Qiaozhi: the point is if you can't buy the detector, make it. Of course, 20 years I'm working in different...
The PCB is original of Mineoro, failure detector. I dissamble it and "peel" the copper. Only use the magnetic and resonant printed coils. I use individual PCB circuits for to try different of these, wich part is better, etc.
My idea is to sell Mineoro. At this moment is very stable and extremely sensitive and with great immunity to electric lines.
The electric field detector (brown PCB) I had tried 5 years ago and become very sensitive. I don't understand why I abandon this project (original with three antennas)... Grrrr!!!!:mad:
Another "candidate":
http://www.mytempdir.com/818321