Gentlemen, Start Your Engines!
The article mentioned, that there is a surprising amount of activity in home built gas turbine engines. Surprising doesn’t even cover it. “HOLY CRAP” is more like it.
Check this out:
Mike’s Home Built Turbojet Engine
Larry’s gas turbine jet engine
John Williamson’s gas turbine and pulse jet stuff!
And that’s just the first page from google!
The dudes who make ray guns out of microwave magnetrons pale in comparison.