HP 85027A/B/C Adjustments
NOTE
Steps 19 and 20 must be rel)eated until no further change is
noted.
DC Mode RF Adjustment Check
21.
Turn on the source RF.
22.
Connect the power meter sensor to the calibrated 10 dB step attenuatoi-.
23.
Set the attenuator for 0 dB.
24.
Preset the source. Set it to generate 50 MHz CW without modulation. Adjust the
output for a reading of +6.5 dBm on the power meter.
25.
Disconnect the powei- sensor from the attenuatom~. Connect the input port of the
bridge to the attenuator. Leave the test port open.
26.
On the analyzem~,confirm that smoothing (5%, default factor), averaging (8, default
factor) and the cursor ai-e on.
27.
ONLY if the cursor does not indicate -6±0.8dBm, adjust the bridge’s gain
potentiometer (R5) for a cursor reading of 0±0.8dB.
28.
Set the attenuator for 30 dB. Only if the cursor does not indicate calibrated -30
minus 6+-0.8dBm, adjust the bridge’s load potentiometer (R29) for that cursor
reading.
29.
Set the attenuator to 0 dB and readjust the gain potentiometer (if required) until
the cursor indicates -6±0.8dBm.
30.
Repeat steps 27 thi-ough 30 ONLY until the change in level is equal to the
calibrated 30 dB ±0.8dB and the cursor with 0 dB attenuation indicates -6 dB±0.8
dB.
5-4