I bought a venerable old Tektronix 2645b for the same reason - last reparable oscilloscope.?
This microscope is an old Zeiss (West Germany) with some snazzy add-ons like the Epi-Illumination attachments (which offer great options for custom Raman and Fluorescence work) as well as some polarizers for petrographic analysis.?
It's nice to know of people's experience with vacuum tubes, HV, etc. There are a bunch of Spellman HV power supplies on eBay. And, the old Glassman service manuals give some good insights into basic HV power supply design topology. Reading through the Newton Scientific Patent on the mini X-ray tube make one wonder what is really novel about the design since it just uses most of the classic HV building blocks only in miniature.
There is a channel on YouTube - "Glasslinger" - where you get to watch the construction of custom vacuum tubes. If glassblowing is an esoteric art, then scientific vacuum tube glassblowing is something else entirely. There is even an episode on build a custom mini X-ray tube:?
Another great youtube channel is "Applied Science" where this guy Ben in California shows some interesting DIY projects - if you consider sputter coating, building a scanning electronic microscope from scratch, or cooling things to 4K with the cryocooler in your garage to be a DIY project. He has a few episodes on XRF and even one on making X-Rays by unrolling plastic tape (a process that has actually been patented). See:?
Another very well made channel is "Tech Ingredients" but focuses more on lasers, plasma, and magnetics.
