I had always wanted a geiger counter since I can remember. I bought a simple one that was being sold in the Tampere Spy Museum in Finland. It had a needle meter and was gamma only. Soon I realised that a digital readout and datalogging capabilities were essential for anything interesting. So I built this MyGeiger kit from RH electronics. In addition to the kit, a Li-Ion battery, charger and USB-TTL converter unit were fitted, to provide a complete solution.
A pancake proble detector wand was made from a plastic wine bottle corking device, available in homebrew shops. It was the ideal size to contain an Si-15BG pancake geiger tube. A rubber grommet was epoxied into the back of the wand to provide the cable exit. A discarded aluminium volume control knob was used as a cap.
A waterproof external probe/hand wand for an SBM-20 beta/gamma tube was made from a piece of plastic pipe and some plastic wine bottle corks.
I needed somewhere to log background radiation. But where? https://radmon.org