Ulrich, I must have lost the plot here but I thought that was only for HPIB data. How are you collecting the data?
73, Steve 2009/6/17 Ulrich Bangert <df...@ulrich-bangert.de>: > Steve, > > my PLOTTER utility. I thought you did already try it out? > > 73s Ulrich, DF6JB > >> -----Ursprungliche Nachricht----- >> Von: time-nuts-boun...@febo.com >> [mailto:time-nuts-boun...@febo.com] Im Auftrag von Steve Rooke >> Gesendet: Mittwoch, 17. Juni 2009 11:03 >> An: Discussion of precise time and frequency measurement >> Betreff: Re: [time-nuts] Z3805 initial behaviour after power up >> >> >> Ulrich, >> >> What are you using to produce the graph you attached please? >> >> 73, >> Steve >> >> 2009/6/17 Ulrich Bangert <df...@ulrich-bangert.de>: >> > Gents, >> > >> > yesterday I received the Z3805 that I had bought from >> fluke.I on eBay >> > and immediately put it to work. I recorded the EFC value as well as >> > the PPS TI value over about 20 hours. Attached is the graph of thes >> > two values. >> > >> > I interprete this graph in this way: >> > >> > 1) Immediately after power up (perhaps up to the end of the site >> > survey) the regulation loop seems to work with a very short time >> > constant which is able to bring the PPS TI close to zero >> although the >> > OCXO has lots of drift at this time. >> > >> > 2) Then the loop time constant seems to switch to a >> significant higher >> > value which does not keep up with the oscillator's drift, >> which leads >> > to the negative excursion of nearly 500 ns. >> > >> > 3) This seems to be too much for the regulation which leads to >> > switching back to the short time constant and to bring the >> PPS TI back >> > to near zero and to return to the longer time constant again... >> > >> > 4) ...which lets the procedure repeat again and again: >> Drift to -500 >> > ns and pullback. >> > >> > 5) Note that I thought it was a kind of malfunction and send a >> > :system:preset command to the device after the last negative PPS TI >> > spike. The result was, that the total procedure repeated: About 2 >> > hours of PPS TI close to zero then again the drift and pullback >> > procedure however with a reduced drift rate. >> > >> > 6) After 11 hours or so the regulation loop's time constant >> seems to >> > match the OCXO's drift and a "real" lock of the pll seems to take >> > place. (The lock led had been on already hours ago...) >> > >> > Since I do not have an manual for the Z3805: Can any of you Z3801 >> > owners second this behaviour to be normal or would you >> think that it >> > is kind of special for the Z3805 or even a real malfunction (in the >> > sense that the OCXO's drift is above the specs in the beginning)? >> > >> > Best regards >> > Ulrich Bangert >> > >> > Ulrich Bangert >> > www.ulrich-bangert.de >> > Ortholzer Weg 1 >> > 27243 Gross Ippener >> > >> > _______________________________________________ >> > time-nuts mailing list -- time-nuts@febo.com >> > To unsubscribe, go to >> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> > and follow the instructions there. >> > >> >> >> >> -- >> Steve Rooke - ZL3TUV & G8KVD & JAKDTTNW >> A man with one clock knows what time it is; >> A man with two clocks is never quite sure. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@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@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Steve Rooke - ZL3TUV & G8KVD & JAKDTTNW A man with one clock knows what time it is; A man with two clocks is never quite sure. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.