[time-nuts] [qs1r] Looking for good, cheap, external reference

[Peter Vince]

Hello Lester,

     To expand on Bob's message a little, do you need medium to
long-term accuracy (for a frequency counter reference for example), or
something that is both accurate AND has low phase noise, suitable for
multiplying up to GigaHertz, say, for communications?  Particularly if
the latter, does the absolute frequency have to be accurate, or would
a knowledge of the offset be adequate?  If the latter, you could use a
nice quiet OCXO, and use John's suggested Thunderbolt as a reference
to your counter to determine the error.

     In any case, for private use there is no need to spend anything
like $8000, lots of Rubidiums can be found on ebay for under a tenth
of that. There is a lot of experience on this list with the
Thunderbolt GPSDOs mentioned by John, and the complete kits offered on
ebay make it an easy way to get an excellent reference.

     John, unless I am going mad, the ADEV plots for both auctions you
mentioned look the same - maybe the bad one has been replaced since
you posted your message?

     Regards,

          Peter