The 6X5GTY is full wave rectifier for mains powered sets and is probably a 1930s design in a later glass tubular package.
The valve required a 50 Ohm series resistance and could only supply a reservoir capacitor of 8 µF.
The wide glass tube envelope is 28 mm in diameter and, excluding the IO base pins, is 67 mm tall.
References: Datasheet, 1040 & 1043. Type 6X5GTY was first introduced in 1936.
Absolute Maximum Operating Conditions¶
Updated October 02, 2015. shape:wide.glass.tube construction:pinch type:rectifier.fw age:1930.1940 base:io heater:6.3v pins:8 pin:1.m pin:2.h pin:3.a(2) pin:4.nc pin:5.a(1) pin:6.nc pin:7.h pin:8.k