Agilent Technologies E4418B, Service Manual

Page: 62 / 154

Performance Tests
Output Standing Wave Ratio (SWR) Test
2-26 Agilent E4418B/E4419B Service Guide
5. Round off the DVM reading to two decimal places. Record this value as
the first internal bridge resistance (R
1
) of the Agilent 432A:
• R
1
___________
Ω
6. Set the Agilent 432A mount resistance switch to 100
Ω
.
7. Round off the DVM reading to two decimal places. Record this value as
the second internal bridge resistance (R
2
) of the Agilent 432A:
• R
2
___________
Ω
8. Set the Agilent 432A mount resistance switch to 200
Ω
.
9. Connect the equipment as shown in Figure 2-7 ensuring that the DVM
input leads are isolated from chassis ground.
Note Ensure that the Agilent 432A and the power meter under test have
been switched on for at least 30 minutes before performing the
following steps.
10.Preset the power meter:
• Press , then on the power meter.
• Set the Agilent 432A RANGE switch to Coarse Zero.
• Adjust the front panel Coarse Zero control to obtain a zero meter
indication.
11.Zero the Agilent 432A test power meter:
• Fine zero the Agilent 432A on the most sensitive range.
• Set the RANGE switch to 1 mW.
12.Set the DVM to measure microvolts.
13.Connect the positive and negative input leads to the V
comp
and V
RF
connectors respectively, on the rear panel of the Agilent 432A.
14.Observe the reading on the DVM:
If less than 400 uV, go to step 15. If 400 uV or more, press and hold the
Agilent 432A Fine Zero switch and adjust the Coarse Zero control so
that the DVM indicates 200 uV or less. Release the Fine Zero switch
and go to step 15.
15.Round off the DVM value to two decimal places. Record this value as
V
o
:
• V
o
___________
16.Turn the power reference on:
Press , , .
Preset
Local
Confirm
System
Inputs
More
Power Ref On
4402serv.book Page 26 Tuesday, October 14, 2003 3:18 PM