Scientific Instruments
Fessenden electrolytic radio signal detector
Smithsonian, National Museum of American History. Open access, CC0.

Fessenden electrolytic radio signal detector

A fine wire tip dipped in acid turned incoming radio waves into a current that earphones could play as sound.

Date
1903
Maker
Reginald Aubrey Fessenden
Dimensions
overall: 5 1/2 in x 6 in x 3 1/2 in; 13.97 cm x 15.24 cm x 8.89 cm
Others named in the record
Fessenden, Reginald Aubrey (associated person)
Museum
National Museum of American History
Credit line
from Marion Armstrong

The museum's own record (Smithsonian, National Museum of American History)