Fusor Forums

Building your own is all that easy (although it's not trivial either). It doesn't take much electrical knowledge, just some craft in insulating everything. You can order cores very cheap from TSC international.

As for amazing1, they are a legitimate company and will send you what you order. As to whether the products are legitimately quality is another question.

I am very unknowledgeable on HV above 10 KeV but I listen to people who are and some of what "bwang" says is correct (about diodes, least.) Maybe his overall approach is correct. Maybe use some of bwang's ideas as a starting point to search both here and for google. Building a very HV, 30+ ma system is something that will pay off both in savings and safety later on. Can’t say for sure but that is my limited take on what they wrote.

Amazing1.com is Bob Iannini's site. He was formerly a rather prolific author of DIY articles for Popular Electronics, Radio Electronics, and some other publications, as well as his own books. His e-business is legitimate; I've bought some little things from the site in the past for the hands-on volunteer activities I do with a local museum, and it's decent stuff (although understandably quite a bit more expensive than the equivalent found through opportunistic scrounging or rolling your own).

The voltage / current capabilities quoted on Amazing1 for the flyback transformers are definitely pushing it for continuous duty. I have no doubt you could obtain the voltages instantaneously, the currents instantaneously, or perhaps both instantaneously if the driver is suitably beefy, but I don't think you can bank on continuous operation at ~30 kV / 20 mA from such an item. My opinion is that you would do better to wind your own lower-voltage (~10-kV) transformer and follow it with a Cockroft-Walton multiplier.

-Carl