I have a $4000 dollar airplane and am flying it at your flying field. You arbitrarily change the crystal in your transmitter and because iyour transmitter hasn't been retuned to the discreet frequency it slops over onto my channel and causes my airplane to crash. I am going to be very, very, very upset and I can almost guarantee that you will be buying me a new aircraft.
DON'T CHANGE YOUR TRANSMITTER CRYSTAL WITHOUT HAVING THE TRANSMITTER RETUNED!!!!

doubledee