Tektronix CURVE-TRACER 576 Instruction Manual page 133

Fig. S-1. L.V. REGULA TOR circuit board: Location of test points
and adjustments in steps I and 3.
Performance Check/Calibration-Type 576
c. Connect the negative lead of the DC voltmeter to
ground, pin M on the L.V. REGULATOR board, (see Fig.
5-1). Connect the positive lead to the - 75 volt supply, pin
K. Be sure the polarity of the DC voltmeter is set for meas-
uring a negative voltage.
d. Check for DC voltmeter reading of - 75 volts ±0.375
volts (-75 V ±0.5%).
e. ADJUST -R721, - 75-V adjustment, (see Fig. 5-1) if
the voltage is not correct.
NOTE
The voltage level of the -75-volt supply affects the
calibration of the entire instrument. Do not adjust
R721 unless the voltage measured in part d is out of
tolerance or unless a complete calibration is being
performed.
2. Adjust Calibrator Voltage
0
a. Connect the positive lead of the DC voltmeter to
TP510 on the DISPLAY AMPLIFIER c ircuit board (see
Fig. 5-2).
b. Check for DC voltmeter reading of - 2 volts ±0.01
volt (-2 V ±0.5%).
c. ADJUST - R512, CAL adjustment (see Fig. 5-2), if the
voltage is not correct.
Fig. S-2. DISPLAY AMP circuit board: Location of voltage checks and adju st men ts in steps 2, 3 and 8 through 14.
REV C JUL 1980
5-5