Hi I suspect all of that's not entirely accidental.
If tidal shifts were easily seen on stable OCXO's, there would be a lot more attention paid to acceleration compensation. OCXO's with parts in 10^-12 / day aging rates are not uncommon. Just leave them continuously on power for a long time. A big fat crystal inside also helps a bit :)...... If you got a significant chunk of a few parts in 10^-12 from tides, people would have noticed - and complained. Bob On Mar 28, 2010, at 8:49 PM, Tom Van Baak wrote: > Warren, > > No, measuring an oscillator every second will not help. > > The change in g = ~9.81 m/s due to tides is about 1e-7 over > part of a day. So g changes by about 1e-8 per hour; that's > about 1e-12 per second. > > Now df/dg for a 10811 is on the order of 1e-9. So the tidal > effect of the sun/moon will change a 10811's frequency by > about 1e-12 x 1e-9 = 1e-21 per second, which is about a > billion times below the short-term noise level of a 10811. > > Now the reason pendulum clocks can "detect" tides (and > only a few of the world's best have ever done so) is that > their frequency is directly dependent on g. That is, df/dg > for a pendulum clock is 0.5! By contrast df/dg for a 10811 > quartz oscillator is around 0.000000001. > > /tvb > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
