Do rubidium standards use an OCXO? Bob Q. ----- Original Message ----- From: "Rick Karlquist" <[EMAIL PROTECTED]> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Wednesday, October 22, 2008 2:23 PM Subject: Re: [time-nuts] Question on crystal jumps
> I'm not quite sure what the question is here, but when > we made 10811 oscillators at HP, "jumps happened". Some > crystals were better than others, but no crystal was immune > from jumps. With good quality crystals, you might be able > to put an upper bound on the magnitude of jumps, like 10-9, > but not on the time between jumps. I also noticed that there > didn't seem to be any correlation between jump activity > and stability between jumps. You could have an oscillator > with really low aging, say a few parts in 1E11 per day that > looked really good for quite a while, but then the frequency > jumps. After you've controlled everything you can about the > crystal process, the electronics, the oven and the environment, > you are still left with jumps. If you want no jumps, go to > an atomic standard like rubidium. There are mechanisms that > can cause jumps in rubidium standards as well, but good > rubidium standards don't jump. > > Rick Karlquist N6RK > > > [EMAIL PROTECTED] wrote: >> I would be very pleased to know when (date and time) anybody >> out there happened to record jumps in frequency of crystals. >> I have stable (e-07) tuning forks which happen to jump too, >> and I don't understand why, even having under control >> temperature and air pressure. Sometimes they return to their >> prior frequency with another jump, and this could happen even >> days later, sometimes they jump and then recover smoothly the >> prior frequency in a short time (such as one hour). >> I have no idea whether any correlations would exist between >> crystals and tuning forks jumps, regarding the causes that >> could trigger metastability, and hence I would have a look at >> crystal data in order to improve the base for future >> speculation. >> >> Thanks in advance. >> Antonio I8IOV >> >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.