The GTR150W is a voltage reference. It is too small to stabilise voltage directly for more than a few µA and so was probably used in a valve voltage stabiliser. In this application only a few µA of current would need to flow through the device.

The thin glass tube envelope is 9 mm in diameter, and excluding the flying leads is 31 mm tall.

 
Absolute Maximum Operating Conditions

Stabiliser	Va	mAa
	150	2.0

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 02 February 2008 {find valves by name}