I too had the Bob Archer antenna, mounted behind the baggage bulkhead on my
360.  I received too many complaints from ATC so I mounted a belly antenna and
had no further ATC problems.  However I do have some noise, kind of a buzz or
sizzle sound over the Bose headset when the 'R' symbol shows on the King 76C
unit.  I've tried expanding the ground plane with aluminum foil to no effect.
Any ideas?  (A minor nuisance compared to hitting deer!)

Ed de Chazal
N361DC