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One View: Time for a Reality Check on IBOC

As an owner/engineer who has been around this crazy business since the ‘60s, I think I can offer some insight into all this IBOC talk.

(click thumbnail)Larry LangfordAs an owner/engineer who has been around this crazy business since the ‘60s, I think I can offer some insight into all this IBOC talk.

At first glance it seemed Ibiquity did everything right. They pulled together several teams to design the digital scheme and got major broadcasters to get behind it.

Ibiquity then designed a perpetual income machine with user fees. But suddenly it became loud and clear, like an old 10-bell bulletin on a teletype machine: For AM it’s not working.

Yes, I can hear the supporters say, “Sure it works. We just have to work out the bugs and give it time to catch on.” And they are so quick to point out how long it took FM to really catch on.

To use that as a benchmark is not only dumb, it’s stupid.

FM benchmark ‘stupid’

FM did not take off until people demanded and got it in their cars as standard (read: “no extra cost”) equipment.

Do you really think FM would have caught on if the carmakers had to pay a fee for every radio they built? Come on, wake up, people.

What if adding FM reduced coverage of AM? Or degraded the audio? Do you really think owners would have tolerated degraded AM while they waited for FM to “catch on”?

Some of the biggest companies in the business are behind AM IBOC and yet even their people are saying it’s not working.

The interference to adjacent stations is serious, especially for small stations near 50 kW operations, and Ibiquity would have us tolerate additional hiss from our own IBOC carrier.

I have done some extensive listening in the service area of my WGTO (910 kHz, 1 kW).

WLS (890 kHz, 50 kW) is about 85 miles away to the west. WOKY in Milwaukee (920 kHz, 5 kW) is about the same distance away but more north. Both are running IBOC with both stations putting hash deep into my protected contour at 905 kHz (890 + 15 kHz = 905 kHz, and 920 – 15 kHz = 905 kHz.)

I can testify that my coverage has indeed suffered. The hiss from WLS and WOKY is clearly audible in most car radios all the way to my 2 mV/m contour.

The IBOC hash has taken out an entire market for me that was in the 1 to 2 mV/m contour along the resort shore of Lake Michigan.

Those who support AM IBOC say that Ibiquity will work out the kinks and have a solution. Who are they kidding? If it’s the digital carrier that is causing the hiss on the analog signal, there is no way to “fix” that. Reducing the digital power will make lock and range problems even worse.

Oh yes I forgot, we are being told that analog radios need to be narrowed more. How will you replace all those radios that get the hiss now?

What about the telephone-quality audio that results from even more narrowing? I know we are told that most AM radios have little response over 4 kHz, but they do have some response over 4 kHz and in an honest A/B comparison, there is noticeable change in perceived quality when you tighten the high pass of the transmitter down to a sharp cutoff at 5 kHz from 10 kHz.


Let’s not forget, the human ear is better than any audio meter in detecting quality changes. The ear is also very sensitive to sounds like hiss.

In case you have not heard it, that hiss sounds just like your main carrier has suddenly become weak and the noise is from the radio front end. Most people think your power has dropped.

That is just what we small AM stations don’t need: a perception of weak carrier.

Here is the biggest joke of all of this mess. IBOC supporters say we can now play music again and sound like FM, right? But in the meantime we have to narrow the analog so that the music over the vast majority of radios in use sounds worse than before. Remember why so many AMs switched to talk in the first place?

And we are supposed to pay an annual fee for the privilege of shooting ourselves in the foot?

Ibiquity is asking me to:

  • Pay about $25,000 for an installed IBOC exciter, and then who knows how much the fees will rise in later years;
  • Spend a small fortune to have my 20-year-old directional “optimized” for perfectly symmetrical sidebands and broad-enough response;
  • Degrade my listener base by adding nasty hiss to my own signal at a time when I am already fighting a multitude of other noise sources;
  • Degrade my own audio bandwidth to 5 kHz or less to allow the digital carrier to work; and
  • Wait for 10 years for car radios to become popular while paying a fee each year.

It is just me, or do they take us for fools?

In my earlier article on IBOC reception (RW, Aug. 2, 2006), I noted that FM IBOC does not sound that much better than properly processed analog in the great majority of listening situations, but on the other hand, it does no harm.

The same cannot be said for AM IBOC. I have listened to local Chicago stations when IBOC was first permitted to go on at night. It was not pretty. Even in the city, holding lock was hard.

The radio would slip back and forth from analog to digital every couple of minutes. AM 1000, WMVP (WCFL for us old guys) has never been able to make it work on their three-tower DA. My sources tell me they have spent millions on a rebuild.

Will Ibiquity give me my money back if my DA cannot be made to pass it? The only winners in this IBOC deal are the big companies that will make out on the FM HD2 and HD3. For us little AM guys it’s just another nail in the coffin.

I can only hope that Detroit will take a hard stand on Ibiquity license fees. Maybe the Ibiquity beancounters never figured out that without IBOC as standard dashboard equipment, you can forget it.

If they expect me to pay an annual fee while screwing up my own sound for the analog listeners that are going to be the main audience for years to come, they have completely lost their minds.

A Chicago radio engineer who was one of my mentors said it best: “IBOC FM is junk science. AM IBOC is science fiction.” Any AM small-station owner who buys into this is asking for complaints, headaches and severe disappointment.

I now think I know why the FCC never adopted the NRSC 10 kHz receiver standard as a mandate to manufacturers. The folks at Ibiquity knew that the wider NRSC radio would make the eventual rollout of AM HD even harder.

Fringe reception

So they probably lobbied against the wide-band standard. Now that AM IBOC is here, corporate engineers for some of the big companies that support IBOC are leading the call for severe narrow-banding. Hmm, I think I smell a rat, again. These were some of the same people that said NRSC wideband would be the savior of AM providing FM like sound.

Do you realize the NRSC standard would have given us radios with an audio pass of about 7.5 kHz?

Sure, we could have used a narrow switch for fringe reception, but for the most part, the NRSC standard would have given us radios that would have sounded great in areas where most local AM listening occurs. And the NRSC radios would have been delay-free.

Don’t tell me wide-band cannot sound good. It’s all in the receiver.

The stock Ford Crown Victoria radio for model year 2001 is a beautiful example of “FM-like” AM audio from stations that are still transmitting NRSC audio. And let’s not forget the GE SuperRadio. It is still in production and sounds great at levels over 2 millivolts.

We expected that you can’t mix IBOC and wideband, but it is now clear that even normal AM bandwidth is too wide. So now we must really squeeze it down and that will hurt analog badly.

You think the NAB move to put AM stations on FM translators is independent of trouble with AM IBOC? You think the call for even sharper cutoff AM receivers is independent of the trouble with IBOC AM? It is time to stop CPR and “call it.” The AM IBOC patient is dead.