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

/ AlABOSl

- AlA7TP3

AlA H I G H

V O L T A G E

/ R E G U L A T O R

- AlA6R103

Figure 3-13. Location of High Voltage Adjustments

4.Set the LINE switch to ON. Set the front-panel INTENSITY control fully counterclockwise (CRT beam at cut-off) to prevent possible damage to the CRT.

5.Note the DVM indication at AlA7TP3.

DVM Indication:

6.Connect the high-voltage probe to the DVM, and connect the probe to AlA7TP3.

7.Note the DVM indication.

DVM Indication:

8.Divide the DVM indication in step 7 by the DVM indication in

step 5. This gives the calibration factor needed to compensate for high-voltage probe error.

Calibration Factor:

9.Disconnect the high-voltage probe from AlA7TP3. Set the LINE switch to STANDBY. Remove the ac line cord from both instrument sections.

Warning The MAINS power-on indicator AlASDSl (red LED) should be completely off before proceeding with this procedure. See Figure 3-13 The indicator will remain lit for several seconds after the ac line cord has been removed, and will go out slowly (the light becomes dimmer until it is completely out).

Warning

With the protective cover removed in the following step, do not

 

place hands near the AlA High-Voltage assembly. High voltage

 

(approximately -2400 V dc) can present even when the ac line

 

cord is disconnected.

 

 

 

10. Wait at least one minute for capacitors to discharge to a safe

 

level.

Adjustments 3-41