I built a 900MHz Quagi antenna last night for the telemetry / command to and from the UAV. Obviously this will be the ground antenna on a tracker to so automatically points towards the UAV. I have a 2 channel microwave rotary joint I'm going to use for the tracker to that it can turn 360 deg. Here is a link the design for the Quagi Here are some pictures of the dual channel or path rotary joint. Military surplus good stuff!