Pirani gage
How we built a pirani gage with all the joys and flaws of the kilobuck commercial versions, but for under $20.We use these all over the place, including as a sanity check on the expensive gages. Contact us for sources of the hard to find parts, Protel PCB files and so on. This is an oldie but goodie that has withstood the tests of time. We still use these, and they do cover the range of interest for Farnsworth type fusors quite nicely, as well as the range of interest for forelines in vacuum systems.
HV vacuum feedthrough
Having become disgusted with the prices, lead times, and lack of reliability of commercial offerings for HV vacuum feed throughs, we decided to design and build our own versions that are rugged, easy to repair as needed, and purpose designed for fusor conditions with gas and ions present, rather than UHV, which is a different tradeoff set entirely. The only component of these that can fail even under extreme conditions is also cheap and easy to replace. In addition, this design allows for heat conduction out of the vacuum system for use with extreme power inputs. We learned a few things along the way...
Microwave/ECR ion source
To be able to run fusors at all sorts of pressures, rather than having to balance between enough gas to light off at all, which then
requires too much current, and not enough gas to light off at all, which means having to do a dance with gas pressure at startup, we have used various ion sources to help things along. This one works the best of them all, very reliable, low maintenance, trouble free, and works across the widest range of pressures we've even heard of. This one is a winner and is not too expensive or difficult to make.
Highly recommended!
Vacuum Conductance servo valve
We are using a big turbo in the big tank and loving it. However, you can have too much of a good thing, and this is the cure.
Although you can spin a turbo down to a standby setting, that can still be too much. This is the cure for that, a homebrew that saves a few bucks over just buying one. This is meant to fit inside the tank (actually the bellows for the pump, mostly) where there is more room in my setup.Maybe you've noticed I like making things out of copper. "After it's time to build railroads, there's time to build a beautiful railroad" (John Varley).