Erik, When I was working at my last (pre-retirement) job, I encountered an old PRS-10 gathering dust. It worked well free-running, but when I tried to lock it to 1PPS, it would do nothing for a while, then would begin deviating further and further from a correct lock. Over a period of a few hours it would basically run amok.
Dana On Thu, Jan 7, 2021 at 10:10 AM <[email protected]> wrote: > Hi All, > > I have done an experiment using the PSR10. > I have set the Magnetic offset to mid-range MO2950 > Than set the Set frequency to 0 SF0. To have 0 frequency offset. > Measured the output frequency and calculate the average deviation. > By using the Frequency Synthesizer Table from Appendix A I have selected > the > smallest frequency deviation by changing via the Frequency Synthesizer > Control command SP. > Than measured the frequency deviation again and use the Set frequency > command for > the correction of the deviation (by SF). By monitoring the Magnetic read > you > are able to see > the Magnetic C field effect from the SF setting. Than enter the Magnetic > offset to the value of > magnetic read via MO. Finally set the SF to 0. > By this procedure the frequency deviation is < than a few parts to -12. > And within the Magnetic offset range. > However still the 1pps control is not working and stops the internal time > interval. > Maybe by corrupted eprom TO setting. > But the unit is good for un-steered operation. > > Thanks for your help > > Erik (PE1RQF) > > > > -----Original Message----- > From: time-nuts <[email protected]> On Behalf Of Dana > Whitlow > Sent: maandag 4 januari 2021 21:02 > To: Discussion of precise time and frequency measurement > <[email protected]> > Subject: Re: [time-nuts] PRS10 not locking to 1PPS > > Erik, the PRS-10 does have provisions for changing the internal > synthesizer's "ratio", which could provide a way of getting an essentially > fresh start on aging. > There's a > big table of values somewhere in the documentation (but not necessarily in > any convenient order). > > My old PRS-10 is getting towards one end of its magnetic tuning range and > will probably "die" in another couple of years use, but I have high > expectations of winning it back via this mechanism. > > Have you looked into this? > > Dana > > > On Mon, Jan 4, 2021 at 1:36 PM <[email protected]> wrote: > > > Hi all, > > > > The PSR10 is working now for 15 years at my place (total >25 years). > > For the 1pps a Trimble Resolution T is used and has a good 1pps signal. > > The Magnetic Offset MO is on the limit value of 2300 when using the > > 1pps correction. > > Therefore I think the unit is on end of life. I tried a factory reset > > to see what will happen. > > However due to the change of the TO to 1814 the unit stopped measuring > > the 1pps time pulses after 256 measurements and no 1pps measurement > > are possible when PL=1. > > The other values are responsive. Only after a RS1 it will measure > > again the pps. > > My thought was due to the strange TO of 1814 (before factory reset is > > was > > -1814) > > the internal calculation is messed up. > > When PL=0 the pps measurements continues but the MO is not controlled > > to GPS. > > I am not sure how to update the firmware. > > While the unit is still stable, it has now an frequency offset of > > -2.7E-10 Hz/Hz stability still is > > 2.4E-12 for 20k seconds. > > Probably I need another rubidium frequency standard. > > > > ST5 when PL=0 > > 3 = PPL disabled, < 256 good 1pps inputs Provide stable 1pps inputs > > > > ST5 when PL=1 and when 1pps hangs > > 4 = Excessive time interval (while 1pps is still good of the GPS) > > > > Regards, > > Erik (PE1RQF) > > > > > > > > > > -----Original Message----- > > From: Miikka Raninen <[email protected]> > > Sent: zondag 3 januari 2021 21:44 > > To: [email protected] > > Cc: [email protected] > > Subject: PRS10 not locking to 1PPS > > > > > Hello Time-Nuts, > > > > > > I am an user of a PRS10 Rubidium standard. > > > The unit has firmware revision 3.15. > > > After reset to factory settings the Time Offset (TO) was set to 1814. > > > Normally it was -1814. Now de PRS10 is not locking to the 1PPS anymore. > > > It will freeze when PL = 1. It will freeze after 256 seconds. > > > Is there a known way to set the TO back to -1814 for the firmware > > revision? > > > As it is a factory setting for this firmware revision. > > > > > > Regards, > > > Erik pe1RQF (former time keeper for the Netherlands at VSL) > > > > Ref manual for PRS10 : > > https://www.thinksrs.com/downloads/pdfs/manuals/PRS10m.pdf > > > > Check the quality of the input 1PPS. When the unit fails to lock on to > > 1PSS input after 256 seconds it is usually due to the 1PPS being too > > unstable in phase > > > > What do you mean by freezing? Can you check the status bytes with ST? > > command? They might indicate the reason for the fault : > > > > ST5: Frequency Lock to External 1pps > > ST5 bit Condition which sets bit Corrective Action > > > > 0 PLL disabled Send PL 1 to enable > > 1 < 256 good 1pps inputs Provide stable 1pps inputs > > 2 PLL active > > 3 > 256 bad 1pps inputs Provide stable 1pps inputs > > 4 Excessive time interval Provide accurate 1pps > > 5 PLL restarted Provide stable 1pps inputs > > 6 f control saturated Wait, check 1pps inputs > > 7 No 1pps input Provide 1pps input > > > > You might also want to consider updating the firmware as "(Note: > > Firmware revisions prior to Rev 3.23 do not allow user TO! commands. > > Check the firmware revision with the ID? command)" > > > > - Miikka Raninen OH3GPJ > > > > > > -- > > This email has been checked for viruses by AVG. > > https://www.avg.com > > > > > > _______________________________________________ > > time-nuts mailing list -- [email protected] To unsubscribe, go > > to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > > > -- > This email has been checked for viruses by AVG. > https://www.avg.com > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
