dailing out foil or pull tabs loses gold --dailing out iron will lose iron relics (possible guns ,swords and such)--it simple--to get to gold you will have to dig pull tabs and screw caps--theres no way around it---there is not silver/gold only finding machine if so everyone and their brother would buy one ---it really very simple the machine puts an electric feild in the ground (the size and depth of the feild differ from machine to machine and the types of heads you use on the machines----metals that conduct electric current like the following copper,brass,silver,gold,iron and aluminum causes the feild to act up the machine notices that the feild signel is acting up and causes the machine to beep or tell you somehow that it is hitting a conductive metal --the higher dollar machines (like the time ranger) can sort out the types of metals somewhat and tell you the depth at which it is reading it at---however sadly some metals are very close to each other on the conductivity scale like gold and aluminum so "notching" out the aluminum range knocks out some or all of the gold range signels---there is a bit of a learning curve and it takes a bit of time to learn your machine--a steady all the time beep often means you just have the sensitvity too high --stray power line "bleed off" can affect your detector as can other electrical items also some minerals in the ground and in saltwater areas can like wise affect your machine-- because their conductive--remember the "electric feild" reading is how your detector works in very basic terms --things that mess with its "electric feild" can cause false readings or steady beeping turning down the sensitivity and turning up the discrimation might help settle down a "unstable" machine this is why having the manual dails is important ---most of the time (80-90%) using the preset ground balance is just fine **however there are places that a preset balance simply will not work right --then you have to "tune" your machine to the area using the manual mode--its a bit of a bear tuning them (it the main reason lots of detectors now have some form of "preset" balance--because lots of folks were turned off to metal detecting simply because they could not get the hang of "tuning" a metal detector to the area)--now know this you will not walk out on the beach and find 5 million dollars in gold bars in 10 min --sorry it doesn't work like that ---however you can greatly improve your odds of finding high dollar good items by knowing your local history and doing good research (but to lots of people research is boring and frankly can be rather time consuming--I like history so to me research is fun)-- hunting tips ***well any places lots of folks gather today or in the past are likely to be good--- some of course better than others depending on what your looking for--- relics? look for old battle feilds or homesites--spanish silver and gold ?--look for ship wreck info --the longer in the past the older and often better the items ----silver coins pre 1968 40% silver --pre 1964 90 % silver --old gold pre 1932---local beachs and bathing areas , fair grounds and parks (if legal in your area) are great places to find coins and jewelry---I hope this helps ---Ivan