Tektronix CURVE-TRACER 576 Instruction Manual page 156

Performance Check/Calibration-Type 576
Fig. 5·10. Location of adjustments in steps 32 and 33.
e. Set the DISPLAY OFFSET Selector switch to VERT
X1 and the MAX PEAK VOLTS switch to 1500. Set the
HORIZONTAL switch to 200 COLLECTOR.
f. Check that the spot has minimum vertical width.
g. ADJUST -C339, 350 V and 1500 V LOOPING
COMPENSATION adjustment (see Fig. 5-10) for minimum
vertical width.
h. Set MAX PEAK VOLTS switch to 350 and repeat
parts f and g. Set C339 for minimum vertical width
between the two settings of the MAX PEAK VOLTS
switch.
i. Set the MAX PEAK VOLTS switch to 1500 and the
MODE switch to NORM.
j. Check for trace with minimum deviation from hori-
zontal line at start of sweep.
k. ADJUST -C341, H.F. NOISE REJECTION adjust-
ment (see Fig. 5-10), for minimum deviation of line.
Typical setting of C341 is almost fully counterclockwise.
Adjust front panel LOOPING COMPENSATION control if
necessary to get a display. High voltage will appear on this
capacitor. Use a non-conducting tool to make the adjust-
ment.
33. Check and Adjust LOOPING COMPEN-
SATION Control
0
a. Set the MAX PEAK VOLTS switch and HOR 1-
ZONTAL switch as shown in Table 5-16. (Always set MAX
PEAK VOLTS switch first to avoid damage to horizontal
amplifier.)
5-28
TABLE 5-16
Check LOOPING COMPENSATION Control
MAX PEAK VOLTS HORIZONTAL
1500
200 V COLLECTOR
350 50 V COLLECTOR
75 10 V COLLECTOR
15 2 V COLLECTOR
b. For each setting of the MAX PEAK VOLTS switch,
turn the LOOPING COMPENSATION control throughout
its range.
c. CHECK FOR-Looping passing through zero for each
setting of the MAX PEAK VOLTS switch.
d. Set the MODE switch to DC.
e. ADJUST -LOOPING COMPENSATION control for
minimum vertical width.
If the side panels have been removed, replace them.
34. Check Series Resistors
a. Set the Type 576controls as shown in the list of initial
control settings at the beginning of the procedure except as
noted below:
SERIES RESISTORS .3 0
VERTICAL CURRENT /DIV 2 A
HORIZONTAL VOLTS/
DIV .5 V COLLECTOR
b. Connect shorting strap from COLLECTOR to
EMITIER terminals on front porch (right side).
c. Position crt dot display to center of graticule area.
d. Adjust VARIABLE COLLECTOR SUPPLY control for
10 divisions of horizontal deflection.
e. Set LEFT-OFF-RIGHT switch to RIGHT.
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f. CHECK FOR-6 divisions or more of vertical deflec-
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tion.
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REV D JUL 1980
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