Technical data

4-40 Service Guide N5230-90025
Troubleshooting PNA Series Microwave Network Analyzers
Measurement System Troubleshooting N5230C
• Analyzers with Options 145 and 245
— Port; W40 of A19
— Port 2; W41 of A19
— Port 3; W42 of A19
— Port 4; W43 of A19
• Analyzers with Options 146 and 246
— Port 1; W40 of A19
— Port 2; W41 of A19
— Port 3; W64 of A18
— Port 4; W65 of A18
2. Using a 5/16-inch torque wrench, disconnect the semirigid cable at the MASSQuad.
3. Connect the spectrum analyzer to the open connector. Set the spectrum analyzer to measure a signal at
1 GHz.
4. If the 1 GHz signal is not present and the analyzer has a source step attenuator, reconnect the cable to
the MASSQuad and continue testing at “Checking the A25 60-dB Source Step Attenuator (Options 145,
245, 146, and 246)” on page 4-40 or “Checking the A26 60-dB Source Step Attenuator (Options 146 and
246)” on page 4-41, whichever is appropriate.
5. If the 1 GHz signal is not present and the analyzer does not have a source step attenuator, replace the
MASSQuad Refer to “Removing and Replacing the A19 MASS 26.5 (MASSQuad) and MASSQuad
Mounting Block” on page 7-34 or “Removing and Replacing the A18 MASS 26.5 (MASSQuad)” on
page 7-32, whichever is appropriate.
6. If the 1 GHz signal is present, reconnect the cable to the MASSQuad and replace the appropriate test
port coupler. Refer to “Removing and Replacing the A21, A22, A23, and A24 Test Port Couplers and
Coupler Mounting Blocks” on page 7-38.
Checking the A25 60-dB Source Step Attenuator (Options 145, 245, 146, and 246)
1. Locate semirigid cable W59 at the output of the A25 source step attenuator.
2. Using a 5/16-inch torque wrench, disconnect the semirigid cable at the A25 step attenuator.
3. Connect the spectrum analyzer to the A25 step attenuator connector. Set the spectrum analyzer to
measure a signal at 1 GHz.
4. If the 1 GHz signal is not present, continue troubleshooting at “Checking the Output of the A19
MASSQuad to the A25 Source Step Attenuator (Options 145, 245, 146, and 246)” on page 4-40.
5. If the 1 GHz signal is present, replace the A19 MASSQuad. Refer to “Removing and Replacing the A19
MASS 26.5 (MASSQuad) and MASSQuad Mounting Block” on page 7-34.
Checking the Output of the A19 MASSQuad to the A25 Source Step Attenuator (Options 145, 245, 146, and
246)
1. Locate semirigid cable W58 at the output of the A19 MASSQuad that goes to the input of the A25 source
step attenuator.