SHS Testing - TangoGPS, GPS Antenna

Philip Rhoades phil at
Wed Nov 3 18:17:57 CET 2010

Mariusz, Nikolaus, Sebastian,

Thanks for the fast responses!

See inline responses:

On 2010-11-04 03:27, Dr. H. Nikolaus Schaller wrote:
> Am 03.11.2010 um 17:08 schrieb Philip Rhoades:
>> People,
>> I wanted to start using the GPS facilities on my FreeRunner but there is
>> a Catch 22 situation:
>> - If I am inside, there is too much concrete to get GPS signals
>> - If I am outside, I don't have a connection to download maps
>> I thought if I could get an external GPS antenna connected and lead it
>> outside to my balcony, I could get GPS reception while I was still
>> inside (it is not always convenient to go out to the balcony and use
>> WiFi).  I assumed (!) the little antenna connection on the top right
>> edge of the freerunner was for a GPS antenna but when I went to buy one
>> the guy told me the connection is for a 3G antenna . . if I look at:
>> it seems to suggest that there IS an external connector for GPS?
>> Can someone clarify?
> The guy is definitively wrong. The Freerunner doesn't support 3G...
> There is a connector for an external GSM antenna just near one
> of the two Torx screws. You can see it when you open the battery cover.
> The golden connector is a "MMCX" type and provides approx. 3V 15mA for
> an external antenna.
> I am using a Navilock antenna similar to this one (sorry, it is in German):
> Please make sure you get a MMCX (and not a MCX) connector.


> For the GPS performance tests we do, I simply place the Freerunner
> on a window board so that it looks upright and the upper part of
> the Freerunner looks outside. You may have to use one or two
> books (e.g. Shakespeare complete edition...).

My balcony windows face more residential blocks - in the past I have had 
to go out on the balcony and put the FR near the railing to get anything . .

> This is not optimal for satellite reception with the built-in antenna,
> but much better than inside a room. With that setup you usually get a fix
> within 2 minutes (sometimes it may take 15 minutes since the
> receiver can only see less than half of the sky and there may not be
> enough visible satllites).
> After getting a fix, the receiver is sensitive enough to track even inside
> a room.

I am hoping that I can get an antenna connection and connect it to a 
wire going outside?

> Finally, you can download the important maps off-line onto a SD card.

I now have 611 dirs and files under ~/Maps but I have tried all the zoom 
levels and tried dragging around on the screen but I can't get any 
pictures . .  Is there a way of (conveniently) setting my long and lat 
and then downloading so that I know the maps I am getting are from my area?


Philip Rhoades

GPO Box 3411
Sydney NSW	2001
E-mail:  phil at

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