If the Radiant is the same as the Quasar (and they say it is) and you want to center the aileron servo turn the key lock switch off and use the function select to select the s-trm function, use the Ch+ button to select channel 2 (aileron channel). Then use the yes/inc + or the no/dec - key to set the value to zero. Turn the receiver on and center the aileron trim lever on the Tx. Remove the servo arm and set it back on as close to the center position as you can get it (it might be right on and you're done). If you can't get it exactly centered then use the yes/inc + or the no/dec - keys to set the servo arm to exact center. The other servos (rudder and elevator) can be centered the same way by using the Ch+ button to select the appropriate channel. Set the key-lock switch back to on when you are done. Good-luck.
