Radio

Objectives

• To be able to understand how radio was invented and by who

• To gain an understanding of how radio has developed over

the centuries and the difference between 20th century radio

and 21st century radio

• To be able to understand the difference between AM and FM

radio

A History Of Audio and Radio

Radio is arguably the oldest electronic media. Yet despite the arrival of new technologies, radio still plays a major

role in our lives. Each week, 90% of the population tunes into radio for at least five

minutes. The average UK radio listener tunes into 22.9 hours of radio a week…

But how did we get to this point?

How it all began…

• The theory of electromagnetic waves was first developed by Scottish physicist James Clerk Maxwell in 1864.

• German physicist Heinrich Hertz confirmed the theory in a laboratory in 1888.

• Italian inventor Guglielmo Marconi achieved the first practical demonstration of radio in 1901 by receiving a signal in

Newfoundland, Canada, transmitted from Cornwall, England

Guglielmo Marconi

• Known as the ‘father of long

distance radio transmission’

• Inventor of radio in 1909

• Radio Broadcasting in the UK began

in 1920 with Marconi's experimental

station 2MT located in Writtle, Essex

• http://www.youtube.com/watch?v=

HxUPXUijuT4

Radio Stations - 1922

TaskIn Groups of 3 using the computer, research

and discuss the following years and find a piece of radio broadcast from that time

19601940 1980

20001950 1970

Some Examples 1940

http://www.youtube.com/watch?v=OWjjxnITG8I&feature=related

1960

http://www.youtube.com/watch?v=Ts5EfWPy-ew

1970

https://www.youtube.com/watch?v=CKvd-2eKg3A

1980

https://www.youtube.com/watch?v=LXvSfv5jhHU

2000

http://www.youtube.com/watch?v=vcWdxKF8N2I&feature=related

Radio stations- 2006

Events in Radio HistoryThere are many major events that have occurred in the 20th century radio history.One good example of a major event in the 20th century that was broadcasted on radio:• Martin Luther King http://www.youtube.com/watch?v=cefI3Fw51bA

AM and FM RadioAmplitude Modulation Frequency Modulation

The names describe how the radio waves that carry the signals are differentiated from each other.

AM varies the length of the waves and FM varies how quickly they pulse. This is why the stations are designated by Hertz and

Megahertz. Those units are used to measure wavelength and frequency.

AM

• AM stands for amplitude modulation• AM radio ranges from 535 to 1705kHz• The ground wave of AM radio doesn't go very

far. This means numerous stations can be put on the same frequency without interfering with each other — assuming they are far enough apart.

FM

• FM stands for frequency modulated• The FM radio band goes from 88 to 108 MHz• To keep from interfering with each other FM

stations must be 200KHz apart within the same geographic area. However, since the signals of FM stations cover only limited distances, the same frequencies can be used in different geographic areas of the country.

Task• Individually listen to a radio show for 20 mins, any radio station of

your choice this could be– Internet Radio– Community Radio– Public Service Broadcasting– Commercial

• You are to now make notes of what you can hear within the show• The structure of the 20 min show you have listened to• Tone of voices used• Audience it is aimed at

You will present this to the rest of your group