As important as television is to many people in the United States, the technology behind the medium hasn't changed that much since its introduction. Early television began in the 1870s, but TV didn't really catch on until the introduction of electronic television in the early 20th century. Though there were regular broadcasts, people at large didn't adopt television until after World War II. In 1945, there were only nine commercial TV stations broadcasting, but by 1949, there were 48. And by 1960, there were 515 commercial stations, with TVs in 85 percent of American homes [source: Federal Communications Commission (FCC)].
Color TV was around as early as 1946, when CBS engineer Peter Goldmark -- who also had a hand in creating the long-playing vinyl record -- developed a method of broadcasting in color. Unfortunately, his color-broadcasting standard wasn't compatible with existing TV sets, and in 1953, the National Television Standards Committee (NTSC) adopted RCA's method of color broadcasting instead.
From there, we have incremental introductions -- the remote control, cable and satellite providers, and videocassette recorders (VCRs), et cetera. But in general, you don't have to have all those things to watch TV. If you live in an area near a broadcast station, you can still plug a pair of rabbit ears into the antenna jack on the back of your set and get programming.
On Feb. 17, 2009, some analog channels in the United States went dark -- with a few exceptions, the rest did so on June 12. Regular broadcasters in the United States have completed the transition to digital television (DTV). The reason? Broadcasters moved their signals to another part of the radio spectrum. One reason for the switch was to free up space for police, fire and other public safety communications. The remaining portion of the broadcast signal will be available to consumers for wireless services.
The original date for the analog-to-digital transition had to be moved because the FCC needed to raise awareness of the change among the population. The idea was to make sure few people are left behind, but their efforts caused some confusion. To receive digital television signals, some people need a converter box.
If you live in the United States and use a regular antenna to get television signals over the air, this is probably the reason why you can't see your old stations today.
Digital TV Conversion
You might think that with the switch to digital television you need to buy a new, expensive high-definition television (HDTV) set. You can do that if you want to, and you'd have many good reasons to do so. HDTV offers better sound, a larger picture and a higher resolution. But despite the drop in prices that has come with more players in the market, these machines are still out of range of many household budgets.
So do you have to buy a fancy new TV and junk the old one? The simple answer is no. If your television has a digital tuner -- the component that helps you tune into TV stations -- already built in, you don't need a new TV. However, if you're still using an older TV with an analog tuner built in, like millions of people, the switch didn't make your TV obsolete. In fact, it should clean up your reception, but it won't make your television show look like high-definition programming.
The difference in analog and digital is pretty simple. Unlike digital broadcasting, which is either off or on, an analog signal can waver in relation to factors such as the strength of the signal. If you've ever had to get up to play with the antenna on your TV to get a better picture, you'll appreciate digital broadcasting. If your digital TV is getting a signal at all, you're getting clear audio and video.
That said, if you have a TV with an analog tuner and a terrestrial antenna -- not a satellite dish antenna -- you need a digital-to-analog converter box to continue watching TV now that the deadline for conversion has passed. You need a converter for every tuner you have, whether it's for a TV or for the videocassette recorder or digital video recorder you use to record shows. So if you have a second TV in another room, you need a box for that one, as long as it has an analog tuner built in.
Televisions with digital tuners built in will probably be labeled as such. If you aren't sure about yours, check your owner's manual or contact the manufacturer for more information. The Web is a good place to look; many companies keep information on older models online for reference.
Do you subscribe to digital cable or satellite TV? If you do, the box that goes on your TV handles the conversion for you. In fact, the analog-to-digital switch really affected just local broadcasters. Satellite and cable stations don't use the same frequencies that your local network affiliates do. So if you're not using an antenna to watch TV, the switch didn't affect you.
Are you an analog cable subscriber? Here's a clue: If you plug the cable directly into the back of your television, your cable company might be offering you analog service. The FCC requires cable companies to provide analog signals for local stations that have switched to digital signals as long as they offer analog feeds for any other channel. You may be fine for now, but if you're concerned that your TV will go dark in the future, you should contact your cable provider.
There are a few exceptions to the conversion rule, though. Low-power, Class A and TV translator stations don't have to make the switch to digital just yet. These stations are usually rural or local community stations, and while they didn't have to switch in June 2009, they'll be required to switch over in the future [source: FCC].
If you watch one of these stations regularly, make sure to get a converter box that has analog pass-through capability, and you can continue to receive those channels. Otherwise, you'll have to get a signal splitter and divide the signal from your antenna for digital and analog stations.
At this point, you may be thinking this is all a pain in the neck. But there are some advantages for switching to a digital signal. Read more about them on the next page.
Analog to Digital Advantages
Switching from analog to digital let broadcasters offer higher picture definition, because a digital signal can be compressed far more than an analog signal. Compression allows stations to fit more information in the signal. That means you're getting a clearer image with digital television than you would from an analog signal. In fact, even though digital signals get weaker with distance, just as analog signals do, digital signals won't degrade in quality. As long as you have a signal, you'll get a clear picture [source: Cringely].
There's another advantage of having additional bandwidth available. Using digital broadcasting, local stations are able to offer more programming to their viewers than they could with an analog signal. How? Multicasting, or broadcasting several shows within a single frequency. Many stations across the United States are already multicasting. For example, WRAL in Raleigh, N.C., broadcasts a 24-hour news feed alongside its regular programming [source: USA Today].
If you have a digital-to-analog converter box and a terrestrial antenna, you can take advantage of your local station's multicasting, if they offer it. Cable and satellite providers may not necessarily add the additional stations to their lineups, however, so you may not see them if you subscribe.
If you still need a converter box, you may still be able to get a $40 coupon from the U.S. government at dtv2009.gov, if there are any still available. You could also buy a new television with a digital tuner, if that's what you would prefer, though that's a more expensive option.
For more information about digital television and related topics, tune in to the links on the next page.
Related HowStuffWorks Articles
More Great Links
- Cringely, Robert X. "Digital TV: A Cringely Crash Course." PBS.org. http://www.pbs.org/opb/crashcourse/
- Davidson, Paul. "Local Stations Multicast Multishows." USA Today. Jan. 28, 2004. Updated Jan. 29, 2004. May 8, 2008. http://www.usatoday.com/money/media/2004-01-28-multicast_x.htm
- Digital Television (DTV). Regulatory Information. Federal Communications Commission http://www.fcc.gov/dtv/
- The Digital TV Transition. Federal Communications Commission. http://www.dtv.gov/
- "'DTV' is Coming (and Sooner Than You Think)!" Federal Communications Commission. http://www.fcc.gov/cgb/consumerfacts/digitaltv.html
- LaGesse, David. " Many TV Stations Won't Make Switch to Digital." http://www.usnews.com/blogs/daves-download/2007/12/24/many-tv-stations-wont-make-the-digital-switch.html
- "Lawsuit claims switch to digital TV next year would bankrupt owners of small stations." Associated Press. International Herald Tribune. Mar. 27, 2008. May 12, 2008. http://www.iht.com/articles/ap/2008/03/27/america/Digital-TV-Lawsuit.php
- "Peter Goldmark." Consumer Electronics Association. http://www.ce.org/Events/Awards/487.htm
- Sarkar, Dibya. "Major retailers fined over digital TV regulations." Associated Press. SF Gate. Apr. 11, 2008. May 12, 2008. http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/04/11/BU4G103LKO.DTL
- "WICU-DTV -- Channel 52 --Erie, PA." WICU. May 12, 2008. http://www.wicu12.com/dtv_info/