I HAVE A 9CAP WITH PCM RECEIVER IN A GOLDBERG EXTRA 300. HAD NOT FLOWN THIS MODEL IN 6 MONTHS AND THE OTHER DAY WHEN I WENT TO FLY, I TURNED ON THE RADIO, THEN THE RECEIVER AND DOING A CHECK, FOUND THAT WHEN I PULLED UP ELEVATOR,LEFT HALF GOES UP, RIGHT HALF GOES DOWN. I CANNOT FIGURE OUT WHAT I MAY HAVE DONE TO CAUSE THIS. OBVIOUSLY, THE ELEVATOR HALVES ARE CONTROLLED BY SEPERATE SERVOS ON A Y- WIRE. I HAVE CHECKED ALL THE MIXING SWITCHES WITH NO LUCK. tHANKS FOR THE HELP.