not sure about the 40mhz. You must be from europe because it is not used here in america. The difference between AM and FM (I think that is what you mean)is thet the am is more susceptable to interferencethan FM, like a radio in a car
Work because i gotta, play because i wanna
People here hate Nitro, I love it. I start it, run it about 50 ft from me and it dies, I go after it. Perfect exercise