Radio mirror (Jan-Oct 1923)

October U, 1933 RADIO DICES T — Illustrated NEW "ROLLS ROYCE" SET RANKED FINEST CAPABLE OF TUNING FROM 200-700 METERS Sam Curtis, Ex-Operator at WNAC, Completes His Outfit De Luxe BOSTON, MASS. — Sam Curtis, Radio expert of the C. C. Harvey Cb., former announcer and Radio operator of the WNAC broadcasting station, has built a receiving set of the "Rolls-Royce" typo, meaning a set do luxe, using seven dry cell tubes, with a loop, and embodying all the principles of the super-heterodyne and neutrodyne combined. ' With his experience at WNAC, and with the Radio Corporation and in various naval Radio positions, Curtis has been able to design what is perhaps the finest receiving set obtainable at the present time. It is capable of tuning from 200 to 700 meters, and has an intermediate frequency of 4S.000 cycles. The principal features are the combination of all batteries inside the cabinet which is of American walnut. polished and made five-sided, like the official French naval receivers. Parts and Construction of Set One rheostat controls the seven UV-199 tubes, which are used in the following order: 1, oscillator; 2, first detector; 3, 4 and 5, intermediate frequency amplifiers; 6, second detector, and 7, states of audio frequency. Three long wave transformers have been supplied for the Radio frequency amplification. The set of tubes is mounted on a strip having rubber cushion supports, the sockeffe laid flush with the wood. These supports are encased in a holder of solid brass, while the cabinet and panel are lined with sheet copper. A.high efficiency is obtained by the use of two .001 mfd. low loss variable condensers, these constituting the only two adjustments except for one filament rheostat. Differences in Hook-Up In the following details, the circuit differs from the general super-heterodyne circuit: single control for all tube filaments; batteries all located inside the cabinet; embodiment of the neutrodyne principle in stabilizing; use of a loop with the center of its winding grounded, thus minimizing the antenna effect and allowing for much sharper directional tuning. Mr. Curtis spent two months designing and constructing this set, which also includes plate volt meters inlaid into the panel and filament meter, showing at all times the exact amount of plate and filament voltage in the batteries. With a two foot loop, Curtis and Henry Clapp. who assisted him in the construction, picked up twenty-two broadcasting stations in one evening, including WBZ, WEAF, WSAI, KOP, WWJ, KDKA, WEAN, WLAG, PWX, "WJAR and WJAZ. There was very little static noticed. "BUGS" AID OFFICIALS RELAYING MESSAGES Springfield, Mass., Amateurs Give Services Voluntarily SPRINGFIELD, MASS.— Radio amateurs residing in this city are giving their services voluntarily in the first naval district by relaying official messages, requiring prompt attention, between the reserve division here and the brigade headquarters at Boston. Commander J. T. Nelson in a recent letter addressed to Ensign H. F. Johnson of Springfield commended this work in these terms: "The work of your division in training men for Radio operators is greatly appreciated and your division is the only unit where training of this nature is being carried on. It is the brigade commander's wish that you continue this work and expand this Radio department if it can be done without detracting from the general training of your division." RADIO AS TRAIN GUIDE ATTEMPT BY EXPERTS CHICAGO.— The possibility oi directing fast trains by Radio without Interrupting their speed will be demonstrated soon on the Rock Island's Rocky Mountain Limited train by experts from all the big roads of the country. Riding in special coaches, they expect to keep in constant touch with stations here, WOC at Davenport and WOAW at Omaha, and later with Denver stations. WCAE FINDS ROAMING LAD 30 MILES AWAY PITTSBURGH, PA.— WCAE. Pittaburgh Press, probably broke the record recently as an air sleuth. The mother of Tommy Moran, 14, reported to WCAE that the police had failed to find her son who had been lost for twenty-four hours. Twenty-one minutes after the report was broadcast the boy was found by a policeman who had heard WCAE, thirty miles away, announce the quest. YOUNG FAN HAS SET LIKE BOOK Little Miss Stella Pogany of Philadelphia listening in on the unusual booklike receiving set her father has made for her. Another view of the instrument is given on the back page. The "book" is entitled "My Set" KGB Broadcasts Twenty Voice Two-Act College Operetta TACOMA, WASH. — An entire operetta in two acts, with the original cast of twenty voices, was presented recently at KGB, The Tacoma Ledger station here. The operetta was "The Pennant," a tuneful college comedy, which met with much favor. It took two hours to broadcast. Open Meeting of Trade Chiefs at Gotham Palace NEW YORK. — L. A. Nixon, secretary of the Radio Trade Association, has announced an open meeting for tfie Radio trade conducted under the auspices of this association for October 9 at 3:00 p. m. at Grand Central Palace in this city. AIR COMPASS CITED AS MARINE SAVIOR NAVY VESSELS DISREGARD BEARINGS AND GROUND New Englander Declares Cable in New York Harbor Would Have Averted Destroyer Disaster SAN DIEGO, CALIF.— Disregard of the course indicated uneriiriKly by the Radio compass at Point Arguello station, on the California coast, was the direct cause of the recent loss of twenty-three enlisted men and the destruction of seven destroyers, valued at $10,000,000, when they ran on the rocks off Point Hondli during a fog. This was the gist of the evidence presented to the naval court of Inquiry here. Had the commander of the squadron and the navigating officers of each destroyer heeded the warnings of the Radio signals, had they believed that Radio was efficient, the wreck could have been avoided. According to the statement of E. C. Hanson, of Reading, Mass., inventor of the Radio pilot cable, the latter device also, if installed, would have prevented the wreck. . Cable Sixteen Miles Long" As an instance of the reliability of the Radio pilot cable, Mr. Hanson cited its achievements in Ambrose channel, New York harbor. The cable, as operated by the Navy department, has guided hundreds of vessels to safety. It is sixteen miles long, energized by a 500-cycle low frequency current from the shore. The current establishes a powerful magnetic field whose characteristics are readily recognized by an observer aboard ship. A vessel equipped in accordance with the requirements of the Radio pilot system bears on each side "pickup" coils which are affected by or sensitized to the magnetic field. When the ship passes directly over the cable the coils are affected equally, that is, cause like response in any pair of earphones worn by the watch aboard the ship. The coils are connected with the earphones by an ordinary twostep amplifier. Sound Intensities Guide Ship When the craft deviates from the course set by the cable a dissimilar response is registered by the earphones. The side of the ship nearer the cable produces the louder sound or response in the earphones. The navigating officer thus is enabled to right his course. He is also assisted by a mechanical visible indicator which forms part of the steering apparatus. In the opinion of Mr. Hanson, the Atlantic coast from Maine to Florida and the Pacific littoral from Canada to Mexico, when equipped with his Radio pilot, would be virtually free from shipwrecks caused by fogs. The cost of operating the Radio pilot, he said, is about ten cents an hour. Picks Up Broadcasts Deep in Grand Canyon Prediction of Experts Prove to Be Incorrect DENVER, COL. — The Geological Survey party carrying a Radio set on a trip through the Grand Canyon of the Colorado, has arrived safely at Bright Angel trail. Notwithstanding the predictions of experts that it would be impossible to receive Radio messages while in the bottom of Grand Canyon, Colonel Birdseye reports that he is in daily receipt of messages broadcast from Los Angeles, Salt Lake, and Chicago. He received the news of President Harding's death within fortyfive minutes after it occurred. Reports of his progress will be sent out for broadcasting when he reached Basstrail about September 10. Supai Creek, September 20, and Diamond Creek, October 15. It is a violation of a city ordinance of Newark, N. J., to erect an antenna without a permit. THE ANTENNA BROTHERS Spir L. and Lew P. Note: Jack Sells Ads in N. Y.