KC36330

yes one is + one is -, if not then you'd be adding the same tail input and in one of the two cases you would worsen the problem. the only way to set the down portion and have it set correctly is to climb to about 50' with power on and then smoothly bring the stick back down to less then 1/4 stick, adjust the revo then to counteract any yawing.

kc

EDIT: just to add, revo mixing only counteracts normal torque, it will not prevent yawing when you 'punch' the stick in either direction, only for smooth transitions.