Wal-Mart Rolls Out HD Digital Radio

[TheRover]

Bump--- To climb out from under the stack of Pocket Radio threads....

 

[Chuck]

I have to drive in to Dallas tomorrow. It would be impractical to drag the Sangean with me, but I'll give a careful listen on my car radio to see if the problem is present on other stations. There are plenty of HD signals in Dallas.

When tuning in to Dallas FM stations on my analog GM/Bose radio in a 2007 Chevy Tahoe, it is very easy to figure out which are HD, and which are not. That is because every HD station has a noticeable (and predictable) hiss on its adjacent channels. It sounds quite similar to the hissing we’ve all acknowledged on AM HD stations. With careful listening you’ll note there is superimposed on this hiss a strange sounding digital noise. It is relatively faint, but it is reminiscent of the noise that some cell phones can induce into nearby electronic equipment. I’m surprised that Mike can’t hear this on his Chevy Equinox radio. It is very similar to mine. Does it do it on all radios? I don’t know, but I suspect that it does.

Now I know you will say that I'm hearing things, and this hiss is merely inter-station white noise. It is not. It sounds very different from the noise you get on adjacent channels on analog only stations. The tonal quality is quite different. It is closer to "Pink Noise" than White Noise." There is more low end in it. It is also considerably louder. When tuned in to the adjacent channels of analog stations, you usually also hear some audio from a distant station, or even splatter (or receiver overload) on the adjacent channels. If the adjacent channel is weak, then you hear some white noise too. The acid test for this is when you tune up and down from the analog channel. The lower adjacent channel will sound entirely different than the upper adjacent channel. On the HD stations, the noise is exactly the same. Is that a coincidence?

Perhaps my theory is true that many HD tuners ignore this noise, but for the 99.99% of us who still have analog radios it seems to be true. As to whether this noise is a real problem or not, I'd say the jury is out on that one. It does not appear to be a problem for most listeners. As long as you are dealing with all high power stations it may not make any difference. My concern is what happens when these high power stations mix with a group of lower power stations. I think that FM spacing requirements are rigorous enough that it may not make much difference, including with LPFM as it currently stands. On the other hand, for translators and some full power stations are short spaced, and I'll predict that they will have problems.

None-the less, it is nowhere near as pronounced as it is on AM. That’s where the real problems will be.

 

[clouseau]

When tuning in to Dallas FM stations on my analog GM/Bose radio in a 2007 Chevy Tahoe, it is very easy to figure out which are HD, and which are not. That is because every HD station has a noticeable (and predictable) hiss on its adjacent channels. It sounds quite similar to the hissing we’ve all acknowledged on AM HD stations. With careful listening you’ll note there is superimposed on this hiss a strange sounding digital noise. It is relatively faint, but it is reminiscent of the noise that some cell phones can induce into nearby electronic equipment. I’m surprised that Mike can’t hear this on his Chevy Equinox radio. It is very similar to mine. Does it do it on all radios? I don’t know, but I suspect that it does.

Now I know you will say that I'm hearing things, and this hiss is merely inter-station white noise. It is not. It sounds very different from the noise you get on adjacent channels on analog only stations. The tonal quality is quite different. It is closer to "Pink Noise" than White Noise." There is more low end in it. It is also considerably louder. When tuned in to the adjacent channels of analog stations, you usually also hear some audio from a distant station, or even splatter (or receiver overload) on the adjacent channels. If the adjacent channel is weak, then you hear some white noise too. The acid test for this is when you tune up and down from the analog channel. The lower adjacent channel will sound entirely different than the upper adjacent channel. On the HD stations, the noise is exactly the same. Is that a coincidence?

Perhaps my theory is true that many HD tuners ignore this noise, but for the 99.99% of us who still have analog radios it seems to be true. As to whether this noise is a real problem or not, I'd say the jury is out on that one. It does not appear to be a problem for most listeners. As long as you are dealing with all high power stations it may not make any difference. My concern is what happens when these high power stations mix with a group of lower power stations. I think that FM spacing requirements are rigorous enough that it may not make much difference, including with LPFM as it currently stands.

This is one of the most rational assessments I have heard about the effects of HD on Analog.

I have heard this noise everyday. It's not real pronounced, but it IS there. For lack of a better term it sounds like the noise floor is higher on 1st adjacents of HD Stations.

Keep in mind that with our current system of allocation, 1st adjacent is NEVER supposed to provide service. Period. Protected contours NEVER overlap on 1st adjacents. (I'm sure there might be exceptions, but not for new apps.)

The translator issue may be interesting. There are Numerous Translators on 2nd adjacents. Translators are required to eliminate interference to licensed stations. I would assume this includes "HD" interference, but who knows. Not to mention how you would determine what "HD Interference" actually is.

Chuck, AS you do, I too have an interest in translators. Here's a thought...

If a translator goes HD and everything is cool and then an adjacent FM goes HD and screws up the translator, does the translator have any recourse? NO is the answer, but it sucks if you're the translator. MAybe we'll all get hosed. We'll see.

Clouseau

 

[PhilJSmith67]

With careful listening you’ll note there is superimposed on this hiss a strange sounding digital noise. It is relatively faint, but it is reminiscent of the noise that some cell phones can induce into nearby electronic equipment.

[...]

Now I know you will say that I'm hearing things, and this hiss is merely inter-station white noise. It is not. It sounds very different from the noise you get on adjacent channels on analog only stations. The tonal quality is quite different. It is closer to "Pink Noise" than White Noise." There is more low end in it. It is also considerably louder. When tuned in to the adjacent channels of analog stations, you usually also hear some audio from a distant station, or even splatter (or receiver overload) on the adjacent channels. If the adjacent channel is weak, then you hear some white noise too. The acid test for this is when you tune up and down from the analog channel. The lower adjacent channel will sound entirely different than the upper adjacent channel. On the HD stations, the noise is exactly the same.

Thank you. This is a highly accurate description of the FM HD Radio noise I get on every receiver I own.

Perhaps my theory is true that many HD tuners ignore this noise, but for the 99.99% of us who still have analog radios it seems to be true.

Actually, I can hear the noise on adjacent channels on my Sangean HDR-1, too. When I say "adjacent" I don't mean one tuning step (0.1 MHz), I mean on 0.2-MHz first-adjacents.

As to whether this noise is a real problem or not, I'd say the jury is out on that one. It does not appear to be a problem for most listeners.

I agree that it isn't a problem for most listeners. As for me, personally, this phenomenon renders three previously-listenable stations on first-adjacent channels unlistenable where I live. But, the this is exactly where the FCC's interpretation of their own rules takes over, which says that I have no business listening to those stations anyway, because I am slightly outside their protected contours.

None-the less, it is nowhere near as pronounced as it is on AM. That’s where the real problems will be.

Indeed. My flair for experimentation says, "Light up all those HD signals at night!" Let's just see what a mess we can make of the entire AM band. I can't wait to see what happens when people in Nassau County / Long Island can't get WABC-HD at night because of analog WBBM Chicago and analog WJR Detroit, only to find that analog WABC sounds horrid because of hash from WBBM-HD and WJR-HD... Meanwhile, the reciprocal situation will be occurring in the Chicago and Detroit metros because of WABC. And, that's just one small segment of the dial.

 

[Chuck]

If a translator goes HD and everything is cool and then an adjacent FM goes HD and screws up the translator, does the translator have any recourse? NO is the answer, but it sucks if you're the translator. MAybe we'll all get hosed. We'll see.

Clouseau

That's the way I read the rules. Translators are obligated to accept the interference. Things could get quite interesting. For many "normal" translator operators who are simply augmenting their existing service area, there probably isn't much real reason to go HD. They may receive interference from HD stations, but they can probably keep out of trouble with their neighbors by remaining analog.

That said, NPR affiliates may want to run HD on translators, since their originating stations either have or soon will have secondary channels. Quite a few NPR stations have large translator networks. That may cause some problems in populated areas. In sparsely populated places like New Mexico or Alaska it’s unlikely that they will cause any serious issues.

What really concerns me are the thousands of "satillators" that belong to the top ten religious networks. I'll pick on EMF for no particular reason other than they are rapidly becoming huge. They have two basic services, "K-Love" and "Air-1." Right now, it takes two translators to bring both services to a community. One translator running HD could bring both formats quite easily. (Of course, they could do that with FMExtra too). They might even be able to make some money by marketing the radios to their listeners. For broadcasters who are engaged in the "satillator" biz, multicasting makes a lot of sense.

The problem is there are a lot of them, and a great deal more possibly coming on line. There were some 13,400+ translator applications in the Great Translator Invasion which happened a couple of years ago. Before the FCC froze the process, they actually awarded something like 3000+ new Construction Permits for translators. That leaves another 10000 to be dealt with in some fashion. Some certainly will be dismissed, but if 50% of them ever make it on the air, things are going to get real crowded. It will be even worse if a lot of them go HD. There is only so much spectrum.

 

[clouseau]

If a translator goes HD and everything is cool and then an adjacent FM goes HD and screws up the translator, does the translator have any recourse? NO is the answer, but it sucks if you're the translator. MAybe we'll all get hosed. We'll see.

Clouseau

That's the way I read the rules. Translators are obligated to accept the interference. Things could get quite interesting. For many "normal" translator operators who are simply augmenting their existing service area, there probably isn't much real reason to go HD. They may receive interference from HD stations, but they can probably keep out of trouble with their neighbors by remaining analog.

That said, NPR affiliates may want to run HD on translators, since their originating stations either have or soon will have secondary channels. Quite a few NPR stations have large translator networks. That may cause some problems in populated areas. In sparsely populated places like New Mexico or Alaska it’s unlikely that they will cause any serious issues.

What really concerns me are the thousands of "satillators" that belong to the top ten religious networks. I'll pick on EMF for no particular reason other than they are rapidly becoming huge. They have two basic services, "K-Love" and "Air-1." Right now, it takes two translators to bring both services to a community. One translator running HD could bring both formats quite easily. (Of course, they could do that with FMExtra too). They might even be able to make some money by marketing the radios to their listeners. For broadcasters who are engaged in the "satillator" biz, multicasting makes a lot of sense.

The problem is there are a lot of them, and a great deal more possibly coming on line. There were some 13,400+ translator applications in the Great Translator Invasion which happened a couple of years ago. Before the FCC froze the process, they actually awarded something like 3000+ new Construction Permits for translators. That leaves another 10000 to be dealt with in some fashion. Some certainly will be dismissed, but if 50% of them ever make it on the air, things are going to get real crowded. It will be even worse if a lot of them go HD. There is only so much spectrum.

I know neither you or I will speak horrifically badly about the great translator invasion.
What concerns me about it is how Ibiquity might decide that translators are never going to adopt HD and license them seperately under an "All the Translators you can build for $100,000" deal.

EMF, Family Stations and the like pony up the cash (Small change) and there is HD everywhere. Of course the Big Guys still need to pay, but they have a reason to sell more radios and don't really lose any serious money.

This would NOT make me happy... Or you either I'll bet.

Clouseau

 

[Chuck]

EMF, Family Stations and the like pony up the cash (Small change) and there is HD everywhere. Of course the Big Guys still need to pay, but they have a reason to sell more radios and don't really lose any serious money.

This would NOT make me happy... Or you either I'll bet.

Clouseau

No, it wouldn't please me, and it is a definite possibility. As usual, follow the money. Little guys like us will be the losers, along with the listening public. That's just the way things are and always have been.