The Burndept H310 triode was designed as an RF amplifier. The early H310's had top sited vacuum seals but this exhibit is a later type where the seal is hidden in the composition base.
Burndept ceased making valves after its bankruptcy in 1927 and subsequent re-forming. The new company concentrated on the manufacturing of radio equipment.
The text etched into the bulb is Burndept Super Valve. The H stands for HF and the 3 is the filament voltage.
The other three etched letter are difficult to read.
The base has simple split pins with wires soldered below the base.
The gettering prevents seeing the electrodes in normal observation but seen at a shallow angle from the base the flattened cylinder anode etc become visable.
Another view of the electrodes and their supports.
The wide glass tube envelope is 25 mm in diameter, and excluding the B4 base pins is 79 mm tall.
Reference: 1043. Type H310 was first introduced in 1925. See also1925 adverts.
