[time-nuts] Re: Please help. Motorola Oncore

Wed Sep 21 09:08:27 UTC 2022

The Motorola service note, that John Ackermann was referring to, should be this:

<https://synergy-gps.com/wp-content/uploads/2019/06/VP_SERVICE_NOTE.pdf>

It should be not relevant for the GT+ and UT+ mentioned here.

On Tue, Sep 20, 2022 at 6:23 PM Marcelo Dantas via time-nuts
<time-nuts at lists.febo.com> wrote:
>
> I am wondering if this issue could be caused by the way I am setting the
> date/time when setting it up on WinOncore.
> I am in NY, N 41.10.0481, W 074.11.2900, 408ft. So I enter this data into
> the initial reference position. Telling the software to set it into the
> position hold position.
> For the initial reference time I tried entering UTC time and leaving the
> GMT offset +0, or my local time and setting the GMT offset to -4, also some
> combinations of that.
> I already gave up on the UT+, but the GT+ at some point showed "visible
> satellites", though it wouldn't track any. As this happened way into my
> trial and error process, I was unable to verify which combination gave me
> these results.
> Sorry if I sound like a complete noob (which I am) but I have noticed that,
> by changing the time it would show different satellites in different
> positions, so I thought: aha, it is based on almanac+time, not on what it
> is actually "seeing" in the sky. I mean, I am not a specialist on this by
> any means, but I am suspecting it tracks based on where the satellites
> should be at a given time, not by listening to where they actually are?
> (please don't give up on me)
> Anyways, could be that I am telling the GPS wrong information on its
> initialization, which makes it go bananas and not find anything. And
> lacking a valid almanac it would not be able to even build one based on the
> wrong information I provided?  I am shooting in the dark here.
>
> Thanks,
> Marcelo.
>
>
>
> On Tue, Sep 20, 2022 at 4:27 AM Magnus Danielson via time-nuts <
> time-nuts at lists.febo.com> wrote:
>
> > Hi,
> >
> > Not really. The format is the same. Subtle clarifications and use of
> > flag fields is however.
> >
> > One aviation GPS receiver crashed whenever the flag was set as a new
> > satellite was introduced into the constellation. Considering the cost
> > and effort involved of recertifying it after a bugfix, it became a
> > hesitation to fix it. I think this was a learning experience to the air
> > industry, so I think they now have means to address it on more regular
> > basis, since I know that in more recent history the lack of timely
> > update has been the reason for GPS receiver problems, not the lack of
> > update as such. I will ask around on this.
> >
> > It's the GPS III signals which will be very different, as it is packet
> > based.
> >
> > Cheers,
> > Magnus
> >
> > On 2022-09-20 00:27, Bob kb8tq via time-nuts wrote:
> > > Hi
> > >
> > > It would not surprise me at all to find that a modern version of the
> > > almanac is different than the 1998 version. A lot has changed since
> > > then.
> > >
> > > Given that you can find these for < $10 on eBay. I would not invest
> > > a lot in them at this point â€¦. Once you get them running, you will
> > > have roll over issues.
> > >
> > > Bob
> > >
> > >> On Sep 19, 2022, at 4:36 PM, Marcelo Dantas <marcelo.f.dantas at gmail.com>
> > wrote:
> > >>
> > >> Hi Bob,
> > >>
> > >> The modules are old. 1998/2000.
> > >>
> > >> I have left the UT+ running for about 36 Hrs. I have noticed that the
> > battery on the UT+ is dead, so I am ordering a replacement.
> > >> However, while running powered for 36 hours I expected it would see
> > "something". I wish there was a way to verify some of its internal
> > information, to see if it was actually collecting something.
> > >>
> > >> The WinOncore software allows you to upload an almanac, and it talks
> > about a .alm file extension, and on the .gov site I only found a
> > latest_yuma.alm file, which I uploaded, but it would still show "bad
> > almanac".
> > >> I have also tried to upload a .al3 (SEM) file, with the same result.
> > >> Both files seem to upload, so I am not sure which one should be the
> > correct one, or if both are.   I am assuming the yuma because it has the
> > .alm extension. (still a noob in this matter)
> > >>
> > >> On a new development, the GT+ started showing satellites, it shows 10
> > satellites visible, zero tracked.
> > >> The UT+ regardless of the almanacs uploaded, still shows zero visible,
> > zero tracked.
> > >>
> > >> I am still trying to find a reference to the correct (expected) almanac
> > file format and to the eventual calibration procedure referred previously.
> > >>
> > >> Thanks,
> > >> Marcelo.
> > >>
> > >>
> > >> On Mon, Sep 19, 2022 at 5:10 PM Bob kb8tq <kb8tq at n1k.org <mailto:
> > kb8tq at n1k.org>> wrote:
> > >> Hi
> > >>
> > >> If itâ€™s showing â€œbad almanacâ€ then that is part of the issue.
> > >> It may not be *all* of the issue â€¦.
> > >>
> > >> How old are these modules? They went through several
> > >> revisions and each one was a big leap over the previous
> > >> version. If they date back far enough, it could take a very
> > >> long time to come up with an almanac.
> > >>
> > >> Bob
> > >>
> > >>> On Sep 19, 2022, at 3:41 PM, Marcelo Dantas <
> > marcelo.f.dantas at gmail.com <mailto:marcelo.f.dantas at gmail.com>> wrote:
> > >>>
> > >>> @Bjorn: It is the same antenna which worked back then, it was sitting
> > there in the same drawer. So, unless it degrades somehow over time, it
> > should continue to work I guess.
> > >>> I have no idea though how to measure/verify if there's saturation
> > going on.
> > >>> When I plugged this antenna to a U-Blox it immediately kicked in with
> > a bunch of satellites in view, but the U-Blox might also have a different
> > input impedance.
> > >>>
> > >>> @Bob "off for a while" means since mid 2018. So I immediately thought
> > of an almanac, however I could not yet figure out the .alm file it would
> > require.
> > >>> I have downloaded almanac files from the web, not oncore specific, but
> > when importing them via WinOncore I do not get any success/failure
> > messages, and the device continues to show "bad almanac"  on its status.
> > >>> I have a feeling that the issue is towards bad/outdated internal
> > information. Or maybe the calibration John spoke about, if I can figure it
> > out, could help.
> > >>>
> > >>> Thanks,
> > >>> Marcelo.
> > >>>
> > >>>
> > >>>
> > >>> On Mon, Sep 19, 2022 at 4:26 PM Bob kb8tq via time-nuts <
> > time-nuts at lists.febo.com <mailto:time-nuts at lists.febo.com>> wrote:
> > >>> Hi
> > >>>
> > >>> The other gotcha depends a lot on just how long â€œoff for a whileâ€ is.
> > >>> If any of these devices are off power for decades, the internal data
> > >>> for the almanac ( = which sats are where ) will be way off.
> > >>>
> > >>> The process of random search is a lot faster with the newer modules.
> > >>> They have way more processing horsepower. Just how many hours
> > >>> (or days) it takes this or that example of an early module to come
> > >>> back to life â€¦. who knows â€¦.
> > >>>
> > >>> Bob
> > >>>
> > >>>> On Sep 19, 2022, at 2:14 PM, John Ackermann N8UR via time-nuts <
> > time-nuts at lists.febo.com <mailto:time-nuts at lists.febo.com>> wrote:
> > >>>>
> > >>>> Some of the early Motorola receivers had an issue with long-term XO
> > drift.  That can result in failure to lock if the unit has been powered off
> > for a long time.  There is a procedure to recalibrate it (no test equipment
> > required).  I think it was written up in a Motorola app note that's
> > available on line, but I can't put my finger on it right now.
> > >>>>
> > >>>> John
> > >>>> -----
> > >>>>
> > >>>> On 9/19/22 07:53, Gregory Beat via time-nuts wrote:
> > >>>>> IF you start with Fixed Position mode, THEN this speeds up process.
> > >>>>> I would also suggest a CLEAR View of Sky for the Antenna.
> > >>>>> Motorola Oncore UT Plus Engineering Notes (circa 2000)
> > >>>>> https://synergy-gps.com/wp-content/uploads/2018/11/ut-engg-notes.pdf
> > <https://synergy-gps.com/wp-content/uploads/2018/11/ut-engg-notes.pdf>
> > >>>>> Motorola Oncore GT Plus Engineering Notes (circa 2000)
> > >>>>> https://www.tapr.org/pdf/GT_Eng_Notes.pdf <
> > https://www.tapr.org/pdf/GT_Eng_Notes.pdf>
> > >>>>> UT Plus model numbers:
> > >>>>> R5122U111x - right angle OSX
> > >>>>> R5222U111x - right angle OSX, on-board Lithium battery
> > >>>>> R5122U115x - straight OSX
> > >>>>> GT Plus model numbers:
> > >>>>> R3111G111x - standard version
> > >>>>> R3211G111x - on-board Lithium battery
> > >>>>> R3111G114x - SMB antenna connector
> > >>>>> greg, w9gb
> > >>>>> ==
> > >>>>> Date: Sun, 18 Sep 2022 08:42:18 -0400
> > >>>>> From: Marcelo Dantas <marcelo.f.dantas at gmail.com <mailto:
> > marcelo.f.dantas at gmail.com>>
> > >>>>> Subject: [time-nuts] Thanks for adding me, and please help. Motorola
> > Oncore
> > >>>>> To: time-nuts at lists.febo.com <mailto:time-nuts at lists.febo.com>
> > >>>>> Hi there Everyone,
> > >>>>> Thanks for accepting me to this list.
> > >>>>> I am in (dire) need of help here and maybe one of you is a Motorola
> > Oncore
> > >>>>> user and could assist.
> > >>>>> I have a couple Motorola Oncore modules, which I use mounted to a
> > >>>>> "baseboard" for timing purposes.
> > >>>>> One is a R5222U1115 and the other a R3111G1112.
> > >>>>> They have been sitting in a drawer for some time. Being "some time"
> > since
> > >>>>> the pre-pandemic era.
> > >>>>> Now I am trying to use them again but for whatever reason they won't
> > lock
> > >>>>> to any satellites.
> > >>>>> The modules are starting up, sending 1pps and seem to be accepting
> > commands
> > >>>>> correctly.
> > >>>>> I have also tested the baseboard (power, serial, etc) and the
> > antenna.
> > >>>>> The antenna works well on a third (non-motorola) module.
> > >>>>> I have tried everything, left the modules there running for 24 hours.
> > >>>>> No joy. None of them will lock to any satellites.
> > >>>>> I have tried defaulting them using WinOncore, no change.
> > >>>>> I have also tried to find an almanac file to upload, hoping it would
> > help,
> > >>>>> but couldn't find one with the required .alm file extension.
> > >>>>> At this point I do not know what to do anymore. I have a system
> > (module,
> > >>>>> board, antenna, power, etc.) that should just work, and yet it
> > refuses to.
> > >>>>> Maybe there's some special factory reset? Maybe there's some command
> > I do
> > >>>>> not know about? Maybe other software than WinOncore with some extra
> > >>>>> debug options?
> > >>>>> Any guidance here would be deeply appreciated.
> > >>>>> Thanks a lot in advance,
> > >>>>> Marcelo.
> > >>>>> _______________________________________________
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