1390-B: Difference between revisions
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It first appears in {{Catalog Q}} and remained available through {{Catalog 1978}}. | It first appears in {{Catalog Q}} and remained available through {{Catalog 1978}}. | ||
The Type 1390-B provides random noise on three ranges from 20 kHz to 5 MHz | The Type 1390-B provides random noise on three ranges from 20 kHz to 5 MHz, produced using a [[6D4]] gas-discharge tube, V2, operated in the field of a permanent magnet. | ||
The noisy plate voltage of the 6D4 tube drives two stages of amplification. | |||
The noisy plate voltage of the 6D4 tube drives two stages of amplification. | |||
Between the amplifier stages, filter networks shape the three bands. | Between the amplifier stages, filter networks shape the three bands. | ||
A voltmeter displays RMS voltage | |||
A voltmeter displays RMS voltage of the noise signal before it is fed to a five-position decade attenuator at the output. | |||
==Specifications== | ==Specifications== | ||
* '''Frequency Range:''' 5 Hz to 5 MHz in three bands | * '''Frequency Range:''' 5 Hz to 5 MHz in three bands | ||
* '''Output Voltage:''' 3 V for 20 kHz range, 2 V for 500 kHz range, and 1 V for 5 MHz range | * '''Output Voltage:''' 3 V for 20 kHz range, 2 V for 500 kHz range, and 1 V for 5 MHz range | ||
* '''Output Impedance:''' 900 Ω | * '''Output Impedance:''' 900 Ω | ||
* '''Output Attenuator:''' 1, .1, .01, .001, and .0001 times the RMS Voltmeter reading | * '''Output Attenuator:''' 1, 0.1, 0.01, 0.001, and 0.0001 times the RMS Voltmeter reading | ||
==Links== | ==Links== | ||
* [[Media:GRwiki Exp 12_1951.pdf|Experimenter describing 1390-A | * [[Media:GRwiki Exp 12_1951.pdf|Experimenter December 1951 describing 1390-A]] | ||
* [[Media:GRwiki Exp 01_1960.pdf|Experimenter describing 1390-B | * [[Media:GRwiki Exp 01_1960.pdf|Experimenter January 1960 describing 1390-B]] | ||
==Photos== | ==Photos== | ||
Revision as of 15:40, 13 May 2024
The General Radio 1390-B is a random noise generator introduced in 1961. It first appears in Catalog Q (1961) and remained available through Catalog 1978.
The Type 1390-B provides random noise on three ranges from 20 kHz to 5 MHz, produced using a 6D4 gas-discharge tube, V2, operated in the field of a permanent magnet. The noisy plate voltage of the 6D4 tube drives two stages of amplification. Between the amplifier stages, filter networks shape the three bands.
A voltmeter displays RMS voltage of the noise signal before it is fed to a five-position decade attenuator at the output.
Specifications
- Frequency Range: 5 Hz to 5 MHz in three bands
- Output Voltage: 3 V for 20 kHz range, 2 V for 500 kHz range, and 1 V for 5 MHz range
- Output Impedance: 900 Ω
- Output Attenuator: 1, 0.1, 0.01, 0.001, and 0.0001 times the RMS Voltmeter reading
Links
Photos
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Noise tube, V2, operating in magnetic field
