Luke -

Probably not a useful suggestion on a completed airplane but I'll pass this on in case you get to your wit's end.

I provided access thru my wing tips and outboard rib to mount my Xpndr antenna and 8" x 8" groundplane to the inside of the wing tip, attached to the bottom of the upper skin. Cable was routed thru the nav lights wiring conduit in the leading edge (a plastic tube) and then back thru the access hole in the rib. Have always enjoyed uninterrupted radar contact in any orientation further out than on any spam-can, with an external antenna rod.

To get at the access hole in the outer rib, I made the lower section of the wing tip closeout removeable - this also provides access to the nav lights and strobe for bulb change.

Dan Schaefer
N235SP --
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