Am 16.10.2012 um 04:35 schrieb Paul E Condon:
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 also like precise watches and have radio clocks in every room. Here in continental Europe the radio clocks usually receive the DCF77 signal.
As written by others in this thread the clocks only synchronize once a day to the signal. The rest of the day the clock is controlled by crystal quartz which has a precision of +/- 1 minute/year.
My experience with radio clocks is that they have cheap electronic components failing to work after some time. In the last 15 years I had to throw away ~8 of them. Shortest lifetime was below 6 months, longest 12 years. In your case I assume that the synchronization of the clock isn't working any more since some months and it runs only under control of the crystal quartz.
ntpd in the default debian configuration is usually accurate at +/- 2 ms.
You can use as root on the console terminal # ntpq -premote refid st t when poll reach delay offset jitter = = = = = = ======================================================================== +dns2.teleport-i 73.120.242.92 2 u 562 1024 377 21.244 -3.468 1.467 -lswb-de-01.serv 95.211.148.1 3 u 746 1024 377 22.068 1.015 12.176 +78-159-107-102. 193.171.23.163 2 u 753 1024 377 34.084 2.664 47.216 *ntp3.rrze.uni-e .PPS. 1 u 403 1024 375 25.044 -1.860 1.541
Helmut Wollmersdorfer