Should HD AM keep going?

[jras20]

I'm kind of having doupts about them HD-AM keep on going, I think they should focus more on FM than AM, if they half to cut it off at night, than there is really no reason to keep pushing it for AM. I have really not much use on am at night, I wish my sports station would get back on their better tower for nighttime coverage but.......... I see no problem with FM & DX'n with stations that have HD on.. I acually dont have any more reception problems any more with any of my analog radios. Any thoughts?

 

[700WLW]

I have been reading rumors of IBOC just being approved for daytime, because the bulk of revenue comes from daytime AM, and IBOC would only cause reception problems at night - that certainly would be a victory for AM DX'ers.

 

[IBOCRocks]

I have been reading rumors of IBOC just being approved for daytime, because the bulk of revenue comes from daytime AM, and IBOC would only cause reception problems at night - that certainly would be a victory for AM DX'ers.

Yes, and I wouldn't necessarily disagree with that decision, either.

 

[jras20]

Which is why I think they should just focus more on FM and just leave AM to analog.

 

[4dude]

I agree completly..... IBOC is very compromising on AM!!

 

[IBOCRocks]

Which is why I think they should just focus more on FM and just leave AM to analog.

I think that's why you're seeing a slower AM adoption rate compared to FM...

 

[autopaint-1]

When AM IBOC is done correctly, and we have six in NYC, it can sound like FM quality. So far WCBS is the best sounding IBOC AM station.

 

[Len14043]

WLW has a great sounding IBOC signal and can be received in Columbus.

 

[w9wi]

WLW has a great sounding IBOC signal and can be received in Columbus.

What kind of antenna?

With my 260-foot ham antenna I get 100% reliable reception of WLAC-HD and have decoded PAD data from WOWO-HD and WOAI-HD. (WLAC is the only AM HD station within 100 miles)

However, with the loop antenna that comes with the set, careful manipulation of the antenna's location and orientation is necessary to get any WLAC-HD reception at all and I've yet to hear more than 5 seconds of HD audio with that antenna. Most reception is only PAD data. (the "sweet spot" involves holding the antenna in mid-air in the middle of the living room floor! Doesn't it seem that's also the orientation that's always necessary to get that distant FM station with the interesting format?<grin>)

WLAC's transmitter is **18 miles** away.

(and remember, this is daytime-only right now so WLAC is non-directional at the time)

What I'm finding is that by the time there's enough signal for the HD to decode, the *analog* sounds like FM.

 

[rbrucecarter5]

However, with the loop antenna that comes with the set, careful manipulation of the antenna's location and orientation is necessary to get any WLAC-HD reception at all and I've yet to hear more than 5 seconds of HD audio with that antenna. Most reception is only PAD data. (the "sweet spot" involves holding the antenna in mid-air in the middle of the living room floor! Doesn't it seem that's also the orientation that's always necessary to get that distant FM station with the interesting format?<grin>)

WLAC's transmitter is **18 miles** away.

(and remember, this is daytime-only right now so WLAC is non-directional at the time)

Those loop antennas that come with modern tuners are NOT tuned box loop antennas. And - they are much too small to be effective even if tuned. They seem to be operated in a broadband fashion such that the tuner attempts to compensate for their low gain by having tons of front end gain. The net result is noise.

This does not bode well for AM IBOC at all. The signal has no range. Personally - I would like to see IBOC only for FM, and C-Quam back, and MANDATED for AM. It is a robust technology that I have received 300 miles away daytime, and over 1000 nighttime. That, combined with wideband frequency response, would make for some NICE AM listening. Stereo AM sounds better to some listeners than FM, when done right.

 

[autopaint-1]

But AM stereo analogue audio isn't going to attract peole who aren't accustomed to all the analogue AM noise and also the platform effect from the AM stereo systems. AM stereo is a dead science.

 

[rbrucecarter5]

Re: Should HD AM keep going? - and an FM comment.

But AM stereo analogue audio isn't going to attract peole who aren't accustomed to all the analogue AM noise and also the platform effect from the AM stereo systems. AM stereo is a dead science.

Analog AM noise is going to be much worse when it suddenly switches from beautiful, error free IBOC reception to MUCH LOUDER analog interference. There are many locations in the area where a local - powerhouse of a station is completely obiliterated by power lines. You can't tell me that IBOC will continue to function under those conditions. There is no trace of analog audio - how can sidebands transmitted at lower level punch through? At least now, when powerlines approach, I can react and turn down the volume. With IBOC - there will be no warning. I can even see it being a bit of a safety issue as drivers are startled by the sudden transition to very loud noise.

The platform effect has been resolved long ago. Newer generations of chips had a fix. But I agree - the Kahn system was probably better.

As for AM stereo being dead, the ONLY reason is that it was not mandated. The FCC mandated teletext for the deaf in TVs, they have the power to mandate AM stereo and / or IBOC. Unless they do - IBOC AM is as DOA as AM stereo. Guaranteed. It is a fix for something that's not broken in most people's eyes, and they won't buy it. What is the advantage? Stereo musical beds and commercials on talk stations? Give me a break - I wouldn't pay $5 extra for that capability in a radio, much less $200 or $300.

There are some current ads for HD radio that talk about "the signals between the stations". But to get HD reception on FM in the suburbs, you will need a deep fringe FM antenna to get the signal 50 to 60 miles away. But guess what? That is the exact thing you need to hear the REAL signals between the stations: STATIONS FROM OTHER MARKETS!!!! Why should the listener then bother with HD-2 formats when they have suddenly doubled or tripled the number of stations they can receive? Would I care about top 40 in Espanol on KISS-FM locally, when I can get REAL top 40 from Wichita Falls only 130 miles away - in better quality stereo than low bit rate mono on the HD-2 of the local station? I think not. The HD radio revolution may be creating a monster - even more DX'ers than they could possibly have imagined. Who will differentiate between a receivable station in HD that drops out a lot back into analog, and a receivable station that never drops out because its always in analog? Which is less annoying, especially if the delay is programmed wrong or not at all?

Kludgy design engineering on the part of Ibiquity - and I would say that right to the designer's face:

--- The sidebands on AM and FM slop all over adjacent stations that are sometimes NOT unused.
--- The signal isn't robust enough to even reach suburbs of many metro areas - it forces everybody to use at least near fringe antennas to even work.
--- The chipset drinks power making portable radios and head units unlikely any time in the near future.
--- The algorithms so complex it takes several seconds to acquire the digital signal.
--- HD-2 and 3 degrade the primary digital signal by lowering its bit rate, and have such low bitrates themselves that stereo is all but impossible and the quality is worse than present AM.

I could keep going on and on. Now flame away, I don't care. I was right about HDTV when I spoke out 20 years ago how it wouldn't revive domestic TV manufacturing, and I predict 20 years from now there will hardly be an HD radio to be found anywhere but eBay for die-hards.

 

[autopaint-1]

"There is no trace of analog audio - how can sidebands transmitted at lower level punch through? At least now, when powerlines approach, I can react and turn down the volume. With IBOC - there will be no warning. I can even see it being a bit of a safety issue as drivers are startled by the sudden transition to very loud noise."


The radio will not switch to analogue noise that fast. I have ongoing computer hash which is picked up by the radio. It nonetheless stays in HD mode. Actually I have driven to some intersections which sound like a IBOC generator. I don't see IBOC as any serious safety issue. Now cell phones they are a BIG safety issue and illegal to use without a hands free device in NY. I only wish the law was strictly enforced, but that's another subject.



"The platform effect has been resolved long ago. Newer generations of chips had a fix. But I agree - the Kahn system was probably better"


The newest AM stereo radio I own is the SRF 42. It only does C-Quam and suffers seriously from platform effect. I believe you are wrong about AM strereo and the law. All X band stations were supposed to run C-Quam generators. Kahns system didn't allow for things such as stereo indicators etc. It was a relatively antiquated system.

"The FCC mandated teletext for the deaf in TVs, they have the power to mandate AM stereo and / or IBOC. Unless they do - IBOC AM is as DOA as AM stereo. Guaranteed. It is a fix for something that's not broken in most people's eyes, and they won't buy it. What is the advantage? Stereo musical beds and commercials on talk stations? Give me a break - I wouldn't pay $5 extra for that capability in a radio, much less $200 or $300."


You are making quite and assumption that AM stations will remain all talk. I bought 3 AM stereo radios and now the closet statioon to me which runs C-Quam is WREF in Ridgefield Comm. I can here it here but it's very noisy and about 60 miles away. The platform shift is really annoying and the fidelity and noise floor don't come close to AM HD.

"There are some current ads for HD radio that talk about "the signals between the stations". But to get HD reception on FM in the suburbs, you will need a deep fringe FM antenna to get the signal 50 to 60 miles away."

What do you consider a suburb? I live 25 miles from my local FM transmitters (Empire state building) and I only use a dipole and before that rabbit ears lying on the floor and get every HD station in my market. This deep fringe stuff is nonesense promoted by anti IBOC people or those who consider living 75 miles from a city a suburb.

"I predict 20 years from now there will hardly be an HD radio to be found anywhere but eBay for die-hards."

20 years from now the world wil be a different place. You probably won't see CD's for sale. Every computer manufactured today will be as outdated as a C-Quam exciter. Let's worry about the next year or two first.

 

[rbrucecarter5]

The radio will not switch to analogue noise that fast. I have ongoing computer hash which is picked up by the radio. It nonetheless stays in HD mode. Actually I have driven to some intersections which sound like a IBOC generator. I don't see IBOC as any serious safety issue. Now cell phones they are a BIG safety issue and illegal to use without a hands free device in NY. I only wish the law was strictly enforced, but that's another subject.

The newest AM stereo radio I own is the SRF 42.

You are making quite and assumption that AM stations will remain all talk. I bought 3 AM stereo radios and now the closet statioon to me which runs C-Quam is WREF in Ridgefield Comm. I can here it here but it's very noisy and about 60 miles away. The platform shift is really annoying and the fidelity and noise floor don't come close to AM HD.

What do you consider a suburb? I live 25 miles from my local FM transmitters (Empire state building) and I only use a dipole and before that rabbit ears lying on the floor and get every HD station in my market. This deep fringe stuff is nonesense promoted by anti IBOC people or those who consider living 75 miles from a city a suburb.

20 years from now the world wil be a different place. You probably won't see CD's for sale. Every computer manufactured today will be as outdated as a C-Quam exciter. Let's worry about the next year or two first.

I am glad to hear there is a delay in switching - but what about the volume level of an AM station jammed with power line interference. No matter what the delay - you are going to hear a huge difference in volume when the switch does occur, unless the radio employs muting on interference.

As far as the cell phone issue - I don't think it is necessary to complicate the issue of AM stations switching to noise by bringing in an irrelevant issue.

The SRF-42 is subject to platform motion. The decoder IC was developed before the solution to that problem was developed. My sympathies - it is otherwise an excellent little radio.

When the top rated AM stations in most markets are talk - there is strong incentive to continue that format. HD is wasted on talk and sports formats. Who in their right mind wants to hear HD fans cheering? Or who can tell the difference on talk radio between audio that is chopped at 5 kHz and audio that is chopped at 15 kHz. When it is people talking that is.

Congratulations on you station purchases. Given that your listening environment is New York, it is no wonder you have noisy reception on WREF.

Suburbs ARE 75 miles away in Dallas, Houston, Los Angeles, Chicago, and many other metro areas. Stating that suburbs are too far away for reliable HD reception does not make a person an HD opponent or proponent. It is a statement of fact. New York City reception issues are confined to the residents of New York City and have no bearing on the rest of the country. Solutions to reception issues in metro areas spread over a wide geographical area will be similar to those employed now by DX'ers - and those solutions are not a conspiracy theory promoted solely to undermine HD radio. There are many HD radio fans in those suburbs who will be employing deep fringe techniques to receive a reliable HD signal.

Since you are concerned about the next year or two only - a lot more stations will convert to HD, only to find that listeners are not buying the radios. AM music stations will convert, then when they figure out that 99.99% of their listeners are still listening to the analog feed - which sounds awful - and they will switch back to wideband mono so they don't lose what little audience they have. HD radio sales will pick up 50 to 100 percent - which will still be dismal sales figures. Most consumers still won't have a clue they need new radios to hear HD. I'll probably have a head unit / adapter to see what all the fuss is about - if it costs $50 or less. Want to check back in a year or two and see if I was right>