If you built this replica of an old-time radio when it was published, then today, it really is an old-time radio. The plans appeared in the July 1974 issue of Elementary Electronics for this crystal set. According to the magazine, the set is very selective, in part because it relies upon a loop antenna, which can be rotated to null out interfering stations. It requires no external antenna or ground, which also reduces static, and means that you don’t have to worry about lightning.

It had a galena crystal and cats whisker on front. But if you got tired of searching the crystal for the sweet spot, you could cheat by moving the headphone to a different socket, which was hooked up to a germanium diode hidden inside the cabinet.