Transponder antenna ground plane - Help!

On Monday, March 24, 2014 8:37:57 PM UTC-7, Bill T wrote:
Don't let them cut your fiberglass...

That's all well and good if it is indeed fiberglass. I can't remember if the original poster said what their fuselage is made of. But if it's carbon fiber, an internal antenna will not work because of the opacity of carbon to radio waves.

With carbon fuselages, you have to either put the antenna somewhere that isn't carbon (sometimes the fin and/or rudder are made with radio-transparent fiberglass or aramid fibers), or you must install an external antenna.

With my gliders, the fuselage and fin is made with carbon, but we put the com antenna in the aramid fiber rudder. We haven't installed any transponder antennas yet, but when we do we'll probably just install an external blade antenna and call it good.

Thanks, Bob K.