i have the xs3
i dont know if you can use other radios or not ...ill look in the book. if you do use another one im sure you will have to use rx crystals, becuase the rx that comes with the xs3 has dials on it you turn when you choose your freq.
the radio itself has all 30 channels inside so you would only need 1 for the rx. that kinda defeats the purpose of buying that radio.