1232-A
The General Radio 1232-A Tuned Amplifier and Null Detector was introduced in 1961 Catalog Q and remained available through Catalog 1978.
The Type is a solid state battery operated tuned amplifier and null detector. Its tuned frequency range covers 20 to 20 kHz in 5 bands plus a flat response setting. As a null detector its part of the GR 1660-A Inductance and 1620-A Capacitance Measurement Systems. Battery operation is provided by 9 now obsolete M72 cells. The instrument used for this article has been converted to a rechargeable battery pack. The instructions for this conversion are covered in a document below.
Specifications
- Frequency Response:
- Tunable Filters: 20 Hz to 20 kHz in 3 ranges; 5% bandwidth; 2nd harmonic at least 34 dB down from peak, 3rd at least 40 dB down.
- 50 kHz and 100 kHz Filters: 2nd harmonic 44 and 53 dB down, respectively.
- Flat Response: ±3db 20 cps to 100 kc.
- Input Impedance: Approximately 50 kΩ at maximum gain, varies inversely with gain to 1 MΩ at minimum gain.
- Gain: 120 dB on the tunable ranges; 100 dB, flat range; 106 dB at 50 kHz; 100 dB at l00 kHz position.
