Re: [time-nuts] GPS clock error.
On 04/13/2011 05:27 AM, Max Robinson wrote: This morning at 10 AM CDT my GPS clock read 8 PM July 5th. My wife reported that the time had been 2 hours off at 6 AM local time. She didn't notice if it was AM or PM. The parabolic dish icon was missing from the display. I manually set the time and date but when compared to my two WWVB clocks it was clear it was in holdover mode. I waited about 3 hours then removed the batteries and reinstalled them. I set the time zone and left it to it's own devices. It set itself correctly in about 10 minutes and the dish icon was back. I wonder what happened. Could their have been a shortage of satellites that caused the receiver to lose lock? Not very likely. With 32 birds in the sky, there is no lack of them, it's the maximum amount normal GPS receivers can handle. Why wouldn't it reacquire on it's own? If I had been a little more patient would it have reacquired on its own? I'm sure no one knows the answer to the last question. Speculation is welcome. If the GPS receiver or the presentation computer hangs is two different things. I guess the later would be more likely. Cheers, Magnus ___ 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] GPS clock error.
On Tue, Apr 12, 2011 at 8:27 PM, Max Robinson m...@maxsmusicplace.com wrote: This morning at 10 AM CDT my GPS clock read 8 PM July 5th. My wife reported that the time had been 2 hours off at 6 AM local time. . I'm sure no one knows the answer to the last question. Speculation is welcome. Power interruption nd the backup battery that holds memory is dead? There are also endless ways that logic inside th GPS can fail in a soft way. Memory can become pattern sensitive or a tiny sense amp in a RAM chip can get noisy and cause one in a billion type soft errors. I don't bother to fix things until I can make it repeat on demand -- = Chris Albertson Redondo Beach, California ___ 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] GPS clock error.
This morning at 10 AM CDT my GPS clock read 8 PM July 5th. My wife reported that the time had been 2 hours off at 6 AM local time. She didn't notice if it was AM or PM. The parabolic dish icon was missing from the display. I manually set the time and date but when compared to my two WWVB clocks it was clear it was in holdover mode. I waited about 3 hours then removed the batteries and reinstalled them. ... Could you say more about this clock? How long do the batteries last? ... I'm familiar with battery operated atomic clocks that listen to WWVB. I didn't know about GPS versions. I'd expect a WWVB receiver to use much less power but maybe modern GPS receivers are good enough so they would have reasonable battery life. My best guess is that your receiver got tricked by noise that looked good enough. I've seen GPS receivers report that their info was valid when it was miles from the reported location. Usually, that's right after recovering from not-enough-satellites. albertson.ch...@gmail.com said: There are also endless ways that logic inside th GPS can fail in a soft way. Memory can become pattern sensitive or a tiny sense amp in a RAM chip can get noisy and cause one in a billion type soft errors. I don't bother to fix things until I can make it repeat on demand Memory doesn't usually become pattern sensitive. It might be designed that way. Cosmic rays or alpha particles are the usual ways that DRAM gets soft errors. You can also have noise/crosstalk at the board level (or on chip) or power supply problems. If you want to build a reliable system, you have to pay attention to rare bugs. If nothing else, you want to collect data on them so you know if you have a problem and/or how bad it is. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] GPS clock error.
Magnus. Thank you for your reply. Regards. Max. K 4 O D S. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com - Original Message - From: Magnus Danielson mag...@rubidium.dyndns.org To: time-nuts@febo.com Sent: Wednesday, April 13, 2011 1:19 PM Subject: Re: [time-nuts] GPS clock error. On 04/13/2011 05:27 AM, Max Robinson wrote: This morning at 10 AM CDT my GPS clock read 8 PM July 5th. My wife reported that the time had been 2 hours off at 6 AM local time. She didn't notice if it was AM or PM. The parabolic dish icon was missing from the display. I manually set the time and date but when compared to my two WWVB clocks it was clear it was in holdover mode. I waited about 3 hours then removed the batteries and reinstalled them. I set the time zone and left it to it's own devices. It set itself correctly in about 10 minutes and the dish icon was back. I wonder what happened. Could their have been a shortage of satellites that caused the receiver to lose lock? Not very likely. With 32 birds in the sky, there is no lack of them, it's the maximum amount normal GPS receivers can handle. Why wouldn't it reacquire on it's own? If I had been a little more patient would it have reacquired on its own? I'm sure no one knows the answer to the last question. Speculation is welcome. If the GPS receiver or the presentation computer hangs is two different things. I guess the later would be more likely. Cheers, Magnus ___ 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] GPS clock error.
Hi Hal. The manufacturers logo consists of the lower case letters ila next to an hour glass. The instruction book calls it a talking atomic alarm clock. It is somewhat of a battery hog. They have to be replaced every 2 or 3 months. Regards. Max. K 4 O D S. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com - Original Message - From: Hal Murray hmur...@megapathdsl.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, April 13, 2011 3:29 PM Subject: Re: [time-nuts] GPS clock error. This morning at 10 AM CDT my GPS clock read 8 PM July 5th. My wife reported that the time had been 2 hours off at 6 AM local time. She didn't notice if it was AM or PM. The parabolic dish icon was missing from the display. I manually set the time and date but when compared to my two WWVB clocks it was clear it was in holdover mode. I waited about 3 hours then removed the batteries and reinstalled them. ... Could you say more about this clock? How long do the batteries last? ... I'm familiar with battery operated atomic clocks that listen to WWVB. I didn't know about GPS versions. I'd expect a WWVB receiver to use much less power but maybe modern GPS receivers are good enough so they would have reasonable battery life. My best guess is that your receiver got tricked by noise that looked good enough. I've seen GPS receivers report that their info was valid when it was miles from the reported location. Usually, that's right after recovering from not-enough-satellites. albertson.ch...@gmail.com said: There are also endless ways that logic inside th GPS can fail in a soft way. Memory can become pattern sensitive or a tiny sense amp in a RAM chip can get noisy and cause one in a billion type soft errors. I don't bother to fix things until I can make it repeat on demand Memory doesn't usually become pattern sensitive. It might be designed that way. Cosmic rays or alpha particles are the usual ways that DRAM gets soft errors. You can also have noise/crosstalk at the board level (or on chip) or power supply problems. If you want to build a reliable system, you have to pay attention to rare bugs. If nothing else, you want to collect data on them so you know if you have a problem and/or how bad it is. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] GPS clock error.
This morning at 10 AM CDT my GPS clock read 8 PM July 5th. My wife reported that the time had been 2 hours off at 6 AM local time. She didn't notice if it was AM or PM. The parabolic dish icon was missing from the display. I manually set the time and date but when compared to my two WWVB clocks it was clear it was in holdover mode. I waited about 3 hours then removed the batteries and reinstalled them. I set the time zone and left it to it's own devices. It set itself correctly in about 10 minutes and the dish icon was back. I wonder what happened. Could their have been a shortage of satellites that caused the receiver to lose lock? Why wouldn't it reacquire on it's own? If I had been a little more patient would it have reacquired on its own? I'm sure no one knows the answer to the last question. Speculation is welcome. Regards. Max. K 4 O D S. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com ___ 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.
