B.T.S. A.C./D.C. Short-Wave Kit

BTS (B.T.S.) British Television Supplies; London

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  • Year
  • 1935 ?
  • Category
  • Kit (Parts plus instruction) or building instructions only
  • Radiomuseum.org ID
  • 361610

 Technical Specifications

  • Number of Tubes
  • 4
  • Main principle
  • TRF with regeneration
  • Wave bands
  • Short Wave (SW only)
  • Power type and voltage
  • AC/DC-set / 190 - 250 Volt
  • Loudspeaker
  • - This model requires external speaker(s).
  • Material
  • Metal case, TUBES VISIBLE
  • from Radiomuseum.org
  • Model: B.T.S. A.C./D.C. Short-Wave Kit - BTS B.T.S. British Television
  • Shape
  • Chassis only or for «building in»
  • Notes

  • The B.T.S. A.C./D.C. Short-Wave Kit is a three-valve shortwave receiver kit designed for both AC and DC mains operation. It was marketed as a reliable and efficient receiver for enthusiasts, priced at £8 8s (excluding valves, cabinet, and loudspeaker).

    Circuit and Valve Lineup

    • The receiver uses a well-proven three-valve TRF circuit:
      • Variable-mu high-frequency amplifier (Marconi or Osram W30)
      • Leaky-grid detector (Marconi-Osram H30)
      • Pentode output stage (Marconi-Osram N30)
    • For AC mains operation, a Marconi or Osram U30 valve rectifier is included.
    • The output pentode (Catkin type) can deliver up to 2.5 watts of undistorted audio.

    Tuning and Coils

    • The high-frequency amplifier stage is untuned, with a single plug-in tuning coil used for band selection.
    • Four plug-in coils are supplied, covering 13 to 260 metres (1.5 - 23 MHz).
    • The tuning condenser is 0.00016 μF, fitted with a double slow-motion drive featuring 7:1 and 100:1 gear ratios, which enhances tuning precision.
    • The reaction condenser also features a slow-motion drive for fine adjustment.

    Panel and Controls

    • The panel features a large semi-circular, full-vision scale calibrated from 0 to 180 degrees.
    • Main tuning control is centrally located, with a superimposed knob for the slow-motion drive.
    • On/off switch is at the bottom centre, with the reaction control to its right.
    • Mains voltage is selected via tappings on a Bulgin mains resistance.

    Connectivity and Features

    • Sockets are provided for the loudspeaker, two aerial connections, and earth.
    • A plug and jack are included for pickup (gramophone) use.

    Power Supply

    • Operates from 190 to 250 volts, AC or DC mains.

    Design and Usability

    • The kit is noted for its attractive panel layout and practical design.
    • Careful attention to tuning and reaction controls allows for efficient and stable shortwave reception.
    • The inclusion of slow-motion drives for both tuning and reaction condensers is highlighted as a user-friendly feature.

    Intended Audience

    The kit is aimed at hobbyists and home constructors seeking reliable shortwave performance with straightforward assembly and operation.

  • Price in first year of sale
  • 8.20 GB £
  • Mentioned in
  • -- Original prospect or advert (Practical Wireless Magazine Sep 1935, Page 128.)
  • Author
  • Model page created by Gary Cowans. See "Data change" for further contributors.

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