Excellent info on a tweaked J-tube RMH design. It deserves to be made "sticky" if not already
Non electronics nerds (and non ham radio ops;) will probably not have a clue as to what a 555 timer is, at least not without the prefix for a complete part number. I.e. NE555, which is a common integrated circuit that has been around for decades. Searching for "NE555 timer circuits" will bring up many schematic diagrams and application notes.
But being a firm believer in the KISS method <Keep It Super Simple:-> I'd do everything I could in the construction of an RMH with the best chimney available to avoid the need of an electric fan in the exhaust for "forced drafting". But it is not a bad option for a temporary setup etc.