650-A

The General Radio 650-A is an impedance bridge introduced in 1933.

Frederick Van Veen writes:

The most noteworthy introduction of 1933 was the Type 650-A Impedance Bridge, the work of GR engineers Horton and Field.

Priced at $175¹, the 650 was one of the most successful instruments in the Company’s history, remaining in the GR catalog for the next quarter century.

Links

• Robert F. Field, The Convenient Measurement of R, L, and C. General Radio Experimenter, Vol. 7, Nos. 11 and 12, April-May, 1933.
• General Radio Type 650-A Impedance Bridge @ Science and History Institute Museum Digital Collection

¹About $4,100 in 2023 dollars