New Method Pertaining to the Reduction of Interference in the Reception of Wireless Telegraphy and Telephony

The usefulness of directional reception and of resonant circuit selectivity in reducing the effect of atmospheric disturbances of reception is first considered. Assuming that sinusoidal forces coexist in a system with much larger impulses, it is shown that the sinusoidal forces will not pass through systems having internal frictional losses under certain definite conditions. The analogy between mechanical frictional systems and magnetic hysteretic systems is utilized in devising differential circuit arrangements whereby strong impulses, passing through two opposing circuits of controllable hysteric damping, are ultimately balanced out, whereas smaller sinusoidal currents are delivered at the output of the system. The application to radio reception is described in detail.