Jan,

You did not state why you need to construct a ground plane. Is your
plane composite? In that case you could get a half wave antenna from
Spruce and not worry about a ground plane. Its only about 5.5" long
- but a bit pricier.

-----------------------------------------------------------
Paul Lee, SQ2000 canard project: http://www.abri.com/sq2000

"Mads" wrote in message ...
Anyone with depth knowledge of groundplanes for transponders?

- their mission (any theory would be appreciated)?
- required dimension
- required shape (is a cross OK or does it have to circular)
- material (is aluminium tape OK?)
- installation - follow the a/c body, or flat
- how critical is the above (loss of signal strength?)


regards


Jan Ivar