[time-nuts] MT3339 PA6H and Racal Dana GPIB, update

Azelio Boriani azelio.boriani at screen.it
Thu Dec 13 14:38:01 UTC 2012


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 <lists at rtty.us> wrote:

> Hi
>
> Ok, those plots look much more "real". Thanks for sharing.
>
> Bob
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Fabio Eboli
> Sent: Thursday, December 13, 2012 7:58 AM
> To: time-nuts at febo.com
> 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 <lists at rtty.us> 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 -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


More information about the time-nuts mailing list