HP 8560A, Service Manual

Page: 69 / 450

6. Sampling Oscillator Adjustment
12. Record the displayed voltage in Table 2-11 as the displayed voltage for the sampling
oscillator frequency of 288 MHz.
13. Press on the HP 8560A. Use the step keys to set the analyzer center
frequency to the frequencies listed in Table 2-11. At each listed frequency, record the
displayed voltage in the table.
14. If the difference between the maximum and minimum voltages is less than 0.50 V, and all
voltage readings are between and Vdc, proceed to step 19.
15. Locate the center frequency at which the voltage is lowest. Use the and keys to set
the HP 8560A to this frequency.
16. Readjust SMPL MATCH 1 to set the displayed voltage to 0.8 Vdc.
17. Move the positive DVM test lead to pin 3.
18. Set the HP 8560A center frequency to 511 MHz.
19. Readjust SMPL PWR ADJ if necessary, until the voltage at pin 3 is
-0.5 to -2.5 Vdc and the voltage at pin 1 is -0.5 to i-2.5 Vdc.
20. Disconnect the DVM probes from
Coarse-Tune Adjustment
Note This adjustment should be necessary only if the coaxial resonator 2200 has
been replaced or if there was insufficient range in the Sampling Oscillator
Fine-Tune Adjustment.
FREQUENCY
COUNTER
POWER
SUPPLY
A 1 4
SPECTRUM
ANALYZER
Figure 2-9. Coarse-Tune Adjustment Setup
S K 1 8
21. Set the HP 8560A switch off and remove the top shield over the sampling oscillator.
Connect the equipment as shown in Figure 2-9.
22. Remove any existing shorts from the exposed center-conductor of coaxial resonator 2200
to the ground plane.
Adjustment Procedures
2-35