Amplifier, Modified, Ex US Military

Radford Electronics Ltd.; Bristol

  • Jahr
  • 1948 ?
  • Kategorie
  • NF-(Niederfrequenz-) Verstärker oder -Mixer
  • Radiomuseum.org ID
  • 360430

 Technische Daten

  • Anzahl Röhren
  • 7
  • Hauptprinzip
  • NF-Verstärkung
  • Wellenbereiche
  • - ohne
  • Betriebsart / Volt
  • Wechselstromspeisung / 110 Volt
  • Lautsprecher
  • - Dieses Modell benötigt externe(n) Lautsprecher.
  • Material
  • Metallausführung
  • von Radiomuseum.org
  • Modell: Amplifier, Modified, Ex US Military - Radford Electronics Ltd.;
  • Form
  • Tischgerät, Truhenform, meist mit Deckel (NICHT Schrägpult).
  • Bemerkung
  • In December 1948 Radford advertised surplus US military 25 W TG10 Keyer amplifiers modified to work with a microphone or gram and a transformer to work from 110 V to 230/240 V mains.

    This amplifier featured:
    Circuit Topology

    • Output Stage: Push-pull configuration using two 6L6 power pentodes, capable of delivering 25 watts RMS.
    • Phase Inverter: A 6N7 dual triode likely served as a split-load phase inverter, enabling balanced drive signals for the output stage.
    • Preamp/Driver Stage: Two 6J7 pentodes (possibly RF-type valves) handled initial signal amplification and tone control integration.
    • Power Supply: A 5U4G rectifier tube in a choke-input or capacitor-filtered design, originally configured for 110V AC. An optional auto-transformer allowed operation on 210–230V mains. 21/- extra.

    Key Features

    • Input Flexibility: Modified to accept microphone and gramophone inputs, with adjustable tone controls for broader usability.
    • Output Options: Multi-tap output transformer supporting 4 Ω, 8 Ω, and 15 Ω loads, reflecting adaptability for diverse speaker systems.
    • Low Distortion: Early emphasis on precision, with distortion levels low enough to necessitate custom measurement tools—a hallmark of Radford’s engineering rigor even in this era.
    • Cabinet: Mounted in a smart black crackle carrying case.
    • Price: £7/12/ 6 with valves.

    These designs laid the foundation for Radford’s later hi-fi innovations, combining pragmatic reuse of wartime hardware with thoughtful circuit optimisation.

  • Originalpreis
  • 2.63 GB £
  • Autor
  • Modellseite von Gary Cowans angelegt. Siehe bei "Änderungsvorschlag" für weitere Mitarbeit.

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