[gta02] GPS performance issues on GTA02v5

Daniel Willmann daniel at openmoko.org
Thu Apr 24 17:27:15 CEST 2008

On Thu, 24 Apr 2008 11:30:19 +0800
"Neng-Yu Tu (Tony Tu)" <tony at openmoko.com> wrote:

> Daniel Willmann ??:
> > Hello,
> > 
> > I think I might have found out why recent GPS performance has been
> > so crappy. First of all the GPS on my GTA02v5 does work, but it's
> > much worse than what I was used to. I have checked with
> > openmoko-agpsui from http://people.openmoko.org/olv/tmp/ and on
> > average the S/N ratio is about 5-7dB worse on my 2v5 compared to
> > Stefan's 2v4.
> Could you switch the another GPS antenna see if make difference, it 
> sound like the connector or cable was damaged.

I just swapped the GPS antennas of the v4 and v5 and if there is any
difference at all it's worse. So the problem persists. I don't have a
SIM card in any of the devices so interference from there shouldn't be
an issue.

> We been test about 50 pcs GTA02 DVT units for C/N ratio, it's about
> no difference between v4 and v5. So, it's must be something in the
> signal path was not correct.

Since Mickey is here today I just tested his v5 and compare it
against the other phones. The v4 was always the one that would get the
fastest fix, see the most satellites, ...
You can check with a v4 and v5 side by side standing outside and
comparing C/N ratio between both devices for the same satellites.

Daniel Willmann
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