Small gold chains and tiny earrings fall in the foil range and you can kiss those good bye if you discriminate out foil. Sometimes you can tell the difference in the audio tone on small pieces of can slaw, but tiny pieces of foil is a different story. They all sound good to me.
Some swear that they can thumb the discrimination dial and can determine if it's a good target or not by how cleanly the target's audio discriminates in or out. That technique does work to some extent for me on can slaw, but I've never had much success using that technique on foil. I mainly go by ear, but I mainly dig everything anyway to see for sure what it is.
The best thing to do is to dig all targets above iron if you don't want to miss anything. In my opinion the second best thing to do is to set the discrimination just high enough to get rid of the small foil and then dig all clear audio signals. I have a super tiny .97g 14k gold ring (I use for testing) that will still sound off even if I set the discrimination just barely high enough to discriminate out a Gatorade sports drink foil cap.
No other detector that I've used finds more gold jewelry than a Tesoro.
tabman
