Well, I'm not having much success, just lots of frustration. I epoxied the rigging wires on the top center section so they wouldn't rub and the interference is still there. It was 20 degrees out yesterday and prop wash on the hands was a killer, so testing was short. Removing the antenna from the fuselage didn't help either. The interference does increase with engine speed. I've done a little searching and found several comments regarding the rigging acting as an antenna creating interference on a biplane, and that a PCM receiver should be used. The supplier of the plane also said to use PCM. I've always tried to eliminate interference and fly a plane with PPM before switching to PCM, but it's starting to sound like that might not be possible. Does any one know much about flying wires causing interference on biplanes?

I've got a few more things to try yet as the process of elimination continues.

Chuck