HP 8568B Figure, 14. 249 MHz Phase Lock Oscillator Adjustments, Location of 249 MHz Phase Lock Oscillator Adjustments

14. 249 MHz Phase Lock Oscillator Adjustments

Procedure 1. Place instrument on right side with IF-Display Section facing right as shown in Figure 3-59.

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

3.Connect DVM to A7TPl and ground to A22TP12.

4.Key in [CENTER FREQUENCY) 17.6 MHz and [FREQUENCY SPAN) 0 Hz

on HP 8568B.

5.Adjust A7 PLO A7C3 for DVM indication between +5.2 V dc and +6.0 V dc. See Figure 3-60 for location of adjustment.

A7 2 4 9 M H z

P H A S E L O C K O S C I L L A T O R

Figure 3-60.

Location of 249 MHz Phase Lock Oscillator Adjustments

6.Key in ~CENTER FREQUENCY] 37.1 MHz.

7.DVM indication should be between + 12.9 V dc and + 16.9 V dc. If DVM indication is within the given range, disconnect DVM from A7TPl and proceed to step 18. Otherwise, key in CRAVE_) 2, SET LINE switch to STANDBY, and place A7 249 MHz PLO on extender (with DVM still connected to A7TPl).

8.Set LINE switch to ON and key in [RECALL_) 2 on HP 8568B S p e c t r u m A n a l y z e r .

9.Adjust A7 PLO A7C3 for DVM indication of + 13.0 ho.1 V dc.

10.Key in [CENTER FREQUENCY) 17.6 MHz, CFREQUENCY SPAN] 0 Hz, and [SAVE_) 1.

11.Adjust A7 PLO A7L2 for DVM indication of +5.2 f0.05 V dc. (A7L2 slug should be near center of coil form when A7L2 is properly adjusted.)

12.Key in [=J 2 and adjust A7C3 for + 13.0 fO.l V dc at A7Pl.

13.Press 1 (RECALL 1) and adjust A7L2 for +5.2 rtO.05 V dc.

14.Repeat steps 12 and 13 until A7C3 and A7L2 need no further adjustment.

3-108 Adjustments