I'm attempting to create my own Geiger-Muller counter based on an old, soviet STS-5 tube.
I want it to be as compact as possible. I don't want to use ready-made modules, like this one, instead I want to put everything on one PCB. My only struggle concerns the high voltage part. I want the circuit to be as compact as possible, hence I wonder if there's a simpler, more compact option to bring, let's say 9V to the required 400+ V DC. Using a simple transformer and a MOSFET to switch the 9V on primary would be the easiest method, but maybe there is something better, more compact, that I have no knowledge about yet?