Many a scientific cloud on the horizon promises, or threatens, to revolutionize postwar living. One is the "microwave." Microwaves lie in the largely uncharted area of the radio spectrum above the part now used for conventional sound and television broadcasting (upper limit: roughly 80 megacycles). Microwaves are used in radar, and most of the wartime discoveries about them are still military secrets. But radio engineers have found their potentialities dazzling. This week plain citizens were given a glimpse of what the engineers envision.
New Design for Living. The Federal Communications Commission, which has been holding hearings on postwar broadcasting and microwave plans, heard the most ambitious yet. The Raytheon Manufacturing Co., a major manufacturer of electronic tubes for the Army & Navy, announced that it is prepared to begin construction this year of a coast-to-coast chain of microwave transmitting stations along airline routes. This system, says Raytheon, will:
¶ Give every pilot in the air constant, automatic reports of his own position and those of approaching planes, warn him of his approach to mountains and other potential collision dangers.
¶ Provide each airport with a glass map on which lights will automatically show the position of every plane in the air in its area.
¶ Make possible direct wireless telephone conversations between a plane and a hotel, private house or automobile on the road.
¶ Relay to anyone with a receiving set a coast-to-coast broadcast of a movie, television or a facsimile of a newspaper. Raytheon says that microwaves will make possible much better television and radio reception and faster telegraphy than is now possible.
¶ Protect railroad trains and ships at sea against collisions in any weather; by means of microwaves a ship's pilot will be able to see hidden rocks and shoals.
¶ Detect and sound warnings of floods, forest fires, etc.
Beyond the Horizon. This sweeping scheme was outlined by Raytheon's engineer Joseph Pierson as he applied for three microwave bands, at 1,900 megacycles and above. Said Pierson: if it gets these allocations, Raytheon will start work at once on the eastern (Boston, New York, Washington) and West Coast terminals of the microwave system. Raytheon plans to build a string of stations on western mountain tops, from Mt. Adams, Washington, to Mt. Whitney, California. Eventually the east and west terminals will be connected by chains of relay transmitters at about 30-mile intervals across the country.
Like the short radio waves (about 80 megacycles) now used for television, microwaves (over 300 megacycles) cannot be sent beyond the horizon. But Raytheon's engineers say that microwaves have two advantages for transmitting pictures: 1) they can be relayed more easily, by means of automatic pickup and amplifying stations in towers about 30 miles apart, and 2) they can carry a picture on a narrower band in the spectrum, thus providing a great many more channels for transmission.
Raytheon plans to use a system of automatic transmission of microwaves along such a chain of towers, as an alternative to the expensive coaxial cables used in television. Raytheon's broadcasting stations will scan a wide area, transmit what they see from coast to coast.