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WHEN cleaning your variable condenser think not only of the plates but ofthose nearest you!

July 17, 1926 RADIO WORLD

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Vol. IXNo. 17

Whole No. 225

JULY 17, 1926115c Per Copy. 56.00 a Year

REG. U.S PAT. OFF.

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

Street, N. Y., N. Y.Phones: BRYant 0555 and 0559.

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

A Double Duty Loop Aerial

FIGS. 1, 2 AND 3The finished loop and the lower pivot arrangement.

Embroidery Hoops AreUsed for the Frame-One Winding Turns In-side the Other and Af-fords Variety of Uses.

By J. E. AndersonConsulting Engineer

EVERYBODY knows what an em-broidery hoop is, but everybody does

not know that an excellent loop forradio reception may be wound on oneof these hoops. An embroidery hoopconsists of two wooden rings, one fit-ting snugly inside the other. The in-side of the rings has a strip of felt gluedto its outside periphery. This strip offelt is set into a groove about 1/16"deep,and about .A" wide. Remove this stripof felt and clean the groove of all hard-ened glue. When this has been done,it will be seen that the groove is slight-ly deeper near the side flanges. Bymeans of the edge of a large file or othersuitable instrument file clown the centerof the groove until the depth is the sameall over. In doing so be very careful notto injure the side flanges. When thebottom of the groove has been filed flatall around drill two tiny holes (about No.50) radially through the bottom, onenear each flange. The next step is towind the loop.

The number of turns to be put on de.-pends on the inductance required, onthe diameter of the hoop, and on the sizeof the wire to be used. If the loop is

nil wim

gaingiLL.:

,11:a aIMm. L.

A.

iiimiu INE161. 1:71 1411110i

C

d A

FIG. 4The cross-sectional drawing.

to be used for broadcast reception witha .0005 mfd. variable condenser, about 170microhenries inductance will be requiredFor this a 12" hoop is fecommended. Us-ing No. 24 double silk covered wire, 14turns will do the trick.

The Extra Two TurnsThe width of the groove is such that

only 12 turns of this wire can be wound

LIST OF PARTSOne 12" embroidery hoop.One 10" embroidery hoop.About 80 feet of No. 24 double silk

covered wire,Four small binding posts.A few nuts, screws and angles as sug-

gested.A few strips of hard rubber.A wooden base about 1" thick and

5" diameter.

Inductance Suitable forTuning With .0005 or.00025 Mfd. Condenser- Regeneration MadeAvailable in SeveralWays.

in the first layer. Hence it will be neces-sary to bank wind two turns to get onthe 14 turns. It is convenient to windfirst two turns, then put the third turnon top of the two, then continue thewinding as a single layer coil until 13turns have been out on. The fourteenthturn may be put on top of the twelfthand thirteenth turns.

If bulkier wire is used for winding thecoil more turns have to be put in the sec-ond layer, but if finer wire than No.24 is used it will not be necessary tobank wind at all. But finer wire is notrecommended.

The two small holes drilled in the bot-tom of the groove are, of course, used forthe terminals. The ends of the wire arebrought through these holes and leftpointirig toward the center of the hoop.

The loop is now ready for use, but itis not yet finished. Just as a matter ofprotection of the wiring the outside hoopshould now be slipped over the woundring. It will be found that the Outsidering is now considerably too large. Thismust be fixed. The simplest way is to put.padding between the two rings. Cutstrips of cardboard, fibre, or bristol boardof the same width as the width of thetwo rings. Then lay the two rings flatnn the table, one inside the other, and

(Concluded sum page 4)

4 RADIO \V 0 R L D July 17, 1926

Tester Shows You at Glance Efficiency of a Tube

I

THE INSIDE works of a laboratory tube tester are at left, while to the right is the panel view. The meters are wired soas to show the filament amperage, plate milliamperage, filament voltage, and grid voltage at a specified plate voltage,varied with the aid of the resistor batch to the lower left in the back view. With the varying of these resistances, itis, also possible to calculate the amplification factor. The buzzer aids in determining the proper amplification of the tube.The mutual conductance is calculated from readings given by the meters.

Same Loop Used With VOLTS PUSH

.00025 or .0005 Capacity AMPERES IN(Concluded front page 3) the hard rubber plate e. The larger loop ANY CIRCUITfill up the space between them with the is clamped to this plate by means of two

strips of padding. Force enough in, even brass screws and the double hard rub -all the way around, to make the two ber plate cd. The latter is made double Water will not flow in a pipe line unlessrings stay firmly together. Then run for strength and also .for centering the a force pushes it along, e.g., a pump. Thesome glue or cement along the sides and smaller loop. The lengths of the upper water will not keep on flowing unless thelet dry. and lower pivots are such that the in- pump supplies pressure. Electricity will

Now binding posts could be provided side loop may be slipped in place by not flow in a circuit unless there is a bat -and the loop could be used for picking elongating the outside loop along the tery, or some other electrical source, inup signals, but only as a simple loop. vertical and the inside along the hori- the circuit. The battery is similar to theThere is more to be done. Procure an- zontal, yet such that the inside loop can- pump in action, e.g.. supplies pressure.other embroidery hoop, one which may be not come out accidentally. The mounting This pressure is what is commonly knownturned inside the other. A ten inch hoop of the loop assembly into the base P as voltage or electromotive force. Theis about right. Prepare and wind this in is similar to that of the inside loop into more cells in the battery connected inthe same manner as. the first, except that the plate cd. series, so that pressures will add, theonly twelve turns should be put on it. It was at first intended to have the greater the electric pressure and theWhen the two loops have had time to outside loop turn without turning the voltage produced.dry, mount the smaller loop inside the base, but it was found that this did not Suppose an electric current to be sup -larger in such a manner that it may be give satisfactory control of the loop. plied to the motors of a trolley car, withturned freely. One way of mounting Hence the larger loop was rigidly se- the aid of a generator and two conduct -will be shown in detail below, cured to the base so that it is necssary ors, e.g., trolley wire and track. A. steam

The finished loop is depicted in Fig. to turn the base with the loop. In view engine supplies the mechanical energy to1. Observe that the two loops are very of this it may be simpler to fasten the the generator, which is transferring thisnearly concentric. It is desirable to ob- outside loop to a circular piece of wood mechanical energy to electrical energy.

The changing of this energy causestain this condition as nearly as possible. in the same manner that the inside loop cur -The upper pivot is very simple. Two is fastened- to the plate b. A base such rent to flow when the circuit is completed

strips of hard rubber of the same width as that used in this loop is not easy to through the car. Between the terminalsofthe trolley wire and the track exists aas the rings are bent to conform to the obtain,

curvature of the rings, a hole is drilled The outside loop alone tunes the broad- difference of electric potentialAll generators have for their purposein the center of each of these strips, cast range of wavelengths with a .0005

and then they are glued in place. The mfd. condenser. When the inside and the setting up of such a difference of po-tential which is a difference in electricglue will hold better if the glace on the outside loops are connected in series condition determining the direction ofrubber is removed by means of a file or aiding, the combination tunes the same flow of electricity front one point to an -sandpaper. The pivot proper is an old range approximately with a .00025 mfd other.time inductance switch stop and a nut condenser. The iitside loop may also be An electric potential difference may beto match. used for tuning in the shorter waves considered as establishing an emf, whichThe lower pivot arrangement may be in case a .0005 mfd, condenser is used.causes a flow of electricity, when a con -seen front Figs. 2 and 3, or more plain- If it is desired to make the set regen- ducting path, is provided. Therefore,ly from the cross-sectional drawing, Fig. erative, the inside loop makes a very electromotive force is that which drives an4. BB are the two binding posts to which good tickler, as the regeneration may be electric current, the volt being the unitthe wire terminals are connected, 'as are controlled by turning the inner coil. The of emf.two small brass angles by means of which smaller loop May also be clamped in the The current is the water in the pumpthe inner loop is held to the hard rub- plane of the larger and the regeneration parallel, while the voltage is the pump.ber plate b. This plate has three No. controlled by means of a small variable Current is measured in amperes.29 holes, two for the binding posts and condenser.

one for the pivot. The latter is simply If a .00025 rnfd. condenser is employeda %" flat head brass screw secured to for tuning, the circuit may still be made Tip Jacks Usefulthe plate by means of a nut under the regenerative by connecting the two loops at Detector Outputplate and extending into a No. 28 hole in series aiding, the free terminal of thein the double plate cd. The dotted areas large loop to the grid, the free terminal A pair of phone tip jacks mounted inin Fig. 4 represent the sections of the of the small loop to the plate, and the an accessible place, such as the panel,two loops, and the non -shaded rectangles junction of the two loops to the, filament. connected to the primary posts of thein these areas are the two winding spaces. In this case the regeneration would be first- audio frequency transformer or theAA are the two binding posts for the controlled by means of a small condenser detector output, may be used for listen -outside loop, and these are secured to in series with the lead to the plate. ing to DX.

July 17, 1926 RADIO WORLD

How to Measure CouplingClose Coupling Is Less Ef-

fective Than Many Sup-pose - The OptimumPoint Is Critical Coup-ling, for as Fields AreMore Strongly LinkedAbsorption Losses TakePlace.

[Following is the third of a series of ar-ticles telling how to equip yourself witha real radio laboratory at small cost. Forhookup fans and manufacturers alike sucha laboratory is very valuable. The firstarticle, published in the June 19 issue, dealtwith the construction of ass RF oscillator,a modulated audio oscillator. The secondpublished June 26, showed how to determinewave forms. More details along the line ofthe following article will be published nextweek, issue of July 24.]

By John F. RiderMember, Institute of Radio Engineers

TREE more units must be constructedbefore we can start actual experi-

mental work. These are a radio frequencyamplifying .unit, a detecting unit and anaudio amplifying unit. The radio frequencyamplifier is of the tuned type. The de-sign is conventional and consists of twostages. The tuning capacities are .0005mfd. variable condensers and the coilsconsist of single layer inductances. Thewinding forms are 2" in diameter. Thesecondary winding consists of 64 turns ofNo. 24 DSC wire. The primary windingconsists of 3 turns of No. 24 DSC wounddirectly over the secondary winding, atthe midpoint. A piece of empire paperis the insulation used to separate theprimary from the secondary. The reasonfor the very few turns in the primarywinding is the demand for utmost stabil-ity, sensitivity and energy output beingsecondary considerations. The layout ofthe system is shown in Fig. 1. All con-nections are made to Fahnestock clips.One rheostat is used to control the twofilaments, and clips for automatic filamentcontrol devices are shunted around therheostat.

To provide variable coupling into thisradio frequency amplifying system it isnecessary to construct another input coil.This consists of two separate units, aprimary and a secondary. In design thesecondary is an exact duplicate of the onementioned previously. The primary, how-ever, is a separate winding on a 134" dia-meter tubing and consists of 12 turns ofNo, 24 DSC. This is not fastened or at-tached to the secondary hi any manner.When it is desired. to alter the couplingbetween the primary and secondary theposition of the primary with respect tothe secondary is simply moved. Thisvariable unit is that it will be found ofgreat utility in later experiments.

The Detector UnitThe next unit is the detector, and will

lie made regenerative to increase itsscope of operation. If the regeneratorcontrol is not desired, it can be shortedout of the circuit very easily, being of thetickler coil type. The detecting unit ismounted on a separate baseboard, beinganother open model. In fact, all the test-ing equipment is open models. This per -nuts greatest accessibility. The layoutand wiring diagram are given in Fig. 2.

RerialGround

Input1

03

1111111111111111111111111111

11111111111111111111111111111

Ov-tp-u-t

FIG. 1THE WIRING of the radio frequency test amplifier and the suggested baseboard

layout. All equipment is of the open construction type.

An individual primary and secondary arenot provided for the detecting unit. Whenit is desired -to utilize the detecting unitin conjunction with the radio frequencyamplifier the coupling device between thedetector and the last stage of RE is an-other unit similar to the regular radiofrequency transformer.

When it is desired to use the detectordirectly connected to the aerial, withoutany radio frequency amplification, the vari-able coupler is used to replace the radiofrequency transformer. As is evident, theassembly and wiring of the detecting unitare independent of the amplifying unit.

'The coils which comprise the primaryand secondary inductance are not fast-ened to the baseboard. The tickler coilconsists of 25 turns of No. 26 DSC wire ona 13/4" diameter tubing. The tuning con-denser is an enclosed General Radio unitof 500 mfd. (.0005 mfd.) equipped with avariable grid leak and also with clips forfixed leaks, so that either may be used atwill. The grid condenser is a .00025 mfd.unit. The filament control is by means ofa rheostat, but clips for filament controldevices also are provided.

Binder Used on CoilsAll inductances are. given a thin coat-

ing of collodion and permitted to drythoroughly. This binder substance can beapplied with perfect impunity to all in-ductances utilized in the radio frequencyamplifier and the detector unit, for thedetrimental effect of the binder is entirelynegligible when the binder is thoroughlydry.

The leads from the coils used in the

detector unit, when the variable couplingis being utilized, are flexible so the coilsmay be moved with ease and remain fixedin their position, thus obviating the tend-ency to shift due to the tension of theconnecting lead.

The First ExperimentThe layout of the audio amplifying unit

is given in fig. 3. Transformer coupledaudio amplification is used at this timebecause it provides the greatest outputwith the minimum number of tubes, con-sidered solely from a power angle. Re-sistance and impedance coupled unitswill be considered later. The transform-ers are not limited to any one manufac-ture. The only requisite is that they beof reputable manufacture and be of from3f6 to 4 -to -1 turns ratio. The connectingposts are again Fahnestock clips. Bothrheostats and automatic filament controlclips are provided. The transformers aremounted as shown in the drawing. Theinput clips are located at the extreme leftof the baseboard, permiting easy connec-tion to the output of the detector unit.Sufficient space should be left betweenthe second audio transformer and the sec-ond tube to permit the location of a vari-able resistance. across the secondary ofthat transformer. Two B plus terminalsare provided, one for each audio tube.The same applies to the C potentials. AC battery minus terminal is provided foreach audio tube so as to allow separatevalues of negative grid, bias. The rheo-stats are 10 -ohm units and capable ofcarrying .5 ampere.

Assuming that the units are completM,

6 R.\ DI 0 WORLD July 17, 1926

A Laboratory ExperimentDaYeator On

ri4116G 4.

Condense

11G

iii11111111111111111111

173B BA- Si- 8- 8 -1 -

'shoo

03

03

FIG. 2we can start on a series of interestingexperiments.

The first test is that pertaining to coup-ling, that is, the transfer of energy be-tween coils: Coupling has been, forsome unknown reason, very much neg-lected by radio writers, although it mani-fests a very great effect upon the gen-eral operation receiver, by virtueof its control of selectivity and volume.With the large number of broadcastingstations in operation, selectivity is of para-mount importance.

Types of CouplingCoupling is divided into various types,

depending upon the medium used totransfer the energy from one circuit to

,the other. For instance, if a condenseris used to interlink the two circuits, andthe energy when passed from one circuitto the other is caused to go across thiscapacity, the circuits are capacitativelycoupled. If the coupling device is a re-sistance,. the circuits are resistancecoupled; if the coupling device is a chokecoil, as in many audio circuits, the cir-cuits are impedance coupled. If there isno direct connection between the circuitsthe energy being induced in one coil bythe action of the current flowing in theother coil, the circuits are inductivelycoupled, and if the two circuits utilize thesame coil, the circuits are conductivelycoupled.

Being concerned with the type whichmanifests its effect upon selectivity, we

Calibrareds

couplinclin 2nche

Signal Strength Is Deter-mined in Arbitrary ButAccurate Relative Val-ues by Rectifying Out-put and Hooking up a0 -to -1 Milliammeter -Deflections of NeedleShow Effect Due toCoupling Variation.

can devote our attention at this time toradio frequency circuits and ignore forthe present methods of coupling. Andsince in radio frequency circuits pertain-ing to conventional reception, the preval-ent type of coupling is inductive, we willdelve into this type of coupling.

Degrees of CouplingNow, in addition to various types of

coupling, we also have various degrees ofcoupling, such as loose, critical and close.If one were to immediately interpret thesedegrees of coupling as direct indicationsof the transfer of energy from one circuitto the other, and interpret the energytransfer as different values of signal in-tensity, it would be only logical to thinkthat maximum or close coupling wouldafford the greatest signal intensity andvolume. Such, however, is not the case!

The reason for this phenomenon is notvery difficult to comprehend. Just tryto visualize two inductances. Alternatingcurrent is flowing in one of the coils.When another inductance is placed inproximity to the first one, current will beinduced in the second. We are assumingat this time that the two inductances aretuned to the same frequency or wave-length.

Now, if we place a recording deviceinto the circuit of the second inductancewe find that a certain current from thefirst coil is induced in the- second coil,let us say, with a 5" separation betweenthe coils. We gradually reduce the sep-aration between the two coils and notethat the current in the second cirit isincreasing, until when the coils areapart the current indicator has passed thepeak and is beginning to show a declinefrom the peak reading.

Measures Signal StrengthWe increase the separation until the

current indication -is maximum and notethat the separation between the two coilsis %". Now, it is quite safe to assumethat the current indications in the second

Crystaloer: of or

Variable coup/ s.0 -.1

tit Li a al Irt,re

11111 11111111 111

FIG. 4METHOD of measuring the signal intensity.

I AAA 5

dir

FIG. 3LAYOUT for audio frequency amplifier.

circuit can be interpreted in terms of sig-nal intensity, for the greater the currentinduced in the second circuit, the greateris the energy transferred to that circuit,and if that circuit were connected to avacuum tube amplifier or detector, theoutput- would be greatest when the cur-rent in this arrangement shows maximum.

We are now in a peculiar position. Wenote that the energy transfer reaches amaximum value before the coupling be-tween the two coils is maximum, or in-terpreted differently, the current in thesecond circuit is maximum although theseparation between the two circuits is notminimum. Further as the separation isnow reduced, that is, the coupling is in-creased, the current decreases instead Ofincreasing! The second inductance reactsupon the first, and this reaction resultsin a cumulative effect which reduces theamount of actual energy transferred fromthe first coil to the second. This effect isincreased as the coupling is increased, un-til at maximum coupling the energy trans-fer is much less than at the point ofcritical coupling, when it is maximum.

To determine this phenomenon experi-mentally, set the detector unit into opera-tion. Connect the aerial and groffnd tothe respective posts, and tune in anylocal station, with 1" separation betweenthe primary and secondary coils. It isbest to select a powerful local brIoad-caster. With a strong signal in thephones, reduce the coupling between theprimary and secondary coils (increase theseparation). You will observe how thesignal in the phones decreases. Nowgradually increase the coupling, (decreasethe separation) until the primary coil ispartly within the secondary coil. Youobserve a gradual increase as the coup-ling is increased, and then a gradual de-crease in signal intensity from the peakintensity as the coupling is still furtherincreased.

The Coupling CurveVarious degrees of signal intensity are

obtained with the three degrees of coon -ling, because of the large scope of opera-tion of loose coupling and close coupling.Loose coupling exists until the couplingbecomes critical, and then close couplingexists from critical until unity is reached.The closest coupling is obtained whenall the lines of force from one coil cutall the turns of the other. The loosestcoupling is obtained when the separationbetween the two coils is infinite. Criticalcoupling is obtained when the magneticlines of force of the first coil cut themaximum number of turns of the secondcoil without any reaction from the secondcoil back to the first.

The rise and fall of this energy transferphenomenon can be shown by what isknown as a coupling curve. Revealingthe transfer of energy plotted against de-grees of coupling. In our case the vari-ous degrees of coupling are marked off asseparations in inches between the coils_

(Concluded next week)

Tula L. 1.026 k \ 1) 1 ) \ \ ) 1 I)

A 1-Control Crystal Set

(Radio World Staff Photo)FIGS. 2 AND 3

The method of attaching the bushing to the condenser shaft is shown at left. The rotary coil shaft (at right) then is slippedinto the bushing. The rotary coil should not be at zero coupling when the condenser plates are nearly nested, as shown in

the photograph.

By Smedley LyonsMANY persons perhaps wonder at the

origin of articles on how to con-struct a simple crystal receiver. It is al--ways a simple set, for even engineeringtalent has been unable to impress anymarks of complication upon the crystalreceiver.

The articles originateA radio experimenter blows out all the

tubes he has in the house, or his A bat-tery runs down so low that he can notlight the tubes, or the B batteries arriveat the end of their career. Hence hecan not get reception that night on thefamily receiver. Yet he is itching todo something along radio lines, prefer-ably something constructional.

Lo, the Poor CrystalOn a shelf he espies a crystal detector.

Ah, there is the inspiration! "How ToBuild a Simple Crystal Set!" The idea andthe title flash simultaneously upon thescreen of his imagination. And he goesto work.

Building the set takes him about 40minutes. Then he hooks aerial andground to their proper connecting points,casts a contemptuous glance at the charg-ing A battery, or the dead tubes, or the-exhausted B batteries, and listens to pro-grams on the simple crystal set.

Mother has to stop rattling the news-paper as she turns the pages, and allothers in the house must keep quiet, too,else he will hear little if anything. Thefolk are not used to that, having been-cured of the habit with the advent of the

FIG. 1Wiring diagram of a crystal receiverwhich may be operated with single

control.

OneOneOneOneOneOneOne

LIST OF PARTS7x7" panel.6x7" baseboard.variocoupler, L1L2..0005 mfd. variable condenser, Cl.

.001 mfd. fixed condenser, C2.crystal detector.pair of earphones.

tube receiver in the home several yearsago. But -the reception is enjoyable tohim, although few close relatives mayfeel annoyed, and the experimenter tem-porarily renews his admiration for, one ofthe popular circuits of years gone by, al-though one not in great favor today. Theunderlying thought, however, and theonly one that offers any solace, is thatthe youngsters will build the simple cry-stal set, and likewise those oldsters whonever before built a receiver and are anx-ious to get started on this fascinatingwork. So he writes an article on the sub-ject and it is bought by a magazine whilethe editor is on vacation.

The Set in Fig. 1So it was that the crystal receiver

shown in Fig. 1 came into existence inone particular home. The diagram revealsa variocoupler, connected with primary toaerial and ground and secondary to oneside of the crystal and to ground, a vari-able condenser tuning the secondary.With a good fixed detector, like the Car-borundum, this is an acceptable set. Toobtain signals, connect the phones tothe other side of the crystal and to theground, a fixed condenser, C2, bridgingthe phones, to bypass the radio fre-quency currents around them, thus avoid-ing the resistance effect of the magnetwindings.

The tuning may be accomplished witha single control by connecting the variablecondenser shaft to the rotary coil shaft.This can be done conveniently only if theshaft of the condenser protrudes at rear.A 9/32" bushing is used, if the shafts arethat size, as is customary.

The rotary or primary coil is turnedso that coupling is just enough to enableone to get fair volume on any low wave-length station within range. As the con-denser dial is turned it will cause thecoupling to become greater, that is, the

primary and secondary windings comecloset and closer to parallel position. Thisgives you greater selectivity on the lowerwavelengths than if the coupling werefixed. Also you obtain single control.

Coil Data For the SetThe primary coil winding depends on

the dimensions of the coupler. You mayuse an existing- 3 -circuit tuner for thisreceiver, omitting the small winding onthe -stationary form, or may rewind formsof an old variocoupler, or use an Old.variocoupler "as is."

If the primary form is 2" 'to 3" dia-meter, put on about 18 turns of wire.preferably No. 22 double cotton covered:The secondary then would be 41' dia-meter and would have 40 turns of thesame kind of wire, if Cl is .0005 mfd. Ifit is .00035, then secondary turns wouldnumber 50, while if .00025 the secondarywould have 60 turns. A crystal set needsmore wire than a tube set for 'tuning inthe same wave band.

If the primary is 2" or thereabouts, puton 22 turns, and use a 3" or 3I/2" second-ary. For 35/2" put on 50 turns and for3" put on 57 turns. This is for .0005 mfd.tuning. For lower capacity condensers,put on more secondary wire.

One end of the secondary winding is. (Concluded on page 8)

(RADIO WORLD Staff Photo)FIG. 4

The Panel view.

8 RADIO WORLD July 17, 1926

Ionization Is PivotOf Operation of Tube

Unless a cold electrode in a tube issubjected to much electron bombard-ment, no appreciable amount of electronswill be given off. Therefore in a two -electrode tube, if the plate is made nega-tive with respect to the filament, no cur-rent will flow.

That is, if the plate is made negative,any current which will flow from the plateto the filament must be caused by theelectrons which leave the cold plate.When a cold electrode, which may beeither a plate or grid element, showsthat current is flowing in such a direc-tion as to indicate that electrons are flow-ing from the element, the tube has gas init, which is serving as a means of conduct-ing the current.

Even in the highest vacuum obtainablethere is still a tremendous number of gasmolecules in the supposed completely eva-cuated space.

Usually a gas is a fairly good insulatorand provides a' difficult path for the con-duction of current.

However, when a gas is under lowpressure, it may be made to carry a heavyflow of current, if this gas becomes ion-ized.

That is, when the normal gas atoms arebroken into two parts, e.g., a free elec-tron and a positively charged nucleus,ionization is taking place.

The ionization, or breaking up of thegas atoms, is equal to a breakdown of

insulator when subjected to a too highvoltage.

Ionization of the gas in the radio tubesoccur as low as 22% volts. The hot fila-ment furnishes the electrons, which areso active, due to positive plate voltage,that the ionization of the gas atoms isstarted.

Test of Electron ActionA simple test may be used to show what

action the electrons take in producingionization,

If the plate of a known faulty tube issubjected to its usual voltage, with thefilament cold, no plate current will flowand the tube naturally will not show anysigns of being ionized.

But suppose the filament current is in-creased step by step. The emission ofelectrons will start. The plate currentalso will start to flow. At a certain fila-ment temperature, dependent upon theamount of gas in the tube, a blue glowwill appear, the latter accompanied by asurplus amount of plate current.

In this way it is possible to note thatthe filament must be giving off a mini-mum number of electrons before anyionization of the gas takes place'.

It will be remembered that when thefilament current was low, no plate cur-rent flowed. Therefore, if either the platevoltage or filament current is reduced orvice versa, it is possible to control the

Long Aerial Is Neededfor Crystal Reception

(RADIO WORLD Stall Photos) FIGS. 5 AND 6Views of a completed 1 -control crystal receiver. The

clips on the baseboard.(Concluded from page 7)

soldered to one end of the primary wind-ing. If signals are not loud reverse thesecondary connections.

If the crystal has its terminals markedA and G, the A terminal goes to the sec-ondary coil and the G terminal to one ofthe phone cord tips.

The variable condenser may be con-nected with rotor plates to ground, as inFig. 1, or with stator plates to ground,for in a crystal set this makes no differ-ence.

Wiring DirectionsBe sure that you use a long aerial. The

longer the better. But if you have anaerial you use with a tube set, and donot want to monkey with it simplyto get crystal reception, putting more

phones are connected to

turns on the primary coil than were pre-scribed previously may get you strongersignals.

The wiring is done by connecting theaerial to one terminal of the primary andthe ground to the common connectionestablished by the other end of the'prim-ary and one terminal of the secondary.The ground lead also goes to three morepoints: (1) to the rotor plates of the tun-ing condenser, Cl ; (2), to one side of thefixed condenser, C2, and (3), to one of thephone cord tips. The remaining freeterminal of the secondary is connected toone terminal of the crystal, the otherterminal of the crystal being joined to theremaining free side of, the fixed con-denser and to the free phone cord tip.

That completes the wiring.

actual ionization condition of the tube.Usually the state of ionization paralyzesthe proper action of the tube in poweramplifier tubes only. Although ionizationoccurs very little in tungsten or thoriatedtubes, because of the high type of vacuumusually employed, the oxide filament typeof tube usually offers trouble.

Action In TubeThat is, in these tubes much gas is pres-

ent in the filament, grid and plate. Whenionization starts, the electrons of the ion-ized gas go to plate, which is positive.The positive nuclei, however, gd back tothe filament, subjecting it to a bombard-ment, which results in the extra heatingof the filament in one spot,.,Avith the re-sultant burning out of the filament atthis one spot. '

Of course, the greater the filament cur-rent, the greater the electron emission,which in turn causes the ionization to in-crease, increasing the return bombard-ment of the electrons at one spot and theconsequent burning out of the filamentat that one spot.

Tubes which have quantity of gas areemployed with great satisfaction as de-tector tubes. The grid and the plate volt-age must be so adjusted that it is justabout enough to bring about the ioniza-tion. The small increase in grid voltagedue to the incoming signal brings it upto the point of ionization with a result-ant increase in plate current. This typeof tube is difficult to control, althoughvery sensitive.

DX Heard on Crystal;Mystery Is Unsolved

The story of miraculous radio receptioncrops up every so often. KFI has hadseveral well authenticated reports of DXcrystal set reception, among them beingnotifications from Stewart Borg, whoheard KFI on a crystal set in Seattle,900 miles from Los Angeles, and G. E.Tuttle and W. L. Coon, who heard -KFIon home-made crystal sets in Denver,800 miles from Los Angeles. So far, noexplanation except re -radiation from re-generative sets has been advanced to ac-count for these super -reception records.The theory does not hold good, however,when there are no radiating receiverswithin a mile or so of the crystal set,which was true of Borg's reception.

As remarkable as the crystal set re-ception is the authentic reception of KFIon one tube in Brooklyn, Havre de Grace,Lynn and other Atlantic seaboard points.As one fan expressed it, the only ex-planation seems to be that some nightsradio waves -just naturally get togetherand travel high, wide and handsome.

Many Requests Receivedfor Frequency Signals

Although it is known that the Govern-ment desires to do away with transmit-ting standard frequency signals, lettershave been received which have causedofficials at the Bureau of Standards todecide to continue the sending of thesesignals on the 20th of each month asusual until October.

Ultimately, however, it is expected todo away with the sending of these sig-nals, since other means of disseminatingthe Government standards of radio sig-nals of definitely announced frequencieshave become increasingly available. Thisis in part due to the increasing use ofPiezo oscillators arid the wide availabil-ity of reliable standards testing servicefrom a number of laboratories that docommercial testing of frequency meters.None of these was available when thestandard frequency transmissions were in-augurated three years ago.

July 17, 1926 RADIO WORLD 9

Circuits of Losses and GainsTube Economy Is Stressed in Group of Hookups

L

VANRIA

z<DGrC>

O

PR

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THE SCHEMATIC diagram of the Light 5 Portable, described by Herman Bernard in the June 12, 19 and 26 issues ofRADIO WORLD. The antenna coupler used is of the conductive type. It is the most energetic form of antenna inputthat can be used. Two stages of tuned radio frequency amplification, a non -regenerative detector end two stages of trans-former coupled audio frequency amplification are used. Since the filament control of the RF and the detector tubes is notcritical, they are controlled by a single rheostat, Rl. The filaments of each of the two audio tubes are controlled by a bal-last resistor. SI is employed for short circuiting a part of the antenna coil so that the entire waveband may be covered

without using a larger condenser across the winding, than .0005 mfd.

Power Used.18 Watt

Power LostNone

UV 199

Current.06 Ampere

Power Used.18 Watt

Resistance25 Ohms

Power Lost0.9 Watt

UV 199

Current1 .06 Ampere

Power Used.18 Watt

Resistance50 Ohms

Power Lost.18 Watt

UV 199

Current.06 Ampere

Purser Used1.25 Wart

Resistance4 Ohms

Power Lost.25 Watt

UV -201 A

A Current

1

.25 Ampere

3 -Volts 4.5 Volts 6 -Volt

HOW IT is possible, when the -99 type tubes is used with different voltages and rheostats, to save or lose power, Acomplete discussion of saving power with different voltages and rheostats with various types tubes was given by J. E. An-derson in the Dec. 5, 1925, issue of RADIO WORLD. As to the above diagram, in the first case, when the -99 tube is oper-ated directly from a 3 -volt source, with no rheostat, no power is lost. However in the next case, when the same tube isoperated from a 9.5 volt source, with a rheostat connected in the circuit, 0.9 watt is lost. From a 6 -volt source the loss is

.18 watt. At right the loss in a 6 -volt tube hookup is shown.

DETECTOR

DETECTOR tel STAGE

1st STAGE

2nd STAGE

2nd STAGE

3rd STAGE

Phones

THE SCHEMATIC diagram of asimple and effective crystal receiver,wherein are used a tapped radio fre-quency coil, which should have avariable primary; a variable conden-ser, having the proper capacity toshunt the secondary; a crystal detec-tor; a .001 mfd. fixed condenser and a

pair of phones.

THE ELECTRICAL diagram of thefrequency changing system, or theTHE CIRCUIT diagrams of two popular forms of AF amplifiers. At the bottom oscillator and modulator (first de -is shown a 3 -stage straight resistance coupled AF amplifier, while on top is a dia- tector) used in Western Electricgram of a stage of transformer coupled and a stage- of resistance coupled AF Super -Heterodynes. The Hartleyamplification. oscillator is employed.

10 RADIO WORLD July 17, 1926

Resistorc>

0G2

C CozC> V,ANRes

or Regeneration

()E`-2+ I

.5"

FIG. 370The electrical diagram of the Drum Dial Type Set.

Radio University

0 e

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

When writing for information give your Radio University subscription number.

PLEASE GIVE the circuit diagram,with data and any special wiring detailsof the set shown in the photographs inthe July 3 issue of RADIO WORLD, where-in the making of a drum dial used in con-nection with this set, was described. Thelayout, etc., is very attractive and seemsto be ideal for a portable.-CarolynJenks, Lavery, Pa.

Fig. 370 shows the electrical wiring dia-gram of this receiver. The coil is woundin spiderweave fashion, on 15 point, 5"cross section forms. The primary iswound toward the center of the hub,which is 1/2." cross section, and consistsof 15 turns. The secondary, wound im-mediately after the primary, consists of50 turns. The dowels, over and underwhich the wire is wound, are 1/8" in dia-meter. The windings should be very closeto each other. If this is done the entirecoil will take up no more space than 3".The dowel sticks should be so insertedthat they may be taken out. That is,either a commercial or home-made spid-erweave form, which can be taken apart,should be used. The plate coil, if woundon such a form as just mentioned, con-sists of 40 turns. It is placed close upagainst the primary and secondary wind-ings and held together with tape or someother binding substance. When windingthe primary and secondary, use No. 24single silk covered wire. When windingthe plate coil, use No. 26 or 28 ssc. Ifa variable resistance having a small bar-rel is used, it may be placed through thehub or center of the coils and held therewith small angle brackets, which are boltedto a piece of Bakelite or hard rubberplaced over the plate and primary -secon-dary windings, which have also beenbolted together with small screws throughtheir centers. Binding posts, to whichare attached the terminals from the coils,are also placed on these mounts. If thevariable resistance is of the rheostatmounted type, it may be placed directlyin front of the two windings and alsomounted on the form with angle brackets,or on the panel. The knob of the va-riable resistance, RI, is shown protruding

from the panel, to the right, in the July3 photos. The knob in the center of thepanel is that on the shaft of the rheostat,R2, which is of the 10 -ohm type. Thesingle circuit jack is to the right, whilethe antenna and the ground posts are tothe upper left. R3 is 2-megohm gridleak. The secondary is shunted by a .0005mfd. variable condenser, Cl. C2 is a.00025 mfd. fixed grid condenser, C3 is a.001 mfd. fixed condenser, which as in-dicated by the dotted lines, is not anabsolutely essential unit. R4 is a 10 ohmrheostat, but not variable. That is, oncethe correct filament temperature of a spe-cific tube is found, the resistance is notvaried again. This unit is placed on oneof the socket shelves. Both the AFT usedare of the low ratio type. The -99 typetubes are employed, although larger tubesmay be used. The plates of the amplifiertubes should receive 90 volts, while theplate of the detector tube should receiveabout 45. A 4.5 volt C battery should beused for grid biasing. Two other suchbatteries, connected up in parallel, areused as the A battery to light the fila-ments of the tubes.Be very sure that the rotary platesof the variable condenser are connectedto the low potential point of the coil, e. g.,positive A, and beginning of secondarywinding, which is adjacent to the end of

the primary winding, is connected to theground.

*

Speaker Goes InsideCabinet, Size 8 1-2 x 24 in.I WOULD like to have the electrical

diagram, circuit data, etc., of the set builtin a 81/2" deep, 7" high and 24" longcabinet, wherein a midget speaker wasincluded. A 7x24" panel was used. The de-scription of the placing of the speaker,was described in the May 22 issue ofRADIO WORLD.-Thomas Stephens, Mont-gomery. Ind,

The circuit diagram of this set appearsin Fig. 371. The primary, LI, and thesecondary, L2, are a fixed radio frequencytransformer. The primary, L3 and the sec-ondary L4, represent a tuned radio fre-quency transformer. This primary consistsof 10 turns. The secondary consists of 50turns. It is wound on a tubing 3 in. indiameter, using No. 22 double cotton cov-ered wire. There is a 3/4 in. separationbetween the two windings. The secondarywinding is tapped at the 8th turn from thebeginning.. Cl is a .0005 mfd, variablecondenser, while C2 is a .00025 find. vari-able condenser. This condenser tunes the

-plate and controls the regenerative actionof the tube. C3 is a .00025 mfd. fixed gridcondenser. R6 is a 2 megohm grid leak.R1 is a 1.0 megohm grid leak, while R2is also a 1.0 megohm grid leak. C4 is a1 mfd. fixed condenser, although a .25 mfd.fixed type will work satisfactorily. RIis a M. ampere ballast resistor. AFT1 andAFT2 are of a low and high ratio typerespectively. J1 is the single circuit jack.R3 and R4 are 10 -ohm rheostats. Thebeginning and the end of the primarywinding of the tuned radio frequencytransformer do not go to the plate and Bplus posts directly. Instead they arebrought to binding posts. The plate andthe B plus posts are also brought to bind-ing posts. In this way, the RFtube may be cut out of the circuitand the antenna and the groundconnected to the beginning and the end ofthe primary winding. The stationaryplates of both variable condensers areconnected together and then to the be-ginning of the secondary winding of theTRFT. The tapped portion of this coil isbrought to the plus post of the socketholding the detector tube. The plates ofthe detector, first and second amplifiertubes are connected to one B voltage. Thedetector plate is connected to the amplifierB source, because of the resistance in theplate detector plate circuit. This voltageshould range from 67% to 90. From 45 to67% volts (B plus 1), is applied to the plateof the RF tube. The plate of the lastamplifier tube should receive at least 112%

FIG. 371The electrical diagram of the set requested by Thomas Stephens.

July 17, 1926 R A 1) 1 () ()I,Z I) 11

How to Make an RF Choketiding chucking the coil form in a handdrill. The drill is placed in a bench vise,and the coil is ready to be wound. Thewire used is No. 40 enameled copper.This fine wire is very difficult to handle.It will be necessary to mount a stock

PTJ

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o B.,De

FIG .372The winding diagram of the new model Powertone. 1..5 has both of its terminals con-nected to A minus. Also the beginning of eacb secondary, L2 and 4, goes to A minus.

volts. It will be noted that there are twoC voltages, one for the grids of the firsttwo AF tube and one for the grid of the.last AF tube. The first C voltage shouldbe 4.5, while the second C voltage mayvary from 6 to 9. A filament switch, S, isinserted in series with the A plus B minuslead. The -01A tube are used through-out the set, with a 6 volt A supply.

* * *

The New PowertoneWith Novel Gain Knob

PLEASE GIVE the circuit diagram ofthe new Powertone, with data on the coils.condensers, and a brief wiring descriptionof the set-Frank Hardrans, Unionville,Mass.

Fig. 372 shows the circuit diagram. Theprimaries and the secondaries, LI and L.3,consist of 10 turns. The secondaries, L2and L4, consist of 53 turns. These arewound on a tubing 2% in. diameter and4 in. high. No. 22 double cotton coveredwire is used. Cl is a double condenser,each section having a capacity of .0005mfd., with a total capacity of .001 mfd.One ballast resistor, R1, is used to controlthe filaments of all the tubes. If the -01Atype tubes are used, then this ballast re-sistor should be of the 1% ampere type.If a 112 power type tube is used in thelast stage, a PA ampere ballast resistorshould be used. The tickler coil, L5, isused for non -regenerative purposes. Thecoil here is in the grid -filament circuit,conductively coupled to the secondary, L4,and is used as a volume control. Thefickler coil should have only 6 turns ona 1 in. diameter. C2 is a .00025 mfd. gridcondenser, while R2 is a 2-megohm gridleak. R3, R4, R5 and R6 are all 1.0megohm resistors. C3 and C4 are .006mfd. fixed condensers. The AFT usedmay be of a high ratio type. LS is aBruno light switch. The -01A type tubesare used. The detector B voltage is about45, while the amplifier voltage is 90. Theplate of the radio frequency tube also hasa special B voltage, ranging from 45 to67%. This voltage is quite critical andshould be 'adjusted with care. The endsof' both secondary windings (outsidepoints) are brought to the respective sta-tionary plate connections of the conden-ser, posts, Y and Z. The beginnings ofboth these ,coils (adjoining secondary) areconnected together and thence to the com-mon rotary plate connection of Cl and toA minus. This same terminal is alsobrought to both terminals of the short-circuited tickler coil, L5. The grid leak isconnected in shunt to the positive fila-ment circuit. It should not be shuntedacross the grid condenser, C2. The C bat-

tery is connected in series with the gridreturn of the last tube only. If 90 voltsare used as the amplifier plate supply, thena 4.5 volt C battery should be used. Ifthe 112 tube is used, then a 6 -volt C bat-tery should be used. The phone tip jacksPTJ, may be substituted with a singlecircuit jack. Upon the coil, L5, falls theentire honors of this set. This coil stabi-lizes the set, serving as a fine volume con-trol.

* *

Fine Wire AdvisableIn Winding Choke Coil

I READ with interest J. E. Anderson'sarticle in the July 10 issue on how tomake a coil winder. Please show photo-graph of -arts used. (2) Details are re-quested on how to wind a radio fre-quency choke coil.-Elmer Hunt, Scars-dale, N. Y.

(1) Fig. 373 shows the requested photo-graph. (2) In many circuits RF chokesof the order of 5 millihenries are re-quired. It has been the practice of usinghoneycomb coils for this purpose, butthese coils are rather bulky despite thecompactness of the winding method. Thebulk, of course, is due to the heavy wireused in winding these coils. For chokesit is not always necessary nor desirableto use heavy wire, and it is at all timesdesirable to use choke coils with fieldsconcentrated as much as posible. Fig.374 shows the finished coil alongside ofa ruler. The form upon which the wireis wound is a wood dowel 1" in diameterand 3" long. Before winding, polish thedowel with fine emery cloth, finishing upwith the non-abrasive side of it. Forterminals two wood screws are driveninto the centers of the ends of the dowel.Temporarily one of these screws is verylong and a sleeve made of small brasstubing is placed between the. wood andthe head of the screw. This is for facili-

wire spool on a reel so that the spoolwill turn easily yet not so freely thatthe spool will continue to unwind formore than a turn or two after the wind-ing is stopped. It is probable that duringthe process of windinv one of these coilsit will be necessary to stop several timesto correct errors and to straighten outkinks. If the stock spool continues tounwind after stopping the winder therewill be a thousand kinks formed for everyone that is taken out. To prevent thewire from breaking the distance betweenthe stock spool and the winder shouldlie at least ten feet, and to make thewinding easier the axes of rotation ofthe two rotating parts should be paralleland the feed wire should make as nearlyas possible a right angle with either ofthese axes. Slow speed of winding willinvariably give rise to trouble from kink-ing, breaking and faulty winding. Thewire should be guided toward the woundportion of the coil just a little ratherthan straight on. If it is guided straighton there will invariably be vacant spaceson the coil. If it is guided toward thewound portion, with a slight tension onthe wire, the winding will be smooth anduniform. In case the wire is guided toofar toward the wound portion, with toolight tension, the winding will double back,requiring stoppage of the winder and cor-rection of the error. The better the polishon the form the less the trouble will be.After a little experience there will prac-tically be no trouble. With this size ofdiameter and this small gauge of wireit will require 750 turns to give an in-ductance of approximately 5 millihenries.This will make the winding about 2.5"long. This will leave 7/4" at each end freefrom .wire. To bring the wire from thecoil to the terminals cut tiny groovesaxially on the convex surface and radiallyon the ends, place the wire terminals inthese grooves and cover up with beeswax.When the wire terminals have been fast-ened, remove the coil from the hand drill,replace the long screw and sleeve witha short screw, and then solder the finewire to the screw heads. It is well to putlugs under the two terminal screws forconnection to other apparatus. To pro-tect the fine wire on the coil cover theentire dowel with a layer or two of manila-paper, preferably treated with paraffine.

* * *

2 -Tube Reflex GivesGood Speaker Operation

PLEASE GIVE the wiring diagram,panel layout, with complete wiring de-scription, coil, condenser, data, etc., on a

FIGS. 373 AND 374Detail of coil winder parts at left and.photograph of a choke coil form at right.

12 RADIO \\ ORLD 1 1.7 102(

Tickler Affords VolumeC.D.

C2

AFT 2

FIG. 375The circuit diagram of the set requested by Henry Schultz.

OB

OA.

OA

/6

FIG. 376The panel layout for the set shown diagrammatically in Fig. 375

2 -tube set, employing a regenerative radiofrequency amplifier, a crystal as a detec-tor and a stage of transformer coupledaudio frequency amplification. I have twotransformers, one of a high ratio and oneof a low ratio. Can these be used?-Henry Schultz, Warrick, Mont.

The diagram of such a set is shown inFig. 375. A 3 -circuit tuner and a radiofrequency coil are used. The primariesof both these coils have 10 turns. Thesecondaries, L3 and L5, consist of 50 turns.Tubing 3% in. in diameter is used. No.22 double cotton covered wire is used asthe conductor. The tickler consists of 36turns of No. 26 single silk covered wire;wound on a tubing 2.3 in. in diameter. Cland C2 are .0005 mfd, variable condensers,shunting the secondaries. The filaments ofboth tubes are controlled by a single rheo-stat. However two single rheostats tocontrol the filaments of both rheostatsmay be used with better success. In thepanel layout this latter method is used.As to the wiring. The beginning of theprimary winding, LI, is brought to theantenna post on the strip. The end of thiswinding is brought to the ground. The be-ginning of the secondary winding, L2, isbrought to the rotary plate connection ofCl and to the G post on the first AFT.This sante connection is extended to oneterminal cif the fixed condenser, which hasa capacity of .001 mid. The F post ofthis AFT is brought to the A minus poston the strip to one terminal of anotherfixed condenser, having a capacity of Allmfd. and the other terminal of other fixedcondenser. The end of the secondarywinding, 12, is brought to the stationaryplate connection of Cl and to the grid postof the RF tube socket. The plate postof this socket is brought to the beginningof the tickler coil winding, I-3. The end of

this winding is brought to the beginning ofthe primary winding, L4, the end of whichis brought to the other terminal of C4 andto the P post on the second. AFT. TheP post on the first AFT is brought to thelow potential point of the crystal detector.The high potential point of this detectoris brought to the end of the secondarywinding, L5 and to the stationary plateconnection of C2. The rotary plate con-nection of this condenser is brought to thebeginning of the secondary winding, L5and to the B post on the first AFT. TheB post on the second AFT is brought tothe 67V, volt B post. The G post on thesecond AFT is brought to the G post onthe second and last socket, with the IF

post going to the A minus post on thestrip. The plate post of this socket isbrought to the top terminal of the singlecircuit jack. The bottom terminal of thisjack is brought to the B plus 07l', voltpost. If a single rheostat is used, thenthe F minus posts on both sockets areconnected together and to one terminal ofthe rheostat. The other terminal of thisrheostat is brought to the A minus posts.The F plus posts of both sockets are con-nected to the A plus post on the strip.This is regardless of whether one or tworheostats are employed. If two rheostatsare employed, then the rheostats are in-serted in series with the minus legs of thefilaments. The center dial controls thetickler coil, while the condenser tuningthe secondary of the tuning coil and thecondenser tuning the secondary of theRFT are controlled by dials to the leftand the right of center dial respectively.For convenience, a switch, such as isplaced in the lower left hand corner of thepanel, may be inserted in series withpositive A lead,

How Switch WorksIn the I -Turn ReceiN

PLEASE DESCRIBE*Lion of the filament switch is,

ith A 1 -Turn Primary, described himan Bernard in the July 3 issue .

Woisi.D. A brief description ofmeat wiring of the second RF tub(be appreciated.-Nathan Catan, FarRockaway, N. Y.

The set is turned on or off as a luau bythe A battery switch 5, With the exceptionthat the sixth tube is turned on by a rheo-stat. The switch, however, if "off," willturn out all six tubes. You must use therheostat independentlY to turn the sixthtube on or off as an individual unit, al-though the switch controls the chain. Lt

is impossible to have any tube burning ifthe switch S is in au -off" position,

The single loop design next to the switchin the Fig. is the lamp that you should in-sert in the switch socket. This lamp isof the 6 -volt variety (flashlight typel anddraws about .23 ampere at that voltage.It causes the rubv window to shine veryprettily when the set is in operation.'When the tubes are extinguished theswitch lamp goes out with therm

The actual wiring of the circuit is alongorthodox lilies. Remember that the tubes1 and 2 are connected in parallel, that isgrid it, grid, plate to plate, I, plus to Fplums. Note that the rheostat interruptsthe F minus lead of tube 2, while a bal-last resistor is in the negative leg oftube 1. These resistors, all marked RI,are No. 1-A Amperites, for the -0IAtubes. If a 112 power tube is used in thelast stage, however. 1 he 112 Am peril eshould be used in place of the I -A type.

*

A 5 -Tube, 1 -ControlResistance AF Set

I WOULD like to build a single -controlreceiver with 3 stages ot iesisiancecoupled AF.-Julian Stone, Hudson, N. C

Fig. 377 shows the electrical wiring dia-gram of the set you request. The primaryLl, consists of ii turns. The secondary,12, consists of 50 turns, The primary,L3, consists of 10 turns. The secondary,L4, consists of 50 turns. Tubings 3l".; in. indiameter are employed for 1.2, 1-3 and L4.No. 22 double cotton covered wire is used.The primary, LI, is variable and wound Ona tubing 2a,j in. in diameter and placed in-side of the secondary. winding, 12. CIis the double condenser, having two sec-tions, each of which has a capacity of.0005 mfd., making a total capacity of .001mid. RI is a 10 ohm rheostat. C2 is a.00025 mfd. grid condenser. R4 is amegolun grid leak. R2 is a 45 ampereballast resistor. The filament of the lasttube is controlled by a singular ballastresistor, which facilitates the use ed thepower tube. It will be noted that theplates of the detector, 14F and the ampli-fier tubes are connected ten separate Bvoltages. A few pointers on the wiring.The beginning of the variable primaryWinding, is brought to the antenna. Theend of this 'winding is brought to theground. The beginning, of the secondarywinding, is brought to the common rotaryplate connection of Cl, as well as to thebeginning of the secondary winding, 54.The stationary plate connections arebrought to the ends of the secondarywindings, L2 and IA, respectively. Theend of the secondary- winding, 1.2, isbrought to the grid post of the RF tubesocket, while the end of the secondarywinding-, 1-4, is brought to one terminalof the grid condenser. The other terminalof the grid condenser is brought to one

lilt 1-, 102t) \ 1)1t) \\ ()NI I)

How toWork Single Control

t,

FIG. 377The electrical wiring diagram of the 1 -control, 5 -tubs- ,v r, using res,sta

terminal of R4. The other terminal of thisresistance is brought to the A plus post.The rheostat and ballast resistance,: arconnected in series with the nev:iticof their respective tubes. Th,three audio tubes receive !

plate of the detector tube reek ,

although it might be found tte,increase this voltage, since theredrop in the resistance in the plate cir-cuit. The plate of the RE tube receive,67.T,-; volts. A phone tip jack or single cir-cuit jack is placed on the output. Thc--OIA type tubes should he used through-out this set, with a 6 volt source of fila-ment supply. The grid bias on the lasttube should be 9 volts, if 135 volts (B)are used. Higher B voltage, c. g., ISO,

may be used with success. The C batteryvoltage should be increased to 12. In thislast stage of audio, the 112 or 171 type tubecan be used, the grid and plate voltage&corresponding with the individual char-acteristics of the tubes. However, whenusing these tubes, it is best to supply theplate with a separate B voltage. Other-wise, the others will become parallelyzed.

*

Test for DeterminingSeries -Aiding Hookup

I WOULD like to have the circuit dia-gram of a method of testing an AF trans-former, when it is used as a choke coil, todetermine which way affords series -aidingrelationship. Please give a short descrip-tion of the method of operation and thereason for testing it.-Herbert Valert,Greele, Ala.

Fig. 378 shows the electrical diagramillustrating that point. When AFT areemployed as choke coupling coils in aninpedance coupled AF amplifier it is veryimportant that the two windings be con-nected in series aiding, rather than in ser-ies opposing. Therefore, it is important toknow how to connect the windings, to getthem connected in the manner which willgive the best results. Taking for granted,that the majorityy of AFT do not havethe same markings, or that we are doubt-ful as to the positiveness of the markingswe will employ that method diagrammedin Fig. 377, which is operated in the fol-lowing manner. First throw the switch topoint 2, to give the condenser a charge of45 volts. Then quickly transfer the switchto point 1. The charged condenser C, nowdischarges through the headset and thetransformer windings. The discharge ishighly damped, but the oscillations persistlong enough to give the nature of the pitch

oupl eel a

FIG. 378The circuit diagram illustrating method whereby a series -aiding orseries -opposing connection with an AFT when used as a choke coil Can

be known.

of the oscitlat .Charge and discharge

the condenser in rapid snrcessiCm a num-ber of times, until the pitch of the soundin the headset is firmly fixed in mind.Then reverse one pair of leads cm thetransformer and repeat the process rsf

charging and discharging. The pitch isnow different, it being higher or lower.The connection which gives the lowerpitch is the series -aiding. The actualsound to listen to, is that which is orffi-narily called the "click." The duller this

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It tear

f r

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14 RADIO WORLD July 17, 1926

An 8 -Tube Set on 7x14" Panel

Pod,o lv orlo Staff Photo)

A FAN wanted an 8 -tube set on a 7x14" panel. Photos show how this was accom-plished, using the Super -Heterodyne circuit,

Some Short Waves TurnDay Into Radio Night

An investigation of the "skip -distance"effect and other phases of short-waveradio transmission has been carried onat the experimental station of the BellTelephone Laboratories at Deal Beach,N. J. The results of these studies weredescribed in a paper presented to the In-stitute of Radio Engineers by R. A. Heis-ing and J. C. Schelleng of the Labora-tories and G. C. Southworth of the Ameri-can Telephone and Telegraph Company.

Most of the questions of short-wavework have been touched upon duringthe investigation. Field strength varia-tions over twenty -four-hour periods weremeasured as were the variations withchange in frequency and distance. Fadingand its effect on intelligibility and quality,night versus day transmission and over-land versus overwater transmission havealso been investigated. Tests were made/comparing vertical and horizonal antennastructures. Observations were made withfield -strength measuring sets and auto-matic recorder, both of which were de-

veloped in the laboratories.In the overhead wave theory it is as-

sumed that a portion of the wave travelsby an indirect path and is finally deflectedto earth by an ionized layer existing abovethe earth. It was found that as the wave-length is shortened the "skip -distance"becomes larger, -and the signals becomeweaker. Fading was found to be less onlonger Waves in most instances. Thequality varies somewhat when the car-rier and side bands fade simultaneouslybut the greatest variation is noted whenthe frequencies do not fade at the sametime.

For distances between a few hundredmiles and 1,000 miles there is little dif-ference between overwater and overlandtransmission. Night transmission is bet-ter than day on high wave lengths andday is better than night transmissionsome of the short waves. Tests are stillin progress and their scope has been ex-tended to include observation points asfar west as Seattle.

Four Win Scholarshi sIn Westinghouse Test

PITTSBURGH.Fifty-two applicants contested in the

1926 examination for War MemorialScholarships established in remembranceof employes who served in the WorldWar by the Westinghouse Electric andManufacturing Company.

Four scholarships are awarded annuallyand the winners for 1926 are Robert R.Lockwood, an employe of the companyand student in the night school at Car-negie Institute of Technology, Pitts-burgh; William J. Morlock, graduate ofMcKeesport, Pa., High School; Frank M.Redman, graduate of Grant High School,Portland, Oregon, and Harry W. Thie-mecke, company employe and student atCarnegie Institute of Technology.

By terms of the award they are noweligible to a full engineering course inan approved technical school. Each awardprovides for an annual payment of $500for a period of not more than four years.

Expert Flies Abroad .

to Get Data for FansMajor Lester D. Gardner, editor of

"Aviation," and expert on aviation mat-ters for Station WJZ, is now making anextensive airplane trip in Europe andthe Near East. He has aiready flownmore than 8,000 miles and is scarcely halfway through his journey. He intends toreturn to America in the Fall and relatehis experiences on WJZ's wavelength.

KNX Has EnormousRemote Control Line

LOS ANGELES.KNX, the "Evening Express" radio sta-

tion, is claiming the distinction of havingone of the longest remote control linesin the country. With the completion ofthe Edgewater Club, on the beach ofSanta Monica, programs almost everyevening are sent out by remote control.

The Edgewater Club has -obtainedHenry Halstead's orchestra to play inthe Marigold supper room every eveningfor an hour.

The Halsted Orchestra, formerly at thePalace Hotel in San Francisco, has re-ceived a great deal of favorable commentthroughout Southern California.

Deaf Man Can HearStations on Earphones

Radio meant the gift of a new senseto Ewald Emling of 305 North Street,Waukesha. His deafness seemed to dis-appear by magic when he put on theheadphones at the request of friends whohad heard of instances where those sim-ilarly afflicted had been able to detectmusic and speech by radio.

"I was surprised indeed to ascertainthat I could hear music," stated Mr. Em -ling in a letter to The Freed-EisemannRadio Corporation. "Now I keep timeby swinging my hand as the music plays,like the leader of an orchestra with hisbaton." Mr. Emling says that he listensto WEAF, WGN, KYW, WJAZ, andWDAF regularly.

TUBE ACTS

LIKE MOTOR

GENERATORWhen an alternating potential differ-

ence is impressed upon the grid of atube, the plate current increases and de-creases at specific periods. The pulsatingplate circuit is made to produce fluctua-tions in the succeeding grid qmtential bymeans of a transformer, wherein theprimary is connected in the plate circuitand the secondary is connected betweenthe filament and the grid. When the prop-er capacity condenser is shunted acrosseither of these windings, so as to obtaina natural period in the circuit, the fluc-tuations in the plate current are kept upby their relative action on the grid volt-age. Using this scheme, the current in theplate circuit fluctuates between maximumand minimum values. The voltage of thegrid alternates and alternating currentflows in the condeffser, regardless of cir-cuit in which the condenser is connected.In this way the tube becomes a generatorof alternating -current power. It might beeve given a better name by calling it aconverter or motor -generator. The in-ductance and the capacity of the circuitdetermine the frequency of the alternatingcurrent. The total amount of power athand depends upon the average value ofthe plate current and the voltage of thebattery, which is at the supply source.

Inattention to ReceiverSpoils Joy of Reception

The self-evident maxim that a receiv-ing set should be properly serviced can-not be stressed too often. After money,care and time have been put forth tobroadcast a fine program, loose connec-tions, poorly seated tubes, faulty insula,-dons or ally one of a number of othereasily remedied defects ill a set will pre-vent good reception. According to thetechnical staff of KFI, a radio expertshould be called in whenever the pleasureof radio reception begins to pall. Theloss of radio appetite may be due to afault in the set rather than in the fareoffered which is generally of uniformquality.

A good investment is a voltmeter, anda recharging outfit, by means of whichthe batteries may be kept at their max-imum strength.

Many letters received at KFI indicatethat receptionists are equipping their setswith, an inside loop and an outside aerialso that either may be used at Will, ac-cording to the need of the moment.

The surest method of getting the mostout of a receiving set investment is tobuy only reputable merchandise fromreputable dealers.

WAAM Player UsesI njo As a Violin

Radio orchestras are forever bringingto light odd ways of playing well-knowninstruments. The latest musical freak isone being used by a member of theDorn -Bauer Orchestra which broadcastsfrom WAAM, Newark, N. J. This manplays the banjo in the orchestra, but onoccasion discards the pick and, holdingthe banjo in vertical position; plays witha bow, employing violin technique. Heplays on all strings.

July 17, 1926 RADIO WORLD

Variety CharacterizesThe Making of the Grid

The grids used in the manufacture ofmost tubes vary from a very fine meshof the best obtainable tungsten wire toa network of fairly coarse tungsten wire.The grid usually takes either the flator cylindrical shape. The plates used are

also various. Either a zig-zag shapedtungsten wire about 6 cm. long, or a smallthimble, 0.4 cm. in diameter, or two heavyplates 6 cm. long are used. Nickle ormolybdenum is also used- for grids andplates.

Mother Uses Broadcast;Gets ack Her Boy

James ToolteN , of lookers, 11 yearsold, after being missing for three daysfrom his home in Yonkers, N. Y., wasreturned to his anxious mother's arms,due to a "missing persons alarm," broad-cast at her request.

James, who explained that he ranaway because he thought he had failedin his examinations at the MonasterySchool in Yonkers, heard the radio an-nouncement in the home of Mrs. JohnAdams in Thornhan, N. Y., a little vil-lage in the Adirondack Mountains.

He discovered when he arrived at homethat he did not fail in his examinationsafter all. He made the return trip inan automobile with David J. Luddy of154 Court Street, Brooklyn. Mr. Luddyhad been on a camping trip to the Adiron-dacks, and offered to bring James backwith him when he learned of his plight.The boy said he had obtained automobilerides to the mountains, and had workedfor a while at.a New Yorker's Summerhome there.

Keep Set from WindowDuring the Summertime

If you have a receiver which employsan outdoor antenna, and one aerial ter-minal is near the window so as to enablea short leadin for maximum efficiency,it is best, at this time of the year, to movethe set far front the window. This is toprevent dampness, prevalent during thesummer, from injuring part of the re-ceiver, especially during rain.

Antenna Measurement

( I AD10 WORLD 51,1 ff Photo)REDUCING THE antenna resistance,by interposing a resistance until theradiation current is reduced) one-half,is a popular way lof measurement.The radiation resistance of the an-tenna is then equal to the amount ofsubstituted resistance. Sidney NortonBaruch, inventor, is shown making

such measurement.

Tide Data from StationAsked by Fisherman

Among the unusual requests for broad-casting service received at KGO, Gen-eral Electric Pacific Coast station, was aletter front a bass fisherman asking thattime of high and low tides

fisherman_broadcast

daily with the weather report."I have talked with several sportsmen,"

wrote George Roberts, San Franciscofisherman, "and it will be valuable forus to know the time to leave our homesfor the various fishing grounds when tideoccurs."

WNYC BroadcastsSubway Strike News

Broadcasting was invoked to warnlisteners that a strike had been called onthe subway lines of the InterboroughRapid Transit Company in New YorkCity.

When at 9 p. m. it became evident thatthe strike was inevitable, CommissionerAlbert Goldman of the city's Departmentof Plant and Structures obtained per-mission from the Transit Commissionerto notify the public from the municipalbroadcasting station, WNYC. Aftermaking the announcement he also hadMayor Walker's notice to the public giv-ing details of emergency transit serviceread in detail.

New Resistors HandleHeavy Loads Easily

Stoner & Heath, New York representa-tives, are showing the . new Centralabrheostats and power controk designedespecially for socket power equipmentand the extra amount of current requiredwith power tubes of all kinds. One rheo-stat is ribbon wound, something entirelynew in rheostat construction, and is ratedat 2 and 3 ohms; the other is wire woundwith a rating of 6-10-20-30 ohms. Bothare of the usual Centralab construction.Laboratory tests of 50 M. H. D. VariableResistance designed for detector and radiofrequency control in B eliminators showedthat the actual ranges were 64 ohms to57,000, 64 ohms to 43,000 -and 33 ohmsto 83,000 They were found to work verysmoothly. The rating of three watts isconservative, as severe tests showed thatfive watts could be dissipated withoutharming the units. The heavy dutyradiohm is designed for socket powerequipment for eliminator use exclusively.Tests show that this unit has full re-sistance and variation with a single turnon the knob;, that resistance value re-mains permanent- as adjusted; that re-sistance value remains the same for anyknob setting; that it is variable front 50,-000 ohms to approximately zero, will notheat' up excessively with a load of, threewatts and will stand up permanently un-der this load. It will carry five watts onan overload test. It will also stand aground test between the live parts andthe mounting bushing of 1,500 volts with-out breaking down. Full information onthese new units may be had from Stoner& Heath, 122 Greenwich Street, NewYork City. Mention RADIO WORLD.

Conducts Orchestra

NICOLAI BEREZOWSKY, conduc-tor of the Atwater Kent Orchestra,heard during the Atwater Kent RadioHour through WEAF, WEEL WGR,WCAP, WWJ, WSAI, WGN, WCCOand KSD every Sunday evening from

9:15 to 9:45

Resistance Measurement

(R SDIO WORLD Staff Photo)

THE RESISTANCE of a rheostat atany setting may be determined byusing an 0 -to -1 ammeter and a volt-meter. Resistance equals voltage div-

ided by the amperage.

Mardon is Nominatedfor Section ManagementFred II. Mardon of 1309 West Farms

Road, the Bronx, New York City, ownerof short wave station 2CWR and for thepast two years assistant manager of theHudson Division of the American' RadioRelay League, was nominated by localamateurs for the post of Section Com-munication Manager of the League. Theposition carries with it control of thetraffic work of transmitting amateurs inthe five boroughs of New York and LongIsland. -

Pending the outcome of the balloting,F. E, Handy, National CominunicationManager of the A. R. R. L., requested'Mardon to occupy the position tempor-arily and to supervise local transmittingactivities.

16 RADIO WORLD July 17, 1926

Sets Puzzle Russian Hinterland Artists

(tilts arid)

THE MARVELS of radio are just becoming known in the outlying provincesof Russia. Here are some Russian children in the out-of-the-way village ofLientseve gathered around a radio set with expressions of awe. The set is a

battery excited crystal receiver.

Single Station ProposedFor Those Sharing Time

Dean D. S. Kimball, of 'Cornell Uni-versity, announced that the AmericanEngineering Council will seek to solvemany pressing radio problems.

An investigating committee will benamed by the Council to examine theentire situation, which, he declared,threatens to create "a radio chaos of in-estimable complexity," affecting 20,000,-000 listeners.

"Many of the problems," Dean Kimballsaid, "are fundamentally of an engineringnature, and will be studied by a specialcommittee in an unbiased, broadminded,and comprehensive way, so that accurateconclusions may be made generally avail-able in convincing form." -

Puts Sales at $500,000,000"The annual sales of radio equipment

exceed in value $500,000,000," Dean Kim-ball said. "It is estimated that there aresome 20,000,000 listeners in the UnitedStates. Hence radio questions -are ofalmost universal concern and of tremend-ous commercial significance.

"There is no doubt that they affect thepublic interest at every point. It is prob-ably fair to state that there is no dis-interested agency of national scope whirlshas attacked these problems with thethought of- a public-service solution.

"It is evident that these problems in-volve many engineering considerations.The subject appears, therefore, a logicalmatter for consideration by the engineer-ing profession.

"The investigators will seek the co-operation of every interest concerned. Theaid of the legal and administrative officialsof the Department of Commerce or anyother radio regulating body that may beestablished by Congress will, it is believed,be readily obtained. -

Has Trade Value"We feel sure that the trade and com-

mercial questions involved will be ade-quately and promptly presented by the

business interests that are responsible,"said Dean Kimball.

"The large broadcasting interests haveexpressed no opposition to an engineer-ing study of radio. Rather they seem in-different to it, apparently being in doubtas to how such a study could serve anyuseful purpose. In our opinion, however.this indifference results wholly from alack of appreciation of the usefulpesswhich might be served through having animpartial, judicially minded committee oftechnical men studying the problems andrecommending certain principles for gen-eral adoption. Factual studies of the radi(-broadcasting problem will usefully servethe public interest through the applica-tion of engineering principles.

Cost Data to Be Obtained"Special attention will be given to an

analysis of the relative costs, effective-ness and difficulties of the variousmethods 'used in broadcasting educa-tional, religious and like programs. An-other important field of inquiry involvesthe economic soundness of division oftime between expensive stations as contrasted with the use of multi -studio sys-tem with a single broadcasting station.

"Numerous conflicts of interest arearising, and difficulty is increased as thereligious, the educational and other fieldsof broadcasting enlarge their activity.There can be at the present time no gen-eralization made as to the proper solutionof these differences. Each local problemmust be separately considered and a deci-sion appropriate to the local circumstancesreached.

"There aft now 540 broadcasting sta-tions of which at least 200 give regularprograms of considerable interest, com-manding substantial audiences. Thereare approximately 650 additional appli-cants to whom broadcasting licenses havenot beets granted by the Department ofCommerce."

R kl,10 0 01(1 Stall- Photos)

A NEW development at WBNY isof the carrier wave, so that the artist Ivolume on certain notes, by drawing avmitter. This has developed forms of sincast listener, are near perfection. Some vlimits within which they must keep theher own voice as it sounds in a receive

A Vital Adjustment

(Radio World Staff Plio!o)

IF you adjust your speaker unit tohandle the loudest station you neednot set it again. The wrong setting

often prevents reception.

Jersey Coast BeaconChanges.,Inauguratei

The characteristics of several of theradio beacons in the trans -Atlantic traffir lane approaching New York Harborhave been changed.

The Fire Island Light Ship sounds ever}180 seconds in groups of two dashes foi60 seconds and silent 120 seconds; Am.brosc Channel Light Ship sounds ever)180 seconds, single dashes for 60 sec-onds and silent 120 seconds ; Sea Gir:Light Station sounds every 180 seconds

THREE ASK STATION LICENSEBringing the number of applications up

to 637, the following applied for permis-sion to broadcast: Austin Kleis, Pough-keepsie, N. Y.; Southwestern UniversityGeorgetown, Tex., and First UnitariarChurch, Los Angeles.

July 17, 1926 RADIO WORLD 17

-e Taught Trick of Improving Quality What-No Dinner?

raining of vocal artists. The necessity of modulating their voices within the limitsher voice just as the radio listener hears it, is taught. The artist must reduce

'rom the microphone, to stay within the modulation limits of the broadcast trans -that in the studio sound very peculiar, but which, when received by the broad -are distorted and unpleasant due to the artists' lack of understanding of the

'Etude of their voices for broadcasting. The pupil singer uses earphones to heard governs herself accordingly. Loud notes are uttered at a distance from the

microphone.

Actress a Broadcaster

DOROTHY BROWN, soprano andprincipal payer in musical comedy, isheard with great delight fromWBNY. She is playing in "Sweet-

heart Time."

Horseshoe PitchingPrompts Song Parody

In accordance with the recent an-nouncement that WAAM, Newark, N. J.,would conduct an inter -studio horseshoe -pitching contest, members of the studiostaff have been spending all their sparetime in the front yard of the studio onBond Street practicing horseshoe -throw-ing. This prompted I. R. Nelson, Jr., themanager of the station, to announce thatthe official WAAM song now goes:"Crazy over horseshoes - horseshoes,horseshoes!"

ALASKAN BEACON NEAR READYIt is expected that it will be only a

short time until the new radio beaconwill be established at Cape Spencer LightStation in Alaska. It will be located inCross Sound every 120 seconds, singledashes for 60 seconds and silent for 60seconds.

NO RADIO LEGISLATIONThe Senate passed the Dill bill. The

House did not. Congress adjourned untilDecember.

12nd U s,let tis'T Phoisi

WHEN mother returned from a mat-inee she found that her son, anardent radio experimenter, h a dusurped the dining room table.Mother, in the interest of science,ordered dinner served in the kitchen.

Four Husbands' AlibisShattered by Broadcast

BOSTON.Babe Herman, featherweight, was

scheduled to box Chick Suggs for thefeatherweight championship at the BravesField ball park recently, but weather con-ditions caused the postponement of thefight until the following night. Duringhis visit in Boston, Herman stayed at theHotel Brunswick, where the studio ofWBZ is located, and with another eve-ning to while away he elected to visit thebroadcasting studio.

W. Gordon Swan, the WBZ announcer,on finding out who his visitor was, in-vited hint to say a few words to the radioaudience. At first, Herman, to whomflying fists mean nothing, shied at thethought of talking into a microphone, butthe studio staff prevailed upon him andconvinced hint that the microphone washarmless.

While broadcasting an interesting littletalk on fighting and incidents that havehappened in the squared ring, Hermancasually mentioned that his fight withSuggs had been postponed until the fol-lowing night.

The evening of the scheduled bout, fourhusbands, friends of one another lefttheir cozy homes to see the much antici-pated conflict. They arrived at the ball

park only to be disappointed to find thatthe match had been postponed. Oppor-tunities for an evening out came few andfar between, they agreed, and decidedthat to relinquish this one was out ofthe question. Arrangements were soonmade for a quiet game of poker.

In the early morning to four differenthomes trudged four weary husbands whobelieved that they had covered theirtracks well. But four wives were waitingfor their appearance and in vain did thehusbands explain. The damage had beendone and unknowingly the husband's idol,Babe Herman, had let the cat out of thebag.

New Fog Signal CutsNeed For Lighthouses

LONDON.A fog -signalling device, brought out

by the Marconi Company of London,operated by radio, and actuated from acentral point, promises to replace light-houses. The first fog -signal has been in-stalled in the Firth of Clyde, Scotland.When the fog is seen, by the keeper atthe central point, a special transmitteris started. This emits timed impulses,which start a gun firing.

Shaw Called Best Artist;Lauder and Wales Next

LONDON.The British Broadcasting Company.

which has a monopoly in England, hasmade known its opinion that Sir HarryLauder and George Bernard Shaw areamong the best performers before! themicrophone. Their voices are particularlygood for transmission, the company says.

Shaw's only appearance before themicrophone was several months ago,

when he read one of his short plays. Thatperformance, however, placed him at thetop of the radio company's list.

The Prince of Wales also is said tohave an admirable delivery over the radio.The voices of 90 per cent. of stage come-dians are, for one reason or another, un-suitable for broadcasting, according tothe radio officials.The statement aroused much interest.

RADIO WORLD July 17, 1926

OFFICIAL L STOF STATIONS

(Corrected and Revised Up toJuly 7)

Station Owner and Location Meters

KDKA-Westinghouse E. & M. Co., Pitts-burgh, Pa. 309

KDLR-Radio Elec. Co., Devils Lake, N. D. 231KDYL-Newhouse Hotel, Salt Lake City, Utah 246!CFAS-Nebraska Buick Auto Co., Lincoln

Neb. 340KFAD-Electrical Equipment Co., Phoenix

Ariz. 273KFAF-A. E. Fowler, San Jose, Calif. 217

KFAU-Ind. School Dist. of Boise, Boise,Idaho . 280

KFBB-F. A. Buttry Co., Havre, Mont. 275KFBC-W. K. Azbill, San Diego, Cal. 216KFBK--Kimball Upson Co., Sacramento, Cal 248KFBL-Leese Bros., Everett, Wash 224KFBS-School District No. I, Trinidad, Col 238KFBU-Bishop N. S. Thomas, Laramie, Wyo 270KFCB-Nielson Radio Co., Phoenix, Ariz 238KFDD-St. Michael's Cathedral, Boise, Idaho 278KFDM-Magnolia Petroleum Co., Beaumont,

Texas 316KFDX-Ist Baptist Church, Shreveport, La 250

KFDY-State College of Agriculture, Brook-ings, S. D. 273

ICFDZ--H. 0. lberson, Minneapolis, Minn.- 231KFEC-Meier & Frank Co., Portland, Ore. 248KFEL-Winner Radio Corp., Denver, Colo.- 254KFEQ-J. L Scroggin, Oak, Neb 268

KFEY-Bunker Hill & Sullivan, Kellogg,Idaho 233

KFFP-1st Baptist Church, Moberly, Mo 242KFGQ-Crary Co., Boone, Iowa 226

KFH-Hotel Lassen., Wichita, Kans 268KFHA-Western State College, Gunnison, Colo 252KFHL-Penn College, Oskaloosa Iowa 240

Kn-E: C. Anthony Inc., Los Angeles, Cal 469KFIF-Benson Institute, Portland, Ore 248KFIO-North Central H. S., Spokane, Wash 266KFIQ-lst Methodist Church, Yakima, Wash... 256KFIU-Alaska Elec. Co., Juneau, Alaska 226KFIZ-Daily Commonwealth, Fond du Lac,

Wis 273KFJB-Marshall Elec. Co., Marshaltown, Ia 2.48

KFJC-R. B. Fegan, Junction City, Kan 219KFJF-National Radio Co., Oklahoma City,

261Okla.KFJI-Liberty Theatre, Astoria, 'Ore 246

ICYJM-University of N. D., Grand Forks,N. 278

KFJR-Ashley C. Dixon & Son, Portland, Ore 263KFJY-Tunwall Radio Co., Ft. Dodge, Iowa 246KFJZ-W. E. Branch, Fort Worth, Tex 254KFKA-State Teachers College, Greeley, Colo 273KFKU-University of Kansas, Lawrence, Kans 275I.C.FICX-Westinghouse E. & M. Co., Hastings,

Neb. 288KFKZ-Chamber of Commerce, Kirksville, Mo 226KFLR-University of N. M., Albuquerque,

N. M. 254KFLU-San Benito Radio Club, San Benito,,

Tex. 236KFLV-Swedish Evangelist Church, Rockford,

nL `229KFLX-George R. Clough, Galveston, Texas SKIICFLZ-Atlantic Auto Co., Annita, Is 273KFMR-Morningside College, Sioux City, Iowa 261KFMW-M. G. Sataren, Houghton, Mich 263KFMX-Carleton College, Northfield, Minn 337KFNF-Henry Field Seed Co., Shenandoah,

Iowa 263KFOA-Rhodes Company, Seattle, Wash. 454KFOB--KFOB Inc., Burlingame, Cal 226KFON-Echophone Radio Shop, Long Beach,

Cal. 233KFOO-Latter Day Saints University, Salt

Lake City, Utah 236KFOR-David City Tire & Elec. Co., David

City, Neb. 226KFOT-College Hill Radio Club, Wichita, Kan 231KFOX-Technical High School, Omaha, Neb. 248KFOY-Beacon Radio Service, St. Paul, Minn. 252KFPL-C C Baxter, Dublin, Texas 252KFPM-New Furniture Co., Greenville, Texas 242K.PPR-Forestry Department, Los Angeles, Cal. 231ICFPW-St. John's Church, Carterville, Mo 258KFPY-Symonds Investment Co., Spokane,

Wash. 266KFQA-The Principia, St. Louis, Mo. 261KFQB-Searchlight Publishing Co., Ft. Worth,

Texas 263KFQD-Chovin Supply Co., Anchorage,

Alaska 227KFQP-G. S. Carson, Jr., Iowa City, Ia. 224KFQU-W. C. Riker, Holy City, Cal 217KFQW-F. C. ICnierim, North Bend, Wash 216KFQZ-Taft Products Co., Hollywood, Cal 226KFRB-Hall Bros., Beeville, Texas 248KFRC-City of Paris, San Francisco, Cal 268KFRU-Stephens College, Columbia, Mo 500KFRW-G. and G. Radio and Electric Shop,

Olympia, Wash. 219KFSD-Airfan Radio Corporation, San Diego,

Cal. 246KFSG-Echo Park Evangelistic Ass'n., Los

Angeles, Cal. 275KFUL-T. Googan & Bro., Galveston, Tex 258KFUM-W. D. Corley, Colorado Springs, Col 240KFUO-Coucordia Theo. Seminary, St. Louis,

Mo. 545l(FUP-Fitzsimmons General Hospital, Denver,

Colo. 234KFUR-Peery Building Co., Ogden, Utah 22A

Cal.KFW0--Lawrence Mott, Avalon, CalKFWU-Louisiana College, Pineville, LaKFWV-Wilbur Jerman, Portland, OreKFXB-B. 0. Heller, Big Bear Lake CalKFXD-Service Radio Co., Logan, UtahKFXF-Pikes Peak Broadcasting Station Co ,

Colo. Springs, Colo 250KFXH-Bledsoe Radio Co., El Paso., Texas 242KFXJ-Mt. States Radio District, Inc., (Port-

able), Col. 216KFXR-Classen Film Finishing Co., Okla

City, Okla. 214KFXY-Mary M. Costigan, Flagstaff, Ariz 205KFYF-Carl's Radio Den, Oxnard, Cal 205KFYJ-Houston Chronicle, Houston, Tex ,

(Portable) 238KFYO-Buchanan Vaugn Co., Texarkana,

Tex. 210KFYR-Hoskins Meyers, Inc., Bismarck,

248KGO-General Electric Company, Oakland,

Ca. 361KGTT-Glad Tidings Tabernacle, San Fran-

cisco, Cal. 207KGU-M. A. Mulrony, Honolulu, Hawaii 270ICGW-The Oregonian. Portland, Ore 492KGY-St. Martin's College, Lacey, Wash 246KHJ-The Times, Los Angeles, Cal 40.5KHQ-Louis Wasmer, Spokane, Wash 273KJBS-J. Brunton & Sons Co., San Francis-

co, Cal. 220KJR-Northwest Radio Co., Seattle, Wash 384KLDS-Reorganized Church of Jesus Christ of

Latter Day Saints, Independence, Mo. 441KLS-Warner Bros., Radio Co., Oakland,

Cal. 250KLX-Tribune, Oakland, Cal 506KLZ-Reynolds Radio Co., Denver, Colo 266KMA-May Seed & Nursery Co., Shenan-

doah, Ia. 252KMJ-Fresno Bee, Fresno, Cal 234KMMJ-M. M. Johnson Co., Clay Center,

Nebr. 229KIVIO-Love Elec. Co., Tacoma, Wash 250KIVIOX-St. Louis Globe/Democrat, St. Louis,

Mo. 280KNRC-C. B. Juneau, Hollywood, Cal 208KNTR-D. S. Garretson & K. M. Turner,

Los Angeles, Cal. 238KNX-Express, Los Angeles, Cal 337KOA-General Electric Co., Denver, Col 322KOAC-Oregon Agricultural College, Cor-

vallist, Ore. 280KOS-College of Agri., State College, N. if 349KOCH-Omaha Central High School, Omaha,

Neb. 258KOCW-Okla. College for Women, Chickashia,

Okla. 252KOIL-Monarch Manufacturing Co., Council

Bluffs, Ia. 278KOWW-Blue Mountain Radio Ass., Walla

Walla, Wash. 256KPO-Hale Brothers, San Francsico, Cal 429KPPC-Pasadena Presbyterian Church, Pasa-

dena, Cal. 229KPRC-Houston Print Co., Houston, Tex 297KPSN-Pasadena Star -News, Pasadena, Cal 316KQP-H. B. Read, Portland, Ore 213KQV-Doubleday- Hill Elec. Co., Pittsburgh,

Pa. 275KQW-First Baptist Chuch, San Jose, Cal 227KRE-Gazette, Berkeley, Cal. 256KSAC-Kansas State Agricultural College,

Manhattan, Kans. 341KSD-Post Dispatch, St. Louis, Mo 545KSL-Radio Service Corp., Salt Lake City,

Utah 300KSMR-S. M. Valley R. R. Co., Santa Maria

Cab 210KSO-A. A. Berry Seed Co., Clarinda, Ia. 242KTAB-Tenth Ave. Baptist Church, Oakland,

Cal. 240KTBI-Bible Inst., Los Angeles, Cal 294KTBR-Brown's Radio Shop, Portland, Ore 263KTCL-American Radio Tel Co., Inc., Seattle,

Wash. 306KTHS-New Arlington Hotel, Hot Springs,

Ark. 375KTNT-N. Baker, Muscatine,Ia 256KTW-lst Presbyterian Church Seattle, Wash 454KUOA-University of Ark., Fayettesville,

Ark.' 300KUOM-State University of Montana, Mis-

soula, Mont. 245KUSD-University of S. D. Vermilion, S. D 278RUT-University of Texas. Austin, Tine.- 231KV00--Voice of Oklahoma, Bristow, Okla..- 375

Station Owner and Location Meters

KFUS-Louis L. Sherman, Oakland, Cal 256KFUT-University of Utah, Salt Lake City,

Utah 261KFUU1-1. C. Colburn and E. L. Mathewson,

Oakland, Cal. 220KFVD-Charles & W. J. McWhinnie, San

Pedro, Cal 205KFVE-Film Corp., St. Louis, Mo 240KFVG-Ist Meth-Epis. Church, Independence,

Kan. 236KFVI-56th Cay. Bridgade, Houston, Tex 240KFVN-C. E. Bagley, Welcome, Minn 227KFVS-Cape Girardeau Battery Station, Cape

Girardeau, Mo. 224KFVY-Radio Supply Co., Albuquerque, N. M. 250KFlYA-Browning Bros. Co., Ogden, Utah 261

KFWB-Warner Bros. Pictures, Inc., Holly-wood, Cal. 252

KFWC-L E. Wall, San Bernardino, Cal 211

KFWF-St. Louis Truth Center, St. Louis,Mo. 214

KFWH-F. Wellington Morse, Jr., Chico, Cal 254KFWI-Radio Entertainers, Inc., South San

Francisco, Cal. 220KFVVM-Oakland Educational Soc., Oakland,

207211238213203205

Station Owner and Location Meters

KWCR-H. F. Paar, Cedar Rapids, la .. . .. 708KWG-Portable Wireless Tel. Co., Stockton

Cal. 248KWKC-Wilson Duncan Studios, Kansas (Sty,

Mo. 236KWKH-W. K. Henderson L W. & S. Co ,

Shreveport, La. 261KWSC-State College, Pullman, Wash 349KWOC-Western Union College, Le Mara, Ia 252KWWG-City of Brownsville, Brownsville,

Tex. 278KYIN-Westinghouse E. & M. Co., Chicago,

DI. 535KZKZ-Electric Supply Co., Manila, P. L 270REM-P. D. Allen, Oakland, Cal 240KZRQ-Far Eastern Radio, Inc., Manila, P. L KaNAA-U. S. Navy, Arlington, Va 435WAAD-Ohio Mech. Institute, Cincinnati, 0 258WAAF-Drovers Journal, Chicago, Ill 278WAAM-I. R. Nelson Co., Newark, N. J 263WAAW-Omaha Grain Exchange, Omaha,

Neb. 278-384WABB-Harrisburg Radio Co., Harrisburg,

Pa. 204WABC-Asheville Battery Co., Inc., Asheville,

N. C. 254WABI-First Universalists Church, Bangor,

Me. 240WABO-Lake Avenue Baptist Church, Ro-

chester, N. Y 278WABQ-Haverford College Radio Club, Haver -"261WABR-Scott High School, Toledo, 0 263WABW College of Wooster, Wooster, 0 207WABX-H. B. Joy, Mt. Clemens, Mich 246WABY-John Magaldi, Philadelphia, Pa 242WABZ-Coliseum Place Baptist Church, New

Orleans, La. 275WADC-Allen T. Simmons, Akron, 0 158WAFD-A. B. Parfet Co., Port Huron, Mich 275WAHG-A. H. Grebe Co., Richmond Hill,

N. Y. 316WAGM-R. L. Miller, Royal Oak, Mich 22SWAIT-A. H. Waite & Co., Taunton, Mass- 229WAIU-American Ins. Union, Columbus, 0 294WAMD-Radisson Co., Minneapolis, Min 244WAPI--Alabama Polytechnic Inst., Auburn,

Ala. 248WARC-American Radio Res. Corp., Medford

Hillside, Mass. 261WATT-Edison Electric Illuminating Co

(Portable), Mass 244WBAA-Purdue University, West Lafayette,

Ind. 273WBAK-State Police, Harrisburg, Pa. 276WBAL-Gas and Electric Co., Baltimore,

Md. 246WBAO-James Millikia University, Decatur,

270.WBAP-Star Telegram, Fort Worth, Tex 476WBAW-lst Baptist Church, Nashville, Tenn 336WBAX-J. H. Stenger, Jr., Wilkes-Barre, Pa 256WBBL-Grace Covenant Presbyterian Church,

Richmond, Va. 229-WBBM-Atlas Investment Co., Chicago, 111.- 1126WBBP-Petoskey High School, Petoskey,

Mich. 238WBBR-Peoples Pulpit Ass'n., Roseville, N.Y 273WBBS-lst Baptist Church, New Orleans, La 25.2WBBW-Ruffner City High School, Norfolk,

Va. 222WBBY-Washigton Light Ii'2fantry, Charles-

ton, S. C. 268WBBZ-C. L. Carrell, (Portable), Chicago, Ill 216WSCNFoster McConnell, Chicago, Ill. 2145

WBDC-Baxter Laundry Co., Grand Rapids,Mich. 256

WBES-Bliss Electrical School, Takoma Park,Mich. 222

WBOQ-A. H. Grebe & Co., Richmond Hill,N. Y. 296

WBNY-Miss S. Katz, New York City 210WBRC-Bell Radio Corp., Birmingham, Ala 248WBRE-Baltimore Radio Ex., Wilkes-Barre,

Pa. 231

WBT-Charlotte Chamber of Commerce,Charlotte, N. C. 275

WBZ-Westinghouse E. & M. Co., Springfield,Mass. 333

WBZA-Westinghouse Electric and Mfg. Co ,Boston, Mass. 242

WCAC-Agricultural College, Mansfield, Conn 275WCAD-St. Lawrence University, Canton,

N. Y 263

WCAE-Kaufman & Baer, Pittsburgh, Pa 461WCAJ-Nebraska Wesleyan University, Uni-

versity Place, Neb. 254WCAL-St. Olaf College, Northfield, Minn 337WCAM-Galvin Radio Supply Co., Camden,

236WCAO-Brager of Baltimore. Baltimore. Md 275WCAP-C. & P. Tel. Co., Washington, D. C 469WCAR--Southern Radio Corp., San Antonio,

Texas 263:

WCAT-School of Mines, Rapids City, S. D 240WCAU-Universal Broadcasting Co., Phila-

delphia, Pa. 278WCAX-University of Vermont, Burlington,

Vt. 250.WCBA-C. W. Heinbach, Allentown, Pa 254,WCBD-W. G. Voliva, Zion, Ill. -345WCBE-Uhalt Radio Co., New Orleans, La 263WCBH-University of Mississippi. Oxford,

Miss. 242WCMA-Culver Military Academy, Culver,

Ind.WCMB-Hotel Chapeau, Baltimore, Md. 229WCBR-C. H. Messter (Portable), R. L 210WCBQ-1st Baptist Church, Nashville, Tenn 236WCCO-Gold Medal Station, Minneapolis, -St.

'Paul, Minn. 416WCK-Stix Baer & Fuller Co., St. Louis, Mo. 273WCLO-C. E. Whitmore, Camp Lake, Wis 231WCLS-H. M. Church, Joliet, Ill 214WCOA-Municipal Broadcasting Station, Pen-

sacola, Fla. 222'

uly 17, 1926 RADIO WORLD 19

d.

Statical Owner and Location MetersWCSH-Henry P. Rines, Portland, He 256WSCO-Wittenberg College, Springfield, Ohio 248WCWS-C. W. Selen, Providence, R. L 210WCX-Detroit Free Press & Jewett Radio and

Phonograph Co., Pontiac, Mich 517WDZ-J. L. Bush, Tuscola, Ill 278WDAD-Dod's Auto Accessories, Inc., Nash-

ville, Tenn. 226WDAE-Tampa Daily News, Tampa, Fla.-- 223WDAF-Kansas City Star, Kansas City, Mo. 366WDAG-J. L Martin, Amarillo, Tex 263WDAH-Trinity Metr. Church, El Paso, Tex 268WDAY-Radio Equipment Corp., Fargo, N. D 261WDBE-Gilharn-Schoen Klee Co., Atlanta,Ga.278WDBJ-Richardson Wayland Eke. Co., Roan-

oke, Va 229WDBK-M. F. Bros. Film., Cleveland, 0 227WDBO-Rollins College, Winter Park, Fla 240WDBZ-Boy Scouts of America, Kingston,

N. Y. 233WDCH-Dartmouth College, Hanover, N. FL 250WDGY-Dr. G. W. Young, Minneapolis, Minn 263WDND-Dod's Auto Accessories, Inc., 160-

164 8th Ave., N., Nashville, Tenn 226WDOD-Chattanooga Radio Co., Chattanooga,

Term. 256WDZ-J. L. Bush, Tuscola, Ill 278WDRC-Doolittle Radio Corp., New Haven.

Coma. 263WDWF-Dutee Wilcox Flint, Inc., Cranston,

R L 441,WEAR -Broadcasting Company of America,

N. Y. City, N. I' 492WEA1-Cornell University, Ithaca, N. Y 254WEAM-Borough of North Plainfield, N

Plainfield, N. J. 261WEAN --Shepard Co., Providence, R. L 270WEAO-Ohio State University, Columbus, 0 294WEAR -Willard Storage Battery Co., Cleve-

land, 0. 390WEAU-Davidson Bros. Co., Sioux City, Ia 275WEBC-W. C. Bridges, Superior, Wise 242WEBD-Elec. Equipment & Service Co.. An-

derson, Ind. 246WEBH-Edgewater Beach Hotel, Chicago, Ill 370WEBJ-Third Avenue R. R. Co., New York,

N. Y. 273WEBL-Radio Corp. of Ama. (Portable) 226WEBQ-Tate Radio Co., Harrisburg, ..... 716WEBR-H. H. Howell, Buffalo, N. Y 244-WHEW-Beloit College, Beloit, Wisc.. .

... 268

WEBZ-Savannah Radio Corp., Savannah, Ga. 263WEEI-Edison Electric Illuminating Co.,

Boston, Mass. 349WENS -Robert E. Hughes, Evanston, 203

WE-MC-Bram. Missionary College, MerriestSprings. Mich. 286

WENR-All-Amer. Radio Corp., Chicago, IlL 266 WEW-St. Louis University, St. Louis, Mo 248WFAA-Dallas News & Journal, Dallas, Tex 476WFAM-The Times, St. Cloud, Minn 273WFAV-University of Nebr., Lincoln, Nebr 275WFBC-1st Baptist Church, Knoxville, Tema 250WFBE-J. V. De Waite, Seymour, Ind 226WFBG-W F. Gable Co., Altoona, Pa 778WFBI-Galvin Radio Supply Co., Camden

N. J 236

WFBJ-St. Johns University,Minn. 236

WFBL-Onondaga Hotel, Syracuse, N. Y 252

WFBM-Merchants Lighting Co., Indianapolis,Ind. 268

WFBR-Maryland National Guard, Baltimore,Md. 254

WFBZ-Knox College, Galesburg, Ill 254WFDF-F. D. Fallain, Flint, Mich 234WFI-Strawbridge & Clothier, Philadelphia,

Pa. 395WFKB-F. K. Bridgman, Chicago, III 217WFRL-R. M. Lacey, Brooklyn, N. Y 205WOAL-Lancaster Elec. Supply. Co., Lancas-

ter. Pa. 248WGBB-H. H. Carman, Freeport, N. Y 244WGBC-lst Baptist Church, Memphis, Tenn 278WGBF-The Finke Furniture Co., Evansville,

Ind. 236WGBI-Scranton Broadcasters, Inc., Scran-

ton, Pa. 240IVGBR-Marshfield Broadcasting Association,

Marshfield. Wis. 229WGBS-Gimbel Brothers. New York, N. Y 316WGBU-Florida Cities Finance Co., Fulford

By -the -Sea, Fla.. 278WGBX-University of Maine, Orono, Maine 234WGES-Oak Leaves Broadcasting Station,

Oak Park, Ill. 250WGHB-G. H. Bottles, Developments, Clear

water, Fla. 266WGN-The Tribune, Chicago, III. 303WGMU-A. H. Grebe & Co., Inc., Richmond

Hill, N. Y. 236WGCP-Grand Central Palace, N. Y. City 252WC,11P-G. H. Phelps, Inc.' Detroit, Mich 270WGR-Federal Telephone Mfg. Co., Buffalo,

N. Y. 319WEST-Ga. School of Tech.. Atlanta, Ga 270WGY-General Elec. Co., Schenectady, N. Y 380WHA-University of Wisconsin, Madison. Wis 535WHAD-Marquette University, Milwaukee,

Wis. 275WHAM -Eastman School of Music, Rochester,

N. Y. 278WHAP-Taylor Finance Corp., 426 West 31st

St., New York City 241WHAR-F. P. Cook's Sons, Atlantic City,N.

WHAS-TheJ Courier Journal -Times, Louis -275

ville, Ky. 400WHAV-Wilmington Elec. Spec. Co.,

Del. 266WHAZ-Rensselaer Polytechnic Ins State,Troy, N. Y. 280

WHB-Sweeney School Co., Kansas City, Mo 366WHBA-Shaffer Music House, Oil City, Pa 250WHBC-Rev. E. P. Graham, Canton, Ohio 254V1411D-Charles W. Howard, Bellefontaine,

Ohio 222

Station Owner and Location MetersWHBF-Beardsley Specialty Co., Rock Island,

111 222WHBG-John S. Skane, Harrisburg, Pa 231WI -MC -Hickson Elec. Co., Rochestr, N. Y 258WHBJ-Laver Auto Co., Ft. Wayne, Ind 234WHBL-C. L. Carroll (Portable), Ill 216WHBM-C. L. Carroll (Portable), Chicago,

III. 233WHBN-1st Ave. Methodist 'Church, St. Pet-

ersburg, Fla. 238WHBP-Johnstown Auto Co., Johnstown, Pa. 256WHBR-Scientific E. & M. Co., Cincinnati, 0. 216WHBQ-St. Johns Meth. Church, Memphis,

Tenn. 233WHBU-B. L. Bing's Sons, Anderson, Ind- 219WHBY-St. Norbit's College, De Pere, Wis 250WHBW-D. R. Kierisle, Philadelphia, Pa 216WHDI-Wm. Hood Dunwoody Md. Inst

Minneapolis, Minn. 278WHEC-Hickson Elec. Co , Rochester, N. Y 258WHN-George Schubel, NewYork, N. Y. , 361WHK-Radio Air Service Corp., Cleveland,

Ohio 273WHO -Bankers Life Co., Des Moines, Ia 526WHT-Radiophone Broadcasting Corp., Derr

field, Ill 400WIAD-H. R. Miller, Philadelphia, Pa 250WIAS-Home Electric Co., Burlington, Ia 254W1BA-Capital Times, Madison, Wis 236WHIG -St. Paul's E. P. Church, Elkins Park,

Pa. 222WIBH-Elite Radio, New Bedford, Mass 210WIBI-Frederick B. Gittetl, Flushing, N. Y 219W1BJ-C. L. Carrell, Chicago, (Portable) 216WIBO-Nelson Bros., Chicago, IlL 226WIBM-Billy Maine, Chicago, Ill. 216WIBR-Thurman A. Owings, Weirton, W. Va 246WIBS-Lieut. Thomas F. Hunt, Elizabeth,

N. J. 203WIBU-The Electric Farm, Poynette, Wis 222WIBW-Dr. L. L. Dill, Logansport, Ind 220WIBX-Grid-Leak, Inc., Utica, N. Y 205WIBZ-A. B. Trum, Montgomery, Ala. 231WIL-Benson Radio Co., St. Louis, Mo 273WIOD-Carl S. Fisher Co., Miami, Fla. 248WIP-Gimbel Brothers, Philadelphia, Pa 508WJAD-Jackson's Radio Elec. Co., Waco, Tex 353WJAG-Norfolk Daily News, Norfolk, Nebr 270WJAK-Kokomo Tribune Station, Kokomo,

Ind. 254WJAM-D. M. Perham, Cedar Rapids, Ia 268WJAR-The Chalet Co., Providence, R. L 306WJAS-Pittsburgh Radio Supply House,

Pittsburgh, Pa. 275WJAX-Voice of Jacksonville, Fla. 337WJAZ-Zenith Radio Corp. Mt. Prospect, DL 322WJBA-D. H. Lentz, Jr., Joilet, Ill 207WJBB-L. W. McClung, St. Petersburg, Fla 254WJBE-Financial Journal, St. Petersburg,

Fla. 254WJBC-Hummer Furniture Co., 2nd and

Joilet Sts., La Salle, Ill. 234WJEI-R. S. Johnson, Red Bank, N. J 219WJBK-Ernest F. Goodwin, Ypsilanti, Mich 233WJBL-Wm. Gushard Dry Goods Co., De-

catur, Ill. 270WJBO-V. Jensen, New Orleans, La 268WJBQ-Bucknell University, Lewisburgh, Pa. 211WJBR-Omro Drug Store,. Omro, Wis 228WJBU-Bucknell University. Lewisburg, Pa 212WJJD-Loyal Order of Moose, Mooseheart,

III. 370WJR-Detroit Free Press and Jewett Radio

and Phonograph Co., Pontiac, Mich. 517WJY-Radio Corp. of Ama.,New York, N. Y. 405 ,WJZ-Radio Corp. of Ama.,'N. Y. -Bound

Brook, N. J. 455WKAF-WKAF broadcasting Co., Milwaukee,

Wis. 261WKAQ-Radio Corp. of Porto Rico, SanJuan, P R. 341WKAR-Mich. Agricultural College, Lansing,

Mich 286VVKAV-Laconia Radio Club, Laconia, N. H 224WKBB-Sanders Bros., Joliet, Ill. 214WKBE-K. & B. Electric Co., Webster. Mass. 231WKBG-C. L. Carrell, (Portable) Chicago, Ill 216WKRC-Kodel li,i;,-, Corp.. Cincinnati. 0. 326-422WKY-C. E. Hill and H. S. Richards. Okla-

homa City, Okla. 275WLAL-1st Presbyterian. Church, Tulsa, Okla. 250WLAP-W. V. Jordan, Louisville, Ky 275WLB-University of Minn., Minneapolis, Minn. 278WLBL-Wisconsin Department of Markets,

Stevens Point, Wis. 278WLIB-Liberty-Weekly Inc., Elgin, Ill. 303WLIT-Lit Brothers, Philadelphia, Pa. 395WLS-Sears Roebuck Co., Chicago, Ill 345WISI-Lincoln Studio Inc., Providence, R. L. 441WLTS-Lane Technical High School, Chicago,

Di. 258WLW-Crosley Radio Corp., Cincinnati, Ohio 422WLWL-Missionary Society of St. Paul the

Apostle, N. Y. City 288WMAC-C. B. Meredith, Cazenovia, N. Y 275WMAF-Round Hills Radio Corp., Dartmouth,

Mass. 444WMAK-Norton Laboratory, Lockport, N. Y. 266WMAL'-Leese Optical Co., Washington,

D. C. 213WMAN-lst Baptist Church. Columbus, 0 278WMAQ-Chicago Daily News, Chicago, Ill 448W1VIAY-Kings Highway Presbyterian Church,

St. Louis, Mo. 248WMAZ-Mercer University, Macon, Ga 261WMBB-American Bond and Mortgage Co ,

Chicago, Ill. 250WMBC-Michigan Broadcasting Co., Detroit,

Mich, 256WMBF-Fleetwood Hotel, Miami Beach, Fla 384WMC-Thee

nn.Commercial Appeal, Memphis,

500WMCA-Hotel McAlpin, Hoboken, N. J 341WMSG-Madison Square Garden Broadcast -

Mg Corporation, N. Y. City, N. Y 213WNAB-Shepard Stores, Boston, Mass 250WNAC-Shepard Stores, Boston, Mass 280WNAD-University of Okla., Norman, Okla 254

Station Owner and Location MetersWNAL-Omaha Central High School, Omaha,

Nebr. 254WNAT-Leaning Bros. Co., Philadelphia, Pa 230WNAX-Dakota Radio App. Co., Yankton,

244WNBH-New Bedford Hotel, New Bedford,

Mass. 248WNJ-Radio Shop, Newark. N. J. 2.53WNOX-Peoples Tel. & Tel. Co., Knoxville,

Tenn. 268WNYG-Municipal Station, New York, N. Y. 526WOAI-South East Equipment So., San An

Mirk, Texas 395WOAN-Vaughan Con. of Music, Lawrence -

burgh, Term. 283WOAW-Woodmen of the World, Omaha,

N ebr. 926WOAX-'F. J. Wolff, Trenton. N. J 210WOC-Palmer School of Chiro, Davenport, Ia. 484WOCL-Hotel Jamestown, Jamestown, N. Y 275WODA-O'Dea Radio and Victrolla Shop,

Paterson, N. J. 224WOI-Iowa State College, Ames, Iowa 270WOK-Neutrowound Radio Mfg. Co., Home-

wood, III. 217WOKO-Earl B. Smith, Patterson, N. J 233WOO -John Wanamaker, Philadelphia, Pa 504WOOD -Grand Rapids Radio Co., Grand

Rapids, Mich. 242WOQ-Unity School of Christianity, Kansas

City, Mo. 278WOR-L. Bamberger & Co., Newark, N. J. 405WORD -Peeples Pulpit Assn. Batavia, Ill 275WOS-Mo. State Marketing Bureau, Jefferson

City. Mo. 441WOVVL-Owl Battery Co., New Orleans, La. 270WOWO-Main Auto Supply Co., Ft. Wayne,

Ind. 272WPAK-N. D. Agricultural College, Agricul-

tural College, N. D. 23'5WPCC-N. Shore Congregational Church,

Chicago III. 258WPDQ-H. L Turner Buffalo, N. Y 205WPG-Municipality, Atlantic City, N. 300WPRC-Whson Printin.r & Radio Co., Harris-

burg, Pa. 216WPSC-Penn State College. State College, Pa. 261WQAA-H. A. Beak, Jr., Parkersburg, Pa 220WQAG-Gish Radio Service. Amarillo, Tex 2.34WQAE-Moore Radio News Station, Spring-

field, Vermont 246WQAM-Electric Equipment Co., Miami, Fla. 263WQAN-Scranton Times, Scranton, Pa. 250WQAO-Calvary Baptist Church, New York,

N. Y. 360WQJ-Calumet Rainbo Broadcasting Co., Chi-

cago, Ill. 4.48WRAF -Laporte Radio Club, Wash., D. C 224WRAK-Economy Light Co., Escanaba, Mich. 256WRAM-Lombard College, Galesburg, IlL., 244WRAV-Antioch College, Yellow Springs, 0 263WRAW-Avenue Radio Shop, Reading, Pa 236WRAX-The Berachah Church of Philadelphia,

Gloucester City, N. J. 240WRBC-Immanuel Lutheran Church, Val-

paraiso, Ind. 271WRC-Radio Corp. of America, Washington,

D. C. 469WRCO-Wynna Radio Co., Raleigh, N. C 252WREG-Wooten's Radio Shop, Cold Water,

Miss 254WREO-Reo Motor Co., Lansing, Mich. 226WRHF-Washington Radio Hospital Fund,

Wash., D. C 256WRHM-Rosedale Hospital, Minneapolis, Minn. 252WRK-Doren Bros., Elec. Co., Hamilton, 0 270WRM-University of Illinois, Urbana, Ill 273WRMU-A; H. Grebe & Co., Inc., Motor

Yacht Mu -I, N. Y. City 23eWRNY-Experimenter Publishing Co., (Radio

News) N. Y. CityWRR-City of Dallas, Tex 246WRST-Radiotol Mfg. Co., Inc., 5 First Ave.

.Bay Shore, N. Y 216WRVA-Laurus & Bros., Co., Richmond, Va , 256WRW-Tarrytown Research Laboratory, Tar-

rytown, N. Y. 273WSAI-U. S. Playing Card Co., Cincinnati, 0. 326WSAJ-Grove City College, Grove City, Pa 229WSAN-Allentown Call, Allentown, Pa.. 229WSAR-Doughty & Welch Elec. Co., Fall

River, Mass. 254WSAX-Zenith Radio Corp., Chicago, 268WSAZ-Chase Electric Shop, Pomeroy, Ohio 244WSB-The Atlanta Journal, Atlanta, Ga 428WSBC-World Battery Co., Chicago, DL 210WSBF-Stix Baer and Fuller, St. Louis, Mo 273WSBT-South Bend Tribune. South Bend, Ind. 271WSDA-Seventh Day Adventist Church, N.

Y. City 2.6.3WSKC-World's Star Knitting Co., Bay City,

Mich. 261WSM-National Life and Accident Ins., Nash-

ville, Tenn 283WSBM-Saenger Amusement Co., New Or-

leans, La. 319WSMH-Shathick Music House, Owosso, Mich. 240WSMK-S. M. K. Radio Corp., Dayton, 0 275WSOE-School of Engineering, Milwaukee,

Wisc. 246WSRO-H. W. Fahlander, Hamilton, Ohio 251WSSH-Tremont Temple Baptist Shurch,

Boston. Mass. 261WSUI-State University of Iowa, Iowa City,

Ia. 484WSVS-Seneca Vocational School, Buffalo,

N. Y. 219WSWS-S. W. Straus & Co, Woodale, III 275WTAB-Fall River Daily Herald, Fall River,

Mass. 266WTAD-R. E. Compton, Carthage, BI 236WTAG-Worcester Telegram Publishing Co ,

Worcester, Mass. 268WTAL-Toledo Radio & Elec. Co., Toledo, 0 252WTAM-Willard Storage Battery Co., Cleve-

land, Ohio 389(Concluded out page 29)

RADIO WORLD July 17, 1926A THOUGHT FOR THE WEEK

SUMMER is here. So is radio. So isgood reception-if you are sensible

enough to do all the things that help thecareful listener -in to get what he wants.Don't kick at ether disturbances. See if yourset is as ship-shape as it should be. Thengo ahead and get what you should reasonablyexpect to get.

PADREC. U.S.PAT. OFF

/ladle World's Slogan: "A radio set for every hem."

TELEPHONE BRYANT 0558, 0559 -PUBLISHED EVERY WEDNESDAY

(Dated Saturday of same week)FROM PUBLICATION OFFICE

ECEENNESSY RADIO PUBLICATION CORPORATION145 WEST 45th STREDY, NEW YORK, N. Y.

Oust FAG of Broadway)ROLAND BURKE HENNESSY. President

M. B. HENNESSY, Vice -PresidentFRED & CLARK, Secretary and Manager

European Representatives: The International News Cs.Breams Bldg., Chancery Lane, London. Eng.Paris. France: Brentano's, 8 Avenue de l'Opere

Lee Angeles: Lloyd B. Chappell, 611 S. Coronado St.

EDITOR, Roland Burke HennessyMANAGING EDITOR, Herman BernardTECHNICAL EDITOR, Lewis WinnerART DIRECTOR, I. Gerard Sheerly

CONTRIBUTING EDITORS, John F. Rider, J. E. Anderson

SUBSCRIPTION RATESFM.n cents a earl, 86.00 a year. $3,00 for ail

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Receipt by new subscribers of the ant C057 of RADIOWORLD mailed to them after sending in their order In

Chtomaticacknowledgment of their subscription order.

anges of address should be received at this office twoweeks before date of publication. Always give old adder.:also state whether subscription is new or a renewal.

ADVERTISING RATESGeneral Advertising

1 Page, 744."311" 463 lines 8800.00% Page, 7}'4"x51/2'T 231 lines 150.00

Page, 853" D. C. 231 lines 150.00Page, 404" D. C, 115 lines

1 Column, 2y4"411" 154 lines 100.001 Inch 10.00

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Time DiscountES consecutive issues 20%20 times con_seectIvely or Ti.. 0. W. one year 15%4 conaecutive issues 10%WEEKLY, dated each Saturday. published Wednesday.

Advertising forma close Tuesday, eleven days to advanceof date of issue.

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order. Business Opportunities ten cents per word, $1.00minimum.

Entered as second-class matter March 23, 1922, atthe Post Office at New York, N. Y., under the Act .0March 3, 1879.

JULY 17, 1926

Bigger Income for TalentTHE broadcasting studio is unlike the

stage, in that the studio producesgreat reputations without much re-muneration attaching thereto, whereasstage celebrities are sometimes even lesscelebrated than their salaries. For in-stance, it is not unusual for the leadingman in a musical comedy in New YorkCity to receive $1,500 a week, while an-nouncers, more famous than he by far,may receive only twice that in a year!The famous announcer's soothing syrupmay be bottled up in the fact that heworks all year round and gets a twoweeks' vacation, with pay, whereas, themusical comedy star works, say 40 weeksa year, the other 12 being a vacationgranted without pay and without optionof refusal.

Often the public is staggered to learnof the tremendous salaries received by fa-mous and -gifted persons. In cases wherethe facts are constantly before the pub-lic, only occasional comment is made ofthe enormity of the pay. For instance,Jack Dempsey will get nearly a milliondollars for his next fight, if ever he does

fight, but this has received so much pub-licity that it is virtually taken for granted.

The key to the pay situation lies inthe financial drawing power of the per-former. None can deny that Dempseyshould get a substantial percentage of thegate receipts, for it is he who draws thecrowd that pays the fancy prices. Like-wise the actor has a cash value on thesame basis. Quite on the other side is thebroadcast performer, be he announcer orartist, since all he will bring tangibly areapplause letters!

Many would like to see their favoritesof the air gain more substantial financialrecognition. About the best paid micro-phone performers are those who are inthe actor class, indeed, have been re-cruited from the stage. They are heardon advertising programs or so-called spon-sored programs, and are paid by the con-cern whose name is uttered into the mic-rophone quite frequently for the good-will that such reiteration may engender.

As for other artists heard at stations,including studio artists on the station pay-roll, these, as well as announcers, aregaining the benefit of special bureaus thatmore and more stations are inaugurating,to develop a concert and recital field forthese deserving entertainers. Many amothers' club would feel flattered to havethe favorite announcer of the vicinity ap-pear in person at the inevitable entertain-ment and dance. Indeed, last winterbroadcast favorites united to give a con-cert in New York City, and the listeningpublic crowded the auditorium. Thisshows a demand exists, and it is well in-deed that stations are helping to findextra money for the announcers andothers. Organizations might well draw onthis fund of talent.

The Misannouncing EvilANNOUNCERS should be careful to

avoid misannouncing. The troubleexists mostly at large stations, where re-mote control broadcasting is done. Themicrophone may be at a hotel, the ampli-fied speech and music being telephoned,as it were, to the studio, where it is puton the air. Lack of teamwork betweenannouncer and the orchestra conductoror other worthy at the point of remotecontrol results in the announcement thata certain song will be sung or played,whereas, a different one ensues. Theapology that precedes the next announce-ment is necessarily crippled.

The listening public experiences astrange feeling over a misannouncernent.It is an admixture of censure for the an-nouncer and station, sympathy for theartist, and general distraction. Somehowthe effect of a song, especially if sung,is almost lost if the rendition is precededby the announcement of a different piece.For instance, if something merry in itsmusic is announced, and instead a senti-mental waltz song is heard, one wonderswhether the soprano will sing the othersong afterwards, how the announcer cameto make the mistake, or perhaps whetherthis is indeed the very song that wasannounced. All this is so distracting tothe audience, that, however credible maybe the performance of the unexpectedpiece, the effect is vitiated.

WJZ, the Radio Corporation of Amer-ica's station in New York City, recentlyhas been offending repeatedly in this re-spect, accompanying this annoyance withsagging modulation, and even completecutoff of transmission a few topies ongiven nights, lasting for a few secondseach time.

The Patent SuitsTHE injunction suit activities of the

Radio Corporation of America andallied corporations are livelier than everbefore, although lately having receivedsome deadly blows.

Most recent of the cases to be decidedwas that brought against the Independent Radio Manufacturers, as the com-bined makers of the Hazeltine Neutro-dyne receivers are known. The chargewas that the Hazeltine neutralizationmethod was an infringement of the Riceand Hartley patents, owned by the plain-tiffs. The complaint was dismissed inFederal Court, Brooklyn, the Judge hold-ing that the Hazeltine method was anoriginal one. The Court went so far asto say some uncomplimentary thingsabout the R. C. A. and its associate cor-porations, all of which concerns are underinvestigation by the Federal Trade Com-mission, on a charge of monopoly in re-straint of trade.

The suit brought by the R. C. A.against the Splitdorff Co., alleging thatthe making of tuned radio frequency setswas an infringement of other patentsowned by the plaintiff, has not been de-cided at this writing, for it is the most re-cent important injunction suit to bebrought by the frequent plaintiffs.

Surely whatever patent rights the R. C.A. and the other members of the radiocombine may own are entitled to and willreceive full protection under the law, butthe R. C. A. should not expect to financedepartmental deficits in the operation oftheir regular business out of the revenuesof other and more successful receivermanufacturers that the R. C. A. hopes areinfringing some of its patents. . JudgeInch, in deciding the Hazeltine patentcase, clearly inferred in his publishedopinion that the R. C. A. and the otherplaintiffs, realizing that the Neutrodynemanufacturers were making considerablemoney, decided, after years of inactivity,to try to scoop in some of this money forthemselves. The failure to achieve thisend was pronounced, since dismissal of acomplaint is about the severest slap inthe face that a plaintiff can receive, shortof being adjudged in contempt of court.

There is good and bad in the R. C..A.in particular. Some of the companiesthat are joined as co -plaintiffs in the suitsare drawn in due to intermingled patentownership arising from previous co-opera-tive arrangements. In sonic instances theformer friendly feeling among these com-mercial brethren has cooled off consider-ably. But a lawsuit makes strange bed-fellows, even as politics.

The R. C. A. represents in some re-spects the best, in others, the worst. Letit be hoped all its conduct will be on thelofty plane henceforth.

Some of the bad spots in R. C. A. con-duct have the ungracious habit of gettingaired in court, of all places, and do soeven in suits begun and strenuouslyprosecuted by the. R. C. A.

One cannot help recall the shame thatevery friend of the radio industry musthave felt when it was revealed, in thesuit by the De Forest Co. to enjoin theR. C. A. from spying on the De Foresttube works, that the R. C. A. had paidDe Forest employes to report to the R.C. A. on the innermost secrets of the DeForest tube factory. When that casecame up in court, counsel for the R. C. A.said that the practises complained of hadceased, and asked therefore that no in-junction be issued. The court scoffed atthis plea of "mercy on the basis of guilt"and the attorney, probably himself a war-den of a church and a well-behavedcitizen, had to bear the brunt of thecourt's ire, while the R. C. A. had donethe dirty deeds.

The R. C. A. should prosecute infringe-ments of its patents, indeed, must do solest the patent rights be deemed to bewaived, but it had better beware of echo-ing empty charges and wringing uncleanhands in the faces of sensible judges andjuries in the expectation that from suchsoiled conduct it may wring the sweetfruits of success.

July 17, 1926 RADIO WORLD 21

R. C. A. Neutrodyne Suit/Thrown Out of Court as

Bold Scheme to Cash InRadio Trust Alleged Ha-

zeltine's Method In-fringed Rice and Hart-ley Patents-Court Sar-castic About Usefulnessand Efficiency of R. C. A.and Associates.

IMPUGNS SINCERITY

Remarks That No ActionWas Even AttemptedUntil Long After Suc-cess of Hazeltine's Cir-cuit.

The suit brought by the Radio Corpora-tion of America and others against the In-dependent Radio Manufacturers, Inc., mak-ers of the Hazeltine licensed Neutrodynesets, alleging that the Hazeltine patent in-fringed the Rice and Hartley patents, wasthrown out of Federal Court in Brooklyn.Judge Inch, who heard the arguments ofboth sides in the suit for injunction andheavy damages, in his opinion openlycharged the plaintiffs-the R. C. A., Gen-eral Electric, Westinghouse and the Amer-ican Telephone and Telegraph Co.-withhaving made not even an attempt to act ontheir alleged claims until the popularity ofthe Neutrodyne was well established, andgood profits were being earned.

The judge also referred sarcastically tothe R. C. A. and its associate members ofthe Trust as "useful corporations" with"various efficient and largo research de-partments."

The judge further wrote:"The first radio receiving set that, if

properly constructed, would not squeal orwhistle and was not a nuisance to the neigh-borhood, was the so-called Hazeltine neutro-dyne apparatus."

Last -Minute GrabJudge Inch declarea in his decision that

"after Hazeltine gave to the commercialworld a new receiving set, there has arisenalmost overnight a great and important in-dustry in the making and selling of receiv-ing sets, a substantial portion of which,$50,000,000 worth, were employing the Ha-zeltine idea."

Then, the decision pointed out, the RadioCorporation of America and its associatedcompanies, brought the suit charging Ha-zeltine had infringed their patents on radioinventions by Rice and Hartley.

A Dig at the TrustIn dismissing the suit the judge said:"Only after success by those dealing in

these (Hazeltine) radio sets, the plaintiffs(Radio Corporation and others) come andclaim that this defendant's apparatus andcircuit infringe certain patents which, sofar as I can see, have been quietly rest-ing, with others, in the archives of thevarious efficient and large research depart-ments of these enormous and useful cor-porations.

"By broad claims which state a discoveryof a principle already given to the world,

this suit is an endeavor to prove infringe-ment of new instrumentalities. Whereforethe defendant is entitled to a decree dis-missing the complaint."

Decision RemovesMenace to Dealers

The suit which the R. C. A. lost, re-garding the Neutrodyne patent, wasknown as the Garod case. The plaintiffssued, among others, the Twentieth Cen-tury Radio Corporation, of 102 FlatbushAvenue, Brooklyn, N. Y., distributors ofGarod Neutrodyne receivers. The chargewas that the Garod set, using the Hazel-tine neutralization method, infringed theinventions of Ralph Hartley and ChesterRice.

The Garod corporation is a member ofthe Independent Radio Manufacturers,Inc., which in 1922 obtained from Profes-sor Hazeltine licenses to make and sellradio sets embodying his inventions. HadJudge Inch's decision been favorable tothe Radio Corporation the decision mighthave given that corporation a virtualmonopoly of the manufacture and distribution of sets, since the R. C. A. con-trols the regeneration and Super-Hetero-dye patents and is claiming the tunedradio frequency patent on the Splitdorffcase. The Judge said in the Garod case :

"It seems to me that this suit is anendeavor, by proof of broad claims, whichstate in slightly different words a discov-ery of a 'principle' already given to theworld, to prove infringement of new in-strumentalities expressly covered byclaims not sued upon.

"The valid claims of the Hartley andRice patents would seem to be for 'in-strumentalities.' Each may representslight steps in the art without disturb-ing the other. The claims in suit setforth a 'principle' well known to theprior art. The claim covering the 'in-strumentalities' is not sued on. Where-fore the defendant is entitled to a decreedismissing the complaint."

Ira Adams, head of the patent depart-ment of the Radio Corporation, admit-ted that a favorable decision on the cor-poration's claims would mean that hun-dreds of small dealers now selling Neu-trodyne sets, as well as firms manufac-turing such sets, would probably go out

Speaker Aids Business

(Courtesy Wave Radio Cur pCUSTOMERS are attracted to the Try-

Mo Radio Store, 9 West Broadway, NewYork City, by a speaker hung to theplate glass window by means of a rub-ber suction cup. The speaker leads areconnected to a set inside the store. Pass-ersby are attracted to the speaker andwindow by the music. Moe Lager, propri-etor, is shown adjusting the Wave Cone.of business. "We shall very probably ap-peal this case," he added.

Edelson Vice -PresidentOf Insulating Company

Samuel Edelson was elected vice-presi-dent and director of the Insulating Com-pany of America, Inc., New York City.This concern, originally known to thetrade as the Radio Panel & Parts Corp.,has atracted widespread attention in radiocircles because of its phenomenal growthunder its founders, A. G. Heller and S. J.Spector.

The Insulating Company of America isoperating one of the largest and bestequipped plants of its kind, occupying theentire building at 59 Warren Street. Theyare manufacturers of insulating materialsand parts which enjoy a world-wide repu-tation for quality. Through their radiopanel and parts division they have becomean important factor in the radio trade.

Mr. Edelson brings to his company arecord of marked achievement in thebusiness world, in the sales field and asa directing executive.

Australia to InvestigateValidity of Many Patents

WASHINGTON.A conference of all interests concerned

with radio broadcasting was held recentlyin Sydney, Australia, according to a re-port to the Department of Commerce.Representatives were present from theFederal Government, the Institution ofEngineers, the English Speaking Union,the Listener's League, the broadcastingcompanies and the radio dealers.

The report on the committee of re-search stated that it was the policy ofthe Wireless Institute of Australia toestablish a scientific laboratory along thelines of the subsidized laboratories exist-ing in other countries. The committee on

broadcasting and copyrights recommended -

the appointment of a royal commission toinquire into the whole question. Thecommittee on patent royalties also recom-mended an investigation by the royalcommission with a view to ascertainingwhether the claims to patent rights bycertain companies were valid. Furtherrecommendations of the committee dealtwith the cost of operating stations andrevenue obtained from the importationof radio material.

A request was also made to the Post-master -General to increase the margin ofwavelengths between certain of the sta-tions now operating.

R A 1) 1 0 WORLD July 17, 1926

Literature Wantedstames of readers of RADIO WORLD

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

I desire to receive radio literatureNameCity or townStateAre you a dealer?

If not, who is your dealer?His NameHis Address

W. E. Scharlach, Corwith, Ia.Hef Candy, 33 Chester Ave., Toronto 6, Canada.Gaspar Arias, Infanta 18, Havana, Cuba.D. M. Hilsabeck, Mt. Grove, Mo.D. K. McLean, 2737 Chamta St., Denver, Col.H. Falconer, 351 Summit Ave., Jersey City, N.

J. (Dealer).Malden Radio Co., 2 Washington St., South,

Malden, Mass. (Dealer).Paul W. Newman, 1916 Cropsey Ave., Brook-

lyn. N. Y.Fred W. Schaefer, Platteville, Wis. (Dealer).A. Beauregard, 43 St. Michel St., St. Hyacinthe,

Quebec, Canada.J. W. Selfe, 4127 Westway, Toledo, 0.Oscar W. Kirsten, 470 39th St. Milwaukee, Wis.J. E. Whitney, 617 N. East St., Indianapolis,

Ind.Mortimer & Kay, 405 Hoke Building, Hutchin-

son, Kans.Chas. H. Jones, Etowah, Tenn. (Dealer).G. N. Rang, S.S. Utacarbon, care Union Oil

Co., Wilmington, Cal.

Drawing Card FeaturesAdopted by Coast Show

LOS ANGELES.The committee in charge of the fourth

annual National Radio exposition, to beheld in the Ambassador Auditorium herefrom September 5 to 11, has adopted sug-gestions believed to bear an importantinfluence in carrying out the dual motiveof the show.

J. A. Hartley, general chairman, de-clared these features will consist of edu-cational programs for the general public,a preview for dealers only, a partly paidticket for distribution by the dealers, anelimination of costly souvenir programsand substitution of a concise directory ofexhibits, standardized :booth equipmentand the use of a complete and experiencedexposition organization, headed by WaldoT. Tupper, Pacific Coast exposition ex, -pert.

Outstanding among the reasons foradoption of the educational program, itwas said, is the fact it insures heavy af-ternoon attendance. Each patron of theprogram is to be tendered a free admis-sion to -the exposition.

Heretofore expositions have had lightcrowds when they opened their afternoonsessions, but as was proven at last year'sradio show, the programs of radio tech-nical talks, personal appearances of an-nouncers and the presence of noted radiostars, have drawn such throngs that when

New Move to Tax RadioOpposedbyManufacturers

BUFFALO, N. Y.The Board of Directors of the Radio

Manufacturers' Association appointed acommittee on radio receiving installation,H. H. Frost, chairman, to co-operate withorganizations in the construction industryin wiring of houses for proper radio re-ceiving installation as a means of im-proving service to the public. The com-mittee will make an intensive study of theprinciples and methods underlying efficientinstallation of radio receiving apparatusand work for their adoption in schools,hotels, homes and other types of build-ings.

In line with the suggestion of SecretaryHoover at the time of the convention atAtlantic City a statistical committee, J.B. Hawley, chairman, was formed withinstructions to make a survey of the sta-tistical needs of the industry and topresent plans for a competent statisticalservice to the association. Such a service,it is thought, will be of distinct value inhelping to stabilize the industry.

Authorize Official OrganAuthorization for publishing "The R.

M. news as the official medium of theassociation under the direction of B. W.Ruark, executive secretary, was voted.

The directors opposed taxes specificallydirected against the products of the in-dustry, in view of the growing tend-ency to single out radio product's fortaxation. Among the reasons advancedin support of such opposition were thefollowing: radio is already taxed as per-sonal property and additional taxes there-fore would constitute double taxation ;radio is an agent of education and in-struction and its use should be encour-aged and it should not be subjected tohindrances brought about by specific tax-ation ; and the imposition of such taxes

would be reflected in higher distributionor maintenance costs and would be aburden both to the industry and the pub-lic.

The fair trade practice committee, C.C. Colby, chairman, was authorized toformulate a code of fair trade practices orprinciples of business conduct for pres-entation to the association as a means ofproviding machinery for the self-govern-ment of the industry and thereby reduceto a minimum the necessity of regulationfront without.

Seek Farmers' BusinessImportant changes in the government

of the association were forecast in theproposed new constitution and by-lawspresented by President A. T. Haugh.This contemplates associate membershipfor jobbers, creation of a technical groupin the association, election of officersunder the Australian ballot system andvarious other matters. It will be presentedto the association at its forthcoming NewYork meeting in September.

The board of directors approved thenational contest proposed by the Depart-ment of Agriculture to intensify interestin radio among farmers and recommendedthat members of the association cooperate through the donation of prizes andotherwise to carry the contest to a suc-cessful conclusion. The importance ofthe farm market to radio manufacturerscannot be over -estimated and the contestwill develop data of value in reaching thatmarket, it was said.

Present were: A. T. Haugh, L. G. Bald-win, P. C. Lenz, Jr., B. W. Ruark, C. D.Boyd, C. C. Colby, Godfrey Gort, S. B.Trainer, D. MacGregor, H. H. Frost, T.K. Webster, W. W. Dowdell, J. B. Haw-ley, H; H. Eby and H. W. Simpson.

The headquarters of the R. M. A. areat 32 West Randolph Street, Chicago.

the radio show gates were opened at least2,000 persons entered immediately. Theeducational programs are to be timed toconclude coincidentally with the openingof the show.

By means of the partly paid ticket, eachradio dealer in Southern California willbe able to offer his patronage a reducedrate order on the box office. He will dis-tribute these free, and the balance duewill be paid at the expositiorrn. Each pat-ron records his name, as well as thatof his dealer on the partly paid ticket, andthese names are listed and returned to thedistributor, thus affording a double checkon his mailing list.

New Tuning CondenserIs Made By Unitrol

A new' type of die-cast variable con-denser has been introduced by the UnitrolCondenser Corporation. The rotor andstator blocks are two complete castings,respectively, which form the main struc-ture. An alloy of aluminum, copper andsilicon is used to produce an accuratesurface. Straight line frequency is ob-tained through tapered circular segmentswithout the usual offset plates, which areused by many manufacturers to obtainthis result.

Only twelve parts are used in the com-plete condenser, the cubic contents ofwhich are about one-half that of othercondensers of the same capacity. In thiscondenser the inter -leaving blades rotateparallel to the axis of the condenser anddiffer from other condensers in that re-spect.

A novel shaft construction is employedand cone bearings substituted for cylin-drical bearings.

One of the bearings is of semi -floatingtype, held under spring tension to com-pensate for any wear on the bearings.The engineer who designed the device ex-plains that the advantage of this con-struction is that no "end play" or "sideplay" will be noticed when the knob isturned, no matter how long this con-denser is in service.

Industries BanquetTo Be Held September 15The third annual radio industries ban-

quet will be held in New York on Wed-nesday, September 15, Paul B. Klugh,chairman of the committee, announced.

More than 1,400 attended the secondannual banquet held during the radioshows last year, while an attendance ofover 2,000 is forecast for the third annualaffair.

Business OpportunitiesRadio and Electrical

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EXPERIENCED ENGINEER DESIGNS, de-velops, builds small electrical and mechanical de-vices; reasonable charges. Miller, 120 West 64thSt., N. Y. C.

RADIO OUTDOOR AERIAL PATENTED,demountable, fits any roof five minutes; wantParty to finance same. Box K, Radio World.

Tole 17 10,6 R A DIO WOR 23

A Battery SubstitutesCalled Unsubstantial

Optimism was the keynote of the meet-ing of the National Battery Manufac-turers Association, held in New YorkCity at the Roosevelt Hotel. It was theannual meeting and reports of the vari-ous activities of the departments operat-ing in the association were given. Presi-dent Kelly, re-elected to succeed himselffor the coming year, made a ringingspeech on the work of the organizationand offered many recommendations as tothe reorganization and replanning of thework for the corning year.

The program for the convention rep -

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resented a continuance Of the policyplanned at the Chicago meeting and in-cluded keveral technical papers. Amongthem was a paper by W. C. Brooks, ofthe Hartford Battery Mfg. Company, onthe trickle charger and combination Abattery units. This load to do with aquestion that is attracting a great deal ofattention among manufacturers becauseof the publicity given to eliminators. Mr.Brooks was impartial its his remarksand placed the exact facts before themembers.

[His article, elsewhere in this issue, em-bodies the gist of his remarks to the meet-ing.]

Business ConditionsOne of the interesting features of the

meeting was a composite report of businessconditions as reported by various members.This was given by 0. B. Towne and showeda varied experience on the part of manu-facturers in different lines. Some of thosewho were confining themselves to only cer-tain features of the battery business indi-cated a falling off 'of business during cer-tain months in their main line and pickingup of other lines. Manufacturers of farmlighting storage batteries and battery platesshowed a substantial increase in their busi-ness. Automobile battery business remainsabout the same.

Lawrence A. Nixon, secretary of theRadio Trade Association of America, gavea very comprehensive address on the out-look for radio batteries. He encouragedparticularly improvements in radio batterieswhich would eliminate certain objections.However, his remarks were more encourag-ing for the radio' batteries than anythingheard for some time. He did not seem tofeel that inventions which have been her-alded recently about doing away with stor-age batteries in radio, were anywhere nearly

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THE VICTOREENHow to build this 8 -tube Super -

Heterodyne described in February20, 27, March 6 and 13 issues ofRADIO WORLD. Send 60c for allfour copies. Send $6 for year's sub-scription and get these four copiesFREEI

throtigh the sNiwriluenl.L1 !Lit;s, :Ind 1,111 -

s,..ittcitily were offering nothing of stlicAan,lial name in 05 II is Mr.Nixon's opinion that littprovennot. .1r,

1/1111Ild t ante and (11.11 1,11sryslumbt he among those to t.ike the hsel.

Officers ElectedIn departmental activity of the Associa-

ti,.ii, a report was given by C. H. Smith, ofthe \ Vest inghouse Union flattery Com-pany, Chairman of the Cost Committee, onprofit leaks or waste in the industry, andindicated a very reinafikable advance incost systems. Mr. Smith load arranged acomplete chart giving the outline of a cirrisystem in each plant.

The following officers were elected forthe coming year:

President, D. H. Kelly, U. S. Light &Heat Corp.

Vice -President, R. D. Mowry, UniversalBattery Co.

2nd Vice -President, 0. L. Schutz, GrantStorage Battery Co.

Secretary, T. D. White, Victor StorageBattery Co.

Treasurer, P. M. Marko, Marko StorageBattery Co.

Membership of the Board of Directors ismade tip of the officers of the Associationand the follow ing directors especially ap-pointed for tht t purpose:

C. H. Smith. Westinghouse Union Bat-tery Co.

L. A. Doughty, Carlilc & Doughty, inc.The Association will meet again in Cleve-

land or Detroit during the last of Septem-ber or early part of October.

Prize From EnglandTo Be Awarded at Show

A gold medal {rem England, in addi-tion to Fair medaland other awards, will go to the winnerof the international amateur set contest,to be held at the Radio World's Fair inMadison Square Garden, New York City,Sept. 13-18. The prize is offered by the"Wireless Magazine." An eliminationcontest will determine the sets to be sentto New York to compete with the re-ceivers built by Americans, as well asa number from France, Belgium, Italy.Spain and Australia.

Sets of exceedingly novel constructionand those of proven extraordinary effi-ciency will be judged in New York. Thewinning sets in all classes will be givenplaces of honor. too, at the Fifth AnnualRadio Show in Chicago.

NEW CORPORATIONSAsparad Radio Corp., Ay.bury Park. N. J.,

radio supplies, Ac.. $10.1.0)0; Hobate W. SimPson,Ocean Grove; W. T. Jackson, Allenhurst; RobertMcMichael, Asbury Park, N. J. (Atty., RobertMcMichael, Asbury Park, N. J.)

Ray -Ad Co., N. Y. City, moving pictures byradio, $.75,(X)0; S. E. Merriam, L. Mushen, H.Harrison. (Atty., B. H. Sandler. 150 B'way.,N. Y. City.)

CAPITAL INCREASESRadio Service Corporation of Ness pork. Wil-

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24 RADIO WORLD July 17, 1926

Man and Girl AloneIn Dark as Iron Fails

The value of having a real good solder-ing iron lies in the assurance that it willkeep on functioning properly and, if it isof the electric type, will not cause you toblow a fuse in your home power wiring(the DC or AC main).

Recently a radio engineer was using apoor iron which had been giving fair serv-ice for a few months. A girl friend tele-phoned him that her set was out of order.He rushed for the garage. Taking someradio tools with him, he sped over to thegirl friend's house. You see, they werein love.

When he got there he found that theA battery switch was disconnected at thepoint where the battery lead should havebeen in constant contact with the switchlug. Obviously this was a soldering job,so he fished the iron out of his little bagand plugged into the electrolier socket.

He Explains FusesAnd nothing happened, except that the

lights went out! Imagine his embarrass-ment, and incidentally hers, at their beingleft alone in a dark house!

"The fuses went!" he exclaimed."Can you fix them up?" she inquired

anxiously, although with some confidenceat that, for she knew he was well versedin things electrical.

"Have you any fuses?" he asked."Fuses?" she inquired innocently.

"What are fuses?""Why, a fuse is something that you put

in the fuse box," he explained darkly."It's a piece of wire in a sort of con-traption and it melts if the house wiringis shorted: That avoids trouble else-where, you see."

"No," she confessed, "I don't see. I'mall in the dark."

He was not of a mind to laugh at herjoke. He asked where the fuse box was.She did not know. There was nobodyelse at home. Maybe some neighborcould tell, she suggested.

"Never mind," he counselled, "I'll gointo the cellar and find the fuse box."

Not Even One FuseSo he did, with the aid of his pocket

flashlight. But there was not an extrafuse to be found. So he made the roundsof the neighbors, without any better luck.The nearest electrical store was two milesaway, and likely closed by this time, as hewas well aware. The clock had struck10:30 p. ns. Strictly speaking, it hadmerely struck once, but he knew it was

10:30 and, to make matters worse, wasP. M. besides.

He helped the girl into his car andtogether they drove to the electrical store,which was locked and dark. They foundout where the electrician lived, wrung himaway from a poker game back to the storeto find a few fuses, and then sped awaywith the precious safety devices. Thesethe engineer quickly installed in the fusebox and all was happy.

"What caused the lights to go -out?"she asked.

"Why, my soldering iron shorted," heexplained. "We'll have to heat the ironon a gas stove."

A Fire Solves Problem"We have no gas," she politely informed

him."Then we'll build a fire."And so, in the back yard, he built a

bon fire and heated the iron so that hecould complete his originally simple, butby this time frightfully complicated, job.

When his work was finished shethanked bins and said :

"I have an alcohol lamp, if that's anygood to you."

He groaned. "No, not now," he said,containing himself with superb exhibitionof will power. "Everything'is all rightnow, except the iron. Tomorrow I'll buythe best iron that the market affords. It'scheap insurance."

Children at the DialsCompel Program Care

"The child in the home can and doestune in to any program that is availableand can absorb many things which hewould not otherwise hear. Under theseconditions it is important that if radiois to accomplish the greatest good forthe greatest number it be in the hands ofthose who realize their responsibility tothe listening public, rather than in thehands of those who for publicity or otherselfish purposes will depreciate this me-dium of communication."

So said William E. Harkness, vice-president and general manager of theBroadcasting Company of America, whichoperates WEAF, New York City.

He rtported that a survey by WEAFdetermined the average listeners per setare 5 and brought out the very interes-

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ing fact that WEAF and a chain of six-teen broadcasting stations in the north-eastern section of the United Statesserved 61.6% of the total number of re-ceiving sets in the United States and52% of the nation's total population.

As the result of another questionnaire,Mr. Harkness pointed out the fact thatdue to the children's choice of operaticand classical music it would seem to in-dicate that the efforts of the city andtown schools to stimulate an interest inthese classes of music have been effec-tive.

In speaking of radio and the newspaper,Mr. Harkness stated that the radio wouldnever supplant the paper, but both wouldhave their own place, particularly in thefield of education.

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CHANGES OF ADDRESSshould be sent to Subscription Department at least two weeks in advanceof publication in order to insure early and proper attention. RADIOWORLD'S subscription list is so large that it is necessary that changes besent in as requested. Address, Subscription Department, RADIO WORLD,145 W. 45th St., New York.

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July 17, 1926 RADIO WORLD 25

Better Programs KeepInterest High in SummerBy Charles B. Popenoe

Manager, Stations WJZ and WJYThe program, after all, is the founda-

tion of the broadcasting structure. Wereit not for the steady flow of increasinglygood program features, radio would havebut a limited appeal to the American pub-lic. Especially is this emphasized dur-ing Summer, when radio must allow forthe vastly increased diversions that comewith the transition from an indoor tooutdoor life.

Broadcasters fully recognize this andradio program directors have prepared ac-cordingly. This season, therefore, willwitness a genuine radio Summer in thematter of suitable radio programs quiteas much as in ample transmitting powerand improved reception.

Highly significant, so far as this Sum-mer's programs are concerned, is themarked change that has taken place inbroadcasting practice during the past fewmonths. Gradually broadcasting has pro-gressed from a rather amateur and hap-hazard means of entertainment to a pro-fessional and thoroughly stablished in-stitution.

The Great ImprovementInstead of a steady procession of ama-

teur talent, with just an occasionalsprinkling of professional performers,present-day programs consist virtually ofall-star talent, so far as the leadingbroadcasting stations are concerned. Forthe first time, through the medium of thesponsored program, the program direc-tor has the necessary means at his dis-posal to summon the best of profession-al talent. Today the program director,

like the theatrical manager, plans hisprogram and then selects and arrangeshis features with a view to providingmaximum enjoyment and value to his in-visible audience which, by its steadilyincreasing attendance, repays both theprogram director and the program spon-sor for the effort and expense involved.

And, under the new circumstances, theprogram director may plan his programsfor the maximum Summer -time appeal.This choice makes for variety and cor-rect balance. Thus the radio audience isassured the highest class of entertain-ment in Summer as well as Winter, borneon powerful radio waves capable of com-batting atmospheric disturbances, whilethe radio performers and their sponsorsare assured a full house, in a manner ofspeaking.

Continuity Is ResultThis new -day program makes for a

continuity in radio that has heretoforebeen most difficult to maintain. Thus thesame program features and the sameradio personalities who have come tothe radio audience week after weekthrough the Fall, Winter and Spring, are,for the most part, to continue throughthe Summer season. There is no rea-son whatever for breaking off one'sradio acquaintances that have beenformed during the cooler seasons. Evenif the Summer takes the radio listenerto the distant farm or remote camp, thelong arm of the high -power broadcast-ing station assures friendly contact amidthe new surroundings, whether the homereceiver be brought along for the pur-pose or whether it be a portable receiverincluded in the vacation luggage. Thus,

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with very few exceptions; indeed, theestablished program features are to con-tinue through the present season, for theprogram sponsors realize fully the im-portance of continuity in maintainingthe public good -will which they have beenbuilding up from week to week.

New Direction FindersSave Extra Patrol Work

The Bureau of Standards has devel-oped for the Coast Guard a simple typeof radio direction finder that will enableone ship to locate another, to relieve itfrom patrol duty. Also to locate ships indistress. Likewise to spot a rum runner.

The new direction finder will be in-stalled on a fleet of small coast patrolboats recently aded to the Coast GuardService which already have been equippedwills radio telephone and telegraph trans-mitting and receiving apparatus whichoperates at a frequency of 2,100 kilo-cycles per second. The direction finderfunctions on the same frequency.

The Coast Guard direction finder coilconsists of four turns of ignition cablewound on a 20" frame. It is installedover the pilot house and rotated from be-low. A tuning unit and coupling trans-former have been designed so that thedirection -finder Coil may be used on theship's receiving set without changing itstuning adjustments, which are locked inthe 2,100 kilocycle position.

Canada a Good NeighborOn Air as Well as EarthThat several American stations, not-

ably KOA, Denver, joined in celebratingCanada's Dominion Day, June 30th, wasa reminder that Canada, with its 4,000miles of unguarded border separating herfrom the United States, has proved asgood a neighbor on the air as otherwise.Through a gentlemen's agreement, andwithout the aid of a treaty of any sort,the United States ocupies 90 wave bandsand Canada 5 in the Class B assignmentof from 280 to 545 meters.

There was quite a flurry recently whenan American station took possession ofone of the Canadian wave bands and itwas feared in some quarters that thismight disturb the friendly air relationsbetween the two countries, but this didnot materialize.

HIGH FREQUENCY TESTSFor conducting tests between 8,000 and

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26 RADIO WORLD July 17, 1926

Trickle Charger Usedtth Small A Battery

Expert Classifies Restorers and Explains How TheyOperate --Prophesies Dry Crystal Charger

Will Be on Market SoonBy H. C. BrooksHartford Battery Mfg. Co.

During the last radio season there waspopularized a new expression among themany others connected with the radio trade,that of trickle charger. Strictly speakingthis refers to a charger for a radio A bat-tery, but often it refers to a combinationcharger and battery.

While the majority of radio sets are oper-ated from a large A battery having about100 ampere hours' capacity, there is anincreasing demand for a combination bat-tery and charging unit so that the radio fanwill always have his battery charged whenit is required.

To keep the cost of the combination aslow as possible and at the same time elim-inate mental effort required to keep thebattery in its best condition, a charger hasbeen designed to charge at such a slowrate that it may be used to charge the bat-ter), at all times when the set is not inuse. It is obvious that this convenient -ar-rangement would be desirable, and therehas been considerable pressure upon bat-tery cbmpanies to produce such a combina-tion.

This idea is not new, having been usedfor several years in railroad signal workwith very good success. inthis case is somewhat different. Since therailroad signal service requires an abso-lutely certain source of current at all times,the trickle charger is kept connected con-tinuously and a Plante type of battery is

sited to withstand this continuous charge.Then if the source of charging current failstemporarily, the battery continues the ser-vice, so this is really a standby and voltageregulating battery combined.

In the combination A battery andcharger, a small 6 -volt storage battery ispermanently connected to a rectifier whichin turn is provided with a standard plug,just as a flat iron, toaster or other appli-ance is equipped. There are four types ofrectifiers used for changing alternating todirect current after it has been trans-formed to the proper voltage for chargingthe battery. All these rectifiers are sim-ilar to radio detectors.

Four Types ExplainedThe four types are, first, bulb or vac-

uum type, more familiarly known astungar and rectigon; second, electrolytic,which is divided into alkaline and acid;third, vibrator; fourth, crystal.

In the bulb type of rectifier, with which

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you are all' familiar, a small 2 -elementvacuum tube is used. This is perhaps themost popular type thus far.

The electrolytic rectifier was developedand most commonly used in the alkalinetype, being formed of a single cell havingaluminum and lead electrodes and a boraxsolution. ThisTectifier was developed andhad considerable use in the ignition bat-tery trade fifteen years ago. It was notfound successful, however, nor has it beenin its revival of the past few years, onaccount of its uncertainty of operationand its high internal resistance.

The second type of electrolytic recti-fier, which is a newer development, usesan acid electrolyte and some rare metalor alloy electrode and a lead electrode.The most familiar combination, of course,is the tantalum rectifier. This has beenvery successfully used and is a desirablearrangement, it has about the same elec-trolyte as that of the battery. The onlydifficulty with this type is a tendency togo dry in continuous operation, especiallyn a warns place, but if it is properly pro-portioned it will need water no oftenerhan the battery and may act as a pro-ection to that neglected article.The third division of rectifiers, that of

the vibrating type, may well be dismissedrom our consideration since it dependsipon a vibrating armature which createsparks that produce interference. Whilehis might be overcome it is extremely

difficult and since there are no compensat-

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ing advantages in this type it will not befurther considered.

Crystal Charger ProphesiedA new type of rectifier for this service,

which will probably, have increasing ap-plication in the future, is the dry crystal.You are all familiar with the crystal de-tector and since the trickle charger willrequire only small current, it seems easilypossible to multiply the number of de-tectors until they have sufficient currentcarrying capacity, to operate a tricklecharger. There is considerable work be-ing done on this charger at present andundoubtedly in the near future some ofthese will be on the market.

We may now consider theteffect of con-tinuous charging on the life of the battery.Some engineers are firmly opposed to theuse of anything like a trickle charger,since they claim that the continuouscharge has a disintegrating effect on theplates and grids to a greater extent thana higher charging rare. This view of thematter may be correct if we consider thematter as being purely continuous charge.If, however, we balance the charging rateproperly and the user is careful that hedoes not allow the battery to charge forweeks at a time without using the set,we believe that in normal operation thebattery will not be injured.

Since most trickle chargers operate atabout 5/10 of an ampere and the average5 -tube radio set requires approximately1% amperes, if the average use of theradio set be taken at four hours, we willremove six ampere hours from the bat-tery, then, in the remaining twenty hours

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July 17, 1926 RADIO WORLD 27

of the day the charger will replace tenampere hours, which will be an overchargeof approximately 2% ampere hours.

Unusual DemandsThis is really a little more than is nec-

essary and it is required to take care ofthe few cases where people operate setsfor longer than the average or have morethan the usual five tubes and an addi-tional drain caused by the use of a oneampere detector or a horn which usesabout one ampere A battery current. Sincethere are these variations in require-ments, some of the trickle chargers areprovided with means to change the charg-ing rate. This is obtained either by tak-ing different taps off the transformer ora small variable resistance is placed inseries with the battery. The formermethod is more economical and will givesufficient gradations of current. In thisway one type of charger will vary thecharging rate from 2/10 to 7/10 of an am-pere.

Various sizes of batteries are producedfor the combination. Theoretically, thebattery need be no more than 10 amperehours capacity, which would be enoughto take care ,of a set for one evening.This is not good policy, however, sinceit would mean almost a complete dis-charge for the battery every day and alsowould leave no reserve supply. At thesame time it would be giving such abattery a complete charge at its normalrate daily and that would shorten its lifevery materially.

Run 30 to 50 HoursMost of the batteries, therefore, which

are being used in this combination willrun from thirty to fifty ampere hours incapacity. Even the smallest of thesetherefore will provide the average 5 -tube

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Personal Radio PhoningMarks German Air Travel

BERLIN.Whether their friends or relatives are

traveling in air or on land, telephone sub-scribers throughout Germany are nowable to communicate with them with thesame ease as when talking over the sta-tionary land phone, due to radio tele-phony. Thirty-six express trains of theBerlin -Hamburg line and the huge airliners of the German Air Service employthis service. Although a three months'trial on the trains did not prove financial-ly profitable, such great scientific successresulted, that the Ministry of Posts andTelegraphs and the Railway Administra-tion decided to extend the service to theentire express service. Experiments arebeing carried out on the Berlin -Munichexpress trains. the results being watched.

by many experts, as it is feared that thehigh voltage cables, which run parallelto the tracks for many miles, may inter-fere with reception and transmission.

No difficulty has been encountered bythe 'plane service, despite the roar of thethree 120 -horsepower motors. Even dur-ing a thunderstorm a pilot circling overStockholm talked with officials at Tern-plehofer Field in Berlin for approximatelyfive minutes. Directors of the Air Serviceannounce that transmitters and receiverswill be placed at the passengers' disposalon the routes between Berlin -Paris,Berlin - Stettin - Stockholm and Berlin -Danzig -Konigsberg. The instrument, asthe passenger sees it, resembles the com-mon telephone.

Is is very easy to use.

set for five or six nights without a charge.This reserve capacity is very desirable.It is conceivable that the owner may for-get to plug in the charger after an unus-ually long session with his radio set andlie naturally wants sufficient reserve ca-pacity to take care of him the next night.

The one real disadvantage of this com-bination is the fact that if the battery isallowed to become discharged there is notsufficient capacity in the charging outfitto restore the charge quickly enough tooperate the set the same day, which maycause the fan to lose an evening's enter-tainment. This, however, is no worse thanhis condition in the ordinary case if hehad not discovered the discharged condi-tion of a standard A battery until hewanted to use it. Some combination setsare so equipped with filters and chokesthat the battery may be used while thecharge is in operation. This method does

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not meet with general approval, as itrequires a chaiger of enough current ca-pacity to carry the load directly andintroduces the usual noise and hum whichseem to be unavoidable when an alter-nating current transformer is used neara radio set.

The advantage of the electrolytic charg-er is apparent when one considers that thelow power required is probably not suffi-cient to start the average watt hourmeter of your line supply. Since mostof the time this charger is operated whenno other current is being used the re-charge is mostly free and even whenadded to other load the continuous oper-ation at 18 watts will cost the owner only31iic per day at 10c per kw. hour. How-ever, the bulb type at 30 watts will cost5.4c per clay. Both above estimates arebased on eighteen hours charge. It isobvious that bulb type chargers must beless efficient at low charging rates, since -

the filament current must be applied inkaddition to the charging current.

Connecticut to GiveSchool Courses Via Air

HARTFORD, CONN.With the co-operation of WTIC, the

Travelers Insurance Company station inthis city, the state Board of Educationwill begin the broadcasting of a regulareducational course in the schools of Con-necticut, during the next school year. Itis thought that this program will becomeNew England Wide, as representatives ofNew Hampshire, Vermont and Massa-chusetts education department have beenappointed to act with the Connecticutboard. Even authorities in Maine haveSignified their intention to cooperate.MuSic appreciation will be the topic ofdiscussion during the broadcasts.

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28 RADIO WORLD July 17, 1926

Prize Winning SoloistsTo Perform at Stadium

The concerts of the New York Phil-harmonic Orchestra from the LewisohnStadium are being broadcast by WJZeach Wednesday and Saturday night at8:30 Eastern Daylight Saving Time, withWRC of Washington, D. C., participat-ing in the broadcasting on Saturdaynights only.

The orchestra is the second oldest or-chestral organization in the world, theLondon Philharmonic, organized early inthe nineteenth century, being first. Found-ed on April 2, 1842, the Philharmonic hasnever had to cancel a single concert,out of more than 2,000 it has given, andonly two have been postponed, one onaccount of the death of President Lin-coln and the other because of the suddendeath of a conductor, Anton Seidl.

Dates of ConcertsThe Philharmonic will be under the

leadership of four conductors during theseries, Willem Van Hookstraten andguest conductors.Nikolai Sokoloff, HenryHadley and Frederick Stock. The dateson which they will conduct are as fol-lows :

Van Hoogstraten, July 27; August 10to August 17; Apgust 25 to August 31;Sokoloff, July 28 to August 3; Hadley,August 4 to August 9; Stock, August 18to August 24.

Among the soloists to be heard in theStadium concerts will be the winners ofthe auditions recently conducted byWJZ. They are Nora Fauchild, soprano;Guiseppe Martino -Rossi, baritone, andEnrique Ros, pianist, with Allice Godil-lot, George Harold Miller and MargaretHamilton as alternates.

The Four ConductorsBorn in Holland, but now an American

citizen, Van Hoogstraten has been the

main conductor of the Stadium concertssince 1922, when he shared the seasonwith Henry Hadley. He has appeared asconductor of the Philharmonic in theWinter season with Willem Mengelbergand the past Winter found him as con-ductor of the Portland Symphony Or-chestra, to which post he will return nextseason. He has also appeared as a guestconductor with the Philadelphia, Detroitand Los Angeles Orchestras, and also atthe Hollywood Bowl.

Sokoloff is a graduate of Yale Uni-versity and is now conducting the Cleve-

land Symphony Orchestra. This will behis second year as a guest conductor atthe Stadium.

After studying at the New EnglandConservatory and in Vienna, Hadleyserved as conductor of the Seattle Sym-phony and" San Francisco Symphony Or-chestras. Since 1915 he has devoted him-self largely to composition, and amonghis works are several operas, tone poemsand numerous works for solo and cham-ber instruments.

Stock studied at the Cologne Univer-sity and upon graduation with highesthonors was chosen from among fifty com-petitors as the first violinist of the famousMunicipal Orchestra. In the latter partof the nineteenth century he came toAmerica to the Chicago Symphony Or-chestra and in 1905 succeeded TheodoreThomas as its conductor, a post whichhe still holds.

Radio a Peace Agency,Says Haiti's President

In two addresses, one delivered inFrench for his people in Haiti and theother in English spoken for listeners inthe United States, Louis Borno, presidentof Haiti, sent messages on the air fromthe studio of WGY recently. PresidentBorno is deeply impressed with the pos-sibilities of radio as a peace preservingagent and pictured for American listenersthe little island republic which is en-deavoring to achieve and. maintain realindependence.

"The United States," he explained, "hasundertaken to assist, by treaty, the Re-public of Haiti in reorganizing its econo-mic, social and political life. This workis being done through cordial coopera-tion between the Haitian and the Amer-ican governments, and gratifying progresshas been made.

"Assistance by the United States Gov-

ernment has taken the form of lendingAmerican personnel to the Haitian Gov-ernment. These Americans are nomin-ated to certain offices in Haiti by thePresident of the United, States and areappointed by me, Activities supervisedby Americans under the terms of thetreaty of 1915 are the constabulary, thefinances, public works, public health andagriculture. Marked progress has beenmade in placing each of the foregoingfunctions of government on a solid basis,and it is wise statesmanship to continue,according to our treaty, the cooperationbetween Haiti and the United States fora period which to some may seem toolong, rather than to terminate such co-operation prematurely and thereby undoall the spendid progress which has beenaccomplished in recent years through thisarrangement."

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

PATENTS-Write for free Guide Books and'Record of Invention Blank" before disclosinginventions. Send model or sketch of your in-vention for our Inspection and Instructions Free.Terms reasonable. Radio, Chemical, Mechanical,Electrical and Trademark experts. Victor J.Evans Co., 924 Ninth, Washington, D. C.

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

THE GREAT AID OF BY-PASS CON-DENSERS, by John F. Rider, appeared in RADIOWORLD dated May 8. Sent on receipt of 15c,or start sub, with that number, RADIO WORLD,145 W. 45th St., N. Y. C.

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

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

BLUE PRINT FOR 1926 DIAMOND OF THEAIR sent on receipt of 50c. Guaranty Radio GoodsCo., 145 West 45th Street, New York City.

CASH PAID FOR Dental Gold, False Teeth,Discarded Jewelry, Diamonds, Platinum. Mail,Florida Gold Refining Co.. 21 Adams, Jackson-ville, Fla.

"LIBERTY AFLAME" and other verses, byRoland Burke Hennessy. Handsomely bound incloth; sent postpaid for $1.00. Guaranty RadioGoods Co., 145 West 45th Street, New York City.

THE BERNARD PORTABLE SUPER -HET-ERODYNE appeared in RADIO WORLD datedApril 3, 10, 17 and 14. Sent on receipt of 60c.or start your subscription with April 3 issue.RADIO WORLD, 145 West 45th St., N. Y. City.

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

HERMAN BERNARD, managing editor ofRADIO WORLD, broadcasts every Friday at 7

p. m.. from WGBS. Gimbel Broa., N. Y. City.315.6 meters. He discusses "What's Your RadioProblem 1" Listen in

CONFESSIONS OF A SUPER BUG, by JamesH. Carroll, appeared in RADIO WORLD datedMay 22. 15c per copy, or start sub. with thatnumber. RADIO WORLD, 145 W. 45th St.,N. Y. C.

SELL AND INSTal T RADIO SETS. With a$25 capital we can put you in the radio businessand show you how to earn a hundred or twoa week. For. full details write Guaranty RadioGoods Co., 145 West 45th Street, New York City.

THE VACATION NUMBER OF RADIOWORLD DATED JUNE 12 contained many greatfeatures. The light 5 -tube Portable, by HermanBernard, The Freshman Masterpiece, by AlbertW. Franklin, The Importance of C Batteries, byJohn F. Rider, etc. Sent on receipt of 15c, orstart sub. with that number. RADIO WORLD,145 W. 45th St., N. Y. C.

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

THE NEW I -DIAL POWERTONE SET, byCapt. P. V. O'Rourke, appeared in RADIOWORLD dated April 17, Sent on receipt of 15c,or start sub. with that number. RADIO WORLD145 W. 45th St., N. Y. C.

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

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July 17, 1926 RADIO WORLD 29

Experts DebaAs TrespassBy Thomas Stevenson

WASHINGTON.Would it be possible for a land owner

to prevent broadcasting stations fromsending out programs or from interfer-ing with other stations? This interestingquestion has arisen in governmental andlegislative circles in connection with dis-cussions of various radio bills.

Leading legal authorities contend thatuntil there is a Congressional declarationthat the ether belongs to the FederalGovernment, "every radio transmissionwhich traverses the sky above a man'sland constitutes legal trespass." Theseauthorities base their argument upon theancient maxim -"he who owns land ownsto the heavens above and to the centerof the earth, from the zenith to the nadir."

Must Prove Ether ExistsIf it can be proven that radio signals

constitute trespass, it would be entirelypossible for the landowner to appeal tothe courts for relief from bad programsor from undue interference, these author-ities say.

Other authorities contend, however, that"existence of the ether must be provenbefore trespass can be claimed." Thevery basis of property is possession, theysay, and all ownership is postulated uponpossibility of control and that which maynot be possessed may not be owned.

For want of a better term, scientistshave designated as the "ether" the hypo-thetical substance which is supposed toexist between and surrounding the atoms

SUMMEROPPORTUNITIES

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to Waveson Property

and electrons of all matter and throughwhich the radio wave is assumed to travel.What the ether is and whether it reallyexists is not susceptible of positive dem-onstration.

An Expert's OpinionHere is an opinion on the subject by a

leading legal authority of the FederalGovernment:

"The claim of ownership of the uppersic has been made by landowners whohave suffered damages from airplanes. Touphold such absolute title would be toprohibit aerial navigation; for every flightwould constitute innumerable trespasses.The tendency of the courts has been toallow damages for actual injury but notupon the theory of nuisance or trespasson the upper air.

"A radio wave passing through air,earth, rock, brick or timber causes nochange in the material. The particlesof matter remain the same as before, theirquality unchanged and position unaltered.

"If we could imagine the space aboveand below the surface of the land to bea vacuum, the radiation would still passthrough it. ,Nothing is added to it andnothing taken away. There is no apprec-iable effect whatever, certainly no physicalentry. The wave cannot be seen, felt ordetected by any of the senses except withartificial aid. It is invisible, intangibleand imponderable.

Question of Annoyance"It becomes of some importance to de-

termine whether or not the sending intoland of an impulse of this sort constitutesa trespass. If it is a trespass, an actionwould lie by the landowner, nominal dam-ages could be recovered without proof ofactual injury or negligence or perhapsrepetition could be enjoined. It it is a

How to BuildTHE FENWA Y

The famous DX se0 that, by the turn of aswitch, is a 4 -tube toned RF set, withregeneration, or a 9 -tube Super -Hetero-dyne, Remarkably sensitive)Described by Leo Fenwny himself in theFebruary g. 13. 20 and 27 issues, includingtrouble shooting. Send 60c for ell four is-sues, or send $6 for year's subscription andget these four copies FREE!RADIO WORLD, 145 W. 45th St., N. Y. C.

trespass, proof of actual damage and neg-ligence or other similar ground of liabil-ity would be essential elements to a re-covery.

"If the landowner could ,prove that aparticular kind of program was of an an-noying nature, or if it could be establishedthat the signals of a station trespassedto the extent of preventing the full en-joyment of the programs of other sta-tions, it is entirely possible that the 'courtsmight allow damages and enjoin repe-tition."(Copyright, 1926, ho Stevenson Radio Syndicate)

Eleanor Edison JoinsWHN Staff of Singers

Eleanor Edison, soprano, formerly withthe Aborn Opera Company and leading ladyin the "Clinging Vine" two years ago, isnow singing at WHN, New York. She isa Washington girl who was started on astage career as a singer by her mother, apianist. She came to New York to studyunder Abbott Jeanett and Dr. Ernest Knoch.She began her stage career as a dancer in"The Poor Little Rich Girl," but preferredsinging and now plans to return to opera.

STATIONS(Concluded front page 19)

Station Owner and Location MetersWTAP-Cambridge Radio Mee. Co., Cam-

bridge, Ill. 242WTAQ-S. Van Gordon & Son, Osseo, Wis 254WTAR-Reliance Radio & Elec. Co., Norfolk,V. 261VVTAW-Agricultural & Mech. College, Col-

lege Station, Tex 270WTAX-Williams Hardware Mfg. Co,Streator, Th. 231

WTAZ-T. J. McGuire, Lambertville, N. J 261WTIC-Travelers Insurance Co., Hartford,Conn. 476

WUBO-V. Jansen, None Orleans, La 268Park, Plainfield, Ill 242

WAG -Michigan College of Mines, Hough-ton, Mich. 263

WWGL-Radio Engineering Corp., RichmondHill, N. Y. 213

WWI -Ford Motor Co, Dearborn, Mich 266WWJ-Detroit News, Detroit, Mich 35WWL-Loyola University, New Orleans, La 275

PERSONAL STATIONERY200 Sheets note size with 100 Envelopes tomatch, printed with your name and addresson white watermarked bond paper. A highgrade packet that will delight you and yourfriends. Send check or money order.

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THE CONTROL OF FEEDBACK, by BarneyFeete, appeared in RADIO WORLD dated April24. Sent on receipt of 15c, or start sub. with thatissue. RADIO WORLD, 145 W. 45th St., N. Y. C

Attention, Radio World Subscribers!Subscribers 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, pleasesend payment for renewal. Changes in expiration dates on wrappers appear two weeksafter receipt of renewal.

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30 RADIO WORLD July 17, 192s

Good Back Numbers ofRADIO WORLDThe lellawiSse Illtustrated articles have ap-peared Its resent Issues of RADIO WORLD:111211:@opt. 1$-The 1 -Dial, 2 -Tube Speaker Set, byPercy Warren. Anderson's Theory of Fad-ing. The Way of the Frequeney Dial, by

Capt. P. V. O'Rourke.Oat. 24--Tne 3 -in -1 RF Receiver, by Sidney R.

Finkelstein. A Phonograph Cabinet Set, byLewis Winner. How To Use Fixed Gee-d...., by J. E. Anderson.Nev. 7-A 2 -Tube Dry -Cell Circuit, by Capt.P. Y. O'Rourke- One of the Beat CrystalSots, by Herbert E. Hayden. 1 -Tube DXPet, Herman Bernard.

Nov. 28-The Zero Potential Loop, by Fran!:Freer. The 1 -Tube Headset Recedver, byJ. E. Anderson. A Discussion of AF Ampli-fication. by Wm. Fortington.

Be,, 12-A Self -Contained Receiver. by H. 5.Hayden (Part 11. B Battery Eliminator, byLewis Winner (Holiday Gifts No.).

Dee. 26-The Regenerative Wave Trap, by JohnF. Elder. The 5 -Tube Tuned RE Set, byCapt. P. V. O'Rourke.

1926:Jan. 2-The 2-C Set for Simplicity, by Capt.

P. V. O'Rourke.Ian. 0-The 4 -Tube DX Symphony Set, by A.

Irving Wits.. A Skillfully Made 1 -Dial Set,by Herman Bernard,

Jan. 16-Anderson's 5 -Tube Quality Receiver,The Raytheon B. Eliminator, by Lewis Win -

Jan. 30-An Individual AP Amplifier, by H. E.Hayden. The Antennatrol, by Herbert Hay-den (Part 21. Trapping Out Super -Powerin New Jersey. by Capt. P. V. O'Rourke

Feb. 6-The Fenway (4 or 9 tubes), by Leo Fen -way (Part 11. The Great 1 -Tube DX Set.by Herman Bernard.

Feb. 13-Anderson's 5 -Tube Economical Receiver.Trouble Shooting for Novices, by IL B.Street, The Forayer, by Leo Penney(Part 2).

Feb. 20. --The 8 -Tube Victoreen, by Herbert E.Hayden. The Fenway, by Loo Fenway(Part 3). Quality Stressed in 3 -Tube Set.by Brainard Foote.

Feb. 27-The 4 -Tube DX Dandy. by Herbert E.Hayden. Umbrella Aerial for DX, by HugoGernsback. Part 2 of The Victoreen.

Mar, 6-The 1 -Tube Set, By Capt, O'Rourke.The Chemistry of Batteries, by A. RI, Reid.The Victoreen Set (Part 3), by Herbert E.Hayden.

Mar. 13-The Non -Regenerative Browning -DrakeSet, by M. B. Sleeper. The Tectron Elimi-nator (Part 1), by Lewis Winner. CuringVictoreen Trouble, by Herbert E. Hayden.

Mar. 20-The Super -Heterodyne, by J. E. Ander-son. A 2 -Tube :`Decker Set, by Percy War-ren. The Browning -Drake Set (Part 2), byM. B. Sleeper, A. 2 -Tube Eliminator, byLewis Winner.

Mar. 27-An Economical 4 -Tube Set, by EdgarT. Colilins. A Practical B Battery. by Capt.P. V. O'Rourke. Teetron Trouble Shooting,by Lewis Winner.

April 3-The Bernard Portable, by HermanBernard (Part 1). How to Get DX, byCapt. P. O'Rourke. A Compact B Sapply,by Lewis Winner.

April 10-The Bernard Portable, by HermanBernard (Part 2). Two Eliminators for DC,by Lewis Winner. A Super Prom An OldSet, by C. King.

April 17-The New 1 -Dial Powertone. by Capt.P. V. O'Rourke. The Bernard Portable(Part 3), by Herman Bernard. The Actionof Transformers, by Lewis Winner.

April 24-All Waves on One Set, by Capt. P.O'Rourke. Bernard's Portable (Conclusion).Control of Feedback, by Barney Feete.

May 1-New Multiple Tube, by Herman Ber-nard. The Aero All -Wave Set, by Capt.O'Rourke. Kilocycle -Meter Chart. OfficialList of Stations. An Analysis of Detection,by J. E. Anderson.

May 8-A study of Detection, by J. E. Ander-son (Part 21. To Wind a Loop on a Card-board Frame. How to Reflex Resistance AF,by Theo. Kerr.

May 15-Super-Heterodyne Results Brought UPto Maximum, by Herman Bernard. The TruthAbout Coll Yields, by J. E. ,Anderson.

May 22-A Built-in Speaker Set, by HerbertE. Hayden. The Powertone in Operation. byCapt. P. V. O'Raurke. Confessions ofSoler Bug, by James H. Carroll.

May 29-Aerials in Ground and Water, by LewisR'inner. Economized Filaments, by J. R.Anderson. How to Get DX, by John 5'.Rider -

June 5-Flve-Tube Compact Receiver, by 2. E.Anderson. A Tester for Tube Circuits, bySpencer Hood. Problems of Portables, byHugo Gernsback.

one 12-The Light 6 -Tube Portable. by Her-man Bernard (Part 1). The Rogers-S.81.dtReceiver, by Wm. A. Sehudt, Jr. (Part 1).The Freshman Masterpiece, by A. w.Franklin.

June 19-Selectivity's Amazing Toll, by J. N.

Anderson. The Light 6 -Tube Portable Set,by Herman Bernard (Part 2). The 1 -TubeRogers-Exchudt, by Wm. A. Selnalt, Jr.(Part 21.

lune 26 --Alto Victoreen Portable, by HermanBernard (Part 11. The Manufacture of a

Tube, by F. C. Kelley. The Light 5 -TubePortable, by Herman Bernard (Part 31. Thellogers-Schudt Circuit (Part 3 concluded), byWm. A. Hchudt.

July 3-Set with A 1 -Turn Primary, by HermanBernard. Part 2 of the Victoreen Portable, byH. Bernard. Trouble Shooting Article for TheLight 5-ttube Portable.

Any seer. 15e. Any 7 copies, $1.00. Allthese 34 copies for $4.50, or start subscriptionwith any Issue. RADIO WORLD, 145 W. 45thSt., N. Y. C.

Circuits Simmer DownTo Five Important Groups

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

There are so many circuits-good, ex-tra good and others-that a beginner islikely to become bewildered and exclaim,"I give up." _ However, there is no needto give up, since, if one has the leastbit of interest in radio, he will be will-ing to spend. a little while in learningmore about it.

Most likely you are using one of fivedifferent fundamental types of radio re-ceivers: (1) The non -regenerative set;(2) the regenerative set; (3) the tunedradio frequency receiver; (4) the Super -Regenerative; and (5) the Super -Hetero-dyne.

These are the five groups -in which allexisting receiving circuits can be class-ified. The theory of operation of eachtype differs from the others.

The Simplest OneThe simplest type is the non -regenera-

tive. This includes the hookup whereinthe antenna is conductively or inductivelycoupled to the tuning circuit. Again, weare not limited to the type of detectorwhich can be used with such a circuit.Thus, we can employ the coherer, thecrystal (with or without a battery), the.microphOnic detector, the electrolytic,Magnetic, colloidal, the tickler, the hetero-dyne, the 2 -element and the 3 -elementtubes.

Each type of detector has its ownpeculiar characteristics and theory oferation, and although one rarely findsnon -regenerative sets being used, crystaland the tube detectors are being used ex-tensively.

With the discovery of the 3 -elementtube canoe the regenerative detector. Re-generation, by the definition generallyused, is the process of feeding a signalhack -from the plate circuit to -the gridcircuit of a tube by means of inductiveor capacitative coupling.

Effect of Regeneration -Regeneration increased the volume and

sensitivity of a set to a very large de-gree. There is one drawback, however,---that of radiation when the set startsto over -oscillate. Thus, if you are usinga single circuit regenerative set, it is

ENWA-for DX

Winter or Stammer the Fenway is a con-sistent DX -getter. Naturally, you want toown one of these super -sensitive receivers.Fenwav Blueprints slum you how to builda laboratory set.

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Adelman strongly advised that you change it to3-circuit tuner, which will not cause

nearly so much trouble with your neigh-bors. In the regenerative classificationare the direct connected and inductivelycoupled antenna systems, both of whichmay be used with regenerative sets em-ploying inductive or capy,citative feed-back. Reflex circuits of the regenerativevariety also fall into the same classifi-cation.

Undoubtedly the most widely used typeof set is that using radio frequency am-plification.

Reflex circuits, there are hundreds ofthem, found great favor in the eyes of theexperimenter. They are either straightreflex or inverse reflex type. The reflexneed not be classified as an independentcircuit.

In coupling radio frequency amplifiertubes together, there have been discov-ered several means which have certainpoints of merit. The coupling arrange-ment can be either of the tuned or un-tuned type. The tuned type producessuperior results. Thus, tuned impedanceand tuned -transformer coupling may havepositive feedback, negative feedback, po-tentiometer stabilization, absorption cir-cuit stabilization or Hazeltine, Rice orFarrand neutralization,

Classifying the NeutrodyneIf, for instance, you have a Neutro-

dyne, you would classify it as follows:It belongs to the radio frequency clas-

sification, and employs tuned transfor-mer coupling. The antenna system maybe either conductively or inductivelycoupled. It is neutralized by the Hazel-tine method and uses in combination, anon -regenerative detector and two stagesof transformer coupled audio frequencyamplification.

The Super -Heterodyne is much morecomplex in its fundamental operationthan any of the others. Likewise theSuper -Regenerative receiver is a very in-teresting development which requires athorough knowledge of radio technique.

"Which is the best circuit and why?"is a question often asked. It is hard toanswer. One can not- tell what the in-quirer means by "best."

With the rapid strides that are beingmade in radio it is possible that newclassifications for circuits will be found,although at present there are but fivechannels into which one can place thethousands of receiving circuits and noth-ing in sight to suggest a sixth group.

CHICAGO ALLIED SHOWTloe Allied Radio Congress and National

Radio Exposition will be held at the HotelSherman, Chicago, September 27 to Oc-tober 2. It is under the direction ofthe International Trade Exposition Co.,Milo E. Westbrooke, manager, at theHotel Sherman,

GETTING DX by Capt. P. V. O'Rourke, ap-peared in RADIO WORLD dated April 3. 15eper copy or start sub. with that issue. RADIOWORLD. 145 West 45th St., N. Y. C.

IF YOU ARE GOING 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

duly 17, 10.20 A 11 t) \\.t)l. 1,11

"04; r HERS BRETWOOD Variable Grid Leak say:The Bretwood Grid Leak came with today's mail. It is now exactly9:00 P.M. and the leak was installed about a half hour ago.This note is not only an expression of appreciation but also anattestation of the truth of your advertising. During the past halfhour I have tuned in stations ALL OVER THE DIALS" atleisure, and can adjust reception with the leak almost equal to avariable condenser.I feel constrained to add that while waiting for reply and thenreceipt of leak from you, there has been on the set a fixed leak andcondenser of well known and thoroughly reliable make, and fairlygood reception has been enjoyed, but during this half -hour -only testthus far the results are inexpressibly beyond expectation.Have been a radio fan only about four years, but feel I have suffident knowledge and experience to recognize a good thing upon fairtrial. Your promptness and desire to satisfy your trade, in this casehas won for you another "BRETWOOD BOOSTER." Thank you.

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I want to thank you for your leak, it makes the set 100% better.I was going to have a Diamond of the Air built, but singe I haveadded your leak to my sct I sin now down in the dining room ofthe first floor and the set is on the second floor. I can hear tins setjust as plainly as if I were up there. I can hear every player inany hand or music which is on air. The first night I gave the leaka very good test, and I got four stations in Chicago, one in Detroit,one in Canada, one in Atlanta, Cla and several others without anynoise. All were good and clear. It in going to make nu: spend moremoney, as I will have to get a good loud speaker. The horn I havenow is a Manhattan Jr., and is good and clear, but as soon as you/leak is installed the howling present when using three tubes is

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RADIO WORLD July 17, 1926

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Al. Kraus, 996 AldusWSBC, Chicago, Ill 10WBBR, Rossville, N. Y 16WEBH, Chicago, Ill 49WHT, Deerfield, Ill. 55WCCO, St. Paul, Minn 61WSB, Atlanta, Ga 66

Aerial in One-half Hour byStreet, New York City.

WGY, Schenectady, N.Y..50WMAK, Lockport, N.Y..14WMSG, New York City .11WOC, Davenport, la....85WFAA, Dallas, Texas...78

SELECTIVITYI live within four blocks of WLWL, and since the open-ing of this station have had great difficulty in chokingthem off my old set. Even after employing a wave trap

could still hear WLWL around the entire dial andwas told by several friends that living so near this power-ful station it would be impossible to entirely cut them outwith anything less than a super -het. It was a very agree-able surprise, therefore, when I installed my new BST -6,to find that while WLWL came in on 25 I could tunein WRNY on 21 and entirely cut out WLWL. This iscertainly real selectivity.-F. S. Clark, 350 West 55thStreet, New Yorl: City.

Match-

Direct from factory to youImmediate Delivery

GuaranteeSatisfaction or Money Back

Each receiver is tested and retested,boxed and inspected before leavingfactory, and guaranteed to reachyou direct in perfect condition.Workmanship throughout guaran-teed the best. Assembled by experts.

Immediate Delivery

$40"SAFETY FIRST!-Why buy obsolete models, or radio failures at department store "bargain sales" when a BST -5,the latest achievement in radio, can be bought direct from the factory with no department store profit added? Hereis a real bargain, sold you with a guarantee of satisfaction or money back.

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GUARANTY RADIO GOODS CO.141 West 45th Street, New York City

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