• Country
• Germany

• Manufacturer / Brand
• Grassmann, Peter, RFW, Radio-Funk-Werkstätten; vor 1945, Berlin & Neuhaldensleben

• Year
• 1939/1940

• Category
• Loudspeaker, headphone or earphone

• Radiomuseum.org ID
• 71964

• Wave bands
• - without

• Power type and voltage
• No Power needed

• Loudspeaker
• Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil)

• Material
• Wooden case

• from Radiomuseum.org
• Model: Helios Perma 681 - Grassmann, Peter, RFW, Radio-

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

• Dimensions (WHD)
• 410 x 530 x 27 mm / 16.1 x 20.9 x 1.1 inch

• Notes
• Anpassungswerte: 1/2/3,5/7/15 kOhm. Maximalbelastbarkeit: 10 W.

• Net weight (2.2 lb = 1 kg)
• 11.5 kg / 25 lb 5.3 oz (25.33 lb)

• Price in first year of sale
• 106.00 RM

• Source of data
• Handbuch WDRG 1939 / Radiokatalog Band 2, Ernst Erb

• Author
• Model page created by Michael Seiffert. See "Data change" for further contributors.

• Other Models

• Here you find 111 models, 76 with images and 30 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Grassmann, Peter, RFW, Radio-Funk-Werkstätten; vor 1945, Berlin & Neuhaldensleben