From: "Kim Bowers"
Subject: Re: Better than 2ppm TCXO for <$25?
Date: Mon, 28 Oct 2002 10:46:12 +0000 (UTC)
Organization: BT Openworld
NNTP-Posting-Date: Mon, 28 Oct 2002 10:46:12 +0000 (UTC)
X-Newsreader: Microsoft Outlook Express 5.00.2919.6700
"Chris Carlen" wrote in message
> Hi folks:
> I'm putting the Dallas Semi. DS32KHZN/DIP 32.768 kHz TCXO on my parts
> list, as the most likely candidate for the clock that will periodically
> prod my future Nixie clocks into flipping digits.
> It seems to offer a decent 2ppm accuracy over 0 to 40C, so I'll probably
> even get about 1ppm since it will be at room temp all the time.
> I'm just wondering if there are any other clocks that might provide
> somewhat better accuracy, in the $10-$25 range, let's say.
> Let's not go off on tangents like Rubidium standards and stuff like
> that. I know all about it. But that is $1000, not $25. My
> specifications are clear: <= $25.
> I suppose there are approaches using standard crystals, and implementing
> the temp compensation myself, but that would require a detailed study
> into Xtal oscillators, which I am not prepared to do right now, as well
> as probably requiring some very accurate instrumentation that I don't
> Thus, it seems advisable to select the best off the shelf clock that can
> maximize accuracy for the price required.
> I also am aware that one could use other methods, like interfacing to a
> radio controlled clock, GPS, the internet time RFC, etc. Those things
> are very interesting, but I'd like to have a clock on my desk before the
> end of the decade. Even with a basic Xtal, that will be a challenge for
> my slow-going self.
> Comments appreciated.
> Good day! (well actually, night.)
> Christopher R. Carlen
> Suse 7.3 Linux 2.4.10
If you don't mind chancing second hand items you can pick up low price OCXOs
I found an Isotemp part for $10. The stability spec is 2 parts in 10^-7 per
year. Aging is 6.5 parts in 10^-10/day.