A crystal radio is basically a high Q resonator tied to an antenna and an envelope detector. These days the envelope detector is a point contact diode such as a 1N34 Germanium diode. The resonant ...

A staple of starting off in electronics ion years past was the crystal set radio, an extremely simple AM radio receiver with little more than a tuned circuit and a point contact diode as its ...

This fun little DIY device is labeled as a “crystal radio circuit in a jam-jar.” But that description doesn’t even to begin to do it justice. According to Tesla, this electronic wonder allows you to ...

Many years ago when I was about 10 years old I received the gift of a crystal radio. I think it had about three parts. What was the crystal and how did it work? A crystal radio? Did you hook the ...

A crystal radio set is almost like magic. Sound appears, seemingly out of nowhere, powered not by cords and batteries, but by the very air around you. “You can’t quite work out how it comes alive,” ...

With Halloween coming up this weekend, it seemed like the perfect time to discuss a problem far too many of us face—homes that are haunted by evil spirits.These gadgets can confirm you are not ...