Keysight N9040B Option 508 - Signal Level Problem with Input Frequencies < 3.6 GHz

Keysight Technologies N9040B UXA Signal Analyzer Service Guide 71
Boot Up and Initialization Troubleshooting
Signal Level Verification
Signal Level Verification
Signal Level Problem with
Input Frequencies < 3.6 GHz
Measure the 50 MHz RF calibrator signal level by pressing Input/Output, RF
Calibrator, 50 MHz. Now press Freq and input 50 MHz. Press SPAN, 1 MHz,
and Peak Search. If the analyzer is functioning correctly in low band, the 50
MHz calibrator level should be −25 dBm ± 2 dB. See the figure below.
Is the signal level correct?
If yes:
The analyzer low band path is functioning properly at least at 50 MHz.
If no:
Refer to Chapter 4, “RF Section Troubleshooting (RF/Microwave
Analyzers)” in this manual.
It is possible that other input frequencies < 3.6 GHz could have an amplitude problem even
though the 50 MHz calibrator is within tolerance. Using the internal RF calibrator provides a
quick check of the low band path.