Mingo is not a far hike for me. I went today over to South Park to practice at the concert stage. I was getting beeps every so often, but found nothing, so I took out my practice quarter and college class ring--pretty heavy white gold. I was getting beeps all the time on the quarter but almost no recognition of the heavy gold ring. All I got today were heavy arms and frustration. The manual that came with my Famous Trails MD9300 is terrible and the one online actually contradicts the one that came with the detector, and has information apparently not for the 9300--a "hole for adjustment of ground balance" that does not exist on my machine. Frankly, I'm inclined to toss the thing in the closet or sell it at a garage sale. I'm checking Amazon for some kind of generic instruction bible, but so far, it ain't workin'. I'm open to any ideas you might have.