RE: Engine noise
Just to throw my 2 cents in here - I used to fly my first gasser with an electronic kill switch installed. Radio and ignition curcuits were separated, the only interface was the kill switch. I had bad interferences when I was flying. On the ground everyting was working fine.
After relocating the batterys and moving the ignition away from everything else, I still got the problem.
That happened until I removed the kill switch, everything worked find, no jitters.
And this was on A 2.4 GHz radio, never had any problems with this before and after this incident.