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Magazine of tKe Hour
VOL. 1.
MAY, 1922.
NUMBER 1
. . IN THIS NUMBER . .
How to Make a Home Radio Set for $6.
An Official U, S. Government Article For Boys.
Chicago Boy's Simple Directions for Making Radiophone at Home.
Fully and Clearly Illustrated.
Questions and Answers.
They Simplify Your Own Radio Problems.
How to Get a Good Radio Set—- Free.
A MAGAZINE FOR A MILLION FANS
For Beginners, Experts, Dealers, Jobbers, Manufacturers
$2.50 a Year
25c a Coiay
Radio Age
f
\\
PROSPECTUS
UR special field : The Middle West and the West. This includes the "Chicago Territory" Avhich is unquestionably the richest agricultural, com- mercial, financial and industrial region in the world. Radiophones accord- ing to late figures published through the Associated Press, are being used in four States as follows : Iowa, 23,000 ; Missouri, 25,000; Nebraska, 22,000; Kansas, 20,000; Wisconsin, 1,500 stations, increasing at the rate of 5 a day. Cleveland alone has 15,000 amateur and professional radio enthusiasts; St. Louis, 2,200; Dallas, 263; Cincinnati, 500; Indianapolis, 1,000; ]Milwaukee, 1,000. Schools and colleges in all states are teaching radio, farmers all over the INIiddle West are installing radio sets; clubs are being organized everywhere.
Chicago — Radio operatives are growing in number so rapidly that their number could only be approximateh^ estimated. Thousands of boys are studying practical radio science in the public schools. Dealers and manufacturers are unable to supply tlie demand for equipment.
Our special circulation: Boy begimiers particularly, and amateurs generally. Radio Age will write Radio so that boys can understand it. There will be technical ai'ticles for the advanced students of Radio but the departments for beginners will not be written OVER THE READERS' HEADS. Numerous illustrations will aid amateurs in constructing HOME RADIO SETS. Getting a printed message across is simply one form of SALESMANSHIP and, it is a highly specialized line. Radio Age knows its market and knows how to supply it.
Our sj^ecial departments: In addition to illustrated articles showing begin- ners how to launch out into the ether waves there will be original articles written by boj^s telling what they have done in Radio and how. There will be a Questions And Answers department, carefully handled; Radio Clubs will have attention with liberal use of names of individuals and photographs ; there will be a department for Trade News, a Radio Readers' Exchange, for letters of interest from our readers. These features will be supplemented by articles presenting facts about the growth of radio in popularity, about the constantly increasing list of practical uses for radio, about the importance of radio in its relation to society generally. Radio Age will have no narrowed view of its subject.
It is the hour of Radio. We offer —
"The Magazine of the Hour"
Radio Ace, The Magazine of the Hour, piililihhed on April 8; a montlily maRrazine. Vol. I, No. 1. Publication ofHee, Garrick Building, 64 \V. Kandolpl) St., Chicago, 111. Soibscription price $2.50' a year. Published bv the M. B. Smith Publishing Co. Kntry as second class matter applied for at the postofflce at Chicago, niinois, under the ACT of March 3, 1879.
(1.) 8ergt. Lawrence W. Bock no longer has "the lonesom.est job in the army." He is the operator of the army radio station at Fort McPherson, Ga. The picture shows him enjoying songs by Galli Curd broadcast from Atlanta, Ga. (2.) Edward Herron, Chicago boy, showing one he made himself. Edward is proud of it and has a right to be. (3.) Chicago Boys' Club No. 2, 1725 Orchard St., has a radio class. Left to right, George Hensel, Charles Coleman, Jr.. Erwin Alanap and William Pour. (4.) Elizabeth A. Bergner, radio instructor at Lane Techni-
cal Hioh School pTrtlni
in hpr rln
Mm
EADIO AGE— "THE MAGAZINE OF THE HOUR"
Who's Who In Radio
"Paddy" O'Neill
/F WE were to fol- low a time-hon- ored custom we zvould devote this page to men who are great and famous. Edison, Fleming, Marconi and De For- est, to he sure. All honor to these celeb- rities.
But the age of radio is essentially a '<ncw era for boys and the boys of today may be Steinmctzes tomor- row.
So our first Who's Who presents "Pad- dy" O'Neill and Eddie Neils en. See Eddie's own story beginning on Page 5 and read about Paddy on this page. Send in your favorite boy radio "experts" for our Who's Who page.
^^^-^
Edzuin Nielsen
/~\NE of the most enthusiastic boy ^-^ radio fans in the Middle "West is "Paddy" O'Neill, 11-year-old son of Detective Patrick J. O'Neill, who was killed by Tommy O'Connor, the Chi- cago gunman.
Little Pat, now the "man of the fami- ly," owns a cheap receiving set, which he has rigged himself, driving a pipe into the ground in his back yard to ground the wires. Driving in the pipe took a whole day of the boy's time.
As soon as his set was rigged and in operation, Pat called in all the neigh-
bors to hear the Chicago Opera Com- pany, hearing the same music as though he and his friends were in the front row at the Auditoi'ium Theater — at $6 a seat.
The concerts are now a nightly fea- ture in the O'Neill home. Detective O'Neill was killed when he and six other detectives went to the home of William Foley, O'Connor's brother-in law, to arrest him for the forfeiture of bonds in a charge of robbery. O'Con- nor dashed from the house, firing as he
ran. O'Neill fell, dying on the way to the hospital.
Little Pat immediately took command of the family — his mother and three small brothers and sisters — acting for the grief-stricken woman in helping comrades of the slain policeman ar- range a fitting funeral.
Through the generosity of Chicago citizens more than $10,000 was raised fo;* the bereaved family.
Pat also wired their little home, and once tapped the service wires of the — — but that's a secret.
II 1 1 111 Ml II 1 1 1 II I III! I M II 1 1 HI I M 1 1 [ 1 1 1 1 1 \ 1 1 1 1 1 II I \M 1 1 1 1 \ 1 1 1 1 1 1 1 1 1 \ 1 1 1 II I u 1 1 n I II I u 1 1 '■ 1 1 1 [ 1 1 1 1 1 nil 1 1 1 1 1 n II I Mil I m \xn:
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FMD/O MGE
4- Tfte Ma^a^ine oe Ifte Hour ^ ^^^^^.>™^ ^.„^*
M,B. SMITH ^ €f y ' -^ FREBERIiliirilllll:
PUBLISHED -M.ONTH1.Y GARRiCK. BL.DG CtiGO.
PUBLISHE^Rj
EDlpepiiiiiiiiiiillii
Hill Mill II in I I I 1 I I I I I I I I I M I I I I I I [ II u I I I I I 1 I n u I 1 I I I 1 I I 11 I u 1 I II I III II I I I I I II n I II I I M I I I I M I I I I I 1 1 I I I I I M I I I 1 I I I I 1 1 I I I iir
Great Radio Shows To Come
THE Radio show at the Hotel Penn- sylvania in New York set that city radio wild and greatly increased the interest in other shows to be given in the larger cities. Pittsburgh and Bos- ton come first and then Chicago is to have two expositions, one in the Leiter Building, from June 26 to July 1, in- clusive, and the other in the Coliseum during the week of October 15 to 21.
How you can send your morning kiss by radio to your wife while speeding over the rails on fast trains, how you can enjoy the great concerts of the country, listen in on vaudeville per- formances and hear the world news while seated comfortably in your home will be visualized by the displays at the National Radio Exposition to be held in the Leiter Building, Chicago, June 26th to July 1st, inclusive. Radio fans will be enabled to see every type of apparatus in operation at this show, Avhere accessories by the gross will be exhibited and where numerous "stunts" will be put on to be broad- cast throughout the middle west. This announcement was made by Milo E. Westbrooke, well known exposition manager, who recently staged the National Shoe Exposition in Chicago and who has put on some of the big- gest trade shows in New York and Chicago. Mr. Westbrooke declared the Chicago Radio Exposition would be bigger and better than the one recently held in New York, Avhere thousands upon thousands were turned away every night.
"This probably will be the most comprehensive Radio exposition ever conducted by, for and in the interest of radio fans," said Mr. Westbrooke. "There will be exhibits of every sort of radio apparatus manufactured, in- cluding the very latest devices and in- ventions. All the parts that are used in the construction of sending and re- ceiving instruments will be on display.
"The working of the radiophone will be demonstrated and the people who have listened to concerts given hun- dreds of miles away and heard the world news transmitted to them while seated comfortably in their homes, will have an opportunity to see the instru- ments in operation and view the vari- ous parts utilized in their construction.
lir> !~>]io\^r in .Tnre will bp orip nf
the greatest educational expositions
ever held in Chicago or any other city.
"The sudden popularity of radio tele-
The Sweet devot( >■ of Radio carries a net in her hand bag.
phony has resulted in the establishment of more than 600,000 receiving sets in the country, and of these 150,000 are located in the middle west. Through- out the United States 20,000 amateurs are qualified as transmitters, capable of sending and receiving a minimum of fifty characters a minute by trans- continental Morse code. For each Radiophone there is an average audi- ence of five persons, thus making a total of 2,500,000 who are associated with the wonders of wireless."
The October Show
U. J. Herrmann, of the Cort Theater, announces that the "Annual Chicago Radio Show" will be given each year in October because deferring the exhi- bition to that season will give the manu- facturers a chance to catch up with de- liveries and will also permit them to complete and perfect many improve- ments in construction and design.
Mr. Herrmann says:
"Because of the enormous demand most manufacturers of radio equipment
October conditions should be greatl; improved. The radio shows which havu been held in other cities during the las^ year have been pronounced successes In New York the public was turner away by the thousands every day dur ing the show in the Pennsylvania hote and the crowds were so great arounc the exhibits as to cause actual discom fort.
"The nation-Avide, ever-growing in terest in radio has amply demonstratec that only the largest exhibition build ings are adequate to properly handh the enormous crowds whose enthusiasn has placed radio shows on the plam with the big national automobile ex hibits. ' '
The Pittsburgh Show Rare harmony from Chicago, musica comedy from Cleveland, trade condi tions information from St. Louis, new flashes from New York, government re ports from the National Capitol, thesi are only a few of the many feature given via radio at the first Pittsburgl radio exhibition in the William Peni hotel, April 11, 12 and 13. A larg^ receiving set erected by the Westing house interests receives and transmit these messages from the air for th benefit of the Pittsburgh fans and th numerous visiting delegations from th neighboring districts and states.
Practically every one of the larges manufacturers of radio equipment ani supplies made reservation for the sho'w but as space it limited at the Williai Penn a few could not be accommodatec Leading local dealers and distributor have extensive displays and thei booths are both beautiful and educ? tional. There are on exhibition set of every one of the leading radio mam facturers as well as a large percentag of the battery and accessory people.
The educational talks and iUustrf ted lectures are held throughout th afternoon and evening of each day c the show, except the opening date whe the doors are open at 7 o'clock. Thes lectures are conducted by men prom nent in the industry and are intende to both instruct the fans as to tl: proper means of assembling their equi] ment and to educate the uninitiated it to the mysteries of the wireless.
KADIO AGE— "THE MAGAZINE OF THE HOUR"
Tune Up and Listen In
roadcasting from these Stations is on 360 meters zvhere not otherwise specified
Midwest Broadcasts
Eiglitli District
,J)KA — Westinghouse Electric & Mfg. Co., Pittsburgh, Pa. Daily, except Sunday, music 10:00-10:15 a. m. and 12:30-1:00, 2:00-2:20 and 4:00-4:20 p. m., with special Saturday concert 3:00-4:00 p. m.; bedtime stories, 7:30 p. m.; press, 7:45; special features and vaudeville acts, 8:00 p. m.; music and news, 8:30-9:30; Sunday, church service, 10:45 a. m., 3:00 p. m. and 7:30 p. m.
|VBL— The Detroit News, 615 Lafayette Bldg., Detroit, Mich. Daily, except Sun- day, 11:30-11:55 a. m., and 3:30-4:00 p. m., phonograph music; 7:00-8:30 p. m., spec- ial musical programs by selected artists.
iQV— Doubleday-Hill Electric Co., 719 Lib- erty Ave., Pittsburgh, Pa. Daily except Saturday and Sunday, music, 4:30-5:00 p. m.; Sunday, 1:00-1:30 p. m. and 4:00 to 5 p. m. ; Monday, Wednesday and Friday, 9:30 to 10:30 p. ra.
I VDZ— Marshall Gerken Ave., Toledo, Ohio.
Co., 27 Ontario
I VPB — Pittsburgh Gazette-Times, Gazette Square, Pittsburgh, Pa.
•VMH — Precision Equipment Co., Cincin- nati, Ohio. Monday, Wednesday and Sat- urday, 8:15-10:00 p. m., music, speeches and news; dally 485 meters; 11:00 a. m. and 4:00 p. m., weather reports.
Ninth District
hVOV— R. B. Howell, 1802 Farnum St.. Omaha, Neb.
|tVHA — University of Wisconsin, Madison, Wis. Daily except Sunday, weather re- ports at 12:35 p. m., Friday at 8:15 p. m.; special music and other dates as an- nounced. Midnight to 1:00 a. m., univer- sity news on 410 meters.
I rtLB — University of Minnesota, Minneapolis, Minn. 485 meters; daily 12 noon, weather and stock reports; 7:30 p. m., wheat and potato market; 7:45 p. m. Wednesday only, music, 360 meters.
I iVLK— Hamilton Mfg. Co., 2011 North Ala- bama St., Indianapolis, Ind., Sunday, 8:00-8:55, religious, vocal and instru- mental music; Tuesday, 8:00-8:55 p. m., jazz, vocal and instrumental music; 9:00- 10:00 p. m., local theatre numbers and news items; Thursday, 8:00-8:55, special numbers from local singers and orches- tras, stories, news and speeches.
|aYW — Westinghouse Electric & Mfg. Co., Ill W. Washington St., Chicago, 111. Daily, except Sunday, 9:30, 10:00, 10:30, 11:30, and 12:00 a. m. and 2:45 p. m., stock and market reports; 2:15, 4:15 and 6:00 p. m., news and market reports; 7:00 p. m., summary of financial report; 7:30 p. m., children's bedtime story; 8:00-9:00 p. m., musical program; 9:00 p. m., news and sports; Sunday, 3:30 p. m.. Radio Chapel.
|tXAB — Western Radio Co., Kansas City, Mo. Market reports and weather fore- cast, 11:30 a. m. and 2:30 p. m.; concerts in the evening.
|>ZAF — Reynolds Radio Co., Denver, Colo. Xews twice daily and concert Sunday
List of stations broadcasting niarlict or weather reports (485 meters) and music, concerts,
lectures, etc. {360 meters), {March 10, 1922).
T, ^ Owner of station. Location of Station
Allen. Preston D Oakland, Calif
American Radio & Research Corp Medford Hillside, Mass.
Atlantic-Pacific Radio Supplies Co Oakland, Calif
Bamberger, L.., & Co. . Newark, N. J
Bible Institute of Los Angeles, Inc Los Angeles, Calif. ...
Church of the Covenant Washington, D. C
City of Chicago Chicago, 111
Cox, Warren R Cleveland, Ohio
Crosley Mfg. Co Cincinnati, Ohio
DePorest Radio Telep. & Teleg. Co New York NY...
Detroit News, The Detroit, Mich
Doubleday-Hill Electric Co Pittsburgh, Pa. . . .
Doron Brothers Electric Co Hamilton, Ohio '.
Duck Co., Wm. B Toledo, Ohio
Dunn & Co., J. J Pasadena, Calif
Electric Lighting & Supply Co Hollywood, Calif
Examiner Printing Co., The San Francisco. Calif. . .
General Electric Co Schenectady. N. Y
Gilbert Co., A. C New Haven. Conn
Gould, C. O Stockton, Calif
Hamilton Mfg. Co Indianapolis, Ind
Hatfield Electric Co •. Indianapolis, Ind
Herrold, Chas. D San Jose, Calif
Hobrecht, J. C Sacramento, Calif
Howlett, Thos. F. J Philadelphia, Pa'.
Karlowa Radio Co Rock Island, 111
Kennedy, Colin B. Co Los Altos, Calif
Kluge. Arno A Los Angeles, Calif. . . .
Kraft, Vincent I Seattle, Wash
Lorden. Edwin L San Francisco, Calif. . .
Marshall-Gerken Co Toledo, Ohio
Metropolitan Utilities District Omaha, Nebr
Meyberg Co., Leo J San Francisco, Calif. . .
Meyberg Co.. Leo J Los Angeles, Calif. . . .
Missouri State Marketing Bureau .lefferson City, Mo
Montgomery Light & Water Power Co Montgomery, Ala
New.spaper Printing Co Pittsburgh, Pa
Northern Radio & Electric Co Seattle, Wash
Palladium Printing Co Richmond, Ind
Pine Bluff Co., The Pine Bluff, Ark
Pomona Fixture & Wiring Co Pomona, Calif
Portable Wireless Telephone Co Stockton. Calif
Precision Equipment Co Cincinnati, Ohio
Precision Shop, The Gridley, Calif
Radio Construction & Electric Co Washington, D. C
Radio Corporation of America Roselle Park, N. J. ...
Radio Shop, The Sunnyvale, Calif
Radio Telephone Shop, The San Francisco, Calif. . . .
Reynolds Radio Co Denver, Colo
Rike Kumler Co., The Dayton, Ohio
Rochester Times Union Rochester. N. Y
Seeley, Stuart W East Lansing, Mich. . . .
.Service Radio Equipment Co Toledo, Ohio
Ship Owners Radio Service New York, N. Y !
Union College Schenectady. N. Y
University of Minnesota Minneapolis, Minn
University of Wisconsin Madison. Wis
W^arner Bros OaTtland. Calif
Wasmer, Louis .Seattle Wash
Westinghouse Electric & Mfg. Co Snringfield. Mass
Westinghouse Electric & Mfg. Co Chicago, 111
Westinghouse Electric & Mfg. Co Newark, N. J
Westinghouse Electric & Mfg. Co East Pittsburgh. Pa. . .
Western Radio Electric Co T,os Angeles, Calif. ...
Western Radio Co Kansas City, Mo
White & Boyer Washington, D. C
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Wave |
Call |
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lengths. |
Signal |
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360 |
KZM. |
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360 |
WGL |
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360 |
KZY. |
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360 |
WCR. |
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360 |
KJS. |
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360 |
WDM. |
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360 |
WBU. |
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360 |
WHK. |
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360 |
WLW. |
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360 |
WJX. |
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360, 4S.5 |
WWJ. |
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360 |
KQV. |
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360 |
WRK. |
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360 |
WHU. |
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360 |
KLB. |
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360 |
KGC. |
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360 |
KUO. |
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360 |
WGY. |
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360 |
WCJ. |
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360 |
KJQ. |
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360 |
WLK. |
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360 |
WOH. |
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360 |
KQW. |
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360 |
KVQ. |
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360 |
WGL. |
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360, 485 |
woe. |
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360 |
KLP. |
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360 |
KQL. |
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360 |
KJR. |
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360 |
KGB. |
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360, 4S.'; |
WSZ. |
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360, 4S5 |
wou. |
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360 |
KDN. |
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360 |
KYJ. |
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485 |
WOS. |
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360, 4S5 |
WGH. |
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360 |
WPB. |
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360 |
KFC. |
|
360, 4S5 |
WOZ. |
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360 |
WOK. |
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360 |
KGF. |
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360 |
KWG. |
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360, 485 |
WMH. |
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360 |
KFU. |
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360 |
WDW. |
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360 |
WDY. |
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360 |
K.I.T. |
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360 |
KYY. |
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360, 4S5 |
KIZ. |
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360, 485 |
WFO. |
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360, 485 |
WHO. |
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485 |
WHW. |
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360 |
W.IK. |
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360 |
WDT. |
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360 |
WRL. |
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360, 485 |
WLB. |
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360, 485 |
WHA. |
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360 |
KLS. |
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360 |
KHQ. |
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360 |
WBZ. |
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360 |
KYW. |
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360 |
W.IZ. |
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360 |
KDKA. ■ |
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360 |
KOG. |
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360, 485 |
WOQ. |
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360 |
W.IH. |
RADIO AGE— "THE MAGAZINE OF THE HOUR"
Boy Tells How To Make 'Em
By EDWIN NIELSEN
(16 years of age)
'PDWIN NIELSEN is a Chicago hoy -*-' zvho works for a big nezuspaper at night and makes receiving sets and ex- periments zvith them -when he gets a chance. His article is brief but if there are points needing more detailed explan- ation inquiries may be addressed to him in care of the Radio Age. Send self addressed and stamped envelope to Ed- zvin Nielsen, Care Radio Age, 1311 Gar- rick Building.
The Editor.
THERE are now about 80 radio sta- tions in the United States, that are sending out news reports, market re- ports, opera and musical concerts, EVERY DAY. All of this broad cast- ing may be received by ANYONE who wishes to listen to it. It can be received on outfits that are almost entirely home- made, and are so simple that they can be made by even the unskilled worker, though with a set of the kind I have in mind, the beginner must not expect to receive from any very great distances, as it will not receive messages from over 50 miles.
With receiving outfits at such a low price, there ought to be a set in every home, even if it be the simplest set that was ever devised.
A radio outfit is usually composed of an aerial system to catch the waves that are sent out by the sending station, a ground system to catch the waves that come from the ground through which they travel as well as through the air, a tuning system to allow the operator to listen to any single sending station so that he does not hear merely a jumble of sounds, a detector system which changes the radio waves to elec- tro-magnetic waves or waves which will act upon the magnets in the tele- phones and produce sounds, and in the new sets a condenser system to make the sounds clearer and louder.
A receiver that would work well es- pecially for the Radiophone concerts would be composed of: 1st, a tuning coil ; 2nd, a condenser, preferably of the Variable type ; 3rd, a crystal detec- tor ; 4th, a small fixed condenser ; and 5th, and last, a pair of receiving tele- phones.
The tuning coil is what is known as a two slide tuning coil and is made of a cardboard tube, wound with about 250 turns of No. 22 wire. The tube is then fastened to two square pieces ofr wood, which has two copper or brass rods, about one-fourth inch square, fast- ened to it. Two sliders are then made of brass bent to fit around the square rod and soldered at the place indicated in Figure 1.
TO GROUND
FIG. 4
TO AERIAL T HOW TO
, J CONNECT
THE INSTRUMENTS
VARIABLE CONDENSER^
TUNING COIL
DETECTOR.
CRYSTAL
TELEPH0NE5
FIG. 2
Figure 1 on follozving page
the rods, keeping contact with the wire, and enable the operator to tune in dif- ferent stations till the desired station is clearly heard.
In figure 1, "A," is the cardboard tube. "B" shows the round wooden discs which fit inside the tube and al- low the tube to be firmly fastened to the square blocks, "C" which holds the whole coil in an upright position so that it can be operated readily. "D" shows the method of making the slid- ers. In figure 2, the complete coil may be seen with both sliders shown, and all instruments in place.
The variable condenser can be made of a semi-circular piece of wood cut according to the directions in figure 3. There are good variable condensers
where from 3 to 65 plates. They wi improve any set, as about 60% of tl tuning is done by a variable condense A fixed condenser can be made of thrc sheets of tinfoil separated by mic sheets. The middle sheet of tinfoil mu protrude at one end of the mica ar must not come in contact with the oth( sheets of tinfoil. The whole condensi is held together with rubber bands ar wires are fastened to the protrudir edges of the tinfoil.
The detector can be made with tv binding posts, a piece of stiff wire, hai pin, or pin, and a piece of Galena cry tal. The binding posts are fastened a wood base about an inch and a ha apart, the crystal fastened to one them, the wire fastened to the otl
RADIO AGE— "THE MAGAZINE OF THE HOUR'
Boy Tells How To Make a Home Set
Continue d form page, fi v e
nd the point of the wii'e resting on the rystal. The instruments are then con-
I eeted as indicated in Fig. 2. The aerial can be of any one of the
I lany types! illustrated but a single ue of 14 gauge wire from 75 to 100 'et in length well insulated will work
|s good if not better than the others. ;y good insulation I mean that the
I 'ire must not touch anything except orcelain, glass, rubber or other sub- tance that will NOT conduct elec- ricity. Fig 4 shows a single wire
I erial with the insulators in place. The ,round wire must be fastened to a
I ^ater pipe or gas pipe, or any other ipe that goes beneath the surface of
I le ground.
The most important instruments now ieeded are the telephones, and as they
lannot be made, they must be bought nd as the best instruments are of little
I r no use unless the telephones are good,
would suggest that they be a good
air that you will not have to discard
I ven when you get an expensive outfit.
To operate the set after you have
verything connected you have to move
I lie sliders of the tuning coil till you et the station you Avish to hear, as )ud as you can get it, then the mov-
I ble part of the condenser is tui-ned ack and forth until the signals come
I learest.
If you do not get results, the crystal 'etector is the probable cause, and the 'ire must be made to touch the crys-
I'al in different places, in search of a ^nsitive spot where the signals can be eard. If this does not work the crys- il must be discarded and one that is lore sensitive purchased.
I
VARIABLE CONDENSER
CUT ON
DOTTED
LINES
FASTEN TINFOIL AND COVER WITH MICA
Y/IRE FASTENED TO STATIONARY PART
_KNOB AND ROD FASTENED TO MOVABLE PART
BASE
WIRE FASTENED TO M0VA3LE PART
SMALL FIXED CONDENSER
WIRES
TINFOIL
WIRES
BINDING POST
RODS
^BINDING POST
SMALL SREW5 FIXING TUBES TO DISCS B
LARGE SCREW FIXING DISCS TO BLOCKS -C
BINDING POST
END WIRE TO BINDING POST
WIRING
BEND STRIP ON DOTTED LINES
CUT ^RASS STRIP THIS SHAPE
THE HNISHED SLIDER.
SOLDER. UNDER EDGE
FIG.l
Radio on the Farm
MICA
Neither the telephone nor the auto- mobile made so great an advancement in the farmer's contact with the vil- lage and the city as the radiophone is doing. Farmer boys, quick to seize upon the radio receiving set as a scien- tific mystery that must be mastered, have brought the rural districts into close association Avith one another and with the life of the big cities. The re- sult is not onlj' entertaining but it is decidedly useful.
An eastern inventor says he will make a plow which can be directed by radio. Many of these dreams may come true but there are other developments in radio that engage the practical farmer in the practical present. For example, there is the plan of the Chi- cago Board of Trade to establish a radio system of crop and produce re- j>orts and market quotations which will be heard throiighout a radius of 500 miles from Chicago.
W. A. Wheeler, of the United States Department of Agriculture, says there is no single use of radio, except for ma- rine and aerial purposes, that should take precedence over its utilization for the benefit of agriculture.
"There are more than 32,000,000 farmers," said Mr. Wheeler, "nearly one-third of the population of the United States. Radio is the only means of getting to them quickly and at small cost. The time element in dispatching weather predictions to the farmer is a big factor. In cutting hay or harvest- ing grain an hour's delay in receiving a weather report may mean a loss of
solve the problem."
As in the city it is the boy who is leading the march toward the perfected radio age in the country. In Ocean Grove, N. J., a group of boys who were interested in radio, pooled their knowl- edge of the science and co-operated in a financial way to establish a radio receiving station, from which they send out telephone calls and messengers with the latest reports on weather, the mar- kets and the crop situation. This club, known as the Ocean County Radio Club, has become so popular that boys in other counties and other states are fol- lowing the Jersey example. This has attracted the active interest of many agricultural colleges.
The St. Louis University is broadcast- ing national and local agricultural re- ports. The United States Department of Agriculture broadcasts this service from stations at Cincinnati, Omaha, Washington, North Platte, Neb., Rock Springs, Wyo., Elko and Reno, Nevada. These are received by thousands of state bureaus, agricultural associations, banks and other interests which relay them to individual farmers.
The official weather prophet in Eng- land sends out warning of approaching thunderstorms by radio and a charge is made of six cents per message.
The Farm Bureau Federation of Chi- cago announces plans to complete its service of sending out by radio market figures, reports and activities of the American Farm Bureau, The United States Grain Growers, the Illinois Ag- ricultural Association and the National
EADIO AGE— "THE MAGAZINE OF THE HOUR"
How To Make A Radio Set For $6
A WIRELESS LESSON BY UNCLE SAM HIMSELF
HI
iifj OW can I make a radiophone re- J-J- ceiving outfit for a small price and listen in on the concerts, speeches; news reports, zveathcr forecasts, etc., that are broadcast each night from the sending stations nearest my home? I know very little about electricity but thousands of novices are making their own radio sets and I zvant to make one, too. I do not understand the long zvords used in most explanations. I zvant some- body to tell me in simple language, witJi clear diagrams, just hozv it can be done." One of the main objects in starting Radio Age is to answer in this first is- sue, and in all succeeding issues, the foregoing question — a question asked by hundreds of thousands of boys and their daddies.
Proof that the government is impressed zvith the necessity for helping radio begin- ners is supplied in the following article. So many boys and girls in radio clubs wanted the information that the States Relations Service of the U. S. Depart- ment of Agriculture asked the U. S. Bu- reau of Standards to prepare the article for beginners. If all points are not made clear send stamped envelope zvith request for explanation and Radio Age will give you the desired information.
The Editor.
THIS article tells how to construct the entire receiving station, includ- ing antenna as well as a crystal-de- tector receiving set. This station will enable one to hear the messages sent from medium-power transmitting sta- tions within an area about the size of a large city, and to hear high-power sta- tions within 50 miles, provided the waves used by those stations have wave frequencies between 500 and 1500 kilo- cycles per second (i. e., wave lengths between 600 and 200 meters). Much greater distances are often covered, es- pecially at night. If a person constructs the coil and other parts as indicated, the total cost of this set can be kept down to about $6.00. If, however, a specially efficient outfit is desired, the cost may be about $15.00.
Essential Parts
There are five essential parts : the an- tenna, lightning switch, ground con- nections, receiving set, and phone. The received signals come into the receiv- ing set through the antenna and ground connection. In the receiving set they are converted into an electric current which produces the sound in the "phone." The phone is either one or a pair of telephone receivers worn on the head of the listener.
The purpose of the lightning switch is to protect the receiving set from dam- age by lightning. It is used to connect the antenna directly to ground when
When the antenna and the connection to the ground are properly made and the lightning switch is closed, an antenna acts as a lightning rod and is a protec- tion rather than a source of danger to the building.
The principal part of the station is the "receiving set." In the set de- scribed herein it is subdivided into two parts, the "tuner" and the "de- tector," and in more complicated sets still other elements are added. Antenna
The antenna is simply a wire sus- pended between two elevated points. Wherever there are two buildings, or a
tenna should not be less than 30 feet above the ground and its length should be about 75 ft. (See Fig. 1.) While this figure indicates a horizontal anten- na, it is not important that it be strictly horizontal. It is in fact desir- able to have the far end as high as possible. The "lead-in" wire or drop- wire from the antenna itself should run as directly as possible to the light- ning switch. If the position of the adjoining buildings or trees is such thai the distance between them is greatei than about 85 ft., the antenna can still be held to a 75 ft. distance between the insulators by increasing the length
house and a tree, or two trees with one of them very close to the house, it re- lieves one of the need of erecting one or both antenna supports. The an-
of the piece of rope (D) to which th€ far end of the antenna is attached The rope (H) tieing the antenna in- sulator to the house should not be lengthened to overcome this difficulty because by so doing the antenna "lead- in" or drop-wire (J) would be length- ened.
Details of Parts. — The parts will bt mentioned here by reference to the letters appearing in Figs. 1 and 2.
A and I are screw eyes .sufficiently strong to anchor the antenna at the ends.
B and H are pieces of rope % or i/i inch in diameter, just long enough tc allow the antenna to swing clear of the two supports.
D is a piece of % or % iiich I'ope suf ficiently long to make the distance be tween E and G about 75 ft.
C is a single-block pulley which maj be used if readily available. Insulators
E and G are two insulators whicl may be constructed of any dry hare wood of sufficient strength to withstane the strain of the antenna ; blocks abou 11/2x2x10 in. will serve. The hole: should be drilled as shown in Fig. 1 suf Omilinii.e.d on vane 8, column 1
RADIO AGE— "THE MAGAZINE OF THE HOUR"
How to Make a Radio Set for $6
Continued from 2i(fff'' seven fieiently far from the ends to give proper strength. If wood is used the insulators should be boiled in paraffin for about 1 hour. If porcelain wiring cleats are available they may be substi- tuted instead of the Avood insulators. If any unglazed porcelain is used as in-
I'sulators, it should be boiled in para- ;fSn the same as the wood. Regular an- 'tenna insulators are advertised on the market, but the two improvised types
I oust mentioned will be satisfactory for an amateur receiving antenna.
P is the antenna about 75 ft. between 'the insulators E and G. The wire may 'be No. 14 or 16 copper wire either bare or insulated. The end of the antenna farthest from the receiving set may be secured to the insulator (E) by any satisfactory method, being careful not 'to kink the wire. Draw the other end
I 'of the antenna wire through the other insulator (G) to a point where the two 'insulators are separated by about 75 ft, twist the insulator (G) so as to form an anchor as shoAvn in Fig. 1. The remainder of the antenna wire (J) which now constitutes the "lead-in" or idrop-wire should be just long enough 'to reach the lightning sAvitch.
Lightning Switch
K is the lightning switch. For the purpose of a small antenna this SAvitch |may be the ordinary porcelain-base, 30 ampere, single-pole double-throAV bat-
I'tery SAvitch. These switches as ordi- narily available, have a porcelain base
|iabout 1 by 4 in. The "lead-in" Avire (J) is attached to this SAvitch at the middle point. The SAvitch blade should alAvays be thrown to the loAver clip Avhen the receiving set is not actually
..being used and to the upper clip Avhen it is desired to receive signals.
L is the ground wire for the light- ning SAvitch; it may be a piece of the same size wire as used in the antenna, Bof sufficient length to reach from the loAver clip of the lightning SAvitch (K) to the clamp on the ground rod (M). M is a piece of iron pipe or rod
I driven 3 to 6 ft. into the ground, pre- ferably Avhere the ground is moist, and
['extending a suificient distance above the ground in order that the ground
Lclamp may be fastened to it. Scrape
'I the rust or paint from the pipe before alriving in the ground.
N is a wire leading from the upper |Clip of the lightning sAvitch through the
[.porcelain tube (0) to the receiving set binding post marked "antenna."
0 is a porcelain tube of sufficient length to reach through the Avindow
['casing or wall. This tube should be
mounted in the casing or AA^all so that
it slopes doAvn toAvard the outside of
,the building. This is done to keep the
■ain from folloAAdng the tube through
|
1 |
M ,1 jl |
|
3 f |
^
I GROUND
® TUNflR
'i-turnto:achtap*
9 8 7 6
4 3 Z I
t 5 6
lb-tURN5' I TO EACH TAP
6^.996
SWITCH C0NTACT5
ANTENNA
GROUND
FIG. 5.
telephone: REJlElVtHS
Ground Wire
Fig. 2 shows the radio receiving set installed in some part of the house.
P is the receiving set Avhich is de- scribed in detail below.
N is the wire leading from the "an- tenna" binding post of the receiving set through the porcelain tube to the upper clip of the lightning SAvitch. This Avire, as Avell as the Avire shoAvn by Q, should be insulated and preferably flexible. A piece of ordinary lamp cord might be unbraided and serve for these tAvo leads.
Q is a piece of flexible Avire leading from the receiA'ing set binding post marked "ground" to a Avater pipe,
conductor to ground, except M, Fig. 1. If there are no Avater pipes nor radiators in the room in AA'hieh the receiving set is located, the Avire should be run out of doors and connected to a special "ground" below the Avindow, which shall not be the same as the "ground" for the lightning SAvitch. It is essential that for the best operation of the re- ceiving set this "ground" be of the very best type. If the soil near the house is dry it is necessary to drive one or more pipes or rods sufficiently deep to encounter moist earth and connect the ground Avire to the pipes or rods. This distance Avill ordinarily not exceed 6 ft. Where clay soil is encountered this distance may be reduced to 3 ft., Avhile
RADIO AGE— "THE MAGAZINE OF THE HOUR"
New Radio Trade Features
IT is expressing it conservatively to say that every day there is some new and interesting development in radio operation, i-adio utility or in radio invention. Some of the novel- ties are more interesting than impor- tant.
But others are beacon lights shoAving the way to perfection in radio uses that were unhoped for a comparatively short time ago. We present two radio de- vices which should interest not only the radio trade generally but the many thousands of individuals who are fol- lowing with amazement the progress of the sound-wave in its silent attack on a lot of our old ideas and customs.
With the ordinary receiving set you have several instruments scattered about a table with wires connecting the different parts. The designer of the Simplex Radiola, J. H. Newman, en- closes all these parts in a fine cabinet similar to a phonograph cabinet, a real piece of furniture. The set is com- plete for receiving any telephone or telegraph messages within a radius of 1000 miles of the sending station.
The features of this machine are : an auxiliary panel with switches for the batteries and horn, rheostat for reduc- ing the volume of sound and also in- creasing it, etc. Two drawers are pro- vided for writing materials, extra head- phones, books and any other materials used.
This machine has been operated in hotel lobbies and before audiences in theatres with tremendous success.
Secrecy in wireless communication may be obtained by the adoption of printing telegraph machines similar to those used on press and commercial telegraph circuits in many parts of the country. Experiments have been under way by the Morkrum Company for months with automatic wireless print- ers and the system has proved success- ful.
The printing machines use a tape in which a punching machanism, oper- ated by the keys of a typewriter key- board, perforates holes in various com- binations of five positions. This tape by means of an automatic transmitter and rotary switch, controls the grid circuit of a e. w. transmitting set and sends interrupted c. w. signals. At the receiving station, the Radio signals are
received in a sensitive receiving s and in place of the telephones, a sp cially designed relay is connected in the circuit. This relay in turn co \ trals a g:otary switch, which operat five magnets in the receiving paj printer and sets up the combinati( which corresponds to the one tran mitted from the perforated taj^e at tl transmitting station.
Secrecy is attained because code eoi binations can be varied at will and tl rotary switches at transmitting and r ceiving stations must also be synchro ized and the speed of these two switch can be varied.
Further information about the Rac ola and the Radiotype will be furnisht by Radio Age on request.
^0
RADIO AGE— "THE MAGAZINE OF THE HOUR"
Questions and Answers
Under this heading Radio Age zmll publish questions and anszvers each month. The anszvers zvill be zvritten by efHcient chnicians. Readers sliould litnit themselves to five questions in each letter. It is preferable that they shoidd zorite on one ide of the page only and use special care to make their name an d address readable.
W. B. encloses copy of hookup and asks (a) What is the approxunate wave length of my set? (b) Could you sug- gest any improvement which might improve this set? (c) Are values of grid leak and condenser coi-rect or would you suggest a change?
F. E. C. Elmwood — Kindly let me now what I would need and the con- ruction of a loud speaker (magnavox yle), suitable for a set equipped Avith loose coupler, A. P. detector and two age radiotron amplifier. Answer — It is not practical to make home-made magnavox receiver. A lud speaker may be made by coupling j' single sensitive receiver, such as the "aldwin or Browne, to a horn or to our phonograph. You can purchase ' coupling device that is made for the arpose.
E. K. encloses a standai'd hetrodyne ook-up that is coupled to the second- ry of an audion receiver and asks : ' 1. The size of each coil (five alto- gether) to receive P. 0. Z.
2. Is there any advantage in using
10 volts on the oscillator through a Iter?
3. Is an A. P. amplifier suitable for le oscillator and a W. E.-V. T. 1 as le detector?
Answer — 1. Use two 1,000-turn coils ,)r primary and secondary, with some nail coil of such as 25 turns to couple he hetrodyne. The hetrodyne may ave two 750-turn coils. You probably i^ould get better results using an Armstrong hook-up with the other bulb is a step of amplification.
2. There is no advantage. It might li'ork, however. The Navy tried this
tunt some time ago, but has discard- d it.
3. The tubes you mention are ex- sllent for the purpose. Use 45 volts V more for the plate.
' J. B. says: I am using one of the nail crystal sets that are so populax, nd I would like to know if there is ny simple way of increasing my over-
«11 efiiciency.
' Answer — The aerial and ground are
•lie logical place to start. See that
our antenna is kept far away from
i;in roofs, trees, chimneys or any ob-
^cts that may steal energy. Solder
I'll connections, increase your antenna
11 d lead-in insulation. Connect your L round lead to gas and water pipes, radiators and any other grounded ob-
5 sets about the station. Try out sev- eral different crystals. When you find , really sensitive detector you will !ave improved matters immensely. T. H. — I just moved from the country •here I had a 100-foot aerial which I sed in conjunction with a receiving Pistrumeut having two steps of ampli- cation. The owner of the house I now !ve in has refused me permission to rect any aerial. I tried a loop, but .'ith very little success. What can I ike the loop rccoT
Answer — ^A larger loop may help you. Failing, we suggest that you add another step to your detector and an- other to your amplifier. This will give you the desired results.
Q. X. — My aerial is 55 feet long and 30 feet high. Can this be improved upon ?
Answer — Yes. Run your aerial out to as near 100 feet as you can. The height is all right providing there is no immediate object which towers over or flanks it.
M. B. says : A friend of mine wants to hook in his set on my aerial. He lives in another house. Do you think that two sets operating from the same aerial will give good results to both of us? If not, can we run another aerial parallel to the one I am using without causing interference to each other?
Answer — Two sets cannot be oper- ated from the same aerial at the same time. If you refer to receiving set there will be no interferenc from either of the two parallel aerials. On the other hand, however, if you have transmit- ting set there is a merry time in store for. both of you, with all the interfer- ence on earth for both of you while try- ing to operate' at the same time es- pecially Hf one of you is trying to receive.
C. E. R. says: I have a loose coup- ler and audion detector, singing does not come in plain, however the an- nouncer's voice comes in plain. Is there any way in which I can make singing come in plain? (b) Can I make this outfit louder without using any ad- ditional apparatus? (c) My aerial is 75 feet long, 30 feet high at one end and 20 feet high at the other, would it improve conditions if I were to make it 100 feet long? (d) Does it Aveaken the B battery to have it connected? (c) Does it dim the signals Avhen there is a splice in the lead-in about two feet from instruments?
Answer (a) The only way we can answer this is to tell you that the an- nouncer is an exceptionally good, clear, distinct and forceful speaker at Station KYW. (b) The only way we could determine how you could do this is to examine your hookup, mail us a copy of your hookup, and we may be able to give you some help, (c) Yes, this would be an improvement, however, we would suggest that you raise your aerial a few more feet, (d) We would have to see your hookup before answer- ing this question, (e) If you have the connection soldered it Avill be perfectly
Answer (a) Your approximate wave length is 800 meters, (b) The only change we could suggest is, make your B battery variable, we think that you might possibly get better results using less voltage on your detector, (c) We think you are using the correct cap- acity for grid condenser, however, you should employ a variable grid leak, as different tubes and conditions require different values of leakage across the condenser, a variable condenser at this point would also be very desirable. However, you can determine the value required at this point, and then make a fixed condenser of the correct value, Vv'hich will be satisfactory.
B. J. : A receiving set could be made to fit in a cigar box. Wind the tuning coil on a block of wood instead of a cylinder. The other pieces do not take up much room.
P. S. : Lester Hart of Rockville Centre, L. I., is using a home-made vari- ometer regenerative receiver, and has copied practically all of the distant phones. The secret seems to be. that he is using one of the old audiotron tubes that are remai'kably sensitive. His B battery is made up of flashlight cells, which he claims work better than the usual block battery. One peculiarity in his circuit is that he uses no grid- leak. This works fine Avith some tubes. It must be remembered that grid-leaks Avere unknoAvn in the early days of the vacuum tube.
A. B. C. : Many people going into the radio game start Avith a small tun- ing coil and crystal detector, then even- tually someone Avill talk to them about building a big set. This immediately creates the impression that if they con- struct a tuning coil about five times as large that they will hear better. In this they are mistaken. The only thing this does is increase the Avave length of the instrument, and does not increase the loudness or efficiency of the set. Get just as much wire on the coil as is necessary and then stop.
R. L. asks: Could I receive KYW Avith a crystal detector and phones?
AnsAver — ^Yes, you could receive this
station with a crystal detector and
afisfactorv and will not decrease sig- phones; however, you should employ a
RADIO AGE— "THE MAGAZINE OP THE HOUR"
11
ROLAND ROGERS has ordered a radiophone for his enterprising store in Wapakoneta, 0. Butcher & Stein- metz have put in a receiving outfit in their store at Waynesfield, 0.
DR. REMSBERG, of Princeton, 111., entertained friends with a radiophone report of the Greb-Gibbons fight. Many Princeton residents have receiving sets.
THE BELL TELEPHONE Company is planning a radiophone* system with a station in each large city.
MUSIC PUBLISHERS are demand- ing a tax from all sending stations that broadcast their copyrighted music. What would the song-writers say if some of their songs were denied the ether waves? Impure air some day may have a double meaning.
AMATEURS, even the very groon
Pickups
readers who are interested may write Radio Age for further information.
CLEVER INVENTORS are trying to find a way to send and receive mes- sages that cannot be understood by others. This effort applies to telephony, not to wireless telegraphy. The plan is to distort the speech so that it will be unintelligible except at the receiv- ing end, which has a set adjusted to straighten out the distortions.
MINING OFFICIALS are consider- ing the radiophone as a means of avert- ing loss of life in mine accidents. They would equip the miner's cap with a miniature transmitter which could send alarm to a powerful receiving station at the mouth of the mine. The receiv- er would not only catch the signal but locate the i)()iiit of danger.
hear William Jennings Bryan, who was talking in Pittsburgh.
JOHN EDWARD SNYDER is install- ing a radio receiver in his ice-cream parlor in Peoria, 111.
CENTRAL HIGH SCHOOL in Rayi
<*Llsf'^l''
Herbert Parish, a sixteen year old youth of Milwaukee, fitted up a Radiophone set in an hour that can receive messages the same as a regular outfit except at extremely far distances. Herbert hopes some day to join the Sig- nal Corps and believes that he could make good use of his speed in the army. — International Photo.
;. ones will find the little book "Radio ij';!., Hook-ups" of great value and interest ':lll. in their making of receiving sets and in operating them. Another good book for amateurs is "Design Data for
THE CANADIAN GOVERNMENT i?. considering the permitting of ama- teurs to use ' continuous wave trans- mission up to 250 meters wave length.
JOE ATHERTON, at Macomb, 111.,
County, Illinois, is ten miles from a railroad or postoffice but has installed a radio set and is now right in the middle of the throbbing world. The students will receive and dissemir ' '
112
RADIO AGE— "THE MAGAZINE OF THE HOUR'
How to Make a Radio Set for $6
Continued from pacje S in sandy soil it may be increased to 10 ft. If some other metallic conductor, such as the casing of a drilled well, is not far away from the windoAv, it will be a satisfactory "ground."
Tuner, Detector and Phone
The detector and phone will have to be purchased. The tuner and certain accessories can be made at home.
Tuner (R, Fig. 3)— This is a piece of pardboard or other non-metallic tub- ing with turns of copper wire wound around it. The cardboard tubing may Jbe an oatmeal box. Its construction is described in detail below.
Crystal Detector (S, Fig. 3)— The construction of a crystal detector may ^e of very simple design and quite satis- iEactory. The crystal, as it is ordinarily purchased, may be unmounted or mounted in a little block of metal. For mechanical reasons the mounted type may be more satisfactory, but that is of no great consequence. It is very im- portant, however, that a very good tested crystal be used. It is probable also that a galena crystal will be more satisfactory to the beginner.
The crystal detector may be made up of a tested crystal, three wood |Screws, short piece of copper wire, a nail, set-screw type of binding post, and a wood knob or cork. The tested crystal is held in position on the wood base by three brass wood-screws as shown at 1, Fig. 3. A bare copper wire may be wrapped tightly around the 'ithree brass screws for contact. The assembling of the rest of the crystal detector is qitite clearly shown in Fig. 3.
Phone (T, Fig. 3) — It is desirable to luse a pair of telephone receivers con- nected by a head band, usually called a double telephone headset. The tele- phone receivers may be any of the standard commercial makes having a 'resistance of between 2000 and 3000 jOhms. The double telephone receiv- ers will cost more than all the other ■ parts of the station combined, but it is Idesirable to get them, especially if one (plans to improve his receiving set later. If one does not care to invest in a set of double telephone receivers, a single (telephone receiver with a head band I'may be used ; it gives results somewhat less satisfactory.
Accessories — Under the heading of ! accessory equipment may be listed bind- iing posts, switch arms, switch contacts, test buzzer, dry battery, and boards on which to mount the complete appa- ■iratus. The binding posts, switch arms and switch contacts may all be pur- chased from dealers who handle such 'goods or they may be quite readily im- Iprovised at home. There is nothing pe- culiar about the pieces of wood on
Cost of Parts
The following list shows the approxi- mate cost of the parts used in the con- struction of this radio receiving station. The total cost will depend largely on the kind of apparatus purchased and on the number of parts constructed at home.
Antenna —
Wire — Copper, bare or insu- lated, No. 14, 100 to 150 ft.,
about $ .75
Rope — % or v., inch. 2c per foot.
2 insulators, porcelain 20
1 pulley 15
Lightning switch — 30 ampere
battery switch 30
1 porcelain tube lo
Ground connections —
Wire (same kind as antenna wire.)
1 clamp 15
1 iron pipe or rod 25
Receiving set —
1/2 pound No. 24 copper wire double cotton covered 75
1 cardboard box.
2 switch knobs and blades complete 1.00
18 switch contacts and nuts.. .75
3 binding posts — set screw type 45
2 binding posts — any type... .30 1 crystal — tested 25
3 wood screws, brass, % in. long 03
Wood for panels (from pack- ing box.)
2 pounds paraffin 30
Lamp cord, 2 to 3c per ft.
Test buzzer 50
Dry battery 30
Telephone receivers 4.00 to $8.00*
Total $11.00 $15.00
If nothing but the antenna wire, lightning switch, porcelain tube, crys- tal, telephone receiver, bolts and buz- zer are purchased this total can be re- duced to about $6.00.
♦still more efficient and expensive telephone receivers are available at prices ranging to about $20.00.
may be obtained from a dry packing- box and covered with paraffin to keep out moisture.
Details of Construction
The following is a detailed descrip- tion of the method of winding the coil, construction of the wood panels, and mounting and wiring the apparatus :
Tuner — See R, Fig. 3. Having sup- plied oneself with a piece of cardboard tubing 4 in. in diameter and about % pound of No. 24 (or No. 26) double cotton covered copper wire, one is ready to start the winding of the tuner. Puncii two holes in the tube about 1/2 in. from one end as shown at 2 on Fig. 3. Weave the wire through these holes in such a way that the end of the wire Avill be quite firmly anchored, leaving about 12 inches of the wire free for connections. Start with the remainder of the wire to wrap the several turns in a single layer about the tube, tightly and closely to- gether. After 10 complete turns have been wound on the tube hold those turns snugly Avhile a tap is being taken off. This tap is made by making a 6 in. loop of the Avire and twisting it together at such a place that it will be slightly stag- gered from the first tap. This method of taking off taps is shown quite clearly at U, Fig. 3. Proceed in this manner until 7 twisted taps have been taken off
turns have been wound on the tube then take off a 6 in. twisted tap for every succeeding single turn until 10 addition- al turns have been wound on the tube. After winding the last turn of wire anchor the end by weaving it through two holes punched in the tube much as was done at the start, leaving about 12 in. of wire free for connecting. It is to be understood that each of the 18 taps is slightly staggered from the one just above, so that the several taps will not be bunched along one line on the cardboard tube. See Fig. 3. It would be advisable, after Avinding the tuner as just described, to dip the tuner in hot paraffin. This Avill help to exclude moisture.
Panel and Base
Having completed the tuner to this point, set it aside and construct the up- right panel shown in Fig. 4. This panel may be a piece of wood approximately 1/2 in- thick. The position of the sever- al holes for the binding posts, switch arms and switch contacts may first be laid out and drilled. The "antenna" and "ground" binding posts may be or- dinary % in. brass bolts of sufficient length and supplied with three nuts and two washers. The first nut binds the bolt to the panel, the second nut holds one of the short pieces of stiff wire, while the third nut holds the antenna or ground wire as the case may be. The switch arm with knob shown at V, Fig. 3, may be purchased in the assembled form or it may be constructed from a thin slice cut from a broom handle and a bolt of sufficient length equipped with four nuts and two washers together with a narrow strip of thin brass some- what as shown. The switch 'contacts
$50 Prizes for Boys
Radio Age will pay prizes as follows for the best original articles (with drawings) from boys of 18 years and under, on
How toriVlake Home Radio Receiving Sets;
First Prize - $20.00
Second Prize 15.00
Third Prize - 10.00
Fourth Prize 5.00
Articles must be clearly illustrated and must be not longer than 2000 words, or shorter than 1000.
Another special prize of $10 will be award- ed to the boy of 18 or under who writes and illustrates (with rough sketches) the best original article of about 500 words on how to make the best variable and the best fixed condenser at home.
Winners will be announced in
Radio Age— July Number.
RADIO AGE— "THE MAGAZINE OF THE HOUR"
13
(W, Fig. 3) may be of the regular type furnished for this purpose or they may be brass bolts equipped with one nut and one washer each or they may even be nails driven through the panel with an individual tap fastened under the head or soldered to the projection of the nail through the panel. The switch contacts should be just close enough that the switch arm will not drop be- tween the contacts, but also far enough apart that the switch arm can be set so as to touch only one contact at a time. The telephone binding post should preferably be of the set screw type as shown at X, Fig. 3.
Instructions for Wiwng'
Having constructed the several parts just mentioned and mounted them on the wood base, one is ready to connect the several taps to the sAvitch contacts and attach the other necessary wires. Scrape the cotton insulation from the loop ends of the sixteen twisted taps as well as from the ends of the two single taps coming from the first and last turns. Fasten the bare ends of these wires to the proper switch con- tacts as shown by the corresponding numbers in Fig. 3. One should be care- ful not to cut or break any of the looped taps. It would be preferable to fasten the connecting wires to the SAvitch con- tacts by binding them back of the bind- ing post marked "ground" (Fig. 3) to the back of the left-hand switch-arm bolt (Y), thence to underneath the left- hand binding post marked "phones." A wire is then run from underneath the right-hand binding post marked "phones" to underneath the binding post (4, Fig. 8), which forms a part of the crystal detector. A piece of No. 24 bare copper wire about 2i/2 iii- long) one end of which is twisted tightly around the nail (the nail passing through binding post 4), the other end of which rests gently by its own weight on the crystal (1). The bare copper wire which was wrapped tightly around the three brass wood-screws holding the crystal in place is lead to and fas- tened at the rear of the right-hand switch arm bolt fv), thence to the up- per left-hand binding post marked "an- tenna." As much as possible of this wiring is shown in Fig. 3.
Directions for Operating
After all the parts of this crystal-de- tector radio receiving set have been con- structed and assembled the first essen- tial operation is to adjust the little piece of wire, which rests lightly on the crys- tal, to a sensitive point. This may be accomplished in several different ways; the use of a miniature buzzer trans- mitter is very satisfactory. Assuming that the most sensitive point on the crystal has been found by method de- scribed in paragraph below, "the Test Buzzer," the rest of the operation is to get the radio receiving set in resonance )r in tune with the station from which
one wishes to hear messages. The tun- ing of the receiving set is attained by adjusting the inductance of the tuner. That is, one or both of the switch arms are rotated until the proper number of turns of wire of the tuner are made a part of the metallic circuit between the antenna and ground, so that together Avith the capacity of the antenna the re- ceiving circuit is in resonance Avith the particular transmitting station. It will be remembered that there are 10 turns of wire between each of the first 8 switch contacts and only one turn of wire betAveen each 2 of the other con- tacts. The tuning of the receiving set is best accomplished by setting the I'ight-hand switch arm on contact (1) and rotating the left-hand SAvitch arm over all its contacts. If the desired signals are not heard, move the right- hand switch arm to contact (2) and again rotate the left-hand switch arm throughout its range. Proceed in this manner until the desired signals are heard.
It Avill be advantageous for the one using this radio receiving equipment to find out the wave frequencies (Avave length) used by the several radio trans- mitting stations in his immediate vi- cinity.
The Test Buzzer (Z, Fig. 3)— As mentioned previously, it is easy to find the more sensitive spots on the crystal by using a test buzzer. The test buzzer is used as a miniature local transmitting set. "When connected to the receiving set as shoAvn at Z, Fig. 3, the current produced by the buzzer Avill be eon- verted into sound by the telephone re- ceivers and the crystal, the loudness of the sound depending on Avhat part of the crystal is in contact Avith the fine Avire. To find the most sensitive spot connect the test buzzer to the receiving set as directed, close the sAvitch (5, Fig. 3) (and if necessary adjust the buzzer armature so that a clear note is emitted m7.7.e.r). set the right-hand
switch arm on contact point No. 8, fas- ten the telephone receivers to the bind ing posts marked "phones," loosen the set screw of the binding post slightl;y and change the position of the fine wire (6, Fig. 3) to several positions of con tact with the crystal unit until tlu loudest sound is heard in the phones then tighten the binding post set screA\ (4) slightly.
WILLIAM TERRELL, a Peoria man Avas suspected of stealing a radio out- fit. A wireless telephone message broadcast from the Bi^adley station des cribed the instrument. An amateui operator in Peoria promptly reported Ihat Terrell had tried to sell him sucl an instrument. Terrell faces the grand jury now. Pretty slick thief who car hide from those wireless waves !
Great Radio Shows
Continiied from jxtye ilirec Delegations from many of the neigh boring states have made reserva tions. A party of at least 30 dealer; went from Detroit alone. The smallei cities and rural districts Avithin easj receiving distance of the local broad casting stations are among the mos enthusiastic centers. All roads in the radio field lead toward Pittsburgh dur ing the week.
The American Radio Exhibitors' as soeiation conducting the shoAv has com- piled information concerning the in- dustry AAdiieh is available to all the dealers, distributors and manufactur ers. Special shipments of complete sets and supplies have been made by sev- eral of the manufacturers. This nui terial is available for the public at the exhibition, says the Pittsburgh Press. Competent engineers are on hand at the information booth to ansAver nn; questions concerning radio Avhich li
14
RADIO AGE— "THE MAGAZINE OF THE HOUR'
B
H
I
J
O
R
V
W
X
Learn the Code
Before one starts receiving, he should
master the language of the air. This
lis not the sound that is broadcast —
but the dot and dash signals of the
International Morse Code.
Don't throw up your hands in de- spair. It is not hard to learn. Once mastered, you Avill be able to get the full pleasure of "listening in" — you Avill get the secrets that are flying about all the time.
A little prac- tice each day and you will be fascinated by decoding these mysterious dots and dashes.
Cut out this chart. Mount it on cardboard for ready ref- erence.
The code may
be learned by
visualiza t i o n .
But it is much
easier to learn
it by sound. A
tapping of a
.pencil will do.
The best way,
however, is to
,rig up a little
' buzzer and hear
the real thing. ^
Get a high ' ■■i«"»«« i
pitched buzzer,
an ordinary telegraph key and a com- mon dry battery. They can be pur- chased in any supply store at a small cost.
Mount tlie key on a table or desk, allowing plenty of room for the fore- arm. Connect the battery and buzzer according to the diagram.
When your hand is set have your wrist clear and your thumb resting lightly against the knob of the key. The index and third fingers should be on top and the other two fingers should be curved back into the hand.
The wrist should do the sending — the thumb and fingers acting merely as a guide for the wrist.
The spring in the key should be screwed down just enough to force the key up after each wrist action.
Dubuque (la.) Times.
WIRELESS CODE
Boy Scouts
Boy Scouts are sure to become an important factor in radio. It was a boy scout at the recent radio confer- ence in Washington who arose and made an eloquent appeal for a closer union between the various government departments and broadcasting stations so that the boys in all communities might learn more of Avhat is going on in the United States. He even suggest- ed that the boys be permitted to listen in on the de- in Con-
THE MORSE ALPHABET
bates gress.
D
K
6
NUMERALS
3
■ ■■■IB
8
4 • ■mi
&
5
PUNCTUATION MARKS, ETC,
Interrogation
9
Period
Unless that scout has heard G some of our
' "■■■ long- winded statesmen wind- M N jamming in the ■^ *■ Senate or the House, he has U little idea of
■ ■B Avhat he is let-
ting himself and other boys i n for. But each new rev- elation might help him to cast an intelligent vote later on.
Boy Scouts are organizing their radio members so 'I'^i .■■■■™^ that they will
be of assistance to the government in emergency. A better, more promiseful spirit could not be manifested by the little fellows who are to be the future masters of the magic science.
INABILITY TO GET PHONES for radiophone receivers is delaying the in- stallation of many amateur plants in Peoria, 111.
Comma
Soldering
Any person installing a radio set should know how to solder and do it right. A book might be written on the subject but only a few points will be given here.
1. Be sure the wires of the parts to be soldered are absolutely clean. File, scrape or sandpaper them^ until they are bright.
2. Use a good soldering flux. Get a can of good soldering paste and learn how to apply it. Use as little as possible and when the joint is com- pleted carefully wipe off all surplus paste which acts as a conductor and may short circuit the wires. Never, under any circumstances, use muriatic or hydrochloric acid cut with zinc. Electrolysis takes place and produces a corroded joint.
3. Always remember that the parts must be as hot as the melted solder be- fore a good joint can be produced. Never let the soldering iron get red hot. A green flame around the iron indicates that the copper is burning and should be removed from the fire.
4. To "tin" the "iron" heat on a gas stove until the green flames just begin to show, take otf the "iron" and file until the copper shows brightly. Dip the tip in a little paste and imme- diately rub on a bar of solder. This Avill leave the tip of the "ii'on" cov- ered with solder and bits of solder may be picked up and deposited wherever desired. If the ' ' iron ' ' is not ' ' tinned ' ' solder will not stick and it is next to impossible to solder joints.
— Orval Whishman in Rockford Star.
Become a Wireless Operator
A splendid opportunity to study wiih Chicago Schoo Teachers on Saturday afternoons. A practical man who had charge of a station in France, now with Western Electric, will assist in the work.
ILLINOIS RADIO SCHOOL,
Room 925, 64 W. Randolph St.. Phone Dearborn 5465 JOHN T. NUTTALL, Principal
1^ B. F. ELBERT, manager of a Des piMoines, la., theater, will have music by wireless as a substitute for an orches- tra.
ALBERT E. PROFFITT, of Provi- dence, R. I., has discovered a means of listening in on telephone conversa- tions with his radio outfit. He declines to tell how he does it. The secret lies ing of his amplifier .
iuii
ampi
MAIL THIS COUPON TO US TODAY,
RADIO AGE, 1311 Garrick Building, Chicago, 111.
Enter my subscription to Radio Age for six months, for which I enclose $1.25. (If for one year mark X here LJ and enclose $2 50.)
Currency and stamps or personal checks will be satisfactory.
Name
Address.
RADIO AGE— "THE MAGAZINE OF THE HOUR'
Radio in School
Thousands of boys are studying prac- tical radio in the public schools. The number of boys devoting their major time to this work is particularly large in the Chicago Technical High Schools. In many schools, in addition to the regular courses in electrical study the boys have radio clubs. Lane, Tilden and Crane, the three larger "tech" schools have Qlubs and interest in them and in radio is increasing daily.
The president of the Peoria School Board has said that radio will be placed on the list of studies "as soon as it be- comes practical" and any number of boys in Peoria reply that it is practical already. They Avant radio classes now. The radio club of Waukegan High School has seventeen members and some of them have sets with which they can hear music broadcast from Chicago.
Athletic events in which rival high schools are engaged are so closely fol- lowed by stay-at-home students that the radio has been brought into action to carry play by play the progress of the struggles. This plan recently was adopted with success by Rockford, 111., high school during a contest with Ur- bana, at Urbana.
Radio interest is by no means limited to the technical and other high schools. 'Varsity men are just the same sort of fans as their younger brothers. As a matter of fact all men are boys when it comes to playing with ether waves and listening to the invisible choir. Michigan University announces a Radio night for April 29. Fielding H. Yost, athletic director at Ann Arbor, plans to make it a wireless reunion of alum- ni. Faculty members, glee club singers and athletic stars will participate in the program and it will be broadcast.
News will be broadcast once a week from the University of Wisconsin sta- tion at Madison. The wave length is 360 meters. The news digest will be sent each Friday night at the close of the weekly radiophone concert.
"Wisconsin students carry on a news exchange between the newspapers of other colleges in Wisconsin and in other states from 10 to 12, midnight, every Monday.
Bradley Station, Peoria, 111., is im- proving the apparatus of the Bradley Institute. The present sending wave length is 200 meters but it will be in- creased to a possible 450 meters with the new equipment.
Union College, Schenectady, N. Y., has resumed its broadcast service. The station will broadcast under its newly assigned call letters WRL but the club retains its old license 2XQ for pur- poses other than broadcasting.
It is reported in the press that New York University will permit students to stay at home and get their lectures via the radiophone. Maybe so, maybe so, but let us not get too close to the
Get This Radio Receiver
= FREE —
THIS OUTFIT, capable of helping you hear music, sermons, news reports, speeches from 15 to 50 miles from sending stations will be given away to any Radio Age reader who sends in six new subscribers, accompanying the written subscriptions with Currency or Money Order for the total amount of subscriptions.
m-
*4il
' ' '^-j!:* '
Men, studying the magic science of Radio, will be interested in our new and different Radio magazine as are the boys. Speed up your subscription campaign before this ofTer closes on May 15.
RADIO AGE
The Magazine of The Hour
1311 Garrick Building
CHICAGO, ILLINOIS
liAinO AGE— "THE MAGAZINE OF THE HOUR"
lanaiii
ANNOUNCING
THE ANNUAL
JNational ivaclio Exposition
TO BE HELD IN THE
LEITER BUILDING
IN THE HEART OF THE LOOP SHOPPING DISTRICT
CHICAGO, JUNE 26th to JULY 1st
INCLUSIVE
THE MOST COMPREHENSIVE
EXHIBIT of every type of Wireless Apparatus ever shown
SUCH RAPID STRIDES HAVE BEEN MADE IN THE PERFECTION of WIRELESS DEVICES THAT EVERY EXHIBIT IN THE BIG EXPOSITION BUILDING WILL DISPLAY SOMETHING NEW AND INTERESTING TO THE RADIO FANS.
For Further Particulars Address ^
National Radio Exposition |
I 4 1 7 South Dearborn Street : : : CHICAGO, ILLINOIS |
'■■■ ■"" ' ' I"
WIZARD
The Compact Radiophone
ST-SS
7
Sent Parcel Post
Prepaid Anywhere.
$^.95
7
Smallest
and Least Expensive
on the
Market.
Measures 5" x 4" x 6"
Concerts - Sermons - Lectures - News
TO YOUR HOME
So Compact and Simple is the Wizard no Mechanical Knowledge is Required to Operate.
FULL INSTRUCTIONS WITH EVERY SET.
Every Set is Tested and Guaranteed. Will be Sent Prepaid Parcel Post on Receipt of Money Order for $7.95. Fill Out Coupon and Delivery will be Made Within 7 Days.
|
OBEY THAT IMPULSE- |
WIZARD RADIO CO.. 64 West Randolph Street, Chicago, 111. Please send to me at once. Parcel Post Prepaid, one Wizard Radiophone. Enclosed find $7.95. Name |
|
DO IT NOW ! |
Address City State |
We are Specialists in Crystal Receiving Sets. We do not sell parts. Phones, wire and other
parts are readily procurable in your neighborhood. The Wizard Radiophone is strongly constructed of Hard Wood with genuine Bakelite panel.
All Metal Parts are Nickel Plated.
If you are within 15 miles of a broadcasting station you should have a Wizard. Guaranteed to be mechanically perfect and fully tested. Money Back if not as fully represented.
Radio in The Home
PRICES ARE THE LOWEST
OPEN SATURDAYS ALL DAY
Enjoyed With Our Quality Apparatus
Westinghouse Radio Receiver
Aeriola Sr. complete with tube and phones $65.00
G. E. 753 Crystals Receiver with phones 18.00
G. E. 1300 Receiver 175-170 meter 50.00
G. E. 1400 Detector (2) step amplifier 75.00
281 Kennedy Receiver 80.00
521 (2) step Amplifier 55.00
CR5 Grebe Receiver 80.00
RORK (2) step Amplifier 55.00
RA Westinghouse Receiver 68.00
DA Westinghouse Detector amplifier 70.00
Bowman Aeriophone with phones 25.00
Radio Apparatus
No. 1 Kellogg socket $0.75
Howard Rheostat 1.10
Howard Socket 1.10
Bradley Carbon pile 1.85
Rheostat
2111 Bradley Stat for primary of filament
transformer 6.50
No. 15 phone plug 1.75
2620 Amplifying transformer 6.00
A. A. R. 3 transformer mtd 4.50
A. A. R. 2 transformer mtd 4.25
2607 Variometer Amrod 6.10
2614 Vario Coupler Amrod 6.90
1423 Tacks 1.00
1435 Jacks 1.20
1438 Jacks 1.50
Radio Phones
Stanley and Patterson 2000 ohms $ 8.59
Kellogg 2400 ohms 10.25
W. E. No. 1002 to 2200 ohms 15.00
F. R. 051 No. 162 2000 ohms 5.00
Brandes superior 2000 ohms 8.00
Brandes navy 3200 ohms 14.00
"Weston Meters
Filament Volt Meter
0- 8 D C Volt 8.00
0-10 D C Volt 8.00
Filament Ammeter
0-1.5 D C Ampere 8.00
0-3 D C Ampere 8.00
0-5 D C Ampere 8.00
0-10 D C Ampere 8.00
Plate Volt Meter
0- 50 D C Volt 8.00
0-100 D C Volt 13.00
Other Meters on Application
Westinghouse Type RC
We fill mail orders promptly and accurately.
Stanley and Patterson Loud Speakers
No. 833 Standard Silvertone loud speaker $35.00
No. 834 Junior De Veau Silvertone 25.00
No. 835 Midget De Veau loud speaker 15.00
No. 835 Station type loud speaker 25.00
If you are in any doubt about anything regarding wireless, drop in and consult our experts. They are always willing to give you as much informa- tion as possible.
Even though you haven't any requests, come in and see our great display and ask all the questions you wish regarding this wonderful and economic means of enjoyment.
E COMMONWEALTH EDISON O LECTRIC SHOPiJ
72 WEST ADAMS STREET, CHICAGO
v^v^vgvl;vfVj^^vr^.r^JV^>^5^vSVS^JVjv^>^^^J^^f^J^^vJ^^J^
JUNE, 1922
25c A COPY
IN THIS NUMBER
Read Pearne's Articles on the Simplified Home Radio
Professor Frank D. Pearne tells beginners each month about construction and operation. Prof. Pearne is chief instructor in electricity at Lane Technical High School, Chicago. Exclusive in Radio Age.
Government Radio Control
New Rules for All Radio Fans
First complete publication of final official conference report on sending and receiving. This radio article vitally important. It's your working handbook.
Questions and Answers Illustrated by an Expert
Here is a magazine whose technical editor, Frank D. Pearne, knows how to get radio instruction over in simplest terms.
GOOD MAGAZINE FOR EVERYBODY BETTER ON EACH APPEARANCE
BEST ALWAYS FOR BEGINNERS
Don't Say Radio Magazine— Say RADIO AGE
It Is the Magazine of the Hour
M
Acknowledgment
To—
Newsdealers, who are re- porting phenomenal sales of Radio Age;
Subscribers, whose names already are in our card files — hundreds of names with more in each mail;
Advertisers, who have let us broadcast their busi- ness messages to many thousands who were waiting for those messages.
From —
The Pubhsher, who has faith in the Rotarian slogan: "He Profits Most Who Serves Best."
RADIO AGE
The Magazine of the Hour
Volume I
Number 2
CONTENTS FOR JUNE, 1922
PAGE
Frontispiece — Portrait of Dr. S. W. Stratton 2
How the Government Will Control Radio 3
By Frederick Smith
Shows Introducing Radio to American Throngs 5-6
How to Make a Receiving Transformer 7
By Frank D. Pearne
Navy's Radio Shatters Distance 9
High School Wins Radio Fame 11
By Edward L. Taylor
"Aerials" Under Ground and Under Water 13
Electric Light Wire as Auxiliaries to Radio 13
New Stuff by Our Boy Readers 14
In Radio Shops and Factories 15
Thought Waves from the Editorial Tower 17-18
The Radio Club of Illinois 19
By Barratt O'Hara
Questions and Answers 20
Conducted and Illustrated by Frank D. Pearne Radio News from Coast to Coast 23-24
Radio Age is published monthly by The M. B. Smith Publishing Co., Garrick Building, Chicago, III.
Frederick Smith, Editor
Frank D. Pearne, Technical Editor
M. B. Smith, Publisher and Business Manager
Advertising Managers: YOUNG & WARD
308 North Michigan Avenue, Chicago, 111.
Eastern Representative:
GEO. W. STEARNS
Flatiron Building, New York City, N. Y.
Advertising Forms Close on 5th of the Month Preceding Date of Issue.
Issued monthly. Vol. I, No. 2. Publication Office: Garrick Building, 64 West Randolph Street, Chicago. Subscription price $2.50 a year. Entry as second- class matter applied for at the postoffice at Chicago, 111., under the Act of March 3, 1879.
Registration of Title Applied for in U. S. Patent Office. Copyright, 1922, Republication of Original Matter Prohibited
What is in Store for Radio Age Readers
The acquisition of Frank D. Pearne as Technical Editor on the staff of RADIO AGE insures ati- thoritative interesting material for our magazine. Mr. Pearne is chief instructor in electricity at Lane Technical High School and knows how to discuss radio technique with beginners.
Mr. Pearne will not only write and illustrate a helpful article each month but he will conduct the questions and answers, always a popular fea- ture in publications dealing with wireless.
There are to be three big radio shows in Chicago and several others in the "Chicago Territory" before August and some of these will be at- tended by important conferences at which radio history will be made.
It is the privilege of the editor to be associated in an advisory capacity with three of these approaching ex- positions and our readers may be sure of getting complete informa- tion of them.
Thfs number contains the com- plete report in the recent Depart- ment of Commerce conference on radio regulation. The report is vo- luminous but we are so sure of the interest in this subject, among big manufacturers as well as among dealers, expert operators and ama- teurs, that we have arranged for other comprehensive articles of a similar nature.
In the July number we are to have a most interesting story by a man who made his own receiving set for $3.85 and went on from there until he — but read his own story.
Nothing would please the editor more than to receive letters from our readers. Criticism in invited. News forwarded to us will be used where practicable and unused manuscripts will be returned if stamped and ad- dressed envelopes are supplied.
RADIO AGE— "THE MAGAZINE OF THE HOUR"
Who's Who m Radio
Dr. Samuel W. Stratton, Chief of the Government Bureau of Standards, was chairman of the Department of Commerce conference called by Secretary Hoover to recommend laws governing radio communication. Dr. Stratton formerly was professor of physics at the University of Chicago and has been director of the Bureau of Standards for more than twenty years. He is an Illinois man.
imi II iiiM i I [ u [ I L II I I III I m fi I I I I I II I I I I I I II I II I \ 111 I I I I I \ I II I I I I I I H n I I I II II I II I I I I I I [ I I I I I [ I I I II I I mill llll ll'i i m nii
iiiiiliilili^iiiiijli
RADIO JIGE
Tfie Ma^a^ine of Ifte Hour
PUBLISHED MONTiiLY GARRICK. BLX)'q CHQO.
FREDERICK :-;^m
EDITOR
III mil II II I 1 1 I I I I I I I I I I I I 1 I I I 1 I I I mi u I II I I II I II I I I I I I 1 II I 1 1 1 1 II I I II 1 1 I I I I 1 1 1 II I II I II 1 1 1 1 I 1 1 1 M M I I I I 1 I I I I 1 I 1 1 1 I I I I I M I iir
How the Government Will Control Radio
AT LAST the radio wise men of the United States have agreed L.upon a definite comprehensive plan whereby users of radio tele- phones and the radio telegraph may know how, where and when they may use the magic electro magnetic waves as a means of communication.
Just before going to press we are in receipt of the complete official text of the report made by the Department ofCommerceconferenceon radio tele- phony, which adjourned its second session on April 19. The report is published in full in this number be- cause it is the most important docu- ment of the day, interesting alike the small boy with his home-made receiving outfit and the million dollar corporation with its powerful trans- mitting station.
A mere glance at the report will convince the public that the confer- ence had a giant task to perform. Since the installation of broadcasting stations started several years ago the number of stations has increased to such an extent that chaotic confusion has resulted. Government broad- casting, public broadcasting, private broadcasting and toll broadcasting have overlapped and clashed until it seemed that it was impossible to straighten out the tangle.
Marine radio service was sadly hindered by operators outside the government service along the coasts. Public and private broadcasts de- stroyed the value on one another un- til the radio telephone listener was frantic over repeated disappointment. Probably most important of all was the status of the amateur who was trying to advance his knowledge of the science by practicing it and thus make himself a valuable unit in the vast system of radio telephony which is soon to be one of our most import- ant national assets. His broadcast- ing very often jammed up the music, speeches, baseball scores, weather
By FREDERICK SMITH
predictions and market information that thousands of persons were try- ing to pick up with their receivers. But the amateur had to be taken care of, nevertheless. Under the new reg-
Radio has caught the boys in England, too. The boys at an elementary school at Haslemere, England, have trans- formed this old windmill into an aerial tower. Kadel & Herbert Photo
ulations he will have his place in the ether.
The recommendations made by the Washington conference will be made 3
the basis for congressional legisla- tion. The bill being drafted by Rep- resentative Wallace H. White, Jr., of Maine, will put the recommendations into the form of a law and this will be the first adequate legislation on the subject in the last decade.
Radio laws will be so amended as to give the Secretary of Commerce (Mr. Hoover) authority to control the establishment of all radio trans- mitting stations except amateur, ex- perimental and government stations. He also will be authorized to control the OPERATION of non-govern- mental radio transmitting stations. How this federal control is to be es- tablished is explained in part in the following conference recommenda- tion, one of the most interesting in the report:
It is recommended that for the purposes of self-policing among the amateurs. Amateur Deputy Radio Inspectors be created, elected from their number of the amateurs of each locality ; that upon receipt of notice of such election the Radio Inspector in charge of the district in which such amateurs are located shall appoint the person chosen a Deputy Radio Inspector, serv- ing without compensation or for the sum of one dollar per year if compensation is legally requir- ed; that the duty of such Ama- teur Deputy Inspector shall be to endeavor to the best of his ability to accomplish, under the direction of the District Radio Inspector, observance of the Radio Communication Laws and the Regulations of the United States and the observance of such local co-operative measures as are agreed to in each commun- ity for the minimization of inter- ference between the various groups of the public interested in radio ; that such amateur Deputy
RADIO AGE— "THE MAGAZINE OF THE HOUR"
Radio Inspectors be clothed with whatever authority may be nec- essary in the opinion of the Dis- trict Radio Inspector.
That means the young trafific cop of the air will be listening in for those reckless and inconsiderate despoil- ers of the air and will report them to headquarters. The transmitting sta- tion will be extremely careful not to commit any evils which may lead to the revocation of its precious sending license.
Direct advertising is explicitly pro- hibited in the recommendations of the conference. Radio is termed a public utility in which the mass of the people is most vitally interested and it is the aim of the proposed leg- islation to gain the most good for the greatest number.
For this reason the conference re- solved "that the types of radio ap- paratus most effective in reducing in- terference should be made freely available to the public without re- striction."
The conference adjourned its first session on March 2 to give the radio public opportunity to discuss and criticise the plans for regulation. The report as finally adopted and here published in full is therefore the con- sensus of that tremendous army of radio enthusiasts which is gaining recruits to the number of many thou- sands each month.
The complete conference report follows :
DEPARTMENT OF COMMERCE Washington
This conference was called by Secre- tary Hoover to consider general questions concerning the regulation of radio com- munication.
The following were invited to serve as members of the Conference, the repre- sentatives of the Government departments being selected by their several depart- ments:
Dr. S. W. Stratton, Chairman (Director of Bureau of Standards).
Mr. Edwin H. Armstrong, Columbia University, New York, N. Y.
Capt. Samuel W. Bryant, U. S. N., Navy Department.
Mr. D. B. Carson, Commissioner of Navigation, Department of Commerce.
Mr. J. C. Edgerton, Supt., Radio Service, Post Office Department.
Dr. Alfred N. Goldsmith, Secretary, In- stitute of Radio Engineers, New York, N. Y.
Mr. R. B. Howell, Metropolitan Utili- ties District, Omaha, Nebr.
Prof. C. M. Jansky, Jr., University of Minnesota.
Senator Frank B. Kellogg of Minne- sota.
Mr. Hiram Percy Maxim, President, American Radio Relay League, Hartford, Conn.
Major General George O. Squier, War Department.
Representative Wallace H. White, Jr., of Maine.
Mr. W. A. Wheeler, Bureau of Markets
Final Allocation of Wave Lengths
We
(1)
(2)
O)
(4) (5) (6) (7) (8) (9) (10)
(M) (12) (13) (14) (15) (16) (17) (18) (19) (20)
(21) (22)
Wave Length
Use Meters
Transoceanic radio telephone experiments, 6,000
non-exclusive. (See Note 3) 5,000
Fixed service radio telephony, non-exclu- 3,300
sive. (See Note 4) 2,850
Mobile service radio telephony, non-exclu- 2,650
sive 2,500
Government broadcasting, non-exclusive. 2,050
(See Note 1) 1,850
Fixed station radio telephony, non-exclu- 1,650
sive. (See Note 5) 1,550
Aircraft radio telephony and telegraphy, 1,550
exclusive 1,500
Government and public broadcasting, non- 1,500
exclusive 1,050
Radio beacons, exclusive. (See Note 6). . 1,050
950
Aircraft radio telephony and telegraphy, 950
exclusive 850
Radio compass service, exclusive. (See 850
Note 7) 750
Government and public broadcasting, 200 750
miles or more from the seacoast, exclusive 700
Government and public broadcasting, 400 700
miles or more from the seacoast, exclusive 650
Marine radio telephony, non-exclusive. 750
(See Note 8) 650
Aircraft radio telephony and telegraphy, 525
exclusive. (See Note 8) 500
Government and public broadcasting, ex- 495
elusive 485
Private and toll broadcasting. (See Note 485
9) 285
Restricted special amateur radio tele- graphy, non-exclusive. (See Note 10) . . . 310 City and state public safety broadcasting, 285
exclusive. (See Note 11) 275
Technical and training schools (shared 275
with amateur). (See Note 12) 200
Amateur telegraphy and telephony (ex- clusive, 150 to 200 meters). (Shared with
technical and training schools, 200 to 275 275
meters). (See Note 13) 150
Private and toll broadcasting, exclusive. . . 150
100 Reserved below 1 00 abo\
ve Frequency Kilocycles per sec.
50.
60.
90.9 105.2 1 13.2 120. 146. 162. 181.8 193.5 193.5 200. 200. 285.7 285.7 316. 316. 353. 353. 400. 400. 428. 428. 462. 400. 462. 572. 600. 606. 618. 618. 1,052.
968. 1,052. 1,091. 1,091. 1,500.
1.091. 2,000. 2,000. 3,-000. 3,000
L
and Crop Estimates, Department of Agri- culture.
The conference was in session from February 27 to March 2, at the end of which time a Tentative Report was pre- pared. This report was sent to all persons who requested it, and to representatives of various interests, which in the judg- ment of the Department of Commerce were interested. A large number of sug- gestions and comments were received. The Conference had subsequent sessions on April 17, 18 and 19. All comments were considered, the general effect of the comments being to approve the substance of the preliminary report with a very few exceptions. The report as finally amended and adopted is given herewith.
In addition to preparing a report on technical matters, the Conference made recommendations as to essential points re- quired in legislation to give the Secretary power to make and enforce regulations. General Resolutions
Resolved that the Conference on Radio Telephony recommend that the radio laws be amended so as to give the Secretary of Commerce adequate legal authority for the effective control of:
(1) the establishment of all radio trans- mitting stations except amateur, experi- mental and Government stations.
(2) the operation of non-Governmental radio transmitting stations.*
Resolved that it is the sense of the Con- ference that radio communication is a public utility and as such should be regu- lated and controlled by the Federal Gov- ernment in the public interest.
Resolved that the types of radio ap- paratus most effective in reducing inter- ference should be made freely available to the public without restriction.
I. Allocation of Wave Bands
A. It is recommended that waves for radio telephony be assigned in bands, ac- cording to the class of service, as given in the accompanying table.
Throughout this report, both wave lengths and wave frequency are given. Wave length in meters is 300,000,000 di- vided by wave frequency in kilocycles per second.
Wave bands marked exclusive can be used for no other type of service; those marked non-exclusive are available for other types of radio communication, sub- ject to regulation.
*It was the desire of the Conference that the present authority of the Secretary of Commerce over the operation of radio transmitting stations be extended and that the Secretary of Commerce be granted authority to control the erection or establishment of certain classes of radio stations.
(Continued on page 25)
RADIO AGE— "THE MAGAZINE OF THE HOUR"
Shows Introducing Radio to Throngs
Middle West Fans Await Milwaukee, Toledo and Chicago Expositions
RADIO showmen appear to have no difficulty in convincing manufacturers and dealers that the radio show is the thing to get the business. This is not sur- prising when we look over the thou- sands of enthusiasts who have been crowdingthese e X h i b i tions. Each demon- stration of a radio outfithas an unmistaka- ble kick of thrilling inter- est in it. The shows have become a means of giv- ing manythou- sands of per- sons their first dip into the ether waves. Also the ex- hibits have in- tensely inter- ested those fans who are beyond the first stage of radio learning and want to see the newest and most im- proved equip- ment.
Shows are supplying ad- ditional proof of the momen- tum the indus- try has accu- mulated. One year ago a ra- dio show on a big scale failed t o deliver a profit. This year the fans have been mobbing the entrances.
New York had one big show in the P e nnsylvania Hotel and will have several others before next winter, the announced for
exhibitions. Toledo's first show is being held during the week of May 29.
Milwaukee Leads the Way
The Wisconsin Section of the American Radio Relay League will
This bear cub, only
but she more likely
Her name is Mari
a month old, may be listening to somebody's broadcasting station, is just hearing the old call of the wild. Science seems to bore her. on and she lives in Seattle, Wash. International News Reel Photo
first of which was the Seventy-First Regiment Armory, May 22 to 29, in- clusive. Boston, Newark and Brook- lyn have dropped into line with big
meet in its first state convention in Milwaukee on dates concurrent with the Wisconsin Radio and Electrical Show, to be held in the Auditorium, Milwaukee, June 21 to 25, inc. The
convention will meet in the same building in which the show is held. Popular and technical talks by na- tionally known speakers are being arranged for the convention pro- gram.
Spearman Lewis, managing direc- tor of the Al- lied Bazaar, the most suc- cessful show ever staged in the Coliseum, Chicago (net cash profits, $535,000), is managing di- rector of the Wisconsin Radio Show. His headquar- ters are at the Plankington Hotel, Mil- waukee. Sell- ing exhibitors' space has been largely a ques- tion of install- ing enough telephones at show head- quarters to get the incoming calls and in- quiries.
Milwaukee claims the finest exposi- tion building in America — the A u d i t o - r i u m — and every indica- tion points to tremendous at- tendance and unusually in- teresting ex- hibits. The famous "K Y W" of Chicago will be repre- sented as a compliment to Mr. Lewis, who arranged the first Mary Garden- Edith Mason grand over "KYW"
opera demonstration last November.
The First Chicago Show For the purpose of discovering the young Edisons of wireless and to
RADIO AGE— "THE MAGAZINE OF THE HOUR"
help make Chicago the radio center of the world the committee in charge of the prizes to be awarded in the various contests at the National Ra- dio Exposition to be held in Chicago June 26th to July 1st, in the Leiter building, have announced the prizes that will be awarded. The com- mittee includes J. C. Hail, in charge of radio station WBU, City Hall, chairman; Prof. R. R. Hughes, Evanston High School, and F. D. Pearne, of the Department of Elec- tricity, Lane Technical High School.
The prize awards are classed as follows :
Grade Schools — For making the best Crystal Detector set— 170 to 600 meters : 1st prize, $25 ; 2nd, $15 ; 3rd, $10.
High Schools and Manual Train- ingSchools — For making the best re- generative Detector, two-stage am- plifier set — 175 to 600 meters: 1st prize, $50; 2nd, $30; 3rd, $20; boys under high school age are eligible, but they must be in school.
Contest Open to Anyone under 21 years old — For making the smallest set for receiving code and of practical use : 1st prize, $50; 2nd, $30; 3rd, $20.
Contest Open to Anyone — For making Loud Speaker of own de- sign throughout ; one grand prize of $100.
Contest Open to Anyone — For making the greatest radio novelty: one grand prize of $100.
All the devices entered in the vari- ous contests must be the headquar- ters of the National Radio Exposi- tion, 417 S. Dearborn Street, Room 401, by 8 o'clock Friday evening, June 23rd. The contestant must ap- pear in person before that time, when he will be given a ticket of admission to the show and will be told the day on which the awards will be made in his particular contest.
Not a Dull Hour Here
An advisory committee of experts is arranging the general details of the exposition. This committee con- sists of J. Elliott Jenkins, chairman ; J. C. Hail, W. S. Hedges, radio edi- tor, Chicago Daily News; Prof. R. E. Hughes; G. H. Jaspert; F. D. Pearne. E. C. Rayner, Editor Radio Digest; L. R. Schmidt; Frederick Smith, editor. Radio Age; Alfred Thomas, Jr., district manager of the Radio Corporation of America ; Nor- man E. Wunderlich, Radio Topics. At the first meeting of this com- mittee it was decided to provide an educational program that will give the visitor to the exposition a liberal education in radio. This program, held in a conference room, will be in
the nature of open forum discussions, with a prominent speaker at each meeting, one at 10 o'clock in the morning and the other at 2 o'clock in the afternoon daily. Days will be set aside for dealers and manufac- turers, doctors and hospital people, ministers, golfers.
In addition to the exhibits of man- ufacturers and dealers there will be many features and demonstrations. A broadcasting outfit will be in- stalled by the Westinghouse station, in charge of G. H. Jaspert, where everything that is in the air will be received and can be heard by the visitors to the exposition. The tech- nical schools of Chicago will have exhibits of their handicraft. The students not only will display what radio parts and outfits they have made in their schools, but they will actually manufacture them at the exposition. Some of the in- structors and students at these schools not only have invented im- provements in radio devices, for which they have obtained patents, but they have made outfits that rival the commercial outfits.
The advisory committee decided to turn over space to the Army, Navy, Department of Commerce, Weather Bureau, Boy Scouts, Girl Scouts, Sea Scouts and Campfire Girls for radio displays.
Pageant of Progress Show
One of the great radio shows of the year in the United States will be a feature — almost surely the fore- most feature of the second annual International Pageant of Progress Exposition which opens on July 29th and closes August 14th, 1922. It is predicted that a million and a half persons will see this exhibition of wireless products.
A preliminary meeting of the radio directors of the Pageant of Progress was held in the Gray Room of the Hotel Sherman, on the evening of May 2. Mayor William Hale Thomp- son was present and delivered a speech which positively identified His Honor as one of us. The Mayor spoke eloquently of the future of radio.
Dr. John Dill Robertson, president of the exposition, introduced George B. Foster, of the Commonwealth Edison Company, as the chairman of the meeting. Mr. Foster called on several speakers, including for- mer Lieutenant Governor Barratt O'Hara, District Inspector L. R. Schmitt, Secretary Tansey of the Radio Club of Illinois, Spearman Lewis, Milo E. Westbrooke, U. J. Herrmann and George E. Carlson,
Chicago Commissioner of Electricity. The speakers all expressed confi- dence in the belief that Chicago had the opportunity to become the center of radio in this country. Mr. Foster, in his interesting and instructive ad- dress, said he was informed there would be five Chicago shows this year.
The interest displayed at this dinner indicates that those who fail to attend the Pageant of Progress radio show or neglect the opportu- nity to exhibit radio wares there will overlook a choice opportunity.
Offices of the Pageant of Progress are at 7 West Madison street.
The October Show
The Chicago Radio Show to be held at the Coliseum, October 14th to 22nd, is rapidly assuming not only definite proportions, but promises to be of unusual interest to the Radio trade in general. The Coliseum be- ing recognized internationally as the center of trade expositions, gives any exposition lield there, prominence throughout the country.
U. J. Herrmann, the managing director, has opened permanent offices in Suite 549 McCormick Bldg., and has appointed James F. Kerr, Manager of the Exposition. Many novel features in the arrangement of floor space are being worked out, to make the Exposition of equal interest to manufacturers and the public in general. Applications are coming in from all corners and the first foreign application was received 'from Paris, France, this week.
Manufacturers have a most opti- mistic view of market conditions bet- tering themselves during the sum- mer months, as much of the patent litigation will be exhausted, thus leaving the manufacturing field in a more settled and stable condition.
Reassuring the Dailies
J. C. McQuiston, former president of the Association of National Ad- vertisers and now manager of West- inghouse publicity, addressed the ad- vertising association in Chicago re- cently.
"Radio cannot replace the news- paper," he said. "Radio will be a supplemental agency and will devel- op more reading of the newspapers for news, as radio broadcasting of bulletins will create the desire for further details and for confirmation. After all, the printed word is neces- sary to give the final touch of au- thority."
RADIO AGE— "THE MAGAZINE OF THE HOUR"
How to Make a Receiving Transformer
By FRANK D. PEARNE
Chief Instructor in Electricity at Lane Technical High School, Chicago
5aMRE BRASS ROD
B
THE American boy is always anxious to make things with his own hands, and it can truthfully be said that more real pleasure can be obtained from something which he makes himself, than from some- thing which he buys.
For the benefit of those so inclined I am going to describe an easily made receiving transformer which when completed and wiredasshown in the diagram Figure 4 of this issue, will give excellent results. F i g- ure 1 shows the complete coil and if the maker will fol- 1 o w the in- structions
closely, he will have a transformer that will look as well as any which he might purchase.
The first thing to do is to get some hard wood to use in the con- struction of the base and the ends for the coils. Mahogany is the best, as it can be given a fine finish, but this is usually hard for the average boy to obtain. If this cannot be secured, oak will do, and if this is outside of his reach, he may go to the grocery store and get a hard wood packing case and use the good parts of it for this work.
The base is made of a good clear piece of wood 16 by 10 inches and % of an inch thick. After this has been made, go over it well with sandpaper, give it a good coat of varnish, and put it away to dry. Figure 2 shows the details of the ends for the primary coil. The primary end "A" is 51/4 inches high, 4^ inches wide, and y% inches thick. A hole 4^4 inches in diameter is cut from this piece, tak- ing as the center, a point 2^ inches from the bottom and 2^ inches from the side. This should be carefully done with a jig saw. A slot is then cut from the front to the back. This should be i/4 inch deep and % inch wide. Sandpaper this, varnish, and Care in Measurement
The primary end "B" is made the same size as "A" but do not cut hole
through this end. Instead of cutting this one out, cut out a circular piece of wood 4 inches in diameter and yi inch thick and glue it on .to the end "B" as shown in the drawing. Care must be taken to see that the center of this round piece comes at exactly 2^ inches from the bottom, and the
5L(DER
^
PRIN\kRY
^ B/NPING- FPSTS W\
SECONDARY
E
ROD
SUPPORT
B/ASE:
riG-URE 1
same distance from the sides. Drill two 1/4 inch holes ^ inch deep at the points indicated in the side view of primary end "B" Figure 2. Cut a j4 inch slot across the top similar to the one made in the end "A" as shown, sandpaper, varnish and set it aside to dry.
The next thing in order is to make the secondary end "C". If possible this should be turned out in one piece on a lathe, as it makes a very neat job when completed, but as the average boy does not have a lathe at his disposal he can make it of two pieces cut out with the jig saw. The
T T SUALLY the first radio receiv- l_y ing set with zuhich the amateur comes in contact is one zvhich uses the double slide timing coil for making the adjustments to receive waves of different lengths. These serve their purpose during the elementary period of the beginner's experience, and then he looks about him for something a little better, which will give sharper tuning and zvhich zvill also enable him to pick up stations which he could not get before. This he finds in the loose coupler, or receiving transfortner, by zvhich the receiving set is inductively coupled to the aerial and ground. With this idea in view, we publish in this issue, the complete instructions for the making of a receiving transformer.
first piece is 4^ inches in diameter and 1/4 of an inch in thickness. Another round piece is cut 3j^ inches in diameter and ^4 of an inch thick, and glued fast to the first piece as shown in the side view of the second- ary end "C" Figure 2. If this is made with the saw, the large piece will have to be very carefully sand - papered to make it look like a real job. A 3^8 inch hole is drilled through the center for mounting the switch lever later. Fifteen holes are then drilled around in a circle with a ]4. irich drill for mounting the switch two binding posts in the location shown in the back view of the sec- ondary end "C" Figure 2. When this is finished it should be varnished and put away to dry.
The Rod Support Now saw out the secondary end "D" Figure 3. This can be made of any kind of wood and should be Z]4, inches in diameter and Yi inch thick. Drill two % inch holes 1 inch from each of the center lines as shown, to be used for the supporting rods. This should also be varnished to pre- vent warping. Next cut out an ob- long piece of hard wood for the rod support "E" as shown on Figure 3. This is to be 3 inches long and 2 inches wide, and ^4 of an inch in thickness. Two holes are to be drilled J4 inch deep in one side in the loca- tion shown on the drawing. These holes should be 1^4 inch in diameter, and great care should be used so that the drill does not go all the way through, as this would spoil the ap- pearance of the coil, when finished. This like the other pieces, should be carefully sandpapered and var- nished.
This completes the wood work,
and the next thing to take up will
be the winding of the coils.
Winding the Coils
Procure a pasteboard tube 6 inches
long 4^4 inches in diameter on the
RADIO AGE— "THE MAGAZINE OF THE HOUR"
outside and 4 inches in diameter on the inside. If this is hard to get use an oatmeal box and cut it off the proper length. The tube on the model coil from which these specifica- tions are taken was made from an oatmeal box. Cut the ends of this tube nice and square all around, and punch two holes through it with a small awl, ^ of an inch from the end. Now punch 2 more holes ^s inch from the other end, exactly opposite from the first two. These holes are to accommodate the ends of the wires and should be about 5^ inch apart. As the wires are to come out on the same side of the tube it is necessary that the holes be on the same side. Use No. ?^. enamel insu- lated wire for this coil.
PR//V\ARY END %
Put about 12 inches of this wire down through one of the holes, and bring it up again through the hole next to it and begin the winding. This winding will begin % inch from the end of the tube and continue to within ^ inch of the other end, which should bring it directly up to the holes punched in that end. An- chor the final end of the winding by threading it through the two holes' as you did on the starting end. When this is done, give the coil a coat of shellac varnish and let it dry. Now there will be a % of an inch of the tube on one end which is not covered with wire. This should be set into the hole in the primary end "A" Fig- ure 2 and glued fast. There will then be % of an inch of the bare tube
showing between this end and the winding. Glue the other end of the tube over the projection on the pri- mary end "B" as shown in the side view Figure 1. Before gluing the tube fast, be sure to see that the terminals of the coil are set so that they will come out at the bottom, so that they may easily be threaded through holes in the base.
Now get another tube, Sy% inches long, 3^ inches outside diameter, and 35^ inches inside diameter. Punch one hole in the end of this tube, as you did in the other. This should be Y^ of an inch from the end. Use No. 24 single cotton in- sulated wire for this coil. Put about 12 inches of the wire down through {Continued on page 22)
I
2^'
5^*--
dX
5^_if
PRIMARY END B' ^sudtJ4'w/deJ^'deep
^'
/-"RONT V/EW
I'
•'%'
IK-
I
I I
4"
- T
.jr_J_
__;__^__ / _ _J__ fc^HOLE HOT THROUG-H
-n
side: v/ew
FRONT VIEW
4-
'.yt^-z*
CIRCULAR V^OOD/^
I
i;j .
/.I
5/DB V/EW
SECONDARY END C
FRONT V/BW
SIPE V/EW BACK VIEW
r/OURE 2 .
RADIO AGE— "THE MAGAZINE OF THE HOUR"
Navy's Radio Shatters Distance
United States Stations Circle the Earth and Make It Seem Small
H
'OW far is Paris — London — Berlin?
"The man in the street and the geography class answer in miles today," says a bulletin issued from the Wash ington, D. C, h e a d- quarters of the National Geo- graphic Soci- ety, "but in a year, or even a few months, the answers may come in quarter- turns of a little black knob.
"For radio is affecting geog- raphy as it is affecting many other fields. If you can hear voices and music, and per- haps even the hum of traffic in the streets ofadistant city, that city must straight- way lose much of its remote- n e s s . ' ' The bulletin c o n - tinues :
"Eventoday, when radio telephony is in its infancy and radio teleg- raphy is mere- 1 y a slightly older brother, our own coun- try s e e m s to b e shrinking rapidly, and nations seem to be gravitat- ing closer to- gether. It is as though Europe and
America, and presently the other continents, were being towed toward one another by tightening hawsers of ether waves. The capstan points for these ethereal cables — the great radio telegraph stations — take on a new geographic interest.
Cavite in the Philippines has been placed on the map by its radio station.
Wave lengths are not an infallible index to the power of a radio station nor to its sending range, but they in- dicate comparative strength at least roughly. The station which of all
All amateurs know the naval radio station at Arlington,
of the powerful station
those in the world now regularly uses the longest waves — 23,000 metres, or approximately 14 miles — is near Bordeaux, France. It is the Lafayette Station, built by the United States Navy to facilitate America's part in the World War, and since sold to France. This sta- tion, which until recently was un-
challenged as the world's most pow- erful station, sends its telegraphic messages with ease — and practically instantaneously, of course — over the 4,000 miles of water and land that separate Bor- deaux from Washington ; and it has been heard occa- s i o n a 1 1 y in French Indo- China, 6,000 miles to the east.
Lafayette's title to first place is now challenged by a commercial station recent- 1}^ opened on Long Island, which, if it is not yet more powerful, will be when addi- tional units are added. This station sends on the second longest wave in use, 19,000 metres, or nearly twelve miles, and is e m- ployed for transmitting messages to Germany, about 4,000 miles away.
Although t h e U n i t e d States Navy's station at Ann- apolis, Md., is assigned a wave of 17,145 metres (rough- ly I0y2 miles), the third long- est in use, it is easily one of the world's most powerful stations. For that matter, so is the navy station at Cavite, Philippine Islands, operating on 13,900 metres.
The navy depends on the An- napolis station — which is operated, incidentally, by remote control by means of keys in the Navy Building in Washing-ton — to transmit mes-
Here's a view of the interior
10
RADIO AGE— "THE MAGAZINE OF THE HOUR"
The navy can flash a radio message to any part of the world at a moment's notice.
Capt. S. W. Bryant, left, explaining the working of the chart globe to Commander
D. C. Bingham, who has succeeded Capt. Bryant as director of naval communications.
International News Reel Photo
sages day in and day out over a radius of about 5,500 miles. This range includes the extreme end of the Mediterranean Sea, and the same territory can also be reached from the opposite direction by the Philip- pine station.
The United States Navy has the most complete system of high power land stations for radio telegraphy of all naval establishments. Southward of the great Annapolis station it has among its larger units the sending plant at Cayey, Porto Rico, using a 10,510 metre wave, and another at Balboa, Canal Zone, sending on 10,- 110 metres. The eastern portion of the Pacific is covered from the con- tinent by a station at San Diego, Cal., and another on Puget Sound. The former uses waves of 9,800 metres and the latter of 7,100. In the Hawaiian Islands the navy has two sending stations, one using 11,500 metres and the other 8,875.
On Guam is a naval station which sends on 9,145 metres ; and finally, in the Philippines is the 13,900-metre station which completes the navy's band of radio stations around the world. In practically no place where its ships are likely to cruise will they be out of range of dots and dashes
from one or more of the navy's send- ing stations.
The British Navy does not main- tain a system of land stations of its own but uses those of the British Post Office. These postal stations practically encircle the earth, but they do so in much smaller "jumps" than those of the United States Navy, and therefore use less power- ful stations.
Other Long Senders
Of the twelve longest wave sta- tions which follow Annapolis, seven are in the United States or its terri- tories. They are commercial stations at Barnegat, N. J., 16,800 metres ; St. James, L. I., 16,465 ; Kohoku, Ha- waiian Islands, 16,300, and Tucker- ton, N. J., 15,900; the navy station at Cavite, P. I., and commercial sta- tions at New Brunswick, N. J., 13,- 600 metres, and Bolinas, Cal., 13,310 metres. The five foreign stations in this group are British stations at Leafield, near Oxford, England, 15,- 600 metres, and Carnarvon, Wales, 14,400 metres; a Dutch station in Java, 15,000 metres; a Japanese sta- tion at Iwaki, 15,000 metres, and a French station at Nantes, France, 18,800 metres.
There are only seven other impor-
tant long distance stations using waves of 11,000 metres or more. They are Abu Zabul, near Cairo, Egypt, 13,300 metres ; Nauen, Ger- many, 12,600; Lyons, Fran'ce, 12,500; Stavenger, Norway, 12,000; Marion, Mass., 28,600; a station on the West Coast of India, 11,200, and Rome, 11,000.
The United States Army has nu- merous sending stations at its forts and posts scattered over the United States, which operate on wave lengths from a few hundred to 10,000 metres. The Post Office Depart- ment at its several stations sends oan waves for the most part between 1,000 and 4,000 metres long.
Service for Seamen
The Hydrographic Office and the Naval Communication Service col- lect and distribute hydrographic in- formation by naval radio. The co- operation of owners, operators, radio companies controlling installations on board vessels, and masters is nec- essary to make this new undertaking a success. In return greater protec- tion is afforded mariners than ever before.
RADIO AGE— "THE MAGAZINE OF THE HOUR"
11
High School Wms Radio Fame
By EDWARD I. TAYOR One of the Boys in Chicago's Lane "Tech."
NOT far from the crowded loop district, yet situated ideally in the midst of Chicago's manu- facturing center is the Lane Tech- nical High School. Situ- ated ideally, is the term used, for a school of this type where everything from aircraft drafting t o the radio de- partment as- sumes busi- ness-like pro- portions, be- comes prop- erly a part of the modern factories and business houses which surround it.
We will deal today with the radio department and electrical shops as space is limit- ed and the story of this school would cover a thick volume. I n thefirstplace. Lane has been gifted with extraordin- arytalent both in its facultyand in its students. This in a way has helped to accomplish the results which are ap- parent on every hand, butsome- thing far more import- ant is that of the feeling of school spirit
which pervades the air and is quite contagious.
There is no issuing of sharp com- mands and orders by the teachers. Everything is well ordered and the
students work with a zest which can only emanate from the interest each has in the work. It is the chief aim of every pupil to build a complete vq-
Lane Technical High School held its annual military review the other day and con- ducted all the maneuvers through its student radio service. Major E. S. Pearsall gave orders in his office at the school by means of a sending set direct to the field of battle and the orders were relayed to the field officers by megaphone
ceiver for himself and learn the code in the radio class. It is not hard to imagine what a boy is apt to do under these circumstances.
If you have been fortunate enough
to have gone through this school, you will remember your surprise in your first sight of the radio appara- tus. There it stood on a table, re- s p 1 e n d e nt i n beautiful nickel plate, polished eb- ony, and rub- bed mahog- any. Perhaps you were one of the many who asked your guide what was the make of ap- p a r a t u s . When he told you that it was made, every bit, at Lane, you of course were surprised. And to prove his assertions your guide undoubtedly ledyou to the shops where construction of other re- ceivers was under way. There you saw the boys winding the vario -meters and vario- couplers, drilling pan- e 1 s , making the cabinets, wiring the sets, and put- ting the fin- ishing licks to outfits that could stand up alongside the best man- ufactured set on the mar- ket today.
The regen- erative re- ceiver made at Lane is a piece of apparatus which is modern and efficient in every respect. Bev- eled dials control the two vari- ometers and the vario-coupler. A {Continued on page 27)
12
RADIO AGE— "THE MAGAZINE OF THE HOUR'
Postmaster General Work is shown in his office listening to radio reports, on having a receiving outfit in his own office.
He insists
"Aerials" Under Ground and Under Water
Wartime inventor knocks out some theories about towers and static
THE latest advance in ra- dio receiving was accom- plished in April in the presence of four witnesses, when, with a coil antenna com- pletely buried beneath the sur- face of the ground, vocal and in- strumental music was clearly heard on a transmitted wave length of 360 meters over a dis- tance of 220 miles. This suc- cessful experiment was accom- plished in the field laboratory of Dr. J. Harris Rogers in Hyatts- ville, Md. The instruments used were a three-stage radio frequency amplifier and a loop antenna.
The far-reaching effect of this experiment will be the elimina- tion of huge aerial towers for the reception of radio telephone or telegraph messages. As a climax to successful experi- ments which have assured the reception of long radio tele- graph waves on underground antenna, the test just performed demonstrates the possibility of regu- lar radiophone communication with- out areial wires above or on the sur- face of the ground. This removes the present limit of underground radio receiving systems, namely, the recep- tion of short wave lengths which to- day represent the bulk of commercial short distance radio traffic. Eliminates Static
Not only the message from KDKA and WJZ were clear and distinct in themselves, but in the presence of severe static, street car and train lines less than 200 yards distant, none of these disturbances interfered with the perfect reception of the trans- mitted messages. This means that in mines, dense forests, in arid wastes and under severe static condi- tions present in extreme north or south latitudes, a hole in the ground will suffice to contain the antenna necessary to receive messages trans- mitted thousands of miles away and at wave lengths heretofore not ap- proached.
J. Harris Rogers, Civil War vet- eran, inventor of the printing tele- graphs, synchronous motors and other devices, is the discoverer of the underground aerial receiving system.
In 1916, during the war period Sec- retary of the Navy Daniels immedi- ately facilitated the securing of pat- ents which protected the discovery of
Dr. Rogers and established stations at Great Lakes, New Orleans and Belmar, N. J., for experimenting with and developing the Rogers system. Meanwhile in Hyattsville, Md., Dr. Rogers and Government officials listened in from the little hut named Mount Hooper in honor of Admiral Hooper, U. S. N., situated three miles in the woods beyond Dr. Rogers' home.
Messages from France
Trenches were dug and wires buried in all directions and at varying depths, the effect being similar to the spokes of a wheel offset from the center.
A wire 4,000 feet long encased in a tile pipe three feet below the surface of the earth was stretched in a west- erly direction. Communications be- tween German army units on the European battle front were clearly heard. The apparatus consisted of a large tuning coil, a variable con- denser, one step audion amplifier, and two pairs of Baldwin head 'phones.
With this equipment and under- ground aerial the officials heard regu- larly Nauen, Germany ; Eiffel Tower, Paris, and all United States stations on long waves. Not only were these stations copied regularly but simul- taneously stations employing the Rogers system at Belmar, N. J., and Great Lakes maintained continuous trans-Atlantic receiving service.
"Aerials" Under Water
The Belmar, N. J., station was in operation twenty-four hours a day ; not a single word was lost during the transmission of thousands of mes- sages. A submarine submerged eight feet off the Atlantic coast heard Nauen, Germany ; twenty-one feet submerged it heard distant stations on 12,000 ineters wave length. A transmitting station operating with forty-eight amperes antenna current 600 feet away from a receiving sta- tion, using the Rogers underground aerial system, did not interfere with Nauen being picked up on 12,600 meters and New Orleans on 5,000 meters. No interference and no static. Aerials far under water were used to receive Cavite, Philippine Islands, 8,100 miles distant, on its regular 11a. m. and 5 p; m. sched- ules.
Transmitting experiments with the Rogers system have been successful over a distance of seven miles ; longer transmission is as yet not fully devel- oped because it is found that insula- tion material now used will not stand the excessive currents used in trans- mission, says the Washington Her- ald. But today radio telegraph and radio telephone messages may be re- ceived over long distances and over very low or very long wave length ranges with antenna buried beneath the ground or submerged beneath the seas.
RADIO AGE— "THE MAGAZINE OF THE HOUR"
13
Electric Light Wires as Auxiliary to Radio
THE B battery heretofore so essential to every radiophone- receiving set for maintaining the plate potential will no longer be needed when an arrangement made by the Bureau of Standards becomes generally practicable. The new de- velopment makes direct connection to the electric light socket possible. B y special modes of connection, the lighting wire may also be used as an antenna.
The warning given some weeks ago when this method of re- ception was suggested i n connect ion with the work of Maj. Gen. Squier is re- peated : Nov- ices should not attempt any meddling with lighting c i r - cuits, hoping to avoid the erection of an antenna or eliminating the storage b a t - tery. The new development is p r a c t i c able only with the proper plug equipment and some knowl- edge of the principles in- volved.
The receiv- ing set con- s i s t s essen- tially of an amplifier with minor auxil- iary parts. This is de- scribed in a paper which has been pre- pared by the Bureau of Standards. A few details of the amplifier, which utilizes 60-cycle c u r -
rent supply for both filaments and plates of the electron tubes, are as follows : This amplifier has three radio-frequency stages and two au- dio-frequency stages, and uses a crys- tal detector. The 60-cycle current when used in an ordinary amplifier circuit introduces a strong 60-cycle
During the war experiments proved that it is possible to use trees
antennae jar wireless receiving outfits. These two Atlantic coast
trees a chance to speak. Press Illustrating Service
note which offers serious interference. This has been practically eliminated by balancing resistances, grid con- densers and special grid leaks of com- paratively low resistance, telephone transformer in the output circuit and crystal detector, instead of electron tube detector.
In the final form of the amplifier there is only a slight residual hum which is not objectionable. The amplifica- tion obtained with a. c. sup- ply was as good as that obtained with the same am- plifier used with d. c. sup- ply. The com- plete unit is light, compact and portable. For the recep- tion of damped waves, the am- plifier as con- structed oper- ated most sat- isfactorily for wave lengths from 200 to 750 meters. This range was deter- mined by the working range of the radio- f r e q u e n ncy t r a nsformers used. By us- i n g suitable radio -frequen- cy transform- ers it is ex- pected that the amplifier will be efifective for the reception of damped waves and un- damped waves as long as 10,- 000 meters. For the recep- t i o n of un- damped waves a separate h e t e r o dyne should be em- ployed, the pa- per says.
instead of the usual boys are giving the Photo
14
RADIO AGE— "THE MAGAZINE OF THE HOUR"
New Stuff by Boy Readers
By Edwin Nielsen
DO YOU have trouble in .srettinp- loud signals on your crystal detector set? Why not use a crystal amplifier in one or two stages simply by connecting one or two crystal detectors in series with your original crystal detector, using an amplifying transformer and a 22-volt B battery as shown in the illustra- tion. This will enable you to get loud signals where only weak ones were formerly heard, will greatly in- crease your receiving range and will enable you to use a loud speaker horn instead of your phones, thus allowing the whole family to listen in, where before only one could listen at a time.
This idea had its origin in the brain of a South American amateur, who has organized the first if not the only Radio club in that part of the world. And I have tried this type of ampli- fier and had the signals far exceed my hopes in loudness and clearness of tone.
To get good results it will be nec- essary to get very sensitive crystals and place the catwhisker wire on the most sensitive place that can be found, the crystals can be tested by connecting a buzzer, battery, a key and a coil of about 10 turns together, as shown in the illustration ; this coil is placed as close as possible to the tuning coil of the receiving coil and the key is pressed. This sets up miniature radio waves which are caught by the receiving coil and car- ried over to the detector where the crystal to be tested is mounted. The catwhisker is moved around un- til the best spot is found. The other crystals can be tested in the same way. If no buzzing is heard in the receivers while the crystal is being tested another crystal must be used.
Beginners Need This
A number of requests have come to the editor asking how the reader could secure the plans of a home- made receiving set published by the Bureau of Standards in Washington. The editor is in receipt of a letter from that department saying that, owing to the great demand, the de- partment is unable to furnish any more free copies of the lessons, but will publish them as Bureau of Stan- dards Circular No. 120, which may be secured by writing the Superin- tendent of Documents, Government Printing Office, Washington, D. C, and giving the number of the docu-
iiiiiiinHiiiiiiiiiiiifnii
By Joseph Stelzer, East St. Louis, 111.
THE rotary tuning coil shown in the one-column sketch gives the complete wiring diagram. The circle is cut from ^-inch stock, 1 inch wide, and well covered with in- sulation. It is then wound with No. 24 single cotton-covered wire so that the coils will lie flat.
All of the arms are ^-inch square and are of brass. The supports are smaller in section. Slides are mounted on the ends of the long arms and are kept in place by set screws. The insulation on the wires is removed with a small piece of sandpaper pasted on a block of wood. This should be temporarily fast- ened to the revolving lever at the point where the contact is wanted; then the lever is turned until the in- sulation is removed. The wiring dia- gram shows the location of the tun- ing coil in the line.
F.C
ment as above. This article with il- lustrations was a feature of the May issue of Radio Age. Copies of that issue will be mailed on receipt of 25c in stamps by Radio Age.
Red Gross Radio
The American Red Cross is consid- ering the use of radio as an aid in its emergency work. At the radio ex- hibition in Boston a radio set with a receiving radius of 2,000 miles was in operation for the reception of first aid calls, which were answered by nurses in attendance at the Red Cross booth in the exposition hall.
Trying the Voice
In an address before the Chicago Rotary Club, Morgan L. Eastman, with the aid of pictures and radio ap- paratus, showed how the voices of singers are tested before they are used for broadcasting purposes. Mr. Eastman devised a microphone, which was worked out by Westing- house engineers, so arranged that a listener may determine .whether a singer in an adjoining room has a voice of the proper carrying quality. Mr. Eastman is in charge of the Westinghouse broadcasting station KYW on the Commonwealth Edison building, Chicago.
BATTERY ^ e.oZ-'Z-'^^
(Tli'l'i-^-
ffi-
COIL
KEY
,^^^^
yiK<i>
->
DETE
CTOR
o^ ^<r.-^Kc^-?:^^s A^Vu^'-"
TWO SLIDE TUNING COIL
AMPLIFYIINQ
TRANSFORMER
CONNECT FONES HERE IF NO AMPLIFYING IS DESIRED
CONNECT HERE IF 2 STAGE. AMPLIFICATION IS DESIRED
CONNECT PONES
HERE IF I STAGE
AMPLIFIER
IS USED.
RADIO AGE— "THE MAGAZINE OF THE HOUR"
15
In Radio Shops and Factories
ASSOCIATIONS of manufac- turers and merchants in the radio trade are becoming the order of the day. The solid element in the business recognizes that it is necessary to mobilize against the wildcat promoters who are in radio purely for stock-rigging purposes or who are in it to shove off a lot of rot- ten equipment while demand is fever- ish and prices are tempting.
While the sheep are being sepa- rated from the goats it is advisable for the public to step warily, dealing with established firms who have suf- ficient business standing to insure their handling good merchandise. At present the demand far exceeds the supply and the fellow who is in the business for a "flyer" is occasionally doing about as well as the fellow who is in business because he means busi- ness.
It was stated by one of the speakers at a recent important Chicago radio conference in Hotel Sherman that the supply situation was being straightened out rapidly and that within sixty days the "sold out" signs would have to be taken down. When that time comes the merchant and manufacturer who have been selling honest goods and exploiting their name and their wares and building a future will still be there making money. The other man will have nothing but ap ast.
Among the new organizations is the National Radio Chamber of Com- merce, with headquarters in New York City and district office in Chi- cago. Alexander Eisemann of the Freed-Eisemann Radio Corporation is president. Mr. Eisemann says :
"The object of the association is to remedy certain conditions which have arisen in the radio 'industry as a result of its tremendous growth within the last few months ; and to group together manufacturers whose radio products are of such dependa- ble character as to maintain favor- able public opinion toward the radio industry.
"All radio manufacturers, whether large or small, will be eligible for membership. Our original group consisted of about fifteen manufac-
tvtrers. To those have been added, by invitation, about twenty addition- al concerns whose business standing and whose products are known to be of high order. New concerns will be eligible only after their apparatus has been passed upon by a board of five members.
"It is planned to exclude from membership various concerns which have been organized purely for stock jobbing purposes, and to exclude also manufacturers who are now turning out radio apparatus which has been found to be untrustworthy and which will eventually bring radio into dis- favor on the part of purchasers of
F. W. Dunmorc, of the radio laboratory of the U. S. Bureau of Stand- ards, brought a "singing valise" to the Drake Hotel in Chicago on April 20. He had a radio receiving set in the grip, with a folding loud speaker. As he walked about the lobby, music and news reports came from the valise. His ground and aerial wires were cleverly concealed and gave him a limited radius of travel with his magic grip.
such undependable apparatus.
"A credit bureau will also be or- ganized shortly for the interchange of credit information."
Other officers of the organization are Charles Keator of the De Forest Radio Telephone and Telegraph Company, William Dubilier of the Dubilier Condenser Company and Frank Hinners of the Home Radio Company.
* * *
The investigating committee of the Radio Conference of the National Re- tail Drygoods Association, in session in New York, considered the quality and efficiency of radio apparatus and the possibility of service in the dis- tribution of such merchandise.
As its first recommendation the In- vestigating Committee adopted a res- olution, "That all responsible manu-
facturers be requested to standardize the efficiency of their various receiv- ing sets and plainly mark on each in- strument the receiving radius under
average atmospheric conditions."
* * *
The manufacture of radio appara- tus in Washington, D. C, has grown to extraordinary proportions. The Radio Instrument Company and the Washington Radio Corporation have completed arrangements for building factories immediately.
* * *
Officials of two leading electrical
companies in Chicago estimate that
from 2,000 to 3,000 dealers have gone
into the radio business in
Chicago during the last
two months.
* * *
Charles T. Powner, bookseller, has a radio department in his shop at 177 West Madison street.
Among other big Chi- cago concerns that may soon be on the list of makers or sellers of radio devices are Lyon & Healy, Sears - Roebuck and Brunswick - Balke. , Hundreds of drug stores, furniture shops and de- partment stores are lay- ing in radio stocks. H^ ^ ^
The Scientific Ameri- can says there is'a wide- spread opinion that the radio business will out- strip the phonograph business, which has been in excess of 400,000,000
per year.
It is estimated that the monthly production of vacuum tubes is about 100,000.
All through the Mississippi Valley an interesting phenomenon is being observed. Otherwise modest and humble citizens appear on the street with their chin in the air and a proud glint in their eye. There is nothing wrong with these fellows. They merely have succeeded in getting Schenectady for the first time. How can they be expected to remain in the same social stratum with the plodder who has picked up stuff from no greater distance than Detroit or In- dianapolis?
16
RADIO AGE— "THE MAGAZINE OF THE HOUR"
Suminer Static and How to Meet It
SAY "static" to a radio enthusiast and listen to what he says, or else cover your ears. His opin- ion of the greatest nuisance which be- sets radio telegraphy and telephony will no doubt be fervent if he is an experienced operator. If he is an amateur, it will be despairing.
When a radio fan talks of "static" he means the small charges of positive electricity which infest the atmosphere, forever seeking an outlet to the nega- tive earth. They are in effect minia- ture bolts of lightning which have not the force to strike under their own power. Hence they seek assistance, which is unwittingly extended to them by the aerial of the radio apparatus. By means of this they find a ready passage to the ground, where they cease to be troublesome.
But woe to the amateur whose aerial is not well "grounded." Balked of their goal, static charges have been known to start fires. Even greater is the danger during a thunderstorm, un- less a good grovind wire is provided. Any ground installation which com- plies with the underwriters' require- ments will furnish adequate protec- tion, however, against this. It is al- ways advisable to stay away from wireless apparatus during a storm.
Commencing with the next few weeks, radio operators and amateurs will encounter static with increasing frequency due to the approach of warm weather. Static is more abund- ant in summer than at any other time of the year, making it extremely diffi- cult for the average radio enthusiast to operate his set.
The cause of this trouble is some- times in the use of an aerial that is too lengthy. No aerial for receiving broadcasts should be more than 150 feet in length. Where a two-wire type is u.sed, the length, including the lead-in wire should not exceed sixty- five feet.
Where a station is located near a broadcasting center, indoor aerials will be found superior in summer. These may be made in the form of a grid or coil, either mounted on an insulated stand, or attached to porcelain insula- tors fixed in the beams of the attic of the house. This device is only for use in houses where metal roofing is not employed. All wires must be kept as far as possible from the lighting system wires of the house. Vacuum tubes are imperative in using this type of aerial, but their expense is offset by the resultant freedom from static.
THE WIRELESS CODE
1. A dash is equal to three dots.
2. The space between parts of the same letter is equal to one dot. 3. The space between two letters is equal to three dots. 4. The space between two
words is equal to five dots
A* Mi
^ ■■ • • •
Dm** E*
F • • Hi *
H**** I**
L • 1^ • •
N ^*
P * Mi ■■ *
R* iM*
S * * *
U**H
V* • AM
X ■■ • • HI z ■■ ^ * •
Period...; - •• •
Semicolon ^m • ■
Comma • ^m •
Colon i^ ^
Interrogation • • ik
Exclamation point ^ h*
Apostrophe • hh ■
Hjphen ^ • •
Bar indicating fraction ■■ • •
Parenthesis i^ • ■
Inverted commas • ^ •
Underline
Double dash
Distress CalJ
• • ^ I
• • • ■■
Attention call to precede every transmission -'
General inquiry call
From (de)
Invitatitn to transmit (go ahead ]
- A (German)
1 • ^ ^ ^ ^ « ^ « wm
^ *" A or A (SpBoish-SraodioaviaD)
4 • * * • « CH (German-Spanish)
6 ^ • • • * ^ (French)
• • ■■ * *
^ ^ ^ • • • N (Spanish)
9 ^ HH wa BH • O (German) t) (German)
Warning— high power
Question (please repeat after ) — inter- rupting loag messages
Wait ,
Break (Bb.) (double dash)
Understand
Error
Received (O. K.l .
Position report (to precede all position mes. sages)
End of each message (cross)
Transmission fiDishcd (end of work) (conclu- siOB of correspondence]
The curious fact that so-called "air- pockets," impenetrable to wireless tele- graph or telephone waves, exist in the atmosphere was commented on re- cently by F. B. Chambers, a Phila- delphia authority on radio matters.
"There are three well-known 'pock- ets' here in the east," said Mr. Cham- bers. "One is near Pittsburgh, an- other somewhat north of New York city, and the third in the gulf of Mexico.
"The Pittsburgh one covers an area about a mile and a half square. The New York one is the largest, being fifty miles in extent. Many theories are offered to account for these strange phenomena. The most plausi- ble one is that there are certain strata of minerals underlying them which de- flect the wireless waves off at a large angle. The question of their origin, though, has never been satisfactorily solved." — Philadelphia No. American.
Learning the Code
A practical method devised for mastering the code at home is to be found in the set of six Victor-Mar- coni records which reproduce on the phonograph the international Morse Code characters exactly as they are heard by wireless. There are twelve lessons, which carry one from the novice to the expert stage.
National observers say that new radio factories have helped take the edge off the unemployment situation.
River Affects Waves
Fletcher H. Hiles of Cincinnati, a steward on the Big Four limited, run- ning between Cincinnati and Cleve- land, is perfecting a system of inter- communication between trains by means of radio telephony. He has been picking up concerts, also, while the trains are at top speed. At points where the track parallels a river the receiving is fine, but goes dead when the tracks are at right angles with the river.
RADIO AGE— "THE MAGAZINE OF THE HOUR'
17
THOUGHT WAVES m
STRANGE, indeed, that people should still be asking the ques- tion "Is radio merely a passing fancy?" Only the other day the In- ternational News Reel Corporation dug up from musty records in Eng- land papers showing how a receiving set had been made in 1879 with de- tector, condenser and all the funda- mentals of the "newly discovered devices" now engaging the fasci- nated attention of at least one and one-half millions of persons in Amer- ica alone. Not only that, but the receiving plant itself was found with the papers and the interesting dis- play has been placed on exhibition in a British museum.
Marconi was doing his wireless stunts before the boy radio enthu- siasts of today were born. DeForest and Fleming and Edison were mak- ing the Hertzian waves perform prac- tical service for the world a decade or longer ago.
Well, then, why the sudden tower- ing wave of interest in radio? Sim- ply this, that broadcasting stations have been established which send forth to the uttermost corners of the earth not only messages in the wire- less telegraph code, but music, speeches, market reports, weather predictions, baseball scores and news of the present hour.
It is the broadcasting station and the development of the vacuum tube for detecting wave lengths and clari- fying the vibrations in the phone diaphrams that have made the radio- phone an implement of universal entertainment and utility.
Men, women and children who took onlv a fleeting interest in a device which enabled them to hear unintelligible Morse code signals are aroused to intense and permanent en- thusiasm over an inexpensive and simple device that brings the great outside world to their dining room tables and to the cosy corners of their living rooms.
That is why radio has become so suddenly "popular," and that is why the present interest is surely the fore- runner of continued developments in radio. These developments will
bring radio to every-day uses which eventually will elifect a peaceful reor- ganization of our social and business life. Radio is rapidly moving for- ward to new uses which even the alert imagination of Edward Bellamy could not reach in his famous story, "Looking Backward."
Dissemination of news by radio is going to be systematized to such an extent that it will make a great dif- ference in the status of the daily press. It is perhaps true that some of our great daily journals look with apprehension at the advancement of this science and its adaptability to broadcasting news facts to the mil- lions. That may explain why some of them are giving the radiophone the most indifferent attention.
One great newspaper, so substan- tial that one might almost be tempted to describe it as "solid," said the other day that a layman might wind a tuning coil, but that the operation would require extreme patience and that he would find it to be a "man's job." Rather amusing when you and I know scores of neighborhood boys who can wind a tuner in fifteen minutes !
They have harnessed Niagara, but they are never going to stop the head- long rush of radio into universal popularity and utility. And it is go- ing to be a giant task to make it a privatelv controlled public uti''ty. Millions upon millions of dollars have already been invested in thi'^
WTORIAL TOWER
new industry and no man can keep account of the new manufacturing and merchandising organizations that are springing up each day.
In a few days we shall have the golf player getting his market and sporting news between games, sit- ting comfortably in his country club chair. Hotel lobbies, flats, apart- ments, automobiles, trains, aero- planes, farm houses, garages, school- rooms, lighthouses, ships, newspaper offices, police stations, police call boxes, prisons, hospitals, churches, theaters, restaurants, department stores, factories, fishing camps, hunting lodges — they are coming into line more rapidly than you or I realize.
It is the hour of radio. If it is a passing hour it is a passing hour that is advancing to yet another hour which shall be more electric with surprises, more fruitful of progress for the human race, more annihilat- ing to geographical distances, and more effective in weaving all peoples into a closer association. That prom- ises the ultimate in civilization.
Radio is neither a fad nor a craze. It is a stupendous social revolution.
EVERY breeze that blows brings some new tale of extravagant success or impending disaster in the radio industry. After sifting the product of the rumor mills we have come to the conclusion that the radio business is merely stabilizing itself, as every new industry must do.
Undoubtedly there are unscrupu- lous manufacturers and dealers in the game. They are trying to get a quick dollar and make a quick with- drawal before their sins of misstate- ment and of inferior merchandise overtake them. But there are many, many more manufacturers and deal- ers who are sincerely trying to estab- lish a permanent, solid radio business on merit.
Undoubtedly there are large inter- ests which would eagerly assume control of radio production and sales. Undoubtedly there are some inter- ests which would gladly adopt the
18
RADIO AGE— "THE MAGAZINE OF THE HOUR"
threadbare method of restricting sup- ply in order to maintain exorbitant prices. But there are too many en- thusiastic, wideawake American men and boys watching the situation to make it discreet for even a giant to get in the way of the steam roller.
It would be best for radio fans and best for the radio "big four" to insist upon and get an early threshing out of that charge by Representative Brittain of Illinois to the effect that the combine is restricting by some mysterious influence the placing of millions of dollars worth of tubes on the open market. Mr. Brittain insists these supplies should be sold to the public inasmuch as the government holds a sufficient supply to last the army and navy "several hundred years."
Whatever are the facts, they will become public in due time. Mean- while there is no need to leap at con- clusions.
Another tale that comes into the editorial sanctum relates to a plan by which a large manufacturer will establish broadcasting which shall be so "scrambled" that it will be im- possible for any person not owning a receiving set sold by that manu- facturer to get the stuff and unscram- ble it. That is, the receiving appara- tus will be so adjusted that it will form a complement to the sending apparatus.
The story seems absurd on its face, but intelligent radioites are seriously discussing it. The majority of them seem to believe that any such attempt at monopoly of a public utility would be defeated promptly by an honest government.
We also hear of a large concern that is sending out letters to pros- pective buyers of expensive equip- ment advising them to hold ofif a few months, as there is something new coming into the market that will make all present receiving equipment out of date and useless. More power to invention ! Let the wave wave on !
And then our friends drop in and tell us with long faces that summer weather is not conducive to good radio transmission. Therefore look out for that slump! Good old slump, the bogey man of the radio trade ! It might be well to stop and consider that hot weather does not, as a mat- ter of simple fact, seriously interfere with reception of radio waves at or- dinary distances. The boys who are getting messages and concerts from broadcasting stations in their vicin- ity today will be getting the same results on August 1. Of course, for those who want to hear messages from Germany or Hawaii, warm
weather will cause disappointment, but the mass of radio enthusiasts will scarcely detect any difTerence in their ordinary radio pursuits.
Merchants who have been stock- ing up with large consignments are supposed to be frightened by these hot weather stories, just as are the sea bathers by the annual yarns about sea serpents and sharks.
Finally, let us be optimists. Those radio merchants and manufacturers and those radio publications which are trying their best to get solid busi- ness on solid business principles are going to achieve their just reward. Anybody who is afraid of shadows has no business in the field. Roose- velt's advice is as good now as it was when he uttered it : "Speak softly and carry a big stick."
* * *
Since going to press on our pre- vious edition we have been solemnly assured by the newspaper scientists that they have discovered that cock- roaches flash radio messages to one another. We also learn that the lightning bug's lightning and the glowworm's glow and the ant's an- tennae are all a part of the radio game. We should not be surprised if these scientists had proved by the time of our next issue that the mos- quito, in thrusting its rapier into our skin is merely looking for a ground. Also that the office boys who whistle into our ears as we pass along the busy streets are involuntary and un- conscious broadcasters ; that the por- cupine is a perfect detector and the house cat makes a loud speaker when hooked into the receiving system. When the Milwaukee broadcasting stations are particularly active, it is said that near-beer is transformed into the five-per cent stuff, due to the extreme sensitiveness of malt liquor to anything that has waves in it. We agree also that girls who still have hair enough to harbor hairpins may just as well as not use a hairpin for an aerial and false teeth for a receiv- ing Ain't science wonderful?
* * *
We know a youth who made a re- ceiving set from the directions print- ed in the May number of Radio Age. He paid $3.85 for materials and dug tip an old telephone head-set and from the first day was able to get the baseball and market reports and the concerts. Within ten days he had expended $105 for additional parts to make his outfit a regular humdinger. That's the way this radio gets 'em. After listening to the home broad- casting station a few days they want to listen to coolie conversations from Wuhu, China.
Railroad Radio
OFFICIALS of the New York Central Railroad and of the re- search department of the American Telephone and Telegraph Company are studying conditions with a view to using radio in the handling of trains and of the railroad tugs and other craft that ply about the New York harbor.
According to the Central's pro- gram the wireless telephone service would be used in train service not only for communication between the head and rear ends of 50 to 100 car freight trains, but also between mov- ing trains and dispatchers' offices or other fixed stations.
"Such use would be valuable in the operation of the railroads," says the current issue of the company's maga- zine in announcing the plan, "espe- cially for communication between the front and rear of freight trains, some of which are now a mile long. In the event of anything getting out of or- der on such a train while it is run- ning, the ability of the conductor to communicate almost instantly with the engineer would be a most valua- ble adjunct to the present methods. In handling the New York Central fleet of tugs and other boats — this carrier's fleet numbers 306 units — the use of the radio telephone would be particularly worth while in time of heavy fog or other emergencies."
In course of time, officials believe, a passenger will be able to go to the observation or club car oh the Twen- tieth Century Limited and put in a call, while riding over the lines, for his office at New York to issue orders regarding business transactions ; or for his residence, perhaps, to tell his wife that he forgot some of his ward- robe and have it forwarded on the next train.
* * *
The Fere Marquette railroad has under consideration the equipment of fifty miles of its road with a new sys- tem of wireless train control, which has been invented by a Detroit man.
* * *
The Lackawanna operated a spe- cial train from Ithaca, N. Y., to New York City, on April 5, the train hav- ing been equipped with both sending and receiving apparatus. The pas- sengers were Corsell students. Dur- ing the entire run communication was maintained with several amateur stations and special programs were received from two broadcasting sta- tions.
* * *
The Chicago, Milwaukee & St. Paul road has installed receiving sets on the Pioneer Limited.
RADIO AGE— "THE MAGAZINE OF THE HOUR'
19
The Radio Club of Illinois
By BARRATT O'HARA
One of the Directors of the Club and Former Lieutenant Governor of Illinois.
CHICAGO is out to lead the world in radio. From early summer until late autumn the metropolis on the lake is to be turned over to the pioneers in what Mayor William Hale Thompson declares is an industry that will surpass in mag- nitude anything the world has ever known. The mayor, the city council and the leading business and profes- sional men of the city have united in putting Chicago in the race to be- come the world's radio capital.
"No one can even dream how rap- idly the radio industry will grow," said Mayor Thompson. "Chicago is now the third largest city in the world. If we can center the radio interests here, within five years Chi- cago will be the largest city in the world. So far from believing that radio is a temporary fad, we in Chi- cago are so convinced of its per- manency and importance that we are willing to let our dreams of leading the cities of the universe in popula- tion rise or fall with the radio indus- try."
The first step in Chicago's cam- paign was the organization of the Radio Club of IlHnois. Starting with a $125,000 club house at 4220 Sheri- dan Road, in the finest section of the city, the Radio Club of Illinois almost overnight took its place among the best of many magnificent social club organizations of Chicago. Mr. Schmitt Is President
It was fortunate in its selection of a president, Lawrence B. Schmitt, the government inspector for radio in the thirteen middle western states, being unanimously elected to head the club during the first year of its existence. Mr. Schmitt is a young- man of thirty, full of pep and enthusi- asm and one of the best authorities on the wireless in the country. He is extremely popular among radioists throughout the extensive district that he serves. Col. John P. Tansey was made secretary of the club. Among the directors elected was Al- fred Thomas, Chicago manager for the Radio Corporation of America. All persons interested in the wireless are eligible in membership, the aim of the club being to furnish the tech- nical, professional, commercial and amateur radioists a common meeting l-'lace, with extensive privileges and conveniences usual with first-class clubs. The club is the center of the radio activities of Chicago, and Hs
influence in the crystalization of sen- timent back of needed radio legisla- tion is probably destined to be second to no organization or group.
The club is in charge of an inter- national radio congress to be held in
"^""^
Inspector L. R. Schmitt
Chicago during the first week in August in connection with the Pageant of Progress. Delegates from every state in the union and many foreign countries will partici- pate in the Congress, at which sub- jects of vital interest in the industry will be discussed by such authorities as Steinmetz, Armstrong and Secre- tary of Commerce Hoover.
Mexican President Coming?
As indicating the widespread in- terest in the congress outside of Chicago it may be mentioned that President Obregon, of Mexico, who is a great radio fan, has intimated his intention of attending as the head of
the Mexican delegation. Invitations have been sent to the governors of all the states to attend as the chair- men of their respective state delega- tions, and it is not unlikely that most of them will accept.
An interesting feature of the con- gress will be sessions devoted to the boy radioists. This will be presided liver by one of their own number, possibly the young son of Secretary < if Commerce Hoover. It is reported irom Washington, on authority that ^eems to be reliable, that Mr. Secre- tary Hoover's final arbiter on all deli- cate radio questions is his son. The boy knows radio from start to finish. He is called into every conference on radio held in the official offices at Washington. He will attend the congress with his distinguished father, and it is more than likely that the boy radioists will call upon him to preside over them.
Mayor William Hale Thompson and Dr. John Dill Robertson, presi- dent of the Pageant of Progress, are naturally taking a keen interest in the success of the congress. They are ex-officio members of the execu- tive committee of the congress, con- sisting of City Electrician George E. Carlson, chairman ; Col. John P. Tan- sey, secretary; George B. Foster, vice-president of the Commonwealth Edison Company; Lawrence B. Schmitt, U. J. Herrmann, Dr. W. A. Evans and Barratt O'Hara. This committee will meet weekly on Mon- day evenings at the offices of the Pageant of Progress, 7 West Madi- son Street.
Personnel of Committees
Radioists with suggestions to make for the success of the congress will be welcome at any of the meet- ings of the committee. Barratt O'Hara was made chairman of the publicity committee, the other mem- bers of which are Frederick Smith, editor of Radio Age ; W. G. Wunder- lich, editor of Radio Topics; G. H. Jaspert, in charge of radio in the Chi- cago office of the Westinghouse com- pany ; W. S. Hedges, radio editor of the Chicago Daily News ; Charles Sloan, radio editor of the Chicago Daily Tribune, and William J. Clark, radio editor of the Chicago Amer- ican.
Interesting programs have already been outlined for radio meetings that will mold radio history.
20
RADIO AGE— "THE MAGAZINE OF THE HOUR"
Questions and Answers
Conducted by FRANK D. PEARNE
C. H. N., Belleville, 111.
Question : x^m making a radio set according to the lesson prepared by the U. S. Bureau of Standards, and am puzzled in platting up the an- tenna. The only way I can run a 75- foot wire is by erecting a support, which I do not wish to do if there is another way. Can I run the wire around the four corners of the roof or can I run several wires parallel to each other, and how far apart should the wires be? Do you think a loop will work satisfactory, and how is it made?
Answer : It is not so much a ques- tion of whether the aerial will work or not, but how well it will work. Al- most any kind of an aerial will work, and you must remember that you are trying to work with a crystal detec- tor set, which, at the best, is not very strong, so the only way you can make up for this weakness is to use the best possible aerial. A single wire 150 feet long would be the best. You can run several wires in parallel as you suggest, but make them as long as possible and space them two or three feet apart. You can also run the wire around the roof if you wish, but such aerials are not considered very good on account of the water spouts, etc., which run down to the ground, causing a leakage. J. L. G., St. Louis Mo.
Question : I am now constructing a crystal detector set as described in your May number, and would like a little information. Would a fixed condenser, or a variable condenser, or both, increase the efficiency of this set? If so, how would I wire the condensers to the set? I am just a beginner at this game, and would ap- preciate any information you can give me as to how to make these con- densers and wire them to my set. In Figure 4 of your April number, page 13, in drawing of completed set, it shows two short pieces of wire be- tween your ground and antenna. Should these short pieces be touch- ing, or a gap in between ? What pur- pose does this accomplish?
Answer: Yes. Connect the fixed condenser across the two binding posts, to which the head phones are connected, and connect the variable condenser across the aerial and ground binding posts. It would not pay to make these condensers, as the fixed condenser can be purchased for about 50 cents, and the variable re- quires too much skill, and too many special tools. The two short pieces of
wire which you mention should not touch, but should be spaced about jj- of an inch apart. They act as a safety discharge gap for charges which may accumulate on the aerial during an electrical storm. W. R. N., Maywood, 111.
Question : Can my set be im- proved by using a variable con- denser, and how much farther will I be able to receive radio messages if I use one in my set? I am enclosing a diagram showing how I have it con- nected up. Will you kindly make a sketch telling me how to connect it in my set? Is an antenna 75 feet long with 4 wires all right for this outfit? One end is fastened to a tree. Will this make any difference?
Answer : No doubt the addition of a variable condenser will help your set, but it would be hard to say how much it would increase the range. You will find that on certain nights you can hear much farther than on others. This is due to atmospheric conditions, and you should not blame it on to your receiver. Your aerial is good if it is high enough. It should be at least 35 feet in height. The tree will not interfere with it. Dia- gram showing the connection for the variable condenser follows :
TWO SLIDE TUTSriN& COIL
DETECTOR
-[>
FKED CONDEESEE
#
CONDENSEK
■^ GROUOT)
R. D. M., St. Louis, Mo.
Question : I am contemplating building a radio set described on page 7 of your May issue, but wish to build the tuning coil on a cylinder 2}i inches in diameter instead of 4 inches. Can I use the same number of turns and taps as on the 4-inch coil? If not, what do you advise?
Answer: Yes, you may use the same number of taps and turns. The only difiference will be a slight reduc- tion in the wave length on account of the decreased inductive efifect. V. B., Evanston, 111.
Question : Please tell me how to hook up a vacuum tube with the ter- minals marked +, ^, G and W. Will a sal ammoniac or battery work on
a vacuum tube? If they will, how many will it take ?
Answer : I do not understand your first question. The terminals on a vacuum tube should be marked F, F, G and P, in which F means filament, G means grid, and P means plate. If you are speaking of the marking on the panel, it would be necessary for you to send in a draw- ing of the circuit of your set. The batteries which you mention will not do, as the sal ammoniac cells would polarize in a few minutes, and the current from the gravity battery is not strong enough. N. E. C, Chicago, 111.
Question : Where can I buy the parts for making a radio set which will receive messages from all the stations east of here? What kind of a radiophone will be required, and how much will it cost?
Answer : There are numerous ra- dio supply houses in Chicago, and most of them advertise in the maga- zines and papers. You will need an audion detector set and a two-stage amplifier for this work, and if you are going to construct it yourself, I should judge that it would cost you fifty or sixty dollars. With this out- fit you should be able to receive mes- sages from a distance of 1,000 miles or more. C. B., Chicago, 111.
Question : What causes the crack- ling noise in my phones? Some nights I can hear Detroit and Pitts- burgh' just fine, and then on another night I don't get them at all. I have looked over all the connections and they seem to be all right. Do you think it could be in my batteries? I have changed them once and it did not seem to make any difiference. The nearest trolley line is three blocks away ; could this make the noice and if so, why don't I hear it all the time, as the cars run day and night?
Answer : Your trouble is no doubt due to static. This is a condition which occurs quite often, and espe- cially so in the summer time. There is no remedy for it that I know of, and if you are sure that all your con- nections are good and your batteries are all right you can not do anything more. B. J. E., Janesville, Wis.
Question : The boys of our club are building a radiophone sending station and we would like to know whether or not we will have to get a license for sending before we can use
RADIO AGE— "THE MAGAZINE OF THE HOUR"
21
Questions and Answers
Conducted by FRANK D. PEARNE
it. We only expect to use one 5-watt tube, but might possibly get another one if necessary.
Answer: You must procure a li- cense from the Government inspec- tor in charge of your district, or you will be in trouble as soon as you be- gin to use it. This will cost you nothing, but you will have to show that you understand what you are doing before a license will be granted. You will also have to be able to send and receive the required number of words per minute, and keep your wave length down to 200 meters. W. B. R, Lincoln, 111.
Question : I have a radio outfit which is made up of a two-slide tun- ing coil, crystal detector, condenser, and a pair of 2,000 ohm receivers. I have tried to connect them every possible way, but the best I can get out of it is a humming noise. Will you please tell me what is the matter, and draw a picture showing just how it should be hooked up so that I can hear something besides a hum?
Answer : The two diagrams which you enclosed are wrong. Connect the set as shown in the following diagram :
CSOUND
The humming noise which you hear sounds as though you were pretty close to some electric power line. If this is true, change your aerial so that it will be at right angles to this line. R. J. Z., Fort Wayne, Ind.
Question : If it will not be impos- ing too much upon your good nature I should like to have you answer a few questions for me, as I am in great trouble. Will an aerial which is 6 feet above the roof attract lightning? My landlord says that it will and in- sists that I take down my antenna or move out. I understand that it is really a protection, rather than a
hazard, but he says the insurance company will raise his insurance un- less it is removed.
Answer: Your landlord is mis- taken. If you protect your aerial with the proper kind of a lightning arrester and switch, the building is safer than it would be if the aerial were not there. I think the question of insurance is a bluff, because the in- surance companies as a rule know that a properly protected aerial is really a safeguard against lightning. C. C. C South Bend, Ind.
Question : Does it make any dif- ference which way the battery is hooked up to my audion set. I was told that it made no difference which way it was wired. It seems to work much better when the red wire is connected to the receivers, but when I connect it this way the bulb gets blue inside after I use it a few minutes.
Answer : By all means connect the positive to the plate, otherwise no current will fiow through the tube and the receivers. This is probably the red wire which you speak of, as you say it works best this way. The blue appearance of the bulb is caused by too high a voltage on the plate. Try cutting it down and see if this don't stop it. E. L., Muscatine, Iowa.
Question : My crystal detector set is an Amrad. How far should I be able to hear music with this set? I have never been able to hear KYW at Chicago, although I can hear Dav- enport quite well at times. Please let me know as soon as possible, as I understand the Chicago music is good, detector set is about 50 miles.
Answer : The range of a crystal detector set is about 50 miles.
Inside Aerials Safer?
Ben F. Clark, chief electrical in- spector for the city of Detroit, is tell- ing radio fans of safeguards against the hazards of lightning and high fre- quency surges from electrical power lines.
"Outside aerials can not be made absolutely safe," Mr. Clark says. "The utmost precautions known to electrical engineers can only mini- mize the danger from lightning and high frequency surges.
"The inside loop or aerial can be made absolutely safe, and inside in- stallation is just as effective as out- side installation for receiving from
all ranges, and with all kinds of equipment.
"The city bureau of electrical in- spection urgently recommends inside aerials without exception. Fire in- surance companies are joining us in this recommendation. All radio en- thusiasts who insist on using outside aerials should arrange for the bureau of electrical inspection to supervise the installation. The city electrical engineers will be glad to do this in every case."
Newspapers and Radio
ONE after another the newspapers of the country are adding a ra- dio department to their news sec- tions. Many of them are producing really comprehensive, instructive ma- terial on construction and operation. Almost all of them in the neighbor- hood of the larger broadcasting sta- tions are publishing the daily pro- grams.
The Chicago Herald and Exam- iner, which has one of the best radio departments in the country, edited by "Tom" Coates, publishes pro- grams of eight stations in as many widely distant cities. The Herald and Examiner wisely gives the Chi- cago time of the commencement of these programs, relieving the reader of much trouble in trying to adjust geographical differences and in sort- ing out those cities that differ in their daylight saving ideas.
The Chicago American also has a useful radio section. The American is a pioneer in this field. The Chi- cago Daily News not only has a daily radio department, but issues a spe- cial radio section on Saturdays. The Daily News has established a radio service to be broadcast through the Fair radio station. Meanwhile it is using the KYW station.
The Detroit Daily News has at- tracted country-wide attention with its powerful transmitting station and its alert radio news department. The News has a booklet on the press which it will mail free to all who send their names and addresses and ask for a copy.
A radio broadcasting station has been opened in the building of the San Francisco Examiner.
The Kansas City Star has installed a 500- Watt, Western Electric broad- casting station similar to the Detroit News equipment. The new station already has stimulated radio interest in Missouri, Kansas and Nebraska.
22
RADIO AGE— "THE MAGAZINE OF THE HOUR"
Making a Transformer
(Continued from page 8)
the hole and begin winding. After 12 turns have been wound punch an- other hole in the tube and twist the wire into a long loop about 12 inches long, which is threaded down into the tube through the hole and then continue with the winding until an- other 12 turns are wound, when an- other hole is punched, and another loop is made and put down into the tube.
This process is continued until 15 coils of 12 turns each have been wound, and the final end of the wind- ing is brought down through the last hole. There should now be 14 loops and 2 single ends of the wire which have been put down into the tube, and the winding on the outside should be perfectly smooth. As these ends and loops begin to bother while winding, they can be temporarily folded back inside of the tube to keep them out of the way. This coil should now be varnished with shellac and allowed to dry.
Making the Switch
The switch should now be con- structed. The best way to make this is to purchase the contact points and the switch lever with a hard rubber handle already mounted on it, from some electrical supply dealer. Any store that deals in radio apparatus can supply this, but if it is not con- venient to do this make the switch contacts out of 6-32 brass machine screws. These are put through the holes shown in the frpnt view of secondary end "C" Figure 2 and fast- ened on the other side with a brass nut. The switch lever "L" as shown in Figure 3 is made of spring brass g'a of an inch thick and turnover about -^ inch on the end, so that it will make a good contact on the con- tacts. An 8-32 brass machine screw holds this in place on the secondary end "C" Figure 2. A brass washer is first placed on the screw, then the switch lever, another washer, and the screw is then put down through the hole in the center of "C" and clamped fast with a nut on the other side. Before this is fastened how- ever, some kind of a knob should be pinned fast to the switch lever as shown in Figure 1. Fasten 2 bind- ing posts with screws through the 2 bottom holes shown on "C" and you are now ready to wire the switch.
All the loops and ends are all brought out of one end of the tube. As the end of the tube from which the wires now project is to be forced over the projection on "C" and glued fast, the connections will have to be
SECONDARY END "D"
ROD SUPPORT E'
FRONT VIEW
SHEtT BRASS F
T
END VtEW
Switch LsvEJi "L '
— ^-■t' iV
1/8
I
\J
^ I" ^
SQUARE BRASS ROD J
EZ
It-/"--)!
Z2i:p:>V
FRONT VIEW END VIEW
SPRING BRASS "H "
I
It --2"- - ^ /(,4TMICH
ROUND BRASS Rod "K '
D
_ _7" 4 %V
T.r:Sr'/^
-H'A-
FIGURE 3.
made with plenty of slack in the wires, so that they can be pushed back into the tube after they are soldered to the switch contacts. Be- gin by soldering the wire from the distant end of the coil, to the last contact and the loop next to it, to the next contact etc., until they are all connected, except the last single wire which is connected to one of the bind- ing posts. The screw which holds the switch arm, is then connected to the other binding post. Now push the tube over the projection on "C" and glue it fast.
Assembling the Coil
The secondary end "D" Figure 3 is now glued into the other end of the tube, being careful to see that the y^ inch holes for the supporting rods line up right. Next, the 2 brass supporting rods "K" Figure 3 are put through the holes in both sec- ondary ends, and the coil is as- sembled and mounted on the base, as shown in Figure 1. One end of the brass supporting rods is held in place by the holes in the primary end "B", and the other by means of the holes in rod support "E" Figure 3. When all the parts are mounted as shown in Figure 1, the secondary should slide in and out of the primary without touching it at any point. Now procure a piece of square brass rod J4 inch square and 7 inches long and drill a Y^ inch hole at a distance of -i^ of an inch from each end, as shown as "J" Figure 3.
A piece of soft brass 1 inch square and -^ inch thick, "F" Figure 3 is bent so that it will fit around the brass rod, as shown at "G" in Figure 3. A piece of thin spring brass "H"
is soldered fast to the bottom of "G" as shown at "1" and is bent into the proper shape to press on the wires of the primary, when placed on the rod and mounted as shown in Figure 1. A hard rubber or wooden knob can be fastened to the slider.
The square brass rod is placed in the slots in the top of the primary ends and fastened with brass wood screws.
Carefully clean ofif the insulation from the wire on the primary in a straight line under the slider, so that the slider spring will make a good electrical contact with the wires, as it slides back and forth. Connect a wire from the slider rod to one of the bind- ing posts on the base, and connect one end of the primary coil to the other binding post, leaving the other end of the primary coil dead, and not connected to anvthing.
WIRING DIAGRAM 'aerial
DETECTOR
— [H
SECONDARY
8
PHONES)
^^ G-RQUND
FIGURE 4.
RADIO AGE— "THE MAGAZINE OF THE HOUR"
23
Radio News from Coast to Coast
Readers who have reason to be proud of achievements in Radio in their own localities have a place in this depart- ment of Radio Age to tell the rest of the country about it. Contributions will be welcomed.
Arkansas
RADIO fans cannot be classed as nuisances, according to a court decision in Little Rock. It was objected that operators of wireless equipment were making "buzzing noises" between the hours of 9 p. m. and 7 a. m. The court held that wireless inconveniences must be tolerated just as we have to tolerate the blowing of whistles and the rattle of street cars.
Citizens of Pine Bluff are buying a fine receiving outfit for the State's Industrial School for Boys.
California
San Francisco police say they have nipped a system of tapping news of stock market operations. The wireless tappers are said to wear a hidden belt supplied with power sufficient to transmit mes- sages. Even if true, the police fail to explain how any law is violated.
Amateurs' interference prevented the clear receipt of a telephone mes- sage sent from the Westinghouse station in Newark, N. J., to the Rockridge station at Oakland. An- other test will be made. Newark stations report having heard conver- sation from San Francisco, but not during official tests.
Church of the Open Door at Los Angeles claims to be the first church to install a transmitting station. It will operate Sunday mornings and evenings and Wednesday evenings.
Mr. and Mrs. Charles Adair of Los Angeles started on an automo- bile trip to New York April 21. Their car is equipped with a radio phone.
Colorado
The Northeastern Colorado Radio Club has been organized at Ster- ling. H. T. Van Valkenburgh is president.
Indiana
Radio phone has been purchased by Paul O. Moyer Post, American Legion, at Hartford City. Public concerts and market reports for farmers will be featured.
Mrs. Harriet Steele, 68 years old, listened to songs by her daughter, Miss Floss Steele, transmitted from Chicago to LaPorte while a 5S-mile storm was raging.
Iowa
Davenport's transmitting station is lo- cated in the Palmer School. It sends out educational talks between 3:30 and 4 p. m. Concerts are broadcast between 7 and 8 evenings.
The radio phone at the Auto Supply Co. at Estherville has become the most popu- lar thing in that part of Iowa.
The Times-Record Co. of Aledo has in- stalled a radio outfit.
',J>^
Alan N. Cormack's motor launch "Spoonbill," of San Francisco, is completely
equipped with radio apparatus. When tired of navigating, he listens to concerts and
news reports. International News Reel Photo.
Charles G. Pelton of Waterloo, 21 years old, has been a radio student for seven years. He formerly was in charge of wireless work for the Government in Samoa and at Honolulu. He was the only white resident on one little Pacific island for 17 months.
Davenport Y. M. C. A. will not only install radio equipment but will start a radio school.
Iowa Radio Convention was held in Boone April 28 and 29 under direction of
Iowa State College, and attracted visitors from all over the state.
Dyersville has a station that picks up Newark on the east and Denver on the
west.
Frank Allen, 117 Marshall street, Boone, sent a message that was heard in Chris- tobal, Panama, 2,500 miles distant.
Kansas
Hutchinson and Wichita are installing radio equipment for police communication
24
RADIO AGE— "THE MAGAZINE OF THE HOUR"
concerning pursuit of escaped criminals and automobile tiiieves.
It is reported that the American Tele- graph and Telephone Co. is contemplating installing a broadcasting station at Hutch- inson. The announcement was made by H. J. Bamford, radio specialist, connected with the Hutchinson Grain Radio Club, Inc
Louisiana
M. M. Mandot, superintendent of the Columbia Light and Power plant at Co- lumbia, is back of a plan to install a trans- mitting station at Columbia.
Mr. Edward T. Jones, formerly radio supervisor Gulf Division, U. S. Shipping Board, and at one time associate editor Radio News of New York, radio editor, experimental science of Washington, D. C, has resigned from the board to ac- cept a position in the capacity of manager radio department of the Electric Supply Co., 324 Camp street, New Orleans. The Electric Supply Co. has been appointed a RCOA distributor.
The Louisiana Fire Prevention Bureau warns radio users not to ignore fire laws and insurance regulations in installing out- fits. It offers to inspect outfits on request.
Massachusetts
Boston experts are interested in devices designed to not only automatically regis- ter S O S calls from ships but have such calls accompanied by an alarm device tl.at will attract the attention of any person in or near the station.
It is announced in Boston that the In- ternational Radio Corporation will have a string of 100 retail stores in the principal cities of the country.
Hundreds of New England amateurs heard the remarkable tests carried on 1,600 miles between the steamship America and several land stations. The America was equipped with two distinct aerials, one for transmission and one for receiving.
A radio constructor and adviser sued for his pay and when he tried to explain tech- nical radio to a jury in Everett the venire- men asked that he repeat it all. Then they took a recess to rest their brains.
Carl E. Berg, 8 Douglas street, East Lynn, a radio specialist, induced the an- nouncer at the Medford Hillside one night recently and