"peter" wrote:

Apparently, (I do not have one) garmin has a MAGNET in the base of
the
antenna (for holding it in place in a vehicle) that they ship with
the
396.. (!)

The Gilsson (www.gilsson.com) external antennas work fine with Garmin
GPS receivers and sell for about $20 at:

The OP is probably refering to the XM antenna, for which there is no
substitute. Some owners have apparently successfully removed the
magnets, though it is difficult to do and Garmin warns doing it will
void the warranty.