That is very interesting in my opinion and, for those who have access to more than one PRS10, further investigation should be done. I had a new PRS10 and, just out-of-the-box, it locked (not instantly, of course) to the HP53508 PPS.
On Sun, Apr 22, 2012 at 10:47 PM, <[email protected]> wrote: > With factory default settings with 2 PRS-10s, connecting 1PPS_out from one > unit to 1PPS_in on the other, would not align the 1PPS_out pulses. They > were off by several hundred of ns. It was probably an operator error > somewhere. We just did not find the error in the time frame we had > available. > > -- > > Björn > > > > Björn, what do you mean with "We never got one to track the other in a > > reliable way"? > > Thai is, how can it be that a PRS10 cannot track another PRS10? What do > > you > > get when trying to track one with the other? > > > > On Sun, Apr 22, 2012 at 8:44 PM, Poul-Henning Kamp > > <[email protected]>wrote: > > > >> In message <[email protected]>, Magnus Danielson > >> writes: > >> > >> >The input calibration would be something in the similar way, > >> > >> What I did: > >> > >> Detune an OCXO slightly (I actually have a 9.99997 MHz OCXO from > >> IsoTemp), feed it to PPSDIV, disable the discipline code in the > >> PRS10, collect the measured input time stamps over some hours. > >> > >> Either you get a nice ramp, or you get som kind of demented staircase, > >> in which case you try to figure out which of the calibration constants > >> to mess with. > >> > >> An alternative is to feed the PRS10 output to a HP333x Synthesizer > >> and have that generate your 10-epsilon MHz for the PPSdiv. > >> > >> This general "vernier" method can be used to measure all sorts of tricky > >> stuff, from interrupt latencies in operating system kernels to > >> stuff like the above. > >> > >> -- > >> Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > >> [email protected] | TCP/IP since RFC 956 > >> FreeBSD committer | BSD since 4.3-tahoe > >> Never attribute to malice what can adequately be explained by > >> incompetence. > >> > >> _______________________________________________ > >> 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. > > > > > > _______________________________________________ > 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.
