Re: [time-nuts] z3801 - holdover and recovery issue
On 7/11/2011 3:57 PM, Charles P. Steinmetz wrote: Ron wrote: Colleagues, My Z3801 has developed a peculiar problem over the last few weeks. The problem is that it seems to oscillate between gps-lock and holdover. When I checked further it seems to be oscillating between, locked, recovery, and holdover, mostly staying in recovery and holdover. Have you tried substituting another antenna and cable (even just a short cable with the antenna indoors)? This looks like what I'd expect a 3801 to do if its antenna or antenna connection were intermittent. While you have it disconnected, check that the 3801 is putting antenna power on the coax. Hi Charles, I disconnected the mushroom-style antenna and measured the voltage between the TNC centre pin and shield; This was 5 volts. Connection looked clean and unaffected by weather or moisture ingress. Reattached the connector and screwed it on until it was tight, then rechecked gpscon. Satellites are now being received. So I can only deduce from this that the TNC male (cable end) to TNC female (mushroom antenna) is intermittent. Don't understand why but it now looks like it is receiving 6 satellites and the 3801 is in recovery mode. http://www.ei2jp.org/gpscon/gpsstat.htm R ___ 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] z3801 - holdover and recovery issue
On 15/07/11 15:06, Ron Hahn (EI2JP) wrote: On 7/11/2011 3:57 PM, Charles P. Steinmetz wrote: Ron wrote: Colleagues, My Z3801 has developed a peculiar problem over the last few weeks. The problem is that it seems to oscillate between gps-lock and holdover. When I checked further it seems to be oscillating between, locked, recovery, and holdover, mostly staying in recovery and holdover. Have you tried substituting another antenna and cable (even just a short cable with the antenna indoors)? This looks like what I'd expect a 3801 to do if its antenna or antenna connection were intermittent. While you have it disconnected, check that the 3801 is putting antenna power on the coax. Hi Charles, I disconnected the mushroom-style antenna and measured the voltage between the TNC centre pin and shield; This was 5 volts. Connection looked clean and unaffected by weather or moisture ingress. Reattached the connector and screwed it on until it was tight, then rechecked gpscon. Satellites are now being received. So I can only deduce from this that the TNC male (cable end) to TNC female (mushroom antenna) is intermittent. Don't understand why but it now looks like it is receiving 6 satellites and the 3801 is in recovery mode. http://www.ei2jp.org/gpscon/gpsstat.htm Somehow I am not surpriced, as similar problems have been showing up at my place. Fixing some cable and connector problems removed the issues. Hope it stays stable now and you get good lockup. 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] z3801 - holdover and recovery issue
So I can only deduce from this that the TNC male (cable end) to TNC female (mushroom antenna) is intermittent. Don't understand why but it now looks like it is receiving 6 satellites and the 3801 is in recovery mode. I wouldn't be quite so sure My Z3801 stopped working right a while ago. I fiddled with the antenna and such. Sometimes it would work well enough to confuse me, then it would fade out again. It finally started working correctly after I power cycled it. It might have been a power glitch. It might have been a software bug that just happened to get tickled by my setup which has a poor antenna location. -- 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] z3801 - holdover and recovery issue
Colleagues, My Z3801 has developed a peculiar problem over the last few weeks. Its been running for several years now (at three different QTHs) and has worked flawlessly until recently. The problem is that it seems to oscillate between gps-lock and holdover. When I checked further it seems to be oscillating between, locked, recovery, and holdover, mostly staying in recovery and holdover. The gpscon status page is here - http://www.ei2jp.org/gpscon/gpsstat.htm Having checked closer today, I noticed that the EFC is only today showing err in the health monitor. Suggestions on whan'ts gone wrong please? Thanks, Ron EI2JP ___ 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] z3801 - holdover and recovery issue
Hi I also have a sick Z3801. In my case I'm betting it's the Oncore receiver in it. The symptoms aren't quite the same as yours, but similar. Bob On Jul 11, 2011, at 6:22 AM, Ron Hahn (EI2JP) wrote: Colleagues, My Z3801 has developed a peculiar problem over the last few weeks. Its been running for several years now (at three different QTHs) and has worked flawlessly until recently. The problem is that it seems to oscillate between gps-lock and holdover. When I checked further it seems to be oscillating between, locked, recovery, and holdover, mostly staying in recovery and holdover. The gpscon status page is here - http://www.ei2jp.org/gpscon/gpsstat.htm Having checked closer today, I noticed that the EFC is only today showing err in the health monitor. Suggestions on whan'ts gone wrong please? Thanks, Ron EI2JP ___ 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] z3801 - holdover and recovery issue
Ron, My guess would be one of two things... First check the EFC on the OXCO, if it's near the edge of the tuning range you might need to adjust the Coarse Adjustment screw to get it back to near-center of the EFC range. Second, as Bob said, it could be the GPS receiver (I believe these had Oncore 6-channel VP receivers), or maybe even the GPS antenna or possibly the cable run. The VP receivers appear on eBay every now and then. I'm *pretty* sure the 8-channel VP models can be sent a command to emulate the 6-channel models. ___ 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] z3801 - holdover and recovery issue
Ron wrote: Colleagues, My Z3801 has developed a peculiar problem over the last few weeks. The problem is that it seems to oscillate between gps-lock and holdover. When I checked further it seems to be oscillating between, locked, recovery, and holdover, mostly staying in recovery and holdover. Have you tried substituting another antenna and cable (even just a short cable with the antenna indoors)? This looks like what I'd expect a 3801 to do if its antenna or antenna connection were intermittent. While you have it disconnected, check that the 3801 is putting antenna power on the coax. Best regards, Charles ___ 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] z3801 - holdover and recovery issue
Dear Ron, On 07/11/2011 12:22 PM, Ron Hahn (EI2JP) wrote: Colleagues, My Z3801 has developed a peculiar problem over the last few weeks. Its been running for several years now (at three different QTHs) and has worked flawlessly until recently. The problem is that it seems to oscillate between gps-lock and holdover. When I checked further it seems to be oscillating between, locked, recovery, and holdover, mostly staying in recovery and holdover. The gpscon status page is here - http://www.ei2jp.org/gpscon/gpsstat.htm Having checked closer today, I noticed that the EFC is only today showing err in the health monitor. Suggestions on whan'ts gone wrong please? You aren’t tracking satellites! Looking at your history you flip between tracking 0 or 1 sats. I would start looking at the signal strength issue. Are your antenna OK? Do another GPS lockup nicely on the same signal? The GPS receiver there eats power and delivers a PPS and some serial data to the rest of the GPS. If the GPS receiver isn't happy about the input signal, all the rest will be unhappy, so you will have to focus on proper GPS reception conditions first. I've found that sloppy antenna mounting, sloppy done connector work on home-made cables etc. been part of my overall problem with signal quality to my rig. So do start in that end of the world. Best Regards, 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.
