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VactuphoneGlobe "Vactuphone". VACuum TUbe TelePHONE. Made to order by Western Electric Company for Globe. The first hearing aid to use a vacuum tube! Case was 18.4 cm x 10.0 cm x 18.3 cm. Fist made in 1921. Model shown is the commercial model. The engineers' model (not shown) was not leather covered and did not have a name and patent plate. Also shown is the single vacuum tube used in the hearing aid. |
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