Narrow Foil Strips for Ground Plane

I would be interested to see some pictures of the ground plane inside the
Diamond Star if you have them handy. The relative locations of the carbon
and the foil would be of particular interest if the pictures show that.

I have seen a similar metallic strip along the bottom of the fuselage in
other composite aircraft that all the antenna earth to.

The use of mesh in lieu of foil just makes it easier to bond in place (and
more reliable) because the adhesive impregnates the mesh. The mesh is cheap
at a few dollars / sq ft. They also make aluminium and possibly monel mesh -
although I won't use aluminium on a carbon structure because they are widely
separated on the galvanic scale. Both Exmet and Astroseal (Astrostrike) can
be found on the web.


"Steve Chalfin" wrote in message
om...
"Dennis Mountains" wrote in message
...
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 put foil on the inside of the fuselage as a ground plane?
That's what Diamond did on my Star. The entire 'scuppers' of the
fuselage is lined with metal (but not copper) foil, as a ground plane
for the Com 2, DME, Marker, and Transponder antennas. Although not
entirely made of carbon fiber, the Star has a lot of it in that area
(spar carry through structure). I can e-mail some pics to you if you
are interested.

Com 1 and GPS antennas on the 'roof' have metal plate ground planes,
also located inside.

Steve