Re: A puzzle with internet time and NIST time

[Doug <dmcgarrett@optonline.net>]

On 10/15/2012 10:35 PM, Paul E Condon wrote:
> I've been running Debian for many years. During most of those years I
> have had a SkyScan(tm) 'Atomic Clock' on the wall near my Debian
> desktop computer. The physical computer has changed over the years,
> but not my using Debian, or my Atomic Clock. Until a few weeks ago,
> they always displayed the same time, once I had correctly installed
> the chrony or the ntp package. But some time recently they started
> disagreeing by about 18 seconds with Debian/Squeeze running ahead, yes
> ahead, of the Atomic Clock which is supposedly getting its signal by
> radio direclty from the NIST transmitter. How can this be???? I've
> reinstalled the software, but that didn't change the behavior, except
> for a brief period when the local computer clock resynchoronized with
> the time server pool. There's nothing remarkable about my hardware.
> An aging dual core pentium, marketed by HP and running Squeeze with
> Gnome desktop. Ideas?
Your Atomic Clock only resyncs once a day at about 3AM. Is it
possible that the mechanism of the clock is running slow during
the time after sync?  I don't know if these clocks are crystal
controlled--if they are, then 18 seconds in a day would be quite
excessive. But if they're not, then perhaps something in the circuit
has aged out.

Alternatively, how often does your computer clock get resynchronized?
Maybe the circuit in the computer just runs fast?

--doug

--
Blessed are the peacekeepers...for they shall be shot at from both sides. --A.M. Greeley