What is ground canceling, and how can I adjust my detector to the right point?
Think of ground canceling as being exactly the same thing as discrimination. If your ground control is set too low (counter-clockwise) the detector will ‘reject’ the ground. If your ground control is set too high (clockwise) the detector will ‘find’ the ground by beeping as the coil approaches the ground. Your aim is to set the ground control so that the detector remains neutral to the ground, or doesn’t see the ground at all. It will then detect as deep in the ground as it does in the air. To accomplish this, first tune the detector to a threshold tone while holding the coil in the air. Then lower the coil to the ground and listen. If the threshold dies away, turn the ground control in a clockwise direction. If the threshold tone gets very loud, turn the ground control counter-clockwise. Next, raise the coil, retune to a threshold tone and repeat the above operations. When you get it right, the sound will change very little as you lower the coil.
Think of ground canceling as being exactly the same thing as discrimination. If your ground control is set too low (counter-clockwise) the detector will ‘reject’ the ground. If your ground control is set too high (clockwise) the detector will ‘find’ the ground by beeping as the coil approaches the ground. Your aim is to set the ground control so that the detector remains neutral to the ground, or doesn’t see the ground at all. It will then detect as deep in the ground as it does in the air. To accomplish this, first tune the detector to a threshold tone while holding the coil in the air. Then lower the coil to the ground and listen. If the threshold dies away, turn the ground control in a clockwise direction. If the threshold tone gets very loud, turn the ground control counter-clockwise. Next, raise the coil, retune to a threshold tone and repeat the above operations. When you get it right, the sound will change very little as you lower the coil.
