Agilent Technologies E4418B, Service Manual

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Adjustments
Power Reference Oscillator Level Adjustment
Agilent E4418B/E4419B Service Guide 3-9
3. Connect the equipment as shown in Figure 3-3. The leads should be
isolated from ground. Ensure that the power reference oscillator is off.
Ensure that both the power meter under test and the Agilent 432A
have been powered on for at least 30 minutes before proceeding to the
next step.
4. Set the Agilent 432A range switch to coarse zero and adjust the front
panel coarse zero control to obtain a zero meter indication.
5. Fine zero the Agilent 432A on the most sensitive range, then set the
range switch to 1 mW.
Note Ensure that the DVM input leads are isolated from chassis ground
when performing the next step.
6. Set up the DVM to measure microvolts.
7. Connect the positive and negative input leads, respectively, to the
V
comp
and V
RF
connectors on the rear panel of the Agilent 432A.
8. Observe the reading on the DVM. If less than 400
µ
V, proceed with the
next step. If 400
µ
V or greater, press and hold the Agilent 432A fine
zero switch and adjust the coarse zero control so that the DVM
indicates 200
µ
V or less. Then release the fine zero switch and proceed
to the next step.
9. Round off the DVM reading to the nearest microvolt and record
this value as V
0
.
• V
0
________________
µ
V
• Disconnect the DVM negative input lead from the V
RF
connector on
the test power meter and reconnect it to chassis ground.
10. Turn the power reference on by pressing
■
, .
11.Record the reading on the DVM to two decimal places. This is V
comp
.
• V
comp
_____________V
12.Reconnect the negative lead to the V
RF
connector on the rear panel of
the Agilent 432A. The DVM is now set up to measure V
1
which
represents the power reference oscillator output level.
13.Calculate the required value of V
1
using equation 2.
Zero
Cal
Power Ref On
V
1
V
comp
V
0
V
comp
2
10
( )
3
–
–
4R
( )
CalibrationFactor
( )
–
+ =
4402serv.book Page 9 Tuesday, October 14, 2003 3:18 PM