Lots of differing replies on this thread, but the simplest thing to do, is to mount the IGN switch on the side of the fuse right behind the cowl, and mount the receiver switches as far back as possible on each side of the plane. Keep ALL IGN related components as far away as possible from ALL radio related components. There is no magic number of inches for this. There is no 20" rule, no 12" rule. If you can separate these components 48" then do it. Obviously you wouldn't put everything in the tail to keep them away from the IGN, but as far apart as practically possible is a good rule. If this plane is an aerobat with a canopy like an Extra, I would mount them on the sides right where the canopy meets the turtle deck. Done this way, there would be no need for opto isolators or other trinkets that are not needed. Metal rods on throttles are a definite no no. I use Sullivan precision rods. They are a black CF impregnated nyrod with a white outer sheath. They do not expand and contract as much with temperature like standard nyrods do. They also do not contain enough CF in the plastic to transmit EMI or RFI. I also read about patches on high tension leads...not advisable...replace it...if the outer shielding is compromised it can lead to a crash. Replacing a lead is not that expensive, but a crashed model is. Ask yourself if it's worth the risk. When I look at my big gasser the answer I give to that question is definitely NOT! To keep the high tension lead from chafing wrap a small piece of the fuzzy side of some velcro around it. I separate all wires going back to the tail a minimum of four inches...don't bundle wires all together...that is asking for an EMI problem. EMI is electro magnetic interference, and it's caused by electrical (magnetic) current passing through the wires which create magnetic fields. Putting these magnetic fields in close proximity to each other can result in 'cross talk' between the wires. It is a rare occurrence, but it's just good practice to eliminate this possible problem from the equation. On long leads use 22 awg HD extensions. It carries current better, and generally this wire has thicker insulation which also guards against possble EMI. Like Jim said using metal 'shielding' does nothing unless it is grounded. With a well thought out radio installation that is neatly done, I can see no reason for shielding of the wires. Patience and time spent on the radio install pays big dividends with these planes. I spend almost as much time on a the planning and actual work on a radio install as it takes me to cover one, and that's a bunch of time. One last suggestion, if a problem is found with a wire on the radio system or a high tension lead on an IGN, it belongs in the trash, replace it...don't try to patch it, or rig something up...it's just not worth it. By throwing spent items in the trash and replacing them, it will keep you from bringing the trash can to the crash site. Hope this answers your questions.