ASeminar

On “DOORDARSHAN”

Taken At DOORDARSHAN KENDRA , JAIPUR

SUBMITTED BY:ASHISH JAISWALIV Yr. ECE (014)

GUIDED BY:Prof. (Dr.) A. WILLIAMSONDean & H.O.D

http://powerpointpresentationon.blogspot.com

COMPANY PROFILE

• DOORDARSHAN- Broadcasting Corporation of india.

• Head Office : Copernicus Marg, New Delhi.• Dir. General : Ms. Aruna Sharma• Engineer -in- Chief : Mr. R.R. Prasad• Chief Executive Officer: Mr. B.S Lalli• Jaipur Station Engineer : Mr. R.S. Tyagi• Website: www.ddindia.com

AIM / SERVICES

• Awareness by means of – krishi darshan, Kalyani, Paramarsh, etc.

• Knowledge by means of – Prashnotri, Khuli Charcha, etc.

• Entertainment by means of – Chitrahaar, Sanskriti Darpan & live Coverages of other activities, etc.

CONTENTS• Introduction• TV STUDIO• VISION MIXER• AUDIO/ VIDEO CHAINS• MSR • EARTHSTATION• TV Tx• ANTENNAS & SATELLITES• OB VAN & DSNG• SETUP IN RAJASTHAN

INTRODUCTION

To Broadcasting• A process of sending information to a distant

place is called Broadcasting.• Need ?• Means of Broadcasting in India:

1. Terrestrial 2. Satellite3. Internet• Both AIR & DD make use of both Terrestrial &

satellite.

• Intro cont...• Broadcasting started in India in the year

1923.• AIR was formed in the year 1936.• In 1947, AIR was covering 2.5% & about

11% of land & population respectively.• 1st T.V Station was established in Delhi in

1959• T.V was separated from AIR in 1976

• Intro cont...• DD has 1500 Transmitters and 70

Production centers across the Country.• These centers are divided in 3 levels-National centers-Regional centers-Local centers • On 1st June 1987, Jaipur Doordarshan

Kendra was set up at Jhalana Doongri and transmission started on 6th July 1987.

TV STUDIO

• A television studio is an installation in which television or video productions take place .

COMPONENTS OF TV STUDIO

• Camera• Lighting• Microphones• Vision mixer and Audio consoles• MSR• VTR• Acoustics• Post production and video effects• Supporting services like AC, UPS

VISION MIXER• A vision mixer (also called video

switcher, video mixer orproduction switcher) is a device used to select between several different video sources and in some cases mix video sources together and add special effects.

• It has many input sources such as cameras, VCR/ server, Graphics/Character Generators,etc.

• Out of these i/p, any source can be taken as o/p.

• Sources can be changed as cut to cut, dissolve, wipe and other special effects.

TYPICAL VIDEO CHAIN

TYPICAL AUDIO CHAIN

DistributorVision Mixer LOGOGenerator

Earth station through

Optical Fiber

STLLink

Sources

DistributorAudio Console

Analog to AES

Converter

Earth station through

Optical Fiber

Sources

STL Link

MSR

• It is the heart of the studio.• Most of the switching

electronics is kept e.g. camera base stations, switcher main frame, SPG, Satellite receivers, MW link, DDA & most of the patch panels.

• Signal is routed through MSR.• Signal can be Monitored at

various stages

EARTH STATION• Earth Station is a very important part of satellite

communication system for broadcasting of signals.

• It is an uplink center from which the signals are fed to Satellite for distribution in a specified area covered by the Satellite.

• The signal is up-linked from the Earth Station and received by many down link centers in TV broad casting via PDA.

• Two Types: 1) Analog2) Digital• Digital Earth Stations are widely used because of

various advantages over analog.

Major Components of Digital Earth Station

• PDA (Parabolic Dish Antenna)• FEED• Wave Guide / Low Loss Cable• HPA (TWTA, Klystrons)• Up converter• Modulator• Encoder• Multiplexer• IRD (Integrated Receiver Decoder)

Types of TV Transmitters • VLPT’s, LPT’s & HPT’s• A 10 KW HPT of Jaipur zone is

situated at the highest mountain peak i.e Nahargarh.

• It is only 10-20% efficient.• It has beamwidth of 360 deg,

hence can cover upto 65 kms of area around it.

• It has various other supporting units with it to maintain the quality of s/g to be Txd. Like- Monitoring section, blower section, amplification section

Antennas & Satellites• An antenna (or aerial) is a transducer

designed to transmit or receive electromagnetic waves. In other words, antennas convert electromagnetic waves into electrical currents and vice versa.

Electromagnetic waveElectrical signal

Transmitting Antenna

Receiving Antenna

TYPES

• Isotropic antenna (idealized)o Radiates power equally in all

directions• Dipole antennas

o Half-wave dipole antenna (or Hertz antenna)

o Quarter-wave vertical antenna (or Marconi antenna)

• Parabolic Dish / Reflective Antenna

OB Van & DSNG

• A typical OB Van is usually divided into 4 parts.

• The first and largest part is the production area or sitting area for all directors & producers.

• The second part of a van is for the audio engineer.

• The 3rd part of the van is video tape

• The 4th part is transmission where the signal is monitored by and engineered for quality control purposes and is transmitted or sent to other trucks.

• DSNG is a portable uplinking centre.

DD Setup In Rajasthan• Modes-

-Terrestrial (Area coverage – 72%)-Satellite (Area coverage – 100%)• Transmitters - 90• Satellite – INSAT• Transponder used - C-6• Satellite Position - 93.5’ E• Uplinking frequency – 6165.5 MHz• Downlinking frequency – 3940.5 MHz• Modulation Scheme - QPSK

Thank You

Any Queries?