I had a strange one a few years ago: new JR radio, new airplane with dowel/wire combo rod wyed and going to split elevators; would glitch like crazy in flight only when I put it into a shallow dive. The prop would unload, the rpm's would go up, and when they got into a certain range, the radio would glitch like crazy. NO METAL TO METAL ANYWHERE! I finally replaced the el rod with nyrod, problem solved! Evidently, the wire ends on the el rod set up a sympathetic vibe at a certain engine rpm. The fix would be to change the resonance of the wires by changinging their length (shorter for higher rpm) or diameter (heavier wire would change it), if you must use that type of pushrod. I also had a case recently where I suspected a solid wire throttle pushrod(4c glow power); the glitch would not go away until I tried a PCM receiver.