HP 8566B Adjustment Manual page 288

17. 20/30 Loop Phase Lock Adjustments
3-148 Adjustments
3. Set the frequency synthesizer for a 20 kHz, 0 dBm output.
Connect the frequency synthesizer
using a BNC to Alligator clip adapter. Connect the ground lead of
the
adapter to the metal cover of the AlOAl PLLl VCO Assembly.
4. Connect the high-frequency active probe to the RF INPUT of
the second spectrum analyzer and to the probe power supply, as
shown in Figure 3-77.
5. Press @ZZZJ on the second spectrum analyzer. Connect the
active probe tip to the CAL OUTPUT signal, and press (RECALL].
6. Adjust the AMPTD CAL control on the second spectrum analyzer
for a -10.00 dBm displayed signal, and then press ISYIFT)
7. Set the controls of the second spectrum analyzer as follows:
CENTER FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 kHz
FREQUENCY SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 kHz
REFERENCE LEVEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 dBm
LOG SCALE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 dB/DIV
VIDEO BW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .300 Hz
8. Connect the active probe tip to the lead of A10AlL7 closest to
the 40 kHz LPF) should be visible on the display of the second
spectrum analyzer.
[
9. Press MARKER
PEAK SEARCH
spectrum analyzer to position the peak of the 20 kHz signal at the
top graticule line. Press MARKER la] on
analyzer.
10. Set the frequency synthesizer for an output frequency of 50 kHz.
Adjustments AlOAlL7 and AlOAlL8 are
normally do not require readjustment unless a component failure has
occurred. To verify their proper adjustment, skip to step 12.
11. Adjust AlOAlL7 and AlOAlL8 50 kHz NULL adjustments to
minimize the amplitude of the 50 kHz signal displayed on the
second spectrum analyzer. Refer to Figure 3-78 for the location of
50-ohm
OUTPUT to AlOAlTP3
], ~MKR +
on the second
REF
the second spectrum
sealed
at the factory and