This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Inductively coupled crystal radio circuit.svg circuit of an inductivelycoupled crystal radio receiver with impedance matching This type of circuit called two circuit or loose coupler receiver was used in most sophisticated crystal receivers from the wireless telegraphy era which ended in the until today Instead of single tuning coil