Enigma Metal Detector ?

[q@l@p]

Hello Sirs,

I have found interesting metal detector on Youtube.

https://www.youtube.com/watch?v=nJcoIye0H7E

Auther says that he made it by himself.
Is it possible to find the circuit diagram of the Enigma metal detector he is saying on the net?
Is there any website where I can buy the Enigma detector actually?
If like this thread has already been written, please let me know the thread.
I am sorry for my English because English is my second language.

Thank you for all.

[N@SKO]

enjoy

[q@l@p]

Thank you for the picture of schematic. It is very useful for constructing the detector.