Sensibly equivalent¶ to:
The 25L6GT is designed for use in single ended audio stages in apparatus using a 300 mA series heater chain. As a single ended audio amplifier it can produce 4.3 Watts.
This exhibit is British made by Brimar but the etched octagon containing the Type designation looks very much like the RCA style.
The Brimar Name. Through the smokey glass the shape of the anode can just be determined as a rectangular box with side fixing flanges. The box itself is blackened to radiate more efficiently.
The wide glass envelope is 29 mm in diameter and, excluding the IO base pins, is 72 mm tall.
References: Datasheet, 1040 & 1043. Type 25L6GT was first introduced in 1937.
Absolute Maximum Operating Conditions¶
Updated September 06, 2019. shape:wide.glass.tube construction:pinch type:beam.tetrode age:1930.1940 base:io heater:300ma pins:8 pin:1.m pin:2.h pin:3.a pin:4.g2 pin:5.g1 pin:6.- pin:7.h pin:8.k