Sigma CBG-2655A Service Manual

CBG-2655A

COLOR BAR, TONE, & ID GENERATOR

SERVICE MANUAL

SIGMA ELECTRONICS, INC.

P.O. Box 448

1027 COMMERCIAL AVENUE

EAST PETERSBURG, PA 17520-0448

[phone]

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GENERAL:
The CBG-2655A provides three (3) identical outputs of EIA Split-field Color Bars with Reverse Bars,

Pluge Signal, and 100% White Signal for system and monitor setup. A stereo audio tone generator is
also provided by the CBG-2655A. The module is compatible with either balanced or unbalanced audio
signal configuration. A twelve (12) character ID is available. The character generator must be
programmed by Sigma Electronics at the time of the order. If the character generator ID needs to be
changed or added after the module is delivered, Sigma Electronics will perform this task for a small
setup charge upon the return of the module.
The CBG-2655A consists of a CBG-2155A module and the Sigma Stand-Alone Box, SSB-21. For
proper operation this module should not be mounted into any other 2100 Series frame. Installation of
this module into any other power supply/frame manufactured by Sigma or any other manufacturer may
void the warranty.

POWER:

The CBG-2655A operates from bus voltages of unregulated +20Vdc and -20Vdc. These voltages are
supplied by the Sigma Stand-Alone Box SSB-21 power supply. The module regulates the bus voltage to
+5Vdc and -5Vdc. Circuit protection is provided by PTC thermistors (Positive Temperature Coefficient
Thermal Resistor) which serve as a permanent self-resetting fuse. In the event of excessive current draw
on either of the two bus lines the PTC thermistor on that line will open. Upon correction of the fault, the
PTC thermistor will cool to an operational temperature and reset.

FRAME:

The CBG-2655A module must reside in the Sigma Stand-Alone Box, SSB-21. This is a desk top
box. Rack mounting is achieved with the optional RMK-26 rack mount kit. This will hold up to three
stand-alone Boxes in 1 RU (1.75”) without the need for blank panels when mounting only one or two
boxes.

CONNECTIONS:

Wiring to the module is performed via the connectors located on the rear panel. BNC connectors are
used for the video outputs. Three-pin screw terminal connectors are provided for the audio. (Figure 1)
OUTPUT: There are three (3) video outputs on the rear panel of the unit. Each output is designed to
drive a 75? load. The outputs are common in signal content. The audio screw terminals provide both
continuous (channel 1) and 50% duty cycle (channel 2) tones for stereo system checks.

REAR PANEL CONNECTIONS
Figure 1

CB1

CB2

115
VAC

CB3

AUDIO 1

¼ AMP

AUDIO 2

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CBG-2655A

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