[time-nuts] Looking for OCXO info - MTI 250-0709-B

[ed breya]

I've been scrounging around in the OCXO department and found two of 
these that I likely pulled from something junked out long ago. I found 
the MTI website, current catalog, model line etc, but of course no 
mention of this specific version, or anything close, numerically. I 
can't make any sense of the sub-model numbers, so assume this was a 
custom version for somebody, or long obsolete. Does anyone know of this 
particular model version, or if there's a "system" to the sub-model 
numbering scheme?

Frequency 10 MHz
Model 250-0709-B
Part # 010209-0709

I believe the date codes are 1997 and 1998

The notes I made on them say they're +12V powered, which I must have 
figured out back when I pulled them.

One thing different about these versus the current ones pictured is they 
have no screw-plug port to access mechanical/coarse tuning - they're 
solid all around. It might be that the "-B" suffix deletes this access. 
I suppose that this could be a good or a bad thing, depending on use. 
Maybe it's very stable, long term, or maybe it has a very wide EFC 
tuning range.

I'm hoping it's an SC-cut, sine out, for lowest available phase noise 
and utility for my needs. Worst case would be AT, HCMOS, poor phase 
noise and excessive tuning range, so of course, that's most likely.

If no info is available, I can fire it up and check the output type easy 
enough. Also, as I recall, you can tell the cut by the frequency 
behavior during warm up, but I forget which does which. Any suggestions 
on how to assess this definitively?

Anyway, here's hoping there's some actual data available, and it's a 
good one for my needs.

Ed