BOSTON — Get ready to replace your television.
Maybe not soon, but starting in 2006, today's analog TVs may go on the blink in many major US cities.
That's when the Federal Communications Commission (FCC) will allow TV stations to turn off the analog signal they now broadcast and switch to a new digital standard.
But the conversion started last week. Boston's ABC affiliate broadcast John Glenn's launch on the space shuttle Discovery Thursday in digital format.
Around the country, 40 commercial and public TV stations began broadcasting digitally - alongside their analog broadcasts - yesterday.
"Eventually, you are going to have to [go digital]," says Karen Fox, of Whitman, Mass., looking at a new digital TV at a Circuit City store in Somerville, Mass.
Indeed, consumers have voted with their wallets for digital clocks, music, and cellular telephones. And digital TVs boast many advantages over traditional broadcasts.
* Clarity. The long-awaited high definition televisions (HDTVs) deliver digital pictures that make today's TVs look fuzzy. "The water actually looks wet," says Arthur Del Luca, of Medford, Mass., watching an alligator slide into a river.
* The big picture. All digital TVs use a movie-format screen that is 1/3 wider than today's.
* Big sound. Digital broadcasts arrive in your home with movie-format, surround sound.
* Visual variety. Digital TVs can simultaneously display as many as four shows, plus data such as stock tickers, sports scores, or news headlines. Or, for instance, you could watch a game from four different camera angles at once.
* Technological variety. The TVs can connect to a keyboard or phone line so you can, for example, send messages to the broadcaster or place an order.
* Wall-to-wall TV. The new, skinny flat televisions that hang on walls are high-definition digital TVs.
The main obstacle is price. Today's digital TVs start out at $7,000 and go up. Way up.
"I don't think I'd pay $10,000 just for clarity," says Ms. Fox.
"I've been looking at [my old TV] for years and it never bothered me before," she says.
So far, digital TVs are just toys for those who have to be on the cutting edge. Until the first stations begin broadcasting a few programs in November, digital videodisc players are the only way to watch digital TV.
"I'm really impressed with the clarity, but it's definitely not worth 10 grand," says Jay Sullivan, another Circuit City shopper from Wilmington, Mass. "I don't have that kind of toy money."
Baseball fan Charles Wood of Southborough, Mass., however, came to see "if I can tell the difference between a curve and a slider [on a digital TV]. If I can tell the difference, I'll get it sooner or later."
But prices should come down. By 2003, the cost should be no more than $150 to $200 more than analog TVs, according to Linda Schumann of Philips Electronics, the first to market with digital TVs.
Consumers won't have to replace their TVs if they don't want to. Philips and other manufacturers are developing external set-top boxes that can receive the digital signals and display them on today's analog TVs.
It is not clear how many of digital TV's new functions will make their way to the set-top boxes.
Some consumers might opt to watch digital TV on their computers. Microsoft's Windows98 supports digital broadcasts with an extra digital TV card.
Either way, the new, wider digital TV transmissions won't fit precisely on today's analog screens. Viewers can choose an image with true dimensions and a narrow black bar at the top and bottom of the screen or an image distorted to fit today's 4-by-3 screens.
While the digital broadcasts mark the first milestone in the conversion to digital TV, they are only a baby step.
That's because 60 percent of Americans receive their TV signals via cable, which is not governed by the new regulations. Instead, regulators are working on new guidelines for digital cable.
A digital cable feed into your house could control everything from thermostats to lights and the dishwasher, in addition to transmitting TV shows. It could also provide access to the Internet and potentially telephone service.
Many cable companies will likely start digital programming well before 2006, and may provide many additional services before broadcasters do.
Observers have compared converting Americans to digital TV with going to color in the 1960s. The difference is that no one required broadcasters to transmit color or set a deadline, says Jud French, a spokesman promoting digital TV.
* Nov. 1, 1998
40 commercial and public TV stations begin some digital broadcasts.
* May 1, 1999
Network affiliates in the top 10 TV markets are required to broadcast digitally.
* Nov. 1, 1999
Network affiliates in the top 30 markets, (50 percent of US households) must carry digital.
* Jan. 1, 2002
All commercial stations must carry digital.
* Jan. 1, 2003
All public TV stations must begin digital broadcasting.
* Jan. 1, 2006
The FCC will auction the radio frequencies that carry today's analog TV broadcasts. Once 85 percent of households in a market receive digital, stations may shut off analog signals.