hi all havnt been on in a while but got my new machine and found some coins with it plus a gold ring but does anyone have any tips i get some strange readings sometimes with the imaging like it will show a large can size object at 12 inches deep but this isnt always the case i did hear somewhere that if you get an iffy signal if u stamp the ground and then go over it again if its trash it will show as trash (something to do with dislodging the corrosion) also i pinpoint dead centre dig a small hole and sometimes when i try to locate the item its in a diff place by as much as 6 inches any ideas?