Agilent Technologies PNA Series Service Manual page 121

PNA Series Microwave Network Analyzers
E8361A
Source Group Tests
NOTE A defective A22 switch can exhibit the same symptom as a faulty source.
Therefore, if it is determined that the source is functioning properly, you are
directed to
Equipment Used for These Tests
Equipment Type
Spectrum analyzer
Power meter
Power sensor, 1.85 mm
RF cable, SMA (f) to SMA (f)
SMB (m) to SMA (f) adapter
SMA (m) to SMA (m) adapter
Power sensor, 2.4 mm
RF cable, 2.4 mm (f) to 2.4 mm (f)
Getting Ready to Test
Before checking the assemblies, you must open the analyzer.
CAUTION Use an antistatic work surface and wrist strap to reduce the chance of
electrostatic discharge for all of the procedures in this chapter.
1. Turn off the analyzer power.
2. Unplug the power to the analyzer and disconnect all rear panel connections.
3. Remove the covers from the analyzer. Refer to
4. With the covers off, plug in the analyzer and turn on the power.
Single vs. Broadband Failure
There are two main types of failures that are related to the source group. The failures are
classified as:
• broadband
• single band
Single band failures are indicated by all four channel traces having partial dropouts across
the frequency range or intermittent phase lock problems. Troubleshooting information is
provided under "If the traces faults are band-related," under
Broadband failures are indicated by all four channel traces being in the noise floor. Most
often this is due to problems in the phase lock signal path and will be characterized by a
"PHASE LOCK LOST" error message on the display.
Service Guide E8361-90001
"Checking the Signal Separation Group" on page
Model or
Part Number
8565E
E4418B/19B
V8486A
Any
1250-0674
1250-1159
8487A
85133C
Measurement System Troubleshooting
Alternate Model
or Part Number
None
E4418A/19A
None
Any
Any
Any
None
Any
"Removing the Covers" on page
"All Traces" on page
Troubleshooting
4-49.
7-6.
4-32.
4- 41