SYNC GENERATOR - giantmolecules/SANDIN-IMAGE-PROCESSOR GitHub Wiki

This module generates full NTSC color sync conforming to RS 170 EIA after trimming the master oscillator. The sync generator should stay well within the broadcast standard.

All outputs are -4V. into 75 OHM except the 14MHZ. (JO13) which is an open collector TTL. JO13 is not used except for work with digital computers.

JI1 horizontal reset and JI2 vertical reset are not implemented in full.

The sync generator requires starting pulses which are provided by capacitors associated with JI1 and JI2. Time must be allotted after power-down before power-up (at least 30 seconds) to assure proper starting of sync generator.

Master osscillator trim:

Adjust the master osscillator frequency to 14.318180 MHZ. A convenient way to do this is to run a lead from horizontal drive and wrap it (still fully insulated) around the antennae of a TV receiver. Tune the receiver to a station on feed from a major network (in color). You will notice two vertical lines or one vertical bar drifting across the screen. Adjust the master osscillator with a long insulated screwdriver through the access hole in the front panel of module until vertical lines do not drift.