HP 8901B Operation And Calibration Manual page 367

Model 8901B Performance Tests
-
POS VCWP
D I G I T A L VOLTMETER
NEQ
VRF
connector of the
HP
432A Power Meter, the negative input
to
the VRF connector. Switch the
equipment on and let it warm up for at least 30 minutes.
0
0
000000 0000
0
0
0 0
DODOOP
0 0 0 0 0
0
HP 432A
POWER METER
O D
: :
8 8 8 : :
0
NOTE
n o m this point on do not handle the HP 478A in order to maintain its
thermal stability.
Figure
4-6. Power Reference Performance Test Setup
3. On the Modulation Analyzer, key in 45.0 SPCL to
switch
the power reference
o f f .
4. Set the H P 432A Power Meter RANGE to COARSE ZERO and adjust the front-panel COARSE
ZERO to obtain a zero meter indication.
5. Fine zero the
HP
432A Power Meter on the most sensitive range, then set the RANGE switch to
1
m W
(0 dE3m).
6. Observe the voltage reading on the voltmeter. If the reading is greater than 400
pV,
press and
hold the
FINE
ZERO switch on the H P 432A Power Meter and adjust COARSE ZERO
80
that
the voltmeter reads less than 200
p V
then release the FINE ZERO switch. Record the voltmeter
reading for future reference.
V c o ~ p
-
VRF
with
No
Power
(Vo):
Vdc
NOTE
Steps 6, 7, and 8 should be performed as quickly as possible to minimize
drift.
7. On the Modulation Analyzer, key in 45.16 SPCL. Record the voltmeter reading.
V c o ~ p
-
VRF
with
1
mW
(Vi):
Vdc
8. Connect the voltmeter to read VCOMP (with respect to chassis ground) on the H P 432A Power
Meter. (The voltmeter's negative input should connect to chassis ground.) Record the voltmeter
reading.
V c o ~ p
with
1
m W Vdc
rev.lOJUU7 Performance Test 7 4-27