• Country
• Germany

• Manufacturer / Brand
• Nora, Aron, Heliowatt; Berlin

• Year
• 1935/1936

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 7937

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

• Number of Tubes
• 3

• Valves / Tubes
• AF7 RES164 RGN564

• Main principle
• TRF with regeneration; 1 AF stage(s)

• Tuned circuits
• 1 AM circuit(s)

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

• Power type and voltage
• Alternating Current supply (AC) / 110; 125; 150; 220; 240 Volt

• Loudspeaker
• Magnetic loudspeaker (reed) of high quality (free mooving - only possible past 1931).

• Material
• Wooden case

• from Radiomuseum.org
• Model: Undine 4 W204L - Nora, Aron, Heliowatt; Berlin

• Shape
• Tablemodel, high profile (upright - NOT Cathedral nor decorative).

• Dimensions (WHD)
• 370 x 385 x 245 mm / 14.6 x 15.2 x 9.6 inch

• Notes
• Eisenkernspulen

• Net weight (2.2 lb = 1 kg)
• 10 kg / 22 lb 0.4 oz (22.026 lb)

• Price in first year of sale
• 145.00 RM

• Source of data
• Katalog Radio-Zentrale Alex v. Prohaska 1935/1936 / Radiokatalog Band 1, Ernst Erb

• Circuit diagram reference
• Lange+Schenk+FS-Röhrenbestückung

• Mentioned in
• Fortschritte der Funktechnik und ihrer Grenzgebiete (8 Bände) (1)

• Literature/Schematics (1)
• -- Schematic (OTO-Schaltungen)

• Other Models

• Here you find 633 models, 556 with images and 342 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Nora, Aron, Heliowatt; Berlin