• Country
• Germany

• Manufacturer / Brand
• Stahlwerk Mark AG; Berlin-Breslau

• Year
• 1924/1925

• Category
• Audio Amplifier or -mixer

• Radiomuseum.org ID
• 17050

• Number of Tubes
• 4

• Valves / Tubes

• Main principle
• Audio-Amplification; 4 AF stage(s)

• Wave bands
• - without

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

• Loudspeaker
• - This model requires external speaker(s).

• Material
• Wooden case, TUBES VISIBLE.

• from Radiomuseum.org
• Model: NF-Verstärker NV-4 - Stahlwerk Mark AG; Berlin-

• Shape
• Tablemodel, slant panel.

• Dimensions (WHD)
• 200 x 130 x 145 mm / 7.9 x 5.1 x 5.7 inch

• Notes
• Gerät mit Transformatorkopplung RTV-Stempel vom 23.02.1924

• Net weight (2.2 lb = 1 kg)
• 1.850 kg / 4 lb 1.2 oz (4.075 lb)

• External source of data
• E. Erb 3-907007-36-0

• Source of data
• - - Data from my own collection / Radiokatalog Band 2, Ernst Erb

• Circuit diagram reference
• Info Dr. H. Börner without schematic

• Picture reference
• Das Modell ist im «Radiokatalog» (Erb) abgebildet.

• Other Models

• Here you find 16 models, 4 with images and 0 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Stahlwerk Mark AG; Berlin-Breslau