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1930's Card File Microphone. | Purchased on eBay in 1999. | No other information found on the web. | |
Detective Dictograph in Case (1907). | Additional photos: | Here is another website devoted to the Detective Dictograph with excellent photos while this one is a website on the history of the Dictograph company. | |
Model 114 Surveillance Briefcase by Federal Laboratories (1939) - also called "Federal Sound Detector". |
Additional photos:
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Limited research indicates no other information available on the web. | |
Microphone with thin wooden membrane - circa 1890. |
Microphone with thin wooden membrane - the wood is actually from pitch pine and is unique to the 1000 Islands (U.S. and Canadian border) along the St Lawrence River. Circa 1890. This primitive microphone was typically hidden behind tapestry or paintings. Additional photos: |
Limited research indicates no other information available on the web. |