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

Equipment

High-Voltage Adjustment Procedure

Warning

Digital Voltmeter (DVM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .HP 3456A DC High-Voltage Probe (1000: 1 divider) . . . . . . . . . . . . . . . . . . HP 34lllA

In the following procedure, it is necessary to probe voltages which, if contacted, could cause serious personal injury. Use a nonmetallic alignment tool when making adjustments. Be extremely careful.

Warning Do not attempt to measure the CRT filament voltage directly. The filament voltage is referenced to the high-voltage cathode and can only be measured safely with a special high-voltage true-rms voltmeter and probe.

1.Set the spectrum analyzer’s LINE switch to STANDBY.

2.Remove the top cover from the IF-Display Section and connect the equipment as shown in Figure 3- 12.

SPECTRUM ANALYZER

Figure 3-12. High Voltage Adjustment Setup

3.Set the DVM to the 1OOV range, and connect the DVM to AlA7TP3 (+ 120V) without the high-voltage probe. See Figure 3-13.

Note The accuracy of the high-voltage probe is specified for a probe connected to a de voltmeter with 10 MO input resistance. HP 3456A and HP 3455A digital voltmeters have a 10 MQ input resistance on the 100 V and 1000 V ranges. All measurements in this procedure should be performed with the DVM manually set to the 100 V range (&OO.OOO on the HP 3456A display).

3-40 Adjustments