874-GA
The General Radio 874-GA Adjustable Attenuator was introduced in Catalog M (1951) and remained available through Catalog Q (1961).
The Type 874-GA is a mutual-inductance (waveguide-below-cutoff) type attenuator. A micrometer type barrel adjusts the distance between a pick-up loop attached to three foot coaxial cable and the short section of the input coaxial line. Both the barrel and adjusting sleeve are calibrated in decibels, one turn produces a change of 20 dB for a total or 120 dB of attenuation. Used with other coaxial elements the such as 874-VI voltmeter indicator and 874-VR voltmeter rectifier 874-GA can be used to attenuate and monitor signal generators and oscillators. The attenuator can also be used to measure the attenuation of a network by the substitution method.
Specifications
- Calibrated Range: 120 dB
- Accuracy of Attenuation: ±0.5 db when corrected
- Frequency Range: 100 MHz to 3000 MHz
- Waveguide Mode: TE 1,1 ; cutoff frequency 12,300 MHz
