Posted for "Tom Gourley" <tom.gourley@verizon.net>:

 I know John Halle's Legacy has the antenna mounted directly to the carbon
fiber skin with no special ground planes.  I believe he used lock washers
(what I call star washers, not split ring) to provide a little bite into the
carbon.  (This is the same technique JPI specifies for connecting the ring
lugs of their EGT and CHT probes to the ring lugs of their wiring harness.)
 His plane's been flying with this arrangement for about 5 years now.  Many
times I've heard him on my handheld, and while flying my 112, and his radios
sound great.  A week ago Saturday I was flying from Eugene back to Hillsboro
and, from 75 NM out, I heard John entering the pattern at Hillsboro.  His
radio was clear and strong, no scratchiness, and I easily recognized his
voice.
 
 Tom Gourley
 Still building, off and on