1605-A

The General Radio 1605-A Impedance Comparator was introduced in Catalog O (1956) and remained available through Catalog T (1968).

The Type 1605-A can be used to compare pairs of components for magnitude and phase difference. It displays the results on separate meters (magnitude, phase). Using the built-in guard circuit during measurement, the unknown can be remotely located during measurement.

Some other applications include checking ganged potentiometers or variable capacitors for tracking, checking balances of transformer windings, or adjusting coils to a standard.

Specifications

• Impedance Ranges:
  • Resistance: 2 Ω to 20 MΩ
  • Capacitance: 40 pF to 500 μF
  • Inductance: 20 μH to 10,000 H
• Internal Oscillator Frequencies: 100 Hz, 1 kHz, 10 kHz, 100 kHz
• Meter Ranges:
  • Impedance Magnitude Difference: ±0.3%, ± 1%, ±3%, ± 10% full scale
  • Phase Angle Difference: ±0.003, ±0.01, ±0.03, ± 0.1 radian full scale
• Voltage Across Standard and Unknown: approx. 0.15 V

Links

• Experimenter April 1956 describing Type 1605-A
• Predecessor: General Radio 1604-B Comparison Bridge (1954)
• Successor: General Radio 1654 Impedance Comparator (1970)

Photos

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  Test Jig