I have seen these electronic gold testing kits marketed for upwards of $100-400, from the outside they don't look like much.
Being a former electronics student, I believe there can't be much sophistication to them. Does anyone know of a kit or schematic available so that I can make my own (for much cheaper!)?
Being a former electronics student, I believe there can't be much sophistication to them. Does anyone know of a kit or schematic available so that I can make my own (for much cheaper!)?