Just as the Victrola and the party line have given way to MP3s and text messaging, analog TV signals, which brought the first black-and-white television program to American homes in the late 1940s, are gradually being replaced by digital signals, a TV broadcasting format developed during the 1990s.
The difference between digital and analog TV pictures is as dramatic as the difference between a photo from a 10-megapixel digital camera and one taken with Instamatic color film in 1963. Digital broadcasting offers several advantages over analog broadcasting: It enables TV stations to send much higher-resolution pictures-clearer, crisper, and more detailed-and better sound quality. The highest resolution currently possible is the much-ballyhooed high-definition signal, called HDTV, which is so vivid it shows freckles, crow’s feet and five-o’clock shadow, usually to the chagrin of TV celebrities and news anchors. HDTV also makes possible widescreen pictures and vastly improved sound.
Digital transmission is more efficient than analog transmission because it allows several channels to share the same bandwidth, called “multicasting.” This enables broadcasters to transmit more channels in the same space than is possible with analog signals.
Whether TV viewers can reap the benefits of digital broadcasting depends on at least two things: the quality of the signal the broadcaster transmits, and the kind of TV the viewer uses.
Digital broadcasting includes a mix of picture and sound quality. Not all shows are broadcast using HDTV. Even so, the picture and sound produced by standard digital signals- SDTV-are still a significant improvement over those produced by analog signals.
How can consumers take advantage of digital broadcasting? The simple answer is: It depends.
· TV viewers who receive just the free broadcast channels, that is, with no cable or satellite service, on digital or digital-ready TVs-DTVs-need antennas that receive UHF signals (channel 14 and above). TV viewers who receive only the free broadcast channels on older analog TVs need to purchase and connect digital-to-analog converter boxes to their TVs, and, like DTV-owners, need antennas that receive UHF signals (channel 14 and above). Even though the converters enable analog-TV viewers to watch programming broadcast in digital format, their picture and sound will show no improvement; this is only possible with DTVs.
· Cable subscribers with DTVs need to do nothing. Cable subscribers with analog TVs may or may not need digital-to-analog converter boxes; they will be notified by their cable service providers what they need to do to receive digital signals when digital broadcasts become available to subscribers. Note: Digital cable is not the same as digital TV; digital cable refers only to how signals are sent across cable.
· Satellite subscribers need to do nothing, regardless of whether their TV is analog or digital.
Consumers who are not sure if their TVs are analog or digital should note the model number and go to the manufacturer’s web site to find out. Most new TV sets include digital tuners; make sure any TV you intend to buy is digital and not an older analog TV that is still in inventory.
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