Reassembly - Raytheon DIDS-400 Series Technical Manual

DIDS-402-2AM13
2-3.3.5 Horizontal and Vertical Deflection Am.plifier A2
This adjustment should be performed only when the raster is not centered
on the display terminal screen or when insufficient raster height or width is
present. To properly position the raster, perform the following adjustments:
a. Either type in a full screen of characters or increase the brightness
control until all 13 scan lines are visible. Note the screen
presentation. Thirteen line s of 80 characters each should be visible
and centered within the screen area.
b. If the raster is vertically off-center:
(1) Adjust vertical centering control R-4 (see figure 2-5) to
vertically center the raster.
(2) Adjust vertical amplitude control R-27 to produce the required
raster height.
c.
If the raster is horizontally off-center:
(1) Adjust horizontal centering control R-35 to horizontally center
the raster.
(2) Adjust horizontal amplitude control R-50 to produce the required
raster width.
d. If the raster is tilted, loosen the wing nut holding the yoke (see fig-
ure 2-2) in position and adjust the yoke to the position providing scan
lines which parallel an imaginery line drawn through the center of the
screen. Retighten the yoke clamp.
2-4 REASSEMBLY
When the Display Terminal is completely aligned, the cover may be replaced
by reversing the removal procedure. Make sure that all rf shields are in place
and all screws are secured before operating the Display Terminal.
2-11