BFO Metal Detector [3]

I realised that one of my most radical designs is "out there", all over the Internet, yet doesn't appear on my own blog. So here it is. Before I appeared on the scene, the simplest metal detectors (even those requiring a complementary AM radio) were much more complex than this. This digital approach was my first "super simple" design -- then I further simplified it with an analog approach -- see BFO Metal Detector [1]. Finally I hit on the BB idea -- a self-contained "super simple" design -- see BB Metal Detector. You may click on this image to enlarge to 170k. See BFO Metal Detector [2] for another coil, which is just as suitable as the one described here, only there's more detail. Happy hunting!