Friday 5 April 2013

A.M & F.M Radio

Definition of Radio:
Radio is "wireless telegraphy or telephony: speeches broadcast by radio." However "radio" describes the tool with which we receive this wireless transmission. Radio means anything associated with radio waves.
History of Radio:
In 1906 some folks aboard a ship who where used to hearing the blips and bleeps of Morse code all day and transcribing it down were treated to a special surprise. They heard over their transmissions the sound of a violin--it was Christmas Eve so the violin was playing "Silent Night." It was magical then, but the idea of creating a public medium out of the ingenious invention came a whole decade later with Frank Conrad who began playing records for his friends over the air, thus radio as we know it was born.
How It Works:Radio waves can bounce around all they want, but no one is going to hear or "intercept" them without a receiver. A radio wave is transmitted from a station's giant transmitter, and these waves go out into the air, in all directions. Your radio antenna, whether external or built into your AM/FM radio, picks up pieces of this wave. The waves don't actually transmit sounds--they carry electronic pulses, and your radio translates these pulses into sound, but all before you can blink your eyes a few times.
FM Radio Vs. AM Radio:
AM (amplitude modulation) and FM (frequency modulation) radio are the same kind of radio wave. They originate as the exact same radio wave, and are encrypted or "modulated" differently. FM radio has a strong advantage over AM radio because it is less likely to have static from fluctuations in signal due to changes in amplitude. FM radio ignores these fluctuations, producing less static, which provides for a better listening experience.
The Physics:
When you listen to your radio you are hearing the movement of atoms. When a radio signal is sent it is made up of lots of atoms that have dispersed from the transmitter antenna to the air. These atoms then travel at light speed in all directions until they reach a radio antenna. Radio transmission may seem like sound just bouncing around in the air, but it's actually a transfer of physical matter.

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