Section 7
7-18
7. Record the voltage.
8. Set the voltage to 0 V.
9. Using a DMM, monitor the ac voltage (noise level) at the Rx
Ground terminal.
10. Set the voltage to 990 V. Ensure that the noise level is 40 mV
rms.
11. Record the noise level.
12. Set the voltage to 0 V and disconnect the DMM.
13. Ensure that the Primary Current Drive module covers have been re-
installed (if removed).
7.2.4.3.4.Servo-loop/Comparator Toroid Gain Adjustment
1. Remove the 10 0.01% resistors and the links connected to the Rs
and Rx test set front panel terminals, and install one of the 10
0.01% resistors across the Rx C
1
and C
2
terminals.
2. Set the number of turns to 1 and the current to 0 mA.
NOTE:
To set the number of turns, press the menu key under "More
x-x" until the "Monitor/Dacs/Turns/More 1-4" screen appears.
Press the menu key under "Turns", key in the number of turns
and press the menu key under "Turns" again.
3. Using the Scopemeter, observe the waveform on the Servo-loop
PCB at TP200 with respect to TP302.
4. Check the sense amp gain as follows :
a) Set the current to 1 mA while remaining in Sofcal diagnostic
mode.
b) The DC level of TP200 should be between +0.43 and +0.53
Volts.
c) Exit Sofcal Diagnostic mode
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