Automatic protection switching for TD-2 radio system

Intercity transmission of television programs and telephone conversations is now provided via a network of TD-2 microwave radio relay equipment operating on a transcontinental basis. Whenever service interruption threatens because of equipment troubles or atmospheric disturbances in the transmission path, a switching system automatically and quickly substitutes a stand-by wide-band microwave radio channel for the defective channel. The circuits and operation of this switching equipment are described.