Marconiphone "Personal K12" P20B

• Country
• Great Britain (UK)

• Manufacturer / Brand
• Marconi Co. (Marconiphone, Marconi's Wireless Telegraph Co. Ltd.), GB (not tubes - see also HMV His Master's Voice)

• Year
• 1948

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 79271

• Picture
• Schematics

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

• Number of Tubes
• 4

• Valves / Tubes
• X17 W17 ZD17 N17

• Main principle
• Superheterodyne (common); ZF/IF 365 kHz

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

• Power type and voltage
• Dry Batteries / 1.5 & 69 Volt

• Loudspeaker
• Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) / Ø 7.5 cm = 3 inch

• Power out
• 0.08 W (unknown quality)

• Material
• Various materials

• from Radiomuseum.org
• Model: Marconiphone "Personal K12" P20B - Marconi Co. Marconiphone,

• Shape
• Very small Portable or Pocket-Set (Handheld) < 8 inch.

• Dimensions (WHD)
• 7 x 3 x 5 inch / 178 x 76 x 127 mm

• Notes

• Uses a B114 combination battery pack  for about 30 hours operation (assuming F cell internally for LT, HT was Layer type cells).. HT 8mA and LT 250mA (approximately).

  The Marconiphone P20B is a "Personal" Miniature Portable, also named K12. "Snakeskin" effect covered cast metal body with cream plastic base & lid. Lift-up lid switches radio on when opened. Cream painted metal front panel.

  LW 1000 ... 2000 m

  MW 200 ... 550 m

  It's based on the P17B design (MW only) with addition of LW by addition of a loading coil for the loop aerial and switching at the Local oscillator coil.

  The P20BX is the "export" version

• Net weight (2.2 lb = 1 kg)
• 1.8 kg / 3 lb 15.4 oz (3.965 lb)

• Price in first year of sale
• 11.00 £

• External source of data
• Radios von gestern, page 90

• Source of data
• Radio! Radio!

• Mentioned in
• Funk-Technik (FT) (1951/4 S134)

• Literature/Schematics (2)
• Radio And Television Servicing books (R&TVS) (1951 Ed., Vol I, Pg. 418)

• Literature/Schematics (3)
• Attaché Radios, Mark Johnson 2005, BVWS GB

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

• Other Models

• Here you find 500 models, 334 with images and 316 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Marconi Co. (Marconiphone, Marconi's Wireless Telegraph Co. Ltd.), GB (not tubes - see also HMV His Master's Voice)