Periscope Films provides this vintage training film and the following commentary with callouts for specific aspects of radio navigation, including the Four Course Radio Range (Adcock Range), and both manual and automatic radio compasses (direction finders).
Although modern GPS navigation makes these methods seem crude, the importance of radio aids to navigation for both commercial and military purposes was immense.
This Army Air Corps training film is part of a larger group of training films on aerial navigation. Produced in 1941, Aerial Navigation: Radio Aids gives an overview of how to use radio frequencies to determine an aircraft’s position. The film opens with a B-17 Flying Fortress flying through the clouds, then the film shows several radio towers. Footage shows the cockpit and instrument panel of an aircraft, presumably of the B-17. The film shows the Air Navigation Radio Aids handbook published by the Civil Aeronautics Administration (01:45). There is an aerial view of a radio range station. Graphics are used to show how radio fields are set up at a range station using radiators. A map shows radio range coverage in the U.S. (05:27). The film shows a radio tower and discusses the “cone of silence,” which is located directly above a radio tower (06:50). A pilot sits in the cockpit and adjusts knobs on his radio panel (07:29). Z-type markers are used at a radio range station (08:58). A marker beacon in the plane flashes when a plane flies over the Z-type marker (09:41). A fan marker can also be used as a position marker at a radio range system (10:05). The pilot watches the plane’s marker beacon signaling when it is in range of the fan marker. A pilot dials in his range receiver (12:29). The pilot looks at his radio facilities chart. A graphic is used to show how a pilot adjusts his course based on the signals he receives from a radio beam. The film uses basic animation over an aerial photograph to show how a plane can make minor adjustments while the pilot is trying to determine the correct course (18:00). A pilot adjusts the volume of his radio in the cockpit (18:40). A man in a range station transmits regular weather reports (22:31). The film shows the fifth radio tower of a range station that is for voice transmissions, primarily weather reports. The film then shows the radio compass on the instrument panel (23:29) and its antennae on the exterior of the plane. A man takes off the cover of a loop antennae on the top of an aircraft (24:40). A pilot plots his location on a chart (26:30). The film then shows the new automatic compass panel (26:47). A plane flies over a radio tower of a radio range station, concluding the film.
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International Crystal and the crystal synthesizerHow a crystal company reduced the number of crystals neededCategory: Vintage Radio
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If, like me, you enjoy flipping through old issues of 73 magazine from the 60s, you're bound to have at least seen the ads for the Transcom SBT-3 three-band SSB tranceiver. Being made in Escondido CA in the mid-60s, my guess has always been that engineers from other San Diego SSB compnanies such as Don Stoner, Les Earnshaw from Southcom, Herb Johnson, founder of Swan or Faust Gonsett may... READ MORE
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Alexander M. Lewyt died in 1988 at the age of 79, a holder of patents on scores of inventions. His penchant for invention, he once said, was so strong that he had chronic insomnia from lying awake at night envisioning new products. When he learned of undertakers’ difficulty in fastening neckties on corpses, the teen-age Lewyt devised a new kind of bow tie that clipped on. He sold 50,000 of t... READ MORE
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The Korean-war vintage AN/GRC-9 is one of the most useful and fun military field radios for ham use, as with AM and CW modes and 2-12 MHz coverage and a VFO it's all ready to go on several ham bands. The battery tube superhet receiver is also power-friendly and sensitive and stable enough to copy CW and SSB but has one annoying flaw - the 4 volt bias battery used by the audio... READ MORE
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Halogen type MR-16 lamps are commonly used in track lights and other spot lighting applications so what would be cooler than to drop in LED replacements! A lot, as it turns out. The LED replacements are HORRIBLE RFI emitters that totally trashed several ham bands when I unknowingly installed them.Halogen spot lights are 12 volt devices so it's long been common prac... READ MORE
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