The radio is a communication method that sends sound signals by radio waves.
It’s really hard to claim this invention to only one person, but officially it is claimed to Guglielmo Marconi, a Bologna (All radios have an electric circuit than can separate a few current from the antenna and send it to the loudspeaker.
Radio signals travel by four types of waves:
- High frequency waves travel short distances. (They are used in villages).
- Long waves travel to
- Medium waves can travel around a hundred km. (they are used by national and local radio stations).
- Short waves can travel thousands of km. (they are used by international radio stations).
HISTORY
- In 1924, Radio Barcelona is created, the first Spanish transmitter.
- In 1932, Edwin Armstrong invents frequency modulation that minimizes interferences.
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- 1988, first car with radio.
Today. radios are used for listening to the news, music or other programs. Everybody has one, on our mobile phone, Mp3 or in our cars. But in the past it was really hard to have a radio.
Hello Javier.
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