jphoenix wrote:
I installed mine this past weekend, the antenna is located forward and
under the instrument panel glareshield, attached to the rudder pedal
bracket and installed within 20° of vertical as required by the
manual.

AmeriKing, $206 including shipping from Paul Remde.

I have sold and installed the Ameri-King ELT's (I still sell these for just
$189.00) and other ELT's using a variety of antenna installations, usually a
rubber duck mounted on a metal ground plane in the baggage area is the
easiest and cleanest installation, providing you don't have a carbon fiber
or metal fuselage. I've also seen installations of the same antenna type
from some glider manufacturers mounted on simple brackets in the cockpit
that provide little of no ground plane....I have "unscientifically tested"
my own installations and they work, at least TX with reasonable strength and
range but I don't know how well the antenna performs without some ground
plane. Some time ago I did however speak with someone at Ameri-King who told
me then they actually certified their AK-450 while it was simply sitting on
a wing without an antenna attached (there is also a telescoping antenna
provided with the ELT so it can be used as a portable unit as well).
Consider though that handheld radios use nothing more than the radio body as
the grounding plane, and they do work, although not with the same range or
power as an external antenna, and it's easy to see that most antenna
installations will allow transmit, if even at less than optimum.
Also keep in mind the ground plane doe not have to be a larger metal
plate......it can be wire "whiskers" like many base station antennas use, or
even foil tape (check out any heating supply or even the Home Depot and
you'll find a variety of foil tapes used mostly for heating ductwork and the
ground plane issue becomes a " non-issue" very simply.
best regards
Tim
Wings & Wheels
www.wingsandwheels.com