[ntp:questions] ATOM falseticker with flag3 enabled
David Lord
snews at lordynet.org
Sun Apr 1 14:56:17 UTC 2012
David J Taylor wrote:
> "David Lord" <snews at lordynet.org> wrote in message
> news:t1bk49-6hi.ln1 at me6000g.home.lordynet.org...
> []
>> I'm not sure which value you are referring to. From the
>> "ntpq -p" billboard over a day, I see values of jitter
>> of the GPS as low as 0.002
>>
>> jitter No of
>> 0.002 156
>> 0.003 50
>> 0.004 22
>> 0.005 4
>> 0.006 4
>> 0.007 1
>> 0.012 1
>> 0.014 1
>> 0.025 1
>>
>> "ntpq -c rv" for that system reports "precision=-19". ie 2^-19,
>> but another couple of systems without PPS source are reporting
>> "precision=-20" and I think that these two systems have done
>> better than that when temperatures have not been as varied.
>>
>>
>> David
>
> Feel the need for more than 3 digits here?
Not at the moment. Changes due to temperature variation
are about 30us, which is 15x the lowest figure of 2us I
have for jitter.
An oven controlled or temperature compensated system
clock source would be required to take advantage of the
already existing digits.
David
More information about the questions
mailing list