Back before cell phones … before video games … before television … even before electric radios, there were crystal radio receivers. In the early 1920s and 1930s, magazines offered instructions on how ...

If you are ready to take a break from high-speed, complex digital systems, consider becoming a “rock hound” and constructing a crystal radio, one of the earliest forms of receivers. For close to 100 ...

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 ...

Marked: "Radiogem / The Radiogem / Corporation / New York". A kit to make a crystal radio receiver, including original package and instruction manual. Unit is a commercial variety of the old Quaker ...

No extant maker's markings. A crystal radio detector with dual elements. Components are mounted on a marble base. Though unmarked, unit seems commercial in appearance. Two tuners may be connected and ...