General Radio 1390B Random Noise Generator

General Radio 1390B
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The Genrad 1390B provides a high level of electrical noise at its output terminals. This type of signal is useful in room acoustic measurements, loudspeaker and microphone tests, psychoacoustic tests, filter tests, cross-talk measurements for multichannel carrier systems, calibration checks on recording systems, modulation of signal generators and test oscillators, tests of rms response of meters, observation of resonance in systems, electrical averaging of resonant responses, and comparisons of effective bandwidth. A pair of these generators can be used as signal sources for demonstration of various degrees of correlation, possible errors of random sampling, and other concepts of statistical theory.



Frequency Range 5 Hz to 5 MHz
Adjustable output level 30 µVolts to 3 Volts
Audio-Spectrum-Level uniformity ± 1 dB
Output Voltage (Max open-circuit) 3 V for 20 KHz range
2 V for 500 KHz range
1 V for 5 MHz range
Impedance Source impedance for max output is approx. 900 Ω Output is taken from a 2,500 Ω potentiometer. Source impedance for attenuated output is 200 Ω One output terminal is grounded