Satellite Tv Service

Television broadcasts started before the digital revolution started. As such it, and its little brother radio, began with analog signals. Analog signals are better adapted to the vacuum tube technology that was used in the early days of both television and radio. With the rise of transistors and integrated circuit boards in the 1960's it became possible to convert to the more efficient digital format. Unfortunately, too many people had invested money in equipment that was only suited to the analog format. Besides there was still the one large vacuum tube in all television sets, the picture tube.

Analog signals were perfectly fine for television programming. Pictures and sound did not require large amounts of information processing. The wide signal bandwidth necessary for the transmission was not a problem because there were few local broadcasters taking up little of the electromagnetic spectrum set aside for television in any given area. All of this meant that there was no incentive to change from old style analog broadcasting to digital broadcasting.

Digital circuits made their way into television sets anyway. The digital tuner enabled television sets to pull in stations that were further away. Various digital filters and signal processors were added to increase the quality of the picture seen on the set. Even with all of these digital circuits the broadcast was still analog.

It wasn't until the 1980s that there became a need for digital broadcast, not over the airways but over the cable systems. The explosion of cable channels made bandwidth conservation a necessity. The analog television signal was processed by the cable supplier into a digital signal that was then sent out over their wire (and later fiber-optic) cables to the set top box where it was reconverted to an analog signal that could be used by the television set.

While originally designed to solve the bandwidth problem for cable systems, the cable companies quickly realized that it would also give them better control over who watched which channel. This allowed them to increase their revenue streams while keeping basic cable prices steady. This was important because of the political pressure on Congress to control the rising costs of Cable TV.

With the rise of the number of C-Band satellite dishes taking the satellite signal direct from space to the television receiver (through a digital to analog converter box) instead of thru cable companies, broadcasters like HBO saw a decline in the number of people that were paying for their service through the cable companies. HBO began to encrypt their transmitted digital signals so that only the cable company customers that paid for the service could view it. Most of the new cable television stations started doing the same thing to protect their revenues as well. Most programming was now leaving the source as a digital signal, only to be converted to analog by a converter box for the analog television sets. Many television sets came with the converter box built into the cabinet; they were known as cable ready televisions, but the picture was still analog.

It wasn't until the rise of the lap top computer that the final piece of technology was in place for true digital television. The digital screen used in laptops was the necessary replacement for the last vacuum tube that made analog signals necessary for television. With the wide spread use of lap top computers came the rapid decrease in price for these screens that were necessary for truly digital television.

The final requirement for wide spread use of digital television and the scrapping of the old analog system was political. With millions of perfectly good analog sets in place and the initial high cost of digital televisions, it would take politicians to work out the details of the conversion from analog to digital. Each country has a different phase-in schedule, but it looks like the entire world will be converted to digital television by 2015.