Shakes,

Just set both low and high on the same settings for the elevator. There is really no need for a low rate as once you get it dialed in the planes flies so very well. Like I mentioned before 3/8 inch is a good start but if you really want to find the "sweet spot" on your own start out at no more than 1/2 or 3/4 inch max throw both up and down and work your way back and you'll find that you'll be very close to 3/8 inch