Chris Wilson wrote: > I have used Meinberg NTP ... It's important to keep in mind that the NTP software for Windows has not been written by Meinberg. It's just the reference implementation of the NTP protocol provided by the NTP project at http://www.ntp.org
Releases are normally available as source code only at the NTP community pages at https://support.ntp.org We at Meinberg support the NTP project by sponsoring, testing, submitting bug reports, and eventually providing patches. We also pick up the source code releases, build the binaries for Windows, provide them with a cryptographic signature, and put them into a GUI installer/setup program to simplify installation under Windows: https://www.meinbergglobal.com/english/sw/ntp.htm#ntp_stable > ... and also Thinking Man's Dimension 4 as NTP > applications on Windows 7 64 bit OS's on 3 PC's. I use them to sync > the PC time for WSJT-X WSPR (a low power digital amateur radio mode) > which requires an accurate time on the PC's for successful decoding > and transmitting of digital signals. > > Both Dimension 4 and Meinberg have occasionally not allowed proper > syncing with the WSPR application attempting to decode up to 4 seconds > late, despite my Trimble Thunderbolt and Lady Heather showing the PC > is synced to GPS time within less than a second, by eye. Hm, it would have been interesting to find out *why* this didn't work. Normally, ntpd considers a time offset that exceeds 128 ms so huge that it steps the system time. If the time offset is below this limit the Windows system time is slowly slewed so that the offset becomes (and continuously stays) as small as possible. This slewing is normally not even noticeable for applications. However, this only works properly if there is no other tool that fiddles with the system time. If you change the system time manually, or another program sets the system time periodically then ntpd will be unable to compensate this quickly. BTW, running Microsoft's w32time and ntpd together will not work properly since both programs try to use network port 123 at the same time, which is not possible. This is why the NTP installer disables the w32time service by default when ntpd is installed. Please note that in the past there have been lots of problems with accurate timekeeping, depending on the Windows version. Usually this was due to limitations in Windows. For example, some years ago there were some kernel drivers which caused the Windows kernel to loose time. In another case the Windows system time was off by about 30 seconds whenever a big database application had run some maintenance task in the night. The fact that 2 different software packages showed similar errors makes me assume that - time sources were not reachable, or - system time was changed by a different application, or - there is some program that unintentionally affects the system time > I am now trying another NTP app by DL4YHF Wolfgang Buscher. My > questions are, is such an anomaly known and should I disable Windows > Internet Time synchronization when using another NTP app? I see no > mention of disabling this in any of the NTP application's notes... The > WSPR application, WSJT-X has very recently been released in a 64 bit > version, which is what I am using, and I have to wonder if the new > version has some minor bug as I find it hard to believe two well known > and used NTP apps are buggy. As already mentioned in other replies, you should *never* have 2 applications running at the same time that try to adjust the system time. Martin (working @Meinberg) _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
