Hertzian receiving resonator, 1890-1894

1890-1894

Helmholtz Resonator

1880-1900

Helmholtz Resonator

1880-1900

330 metre Piezo-electric resonator in bakelite box

Helmholtz Resonator

1880-1900

Helmholtz Resonator

1880-1900

Helmholtz Resonator

1880-1900

Oudin resonator with two Leyden jars

1897-1910

Resonator of adjustable pitch

1876