eli5: On old radios, how does turning the dial tune into a different station? what is happening inside the radio to achieve this?

Question

eli5: On old radios, how does turning the dial tune into a different station? what is happening inside the radio to achieve this?

In: 70

Answer 1

Tuning a station is mostly done by filtering all the signals down to just the frequency you want.

Basic filter circuits are made from electric components like resistors and capacitors.

Capacitors are devices that store electric charge usually on two thin metal plates. You can adjust what frequency they help to filter by adjusting the distance between the plates.

Turning the knob changed the distance between the plates.