Arcadia Magnascopic Dial

Ferranti, GB

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  • Année
  • 1936/1937
  • Catégorie
  • Radio - ou tuner d'après la guerre 1939-45
  • Radiomuseum.org ID
  • 78665

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 Spécifications techniques

  • No. de tubes
  • 5
  • Principe général
  • Super hétérodyne (en général); FI/IF 125 kHz
  • Gammes d'ondes
  • PO, GO et OC
  • Tension / type courant
  • Alimentation Courant Alternatif (CA) / 200-250 Volt
  • Haut-parleur
  • HP dynamique à électro-aimant (électrodynamique)
  • Matière
  • Boitier en bois
  • De Radiomuseum.org
  • Modèle: Arcadia [Magnascopic Dial] - Ferranti, GB
  • Forme
  • Modèle de table vertical (pas forme catédrale)
  • Dimensions (LHP)
  • 16 x 18 x 9.25 inch / 406 x 457 x 235 mm
  • Remarques

  • Ferranti “Arcadia” Receiver with Magnascopic Dial

    The Ferranti Arcadia was a high-performance, five-valve superheterodyne receiver representing a significant advancement over the earlier model. It was designed with a focus on refined performance and user-friendly operation, incorporating several features considered advanced for its time.

    Technical Features:

    • Circuit Design: The circuit incorporated a heptode frequency changer and a variable-mu pentode Intermediate Frequency (IF) amplifier operating at a frequency of 125 kc/s. A double-diode triode served as the second detector, AVC rectifier, and first audio amplifier.
    • Variable Selectivity and Tone Control: A unique design allowed for variable selectivity by adjusting the coupling in the IF transformer. This control could reduce interference, particularly on distant stations. The set automatically returned to a high-selectivity setting when the tuning dial was moved.
    • Inter-station Noise Suppression: An integrated noise suppression circuit worked by switching the IF amplifier's AVC supply to the undelayed signal rectifier, effectively quieting the receiver between stations.
    • Magnascopic Dial: For precise tuning, especially on the shortwave band, the receiver featured a "Magnascopic" optical device. This magnified a portion of the 180-degree translucent tuning scale and projected it onto a ground glass screen, providing an effective scale length of over six feet and allowing for accurate, backlash-free tuning.
    • Audio and Loudspeaker: The moving-coil loudspeaker was modified with a free-suspension cone to enhance bass response, resulting in a full and smooth low-end. While the high-note response was adequate, it was intentionally limited to avoid accentuating local interference noises.
    • Aerial Circuit: The aerial tuning circuit was a well-designed band-pass filter that included an image rejector to minimize unwanted signals. It used mixed coupling for medium and long waves and inductive coupling for the shortwave range.

    A similar chassis is fitted into the 1936/7 Arcadia console radio and Arcadiagram radiogram.

  • Prix de mise sur le marché
  • 15.75 GB £

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