Summary

Used as a driver and output amplifier in radio receivers and amplifiers (Class A amplifier and Class B push/pull amplifier). It was introduced in 1932, and has a 2.5 volt directly heated cathode.

Although this valve had two grids, it was designed to be used as a triode, either with both grids tied together or with the outer grid tied to the plate. With both the grids tied together the tube was suitable for zero bias class B operation, with the outer grid tied to the plate the tube was suitable for use as a driver for a class B output stage. Three of these tubes could be used to produce up to 20 watts with one as a driver driving a pair in push-pull. This idea did not catch on.

Physical Description

Five pin American style base. Blue glass bulb

More Information