Agilent Technologies N5242A, Руководство по обслуживанию

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Service Guide N5242-90001 4-29
PNA Series Microwave Network Analyzers Troubleshooting
N5242A Measurement System Troubleshooting
Checking the Source Group
Source Group Tests
Before checking the source group 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 front and rear panel connections
except installed jumpers.
3. Remove the outer and inner covers from the analyzer. Refer to “Removing the Covers” on page 7-6 .
WARNING Procedures described in this document are performed with power
supplied to the product while protective covers are removed. Energy
available at many points may, if contacted, result in personal injury.
4. With the covers off, plug in the analyzer and turn on the power.
CAUTION Do not operate the analyzer with the outer cover removed for more than 30 minutes,
as this could cause the analyzer to overheat which could result in costly damage.
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 trace faults are band-related,” under
“All Traces” on page 4-28 .
Broadband failures are indicated by all four channel traces being in the noise floor.
Proceed to
“RF Signal Troubleshooting” .
RF Signal Troubleshooting
To isolate a broadband RF signal generation failure, check the test port output power:
1. Connect a power meter and power sensor to Port 1 of the analyzer.
2. Press UTILITY . Press STIMULUS , then . Set the
Center
Frequency to 2 GHz
and press ENTRY . Press , set the
Span Frequency
to
0 Hz
and press ENTRY .
3. Note the power reading displayed on the power meter; it should be at least 0 dBm.
4. Connect the power sensor, in turn, to Ports 2, 3, and 4 and set trace to measure S
22
, S
33
,
and S
44
respectively. Note the power reading displayed on the power meter.
Preset Freq
Center
Enter Span
Enter