Andy Talbot said: > I also heard a case of a GPS antenna going unstable, oscillating and taking > out most of the boats in a marina. The Radio Communications Agency (as our > enforcement body was then, before it became Ofcom) had to be called out to > identify the problem. There was an interesting story about a similar event in GPS World back in Jan 2003 This was from TV antenna amplifiers that were oscillating in/near the GPS band. It/they took out the Moss Landing (Monterey Bay) harbor. The Hunt for RFI http://gpsworld.com/the-hunt-rfi/ Unjamming a Coast Harbor James R. Clynch, Andrew A. Parker, George Badger, Wilbur R. Vincent, Paul McGill, Richard W. Adler -- These are my opinions. I hate spam.