j3tstream writes:
I “rebuild” my Geiger counter, the SBM-20 tube was initially inside the box, i have put this one inside a 32mm diam plastic tube, for more convenience, wired through a XLR3 cable. This counter is from “Electronique-Pratique” n°368, a french electronic magazine. Shem, pcb, and PIC hex & C source code available.
More details at Weird-Lab blog.