Metallic paint and composite antenna signal strength

What about metal flake paint?

On Fri, 24 Jun 2005 08:56:02 -0700, "RST Engineering"
wrote:


"firstflight" wrote in message
...

Will a metallic paint interfere with the strength of signal with impeded
antennas

What is an impeded antenna?



in a composite airplane?

I ran some tests with both nav, com, dme, and transponder antennas imbedded
in the wing of a Bellanca aircraft under controlled test conditions at the
Bellanca factory back in the 1970s. The wing was wood with fabric covering.
The fabric had the standard silver (aluminum) UV dope over the fabric and
then polyurethane paint over the dope.

We measured (both ground and airborne) the signal strength from both the
standard antenna on the exterior of the aircraft and the ones imbedded in
the wings and found no degradation of signal strength from the imbedded
antennas from the reference antennas mounted on the fuselage.

Does this mean that you can't go out there and find some paint that will
screw up the reception? No. What it means is that we DID try it with one
form of metallic paint and there were no effects. Certainly you would think
that out of ten thousand internal plastic plane antennas we've sold over the
last thirty years we would have had at least ONE complaint from metallic
paint problems. We haven't. You may be the first. That's why we paint
EXPERIMENTAL on the sides of our aircraft.



I have a small transponder antenna and a
Comm antenna bonded to the inside of the fuselage.

Why on earth would you bond a transponder antenna to the inside of the
fuselage? How do you get lower hemispherical (not biconical) radiation from
something bonded to the fuselage?

Jim