Wavecrest DTS2070 PAC-1A

[rubidium]

I picked up this colossus recently for essentially the cost of shipping, and it arrived today - along with the specter of a hernia.    It's in great physical shape, it powered on, all of the DC voltages measure within spec, no burnt or leaking passives, and it performed its 300 sec internal calibration without a hitch. I have the user's manual, but it's rather light on detail. I also have no clue as to what the "PAC-1A" nomenclature means. So there's a lot of exploration to perform. For now, I simply hooked up 2 same-length RG-58 lines to the internal 200MHz cal outputs and performed the external cal procedure for cable compensation. The result is shown in the display, and it's rather amazing how just turning one of the SMA connectors just a fraction of a turn is *easily* sensed and quantified by this instrument.

I did notice that the internal 100MHz OCXO was off by about 13Hz. There is a multi-turn pot inside the OCXO that is accessible, and I can adjust it to be within a few 10'ths of a Hz of 100MHz, but, magically, there appears to be a glitch in the pot at that very point so I can't do much better.  I suppose after I spend more time navigating about this system, I can perhaps get inside the OCXO and replace the pot.

This may not be as heavy as my HP8664A, but it's damn heavy. 
Jim

[wn1fju]

I have the DTS-2075 and it is a wonder of technology.  Not sure how it differs from your 2070 (nor do I know what PAC-1A means) - maybe the 2075 can do a bit higher frequency?

Anyway, in case you haven't found this already, go to KO4BB's site, go to the manual section and search on "wavecrest".  You will see tons of application notes and near the bottom is a .zip file containing a lot of useful information on these digital time scopes.

[rubidium]

I have the DTS-2075 and it is a wonder of technology.  Not sure how it differs from your 2070 (nor do I know what PAC-1A means) - maybe the 2075 can do a bit higher frequency?

Anyway, in case you haven't found this already, go to KO4BB's site, go to the manual section and search on "wavecrest".  You will see tons of application notes and near the bottom is a .zip file containing a lot of useful information on these digital time scopes.

From the various user's manuals, the older 2070 and the more recent 2075, 2077, and 2079 don't differ a whole lot in terms of resolution. The later models accommodate higher frequency and have more memory to store measurements.

The unit i have is very clean and appears to be fully functional. My only qualm is that the internal 100 MHzOCXO has drifted nearly 3 Hz overnight and apparently still hasn't settled down. Perhaps the unit has been idle for a long time and needs to be under power for a significant period before things settle down. There's also the issue of the OCXO adjustment pot. There's a glitch right around the spot you want to calibrate to, and smoothly adjusts the frequency everywhere else. 
Jim