How does a radio convert signals into sound?

Answer

Bye Rens

Thank you for your interest in radio technology.

Unfortunately, the answer to your question is not that simple. Radio signals as emitted by the transmitter are actually electromagnetic waves. Other electromagnetic waves are, for example, radar waves or light. One of their characteristics is that they are very fast: they propagate at 300 000 km per second, or seven and a half times around the earth in one second! Now when such a fast electromagnetic wave reaches the antenna of a receiver, that antenna has a very important task: it converts the electromagnetic wave into electricity. That’s just an incredibly small amount of electrical energy, of course, but: it IS electricity. And we can amplify that electricity so that we can do something useful with it.

A radio will now filter that electrical signal: choose one signal from the entire range, with which we want to work further. We will then amplify that one signal again, and then we will use a certain circuit (the detector) to extract the information that the transmitter has packed into it. Once that’s done, we’re going to amplify the information again so that it can be heard through a loudspeaker.

If radio technology really interests you, you might just have to type ‘jampot receiver’ into some search engine: that is a design for a super simple radio that you can also build yourself. And I should know: I built mine too when I was…13!