On Feb 5, 10:26*pm, Dick wrote:
I am installing a new vane style antenna for my transponder. *My
original antenna was located where the cg hook used to be on my
discus. *This location often tangled with the trailer ramp when
loading the glider. *Next I tried a whip style on top of my instrument
panel cover. *All of the self proclaimed experts said that was a
terrible place. *Much to much power too close to the rest of my
avionics and electronics. *I now intend to place it on the underside
of the fuselage as far aft of the main gear housing as I can reach.
My question is, does it have to be mounted near the centerline, *I'd
rather not tangle with the overlap of the two fuselage halves. *How
far off the center line can I go before the biannual inspector will
object or I will lose effectiveness? *IT

We've use the Advanced Aircraft Electronics L2 antenna on several
installations, with excellent results. This antenna mounts
internally in the fuselage tail boom. (won't work with carbon fiber
in the fuselage though...)

On gliders with carbon fiber, we used typical stub antenna, mounted
per manufacturer's drawings....we fabricated a "ground plane" plate to
go inside the fuselage......you need some space for this.

The antenna can be quite far off center line...but I would worry about
not going too far off vertical orientation.

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