• Country
• Great Britain (UK)

• Manufacturer / Brand
• Radio Instruments Ltd (RI)., London

• Year
• 1929

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 77437

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

• Number of Tubes
• 4

• Valves / Tubes
• MH4 MS4B MKT4 U30/250

• Main principle
• TRF with regeneration

• Tuned circuits
• 1 AM circuit(s)

• Wave bands
• Broadcast (MW) and Long Wave.

• Power type and voltage
• Alternating Current supply (AC) / 110-120 ; 200-250 Volt

• Loudspeaker
• - For headphones or amp.

• Material
• Wooden case

• from Radiomuseum.org
• Model: All-Electric Transportable Madrigal - Radio Instruments Ltd RI.,

• Shape
• Console, Lowboy (legs < 50 %).

• Dimensions (WHD)
• 14.5 x 15 x 11 inch / 368 x 381 x 279 mm

• Notes

•  

  Anode-bend detection. Series connected battery valves are used. Rectification folowing the mains transformer is by a bridge-connected metal rectifier. Wave range: 225-550 and 950-2000 meters. There is also a DC model that operates on 200 to 250 volts. Sold with a moving coil loudspeaker cabinet, with metal rectifier. The complete set forms a low-boy cabinet.

  Marconi 1931 valve catalogue lists a  "Radio Instruments"  4 valve Madrigal
  MS4 MS4 MH4 MPT4 U10 (rather than Metal Rectifier)
  This may be a 1930 version of the same model.

• Source of data
• Radio! Radio!

• Literature/Schematics (1)
• Wireless Weekly

• Author
• Model page created by Konrad Birkner † 12.08.2014. See "Data change" for further contributors.

• Other Models

• Here you find 48 models, 42 with images and 3 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Radio Instruments Ltd (RI)., London