18.Frequency Control Adjustments

Reference

Related Performance Tests

Description

18. Frequency Control Adjustments

RF Section:

A22 Frequency Control

Sweep Time Accuracy Test

Frequency Span Accuracy Test

Center Frequency Readout Accuracy Test

The sweep reference voltage is adjusted and then the sweep times are adjusted for proper tolerances. The sweep tune voltage is adjusted. Then the YTO DAC, VT0 DAC, and LSD VT0 DAC are adjusted, each to within its tolerance. Next, the Start and Stop frequencies are adjusted. FM Span is adjusted next for the proper amount of FM deviation.

SPECTRUM ANALYZER

DIGITAL VOLTMETER

FREPUENCY COUNTER

 

Figure 3-70. Frequency Control Adjustments Setup

Equipment

Digital Voltmeter (DVM) . . . . . . . . . . . . . . . . . . . . . . . .

HP 3456A

 

Frequency Counter . . . . . . . . . . . . . . . . . . . . . . . . . . .

. HP 5340A

Procedure 1. Place instrument on right side with IF-Display facing right as shown in Figure 3-70 and remove bottom cover.

2.Set LINE switch to ON and press QNSTR PRESET).

3.Connect DVM to A22TP15 and ground to A22TP12.

4.Adjust A22 REF A22R94 for DVM indication of + 10.00 ho.01 V dc.

See Figure 3-71 for location of adjustment.

Adjustments 3-l 19