If you’ve ever built a crystal radio, there’s something magical about being able to pull voices and music from far away out of thin air. If you haven’t built one, maybe you should while there’s still ...

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 whisker design ...

Marked: "Martian / Big Four / Newark, New Jersey / Pat. Pend.". A crystal radio detector with binding posts for headphone connections on top, posts for antenna and ground connections on bottom.