[ntp:questions] site with lots of GPS's and accessories

Chris Albertson albertson.chris at gmail.com
Mon Mar 19 18:34:10 UTC 2012

By theat chart, my Trimble GPS is abot a 1960 level standard.   But GPSes
are not portable, not if you need that level of accuracy.  High end GPSes
need a fixed antenna, a survey and a few hours or days to reach the 1E-14
level.   But they can with effort be as good as a Cesium clock

If you need "portable" and accurate.  Look at getting one of those $40
Rubidium oscillators on eBay.   I bought one a while back and I'd say it is
certainly good at the 1E-9 level and likely good to 1E-11 but I've not
taken the time to measure it to that level yet.  These sell for $40 and are
the size of a hard disk drive.  These are the best bang per buck in atomic
clocks today.

See eBay item # 300606871861 for an example.

On Mon, Mar 19, 2012 at 10:58 AM, Alby VA <albyva at empire.org> wrote:

>  Compared to this history of Atomic Clocks at NIST
> and this chart of accuracy, I'd say my NTP Server is
> in the 50yrs behind the curve.   lol  At least its portable.
> History: http://www.nist.gov/pml/div688/grp40/nist-clocks.cfm
> Chart:
> http://upload.wikimedia.org/wikipedia/commons/9/9a/Clock_accurcy.jpg
> _______________________________________________
> questions mailing list
> questions at lists.ntp.org
> http://lists.ntp.org/listinfo/questions


Chris Albertson
Redondo Beach, California

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