Pictures:

Details:

The MCT-17 is a Geiger-Muller tube, that has mica window to allow registration of beta-radiation.
Working power begins at: 1650 Volt
Plateau length: at least 150 Volt
Plateau slope: not more than 0.03%
Self noise: not more than 25 pulses/min
Density of window mica: 3 mg/cm2
Length of counter: no more than 90 mm
Diameter of counter: no more than 38 mm
Working life: 50 million pulses
Load Resistance to anode: 7…10 MOhm
Allowable stray input capacitance: not more than 10 pF
Working ambient temperature: -25 … +40 OC
Allowable radiation: not more than 10000 pulses/min

Datasheet:

Links:

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