old gas station

[icegator]

detected an old gas station that burned down. well around the gas station the parking lot is gravels and i had plenty of hits on the detector and dug up about 20 pulltabs in 30 min. i found 3 clad pennies. how should i go about detecting this it is hard digging. do you think i should just dig all the pulltabs. i turned up the discrimination on my detector but it will miss most coins that high. any help is appreciated.

[herb pi]

YOU SHOULD NOT BE LOSING MOST COINS AS YOU STATED JUST BECAUSE YOU ELIMANATED PULLTABS.YOU DIDN'T STATE WHAT TYPE OF DETECTOR YOU OWN BUT IT MIGHT NOT BE OPERATING AS IT SHOULD.

[herb pi]

OOPS I JUST NOTICED YOU HAVE A FISHER DETECTOR. YOU MIGHT WANT TO CHECK THE FISHER MANUAL NORMALLY AN INCREASE IN DISCRIMANATION EFFECTS DEPTH AND LOSS OF SOME METALS LIKE GOLD FOE EXAMPLE BUT YOU SHOULD NOT BE LOSING A LOT OF COINS AS A SHELL PARKING LOT KEEPS THE COINS FROM SLIPPING DOWN REAL DEEP.

[Charlie P. (NY)]

You'll lose nickels but you'd be way over pulltabs before you eliminated copper and silver. My Minelab Musketeer likes aluminum twist caps about as much as clad quarters, but I can tweek out pultabs and steel bottle caps pretty well - at the loss of nickels.

[Shortstack]

Here's the technique I use with both my Bandido II and DeLeon. I set the disc. at middle or high " foil " then, when I get a target hit, I will slowly increase the disc level until the target just " pops " or cancells out. If the target cancels BEFORE the tab mark, the possiblity that it's a nickel jumps higher. If the target cancels AFTER the tab mark then it's more probable that it's a tab. Gold is the last thing that will cancel ( if at all ). Silver is a close second with copper coming in third at the very top end of the disc dial. ( at least on Tesoros ) You need to use fresh batteries in you detector and check where your particular machine cancels out each item and make a note ( or mark the disc dial ).
I place my test pieces on the ground when I do this check so that the ground mineralization is taken into account as part of the discrimation matrix.