My receiver battery is alongside the receiver and 1 inch away, my ignition battery is about 4 inches ahead of the reciver battery on the same side of the fuselage...Engine is a converted Red Max 42cc brushcutter...Ignition is mine, inside the crankcase, coil is mounted like a G26 under the carb on the outside...Coil is from a G62 with unshielded spark plug wire, rubber cap, resistor spark plug...Futaba 7C radio and receiver..Receiver switch is 4 inches back from the firewall, ignition switch the same distance on the other side..The wire from the ignition switch plugs into the rear crankcase using RCA audio jacks from Radio Shack...The wire from the engine IS shielded to the switch..Nyrod from the throttle servo to the carb....[8D].NO interference.....