1650-A: Difference between revisions
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The '''General Radio 1650-A''' is a portable impedance bridge introduced in 1959. It was succeeded by the [[1650-B]] in 1968. | The '''General Radio 1650-A''' is a portable impedance bridge introduced in 1959. It was succeeded by the [[1650-B]] in 1968. | ||
The 1650 | The 1650 was the first GR impedance bridge to feature the "Orthonull" function, which is a mechanical link driving the DQ dial from the CRL dial through a friction clutch. (Conversely, turning the DQ dial will ''not'' turn the CRL dial.) | ||
It helps avoid the "sliding null" problem when measuring components with high losses. | It helps avoid the "sliding null" problem when measuring components with high losses. | ||
| Line 28: | Line 28: | ||
* Frequency range: 20 Hz to 20 kHz (to 100 kHz with reduced accuracy) | * Frequency range: 20 Hz to 20 kHz (to 100 kHz with reduced accuracy) | ||
* DC Supply: 6 V, max. 60 mA; Battery: Four D cells, current drain 10 mA (AC measurements) | * DC Supply: 6 V, max. 60 mA; Battery: Four D cells, current drain 10 mA (AC measurements) | ||
* External Oscillator and Detector: [[1210-C|Type 1210-C Unit R-C Oscillator]], [[1311-A|Type 1311-A Audio Oscillator]] and [[1232-A|Type 1232-A Tuned Amplifier and Null Detector]] are recommended for audio measurements at frequencies other than | * External Oscillator and Detector: [[1210-C|Type 1210-C Unit R-C Oscillator]], [[1311-A|Type 1311-A Audio Oscillator]] and [[1232-A|Type 1232-A Tuned Amplifier and Null Detector]] are recommended for audio measurements at frequencies other than 1 kHz | ||
* DC Polarization: 600 V may be applied (from external source) for series capacitance measurements | * DC Polarization: 600 V may be applied (from external source) for series capacitance measurements | ||
* Weight: 17 pounds (8 kg) net | * Weight: 17 pounds (8 kg) net | ||
Revision as of 00:18, 26 March 2024
The General Radio 1650-A is a portable impedance bridge introduced in 1959. It was succeeded by the 1650-B in 1968.
The 1650 was the first GR impedance bridge to feature the "Orthonull" function, which is a mechanical link driving the DQ dial from the CRL dial through a friction clutch. (Conversely, turning the DQ dial will not turn the CRL dial.) It helps avoid the "sliding null" problem when measuring components with high losses.
Key Specifications
- Capacitance: 1 pF to 1100 μF in 7 ranges.
- Inductance: 1 μH to 1100 H in 7 ranges
- Resistance: 1 mΩ to 11 MΩ in 8 ranges, AC or DC
- D: (of series capacitance) 0.001 to 1 at 1 kHz, (parallel capacitance) 0.1 to 50 at 1 kHz
- Q: (of series inductance) 0.02 to 10 at 1 kHz, (parallel inductance) 1 to 1000 at 1 kHz
- Basic accuracy: ±1% of full scale, ±5% for dissipation factor
- Internal oscillator: 1 kHz ±2%
- Frequency range: 20 Hz to 20 kHz (to 100 kHz with reduced accuracy)
- DC Supply: 6 V, max. 60 mA; Battery: Four D cells, current drain 10 mA (AC measurements)
- External Oscillator and Detector: Type 1210-C Unit R-C Oscillator, Type 1311-A Audio Oscillator and Type 1232-A Tuned Amplifier and Null Detector are recommended for audio measurements at frequencies other than 1 kHz
- DC Polarization: 600 V may be applied (from external source) for series capacitance measurements
- Weight: 17 pounds (8 kg) net
Links
- The GR 1650-A & 1650-B Portable Bridges @ conradhoffman.com
- US Patent 2872639, Henry P Hall, Electrical bridge and method. Filed Oct. 10, 1956; Granted Feb. 3, 1959 (describing the Orthonull feature)
- US Patent 2966257, Henry C Littlejohn, Instrument carrying case. Filed Nov. 5, 1959; Granted Dec. 27, 1960
- Henry P. Hall, A New Universal Impedance Bridge. General Radio Experimenter Volume 33, No. 3, March 1959, page 3.
- Henry P. Hall, Orthonull - A Mechanical Device to Improve Bridge Balance Convergence. General Radio Experimenter Volume 33, No. 4, April 1959, page 7.
- IET Labs Application Note, Henry Hall: Father of the Digibridge
Videos
- General Radio Genrad 1650 impedance bridge - Oscillator Circuit repair and calibration @ YouTube
- General Radio 1650-A Experimentation with Coils Capacitors and Tank circuits @ YouTube
- Vacuum Tube Audio Transformer Impedance Determined With General Radio Impedance Bridge @ YouTube
Pictures
Internal
