All india radio,alwar

ALWAR INSTITUTE OF ENGINEERING &TECHNOLOGY

A
TRAINING REPORT
ON

ALL INDIA RADIO “PRASAR BHARTI”

Submitted by-

Submitted to-

Govil Sharma

Sanjay kumarsingh

7thSem E.C.E.

E.C.E. Department

ALWAR INSTITUTE OF ENGINEERING & TECHNOLOGY, ALWAR

Session 2013-14

1


CERETIFICATE
This is to certify that the project report entitled “_ALL INDIA
RADIO”

submitted by Govil Sharma

under my supervision is

students own work and has not been submitted elsewhere for the
award of any degree, to the best of my knowledge & belief.

Amrinder B. Singh
H.O.D.

Electronics & communication

2


ACKNOWLEDGEMENT
This report is outcome of "On the Practical training which I received at Prasar Bharti
Akashvani Shimla (H.P.)". It includes the organizational Structure, Procedure, function &
performance of the station.
First of all I would like to express deep sense of gratitude towards Mr.ISRANI
(S.E.) (engineering head)) who permitted us to undergo training in the Prasar Bharti
Akashvani (B.C.!.) Alwar. I would like to express my special thanks to Mr. B.L. MEENA
(A.E. (training coordinator)) who prepared our training schedule &helped us to complete
our training.
I would also like to express my thanks to Mr. PRAVENDRA SINGH (training
incharge) to give me full support to prepare this report / also thanks to Mr. MUKESH
KUMAR gupta for guiding me.

Regarded
Govil Sharma
Electronics & Communication Engineering
4th Year.7thSem

3


ABSTRACT

 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 Nov1924The 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.
 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.CThe introduction of the

commercial channel „Vividh Bharti‟ in October 1957 increased the interest and
popularity of radio.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
1933

4


INTRODUCTION

•

Radioisthetransmission

of

signalsbymodulation

of

electromagneticwaveswithfrequenciesbelowthose of visible light.
•

Radio isbasedonwirelesscommunicationorsetellitecommunication.

•

In this era of technology due to need of wireless communication, A national
service was planned and developed by the PrasarBharati Broadcasting Corporation
of India.

1. CONTROL ROOM :

2-9

INTRODUCTION-------------------------------------------CONSOL BOARD--------------------------------REECIVERS---------------------------------------------ACTION AREA---------------------------

2. STUDIO :

3-4
4-7
8
8-9

10-17

INTRODUCTION ----------------------------------------------MICROPHONE RECORDING-----------------------------HDBS & PHONE IN CONSOLE----------------------------TRANSMISION-------------------------------------------

3. BROADCAST SECTION :

11-12
12-13
13-16
17

18-23

 LIVE BROADCASTING-------------------- TRANSMISION -------------------- ENTERTAINMENT PROGRAM-------------5

19-20
20-21
21-23


4. TRANSMITTER :

24-43

INTRODUCTION ------------------------------------------------------PRINCIPAL FEATURES OF 10 KW TV TRANSMITTER ------GENERAL TECHNICAL DESCRIPTION ------------------------TRANSMITTER BLOCK DIAGRAM ---------------AMPLIFIERS---------------------------------EXCITERS-----------------------------------------MODULATION & DEMODULATION--------------------ANTENNA--------------------------------------

25
25-26
26
27-31
32
32-35
35-39
39-40

POWER SUPPLY ---------

41-42

CONCLUSION---------------------------------------

47

6


7


CONTROL ROOMNow let us move to the main technical area of the radio station which is often called a control
room. Whatever is spoken in the studio or played from a CD player or computer is sent to this
control room. All the programmes are sent from here to the transmitter.
• The control room occupies an important place in the radio broadcast. It is the place,
connected with all the other segments of broadcast.
• Whatever the speaker/announcer speaks from the studio, it reaches the control room. From
here they are sent to the transmitter for its onward transmission to the listeners. A lot of
changes take place when one speaks through a microphone.
You may have noticed that your voice sounds different when it is recorded.
• In the control room, technical people control the whole process and immediately send these
waves to the transmitter.
• The transmitter sends these sound waves to the listeners‟ radio sets which convert them into
sounds. There is no time gap in the whole process.

8


• Transmitters are generally located outside the city boundries.
.
• The transmitters are of different capacities such as 1 KW to 100 KW, 200KW or 250 KW or
above.
• Their locations are decided according to their capacity.
• A 1 KW transmitter is normally installed in the vicinity of the studio control room whereas
the high power transmitters are installed outside the city.

9


CONSOL BOARD-

The SW1 and SW2 switch banks are incredibly versatile and allow the announcer to access
several types of audio. By accessing the corresponding button to the desired audio, then
putting the correct pot into ―PGM‖…short for program, and raising the volume slider,
several different audio sources can be accessed through these two switch banks.

The VU METERSmonitor audio output levels. If the meters are staying “in the red” ,the
music is too “hot”. If the meters are pulled down toward the left, you are “in the mud”, and
the levels are too low. Keep the frequencies in the middle between 80%-100%. This is
referred to as “THE SWEET SPOT.”

10


Studio afeatures five separate headphone and microphoneelocations. The headphone jacks
have separate level adjustments (including volume, bass, and treble) via the Behringer headphone amplifier. NOTE: Headphone stations 1 thru 3 have their own individual controls and
stations 4 & 5are wired together and controlled by Channel 4 on theamplifier.

11


12


13


RADIO RECEIVER-

Each radio receiver must have a reception antenna. It is an electrical conductor, where
voltages of various frequencies and amplitudes are being induced, under the influence of
electromagnetic fields from various radio transmitters. Besides these voltages, those induced
by EM fields that are created by various disturbance sources (such as electrical motors,
various household appliances spark-plugs of an automobile and all other devices where
electrical current is being switched on/off during work) are also present in the antenna, as
well as those from fields originating from outer space or the Earth‟s atmosphere. Basic roles
that a radio receiver has are:

ACTION AREAThis is the where all control action are done, all staf of the station are presented here this
members are do his working properly. They are….

Station Director
The Station Director is in charge of the radio station and also the head of the programme
wing. In some stations they are called managers.

Station Engineer
The Station Engineer heads the engineering wing and is responsible for all the technical work
at the radio station.

14


In addition there is a group of technicians and engineers, working quietly behind the scene.
They operate and maintain broadcast equipment and oversee the control room. They are
responsible for the technical quality of the broadcasts.

Programme personnel
These are persons who are engaged in planning, production , preparation and presentation of
radio programmes. They are known as progamme executives or producers. They are part of
the pogramme broadcast process.

Transmission staff
Persons who are responsible for a smooth and trouble free transmission process are known as
transmission executives.

15


16


INTERODUCTION-

A

studio is an acoustically treated compact anechoic room. It is suitably furnished and

equipped.

The selection and placement of microphones can have a major influence on the sound
of an acoustic recording. It is a common view in the recording industry that the music
played by a skilled musician with a quality instrument properly miked can be sent
directly to the recorder with little or no modification. This simple approach can often
sound better than an instrument that has been reshaped by amultitude of signal
processing gear.

17


MICROPHONE RECORDING-

1) Use a microphone with a frequency response that issuited to the frequency range of the
sound, ifpossible, or filter out frequencies above and/or belowthe highest and lowest
frequencies of the sound.

2) Place the microphone at various distances andpositions until you find a spot where you
hear from thestudio monitors the desired tonal balance and thedesired amount of room
acoustics. If you don‟t like it,try another position, try another microphone, tryisolating the
instrument further, or change the soundof the instrument itself. For example, replacing
wornout strings will change the sound of a guitar.

The Arrakis board is a digital/analog board giving the user access to12 channels of digital
capability and 20 analog.

NOTE: Even though there 32 input channels, only 12 can be accessed at the same time

18


CHANNELS 1-5 MICS
(Pot 5 doubles as CD 1 and MIC 5)
CHANNELS 5—7 CD PLAYER
CHANNELS 8—10 SS1, SS2 & HK
(Scott Studio Pot 1, 2 & Hot
Keys)
CHANNELS 11-12 SW1 & SW2
(Switch bank of buttons)

HDBS & PHONE IN CONSOL-

The GENTNER FEED UNIT is specifically designed to receive LIVE phone calls via the
phone line and converts the phone signal to be used over the air.
This facility is provided so that if correspondent want to give any information in the form
of only audio.
19


There are two major parts to the GETNER PHONE SYSTEM:
1. THE MASTER UNIT.(pictured below)

2. THE TELESWITCH LINE CONTROL CONSOLE. (pictured below)

RSU Radio has four editing computers open to students either enrolled in the audio classes
and/or those who have already passed the classes or work at the station.

20


Editing is meant to edit or to produce the final program after modifications. In CPS editing
plays an important role. We need editing to cut clip from a complete program to use that in
news section. Let‟s assume a programme held in USA, which we received through IRDs
in feed room and have its complete recording in video cassettes and now we want to show
1 3-minute of this 2-hour program in News.
Then the process that wills produce this 3-minute clip from 2-hours program will be called
editing
.
Editing can be of two types:
Linear Editing and
Non Linear Editing

Linear Editing
In linear editing we view the complete program through some playing equipments and
then cut desired part of program and then record that in a special type of cassette through
any recording equipment and then send it to News control room where these are used at
the time of News broadcasting. This is about linear editing.

Non-Linear Editing
When we use the term NLE, we mean editing video from your hard drive, NLE requires
two things: editing software and a video capture card to gets the video into your computer.
Once the video clip are digitized and on your hard drive they can be assembled in any
order, with the drag of a mouse, much like moving around sentences in a word processing
program.
Non linear editing software is timeline based. You start by selecting the in and out points
of your scene. Remember, that since everything is digital, we can get frame accurate edit
points every time. Each scene is then placed on the timeline. You can lay down more than
one track of video and audio onto your timeline. If you want to set your video to music,
you start by placing the captured sound file onto the timeline. Next you select and arrange
all of your video scenes. You can move scenes and clips around in your video just by
dragging them with your mouse. It really is that easy!

21


In the waveform display, drag to select the range of audio you want to remove. Then choose
Edit>Delete Selection. Or, you can select the segment of audio you want to keep and choose
Edit>Trim.

For removeing the unwanted part of recording-

22


TRANSMISSION UNIT-

The transmitter remote control unit is a very important piece of equipment in the radio
station. It is responsible for keeping the station on the air. The WVRC-8 system unit controls
and monitors the large transmitter housed in a secured building near the tower on campus.
The WVRC-8 transmitter remote is equipped with eight separate channels that offer lowering
or raising functions.

Transmitter readings should be monitored and taken from the computer to the left of
the console.

23


.

24


RADIO BROADCASTINGWhat is broadcasting:The process of sending information to a distant place is called broadcasting.

Need:We can not send information to a distant place with good quality of intelligence.

Means of broadcasting:1. Terrestrial
2. Satellite
3. Internet
1. Terrestrial(line of sight) :H.P.T. (High Power Transmitter) > 1 kW
L.P.T. (Low Power Transmitter) > 100 W
V.L.P.T. (Very Low Power Transmitter) = 10 W
2. Satellite: - In this signal is transmitted to satellite which is at 36000 KM from earth.

HISTORY: The birth of broadcasting in India has started on an experimental basis in the year
1921when times of India in collaboration with P & T department broadcasts a musical
programme.
 In the year 1930 radio broadcasting started operating under the Indian broadcasting
company.
 The government took over the charge of broadcasting in March 1935.
 A separate office of the controller of broadcasting was created.
 The landmark in the history of broadcasting is the change of the name of the Indian
broadcasting to air in 1936 and in the same year Delhi station was formed.
 From 1936 onwards the development of air was very slow;nine stations were opened up in
different places like Delhi, Calcutta, Bombay, Madras,Lucknow and Tiruchi.
 From 1956 on wards air was popularly known as AKASHWANI.
 On 12th November 1947 the voice of Gandhiji was broadcasted in air and since then it is
celebrated as broadcasting day.
25


 AIR and DOORDARSHAN aims to provide information,education and entertainment for
the public.
 Television (Doordarshan) started in India in the year 1959 with black and white
transmission.
 The black & white transmission was converted fully into color in 1982 during Asian
games.

Radio broadcasting, while essentially primarily European at its origin, has encountered
exceptionally favourable to conditions in Senegal and has thus become established over
time as not only the most popular means of communication and of disseminating
information.

Broadcasting consol with transmission-

26


SPECIFICATIONS OF 10KW BROADCAST
MONITOR (THROUGHLINE POWER METER):

POWER

1. Introduction:
1.1 Broadcast Power Monitor, UHF Band IV/V, with 3 ⅛” EIA unflanged line section
and suitable elements for measurement of Max Forward power of 5 kW and reflected
power of 0.5 KW, VSWR, Return Loss etc.
1.2 Ethernet & RS 232 enabled- Remote monitoring, control & instant alarm alert with 50
feet of cable to connect RS 232 and serial port between monitoring unit and line section,
and serial interface cable.
1.3 Data logging capabilities – System trends and anomalies before failure.
1.4 Integral RF Test Port facility.
1.5 Frequency / Channel field configurable.

Entertainment Programs for broadcastingVIVIDH BHARATI-

The entertainment channel of AIR, VividhBharati service was started in October 1957, with
popular film music as its main ingredient. It started accepting commercials from November
1967. VividhBharati Service provides entertainment for 15 hours a day. Nearly 85 percent
of programming is based on music with film music topping the chart. Classical, folk, light
and devotional music are also broadcast.
Or other entertainment channel of AIR are jai jawan- jai kisan,aajkefankaar
,bhoolebisregeet,hellofarmaish etc.

27


RADIO KISAN DIWAS –
All India Radio observed 15th February as “KISAN DIVAS” from its 96 Kisanvani
broadcasting stations. Special programmes were broadcast on the occasion by these stations.

Farm & Home Broadcasts
The commitment of All India Radio to the rural audience dates back to more than 50
years. All stations of All India Radio broadcast Farm & Home programmes directed at
rural audience. In fact, special programmes have been designed to cater to the day-today seasonal needs of the farming community

MANAGE TRAINING
Two Trainings and one Review workshop were organized by MANAGE, Hyderabad.
Almost 40 Farm and Home Programme Producers were trained in these Workshops.

ENVIRONMENT PROGRAMMES
Keeping in view the importance of the subject, all the AIR stations are broadcasting
daily programmes on Environment for 5 to 7 minutes duration and weekly
programmes of longer duration for more than a decade. The importance of protecting
environment is being discussed in our other programmes i.e. health/ women / rural
women / youth & children programmes also for making people aware of this serious
issue. The AIR stations are broadcasting programmes on the subject on the basis of
instructions and guidelines issued by the Directorate. In order to inform and educate
the listeners,

28


29


30


TRANSMITTER:– A transmitter is the equipment through which we receive the radio broadcast on our sets.
– This is big equipment in comparison to other equipment installed in the studio or control
room.
– The strength and type of the transmitter determines the coverage area of broadcast.
– There are two types of transmitters.
� Low Power Transmitter (LPT) and
�High Power Transmitter (HPT)
– Likewise, there are:
�Medium Wave (MW) radio broadcast transmitters and
� Short Wave (SW) radio broadcast transmitters

The transmitter that generates the RF1 power to drive the antenna is usuallylocated at some
distance from the antenna terminals. The connecting linkbetween the two is the RF
transmission .

FEATURESUp to 20kW transmitter output power per 19” standard rack
Fully digital exciter with digital input via AES/EBU or optional analog inputs
Direct Digital Synthesis (DDS)
Integrated stereo encoder with deviation limiter
High internal redundancy; even in 2.5kW version; dual redundant 24V power supply
Amplifier modules are hot-pluggable, only 25mW input power per module
Each amplifier module includes its own primary power supply unit
�Low output transistor junction temperatures for a high MTBF
31


Easy handling for comfortable replacement, each amplifier module weighs about 15kg
Multi-Transmitter-Option offers n+1 solutions in one 19” rack
Integrated air-cooling up to 10kW per 19” rack
Support of future proof function for SFN (Single and audio networks)

32


33


34


35


The 10kW VHF/FM Transmitter T3403 is designedfor frequency modulated broadcast, mono
or stereo,in the frequency range of 87.5 to 108 MHz.The integrated digital exciter offers fully
digital designand digital inputs via AES/EBU.The high-power VHF/FM transmitter familiy
includesthe power classes of 2.5kW, 5kW, 10kW and 20Kw

.

36


37


AMPLIFIERSAs mentioned earlier, antennas do not actually create power. They simplydirect all available
power into a particular pattern. By using a power amplifier,you can use DC power to
augment your available signal. An amplifierconnects between the radio transmitter and the
antenna, and has an additional.

Lead that connects to a power source. Amplifiers are available thatwork at 2.4�
GHz, and
can add several Watts of power to your transmission.These devices sense when an attached
radio is transmitting, and quicklypower up and amplify the signal. They then switch off
again when transmissionends. When receiving, they also add amplification to the signal
beforesending it to the radio.

Unfortunately, simply adding amplifiers will not magically solve all of yournetworking
problems. We do not discuss power amplifiers at length in thisbook because there are a
number of significant drawbacks to using them:
• They are expensive. Amplifiers must work at relatively wide bandwidths at2.4� GHz,
and must switch quickly enough to work for Wi-Fi applications.

EXCITERS -

a) DP/DG Corrector:
This unit is used for pre-correcting the differential gain of the final output of the
transmitter. The pre-correction is achieved by introducing nonlinearity introduced in
opposite tot hat of non-linearity existing in thedemodulated video from the 1 Kilo watt
output stays.

38


b) Low Pass Filter:
The Low Pass filter unit cuts off the video frequencies beyond 5 MHz so that video
information beyond 5 MHz does not interfere with the sound signal which will be appearing
as frequency modulated signal at 5.5 MHz and around in the RF spectrum. The resultant
group delay is corrected in a delay equalizer circuit in this unit to preserve video
characteristics.

c) Delay Equalizer:
This unit comprises of two sections namely the receiver pre-corrector and transmitter
delay corrector section. The former, the later or both or none can be brought into the line
up by selection on the front panel. The receiver pre-corrector required for achieving a god
video wave form at the domestic receivers where in delays are introduced .

39


e) IF Oscillator:
This unit generates using a crystal oscillator the visual I frequency of 38.9 MHz.
Four outputs are available in this unit of these four outputs are the first one goes to the
Visual Modulator Unit., second one is used for monitoring third one is taken to the Local
Oscillator and the fourth one to the Aural Modulator Unit.

f) Local Oscillator UnitThis unit generates the visual oscillator frequency (fc + 38.9 MHz) of the required channel.
The basic oscillator is crystal oscillator at fc/4 frequency. The crystal is housed
iproportionately controlled over to maintain frequency .stability..

40


MODULATION & DEMODULATION-

Modulatin is the process in which low or weak signasl are superimpose with high frequency
signals this process is called modulation.
Modulation are three types--1. Amplitude modulation
2. Frequency modulation
3. Phase modulation
41


In radio transmission frequency modulation is used for better performance.In frequency
modulation frequency does not overlap to onather frequencies but in amplitude
modulation frequency are easily can read soo it is not security.

FREQUENCY MODULATIONIn frequency modulation , frequency of the modulated signal is varied according to the
carrier wave.this is called frequency modulation.

Whereas in AM the amplitude of a sinusoidal function is varied with time to include
information of a message signal, in FM

and PM (phase modulation) we vary the phase with time. A pair of sinusoidal functions used
in baseband modulation of which only the phase varies with time can be expressed
as{Acos(ϕ (t)), Asin(ϕ (t))}. At any point in time, ϕ (t) has a certain value and is therefore
referred to as the instantaneous phase.

42


The rate of change of the instantaneous phase isindicated with the instantaneous frequency. In
FM, this instantaneous frequency is varied with the message signal

DEMODULATIONModulation consists of on-off keying of a carrier wave. To recover on-off keyed information.

we need a method of detecting the presence or absence of rf oscillations. The CW
DEMODULATOR detects the presence of rf oscillations
recognizable .

43

and converts them into a


FM DEMODULATION-

In fm demodulators, the intelligence to be recovered is not in amplitude variations; it is in the
variation of the instantaneous frequency of the carrier, either above or below the center
frequency. The 3-11 detecting device must be constructed so that its output amplitude will
vary linearly according to the
instantaneous frequency of the incoming signal, whereas in PM the instantaneous phase is
varied with the message signal.

44


ANTENNA-

Extremely important factor for good work of simple radio receivers is the outside antenna
that has to beNlong enough, and in which voltages induced by the radio transmitters will be
high enough. At first sight, one can think of using instead some modest antenna made of a
piece of wire, compensating that with supplying the receiver with amplifier strong enough to
give the end result as if much better antenna havebeen used. That, of course, is not the case,
since every amplifier creates noise that makes the reception worse, if not impossible. This
fact is the cause for a radio-amateur saying that "Antenna is the best HF amplifier." The
external (outside) antenna is being made of copper wire, thick enough to resist strong wind
conditions. In the sense of mechanical strength, the best thing is to use the litz wire (cable),

. Antennas demonstratea property known as reciprocity,..

45


Test Proposal: Test Case
_ VSWR Test
_ Frequency Band Test
_ Isolation between port Test
_ Direct Ground Test

Test Proposal
• TEST CASE:Huawei to submit test case for VT
• UNDERTAKING: Huawei to give undertaking where test is notpossible.
• LAB TEST REPORT: Huawei to give lab test reports for testwhich are not possible in field.

46


POWER SUPPLY-

There are four types of power supply which are .used in transmitter section. These are as
follows:

i) Filament Supply
ii) Bias supply
iii) Plate Voltage Supply
iv) Screen Grid Voltage Supply

i)

Fillament Supply:This supply for 1 KW PA (BEL 4000 Ix) is derived from a three phase full wave

rectifier using silicon rectifier. The rectifier is followed by a single section LC filter for the
reduction of ripples. The filament transformer is of the leakage type so as to limit the
starting current drawn by the valve filament under initial switching condition. The
transformer is provided with tapes to adjust the filament voltage precisely to the rated value.

ii)

Bias Power Supply:
This supply feeds the grid of 1 KW valve stage. It consist of 2

independent

sections of Dc power supply with a common ac input. The first section can deliver on O/P
adjustable voltage between-50V to -80V dc, while the second section can deliver in O/P
adjustable voltage between-80V to -120V dC each section has the capacity to supply current
of 200 mA and operates at an ac input voltage 200 V single phasesupply. During normal
operation the first section only is used. The second section is used as stand by in event of
failure of the first section.

47


iii)

Screen Grid Power Supply:

This provides a regulated output at 1000V dc. A constant voltage transformer (CVT) Tl
feeds a constant ac voltage through the magnetic amplifier. The O/P voltage can be adjusted
by changing the taps of the CVT. The screen voltages set between 700 V to 750 V & the
screen dissipation islimited to 100 W.

+ 28V SMPS :

The +28V SMPS unit consists of two separate 28V modules. Each module feeds one
80W power amplifier & the corresponding dual driver section. Remote sensing & TTL
ON/OFF facilities for each module are provided.

48


CONCLUSIONS
Akashvani, Alwar is a broadcasting and production type of organization. It basically deals
with the broadcasting of channels like DD National, DD News and regional channels.
It is a free of cost service. In villages where cable connection and other modes of
entertainments are not present Doordarshan is the only mode of entertainment and through
this they get connected to the outside world and stay updated.
The programmes are produced in
Delhi but some regional programmes are produced in DDK, Alwar. These are
entertainment, knowledge adding, health related, and general awareness and programmes on
heritage and culture.
To be in touch with new generation with not forgiving the heritage
and culture Doordarshan is the best way. Actually Doordarshan is covering all most 75% of
whole over India and as it is free of cost in these aspects it is No.1 service provider.
Service quality provided by Doordarshan is simply
appreciable. They are now providing HD signals. And you know that the Asian games
recording are recorded in HD format. Equipments and machines they are using are hightech. more than 10,000 employees are there in Doordarshan all over India. And the
technical and non-technical both staffs are perfectly trained in their respected field.

49


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