HP 8560A Service Manual page 75

4. Set the HP 3456A controls as follows:
FUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DCVOLTS
RANGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1OV
RESOLUTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..lmV
5. Turn the HP 8560A m switch on.
6. Adjust A14R628 GATE BIAS for a DVM reading within 5% of the GATE BIAS voltage
printed on the A7 LO Distribution Amplifier label.
7. Zero and calibrate the HP 8902A/HP 8485A in LOG mode (power levels read in dBm).
Enter the power sensor 1 GHz Cal Factor into the HP 8902A.
8. Connect the power sensor to the 1ST LO OUTPUT on the HP 8560A.
9. On the HP 8560A, press (PRESET) (SPAN) ZERO SPAN (w) 1.0893 (GHz).
10. Connect the positive DVM lead to A14J18 pin 13.
11. Note the LO SENSE voltage printed on the A7 LODA label. Adjust A14R621 LO
AMPTD until the DVM reads 6 mV more negative than the LO SENSE voltage printed
on the A7 LODA label. For example, if the LO SENSE voltage is -170 mV, adjust
12. Check that the HP 8902A power level reads greater than +15.2 dBm.
13. Disconnect the power sensor from the 1ST LO OUTPUT and reconnect the 5052
termination.
14. Disconnect the DVM leads from A14J18.
8. First LO Distribution Amplifier Adjustment
Adjustment Procedures 2-41