EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: NickyDoes on January 27, 2022, 08:59:09 pm
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Hello,
I came upon an Agilent 8563EC 26.5 GHz spectrum analyzer. I'm getting into RF, but am not experienced at this point - and don't have much in the way of cables, adapters, let alone synthesizers. I do have an older HP 1.8 GHz analyzer that works great, so I can check some things. I checked the attenuator, for example. The attenuator appears to work well.
This SA is failing in ways unknown to me. I've read through the service manual, and could do quite a few of the checks - but would appreciate a bit of guidance in the rationale of what to check and what just doesn't make sense to try.
I attached photos rather than describe all the situations. I get normal looking spectra with excessive amplitude when measuring the Cal output with a span under 1.8 MHz. At and above 1.8 MHz, the measured amplitude moves to saturation. I realize there's a mode switch at 1.8 MHz, but I'm not yet grasping the fundamentals of what is going on.