sensitive metal detector

Several readers have asked us to design a good metal detector. When our `research and development` group took a closer look at the problem, they soon discovered why: most conventional designs are not really suitable for the home constructor! In most designs, extreme care must be taken to screen the various sections of the circuit from one another and the power supply must be carefully filtered. A different design approach was chosen for the circuit described here. With a little care, the average home constructor should be able to build a highly sensitive metal detector, which will be suitable for a wide variety of uses.