There is a lot more detail on the techlib site, including the theory behind the detector and test circuits along with other cool projects, so I’d encourage you to take a look.
Here is the schematic for the detector that I built.
I initially put it together on a bread board.
I used my little slayer exciter circuit to test the detector.
Once I knew that the circuit worked, I transferred everything to a piece of perf board.
Now for the final test…
It still works!
I guess the actual final test would be to wait until there is an actual thunderstorm and see how well it performs.