General Instrument C6M-II, Installation Manual

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2-2 Overview
C6M-II Installation Manual
C6M-II-MOB Kit
The C6M-II-MOB accessory module provides baseband audio and video switching, audio and
video AGC, a 4.5 MHz audio subcarrier input, and switched IF input capabilities. The video
switching system includes video A signal sensing to allow automatic switching to video B input
when the video A signal is absent. The audio A and audio B input selection is controlled by the
same circuitry as the video switch section, ensuring the audio input switching follows the video
selection automatically. A rear panel connection allows external control of the input source
switching.
Defeatable video and audio AGC is for applications involving baseband signal levels. Preset
modulation levels are maintained despite fluctuations in the audio/video input levels from the
source or resulting from switching between baseband sources.
An additional IF signal input labeled PROGRAM is identical to the AUX IF switching except
that it has a lower switching priority. The PRGM IF switch is used for program switching or
automatic program replacement when video A and/or video B are absent.
The MOB accessory also accepts the external 4.5 MHz input. The 4.5 MHz input is for audio
interfacing to the output of a stereo encoder, satellite receivers, or demodulator.
C6-DC
The dc power input option accepts a dc input in the range of
−
20 to
−
60 Vdc. This option, which
includes a dc-to-dc converter and a rear panel dc inlet, replaces the standard ac power input.
This option is only available from the factory.
C6-RC-II Kit
The C6-RC-II accessory module allows the modulator to be remotely control via a personal
computer. All front panel controls, operating parameters, and adjustments can be monitored
and changed from a remote location. This kit includes a remote control communications board
with an RS-485 type interface using RJ-12 connectors.
C6M-II-SE Kit
The C6M-II-SE is a stereo encoder option for generating stereo sound. It encodes baseband
audio based on BTSC standards, and employs dbx-TV noise reduction circuitry to ensure a
quality signal. This option does not have Second Audio Program (SAP). For SAP applications,
the CMTS should be used.