HP 8590L spectrum analyzer narrow RBW fail.

[ciasteczkowypotwor]

I have an HP 8590L spectrum analyzer, which sometimes works well, and sometimes poorly.

The problem is with the RBW. It displays incorrectly between 1-30 kHz, as shown in the image, but above 100 kHz it's OK.



Of course, it doesn't pass the amplitude calibration, despite adjusting filters A11 and A13.

The adjustments in the instructions for the Crystal alignment and LC alignment steps seem correct, but they have no effect on the application's calibration or on the RBW display below 30 kHz.

Strangely enough, it sometimes works perfectly.

Has anyone encountered this problem?

[MarkL]

I have seen this shape before on an 8595E.  Mine was due to an intermittent attenuator step which created bad calibration data during the self-cal.

Try turning off corrections (CAL --> CORRECT --> OFF) and check if the trace is more normal looking.