• Country
• United States of America (USA)

• Manufacturer / Brand
• DeForest Radio Telephone & Telegraph Co. (De Forest); New York

• Year
• 1921 ?

• Category
• Audio Amplifier or -mixer

• Radiomuseum.org ID
• 103636

• • alternative name: Lee De Forest Mfg.

• Number of Tubes
• 2

• Valves / Tubes

• Main principle
• Audio-Amplification

• Wave bands
• - without

• Power type and voltage
• Storage and/or dry batteries

• Loudspeaker
• - For headphones or amp.

• Material
• Wooden case

• from Radiomuseum.org
• Model: Interpanel amplifier MP400 - DeForest Radio Telephone &

• Shape
• Tablemodel, Box - most often with Lid (NOT slant panel).

• Dimensions (WHD)
• 5 x 4.5 x 0 inch / 127 x 114 x 0 mm

• Notes
• Two tube amplifier. The one tube version is the MP200.

• Source of data
• -- Collector info (Sammler)

• Author
• Model page created by John Koster. See "Data change" for further contributors.

• Other Models

• Here you find 158 models, 132 with images and 16 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from DeForest Radio Telephone & Telegraph Co. (De Forest); New York