In this theory-based video, we combine our knowledge of tank circuits and diodes to create the simplest of radios - the crystal receiver. We'll look at the V-I characteristics of germanium and silicon, as well as the lead-sulphide crystal Galena. I'll show how to design an air core inductor to work in concert with a variable capacitor, which will act as a tuning device for our radio. Our diode will act as a detector, which recovers the audio signal and removes the RF component. This is a great beginner project, a lot of fun to put together, and a good opportunity to show off your build skills!
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