(PhysOrg.com) -- If everything goes as planned, on Feb. 17 the long-awaited switch from analog to digital broadcasting will take place and millions of analog television sets across the nation will go black. Temple University electrical and computer engineering Professor Dennis Silage, an expert in both analog and digital communications, has answered some questions about this digital TV transition and what it will mean for consumers.
Q: Why are we switching from analog?
DS: Analog is a 60-plus-year-old technology that has basically lasted the test of time, but doesn’t really allow more advanced services, such as additional channels and information using the existing the broadcast spectrum. It’s not as versatile as a digital TV transmission, provided you can get a good signal into your receiver.
Q: Most of the TVs that are out there today are analog?
DS: Until 1998, most television sets were analog only — and many of them are still being used today. After 1992 manufacturers began to offer ‘cable-ready’ television sets, which are actually merely analog TVs that work with analog cable. Over the past few years, the industry has developed over-the-air, digital television transmissions. You don’t need a digital converter box for this, but you would have had to purchase a digitally ready television set within the last few years. If your TV is older than 10 years, it is probably an analog set.
Q: What do I need for my analog television set to receive digital transmissions?
DS: You would need a digital converter box. The Federal Government was offering a coupon program that allowed you to get a reduced cost converter box, but it seems they have now run out of coupons. You can buy a digital converter box at any electronic appliance store like Radio Shack. They generally cost anywhere between $40-$60. It will depend on the capabilities of the box, but you should definitely be able to purchase one for under $75.
Q: If I install a digital converter box to my television set, what will I get?
DS: Provided that the digital converter box has a reasonably good antenna, you would be able to receive the over-the-air digital signals that the broadcasters are transmitting; basically, your local television stations. You have to hook the converter box up to an antenna and even a simple a ‘rabbit ear’ antenna may work for you. We’re going back to the future, if you remember when you used to have rabbit ear antennas on your TV and you had to play around with them to get the best picture. Now, because of the digital conversion, your local television stations also have subsidiary channels that would be very interesting to see. They may have as many as three subsidiary channels. The programming right now in some cases is a bit restrictive; for example, you might get to see continuous weather reporting on one of the channels, but in the future as broadcasters get organized, you’ll see alternative programming on these channels.
Q: So a local television station can split their signal into several channels by broadcasting in digital?
DS: Yes, there is a lot of flexibility with the digital signals because you can actually reconfigure them depending upon whether you want standard definition or a little better resolution in the picture.
Q: Will my television picture look any different when I install a digital converter box to my analog TV?
DS: Well, with the digital picture you will notice a difference in clarity and some performance differences. The picture will certainly look better, how much depends on the quality of the set. Even if you have an older Sony Trinitron, it is going to look great. But if you have an old Muntz TV from the 1950s, it may not look so good. A good analogy would be if you watched a DVD on your analog TV, the picture is much crisper than watching a VHS tape. Well, that is about how it would be with a digital picture versus an analog picture.
Q: How do I know if my television set is an over-the-air, digitally capable set?
DS: If your television is digitally capable, you will find the code “ATSC” in the description; it should also be in the user’s manual. All that really means is that the TV, without a converter box, will receive over-the-air, digital signals directly. But that has nothing to do with digital cable, which is a totally different system.
Q: I presently get cable at my house, so do I need to get a digital converter box?
DS: This is where it becomes a little cloudy for the consumer. For example, I currently have analog cable. Right now, at my home, we are watching analog cable using multiple existing television sets, some of which are 10 or more years old. I distribute the analog cable throughout my home and I need no cable boxes. The question for consumers is, how much longer will it be like it is now? Many consumers have had analog cable for decades. It is not clear how rapidly the analog cable itself will disappear, but there is some indication that by 2012 all cable will be digital also.
Q: So what is the difference between analog cable and digital cable?
DS: Analog cable allows you to use your existing cable-ready television sets. The same televisions sets they would connect up to an outdoor or ‘rabbit ear’ antenna can usually be used on analog cable directly, you don’t need anything additional. So that is certainly an advantage for the consumer. Between now and 2012, the cable companies will convert their digital signal to an analog signal so that it can be viewed on analog sets over the cable.
However, it is not clear how much content the cable companies will provide. Up until 2012, they are only mandated to provide over-the-air service. For example, I’m watching analog cable right now in my home and I get History Channel, Discovery, Home & Garden Channel; in other words, basic analog cable. But it is not clear how long that will remain available. What the cable company would want you to do is at least convert to basic digital cable. But that is going to require a set top box for each television set, which they may rent to you in addition to the cable service fees. This could allow the cable company to control how many sets are hooked up to the digital cable, whereas on my analog cable which I have in my home, I have eight TVs hooked up through one cable because I have a distribution system that I’ve installed.
Q: I have read recently that the digital TV conversion might be delayed beyond Feb. 17?
DS: The digital TV conversion was originally scheduled to take effect in 2005, so it has been delayed several times already. My sense is that Congress may be able to delay it again, although there will be repercussions in the broadcast industry because there has been a lot of capital investment and broadcasters really want to decommission their old analog equipment.
Provided by Temple University
Explore further: Analog to digital converter research improves Internet speeds to 100 Gb/second