[time-nuts] Disciplining Rubidium

christopher hoover ch at murgatroid.com
Thu Apr 24 23:35:43 EDT 2008

Said wrote:

> For such a large phase error I would have expected the PRS10 to just reset

> the 1PPS rather than drift it.

The PRS10 uses a straightforward second order PLL to lock itself to an
external 1PPS, so you will see a frequency error on phase jumps as it has to
slew the frequency to get back on phase.

There's a quite detailed description of the PLL in the manual.

Incidentally, it is my experience that the PRS10 behaves fairly poorly if
you simply feed it 1PPS without sawtooth correction.  I'm in the midst of a
move so I can't relate numbers at the moment.

(Someone once mentioned of a firmware upgrade or a magic command or
something to allow you to feed the sawtooth corrections from the receiver to
the PRS10's time tagging circuit, but I've yet to find any documentation on


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