OK, interesting but putting an attenuator on the antenna input seems not a good idea when there are 5V present...
On Sat, Jul 20, 2013 at 6:01 PM, Mark C. Stephens <ma...@non-stop.com.au> wrote: > Azelio, I had an interesting experience with the same symptoms tonight. > I inserted a 6 dB pad on the antenna input and it appears to alleviated the > problem. > Perhaps the GPS module is being overloaded with too much signal? > > --marki > > -----Original Message----- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Azelio Boriani > Sent: Tuesday, 16 July 2013 5:57 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Advice Z3816A jumping to Holdover: 1PPS TI exceeds > hold threshold, then Recovery: phase alignment for 3-4 hours. > > I have a 58503 that occasionally is not able to track satellites. > Usually I wait until the holdover expires but then the only fix seems to > restart the 58503 (SYST:PRESET) better than power cycle. It seems there is a > command to reset only the GPS receiver but it is not in the > 58503 manual. > > On Tue, Jul 16, 2013 at 6:33 AM, Mark C. Stephens <ma...@non-stop.com.au> > wrote: >> I have a Z3816A and it periodically jumps into holdover with error message: >> Holdover: 1PPS TI exceeds hold threshold Then for the next 3-4 hours >> it gradually adjusts the phase alignment. >> The error message is Recovery: phase alignment [TI +435.5 us] (when I >> noticed it had changed, they figure was likely to have been much >> higher) The TI then gradually decreases, currently it is sitting on: >> Recovery: phase alignment [TI +129.9 us] >> >> I am hoping that I won't have to power cycle the GPSDO to get it locked >> again. >> >> I emailed the seller (Yixun HK) and they are trying to tell me power cycle >> is only fix. >> They also claim the cause is due to weather? >> >> I explained to Yixun I have a lot of smart clocks here and none have >> exhibited the same problem ever. >> This is the 3rd defective Z3816A I have got off Yixun and it is costing me a >> small fortune to send these back. >> The first was reporting the 12v Supply was out of tolerance, a quick jump >> into pForth confirmed the A, B and C 12v supplies were over 12.5v. >> I ended up sending it back to Yixun. >> The second I was able to fix myself, apparently someone had changed the OCXO >> but left the insulating-spacing washers out from the pins of the OCXO. >> This was causing a short on the EFC. >> That Z3816A unit and now appears to be running normally except the PU is >> terrible, I'll run Cal for 24 hours and see if it improves. >> >> However, Now the 3rd unit is getting this TI exceeded error. >> I think I have had enough of shipping things back to these guys - they won't >> replace anything, including parts, unless you ship back to them first. >> >> >> I would just like to get some informed opinions, could the issue be with: >> >> a) Antenna >> >> b) GPS Module >> >> c) OCXO >> >> d) PLL circuit on main board. >> >> Many thanks, >> --marki >> _______________________________________________ >> 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.