Hertz Resonator is a dumbbell-shaped transmitting antenna connected to a spark generator. At the center of the dumbbell is a small spark gap across which the spark generated by the high voltage circuitry jumps. The oscillator sends out a polarized electromagnetic wave in the radio spectrum. A simple dipole antenna made of an aluminum rod is attached to a piece of structural plastic. The four-foot-long receiving antenna has a neon lamp at its center which picks up the radio waves emitted by the oscillator. The neon lamp lights, but only when the antenna is held horizontally in line with the transmitted signal. When the receiving antenna is held vertically, the lamp remains dark. This exhibit clearly shows that a radio frequency signal can be transmitted and received.
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