Hey Flybeetus, I'm have the same set up. My GR-12L appears to bind to the tx, I can control the rudder and elevator, but it never gives a green LED. It also beeps and blinks via the Graupner logo. Also the motor will judder unloaded until I push the throttle slowly forward and then it will spin. As soon as I put the prop on it judders uncontrollably.
Anyone got any advice for us?