We have all seen satellite dishes on rooftops all over America. You might already be a subscriber to DIRECTV or DISH Network, but you do not know how the signal travels to your television set. You might ask yourself, how does a satellite TV dish work anyway? Very good question and you have come to the right place for your answers.
For communication to exist between the dish on your roof and the satellite orbiting the earth, they need to stay in direct line view of each other, 24 hours a day. Since your house is not going anywhere, staying in direct line view rests on the satellite in the sky. This is accomplished by the satellite orbiting in what is called the “Clarke Belt” (area in space approximately 22,000 miles above the plane of the equator at sea level). The orbit path for a satellite in the Clarke Belt is approximately 165,000 miles long, which means the satellite is traveling at 6,875 mph to stay locked on the dish affixed to your house.
The Clarke Belt is chosen for the path of communications satellites because the distance from the earth places the satellite in an area of space where the gravitational (pull toward earth) and centrifugal (push away from earth) are in equilibrium. In addition, the distance and position from the earth for the satellite remains fixed. Although the earth and the satellite are physically moving, to the novice astronomer the satellite would appear to be stationary.
Satellite TV Signal Path
The programming choices enjoyed by the viewer at home have traveled many miles before reaching your television. The signal is packaged at a television studio and compressed into MPEG 4 format (excellent quality for HD content). After compression, the signal is sent to an up link station to be transmitted to the satellite orbiting the earth. From there, the signal is transmitted directly to the dish located on the outside of your home or business.
The Dish
The original satellite TV dishes from the 1970s could not be mounted to the side of a building or the eaves of a roof due to weight from heavy fiberglass and their cumbersome size, a whopping 10 feet in diameter. Todays dishes are a modest 18″ in diameter and are made of lightweight aluminum mesh.
Both DIRECTV and DISH Network receive transponder signals from the orbiting satellite in Ku or Ka bands. These bands denote the frequency of each signal and both DIRECTV and DISH Network integrate a built in switch to handle the Ku and Ka satellite signals.
Programming Choices
Now that television has made the transition from analog to digital, the future for satellite programming choices are also digital. With analog, only one channel per transponder could be used, but digital can handle up to 10 channels per transponder. This means a substantial savings for the broadcaster and the consumer. Satellite TV has programming in HD and more than 250 viewing choices and a variety of packages to boggle the entertainment mind!
Taylor Jensen writes about DISH Network and DIRECTV,is considered an expert in the field of satellite TV,HD TV, DVR, sports on TV, and has published hundreds of articles informing consumers about what to look for when considering satellite TV service for your home.
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