TB 9-4931-443-24
(7) Turn FREQUENCY HZ controls to 900 X100 (90 kHz).
(8) Adjust C207 (fig. 2) for minimum distortion (R).
Figure 2. Power unit top view
(9) Repeat a (3) through (7) above.
10. Power Unit Voltage and Stability
a. Performance Check
(1) Connect multimeter between POWER UNIT 160V jack and common.
(2) Turn FREQUENCY HZ controls to 100 X10 and adjust VOLTAGE and
ATTENUATOR switches until multimeter indicates 100V on the most sensitive null position.
(3) After two minutes, multimeter indication will not drift more than 2 mv.
(4) Record multimeter indication.
(5) Vary autotransformer between 105 and 125 volts (wait one minute at 105 and
125 volts). Multimeter indication will remain within 0.05% of value recorded in (4) above
at each autotransformer voltage setting.
(6) Adjust autotransformer to 115 volts.
b. Adjustments. No adjustments can be made.