I have been MD for a short time now (probably less than 20 hours) and I'm wondering if someone can define how I can know if I am on gold with an ACE 250. I dig almost everything, but I end up with lots of iron and junk metal. Will gold ring repeatedly like coins or just sound a dull beep like iron? I'm a bit frustrated. I read the forums and have gotten some good info on MD in general, but was hoping another ACE 250 user could provide some advice on this machine. Thanks in advance!