I am getting High and medium signals at the ends of my swings that are not targets with the large stock AT pro coil. I am also not lifting the coil at the ends of my swings.Am I doing something wrong? Also should I pinpoint shallow targets with the center of my coil or the tip of the front of my coil? I also seem to be having nickles pinpoint several inches off center.Is this normal? any help would be greatly appreciated.