[Swlug] DIY Geiger counter

[Rhys Sage]

Reading around and researching this evening after my workday, I came across this document:https://nsi.ir/wp-content/uploads/2025/01/Radiation-Measurment.pdf

Page 78 has an interesting circuit diagram that uses a Geiger-Muller tube. They're using a BC517 as the sole detector transistor. I think the 100n capacitor is slowing the pulses that will be received by an Arduino. The 10M resistor must be some kind of voltage pulse limiter. I'm guessing wildly there - my actual electronics knowledge is about the level of a well read amoeba (or whatever Mr Pugh taught us in 5th form gen science back in 1982/1983). I'd love to know what those two components are really doing.

So, that looks like something simple and worth trying on a breadboard. I have several spare breadboards so I can try that and compare with the circuits James sketched in unispace text.

This weekend is a 3-day weekend so I have a bit more time than usual even though Monday I have to take 'er indoors to one of her doctor's appointments.

Rhys Sage