Technology History | Alexandra Palace — A Coin Toss Decided Which System Went First

The mast in the photograph is bolted to the east wing of a Victorian pleasure palace, and on 2 November 1936 it carried the world's first regular high-definition television service, where high definition meant more than two hundred lines. The BBC had leased this wing the year before and fitted out two studios, because a government committee under Lord Selsdon had declined to choose between two rival systems and ordered a competition instead. Studio B held John Logie Baird's 240-line system. Studio A held Marconi-EMI's 405-line all-electronic one, built around the Emitron camera under Isaac Shoenberg, who had gambled on a line count nobody had asked for. A coin toss decided who opened. Baird's company won it, so the opening programme went out on the mechanical system at three in the afternoon, and Marconi-EMI repeated the same programme later that day. The two systems then alternated week about, and receivers were sold with switches to handle both. Estimates of how many sets were watching run from a few hundred to a few thousand, which tells you how much of this was aimed at posterity rather than an audience. There is a detail in Baird's studio that undoes the usual framing of a mechanical-versus-electronic fight. Baird's company was licensing Philo Farnsworth's image dissector, so an American electronic tube was already inside the British mechanical entrant. One of those tubes survives as a melted lump in the Science Museum's collection, pulled from the ruins of the Crystal Palace after the fire of 30 November 1936 destroyed Baird's own studios and his spare equipment four weeks into the trial. By February 1937 the BBC had declared for Marconi-EMI and dropped the Baird system. The 405-line standard it chose stayed on air in Britain until 1985. The service closed on the eve of war in 1939 and came back in 1946. The BBC left the building for good in 1981, and the mast still stands over a hall used for concerts, ice skating and a preserved 1930s studio open on guided tours. Photo: Keith Page, CC BY-SA 4.0, via Wikimedia Commons