Changing tx/rx crystals
Not sure if Tower Hobbies is 100% correct on this but here's a quote right from their website:
*Transmitter Crystals Can Not be changed to another channel except
by a licensed service center. It is against FCC regulations, and
illegal for the user to change a frequency determining component
of a transmitter. If the radio is not retuned, it can be a hazard
spectators, modelers or property, and void AMA insurance coverage