Thanks to all for the comments. I recently traded for another Z3801A that I was told didn't work. I don't know what is wrong with it, as I haven't had time to put it on the bench yet. I understand that the OCXO is putting out a decent 10 MHz, so perhaps it also has a bad Oncore.
Joe Gray W5JG On Wed, Mar 16, 2016 at 3:56 PM, Artek Manuals <manu...@artekmanuals.com> wrote: > Joe > > The newer Motorola VP-Oncore receivers are known to be an improved design > over the original Oncores that came with the Z3801A's . > > I have recently done some side by side comparison's with two z3801A's on > the same antenna the newer Vp-Oncore's ran SS numbers 15-30 points higher on > the same bird than the older receiver. In all fairness the older receiver is > on its last legs (see last paragraph below) > > I also found out that there are two versions of the newer VP-Oncore. These > can be distinguished by the antenna connector, One version has a right-angle > chassis mounted connector like the original 6CH Oncore, the 2nd version has > a straight on antenna connector. This 2nd version while they will work in a > Z3801A, have an interference fit problem with a an IC on the board below > when the antenna cable is plugged in and you can't tighten down all the > receiver board mounting screws. I am told that the straight on version fits > the Z3816A with no problem. I have not verified this since I don't have a > Z3816. I have no info on the other Z38xx models and the fit of the later > VP-Oncore > > The older 6ch Oncore receivers receivers are beginning to die apparently. I > have had one fail here a few months ago and recently acquired a 2nd Z3801A > that is displaying similar symptoms to the first failure in that the > receiver just stops working after a few hours...over time the symptom are > the receiver drops out for no apparent reason then revives if the unit is > powered off for a while. Over time the time to receiver drop out gets > shorter and shorter after each successive power cycle, I have one receiver > that will now fail within 20 minutes predictably. > > Dave > NR1DX > > > > > On 3/16/2016 7:03 AM, Joseph Gray wrote: >> >> I understand that the Oncore GPS in the Lucent units is a newer module >> that tracks eight satellites, vs the older Oncore in the Z3801A that >> only tracks six satellites. >> >> I decided to do a re-survey with my Z3801A that has been in holdover >> for some time, just as a test. Watching the status screens from both >> GPSDOs, both are seeing the same number of satellites, however, the >> Z3801A is consistently locking to 3-4 fewer than the Lucent. >> >> This begs the question, is the older Oncore module that deaf, or is >> mine defective. BTW, same antenna on a 4-port splitter, same elevation >> mask. >> >> Joe Gray >> W5JG >> _______________________________________________ >> 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. >> > > > -- > 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.
