Amergin, what a great question you've asked and fellow Tneters what great answers you've offered!!
My "Old 6000D" was a good machine that became better after I purchased a set of setup techniques for it. With all the knobs and switches labeled and when following the process of changing the settings in the proper order I knew what was in the ground before I pulled the target from the ground. At least, most of the time. Even then I still dug most signals till I learned to trust the machine. So a machine can get pretty close to 100%. Point here practice a lot, learn your machine as it will pay off in the long run!
I found my first gold ring under a sidewalk tearout but thought it was a bottle cap, dug it anyway. Then I had this iffy signal and not far away was a really good signal, again I dug them both. One (the good signal) was a sterling silver Mickey Mouse ring. The other (iffy signal) was also a ring but aluminum and it says "Sharp Shooter" across the top of it and one side was cracked. Guess which one the collector offered me the most money for? Right the sharp shooter ring. (Note: I still have both of them)
Point here is even a 'iffy' target made of junk metal can be valuable.
My first gold was the ring at the sidewalk tearout. My second gold was a gold tooth crown and I found it back in the day Before people started digging plugs in lawns. I used a brass probe to locate targets (did not have a pin pointer back then) but this yard had a lot of pea gravel making if very hard to locate that tooth but I finally did. Point here is to learn to pinpoint with your coil as it really helps to have the target centered under the coil and to jam a wooden stick into the center point by just slipping your open coil a little to one side.
You will always be thrown off by the brass water faucet, etc. Like has been said already if you are not finding nickels your are missing Gold. With my 6000D I would run it in simplest all metal tone and then step down slowly into the various filter ranges, you should be able to do this with your 800 if you feel like it. Point here is learn at which setting (or combination of settings) your machine just rejects the good stuff.
No matter what, have fun, enjoy yourself out there as even being in your own yard seriously listening to the sounds from the earphones means you are tuned out to the world around you so you are relaxed.............63bkpkr
Then of course, especially with the 6" coil, your 800 should pick up gold in mineralized ground, gold like this:
That's about 1/4 oz of gold flakes (pickers) I found with my GMT, your 800 should pick them out easily, umm after you learn how.
