Antique Tube Radios

All radios produced during the first half of the 20th century were tube radios, since transistors were not invented until 1947 and did not start to replace tubes in radios until 1954. Which means that whether your antique radio is a cathedral or a console, an Art Deco beauty made of wood or Bakelite, its guts are filled with tubes. The originals of the vacuum tube, or valve as it’s called in the United Kingdom, dates to 1883, when Thomas Edison discovered that an electrical current could flow through a vacuum. This “Edison effect,” as it was called, was patented as the Edison Indicator. Then, in 1905, a former Edison employee named John Ambrose Fleming, who was working for Marconi Wireless in London, gave the invention a practical purpose when he patented an oscillation valve to visually detect radio signals. But weak radio signals required amplification, and they were better heard than seen, which is why Fleming’s breakthrough was eclipsed by Lee de Forest’s 1906 Audion, which not only boosted the signals, but eventually made them audible. The first use for de Forest’s Audion was to boost signals in the nascent telecommunications industry. In 1913, AT&T was using Audions to help signals move along its growing network, and by 1914 the technology was mature enough that AT&T had bought the rights to have its Western Electric division manufacture vacuum tubes for everything from telephones to equipment for the U.S. Signal Corps. But the dominance of radio tubes took hold in 1919, when RCA began putting General Electric tubes in its receivers. In the decades that followed, companies like Philco, Sylvania, and Westinghouse also made tubes, which were used in their radios, as well as ones made by Atwater Kent, Crosley, Emerson, Stromberg, and Zenith.