On Fri, 04 Aug 2006 09:37:44 -0400, Jonathan Goodish
wrote:

In article .com,
"Jay Honeck" wrote:
http://www.scn.org/~bk269/gps.html

This is an interesting site that explains why some pilots (seemingly
mostly running Garmin-brand portable GPS units) are having trouble with
losing satellite lock.


We had a problem in our PA28 with a Skymap II (panel mounted GPS) when
using an antenna on the top of the instrument panel. The culprit was
the Narco IDME 825 and depended which frequency the DME was tuned. The
DME transmitter blocked the GPS receiver. There was a considerable
improvement when we fitted an external roof antenna. We have now
fitted a Skymap IIIc GPS which is understand has a better receiver
and so far appears ok.