• Year
  • 1934
  • Category
  • Broadcast Receiver - or past WW2 Tuner
  • Radiomuseum.org ID
  • 78219

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

 Technical Specifications

  • Number of Tubes
  • 4
  • Main principle
  • TRF with regeneration; 1 AF stage(s)
  • Tuned circuits
  • 2 AM circuit(s)
  • Wave bands
  • Broadcast (MW) and Long Wave.
  • Power type and voltage
  • AC/DC-set / 200-250 Volt
  • Loudspeaker
  • Electro Magnetic Dynamic LS (moving-coil with field excitation coil)
  • Material
  • Wooden case
  • from Radiomuseum.org
  • Model: CN213 - Vidor Ltd.; Erith Kent
  • Shape
  • Tablemodel, low profile (big size).
  • Dimensions (WHD)
  • 15 x 12.5 x 8 inch / 381 x 318 x 203 mm
  • Notes
  • C1 is Barretter rather than true tube.

    SG, Det, Audio TRF, but all Pentodes. Volume is via V1 cathode bias affecting control and screen Grids.

    UR2 / CY2 rectifiers wired in parallel to lower resistance (esp. on DC mains), it is in series with a 500mA MES lamp bulb as fuse. In all such series applications the current rating is more important than voltage.

    Early versions "shunt feed" the Speaker field winding. Later versions use the field coil as PSU choke instead of L11. Two versions of Electrodynamic speaker used, early (shunt) 7,500 Ohms Field coil and later (series) 820 Ohms field coil.

    External Aerial and Earth sockets (required).

    Live Chassis and Aerial and Earth only capacitor isolated.  As the aerial series capacitor is a rear panel trimmer (175pf max) putting 2.2nF 1kV ceramic in series should be considered. The C1 20nF "Earth Isolation" capacitor can be a 630V or more Y rated 22nF part. Operation is unsafe otherwise.

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