Thought this would be of interest so I am forwarding it to
LML.
Steve Colwell Legacy
Bob,
I bought a Artex ME406 ELT http://www.artex.net/me406.html that
transmits on both 121.5 and 406. My project is a carbon fiber Lancair
Legacy. I don’t want to hang another antenna on the outside of the
airframe and this airplane is all carbon fiber. Can I place the supplied
antenna http://www.artex.net/documents/110-773.pdf
diagonally (21.5” exposed length) across the rear window without too much
loss of signal? Any alternative ideas?
Thanks,
Steve Colwell
From: Steve/Claudette
Colwell
Sent: Saturday, October
07, 2006 3:02 PM
Unlike most ELT antennas this one looks like it has some science
incorporated. Most ELT antennas are very poor. This one is surely meant to be
installed externally on a metal aircraft. I would guess that the cylindrical
object a bit above the conical base is a choke that keeps the 406 mhz
from continuing out the antenna. That antenna should work ok if you install it
in the window as you suggest. Make a bracket to accept the antenna base at one
corner of the window, making sure it is grounded to the graphite and bond it in
some way across the window. It would be best to try to keep it as far away from
the graphite frame as possible. It is not necessary to have the antenna
vertical because the satellites looking down like to see horizontal
polarization anyway.
Hope this helps. Too bad Lancair didn't incorporate more fiberglass
windows so you wouldn't have so many external antennas. They do cause quite
abit of drag.