Figure 3-26.—Combiner-Demodulator MD-900/SSR-1.
Figure 3-27.—Demu1tiplexer TD-1063/SSR-1.
Modem Group OM-43A/USC
The OM-43A/USC shown in figure 3-28 is used
primarily with the AN/WSC-5(V) transceiver at shore
installations. It performs differential phase-shift keying
(DPSK) modulation and demodulation of a
Figure 3-28.—Modem Group OM-43A/USC.
serial data stream at data rates of 75, 300, 1200, 2400,
4800, and 9600 bits per second. This modem can be
operated in fill-duplex, although normal operation is half-
duplex.
Modulator-Demodulator OM-51A/FR
This modem is an integral part of the Fleet Satellite
Broadcast subsystem. It is a spread spectrum (wide
bandwidth with frequency modulation of a transmitter and
receiver in exact synchronization) type modem used with
the AN/FSC-79 satellite communications terminal to
provide rf transmission capability in a high-level jamming
environment. Shown in figure 3-29, its basic function is to
provide rf analog and digital conditioning circuits and
frequency synthesizing for dual-redundant transmission
and reception. It interfaces with the AN/FSC-79 terminal
and the AM-6534/ SSR-1 amplifier-convertor.
Figure 3-29.—Modulator-Demodulator Group OM-51A/FR.
3-29
