[time-nuts] What's the best HP OCXO for frequency counter reference?

[Dr. David Kirkby]

I have a 5352B 40 GHz frequency counter which was fitted with a TCXO. I
removed that and fitted an HP 10811-60111 S/N 2332A17049 which I removed
from a 5370B time interval counter - I have a few of those, and the
microwave frequency counter needed the oven more than the time-interval
counter.

Looking at the specification of the 5352B, there were 3 oscillator options

* Standard TCXO
* Option 001 Oven time based. Long-term aging < 5 x 10^-10 / day after 24
hour warmup. < 1 x 10^-7 / year for continuous operation.
* Option 010 High stability time base. Long term aging < 1 x 10^-10 / day.
< 3.6 x 10^-8 / year for continuous operation.

To be honest, when the instrument is here, I will use a GPS reference. But
I might want to take it to the amateur radio club sometimes. I would like
to get the best oscillator I can. Are any models going to be better than
others, or by this time, is it just pot luck? I think it's the latter, but
maybe some are double-ovens and some single.

With the exception of power cuts of up to a few hours, the HP 10811-60111 I
fitted has been continuously powered on for a few years. But due to soaring
power costs, I am going to switch my ovens off.

Dr David Kirkby Ph.D
Email: drkirkby at kirkbymicrowave.co.uk Web:
https://www.kirkbymicrowave.co.uk/
Kirkby Microwave Ltd (Tel 01621-680100 / +44 1621-680100)
Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3 6DT.