• Year
  • 1928/1929
  • Category
  • Loudspeaker, headphone or earphone
  • Radiomuseum.org ID
  • 300432

 Technical Specifications

  • Wave bands
  • - without
  • Power type and voltage
  • No Power needed
  • Loudspeaker
  • Magnetic loudspeaker (reed) generic.
  • Material
  • Wooden case
  • from Radiomuseum.org
  • Model: 7-A Peerless Magnetic Reproducer - United Reproducers Corp.
  • Shape
  • Table-Cathedral-Type (upright, round top or gothic arch, not rounded edges only).
  • Dimensions (WHD)
  • 292 x 328 x 182 mm / 11.5 x 12.9 x 7.2 inch
  • Notes
  • The logo says: "Peerless Reproducer - Manufactured by United Reproducers Corp., Rochester, NY, USA". Peerless used parchment cones.  This speaker is essentially identical to the 7-A Peerless Magnetic Reproducer that was manufactured by the predesessor company United Radio Corp.    

    There are two key patents for the Reproducer. Number 1,726,524, filed in July 1927, covers the design of an annular of freely flexible inelastic material. Igor Bobrovsky, the inventor, claimed that the ring improved sound quality of the cone. The ring is clearly visible between the beige paper cone and black steel frame. The second patent, filed in June 1927, is for a speaker with a U-shaped permanent magnet that surrounds an actuating winding. The winding drives a piston that connects to the speaker cone, producing sound. Bobrovsky filed the patent application and claimed that the actuating winding vibrates an “armature” connected to a “driving rod” connected to the cone. A lever provides a 3:2 ratio of driving rod movement compared to the armature movement.

    Isaac Harris of Buffalo NY designed the box and filed a patent application in March 1928.

    Note that the model picture of the cone show a "D".  This is believed to denote a Series D of Model 7-A.  

  • Author
  • Model page created by David Erali. See "Data change" for further contributors.

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The model 7-A Peerless Magnetic Reproducer is part of the collections of the following members.

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