Futaba PA 1 assistance
I had virtually the exact same setup, but a 7UAP radio - and I experienced the same problem...unfortunately, I can't remember what I did to remedy it, but will give you the steps I would take to help.
1). you say you've had it both X and + mode...did you leave the settings on the PA the same when you changed to direction the PA pointed? Or did you change the settings? If I remember, it's easy to mistake the X for the + on the PA, so if you inadvertently had the settings to X when you had it physically in +, then if youchanged both settings and direction, you would have had + while pointing in X...I would put it how I thought was right, then try it, if it was squirrely, I would just change the physical pointing of the PA, and leave the settings alone...that would eliminate that.
2) Check and make sure your servos are not reversed, on the PA - you said the control surfaces move, but be VERY sure that they move in the right direction - that is, with the PA turned on, when you lift the nose, the elevator should go down, and when you tip the plane to a left turn, the right aileron should go up. Check, double check, then check once more...if possible, have a buddy check, as well...
3) on the 8UA, I would put the PA on channel 6, so that the PA is off at the farthest left of the knob, and full on when you turn the know all the way to the right. That way, you can fly "hands off", then s-l-o-w-l-y add channel 6, so that the PA comes to life very little at a time, and try to figure out just exactly what is happenning...is it climbing? dropping? right turn? left turn? This can make it easier to determine exactly what is happening, in less than "real time", so instead of just "being squirrely", you can be a little more specific as to what exact inputs the PA is giving to the control surfaces, making it easier to determine what is going on. When you do that, set your PA at the highest sensitivity - the variable input from channel 6, serves as a sensitivity adjustment in and of itself.
4) the PA Sensor HAS to be exactly on the same level plane as the planes centerline...if not, it won't work as it's supposed to. In other words, exactly parallel with the wing saddle. there is no way to compensate for it if it's pointed up or down, the plane will try to make the PA sensor exactly level, not the plane!
5) Are you using a 5-cell, 6V pack? The PA-1's do NOT like 6 volts!! I found out the hard way, and when I went to a 4-cell pack, all the jitters, and subsequent "squirrely" flying went away on one of the trainers....
I hope this helps - I have 3 planes currently with the PA-1, and one with the PA-2....I think they are great, and lot's of fun, and an aid to flying - lot's of people disagree...I think they are fine, as long as you don't become "dependent" on them, and ww it as a solution to poor piloting skills...I have mine set up, so that when my plane goes to "fail-safe" for any reason, the throttle drops to idle, the rudder goes to a crisp left, not enough to snap, but enough to give it a nice, easy left turn, and the PA kicks in, so in effect, the plane goes into a nice, slow left turn, flat and level, because of the PA, and slowly settles to the ground. At least that's the theory...I have shut the transmitter off, and it does exactly that - nice, slow circling of the field, but I don't have the guts, to let it land itself...probably because I know that's not the safest thing to do, but I am confident, that if I ever DID lose radio for any reason, it would be the safest solution.
If you can be a little more specific on the "squirrely" definition, I will try to be of more help - can try to duplicate it with one of mine...
Hey, when you get it working, put the switch on channel 5, get real high, go into a "death spiral", about half way down, flip the switch...amazing what these things can do!!
Keep us posted on your results, and if you need any more info or input, please feel free to email me....