Kurt, the recipe of turning down the disc, and digging pulltabs till your arms fall off, is not the answer to finding a gold coin. The much bigger part of the formula, is where you're hunting. You simply have to be at a location where coins from 1900 or earlier, or prolific. You know, like sidewalk tearouts, relicky sites like old stage stops, old-town urban demolition sites, etc...... And yes, once there, of course dig all conductors. But to simply say "lower your disc." and waltz out to blighted inner city turfed parks, will net you only pulltabs, at the ratios of millions to one.
Also, be aware that it's only $2.50 and $1.00's that you'd miss if you truly tuned out pulltabs. You can still get $5.00s, $10.00s and $20.00s when knocking out pulltabs. I got one of my $5.00's while having tabs nixed out, when hunting under a stadium bleacher demolition project (where an ocean of pulltabs kept me from "being a hero" and so I only was after silver, in the short-span-of time that the earth was exposed). In fact, in that particular case, I was using a Whites eagle, and had chosen 45 as my cutoff point in disc, because about 45 was where the beefier square tabs start to cut out at. Imagine my surprise when a $5 gold piece turned up amidst the silver and wheaties I was finding! At first I thought "wait a second, I thought I had gold nixed out?". So I air-tested it, and it came in about 47-ish. PHEEEWW!! If I'd had my disc. a hair higher, it too would have been nixed

Point is though, that's still well above round tab.