Re: [time-nuts] TymServe 2100 and the 1995 GPS issue
Gerhard Wittreich kirjoitti: Once locked I did notice something interesting but maybe not important. The control voltage to the oscillator (timing util tfp 0) went from a very consistent 0xba6f to a 0xbb02. That's about 0.2% of scale. I'll watch it over the next few days to see where it settles in. Sounds like oscillator aging to me, sometimes they do larger jumps, stay there for a while and then again... Also it would not be suprising that this would happen just after the power was off and oven was cooled down for a moment. Also, brand new oscillators seem to age more rapidly at start and then settles down when older but the effects of aging will never stop completely. But they seem to get better and better when aging. I'm also waiting my MTI OCXO to arrive... -- 73s! Esa OH4KJU ___ 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.
Re: [time-nuts] TymServe 2100 and the 1995 GPS issue
Very good point...It is a new oscillator that has been sitting in a box for 10-15 years. I'll give it a few weeks to settle in. The other very interesting thing I noticed was the variability in the oscillator control voltage before and after installing the new Heol Design GPS. The moving average of the standard deviation of the oscillator control voltage before and after installing the Heol Design gps was striking. The variability of the control voltage for the Heal Design is nearly 1/3 of that for the original Trimble gps. That suggests that the pps signal from the new gps module has 1/3 the variability vs the original gps module. I did consider that this could be due to the new oscillator aging but when I do a linear regression on the standard error of the control voltage before replacing the gps module the p-value for the slope of the line is about 0.5 suggesting that the null hypothesis, that the slope is actually zero, cannot be rejected. Therefore, one would need to conclude that there is no change if control voltage variability vs time prior to the installation of the new gps module and, consequently, there was no change in the stability of the new oscillator (since everything else remained unchanged). Unfortunately, I do not have sufficient run time on the new gps module to reach any meaningful conclusion of variability vs time. If anything it still appears to be dropping at this point. I can further update once I get additional run time. I also noted a very marked improvement in the satellite signal strength reported by the TS-2100. While I don't have any statistically sound data my observation is that the signal strengths are significantly higher and there are always more viable satellites in view. In the past I would never see more that 6-8 with 4-6 having sufficient signal strength. Now I routinely see 10 with 6 - 8 having sufficient signals strength. [image: Inline image 1] Note: The straight lines represent the mean value and are not linear regression although the linear regression and the mean line are very nearly the same for the original GPS data. I suspect the same will happen once I get some run time with the new GPS. Both imply that there is little time dependence, in the short term, on control voltage variability. Gerhard R Wittreich, P.E. On Tue, Jun 9, 2015 at 8:59 AM, Esa Heikkinen tn1...@nic.fi wrote: Gerhard Wittreich kirjoitti: Once locked I did notice something interesting but maybe not important. The control voltage to the oscillator (timing util tfp 0) went from a very consistent 0xba6f to a 0xbb02. That's about 0.2% of scale. I'll watch it over the next few days to see where it settles in. Sounds like oscillator aging to me, sometimes they do larger jumps, stay there for a while and then again... Also it would not be suprising that this would happen just after the power was off and oven was cooled down for a moment. Also, brand new oscillators seem to age more rapidly at start and then settles down when older but the effects of aging will never stop completely. But they seem to get better and better when aging. I'm also waiting my MTI OCXO to arrive... -- 73s! Esa OH4KJU ___ 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.
Re: [time-nuts] TymServe 2100 and the 1995 GPS issue
That sort of control voltage shift is not unusual if you take an OCXO that had been on for an extended period (for some of us... years or decades!), let it cool, then start it up again. Good google search terms are OCXO retrace and OCXO hysteresis. Tim N3QE On Mon, Jun 8, 2015 at 4:45 PM, Gerhard Wittreich gerh...@wittreich.org wrote: I just received the Heol Design N024 Trimble ACE III clone to resolve the week rollover problem we have been experiencing in the TS-2100's with the original Trimble ACE III gps units. Installation was very straight forward taking about 5 minutes. On a cold restart I had Tracking within 40 seconds with the correct date and time (Leap second issue also resolved) and Locked with my new OCXO in ~20 minutes. Once locked I did notice something interesting but maybe not important. The control voltage to the oscillator (timing util tfp 0) went from a very consistent 0xba6f to a 0xbb02. That's about 0.2% of scale. I'll watch it over the next few days to see where it settles in. Gerhard R Wittreich, P.E. On Thu, Jun 4, 2015 at 11:38 AM, Sean Gallagher s...@wetstonetech.com wrote: Hey everyone, Just wanted to send this out. It is The documentation that Heol has sent me regarding the GPS replacement boards in the 2100. According to them so far they were able to correct the issues with some fancy firmware on their N024 board. He also told me they are going to support firmware updates up to 2035 in case more issues arise. He is sending me one of these new units and should arrive within the next 2 weeks and I'll let you know if it works in my 2100's and my Datum/Symmetricom BC635pci cards. Respectfully, Sean Gallagher Malware Analyst 571-340-3475 ___ 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. ___ 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.
Re: [time-nuts] TymServe 2100 and the 1995 GPS issue
I just received the Heol Design N024 Trimble ACE III clone to resolve the week rollover problem we have been experiencing in the TS-2100's with the original Trimble ACE III gps units. Installation was very straight forward taking about 5 minutes. On a cold restart I had Tracking within 40 seconds with the correct date and time (Leap second issue also resolved) and Locked with my new OCXO in ~20 minutes. Once locked I did notice something interesting but maybe not important. The control voltage to the oscillator (timing util tfp 0) went from a very consistent 0xba6f to a 0xbb02. That's about 0.2% of scale. I'll watch it over the next few days to see where it settles in. Gerhard R Wittreich, P.E. On Thu, Jun 4, 2015 at 11:38 AM, Sean Gallagher s...@wetstonetech.com wrote: Hey everyone, Just wanted to send this out. It is The documentation that Heol has sent me regarding the GPS replacement boards in the 2100. According to them so far they were able to correct the issues with some fancy firmware on their N024 board. He also told me they are going to support firmware updates up to 2035 in case more issues arise. He is sending me one of these new units and should arrive within the next 2 weeks and I'll let you know if it works in my 2100's and my Datum/Symmetricom BC635pci cards. Respectfully, Sean Gallagher Malware Analyst 571-340-3475 ___ 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.
Re: [time-nuts] TymServe 2100 and the 1995 GPS issue
Sean, I have one on the way as well along with an MTI 240-0530-D OCXO. Looks like my TS-2100 is getting a complete makeover. I'll provide feedback as well. On Thu, Jun 4, 2015 at 11:38 AM, Sean Gallagher s...@wetstonetech.com wrote: Hey everyone, Just wanted to send this out. It is The documentation that Heol has sent me regarding the GPS replacement boards in the 2100. According to them so far they were able to correct the issues with some fancy firmware on their N024 board. He also told me they are going to support firmware updates up to 2035 in case more issues arise. He is sending me one of these new units and should arrive within the next 2 weeks and I'll let you know if it works in my 2100's and my Datum/Symmetricom BC635pci cards. Respectfully, Sean Gallagher Malware Analyst 571-340-3475 ___ 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.
