General Radio type 726-A vacuum tube voltmeter

It measured the strength of an alternating electrical signal using a vacuum tube, without drawing much power from the circuit.

Maker

General Radio Company

Dimensions

overall: 8 in x 9 in x 14 in; 20.32 cm x 22.86 cm x 35.56 cm

Museum

National Museum of American History

Credit line

from Princeton University, Department of Physics, thru Frank Shoemaker

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

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