Tektronix CURVE-TRACER 576 Instruction Manual page 170

Adjustment-Type 576
e. ADJUST -R536, 5'S GAIN adjustment, on the
DISPLAY AMP circuit board (see Fig. 1-5) if the spot is not
centered.
f. Press the CAL button and check that the spot is still
vertically centered on the graticule?
g. Release the CAL button and set the VERTICAL
switch to .2 A.
h. Set the Calibration Fixture Calibrator Range switch
to 50 mV.
i. Check for spot vertically centered on the CRT grati-
cule.
j. ADJUST -R538, 2'S GAIN adjustment, on the DIS-
PLAY AMP circuit board (see Fig. 1-5) if the spot is not
centered.
k. Press the CAL button and check that the spot is still
vertically centered on the graticule?
I. Release the CAL button and set the VERTICAL
switch to .1 A.
m. Set the Calibration Fixture Calibration Range switch
to 25 mV.
n. Check for spot vertically centered on the graticule.
o. ADJUST -R541, 1 'S GAIN adjustment, on the DIS-
PLAY AMP circuit board (see Fig. 1-5) if the spot is not
centered.
p. Press the CAL button and check that the spot is still
vertically centered on the graticule.
11. Adjust Horizontal Compensation
NOTE
This is a factory adjustment and does not require
readjustment when doing a normal maintenance cali-
bration.
3 1t the spot is not vertically centered on the CRT graticule, R512 is
out of adjustment or the calibrator divider is out of tolerance.
A-12
a. Turn off the Type 576, remove the calibration fixture
and install the Standard Test Fixture. Turn on the Type
576.
b. Install the transistor adapter (Tektronix Part No.
013-0098-00) on the Standard Test Fixture.
c. Install a NPN transistor, with a BVcEO of at least 50
volts, in one of the transistor sockets on the right side of
the adapter. Install the high voltage protective box on the
Standard Test Fixture.
d. Set the following Type 576 controls as listed:
VERTICAL
DISPLAY OFFSET
Selector
CENTERLINE VALUE
HORIZONTAL
MAX PEAK VOLTS
MAX PEAK POWER
WATTS
STEP GENERATOR
AMPLITUDE
PULSED STEPS
STEP FAMILY
LEFT-OFF-RIGHT
1 rnA
HORIZ X10
.5
50 V COLLECTOR
75
0.5
.05 pA
300 JlS
REP
RIGHT
e. Turn the VARIABLE COLLECTOR SUPPLY control
and the AMPLITUDE switch clockwise until a display
similar to Fig. 1-6A or B is obtained. Note that the hori·
zontal deflection factor for this setup is 5 V /division.
f. Remove the bottom screw from the high voltage pro-
tection shield on the HORIZ VOL TS/DIV circuit board.
Carefully swing the shield to the right, exposing C433.
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WARNING
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High voltage may appear on this capacitor. Use a non-
conducting tool to make this adjustment.
g. Turn C433, HORIZ COMP adjustment, on the
HORIZ VOLTS/DIV circuit board (see Fig. 1-7) through-
out its range.
h. Note the tails on the spots in the display for certain
positions of the control (see Fig. 1-6A).
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i. ADJUST -C433 for no tails or minimum tail length
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on the spots (see Fig. 1-68).
ADD AUG 1984
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