http://www.stormcam.org/antenna-garmin/
On a Garmin Gps (C340)What is the difference b/w using a traffic antenna: GTM 10 versus the GTM 12, just $?
Also, I just bought the Streetpilot C340, It is preloaded, but I cannot download updated maps because it says I don’t have Mapsource. I cannot download that because my garmin was preloaded… how do I add new maps if I decide to buy them?
Oh, and yes, the antenna question please.
Thanks
The GTM10 has to be installed in the vehicle, meaning you have to pull the radio to install to the exterior antenna. The GTM 12 does not require the installation and is much easier to use.
If you have a version prior to version 8, you may obtain the update disk from the garmin site. If you have version 8 already, there is nothing to update.
Garmin GA25MCX External Antenna @ GPSCity 010-10702-00