This Japanese, Miroku Watanabe has on his blog to download the experiment in pdf here:
https://watanabe-japan-miroku.jimdofree.com/
Interesting to see other experience on energy,
It uses 6 E core ferrites Core, L1 150 tur ns and L2 300 turns, it seems to have twice as much power at the output
Another experiment here: https://s6cvq6nolqjf.blog.fc2.com/blog-entry-29.html
Jagau