Abstract :
THE EQUIPMENT DESCRIBED in this article was the result of conclusions reached while contemplating the problem of how best to utilize the 30-kc “Audio” spectrum offered by the Type-FB microwave radio equipment. The market for the radio equipment primarily was to be in the electrical utility field. It was proposed as especially suitable for providing telephone, telemetering, load-frequency control, supervisory control, and similar communication circuits over distances up to about 50 miles. It was recognized that with microwave radio, the terrain would be a control factor in the maximum length of a radio circuit without repeater stations. A need exists for a communication facility of multicircuit capacity for such distances, both because of the growing congestion of the power-line carrier frequency spectrum and because of the increasing difficulty of applying carrier to the shorter power lines.
