Radio age (Jan 1927-Jan 1928)

RADIO AGE for October, 1927 the Atlantic lanes. Such reports, supplemented by reports from land stations in this country, in Canada, in Greenland and Iceland, and also in Europe would make possible the preparation of complete ocean weather charts and dependable forecasts every day. It is easy for shipmasters to give the required information. They are asked merely to state the position of their vessel, the barometric pressure, the barometric change in the preceding two hours, the force and direction of the wind, the kind, quantity, and movement of clouds, the presence or absence of fog, and brief remarks on any unusual weather conditions that may prevail, such as squalls, storms, or heavy seas. Radio transmission is simplified by the use of a code. Loud Speakers a Thief Trap A new burglar alarm which will call for help if the wall of a bank vault is merely tapped once or twice with a hammer has been perfected by the Bell Telephone Laboratories and is described in a recent issue of the Bell Laboratories Record, circulated privately by that institution. The device does not respond to the sound of the blow, as an ordinary telephone would, but to the vibration set up by the hammerstroke in the steel or concrete of the vault. This vibration is made to move a delicate electric apparatus, first developed during the war for the purpose of detecting enemy submarines. This device then operates a second instrument which is a modification of the unit used in radio loudspeakers. This, in turn, sends an alarm signal over a wire to a central office, from which help is sent. The vibrations set up in the vault by drilling into it or even by the sputtering of the steel while being melted with an oxy-hydrogen torch or with an electric arc, will also be detected by the apparatus. On the other hand, the vibration-detector is so constructed that it does not respond to vibrations caused by persons walking nearby or by railway trains or passing vehicles. The device is "tuned" only to those particular vibrations which indicate danger, just as a string of a violin is tuned to one particular note. The new system has been installed by the Holmes Electric Protective Company in two cities, New York and Philadelphia. Radio's Acute Ear The superiority of modern radio apparatus to the human ear, considered as a listening device, was demonstrated recently in England during an attempt to broadcast the song of that seldom-heard bird, the nightingale. A feathered songster far off in the distance burst into song while the experiment was going on. The engineers at the microphone heard nothing. The distant song was too faint and the engineers were trying to hear and to broadcast the song of another bird, believed to be near at hand but silent. However, the distant song, missed by the human ears that were on the spot, was picked up by the specially sensitive microphone that was being used and was ' broadcast, without the knowledge of the engineers directing the experiment. Radio listeners many miles away heard it perfectly, although the sounds themselves seem to have been quite inaudible to the nearby ears. Modern radio apparatus can act as a magnifier for sounds, much as a microscope can magnify objects too small to be visible to the naked eye. Radio's Record Order The largest order for radio sets ever written was reGently given to John L. Limes, assistant sales manager of the Crosley Radio Corporation, by R. B. Austrian and R. B. Rose of the R. B. Rose Company, New York City. The order called for $1,000,000 worth of Crosley radio sets to be sold through radio departments operated by the Rose Company in 33 stores throughout the country. Fortyeight radio departments were included in the contract in twenty-eight large cities extending from coast to coast. According to Limes, in taking this order the Crosley Radio Corporation acted only as agent for its distributors. The sets will be delivered to the Rose retail departments by local Crosley distributors and the orders handled through them. We Carry a Complete Line of Parts for the Following Circuits : Worlds Record Super Ten Thompson Super Seven 1928 Infradyne Melo-Heald Fourteen Tubes Electrically Operated T. R. F. Receiver St. James Super A Portable "B" Eliminator Tester Tyrman Ten Victoreen Super Q. R. S. ABC Unit Aerodyne Raytheon ABC Power Unit Camfield Super 9 Strobodyne Silver-Marshall Magnaformer 9-8 WHOLESALE Improved Remler 45 KC Super Heterodyne Aero Short Wave Improved Nine-in-Line Receiver Aero Seven Tube Phasatrol Eight-in-Line Super Ultra Powerful Distortionless Amplifier The "Best Lincoln" Nine Super Heterodyne Two Tube Browning Drake Amertran Power Supply Camfield Seven Chicago Daily News Receiver Karas Equamatic Two Dial RETAIL WEST MADISON STREET TELEPHONE, MAIN 4627 J0£ Iftft CHICAGO ILLINOIS