Agilent Technologies N5241A, Руководство по обслуживанию

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4-30 Service Guide N5242-90001
Troubleshooting PNA Series Microwave Network Analyzers
Measurement System Troubleshooting N5241A/42A
Equipment Setup
1. Before starting these checks, zero and calibrate the power meter. (See the power meter
user’s guide for instructions on setting the calibration factor.)
2. If the Receiver Display (
Figure 4-6
or
Figure 4-7
) is not on the analyzer screen, perform
the following: Press UTILITY , then , then , then
.
3. Set the sweep speed for a 10 second sweep: Press STIMULUS , then
. Set the time to 10.000 seconds in the Sweep Time box.
To isolate a broadband RF signal generation failure, check the test port output power:
4. Note the power reading displayed on the power meter; it should be the preset power
level +/- 1 dB.
5. 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.
• If the power level is low or high on all test ports, the problem is LO signal related.
Continue with “Checking the A10 50 MHz Reference Outputs” .
• If the power level is low or high on only one of the test ports, the problem is either
source group or in the signal separation group. Continue with
“Checking the A10 50 MHz
Reference Outputs”
to check the source group.
Checking the A10 50 MHz Reference Outputs
1. Refer to the block diagram at the end of this chapter and to “Top Cables, All Cables—All
Options” on page 6-16 . Locate flexible cables W65, W66, and W67, at the A10 frequency
reference board.
2. Disconnect cables W65, W66, and W67, one at a time, from the A10 board.
3. Connect the spectrum analyzer to the open connector on the A10 board.
4. The spectrum analyzer should measure a signal at 50 MHz.
5. If any of the 50 MHz signals are not present, replace the A10 frequency reference board.
Refer to “Removing and Replacing the A4–A13 Boards” on page 7-14 .
6. If the 50 MHz signals are present, reconnect the cables, and then:
• for LO related problems, continue testing at “Checking the A11 13.5 GHz LO
Synthesizer Output” .
• for source related problems, continue testing at “Checking the A4 and A13 Source
Synthesizer Outputs” on page 4-32 .
Checking the A11 13.5 GHz LO Synthesizer Output
1. Refer to the block diagram at the end of this chapter and to “Top Cables, All Cables—All
Options” on page 6-16 . Locate the flexible cable W41 at the A11 LO synthesizer board.
2. Disconnect W41 from J1207.
System
Service Utilities
Receiver Display
Sweep
Sweep Time