Satellite TV
           Satellite TV is a broadcasting service which  allows            subscribers to receive television signals through a  dish-shaped            receiver unit. These signals are originally uploaded to a            communications satellite that is in a fixed orbit above the  earth, and            then electronically scrambled to prevent unauthorized  downloading.            Those who pay a subscription fee for satellite TV service are  issued            both the receiving dish and a
 descrambler. The actual tuning            information is fed into the 
television through a cable, much  like the            earth-bound cable 
television services in competition with  satellite TV            providers.
  Satellite TV solves
 many of the problems  associated            with earlier television 
broadcasting methods. Television  stations            originally 
broadcast their signals in two specific radio wave  bands-            VHF (very high frequency) and UHF
 (ultra-high frequency).  Aerial            antennas placed on roofs or 
attached to the television itself  would            receive as much of 
these radio wave transmissions as possible,  but the            results could be barely watch able depending on the strength  of the            signal, the terrain between the station and the television  set, and 
           the atmospheric conditions. Cable television systems could  
provide a            better television signal, but this involved 
stringing miles of             insulated wire and creating subscription services.
           Satellite TV provides a strong digital signal  to            subscribers' television sets and is almost completely  wireless.            Earlier satellite TV systems
 used very large dish receivers in  order            to focus the 
distant signals onto a powered antenna. Since  different            
television channels were located on different communication            satellites,
 these dishes would have to physically turn to            predetermined 
points in the sky in order to receive the proper             signals. 
Because regulation of these early dishes was not  uniform,
            illegal electronic descramblers became a lucrative 
underground  market.            Stiffer penalties for unauthorized 
descramblers paved the way  for            legitimate satellite TV subscription services.
           Modern satellite TV services have streamlined  the            process. A single communication satellite now
 remains in a  steady            orbit above the Earth, allowing all 
subscribers to mount a  much            smaller dish receiver at a fixed
 point. Technicians from the  satellite            TV provider may install the dish or owners can determine the  proper            receiving angle and do it themselves. Instead of scanning  various            satellites for different channels, modern satellite television
             providers license the use of popular cable or broadcast  
channels. Much            like a cable system, the tuner descrambles 
selected programs  sent out            on a specific frequency. This 
allows satellite providers the  option of            pay-per-view movie rentals or the blocking of adult-oriented  or            premium movie channels.
           Satellite TV services are especially popular in  rural            areas with poor broadcast reception and/or no cable service.  Purchase            of a receiving dish is generally limited to homeowners, not  renters.            Satellite dishes must have a clear line of sight to the  satellite 
           itself for best reception. Some homeowners discover that a  
grove of            trees or mountainous terrain can be problematic. 
Critics of  satellite            TV also mention reception problems during heavy rains or  snowfall.            Signals between an earth-bound receiver and a space-based  satellite 
           can be affected by atmospheric conditions between them, but  
other            television services also have similar drawbacks. Many  
customers prefer            the additional channels available on satellite TV systems and  the            clarity of the digital signals.
 
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