1603-A

The General Radio 1603-A is a Z-Y impedance bridge introduced in 1956 Catalog O and remained available through Catalog T 1968.

Known as the bridge that always has an answer, its claim to fame is that it can be balanced for any impedance connected to its terminals. The 1603-A is accurate at audio frequencies from 20 Hz to 20 kHz. It requires an audio oscillator and detector for operation.

The 1603-A directly measures the quadrature components of a complex impedance Z = R + jX, or a complex admittance Y = G + jB. The unknown Z or Y may lie in any of the four quadrants of the complex plane, since this bridge can measure both positive and negative values of R and G as well as X and B.

Specifications

• Frequency Range: 20 Hz to 20 kHz
• Impedance and Admittance: -infinity to +infinity
• Accuracy (with unknown grounded): 1% (see manual)

Links

• GR Experimenter July 1955 describing the 1603-A
• GR 1603-A @ Fred PA4TIM's page

Photos

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