[Swlug] DIY Geiger counter

[Rhys Sage]

I had a go at putting the Geiger counter together today. I'd been waiting while paint cured on the crystal housing. So I put two BC547s with a 10K resistor and 1uF capacitor, reading off the BPX61. I connected it to my oscilloscope and there is a detected variance but I can't see much happening on the graph.

I'm getting a Vmax of 10.74, Vmin of 6.82. The changes are probably too rapid for the scope to read as the frequency is 0khz.

I wonder if the BC547 is either not sensitive enough or whether the 1uf capacitor needs to be smaller.

Anyway, a bit of progress. I might switch to the OPA2134PA chip and try that tomorrow.

Rhys Sage