Analog And Digital For Dummies
Lots of people talk these days about digital television, but very few actually know what is the difference between analog and digital television. Actually the only difference is the way the signal is transmitted. Analog television signal is transmitted very much like radio signals. The video signal of analog television is AM, and the audio is FM. Because of this, there can be annoying interferences in the signal, depending on meteorological conditions or geographical location.
If this is not enough, certain bandwidths are assigned to analog TV channels, and this means the resolution and image quality are restricted. In the United States, the analog TV signal is NTSC. This standard had been adopted after the end of World War II, and it is a good system, but it was not engineered with color TV broadcasting in mind. Color implementation into the NTSC format is a weakness of this standard, and this is why many professionals call the NTSC standard “Never Twice The Same Color”.
Digital TV signal, unlike analog signal, resembles very much the way computers work: there are two kinds of signal, “on” or “off”. The viewer either sees an image, or not. Because of this, gradual loss of signal or interferences are an unknown term in the era of digital TV. It doesn’t make any difference how close or far the transmitter is from the TV, and weather conditions also have no importance.
Digital format was thought with all the main factors of present-day television signals in mind: B/W, color and audio can be transmitted as interlaced or progressive signal. This means the signal content has greater integrity and flexibility.
The same bandwidth an analog TV signals requires can host higher quality digital image and there will be even extra space left, which can be used for extra video, audio or texts signals.
This way broadcasters using digital technology can supply more features, like surround sound, multiple language audio or text using the same bandwidth a standard analog TV signal requires. Digital TV has one more advantage: it is able to transmit High Definition (HDTV) signal.
Digital technology is also able to broadcast programs in true wide screen (16×9) format. The shape of the picture is like a movie screen, so there will be no black bars on the top and the bottom of the image. This way movies can be viewed exactly the same way filmmakers intended to be seen. Sports fans will also love the 16×9 format, because this allows them to see the whole length of a football field.
The United States made the transition to digital broadcasting on June 12, 2009. This means that all analog TV signals went off on that day. After this date, analog TV sets could be used only with an analog-to-digital converter connected to them. The preparations for transition from the analog to digital took quite some time for the consumers, broadcasters and authorities. The transition was originally planned for 2006, but authorities decided to postpone it because they thought consumers were not ready yet to embrace the new technology.
Edward McKellen is an HDTV expert who writes lcd tv reviews for HDTVreviewlab.com. To read our latest HDTV review – The Samsung UN55B7000 55-Inch LED HDTV or check out the latest Sony HDTV reviews visit HDTVreviewlab.com