Radio Digest (July 1924-Apr 1925)

RADIO DIGES T— Illustrated August 9, 1924 RADIO COMPLAINTS CLASSIFIED; SPARK WORST OFFENDERS WHISTLES HOLD SECOND, AND CROSS TALK THIRD Listeners Give Valuable Data Which Helps Radio Engineers ; Change of Wave Lengths Likely NEW YORK. — The final talk of the series by John V. L. Hogan, past president of the Institute of Radio engineers, before WEAF'S microphone, concluded with a request for specific data regarding interference difficulties experienced by WEAF's listeners. These have yielded very valuable figures regarding the problems to be met before Radio's ills are entirely cured. The sources of greatest interference were spark telegraph signals, which were rated as the worst source of interference by 39% of those complying with Mr. Hogan's request. "Whistles came second, with 31.4% and cross talk (that is, interference from other Radiocasting stations) 29.6%. Radio listeners were also requested to indicate their second and third choice as to the most troublesome sources of interference. Whistles were the second cause of interference on 43% of the questionnaires, spark on 37% and cross talk on 20%. Third choice was assigned to cross talk by 60%, whistles by 22.5% and spark by 17.5% of those replying to the questionnaire. The consistency of these figures are quite notable, spark interference holding first place in the first choice, second place in the second choice and third place in the third choice. Although whistles hold only second place in the first choice, the analysis show it to be quite preponderant as the second worst cause of trouble. When the first changes in wave length were made, cross talk was, perhaps, the most serious difficulty but improvements in the design of sets and increased experience on the part of those operating them has made this trouble rank third in both first and second choice. t Arrangements are being made with the principal Radio telegraph companies for reducing the ' amount of traffic handled on wave lengths which are likely to interfere with Radiocast reception. Radio Conference to Be Held Next Month Questionnaire Submitted to Supervisors to Ascertain Views "WASHINGTON, D. C. — The wheels of the department of commerce have started to move toward preliminary arrangements for the third Radio conference which it is expected will be held in this city the latter part of September under the auspices of Secretary of Commerce Hoover. A preliminary list of twelve questions has been prepared by officials of the department which will be a nucleus for a complete program to be prepared later. At the present time officials of the department are unwilling to discuss the questions because they feel that the program should be in a little more definite form before any publicity is given to it. It is understood, however, that these questions deal with such matters as wave lengths, the betterment of Radiocast programs, the question of super-power stations and many other matters of particular interest to Radiophans of the country. Lady Asks Shutdown of Plants to Halt Rain Asks President to Issue Proclamation— Folly Shown WASHINGTON, D. C. — The presidential mail contains many curious requests, but one of the most peculiar has just been received from an Ohio lady who asks the president to issue a proclamation shutting down all of the Radiocasting stations in the United States in order to obtain better weather. The letter goes on to say that the writer is of the opinion that the great quantities of rain which have been experienced in this country this summer have been caused by Radio "and the lady states that she believes that the listeners in of the country would be willing to forego their after dinner amusement for the sake of the poor, downtrodden farmer who is unable to harvest his crops. The Radio section department of commerce, called attention to the fact that if Radio had anything to do with the rain it would be natural to assume that the rainfall would be greatest where there are the greatest number of Radiocasting stations. Thi? is not so. The GREBE CLARIFIER THE first practical, workable solution of the problem of radiation from regenerative receivers. Unlike the "wave-trap" it increases signal intensity. $30 Increases Selectivity Increases Signal Intensity Improves Quality Prevents Radiation And— Is Easily Connected Ask your dealer or write for literature A. H. GREBE & CO. Richmond Hill, N. Y. Western Branch — 451 East 3rd St., Los Angeles, Cal. Prof. Jansky with Signal Corps WASHINGTON, D. C. — Prof. C. M. Jansky, formerly of the University of Minnesota, was appointed Assistant Consulting Radio engineer of the Signal Corps recently. His duties will include research problems in Radio telegraphy and telephony in the Signal Corps Radio laboratory at Camp Alfred Vail, N. J. Chicago Has Another Station CHICAGO. — Another new station opened on the roof of the Webster hotel, located in this city recently. The call letters assigned to it are^WTL, and their power is 10 watts. Lem Brosseau, is chief announcer. They are operating on a wave length of 268 meters. They expect to increase the power of this station soon. No. 25 of a Series Featuring Experiences of "ALL-AMERICAN" Users "Los Angeles to Quebec— Ail-Americans Cannot Be Beat" By C. G. Miles, Fort Wayne, Ind. "I have been using a single circuit regenerative (detector and two stages of audio frequency) employing two of your 5 to 1 ratio audio transformers and have had the pleasure of listening to KFI and KHJ at Los Angeles, KFO at San Francisco, CFCN at Calgary, KGO at Oakland and CJCM at Mont Joli, Quebec, Canada. Of course these stations were not brought in at this time of the year, but all were heard on a small loud speaker during All the better dealers sell the All American Audio Frequency Transformers come in three ratios: the 3 to 1 at $4.50, and the 5 to 1 and 10 to 1 at $4.75. There are no better instruments on the market at any price. the fore part of April of this year. As I said before, your transformers cannot be beat, and this is the opinion of most of the owners of receiving sets that I have talked to." THE KEY BOOK IS OUT I If your copy hasn't come, it will very soon. 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