Yes, this is the typical GPS receiver PPS wander. It is usable for a GPSDO as it seems of timing quality (the Motorola M12M is -20nS..+20nS over 10 days). See:
http://www.jackson-labs.com/assets/uploads/main/Motorola_M12.pdf on page 7. On Thu, Dec 13, 2012 at 2:47 PM, Bob Camp <[email protected]> wrote: > Hi > > Ok, those plots look much more "real". Thanks for sharing. > > Bob > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of Fabio Eboli > Sent: Thursday, December 13, 2012 7:58 AM > To: [email protected] > Subject: Re: [time-nuts] MT3339 PA6H and Racal Dana GPIB, update > > Bob, timenutters > here are the first results, hope > I'm not boring the members with these > posts, for most participants these > are basic things. > Now I'm trying to understand if the > setup is working or I have to modify > some things. > > The logging is at 47000 samples and going, > the script is working well now, and I dont > have glitches so far. > Raw data, time interval between the pulses: > http://www.flickr.com/photos/14336723@N08/8269800802/ > > Positive thing is that the drift seem consistent > with the previous decimated pulse period data. > > Data corrected for linear drift and offset, the > actual values are in the graph: > http://www.flickr.com/photos/14336723@N08/8269800868/ > > Here I dont' like very much what I see, > but surely I'm not knowledgeable enough > to judge the data :) > > Some notes for who didnt read previous posts: > Racal 1992 counter, start on pps from FE5680 #1 > stop on gps pps from PA6H GPS module, > Counter External standard is 10MHz from FE5680 #2. > > The Fe5680 #2 was powered one hour before the > session start, and it's mounted near the FE5680 #1, > so there is some thermal stabilization > in the first hours. > Also I dont have any signal amplification and > squaring, the trigger on the counter is set > at half the pulse peak voltage, both rising > edges. > > Is the graph what I should expect from the gps > signal, or I'm seeing some problems in the > setup? > > Thanks, > Fabio. > > Bob Camp <[email protected]> ha scritto: > > > Hi > > > > That approach works well. If you have them about a half second apart > > I'd stick with that setup. > > > > Bob > > > > > ---------------------------------------------------------------- > This message was sent using IMP, the Internet Messaging Program. > > > > _______________________________________________ > 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.
