He found an assembled Philmore “selective” radio kit. The simple kit had a coil, a germanium diode, and a crystal earphone. We were sad when [Michael] accidentally burned a part of the radio ...

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 ...

It was late afternoon at a conference for the Institute of Radio Engineers. Many people giving talks had complained about the current germanium transistors -- they had a bad habit of not working ...