Most of the time, a bigger coil can sense objects at bigger depths than a scaled-down one, and so it proved in our testing: The Simplex BT very easily picked up a gold ring, a steel bolt, and a small piece of copper buried less than eight inches of dirt. https://marionwfpx.digiblogbox.com/55642728/the-single-best-strategy-to-use-for-metal-detector-banconote