio sets in thelast three years has been in mechanicaldesign and the audio frequency amplifier.If an old radio set is still operating themechanical design must be correct-replacethe old audio amplifier with a FreshmanPower Speaker and the set is up to datein results.

"Even on sets of latest design somemanufacturers, for reasons of cost,have not improved the audio amplifier tothe fullest extent. Indeed this is true ofmost sets, since the voltage required foran amplifier, such as that used in thepower speaker, is so great it cannot beeconomically supplied with batteries."

The mahogany table in which the PowerSpeaker is housed is of conservative andattractive design. It is intended for useas a separate unit detached from the radioset. The size is correct, however, to permitplacing the radio set on top if desired.

Need of Neutralization(Concluded from page 10)

the primary Ll and the secondary. Thevalue is not at all critical in this circuit.The maxianum size is around .00075 mfd.

method of preventing oscilla-tions depends on the absorbtion of energyin eddy currents. This method is notstrictly one of neutralization but a lossermethod. However, it is possible to adjustthe losses so that the oscillation juststops. It is then possible to retain a littleadvantageous regeneration at the higherfrequencies. The loss by this method isgreatest where the need of it is greatest.Hence the eddy current method of pre-senting oscillation yields a fairly evenamplification characteristic over the entirescale. There is danger, however, of over-doing the loss so that the circuit willamplify much less at the higher frequen-

cies than at the lower and middle fre-quencies, but this can be avoided by cor-rect design.

Methods depending on variation of gridshould be avoided. If the bias is

made positive, the plate current will beexcessive when the amplification has beenreduced to the point of stopping oscilla-tion. If the bias is made negative verylarge C batteries will be required and itis necessary to operate the tube so fardown the characteristic that it is virtuallya detector.

Filament current control is sometimeseffective in stopping oscillations. Thefilament current is stopped down to apoint where oscillation is impossible. Butthis method is not to be considered as apractical substitute for one of the neu-tralizing- methods.

The Balsa Wood Speaker(Concluded from page 9)

of Balsa wood (not the ribs), so that theywill just fit into the recesses specially cutin the hardwood frame to receive them.A sharp pen -knife or razor blade will cutthe Balsa wood nicely. Also trim theside edges of these strips, so that whenthe strips are finally glued to the frame,there will be a space of about 1/16 -inchto 1/8 -inch between adjoining strips.When you have fitted the strips, fastenthem into the recessed groove in theframe with glue. Glue in the end stripsfirst. Work with the long side or lengthtoward you, so that the ends are at leftand right.

After the glue has set for fifteen ortwenty minutes under suitable weight,turn the frame over so that the Balsastrips in the frame can rest flush on topof a table or desk. It is well to place asheet of paper underneath so that excessglue will not stick to the table top.

Fasten Ribs UprightNow you are ready to glue the ribs

to the Balsa wood strips. First find thecenter of the frame by drawing diagonal

pencil lines lightly front corner to corner.Now draw two lines, centered on thewidth and the length, each line throughthe point where the diagonals meet, whichis at the center of the frame. Hencethese two lines are at right angles. Takeone of the ribs and cut off the ends sothat when glued later at right angles tothe length, that rib will extend aboutone inch front the long sides of theframe as a cross rib. Notice that this isone rib, whereas the corner -to -cornerribbing will be made up of two pieces ineach instance, due to the presence of thecross rib. Now cut the corner -to -cornerribs so that they will extend to withintwo inches of the corners. Then cut thelengthwise ribs so that they will cometo within two inches of the left and rightsides of the frame.

Spread a sizing of glue along the linesyou have just drawn and also put glue onthe edge of the ribs. These ribs will beglued in on edge. The sizing is on the3/32 -inch edge. In other words, the ribsare put on upright, not flat. When thesizing is dry, spread another layer ofglue on the cross rib line and its rib andglue the rib in. Cut the three other ribs

in half and glue them in. This accountsfor the two-piece ribbing previously re-ferred to, and also for the total of sevenunder previous classification 'b). Be sureall ribs come together at the center likethe spokes of a wheel which all join inthe hub. In making this glue job, be surethat all parts are thoroughly glued, forthere is likely to be a rattle on the high-pitched tones if they are not tightly glued.There is an extra rib in the kit in caseone is broken.

Take the square, which may be eitherhardwood or Balsa wood. Bore a 3/16 -inch hole so that the screw shank of thebushing will pass through. Cut outenough around this hole on, one side tocountersink the little nut so that whenyou glue the square to the ribs the squarewill lay flush on them. The nut must beless than flush with this square. Afterfastening the bushing in the square andturning the bushing tap loosely on thescrew, glue the square on the ribs at thecenter where they all meet. Be sure thatit is glued on firmly at all points and toall ribs.

Test Eradicates RattlingNow center the speaker unit on the

hardwood cross piece so that the styluswill fit into the expansion screw of thebushing. Cut off the stylus to requiredlength. Then fasten the cross -piece tothe hardwood frame. This is done withwood screws. One elevating block goesbetween cross -piece and the frame at eachof the two ends. The stylus must bein the center of the speaker, which willthrow the hardwood crossarm off center.Tighten the expansion screw by compres-sion (not screw motion)- so that the stylusis gripped firmly in the cup -like device.You can tighten down the nut with extrapressure of the fingers. Do not use apair of pliers, as you may overdue it,and unseat the square from the ribs.:When the glue is dry the speaker is readyfor testing.

Pluck the PartsNow take any one rib and pluck it

gently. There will be a low-pitchedreverberation. Pluck each rib this way,also each of the three wide strips. Theobject is to be sure that plucking pro-duces no rattle. If you hear a rattle re-move the cause, which is always a loosepart. This looseness is likely due to poorgluing-. Thus, if one of the wide stripsproduces a rattle when plucked, but noth-ing else produces this result, you knowthat the trouble is in that section. Dosome more gluing at the weak place.

Remember that the small square mustbe securely glued to the crossrib and tothe other ribs.

In other words, any tendency to rattlecan be overcome before the speaker isactually connected to a set.

Never connect the speaker to a re-ceiver until all the gluing is positively dry,as the operation of the speaker willseparate wet -glue joints.

Avoid HollowsAlso be very sure there are no hollows

along the ribs, clue to failure of the glueto stick to the wide strips for the entirelength of the ribs.

With everything testing, 100 per cent.satisfactory, and with every speck of gluepositively dry, connect the speaker cordsto the receiver.

When building your Balsa speaker, andyou surely must build one, if you want theultimate in tone quality be certain thatyour kit is marked Lata Balsa, which ismade of scientifically treated and caredfor Balsa wood. Such kits may be ob-tained from any good dealers.

Further information on the aucousticalproperties of Lata Balsa wood may be hadfront Balso Wood Co. Inc., 331 Madi-son Avenue, New York City, manufac-turers of the genuine Lata kit.


The Radio UniversityI HAVE a five -tube tuned RF receiver,

built exactly as outlined on page 14 ofthe January 9 issue of RADIO WORLD.This set was built about a year ago, anduntil last month behaved very nicely.The set has become very hard to control.When a station is tuned in, the set startsto squeal terrifically. It is also impos-sible to get stations at certain settingsof the dials, e.g., 50-50-50 or at 65-65-65.At these points, nothing but a combina-tion of scratches and intermittent noisesare heard. I tested the batteries andfound them to be all right. The antennaand ground were also found to be satis-factory. Please tell me how to recon-dition this set-GEORGE SQUIRES,N. Y. City.

Undoubtedly the trouble lies in variablecondensers, where several plates areshorted. They touch each other, probablyat those points where you cannot receivea station. It is also possible that theremay be an open circuit in the condensers,it being complete at some points andopen at others. The best way to findout, is with the aid of a small four andone-half volt C battery or a one andone-half volt battery and a pair of phones.One terminal of the phones is connectedto a terminal of the battery, leaving youtwo terminals, which go to the terminalsof the unit to be tested. Clicks indicateshorts. Disconnect one lead from thecondensers, going to the set, when testing.Also test your rheostats. The arm maybe making poor contact with the resis-tance wires, or the screws may haveworked themselves loose, and are causinga make and break circuit.

* * *

IN THE April 9 issue of RADIO WORLDon page 21, there appeared a circuit dia-gram of a single tube reflex. I built thisset, and although the results are good,I have a bit of trouble with the crystalswhich burn out on me. I would, there-fore, like to rebuild this set into a singleregenerative tube model, without the re -flexing. Please explain how this may bedone.-EDGAR WAIL, Providence, R. I.

First break all the leads of the trans-former. Take out the small condenserrunning front the G post to the F poston the transformer and rheostat. Nowconnect the terminal that formerly wentto the G post on the transformer, to the

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This remarkable home-censtructed six -tube re-ceiver is so designed as to incorporate the leastresistance in the N.F. stapes, thus making formaximum sensitivity and selectivity, su essen-tial In ultradistanee reception, which enablesthe 0 X. Inn to satisfy his desires.

Authentic schematic wiring diagram, and namexof every unit amplified from aerial down. at Limyof 400 pick-up. Price $1.00.

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plus A post. Break the lead in serieswith the G post of the socket. Procurea .00025 mfd. fixed condenser and a 2megohm grid leak. Shunt the leak acrossthe condenser. Then connect both in

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series with this broken G lead. Discon-nect the end of L4, the primary coil ofthe radio frequency coil, from the endof the tickler, L3. Connect the end ofthe tickler lead to a terminal of a singlecircuit jack or a binding post. Run theother terminal of the jack or the otherbinding post to the B plus, 45 volt post.The phones are inserted here.

World "A" Power Unit -412.75Automatically provides even, unvarying -A" current fromsour light socket. Absolutely noiseless. Assures fuUtone quality from your set and wider D. X. range. FamousWORLD quality-at less than half of the cost of any simi-lar equipment. Shipped complete, subject to inspection onreceipt of price, or C.O.D. if YOU wish. 25 amp. unit forsets of 4 tubes or less, $12.75. 05 Amp. unit for setsof 5 tubes or more, $15.75. 5% discount if cash In fullis sent with order. Send order today. World Battery Co..1219 So. Wabash Ave., Dept. 22. Chicago. Iii

More VolumGreater DistaraceBetter QualityAll of These at Your CommandWhen You Use a De LuxeModel BRETWOOD VARI-

ABLE GRID LEAK

When you are deciding on whatparts are to go into the receiver youare about to build, under no circum-stances dismiss the grid leak withonly casual 'consideration. Respectthe grid leak as something wellworthy of expert choice.

The best course is to select avariable grid leak with an ampleresistance range, one that may bemounted on baseboard, sub -panel orfront panel, as you prefer.

Such a leak is the BRETWOODVARIABLE GRID LEAK, whichis now on the market in new de luxemodel, representing improvementsin mechanical strength, electricalefficiency and utility.

Higher EfficiencyYou should use a variable grid leak like

the BRETWOOD VARIABLE GRIDLEAK in a set you are about to build, orshould put one in 'our present receiver,because it will enable you to get highestoperating efficiency from the detector tube.As nearly all tubes used as detectors drawgrid current, the resistance value of theleak is important for biasing and dischargepurposes. Not only can exactly the rightdegree of flow be established to discard ex-cess electrons, but the grid -to -filament im-pedence is so affected as to afford bestselectivity under the circumstances. Onlya variable leak gives this precision choice.

Overloading PreventedYou prevent overloading of the detector

tube by correct leak setting. This improvestone quality considerably. Often if yourset sounds distorted, this is immediately andpermanently remedied. Ilence you reapgreater VOIUITIP, better selectivity and purertone quality-all by the simple insertionof a itRETwool) DE LUXE MODELVARIABLE GRID LEAK.

4,SItTatm'.... -1 Knob

.4110glimill Lock Nut

.11411.11EM Milled Nut

n4.1.1.11 Coil Lug

Coil LugonGridCondenser

Grid Lug

.44Eming Syphon

4.111lEK Pedestal

The De Luxe Model Bretwood VariableGrid Leak is shown in actual size. The locknut secures the knob to the threaded shaft.The milled nut secures the leak to the frontpanel, if such mounting is desired. The coillug goes to the outside of the secondary andto the corresponding lug on bullet grid con-denser. The grid lug is connected to thegrid post of the detector tube socket. Thesyphon contains the secret resistance ele-ment. The pedestal is for baseboard mount-ing.

The De Luxe Model Bretwood Variable GridLeak is specified by Herman Bernard forRadio World's four -tube Universal receiver.

North American Bretwood Co., 145 West 45th St., N. Y. City.Gentlemen: Enclosed find $1.75. Send me at once one De Luxe Model BretwoodVariable Grid Leak on 5 -day money -back guarantee. (Or $2.25 for leak with gridcondenser attached.)

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Write for full details and literatureon El MencoGridleaks and Resistors

Eleetro-Motive Engineering Corp.t27 West 17th St. New York, N.Y.

Reception Makes ManyReal Critics of Music

Radio has brought about a change inthe mind of the public about music.

A few years ago the mention of a mu-sical composition or composer frequent-ly brought a titter of laughter. It wasrare to find any except the musicallyeducated who could pronounce the namesof such composers as Liszt and Rach-inaninoff.

Radio has changed this. Announcersmust use extreme care in their pronun-ciation of the titles of compositions andthe names of composers or they are like-ly to receive call downs from very un-expected quarters.

The name Tannhauser no longer callsfor a shifting of the dials. Perhaps theprogram will include "The Evening Star"from this opera, which is one of the mosttuneful and beautiful pieces ever com-posed-so tuneful in fact that with onlya slight change in arrangement and time

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2 Complete sets of Blue Printsfor the Four and Nine Tube $3.00ModelsRADIO WORLD, 145 West 45th St., N. Y. City

GET RADIO WORLD ON YOUR VACATIONBe sure to take RADIO WORLD along with you on your vacation,

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Take Your Choice of 7Other Publications!ForNEW RADIO WORLD Subscribers OrderingNOWRadio World has made arrangements-To offer a year's subscription for any one of the following publications with one year'ssubscription for RADIO WORLDRADIO NEWS or POPULAR RADIO or SCIENCE AND INVENTION or BOYS' LIFEor RADIO DEALER or RADIO (San Francisco) or RADIO AGE.

This is the way to get-for the price of one:Send $6.00 today for RADIO WORLD

--for one year (regular price-for 52 members)-and select any one of the other-nine publications for twelve months.

two publications-Add $1.00 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!

Radio World's Special Two -for -Price -of -One Subscription BlankRADIO WORLD, 145 West 45th Street, New York City.Enclosed find $6.00, for which send me RADIO WORLD for twelve months (52 numbers),beginning and also without additional cost, Popular Radio, orRadio News, or Science and Invention, or Radio Dealer, or Radio (San Francisco), orRadio Age or Boys' Life (or $10.00 for a two-year subscription to one address). No otherpremium with this offer.

Indicate if renewal.Offer Good UntilJune 30, 1927

Name

Street Address

City and State

it became one of the most popular of mod-ern song hits.

Perhaps the public has not yet complete-ly associated the name of the composerand the name of the composition withthe number itself, but when the musicstarts, the listener finds himself whistlingor humming the tune of some old classicas if it were one of the latest popularsongs.

Of course, radio has not yet educatedall of its listeners to the point wherethey are always able to appreciate theheavier classics, but the radio audiencetoday does thoroughly enjoy the orches-trations of the lighter classics that havelived for generations because of theirmelody and tunefulness.

A program which is causing more andmore comment continuously as it is beingdiscovered by more and more people isthat period every other Sunday afternoonbetween 5:30 and 6:30 (E. D. S. T.).These programs are presented by theCrosley Moscow Art Orchestra on the RedChain from New York, comprising twenty-two stations. This period is devoted en-tirely to the lighter classical music ofpresent and bygone clays.

Quality Now Rules,Though DX Is Wanted

Of all the recent mechanical and elec-trical developments perhaps none has un-dergone so many changes as radio. Twoyears ago "volume" and "distance" wereall the rage, and a set which could notregularly pull in distant programs with avolume sufficient to rattle the windows,was considered useless.

Today the situation is radically different;radio sets, it is true, still pull in distantstations better than ever, and with as greata volume, but the determining factor bywhich a set is judged is the quality ofreproduction.

This change in public taste is a logicalchange, and indicates more strongly thananything else the transition of radio fromthe class of a novelty, to the field of recog-nized legitimate entertainment.

As a result of this demand for qualityreproduction, programs from radio stationshave improved to a point where, with agood radio set and loudspeaker, the repro-duction in quality and volume is equal tothe actual efforts of the artists themselves.

TWO factors make possible the highquality reproduction ; first, improved loud-speakers, and second, improved vacuumtubes. The first improvement, loudspeak-ers, may be applied to any set, no matterwhat the design, or how old, but with un-certain results. Unless the radio set de-livers quality to the speaker, the resultswill be unsatisfactory. The second im-provement, vacuum tubes, may only beused to advantage in sets especially de-signed for them, and even here, full ad-vantage is not taken of the improved tubes.To take full advantage of the improvementin speaker and tubes, both must be usedtogether.

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June 11, 1927 RADIO WO.KLD 21

Gernsback's Time ChimeIs Pinnacle of Accuracy

The "Time Chime," a new instrument thatbroadcasts exact Western Union time in awholly automatic fashion went on the airrecently for the first time through stationWRNY, and proved entirely successful, ac-cording to its inventor, Hugo Gernsback,editor of "Radio News" magazine. Theadvent of the device was announced threemonths ago, but because of the labor in-volved in the perfection of the automaticfeature, it was not completed until recently.

WRNY has installed the chime because ofits desire to furnish the maximum serviceto the listening public, it was stated. It isthe only radio station now giving exacthourly time.

Many technical details had to be over-come in the design of the "Time Chime,"the inventor declared after the successfultryout. He explained its operation as fol-lows:

"At the exact stroke of the hour, theTime Chime automatically sounds a beauti-ful Westminster chime sound. So exact isthe time that it cannot vary more than one-half a second.

Greater Exactitude"Listeners may therefore set their watches

more exactly than has been possible hereto-fore, the only time signals of equal accur-acy being those transmitted from Arlington,Va., by the Government station. Thesetime signals, however, are given only twicea day, whereas, the time chime operatesevery hour."

Several innovations have been made,among them the following: 19 seconds be-fore the Time Chime goes on the air, ared warning light flashes in the studio ofWRNY. If no program is on the air, theannouncer will say: "You will now hearthe Time Chime. The sound which youhear gives the exact Eastern Daylight Sav-ing Time of 9 o'clock"-then immediatelythe Time Chime sounds. If there is aprogram going on which runs over the hour,the Time Chime cannot break into it, forthe reason that the announcer must pressa button, which releases a contact, beforethe chime can go on the air. It is thereforeimpossible for the Time Chime to becomemixed with the program.

All of the contact arrangements, suchas the flashing of the warning light tenseconds before the Time Chime is sounded,and the actual sounding of the Chime, aredone by the clock itself. No human handsinterfere with or adjust anything.

Correction Problem SolvedOne of the most intricate problems thathad to be solved was the correcting signal

sent out by the Western Union TelegraphCompany every hour. The electrical con-tacts had to be arranged in such a mannerthat the correcting signal did not interferewith the normal operation of the TimeChime. This problem was finally solved.

The Time Chime uses no batteries at all,it being Mr. Gernsback's idea to have anelectro-magnetic pickup, located aboutof an inch away from the gong chime. Nomicrophone is used, but the effects of thesound are translated into electrical vibra-tions and are at once fed into WRNY'stransmitter, without going through micro-phones of any kind. This is said to be thefirst time the sound of chimes has beentransmitted in this manner. The intensityof the sound can be varied simply by mov-ing the electro-magnetic pickup nearer to orfurther away from the Chime. The clapperthat hits the gong is nothing but a relay,to the armature of which a clapper is at-tached; the head of the latter is made of

4e

hard rubber. This strikes the chime spring -gong one stroke only.

All of the technical and research workon the Time Chime was performed in thelaboratories of "Radio News" magazine.The actual construction was done by M. J.Cuttler, director of the laboratories.

THE AMPERITE BOOK"The Amperite Book, a new book con-

taining diagrams of eight of the season'smost popular circuits, (including the Dia-mond of the Air), and other valuable con-struction data, will be found of real interestto set builders and radio engineers. Thisbook has been published by Radiall Co.,50 Franklin Street, New York, and willbe sent to anyone writing for it. MentionRADIO WORLD.

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Many RADIO WORLD readers aregetting subscriptions for this paper,and are making money.Why not you?Write to Subscription Manager,RADIO WORLD, 145 W. 45th St.,New York City.

From A to ZPractically every wellknown B eliminator man-ufacturer recommends or

uses CLAROSTAT wher-ever a variable resistanceis specified.

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WATCH EXPIRATION OF YOUR SUBSCRIPTIONSubscribers will note that the end of their subscriptions is indicated on the labelson wrappers. If your wrapper shows a date earlier than the current issue, please sendpayment for renewal. Changes in expiration dates on wrappers appear two weeks afterreceipt of renewal. PLEASE ALWAYS INDICATE WHEN SUBSCRIPTION IS ARENEWAL.

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

22 RADIO' WORLD June 11, 1927

Good Back Numbers of

RADIO WORLDThe following illustrated articles have ap-peared in back issues of RADIO WORLD:1926-1927:

Oct. 9-A Practical "A" Eliminator, by ArthurH. Lynch. Building the Eduamatic, by Ca,pLP. V. O'Rourke.

Oct. 16-The Bernard, by Herman Bernard. Howto Box an "A" Supply, by Herbert E.Hayden.

Oct. 23-The 5 -tube P. C Samson, by Capt.P. V. O'Rourke. Getting DX on the Be,nard by Lewis Winner.

Oct. 30-The Oingletrul Receiver. by Herbert E.Hayden. How to Get Rid of Squeals. byHerman Bernard.

Nov. 6-Reduction of Interference, by A. N.Goldsmith. Variations of impedances, by J.E. Anderson

Nov. 13-The 4 -tube 1H -Power Set, by HerbertE. Hayden. A Study of Eliminators. by Her-man Bernard.

Nov. 20-Vital Pointers About Tubes. by CaPLP. V. O'Rourke. The 4 Tube Diamond ofthe Ale, by Dorman Bernard.

Dec. 4-The regenerative 5 -tube Set, by Cap.1'. V. O'Rourke. The 8 -tube Lincoln Super,by Sidney Stack.Winner's DC Eliminator. by Lewis Winner.

Dec. 18-Selectivity on One Tube, by EdgarSpeare. Eliminating Interference, by J. E.Anderson.

Doc. 25-A New Coupling Duke, by J. E.Anderson. Function of Eliminators, by Her-man Bernard.

len. I I927-The 2 Tube DeLuze Receiver, byArthur H. Lynch. The Twin -Choke Ampli°her, by Kenneth Harkness.

Jan. 8-Tuning Out Powerful Locals, by J. EAnderson. A Choice Superheterodyne, by

Brunsten Brunn. The 2 -Tube De Luxe ne-e...ye, by Arthur Ii. Lynch (Part 2).

15-The DeLuxe Receiver, by ArthurLynch (Part 31 The Simple Meter TestUtmost by Herbert E. Hayden. The Super-heterodyne Modulator Analyzed, by J. E.Anderson,

Jan. 22-The Atlantic Radiophone feat, by LewisRand. An Insight Into Resistors, by J. B.A11110,011. A Circuit for Great Power, bySidney Stack.

Jan. 29-The Harkness EH -27 Receiver (Part 11,by Kenneth Harkness. Use of Biasing Re-sistors, by J. E. Anderson.

Feb 5 -3 -Tube, I Dial Set, by Capt. P. V.O'Rourke. The Harkness K11-27 (Part 21,

by Kenneth Harkness. What Produces Tonequality, by J. E. Anderson.

Feb. 12-Phone Talk Put On Speaker, by Her-bert E. Hayden. All Batteries Eliminated.

by Herman Bernard. Tile Harkness K11-27Receiver, by Kenneth Harkness (Part 3).Conclusion,

Feb. 19-The 6 -Tube Victoreen, by Korman Ber-nard (Part 1.) The Big Six Receiver, by

Wentworth Wood. "IV' Eliminator Problem,by Wm. 1'. Lear. The Phasatrol Circuit, byCapt P. V. O'Rourke. The 6 -Tube V letoreen.

by Herman Bernard (I'art 2). ConclusionFeb. 26-The 5 -tube Diamond In a Phonograph,

by Hood A dragon. How To Read Curves. byJohn 10. Rider. Proper Tubes for 5 -ValveReceiver. by J. E. Anderson.

Mar. 5-Introduction of 4 -tube Universal. byHerman Bernard. Discussion on DX, byCapt. P. V. O'Rourke. Sensible VolumeControl, by Chas. Gribben.

Mar. 12-Ten Tell -Tale Points, by J. E. Ander-son. Hole To Figure Resistors, by FrankLogan. The 4 -tube Universal, by HermanBernard. (Part .1

Mar. 19-Psycho-Analyzing Circuits by ThomasL. McKay. The Universal. by Herman Ber-nard (Part 2). How To Use a Wave Tray.by James H. Carroll.

Mar. 26-The Universal. by Herman Bernard,(Part 31. Flow of Current In a VmminiTube, by Radcliffe Parker. Broadcasting hyp-notism.

April 2-1 acts Every Experimenter Should Know,by J. E. Anders.. A Ship Model Sneaker,by Herbert E. Hoyden. The 3 -tube Com-pact, by Jasper Henry. 'The Nine -In -LineReceiver. by Lewis hand (Part 1.

April 9-A 5 -tube Sieltied Set, by Herbert D.Hayden. The Power Compact. by Lewis

Winner. The Ni.-In-Line Receiver. byLewis Rand, (Part 2.)

April 16-The Schoolboy's Set, by Wally Frost.Tile Melo-Heald 11 -tube Set. by Herbert E.Hayden. The Nine -in -Line Circuit (Part3), by Lewis Rand.

April 23-The Melo-Heald Set, by HerbertHayden (Part 21. The Nine -In -Line, by

Lewis Rand. (Conclusion). How Frequen-cies Are Cut-off, by J. E. Anderson.

April 30-A 1 -tube Portable, by Jasper Jellicoe.A Ship Model Receiver. by Smedley Farns-worth. A Double Three Foot Cone, by W.H. Sinclair.

May 7-The Adams -Griffin 6 -tube Set, by DanaAdams -G riffin (Part I). A 2 -tube Portable,by blood Astrakan. How to Improve Super -Heterodyne Sets, by John L. Barrett.

May 14-A 3 -tube Portable, by Herbert E. Hay-den. The Adams -Griffin Receiver. by DanaAdams Griffin. (Conclusion).

May 21-The Victoreen Portable Receiver. byCapt. P. V. O'Rourke. A Low -Passby J. E. Anderson.

May 28-The Console Cone, by Thorvald Larsen.The 3 -tube Reflex by Edgar B. Francis. TheVictoreen Portable Receiver, by Capt. P. V.O'Rourke. (Part 21.

Any copy, I50. Any 7 copies, $1.00. Allthese 32 copies for $4.00, or start subscriptionwith any issue. Any 7 of these numbers sent aspremium with NEW yearly subscription. Noother premiums allowed. RADIO WORLD. 145West 45th Street, New York City.

Battery Economy(Concluded from page 11)

battery current and helps you in tuningyour set.

All that is necessary is to connect adirect current milliammeter in series inthe line between the B- set binding postand the B- post on the battery. Thisis shown in "A" of the figure where Mrepresents the meter. This meter shouldhave a scale range of at least 0-15 milli-amperes. The largest meter that shouldbe employed is the 0-100 milliammeter.Deflections are not noticeable on a largermeter and the smaller models are to bepreferred.

In case the B- is connected directly tothe set's A battery, the meter can be cutin series in this line. This is shown in"B" of the figure.

AR.TENew Voltage Control for"B" Battery EliminatorsAgain leaders. A new voltage controlembodying Carter originality of de-sign and quality workmanship.Equipped for accurate adjustment ofboth "B" and "C" voltages. Un-affected by climatic conditions. Carterreputation is your guarantee.

In Canada: Carter Radio Co., Ltd.. Toronto

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Nine -in -Line SuperDescribed In the Issues dated April 2, 9, 16 and23 in suchcan learn all about it. This circuit has provenIts worth In distance, selectivity, volume and tonequality. Send 60c for these Issues or send inyour subscription for one year and get these coniesas a premium. RADIO WORLD, 145 West 45thSt., New York City.

How to Build Radio World's

UNIVERSALFour -Tube Receiver

Fully described by Herman Bernard, and fullyillustrated, in the March 12 and 19 issues of.Radio World. Trouble shooting set forth inthe March 26 issue. Send 45 cents and get allthree issues.Blueprints of the Universal, $1.00 each.The March 12, 19 and 26 issues and the blue-print, will be sent immediately on receipt of$1.30. Or send $6 for a year's subscription(52 numbers) and get the three copies andblueprint as a premium. No other premiumwith this offer.

RADIO WORLD145 West 45th St., N. Y. City

Since the meter is connected in the'negative side of the B battery lines, itregisters the total B current being con-sumed.

When tuning in a station it will benoticed that the meter reads greatestwhen the station is exactly in tune. Thismeans that more current is used whenthe station is properly tuned in and thata -slight amount of detuning will decreasethe volume and save current. This maybe done on loud signals but there is amore efficient method.

The real value of the meter lies in theadjustment of the filament rheostats. Thestation should first be tuned in until themeter reads maximum and then the rheo-stats should be adjusted. be foundthat this adjustments can be so madeas to preserve the desired volume and stillcut the B battery consumption to amarked degree. It is usually necessaryto experiment with a given set until youare familiar with the necessary adjust-ments. After this is done it is but thework of a few moments to set the rheo-stats so as to preserve the desired volumeand still save considerable B current.Tuning without this method you are vir-tually a blind man.

Special Close Out Sale on allMakes A and B Eliminators

Write for Bargain Lists

Rix Radio Supply House, Inc.5505 4th Avenue, Brooklyn, N.Y.

lA

2100 intelligent questions

2100 correct answers

Ratings of 62 celebrities

and

THE SUPER -TEST

etskitie jelitotit°

Series 2The second question book

THE VIKING PRESS

Sent, postpaid, for $1.60THE COLUMBIA PRINT

145 West 45th St., New York

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(Just East of Broadway)Please send me'RADIO WORLD for months, for which

please find enclosed

SUBSCRIPTION RATES:Single Copy $ .15Three Months 1.50Six Months 3.00One Year, 52 Issues 6.00

Add $1.00 a Year for ForeignPostage; 50c for Canadian Post-age.


Louis Lager ResignsFrom Bruno Radio

Louis Lager has resigned as secretaryand treasurer of the Bruno Radio Corpo-ration, 40 Payntar Avenue, Long IslandCity, N. Y. His holdings revert to thecorporation.

Lewis F. Rodrigues, who has beenassociated with the corporation for eight-een months, in a general capacity, hasbeen elected secretary and treasurer.

Mr. Rodrigues was formerly connectedwith G. Amsinck & Co., Inc., and A. P.Villa and Bros., merchants.

William A. Bruno retains his control-ling interest and remains as presidentand general manager. The same policyof quality that has always been asso-ciated with Bruno radio products willbe continued, with the addition of sev-eral interesting innovations that willbe released for the Fall season.

New Streamline StoreThe Streamline Radio Store is one

of the imposing additions to the clown. -town radio center in New York City. Thisstore is operated by Louis Lager at 223

Why is the Karas Equamatic the MostEfficient Receiver Ever Designed?

Write us for Full Information

KARAS ELECTRIC CO.1148 Association Bldg. Chicago, Ill.

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ForSatisfactory and Lasting Results

NATIONAL COMPANY, INC.Engineers and Manufacturers

W. A. READY, Pres. Malden, Mass.

BLUEPRINTSfor

Radio World's4 -Tube

Universal ReceiverFront Panel andWiring of the Set $1.00Exactly as specified by Herman Bernard

RADIO WORLDt45 W. 45th St. N. Y. City

RADIO WORLD'SQUICK -ACTIONCLASSIFIED ADS

10 CENTS A WORD10 WORDS MINIMUM

CASH WITH ORDER

THE CRAFTSMAN Dollar Speaker Filterguaranteed to protect your speaker and prevenoverloading. Softens tone. Complete; attached ina second. Send a dollar bill now to CraftsmanRadio Products, 9 Orchard St., Newark, N. J.

VALET AUTOSTROP RAZOR-The only razorthat sharpens its own blades. Highly polished,nickel -plated, self -stropping Valet AUTOSTROPRazor, with one blade, in velvet lined metal case.Leather strop especially prepared, and completeoutfit in neat, lithographed carton. Mailed post-paid on receipt of 50c. SPECIAL: Send $2 forone-third of a year subscription for Radio World(yearly price $6), mention this particular ad, andcomplete "Pal" set will be sent as a premium.The Columbia Print, 145 W. 45th St., N. Y. C.

Fulton Street, and was formerly theEnter City Radio Co., occupying smallerquarters next door.

"The Streamline stoi'e will specializein selling direct from manufacturer topublic, as we manufacture a large list ofradio parts," said Mr. Lager, just prior tomotoring with his wife and young son tothe Chicago radio show. "Also we carrya full line of parts for all circuits and pur-poses, besides our own line of products.

"We are working on a set using the 3 -gang Wireless Specialty Co. condenserand Streamline space -wound coils."

RADIO KIT SPECIALSFor All Set Builders

ESSENTIAL KITSUltradyne L-2 (Special) $19.75Diamond -of -the -Air 22.50

LOW -WAVE KITSSilver -Marshall No. 635 $23.00Bremer -Tully Coil Kit 8.50Aero Coil Kit 10.50Let us quote you on complete or essentialkits,-Bremer-Tully Power Six; Browning -Drake (new official); Hamrnarlund Hi Q;Loftin -White;. Karas Equamatic; GrimesR.G.S. Victoreen Super, complete parts,$69.50. Also "Nine -in -Line," IVIelo-Heald, orany Super -Het. kit.Melocone 36 -Inch Double Cone, completekit, nothing else to buy, with the newbalanced Armature double -drive unit, guar-anteed the finest obtainable $11.95Unit Only 8.50We can furnish kits for any known circuit,complete or essential. Get our prices.Orders shipped immediately. Satisfactionguaranteed.

RADIO KIT COMPANY72 Cortlandt Street, New York City

Peitv

and Improved

TASTE' '1E0AT AUTHORIZED

FRESHMAN DEALERS ONLY

of Your TubesPermits just the right amount of fila-

ment current-no more, no less, while 801.cient current is there - for each tube's bestindividual performance. Insist on Amperite.Nothing else will do.Eliminates hand rheostats,Simplifies wiring.

Send for FREE Amperite BookFully explains Amperite operation. Gives sea-sons most popular Hook - Ups and valuableConstruction Data. Address Dept. R. W. 13

RADIALL CO.,50 Franklin St., N.Y.

Price $1.10complete On U.S.A.)

Sold Everywhere

RITENEW DE LUXE BST RECEIVER, 5 -tube set,

. resistance coupled audio, built-in C eliminator, gen-uine mahogany cabinet. Price $60. Five-daymoney -back guarantee. Guaranty Radio GoodsCo., 145 W. 45th St., N. Y. City.

Another "Ensco" WinnerAt last you can have clear summer reception without interference.

Only $2PostagePrepaid

MAcroarn!

SE TOnly $2

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The Ensco Selectostat works on an entirely new principle. It is not a wave-trap-it works automatically.Here is what Selectostat does:Gives your set perfect selectivity without adjustment;Perfect control of volume without distortion;Separates and brings in the low -wave stations;Reduces summer static and allows all -summer reception;Brings through the DX signals loud and clear.It requires but a moment to attach to your set.Sold under the Ensco guarantee. If not entirely satisfactory return in tendays and your money will be refunded.

DON'T FORGET !THE FAMOUS ENSCO 3 FOOT CONE KIT

Standard Kit with Ensco unit, decorated and marked Alhambra for cone,apexes. Booklet, etc., only $10. Kit with hardwood wall frame $11 prepaid orC.O.D. Ask your dealer or send your order to our nearest office. Ensco products ,are sold under absolute money -back guarantee.

ENGINEERS' SERVICE CO.25 Church Street, New York

73 Cornhill, Boston, Mass., or 28 E. Jackson Blvd., Chicago, Ill.

WHEN YOU GO AWAY ON YOUR VACATIONTell your newsdealer to save a copy of RADIO WORLD for you eachweek. In this way, you will have a complete file-as sometimes it is diffi-cult to get back numbers.Or send us $1.00 and we will save you a copy of each week's issue untilSeptember 15, 1926, and mail them to you at whatever date you specify.Circulation Manager, RADIO WORLD, 145 West 45th Street, N. Y. City.


NOW!!T e Complete Listeners'Guide to Radio Programs

NEW YORKRADIO PROGRAM WEEKLY

For the first timea really COMPLETE program will be printed for New York and its environs.Not only will all the features be listed, by their full name, but we aim to printthe program in such a way that the title of every selection to be rendered, be itvocal or instrumental, will be printed, so that if you wish to listen -in to a certainstation you will know in advance just what its program will be to a detail.

RAnto PROGRAM WEEKLY is also a weekly magazine in which you will findreflected everything that happens or will happen in broadcasting that is of interestto you. You who listen constantly to radio programs must often feel curious asto what goes on behind the scenes, and what the process of broadcasting entails.You can not help but be interested in the artists, the radio station directors, andthe announcers. All of this and more will be represented each week in RADIOPROGRAM WEEKLY in a non -technical interesting manner. The magazine has beenbuilt in such a way that it will be of interest to every one of the family.

ALTOGETHER RADIO PROGRAM WEEKLYCan be summed up as follows:

1st, A non -technical radio magazine, published and edited for the radio,listener ;

2nd, Brings to all radio listeners correct and exhaustive radio programs;3rd, Keeps listener informed of each and every phase of radio broadcasting

of interest to him;4th, Serves as an effective link between the listener and the broadcaster ;5th, Helps uphold the listener's rights; and

6th, Is fair to broadcasters and artists./ C.THE

ISSUE

ON ALL NEWSSTANDSEXPERIMENTER PUBLISHING CO., INC.230 Fifth Avenue New York, N. Y.

REG-U.S. PAT. OFF AN AC POWER AMPLIFIER AND 400-v B ... · THE SUITCASE SIX FOR OUTINGS (Hayden)...

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Transcript of REG-U.S. PAT. OFF AN AC POWER AMPLIFIER AND 400-v B ... · THE SUITCASE SIX FOR OUTINGS (Hayden)...