Hi You may well over drive the GPS board if you put more amplification in the line. If the antenna and coax work ok with a 3801, they should be fine with a 3805. If you have a very high gain setup, it may be ok for the 3801 and be over driving the 3805 already.
What kind of antenna and coax are you using? Bob On Nov 11, 2012, at 2:24 PM, Doug Parker <doug.par...@btinternet.com> wrote: > Hi John, > > Thanks for the observation, with the same antenna plugged into my Z3801, I > get an SS of at least 90. > > I'll place a preamp in line to see if that increases the SS on the 3805 , > maybe my problem is the GPS RX isn't well. Great point. > > Of course, I'll watch out for the 5V power feed going up the coax for the > preamp in the antenna. > > 73s > Doug > G4DZU > > > ________________________________ > From: jmfranke <jmfra...@cox.net> > To: Doug Parker <doug.par...@btinternet.com>; time-nuts@febo.com > Sent: Sunday, 11 November 2012, 19:04 > Subject: Re: [time-nuts] Z3805 hold-Over > > Your 21 ns for 1PPS and T1 does not look too bad, but the satellite received > signal strengths are too low. You should have at least four or five SS values > above 60-80. I always have at least three SS readings above 100. My Holdover > runs between 03 and 4 microseconds. > > John WA4WDL > > -------------------------------------------------- > From: "Doug Parker" <doug.par...@btinternet.com> > Sent: Sunday, November 11, 2012 1:36 PM > To: <time-nuts@febo.com> > Subject: Re: [time-nuts] Z3805 hold-Over > >> >> >> >> Hi, >> >> I've got a Z3805 from one of the Chineese sources and had problems with the >> HP 11801 oscillator which came with it. Even after a couple of weeks >> operartion it was moving vast EFC voltages with the 'Holdover Uncertainty >> Predict' reaching a lowest of 19uS. >> >> So I tried the HP oscillator from my Z3801 in the Z3805 and the daily EFC >> change is back to a resonable level, but after 5 days of settling down, the >> 'Holdeover Uncertainy Predict' has only got down to 10uS.and is holding >> about that value. >> >> Could some one please advise what figures they are getting. As there's >> something sticking in my mind that the whole system should be lower than >> 6.3uS after 3 days of locked operation. Or have I been dreaming..... >> >> I have attached a JPG of my GPSCon graph, hope it helps >> >> thanks & 73s >> Doug >> G4DZU >> http://www.g4dzu.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. > _______________________________________________ > 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.
