HP 8560A Service Manual page 104

19. 10 MHz Reference Adjustment (Option 003)
2. Set the frequency counter controls as follows:
FUNCTION/DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .FREQ A
INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A:
AC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OFF (DC coupled)
AUTO TRIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ON
100 kHz FILTER A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OFF
3. On the HP 5334A/B Frequency Counter, select a 1 second gate time by pressing
1
MATH
frequency counter should now display the difference between the frequency of the INPUT A
signal and 10.0 MHz with a displayed resolution of 0.010 Hz (10 mHz).
4.
Locate the FREQ ADJ control on the HP 8560A. This control is accessible through the
center deck of the spectrum analyzer. See Figure 2-22.
5. Remove the dust cap screw.
6. Use a nonconductive adjustment tool to adjust the FREQ ADJ control on the A21 OCXO
for a frequency counter indication of 0.00 Hz.
7. On the HP 5334A/B Frequency Counter, select a 10 second gate time by pressing
between the frequency of the INPUT A signal and 10.0 MHz with a resolution of 0.001 Hz
(1 mHz).
8. Wait at least 2 gate periods for the frequency counter to stabilize, and then adjust the
FREQ ADJ control on the A21 OCXO for a stable frequency counter indication of 0.000
fO.O1O Hz.
9. Replace the dust cap screw on the A21 OCXO.
2-70 Adjustment Procedures
e rsp ayed frequency by -10.0 MHz by pressing
The