7-A Peerless Magnetic Reproducer

• Paese
• USA (Stati Uniti d'America)

• Produttore / Marca
• United Radio Corporation (Peerless); Rochester NY

• Anno
• 1928/1929

• Categoria
• Altoparlante, cuffia o auricolare

• Radiomuseum.org ID
• 84323

• Immagini
• Schemi

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Clicca sulla miniatura dello schema per richiederlo come documento gratuito.

• Gamme d'onda
• - senza

• Tensioni di funzionamento
• Alimentazione non richiesta

• Altoparlante
• Altoparlante magnetico (a spillo)

• Materiali
• Mobile in legno

• Radiomuseum.org
• Modello: 7-A Peerless Magnetic Reproducer - United Radio Corporation

• Forma
• Soprammobile a cattedrale o cupola (upright, round top or pinted arch, not rounded edges only).

• Dimensioni (LxAxP)
• 292 x 328 x 182 mm / 11.5 x 12.9 x 7.2 inch

• Annotazioni

• The logo says: "Peerless Reproducer - Manufactured by United Radio 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 successor company United Reproducers 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 some of the model pictures show a "C" rather than an "A" on the cone.  These are Series designations.  The "C" model is still believed to be a model 7-A.

• Prezzo nel primo anno
• 30.00 $

• Bibliografia
• Classic Cones (page 66)

• Letteratura / Schemi (1)
• Chicago Salvage Stock Store catalogue, 1928?

• Letteratura / Schemi (2)
• Radio Broadcast Magazine (Oct. 1927, Page 370)

• Autore
• Modello inviato da Alessandro De Poi. Utilizzare "Proponi modifica" per inviare ulteriori dati.

• Altri modelli

• In questo link sono elencati 7 modelli, di cui 5 con immagini e 2 con schemi.
  Elenco delle radio e altri apparecchi della United Radio Corporation (Peerless); Rochester NY