I was playing with my 5x10 coiltek on the beach on my nox800 and had something strange happen, or at least strange to me.
I was getting loud and deep hits for screws, nails, coins and melted aluminum. the coins and aluminum were screaming down to a foot or so.
It was set on beach 1, auto ground balance and I was swinging over a small stick and I kicked the stick out of the way. When I kicked it I realized it was a piece of metal but it didnt give a signal. I checked it a few times before putting it in my trash sack. A few minutes later I came across a couple of pins used to secure a trailer hitch and cheap tent stakes and the same thing happened, no signals. I tossed some of my other finds in the sand to test and I did get a signal so the machine was working somewhat...
The screws, nails were small and buried while the no-signal targets were much bigger. Is there a setting that will make the machine or coil not show that stuff?