Ekran
Encyclopedia
Ekran was a Soviet-Russian type of geostationary satellite
, developed for a national system of Direct-To-Home television
.
The first satellite of Ekran series was launched in 1976. Each satellite in the Ekran series was designed to provide one TV and 2 radio
program channel
s to cable
TV system
s throughout the USSR and to individual home receiver
s in northern Siberia
. Ekran's downlink is in the UHF
range.
Early Ekran satellites used orbital positions in the range from 48 degree
s E to 95 degrees E, but recent Ekrans, including the current Ekran 20, have been stationed at 99 degrees E. These 3-axis stabilized satellites carry a single 24 MHz, 200 W transponder, feeding a 28 dB gain antenna
transmitting on right-hand circular polarization to produce equivalent isotropically radiated power
s in Siberia in the range 50 to 55 dBW at 714 MHz. The corresponding feeder link uses left-hand circular polarization at 6200 MHz. Therefore, almost every householder could receive the TV signal at home from Ekran's transponder
using a simple Yagi-Uda antenna
. There were also various kinds of collective or individual satellite receivers, such as Ekran KR-10, Ekran-KR-01 and Ekran. Latest version of receiver represents a simple individual TV set-top box
itself. A modified version of Ekran was called Ekran-M. Ekran satellites have been replaced by improved geostationary craft for DBS
, such as Gorizont, Gals, and Express.
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
, developed for a national system of Direct-To-Home television
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
.
The first satellite of Ekran series was launched in 1976. Each satellite in the Ekran series was designed to provide one TV and 2 radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
program channel
Television channel
A television channel is a physical or virtual channel over which a television station or television network is distributed. For example, in North America, "channel 2" refers to the broadcast or cable band of 54 to 60 MHz, with carrier frequencies of 55.25 MHz for NTSC analog video and...
s to cable
Cable
A cable is two or more wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables are used to carry...
TV system
System
System is a set of interacting or interdependent components forming an integrated whole....
s throughout the USSR and to individual home receiver
Receiver (radio)
A radio receiver converts signals from a radio antenna to a usable form. It uses electronic filters to separate a wanted radio frequency signal from all other signals, the electronic amplifier increases the level suitable for further processing, and finally recovers the desired information through...
s in northern Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
. Ekran's downlink is in the UHF
Ultra high frequency
Ultra-High Frequency designates the ITU Radio frequency range of electromagnetic waves between 300 MHz and 3 GHz , also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres...
range.
Early Ekran satellites used orbital positions in the range from 48 degree
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
s E to 95 degrees E, but recent Ekrans, including the current Ekran 20, have been stationed at 99 degrees E. These 3-axis stabilized satellites carry a single 24 MHz, 200 W transponder, feeding a 28 dB gain antenna
Antenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...
transmitting on right-hand circular polarization to produce equivalent isotropically radiated power
Equivalent isotropically radiated power
In radio communication systems, Equivalent isotropically radiated power or, alternatively, Effective isotropically radiated power is the amount of power that a theoretical isotropic antenna would emit to produce the peak power density observed in the direction of maximum antenna gain...
s in Siberia in the range 50 to 55 dBW at 714 MHz. The corresponding feeder link uses left-hand circular polarization at 6200 MHz. Therefore, almost every householder could receive the TV signal at home from Ekran's transponder
Transponder
In telecommunication, the term transponder has the following meanings:...
using a simple Yagi-Uda antenna
Antenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...
. There were also various kinds of collective or individual satellite receivers, such as Ekran KR-10, Ekran-KR-01 and Ekran. Latest version of receiver represents a simple individual TV set-top box
Set-top box
A set-top box or set-top unit is an information appliance device that generally contains a tuner and connects to a television set and an external source of signal, turning the signal into content which is then displayed on the television screen or other display device.-History:Before the...
itself. A modified version of Ekran was called Ekran-M. Ekran satellites have been replaced by improved geostationary craft for DBS
DBS
-Automobiles:*Aston Martin DBS, 1967–72 automobile model*Aston Martin DBS V12, 2008- automobile model, officially also called the Aston Martin DBS-Technology:*Database system*Discbox Slider, a carton board disc case...
, such as Gorizont, Gals, and Express.
External links
- Ekran satellite
- Ekran satellite : a short history of development
- Ekran-M
- Communicaion satellites : Voices from Space - in Russian
- Russian Geostationary Satellites
- Experiments of amateur Direct-To-Home reception of TV signal from Ekran satellite (included some photo)
- Development of direct satellite broadcasting
- Abstract
- Pacific Telecommunications Review