ok iam frustrated with this problem. i have a da-50 on the plane. during a range check with motor running and 1 section of the antenna up, 1 elevator half is slower than the other. it is set up on channel 2&8. if you switch the halves to 8&2 the lazy half also changes. (i think channel 8 is working properly). this is a new pcm receiver. and a 8u transmitter. i am testing at about 100 feet. if i pull up the antenna it seems to work fine, if i cut off the engine it works fine. it actually works at low throttle setting. it gets worst above 1/2 throttle. it had the same problem with a different radio/ receiver. there are also some other glitches (rudder and ailerons seem to stick) i flew the plane 5 times when i first installed the receiver with no problems. i have moved all ignition parts. receiver has been moved all over. antenna away from everything.