Class Book

Scanned from the collections of The Library of Congress

Packard Campus for Audio Visual Conservation www.loc.gov/avconservation

Motion Picture and Television Reading Room www.loc.gov/rr/mopic

Recorded Sound Reference Center www.loc.gov/rr/record

0

nnouncing

HI-MU Amplifier

Five Volt '4 amp. Filament Mu of Thirty

type Q340

The development of radio centers around the radio tube. In offering this new type we take another step forward in fulfilling the obligation of leadership.

Witk the advent of the CX-340, heights of efficiency hereto- fore unattainable in resistance and impedance coupled audio circuits are placed within easy reach of the radio world. This new Cunningham Radio Tube is especially designed for use in receiving, sets employing, resistance or impedance coupled audio frequency amplification.

Consult your dealer as to its proper installation or write us for the special CX-340 Bulletin.

Sixteen Types, all in the Orange and Blue Carton

NEW YORK

CHICAGO

SAN FRANCISCO

Manufactured and sold under rights, patents and inventions owned and/or controlled by Radio Corporation of America

RADIO BROADCAST ADVERTISER

1

a

R

TRADE MARK R G I ST E R £ D

5

Oc t I

Gaseo

us

Rectifier Tubes

The Sensation of Radio Development for your

Radio Battery Eliminator

When your B Eliminator needs a new tube ask for a Q * R S Rec- tifier Tube with a guarantee of a full year's service or a refund for every month less than a year it fails to function.

In conjunction with a filter cir- cuit for which we will furnish diagram and instructions free, the Q R S 400 Milliampere Tube will eliminate all A, B, and C Batteries and run your set from your house current supply.

65 Milliampere and 85 Milliampere type for B Battery Eliminators,

Price, $5°° each

0^

7c

0)

For over a quarter of a century we have been manufacturing Quality merchandise Quality always costs a little more but that's why

Q R S Radio Tubes Are Better

For full details ask your dealer or if he is unable to serve you yet, address

The Q R S Music Company

Mfrs. of Q R S Player Rolls used in over a Million Homes

New York Chicago 135th St. & Walnut Ave. 306 S. Wabash Ave.

400 Milliampere type for A, B, and C Battery Elim- inators

$ yoo

San Francisco

306 7th St.

2

RADIO BROADCAST ADVERTISER

For Genuine Satisfaction

There is nothing so satisfying in radio re- ception as to know that every adjustment, affecting the sensitivity of your receiver, is correct.

A voltmeter will tell you much about your set that you are now guessing at. Take the filament voltage for example. You can only guess at the proper position for the filament rheostat, and it is one of the most important adjustments on your set.

The Jewell Pattern No. 135 is an ideal in- strument for the set owner or builder. This two-inch panel mounting instrument is avail- able as either voltmeter or milliammeter. It is of the very best construction operating on the D'Arsonval moving coil principle. Move- ment parts are all silvered and the scale is silver etched with black characters.

Ranges of 0-5, 0-8 or 0-10 volts and 0-10, 15, 25, 50 or 100 milliamperes are most popular. Other ranges are available.

Write for

Radio Instrument Catalog No. 15-C

Pattern No. 135 Panel Mounting Instrument

Jewell Electrical Instrument Co.

1650 Walnut Street, Chicago

"27 YEARS MAKING GOOD INSTRUMENTS"

These Coils

T. R. F. KIT

>rove Any Radio Receiver!

"y List $12.00

This set of supersensitive Aero Tuned Radio Frequency Coils has never failed to improve the performance of any radio receiver. Tremendously increased power, extreme selectivity, and improved tone quality are sure to result from their use.

This kit of Aero Coils has a much lower high frequency resistance than other types of inductances. You

should use them in any circuit, if you want the best possible results.

D 17 17 Big 8-page 4-colored layout system (actual size blue prints) and complete in' * rVH-I-i structions for building the 5-tube AercDyne Receiver free with each kit. Also insert showing how to wire for a power tube if desired. Extra copies, 75c each.

Get these Aero Coils from your dealer. If he is out of stock, order direct from the factory.

AERO PRODUCTS, INC., Dept. 109, 1772 Wilson Ave., Chicago, 111.

Copper Shielding

Gives better reception closer selectivity and finer tone quality.

Sheet copper combines higher conductivity with easy working qualities.

COPPER ^ BRASS

RESEARCH ASSOCIATION 25 Broadway New York

Why confine your radio programs to a few local stations when the ex- pensive concerts, dance music and lectures of hundreds of big cities are readv for you? Connect this DIS- TANCE GETTER to your radio, tune accordi ng to instructions and presto note the distant programs roll in! Satisfaction Guaranteed Your money instantly refunded if you are not satisfied. The arti- cle on proper tuning furnished FREE with each Distance Get- ter, alone is worth the price. Galloway of Chicago writes: '*Results beyond all expecta- tions. Cuts through locals like a knife." Homes of Palos. 111., says: ''Send three more for my friends. I get Denver and California easily."

MAIL COUPON TODAY

HAZLETON LABORATORIES 4554 Maiden St., Dept. R. B., Chicago, III.

Send me Distance Getter, postpaid. Enclosed find $1.00 (M. O. stamps or check.) Send C. O. D. plus small postage added.

Name

Address

City State

SET BUILDERS

GetthisBooH

Set builders, make money and greater profits with the CtimfieU Super-Selective Nine, the receiver of remarkable per- formance, that has caused a stir from coast to coast.

More Profits

The Citizens Radio Call Book article on Cam-field's Super-Selective Nine has created a demand so great as to be unparalleled in radio history. Never before has a re- ceiver received such favorable comment. It is truly a won- der circuit and one that every set builder will recognize instantly, once it is set up. Here is a field for more prof- its, greater satisfaction and really remarkable results. Send 25^ today for booklet and have the facts before you.

CAMFIELD RADIO MFG. CO. 357-359 JE. Ohio St. Dept. xxxx Chicago, m.

t

25

Order your copy of Radio Broadcast from your news dealer or radio store. Make sure that he reserves a copy for you each month. If your favorite radio store does not stock the magazine write us giving name of radio dealer and address.

Only Make Your Own Qnly (t.|/\ Three Foot Cone Speaker (in *1U In Less Than An Hour f*u

Complete parts furnished in kit form. We guar- antee this speaker the equal of any manufactured cone speaker at any price.

With this THREE FOOT CONE SPEAKER you hear all the tones. It brings out the true depth and beauty of orchestral and instrumental music. Can be operated softly for living room music or full volume for dancing, and without trace of dis- tortion.

Kit includes famous "ENSCO" cone unit, the only direct-drive, distortionless unit for large cones; Alhambra Fonotex for big cone, with brass apex, two Blue Prints showing cabinet or stand, wall, or roll type construction for cone speaker. All neces- sary instructions.

Buy this wonderful speaker under our absolute guarantee. Your money back if you are not con- vinced that it is the finest reproducing medium obtainable at any price. It works on any set, with ordinary Tubes or with Power Output.

SEND NO MONEY!

Write your name plainly as indicated below, then mail and complete kit will be forwarded to you. Just pay postman $10.00 upon delivery.

Name

Address

ENGINEERS' SERVICE CO. 25 Church St. Desk X New York City

Radio Broadcast. May, 1927. Published monthly. Vol. XI. No. 1. Published at Garden City. N. Y. Subscription price $4.00 a year. Entered at the post.

Garden City. N. Y.. as second class mail matter. Doubleday. Page & Company. Garden City, N. Y.

RADIO BROADCAST ADVERTISER

6

The MADISON-MOORE

WAVE TRAP

enables the user of a loop set in practically every locality to get within 10 to 20 kilocycles nearer the offending station. If, with your present receiver, you have trouble in eliminating powerful near-by stations, the Madison-Moore Wave Trap will materally assist the selectivity.

With this latest achievement in radio engineering, even small sets give satis- factory performance, making them more like loop sets.

The Madison-Moore Wave Trap is made of the finest materials, precision tested, in our laboratory. A model adapted for use with any set. It is encased in a No. 12 aluminum solid box; it tunes so sharply that a Vernier dial must be used. Simple to operate comes complete with Vernier dial and instructions for connecting and operation. Priced within the reach of everyone.

The MADISON-MOORE WAVE TRAP is made by the manufacturers of the famous

ONE»SPOT TRANSFORMER

C Try your dealer first. If he can't supply you, write us. 3

MADISON-MOORE RADIO CORPORATION 2524 K Federal Boulevard Denver, Colorado » U. S. A.

RADIO BROADCAST ADVERTISER

v

Pep Up Your Receiver use TYPE "K"

The New Q G Radio Frequency Tube

Endorsed and Recommended by Radio Au- thorities

Type for Every Radio <Need

Tends to increase distant reception while improving the tone.

Price $3°_°

Write for complete data sheet

C. E. MFG. CO.

INC.

Providence, R. I., U. S. A.

A NEW BOOKLET

O/? pages of the latest radio diagrams, «JU parts, circuits and blueprints.

General description and constructional data written in simple style by a Master of radio technique. Truly instructive.

4 wiring diagrams, 4 circuits, 4 blueprints, 47 il- lustrations, 3 complete pages of parts, 36 pages of radio knowledge.

Send 25 cents for your copy

BRUNO RADIO CORPORATION, Long Island City, N.Y.

Type 612— $42.50

The trcB" Without a Wuzz

Also Complete set of parts for home- builders at reasonable prices. Write us.

MAYOLIAN

RADIO CORPORATION

1 66S Webster Ave., New York, N. Y.

'Pioneers in 'Battery Elimination

The Tower of 'Niagara The Quiet of an oArctic ^ight

r

SDNOCHOROf

T TEAR this cone on both music li and voice and you'll never be satisfied with any other. Equipped with super-powered unit with four heavy magnets, balanced and angu- larly spaced. Rich wine-colored silk front, unbreakable mahogany finish frame, protected back.

Ask your Dealer or Write Us.

BOUDETTE MFG. CO.

Chelsea, Mass.

FLOATI NG SOCKETS

Stop microphonic noises, mechanical feed-back and audio vibration!

Amsco Floating Sockets make it possible to operate your tubes at highest efficiency.

They take all the new type tubes— with the click that guar- antees positive contact. Ask your dealer or write for leaflet AMSCO PRODUCTS, INC. Broome and Lafayette Streets New York City

FOR INFORMATION ON SPECIAL EQUIPMENT

Write to

NORDEM-HAUCK, INC.

Engineers

Builders of the Highest Class Radio Appara- tus in the World.

Marine Building

PHILADELPHIA, PA.

Learn the Code at Home With the Omnigraph

Morse and Wireless taught at home in half usual time and at trifling cost. Omni- graph Automatic Transmitter will send, on Sounder or Buzzer, unlimited messages, any speed, just as expert operator would. Adopted by U. S. Govt, and used by lead' ing Universities, Colleges, Technical and Telegraph Schools throughout U. S. Send 6c for Catalog.

OMNIGRAPH MFG. CO.,13K, Hudson St., New York

Helpful Technical Information

A regular feature of Radio Broadcast is the series of Laboratory Information Sheets, which cover a wide range of information of immediate value to every radio worker, presented in a form making it easy to preserve them. To in- sure your having every issue, send your check for #4.00 to Subscription Department, Doubleday, Page & Co., Garden City, N. Y.

J^IGGEST Voh lar's Worth in Radio. Tunes out short wave inter. ' j ference, increas* ing selectivity of any set (not us- , ing loop) on sta« tions close to local, except same wave I length stations. Not a wave trap. No adjustments. At dealer's or send us dollar bill. Money -Back Guarantee, , Satisfaction guaranteed.

Central Radio Laboratories

22 Keefe Ave. Milwaukee, Wis. Parts manufacturers for 69 makers of ' leading standard sets.

RADIO BROADCAST ADVERTISER

5

NATIONAL TUNING UNITS

New Type

Designed and Officially Approved by Glenn H. Browning

These new NATIONAL TUNING-UNITS com- prise the OFFICIAL BROWNING -DRAKE Coils and R. F. Trans- lormers; mounted on the New_ NATIONAL EQUI- TUNE Variable Condensers ■with their light, rigid Girder- Frames.

Each TUNING-UNIT is

fitted with a NATIONAL ILLUMINATED VEL- VET-VERNIER DIAL— Type C, with variable ratio and smoothest action. Each tuning unit is packed mounted as shown so that it may be used without change for experimental work or easily installed on a panel.

NATIONAL TUNING UNITS COVER THE BROADEST BAND

Price BD-iE, with Genuine BD Antenna Coil and .0005 Condenser $10.75

Price BD-2E, with Genuine B-D Transformer and .00025 Condenser $14.25

SATIOXAL Tunins Units are standard for good Radio sets. So -.re NATIONAL Im- pedaformers for 'juality audio, NAT- IONAL Tone-Filters, for power tube output connection.

NATIONAL Co. makes heavy-duty B-Supply Units and 3-stage Power Amplifiers. Write Na- tional Company, IncW. A. READY, President, Cambridge. Mass., for Bulletin 116-B-5.

BROADCASTING From The INSIDE

ETCRY month in RADIO BROADCAST appears the department. As the Broadcaster Sees It," written by Carl Dreher, one of Ule best known broadcast engineers in the country. Alive with Junior, news, apt and searching comment, Mr. Dreher's writings nave become one of the most popular features of radio writing any- where. Are you reading itf Subscribe by the year and make sure of not missing a single issue. Mail your check for $4,110 to Sub- scription Department, Doubleday. Page & Co., Garden City, N. Y

E

METALLIZE

1L JL ^ v%^7

Warranted Fixed Resistors

HEAVY-DUTY TYPE

The new Lynch wire-wound heavy duty re- sistors for eliminator and power work are now ready. These units are ideal for use in Raytheon and all other power circuits.

EQUALIZORS

For perfect filament control use the Lynch Equalizo.s. 1 here is a type for every type of tube and for any com- binat.on of tubes. A Lynch Equalizer will take the place ot your filament rheostats. Complete with mounting, gi.oo. 6'

Lynch Suppressors and Low-loss mountings mean better radio.

At All Good Dealers

Arthur H.

Lynch, inc.

250 W. 57th St. New York, N. Y.

AmerTran DpLuxb Audio Tranr- lormer. Two lypes for 1st and 2nd Stages S1Q.0O Each

RADIO PRODUCTS

AmerChoke TyDe BS4 S6.0G Each

Bring Your Set Up-To-Date With AmerTran Radio Products

Today, the better class of broadcast stations are radiating fine programs with the highest quality possible. To take full advantage of this the audio amplifier in your set should be up-to-date. You can make this improve- ment by installing a pair of AmerTran DeLuxe audio transformers. In so doing be sure your last tube is a power tube capable of handling the higher plate voltages and current. It will then take care of the greater input signal and not overload or blast. The quality of reproduc- tion will more than repay you for investing in AmerTrans. The tones from your cone speaker will be faithful and life- like. You will realize a new degree of reality from all good broadcasting.

Eliminating Batteries

AmerTran Power Transformer Type PF52, AmerChokes Type 854 and the AmerTran Resistor Type 400 will enable you to construct the best of high voltage plate supplies. And with slight changes in your set, you may eliminate entirely all batteries.

Write for further information that will enable you to make your present or contemplated set meet the high standards of modern broadcasting.

Free Booklet "Improving the Audio Amplifier" and other technical data will be sent on request.

AMERICAN TRANSFORMER COMPANY

178 Emmet Street Newark, N. J.

"Transformer Builders for over 26 Years"

6

RADIO BROADCAST ADVERTISER

Automatic Power Control

Here is the way to control the switching of your B eliminator and trickle charger or either automatically.

When you turn the switch on your set, the Automatic Power Control switches on the B eliminator and cuts out the trickle charger or does either. When you turn the set off. the Power Control is working automatically, surely and without fail turning off the B eliminator and the trickle charger on.

No. 444-Automatic Power Control, Se- ries Type for use with sets having tubes v/ith a current draw equal to or greater than 6 U. V.-199 type of tubes. Each $5.00.

At your dealer's. If he can- not supply you send his name ivith your order to

Yaxley Mfg. Co.

Dept. B, 9 So. Clinton St. Chicago, HI.

[quality

Specialization Has Its cBgward

Dongan, for years, has maintained complete experimental laborator- ies. Many of the ad- vancements in design have found their origin in the Dongan plant. All this time, Dongan has specialized in one thing the manufac- ture of transformers and chokes.

Today manufacturers of receiving sets, power amplifiers and eliminat- ors, look to Dongan as the logical source of supply on standard and special transformers.

DONGAN ELECTRIC MFG. CO.

2991-3001 Franklin St., Detroit, Michigan

y he flux is everything

in radio soldering

says this Radio Engineer

"In our laboratory we made a thoro analysis of the two groups of fluxes (natural and chemical) . We found the natural flux, rosin, the only safe one to use on radio work.

Pure rosin, as in Kester Radio Solder, will not fume, sputter, or creep over large areas, and being a hard, dense substance, rosin will not attract and collect dust (car- bon particles), which makes an excellent path for leakages. These are the faults of fluxes containing chloride, be it either in paste, liquid or compound form. Any flux containing chloride will eventually cause heavy leakage. Hence they should be strictly avoided.

We find Kester Radio Solder the most convenient way to solder on radio work, for it has the proper amount of pure rosin right inside the solder itself. In fact, we used it exclusively on all of our work."

There's your guide, radio fans the approval of an expert radio engineer. Surely there can be no doubt as to what you should use on YOUR SET.

A free Sample toriteforitnoxo

KESTER

Radio

SOLDER

the safe solder for radio, requires only heat CHICAGO SOLDER CO.

42ZZ Wrightwood Ave. Chicago, U. S. A.

Originators and the World's Largest Manufacturers of Self-fluxing Solder

FROST-RADIO f HOST RADIO f HOST' RADIO f HOST- RADIO

Q

FROST-RADIO

IMPROVE THE OPERATION OF YOUR SET

By equipping1 your receiver with Frost - Radio Super Variable Hi^h Resistance Units, Rheo- stats, Potentiometers, Gem-Jacs, Plugs and other items from our line of high quality apparatus you will greatly increase its ef- ficiency— secure better reception and improve its operation. Every Frost-Radio Product is designed to give ioo# effici- ency— and delivers it.

YOUR DEALER CAN SUPPLY YOU

Ask your dealer for Frost-Radio. Have him show you the new Super Variable High Resistance Unit, in resistances of from 50,000 to 500,000 ohms, list $1. 25. Metal Frame Rheostats, 2% to 75 ohms, list 50c, (Bakelite Type, 75c)_or other items that you will tind mighty useful in your new recei- ver. Write us for complete de- scriptive literature.

HERBERT H. FROST, Inc. 9 160 N. La Salle St.. Chicago > New York Los Ang

Irost-raokd fROSTRAOlO FROST-RADIO frost-radis

Fahnestock Clips

RADIO'S GREATEST CONVENIENCE

Used by Manufacturers of Standard Sets and Parts and by Manufac- turers of High Grade Wet and Dry Batteries.

ALL GENUINE FAHNESTOCK CLIPS

bear our imprint on the thumb piece of the clip.

WORLD'S LARGEST MAKER OF CLIP TERMINALS

48 different sizes and styles to meet all requirements.

Send for Catalog and Samples

FAHNESTOCK ELECT. CO.

L. I. City New York

R U ONE?

Co-operative member- ship in E I A RADIO is establishing an honest, industrious man in each locality in a successful radio industry of his own. Young married men preferred. Apply by letter, giving the name of your county, to EQUITABLE INDUSTRIES ASS'N, RADIO DIV. 350-B Broadway, New York

MIBGAP

K/jL socket Vtyets that fast mile"

Results in easier tuning, more distance, volume and clarity greater stability. Indorsed by leading authorities.

MODEL "N" A slight turn ohtains correct tube os- cillation on all tuned radio frequency circuits. Neutro- dyne, Roberts two tube Browning-Drake McMurdo Sil- ver's Knockout, etc., capacity range 1.8 to 20 micro- microfarads. Price $1.00 MODEL "G" With grid clips obtains the proper grid capacity on Cockaday circuits, filter and intermed- iate frequency tuning in heterodyne and positive grid bias in all sets. Capacity range. Model G-l .00002 to .0001 MFD Model G-5 .0001 to .0005 MFD Model G-10 .0003 to .001 MFD Price $1.50 X-L PUSH POST. Push it down with your thumb, insert wire, remove pres- sure and wire is firmly held. Re- leases instantly. Trice 15c PUSH POST PANEL permanently marked in white on black rubber. In box including soldering lugs, raising bushings and screws for mounting. . etc. Price $1.50 Free Wiring Diagrams showing use in most popular circuits. Write to-day.

U 0 0 G Q D

X-L Radio Laboratories ch/cago!" ill!

RADIO BROADCAST ADVERTISER

7

ALUMINUM BOX SHIELDS

Made of "Alcoa Aluminum

99

Consist of: Top, Bottom, Sides 4 Extruded Corner Posts 8 Aluminum Screws

(J\ //EETING the highest radio standards shipped to QyYji you in the most convenient knocked-down form for easy assembly. These Box Shields are made of heavy aluminum (.080" No. 12 B. & S.) and are sup- plied 5" x 9" x 6", which will cover most requirements. If the size does not meet your exact needs, change it Alum- inum is easy to work.

Manufacturers can obtain these shields made to their exact specifications or they can secure the necessary corner-post moulding and sheet to manufacture under their own super- vision.

Those who use Aluminum have ample proof of its advan- tages. Insist on "Alcoa Aluminum," ask your dealer or write us.

"ALCOA ALUMINUM" is furnished to manufac- turers in the following forms:

Sheet: for shields, chassis, variable condensers, cabinets.

Panels finished in walnut and mahogany. Die and Sand Castings. Screw Machine Products. Foil for fixed condensers. High Purity Rods for rectifiers. Stamping, rod, wire, rivets.

ALUMINUM IN EVERY COMMERCIAL FORM

Aluminum Company of America

2320 OLIVER BUILDING, PITTSBURGH, PA.

M

ALUMINUM//

Output oj Battery EUrninators

THE ordinary type of low resistance volt' meter cannot be used to measure the out' put of battery eliminators because most eliminators cannot deliver sufficient cur' rent to operate the voltmeter and still maintain their voltage. For this service Weston now offers a special voltmeter with an exceptionally high self-con' tained resistance of 1,000 ohms per volt Model 489 Battery Eliminator Voltmeter. This new instrument, because of its high resistance, re quires a current of only one milli' ampere to produce full scale de' flection. It is made in two double range combinations of 200/8 and 250/50 volts. The latter range can be supplied with an external multiplier to increase it to 500 volts. Ask your dealer or ad' dress

WESTON ELECTRICAL

INSTRUMENT CORPORATION

179 Weston Avenue, Newark, N. J.

STANDARD THE WORLD OVER

WESTON

Pioneers since 1888

RADIO BROADCAST

MAY, 1927

Willis K. Wing, Editor

Keith Henney John B. Brennan

Director of the Laboratory Technical Editor

Edgar H. Felix, Contributing Editor

Vol. Xi, No. 1

QOJiTEKTS

Cover Design ' ' From a Painting by Fred J. Edgars

Frontispiece The Towers of Station WOW, at Omaha, J^[ebras\a 10

With MacMillan to the Arctic-

The March of Radio

Austin G. Cooler n

An Editorial Interpretation 15

What Does the Listener Want? Let Him Speak "Christian" Mud Throwing Questionnaire: Which Stations Shall Broad- A New Term for "A^ C. Supply" Units cast?

Objections to the Radio Law The Question of Vested Rights

There Are no Radio Engineers A Survey of Radio Conditions The Month in Radio

The Electrical Phonograph - - A Balanced Short' Wave Receiver What About the A Battery? The Listeners' Point of View

How Long Will Radio Broadcasting Prosper? Why a Good Program Was Good Thumb Nail Reviews

- James Millen Fran\ C. Jones Edgar H. Felix

Microphone Miscellany Communications

What the Listener Likes and How He Likes It

Filament Lighting from the A. C. Mains As the Broadcaster Sees It ' ' ' '

One Explanation of the Plethora of Broad- The Radio Club of America

casting Stations Technical Operation of Broadcasting Stations

Broadcasting and Social Upheavals (Volume Indicators)

Glad Tidings From the West Something About Gain Control

Some Facts About Coil Design ' ' Perfecting the B Socket Power Device

'Radio Broadcast's" Laboratory Information Sheets

No. 89 Short-Wave Coils

No. go Loop Antennas

No. qi A Simple Tube Tester

No. 92 Circuit Diagram of Tube Tester

No. 03 Audio Amplifying Systems

No. 94 The Principle of Reflexing

No. 95 Storage Batteries

No. 96 Analysis of Voice Frequencies

Equipment for the Home Constructor A Key to Recent Radio Articles International Short-Wave Test - - Manufacturers' Booklets Available -

John Wallace 29

Roland F. B:ers 33 Carl Dreher 36

Ross Gunn 40

Howard E. Rhodes 43

Methods of Measuring Tube Characteristics - - Keith Henney 46

?2

58

E. G. Shal\hauser 60

60

61

AMOHG OTHER THINGS. . ..

V\ 7"ITH this issue, Radio Broadcast starts its sixth year of " * publication. The five years just concluded have seen many changes in the radio industry and among radio experi- menters and fans. American radio magazines of to-day are quite different from those of 1922; Radio Broadcast has changed considerably, both in physical appearance and in type of con- tents, since those days. We believe the changes are improve- ments, for certainly our files are filled with countless letters of approval. The aim of Doubleday, Page fe? Company has been to publish the highest class radio magazine possible. This we have attempted to do, first, in setting the standard of physical ap- pearance of the magazine where it now is, and secondly, to spare no pains or expense in making our technical material as completely accurate and helpful as possible. Two large labora- tories are maintained in Garden City where practical and theoretical experiments are constantly under way; and our ad- vertising pages are carefully supervised.

"X ,rf ANY editorial features in Radio Broadcast have given XVX the magazine a unique position in its field. The '"March of Radio" provides an editorial comment and suggestion about all branches of radio. "The Listeners' Point of View" stands alone as a national review of broadcasting, particular and general. "As the Broadcaster Sees It" has turned out to be a unique department (prepared, incidentally, by one of the ablest broadcast engineers in the country) where engineer, program director, listener, and general reader alike, may meet. The re- view of current radio periodicals, the Laboratory Data Sheets, the listing of informative manufacturers' booklets, all furnish valuable information for our readers. Our constructional articles are chosen carefully for accuracy and greatest help and interest for the reader. We are at work on an editorial schedule now which holds much for everyone interested in radio in all its branches. Unfortunately there is insufficient space here to outline that schedule, but we prefer to let each issue of Radio Broadcast speak for itself in that connection.

PRINTERS' IA[fC, in its tabulation of advertising lineage for March magazines, shows that Radio Broadcast led the field with a total of 20,621 lines, followed by Radio T^ews with 18,930 lines, Popular Radio with 14,872, Radio with 12,770, and Radio Age with 4395.

IN THE June Radio Broadcast, a fine story for the home experimenter is scheduled, describing the construction and use of. a modulated oscillator. Other articles deal with short waves, the problems of series filament connection for 201-A type tubes, how to use new apparatus, technical problems for broad- cast operators and others, and many other features of unusual interest.

Willis K. Wing.

Doubleday, Page Co.

MAGAZINES

Country Life World's Work Garden & Home Builder Radio Broadcast Short Stories Educational Review Le Petit Journal Ei Fco

Frontier Stories West

Doubleday, Page Sr Co.

BOOK SHOPS (Books of all Publishers) I Lord & Taylor

\ Pennsylvania Terminal (2 Shops) New York < Grand Central Terminal

I 38 Wall St. and 520 Lexington Ave.

\ 848 Madison Ave. and 166 West 32ND St. St Louis: 223 N. 8th St. and 4914 Maryland Ave. Kansas City: 920 Grand Ave. and 20b W. 47TH St. Cleveland: Higbfe Co

Springfield, Mass.: Meekins, Packard & Wheat

Doubleday, Page & Co. OFFICES Garden City, N. Y. New York: 281 Madison Ave. Boston: Park Square Building Chicago: Peoples Gas Building Santa Barbara, Cal. London: Wm. Heinemann Ltd. Toronto: Oxford University Press

Doubleday, Page S- Co. OFFICERS F. N. Doubleday, President Nelson Doubleday, Vice-President S. A. Everitt, Vice-President Russell Doubleday, Secretary John J. Hessian, Treasurer L. A. Comstock, Asst. Secretary L. J McNaughton, Asst. Treasurer

OOUBLEDAY, 'PAGE & QOMPAKT, Garden Qity, Hew Tor\

Copyright, 1927, in the United States, Newfoundland, Great Britain, Canada, and other countries by Doubleday, Page &• Company. AH rights reserved.

TERMS: $4.00 a year; single copies 35 cents.

RADIO BROADCAST ADVERTISER

9

A R E A ABUSE TEST

So many people run their batteries up too high that, having made good Radiotrons for careful users, RCA set about to make Radiotrons that would stand abuse.

A year ago, an RCA I Radiotron could stand II about twenty hours of! running under too heavy it a current. Now it will outlive a hundred hours of such abuse.

Many very minute changes brought about through laboratory study have effected this im- l| provement.

If you have children who j are apt to turn up the rheostats carelessly, of \ course it is hard on the tubes. No tubes can be proof against ruin, but ifl you are using RCA Ra- diotrons, you know at least that they'll stand more than ordinary tubes.

Look for that RCA mark' You'll find it on Radio- trons for every purpose.

RADIO CORPORATION!

OF AMERICA New York Chicago San Francisco

The stations are there get them !

You're not getting the most out of that storage bat- tery set of yours. The set has a bigger distance reach ... all it needs is a different tube in the detector socket. Put in the RCA super-detector Radiotron UX-200-A. You'll get more stations— get the far- away ones more regularly and more easily! It's a small change, but it brings big results,

_p Bring your storage battery set up-to-date with r a power RADIOTRON ux-171 or UX-112 a detector radiotron ux-200-a and radiotrons ux-20l-Afor ali-rourm quality. Bring your dry battery set up-to-date with a power radiotron ux-120 U and radiotrons ux-199 for all-round quality.

RC A IVad i o t r o n

MADE

THE MAKERS OF THE RADIOL* A

THE TOWERS OF STATION WOW, oAT OMAHA, NEBRASKA

Formerly known as WO AW, this station has enjoyed a wide national popularity. In April, this station celebrates its fourth anniversary. The illustration shotsis the hoisting of a large section of plate glass, which now forms the front of a unique studio atop this 19-story building. The studio is arranged as a stage, properly insulated against sound inside, but with a front panel of glass to allow those seated in a small auditorium to watch and to hear the broadcasting as it occurs

APR-9'27

Radio Broadcast

Volume XI

MAY, 1927

Number 1

With MacMillan to the Arctic

Tales from the Pen of the Sachem's Radio Operator Not so Stupid, These Eskimo Flappers Some Notes on the Aurora, Mirages, and Radio Abe Puts One Over!

TA K I NG up the threads of our story from where we dropped them last month, we on the Sachem and our friends on the Bowdoin find our- selves at Godhaven, Disko Island, the northernmost port of call of the expedi- tion.

Let us deviate a little, though, to tell of the inhabitants of these arctic regions, for an account of an expedition into the land of the Eskimos is not complete without some mention of these most interesting people. Although the full-blooded Eskimos are few and far between, their habits and methods of living are preserved by those who possess considerable Danish blood. They are all wards of the Danish Govern- ment and are well cared for, and every effort is made to preserve their native cus- toms and practices.

The Eskimo flappers are not so stupid; in fact, they have many of the same instincts that are common among the American beauties. In the matter of short skirts, they are years ahead of the best of our stenogra- phers. The complete absence of skirts is due in a large measure to the Dan- ish rulings that prevent them from changing from their native custom of sealskin pants and boots. They take great pride in making their boots the most attractive in the settlement. Generally they are dyed with a brilliant white or bright red. The girls all make large bead collars for themselves of their own design, with beads imported from Denmark. Ordinarily it is very difficult to ob- tain these collars but this year a few were purchased for thirty kroner (Danish money). Many of the girls, if they have considerable Danish blood in them, are quite pretty; otherwise they look too much like Eskimos.

By AUSTIN G. COOLEY

A few of the Eskimos live in small frame houses or shacks while the others have their homes built of sod. These houses, or igloos, are built very scientifically with a selected sod that is a good heat insulator. The walls are built very thick and the doors all have tunnel approaches built of sod, entering at an angle to the door. Each igloo has a bed consisting of a raised platform large enough to accommodate the entire family. The Greenland Eskimos, and the igloos that we saw, were very clean.

Many of the expedition found it great sport trading with the Eskimos for souve- nirs, such as harpoons, bird spears, model kyaks, etc. In Sukkertoppen, Mrs. Metcalf wanted to get a model of a woman's skin boat. She asked some of the Eskimos in their language if they had any "coumiaks."

AND ABE

CAPTAIN MAC The latter was the Eskimo interpreter of the Expedition. He returned with the others to America when the Sachem and Bowdoin came back and, among many other things, saw a train for the first time in his life

Considerable laughter among the Eskimos immediately resulted. Abe Bromfield, Com- mander MacMillan's interpreter, had to come to her assistance. It was an "umiak" she wanted. "Coumiak" is the Eskimo word for "lice"!

For exchange, the Eskimos generally wanted tobacco and calico, although some asked for kroner which could be used at the stores run in the large settlements by the Danish government. The Danish money used in Greenland bears pictures of animals, such as polar bears, whales, seals, and ducks, so that the value may be recog- nized by the Eskimos.

During certain seasons, the Eskimos work in fisheries operated by the Govern- ment, and at other times they are busy sealing and hunting. The womens' work includes the chewing of seal skins so as to soften them, and the mak- ing of boots and clothing.

Anyone espied walking ashore with a camera was sure to have a large following, for the Eskimo girls are as anxious to have their pictures taken as are some American girls to appear in the movies. When preparing for a shore trip with the cameras, I always considered a supply of gum and cig- arettes as important as the films. After taking pictures, these would be passed around to the eager na- tives, who were especially anxious for cigarettes; even the babies in their mother's arms made manifest a desire to smoke. They seemed to enjoy smoking as much as their grandmothers.

The Eskimo's Santa Claus is more of a fact than a myth. His phase angle displacement is 180 degrees from ours! He comes from the south in the summer time in a white schooner, and brings toys and candy for the bad little bovs and girls as

12

RADIO BROADCAST

MAY, 1927

well as the good ones. He is known to them as "Captain Mac." Captain Mac's own generosity is always backed up by various candy manufacturers who see that the ex- pedition does not leave American shores without a plentiful supply of all kinds of candy for the natives. The toys distributed by Captain Mac are generally of the nickel and dime variety, but some of the most deserving Eskimo men receive presents of excellent jack knives.

Some of the unfortunate Eskimos re- ceive presents of lemons and a pleasant visit by the expedition's doctor Doctor Thomas of Chicago. Doctor Thomas trea- ted a number of cases among the Labrador Eskimos and in one instance performed an operation.

At practically all of the settlements at which we stopped. Captain Mac put on movie shows for the natives. The atten- dance was always one hundred per cent. "Robbie,'' the mate of the Bowdoin, was skilled in packing whole settlements into a small room so as to give each Eskimo a good view of the screen.

I WE START OUR TRIP HOME

/^OMMANDER MacMillan planned on running south from Godhaven, Greenland, to Holsteinborg, then across to Baffin Land, but the problem of re- plenishing our fuel supply required some changes in the schedule. We went south to a whaling station at Edgesminde where ten barrels of fuel oil were obtained, but this was not enough to take us home. Using the engines seemed more desirable than the sails, so we went further on, to Sukkertoppen, where a larger supply could be had.

This southbound trip included a few days' stop at Holsteinborg, formerly a cen- ter for American halibut fisheries. In the cemetery were found a number of graves of Gloucester fishermen. All foreign fishermen are now barred from the coast of Greenland and the Danish Government is operating the halibut fishing industry at Holstein- borg with great success. During our stay at this port, we enjoyed many meals of hali- but. It was delivered to the ship at a price corresponding to one cent a pound.

Except for the fog at sea, the weather we experienced in Greenland was of the best. During the day, the temperature generally ran around 70 degrees. This weather, on the middle western Greenland coast, is due to a warm ocean current which pre- vents the winters from being any more severe than they are in Maine.

Our call at Sukkertoppen for fuel lasted only a few hours. Before leaving, plans were made to set a course for Cape Murchison, Bevoort Island. If the ice was not too heavy, we planned to run up Robinson Sound, between Bevoort Island and Baffin Island, and anchor in a harbor that was dotted in on the chart. The dots meant: "Harbor about here."

The radio conditions during our last few days in Greenland were very poor. Even the powerful commercial stations

faded out completely at times. While going across to Baffin Land it was hardly possible to get through any amount of traffic to the States because of complete fading. Radio 1 aay (Kenneth M. Gold, Holvoke, Massachusetts) was worked a couple of times but it was only possible to get one complete message of about fifty words from him. Other stations were worked but communications only lasted a few minutes before they faded out completely.

Davis Straits had