Keysight NFA Series Noise Figure Analyzers Service Guide
155
RF Section Troubleshooting (N8973B, 74B, 75B Analyzers)
Troubleshooting
When the input attenuation is changed from 0 dB to 2 dB, the 2 dB Step LED
DS15 should illuminate. When the input attenuation is changed from 2 dB to
4 dB, DS15 and DS16 should be illuminated as per
The analyzer default setting for RF Coupling is AC mode. Verify the AC Select
LED DS14 is illuminated at this time. Set
Input/Output
,
RF Coupling
to DC.
DS14 turns off, DS11 DC Select yellow LED should illuminate. Switch the RF
Coupling back to AC. If the LED's illuminate correctly, the switch control logic
to Input Attenuator A from the A15 Front End Control Assembly is correct. If the
LED's are not illuminating as expected, the most probable cause is the A15
Front End Control Assembly.
Table 4-3
Attenuator A Logic
Attenuator Setting (dB)
DS15
2 dB
Step LED
DS16
2 dB
Step LED
0
2
X
4
X
X
Содержание N8973B
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Страница 44: ...44 Keysight NFA Series Noise Figure Analyzers Service Guide Overview How to Return Your Instrument for Service ...
Страница 132: ...132 Keysight NFA Series Noise Figure Analyzers Service Guide Instrument Messages Condition Messages ...
Страница 228: ...228 Keysight NFA Series Noise Figure Analyzers Service Guide RF Section Troubleshooting N8976B Troubleshooting ...
Страница 268: ...268 Keysight NFA Series Noise Figure Analyzers Service Guide Analog Digital IF Troubleshooting 25 MHz BW IF Section ...
Страница 322: ...322 Keysight NFA Series Noise Figure Analyzers Service Guide Block Diagrams Block Diagrams Block Diagrams ...
Страница 332: ...332 Keysight NFA Series Noise Figure Analyzers Service Guide Block Diagrams Block Diagrams NFA Computer Block Diagram ...
Страница 350: ...350 Keysight NFA Series Noise Figure Analyzers Service Guide Service and Diagnostics Menus Front Panel Key Test ...
Страница 470: ...470 Keysight NFA Series Noise Figure Analyzers Service Guide Assembly Replacement Procedures Front Frame Assembly ...