HP 8562E, Service Manual

Page: 56 / 482

2. Display Adjustment
Perform the 16 MHz PLL Adjustment in this chapter before proceeding with
this adjustment.
1. Turn the spectrum analyzer off by pressing (LINE). Remove the spectrum analyzer cover
and fold out the A2 controller and A3 interface assemblies as illustrated in Figure 2-2.
Connect the CAL OUTPUT to the INPUT. Adjustment locations are shown on the CRT
neck for Al7 adjustments and in Figure 2-4 for the A2 adjustments.
2. Set X GAIN, Y GAIN, DDD, ASTIG, DGTL
X GAIN, DGTL Y GAIN, STOP BLANK, and START
BLANK to midrange. Also set the rear-panel X POSN, Y POSN, and TRACE ALIGN to
midrange.
3. Set Z FOCUS, X FOCUS, and CUTOFF to midrange.
4. Set Z GAIN fully clockwise.
5. Turn the spectrum analyzer on and allow it to warm up for at least 3 minutes. Adjust
CUTOFF until the display is visible and COARSE FOCUS for best
possible focus.
Press (DISPLAY), , 255 STORE , MORE of 2,
FOCUS, 127 STORE then GRAT OM OFF (OFF). Adjust CUTOFF
until the retrace line between the bottom of trace A and the annunciators at the bottom
of the display just disappears.
Press ON OFF (ON), 2 of 2 , INTENSITY, 80 (ENTER), STORE ,
of 2 , and CRT PATTERN . Fold up the A3 interface assembly to access
the adjustments on the A2 controller assembly.
8. Refer to Figure 2-3 for locating the lines used for adjusting DGTL X GAIN and DGTL Y
GAIN. Each of these lines is actually two lines adjusted for coincidence. The two lines will
form an “X” if they are not adjusted properly.
9. Adjust DGTL X GAIN until the two vertical lines near the left edge of the
display converge to one single line.
10. Adjust DGTL Y GAIN until the two horizontal lines near the top edge of the
display converge to one single line.
11. Adjust STOP BLANK and START BLANK for the sharpest corners of
the outer box in the test pattern. The intensity of the corners should be the same as the
middle of the lines between the corners.
2-16 Adjustment Procedures