X-Ray detector / Geiger wannabe

Another small project from many moons ago from when I started collecting parts for building a small X-Ray machine. One of those simple yet important devices especially usefull when doing any kind of high voltage work and high vacuums.

It's a rather simple design made from scrap parts (except the Russian SI-39G detector tube) placed into a plastic project box with some holes for an indicator LED, headphone jack, recharging jack and power switch.

If I remember correctly the transformer is from a very old Point Of Sale CCFL backlight, that along with the high voltage zener diodes and detector tube are the only specialized parts. The rest is generic components all powered by a tiny LiPo that gets charged once every year or two.

Not much too it, after looking at lots of online schematics I wanted something with very low part count and regulated voltage so I'm pretty happy with the design.
I've had it for about 6 years maybe and have taken it to many places. It's quite interesting to walk around and placing it on granite and finding more active spots :)