[ntp:questions] ARRGH!!! I woke up to a 50 SECOND clock error.

Ron Frazier (NTP) timekeepingntplist at c3energy.com
Tue Mar 13 18:55:42 UTC 2012

On 3/13/2012 2:40 PM, Chris Albertson wrote:
> On Tue, Mar 13, 2012 at 9:52 AM, Ron Frazier (NTP)
> <timekeepingntplist at c3energy.com>  wrote:
>> Hi all,
>> I just woke up to a 50 SECOND clock error.  Prior to the error, with my PC
>> locked into the GPS and the internet servers noselected, here's what my
>> peerstats looked like.  Baseline is the GPS.  Colored lines are internet
>> servers.
>> http://dl.dropbox.com/u/9879631/drifting01-peerstats.20120312.jpg
> Looks to me like that GPS, maybe lock lock and was able to "coast" on
> hold over for a while then fell off a cliff.     If you have a log of
> satellite  signal to noise ratios you might be able to figure out why.
> The internet servers appear to be 100% reliable seeing as they all agree.
> These kinds of things are why some hobbysts end up buying multiple GPS
> (different brands)  Otherwise it is hard to sort out a GPS firmware
> bug from a solar storm or just that there were not sats visable to
> your indoor antenna for a few minutes
> I think your goal is to learn about all of this so these problems are
> a good thing.  No one learns much from working systems.   But if the
> goal is a reliable NTP server, the pool NTP servers can't be beat
> except by a good timing mode GPS, that has good self diagnostics and
> PPS.  The self diagnostics part is important

The link you quoted just now is not the one that bugs me so much today.  
This one is the one that bugs me today, where my clock was stepped by 50 
seconds for some reason.


When I get the Sure board, I plan to hang it on the pc in tandem with 
this GPS and compare.




(PS - If you email me and don't get a quick response, don't be concerned.
I get about 300 emails per day from alternate energy mailing lists and
such.  I don't always see new messages very quickly.  If you need a
reply and have not heard from me in 1 - 2 weeks, send your message again.)

Ron Frazier
timekeepingdude AT c3energy.com

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