[Swlug] DIY Geiger counter

[Rhys Sage]

I'm in the middle of my workday. Reading this all with great interest.

I played with chatGPT and of the list of transistors I have (I have some mosfets too), it indicated my BC517s might be better than the BC547 setup. It'd certainly be simpler.

The key points seem to be 30K times current gain and it's good up to 30v. I'll be using 4.7v. I'm only using 4.7v because that was the closest I could adjust my buck converter with the screwdriver at the weekend.

I might have a 102 ceramic capacitor somewhere - there were some extra parts in a kit I built. Maybe I need to order a pack of polyester film capacitors? I have electrolytic and metal film assortment trays. 

The photodiode in use is a BPX61. I did buy some BPX34s but couldn't find them. They're in a TO46 can style. Curiously no markings on them to indicate what they are nor the manufacturer's name. I'll attempt to include a photo.

Rhys Sage
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