Abstract: An improved coin acceptor mechanism employing an oscillator and a resonant circuit for detecting the electromagnetic effect of valid and invalid coins passing through a coil of the tuned circuit. A particular linear coil configuration provides a unique signature for each coin including at least one maximum and one minimum amplitude level of resonant circuit current. A comparator establishes at least two electrical signal amplitude windows representative of each valid coin signature. A logic circuit responds only to the coin falling within the two electrical signal amplitude windows for actuation. A novel coil design and assembly are enclosed.