Technical data

Service Guide N5230-90025 4-39
PNA Series Microwave Network Analyzers Troubleshooting
N5230C Measurement System Troubleshooting
Checking the Signal through the Signal Separation Path
For all of the following checks, refer to the block diagrams at the end of this chapter and to:
• “Bottom Assemblies, Options 140 and 240” on page 6-22
• “Bottom Assemblies, Options 146 and 246” on page 6-30
Trace loss in the signal separation group is due to one or more of the following assemblies being defective:
• A18 MASSQuad (Options 146 and 246 only)
• A19 MASSQuad
• A25 source step attenuator (Options 145, 245, 146, and 246 only)
• A26 source step attenuator (Options 146 and 246 only)
• A21, A22, A23, or A24 test port coupler
Equipment Used for These Tests
To determine which assembly is defective, check the signal at each available measurement point in the
signal path from the switch splitter in the A19 MASSQuad (and A18 MASSQuad for Options 146 and 246) to
the output port.
For Port 1 measurements, set the network analyzer for an S
11
measurement with a CW frequency of 1 GHz.
For Port 2, 3, and 4 measurements, set the network analyzer for an S
22,
S
33,
or S
44,
measurement with a CW
frequency of 1 GHz.
Perform the following checks in the order presented.
Checking the A19 MASSQuad A18 MASSQuad and the A21–A24 Test Port Couplers
1. Locate the following semirigid cable at the appropriate output of the either the A19 or A18 MASSQuad:
• Analyzers with Options 140 and 240
— Port 1; W8 of A19
— Port 2; W9 of A19
— Port 3; W10 of A19
— Port 4; W11 or A19
Equipment Type
Model or
Part Number
Alternate Model or Part
Number
Spectrum analyzer 8565E
856xE
a
a. Must be capable of measuring a signal at 1 GHz.