Re: A puzzle with internet time and NIST time
On Tue, 2012-10-16 at 12:54 -0400, Doug wrote:
> It is instructive to look at the NIST website that discusses the time
> standards and the broadcasting of the time.
>
> http://tf.nist.gov/general/pdf/1383.pdf
>
> There is a useful chart of available sources of time and the accuracy
> available
> on page 11, table 1.1.
In the old day clocks were synced by mains frequency. Mains frequency in
western industrialized countries usually is very accurate. :p
I know a nice anecdote of very inaccurate mains frequency from an
US-American engineer and I experienced inaccurate mains frequencies in
western Germany myself, but in general at least crystal clocks aren't
accurate, perhaps clocks synced by mains might be more accurate, I don't
know. Regarding to sync via air, I experienced that a DVB-T receiver I
own, very often get no signal to sync. I guess crystal clocks fail
regarding to temperature swings.
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