ElectronicsFact 3 of 8
Since their invention early in this century, electron tubes have depended on copper and copper alloys for their internal components. In spite of the dominance of semiconductors, some $2 billion worth of vacuum tubes are manufactured annually. They include the cathode ray tubes used in TVs and computer monitors, voltage rectifiers, audio and video amplification and broadcast applications, and the magnetrons in microwave ovens.
