Ready-made board of the metal detector Pirate. The size of the board 3/7cm. Speaker included. Working, tested boards. The Pirat metal detector is one of the most famous because of its simplicity and quite good characteristics.  This device is able to pick up coins under the ground at a distance of 15-20 cm, large metal objects - up to 120 cm. Tuning of the Pirate metal detector A properly assembled metal detector does not need fine tuning, but for fine tuning there are two variable resistors R12 and R13 in the circuit. To tune it, turn R12 and R13 until you get rare clicks in the speaker. Before tuning, turn on the metal detector and wait 10-20 seconds. Move all metal objects away from the search coil. Specifications Coin detection depth, to 20 - 22 cm Depth of detection of large objects, 100 - 120 cm Supply voltage, 9 - 14 V Current consumption, 60 - 70 mA Impulse current consumption, 1 - 2 A Board dimensions, 45 X 52 mm