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

Lester Veenstra Lester at veenstras.com
Wed Sep 22 16:28:04 UTC 2010

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Peter Vince
Sent: Wednesday, September 22, 2010 2:27 PM
To: lester at veenstras.com; Discussion of precise time and frequency
Subject: Re: [time-nuts] [qs1r] Looking for good, cheap, external reference

Hello DAVID....xLester,

     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?



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