Agilent Technologies N5241A, Service Manual

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4-36 Service Guide N5242-90001
Troubleshooting PNA Series Microwave Network Analyzers
Measurement System Troubleshooting N5241A/42A
6. If the 800 MHz signal is present and the analyzer has source attenuators and bias tees,
reconnect the cable to the bridge and continue testing at “Checking the A34, A35, A36,
and A37 60-dB Source Step Attenuators” on page 4-36
7. If the 800 MHz signal is present and the analyzer does not have source attenuators and
bias tees, replace the test port coupler. Refer to “Removing and Replacing the A29–A32
Test Port Couplers” on page 7-38 .
Checking the A34, A35, A36, and A37 60-dB Source Step Attenuators
1. Locate the appropriate semirigid cable at the output of the source step attenuator to be
checked:
• Options 219, 224, 419, and 423
— Port 1; W72 of A34
— Port 2; W84 of A37
— Port 3; W76 of A35
— Port 4; W80 of A36
2. Using a 5/16-inch torque wrench, disconnect the semirigid cable at the step attenuator.
3. Connect the spectrum analyzer to the open step attenuator connector. Set the spectrum
analyzer to measure a signal at 800 MHz.
4. If the 800 MHz signal is not present, replace the source step attenuator. Refer to
“Removing and Replacing the A34–A37 Source Attenuators, the A38–A41 Bias Tees,
and the A42–A45 Receiver Attenuators” on page 7-42
.
5. If the 800 MHz signal is present, replace the associated bias tee. Refer to “Removing
and Replacing the A34–A37 Source Attenuators, the A38–A41 Bias Tees, and the
A42–A45 Receiver Attenuators” on page 7-42
.
Checking the A46, A47, A48, and A49 Mechanical Switches
1. Locate the appropriate semirigid cable at the output of the mechanical switch to be
checked:
• Options 224 and 423
— Port 1; W96 of A46
— Port 2; W110 of A49
— Port 3; W102 of A47
— Port 4; W106 of A48
2. Using a 5/16-inch torque wrench, disconnect the semirigid cable at the bypass switch.
3. Connect the spectrum analyzer to the open bypass switch connector. Set the spectrum
analyzer to measure a signal at 800 MHz.
4. If the 800 MHz signal is not present, replace the mechanical switch. Refer to “Removing
and Replacing the A46–A49 Bypass Switches and the A50 Combiner” on page 7-46 .
5. If the 800 MHz signal is present, replace the associated bridge. Refer to “Removing and
Replacing the A25–A28 Bridges and Bridge Mounting Brackets” on page 7-36 .