Hello, On Tuesday, July 19, 2005 at 19:58:42 +0200, Serge Bets wrote:
>> Now the idea: Patch radioclkd to feed 2 SHM slots with same values >> from only 1 receiver > >| server 127.127.28.0 maxpoll 6 prefer >| fudge 127.127.28.0 time1 0.020 refid DCF1 >| server 127.127.28.1 minpoll 10 >| fudge 127.127.28.1 time1 0.020 refid DCF2 > >| remote refid st t when poll reach delay offset >jitter >| >============================================================================== >| *SHM(0) .DCF1. 0 l 41 64 377 0.000 0.116 >0.238 >| +SHM(1) .DCF2. 0 l 10 1024 377 0.000 0.116 >0.194 > > And sync survives well over an hour with radioclkd stopped. I seem to > get the expected low offsets and high autonomy. Now I wait next > thuderstorm and will update you. Update after some monthes and several thunderstorms using this twin radioclock. The prefered one at poll 6 gave me low offsets, and the second at poll 10 really gave me extended sync during periods of bad signal reception. Up to 6 hours of storm, up to 80 consecutive minutes of lost signal, and no sync loss. Fine! But I stopped the experiment, and consider it failed. The problem is that during stormy days, with the random rate of parasited undecodable minutes, ntpd clockhops several times between SHM(0) and SHM(1). And these clockhops perturbate the frequency, giving it a sometimes important kick. This in turn perturbates the offset for a long time. Result: I get a degraded accuracy during several hours, even long after the return of good DCF signal. Since some weeks I experiment another setup, with one only SHM(0) radioclock at poll 6, and the new orphan mode that appeared in recent ntp-dev versions (now using [EMAIL PROTECTED]). The clockhoping between SHM(0) an orphan mode seems to not have bad effects on frequency stability. Only bad effects are transient wrong leap bits. So I wait with confidence for the next thunderstorm, but hope it will not be the 31 around midnight. ;-) Serge. -- Serge point Bets arobase laposte point net _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
