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. shape:thin.glass.tube construction:all.glass type:counter/indicator age:1960.1975 base:b7g pins:7 pin:1.t pin:2.t pin:3.k pin:4.k pin:5.ic pin:6.k(2) pin:7.a