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CV2255 trigger tube

Size This measures 43x20mm overall and has a B9A base

This is a four electrode trigger tube primarily intended for use in Geiger counters.

Nominal maintaining voltage at 2 mA 105V
Primary current 0.4µA
Max. anode voltage for no self ignition 170V
Minimum anode - cathode voltage for trigger capacitance of 120 pF 150V
Maximum peak cathode current 10mA
Maximum mean cathode current 2.5mA
Maximum peak auxilliary cathode current 4mA
Maximum mean auxilliary cathode current 1mA
Maximum priming current (trigger to aux. cathode) 0.6µA
Minimum priming current 0.25µA
Minimum charge to auxilliary cathode to ensure triggering 45 pC
Maximum speed 400cps approx.