The industrial training was presented by Delia James, Anusha Wilson, Athira Varghese, and Megha Merin Jose at All India Radio in Calicut from December 18th to 23rd, 2014. The training provided an overview of All India Radio, including its history, profile, services like Vividh Bharati, external services, control room, studios, typical studio layout, software used, control room equipment, microphones, transmitters, and cooling techniques. The trainees gained valuable hands-on experience and new information about broadcasting through interactions with experienced engineers and technicians.
2. INTRODUCTION
All India radio also known as Akashavani is the official broadcaster of
India.
Developed and maintained by Prasar Bharathi Broadcasting
Corporation of India.
Sound broadcasting started in India in 1927.
In radio transmission, audio signal from a broadcasting station covers
a great distance to a receiver.
The radiation of electrical energy is practicable only at high
frequencies(about 20 KHz).
The signal is amplified and reproduced into sound by loudspeaker.
3. ALL INDIA RADIO PROFILE
Formally began in 1936 as a government organization
The headquarters is at Akashvani Bhavan, New Delhi
Network of 232 broadcasting centers
91.79% coverage area
Covers 24 languages and 146 dialects in home services
Objectives are to inform ,educate and entertain the people
4. VIVIDH BHARATI
One of the best known services of AIR
Also known as commercial broadcasting
service(CBS)
Popular in Mumbai and other large cities
Operates on different medium wave band
frequencies
Programs- news, film, music, comedy programs
5. EXTERNAL SERVICES:
External broadcast began on 1 Oct 1939 by the British
government
Covers 27 languages ,17 national and 10 foreign
languages
Other services are: news on phone service, direct to
home service, documentaries, Central Drama Unit, DRM
Transmission.
6. CONTROL ROOM
Providing interruption free transmission in both
channels
Manage and maintain all studios and recordings
Manage the computer networks
Mange power supply system
Outside broadcasting
Program routing as per cue sheet
7. STUDIO
• Acoustically treated hall specially for recording
various program.
Studio types:
1. Talk studio: used for recording and broadcasting of
talk shows
2. Music studio: used for recording of musical events
3. Playback studio: used for making usual
announcements, regular news bulletins and other
interactive programs
4. Drama studio: exclusively meant for recording
drama
8. TYPICAL STUDIO LAYOUT
It has 3 rooms, especially designed for reducing external
noise, called sound lock room, console or announcer room
and studio.
Studio : It is the recording and is the largest in the studio block.
The acoustical features are different and are carefully
designed to meet noise criteria.
Sound lock room: provides extra isolation from the external
noises for smooth recording and production of audio tracks.
Announcer /console room: the recorded program is edited and
stored in the memory queued for broadcasting.
9. SOFTWARES USED
Cool edit
Application: recording, editing and mixing
Virtual player
Application: playback of audio, program searching, playlist creating
Library manager
Application: manage the auto database
Commercial manager
Application: manages and schedule commercial
AIR browser
Application: to schedule programs
SMS gateway
Application: manage SMS received for different programs
CD copy
Application: to convert audio format
10. CONTROL ROOM
Consist of switching console, a receiver , ISDN, STL, internal radio
synthesizer, distribution rack etc
Switching console:
Master console of all the studios.
Receiver:
Receiver rack consist of tuner, with which various remote station
programs are received
Integrated service digital network:
Connected to control room for receiving programs from different
stations across India through for dedicated phone lines
Distribution rack:
To monitor and tap incase of problems
Internal radio synthesizer:
Radio in this rack is tuned to the same station frequency to check
the reception
12. MICROPHONE
• Converts sound signals to electrical signals .
• Types of Microphones:
1. Dynamic or moving coil Microphone
2. Ribbon / Velocity Microphone
3. Electrostatic or Condenser Microphone
13. FM TRANSMITTER
Salient features :
Completely solid state
Remote operation
Mono or stereo broadcasting
Parallel operation in passive exciter standby
mode
Air cooled with the help of rack-integrated
blowers
15. MW TRANSMITTER
• Range from 1KW to 500KW power
100 KW HMB 140 Medium Wave Transmitter:
AIR has 52 transmitters of this type and is the backbone
of MW service
RF stage:
• Consist of crystal oscillator, transistor power amplifier, RF
Driver and Power Amplifier
AF stage:
• Supply the audio power required to amplitude modulate
the final RF stage
• Consists of: high pass filter, AF Pre-amplifier, AF Pre-
Corrector, AF Driver, AF Final Stage
Control & Interlock Systems in Transmitter:
• Ensure correct switching sequence, safety, indicates
status of transmitter
16. COOLING TECHNIQUES IN TRANSMITTER
Air cooling
Vapour cooling
Condensed vapour cooling
17. CONCLUSION
Thus the industrial inplant training is
completed with the help and support from the
engineers and technicians in the AIR station, Calicut.
It has been a great experience which could boost
the academic knowledge. Training has been very
informative and gave lots of new information
regarding broadcasting of the popular AIR service.
We were lucky enough to interact with the most
experienced engineers and technicians in the field of
broadcasting.