A crystal radio was the very first circuit I built. I was 9 at the time, which makes it, what, 49 years ago. Still remember the first time I actually heard a station come in.

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 ...

Tesla’s Spirit Radio uses a simple crystal radio circuit connected to a computer sound-in jack to generate spooky sounds from all kinds of electromagnetic sources. As you will see, it creeped ...

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 ...

Nikola Tesla’s Spirit Radio is built with a simple crystal radio circuit, but it has the ability to generate spooky sounds from all kinds of electromagnetic interference.

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 ...

A crystal radio is a passive receiver. That means it takes its power from the radio signal itself and not from some external source, such as a battery or wall outlet.

The transmitter on 2 meters 144 MHz was designed mainly for use by radio amateurs as radio beacon and to this end, it produces a signal of good quality and without unwanted harmonics. T1 transistor, ...