Isnt it possible for the Rx filter at times to just have too much RF to filter out and in turn cause jittering or other output problems ? such as the Rx too close to the servos and maybe the Rx antena too close to the servo leads . and maybe its not acting up till someone comes too close to it with a Say ringing cell phone ! And then the blane gets thrown to the cell phone when the real blame should be at the builder of the aircraft . In my shop I can set a Rx and servos all on my bench conect them up to see if all is working. And if I have the Rx ant laying with the servos they will jitter. And yet if the Tx is too close with its ant colapsed they jitter. Also if I have the Rx ant laying off the end of my bench. This happens to be in parallel to the florecent lights in my shop they seem to again jitter. But move the Rx ant just a little bit then it all works fine . I know it must be Rf thats causing this in my shop because if i just shut off my lights all is well again ! just my 2 cents worth .