Neutralizing push-pull amp In pictures I see about a 2” long rod about 1” from the tube plate. How do you tune it? Keep making the rod longer/shorter? How do you arrive at the initial location? This is for a pair of 4CX1500Bs: 2750V Plate, 225V Screen, -34V bias on the grid, Class AB1, 160M-20M. Brad AB0YD