Dave, I haven't monitored the Z3801A in quite some time, but I do remember that it used to track more satellites. For probably a year, the unit would go into holdover often. Then a few months ago, it stayed in holdover. Last night was the first time that I have looked at the stats and information recently.
The antenna is a Symmetricom timing antenna. It used to sit on top of my service monitor, but has recently been raised up several feet, in the clear. I can't easily get it outside because I'm renting (single-story frame house). When the Z3801A used to track more sats, the antenna was in the old location. I am using a 4-port Symmetricom GPS splitter. My Lucent 2-box GPSDO is on one of the ports. I moved the Z3801A to another port, to make sure that wasn't the problem. What I will do tonight when I get home is to see how many sats the Lucent is tracking. Joe Gray W5JG On Thu, Feb 25, 2016 at 8:52 AM, Artek Manuals <manu...@artekmanuals.com> wrote: > Joe, Joe and Bob > > I am still not ready to condemn the receiver until we have more data.. > > Do you have any history on how many satellites you were tracking in the > past, i.e are the number of sats being tracked and the sat strengths typical > for your setup or are they noticeably lower now than in the past? Describe > the antenna and its installation. While not ideal at just tracking 4 sats > the unit will still track and lock with that few, what is more likely to > suffer than anything is the holdover performance than the power up GPSDO > accuracy > > I have a dead on Oncore here on the bench and there are as far as I know no > schematics available and even if there were troubleshooting it could be a > REAL challenge, certainly there no "adjustments". > > If anyone REALLY wants to see one I can post some up close and personal > photos of the receiver board ...only helpful in discouraging thoughts of > repairing it as near as I can tell especially since replacement receivers > abound from a list member and on Evil-Bay at reasonable prices > > Dave > NR1DX > > > > > On 2/25/2016 9:15 AM, J. L. Trantham wrote: >> >> Joe, >> >> I recently had a problem with my Z3816A where it reported an erroneous >> date, 2035 IIRC. However, the time was accurate. >> >> It was only tracking 4 sats and the signal strengths were low. My TBolt >> was tracking 8 sats with good signal strength. My antenna feeds a >> Symmetricom 58536A 4 way splitter and that feeds the receivers. >> >> I 'rebooted' the unit by turning off power, leaving it overnight then >> turned it on. Same thing. >> >> I then removed and replaced the 'battery backup batteries' (they tested >> good) that I had installed and restarted it. It never found itself. I then >> gave it the Lat/Long and it found itself, with the correct time but with >> only 4 sats and with low signal strength. >> >> I then replaced the GPS receiver and now all is well. It found itself, 8 >> sats, good signal strength, correct date and time, as compared to the TBolt. >> >> So, the GPS receiver might be on the list for your problem. >> >> Does anyone know anything about how to repair these receivers? >> >> Thanks. >> >> Joe >> WB4BPP >> >> >> >> -----Original Message----- >> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Joseph >> Gray >> Sent: Wednesday, February 24, 2016 10:37 PM >> To: Discussion of precise time and frequency measurement >> Subject: [Bulk] [time-nuts] Z3801A holdover >> >> I just took a look at my Z3801A that has been in holdover for some time. I >> have been too busy to do anything about it until now. >> >> Before looking at the receiver stats just now, my first guess was that the >> Oncore GPS board went bad. However, I see that it is currently tracking 4 >> sats. I also see that the 1pps is invalid. Does this still point to a failed >> Oncore board? >> >> Attached is a screenshot showing the receiver stats. >> >> I will open this thing up over the weekend to check voltages and such. >> Until then, any tips on where to look are appreciated. >> >> Joe Gray >> W5JG >> >> _______________________________________________ > > > -- > Dave > manu...@artekmanuals.com > www.ArtekManuals.com > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > _______________________________________________ > 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.