• Country
• Austria

• Manufacturer / Brand
• Stefra (Marke), Rudolf Franek; Wien

• Year
• 1951 ?

• Category
• Detector-Radio (Crystal or diode, without tubes/transistors)

• Radiomuseum.org ID
• 10740

• • Brand: Franek, Rudolf; Wien

• Main principle
• Crystal or Solid State Detector; Crystal-detection 1 circuit (no tubes)

• Tuned circuits
• 1 AM circuit(s)

• Wave bands
• Broadcast only (MW).

• Power type and voltage
• No Power needed

• Loudspeaker
• - For headphones or amp.

• Material
• Plastics (no bakelite or catalin)

• from Radiomuseum.org
• Model: Detektor-Empfänger M51 - Stefra Marke, Rudolf Franek;

• Dimensions (WHD)
• 65 x 30 x 82 mm / 2.6 x 1.2 x 3.2 inch

• Notes
• Spule mit verstellbarem Eisenkern; Steckdetektor.

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

• Source of data
• -- Collector info (Sammler) / Radiokatalog Band 2, Ernst Erb

• Other Models

• Here you find 20 models, 19 with images and 4 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Stefra (Marke), Rudolf Franek; Wien