Observation: Crystal Radios can be thought of as Radio Frequency (RF) to Direct Current (DC) "diodes"... Also they can be thought of as RF to DC Transducers: h

Observation: Crystal Radios can be thought of as Radio Frequency (RF) to Direct Current (DC) "diodes"... Also they can be thought of as RF to DC Transducers: https://en.wikipedia.org/wiki/Transducer https://en.wikipedia.org/wiki/Transducer