PC Clock drift can be quite bad as we all know. The default NTP server sync interval for Windows 10, is once a week. So your clock can be way off by the time you sync again. With a one time NTP sync, you can still be off into the 100 ms range. I suspect some of the JST related software etc... might force a sync at startup and or do NTP server syncs on their own? Someone else will need to chime in on that.
The best time sync you are going to get for Windows and Linux / BSD based operating systems will be us use the full on NTP client. For windows, Meinberg has a nice graphical client that installs and sets itself up as a service and disables the windows NTP client service. During the Meinberg NTP install, you have an option to draw from the NTP pool of NTP servers and you can also type in your own preferred NTP server list. The full NTP client does more than just sync your clock... over time it will calculate the drift of your clock and discipline your clock automatically between sync checks to your selected NTP servers. The drift is calculated in PPM and for the curious you can see how bad your clock is. Here is the link for the Win32 install of the Meinberg client (free): <goog_605187876> https://www.meinbergglobal.com/english/sw/ntp.htm#ntp_stable I run 3 GPS disciplined NTP servers (3 separate GPS receivers) here at my QTH and if you want, you are welcome to use time.nc7j.com as one of your NTP servers. On this end, time.nc7j.com is accurate into the nano second range as compared to the GPS on board atomic clocks. Via NTP UDP sync over the Internet, the best you will typically do is get down into the lower microsecond range... and far more accurate than any thing most would ever need. time.nc7j.com is also a member of the NTP pool and you can see if it's up and running be going to this link: http://www.pool.ntp.org/scores/time.nc7j.com The chart here doesn't show the accuracy of the time.nc7j.com, but it shows the ping offset from LA to Utah and it's normal to vary +- 10ms. Your mileage will vary with your round trip ping times to any NTP server, but over time, NTP will do an amazing job of figuring out your PC clock drift and then disciplining it on the fly. For the totally 'time accuracy obsessed', you can install the Meinberg NTP monitor too and monitor your clock accuracy via logged NTP statistics: https://www.meinbergglobal.com/english/sw/ntp-server-monitor.htm#download The Meinberg apps are GUI's that make native calls to the full NTP install under the covers and they are totally free and free of any nag related nonsense. If you are running Linux or iOS, you are already running a native NTP client I suspect and you can read up on how to configure it just like the Meinberg Windows GUI's do for Windows. Max NG7M mg On Mon, Jan 16, 2017 at 7:30 PM, stengrevics <[email protected]> wrote: > My clock is synched to time.nist.gov. But, when I transmit on MSK144, I > have > a delay of 900 ms that pushes my transmission into the next sequence. Any > thoughts? > > Thanks, > > John > WA1EAZ > > > > -- > View this message in context: http://elecraft.365791.n2. > nabble.com/WSJT-X-MSK144-Transmit-Delay-tp7625818.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] > -- M. George ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]

