Paul Yeager: For many Iowans it has come down to this and this. Two weeks from tonight, IPTV and all other broadcasters in your area still broadcasting in analog will be shutting off those analog transmitters and broadcast only in digital. We'll be addressing reception issues, giving you the latest updates and we'll be taking your questions, next.
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Paul Yeager: Hi, I'm Paul Yeager. Thank you for joining us. Tonight we're going to take your questions about the analog TV shutoff and concentrate on giving you information designed to help you get the best possible reception of digital television broadcast signals. You can call the toll free number you see on the screen any time during this program and qualified Iowa Public Television staff will do their very best to answer your questions and address your concerns. You'll also see IPTV's toll free number there on the screen, you can call that number during business hours if you'd like to talk with us about DTV or really anything else for that matter, and we do encourage you to do that.
Paul Yeager: Some viewers using antennas to receive digital TV are quite pleased with the improved picture and sound quality, the electronic programming guide and the additional channels that they are receiving. But others of you are simply having some difficulty taking advantage of these improved services. That's why we're here. The focus tonight will be on how you can get the best possible reception of digital TV signals.
Paul Yeager: Let's take care of some of the basics first. Most of you have heard all of this before, if you're receiving TV over the air using an antenna hooked up to analog TV you won't be able to receive a signal after June 12. Now, you have three options, one of those is to get a digital converter box like this one, that would be for your analog TV. You can also purchase a new digital TV or subscribe to a pay service like satellite or cable TV.
Paul Yeager: The federal government DTV converter box coupon program is alive and well. You can order coupons by going online to the following Web address, that's www.dtv2009.gov. Or you can also call 888-388-2009. Applications will be accepted through July 31 of this year. Some relatively recent developments are that if you have ordered coupons in the past and they expired before you could use them you now can order replacement coupons. Keep in mind that there is a limit still of two per household. And now residents of state licensed nursing homes, intermediate care and assisted living facilities are also eligible to receive one coupon. Those folks, though, need to apply by mail. Further information is available online at that www.dtv2009.gov site.
Paul Yeager: The Nielsen Company reported that at the end of last week only 2.7% of U.S. households were completely unready for the analog shutoff. And if you're one of those people who are about to make yourself ready by connecting to a digital converter box to your analog TV we thought it might be helpful to give you this quick how-to guide.
Setting up your converter box is easy. Once you open the package your box comes in you will find directions, a coaxial cable, a remote control and the converter box. Start by unhooking the antenna cable from your TV and plug that cable into the antenna in port on the back of your converter box. Then use the supplied cable to connect the antenna out port on the converter box to the antenna in on the back of your TV. If your antenna is connected to your TV through a thin, flat wire with a pair of screws you'll need to use an inexpensive antenna adapter available from your local electronics retailer. Next, you'll want to plug the converter box power cable into the wall and make sure batteries are installed to that remote control.
Turn on the television and tune it to channel 3. If channel 3 is in use in your area you should use channel 4. But look at the converter box instruction manual for directions. Point the remote at the converter box and push the power button. A light will come on or change color to let you know that the box is getting power and has turned on. The first time you turn the box on it will either prompt you to scan for local channels or it will do it automatically. This could take a little while but will only happen once. As soon as it is finished your box will be ready for use.
Use the channel up button on the converter box remote to explore all your new digital channels. Don't be surprised if you suddenly receive many more channels. And remember, from now on, you will use the converter box remote to change channels, not your TV remote. If you are missing any of your favorite channels your instruction manual can guide you through adding additional channels. With your converter box remote you'll also be able to access the electronic program guide and get information about what you are watching, upcoming programs, signal strength and other stuff. Now, sit back and enjoy the new features of digital television including three Iowa Public Television channels.
Paul Yeager: Now, we've also got a bit of other business to take care of here tonight. We're required by the FCC to let you know about the other full power broadcasters in our broadcast area who will be shutting off their analog transmitters on June 12 and broadcast only in digital. We have taken information available from the Iowa Broadcasters Association and from the federal government's DTV Web site and we're going to show that to you right now. Now, if you don't see a station listed that you watch that means they are already broadcasting exclusively in digital. Because IPTV's broadcast area is the entire state it makes for a somewhat long list but here it is.
Paul Yeager: Joining me now is Iowa Public Television's director of engineering, that's Bill Hayes. Bill is also the current president of the Broadcast Technology Society of the Institute of Electrical and Electronics Engineers. Now, Bill, we've just shown our viewers there the list of the other Iowa stations shutting off their analog transmitters. Obviously IPTV is shutting off its full power analog transmitters on June 12 as well. But there's a little more to the story here. What is it?
Bill Hayes: Well, there's a couple of things, one is when the FCC authorized stations to shut down they let them shut down by day part so there's no guarantee or no requirement that all the stations in a market shut off at the same time. Since it's a Friday we have made the decision to shut all of our analog services off at 12:01AM Friday morning.
Paul Yeager: The first minute that you can.
Bill Hayes: The first minute that we can, that gives us the entire day on Friday to answer questions from viewers who wake up on Friday morning, go to tune us in and we're gone so we can then instruct them on how to tune in, how to re-scan their converters and then there are some other concerns. Iowa Public Television, in addition to having nine full power transmitter sites, we also have translators and translators and low power televisions don't have the same requirement for shutting off analog service. So, in some places where there are translators analog will continue. Now, IPTV operates eight translators throughout the state and I think we have a graphic that shows it. As you can see, if you look at the graphic, the names that are in yellow in the northwest, northeast and southeast corner of the state, those are our translator sites. Those sites are going to stay on analog initially after June 12 but we are moving rapidly to convert them to digital so we hope that by the end of the summer or early in the fall to have all of those converted as well and those will all be digital and then IPTV's entire network will be digital.
Paul Yeager: Okay, now on Friday June 12 at 12:01 AM when we switch there will be people here in the daylight hours to answer any questions, a phone bank much like we've seen here tonight.
Bill Hayes: Correct, we plan on operating a phone bank here on Friday through the weekend if needed and for pretty much as long as necessary to answer viewer questions.
Paul Yeager: That is something that we've continued to do just like we've done with several of these programs as well. Very good, Bill Hayes. Now, also on the program tonight we welcome back our other friend on this program, that's Gary Sgrignoli. Gary is a consulting engineer with the firm of Meintel, Sgrignoli and Wallace and he currently is working with a couple of groups and that would be the Institute of Electrical and Electronics Engineers or the IEEE as a special consultant. So, gentlemen, some viewers are telling us that they have got the converter box, much like what we see here, and they have got that new digital TV hooked up to an antenna that worked with their analog TV and they're still having problems. We certainly have a lot of things to get through here and we're going to get into some greater detail about the DTV reception during the program. But, share with us a few general thoughts to help us ease into what can be a very complicated subject.
Gary Sgrignoli: Well, first of all, the analog to digital conversion is almost over. It's been a long time. We're happy about that. But viewer education is the key to this, educating yourself about DTV reception, the pros, the cons, what can go wrong, etc., that's very important. You don't need to be an expert for certain but if you have the basic information and you understand just the basic concepts you can mitigate or avoid some of the most common problems that people have been calling in.
Paul Yeager: Well, we know that the phones ring pretty much every single time once we turn this program on, Bill. What are some of the big questions that keep recurring through your staff that they're getting?
Bill Hayes: Well, we hear a lot of people talking about -- in Central Iowa we hear a lot of people who put up an antenna 25 years ago and it turned out to be a VHF only antenna and since 10 years ago we've been on the air with digital service but it's all been UHF. So, if the antenna doesn't get UHF they have trouble there. Now we have some concerns because a lot of stations are going to go back to their VHF channels as part of their conversion so they'll shut down their UHF and they'll go back to their VHF channels. Other stations won't. So, in a lot of these markets where there have been some stations have converted and some haven't we've heard a lot of people talking about well, I used to get their DTV service, now I don't, you tell them re-scan your box because they're there, it's just they've changed channels again.
Paul Yeager: The channel assignment that you've talked about before. Okay, this sounds like a pretty good time to divert from this conversation and look at the difference between analog and DTV. To help us out with that Bill and Gary recorded this primer earlier.
Bill Hayes: So let's talk a little about how the signals get to your home. As we've already explained, whether it's analog or digital, we're using the same channels, they're the same size, and they're in the same television bands. So it should be no surprise that the paths they take to your home are identical. But they do behave a little differently, and here's why. This is the broadcast spectrum. And as you can see in the areas in green, we're showing you the various channels. Now, on your television dial, they're one right after another, but in reality they're not.
Bill Hayes: Channels 2 through 6, the low VHF band, is here. Channels 7 through 13, the high VHF band, is here. And the UHF band, 14 through 69, is up here. And you can see there are spaces between those bands. As a matter of fact, between channels 6 and 7 is the FM broadcast band. So because of those spaces, that distance, each band behaves a little differently as it travels. Channels 2 through 6, the low VHF band, require the least amount of power to go the greatest distance. However, what that means at the receive site is that the signal is lower in strength, which means that it's more susceptible to interference. Someone turns on the blender, kicks on the washing machine, and you see those white sparkles in the picture; that's electrical noise. That happens at low VHF.
Bill Hayes: If you go to high VHF, it takes a little more power to go the same distance, but because the signal is stronger, you have a lot less electrical interference. When you get into the UHF band, now you need the most amount of power to go the greatest distance, but the signal at the receiver is so strong that it is virtually immune to electrical interference. So there's a tradeoff of power for distance and the quality of the signal. So the channel band and the path that the signal takes is just one of the things that can impact how well the signal is received. Gary is going to talk to you about some other things that may impact how good of reception you get.
Gary Sgrignoli: Let's talk about propagation effects of both analog and digital television. Television signals essentially travel in a straight line limited by the horizon. For a typical transmitter tower height, it can go 50 to 60 miles. In this real-world example, that is shown right here, 56 miles with very little effects from the naturally occurring terrain. On the other hand there are many places that have irregular terrain where the signal is blocked or shaded, causing weak or even nonexistent signals. A severe case is shown here where only 10 miles away from the transmitter, these mountains totally block the signal and it can not be received.
Gary Sgrignoli: But besides terrain effects, there can be man-made effects that can cause problems. For instance, this signal here has a direct path to the home, which is the desired case, where you can have man-made objects that cause reflections, water towers, office buildings, bridges, et cetera, that cause these echoes to self-interfere with the signal, and that's not a good thing. Perhaps the antenna here can be directive enough so that it will eliminate or mitigate the extra echoes, but not just these outdoor man-made effects. There can be indoor man-made effects in your home where the signal is bouncing off the ceilings, the walls, et cetera, causing, again, self-interference, which is why we strongly urge you, whenever possible, to use outdoor antennas.
Paul Yeager: Well, it's good to kind of get a refresher on these pieces. It's been a while since we've seen them, maybe a while since some of you have seen it. Plenty of you are still having questions tonight as our phone operators are busy. Please be patient if you are calling. You can also send an e-mail to dtv@iptv.org, we'll get to you that way. You can also call during regular business hours as well and some of these same folks that are here answering tonight will be the same way. Both Gary and Bill, we just kind of went over some of the big highlights. Again, give me a quick highlight, propagation -- I've set up since we have last done this program a converter box in my basement, didn't have a cable, I've got a window that is not facing the same way the antenna is. What is my best solution for getting the best signal?
Gary Sgrignoli: You've got a tough situation being low to the ground, very low to the ground and facing the wrong direction so you do not have line of sight. You always want to try as best as possible to have line of sight because television signals, both VHF and UHF, primarily travel in a straight line. So, you may have to either try a new location for your antenna if possible or aim it at some object that you hope will reflect the signal strongly enough.
Paul Yeager: Okay, so that's something that I have to worry about on the inside. Other things, Bill, that you want to add that we've been talking about here?
Bill Hayes: Well, really the only thing I would add is that there are a lot of people out there who are watching digital now and so some of the questions we're expecting after the shutoff is, again, in Des Moines right now our digital service is on a UHF channel and we'll be switching to our VHF channel. In theory we will go away so they do need to know to re-scan their box and they need to understand, as I said in that piece, we're trading power for distance based on what frequency band we're in. As we go from a UHF DTV signal to a VHF DTV signal our power, our radiant power will drop down. The amount of area we cover is the same but we're actually doing it with less power. So, indoor reception may be a little bit more of a problem than it was.
Paul Yeager: So, less power. Is that something that would change if we have enough calls and people concerned about I'm not getting the signal like I used to?
Bill Hayes: It would be certainly something we would work on trying to change but at that point in time we now have to work with the FCC, any change we make to our signal has an impact because the signal travels further than we expect it to so there are guidelines on how much power you can have because we can go into another market and interfere with them.
Paul Yeager: And then we'll get into big trouble and that's a whole other conversation. Gary and Bill have also been very busy, they have another primer for us to help us understand a little bit better about how the digital broadcast signal differs from the analog signal.
Gary Sgrignoli: We have a chart here that shows strong signal to weak signal and the quality of the picture. When the signal is strong, one would expect an analog picture to be excellent. As the signal decreases, we would normally expect a gradual decrease in picture quality as shown on the chart going from clean to noisy picture and sound. The other thing to remember with analog reception is that even though you have a strong signal here, there may be other impairments at that strong signal level.
Gary Sgrignoli: For instance, the electrical impulse noise that occurs when a blender or a vacuum cleaner is turned on would cause picture degradation even though the picture is strong. So will multipath, which is the multiple paths taken from the transmitter to the receiver, causing self-interference. So as we look at this, you'll see that gradual effect of the picture degrading. Well, that's the analog signal. Let's look at the digital signal now and see how that compares. Again, from strong signal to weak signal, the picture is great, perfect until you get to some magical point, some magical threshold beyond which you have no picture. It goes from an error-free perfect picture and sound to an all-error frozen picture and muted sound very quickly. This is called the digital cliff effect.
Gary Sgrignoli: Now, as you look at this, you say, well, let's compare the two. If you compare the two, there's a region up here where the digital will outperform the analog, and then beyond which that the picture of the analog is still not very good, but it's noisy and distorted, yet watchable, where you will have no digital signal. So the goal is to have enough margin above this point so that you're always staying in this region. Broadcasters have optimized their transmitters as much as possible to provide margin above this digital cliff effect. Bill?
Bill Hayes: One of the interesting things about digital tuners is that when you tune a digital television signal in, the channel number that the tuner tells you about is not always the real channel. It's called virtual channels and it was designed to help with this transition. The reason this becomes important to you is that if a station has a virtual channel of 2 but its real channel is 50, that's a very different antenna. So we'll talk more about virtual channels and antenna selection, but it's important to remember that.
Bill Hayes: Now, as part of the conversion, most broadcasters were able to replicate their service. The idea here was to have digital service go everywhere that analog service went. Here's an example of a broadcaster whose analog service is represented by the large dark circle and their digital service has a slightly larger circle. But for the most part, anywhere that their analog service went, their digital service goes as well. That's what we call complete replication. But not all broadcasters were able to do this.
Bill Hayes: Here's an example of a broadcaster whose analog service covers a significantly larger area than its digital service. Viewers in this area who are used to getting analog service from this station may or may not be able to get their digital service. Conversely, some broadcasters were able to take their digital service and actually increase the amount of area they covered compared to their analog service. So when you're tuning your tuner and trying to find service, if you are not getting a station you expected to get, you need to contact that local broadcaster and find out if there was a change that will prevent you from getting the service. Conversely, if you happen to now get a service that you never used to get, you might want to call that broadcaster and let them know that you're now getting their service. They would appreciate it very much.
Paul Yeager: Bill, you just showed us three maps and two of those are in Iowa and that last one is Iowa, that's an increase for some of the folks, it looks like northwest Iowa?
Bill Hayes: That is actually our service in Mason City and that was one particular area where when we were putting up or planning for our new tower site we found a location and based on the FCC contours and allocations we were actually able to increase our coverage. We did that in a number of our markets for our full power markets. I'm not aware of any station in Iowa that has sacrificed coverage but I am aware of a number of stations who have done maximizations to increase their coverage. And likewise, I talked about our translators, all of our translators when they go digital as part of that process we have applied and been granted applications to increase the power so we're increasing the coverage of our translators especially because the fringe areas of Iowa, the corners of Iowa are where we don't have full power service so we wanted to try and make sure that we got as much service there as possible.
Paul Yeager: In some of those parts it's a little bit of a cliff effect. Review a little bit for us, Gary, kind of how that cliff effect may impact some of those farther regions or if they don't impact them at all.
Gary Sgrignoli: Well, keep in mind that the analog and digital signals have the same propagation if they are nearby in frequency. The difference is how they are received and how they are decoded. So, with the graceful degradation of analog somebody out in the fringe could watch a lousy picture and yet it's watchable whereas with the digital cliff effect, for the most part, you either see it or you don't. It's a very important fact that you need to be well above that cliff with enough margin so that when the signal breathes and so forth up and down and level you won't get very frustrated with the signal coming in and out.
Paul Yeager: Now, there's one thing, the last time we discussed this or at least the shutoff was looking like it was in winter and we didn't have leaves on trees, some people may have put antennas up outside, I know that's one call that we get a lot of at our front desk. Talk a little bit about some of these antennas that might be better, at least getting up ten extra feet, twenty extra feet and how they could reduce some of this degradation.
Gary Sgrignoli: I can tell you from personal experience about a week ago I replaced my twenty year old antenna.
Paul Yeager: Finally, you got it done.
Gary Sgrignoli: Yes, procrastination. One of the things I did is I got rid of the old antenna, I put in a new antenna, moved it, relocated it on the roof away from the trees which I trimmed back anyway and we put it up a little taller, another foot and a half, had low loss cable put in and a distribution amplifier and the improvement in my reception, I'm only 20 miles away in Chicago, flat terrain but it's amazing how much the trees when they get wet can affect the different signal characteristics. And, of course, when the wind is blowing what are the leaves doing on the trees and that causes dynamic multipath which makes it more challenging for the receivers. So, do your best to get that line of sight away from all the objects with the best equipment possible.
Paul Yeager: Anything you want to add, Bill?
Bill Hayes: Well, the leaves are a big concern because we have actually started hearing calls from people who did the conversion and put up their antennas and they have been watching our digital service and now they're saying, when I first did this I didn't have a problem and now I'm starting to see a little bit of a problem and that’s when we start to say, okay, where is the antenna and we get a little bit more information and you find out you're shooting through trees, those trees were bare in February and now they are loaded with leaves and if they're damp it creates some problems.
Paul Yeager: That certainly is something that is always coming up for everybody. We do talk about graphs and charts and they do help us understand digital TV just a little bit better and how it differs from analog. But what does this all mean for those of you who are watching at home tonight? Bill was kind enough to invite our cameras into his home and we got a chance to find out and he did a little demonstration for us. Here's Bill at home.
Bill Hayes: One of the challenges we face as we go digital is that many people currently use indoor antennas to receive analog services. Now, indoor antennas work for some folks very well, but they do have their issues. Indoor antenna have ghosting and noise problems that we've just become accustomed to. We've learned that when we see a ghost, to move the antenna slightly. When we see noise, we know we're dealing with a slightly weak signal. In the digital world, these problems are compounded because unlike analog, which receives and displays the picture instantaneously, the digital signal requires a lot more information in order to display the picture. When that information isn't present, the digital signal fails.
Bill Hayes: So let's compare the two. Let's take a look at analog reception using indoor and attic-mount antennas. What you see on the screen in front of you is two services - it's the same service - one being received with rabbit ears showing up on this side of the screen. The other service is using an attic-mount antenna, and it shows up on the other side of the screen. There are artifacts happening to this picture that are not happening to this picture. Why? Everything in this room is impacting the service that's reaching this antenna. The signal coming in is bouncing off the walls. It's bouncing off the ceiling. It's being absorbed by furniture. All of the things in this room, including myself, are impact the service. And the further I am away from the transmitter site, the more detrimental those things are to the service.
Bill Hayes: So as you can see, the picture is quite watchable right now, but if I make a small change to the antenna by rotating it, you can see the picture getting noisier and noisier, breaking up, all the while those changes are having no impact on the attic-mount antenna. There's nothing in the attic interacting with the service, so the attic antenna continues to work fine. Now let's take a look at the same situation using digital converters. These two boxes are designed to convert the digital signal they're receiving to analog and display it on a television set.
Bill Hayes: On this particular display, what I've set up is on the left side of the screen is the digital converter box using the attic-mount antenna. On the right side of the screen is the digital converter box using the rabbit ears, indoor antenna. As you can see right now, both are displaying the signal. But it doesn't take a lot, if I move this antenna slightly, for the digital service using the rabbit ears to start to fail. As you can see, the image on the left side is going smoothly. The image on the right side is jerky. It has breakups, sometimes called pixilation, or macro blocking, frozen screen. These are all common symptoms of digital services running out of information and being unable to decode the picture.
Bill Hayes: So if you decide that you actually do need to stay with indoor antennas, rabbit ears may not be your best choice. Notice as I rotate the rabbit ears, the picture freezes, it pixilates, and I'm not really turning them very much. It takes very little change to impact the rabbit ears. On the other antenna we have, it's a directional antenna. You'll notice that when I go over here to this antenna, again, it's indoor, it's still in the same hostile environment, but it's getting a much more stable signal because it's ignoring a lot of the bounces that are coming in. So, when I move this antenna, it's less likely to lose signal. It's still not as good as an outdoor antenna, but it does do a better job. So in an indoor environment, if you have to use indoor antennas, a better choice might be going with a directional antenna like this one or something even larger. It depends on how far you are from the transmitter site.
Paul Yeager: Thank you very much, Bill, for letting us go in your house. Gentlemen, we just did a little bit there where we talked about indoor/outdoor antennas. You were finishing a thought right as we were coming out. I want you to continue.
Bill Hayes: Well, it's kind of amusing because the rabbit ears I use, it's a set I've had literally forever and what I have in front of me this is the updated version of it. Literally I got this about a week ago from a company. It's the same basic concept, it's rabbit ears with a UHF receive antenna but it's got a built-in preamplifier.
Paul Yeager: Tell me again what a preamp is?
Bill Hayes: A preamp takes the signal and amplifies it so it makes it a little stronger so it helps overcome some of the losses. Typically preamps only work for cable loss but every little bit helps especially indoors. So, I haven't had a chance to really run through the tests but the numbers on it seem to indicate that it will perform better than those old rabbit ears I have so I'm going to try it out. But there are other antennas, I've seen a couple of companies now have come out with essentially flat plane antennas and they are theoretically omnidirectional, it's a technology that is used by, quite frankly it was used by the military for putting antennas on jet aircraft. They couldn't have them sticking up so they created antennas, stripline antennas that are designed to lay flat so they can build them into wind surfaces. So, that technology is now starting to show up in homes as well.
Paul Yeager: That's something that we didn't even see six, eight months ago when we had conversations.
Bill Hayes: Well, they were just starting to try to figure out how to make it work and how to do it in a package that a consumer would buy. And so I have a couple of them, the only downside that I see to them is that if you lay them flat at my house my wife will put a doily over them and put something on top of them which kind of impacts how well they work.
Paul Yeager: Any idea what that costs?
Bill Hayes: This particular antenna is probably a $60 antenna.
Paul Yeager: So, quickly on outdoor, we have one right here, an outdoor antenna that we talked about. What is the one that you set up that worked best for you when you said you're only 20 miles from a tower?
Gary Sgrignoli: Right, keep in mind that if you have to use an indoor antenna, pick a good antenna, but it's always better to use an outdoor antenna, you get up higher, you don't have the building attenuation. What I chose to do because I live in Chicago is to get a higher gain antenna which is more directional but it only covers channel 7 through channel 69, ultimately it's going to be only channel 51 in the core spectrum because we're not going to have any low VHF in Chicago and I found out that it behaved much better. I have an aluminum sided house, signals don't get in.
Paul Yeager: You've got your outdoor antenna set up that we just talked about but some people are still finding that there's still more that needs to be done. We did talk a little bit about preamp but let's go back to Bill's living room again to get a firsthand look at what can affect your DTV signal after it reaches your home antenna.
Bill Hayes: I'd like to talk a little bit about what makes digital reception so much different than analog reception. Typically with an analog signal, we're used to the impairments that we see on the screen, the nosy video, the ghosting, all those things that happen to an analog signal. The same things that cause those to happen to a digital signal, but the digital signal won't show that to you.
Bill Hayes: In order to demonstrate this, I've set up a little experiment here. I'm using a converter box and I'm receiving a local television station using my indoor attic antenna. And I put the signal strength meter on the converter box up on the display. As you can see on this particular display, it not only displays the signal strength, which is the amount of signal getting to the box, but it also displays the signal quality, which is the quality of the information on the signal. And if you notice occasionally, you'll see this number fluctuate between 80 to 86 percent. That means I'm getting somewhere between 80 to 86 percent of the signal according to this box. Now, that little fluctuation is called signal breathing. That happens to any signal that travels through the air, whether it's analog or digital. The outdoor environment has an impact on it and, as a result, the signal fluctuates a little, and that can become important.
Bill Hayes: In order to show the experiment, what I've done is I've put into the circuit this little box called an attenuator. All this box does is it adds - it fools the converter box into thinking that it's further away from the receiving antenna or that the receiving antenna itself is further away from the transmitter. By adding attenuation, what I'm doing is I'm adding or degrading the signal. But I want to watch what happens to the quality of the signal as well as the signal strength and the actual image itself as I add attenuation. So as I start to crank in this attenuation, you'll notice that the lower number, that 86 begins to drop. As you can see, it's now dropped into the 70s. And as I crank more, it's now in the 60s.
Bill Hayes: But notice that the signal quality is still at 100 percent. That means that even though the signal has been degraded, the signal quality is still excellent. As I add more attenuation and drop the signal even further, you can see that the signal strength continues to decline, the amount of signal getting to the box continues to go down, but the actual quality of the image and the actual display quality are the same. They're still at 100 percent. It's not until I actually get into the 30 percent range that you now see I've actually started to impact the actual signal quality.
Bill Hayes: What this means is that the decoder in the box is working harder to make the image, but it's still making a very, very good image. You don't see any errors. You don't see any noise. As I add even more attenuation, you can see that the signal quality meter drops - and now it's in the 70 percent range - the signal still looks good. The image still looks fine. The signal strength is now down around 10 percent. We're actually to the point where I doubt the box is very accurate at this point in time measuring signal strength, but you can see that the image still looks great. It is not until I actually get the signal quality meter to the 50 percent range that you start to see digital breakup.
Bill Hayes: What does this mean? I've just gone over the digital cliff. This signal has now failed by - add back a little bit or take out a little bit of attenuation, the signal comes back. You'll notice it's dropping in and out. Remember that breathing I showed you at the beginning? That's still happening, only now what it's doing is it's taking the signal over and back across that cliff, so the signal is failing and then coming back. And that's one of the very different behaviors of digital versus analog.
Paul Yeager: Gentlemen, we did talk a little bit about preamp but let's start off with some of the toys you have in front.
Gary Sgrignoli: First of all, this is a mass mounted preamplifier that goes up right at the output of the antenna, physically on the mast outdoor, it boosts the signal so that it could boost it before it travels down the coaxial cable which would then attenuate the signal. It also has the capability of throwing in a FM trap to trap out or remove FM radio signals which we know can cause interference at the high VHF signals.
Bill Hayes: And then for indoor use if your signal is getting into the house then this is a preamplifier and this essentially is designed to take the signal from the antenna but it's designed to be mounted indoors and it takes the signal and unlike a passive splitter it actively splits it so that it amplifies and sends an amplified signal to as many as, this one does four, there are all sizes up to sixteen, drive as many TVs as you want.
Paul Yeager: That looks like a fancier version of what you're holding up. Are these pretty much the same thing just one has a little more strength than the other?
Gary Sgrignoli: These are basically the same principle. The difference is this splits the signal two ways, this four ways which means you have signal loss, half the signal goes one direction, the other half goes to the other TV set when you have multiple television sets, this is four way. The problem is you take that loss in the signal, not to mention the cable that follows this to each signal therefore you would use a distribution amp in front of this or you can buy the fancy one that Bill has that has these built in.
Paul Yeager: You can get those fairly cheap, I've seen those under $10. How much is something like that?
Bill Hayes: That's like a $39 purchase.
Paul Yeager: And then what's the next step?
Bill Hayes: And then, of course, we've talked about cable -- cable has actually improved over time so if your antenna that you're using now is using old twin lead, the flat ribbon cable or even RG59 those cables tend to be pretty lossy. RG6 is the cable that I'm holding here, this is a much lower loss and it behaves well across the entire channel band so that every channel that goes through it is treated the same. And the difference really between these devices, between the splitters is these are active devices, these actually physically take the signal and actively amplify it. The splitters are passive devices and all they can do is take the signal and divide it.
Paul Yeager: Simple enough because what we're trying to get is the end result of either a converter box or our digital TV that we have set up in our house. Some of you, though, are very handy and you will be able to make any of these things that we've suggested or any needed antenna modifications yourselves but others may need the help of a local retailer. We did visit a local retailer to address some common consumer questions.
One of the first questions we get asked is, you know, $29 for a little rabbit ear, that I can afford. I don't know about an antenna, that sounds like a huge investment. And indeed, it is an investment. It's an investment for the future of your viewing in your house. But when we do that we can more or less guarantee what the signal strength is going to be whether it be a TV that's in the basement or one that's on the second floor. Now, when we talk about costs, rabbit ears anywhere from $20 to if you get the amplified type you can go over $100. Well, an external antenna whether it be in the attic or on your roof we're probably looking somewhere between $400 to $500 total for installation, the material, the technician, labor, all that stuff together and so we have to look at that as an investment and that is a lot of money. But when you break that down over the period of time that you're going to be in your house and then divide it by the number of televisions you'd have hooked to it we think that's a good investment.
Some people will say, well, if I spend that or make that investment how long will that last? That's a great question. If the antenna can be located in the attic and we have to take that on a case-by-case basis that antenna could last the lifetime of the house. If we have to put it outside now we're subject to the elements of nature, we have ice, we have wind, we have blowing branches here in the summertime when the thunderstorms come in and we have birds that like to sit up there too. So, that will cut down on the age and lifespan of an antenna.
Will my current antenna that I've had up there for 20 years work on my new DTV signals? The answer to that is a definite maybe. The maybe consists of this -- right now our DTV signals are being broadcast in the UHF frequency band. Those are the channels from 14 up through channel 69. That is a different type of antenna than we use for channels 2 through 13 which is the VHF, very high frequencies. So, we need to have an antenna that does both.
Now, some of these DTV transmissions are going to revert back to VHF so it isn't like we can abandon our VHF antennas, we really need to have both. So, if your antenna right now is receiving channels 2 through 13 adequately and it's also receiving your UHF channels adequately there is a good likelihood that it will be okay for DTV. That's good news for a lot of people.
One of the questions that most people will have is, yeah, I'm going to make the investment. All right, which antenna? Well, that's a really good question because it isn't always the same antenna. Now, if we're talking about just being in one city, take Des Moines for instance, we can basically use one antenna in most of our areas of Des Moines and be okay. But what if we go to Ames, what if we go to Corydon, what if we go to Hummeston? What would we use then? So, what we have to use to decide the criteria is how far are you from the transmitter? Are you geographically in a low-lying area because RF signals don't follow the curvature of the Earth, they tend to go straight? So, those are things we have to take into consideration. That's why if you're going to make the investment in an antenna we really recommend that you find somebody locally that knows antenna technology so they can help you make that investment so that it works right when it's done.
Paul Yeager: Those costs vary, they talk a little bit about different in Des Moines. What did you pay in Chicago? Give us a little reference if we're high or low in this state.
Gary Sgrignoli: Typically talking to an independent contractor as well as a major store they estimated that for a simple, straightforward installation with one television set and a reasonable roof basically it was between $250 to $300, not the cost of material but just for the installation and then you add the cost of the material on top of that.
Paul Yeager: Which will vary from each place. Now, there's another little piece of this that folks do need to know. Let's get to that right now. What we're going to talk about has to do with channel assignments and also the importance of doing a frequent channel scan. That's something that is very important as well. And we're also going to continue, I need to let you know that we did talk about the importance of the outdoor antenna and I do want to get a little bit more about what kind of outdoor antenna. It was talked about briefly right there but let's now talk about some of the great resources that are out there for you.
Gary Sgrignoli: Here we are at antennaweb.org Web site, the home page. Lots of good information. What you're going to see here are a list of FAQs, resources, antenna info. As we scroll down, more information for you to study about the DTV transition, and a particular mygreenelectronics.org, a Web site that will give you information regarding recycling of electronic products.
Gary Sgrignoli: Now, let's scroll back up. I'm going to come back and let's focus on antenna info. What this is going to do is it's going to show you that they've divided the amount of outdoor types of outdoor antennas - this is only for outdoor antennas - into the six different colors. The types of antennas that the colors represent are listed here. You can read that at your leisure.
Gary Sgrignoli: Going back to the home page, we should be able then to select the choose an antenna button, and that takes us to the request for your address and zip code. You only need a zip code minimal, but we strongly advise that you put the entire address in so that it can give you the most accurate results from the transmitters - various transmitters to your home. Now, you can unclick the boxes if you don't want marketing info or research surveys coming to you.
Gary Sgrignoli: Two more questions. One is are there any obstructions nearby that are taller than four stories. In our case the answer is no. Also whether your residence is a single story or multiple story. For our case we're going to say single story, but that determines the height above the ground that they're going to assume in their calculations. Well, we're ready to submit. Let's do that. It did the calculations for all the possible stations in your area. You can see on the top there's something called antenna type, and you see it's color coded and there's both analog and digital channels included.
Gary Sgrignoli: Well, let's just show the digital stations only to simplify this. When you do that, you see that now there's a couple other colors down there for stations that are farther away. And you can see now that if you pick all your desired stations, the farthest one down the list requires the largest antenna. That's the one you should purchase. Go out to the store and find one to buy. That gives you an idea of what antenna to use for your desired channels. If that's all the information that was given to you, that would still be great. But we have more.
Gary Sgrignoli: Notice that for each virtual channel here, there is an actual channel listed. And you see, for example, at the top, channel 23.1 is assigned to 56 today, pretransition. That's because the live date is blank. But you know 56 is outside the FCC core and, therefore, it must move. Well, if you also look here, 23.1 is listed as a live date of February 17, 2009, which means it's going to change to channel 31 - from 56 to 31. Your receiver or converter box will not know that unless you rescan. That's the reason to rescan. One more thing to do. Let's scroll up.
Gary Sgrignoli: Let's view the street level map. Now, the nice thing about this is it will show a map of your house on the screen. It will list all the virtual channels that you can possibly receive conservatively, as they point out, with the appropriate color coded outdoor antenna. And you can see in this case, there's three different directions. And that helps you once you purchase your antenna and place it up on the roof or the attic is the next best place, but preferably on the roof. Point it in these directions, and that will optimize your DTV reception for your favorite channels. All that is left to do is to enjoy DTV.
Paul Yeager: So, if you thought that was fun we've got several other sites that we're going to go through right now. Let's take a look at some other Web sites in addition to antennaweb.org. Here are some ones, the first one is TVFool.
Bill Hayes: TVFool is kind of like antennaweb.org only it's a lot more detailed, it's for geeks.
Paul Yeager: Antennaweb.org, again?
Gary Sgrignoli: How to choose an antenna and point it.
Paul Yeager: dtv2009.gov.
Bill Hayes: That is the NTIA's coupon Web site.
Paul Yeager: dtvanswers.com.
Gary Sgrignoli: General DTV information and more.
Paul Yeager: And the final couple, the first one we're going to talk about is dtv.gov.
Bill Hayes: That is the FCC's Web site and it's actually a very good information site.
Paul Yeager: And the last one that we're going to mention here is digitaltips.org.
Gary Sgrignoli: Basic consumer hookups.
Paul Yeager: That's a lot of stuff, those are all on our Web site at iptv.org. Once you do get an idea of what type of antenna that you need in your area Bill and Gary thought it would be great and helpful for you to see a few of the examples. Here is a brief tour of the outdoor antennas that they did for us earlier.
Paul Yeager: Okay, Bill, let's start at the top. This one is a very large antenna that would be outside. This one looks like it could collect a lot of signals, is that the case?
Bill Hayes: That's exactly what it's designed for. This is sort of the standard outdoor all-band VHF/UHF antenna. You see it installed at lots of homes. Its size is because it is designed to receive channels 2 to 69, low band channels require longer elements, that's why it has those long elements at the back. And the number of elements give it what we call gain which is the ability to collect signal. So, this is a great antenna to use if you're farther away from the transmitting sources.
Paul Yeager: Okay, now number 2 looks similar, Gary, but it's not. Why not?
Gary Sgrignoli: Because it doesn't have the longer elements for the low VHF band, it only covers channel 7 to 69 which is the high band VHF and UHF yet it still can be used in weak signal areas.
Paul Yeager: Number 3 is different looking but how different is it?
Bill Hayes: It's a different design for the antenna itself but it's also designed only for UHF reception, 14 to 69, lots of places where there won't be VHF services after the digital conversion is complete, channel 14 to 69 antenna is probably a good choice. And, as you can see, it's physically a lot smaller so it makes it a lot easier to install.
Paul Yeager: You're also going to put this one over here on your side of the room, Gary, number 4, that one goes outside but that also looks like it belongs on this side, very similar but how is it different?
Gary Sgrignoli: It's an alternative design, UHF only, yet it gives us enough gain to work in weak signal areas as well.
Paul Yeager: The one below it is a completely different design than what we've seen. This one looks very aerodynamic. What is that one used for?
Gary Sgrignoli: Interestingly enough it's an all band antenna channel 2 to 69, it has a little bit lower gain so it needs to be used in the yellow area or stronger signals. It has bidirectional antennas for VHF, still has directional pattern for UHF.
Paul Yeager: We touched on the yellow and that was a yellow color. What again does that mean?
Bill Hayes: Yellow is for in areas where the signal is pretty strong, you're pretty close to the transmitters.
Paul Yeager: And red would mean?
Bill Hayes: Red is you're much further out so you're in weaker signal areas so you need the gain of the antenna to collect more signal.
Paul Yeager: And that's the one, Gary, that is below right there, that has a red. Tell us about that one too.
Gary Sgrignoli: This is a channel 7 to 69 high band UHF antenna which will be very popular, we believe, after the digital transition has been completed.
Paul Yeager: There's one other one we want to show, it's the one right behind you, Gary, this one Bill is going to put on a rotor here. We're not cooking anything on that but we're changing for signals. What is that?
Gary Sgrignoli: This is a rotor that is controlled remotely, typically from inside the house, you put a directional antenna on there so that you can point it in different directions depending on where your various transmitters are.
Paul Yeager: Let's talk about how to point these antennas. So, when you got yours put up at your house you had the professional installer, use this example right here because we were just talking in the break looking at this antenna that is set up, one is pointed in the correct direction, one is not.
Gary Sgrignoli: The one that's on the screen right now would be pointed towards a transmitter that is to the left as it appears on the screen. However, Bill pointed out, perhaps you can talk about the one that's on the bottom, that they can pan down.
Bill Hayes: If you look at the lower antenna that's actually, what we're looking at, what's closest to us is actually the back of that antenna, it's actually pointed if the transmitter was up a back wall. So, it's important when you're putting up the antenna to sort of understand, okay, what are the receiving elements and those elements need to be oriented from wherever the transmitter is coming from. That is the information you got off the antenna Web site is sort of point it this way.
Paul Yeager: Point it at a northeast angle, don't point it southeast, a little more south than southeast, trying to figure that out and I think you both have talked about the signal strength that would be when you're doing a channel scan or at least a menu setup on either your converter box or your digital TV.
Gary Sgrignoli: Where you point the antenna we incur it because you can't look at the picture and determine the quality of the signal, use the signal quality meter and you tend to optimize that as you rotate the antenna.
Paul Yeager: Because it's either there or it's not and you don't know if it's stronger, that's something we saw with Bill. Have there been questions tonight or in previous times about I wasn't pointed in the right direction? How, if it's not antennaweb.org, are there other ways to know if you're pointed in the right direction?
Bill Hayes: Well, if you do have the capability of physically rotating the signal, rotating the antenna while looking at the signal strength meter on your television you can orient it and essentially peak the meters. I always tell the story when I'm doing my presentations about being the rotator for my dad when we lived in a trailer. He'd send me outside and say rotate the antenna and then when the picture got good he'd yell, stop. So, essentially that's what you're trying to do because you want to make sure that you're capturing as much of the signal as you can and it becomes even more critical in digital because, as Gary pointed out, with the cliff effect the signal is either good or bad, it's there or not, it doesn't go through that graceful degradation so you can't really watch a marginal signal. If it's not good enough to make the decoder work you can't watch it.
Paul Yeager: There was a place I was at today for lunch and he was watching the converter, he was watching .2 of our signal and it wasn't coming in very well and he was concerned or he thought that once we shut off analog his signal will get better. Is that a true statement?
Bill Hayes: Well, not from our standpoint because some broadcasters were broadcasting at lower power but most were not so in the case of Iowa Public Television all of our digital television stations are all full power. So, our signal is as good as it's going to get. Now, in the case of Des Moines and Iowa City where we're going back to our VHF channel, they'll have to do a rescan but, again, the signal strength has been designed to replicate what the UHF is currently doing. So, we don't expect to see any loss of signal coverage but we do expect it to be VHF so we need to rescan.
Gary Sgrignoli: Keep in mind that you need to rescan before, during and after June 12 because stations will be changing channels as well as possible increasing their power.
Paul Yeager: Hard to believe this but we have just two weeks before this transition. I need your final thoughts. First, final thoughts here as we approach things people need to know.
Gary Sgrignoli: It's been a long haul, a long process, the broadcasters have optimized their transmitters, their equipment to send out the best signal possible, not it's time for the viewers to do their part and that was the expectation of the FCC that there would be an effort put into the right antennas and cable and amplifiers, etc. So, I want to urge viewers to continue to educate themselves about DTV reception.
Bill Hayes: I think that's the key is that this is not rocket science, it's actually science that we're pretty much familiar with but the idea here is that make sure you understand, don't be intimidated by it, try stuff. The reality of it is when you try it, you move things around, you will find that you'll get the service back and it will be stable and when you do have digital service it actually is better than analog service.
Paul Yeager: I appreciate it, gentlemen, we have run out of time for tonight. I do want to thank Gary Sgrignoli and Bill Hayes for being with us tonight. I do want to thank you as well who called in with your questions. I know some of you did get through tonight, if you didn't get your question answered though please contact us during regular business hours at 800-532-1290. That is the number we've been showing you throughout. You can also e-mail us at dtv@iptv.org. Remember, though, you've only got two weeks left before analog goes away. But remember too, we are here for you. I'm Paul Yeager, thank you so much for watching. Good night.
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