Hi I agree that if you simply bolt the rubidium to an old engine block and toss a blanket over it, you might get some pretty good thermal stability in the "hour to couple hours" time period. That's certainly a better approach than putting some kind of DC heater (and it's varying magnetic field) near the rubidium.
I'm still wondering if they do indeed hit 1x10-13 (as in almost 1x10-14) or not. I suspect not. I'm sure that they do indeed get into the 1x10-13's, just not sure they get to the bottom of that region. Bob On Dec 22, 2009, at 8:26 PM, Bruce Griffiths wrote: > Bob Camp wrote: >> Hi >> >> If I randomly pick up a FE 5680A data sheet, I find that it's short term >> stability is 1.4/sqrt(Tau) x 10-11. Since I never doubt anything I see on a >> data sheet, this immediately tells me I should get 1.4x10-12 at 100 seconds, >> and I only have to wait for 10,000 seconds to get to 1.4x10-13. >> >> Since the temperature performance is at the 1x10-12 / C level, I would need >> a room that's stable to *much* better than 0.1 C over a 3 hour period to get >> there. I suspect that 0.01C might not be good enough ... >> >> So here's the question: >> >> Has anybody run any of the cheap rubidiums (FE or Efratom) in a *very* >> stable temperature environment to see how close they get / what the floor >> is? I've run through a lot of data on the web, but I haven't really found >> what I'm looking for. >> >> Thanks! >> >> Bob >> >> > Figure 7 on the FE5680 page (also on the data sheet) indicates that you may > need somewhat less than 3hours to achieve ADEV ~1E-13. > 0.01C stability should be adequate.however its not necessary to control the > room temperature to this stability if the FE5680 is in an enclosure with a > sufficiently high time constant whilst having a sufficiently low thermal > resistance so as to avoid overheating the FE5680. > > Bruce > > > _______________________________________________ > 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.
