Frenophone amplifying speaker

Brown S. G. Ltd.; London

  • Year
  • 1923
  • Category
  • Loudspeaker, headphone or earphone
  • ID
  • 104229

 Technical Specifications

  • Wave bands
  • - without
  • Power type and voltage
  • No Power needed
  • Loudspeaker
  • Horn
  • Material
  • Various materials
  • from
  • Model: Frenophone amplifying speaker - Brown S. G. Ltd.; London
  • Shape
  • Miscellaneous shapes - described under notes.
  • Dimensions (WHD)
  • 25 x 13.25 x 10.25 inch / 635 x 337 x 260 mm
  • Notes
  • Nickel-plated fittings, black enamelled metal horn, mahagony cabinet. A mechanical loud-speaker/amplifier primarily designed for use with crystal sets. The amplifying action depended on the friction between a revolving glass disc (driven by a 70 rpm clockwork gramophone motor) and a thin pad of cork: the pressure of the pad varied through a reed connected to the armature of a S.G. Brown Type 'A' headphone earpièce. The vibrations of the armature were magnified by the power in the friction drive and were applied to a horn-loaded diaphragm connected to the cork pad. (Radio!Radio Jonathan-Hill)
  • Author
  • Model page created by Jean-Luc Comblin. See "Data change" for further contributors.

 Collections | Museums | Literature