How metal detectors work (400–600 words)
The weak signal from the oscillator must be boosted to create a magnetic field strong enough to penetrate the ground. Power transistors or operational amplifiers (op-amps) are used to push high current into the TX coil. The Receiver Pre-Amplifier inside the metal detector pdf
Directly addresses common detectorist myths: How metal detectors work (400–600 words) The weak
In Concentric and DD configurations, the TX and RX coils must be physically arranged so that they perfectly cancel each other out when no metal is present. This state is called "zero balance." The interior of the coil housing is coated with a conductive carbon or silver spray (Faraday shield) to eliminate static interference from wet grass and soil. inside the metal detector pdf