More HD AM comments

[Tom Wells]

Lino,
Hilmer Swanson's invention of pulse-width modulation for AM has saved a gazillion dollars in electricity costs, but has done music
no favors, as you notice comparing WABC to the old WQEW.

The modulated envelope created by these transmitters is "stair stepped", and each quantized step-change creates multiple harmonics related to the modulation and the instantaneous non-linearity.
These are very small steps, though, not large enough to do more than create the fuzz or mush you describe.
This is the equivalent of yet another step of digitization which can exacerbate the "cascading codec" efect.

 

[wgliradio]

This is because the 317 runs an old 9100 at full NRSC bandwidth. The analog filtered audio in the DX-50 doesn't sound as good thru the digital processor... ie... they don't make 'em like they used to and the filtering for HD does show up as ringy audio even on narrowband radios. To me it sounds more packed in when we're running the digital Optimod on the DX-50 as opposed to the analog 9100 on the 317.

 

[calstymes]

wgliradio intoned:

I was never more than lukewarm on AM HD, I am now cold on it. Working with it day to day, listening to it, hearing it, experienceing the dropouts driving around, the better audio from the 317-C when it is on, the promise other technologies have, I just don't see it or hear it. It's wrong to me.

Thank you for being an industry professional with a voice of reason.

I have been cold on AM HD since I received my first HD radio and realized it didn't work worth a darn. Please give us back the sound of an AM band that is unfettered with all that sideband garbage from HD carriers. An AM band that is rich and warm with that "classy" AM sound instead of the shrill fatigue-producing sound of HD.

It doesn't get any better than that!

 

[Savage]

Hooray and kudos to wgliradio and Cal. Amen to all that.

Is there ANYONE who has listened to HD for prolonged periods (other than HD supporters with an agenda) who has listened to HD-AM for any appreciable period of time and NOT experienced the fatigue that skanky codec imposes?

Is there ANYONE who has listened to HD for prolonged periods?

Is there ANYONE....hello......testing, 1, 2....

From a reliable source: a major heritage 50kw AM station in Chicago had its HD exciter off for over a month because of one of many technical "issues." The number of complaints because HD was off?

Precisely ONE. And that was from an IBOC "naysayer!" He called to congratulate management on turning the dopey thing off!

 

[LinoNYC]

wgliradio intoned:

I was never more than lukewarm on AM HD, I am now cold on it. Working with it day to day, listening to it, hearing it, experienceing the dropouts driving around, the better audio from the 317-C when it is on, the promise other technologies have, I just don't see it or hear it. It's wrong to me.

Thank you for being an industry professional with a voice of reason.

I have been cold on AM HD since I received my first HD radio and realized it didn't work worth a darn. Please give us back the sound of an AM band that is unfettered with all that sideband garbage from HD carriers. An AM band that is rich and warm with that "classy" AM sound instead of the shrill fatigue-producing sound of HD.

It doesn't get any better than that!

Radios that were "rich and warm" usually meant mostly mid-bass and little else.

"Rich and warm" lost the fidelity race to FM 30+ years ago.

It seems people have learned nothing from AM's current state.

Lino

 

[Len14043]

Is there ANYONE who has listened to HD for prolonged periods (other than HD supporters with an agenda) who has listened to HD-AM for any appreciable period of time and NOT experienced the fatigue that skanky codec imposes?

Is there ANYONE who has listened to HD for prolonged periods?

I don't go out of my way to listen to AM IBOC. However, but I have to admit it was pleasant listening to WLW when they played Christmas music during the holidays. As you probably know from my posts, I'm a advocate for FM but have reservations for AM. I have no agenda but merely take the position: It is what it is.

 

[wgliradio]

It seems people have learned nothing from AM's current state.

Lino

Which is why we have HD

 

[rbrucecarter5]

Oh and where are the line of kids screaming for AM stereo radios. You know the ones that aren't being produced any longer? By the way, kids of that age don't buy electronics. Their parents buy it for them. As has been said eventually HD might be as typical on a radio as the FM band currently is. If and when that occurs then stations running IBOC will have a clear advantage. However, these things take time. You know what they say about a watched pot.

No kids aren't screaming for AM stereo radios. But they might want better sounding radios. AM stereo capable radios are being produced. They are called HD radios - and the code to decode C-Quam is apparently there. But at the time Disney made that poor business decision, C-Quam radios were available through Audiocubes.com. I haven't looked lately.

Yes, parents buy electronics for kids - are they more likely to buy a $200 radio or a $25 radio. It will be a long time before there is price parity between HD and the old C-Quam radios on Audiocubes.com. And -even if there is price parity, AM HD doesn't work very well, especially at night. Wireless internet messes it up. Proximity to TV and computer monitors mess it up. Light dimmers mess it up. Power lines mess it up. Everything that caused interference on analog AM also causes HD to lose lock. The more things change, the more they stay the same. The only way I got AM HD to work is shut off the wireless network in the house, turn off the TV and computer, get rid of ALL CFL bulbs in the house, and all automatic night lights and light dimmers. In other words, everything I would have to do to have good sounding analog AM. What kid is going to shut off Myspace and the TV to listen to Radio Disney in HD? At least C-Quam is more robust and you can hear improvement immediately by moving the radio.

HD was the wrong technology for Radio Disney, given its target audience. They would do better with a good 10 kHz mono audio chain than either C-Quam or HD - it would sound great on the vast majority of new radios with crummy selectivity and cheap wide IF's. the $5 radios you get at Walmart.

 

[rbrucecarter5]

Is there ANYONE who has listened to HD for prolonged periods?

Several hours - even with the listener fatigue caused by the compression and really WIERD things done to high frequency content. It sounds OK - not as good as C-Quam done right but it is listenable. It is the robustness of the signal that bothers me. Really big hurdles for AM HD here:

(1) How do you educate / motivate consumers to become AM DX'ers to receive stable HD reception? It takes a two foot loop to get AM HD that stays in lock - on a station whose towers are less than 10 miles away! When they were C-Quam, I could get clean, reliable stereo on the same station 300 miles away. With a smaller antenna - daytime!

(2) How do you educate motivate consumers to clean up their RF footprint in the house? AM HD requires you to shut off wireless routers, computers, TV's cable boxes, light dimmers, automatic nighlights, DSL, and even the new "green" CFLs! The only people I know of who are willing to do that are hard-core AM DX'ers.

(3) Even if you solve 1 and 2 - the system doesn't work at night. The slightest skywave on adjacent frequencies and the HD lock goes away. C-Quam was rock solid stable for over 1000 miles at night.

The only conceivable solutions are boosting the HD sideband power so high it swamps everything else, but then you would hear it on the analog audio big time. That or better algorithms - but that won't happen. The only way to make HD work is to allocate a band for it - either in the existing AM band, or on a new band. Go full digital on the new band, drop ERP restrictions and blast the heck out of the frequency with 1 million, 5 million watts, whatever it takes to cover the metro area - and have no skywave protection outside of the metro area. That might work.

 

[Tom Wells]

(1) How do you educate / motivate consumers to become AM DX'ers to receive stable HD reception? It takes a two foot loop to get AM HD that stays in lock - on a station whose towers are less than 10 miles away! When they were C-Quam, I could get clean, reliable stereo on the same station 300 miles away. With a smaller antenna - daytime!

(2) How do you educate motivate consumers to clean up their RF footprint in the house? AM HD requires you to shut off wireless routers, computers, TV's cable boxes, light dimmers, automatic nighlights, DSL, and even the new "green" CFLs! The only people I know of who are willing to do that are hard-core AM DX'ers.

How is it that all these devices are even legal for sale in the US when they are clearly not pt 15 compliant?

There is now a 30 history of the FCC permitting such noisemakers, in direct defiance of the terms of their original charter, to regulate radio and devices
utilizing RF energy.

If it has been possible now for 70 years to supress ignition noise from auto engines, (spark discharge of 10s of thousands of volts), there is no excuse
for any device to radiate and intermod MW broadcast signals.

Why hasn't the NAB fought for such compliance? As a body representing the interests of broadcasters, I can't beleive they haven't
tried to force the FCC to require product part 15 compliance. It would require no new rulemaking, only enforcing existing rules.

Even ibiquity stands much to gain from products that don't generate RF hash. Their system is hampered just as badly as analog by this noise.

If the FDA didn't do its job there'd be a lot of impurities in milk. Why such different results when both would seem empowered by the federal government to set standards and require compliance.


It the FCC toothless, or are they killing the AM band by design?

 

[Chuck]

It is interesting to me that a lot of cell phones cause horrendous interference, and nobody says a thing. They periodically make strange noises that bleed into nearby telephones and audio equipment. It seems they do this when they “phone home” to the tower to let it know where it is.

These same phones have a sticker on them saying they are FCC compliant. I complained to AT&T about one of their phones that simply couldn't be left near any audio equipment. I couldn't even take it into the control room without causing big problems on the air. They didn't seem to want to do anything about it until I said, "There is no way this thing could comply with FCC Part 15 Rules." A manager quickly decided it might be a good idea to give me a different phone.

The replacement really didn't work much better. The solution was to go to another carrier that uses different technology. I wonder how many non-compliant AT&T phones there are out there? Maybe if you are big enough, it is OK to interfere.

 

[Len14043]

The only conceivable solutions are boosting the HD sideband power so high it swamps everything else, but then you would hear it on the analog audio big time. That or better algorithms - but that won't happen. The only way to make HD work is to allocate a band for it - either in the existing AM band, or on a new band. Go full digital on the new band, drop ERP restrictions and blast the heck out of the frequency with 1 million, 5 million watts, whatever it takes to cover the metro area - and have no skywave protection outside of the metro area. That might work.

It shouldn't take that much power to cover a metro area with an all digital signal. Remember, the digital is 1/100 the power of the analog signal. WLW is receivable nearly 200 miles from the tower (under ideal conditions, i.e. in a car away from powerlines with no thunderstorms in the area) during the day. Not bad for 500 watts!

 

[rbrucecarter5]

It shouldn't take that much power to cover a metro area with an all digital signal. Remember, the digital is 1/100 the power of the analog signal. WLW is receivable nearly 200 miles from the tower (under ideal conditions, i.e. in a car away from powerlines with no thunderstorms in the area) during the day. Not bad for 500 watts!

I can hear those blasted sidebands for hundreds of miles, long after the analog has faded to oblivion. It is a mystery to me why they don't decode any better than they do.

From the posts here, it sounds like the HD advocates might be strong allies in getting interference generators banned.

 

[LinoNYC]

(1) How do you educate / motivate consumers to become AM DX'ers to receive stable HD reception? It takes a two foot loop to get AM HD that stays in lock - on a station whose towers are less than 10 miles away! When they were C-Quam, I could get clean, reliable stereo on the same station 300 miles away. With a smaller antenna - daytime!

(2) How do you educate motivate consumers to clean up their RF footprint in the house? AM HD requires you to shut off wireless routers, computers, TV's cable boxes, light dimmers, automatic nighlights, DSL, and even the new "green" CFLs! The only people I know of who are willing to do that are hard-core AM DX'ers.

(3) Even if you solve 1 and 2 - the system doesn't work at night. The slightest skywave on adjacent frequencies and the HD lock goes away. C-Quam was rock solid stable for over 1000 miles at night.

In answering #1, You certainly have different conditions than I have here in Manhattan where I am nowhere near any of the towers of WFAN, WOR, WABC, WNYC, WQEW OR WCBS-am - only the latter fails to lock, probably owing to it's weaker rf in relation to the others.

#2 Was a jaw-dropper. especially since I'am in an apartment with 17 cf bulbs and 3 tube flourescent lamps, 11 computers (3 are operating as I write this and a large screen tube tv running in one of the rooms. There are 12 to as many as 23 wi-fi net's signal reaching here (including my own).

I took a Sony portable with a sensitive AM section and walked around the place. CF bulbs produced alot of noise but that died at approx 4-5 ft, regular flourescents were noisy to approx 3ft as are the computers and their monitors (crt and lcd mix) Obviously I can't do anything about all the wi-fi nets.

The only possible explaination that I can think of for the disparity in reception effect between your location and mine from these items is perhaps different wiring used in buildings. Here in NYC all interstitial wiring must be conduit or BX (armored) cable, the plastic Romex common in some areas is banned here, so it's possible that wiring here is better suited to supress interference throught a structure.

The slightest skywave on adjacent frequencies and the HD lock goes away. C-Quam was rock solid stable for over 1000 miles at night

C-Quam may have been "rock stable" at great distances but the fact is that it would still be marred by all the things that plague AM reception and the highest quality receivers that had the capablity to widen their bandpass would only do-so if presented with a strong, clean signal. It was a good technology but it's had it's turn and failed to help AM even with millions of receivers still on the road.

Lino

 

[rbrucecarter5]

The only possible explaination that I can think of for the disparity in reception effect between your location and mine from these items is perhaps different wiring used in buildings. Here in NYC all interstitial wiring must be conduit or BX (armored) cable, the plastic Romex common in some areas is banned here, so it's possible that wiring here is better suited to supress interference throught a structure.

The slightest skywave on adjacent frequencies and the HD lock goes away. C-Quam was rock solid stable for over 1000 miles at night

C-Quam may have been "rock stable" at great distances but the fact is that it would still be marred by all the things that plague AM reception and the highest quality receivers that had the capablity to widen their bandpass would only do-so if presented with a strong, clean signal. It was a good technology but it's had it's turn and failed to help AM even with millions of receivers still on the road.

Lino

Interesting. If anything, I would have thought that wiring in NYC, where a lot of the buildings are older, would be built to the standards in existance when the building was built. And the temptation is always to cut corners - the only reason why that isn't as prevalent today is better enforcement of building codes. I would think a residential area filled with single family dwellings would be infinitely better for HD radio than a high rise environment.

This highlights one issue - if nothing else. Listener experience with HD radio will vary greatly depending on a multitude of variables. It may take a fair amount of luck for the average consumer to have a good experience. It is too bad LED lighting isn't quite ready for consumer penetration yet, it would help the cause of HD radio by eliminating a significant cause of interference. In my case, the main culprit may be a power substation a block away, and a 128kV power line. Neither put any interference on even the most sensitive radios I own, but there is some 60 Hz that seems to be leaking into my HD tuner. It is possible that is creating an issue.

As far as C-Quam - if it was an obsolete system, why was the ability to decode it built into HD radios? Did somebody have a premonition that nighttime HD might not work? Since nighttime HD AM is not workable, the analog signal will be subject to all of the old woes. But having broadband stereo on the signal is better than nothing and would sound better than the present bandwidth limited mono. If station owners do nothing else - at least revert to decent broadband mono when HD is shut down. It can't be that hard to do!

I am surprised WCBS is so weak in your location. Before KRVN signed on, WCBS was a reliable catch in West Texas at night.

 

[Tom Wells]

It is interesting to me that a lot of cell phones cause horrendous interference, and nobody says a thing. They periodically make strange noises that bleed into nearby telephones and audio equipment. It seems they do this when they “phone home” to the tower to let it know where it is.

These same phones have a sticker on them saying they are FCC compliant. I complained to AT&T about one of their phones that simply couldn't be left near any audio equipment. I couldn't even take it into the control room without causing big problems on the air. They didn't seem to want to do anything about it until I said, "There is no way this thing could comply with FCC Part 15 Rules." A manager quickly decided it might be a good idea to give me a different phone.

The replacement really didn't work much better. The solution was to go to another carrier that uses different technology. I wonder how many non-compliant AT&T phones there are out there? Maybe if you are big enough, it is OK to interfere.

My AT&T cellphone also puts the bup-dudda bup noises on any audio devices within 6 feet, but the AT&T wireless card here in the laptop,
which is using cellular technology, does not put any noise into my part 15 operation, and I use the laptop 2 feet from the xmttr.

The level the cellphone xmits at is determined by the received signal strength, so anyone who brings a phone into a weak signal area is more likely
to hear these noises.

One customer I work at here in Chicago is in a basement of an old heavy-construction building (mid 1920's).
There is enough signal to ring, but never enough for me to answer.
In one day working there with no phone calls, the battery goes dead from just trying to keep in touch with the local cell.

 

[Carmine5]

In fact, I used to regularly listen to KDIS when they were broadcasting in AM stereo, primarily because they were broadcasting in AMS and the station sounded very good. When they switched to HD-AM, and totally trashed their analog signal in the process, I stopped listening.

I can relate to that - I pretty much stopped listening when they trashed their audio here. You really have to wonder about their business plan - HD AM for KIDS. I am sure all of those kids are going to go out and buy HD radios with Mickey Ears on them for $200. If I had been in charge - I would have pushed for really good sounding C-Quam on the Disney network, and made a deal with a Japanese manufacturer to sell the radios for $25. Not only would they sound great, but they would work at night and there would be no coverage problems. There is a lot more chance a kid will get a $25 radio that doesn't require a huge antenna than a $200 radio that requires a large antenna and a fair amount of tinkering.

I've already seen one kid tapping a stream of Radio Disney on their cell phone somehow.

There's a commentary today by Jerry Del Colliano that basically confirms what I've been saying about Radio Disney as well as affirming the tremendous popularity of it with children despite the fact that it's on AM.

http://insidemusicmedia.blogspot.com/2008/03/its-3-am-who-do-you-want-programming.html

A few quotes:

"CEO Michael Eisner focused on purchasing crappy little AM signals nationwide instead (and doing long-term affiliations) to carry Radio Disney childrens programming."

"They did arguably the most creative radio on radio, but no one knew -- except the kids. Today I have some of those grown up kids in my classes at USC and I can tell you they speak of Radio Disney with great reverence -- a lot more than they have for radio-as-usual. Few really noticed that this generation would actually grow up someday except Disney."

"Disney knew best that radio, cable, theme parks, merchandising, movies, music and outstanding promotion would eventually lead to "Hannah Montana" and "High School Musical". The radio business may be dead and the television business may be worried about YouTube but who wouldn't want the revenue these programs bring to Disney. Guess that's what radio gets for being shortsighted."

"Disney youth-oriented artists outsell the major record labels when it comes to CDs. Young listeners don't know that CDs suck because Miley Cyrus is on them. The product trumps the technology."

The Del Colliano piece itself is on how radio lost the next generation. As usual from Jerry, it's fascinating reading whether you agree with it or not.

As he says: "All of a sudden digital and analog don't matter" (so much for the argument that Radio Disney would do better on HD).

C5

 

[R.F. Burns]

"

The only possible explaination that I can think of for the disparity in reception effect between your location and mine from these items is perhaps different wiring used in buildings. Here in NYC all interstitial wiring must be conduit or BX (armored) cable, the plastic Romex common in some areas is banned here, so it's possible that wiring here is better suited to supress interference throught a structure."



Although there is old wiring in some NY buildings, that wiring must be kept to code. When you purchase a new electronic appliance, a hairdryer for instance, they use a polorized plug. I have a friend who lives in an older building on Central Park West in NY and his outlets are all polorized even though the building was constructed long before polorized plugs were available. Look at Radio City in NYC. Its a landmark building which means no changes may be made to the outside stucture. The building even has windows that open (and no modern skyscraper has windows that open). I was in an office a few years ago, up on the 60th floor. I had to make a recording and all of the outlets are now polorized and they even have full building air conditoning. Structural laws in NYC are very strict and buildings must be kept to code.


"

The slightest skywave on adjacent frequencies and the HD lock goes away. C-Quam was rock solid stable for over 1000 miles at night

"


That's all well and good for DXing but the average person under the age of 40 isn't listening to AM skywave stations today.

Interesting. If anything, I would have thought that wiring in NYC, where a lot of the buildings are older, would be built to the standards in existance when the building was built. And the temptation is always to cut corners - the only reason why that isn't as prevalent today is better enforcement of building codes. I would think a residential area filled with single family dwellings would be infinitely better for HD radio than a high rise environment.

This highlights one issue - if nothing else. Listener experience with HD radio will vary greatly depending on a multitude of variables. It may take a fair amount of luck for the average consumer to have a good experience. It is too bad LED lighting isn't quite ready for consumer penetration yet, it would help the cause of HD radio by eliminating a significant cause of interference. In my case, the main culprit may be a power substation a block away, and a 128kV power line. Neither put any interference on even the most sensitive radios I own, but there is some 60 Hz that seems to be leaking into my HD tuner. It is possible that is creating an issue.

As far as C-Quam - if it was an obsolete system, why was the ability to decode it built into HD radios? Did somebody have a premonition that nighttime HD might not work? Since nighttime HD AM is not workable, the analog signal will be subject to all of the old woes. But having broadband stereo on the signal is better than nothing and would sound better than the present bandwidth limited mono. If station owners do nothing else - at least revert to decent broadband mono when HD is shut down. It can't be that hard to do!

I am surprised WCBS is so weak in your location. Before KRVN signed on, WCBS was a reliable catch in West Texas at night.

From the Sangean rep in this country its been stated that although the radios will decode C-Quam, they are not licensed to do so and the radios ability to decode C-QUAM is far inferior to my SFR 42. The radios were not designed to decode C-Quam. Geez, I remember hearing KRVN over 20 years ago. That's a long time since WBZ was reliable out there. Here in NY you can't hear WBZ, HD sidebands, or WPHT's or any of the non NY stations HD sidebands. There is so much other interference from other non bc radio devices that those once common stations are noisy at best here. As for WCBS, it is co-located with WFAN with their tower on High Island on the LI Sound, near the Bronx. The signal of both stations in parts of Manhattan is weak at best. There's so much steel concrete and so many forms of interference to the signal that these stations have a better signal 200 miles away than they do in parts of NYC. For instance, WNYC running 1 Kw night into 3 towers on 820 Khz has a far superior signal in midtown Manhattan than either WFAN or WCBS, both of which run 50 Kw non Directional

 

[R.F. Burns]

In fact, I used to regularly listen to KDIS when they were broadcasting in AM stereo, primarily because they were broadcasting in AMS and the station sounded very good. When they switched to HD-AM, and totally trashed their analog signal in the process, I stopped listening.

I can relate to that - I pretty much stopped listening when they trashed their audio here. You really have to wonder about their business plan - HD AM for KIDS. I am sure all of those kids are going to go out and buy HD radios with Mickey Ears on them for $200. If I had been in charge - I would have pushed for really good sounding C-Quam on the Disney network, and made a deal with a Japanese manufacturer to sell the radios for $25. Not only would they sound great, but they would work at night and there would be no coverage problems. There is a lot more chance a kid will get a $25 radio that doesn't require a huge antenna than a $200 radio that requires a large antenna and a fair amount of tinkering.

I've already seen one kid tapping a stream of Radio Disney on their cell phone somehow.

There's a commentary today by Jerry Del Colliano that basically confirms what I've been saying about Radio Disney as well as affirming the tremendous popularity of it with children despite the fact that it's on AM.

http://insidemusicmedia.blogspot.com/2008/03/its-3-am-who-do-you-want-programming.html

A few quotes:

"CEO Michael Eisner focused on purchasing crappy little AM signals nationwide instead (and doing long-term affiliations) to carry Radio Disney childrens programming."

"They did arguably the most creative radio on radio, but no one knew -- except the kids. Today I have some of those grown up kids in my classes at USC and I can tell you they speak of Radio Disney with great reverence -- a lot more than they have for radio-as-usual. Few really noticed that this generation would actually grow up someday except Disney."

"Disney knew best that radio, cable, theme parks, merchandising, movies, music and outstanding promotion would eventually lead to "Hannah Montana" and "High School Musical". The radio business may be dead and the television business may be worried about YouTube but who wouldn't want the revenue these programs bring to Disney. Guess that's what radio gets for being shortsighted."

"Disney youth-oriented artists outsell the major record labels when it comes to CDs. Young listeners don't know that CDs suck because Miley Cyrus is on them. The product trumps the technology."

The Del Colliano piece itself is on how radio lost the next generation. As usual from Jerry, it's fascinating reading whether you agree with it or not.

As he says: "All of a sudden digital and analog don't matter" (so much for the argument that Radio Disney would do better on HD).

C5

This guys name always is brought up here as though his is the voice from on high. Please tell me, what stations is he running successfully today? You'd think this guy was running the number one station in the US with billing in the tens of millions of dollars, the way he's quoted here.

 

[Carmine5]

Jerry is a 30+ year broadcasting veteran, educator and founder of Inside Radio. He knows anyone who's anyone in the business including successful station owners.

Lest we forget the focus of this discussion, namely, that programming is more important than delivery method (AM vs. FM, HD vs. analog), Don Barrett made an interesting observation on his LA Radio column.

He said this:

"It wasn’t that long ago when Comedy Central couldn’t do better than a 0.8 – 0.9 rating. Then they put on South Park. Wow!The half-hour leading into South Park was a 0.8. South Park spiked to a 5. The half-hour after South Park was back to a 0.8. The lesson learned? The public will come if you provide compelling and entertaining content."

And that includes kids listening to Radio Disney on good old analog AM.

C5