In 1961, the communications satellite "Relay" was launched, transmitting television signals. That same year "Syncom" was the first geosynchronous satellite that was capable of transmitting signals continuously in one section of the earth's surface. It wasn't until the 1970s, though, that satellite television became available. Cable television stations were equipped with satellite dishes that received signals that were sent to coaxial cable subscribers. By 1976, cable companies owned 130 satellite dishes.
Since their invention, satellite dishes perform important functions in today's modern world of communications. Satellite dishes transmit signals from a parabolic television antenna that receives signals from communication satellites orbiting earth. The signals are fed by an extended rod, or a steel feed horn, that protrudes from the middle of the satellite dish that are then picked up by cable stations broadcasting television channels. The signals offer viewers with a wider array of television channels.
The original satellite dishes were made of heavy fiberglass and measured at least 10 feet in diameter. The parabolic reflectors of today's typical satellite dishes are much smaller and are instead made of the lighter-weighted aluminum mesh. The mesh or shroud is installed on the dish's perimeter that is perpendicular to its side. This is done to reduce interference and to allow for a better signal. The actual cables are made from vinyl tubing and copper wiring.
The typical satellite has a common, identifying look. Along with the parabolic reflectors which measure at least three feet in diameter and the steel feed horns, satellite dishes also have steel actuators which enable the dish to receive signals from more than one satellite. This allows customers to pick up a variety of television channels and programming choices. Satellite dishes are commonly installed on roofs, though they can be installed in yards as well. Concrete is often used as a foundation for the dishes.
Commercial satellite dishes switched from fiberglass to aluminum because fiberglass tends to be much heavier. Aluminum is not only lighter, but it enables manufacturers to build smaller satellite dishes that can be marketed for commercial home users. During the 1970s, satellite dishes measured ten feet in diameter, making them unwieldy for commercial home use. They were also more expensive. Today, aluminum satellite dishes are not only lighter and smaller, but some are less inexpensive, making home satellite dishes more readily affordable and common.