2.High-Voltage Adjustment (SN 3004A and Above)

11.Remove the protective cover from the AlA High-Voltage Regulator Assembly. A label should be visible on the AlA3Al High Voltage Assembly. (AlASAl is mounted on the non-component side of the High-Voltage Regulator Assembly as shown in Figure 3-14.) Record the voltage listed on the label for use in step 15. In cases where more than one voltage is listed on this label, record the value which is closest to -2400 Vdc.

V dc

Warning With power supplied to the instrument, AlA3TP2A is at a voltage level of approximately -2400 V dc. Be extremely careful.

12.Connect the high-voltage probe to AlA3TP2A. See Figure 3-14 for the location of the test point.

AlA3Al L A B E L

AlA3TPZP

AlA3TP2A

Figure 3-14. Location of AlA Label and Test Point

13.Reconnect ac line cords to both instrument sections. Set the LINE switch to ON.

14.Wait approximately 30 seconds for the de regulator circuits to stabilize.

15.Adjust AlA6R103 HV ADJ for a DVM indication equal to the calibration factor (calculated in step 8) times the voltage labeled on the top of the AlA3Al High-Voltage Assembly (noted in step 11). See Figure 3-13 for the location of the adjustment.

V dc

EXAMPLE:

If the calibration factor calculated in step 8 is 0.00099, and AlASAl is labeled for -2400 V, then adjust AlA6R103 HV ADJ for a DVM indication of:

0.00099 x (-2400 V) = -2.376 V dc

3-42 Adjustments