Radio mirror (Jan-Oct 1923)

limn RADIO DIGEST June 23, 1923 HOW AMATEUR CAN AID NATION IN WAR INTERCEPT MESSAGES OF ENEMY AT FRONT "Qualify in Radio — No Better Way to Serve," Says Signal Corps Officer WASHINGTON. — There is practically no end to the possibilities of Radio for military use, an officer of the signal corps stated recently, adding that, young men who wish to serve their country can do so in no better way than to become qualified in Radio and to join the National Guard or Signal Reserve Corps of the U. S. Armj-. As an instance of the work of former amateurs who served in the signal corps during the war, it is said that 73 percent of the 400 Radio men engaged in intelligence work were ex-amateurs. Not a single "leak" occurred in the service, which intercepted 73,000 enemy messages and recorded 175,000 bearings on enemy Radio stations. The country is greatly indebted to these amateurs for their war work. Radio Intelligence Work Although littfe was known of the work of the Radio intelligence section of the army during or since the war, it was one of the most spectacular. Radio direction finders were placed all along the lines, at a distance of about five miles from the actual front and spaced about twelve miles apart. These receiving sets located the enemy stations in operation, recorded their bearings by means of directional coils, not unlike modern Radio compasses, and forwarded the bearings to headquarters where they were plotted on maps. The reports from many American Radio observers enabled the staff to keep an accurate check on practically all the German stations all the time. Other receiving stations at army headquarters, intercepted and copied -all enemy code messages, and telegraphed them back to general headquarters where code experts worked them out, giving the staff valuable information as to the movements or intentions of the enemy. German's Make "Faux Pas" On one occasion, when the Germans were planning a big offensive, the code all along the line was suddenly changed. The old code, known by the Americans for some time, became valueless. But one German officer could not decipher a long message sent him in the new code and asked his commander to repeat it in the old one. This was done and as the American intercepting stations copied both messages, the staff of experts at headquarters soon had a fair solution of the new code, which they eventually worked out in its entirety. The repetition of the message in both codes was more than they hoped for, and when the new code was transmitted to the French and British headquarters, the American Radio intelligence service was credited with a big "scoop" in aiding the Allies in securing advance information. Vernier Var. Condensers COMPLETE WITH KNOB AND 3 IN. RUBBER DIAL $5.00 Value 11 plate with 3 plate Vernier $2.00 5.50 Value 19 plate with 3 plate Vernier 2.15 6.50 Value 41 plate with 3 plate Vernier 2.50 Plain — I Plain — 3 Plate $0.75 23 Plate $1.25 11 Plate 98 I 43 Plate 1.50 Include 5c per item for parcel post. CHI -CITYRADIO CO. 94S CRESCENT PLACE, CHICAGO, ILL. ."5RMICX A kmimtal PKf nolk Hindensanon Product . SHEETS TUBES RODS RADIO PANELS POLISHED BLACK FINISH CUT PERFECTLY SQUARE TO ANY SIZE 3^32 THICK /2* PER SO. INCH V\%" THICK Y4< PERSQ.INCH %2" THICK \< PER SQ. INCH Ye " THICK l'/2* PER SQ. INCH z/\&" thick 2« per so. inch '/4 " thick 2/2< per sq. inch 3/b " thick a< per sq. inch !/2 " thick 5 v4* per sq inch ;send for complete price list Prompt attention to mail orders dealers prices on application STAR RETT MFG. CO. 519 SOUTH GREEN ST. CHICAGO BRITAIN AIDS JAPAN TO BAR U. S. RADIO Marconi Company's Six Gigantic Stations Will Establish Complete World Monopoly SAN FRANCISCO. — Great Britain is using its diplomatic influence at Peking to aid Japan's opposition to the entry of American Radio companies to China, according to Emmett White, attorney, writer and former director of the insular and foreign division of the American Red Cross in China, who arrived from the Orient recently. It is believed by American residents of Shanghai, says White, that with the completion of six gigantic stations reported to be under construction in England by the British Marconi Company, Great Britain hopes to establish a complete world monopoly of the air, assisted by Japanese stations in China and 3Ianchuria. The Federal Telegraph Company of this city is keeping the cables and telegraph wires busy with appeals to Washington, urging that the State Department take action on the reported refusal of the de facto government at Peking to live up to the terms of an agreement permitting the installation of Federal Radio stations at six Chinese ports. Fort Worth Bids for Third Big G. E. Plant Location in Southern U. as Inducement S. Held FORT WORTH, TEX. — The tremendous Radio interest in the territory for hundreds of miles around Fort Worth, largely developed through Station WBAP, and the fact that Fort Worth is near the center of the southern half of continental United States, is offered as an inducement in bidding for the third huge broadcasting station which the General Electric Company is planning. The ordinary service radius of a station of this kind would be more than 1,500 miles. A similar station is now being erected at Oakland, Calif., and the parent station is WGY, Schenectady, N. Y. Place Radio in Hospital to Cut Use of Narcotics NEW YORK. — A complete Radio outfit with more than 150 headsets is installed in Beth Israel hospital for use of the patients. Louis J. Frank, superintendent, said he believed Radio would diminish the giving of narcotics and sleeping potions and ease the patient's mind. Cockaday Circuit TUNER COILS BC AND D COILS Complete as per specifications No. 18 Wire Used — D CoQ Bankwound. Price, $2.75 Hook-up, directions and material list furnished free with each set of coils. MAIL ORDERS FILLED Dealers, Communicate Eastern Radio Mfg. Co. 22 Warren St., Dept.R.D., New York.N.Y. DON'T PASS THIS-BUY^ I World Radio Batteries SAVE YOU 50% wrntiCN 2yo ciMn vVKITTKN 2 YEAI< GUARANTEE Every World User Is a Booster Because you deal direct with a manufacturer who is responsible for the performance and quality of the Battery. World-Radio-Batteries 6 Volts — 40 Amps., $8.50 6 Volts — 60 Amps., 6 Volts— 80 Amps., $12.50 6 Volts— 100 Amps., $10.00 $14.50 6 Volts $ 1 6.00 120 Amps. Full Rating Guaranteed MAIL YOUR ORDER TODAY. WE SHIP EXPRESS C. 0. D., SUBJECT TO INSPECTION, OR WILL ALLOW 5% FOR CASH WITH ORDER. ALL ORDERS SHIPPED SAME DAY AS RECEIVED. WORLD BATTERY COMPANY, 60 E. Roosevelt Rd., Dept. L, Chicago, 111. SMALL REGENERATOR (Continued from page 5) Rheostat Homemade Because there is very little space on the panel the filament rheostat is fastened on ^.TOGRID CON0.& FIXED PLME.S Of V.C. TO GROUND* V.C. ROTOR,_ 1 ur CONTACT 2 22 CONTACT (—312 CONTACT r<H* CONTACT r-5 -CONTftCT |— .TICK.LE.R* Figure 4 the left side of the case. There being none small enough on the market, the rheostat is made from a piece of % -inch diameter hard rubber rod, %-inch thick, and grooved on its outer edge to take the resistance wire coil. The contact blade is %-inch long and is turned by a %-inch knob and dial 1 %-inch in diameter mounted in the center on the left side of the case as shown in Figure 1. The peephole in the top of the case consists of a hard rubber ring, 1"A inches in diameter, below which is fastened a circle of nickel plated screen. Special Sets Made to Order Let us quote you on any circuit. Sets made under expert supervision. We repair sets and test tubes. FORBES RADIO CO. 127 N. Dearborn St. Chicago, 111. . T"FT^ IY rilViM Crystal Fans Wake Up "The Vacuum Tube's Only Rival" Lasts Indefinitely 50c Approved by Mail, Tribune, Radio World RADIO CORPORATION OF AMERICA OPERATIVES use the L. D. R. Crystal as detector in conjunction with one or more stages of amplification. Satisfaction Guaranteed or money refunded. JACK BINNS OF S. O. S. FAME Badlo Ed. Tribune Badio Laboratory, recently awarded a certificate of excellence to the L. D. B. Super-Crystal, stating— "The L. D. B. Super-Crystal Is exceptionally sensitive and covered with many amplification spots. All that can be desired in a real good radio crystal that will last indefinitely." FREE Crystal Amplification Hook-ups. FREE the 1000 Mile One Tube Beflex Hoot-up. JAYNXON 57 Dey St. LABORATORY New York City Kellogg Radio Equipment For Better Results VARIOCOUPLER The Kellogg variocoupler is of the same standard design as our variometer, being made of molded Bakelite, with reinforced construction. For increasing the wave length from 500 to 2,500 meters, the Kellogg standard wound induction is added to the variocoupler. It is arranged for either panel or base mounting. No. 501 Variocoupler $9.00 With No. 502 Diamond Wound Coil, as shown in illustration $13.00 Kellogg Switchboard & Supply Company CHICAGO front Panel Assembles The front view of the assembled panel is shown in Figure 1. The antenna, switch is in the upper right corner of the panel, surrounded by five contact points. In describing the winding the contacts were referred to as first, second, third, etc. First means the contact nearest the top, while the fifth contact means the one farthest to the right. The two lower left binding posts marked G and A are for ground and aerial respectively, while the two lower right binding posts equipped with phone tip clips are for the headset. It is well to note here that the ground binding post and the aerial switch lever screws go through the screw holes in the Variadon, thus serving to fasten the latter to the front panel. The four holes in the corners of the panel pass the brass machine screws fastened through the reinforcing blocks in the corners of the case, and small knurled knobs fasten to these screws to hold the panel and attached apparatus in the case. This remarkable miniature regenerative set occupies an extremely small space and has excited great interest in Radiophan circles, not only on account of its size but because it has consistently received stations 800 miles away. A meter is equal to 39.37 inches. TWO SUPERSENSITIVE CIRCUITS (Both Copyrighted) My Highly Improved Reinartz brings in all Important stations on both coasts and Mexican border, loud, clear and without distortion. We dance to music from Atlanta received on one loud Baldwin unit. Build one of these wonderful sets from my blueprints and specifications, price 50c. or with a perfect and complete double wound spiderweb coil, $3.00 by mail. No other windings used. Phot* of my set on a glass panel with every order. This copyrighted circuit is the most successful .of any Beinartz modification yet produced, and is imitated the most. Thousands are in use. My W. D. II Circuit is especially designed for use with the "Pickle" tube and brings out the full value of that little tube as no other circuit can. Stations 1000 miles away come in clearly on one tube. This set is small, complete, portable. For the man who wishes the highest efficiency, this is the set to build. Price of blueprint and specifications, 50c, or with complete and perfect windings, $3 00. Photo of set with every order. Either set-4s easy to build, easy to operate. Everything clearly shown. Sets built from these plans will receive all broadcasting stations operating under the new laws. Their wave length range is from 140 to 670 meters. S. A. TWITCHELL 1925 Western Ave. Minneapolis, Minn. t&ma&e PRINTS for the construction of a Flewelling Receiving Unit and two step amplifier. ALL DETAILS FOR ASSEMBLY Description of apparatus and accessories and details of tuning. CABINET DIMENSIONS PANEL LAYOUTS LIST OF PARTS Send only money orders — no checks or stamps. Coins at your own risk. 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