Hi,
Morgan posted already pictures of device, don't you remember ?
That was in public area, Mineoro thread... with all that photos of the thing...
Now even 30cm is very interesting result on the air for such small coin and small device. But he told us (again in public area) that device actually work on medium range (some meters) for long time buried e.g. aluminium.
look at thread "
Mineoro 2-Box -- 492 feet range? ".
About schematic... I've posted whole thing on that public thread too... just look for it. The coils are missing cause I have no sure data on these.
But schematics seems have sense for some things.
Look at it now, I repost original version just for you ...contains errors but I was drunk when I made that!

Enjoy !
Kind regards,
Max