5-5. 20130 LOOP PHASE LOCK, A36, A38, A39, A40, AND A43 (Cont’d)
29. Set the OUT as follows:
a.
Press INSTR PRESET]
b.
Press [STARTFREQ] then enter [2] [0] [MHz]
c.
Press [STOPFREQI then enter [2] [5] [MHz]
d.
Press [SHIFT],
then
[XTAL]
e.
Press [SINGLE]Sweep
30. Adjust A43R27 (5 MHz AF) to center the signal on the Spectrum Analyzer screen.
31. Disconnect the Spectrum Analyzer from A36J1 and reconnect W39 to A36J1 (OUT 20-30 MHz).
PHASE LOCK LOOP 3
32. Set the LINE switch to STANDBY. Remove A39 (PLL3 Up Converter) and install it on an extender
board.
33. Set the LINE switch to ON. Press
[INSTRPRESET]. Press [CW]then enter [5] [GHz].
Press
[SHIFT][M3] to display the PLL2 and PLL3 frequencies.
34. Connect the Spectrum Analyzer to the Test Connector A39J3 on the P.C. board. Tune the Spec-
trum Analyzer center frequency to 160 MHz. Set the reference level to —20 dBm and set the scale
to 1 dB per division.
35. Adjust A39L16, A39L17, and A39C50 (160 MHz PEAK) for maximum signal level at 160 MHz.
Iteration of L16 and L17 adjustment may be necessary. Refer to Figure 5-11 for location of adjust-
ments.
If A39C50 does not have sufficient range, select the value of A39C49 for proper range. (Refer to
Table 5-2.)
36. At the OUT, select the following:
a.
Press [CF]then enter (6]
[.]
[6] [2] [7] [2] [5] [0] [GHz].
b. Press [AF]then enter [1] [0] [0] [kHz].
c.
Press [SINGLE]Sweep
37. Tune the Spectrum Analyzer to a center frequency of 6
MHz. Set the scale to
10 dB per division.
38. The 6
MHz signal displayed should be at least —42
dBm. If not, repeat Steps 33
through 37.
39. Connect the DVM to A39TP3.
40. Adjust A39L11 (PLL3 VCO AOJ) for a DVM indication of —7.5 Vdc
±
0.1 Vdc. The voltage may not
change with initial adjustment but will change once the phase lock loop locks.
41. Press [CF] on the OUT then enter [5] [GHz].Press [SINGLE]SWEEP to initiate a sweep.
42. The DVM indication should be —6.7 Vdc ±0.5Vdc.
43. Set the LINE switch to STANDBY. Disconnect the test equipment and reinstall A39 (PLL3 UP
Converter) in the instrument.
PHASE LOCK LOOP 1
44. Set the LINE switch to STANDBY. Place A36 (PLL1 VCO) on an extender board. Remove all cables
connected to A36.
HP 8340B/41B
Adjustments
5-31