I have a GTI 2500 and after 5 months feel pretty comfortable I have mastered the learning curve. However, I often get a reading of a huge target at 12 inches. It blacks out the entire bottom of my screen. Then if I move the coil around a bit I find a coin or other target showing up at 4" or less. I seldom get the halo signal but if I do it is usually in conjunctin with the 12" black out target. Does anyone know if the blackout at 12" is a default setting or what? I tried to explain this to a Garrett tech but couldn't get them to understand what I was talking about. Is it just me or my machine or does it happen to all the 2500s? JIM