Some metal detectors, when using discrimination, take the U.S. Gold Dollar, as trash item, and filter it out. I do not like to use discrimination myself, search for only faint signals anymore, and they are small and deep in the ground. Either are good targets, or Relic (or old trash items), so the thrill is there, and not gone with the wind.
I enhances my finding and saving things and not throwing them into the trash barrel. What I am doing basically is searching below the trash layers...Now there are people who will not agree with me on what I just said... I used to get a target, and other detector users noticed me digging and pocketing the find, came over to see what I found, so I said swing over this target... They did, replied, "Nothing there"! So down I went, and dug it up, showed them, They were blown away. They kept asking me what I did to my detector... All I did was amplify the faint sound, with a swith on the circuit, into bypass mode, so I could hear it full blast, and then switch back into faint mode. It is not discrimination, but is sound comparison. That is why they could not hear the target. For an example, the photo below, was one day's time I took a photo of the old clumps of cigarette foil, that used to be inside the old cigarette packages, before WWII era. I find a lot of them with my amplified sound methods. I also find old coins and older jewelry down there. I search slow, and deep, and move the coil incremently to hear the faint sounds...
Melbeta