Radio-Relay Communication Systems in the United States Army

This paper describes the use of frequency-modulated, very-high-frequency radio sets in place of wire lines in Army tactical communication circuits. During the early phases of the war and pending development and production of equipment designed to meet requirements, standard police-type frequency-modulation sets were adapted for use. These were used with great success during the Tunisian, Sicilian, and Italian campaigns. Principally they provided simplex teletype circuits from higher headquarters to lower units. By the use of radio-repeater or relay stations these circuits were extended several hundred miles. Representative circuits are shown illustrative of employment, distances covered, and antenna elevations. A broad-band frequency-modulated very-high-frequency set designated AN/TRC-1 was developed for use in conjunction with voice-frequency-carrier equipment CF-1 and CF-2 to provide multichannel voice and teletype circuits over a single radio frequency. This has met with great success and was a most important communication factor in the Normandy invasion and battle of France. It marks the first real marriage of wire and radio communications in the Army and provides an integrated communication system. The advantages of a radio system over conventional wire lines under certain conditions are pointed out, such as a saving in men and material, establishment and maintenance of communications in a fast-moving situation, use over water, enemy territory, and rugged or mountainous terrain. Expanding and wider application of the principle is indicated.