The GTE175M is a trigger tube for driving Dekatron counter tubes, or as a general purpose trigger.
The active electrodes. The anode is a single vertical rod. The trigger is on the right and appears to connect to the cathode plate. In fact there is a small gap between the trigger and the cathode plate.
The thin glass tube envelope is 18 mm in diameter, and excluding the B7G base pins is 34 mm tall.
Reference: Datasheet. Type GTE175M was first introduced in 1964.
Absolute Maximum Operating Conditions¶
Updated April 29, 2013.