The Wave Trap

Radio Record, Volume II, Issue 34, 8 March 1929, Page 30

The Wave Trap

"THE theory of a wave-trap is as fol-lows:-A broadcasting station sends out two waves, ie, an ether wave and a ground wave, in the same mauner that an electric cable carries negative and positive current. The wave-trap resembles the first part of an ordinary receiver. The aerial carries the movements of current down through the primary coil, and, instead of being picked up by induction in the secondary coil, these movements in current (termed radio-frequency ascillations), are earthed. As the other wave from the station is also a ground wave, we might roughly say that the undesired station has been "shorted," thus allowing us to tune in another station without interference,