• Country
• United States of America (USA)

• Manufacturer / Brand
• Silver - Marshall; Chicago, IL

• Year
• 1928 ?

• Category
• Radio part (not a module) 

• Radiomuseum.org ID
• 213660

• Wave bands
• - without

• Power type and voltage
• No Power needed

• Loudspeaker
• - For headphones or amp.

• Material
• Metal case

• from Radiomuseum.org
• Model: Audio Transformer SM-220 - Silver - Marshall; Chicago, IL

• Shape
• Chassis only or for «building in»

• Notes
• Silver Marshall Audio transformer;

• Price in first year of sale
• 8.00 $

• Mentioned in
• Radio News (March 1928; page 1089)

• Author
• Model page created by Karlheinz Gützlaff. See "Data change" for further contributors.

• Other Models

• Here you find 225 models, 116 with images and 122 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Silver - Marshall; Chicago, IL