Thanks everyone, and thanks for the additional cleaning advice, wtfisthat.
Hey, as a future minelab owner, could you enligten me on the ID#, and why you don't normally dig those 12-30's? Is that typically a trashy set of numbers?
I base my decision to dig an id on a number of factors that include, among other things:
-age of site
-amount of time I have
-depth of target
-what else I am finding at the site (is there a common piece of trash that is consistently giving a certain signal? are there a lot of signals to dig or is it relatively clean?)
-how 'solid' (repeatable, from multiple directions, and crispness) is the sound
Coins will come in as, generally (depending on a number of factors including the soil and site):
Nickel=12,13
Indian=34-36 (lower in that range for me)
Zincoln=37,38
Wheat=40-44
Memorial=43,44
Dime=44,45
Through to silver quarter at 47.48.
Anything worn will generally come in lower, and I have dug wheats as low as a 30 id, worn mercs (usually a soild 45 for me) that have sounded like pennies, etc.
Since I am mainly looking for old coins, you can see that I will maximize my efficiency by digging the nickel signals and then 40+ signals if I don't expect to find any indians. If I do, I will expand what I dig.
As for a 12-30 range signal, there is a lot of trash there, but also some good stuff. A men's gold wedding band can id there. There are tokens, badges, old keys, other jewelry, etc. that can id there too. If you are in an old site, and you get a relatively deep and solid 12-30, it's a no-brainer to dig it. Since I was expecting indians, I dug it. I might have anyway, just to get a feel for what was in the ground and it was only my second dig, and as it turned out there was not a lot of modern (ie, high tone) trash in the area, which would also lead to me expanding my range for digging.
Enjoy your new Minelab when you get it...happy hunting!