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Digital broadcast TV explained

Good-bye analog, hello digital: People who get their TV programming for free over the air using an antenna to receive signals from broadcast towers such as this one will be affected by the FCC's mandate that analog TV broadcasts be ended after February 17, 2009. Local TV stations will then broadcast solely on their new digital channels. People will need TVs or other devices with ATSC tuners, rather than the old NTSC tuners, to receive these signals. (photo by Chris Lee)

The key point is that devices with NTSC tuners in them (TVs, VCRs, DVD recorders, etc.) won't work for people who get their television off air after February 17, 2009, unless used with a set-top box or other device that has an ATSC tuner in it.

Digital broadcast TV explained
(especially for people living in the Green Bay or Madison television markets)

By Chris Lee
Owner, Leemark Communications

Originally published online on May 16, 2007
Updated on September 18, 2007

	Disclaimer:
	The content on this Web page is provided as a public service. Every effort is made to provide accurate information. However, as with any human endeavor, mistakes are possible. Please e-mail any suggested corrections to info@leemark.com. Copyright © 2007 Leemark Communications.

This article is geared toward people, like me, who don't have cable television or satellite dish service and receive their TV signals off air. In other words: with an antenna. In other words: free TV.

People who have cable or satellite will likely be able to use their older (NTSC) TVs, VCRs and DVD recorders as they have been, beyond the February 17, 2009 turn-off deadline for analog TV broadcasting. However, they may still find this article useful for getting tips on receiving off-air TV as a backup for when cable or satellite service is down, or in order to get HD (high definition) content from local network affiliates for free.

Most Americans have probably heard about high definition television (HDTV). But the coming end of analog TV broadcasting -- which has been used in the United States since the early days of television -- is really a transition to digital television broadcasting, not just HDTV. Some of this new digital television will be high definition. Some of it will be lower resolutions.

	Definitions:
	ATSC tuner -- new type of TV tuner that will receive digital broadcasts. An ATSC tuner will receive SDTV, EDTV and HDTV broadcasts, but depending on the type of device or display, may not always be capable of displaying a certain broadcast in its original resolution. For example, the ATSC tuners in many DVD recorders released in spring 2007 are only be capable of outputting an HDTV program in standard definition. ATSC stands for Advanced Television Systems Committee. See digital broadcasting. analog broadcasting -- type of TV broadcasting in use since the early days of TV in the United States; uses an NTSC tuner to tune in channels. digital broadcasting -- new type of TV broadcasting that uses a signal composed of ones and zeros; uses an ATSC tuner to tune in channels. Programs can be transmitted in various resolutions and digital TVs may be capable of displaying SDTV, EDTV, HDTV or all three types. interlaced scan -- type of TV broadcasting which transmits all of the even numbered lines in a television picture frame (2, 4, 6, etc.), then all of the odd numbered lines (1, 3, 5, etc.), to make up one frame, and then repeats for the next frame. NTSC broadcasting uses the interlaced method. NTSC tuner -- type of TV tuner around since the early days of TV in the United States; it receives analog broadcasts. A TV purchased before 2005, or a VCR or DVD recorder purchased before mid-2007, most likely has only an NTSC tuner in it, not ATSC. NTSC stands for National Television System Committee. See analog broadcasting. progressive scan -- type of TV broadcasting which displays all of the lines in a television picture frame sequentially, in the method: line 1, line 2, line 3, line 4, etc. without skipping lines as in the interlaced method. Enhanced definition TV (EDTV) is one type of digital television that uses the progressive scan method. Three types of digital television: SDTV (standard definition) -- displays the digital signal but at the standard aspect ratio (4/3) and with 480 interlaced horizontal lines of resolution. It is similar to current analog TV in terms of resolution but is transmitted digitally. EDTV (enhanced definition) -- displays the digital signal at the wide-screen aspect ratio (16/9) and with 480 progressive horizontal lines of resolution, which gives a better picture than using 480 interlaced lines. EDTV televisions are also capable of displaying signals with 480 interlaced lines of resolution. HDTV (high definition) -- displays the digital signal at the wide-screen aspect ratio (16/9) and with either 720 progressive horizontal lines, 1080 interlaced horizontal lines or 1080 progressive horizontal lines of resolution. HDTV televisions are also capable of displaying signals with 480 interlaced or 480 progressive lines of resolution.

This change to digital television broadcasting will require some changes, but also provide some potential benefits, to people who receive their television off air with an antenna.

When this article was written in early 2007, most local TV stations were broadcasting on two channels -- their old analog channel and their new digital channel. For example, WBAY-TV in Green Bay was broadcasting on channel 2 in the VHF band with its old analog signal, as well as on channel 23 in the UHF band with its new digital signal. However, unless you have a device with a digital (ATSC) tuner in it to receive these broadcasts, channel 23 will just look like static or snow.

The end of analog TV broadcasting

The federal government has set February 17, 2009 as the last day for analog broadcasting by television stations in the U.S. According to the government Web site www.dtv.gov, this "will free up parts of the broadcast spectrum for public safety as well as other valuable uses."

After February 17, 2009, local TV stations will broadcast solely on their digital channels. These channels may be in the UHF or VHF band. If you receive your TV off the air, and you do nothing, your old TVs with NTSC tuners won't receive any stations after that date! The same is true for old VCRs and even DVD recorders (with NTSC tuners). You will either need to get a new TV that has an ATSC (digital) tuner, a set-top box with an ATSC tuner in it, or a VCR or DVD recorder with an ATSC tuner in it, in order to get any television off the air.

As a side note, digital TVs (those with ATSC tuners) come in three types: SDTV (standard definition), EDTV (enhanced definition) and HDTV (high definition) -- you can read more about these under "Three types of digital television" in the green box at right. The good news is that any device with an ATSC tuner in it should be able to show all of the various kinds of digital broadcast television being used in the United States. However, a certain device might not be able to show a program at its original, higher resolution, but instead may drop it down to a resolution it is capable of displaying.

The key point is that devices with NTSC tuners in them (TVs, VCRs, DVD recorders, etc.) won't work for people who get their television off air after February 17, 2009, unless used with a set-top box or other device that has an ATSC tuner in it.

The mandate for ATSC tuners

As of March 1, 2007, the FCC is requiring every new VCR, DVD recorder, and TV manufactured for sale in the U.S., if it has any tuner at all in it, to have the capability to receive digital broadcast television signals. This means having an ATSC tuner and associated circuitry.

Despite the March 1, 2007 deadline, it may take a while for old VCRs and DVD recorders with NTSC (non-digital capable) tuners to make their way off store shelves. As of May 6, 2007, for example, the two Circuit City stores in Madison only had one model of DVD recorder/VCR combo with an ATSC tuner in it on display for sale. However, other models with ATSC tuners were available on the Circuit City Web site. The two Best Buy stores in Madison had a few models of DVD recorders with ATSC tuners in them as of May 6, 2007, and more on the Best Buy Web site.

If you buy a VCR or DVD recorder with an ATSC tuner in it, you can use that as your tuner for getting digital television on your old TV both now and after analog broadcasts are turned off. Of course, you might not be able to watch one TV show and record another under this setup after February 17, 2009, unless you have a TV that also has an ATSC tuner in it.

TV sets with ATSC tuners were much more common in stores than DVD recorders with ATSC tuners as of May 2007. The least expensive of these were generally standard definition (SDTV) sets, which will not display high definition programming in the higher resolution but will instead drop it down to 480 interlaced lines (480i) of resolution. I've seen 27-inch SDTV sets starting at around $219 (as of fall, 2006). Just to be clear, if the box has an "SDTV," "EDTV" or "HDTV" logo on it, that means it has an ATSC tuner in it.

For those who don't want to spend the money on a new TV or DVD recorder with an ATSC tuner in it, there's talk of having vouchers that would give people a discount on the price of set-top boxes. These set-top boxes would have ATSC tuners in them and could be connected to traditional TVs or VCRs.

The Good News

While it may anger some people that they have to get a new device to continue receiving TV off air, there is some good news in all of this. The new digital broadcasting (received using an ATSC tuner) will allow many people who receive only off-the-air (free) TV to get more stations than before. This is because with digital, stations can compress the video and fit multiple "channels" of programming on their single digital channel assignment.

Digital TV for Madison market station call letters network affiliate displayed channel actual channel WISC-DT CBS 3.1 50 WISC-DT2 (MyMadison-TV 14) MyNetworkTV 3.2 50 WMTV-DT NBC 15.1 19 WMTV-WX (TrueView 24/7 weather) AccuWeather 15.2 19 WHA-DT1 PBS 21.1 20 WHA-DT2 (instructional/children's) PBS 21.2 20 WHA-DT3 (The Create Channel) PBS 21.3 20 WHA-DT4 (PBS Kids) PBS 21.4 20 WHA-HD (HD programming) PBS 21.5 20 WKOW-DT ABC 27.1 26 WMSN-DT FOX 47.1 11 WBUW-DT The CW 57.1 32

For example, in Madison, Wisconsin, using our TV that was made in 1995 and has an NTSC tuner, we were able to receive five commercial network affiliate stations, plus Wisconsin Public Television (WHA-TV), plus less clear reception of two religious stations, for a total of eight channels. After purchasing a DVD/VHS combo recorder with a new ATSC tuner in it, we are able to watch seven commercial channels, plus between two and four channels from Wisconsin Public Television (depending on the time of day), for a total of between nine and 11 channels (as of spring 2007), all for free. All of this content is digital, but not all of it is in high definition. Assuming the two religious channels move to digital, and we are able to receive them, that will give us between 11 and 13 channels.

Even better is the fact that all nine to 11 channels we receive come in very good, with no ghosting, graininess or fuzz. The digital TV signal is composed of ones and zeros, so if your ATSC tuner can receive the signal well enough to determine the ones and zeros, the picture quality will be good.

Digital TV for Green Bay market station call letters network affiliate displayed channel actual channel WBAY-DT ABC 2.1 23 WBAY-WX (Stormcenter 2 24/7) -- 2.2 23 WFRV-DT CBS 5.1 39 WLUK-DT FOX 11.1 51 WIWB-DT The CW 14.1 21 WGBA-DT NBC 26.1 41 WACY-DT MyNetworkTV 32.1 27 WPNE-DT1 PBS 38.1 42 WPNE-DT2 (instructional/children's) PBS 38.2 42 WPNE-DT3 (The Create Channel) PBS 38.3 42 WPNE-DT4 (PBS Kids) PBS 38.4 42 WPNE-HD (HD programming) PBS 38.5 42

In the Green Bay market, meanwhile, depending on your location and antenna, old NTSC tuners could potentially receive up to six commercial network affiliate stations, plus Wisconsin Public Television (WPNE-TV), plus up to three religious stations, for a total of up to 10 channels off the air. By using a device with an ATSC tuner in it, viewers can receive (as of spring 2007) seven commercial channels, plus between two and four channels from Wisconsin Public Television (depending on the time of day), for a total of between nine and 11 channels, all for free. Again, all of this content is digital, but not all of it is in high definition. Viewers who can receive the religious channels' digital signals will have even more choices.

What are these additional channels? WBAY in Green Bay and WMTV in Madison both put their regular programming on one part of their digital space and a 24-hour weather channel on the other (Stormcenter 2 24/7 and TrueView 24/7, respectively). Wisconsin Public Television has additional educational and instructional programming on its digital space when not broadcasting an HD program. WISC-TV 3 in Madison, meanwhile, provides My Madison TV 14, a MyNetworkTV affiliate, on part of its digital space. It is possible that other stations will add additional programming on their digital subchannels in the future.

Back to the antenna: TV antennas don't always have the traditional roof-top design, or even "rabbit-ears" design for indoor antennas. This photo shows a Philips MANT950 amplified TV antenna mounted on the side of a house, under the eave of the roof. (The inset photo shows a wider view, including copper wire that grounds the antenna in case of a lightning strike.) The MANT950 is a VHF/UHF antenna for indoor or outdoor use and can be mounted on a wall, in an attic, to a railing, or on a mast with a rotor. This antenna works great for receiving digital television signals at our house, but we are on a hill and only about 10-12 miles from the TV towers in Madison. We could also use an amplified indoor table-top antenna. If either of these solutions do not work well enough in your case, a traditional roof-top antenna may be needed. (photo by Chris Lee)

What kind of antenna
to use

Any VHF/UHF antenna should work with an ATSC tuner -- the antenna does not have to say "HDTV compatible" on it. In fact, if the digital TV stations in your market are on the UHF band, you would only need a UHF antenna to receive them.

While any VHF/UHF antenna may work in theory for receiving digital TV signals, in practice, getting a usable signal depends on the quality of the antenna and its placement, as well as your particular location in relation to the TV broadcast towers.

A simple non-amplified indoor antenna (sometimes called "rabbit ears") may work fine if you are relatively close to the TV broadcast towers. Of course, an outdoor antenna mounted on a rooftop will usually give you more consistent reception, and often bring in more stations, especially if you are farther away from the TV towers (such as in a different city) or if there are obstacles in between you and the towers or other reception problems. In between these two choices are an amplified indoor antenna and an amplified outdoor-type antenna placed in an attic.

As of early 2007, all of the digital TV stations in the Green Bay market were in the UHF band, while in the Madison market, all were in the UHF band except WMSN-DT (FOX 47), which has its digital signal on channel 11 (VHF). However, it is possible that other stations may change their digital signal to a VHF channel.

More information on choosing an antenna can be found at the Consumer Electronics Association's antennaweb.org Web site.

More on DVD players and recorders

First generation DVD players and recorders (not including the new Blue-Ray or HD DVD) are capable of showing 480 interlaced or 480 progressive horizontal lines of resolution, depending on whether or not it's a "progressive scan" DVD player. Neither 480i nor 480p is considered high definition. However, DVDs look great compared to VHS because VHS isn't even capable of capturing analog television's full resolution. But again, current traditional DVD players and recorders (other than Blue-Ray or HD DVD) are not considered high definition. As mentioned in the definition for HDTV, high definition (HD) starts at least 720 progressive horizontal lines of resolution.

The new DVD recorders with ATSC tuners will receive all off-the-air digital TV programming -- even that in high definition -- but will only record it in 480i or 480p resolution. Many that I have read about will also only pass through the HD signal to a television in 480i or 480p resolution.

A new era in television

In summary, the transition to digital TV broadcasting in the United States will greatly affect people who receive their television off the air. After February 17, 2009, local TV stations will be able to broadcast only with their digital signals. This means that people will need to have devices with ATSC tuners (and associated circuitry) in order to view the new channels via antenna. While this change may be inconvenient and require some expense, it also brings with it some positives, such as better picture and sound and potentially more channels.

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