Tuning In

Since I’ve been living in Barbados I have really enjoyed discovering Soca music.

I’ve resigned myself to the fact that I’ll never master the dance moves though!

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Switching through the radio stations here I can listen to Soca music to my little hearts desire.

Soca has evolved in the last 20 years, but we’ve been switching radio stations since the 1930s.

BroxSistersRadioTeddyBear

Have you ever just  taken a moment to consider how incredible the radio is?  At one moment you can be listening to someone spouting the news and with the twist of a dial you might be listening to One Direction (well, hopefully not, but let’s be honest the chances are likely).

How does that work?

Well, you aren’t actually listening to real sounds over your radio, what you hear is a translation of the sound.  Let me explain:

If you could see sound it would look like this:

soundwave

This is called a sound wave.

So, say a man in a bowler hat toots his trumpet….

horner-1-hi

 

Waves would be coming out of it and travelling in all directions at once.

Now say he was to toot (love that word) his horn in front of a microphone at a radio station….

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Of course, some of those waves would hit the microphone.

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Consider this microphone to be like the electrical ear of all of the broadcast listeners.

 

 

 

 

 

 

Now this ear is particularly special because it picks up the sound waves and converts them into electrical currents.  These currents are referred to as audio waves.

The trouble with these waves is that they can’t travel very far.  Imagine they are like the ripples in a pond after you have thrown in a pebble.

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Roger McLassus [CC-BY-SA-3.0] 

As the waves spread they get weaker and weaker.

This clearly won’t do if you like to hear One Direction in all of their glory.

 

So, these audio waves needs to hitch a ride on larger waves.

Thumbs_up_by_Wakalani By Wakalani 

This big wave is made by a machine called an oscillator.  Lacking any imagination they called it the ‘carrier wave’ because it effectively carries the sound.

At the transmission station the horn toot is combined with the carrier wave in a process known as modulation and when the two waves combine….

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abracadabra….

…we get the radio wave.

 

 

 

 

 

This is now transmitted from a radio broadcast tower – travelling in all directions at the speed of light.

radio-waves-hi

Here is something crazy.

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Imagine bowler hat man was tooting his horn in front of a big crowd in London – he is a pro after all.

 

 

 

Now imagine this was being broadcast on the radio, which you were tuned into in Bristol.  You would hear the  tooting a fraction of a second faster than the audience right in front of him!  That’s because the radio waves are moving at the speed of light so will get to you quicker than those moving at the speed of sound in the London venue.  

Madness.

As you know, each radio station is assigned a particular channel, which is called the station’s frequency.  By turning your dial you can tune into the same frequency as the waves being transmitted from the station you want to listen to.

Something in your radio called a demodulator picks out the original audio wave, which was hitching a ride with the carrier wave remember.

And finally this audio wave needs to become a sound wave again for our human ears.  So, last but not least, it is the speaker that converts this electrical current (the audio wave) back into physical vibrations (the beautiful sound of ze tooting).

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All in all, a highly successful translation me thinks.

Tune in next time!

toot toot.

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