Magellan SporTrak GPS loosing sensitivity?

[Steve]

This is the second time this has happened with a Magellan
GPS. The acqisition time when its first powered up gets longer,
eventually to the point that its unusable. For this model it should be
2 minutes. Yesterday, it was 18 minutes, and that was in an
open area with a clear view from horizon to horizon. I'm
guessing its because the receiver is loosing sensitivity for
some reason.

Has anyome else delt with this and found a solution?
I'd rather try to fix it myself rather than sending it to Magellan.

Steve

 

[Jeroni Paul]

Consider the following case:

 http://www.gpsworld.com/gpsworld/article/articleDetail.jsp?id=43404

A malfunctioning TV-antenna preamplifier, powered up but stored inside
a paint locker onboard a small boat (!), was radiating enough noise to
knock out GPS reception throughout all of Moss Landing harbor and for
a distance of at least 1 km out to sea!

Curious.
That antenna design has the amplifier inside the antenna loop. Should
the antenna pick its own amplified signal it would oscillate like
crazy. I wonder how did they (attempt to) aboid that.