Category:Gaillard-Ducretet carbon microphone

Media in category "Gaillard-Ducretet carbon microphone"

The following 3 files are in this category, out of 3 total.

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  1901-telefono-bocina-Gaillard.jpg 309 × 449; 24 KB
  
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  Microfono a carbone Gaillard-Ducretet - Museo scienza tecnologia Milano 09847 01.jpg 1,280 × 853; 54 KB
  
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  Microfono a carbone Gaillard-Ducretet - Museo scienza tecnologia Milano 09847 02.jpg 1,280 × 853; 61 KB