I have many hours on my Eq 800 with a lot of success in the last couple of years. One thing that continues to stump me sometimes when land hunting is this: I will get a solid repeatable signal in the 20s to 30s. The signal pinpoints as a tight, smallish target. I dig down very deep (15+ inches) and never able to find anything with my pinpointer. The signal remains the same when I swing over it though. Maybe a piece of big, deep iron? Anyone else have this experience?