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8.
9.
10.
11.
4. Final Display Adjustments (SN 3004A and Above)
For an initial coarse focus, adjust the following potentiometers in
the sequence listed:
AlA3R14
FOCUS LIMIT
AlA2R517
ASTIG
AlA2R513
3D
AlA2R409
FOCUS COMP
Press
QNSTR
PRESET), then adjust the reference level to bring
the displayed noise to the top division of the graticule. Press
CENTER
dB/DIvj
and key in 1 dB/DIV. The noise should now
completely fill the CRT graticule pattern, illuminating a large
rectangular area. If necessary, adjust the reference level until the
graticule pattern is completely filled.
Press
ISHIFT)
(oFF)m
and then
C-1
loFFp to turn off the CRT
annotation and graticule pattern.
Connect a 56503 photometer probe to the Tektronix J-16 digital
photometer. Set the photometer to the Xl range.
Place the photometer light probe hood against the IF-Display
Section glass
RF1
filter, and adjust AlA2R319 INT GAIN for a
photometer reading of 80 NITS
(cd/m’).
Note
This reading must be made with the glass
RF1
filter in place in front of
the CRT. It might be necessary to slightly trim the top and bottom of
the photometer probe’s hood so that it will fit flush against the glass
RF1
filter.
Note
If a standard J-16 photometer is used (instead of metric option
OZ),
adjust AlA2R319 for a photometer reading of 23.5 fl (footlamberts).
12. Set the LINE switch to STANDBY and then back to ON. The
spectrum analyzer power-up annotation should be visible on the
CRT display. (This includes the firmware datecode.)
13. For the best focus near the center of the CRT display, adjust the
following potentiometers in the sequence listed below. Repeat as
needed to optimize center-screen focus.
AlA3R14
FOCUS LIMIT
AlA2R517
ASTIG
AlA2R513
3D
for best focus of annotation (short vectors)
AlA2R409 FOCUS COMP for best focus of graticule lines (long
vectors)
14. Adjust AlA2R426
T/B
FOC for best focus at the top and bottom of
the display.
15. Adjust AlA2R437 R/L FOC for best focus at the right and left
sides of the display.
16. If the top and bottom (or right and left sides) of the display
achieve best focus at different potentiometer settings, adjust
AlA2R427 T/B CTR or AlA2R440 R/L CTR, and then readjust
AlA2R426 T/B FOC or AlA2R437 R/L FOC to optimize overall
focus.
Adjustments 3-63