Broadcasting Telecasting (Jan-Mar 1960)

EQUIPMENT & ENGINEERING 480,000 MILE MOON MESSAGE SENT Navy circuit lunar message bounced from Capitol to Hawaii The day of instantaneous transoceanic television was brought closer last week through a technical feat and a scientific discovery. These are: • The U.S. Navy's Communications Moon Relay in which a four-channel teletypewriter-facsimile circuit is being operated, via the moon, between Washington, D.C., and Pearl Harbor in Hawaii. • The existence of a natural radio pipeline 5,000 ft. over the South Atlantic which can carry radio and "tvtype" signals with little loss. The Navy installation, which has been operating on a more or less regular basis since last fall, but which is still classed as experimental, was made public last week. It uses narrow-beam highly directionalized 435-445 mc signals for 2Vi -second communications between Navy headquarters in Washington and Pacific Fleet headquarters at Pearl Harbor. This is a distance of 5,000 air miles, but the radio path via the moon makes it a 480,000 mile trip. Tv Communications Next • The moon relay system is considered a curtain-raiser for transoceanic radio and tv communications through the use of aluminized orbiting 100-ft. balloons. These are scheduled to be put into 1,000 mile high orbit sometime this spring by the National Aeronautics & Space Administration. The moon relay mode only can be used when the natural satellite is within electronic sight of both sending and receiving sites. The use of three orbiting balloons is projected to permit continuous electronic line-of-sight throughout the earth. The first use of the man-made balloon satellite took place three weeks ago when Bell Labs bounced some 960 mc continuous wave signals off a test balloon sent aloft to a height of 250 miles (Broadcasting, Jan. 25). The moon relay is considered operating with about 10% of the efficiency that Project Echo, the balloon satellite project will operate with. The Navy's moon relay system is an outgrowth of the Army Signal Corps' radar moon shot in 1946. This was accomplished under the direction of Col. John H. DeWitt (now president of WSM AM FM TV Nashville, Tenn.). Naval Research Lab. conducted further tests beginning in 1951. A development contract was awarded to Development Engineering Corp. in 1956 and the present installation is the outcome. Lester H. Carr, Washington radio consulting engineer, is president of DECO. The project cost an estimated $5.5 million. Frequencies Are Crowded • Because the high frequencies are crowded and subject to ionospheric interruptions, the Navy has been greatly interested in using the ultra high and higher frequencies. In discussing the moon relay, Rear Admiral Frank Virden, Navy Communications chief said the moon is "100% reliable, always in orbit and like some of the other best things in life, it's free." Engineers and Navy officials working on the project acknowledged that the next step was to try to use higher frequencies in order to get greater bandwidth for the same power output. When this is accomplished they said, the transmission of tv from the U.S. mainland to other portions of the Tv through pipe • Here's the more than a half-mile of threeinch waveguide (see arrow) which International Telephone & Telegraph reports successfully carries live tv (At Deadline, Jan. 25). The normal distance for waveguide use is 100 ft. Experimental circuit is being checked by engineers at Hertfordshire County, England. The system would ultimately carry 400 tv channels or several hundred thousand telephone channels simultaneously. globe would be an accomplished fact. CMR, as the Navy calls it, utilizes giant, movable, 84-ft. high antenna dishes. They are kept aimed at the moon through the use of astronomical data. A 100-kw transmitter is fed into the high gain antennas resulting in a 400-megawatt radiation of a 1.5° beam. The received signal at the antenna is 1/1, 000th of 0.1 micro microwatt. This is boosted to 0.1 micro microwatt at the received input. The signals are circularly polarized. The bandwidth used is 16 kc and accommodates four, two-way multiplexed teletypewriter channels or one, two-way facsimile channel. Natural Pipeline • The natural radio pipeline over the South Atlantic between South America and Africa was described as "an elevated transoceanic atmospheric duct capable of trapping and propagating radio waves at low loss." Similar 500 ft.-thick ducts are believed available between California and Hawaii, Cape Verde and Puerto Rico, in the Indian Ocean and from the Philippines to Australia. In discussing the possibility of using the upper air radio pipelines for transoceanic television, Air Force project engineer Russell W. Corkum said it might be possible to send "tv-type" signals from England to Spain, thence to French West Africa and via the radio duct across the South Atlantic to South America and northward to the United States. The ducts all may exist above the trade winds areas both north and south of the Equator, the announcement said. The atmospheric study was a joint Air Force-Navy project. Stockholders approve Ampex 3-for-1 split At a special meeting Jan. 25, stockholders of Ampex Corp., Redwood City, Calif., approved a 3-for-l stock split in the corporation's outstanding common shares and an increase in authorized shares from 5 million to 10 million, according to Alexander M. Pontiatoff, chairman of the board. The date of record for the split is today (Feb. 1). Outstanding shares as a result of the split total 7,204,314 with 564,804 shares reserved for stock options, warrants and convertible notes. 84 BROADCASTING, February 1, 1960