HP 8566B Adjustment Manual page 269

TRACE A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CLEAR-WRITE
TRACE B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BLANK
8. Adjust A7A2C4 100 MHz slowly through its full range while
monitoring the display of the second spectrum analyzer. The
output of the 100 MHz VCXO should be a single output signal
with
near 100 MHz, no spurious oscillations at other frequencies.
If spurious oscillations are present, increase the value of
factoryselected component A7A2R3 by
check again for spurious oscillations. Refer to 'lhble 3-3 for the
acceptable range of values, and to Table 3-4 for HP part numbers;
refer to Figure 3-65 for the location of A7A2R3.
9. Disconnect the second spectrum analyzer from A7A2J2 100 MHz
OUT, and connect the frequency counter to A7A2J2.
10. Adjust A7A2C4 100 MHz for a frequency counter indication of
100.0000 fO.0001 MHz (f100 Hz).
11. Disconnect the dc power supply from the A7A2TPl TUNE test
point, and jumper A7A2TPl TUNE to ground.
12. Verify that the frequency counter indication is less than 100.0000
MHz. If it is not, repeat, steps 3 through 11.
13. Disconnect, the jumper from A7A2TPl TUNE and ground. Set the
dc power supply for an output of -25 Vdc, and connect the -25
Vdc output of the dc power supply to A7A2TPl TUNE.
14. Verify that the frequency counter indication is greater than
100.0000 MHz. If it is not, repeat steps 3 through 13.
15. Disconnect the dc power supply from A7A2TPl TUNE, and
reconnect the cable 83 (gray/orange) to A7A2J2 100 MHz OUT.
16. Disconnect the cable 96 (white/blue) from A7A3Jl 400 MHz IN,
and connect this cable to the RF INPUT of the second spectrum
analyzer using a BNC-to-SMB snap-on test cable and an SMB
male-to-male adapter.
17. Set the controls of the second spectrum analyzer as follows:
CENTER FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .500 MHz
FREQUENCY SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 GHz
REFERENCE LEVEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -7 dBm
RES BW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AUTO
LOG SCALE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 dB/div
TRACE A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CLEAR-WRITE
18. The 400 MHz output signal should be visible on the display of
the second spectrum analyzer, along with other harmonics of
100 MHz. Adjust the A7A2C3, A7A2C2, and A7A2Cl 400 MHz
adjustments in sequence to maximize the power level of the 400
MHz output signal and minimize all other harmonics of 100 MHz.
Be sure to perform the adjustments in the proper sequence; it
might be necessary to repeat the sequence more than once.
19. Note the level of any 100 MHz harmonics displayed on the second
spectrum analyzer relative to the power level of the 400 MHz
14. 100 MHz VCXO Adjustments
one standard value and
Adjustments 3-129