Jerry,

FWIW - The Artex ME 406 with the whip antenna has worked perfectly in our airplane since new - no false activations ever. I think most people shy away from it due to the cost - Used to be $1000, now about 50% more so not cheap. The battery is about $200 And is good for 7 years.

I tried to save money on an encoder and originally purchased the Ameri King one which was crap - screwed up 3 times and replaced; and, eventually the company got in trouble for manufacturing unapproved parts and went backrupt (after I replaced it of course) - I decided some people charge less because they know what their junk is worth so I have stayed away from cheap electronics ever since. Ameri King had the same problem (unapproved parts) with their ELTs so if you find a used one of those - don't put it in your plane.