RFI

Is 2.4 GHz immune to Ignition spark noise (RFI)?  At first we heard reports, that nothing would bother the 2.4. Now is seems the consensus is to take the same precaution you would with 72 GHz. I’m for this. I think enough RF noise could get into a servo amp and mess up the whole works. There have been reports of problems that fliers think are caused by ignition noise. The complaint starts like this, when I start my engine the radio goes nuts .When I stop the engine the problem goes away, so it has got to be ignition problems. I have to believe these are vibration induced problems. When they stop the engine the vibration goes away this problem can also be caused by the metal spark plug cap not pushed all the way down on the spark plug, the wire snap ring must be all the way past the hex on the spark plug when installed correctly. The wrong cap and spark plug combination also causes a lot of problems.

I have done some testing on the 2.4 Futaba FASST systems. I built a ignition with no shielding, no resistor wire  No metal cap on the spark plug, no case or cover on the ignition system and installed about four inches from receiver battery pack and receiver. Using a resistor spark plug .Engine running I had solid control at 180 steps about over 500 feet. That was with the range check button pushed in on the transmitter module. I moved the transmitter around in all positions and no funnies. I installed a non-resistor spark plug and a different story. Only had about 50 feet with range check button pushed. So…too much noise will bother a 2.4 system. I would guess the noise could be getting into the servo amps. The noise was so bad it would peg my RFI meter up to about 75 feet. I know it would drive a FM completely nut’s. We have done the same test on a Spectrum with the same results. So to make a long story short RFI noise will bother a 2.4 if bad enough. No one would ever fly an ignition like this, I hope, and always use a resistor spark plug if you can. The 10MM, NGK CM-6 is a none resistor spark plug so it should have a full shielded plug cap and a resistor wire or resistor in the plug cap. CH uses a resistor wire and a full metal spark plug cap. We will check the other 2.4 systems when we have a chance and report on these. So to backup where we started, use the same precautions you would use with a 72 system. Why ask for a problem. Seen some flyers are using the same battery pack for both radio and Ignition. I do not know anything about this but may check it out; this will not be on front burner for things to get done.