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.

1. INDUSTRIAL TRAINING
PRESENTED BY:
DELIA JAMES
ANUSHA WILSON
ATHIRA VARGHESE
MEGHA MERIN JOSE
ALL INDIA RADIO - CALICUT
18/12/2014 - 23/12/2014

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

11. CONTROL ROOM STUDIO CONSOLE

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

14. MODERN FM TRANSMITTER
STEREO
CIKKKKODER
YGDDOIUHOIAUDIO
L
R
MONO
STEREO
STEREO
CODER
VHF OSCILLATOR
& MODULATOR
WIDEBAND POWER
AMPLIFIER
CRYSTAL
OSCILLATOR 10Mhz
RECTIFIER &
FILTER
PROGRAMABLE
DIVIDER 1/N
FREQUENCY
DIVIDER
1/1000
PHASE
DETECTOR
10 KHz
ERROR
VOLTAGE
FM MODULATED
SIGNAL

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.

18. THANK YOU