Open Source Metal Detector Conceptual Design

From [1] - 'This is a VLF (very low frequency) detector tecnology and contains two idenmtical coils : transmiter and receiver coil. In this case each coil contain 55 windings of isolated copper wire with a diameter of approximately 0.5 mm2 . We bend the coils into a shape called a "double D" according to the template you can download at the link below , where you can also download the complete scheme.'