Abstract: An apparatus and method for use with a railroad dragging equipment detecting (DED) system that detects objects hanging from and dragged beneath a train as the train travels along rails of a railroad track. A generator supplies a first signal and is coupled to a magnetic amplifier coil to form a magnetically variable impedance circuit. The magnetic amplifier coil is responsive to the first signal to create a circuit impedance in series with a detection circuit. A magnet is mechanically connected to the cam/follower system and is positioned near the magnetic amplifier core for varying a circuit impedance of the detection circuit. A detection circuit generates a second signal as a function of variations in circuit impedance. A controller is responsive to the second signal for activating an alarm when the magnet moves relative to the magnetic amplifier coil.