TM 11-6625-3081-23
7-31. VIDEO SIGNAL GENERATOR (VSG) CASE ASSEMBLY 2A2A7A1
7-31
INPUT CODE:
VSGST (cont)
a .
DESCRIPTION (cont)
To check the composite video with sine wave, the window in the previous check is
reprogrammed to a brightness level of +0.5 vdc and modulated with a 10 mHz sine
wave programmed for 0.5v p-p.
The difference between the maximum and minimum
samples during the window is checked for 0.25 to 0.30v p-p. the camera sync signals
are checked with the VSG programmed for an 875 line rate. The programmable
digitizer assembly is triggered 10 microseconds into line 18, and samples the camera
sync (encoded sync) signals.
The following checks are made:
The second pulse of the inverted sync signal for 3.7 to 3.9 microseconds.
The third pulse of the inverted sync signal for 3.7 to 3.9 microseconds.
The time interval between the first and second pulses of the inverted sync
signal for 37.6 to 38.6 microseconds.
The time interval between the end of the second pulse and the start of the
third pulse of the inverted sync signal for 0.9 to 1.1 microseconds.
The start of the first pulse of the inverted sync signal to occur at 27.7 to
28.1 microseconds in relation to the programmable digitizer trigger.
The first pulse of the noninverted sync signal for 3.7 to 3.9 microseconds.
The second pulse of the noninverted sync signal for 3.7 to 3.9 microseconds.
The third pulse of the noninverted sync signal for 3.7 to 3.9 microseconds.
The time interval between the first and second pulses of noninverted sync
signal for 37.6 to 38.6 microseconds.
,
The time interval between the end of the second pulse and start of the third
pulse of the noninverted sync signal for 0.9 to 1.1 microseconds.
The start of the first pulse of the noninverted sync signal to occur at 27.7
to 28.1 microseconds in relation to the programmable digitizer trigger.
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