The transmitter portion of the tx is designed to transmit in a specific frequency "range" and that range is 72mhz. Anything outside that and perfomance drops drasticly. Changing to even "Ham" band at 50mhz would require radio rework. I will not get into the specifics of rf transmision but will leave it at this: changing the crystal in ANY RC Tx by someone other than a certified facility is currently illegal according to the FCC. The certified facility will tune the tx to the new frequency and verify that the Tx in "on" frequency and not drifting. This is usually done with a spectrum anilyzer. Just because the FCC set a 25 watt limit on marine vhf radios does not mean they weren't cranked up or had amps put on them. I won't tell you where mine are at! With most tx's you need some tool (hemostats, screwdriver) to get at the crystal some you don't. Sure you can pull the tx crystal and change it, no one would ever know, but let's see now, rx crystal $15 or less and is legal. I know what I do and it aint screwing with the tx.