Look at our illustration of a mechanical TV set. You see the works of the mechanical part. Mechanical sets are actually electromechanical. They require electronic parts: An antenna, a shortwave or VHF radio receiver, and a resistance-coupled television amplifier.

The antenna is a standard, horizontally polarized radio aerial. The receiver detects wideband AM radio signals that represent TV pictures. Together, the two mechanical TV sidebands measure between 10 and 100 kHz across. The detector produces a variable voltage output. The amplifier converts this output to a variable current that drives a neon glow tube. Mouse over the illustration and read about the components...