Hi Back a while, I ran a fleet of TBolt’s and other GPSDO’s for quite a while. They all ran into HP counters to monitor the PPS outputs. I never saw any of them hit or slip at the 100 ns level. Indeed different GPSDO firmware does the time / frequency tradeoff differently. I’ve also run them against various Cs standards. The results there were pretty much the same.
None of the environments I was running in were very crazy. They all held a couple degrees C and the cycles were in the one hour-ish range. Bob > On Apr 8, 2018, at 8:30 AM, John Green <[email protected]> wrote: > > I don't use what LH says about temperature. I compare the 10 MHz output to > something else. With two Tbolts sitting about 2 feet apart on my bench, > both fed from the same antenna, both with factory settings, when the heat > kicks on, I see a change in the difference between the two. Comparing a > Tbolt to another, different GPSDO, the effect is even greater. Next step is > to compare the Tbolt to a rubidium source that has been adjusted to match > the Tbolt as closely as possible at a stable temperature. I suppose you > could say the the Tbolt stays *locked* to GPS since the difference never > gets to 100 nS, meaning they are always within 1 Hz. What I usually see > when comparing the Tbolt to another, different model GPSDO is that the time > difference between the two 10 MHz signals slips at a fairly constant rate, > going from zero past 100 nS, and then through zero, over and over. I also > tried comparing the 1 PPS and the time jumped around quite a bit. Since I > plan to actually use 10 MHz instead of 1 PPS, I decided to quit looking at > 1 PPS. > _______________________________________________ > 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.
