Magnetic detector

Marconi's wireless magnetic detector (London)

The magnetic detector or Marconi magnetic detector, sometimes called the "Maggie", was an early radio wave detector used in some of the first radio receivers to receive Morse code messages during the wireless telegraphy era around the turn of the 20th century.[1][2] Developed in 1902 by radio pioneer Guglielmo Marconi[1][2][3] from a method invented in 1895 by New Zealand physicist Ernest Rutherford[4] it was used in Marconi wireless stations until around 1912, when it was superseded by vacuum tubes.[5] It was widely used on ships because of its reliability and insensitivity to vibration. A magnetic detector was part of the wireless apparatus in the radio room of the RMS Titanic which was used to summon help during its famous 15 April 1912 sinking.[6]

  1. ^ a b Fleming, John Ambrose (1911). "Telegraph" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 26 (11th ed.). Cambridge University Press. pp. 510–541, see page 536, second para, lines 8 & 9 and figure 45. In 1902 Marconi invented two forms of magnetic detector, one of which he developed into an electric wave detector of extraordinary delicacy and utility
  2. ^ a b Fleming, John Ambrose (1908). The Principles of Electric Wave Telegraphy. UK: Longmans, Green and Co. pp. 380–382.
  3. ^ Marconi, Guglielmo (1902). "Note on a magnetic detector of electric waves which can be employed as a receiver in space telegraphy". Proceedings of the Royal Society. 70 (459–466). London: 341–344. Bibcode:1902RSPS...70..341M. doi:10.1098/rspl.1902.0034.
  4. ^ Rutherford, Ernest (1 January 1897). "A magnetic detector of electrical waves and some of its applications". Philosophical Transactions of the Royal Society of London. 189. Royal Society: 1–24. Bibcode:1897RSPTA.189....1R. doi:10.1098/rsta.1897.0001.
  5. ^ Wenaas, Eric P. (2007). Radiola: The Golden Age of RCA, 1919-1929. Sonoran Publishing. p. 2. ISBN 978-1886606210.
  6. ^ Stephenson, Parks (November 2001). "The Marconi Wireless Installation in R.M.S. Titanic". Old Timer's Bulletin. 42 (4). The Antique Wireless Association. Retrieved May 22, 2016. copied on Stephenson's marconigraph.com personal website