The Challenge: Make a Transmitter and Receiver
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How are we going
to transmit our signal?
we decided to go wireless. We may not to able to make a mobile phone system
but our very own radio station with a transmitter and receiver might just
What is a transmitter?
Radio can be incredibly
simple. All you need to transmit a signal is a spark. Radio waves are
composed of electric and magnetic fields. The exact way the two fields
are brought together in the radio wave is rather complex, but the physical
theory that describes these waves means that a changing electric or magnetic
field will create radio waves directly.
The tiny spark produced
in a light switch when you turn it on also produces radio waves which
is why you hear a click on the radio when you turn nearby electrical
items on and off. If we can maintain the spark (rather than just for
an instant when the switch is operated) you can convert the 'click'
into a 'buzz' and use it to send a Morse code type message.
Why does a spark produce radio waves?