Frenophone amplifying speaker

Brown S. G. Ltd.; London

  • Année
  • 1923
  • Catégorie
  • Haut-parleur, casque ou écouteur
  • Radiomuseum.org ID
  • 104229

 Spécifications techniques

  • Gammes d'ondes
  • - sans
  • Tension / type courant
  • Pas d'alimentation nécessaire
  • Haut-parleur
  • Cornet ou pavillon
  • Matière
  • Matériaux divers
  • De Radiomuseum.org
  • Modèle: Frenophone amplifying speaker - Brown S. G. Ltd.; London
  • Forme
  • Formes diverses décrites en notes
  • Dimensions (LHP)
  • 25 x 13.25 x 10.25 inch / 635 x 337 x 260 mm
  • Remarques
  • 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)

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