Tektronix CURVE-TRACER 576 Instruction Manual page 165

d . Connect the 1 X test probe tip to the test points of
each of the power supplies given in Table 1-2.
e. CHECK FOR-Test oscilloscope display of power
supply ripple with the line frequency ripple peak to peak
amplitude not exceeding the maximum value given in Table
1-2 . On the +
1
00-volt and the +225-volt supplies, set the
test oscilloscope time/em to 50 /lS and check the 20 kHz
ripple.
f. Turn off the Type 576. Install the Calibration Fix-
ture . Turn on the Type 576 . (Be s;;re to connect small cable
tothe CAMERA POWER connector.)
g. Set the autotransformer for the lowest voltage within
the voltage range selected by the Line Voltage Selector
assembly on the rear panel.
h. Repeat parts d and e .
i. Disconnect the probe from the Type 576.
j. Disconnect the Type 576 from the autotransformer
and connect it directly to the power source, or set the
autotransformer output votlage to the center of the regu -
lated range selected by the Line Voltage selector assembly.
(The camera power cable may also be disconnected from
the Type 576.)
CRT AND READOUT
4. Adjust CRT Controls
a. Set the Type 576 and Calibrator Fixture controls as
shown in the list of Initial Control Settings at the beginning
of the procedure .
b. Turn the Type 576 FOCUS control fully counter-
clockwise and the INTENSITY control clockwise until a
large spot is visible on the CRT.
c. Check for spot having a circular shape.
d . ADJUST -R891, ASTIGMATISM adjustment on the
left side of the instrument (see Fig. 1-3), if spot is not
circular .
e .
Turn the Type 576 FOCUS control clockwise until
the spot is the smallest possible.
ADD AUG 1984
Adjustment-Type 576
Fig. 1-3. Location of adjustments in step 4.
E~J
At various times throughout this procedure, a single
spot will be displayed on the CRT. When displaying a
single spot reduce the intensity as much as possible,
while still maintaining visibility, to prevent burning of
the CRT phosphor.
f. Position the spot to the center of the CRT graticule
using the Type 576 FINE POSITION controls.
g. Set the Type 576 VARIABLE COLLECTOR
SUPPLY control for a trace 10 divisions long.
h. Check for the trace parallel with the horizontal
centerline (see Fig . 1-4).
i. ADJUST -R897, TRACE ROTATION adjustment on
a chassis bracket on the right of the instrument (see Fig.
1-5) if the trace is not parallel.
j. Set the Calibration Fixture Step Generator Loads
switch to 1 K Collector Short.
k. Check for trace parallel with the vertical centerline
(see Fig . 1-5) .
I. ADJUST -R685, ORTHOGONALITY adjustment, on
the DISPLAY AMP circuit board (See Fig. 1-5) if the trace
is not parallel.
A-7