October 1974 | NTIA Technical Memo OT TM 74 182
AN/FRC-80(V)3 retune and time division multiplex interface investigation
Joseph E. Farrow
Abstract: An analog FM microwave radio was tuned and tested to published specifications. Appropriate interface changes were determined and made to permit this radio to handle a 12.6 Mb/s 3-level partial response digital baseband. Pilot, orderwire, and combiner operation were investigated. Bit error rate performance as a function of received signal level, orderwire subcarrier frequency and deviation, and radio pilot level were investigated and reported. The radiated spectra for several variations of the above parameters are included.