By now, you've probably heard about the digital television (DTV) switchover coming in February, 2009. Lately, I've seen TV ads and even infomercial-like shows trying to explain what will happen, but I've found that these ads don't really do enough to educate people on the switch. Hopefully, this article will help people understand a little more.
First, I want to start out by stating that
if you currently subscribe to a cable or dish television service and plan to continue this service, then this change will not affect you. The switch to DTV only applies for over-the-air (OTA) television signals that are picked up using an antenna.
What Is The Switchover And When Will It Happen?
The switchover is a government mandated change in the way OTA television broadcasts are transmitted. The current television system uses analog transmissions and the new system will use digital transmissions (more on this in the next section). The switchover will occur on February 17, 2009.
What Is Digital Television (DTV)?
To understand the difference between analog television (what we have today) and digital television, think of the difference between an analog clock (one with hands) and a digital clock (one that just displays numbers). On an analog clock, the hands are not always pointing directly to a number; the hands may be between numbers. If the time is 6:30, the hour hand is half way between five and six. So there are many (infinite) positions that the hands of an analog clock can be in. A digital clock, however, shows a specific number at all times. If if it is 6:30, the hour digit still shows a six.
To equate this to OTA television service, think about the reception and picture quality you get today with analog. It might be a perfect picture, it might be very poor with lots of snow, or it might be anywhere in between. So there are many (infinite) different levels of picture quality with an analog transmission. Digital however, will not have those different levels of picture quality. If you are picking up the signal, the TV will display a perfectly crisp image. If you are not picking up the signal, you will see nothing. If you are on the verge of the signal's range, you might pick it up but the transmission might "drop out" leading to frozen images on the screen. Chances are that any station you currently receive with a decent picture quality will become "perfect" with DTV.
Does This Mean All TV Will Be High Definition Television (HDTV)?
Although all TV transmissions must be digital, it
DOES NOT mean that they will all be high definition (HDTV). Different stations and networks can choose what type of resolution they'd like to send out. Resolution refers to the number of pixels (the colored dots that make up the image) displayed in an image. Generally speaking, the higher the resolution, the more detailed the picture can be and the better it will look on a larger screen. You will see broadcasts listed in resolutions such as 1080i, 720p, 720i, 480p, and 480i. The number listed is the vertical resolution of the image (the number of pixels from top to bottom). The letter (P or I) stands for progressive or interlaced. Progressive means that the entire image is displayed in one pass on your screen. Interlaced means that on the first pass, every other line is displayed and then the remaining lines are displayed on the next pass. Progressive scan is generally considered to be a better picture quality but requires hardware fast enough to scan the entire image on a single pass. There is also a 1080p specification that, at the moment, won't really be used for broadcast but will be used by Blu-Ray discs. Generally speaking, broadcasts in 1080i or 720p are considered HDTV, and the majority of shows on major networks will likely be broadcast in one of these two resolutions. 480i (Standard Definition TV, SDTV) is the same resolution as our current analog transmissions.
One of the other advantages of DTV is the ability for a station to transmit multiple channels within their given frequency range. This is called multi-casting. An NBC affiliate which transmits on Channel 7 might also transmit 7.1 (an all weather channel) and 7.2 (a local access channel). The station has a maximum amount of data that they can send out on their frequency (bandwidth) and they can appropriate it however they choose. Higher resolution transmissions require more bandwidth so most stations will likely have a single HDTV transmission on their main channel and one or more SDTV sub-channels. Therefore, another added benefit of DTV is that you might now get more programming choices.
Finally, aside from increased picture quality and resolution, DTV comes with increased audio quality and many programs will include 5.1 channel surround sound.
How Does This Switch to DTV Affect Me?
I can't reiterate enough that this switch is just for over-the-air (OTA) transmissions received by antenna. If you have cable or dish, you will not be affected. The switch will affect anyone using OTA television service, unless you already have a very new TV.
Inside a TV is a tuner. The tuner takes all the incoming transmissions from the antenna, isolates the transmission for the selected channel, and interprets the data so it can be displayed on your TV. DTV channels are still going to be broadcast in the same frequency ranges as the old channels so they will make it to the tuner just fine, but the tuner will not be able to isolate the channel nor will it be able to interpret the data for display. To be able to interpret these signals, a DTV tuner is required.
So if you currently have a TV with an analog tuner in it, you will get NO picture at all after the switch. If you have a new TV that listed as "DTV built in", "HDTV built in", "DTV tuner", or "ATSC tuner", then your TV already has a DTV tuner and it WILL be able to isolate and interpret the signal.
Please note that "HDTV ready" or "HDTV monitor" is a TV which DOES NOT have any tuner inside it and requires an external tuner..
So I Need To Buy A New TV?
Not necessarily. All you need is a new tuner. Buying a new TV with DTV tuner in it is an option, but other options exist. Electronics stores are currently selling what they call a DTV set-top box, or DTV converter box. It's a device containing a DTV tuner that you would set near your TV. Your set-top box would take the signals from the OTA transmissions, isolate and interpret, and then spit the signal out to your TV in an analog signal that it understands.
These set-top boxes can be found for about $50-$80. Since the government is forcing this switch on us, they have decided to help us out on purchasing these set-top boxes. There is currently a $40 rebate form which you can use toward the purchase of one of these boxes. Up to two rebates can be used per house, so if you have seven TVs that need to be outfitted with set-top boxes, you are on your own for five of them.
The rebate form can be found here.
Here are are a few set-top boxes available on Amazon:
There are also several available at other retailers such as
Wal-Mart,
Best Buy, and
BSAT.net.
With these converter boxes, you will be able to use your existing TV and can avoid having to buy a costly new TV set. There are, however, downsides to this method. These converter boxes take the digital signal and convert it to a standard analog signal. This means if you have an HDTV signal coming in, it will be downgraded to an SDTV signal because that's all your TV can handle, thus you don't get all the benefits of HDTV. Another thing to note is that your TV will have to stay on Channel 3 or A/V input and the converter box is where you will do all your channel changing.
So If I Buy A Converter Box For My Old TV I'm Set, Right?
In a sense, yes, you are ready to view DTV on your existing TV. However, you may still have some problems if you like to record TV programs; especially if you use a timer record feature. A VCR, DVR, or DVD Recorder (I'll just use VCR from now on as they all work similarly) also has a tuner built in to it so it can interpret the signal and record it. Unless you have one built specifically for DTV, the VCR's tuner will be an analog one. This means that if you want to be able to record any programming, you will have to hook the converter box up BEFORE the VCR. So the cabling would go from the antenna to converter box to VCR to TV. This would allow you to record programming, but has some
MAJOR downsides to it.
First, when you want to record a show, you'll have to manually set the channel to record on the converter box and set the VCR to record on Channel 3 or A/V input. That's fine if you're around when the show starts, but what about a timed recording session? You'd have to remember to set the channel on the set top box before hand AND remember to leave it turned on. If you're going to be gone for a few days and want to record programs on multiple channels, you're out of luck. The converter box will only stay on one channel. The next problem is that you won't be able to record a show and watch a different show at the same time. Today, most people can do this because their VCR and TV each have separate tuners allowing each to tune to different channels. But if you have one converter box hooked up as described above, then the VCR and TV will always be on the same channel. This problem could be fixed by buying a two converter boxes for the TV and the VCR. Then things get complex in wiring and remote usage, and you'd want to make sure they were different model converters so they weren't picking up each others' remote control signals.
So if you just watch TV and rarely record it, the set top box might be a good option for you.
What's The Best Way To Record My Shows Then?
The best way is to get a DVR with a digital tuner in it and a TV with a digital tuner in it. That way the devices don't require a converter. You'll be able to do timer recording and watch a show on TV at the same time as recording another. The only problem is that DVRs with digital tuners are currently sparse on selection and the ones that do exist are rather expensive. This will get better in the future though.
Do I Need to Buy An HDTV Antenna To Get The DTV Signal?
Short answer: No! Companies have been labeling antennas as HDTV antennas as a marketing ploy. As mentioned earlier, DTV will use the same frequencies that analog TV used. This means existing antennas will still be able to pick up the signals on those frequencies. Our current OTA channel line up is broken down into 3 bands: VHF-Lo (Channels 2-6), VHF-Hi (Channels 7-13), and UHF (Channels 14-69). DTV will use the same bands.
In the old days, having a low channel number was coveted because it was easy to remember, but those days are long gone. The VHF-Lo channels are actually considered to be poorer choices now because of how difficult it is to get a good signal to the viewer. If you've seen a roof-top style antenna, you're probably familiar with the different lengths of arms sticking out from the antenna forming an arrow shape. Those arms are each tuned for a specific frequency. The lower channels have frequencies that require wider arms. Arms tuned specifically for Channel 2 will be about 110 inches wide making for a very large antenna. The UHF portion of an antenna is generally MUCH smaller than the VHF portion, especially the VHF-Lo band portion.
Due to the problems with VHF, especially VHF-Lo, it was expected that most stations would abandon their current frequency for a new UHF frequency during the switch. Manufacturers started making UHF-only antennas and marketing them as HDTV antennas. It turns out that many stations are preferring to stick with their current VHF frequency, and some (although few) are even sticking with their VHF-Lo frequency. So that means that people that have a UHF-only antenna will have a very hard time trying to receive DTV stations on VHF channels.
I Have An HDTV And A UHF-Only Antenna And I'm Getting All My Local Channels So I'm Good, Right?
Not necessarily. For the past couple years most stations have been broadcasting both their analog signal and their digital signal. Since many stations are keeping their current frequency after the switch, they've been broadcasting their DTV signal on temporary frequencies for the past couple years. This means that Channel 7 could be broadcasting analog on Channel 7 and DTV on Channel 42 right now, but once the switch is done, they will turn off Channel 42 and just broadcast DTV on Channel 7. So if you have a UHF-only antenna, you will be out of luck. To find out how the stations in your area will stack up after the switch check out the
FCC's final station selection list (Excel File).
So What Should I Do About My Antenna?
If all the channels you wish to receive will be in the UHF band, then you can get by with a UHF-only antenna. If you need some VHF and UFH channels, you will need a combination antenna like the kind people currently use. If all of your channels are in VHF-Hi or UHF, you could get by with a combination antenna that is smaller and will ignore the VHF-Lo band. Check one out at
Denny's Antenna Service.
For the most part, if you already have a VHF/UHF antenna that is working well, it will probably be fine for DTV as well. The only thing to be concerned about is the quality of your current reception. As mentioned earlier, on analog, you can watch a channel that has really poor reception, but on digital if you drop below the threshold of quality, the picture will just go away. So if most of your channels come in really poorly, you might want to invest in a more sensitive or more directional antenna. A great resource for antenna selection is
AntennaWeb.org. On this site, you can put in your exact location and it will tell you what class of antenna you need and which direction to point it to get the best reception.
If you currently use rabbit ears, they will probably still work with a DTV signal if you are close to the source. Rabbit ear antennas are not very powerful, so distance is a factor when using them.
Summary
In summary, a change in television signals in coming in under a year. If you do nothing, your old television sets will not be able to display the new signals. You can either upgrade your TV (high initial expense), get a converter box (low expense, multiple downsides), or get cable or dish (recurring costs and lower picture quality than OTD HDTV). HDTV antennas are just marketing words for UHF-only antennas and may not be useful if you need to watch VHF channels. For the most part, an existing antenna that is picking up analog signals pretty clearly should be usable for DTV.
So take the steps necessary to ensure you can watch TV after the switch and then sit back and enjoy the crystal clear TV.
If you have any questions I could possibly answer, leave a comment to this post.
Links
http://www.dtv.gov/ - Official site for the DTV switch.
https://www.dtv2009.gov/ - Government rebate form for digital converter boxes.
Wal-Mart - Digital converter box.
Best Buy - Digital converter box.
BSAT.net - Digital converter box.
FCC-07-138A2.xls - FCC List of final channel frequency selections (MS Excel 270KB).
AntennaWeb.org - Advice on antenna purchasing and positioning.
Cruthfield Electronics - Tutorial on antennas for DTV.
HDTVs:
DVR for HDTV:
TV Antennas: