On Feb 24, 2025, at 10:17?AM, jmr via groups.io <jmrhzu@...> wrote:

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I wonder if anyone here has experience or access to an Agilent E5052A signal source analyser? Mine is about 20 years old and is recently showing signs of unreliability.

The main symptom is an occasional power on self test fail and it then reports issues with a 3V3 power supply voltage on the A3 DSP/ADC board where it reads low at typically 2.96V. I think a pass requires >2.96V but this may be firmware dependent. My E5052A is running the latest firmware V2.51.

I think this 3V3 supply is common across the backplane but it gets reported as an A3 test in the service menu. The 5V PSU rail also reads low at between 4.7 and 4.8V but this is still a pass (shows true for the test result)

Also, for several years now it has shown a stubborn internal spurious at 60 kHz at a very low level. This very slightly spoils any phase noise measurements even though it shows up at about -140dBc then the trace is in phase noise mode in dBc/Hz. I'm not sure what causes this internal 60 kHz term, it may be from a PSU or the display or a divided clock. It may be that the 60kHz spurious term is a feature of this analyser as it is present on all my plots dating back over 13 years. It's not caused by anything nearby to the instrument as it does it regardless of position or proximity to other equipment. Plus the other E5052A I've used in the past (in a different location) is exactly the same.

The 60kHz spurious is also present when I swap across to the baseband input even with a very clean LF signal fed to the 0-40 MHz baseband input. So this spurious must be getting in at the ADC if it affects the baseband input as well.

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I've seen similar on another E5052A that also shows a lowish 3V3 voltage (but it never shows a power on test failure) and it also has the permanent 60 kHz spurious on all phase noise tests on the main RF input.

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The service menu password is only three characters long and is 'kid'

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If anyone has access to a healthy E5052A could they enter the service menu and do a manual Power On Test (POT) in the service menus? Then report the 5V and 3.3V results for the A3 module

Mine shows anything from 2.91V to 3.05V and I think the pass/fail threshold for the POT is somewhere around 2.96V. The other E5052A I have some access to shows 2.982V to 3.08V and never reports a POT failure.

Thanks in advance for any replies

Jeremy