[time-nuts] Re: Self monitoring

[André Balsa]

In summary, to measure the accuracy or stability of any clock, you always
need... a better clock. Or you can use the "three cornered hat" method, but
it requires that the accuracy or stability of the three devices under test
**should not be correlated**.

On Fri, Apr 1, 2022 at 1:58 AM Bob kb8tq <kb8tq at n1k.org> wrote:

> Hi
>
> If you are trying to evaluate things like accuracy and stability,
> you really can’t do it internally. You need something else to
> compare to. If you want to count number of dac bits of change
> per hour, you certainly can measure that. Just what it means ….
>
> Bob
>
> > On Mar 31, 2022, at 7:15 PM, Hal Murray <halmurray at sonic.net> wrote:
> >
> >
> > kb8tq at n1k.org said:
> >> You really can???t compute things like ADEV by observing the device
> against
> >> itself. You need an external / stable reference that is (hopefully)
> much more
> >> accurate than the GPSDO to compare it to.
> >
> > What can I conclude when looking at data collected internally by a GPSDO
> (or
> > NTP)?
> >
> >
> > --
> > These are my opinions.  I hate spam.
> >
> >
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at lists.febo.com -- To unsubscribe
> send an email to time-nuts-leave at lists.febo.com
> > To unsubscribe, go to and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com -- To unsubscribe send
> an email to time-nuts-leave at lists.febo.com
> To unsubscribe, go to and follow the instructions there.