Tektronix 323, Instruction Manual

Page: 80 / 170

Performance Check— Type 323
d. Set the time-mark generator for one millisecond mark­
ers.
e. If necessary set the TRIGGER control for a stable dis­
play.
f. CHECK—Markers should be well defined within the
areas indicated in Fig. 5-1 with optimum setting of focus
control.
g. If necessary, adjust FOCUS control and ASTIG adjust­
ment (on bottom) for the best definition of the markers with­
in the areas indicated in Fig. 5-1.
these areas.
Fig. 5 -1 . Typical CRT d is p la y when checking astigm atism .
5. Check Trace A lig n m e n t
REQUIREMENT—Trace parallel to horizontal graticule
lines.
a. Position the baseline of the marker display to the cen­
ter horizontal line with the vertical POSITION control.
b. CHECK— Baseline of marker display should be parallel
to the center horizontal line.
c. If necessary, adjust the TRACE ROTATION adjustment
(on bottom) so the baseline of the marker display is par­
allel to the center horizontal line.
6. Check CRT G eom etry
REQUIREMENT—0.1 division or less curvature of markers.
a. Set the VOLTS/DIV switch to .1.
b. Position the baseline of the marker display below the
bottom of the graticule with the vertical POSITION control.
c. CHECK— CRT display for curvature of vertical lines
(markers) within maximum deviation of 0.1 division from
straight line. Fig. 5-2 shows a typical display of good geom­
etry.
d. Disconnect the time-mark generator.
e. Position the trace to the top line of the graticule with
the vertical POSITION control.
f. CHECK— Deviation from straight line should not exceed
0.1 division.
g. Position the trace to the bottom of the graticule with
the vertical POSITION control.
h. CHECK— Deviation from straight line should not ex­
ceed 0.1 division.
Fig. 5 -2 . Typical CRT d isp la y showing good geometry.
7. Check Lim it C entering
REQUIREMENT— Less than 0.1 division compression or ex­
pansion of a center screen two-division signal when positioned
to the top and bottom of the graticule area.
a. Set the VOLTS/DIV switch to 5 DIV CAL.
b. Position the bottom of the display to the first grati­
cule line below the center horizontal line.
c. Reduce the display to exactly two divisions with the
VARIABLE VOLTS/DIV control.
d. Position the top of the display to the top horizontal
line of the graticule.
e. CHECK— Compression or expansion of signal 0.1 divi­
sion or less.
f. Position the bottom of the display to the bottom hori­
zontal line of the graticule.
g. CHECK— Compression or expansion of signal 0.1 divi­
sion or less.
8. Check V ertical X 1 G ain
REQUIREMENT— Five divisions of deflection at 0.1 VOLTS/
DIV with 50-millivolt square-wave input.
a. Change the following control settings:
VOLTS/DIV .01
VARIABLE VOLTS/DIV CAL
Vertical POSITION Midrange
® i 5 -3