In article ,
"Dennis Mountains" wrote:

Hi,

I'm building a Lancair Legacy (all carbon fiber) and am planning to put
copper foil strips on the belly to serve as a ground plane for the
belly-mounted com antenna. I'm going to use 1/4" wide copper foil with an
adhesive back, attached to the outside of the fuselage and covered with a
thin layer of fiberglass (not carbon fiber) to protect the foil. I'll
solder it together at the center and attach it somehow to the outside of the
BNC connector.

Why not attach it to the INSIDE of the fuselage? That's where all of the
grounding takes place -- and -- you don't have to cover it up!

I would use the 4 strips of the 1/4" tape, at 45 deg from each other and
a piece of thin copper sheet about 1" dia, soldered to the center,
joining all the radials.

1/4" wide is plenty wide for the frequency band you are using -- just
make sure that each radial is about the same or greater length as the
antenna.