Training report on durdarsan

Chapter 1- INT RODU CTION

Doordarshan is the public television broadcaster of India and a division of Prasar Bharti, and nominated by the Government of India. It is one of the largest broadcasting organizations in the world in terms of the infrastructure of studios and transmitters.

Doordarshan Kendra is amilestone in the field of entertainment and education media source. Doordarshan, muzaffarpur is the Program Production Center and transmition .. The studios are housed at same campus and the transmitter is located at the muzaffarpur.

AIR and Doordarshan aims to provide information, education and entertainment for the public. Its network of 1400 terrestrial transmitters cover more than 90.7% of India's

1 GOVERNMENT POLYTECHNIC COLLEGE, BIKANER (Raj.)

Chapter 2- HISTORY

The birth of broadcasting in India has started on an experimental basis in year 1921 whenTimes 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. Government took over the charge of broadcasting in March 1935, a separate office of the controller of broadcasting was created. The land mark in the history of broadcasting is change of name of the Indian broadcasting to AIR in 1936 and in 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 onwards AIR was popularly known as akashwani.

On 12th November 1947 the voice of Gandhi ji was broadcasted in AIR and since then it is celebrated as broadcasting day. Television (Doordarshan) started in India in the year 1959 with black and white transmission. The black & white transmission was converted fully into

colour in 1982 during Asian games.


Chapter 3- SATELLITE COMMUNICATION

In telecommunications, the use of artificial satellites to provide communication links between various points on Earth. Satellite communications play a vital role in the global telecommunications system. Approximately 2,000 artificial satellites orbiting Earth relay analog and digital signals carrying voice, video, and data to and from one or many locations worldwide.

Satellite communication has two main components: the ground segment, which consists of fixed or mobile transmission, reception, and ancillary equipment, and the space segment, which primarily is the satellite itself. A typical satellite link involves the transmission or uplinking of a signal from an Earth station to a satellite. The satellite then receives and amplifies the signal and retransmits it back to Earth, where it is received and re-amplified by Earth stations and terminals. Satellite receivers on the ground include direct-to-home (DTH) satellite equipment,mobile reception equipment in aircraft, satellite telephones, and hand held devices.

Figure 1-Satellite Communication


3.1 SATELLITE ORBITS: a) GEOs = Geostationary Earth Orbits. b) LEOs -= Low Earth Orbits. c) MEOs = Medium Earth Orbits.

1. Geostationary or bit

A circular orbit 35,785 km (22,236 miles) above Earth’s Equator in which a satellite’s orbital period is equal to Earth’s rotation period of 23 hours and 56 minutes. A spacecraft in this orbit appears to an observer on Earth to be stationary in the sky. This particular orbit is used for meteorological and communications satellites. The geostationary orbit is a special case of the geosynchronous orbit, which is any orbit with a period equal to Earth’s rotation period.

2. Low- E arth-or b iting satellites

A Low Earth Orbit (LEO) typically is a circular orbit about 400 kilometers above the earth’s surface and, correspondingly, a period (time to revolve around the earth) of about 90 minutes. Because of their low altitude, these satellites are only visible from within a radius of roughly 1000 kilometers from the sub-satellite point. In addition, satellites in low earth orbit change their position relative to the ground position quickly. So even for local applications, a large number of satellites are needed if the mission requires uninterrupted connectivity.


Table 1-Comparion

S atellite communication

Started in 1960.

Uses Geo Stationary Satellite.

Operates in C-Band & Ku-Band.

Started in India in 1975.

First Indian Satellite INSAT launched in 1982.

Gulf War brought satellite television to prominence

Table 2-satellite transmission frequency bands


Table 3- Terrestrial television


3.2-Antennas:-

Antenna (or aerial) is a transducer that transmits or receives electromagnetic waves. In other words,antennas convert electromagnetic radiation into electrical current, or vice versa. Antennas generally deal in the transmission and reception of radio waves.

Figure 2- Antenna

Types of antenna:� Isotropic antenna (idealized)

Radiates power equally in all directions�

Dipole antennas

Half-wave dipole antenna (or Hertz antenna)

Quarter-wave vertical antenna (or Marconi antenna)�


Parabolic Reflective Antenna

A parabolic antenna is a high-gain reflector antenna used for radio, television and datacommunications, and also for radio location (radar),on the UHF and SHF parts of the electromagnetic spectrum. The relatively short wavelength of electromagnetic radiation at these frequencies allows reasonably sized reflectors to exhibit the desired highly directional response for both receiving and transmitting. A typical parabolic antenna consists of a parabolic reflector with a small feed antenna a tits focus. To find the focus, reflect the light of a flashlight off of the dish. When the reflected beam is parallel, the flashlight is at the focus. The reflector is a metallic surface formed into a paraboloid of revolution and (usually) truncated in a circular rim that forms the diameter of the antenna. This paraboloid possesses adistinct focal point by virtue of having the reflective property of parabolas in that a point light source at this focus produces a parallel light beam aligned with the axis of revolution. The feed antenna at the reflector's focus is typically a low-gain type such as a half-wave dipole or a small waveguide horn.

Figure 3- parabolic anteena


Chapter 4 – PROPAGATION M ODEDS

Ground-wave propagation

Sky-wave propagation

Line-of-sight propagation

Figure 6 - LOS


Chapter 5 - TV ST UDIO

Doordarshan has two studio halls. One is used as News Room and the other one is used for shooting various programs. Artificial sets are created in the studio hall according tor equirements of the program to be shooted.

5.1-PROCEDURE IN RE ORDING

Set is designed in studio as per conceptual thought of program producer. Floor plan is envisaged. Lighting, Audio and placement of the cameras is arranged as per floor plan. Pre testing of cameras, microphones, VCRs etc. is done before recording. Recording begins and desired camera / mike are selected through VM/ Audio

console as per command of producer. Program is recorded on VCR.

5.2-PROCEDURE IN TRANSM ISSION

The programs are transmitted as per the daily cue sheet.

Normal transmission hours are 1600-2000 Hrs.

Cue sheet is discussed daily by program and technical staff for details in it and for any last moment changes if any.

After getting D-link caption from Delhi end program is played from VCR /Server. The program is uplinked by Earth Station.

The program is also transmitted to transmitter at HPT Nahargarh via MW link.

During our slot, both live as well as recorded programs are transmitted.Around 2000 Hrs after getting linking caption from DD# 1, the signalfrom DD#1 is selected and accordingly transmitted by HPT/ ES.

5.3-Video signal generation

Video is nothing but a sequence of pictures. The image we see is maintained in our eye for 1/16sec. So if we see images at the rate more than 16 pictures/sec, our eyes cannot recognize the difference and we see the continuous motion. In movies camera and movie projector it is found that 24 fps is better for human eyes. TV system could also use this rate

10

GOVERNMENT POLYTECHNIC COLLEGE, BIKANER (Raj.)

but in PAL system 25fpm is selected. In TV cameras image is converted in electrical signal using photosensitive material. Whole image is divided into many micro particles known as pixels. These pixels are small enough so that our eyes cannot recognize pixels and we see continuous image. Thus, at any particular instance there are almost infinite numbers of pixels that need to be converted in electrical signal simultaneously for transmitting picture details. How ever this is not possible practical because it is no feasible to provide a separate path for each pixel. In practice this problem is solved by method known as “Scanning” in which information is converted one by one pixel, line by line and frame by frame.

5.4-COLOUR COMPOSITE VIDEO SIGN AL

Active waveform comprises of 2 signals:

Luminance(Y)-black and white

Chrominance(C)- colour signal

Figure 7- CCVS

11


5.5-COMP ONEN TS OF TV STUDIO

Camera

Lighting

Microphones

Vision mixer and Audio consoles

MSR

VCR /Servers

Acoustics

Post production and video effects

supporting services like AC, UPS

12


Chapter 6- TV CAMERA

A TV Camera consists of three sections:

a) A Camera lens and optical block b) A transducer or pick up devicec) Electronics

6.1-CAMERA LENS

The purpose of the camera lens is to focus the optical energy at the face plate of a pickup device i.e. to form an optical image. The lens has following sections:1.Main focus section

2. Zoom section with manual or servo mode operation.

3.Servo drive assembly for Zoom and iris control.

4. Aperture section with manual or auto mode.

5. Back focus section with adjustment facilities for back and micro focus.

Figure 8- Camera lens

6.2- TRA NSDU CER PICK UP DEVICE

13


R, G & B signals, as separated by the optical block are converted to electrical signal in the transducer section of the camera. It is then processed in camera electronics to give CCVS (color composite video signal) output.

Chapter 7- LIGHTING

Lighting for television is very exciting and needs creative talent. There is always a tremendous scope for doing experiments to achieve the required effect. Light is a kind of electro magnetic radiation with a visible spectrum from red to violet i.e. wavelength from 700 nm to 380Nm respectively.

Basic three pointing lighting

Key light :- It gives shape and modeling by a casting shadow. It is treated as a “sun” in the sky and should cast only one shadow.

F ill light :- Controls the lighting contrast by filling in shadows. It can also provide catch lights in the eyes.

Back light:-Separates the body from the background, gives roundness to the subject and reveals texture.

Background lights:- Separates person from the background and reveals background interest and shape.

Lighting equipments:-

HMI lights compared to standard incandescent lights deliver five times the light output per watt. They generate less heat, which is an important consideration when shooting inside in a confined space. (HMI stands for Hydrargyrum Medium Arc-length Iodide). The light on the left side of this picture is a HMI light; the one on the right a standard quartz light.

Figure 9- lighting equipment

14


Cycs (large, seamless, neutral backgrounds) can be lit from the top and bottom with cyclights.The one here sits on the studio floor and is directed up at the background

Chapter 8- MICROPH ONES

A microphone is an acoustic-to-electric transducer or sensor that converts sound in to an electrical signal.

8.1- TYPES OF MICROPH ONES

1.C ONDENSER MICROPHONE:-

In a condenser microphone also called a capacitor microphone or electrostatic microphone, the diaphragm acts as one plate of a capacitor, and the vibrations produce changes in thedistance between the plates.

Insulator very high resistance hantom power

Figure 10- condenser microphone

2. ELECTRET C ONDENSER MICROPHONE

15


An electret microphone is a relatively new type of capacitor microphone invented at Bell laboratories in 1962 by Gerhard Sessler and Jim West. An electret is a ferroelectric material that has been permanently electrically charged or polarized. The name comes from electrostatic and magnet; a static charge is embedded in an electret by alignment of the static charges in the material, much the way a magnet is made by aligning the magnetic domains in a piece of iron.

3. DYNAMIC MICROPHONE:-

Dynamic microphones work via electromagnetic induction. They are robust, relatively in expensive and resistant to moisture. This coupled with their potentially high gain before feedback makes them ideal for on-stage use. Moving-coil microphones use same dynamic principle as in loudspeaker, only reversed

Figure 11- Dynamic microphone

4. RIBBON MICROPHONE:-

Ribbon microphones use a thin, usually corrugated metal ribbon suspended in a magnetic field. The ribbon is electrically connected to the microphone's output, and its vibration within the magnetic field generates the electrical signal. Ribbon microphones are similar to moving coil microphones in the sense that both produce sound by means of magnetic induction.

magnets

16


Figure 12- Ribbion microphone

5. P IEZO EL ECTRIC MICROPHONE:-

A crystal microphone or piezo microphone uses the phenomenon of piezoelectricity - the ability of some materials to produce a voltage when subjected to pressure - to convert vibrations into an electrical signal.

6. LASER MICROPHONE:-

Laser microphones are often portrayed in movies as spy gadgets. A laser beam is aimed at the surface of a window or other plane surface that is affected by sound. The slight vibrations of this surface displace the returned beam, causing it to trace the sound wave. The vibrating laser spot is then converted back to sound. In a more robust and expensive implementation, the returned light is split and fed to an interferometer, which detects movement of the surface.

7. FIBER OPTIC MICROPHONE:-

A fiber optic microphone converts acoustic waves into electrical signals by sensing changes in light intensity, instead of sensing changes in capacitance or magnetic fields as with conventional microphones.

17


Figure 13- fiber optic microphone

Chapter 9- V IDEO CHAIN

The video we see at our home is either pre-recorded in studio or live telecasted. Block diagram shown in fig illustrates different chains of video recording, video playback, news, and live broadcasting. In First chain we will understand studio program recording. Camera output from the studio hall is sent to CCU where many parameters of video signals are controlled. Output signal of CCU after making all corrections is sent to VM in PCR-1 (production control room).Output of 3 to 4 cameras comes here and final signal is selected here using VM according to a director’s choice.

18


Figure 14- VIDEO CHAIN

The final signal from VM is sent to VTR. VTR uses both analog and digital tape recording system. At the time transmitting this pre recorded program cassettes is played in to respective in VTR room. Signal from VTR is sent to PCR-2. PCR-2 has one VM, video monitoring system, and CG (Computer Graphics). From PCR-2, signal travels from MSR to Transmitter or Earth-station for terrestrial and satellite transmission.MSR is the main control room between studio and transmitter or receiver.

Chapter 10-A UDIO CHAIN

In studio program, audio from studio microphones is directly fed to the “AUDIO CONSOLE” place in PCR-1. It is used to mix audio from different sources and maintain its output. From AC, signal is directly recorded on tape with video signal in VTR. While playing back audio is extracted from tape and fed to another audio console placed in PCR-2 and then travels with the video signal.

19


Chapter 11- V ISION M IXER

Vision mixer is the almost final equipment in programme (video) production and its output is used either for recording or transmission.Vision mixing is the process of providing a composite signal from various input sources. It has many input sources such as cameras, VCR/server, Graphics, IRDs. Out of these i/p, any source can be taken on o/p. It is used to switch or cut between 2 video sources, or to combine them in a variety of ways.

20


Figure 16- additive mixing

21


Figure 17- non additive mixing

11.1 TRANSIT ION/SWI TCHING

It involves: Cut

Mix

Wipe

Fade

Keying

Special effects

CUT

The cut is an instantaneous switch from one picture to another. It avoids the frame roll & flash evident, on picture at the moment of cutting.

MIX

It uses additive mixing. The transitions here are less pronounced. As the faders are operated, the established picture fades away, while the new picture progressively.

Chapter 12- MASTER SWITCHING ROOM 22


Master switching room (MSR) is used for transmission media. It is the engineering co-ordination center of activity for selecting & routing the signal from various sources to transmitter and earth station. It is a room where all different sources from the outside studio comes first here and enroots transmission to different destination like transmitter & earth station. This room comprises of Routine switcher, Stab amplifier, Video/Audio distribution amplifier etc.

It is the heart of the studio. Most of the switching electronics are kept here e.g. camera base stations, switcher mainframe, SPG, Satellite receivers, MW link, DDA & most of the patch panels. Signal is routed through MSR. Signal can be monitored at various stages.

A UDIO C ONSOL E

It has many input sources such as microphones, VCR/server, IRDs, tone generators. Out of these i/p, any source can be taken on o/p Audio level of Sources can be adjusted and audio effects can be added.

23


Chapter 13- EARTH STATION

The digital earth station operates in the frequency range of 5.85 GHz to 6.425 GHz for transmission and 3.625 to 4.24 GHz for reception of signals. The whole system operates with DVB/MPEG2 Standards. The base band processor subsystem and base band monitoring subsystem operates in fully digital domain. An OFC carries digital base band signal from studio to earth station site to minimize the noise and interference. It is controlled by a PC called NMS PC.

The compression segment has an MPEG encoder, digital multiplexer and digital modulator. The monitoring and receiving segment comprises of two digital receivers for receiving and decoding program. The output of modulator (70 MHz) is sent to an up converter. The up converted signals are sent to an HPA. Then this signal is given to a PDA (parabolic dish antenna) for up linking to satellite. The uplinked signal is received again by the same PDA for monitoring purposes. The signal between earth station and satellite are given along line of sight which means there must be a clear path from earth to satellite. The uplink signal is fed from the earth station by a large PDA. The satellite is equipped with its own dish antenna which receives the uplink signals and feeds them to a receiver. The signal is then amplified and changed to a different frequency which is downlink frequency. This is done to prevent interference between uplink and downlink signals. The down linked signal is then again sent to the transmitter which again retransmits it. Each satellite has a transponder and a single antenna receives all signals and another one transmits all signals back. A satellite transmits signals towards earth in pattern called the satellite footprint of the satellite. The footprint is strongest at centre and the footprint is used to see if the earth station will be suitable for the reception of the desired signal Converts.

The parts of the DES are Antenna subsystem including LNA Antenna control unit, beacon tracking unit, beacon tracking receiver and up converter system high power amplifier and power system. The system operates in 2 +1mode and is compliant with DVBMPEG 2standards. The base band processor subsystem and base band monitoring system operates in digital domain. An OFC contains the digital base band signal for studio to earth station to minimize noise interference.

The network management system or NMS monitors and controls baseband equipments compression equipments and test instruments like video audio generation and video audio analyzer. They are provided to ensure quality of transmission and help trouble shoot. The base band segment comprises of baseband subsystems at studio site and base band subsystem at earth station site. This baseband segment processes two video Programmes. The base band segment is monitored and controlled using a PC placed near the base band earth station equipments called base band NMS PC. The compression segments comprises of Mpeg encoders in 2 +1 configuration for providing redundancy. It also

24


comprises of digital multiplexers and digital modulators in 1 +1 configuration. The compression segment is monitored and controlled by compression NMS PC. The receive and monitoring segment consists of two digital receivers for receiving and decoding of the video programs and one ASI to SDI decoder for decoding of the transport stream for monitoring video programs at the multiplexers output. RF NMS PC is placed near the receive monitoring segment and video audio generator placed in the base band segment. For monitoring of video programs professional video monitor, LCD video monitor and audio level monitor are provided in the base band segment. An operator console has one 14” professional video monitor a video audio monitor unit for quantitative monitor of video programs and a personal computer for centralized merit and contention of earth station sub system.

13.1 C OMP ONEN TS

PDA(parabolic dish antenna)

IRD(Integrator receiver decoder)

Multiplexer

Encoder

FEED

LNA(Low noise amplifier)/LNBC(low noise block converter)

Waveguide

HPA(TWTA, SSTA, Klystron)

Up Converter

25


Figure 18- Earth station

Digital E arth Station

Earth station is the main part which communicates with satellite in which up linking and downlinking of the signal into/ from the satellite takes place for TV transmission. Earth station is a purely digitization version. The signal is uplinked from the earth station and received by many downlink centers in TV broadcasting. It is a very important part of satellite communication system for broadcasting of signals. A ground-based receiving or transmitting/ receiving station in a satellite communications system. The counterpart to the earth station is the satellite in orbit, which is the "space station." Earth stations use dish-shaped antennas, the diameters of which can be under two feet for satellite TV to as large as fifty feet for satellite operators. Antennas for space exploration have diameters reaching a hundred feet.

Multiplex, Modulate and U p convert

An earth station is generally made up of a multiplexor, a modem, up and down converters, a high power amplifier (HPA) and a low noise amplifier (LNA). Almost all transmission to satellites is digital, and the digital data streams are combined in a multiplexor and fed to a modem that modulates a carrier frequency in the 50 to 180 MHz range. An up converter bumps the carrier into the gigahertz range, which goes to the HPA and dish. Down convert,

D emodulate and D e multiplex

For receiving, the LNA boosts the signals to the down converter, which lowers the frequency and sends it to the modem. The modem demodulates the carrier, and the digital output goes to the demultiplexing device and then to its destinations.

E arth S tation classification

Analog Earth Station

Digital Earth Station

ASNG

DSNG

C-band or Ku-band

Prob lems of Analog

One programme per channel/transponder Comparatively noisy

26


Ghosts in Terrestrial Transmission Lower quality with respect to VCD, DVD digital medium‡ Fixed receptionWhy D igital?

More programmes per channel/Transponder i.e. spectrum efficient.

Noise-Free Reception.

Ghost elimination.

CD quality sound & better than DVD quality picture.

Reduced transmission power.

Flexibility in service planning.

Process involved in transmission of signal

Up-Conversion

High power amplification

Transmission

Reception Up-Converters

The up-conversion is required to raise the frequency of the signal in desired band: C- band, Extended C-band or Ku-band before transmission. The input to up converter is 70 MHz (output of modulator) and output of Up-converter is fed to HPA.The up-conversion may be done in stages or in one stage directly. The 70 MHz signal is first converted into L ±band and then L band signal raised to desired frequency band.

High power amplification

The high power amplifier is used for the final power amplification of the digital RF signal in C-band/Ku band that is fed to the antenna. The important parameters of HPAs are:

1. Frequency range

2. Output power at flange

3. Bandwidth

4. Gain variation (1.0db (max.) for 40 MHz (narrow band)

27


5. 2.50db for full bandwidth.

T he different types of HPAs are

1. KHPA - Klystron High Power Amplifier

2. TWTA -Traveling Wave Tube Amplifier

3. SSPA- Solid state Power Amplifier

28


Chapter 14- TRANSMITTER

The most widely used narrow beam antennas are reflector antennas. The shape is generally a paraboloid of revolution.

For full earth coverage from a geostationary satellite, a horn antenna is used. Horns are also used as feeds for reflector antennas.

A small earth terminal, the feed horn is located at the focus or may be offset to one side of the focus.

Large earth station antennas have a sub reflector at the focus. In the Cassegrain design, the sub reflector is convex with an hyperboloid surface, while in the Gregorian design it is concave with an ellipsoidal surface.

These antennas are used to transmit signal from earth station to satellite.

Figure 19

29


Chapter 15- RECEIVER

The most widely used narrow beam antennas are reflector antennas. The shape is generally a paraboloid of revolution.

1. For full earth coverage from a geostationary satellite, a horn antenna is used. Horns are also used as feeds for reflector antennas.

2. They are basically used to receive signals from the satellite which were transmitted by transmitter.

3. All the waves which fall on receiver are being focused on the feeder which is placed at the center of receiver antenna.

4. This feeder collects all the waves and sends to master switching room through cable sand wires.

5. After that again down conversion and decoding of signals takes place and in this manner we receive our information.

30


Figure 20- Receiver

Chapter 16 ELECT RONI C NEWS GATH ERING

ENG gather news from different outside locations. Its components:

1. Camera

2. Tripods

3. Mikes

4. Lights

5. Camera battery

6. Camera charger

31


7. Camera adapter

8. Headphone

9. Camera cassette

The job of journalists is fulfilled only when their news reaches the viewers, this is why they long for great challenge ± “ability to be present anywhere, anything´. This means faster news from anywhere anytime to everywhere. Further there is a need to send news footages in the shortest possible time and practically from any location. Technologically, Doordarshan has always been far ahead of its competitors. When it came to remote newsgathering, Doordarshan has set precedence by using innovative and cost effective methods.

Chapter 17- OB Van

Outside broadcasting is the production of television or radio programmes (typically to cover news and sports events) from a mobile television studio. This mobile control room is known as an "Outside Broadcasting Van", "OB Van", "Scanner" (a BBC term), "mobile unit", "remote truck", "live truck", or "production truck". Signals from cameras and microphones come in to the OB Van for processing and transmission. A typical OB Van is usually divided into 5 parts:

The 1st and largest part is the production area where the director, technical director, assistant director, character generator operator and producers usually sit in front of a wall of monitors. This area is very similar to a Production control room. The technical director sits in front of the video switcher. The monitors show all the video feeds from various sources, including computer graphics, cameras, video tapes, video servers and slow motion replay machines. The wall of monitors also contains a preview monitor showing what could be the next source on air and a program monitor that shows the feed currently going to air or being recorded. Behind the directors there is usually a desk with monitors for the editors to operate. It is

32


essential that the directors and editor are in connection with each other during events, so that replays and slow-motion shot scan be selected and aired.

The 2nd part of a van is for the audio engineer; it has a sound mixer. The audio engineer can control which channels are added to the output and will follow instructions from the director.

The 3rd part of van is video tape. The tape area has a collection of VTRs and may also house additional power supplies or computer equipment.

The 4th part is the video control area where the cameras are controlled by 1 or 2 people to make sure that the iris is at the correct exposure and that all the cameras look the same.

The 5th part is transmission where the signal is monitored by and engineered for qualitycontrol purposes and is transmitted or sent to other trucks.

Figure 21- OB van

33


Chapter 18- DD Direct+

DD Direct:

Carries all channels of DD directly to homes.

Also carries few private channels and radio channels of AIR.

F eatures:-

Cost effective alternate to cable TV.

One time expenditure for procuring receive system by viewer.

No monthly/activation charges from subscriber.

No smart card/CAM module required for reception.

Receive Eqpt. consists of a 60/90cm Dish Antenna, a Block converter and a Set Top Box (STB). STB readily available in the open market.

Dealers of the equipment available all over the country.

Indicative cost of the receive system ± Rs 3000 to Rs 3500.

Cost likely to come down further with volumes.

34


Figure 22- DD Direct+Doordarshan, the national television service of India, is devoted to public service broadcasting. It is one of the largest terrestrial networks in the world. In my Industrial training at Doordarshan Kendra, Jaipur, I have gained useful knowledge which will surely be of great help in future. This training gave me an opportunity to learn the practical aspects of the knowledge of my field of interest, Electronics and communication.

35


Chapter 19 : Fututre scope

Doordarshan, the national television service of India, is devoted to public service broadcasting. It is one of the largest terrestrial networks in the world. Doordarshan is the first ISO certified channel in India. The largest viewer of India ,watching Doordarshan. It has good future scope in communication world. Because largest network covered by the doordarshan only.

As now a days there is a huge competition and everything is getting digitized there is a wide scope for electronics and communication engineers to show their skills and keep the technology up to date.

In Doordarshan, all the electronic devices used are to be operated by skilled engineers.

It provides with good pay scales.

The selection for the posts is through UPSC examinations.

36


Conclusion

Doordarshan, the national television service of India, is devoted to public service broadcasting.

It is one of the largest terrestrial networks in the world. In my Industrial training at Doordarshan Kendra, hanumangarh, I have gained useful knowledge which will surely be of great help in future.

This training gave me an opportunity to learn the practical aspects of the knowledge of my field of interest, Electrical & Electronics Engineering.

0

37


REFRENCES

www.google.com www.wikipedia.org www.4shared.com www.electronics4you.com

38


Date post:	13-Aug-2015
Category:	Engineering
Upload:	budhi-prakash
View:	143 times
Download:	3 times