Re: [time-nuts] M12+ phase jump due to WAAS/EGNOS DGPS corrections?

Brooks, i live in Germany abt. 500 km north of Franfurt/M and i run a M12+ in continuous duty in my GPSDO. Normally i do not keep track of the receiver's pps. However, on April 23 15:00 UTC i have started to record the phase relationship as measured inside my GPSDO. Will be glad to assist you and

[time-nuts] TADD-1 and Spectracom 8140T Phase Noise

I had a chance today to take a TADD-1 and one of the Spectracom 8140T amplifier modules over to a friend who has an HP 3048 phase noise measurement system. We got some very encouraging results. First, as a point of reference the HP 5087A distribution amp is spec'd at 5MHz to have phase noise

[time-nuts] Recommendations for NTP server

I've just started getting interested in precision timekeeping - if you can call an offset from UTC that is measured in units of milliseconds precision. My current timeserver is a Buffalo Linkstation, patched to run Debian Stable, and slaved via 2MBit ADSL to my ISPs Stratum 2 timeserver, using

Re: [time-nuts] TADD-1 and Spectracom 8140T Phase Noise

John Ackermann N8UR said the following on 04/23/2006 05:02 PM: First, as a point of reference the HP 5087A distribution amp is spec'd at 5MHz to have phase noise less than -145dBc(1 Hz) 1kHz from the carrier. We did our tests at 10MHz, so the results are precisely comparable --

Re: [time-nuts] Recommendations for NTP server

You'll get more than you expect -- the offset you're observing on ADSL is very likely wrong, because the delays your packets experience on adsl aren't symmetric. NTP assumes symmetry. So I wouldn't actually believe that a 1ms offset is really 1ms off, depending on the RTT to your ISP.

Re: [time-nuts] Recommendations for NTP server

David Andersen wrote: You'll get more than you expect -- the offset you're observing on ADSL is very likely wrong, because the delays your packets experience on adsl aren't symmetric. NTP assumes symmetry. So I wouldn't actually believe that a 1ms offset is really 1ms off, depending on the

Re: [time-nuts] Recommendations for NTP server

In article [EMAIL PROTECTED], John Ackermann N8UR [EMAIL PROTECTED] writes FreeBSD is definitely the best tuned OS for NTP timekeeping, but Linux can do OK. The biggest problem is that there's no kernel support for PPS signals in the 2.6 series of kernels. There is a patch available for a few

Re: [time-nuts] Recommendations for NTP server

In article [EMAIL PROTECTED], David Andersen [EMAIL PROTECTED] writes You'll get more than you expect -- the offset you're observing on ADSL is very likely wrong, because the delays your packets experience on adsl aren't symmetric. NTP assumes symmetry. So I wouldn't actually believe that

Re: [time-nuts] Recommendations for NTP server

Geoff Powell wrote: And - most OSes should do the trick. FreeBSD has a really nice precision timekeeping interface, though -- and it makes a marvelously solid time server. I'm running it on a few Net4801s and recommend it. You can very easily build an image for it using another

Re: [time-nuts] Recommendations for NTP server

In article [EMAIL PROTECTED], John Pettitt [EMAIL PROTECTED] writes I'll second the soekris box - my box time.no-such-agency.net is a 4801 running FreeBSD with a GPS18LVC.You can expect offsets in the +/- 5us range except when the box is stressed - the standard xtal in the box is not

Re: [time-nuts] Recommendations for NTP server

Geoff Powell said the following on 04/23/2006 05:42 PM: Is PPS kernel discipline compiled into the default FreeBSD kernel? No, but it's a pretty easy thing to turn on -- you add a line to the config file and tell it to go. Pretty straightforward, *once* you find the instructions. I am not