In about a year, a handful of Mainers will wake up, click on their televisions and find blank screens.

No, it won’t be that the “big one” has finally dropped, or that terrorists have blown up TV transmitters, or even that the antenna has fallen off the roof.

Instead, Feb. 17, 2009, is the date on which the federal government has mandated that all TV stations permanently switch from analog to digital television signals.

This means that those without signals, who still receive their programming over the air on an analog TV, never got the message that the broadcasting industry has been working so hard to get out in advance of the transition.

“People seem unaware that they need to do something,” said George Thomas, operations director at WVII Channel 7 in Bangor.

Why go digital? Because it’s a revolution seen as comparable to when TV began switching from black-and-white to color in the 1960s.

“This isn’t the end of the world,” said Mike Young, vice president and general manager at WABI Channel 5 in Bangor. “Instead it’s the beginning of a whole new world in TV broadcasting.”

Why that particular date? It’s what Congress fixed in the Deficit Reduction Act of 2005, as it fell between the NCAA’s Bowl Championship Series and the Super Bowl and “March Madness,” the NCAA basketball tournament.

The driving force behind this switch is, naturally, economics.

As the bill’s title suggests, switching to digital will open up a new revenue source for the government, which plans to auction off former analog channels to commercial wireless operators, as well as reserving parts of the broadcast spectrum for emergency services.

TV stations have been required to have working digital transmitters since 2002. They’ve been sending out both analog and digital signals with all the costs associated with that.

So switching to digital exclusively will be addition by subtraction, eliminating the costs associated with analog.

Also, digital allows broadcasters to do more with the same resource. An analog signal often bleeds outside the 6 megahertz band each channel receives, meaning viewers on the signal’s periphery get snowy or erratic pictures. Digital is a tighter signal, so broadcasters can send out up to four signals with different programming within their allotted bandwidth.

For example, WABI broadcasts its CBS programming on digital channel 5.1 and The CW shows on 5.2. WVII has ABC series on digital channel 7.1 and Fox on 7.2. WLBZ has NBC on 2.1 and a separate weather channel, Weather Plus, on 2.2. Maine Public Broadcasting Network offers four different digital channels.

This means broadcasters (except for MPBN) have more programming in which to sell advertising, even though the viewership is further splintered. Conversely, viewers – even those who just receive their TV over the air – get more choices.

Also, with better picture clarity and sound, digital TV promises to be a whole new viewing experience.

“It’s as profound a change as going from black-and-white to color,” Young said.

The best part of going digital is that, unlike having to buy a new set to enjoy the full benefit of color TV, most Mainers will have to do absolutely nothing. About 84 percent of Maine households are connected to cable, satellite or other pay TV services that have boxes with built-in ATSC (Advanced Television Systems Committee, the group that sets technical standards for the industry) tuners that convert digital signals to analog for older sets.

Also, more and more households have digital TV sets, which have built-in tuners as well.

According to statistics provided by the Consumer Electronics Association, by the end of 2007, 81.8 million digital TVs had been sold, and 60.6 million of those are high-definition. This means that 50 percent of U.S. households have digital sets. Still, it’s impossible to tell how many Maine viewers have digital sets.

That leaves, at most, 16 percent of Mainers receiving their TV programming free over the air (how many of those households have digital sets is unknown). That number is higher by region: Waldo County at 30 percent, Hancock County at 25 percent, and Lincoln, Oxford, Penobscot and Piscataquis counties at 20 percent. It’s this group that is most at risk of losing TV come Feb. 17, 2009.

The message that Maine broadcasters are trying to get out through news stories, public service announcements, Web sites and community presentations is that this is an easy problem to remedy.

TVs with a built-in digital tuner will continue to get over-the-air digital programming. Your TV probably has a digital tuner if it’s a 25-inch or larger HD TV bought within the past two years or any size or type of TV bought since spring of 2007.

A little research can reveal whether your set is analog or digital. Look at your owner’s manual. Check the set for an indication that it has an ATSC tuner. Go to the manufacturer’s Web site and check the capability of the set by model number.

The least expensive solution for those with analog sets is to buy a converter box at local electronics stores. This easy-to-install device (with two cords to attach) costs $40 to $70 and converts digital signals into analog, thus preventing the need for a new set. A high-definition-capable converter box costs around $100.

To make such a device more affordable, the National Telecommunications and Information Administration will issue up to two converter box coupons valued at $40 each to households (the coupons can’t be combined, or used on an HD-capable box). So far, Mainers have ordered 19,000 coupons. The coupons are available online at www.DTV2009.gov or by calling 888-388-2009.

An $890 million has been allotted for this program, and that amount can grow to $1.34 billion with further authorization by Congress. That would equal 33.5 million coupons, far short of the 112 million households in the United States. So those who drag their feet could be left out of the coupon program, which runs through March 31, 2009, or until funding runs out.

A second option is to buy a standard-definition or high-definition digital TV set. The lower-end models are likely to be SD TV, unable to replicate HD TV signals. Analog TV sets have not been manufactured since July 1, 2007, and such sets still in stores are required to have a sticker warning that they are analog.

Finally, the third option is to sign up for a cable, satellite or phone company pay-TV plan.

Ancillary equipment such as antennas, VCRs, DVRs, DVD players and video-game consoles should continue to work as they did before the conversion. They may not, however, provide digital-quality picture and sound.

If you receive certain channels now over the air, how will things change during the digital age? It’s hard to say.

“It depends, because the physics of a digital signal is so different from an analog signal,” said Suzanne Goucher, president and CEO of the Maine Association of Broadcasters. “Until everyone fires up their digital transmitters to full power, we’re not going to know.”

Those on the outer fringes of a digital signal will notice one difference. Where an analog signal produces a snowy picture at its extremes, a digital signal undergoes what’s known as “the cliff effect.”

“The digital bit stream is so efficient,” Goucher said. “It’s not subject to degradation until its furthest reaches, then it cuts out [like falling off a cliff]. So it’s all or nothing.”

All the broadcasters interviewed for this article agreed that the best digital signal would be one received over the air through a rooftop antenna, since the signal would travel the shortest distance (from a local transmitter to a viewer’s home), unlike satellite and cable TV, which go into space and back to Earth again before arriving in a viewer’s set.

Still, despite whatever technical adjustments viewers may have to make, broadcasters agreed that digital TV represents a huge step forward.

Just ask Judy Horan, general manager for WLBZ Channel 2.

“The advantage of a digital signal is, first and foremost, a dramatically better picture and improved sound,” Horan said. “Also, we are able to program more than one channel. Viewers who receive us on an antenna can even receive an HD signal for free.”

For Information

Digital transition: The “DTV for ME” section at www.mab.org, www.dtvanswers.com, www.DTV.gov, www.dtvtransition.org, www.HearUsNow.org.

Converter box coupons: www.dtv2009.gov, 888-388-2009.

Antennas: AntennaWeb.org.

Are you ready for digital TV?

TVs that have a built-in digital tuner will continue to get over-the-air digital programming. Your TV probably has a digital tuner if it’s a 25-inch or larger high-definition TV bought within the past two years or any size or type of TV bought since spring 2007.

A little research can reveal whether your set is analog or digital. Look at your owner’s manual. Check the set for an indication that it has an ATSC tuner. Go to the manufacturer’s Web site and check the capability of the set by model number.

The National Telecommunications and Information Administration will issue up to two converter box coupons valued at $40 each to households. The coupons can’t be combined or used on a high-definition-capable box. So far, Mainers have ordered 19,000 coupons. The coupons are available online at www.DTV2009.gov or by calling 888-388-2009.