Goldbear,
Gold is tough to find, even in the best of times, but you have a good detector to work with.
Sandman is correct. Gold is found over a very broad range, so anyplace you set your discrimination over "iron" or "foil" runs the risk of discriminating out gold as well.
The downside of that is the amount of trash you are going to dig increases also.
Kinda goes with the territory.
Good luck to you!