HP 8560A, Service Manual

Page: 348 / 450

10. Set the HP 8560A to the following settings:
CENTER FREQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MHz
SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11. If the 1st LO is present, a signal should be displayed at about -10 (approximately
MHz from the center frequency). If no signal is displayed and ERR 334 LO AMPL is
not present, troubleshoot the A7 LODA. If no signal is displayed and ERR 334 LO AMPL
is present, check the All YTO as follows:
Set jumper to the TEST position.
Set the HP 8560A to the following settings:
C E N T E R F R E Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Hz
CF STEP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Hz
Connect a power meter directly to the output of the All YTO.
Press the HP 8560A’s step-up key and measure the YTO output power at each step.
Check that All
output power is between and
Set jumper to the NORM position and reconnect the All YTO.
12. On the HP 8560A press MORE, FREQ DIAGNOSE, and MAIN ROLLER. Note
the Main-Roller Oscillator’s frequency.
Main-Roller Oscillator’s Frequency M Hz
13. Disconnect W32 from and connect the output of a signal source to
Connect a positive lead to pin 1 and negative lead to pin 6. See
Figure 1.
14. Set the signal source to the following settings:
Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..0 dBm
Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Frequency recorded in step 12
15. Tune the source 1 MHz below the Main Roller frequency. The voltage measured on the
DVM should be approximately 8.2 Vdc.
16. Tune the source 1 MHz above the Main Roller frequency. The voltage measured on the
DVM should be approximately -8.2 Vdc.
17. If the DVM reading does not change, the Al4 Frequency Control assembly is defective.
Reconnect W32 to
Synthesizer Section