Portotape

Portogram Radio Electrical Ind. Ltd.; London

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  • Year
  • 1960 ?
  • Category
  • Sound/Video Recorder and/or Player
  • Radiomuseum.org ID
  • 102326

Click on the schematic thumbnail to request the schematic as a free document.

 Technical Specifications

  • Number of Tubes
  • 6
  • Main principle
  • Audio-Amplification
  • Wave bands
  • - without
  • Details
  • Tape Recorder
  • Power type and voltage
  • Alternating Current supply (AC) / 200-240 Volt
  • Loudspeaker
  • Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) - elliptical
  • Material
  • Leather / canvas / plastic - over other material
  • from Radiomuseum.org
  • Model: Portotape - Portogram Radio Electrical Ind
  • Shape
  • Portable set > 8 inch (also usable without mains)
  • Notes

  • Three‑speed dual‑track portable tape recorder using the Collaro “Studio” deck. Employs the same six‑valve amplifier chassis as the Monotape, with minor wiring changes (added resistor R36 in the head circuit). Includes tone control, monitor output, extension speaker socket and superimpose recording facility.

    T​echnical data:

    Tape deck: Collaro Studio three‑speed
    Tape speed: 7 ½, 3 ¾, 1 ⅞ ips  
    Track format: Dual‑track, reversible
    Bias oscillator: 50 kHz; bias 55 V, erase 30 V
    Inputs: Microphone 3.5 mV, Gram 200 mV, Radio input
    Output: Monitor 0.25 V, Extension speaker
    Output power: ≈ 4 W
    Speaker: Elliptical permanent‑magnet
    Cabinet: Portable suitcase type

    Successor to the Monotape, offering multi‑speed operation and improved facilities. A later improved version, the Portotape Mk 2, was introduced around 1962 with updated cabinet styling and companion products; the electronic circuit appears identical to the original Portotape and no confirmed circuit differences are known at this stage.

  • Net weight (2.2 lb = 1 kg)
  • 16.4 kg / 36 lb 2 oz (36.123 lb)
  • Circuit diagram reference
  • Radio and TV Servicing books (R&TVS) book
  • Mentioned in
  • -- Original-techn. papers.
  • Literature/Schematics (1)
  • -- Original prospect or advert (The Gramophone May 1960, p. 60.)
  • Author
  • Model page created by Peter Hoddow. See "Data change" for further contributors.

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