Well the old URQ-13 falls is about 54 years old. But how its been handled over that time will never be known. Poorly is the best guess. No expectation that it will be a super oscillator like the old Sulzers. I am really trying to understand if its been recovered to a respectable state as it may have been intended to be in 1967. It will never be my main reference. The best guidance I have is the URQ-10 that is well published. Over the last 24 hours its really settling down. I am now fine tuning with the digital readout control 1 part E-11 per digit. Appreciate your thoughts. Regards Paul
On Thu, Mar 4, 2021 at 9:51 AM Magnus Danielson <[email protected]> wrote: > Hi, > > On 2021-03-04 11:15, Hal Murray wrote: > > [email protected] said: > >> But since the units been off for at least 15 years and heavens knows > how long > >> before that. Any thoughts on how long it might take to stabilize days > weeks > >> months. Its pretty stable as is just wondering. > > It's an exponential tail. How stable do you call stable? > > > > What do you have to measure it with? How stable is your environment? > > > These tails have been measured for years. As long as it is slower than > the application can handle, it becomes only the issue of being "within > range". This is the "aging" period. Environmental may cause more severe > deviation eventually, but a power-down/power-up even cause retracing and > that will restart the process. > > So, it ends up being about being acceptably stable, as in not being > annoyingly large anymore. > > There is fairly good evidence that crystal oscillators do not have much > of wear mechanisms if done with a bit of care. There is oscillators out > there that has been running 40-50 years in continuous operation. Getting > any atomic clock live that long is more of a challenge, they need to be > serviced because of explicit wear mechanisms. I think the PTB CS2 and > CS3 clocks is the longest operations beam clocks, but they also have > work done on them, and upgrades. We end up discussing some of that in > the IEEE P1193 group on environmental effects on frequency sources. > > Cheers, > Magnus > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
