[ntp:questions] Re: Using a Rubidium clock with NTP
David L. Mills
mills at udel.edu
Fri Oct 8 02:50:24 UTC 2004
David,
I have an old Rubidium oscillator, too. The way to use it is find a
battered old frequency counter with gated output and set it to count
down to 1 PPS. Connect the gate via the PPSAPI and the atom driver, but
do not used the kernel. Use the fudge1 parameter to adjust the phase.
Carefully.
My Rubidium has a voltage input that can change the frequency slightly.
Put a pot on that and use stereo headphones, one connected to a WWV
reciever and the other across the gate. Adjust the pot to match the
1-pps pip on WWV to the click from the gate. Pretend you are a human
feedback loop, because this will be very tricky.
Dave
David Schwartz wrote:
> Unfortunately, NTP does not support the use of an unsynchronized PPS
> source. There are quite a few ways you could synchronize the rubidium output
> yourself, but they all require an output with a much higher frequency than 1
> Hz. Theoretically, NTP could be made to use the PPS input to tweak the rate
> at which time flows.
>
> DS
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