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3Excepting receiver rf BP frequencies 380 ± 10 MHz (allowable interference, 150 dBm).

The RRS was not turned on at launch and remained off through most of the cruise period. It was only turned on once for a VLC UHF equipment checkout prior to the major VLC preseparation checkout. After the preseparation checkout of the VLC, the RRS was left on continuously.

Relay Telemetry Subsystem Purpose and Function

The RTS was the final S/S in the UHF chain of the Viking orbiter as is shown in figure 185. The RTS received the noisy split-phase PCM waveform from the RRS and provided recovered PCM data, synchronization, lock detector status, and telemetry to the appropriate VO subsystem. A simplified block diagram is shown in figure 186, and the primary performance characteristics are shown in table 47. The RTS consisted of two independent, functionally identical, bit synchronizers and their associated power supplies. The synchronizers were powered simultaneously with one synchronizer operating at 4000 bps and the other at 16 000 bps. A functional block diagram of one synchronizer is shown in figure 187. The RTS performed the following functions:

Established synchronization with respect to either a 4000-bps or a 16 000-bps split-phase coded data waveform provided by the RRS

Detected and restored the incoming data from the RRS to an NRZ-L format

Routed the recovered 4000-bps data to the MDS for immediate transmission back to Earth or routed the recovered 4000-bps and the 16 000-bps data along with symbol sync (Symbol rate = 2 x Bit rate) to the DSS

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