On 15 August 2010 17:01, Stanley Reynolds <[email protected]> wrote: > Thanks for looking at my data that was what I was fishing for all along :-) > > I was looking at the article: > > "A Small Dual Mixer Time Difference (DMTD) Clock Measuring System W.J. Riley " > Richard posted > > And thinking it would be nice to do the DSS and Mixer boards to go with the > pictic II.
I have been speaking to Bill Riley about doing this myself and he has sent me all the board designs, software, etc. to enable one to be built. I can ask him if he is OK if I distribute this if you wish. Steve > Or changing the Pictic II to use the Acam TDC GP2 Time to Digital Converter; 2 > channel w/65 ps resolution now under $30. as Bruce suggested a while back. > > My wants sure exceed my cans ;-) > > Stanley > > > > ----- Original Message ---- > From: John Miles <[email protected]> > To: Discussion of precise time and frequency measurement <[email protected]> > Sent: Sat, August 14, 2010 11:25:44 PM > Subject: Re: [time-nuts] PicTic Data > > >> John glad you are getting good results and have something to >> compare to. Back to >> me who doesn't have any knowns but lots of guessing. Attached is >> a run with a >> box cover over the pictic, run is shorter ~ 800 seconds but the >> box does look >> like it helps. >> I need to do a lot more testing but sometimes I just get excited :-) > > I imported your .txt file alongside the traces I captured. Assuming it was > taken with 1 Hz on both START and STOP, it looks like the attached. > > You're getting the exact sort of results that I see if I feed both the START > and STOP inputs at 1 Hz. My guess is that the onboard oscillator limits the > performance in that case, since it has a lot of time to drift during the > measurement if the two pulses occur close to 1 second apart. Even the 5370B > looks much worse if driven with 1 Hz on both inputs than it does with 1 Hz > at START and 10 MHz at STOP. > > So I think you're basically up and running OK. When I get around to trying > a better clock, I'll also go back and see if the 1-pps x2 performance > improves. > > It would be great if the next spin of the board could include sine-to-CMOS > shapers for the input channels as well as an external clock input, for > people who are working directly with RF signals as opposed to 1-pps. > > -- john, KE5FX > > >> ----- Original Message ---- >> From: John Miles <[email protected]> >> To: Discussion of precise time and frequency measurement >> <[email protected]> >> Sent: Sat, August 14, 2010 10:19:46 PM >> Subject: Re: [time-nuts] PicTic Data >> >> A few preliminary measurements here (I'm working on getting some software >> support together): >> http://www.ke5fx.com/pictic.htm >> >> -- john, KE5FX >> >> > -----Original Message----- >> > From: [email protected] [mailto:[email protected]]on >> > Behalf Of Stanley Reynolds >> > Sent: Saturday, August 14, 2010 7:12 PM >> > To: Discussion of precise time and frequency measurement >> > Subject: Re: [time-nuts] PicTic Data >> > >> > >> > >> > >> > My guess as to what the data may indicate is performance of the >> > 10 Mhz 20PPM >> > PICTIC internal oscillator, need to repeat test with precision >> > 10Mhz and auto >> > calibrate off. Fatness of the line/width maybe PICTIC error. Note >> > graph seems to >> > show me leaving the room and returning via the outside door. Not >> > sure what the >> > ~100 sec oscillations are, need to check a/c cycle time. >> > >> > Stanley >> > >> > _______________________________________________ >> > 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. > -- Steve Rooke - ZL3TUV & G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein _______________________________________________ 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.
