The crystal radio is a time-honored build that sadly doesn’t get much traction anymore. Once a rite of passage for electronics hobbyists, the classic coil-on-an-oatmeal-carton and cat’s ...

It’s then a simple matter of hooking up the right pads on the credit card to the rest of a crystal radio circuit, and you’re all set. Of course, [Billy] goes the whole hog, building the entire ...

The RC circuit is a tangible reminder of the 100-year history of racing in the park. You can see it in action in this YouTube clip: It is thought to be the oldest RC track in the country, and is ...