OK I took the MD out in the yard for awhile today. I kept getting signals indicating silver and a very high pitch. I found nothing. My yard is 4 acres, nearest power-lines are about five hundred yards away to the north. The yard was a pasture until about 1985. Low pitches and iron indications produced nails and screws, mostly shallow from different projects around the place. Signals indicating aluminum produced either nothing or an occasional hunk of flashing material maybe the size on a quarter. I did not make any adjustments to anything like the ground balance or disc setting. Just to make sure everything was at the defaults, I turned it on holding the mode button like the manual said. How long did it take you folks to master your equipment. I feel like I don't have a clue what I am doing.