Summary

An output pentode intended to be used in battery powered radios, used as a Class A audio amplifier. Designed for use with 2 volt filament supply from a single lead-acid accumulator or a pair of zinc-air cells.
This valve was used in Australian farm radios from 1934 until about 1936.
Manufacturer: Philips UK (Mullard)
2 V directly heated cathode.

The two volt valves such as this one were mainly used in mantel and console radios used in areas without reticulated power, often referred to as 'farm radios'. These often used a single 2 volt lead-acid cell to light the filaments and two or three large 45 volt carbon-zinc batteries for the plate supply. Sometimes two zinc-air batteries were used for the filament supply instead.
Some sets were made that could be powered from a single 6 volt car battery, with the plate supply being provided by a vibrator supply. These also used the 2 volt filament valves with their filaments wired in series. People would use two 6 volt batteries, one in their car and the other for the radio, swapping them over as needed to keep them both charged.

Physical Description

Conical bulb with five pin UY style base, mounted on wooden display block

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