It is already well known that the second harmonic magnetic transductor has instability regions. It has been found experimentally that in each region two modes of output current exist, differing only by the phase, which these currents have with respect to the exciting voltage. Under suitable parameters and excitation conditions, the transductor will jump from one mode of operation to the other, whenever the exciting current is modulated with a negative pulse. It therefore operates like a bistable element.