Dynamic Reproducer 8K With F57 cone

Rola Company (AUS) Pty. Ltd.; Melbourne

  • Year
  • 1948–1952
  • Category
  • Loudspeaker, headphone or earphone
  • Radiomuseum.org ID
  • 316153

 Technical Specifications

  • Wave bands
  • - without
  • Loudspeaker
  • Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) / Ø 8 inch = 20.3 cm
  • Material
  • Various materials
  • from Radiomuseum.org
  • Model: Dynamic Reproducer 8K [With F57 cone] - Rola Company AUS Pty. Ltd.;
  • Notes
  • The Model 8K permanent magnet type was designed for use in AC operated table and console model receivers and to replace 8-inch electro-dynamic type loudspeakers. In addition it finds a wide application in public address systems for factories, schools and similar establishments. Model 8K has excellent frequency response and, used in conjunction with a correctly designed radio receiver or amplifier, gives balanced reproduction of both speech and music. Its compct design, inherent in all Rola Anistropic Alnico permanent magnet type loudspeakers, makes Model 8K specially valuable to designers of table model radio receivers and is responsible for its adoption by many set manufacturers who previously were using smaller loudspeakers.

    Power Handling Capacity 5½ watts
    Fundamental Diaphragm Resonance 85-95 c.p.s. (Hz) (F57 Cone).
    Voice Coil Impedance 2 ohms at 400 c.p.s. (Hz)
    Transformer C. type Isocore transformer, attatched or detatched for chassis mounting.
    Principal Dimensions Overall diameter of diaphragm housing .. .. .. .. .. ..  8 1/16"
    Diameter of baffle opening .. .. .. .. .. .. .. .. .. .. .. ..  7"
    Diameter of voice coil .. .. .. .. .. .. .. .. .. .. .. .. .. ..  1"
    Depth from pad-ring to rear, including transformer .. 4"
    Mounting Four slots spaced 90º apart on a 7 19/32" pitch circle diameter. Dimensions of the slots 5/16" x 7/32"
    Finish Diaphragm housing bright cadmium plated; magnet black and lacquered, transformer can silver lacquered.
    Weight 2 lb. 11 ozs. (including transformer).

    REPLACEMENT INFORMATION

    This model can be used to replace the Model F6 and Model K8 electro-dynamic type loudspeakers, or the Model FR6 PM, Model 8/8 and Model 8/14 PM types. When using Model 8K as a replacement for Models F6 and K8 replace the field winding with a Type 14/60 choke and a series resistance. The latter should be of the wire-wound type and have a resistance which, combined with that of the choke, is equivalent the field resistance of the loudspeaker being replaced.

  • Literature/Schematics (1)
  • - - Manufacturers Literature (Rola Loudspeaker Catalogue, August 1948.)
  • Author
  • Model page created by Martin Kent. See "Data change" for further contributors.

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