AN/ FSC-78( V)

The AN/ FSC-78( V) is a fixed SHF SATCOM heavy SGT operating in the X-band frequency range. The AN/GSC-39 differs from the AN/FSC-78 18.29 m (60 ft) dish only in using an 11.6 m (38 ft) diameter, DE-222/G, parabolic dish. The terminal is composed of six subsystems, including antenna tracking, transmitter, receiver, frequency reference, control, and monitoring. The antenna is a 60-foot diameter, high-efficiency, parabolic reflector providing an antenna gain-to-noise temperature ratio (G/ T) of 39 dB/ K. The reflector is mounted on an elevation-over-azimuth-configured pedestal. Cryogenically cooled, parametric amplifiers provide 30 dB of gain and an antenna G/ T ratio of 39 dB/ K.

The antenna terminal equipment has a tracking converter, 15 down-converters, and 9 up-converters. Only 10 of the down-converters are normally active at one time; the remaining 5 are in hot standby. The output signals from the up-converters are fed to a 5-kW TWTA, providing a radiated antenna signal of 500-MHz bandwidth at an EIRP of 124 dB referenced to one watt (dBW). A redundant 5 kW power amplifier can be operated in parallel with the primary power amplifier to provide an output equivalent to 10 kW at an EIRP of 127 dBW. The down-converters translate the receive signal of 7.25 to 7.75 GHz to 70-MHz IF (40-MHz bandwidth) or a 700-MHz IF (125-MHz bandwidth).

The up-converters translate the 70 or 700-MHz IF input signal, with bandwidths of 40 or 125 MHz, to the transmit frequency of 7.9 to 8.4 GHz. The Army Heavy Terminal/ Medium Terminal (HT/ MT) modernization of the AN/ FSC-78/ 79 and AN/ GSC-39 Earth terminal will increase the total number of the uplink and downlink converters.

Sources and Resources

• CHAPTER 2 SYSTEM DESCRIPTION NTP 2 NAVAL TELECOMMUNICATIONS PROCEDURES NAVY SUPER HIGH FREQUENCY SATELLITE COMMUNICATIONS