In Missileman's theory the proper term would be "harmonic" and they could get up into 2.4 range. Strong enough to interfere? I honestly don't know. The signal source is in close proximity to the RX. I do know that "spread spectrum" is NOT a valid defense as it only means the radio selects (in the case of Spektrum) one pair of freqs per flight. After that it sticks to those freqs and they are vulnerable like any other. Since Futaba hops from one to another they would be less vulnerable. It is simply ALWAYS a good idea to build to the highest standards that you can for safety sake.

All that said, there should be a much lower possibility of interference using the new 2.4 GHz systems but NOTHING is bullet-proof.