Ive been doing the same at my fairgrounds, using the Golden - THE unsung hero of the Tesoro line-up.
I stake out my grid square and then, contrary to my usual advice, I crank
UP the DISC to pulltab. Digging all the tones above that mark I load up on Zincers, all the Cu's, Dimes and Quarters. And occasionally I find a neat high range doo-dad. The other day it was a little shield-shaped medallion, singin' in that high pitched voice that catches your ear oh, so, sweetly!.
Then I go back to "Nickel Notch" DISC and go the other way, at right angles to my previous pattern. Normally, I turn up one or two coins that I missed the first time due to trash masking and higher DISC settings.
Doing this I clean up the coins, 'natch, and of course all the trash, foil bits, lightbulb bases and the other untold treasures!
At this point I might crank the SENS to max and start overlapping sweeps
diagonally to the others. I say, "might," because I have some idea of this spots background and there is little reason to suspect that greater things lie in wait deep below. I try it from time to time - about every third grid - and my theory is so far correct. Nuttin' old!
BONUS:
I could just cherrypick and be happy, but I continue to torture myself with this exhausting method for one reason. GO HERE here to find out what that reason is:
http://www.findmall.com/read.php?32,442236,442236#msg-442236
SO far the only jewelry that has come up is a coupla Cheapo ID bracelets and a small gold locket. And I did find one old Wheatie on the far side. But, hey it gets me out of the house!