I just bought a used spektrum dx3 with 3000 receiver. Setup was easy and works fine except when the radio is close to the receiver it twitches. Only the throttle servo a small amount back and fourth. When I am running outside there seems to be no problem. The antennas need to be about 3ft or closer to do it. Is this normal due to the antennas being too close?? Very annoying when trying to tune.