[time-nuts] Setting loop TC using thunderbolt internal data.
bruce.griffiths at xtra.co.nz
Mon Jan 26 14:05:30 EST 2009
Some idea of the shift in the minimum can be gleaned by plotting the
Hadamard deviation vs tau.
Bruce Walker wrote:
> I ran the same test as Bruce Griffiths on my tbolt; that is, I turned off
> osc disciplining altogether and created an OADEV plot from the internal
> phase measurements taken from its GPS solution. The plot is attached. It
> has a minimum of about 1e-11 at tau=800, and it has the sane general shape
> as Griffiths'.
> The next experiment I plan to do is to repeat the same thing using manual
> holdover mode rather than "Disable disciplining". That should continue to
> try to compensate for temperature and long-term drift (just not steered by
> GPS), whereas the data taken last night use a fixed DAC.
> --bruce W1BW
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