(Forbes.com)At the stroke of midnight on Feb. 17, 2009, the analog transmissions that have beamed free television over the air in the United States for over half a century will disappear for good. They will be replaced by digital signals, many of which are already broadcasting, in what will be the most significant change to television since the introduction of color.

The "digital switchover" brings with it higher image quality, better sound and a level of versatility and flexibility previously unattainable through free television. It also brings with it a number of significant headaches, as confusion over exactly who will be affected is inspiring panic in viewers fearful of being left behind in a haze of snow and static as the rest of the country moves into the future.

Many of those who will be affected know that the deadline is fast approaching, but are unsure of how to prepare for it. Thankfully, a solution is simple, easily attainable and won't cost you a dime.

There are two major reasons for the switch from analog TV broadcasts to digital TV.

First, digital signals offer superior image quality and allow for the transmission of high-definition signals over the air. This means that a properly equipped HDTV can receive local high-definition broadcasts that will look about as good as what you'd get from cable or satellite television.

Second, switching from analog to digital frees up real estate on the broadcast spectrum for other uses, as digital signals are more efficient and take up less bandwidth.

Telecommunications companies like Verizon and AT&T have spent nearly $20 billion US to secure the rights to the frequencies that were previously occupied by channels 52 through 69, in the hopes of using that airspace to improve their wireless communication networks.

What the digital switchover is actually doing is changing the language that TV broadcasters use to communicate with your television. Since 1941, televisions in the U.S. have utilized a set of broadcast standards laid out by the National Television System Committee. Big broadcast towers sent out information over the air using these NTSC standards and were picked up by the television antenna in your living room. Inside your TV, an NTSC tuner interpreted the information and properly displayed it on screen.

On Feb. 17, 2009, U.S. television broadcast towers are going to stop speaking NTSC permanently and start speaking ATSC.

The digital switchover is introducing a new language, a new set of broadcast standards, this one designed by the Advanced Television Systems Committee. On Feb. 17, those broadcast towers are going to stop speaking NTSC permanently and start speaking ATSC.

Unfortunately, your old television set doesn't know how to translate ATSC into moving pictures and sound. Just about all televisions manufactured and sold after Mar. 1, 2007 feature ATSC tuners, but if you purchased a television any earlier than that, chances are your TV won't be able to pick up over-the-air broadcasts once the switchover occurs.

The solution: A digital converter box, essentially an external ATSC tuner that sits on top of your existing television and is linked between your antenna and your TV. The ATSC signals are grabbed by the same antenna you've always used, then passed to the digital converter box that translates the ATSC signals into something your NTSC television can understand. They are easy to hook up and available at a wide variety of stores, including big box stores like Best Buy, Wal-Mart and Target , as well as online retailers.

Digital converter boxes cost between $40 US and $70 on average, but since the digital switchover is being forced upon consumers, Congress has stepped up and created the "TV Converter Box Coupon Program." Under this initiative, each American household is entitled to two $40 gift cards that can only be used to purchase a digital converter box. Individuals can apply at the official Web site for the DTV switch. You can apply for coupons until Mar. 31, 2009; they expire 90 days after they are issued. You might want to apply for them sooner rather than later because the government has allocated a finite amount of funding.

TV viewers who pay for cable or satellite service need not worry. The digital switchover only applies to over-the-air broadcasts, so consumers who get their television directly from services such as Comcast or DirecTV will not be affected at all, and service will continue uninterrupted and unchanged as the DTV deadline comes and goes.

There is, however, a subtler, unrelated analog-to-digital switchover taking place among cable companies, one that could affect subscribers. It has usually been possible to view a small number of basic cable channels by plugging the coaxial cable directly into a television set, bypassing a cable box entirely.

This was a quick and easy way to bring cable TV to many rooms in a home without renting multiple cable boxes. Unfortunately, this may not be possible in the near future. Cable companies like Comcast and Time Warner are slowly phasing out their analog cable services in favor of digital. By switching over, they free up more space on their cable networks that can be allocated to new high-definition channels and interactive services like "On Demand." The downside is that when all cable channels are converted to digital, renting a cable box will be required to see any channels at all.

Another point of confusion that retailers and manufacturers have been reluctant to clear up: consumers need not purchase an HDTV to weather the digital TV switchover. In addition to the converter boxes, new standard-definition CRT televisions are still available, and they are required by law to include the necessary ATSC tuners. While an HDTV will allow viewers to take advantage of digital TV's high-definition potential, it's important to know that there is a lower-cost option available as well.

With the emergence of free, digital, over-the-air television that includes HD transmissions, it will be interesting to see if Americans, the majority of whom now pay for their television service via cable or satellite, might see the benefit of switching back to the old rabbit ears. While the selection of over-the-air broadcasts will never be as comprehensive as pay services, that same glut of content is often cited as an annoyance — lots of channels that subscribers will never watch.

Of course, all this will depend on how smoothly the digital switchover goes, and whether or not people are actually able to see the improvements on their screen. With just a few short months to go, having the right knowledge to make it through is absolutely crucial.