Analog vs Digital Transmission Written by Gary Davis
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Well..... Actually they do lose quality just like analog transmission system does. Surprised? No Problem. Most people don’t know that digital signals still need to be transmitted by analog transmission systems. The trick is that a digital system doesn’t record analog signals, but encodes analog signals into bits (zeros and ones). A sample is taken many times per second and size of each sample is written down in bits. For instance a sample with value of 9 would be 1001 and 11 would be 1011. The digital transmission system needs to transmit those zeros and ones, and it does this by modulating carrier wave. Low power for a 0 and high power for a 1 (This is most simple way of modulating. There are much more sophisticated forms of modulation, but it would take a whole book to describe them all.) So on receiving end, it doesn’t matter anymore what quality of signal is, as long as it still is possible to identify zeros and ones. Noise in received signal is no problem. A “1” with noise is still a “1” and a “0” with noise is still a “0”. Of course noise can not be too high, otherwise mistakes would be made and a zero would be received as one or a one would be received as a zero. So Digital Transmission Systems are better because they eliminate effect of noise completely. You don’t look and listen to a received signal from an original recording, but you look and listen to a reproduced signal of recording. The reproduction comes from an exact copy of original recording. The quality of what you see and hear now depends on your TV and Sound System. A high quality TV and Sounds System will give you high quality Video and Audio. The negative effects of (still analog) transmission have been eliminated from process. Satellite TV makes use of Digital Transmission Systems. What you see at home will always be of Digital no (much less) noise Quality.
Gary Davis is owner of Dish Network Satellite TV, has several years experience in the Satellite TV Industry and has written several articles on satellite TV.
| | Types of Satellite TV Systems - TVRO and DBSWritten by Gary Davis
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TVRO systems are often referred to as Big Dish TV, C-Band Satellite TV and BUD (Big Ugly Dish). DBS - Direct Broadcast Satellite Satellite TV via DBS is done in Ku-Band. These satellites work on higher frequencies and can transmit higher power signals. This means that much smaller dishes can be used to receive signal. A small dish of 18 inches is already enough to receive all satellite TV by Satellite TV. This makes it possible to have satellite TV from an apartment on 10th floor, if you have a clear line of sight to south. DBS is for everyone. The satellite dish is so small that it is not an obstacle like with for instance TVRO dishes of 3 to 6 feet. Once installed dish needs no maintenance since it is aimed at just one satellite. Some dishes actually have 2 or more feeds which makes it possible to receive signals from more than 1 satellite. There are no free channels available on DBS satellites as these are often owned and used by satellite TV provider it self, while TVRO satellites often are used by those who rent space on satellite for a limited time. TVRO systems are meant for, for instance, transport of unedited materials between continents, but also within one continent. DBS is meant for everyone with a simple, low cost installation of system. Often installation is for free as it really is very easy to do. The only thing that is needed is a bit of knowledge of where to find satellite and tools that make this even easier. A qualified installer will find satellite and point it to maximum reception within minutes.
Gary Davis is owner of Dish Network Satellite TV, has several years experience in the Satellite TV Industry and has written several articles on satellite TV.
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