This Osram DE6 dull emitter battery triode dates from 1925. It is suited to amplification of audio to drive a loud speaker.
The construction is a classic horizontal coaxial configuration. The filament, rated at 1.8V is a single straight wire at the centre of the bright anode cylinder. The grid is a fine wire helix that is attached to a support rod. The rod is fixed at both ends and the grid stands on and above the support.
The balloon envelope is 43 mm in diameter and, excluding the B4 base pins, is 90 mm tall.
References: 4051 & 1003 Type DE6 was first introduced in 1924.
PDF scanned from an original document held by the museum
Updated April 06, 2012. shape:balloon construction:pinch type:triode age:1920.1930 base:b4 pins:4 pin:1.a pin:2.g1 pin:3.f pin:4.f