The LP2 battery triode was a popular design and very similar valves were produced by several companies. As an audio output valve it produced 0.18 Watts. The 2.0 V filament was designed to be supplied from a single lead-acid accumulator.
See alsoLP2 for the later classic enveloped version.
The anode is formed from thin sheet nickel. Unlike our other Osram LP2 the anode is inclined and no mica supports are employed. This is an early version of the design.
The LP2 is etched into the dome. The filament tension springs are fitted into a glass rod as are the grid supports. The filament is a pair of inverted V's.
Another view of the lettering.
The detail of the formation of the lettering can be seen in this enhanced image. To the naked eye the etching appears as a uniform grey.
This photograph was taken looking straight down the length of the anode. The two filament wires are held in folded supports and are connected in parallel.
The bright nickel anode with pressed ridges to give the thin sheet rigidity. The filament can be seen to be oxide coated.
The balloon envelope is 44 mm in diameter and, excluding the B4 base pins, is 92 mm tall.
References: Data-sheet, 1040 & 1043. Type LP2 was first introduced in 1930.