varad aakashwani

8/3/2019 varad aakashwani

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ON

By :

Varad ShastriB.Tech ExTC

SGGSIE&T, NANDED


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Aakashwani- By VARAD SHASTRI

Radio is the transmission of signals by

modulation of electromagnetic waves with

frequencies below those of visible light.

Radio is based on wireless communication or

setellite communication.

In this era of technology due to need of wirelesscommunication, A national service was planned

and developed by the Prasar BharatiBroadcasting Corporation of India.


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The first license granted for transmitting a broadcast wasgiven on February 23, 1922. The Radio Club of Calcutta was

the first radio club to start functioning in Nov-1924

The Government run broadcasting set up was called the India

State Broadcasting Service (ISBS) which is then turned intoAIR (All India Radio) in June 1936.

The introduction of the commercial channel Vividh Bharti in

October 1957 increased the interest and popularity of radio.

AIR today has a network of 232 broadcasting centres with 149medium frequency(MW), 54 high frequency (SW) and 171

FM transmitters.The coverage is 91.79% of the area serving

99.14% of the people.



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Modulation Amplification

Transmission

DemodulationAmplification

Reception

TransmittingA radio wave carries information signal; Signals are

converted into electrical signals. A carrier wave is then

produced from the modulation. The wave is then amplified,

and sent to the antenna that then converts signal into an E.M.

wave.

Receiving

An antenna on receiving the signal send

it to the receiver this then converts the

electrical signal sends it to the amplifier

either a speaker/headphones jack this is

then converted into a

sound wave.



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How radio electromagnetic waves are changed to Radio Waves -

The sound wave is equivalent to a pressure wave.

Modulating

signalMicrophone

Carrier

WaveModulated

Wave

Broadcast Tower Radio



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Studio Centre

Broadcast Studio

Mixing

Control Room



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Recording Room

Dubbing Room

Loud Speakers

Headphones



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AC POWER SUPPLY

DC POWER SUPPLY



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FM broadcasts were introduced in Madras in 1977 and later at

Jalandhar in 1992, but it was only in 1993 when slots came to

be leased to private companies.

On August 15, 1993 a Frequency Modulation (FM) Channel

was launched in Bombay, with nine hours of radio which

sloats was leased to private producers like Times FM, radiostar

and Radio Midday.

In FM Phase II some 338 frequencies were offered of which

about 237 were sold.



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Here is an example of both FMmodulation and AM modulation

you can see from the image that

AM is much looser than the FM

signal meaning that less data canbe sent at one time as it isnt

compressed. The reason for the

difference in sound quality as a

lower bitrate must be sent across

the wave.



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91.1 - Radio City

92.7 - Big FM

93.5 - S FM

94.3 - Radio One

98.3 - Radio Mirchi

101.1 Aakashwani

Nanded

http://en.wikipedia.org/wiki/Big_FMhttp://en.wikipedia.org/wiki/Big_FMhttp://en.wikipedia.org/wiki/Big_FMhttp://en.wikipedia.org/wiki/Big_FM


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o This is only means which can provide multi access two way communication.

o The cost of transmitting information through satellite is independent of

distance involved.

o Satellite can be used for two way communication or broadcast purpose with

the covered area.o Satellites are capable of handling very high bandwidth.

o It is possible to provide large coverage using satellite. For example

Geostationary satellite can cover about 42% of earth surface using global

beam.



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