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.
Our other Osram LP2 is of an earlier batch with sloping anode and no use of mica supports.
The anode is formed from thin sheet nickel with ridges pressed into the wide face to add rigidity. The twin filament tension springs are held on an auxiliary mica support.
The M-OV lozenge is etched into the envelope with the LP2 in the centre. In this false colour image the ND of england can be seen. The LP2 itself is so faint that it can only be seen with considerable difficulty and a magnifying glass.
The shape of the anode section is clearly seen. The anode is attached to the support rods by spot welding. The tension springs have small hooks to hold the oxide coated filament.
The balloon envelope is 41 mm in diameter and, excluding the B4 base pins, is 83 mm tall.
References: Data-sheet & 1040. Type LP2 was first introduced in 1930.