The AN/TRC-97 Radio Set, or TRC-97, is a radio set that has 12 multiplex channels (later expanded to 24 channels and 16 telegraph channels connected to an analog radio. The radio set is a mobile terminal that can transmit up to straight line-of-sight at up to 1 watt, using a traveling wave tube amplifier, or in tropospheric scatter at up to 1 kilowatt, using a tunable klystron amplifier, at a frequency range of 4.4 to 5 gigahertz and 1.2 to 2.2 gigahertz. The set has been manufactured by RCA, Camden, N.J. Features The TRC-97 can be connected to one of three mobile antennas, depending on the distance and signal strength needed. One such antenna that can be used with the TRC-97 is the MRT-2 parabolic tropospheric antenna, measuring across, which is designed to cover distances of up to . Another antenna was a simple feed horn type mounted on a pole. The third is a set of parabolic dishes on (pictured in the photo). These antennas are transported on trailers and have to be manually erected every time they are used, so knowledge of mechanics as well as electronics was needed to erect and maintain that equipment. The system was powered by a 3-cylinder diesel or later by a turbine generator (TG). A typical crew would consist of two or three wideband (Air Force) technicians and one power production (Air Force) technician to service the generator set. Two units could be used back to back to provide a relay capability for extra long haul traffic. This was usually done at the baseband level without need of any other equipment other than cables. It also could be remotely monitored from up to away using the BZ109 test and monitor set. This was accomplished by connecting a single pair of field wires (common military phone line). BZ109 would provide remote order wire, some basic measurements and alarm monitoring. Three modes of propagation could be used; Tropospheric scatter, Obstacle Gain Diffraction, and line-of-sight. Tropospheric Scatter and Obstacle Gain Diffraction typically used the 1 kW klystron while the line-of-sight mode used the 1W Traveling Wave Tube (TWT). The TWT was replaced late in the TRC-97’s life by a solid-state 1W amplifier. The receiver of the TRC-97 can pick up very faint radio signals, as low as -105 dBm. The modified TRC-97A (with 12 channels of added multiplex) can receive signals as low as -102