White's Surfmaster PI is a good quality, fully waterproof, lightweight metal detector with an exceptional depth in saltwater or mineralized ground. It's ideal for those wishing to search beaches, in the surf or shallow diving. It works inland too, but such use is not advised as -- like all PI (Pulse Induction) designs -- there is no effective discrimination of ferrous objects. Runs on eight AA size batteries.
Note: It's best to use the original Surfmaster coil for optimal performance, but you can experiment with different turns, wire gauge and coil diameters, shielding...
A reasonable depth and sensitivity can be obtained with a 23cm diameter coil, 20 turns made with 0.5mm (24 gauge) standard copper enamel coated wire.
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