53310A Modulation Domain Analyzer -- wonderful, not very common or well known instrument.

This one has NO options. Fully working, passes all tests. It is calibrated using my Wavetek/Datron 4808 calibrator (kept in calibration) but that is not something special -- it only needs 5V DC for calibration, no specialized equipment is needed beyond that.

This is the second unit with undamaged cabinet that I was going to use to transplant parts from the other 53310A that I'm selling in another auction and that has one rear leg broken off.  However, it is fully functional and useful if one doesn't need to go over 100MHz and has a good reference oscillator. In any case it is a good parts donor as it has all the parts except option boards, all known good.

It is quite dusty inside as it is seen just by looking into the fan openings so you will have to open it and give it a good cleaning. I did not do it because it would require breaking those calibration seals -- they are essentially useless because there is [almost] nothing to calibrate there but anyway...

BTW, the molded case is UNIQUE for 53310A -- those very similar looking cases from old HP DSOs are very different inside so they can't be used as a replacement. Also worth to mention that Opt.010 (OCXO) can NOT be retrofitted into an instrument without it -- the rear panel is totally different.

Aha, if anybody wanted to know the reason for selling -- I have another one like this, with all options, that I keep for my own use. I was going to keep this one as a spare but all those spares take too much room that I need for something else.