Hi Bob: When we received new computers from HP and plugged them in the date/time was correct. I believe the DS32xx series of RTCs, like those in wrist watches run on almost no power. The trick is in getting a super cap with low leakage and low resistance. The super caps designed to keep memory chips alive may not power anything needing more than a microamp. Mail_Attachment -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Bob Camp wrote: > Hi > > I sort of doubt that a GPS aux supply is quite that low current. I have seen some RTC’s that won’t last a month on a coin cell. My recollection is that the Oncore backup is closer to that category than the “many years on a cap” group. > > Bob > > >> On Oct 31, 2014, at 9:26 PM, Brooke Clarke <brooke@pacific.net> wrote: >> >> Hi Bob: >> >> When HP came out with the 300 series Rocky Mountain Basic computers they were fitted with a super cap to power the RTC. >> I will keep time for some months. >> http://www.prc68.com/I/HPIB.shtml#300 >> >> Mail_Attachment -- >> Have Fun, >> >> Brooke Clarke >> http://www.PRC68.com >> http://www.end2partygovernment.com/2012Issues.html >> http://www.prc68.com/I/DietNutrition.html >> Bob Camp wrote: >>> Hi >>> >>> The ultra cap is a pretty small one (physical small). You might be able to find a larger (more farads) one that would fit in the same space. It’s not going to help for a hours and hours sort of outage. It might get you from dying in 15 minutes to dying in a half hour. >>> >>> Bob >>> >>>> On Oct 31, 2014, at 12:42 PM, Tom Miller <tmiller11147@verizon.net> wrote: >>>> >>>> I thought so too. There is an ultracap in each unit. >>>> >>>> >>>> Tom >>>> >>>> ----- Original Message ----- From: "Mike Seguin" <n1jez@burlingtontelecom.net> >>>> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> >>>> Sent: Friday, October 31, 2014 12:19 PM >>>> Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system >>>> >>>> >>>>> I have both of my units sitting on the bench. I found that I needed to connect them together to get the REF1 unit to come out of standby. >>>>> >>>>> I am using GPSCon to monitor and it appears to work fine. >>>>> >>>>> One thing on my units, when I power cycled them, it started a 'survey' over! I didn't expect that. Are others seeing this. There must be a way to store the surveyed position.... >>>>> >>>>> Tnx, >>>>> Mike >>>>> >>>>> On 10/30/2014 3:59 PM, Bob Stewart wrote: >>>>>> Hi Anthony, >>>>>> Did you power cycle both units as part of connecting them together at J5 to J5? And can you remind me whether you are using the supplied interface cable, or are you using something else? After warmup, the ON light is on for the REF-0 unit and the STBY light is on for the REF-1 unit. While running, there is no output from J8 on the unit marked STBY. J8 works on the unit marked ON. There is a timestamp coming from J6, and I think a 1PPS signal on some pin or other. >>>>>> >>>>>> Bob From: Anthony Roby <aroby@antamy.com> >>>>>> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> >>>>>> Sent: Thursday, October 30, 2014 2:24 PM >>>>>> Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system >>>>>> >>>>>> I'm still having no luck with mine. When I power on, the LEDs cycle, the Fault light is on and the No GPS and Standby lights flash. When I connect my GPS antenna, the No GPS light stops flashing and stays on. After several minutes only the Standby light is on. >>>>>> >>>>>> When I connect both the Ref1 and Ref0 together with the interface cable, the Fault lights on both units are illuminated. >>>>>> >>>>>> Do you see the same? I don't know what to infer from the Fault light since there is no supplemental data to work from. >>>>>> >>>>>> Anthony >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> 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. >>>>>> >>>>> -- >>>>> >>>>> 73, >>>>> Mike, N1JEZ >>>>> "A closed mouth gathers no feet" >>>>> _______________________________________________ >>>>> 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. >>> >> _______________________________________________ >> 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. >

Hi Bob: AFAICR on the old 6-channel Motorola GPS boards there was an option for a backup battery. Without the backup battery if there was any power interruption the memory would erase and you needed to do a cold start. Having the almanac and ephemeris, even if from a year ago has the effect of greatly reducing start-up time. In this case the purpose of the super cap is to prevent memory loss because of a power glitch not for long term power failure. Mail_Attachment -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Bob Camp wrote: > Hi > > Well Q = CV. If delta V = 1 and C = 0.022 then Q = 0.022. That’s 22 ma for 1 second or 22 ua for 1,000 seconds. At 5 ua you would get to about an hour. If the delta V is 2X that, the times would all double. If the current is 10X lower than the spec (it might be …) then you could get out to around a day. > > Bob > > > >> On Nov 1, 2014, at 12:38 AM, Bob Stewart <bob@evoria.net> wrote: >> >> Hi Bob et al, >> I don't understand the direction this question about the supercap has taken. It's connected to pin 1 of the GPS receiver. It looks to be a UT+, so that's the battery backup power. According to my UT+ manual the current draw on this pin is between 5uA (at 2.5V) and 100uA (at 5V)? How many hours will a .022F supercap keep at least 2.5V at that sort of discharge rate? Unless the cap has gone bad, it seems more likely that Bob's comment about it doing a fast survey and then doing a slower one in the background probably has merit. In fact, my unit goes through its survey mode pretty quickly on power up. So do those current/voltage figures imply several hours on the cap? >> >> Bob >> From: Bob Camp <kb8tq@n1k.org> >> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> >> Sent: Friday, October 31, 2014 9:22 PM >> Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system >> >> Hi >> >> I sort of doubt that a GPS aux supply is quite that low current. I have seen some RTC’s that won’t last a month on a coin cell. My recollection is that the Oncore backup is closer to that category than the “many years on a cap” group. >> >> Bob >> >> >>> On Oct 31, 2014, at 9:26 PM, Brooke Clarke <brooke@pacific.net> wrote: >>> >>> Hi Bob: >>> >>> When HP came out with the 300 series Rocky Mountain Basic computers they were fitted with a super cap to power the RTC. >>> I will keep time for some months. >>> http://www.prc68.com/I/HPIB.shtml#300 >>> >>> Mail_Attachment -- >>> Have Fun, >>> >>> Brooke Clarke >>> http://www.PRC68.com >>> http://www.end2partygovernment.com/2012Issues.html >>> http://www.prc68.com/I/DietNutrition.html >>> Bob Camp wrote: >>>> Hi >>>> >>>> The ultra cap is a pretty small one (physical small). You might be able to find a larger (more farads) one that would fit in the same space. It’s not going to help for a hours and hours sort of outage. It might get you from dying in 15 minutes to dying in a half hour. >>>> >>>> Bob >> >> _______________________________________________ >> 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. >

Hi I think if you look at the math, the 0.022 F cap isn’t going to take care of the rated 20 uA current drain for very long. Bob > On Nov 1, 2014, at 4:59 PM, Brooke Clarke <brooke@pacific.net> wrote: > > Hi Bob: > > When we received new computers from HP and plugged them in the date/time was correct. > I believe the DS32xx series of RTCs, like those in wrist watches run on almost no power. > The trick is in getting a super cap with low leakage and low resistance. > The super caps designed to keep memory chips alive may not power anything needing more than a microamp. > Mail_Attachment -- > Have Fun, > > Brooke Clarke > http://www.PRC68.com > http://www.end2partygovernment.com/2012Issues.html > http://www.prc68.com/I/DietNutrition.html > Bob Camp wrote: >> Hi >> >> I sort of doubt that a GPS aux supply is quite that low current. I have seen some RTC’s that won’t last a month on a coin cell. My recollection is that the Oncore backup is closer to that category than the “many years on a cap” group. >> >> Bob >> >> >>> On Oct 31, 2014, at 9:26 PM, Brooke Clarke <brooke@pacific.net> wrote: >>> >>> Hi Bob: >>> >>> When HP came out with the 300 series Rocky Mountain Basic computers they were fitted with a super cap to power the RTC. >>> I will keep time for some months. >>> http://www.prc68.com/I/HPIB.shtml#300 >>> >>> Mail_Attachment -- >>> Have Fun, >>> >>> Brooke Clarke >>> http://www.PRC68.com >>> http://www.end2partygovernment.com/2012Issues.html >>> http://www.prc68.com/I/DietNutrition.html >>> Bob Camp wrote: >>>> Hi >>>> >>>> The ultra cap is a pretty small one (physical small). You might be able to find a larger (more farads) one that would fit in the same space. It’s not going to help for a hours and hours sort of outage. It might get you from dying in 15 minutes to dying in a half hour. >>>> >>>> Bob >>>> >>>>> On Oct 31, 2014, at 12:42 PM, Tom Miller <tmiller11147@verizon.net> wrote: >>>>> >>>>> I thought so too. There is an ultracap in each unit. >>>>> >>>>> >>>>> Tom >>>>> >>>>> ----- Original Message ----- From: "Mike Seguin" <n1jez@burlingtontelecom.net> >>>>> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> >>>>> Sent: Friday, October 31, 2014 12:19 PM >>>>> Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system >>>>> >>>>> >>>>>> I have both of my units sitting on the bench. I found that I needed to connect them together to get the REF1 unit to come out of standby. >>>>>> >>>>>> I am using GPSCon to monitor and it appears to work fine. >>>>>> >>>>>> One thing on my units, when I power cycled them, it started a 'survey' over! I didn't expect that. Are others seeing this. There must be a way to store the surveyed position.... >>>>>> >>>>>> Tnx, >>>>>> Mike >>>>>> >>>>>> On 10/30/2014 3:59 PM, Bob Stewart wrote: >>>>>>> Hi Anthony, >>>>>>> Did you power cycle both units as part of connecting them together at J5 to J5? And can you remind me whether you are using the supplied interface cable, or are you using something else? After warmup, the ON light is on for the REF-0 unit and the STBY light is on for the REF-1 unit. While running, there is no output from J8 on the unit marked STBY. J8 works on the unit marked ON. There is a timestamp coming from J6, and I think a 1PPS signal on some pin or other. >>>>>>> >>>>>>> Bob From: Anthony Roby <aroby@antamy.com> >>>>>>> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> >>>>>>> Sent: Thursday, October 30, 2014 2:24 PM >>>>>>> Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system >>>>>>> >>>>>>> I'm still having no luck with mine. When I power on, the LEDs cycle, the Fault light is on and the No GPS and Standby lights flash. When I connect my GPS antenna, the No GPS light stops flashing and stays on. After several minutes only the Standby light is on. >>>>>>> >>>>>>> When I connect both the Ref1 and Ref0 together with the interface cable, the Fault lights on both units are illuminated. >>>>>>> >>>>>>> Do you see the same? I don't know what to infer from the Fault light since there is no supplemental data to work from. >>>>>>> >>>>>>> Anthony >>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> 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. >>>>>>> >>>>>> -- >>>>>> >>>>>> 73, >>>>>> Mike, N1JEZ >>>>>> "A closed mouth gathers no feet" >>>>>> _______________________________________________ >>>>>> 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. >>>> >>> _______________________________________________ >>> 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.