all India radio summer training ppt

1. A PRESENTATION OF MAJOR TRAINING AT
ALL INDIA RADIO
Vocational training period : (11.07.2017-24.07.2017)
Presented by :-
i) Sayan Chakraborty
ii) Paramita Banik
iii) Suman Biswas
iv) Md.Ramiz Raza

2. INTRODUCTION
 For 75 years, AIR has been distinctive part of
the Indian way of life . With one of the largest
network of SW/MW/FM transmitters, AIR,
reaches the remotest corners of the country.
 All India Radio (abbreviated as AIR), officially
known as Akashvani is the radio broadcaster
of India and a division of Prasar Bharati .

3.  Today AIR has a network of 213
broadcasting centers covering 90% of
the area & almost reaching the entire
population of one billion. All India
Radio is one of the largest radio
networks in the world. The
headquarters is at the Akashwani
Bhavan, New Delhi.
 The External Services Division of All
India Radio broadcasts in 27
languages to countries outside of

4. What is Modulation ?
Modulation is the addition of information to an
electronic or optical carrier signal. A carrier signal
is one with a steady waveform -- constant height
(amplitude) and frequency. Information can be
added to the carrier by varying
its amplitude, frequency, phase, polarization (for
optical signals), and even quantum-level
phenomena like spin.

5. I) AMPLITUDE MODULATION
II) FREQUENCY MODULATION
III) PHASE MODULATION.
There are 3 basic types of modulation:

6. amplitude modulation (am) is
a modulation technique used in electronic
communication, most commonly for
transmitting information via a radio carrier
wave. in amplitude modulation,
the amplitude (signal strength) of the carrier
wave is varied in proportion to the waveform
being transmitted.
What is Amplitude modulation ?

7. I) CORVERAGE AREA OF AM RECIEVER IS
WIDER THAN FM BECAUSE ATMOSPHERIC
PROPAGATION
II)AM IS LONG DISTANCE PROPAGATION
III)AM CIRCUIT IS CHEAPTER AND NON
COMPLEX THAN FM.
IV) AM HAVE BANDWIDTH LIMITED AND
FM UNLIMITED
Advantages of amplitude modulation

8. I) THE ONLY ONE WAY TO WITHANCE TO NOISE
HAPPEN IS INCREASING POWER TRANSMITE
II) SIGNAL OF AM IS NOT STRONGER THAN FM WHEN
IT PROPAGATE TO OBSTACLE. (URBAND)
III) ONLY ONE SIDEBAND OF AM TRANSMITES
INFORMATION SIGNAL, SO IT LOSS POWER ON OTHER
SIDEBAND AND CARRIER.
IV) NOISE MIXES AM SIGNAL IN AMPLITUDE WHEN IT
PROPAGATES IN FREE SPACE THAT IT MAKE
DIFFICULTY TO RECOVER ORIGINAL SIGNAL AT
RECIEVER.
Disadvantages of amplitude modulation

9. in telecommunications and signal
processing, frequency modulation (fm) is the
encoding of information in a carrier wave by
varying the instantaneous frequency of the
wave. this contrasts with amplitude
modulation, in which the amplitude of the
carrier wave varies, while the frequency
remains constant.
What is Frequency modulation?

10. I)ESILIENT TO NOISE
II) RESILIENT TO SIGNAL STRENGTH VARIATIONS
DOES NOT REQUIRE LINEAR AMPLIFIERS IN THE
TRANSMITTER
III)ENABLES GREATER EFFICIENCY THAN MANY
OTHER MODES
Advantages of frequency modulation

11. I)REQUIRES MORE COMPLICATED
DEMODULATOR
II) SOME OTHER MODES HAVE HIGHER DATA
SPECTRAL EFFICIENCY
III) SIDEBANDS EXTEND TO INFINITY EITHER
SIDE
Disadvantages of frequency modulation

12. STAGES OF A RADIO STATION
 Studio
 Control Room
 Transmitter

13. RECEIVING CENTRE
 ANNOUNCER CONSOLE
EQUIPMENTS

14. BROADCAST STUDIO
 A broadcast studio is an acoustically
treated room. It is necessary that the place
where a programme for broadcast purposes is
being produced should be free of extraneous
noise. This is possible only if the area of room
is insulated from outside sound.
 The entry to the studios is generally through
sound isolating lobby called sound lock. Outside
of every studio entrance, there is a warning
lamp, which glows Red when the studio is ON-
AIR .

15. STUDIO TRANSMITTER LINK

16. PC
TURN
TABLE
MICRO
PHONE
PROGRAM
AMPLIFIER
TO CONTROL ROOM
ANNOUNCER CONSOLE

17. Control Room
 Mixing
 Switching
Transmitter
 Amplifiers
 Modulators
 Antennas

18. CONTROL ROOM
Broad functions of switching console in control
room:
 Switching of different sources for transmission
like News, O.Bs. other satellite based relays,
live broadcast from recording studio.
 Level equalization and level control.
 Quality monitoring.
 Signaling to the source location.
 Communication link between control room and
different studios

19. RNT SWITCHING
CENTRE
STUDIO
SWITCHER
MIXER
PROGRAM
AMPLIFIER

20. Mixing
Various equipments are available in a
studio to generate programme as given
below:
 Microphone, which normally provides a
level of 70 dBm.
 Turntable which provides an output of 0
dBm.
 Tape decks which may provide a level of 0
dBm.
 CD and R-DAT will also provide a level of 0
dBm.

22. AMPLIFIER
 Audio Amplifiers
 Power Amplifiers
 Peak Clippers

24. PRINCIPLE OF ANTENNA SYSTEM
 Antenna is usually a metallic device (a rod or
a wire) used for radiating or receiving
electromagnetic waves.
 The radio frequency power developed in the
final stage of a transmitter is delivered
through cables/feeders, without themselves
consuming any power to the transmitting
antenna.