Would it be possible to remove an OCXO from an 8334A 100 MHz counter/timer
and fit it in a 8335A 200 MHz counter/timer?

Would the TXCO from the 8335A then fit in the 8334A so that the 100 MHz
unit?

Are the OCXOs similar,  identical or incompatible?

I expect a detailed look at the service manuals would answer at least some
of the questions,  but I only have access to a mobile phone now, so are
hoping that someone might know.  In any case, different part numbers might
actually work,  even if not as stable as the correct OCXO.

Dave

Dr David Kirkby
Managing Director
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3
6DT, United Kingdom
Registered in England and Wales as company number 08914892
http://www.kirkbymicrowave.co.uk/
Tel 07910 441670 / +44 7910 441670 (0900-2100 GMT)

In general, any 10811 with an edge card type connector
in interchangeable in any instrument, in terms of basic
functionality.  The only differences
are that various part numbers in the 10811 family are
selected for certain critical specs.  Certainly, between
the 5334 and 5335, they are interchangeable.  OTOH,
an instrument like the 8662A might not meet phase noise
without the "official" version of 10811.

A 10811 also must work in any 10544 socket, although the
reverse isn't necessarily true.

The 5334A (as opposed to the 5334B that I was the project
manager on) has a poorly regulated power supply that causes the oven
power voltage to drop to only +12V during warmup, which
is supposedly below the +15V minimum and the +20V nominal.
It turns out that +12V is sufficient to cause the oven
to warm up.  It is not sufficient to operate the oven
well in a steady state.  However, once the oven current
cuts back, the power supply voltage goes back up to over
15 volts so everything works.  I fixed this problem in
the 5334B.  I don't know if the 5335 has a similar problem.

Rick