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Been lots of discussion on antennas lately here in the group. Although I
do have a limited background on antennas and theory I am not an expert.
I will just tell you what I did and state that the antennas work very
well. I bought Jim Weir's kit (RST Engineering) for building dipole
antennas for about $20 several years ago because I thought that was the
way to go in composite airplanes. It is nothing more than a roll of
copper tape and a bag of toroids which slip over the transmission line
at the antenna junction. He also supplies literature where and how to
install and provides antenna lengths for the various components.
Jim is an expert. Not only does he write for Kitplanes but has designed
antennas for Rutan. Has installed and tested antennas in most of the
canard type airplanes; and that is a real challenge.
Anyway, I installed Com 1 in the vert stab. Com 2 is inside the fuselage
just behind the right side rear window. (yes it wraps up onto the top
and down onto the belly somewhat but is still mostly vertically
polarized. The VOR and glide slope antennas are horizontally polarized
and so are installed in the horizontal stabilizer and the wings. The ELT
is a vertically polarized antenna and is folded into a "z" shape on the
inside of the fuselage aft of the baggage door. Marker beacon is on the
belly running forward and aft underneath the elevator push rod
tube.(that is a pretty long antenna)
I have not used a splitter, thinking that if I needed to I would find my
best antenna and split that one. (Com1, Com2) (Vor, Glide Slope) But,
all of the antenas work very well and I have not needed to do that.
Of course you need to plan ahead for antennas in the wings and
horizontal stab by installing them before you close out those
components. (Although, if necessary these antennas could be placed on
the outside of the skin, taped over, and smoothed with micro)
For my transponder I broke down and bought a ready made dipole for about
$80. I think the manufacturer is AAE and is designed for use in
composite aircraft. It is about 10" long amd I simply glued it to the
back of the spar inside my wing. It too, should be vertically polarized.
(Access cover in front of the flap)
Just thought I would let you know what another builder did and works OK.
Bob Stia N96ES
LML homepage: http://www.olsusa.com/Users/Mkaye/maillist.html
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