Yes but zero beat by ear is terrible. Are you talking a scope and I think thats only 1 X 10-7 as I recall. Regards Paul.
On Sat, Jul 23, 2011 at 12:42 PM, Bob Camp <[email protected]> wrote: > Hi > > The simple answer is that normal NTP via the net will give you accuracy > similar to the "zero beat to WWV" approach. It will take a few days to get > to that level. Much faster to fire up the radio and use WWV. > > Bob > > On Jul 23, 2011, at 12:29 PM, paul swed wrote: > > > I may be reading way to much into the question. > > But the goal discipline the local oscillator as an alternate to GPS or > WWVB > > etc > > Further assumption get the same types of services out of the oscillator > > Frequency and time plus pulses. > > > > That said if its one ntp source you look at, potentially far down stream > > with many network hops, doesn't that make your reference only as good as > > that ntp server as it jitters around? > > > > Would it be better to track say 3 servers hopefully up toward the top of > the > > ntp service. Analyze their behavior to each other to attempt to account > for > > network behaviors and the server behaviors. > > > > Essentially compare all three and derive a number to adjust the local > > oscillator. > > > > I might add that by adding any 1 pps source from radio or GPS while > > available would really let you understand what jitter and path delays you > > are getting and then establish the adjustment. (Fully understand that the > > path is variable in IP. > > > > Love simple but I suspect, its much tougher then that otherwise why mess > > with GPS at all. > > ;-) Its that darn radio stuff. > > Regards > > Paul > > WB8TSL > > > > > > On Fri, Jul 22, 2011 at 10:25 PM, Chris Albertson < > [email protected] > >> wrote: > > > >> Yes but in this case it really is easy; Below is an outline (don't > >> try to compile it.). It has a slight problem because just using > >> "sleep" is kind of simplistic. One should wait on the new second and > >> add some error chacking Point here is just to show that this is not > >> weeks and weeks worth of work". The below pulse a bit every second > >> and if the system is running NTP then the length of a second is > >> controlled by NTP. > >> > >> Main() > >> { > >> int status; > >> int fd; > >> int pw = 1000 /* pulse width in uS */ > >> fd=open("dev/tty",O_RDWR); > >> while(1) { > >> status = 1; > >> ioctl(fd, TIOCMSET, &status); > >> ussleep(pw); > >> status = 0; > >> ioctl(fd, TIOCMSET, &status); > >> ussleep(1000000-pw); > >> } > >> } > >> > >> On Fri, Jul 22, 2011 at 6:08 PM, Jim Lux <[email protected]> wrote: > >>> On 7/22/11 3:46 PM, brent evers wrote: > >>>> > >>>> "After that all you need to do is write some code to..." > >>>> > >>>> Oh - if I had a nickel for every time I've heard that! > >>>> > >>>> Brent > >>>> > >>> > >>> When I worked in the physical effects business, we'd get a set of > >>> storyboards from a director, and we'd have to figure out how we were > >> going > >>> to build a rig or arrange the effect as required. The catch phrase > was > >>> always "then, all you gotta do is"... > >>> > >>> representing some sort of incredibly difficult, tedious, or impractical > >>> activity. Sure, install 10,000 lightbulb sockets into a frame and wire > >> them > >>> up before tomorrow morning's call time at 6AM.. *all you gotta do* is > get > >> 50 > >>> people to each wire 200 sockets, screw in the bulbs and test them. > >>> > >>> _______________________________________________ > >>> 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. > >>> > >> > >> > >> > >> -- > >> > >> Chris Albertson > >> Redondo Beach, California > >> > >> _______________________________________________ > >> 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.
