Radio Digest (Apr 1925-Jan 1926)

RADIO DIGES T— Illustrated June 13, 1925 SET NEW RECORD IN RADIO FOR 'PLANES CONVERSATION IS PERFECT IN TWO-WAY AIR TESTS AIRPLANE DH4B CALLING WLS (WA1) Communication Is Clear at Distance of 110 Miles — Make New Tests Soon CHICAGO. — World Radio records -were broken in remarkable tests made between land and airplane stations during the recent military tournament in Chicago, according to Curtis D. Peck, engineer-incharge of WLS, the Sears-Roebuck station, who had charge of the tests made with army airplanes. Rebroadcasting of the conversations between WLS and the flying machines so that the public heard everything .that was said, was another feat performed successfully. During these same tests the world record for plane-to-plane two-way Radio communication also 'was broken. The previous record for two-way communreaijpon between a land station and an airshTp by Radio was forty miles. The record made between WLS and the army airplane, in command of Lieutenants Lawrence P. Hickey and Charles H. Howard, was 110 miles, and the reception was so clear at this record point that Engineer Peck says another attempt to break this new record will be made in the near future. The plane-to-plane record was 15 miles, as compared to a previous record of five miles. The army operators were Lieutenants Johnson and Salsman. Tests at 4,000 Feet "The tests were made while the flyers were 4,000 feet in the air," said Mr. Peck, "and the reception was very clear at both ends. From our station we kept in constant touch with the flyers all the time. When they reached Harvey, 111., we were delighted at the clearness of the talking. Then we .heard them from Madison. Monee, Peotone, Bourbanais and Kankakee. The army fliers came down at Chanute field, which was a distance of 110 miles, and our communication was so good then that I am sure we can make a much greater distance record in our next tests, which will be in the near future." The army airplanes used a 50-watt master oscillator sending set. WLS used a five tube receiving set, while the army men used an army eight tube superheterodyne. A two-pound lead weight held down the trailing antenna. Within the city limits the army men had a -50foot wire over the side of the airplane, while as they got father away they used a 200-foot aerial to transmit. The spectators could hear both conversations as they watched the airplanes obey the broadcast orders. PERFECT SECRET RADIO (Continued from page 1) the government for some time and has been granted certain wave lengths on which to experiment. It will present a scheme to the Theatrical 'Managers' association in opposition to that of the British Broadcasting company, which is now under consideration. As no actual arrangement for the broadcasting of plays exists between the B. B. C. and the T. M. A., the new concern believes it can break down the B. B. C.'s monopoly and establish competition in broadcasting. "It we come to an arrangement with the theater managers," said Mr. Chisholm in an interview, "we would broadcast plays which could only be heard by those in possession of our patent component and of our weekly program, which would give the wave lengths upon which we propose to broadcast each program. "There is no doubt whatever about the success of our experiments, and the government will probably take up the system and use it for official and naval purposes. That is really the chief scope for the scheme." Means Privacy in Radio The system was demonstrated some months ago before representatives of the British air ministry and the war office. The method employed is a variation of wave lengths made synchronously on both the transmitter and the receiver. While oni object of the new concern Is competition with the B. B. C, it is also Bald that the chif-f idea behind the launching of the enterprise is to enable Radio messages to be sent privately, and furthermore that the system may be adopted by the P.. B. C. to circumvent thfactlvities of those fans who refuse to pay their Iicen The broadcasting monopoly held by the British Broadcasting company does not expire until the end of i;»2fi, and no other broadcasting license can be issued during the intervening period un'ess the post office firids serioU8 fault with the conduct of the company in possession of the contract. Iiieut. J. S. Salsman at transmitter in plane, Call DH4B. conversing with WLS (WA1) in tests in which a two-way tali world's record was made. Troy Station Presents Big Patriotic Pageant WHAZ Presents Thirteen Scenes of Revolutionary Days TROY, N. T. — One of the most unusual Radio pageants ever presented to listeners in, was recently produced by Station WHAZ here in commemoration of the sesqui-centennial of the outbreak of the American Revolution. The pageant was given in thirteen scenes and presented a vivid series of mental and oral pictures of the stirring times of the Minute Men. Among the scenes was the ride of Paul Revere, the brawl in the Province House, Boston, the battle of Lexington, the retreat of the British and the introduction of the first American patriotic song, "Yankee Doodle." By the use of cleverly contrived devices more than fifty different sounds and noises were made to add to the "scenes." Among them were the sound of the clock striking, the scuffle in the tavern, the clatter of horses hoofs, the midnight alarm and the firing of musketry and the clash of battle. An Exceptional Condenser Like all Allen-Bradley Radio Devices, the Bradleydenser offers high efficiency and sharp tuning. 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