10-11-2012, 06:16 PM
ALL INDIA RADIO PRSAAR BHARTI
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INTRODUCTION OF AIR
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 wireless communication, A national service was planned and developed by the Prasar Bharati Broadcasting Corporation of India.
HISTORY AND PRESENT SCENERIO
The first license granted for transmitting a broadcast was given 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 into AIR (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 149 medium frequency(MW), 54 high frequency (SW) and 171 FM transmitters.The coverage is 91.79% of the area serving 99.14% of the people.C
PRINCIPLE OF AIR
Transmitting
A 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.
RISE OF FM TECHNIQUE
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.
Why FM is better then AM ?
Here is an example of both FM modulation and AM modulation you can see from the image that AM is much looser than the FM signal meaning that less data can be sent at one time as it isn’t compressed. The reason for the difference in sound quality as a lower bitrate must be sent across the wave.
[attachment=39044]
INTRODUCTION OF AIR
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 wireless communication, A national service was planned and developed by the Prasar Bharati Broadcasting Corporation of India.
HISTORY AND PRESENT SCENERIO
The first license granted for transmitting a broadcast was given 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 into AIR (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 149 medium frequency(MW), 54 high frequency (SW) and 171 FM transmitters.The coverage is 91.79% of the area serving 99.14% of the people.C
PRINCIPLE OF AIR
Transmitting
A 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.
RISE OF FM TECHNIQUE
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.
Why FM is better then AM ?
Here is an example of both FM modulation and AM modulation you can see from the image that AM is much looser than the FM signal meaning that less data can be sent at one time as it isn’t compressed. The reason for the difference in sound quality as a lower bitrate must be sent across the wave.