The G2018 is an audio voltage amplifying triode designed for radio sets with a series heater chain. The 180 mA heater rating is not common in the UK.
The reverse of the zinc painted envelope just carries the makers country of origin - Hungary - the location of the parent company. Tungsram also manufactured in the UK.
The dome has the makers name and the Type designation
The balloon envelope is 45 mm in diameter, and excluding the B5 base pins is 100 mm tall.
Reference: 1043. Type G2018 was first introduced in 1932.
Absolute Maximum Operating Conditions¶
Updated January 10, 2015. shape:balloon construction:pinch type:triode age:1930.1940 base:b5 pins:5 pin:1.a pin:2.g1 pin:3.h pin:4.h pin:5.k