• Country
• United States of America (USA)

• Manufacturer / Brand
• Electrical Research Laboratories Inc. (Erla); Chicago, Illinois

• Year
• 1924

• Category
• Kit (Parts plus instruction) or building instructions only

• Radiomuseum.org ID
• 38141

• Number of Tubes
• 4

• Valves / Tubes

• Main principle
• TRF without regeneration; Reflex

• Tuned circuits
• 1 AM circuit(s)

• Wave bands
• Broadcast only (MW).

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

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

• Material
• Various materials

• from Radiomuseum.org
• Model: Duo-Reflex Four Tube Kit - Electrical Research

• External source of data
• Ernst Erb

• Source of data
• Radio Collector`s Guide 1921-1932

• Mentioned in
• Collector's Guide to Antique Radios 4. Edition

• Other Models

• Here you find 134 models, 47 with images and 61 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Electrical Research Laboratories Inc. (Erla); Chicago, Illinois