Radio age (Jan 1927-Jan 1928)

RADIO AGE /or January, 19" The Magazine of thz Hour When Radio Turns Navigator (Continued from page 14) dyne receiver is employed in connection with the radio direction finder, neatly installed in the metal cabinet which forms the base of the equipment. The tuning controls, exposed to view by a drop cover, consist of two station selectors, a volume control, a filament control, and a switch for obtaining "Line" and "Sense" readings. The batteries are also in the base of the equipment, and are connected with a trickle charger. SO IMPORTANT is the direction finder in navigation that radio beacons, like lighthouses and lightships, have come into existence along our coasts as infallible guides to coastwise and transoceanic and lake navigators. These radio beacons, operated by the U. S. Lighthouse Service, now extend up and down the Atlantic and Pacific coasts, along the Gulf of Mexico, and on the Great Lakes, as well as in Alaska and Hawaii. Operated on regular schedule, the radio beacons are also pressed into service when weather conditions warrant steady operation. They are likewise started on request. Operating on 1,000 meters wavelength assigned for such radio transmission by international regulation, the ICW or interrupted-continuous-wave transmitters employed send out signals that vary in note and in character, so that each beacon may be readily identified. Heretofore, all radio beacons have been operated at the same time, causing considerable and troublesome interference because of the unified wavelength. This interference has been eliminated, however. "Invariably, navigators are enthusiastis in their praise of the direction finder, which, in many cases, has taken precedence over the time-honored sextant in determining a ship's position, even when ideal weather prevailed," according to T. M. Stevens of the Radio Corporation of America. "In foggy and cloudy weather, of course, the radio direction finder serves to solve what has hitherto been a serious predicament. Where sounding are impractical along steep coasts, because of great depths a short distance off shore, navigators have used the radio direction finder and their known speed in guiding their ships along. Delays on account of fog can now be practically eliminated. At WGN Mica Condensers Prevent Shifting of Frequency Bands i standard radio seta with decided Electric Controlling Apparatus 289 Greenfield Avenue Milwaukee, Wis* AW.V.'.W.WAV.W.W.V y.v.v.v.v.VAV.vw.v,v.,.% ijBmdky-Ainplifier;: 5 Resistance-Coupled i ^PERFECT AUDIO AMPLIFIER^ BECAUSE the Sangamo condenser is solidly molded in bakelite, mechanical movement of dialectric or plates is impossible. This is one important factor in the permanent AJsn-Bra^W Ca i , accuracy of the Sangamo. No one has greater need for condenser accuracy than a great broadcasting station like WGN. Read Mr. Leverett's comment : "Last June I used Sangamo Mica Condensers in a multiple band pass filter. This has been in use for some time, and has given the best of results, showing no shifting of the frequency band. This permanency I believe is due entirely to the consistency of these condensers, there being no apparent change in capacity nor leakage across them. I cheerfully recommend them wherever a constant capacity is required. (Signed) Geo. H. Leverett, Asst. Engineer." Station WGN Chicago FULL VOLTAGE Under Any Load £ su/i/ruy 'B" BATTERY ELIMINATOR Smooth constant plate current with ample reserve powers for set of any number of tubes. Operates from house lighting system, using Raytheon tube. First cost the only expense. Write for full description COMPANY STATE AND 64TH STREETS CHICAGO, U. S. A. Makers of Burns Loud Speakers Sangamo Condenser Blocks American-made condensers, wound under uniform tension to eliminate air or ozone bubbles that cause breakdowns. Handv sizes: 12mfd. tapped 8, 2, 2 mfd. 14 mfd. tapped 8. 2, 2, 1, 1 mfd. 14 mfd. tapped 4 (high voltage). 4,2,1,1, 1.1, mfd. Also separate condensers; special capacity blocks to order. Sangamo Electric Company 6332-11 Springfield, Illinois RADIO DIVISION, 50 Church Street, New York SALES OFFICES— PRINCIPAL CITIES Please Mention Radio Age When Writing to Advertisers.