Thanks Hal On 13/06/2012, at 10:08 AM, Hal Murray wrote:
> >> I recently connected up a USB GPS to my Linux box and found it quite easy to >> get NTP to up from the GPS. I was hoping to get the same GPS to update the >> Mac running Lion 10.7.4, however, it has been a very frustrating uphill >> battle. > >> Has anybody managed to get GPS NTP update working on OS-X? > > You will probably get much better answers to NTP questions over on the NTP > lists. > http://lists.ntp.org/listinfo > Down near the bottom is questions > I'll look at ntp.org > GPS over USB generally doesn't work very well. You will probably get better > results over the net. > I will be in an entirely stand alone situation and therefore GPS is my best timekeeping option for WSPR and WSJT - EME ops. > The problem isn't USB polling, it's firmware that adds about 100 ms of > wander. By wander I mean low frequency drift. It's too slow to filter out. > > Here is a graph from a SiRF III, the most common chipset in low cost USB GPS > devices. Most others are similar. > http://www.megapathdsl.net/~hmurray/ntp/GPSSiRF-off.gif > If anybody finds a good one, please let me know. > I've had a UBLox chip on a board working with my Linux laptop perfectly well, however OSX will just not allow the setup to work. > >> I did a sum link to /dev/gps0 and can cat the output and see the NMEA stream >> of alternate $GPRMC and $GPZDA messages, > >> I just cannot get it to accept the gps as a peer. > > The GPRMC sentence has a flag to tell you if it is seeing enough satellites. > Are you seeing A or V? I think A is good and V is bad. > I am seeing satellites and can cat the output of the device OS X will just not allow to to connect to 127.127.20.0, same device plugged into the Linux laptop works very well - just cannot get NTP in OS X to add it as a peer > > > -- > These are my opinions. I hate spam. > > > > > _______________________________________________ > 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.
