Hey guys there is nothing magic about antennas at either 50 or 72 Mhz. I have allways just run the antenna wire back to the rear edge of the cocpit and the up to the top of the verticle fin where I attach it with soider to an enlongated spring and then to the top of the verticle fin with a nylon screw and nut and on a "40" size trainer this leaves about 2 inches remaining to extend freely above the rudder. The antenna provided with most radios is a 1/4 wave long wire and is more influnced buy the metal control rods than length or routing. If you cannot rout it more than a wave length away from the metal control rods they will allways be the controlling factor. Just do it neat and secure and go fly.

Lee K5MRC

PS: Run the antenna wire through the spring to extend along the top of the rudder.