A Six-Channel High-Frequency Telemetry System

A frequency-multiplex FM-AM system is described which provides six continuous channels via which waveforms with frequency components in the approximate band 10 cps to 10 kc may be simultaneously telemetered; extension of the frequency coverage to include the band 0-10 cps is achieved by the use of commutated reference levels. A radio frequency in the 465-mcs band and subcarrier frequencies between 250 and 500 kc are used. A short historical introduction is followed by description of the system and of units of the flight and ground equipment, and details of operational results. Future uses of the system are discussed and methods of increasing the useful range are suggested.