History of Radio Broadcasting

1. RADIO
J.Janardhan

2. WHAT IS FREQUENCY
 Frequency is the rate at which occurs over a particular time
 The rate per second of a vibration constituting a wave
 ‘A’ note on a violin string vibrates at about 440 Hz (440
vibrations per second)
 It is measured in the hertz unit
 The hertz abbreviated Hz

3. AMPLITUDE MODULATION (AM)
 It is a form of modulation used for radio transmission
 It has the two way radio communication applications
 The basic concept is quite straight forward
 The AM signal is changed in line with the instantaneous
intensity of the sound.
 Signal carries the sound or modulation.
 So that Radio frequency signal is the representation of the
sound wave

4. BIRTH OF PRINT MEDIA

5. ADVANTAGES OF AM
 It is simple to implement
 It can be demodulated using a circuit consisting of very few
components
 AM receivers are very cheap
 No specialised components are needed

6. DISADVANTAGES OF AM
 AM is a very basic form of modulation
 Simplicity is one of its major disadvantage
 It is not efficient in terms of its power usage
 It is not efficient in terms of the its use of bandwidth
 It is prone to high levels of noise

7. FREQUENCY MODULATIONS (FM)
 FM-When the frequency of carrier wave is changed with the
intensity of the signal

8. ADVANTAGES OF FM
 It is resilience to signal level variations
 The signals does not fall to a level where the receiver cannot
cope.
 FM is ideal for mobile radio communication
 FM is used for high quality broadcast transmissions
 FM is widely used in many areas of radio technology including
broadcasting
 Specially in two way radio communication.

9. DIFFERENCE B/W AM AND FM

10. DIGITAL AUDIO BROADCAST
 DAB-is also known as digital radio and high definition radio
 Analog audio is converted into a digital signal
 Transmitted the signals on assign channel in the AM or FM
 DAB offers FM quality audio on the AM broadband
 In 1995, DAB technology was first developed UK
 It became common in entire Europe
 DAB is has better sound quality and new radio system
 DAB receivers includes a small display
 That provides information about the audio and visual

11. Thank You