The Future of AM Radio



Can you believe AM radio is still around? Me and a few others still do use it. I listen mostly in the car for traffic, weather, and news, though sometimes I listen to talk programs on a small AM/FM kitchen radio. Seems so retro, but it is still useful.

Nevertheless, AM radio has been in decline for years, with many AM stations going out of business each year. Now there are only 4,684 left as of the end of 2015. That stands in contrast to the 6,701 commercial FM stations that are thriving, a number that does not include an additional 4,095 educational FM stations and 1,433 low power stations. All this is still analog, remember. So some big questions come to mind: Why is AM dying, and what can be done to save it?

AM is dying for a lack of listeners. Only 10 to 20 % of all radio listeners listen to it, and that depends upon the locale. It may be less that 10 % in some places. If stations can’t get listeners, they cannot get the advertising that keeps them alive. Most of the listeners moved on to FM or other radio sources. These other sources include satellite and Internet radio, along with things like iPods or smartphones loaded with songs and podcasts. Satellite radio is now in most vehicles.

Then there is digital radio, although this is not a popular option. The U.S. version (called HD Radio) is available on both the AM and FM bands, but few receive it. The digital version simulcasts the analog content in an OFDM overlay on the same frequency. You need a special radio to get it, an expense justified by its proclaimed benefits of less noise and greater fidelity. I’ve tried it, but it seems about the same to me. Some cars have HD Radio, but otherwise you need a unique receiver. There are not too many sources. Canada launched Digital Audio Broadcast (DAB) in the L microwave band a few years back, but it has not been successful, either. FM still thrives there.

In addition to the many multiple competitive sources of content, AM is also failing because of technical problems inherent in the AM process, along with some unyielding regulations. For example, AM stations lose listeners at night because the FCC makes them cut power or shut down completely to avoid interference to other stations on the same frequency. AM signal propagation in the 535 to 1,705 kHz range changes drastically from day to night.

During the day propagation is primarily by ground wave with a range of no more than 200 miles, so stations can transmit full power. At night there is less upper layer ionization, so the AM signal refracts off the upper layers, causing the signal to skip hundreds or even thousands of miles. This causes interference to other stations. Some stations use complex and expensive directional antenna systems to solve the problem.

Another issue is noise. The AM band is very noisy, with interference from power lines, auto ignition, fluorescent lights, motors, CLFs, and any electronic equipment with switch-mode power supplies, which includes almost every product today. Weak signals are swamped by noise, and even strong signals suffer from it. Noise makes listening annoying at best, and off-putting to the max.

Realizing these problems, back in October of 2013, the FCC issued a Notice of Proposed Rule Making (NPRM) designated 13-249 Revitalization of the AM Radio Service. The FCC solicited input from all sources on how to solve AM’s problems. Just recently, it announced the first of several solutions. The new rules allow some AM stations to use FM translators. A translator rebroadcasts a station’s content on an available FM frequency. In this way, stations can continue to transmit at night, thereby retaining a greater audience.

Other solutions are on the way, including something called Modulation Dependent Carrier Level (MDCL) control. MDCL allows stations to decrease carrier level and adjust sideband power to save power and improve efficiency. Also on the way are other changes that lessen the stringent antenna requirements. It will be interesting to see what else the FCC comes up with.

AM is worth saving; it is a valuable local community resource. AM radio serves a public safety purpose for emergency conditions. It provides valuable services to ethnic and religious populations, as well as high school sports coverage. And still does a great job of news, weather, and traffic coverage. Talk shows are also popular. In short, analog still lives.

What do you recommend to save AM? Or should we just let it go? With spectrum in short supply couldn’t we just repurpose this band? And if so, to what?

Discuss this Blog Entry 39

on Feb 17, 2016

I actually had an HD FM radio and liked it. The main problem is that the range of analog is farther than digital so things get funky on the periphery with it dropping out of digital mode. There is a big difference in the audio quality between analog FM and HD radio. I have switched to satellite to get the same quality but I miss the local stations. I have to now resort to regular analog FM but more for news and an occasional change since satellite tends to be somewhat narrow in musical variety.

on Feb 18, 2016

It's more about revenue models than modulation. Circa 1975, I supplemented my free-lance tech-writing with a part-timeDJ gig as the bridge DJ between the morning-drive and nighttime jocks at a 5-kW am directional (with fm simulcast). I'd play the 45s the program director picked out for me, punched up the carts with the long-running ads, read the one-shot ads the station copywriter typed up, pulled the hourly news off the teletype, taped the feed from Paul Harvey, all for minimum wage.
That's not to complain about how underpaid I was, but to point out how many jobs that pipsqueak operation in a couple of rooms over a candy store: a GM, a couple salesmen, a copywriter, a part-time engineer, 3 DJs, and a admin.
And it made money for the license-owner.
And most of the ads were local. And, when there was a high school basketball game we could get a telco feed from, the night DJ would have a couple of hours of light duty reading the local commercials while one of the salesmen called the play-by-play and interviewed the coaches during halftimes.
Today, local am is all automated with canned feeds from some common source in Texas. Or Mars, or somewhere. One salesperson can service half a state.
Meanwhile the people in the larger demographics are streaming custom content and paying for it directly.
See what you've done, Lou. . . you've made me nostalgic for CONELRAD alerts.

on Feb 19, 2016

DT2, you paint a vivid and accurate picture of how the AM radio business has changed. The biggest problem is that AM stations mostly have no local programming, so they don't really provide any community service anymore. As a result, potential local advertisers lose interest in the medium. This is part of a bigger problem, involving newspapers, and other media: at the local level there are almost no news sources. There is almost no way to know what is happening in your community.
Another useful feature of AM in the past was for travelers on long driving trips. You could tune in to each local station as you traveled, and get useful local info, like weather alerts, ads for restaurants, local attractions, etc. Of course, you can get this info on your phone now, but at a high monthly cost. And local news sources are still absent.
And there is the technical issue. Across the spectrum, from 500KHz up to 30MHz (let's not forget the once-popular shortwave broadcast bands - another form of "AM"), the noise level has been increasing steadily for the past 20 years or so, all due to the proliferation of SMPS's, and other digital devices, and FCC regs that are pretty generous with the amount of hash that is allowed out there. These frequencies, and their unique continent-wide (even worldwide) propagation characteristics, are all but useless now due to high noise levels.

on Feb 19, 2016

I did used to listern to HD Radio when i was driving on holiday in America. It was quite a difference experience to DAB digital radio. Most of the stations are multicasting on FM using HD2 and HD3. nice choice and also different programming but the UK needs to ensure that DAB increase coverage before the great Analouge radio switchoff as most cars dont have DAB yet. hopefully it will be more a standard soon

on Feb 22, 2016

You can't force people to listen to something they don't want to. The declining listenership is made worse by the fact that, when an MP3 player (or similar device) has a radio, it's FM only.

If AM is to be used for "community" services, the FCC should allow unlicensed operation at "reasonable" power levels to anyone. (How long this would last, without abuse, is anyone's guess.)

"You need a special radio to get it, an expense justified by its proclaimed benefits of less noise and greater fidelity."

Greater fidelity compared to what? HD's degradation (with well-made recordings, especially of orchestral music) is obvious.

on May 25, 2016

HD is supposed to have better fidelity than analog FM. However, like digital television, it is very finicky and reception varies greatly and will drop back to analog FM if it can't hold onto a solid signal. Analog FM has very limited bandwidth and AM is even worse.

on Feb 22, 2016

About 80% of radio listeners are in vehicles. However car radios as installed by manufacturers in the US are often versions with Sirius/XM capability and have a stubby antenna that receives satellite, but this is quite poor for AM reception. So despite the AM content (often talk that people want), the station cannot be received.
Also while FM is touted, the range is shorter, and digital broadcast (DAB, DAB+ or DMB) is probably even shorter. Also Norway is soon shutting down FM to go DAB. However DAB/DAB+/DMB frequency bands vary considerably by country so this is a problem for consumer electronics manufacturers. CONELRAD? Please??? The Emergency Alert System does work and saves many lives, and the FCC is asking for comments for improvements so this is expected to be moving soon as a bill passed the Senate (S1180) and House Bills are in the Transportation & Infrastructure Emergency Management Subcommittee (HR1472 and HR1738),

on Feb 22, 2016

AM is inefficient to the extreme. The main benefit is that receivers can be quite simple. You can even build one with junk. I've received AM with a coil of wire, aluminum foil pasted to two sides of a piece of glass, and a corroded piece of metal. This feature was of great benefit in the early days when inexpensive receivers appeared in every household. Today, when complex DSP systems cost pennies, that advantage is gone. I like to listen to AM, but it is being choked by digital encroachment. Power lines today emit not only the 120Hz buzz, but also the digital hash from power line communications. There is so much interference that I cannot listen to a local 20kW station, ten miles away, during the day without carefully positioning my receiver.

on Feb 22, 2016

Three comments: The FCC should be tarred and feathered for giving GE a waiver on the noise created by their new light bulbs. This was probably 30 years ago, but was the start of the rising noise levels. Also, until the 70's or ??, the ownership limit was seven AM, seven FM, and five TV stations. Now there is no limit, and the programming sounds like a juke box. The NRSC filters forced upon the stations may have made a small improvement in the adjacent-channel interference, but gave AM the telephone-quality sound it is accused of. If you think AM is inherently poor quality, listen to a Continental screen-modulated transmitter, or the Harris PWM or solid-state rigs.
Zbigniew Chrysler "Back in my day we had nine planets"

on Feb 22, 2016

There is a common misperception that AM radio has horrible sound quality compared to FM.
I'll be dating myself, but in the early '60s at university, my roommate listened to WXYZ on his little portable AM transistor radio and at one of the station IDs "WXYZ AM and FM" asked me "what is FM?"
So I took him down to the University's radio studios and tuned in WXYZ simulcast on the MacIntosh AM-FM tuner and when I switched between the AM and FM I was blown away, as I couldn't tell the difference on the studio monitors. While I was going on about the fantastic AM tuner, he was going on about what the big deal about FM was.
I was never able to afford a MacIntosh tuner, but when AM stereo came along I got a decent SONY one and the few stations that broadcast in AM stereo had very decent sound quality. Too bad the FCC approved so many different AM stereo systems.

My biggest gripe about FM tuners has always been the 19KHz stereo pilot tone which came through my electrostatic loudspeakers loud and clear giving me a headache. When shopping for FM tuners I could stand listening to, I had to first buy their shop manuals and check if they had a 19KHz filter which very few did.
Along with the 15KHz whistle on CRT TVs and many switching power supplies, it is obvious to me that electronic designs are controlled by the old boys who are deaf to high frequencies, unlike younger people and women. I once put a heart pulse monitor on my sister and could change her pulse rate from 60 to over 80 by switching the old TV on and off (volume down and turned away). I can understand how some women actually got sick when they turned on their computers with CRT monitors. Even the B&K sound level meters with their sharp high frequency cutoff register zip on many of these audible high frequency signals. I adapted a Polaroid condenser ultrasonic sensor that they used for range-finding to a transformerless condenser microphone circuit and was reading well over 110dB on the TV, PC monitors and switching supplies. That's beyond many people's threshold of pain! I'm saddened how my fellow engineers could impose so much suffering by their designs and just sluff it off. And they still do.

on Feb 22, 2016

Interesting that you mentioned the audible 15 kHz horizontal sync rate of the NTSC CRT TV monitors. When working at WCNY during college, I'd hear the oppressive synch whistle when walking into the control room at the start of shift. After a few minutes, I wouldn't notice it. Your brain gets used to it, and ignores it. I'd be interested in the IF filter shapes of that Macintosh AM-FM tuner that produced indistinguishable difference between AM & FM. I've heard close, but AM falls a bit short in sonic capability, and it has more than 50% to do with the receiver. Of course, the broadcaster can mess things up in myriad ways nowadays with DSP processing trying to be just as loud on FM as AM. Sometimes the strong-signal AM signal is less fatiguing to listen to. And, I agree, there sure has been a great reduction in the labor content in the broadcast business.

on Feb 24, 2016

The first time I've ever heard anyone else talk about the 19KHz pilot signal, that used to drive me batty especially when (tape) recording, so I too always checked if there was a 19KHz filter. Most people I talked to would look at me as if I had 2 heads and ask "what high frequency sound", and when I mentioned the nature of the sound their response would be "no one can hear that high", so it's nice to know I'm not the only one :)

on Feb 22, 2016

Being of the demographic that has any basis for being nostalgic about AM broadcasting,
I'll be sorry to see it go.

But it is horse and buggy.

Until it's gone, us geezers will have a choice for something to yell at besides the TV.

( aside to cookiejar : you can't get reliable data from uncontrolled experiments )

on Feb 22, 2016

Though I used to listen to AM broadcast on a regular basis, there is no longer the wide variety of programming that attracted me. Raconteurs such as Long John Nebel, comedians such as Burns and Allen or Groucho Marx, classical music programming and other genres have been replaced by "infomercials" and political diatribes. The ratio of entertainment to commercial message has decreased to the point where I listen only until the latest news, weather or traffic report has finished.

on Feb 22, 2016

Lou, Bill and the other blog contributors are all correct! The woes of AM broadcasting are multiple. Some bad programming decisions came about as a result of reduced listenership. Additionally, automotive designers eliminated vehicle whip antennas, substituting on glass printed antennas or stubby pre-amplified antennas good only for satellite and FM bands.

As far as the FCC initiatives to help AM broadcasting, they are too little, too late.

On the technological side, modern AM transmitters are incredibly efficient compared to their older tube brethren and even compared to today's FM transmitters. FM+HD radio transmitters (IBOC) are even less efficient! Just looking at spectrum usage, AM modulation is way more efficient than FM.

The FCC allowed the RF noise floor to escalate to the point where it now interferes with the FM band. But due to FM modulation the audible artifacts are less obvious than for AM. With digital modulation, a la HD Radio, you don't hear any degradation, but instead lose coverage area. When you lose HD lock on your primary HD signal your radio will switch back to analog FM. In a moving vehicle this usually results in rapid switching back and forth. Any difference in the audio makes for choppy discontinuities which can be very annoying.

The original Ibiquity HD radio system required the digital carriers to be kept at 1/100th the power of the analog FM signals to prevent audible degradation of analog FM reception. During the first few years of real world of HD radio broadcasting it became apparent the 1% digital carrier level was way too low. To get parity with analog FM, the digital carriers must be closer to 10%.

Broadcasters spent a lot of money buying new FM/HD transmitters the first time around with steep licensing fees for the technology and ongoing use. So, having to buy yet another transmitter in such a short time span, just to be able to raise HD power ten fold was not in the cards for many broadcasters. Hence, mobile HD reception remains problematic.

Multi-casting HD radio came about as a result of National Public Radio since many of their member stations offer more formats talk, news and multiple musical genres.

FM band HD digital audio is an interesting topic in itself. In some ways it is superior to FM as the bandwidth can be from 1 Hz to 20 kHz, yielding superior bass response. But at a data rate of 48-96 kb/s, the encoding requires lossy algorithms whose artifacts are quite audible to trained ears.

HD digital on the AM band is interesting. Not only does it provide wide audio bandwidth in stereo but it also adds much digital hash to reception of neighboring analog AM stations! So it isn't popular on the AM band.

By the way, AM stations used to be able to pass audio up to 15 kHz, just as wide as FM stereo. Today the AM band-pass is limited to 10 kHz, still not too shabby. But with the AM band noise floor soaring and some automotive manufacturers not putting in the required effort to quiet the new noise sources from their digital controllers and wiring buses, the cheap and dirty solutions have been brick wall ceramic IF filters at 3 kHz for the AM portion of car radios. Or worse yet, total elimination of the AM band in their dashboard offerings!

on Feb 22, 2016

Content, content, content!

While I listen to a local sports station at times, most of the content of at least our local AM band is owned by one corporation, and consists of content aimed at extremely angry old men.

And even the sports station I listen to is over 50 percent advertisement. You get 5 minutes of talk, about 7 of ads, rinse and repeat.

One AM station here has a tendency to play 2 feeds at once as well.

I think AM is doomed

on Feb 22, 2016

I agree with most of the posted comments as regards content and listening tastes of the audience. I did see one comment regarding quality of the receivers, and that is a very KEY issue to anyone with more than an average "ear" for either music or decent sounding talk voices. Way back in the stone age of the 50s and 60s, some radios had "Wide/Narrow" switches. In the "wide" position, you got rather decent audio fidelity (after all, 5 kHz is allowed, plenty good enough for most voice and some music). I happen to have a modern dinosaur, an RCA (nee GE) Superadio III (AM-FM), which has such a switch. Living in a rural area, I use the "wide" position most of the time when listening to AM. If "hi-fi" capability returned to AM receivers, there might be some increase in listenership.

Next, I blame the FCC (and for that matter, the EU regulators, too) for allowing emission levels within the AM band to be well in excess of what is required for decent AM band reception. (Turning on my laptop within 12 feet of the Superadio wipes out the entire AM band). That blame can be shared with cost-cutting manufacturers and el cheapo consumers who buy electronic garbage based upon price without regard to unintentional consequences. Look, if the car makers (except for BMW and Tesla) can get most of their vehicles to work properly and still have usable AM reception, then you know it can be done. Those of us who are licensed amateur radio operators and who use the MF and HF spectrum have to constantly struggle to avoid high noise emitting devices in our homes, let alone in our neighborhoods. I'd like to see a resurgence of AM radio, but I do believe that some changes, besides content and hours of full power operation, are badly needed, and soon.

on Feb 22, 2016

I remember when the FCC first proposed EMI emissions limits. I could never understand why radiated emissions limits start at 30 MHz. Does this mean that they do not expect anything to emit below 30 MHz? As a result, noise levels in the low and medium frequency bands are repugnant.

I agree with programming--the last thing I want to listen to is some blowhard yacking about politics. Where is all the music? I don't think all those ipods are listening to Rush....they are listening to music. Put together relevant, interesting play lists and I am sure there will be listeners, no matter the delivery channel.

on Feb 22, 2016

All of the comments from others are very well stated and point out the issues the AM Broadcasters are faced with. Is it possible that AM radio requires ownership by creative, entertaining entities that can create the content that would attract interest to all potential listeners? Can we offer an entertainment and/or educational value to the content? Rush and Sean and the other political talk shows have pounded and brainwashed many listeners brains that care to tune in. This is the best we can do in the past thirty years of the talk radio format? How about a Radio Station devoted to World History? How about a Radio Station devoted to the constantly changing world of computer and internet related communications? I am sure their are many of our readers that can create a Radio content that would attract potential listeners which in turn creates revenue for the station. No sense creating new modulation modes and/or new signal schemes just to hear Mike Savage rant and rave clearly about the same boring political news. Y A W N !

on Feb 22, 2016

At one time in the 1960's the Frequently Confused Commission considered raising the power of Class 1-A clear channel stations from 50KW to 100KW or even 250KW. Unfortunately, that would require an act of Congress as the 50KW max was imposed by statute to curb the political power of Powell Crosley and his WLW 500KW operation under the experimental call of W8XO back in the 1930's, Besides the problems and solutions already in the comments, there are others. The number of stations quoted at the beginning of the article is a part of the problem. There are far too many stations than are really needed, let alone be economically viable. The FCC needs to get back to standardized power limits. 5KW should be the minimum and 250KW the maximum. The limits should be 12/12/12 for AM/FM/TV broadcast ownership with no in-band in-market duopolies. Part of the reason programming is so bad is that there's little (if any) competition in markets. Add in a live/local program origination requirement. Again, bring back competition! Another problem is the FCC's permitted degradation of facilities. What happens here is that the owner of a major market station buys one in a smaller market that it must "protect" and "detunes" it to allow the originally owned station to "let out the pattern". This has been done a couple of times on the least coast that I'm aware of. Also, the cost of land in some markets has gotten to where the acreage needed for an efficient DA in the lower part of the band is more valuable than the license on the wall. Thus, the incentive to relocate the transmitter and basically neuter the station. If not take the station silent. I know of one major market that is triplexing at one site with another station seeking to diplex with an existing AM that relocated because the original 58 acre site was more valuable as townhouses. The FCC application by the owner openly admits that service will be degraded from the new site. And, this is for the station that was once the CONELRAD/EBS/EAS key station for its market. So, there needs to be a "stewardship" clause (for lack of a better term) in the FCC license

on Feb 22, 2016

Well I guess this one got attention. And some good comments. Yes, AM is dead. Unless you are one of the few people who don't live near an FM station. Basically been dead for 40 years.

Funny, half the world hates the FCC for enforcing interference regulations (the half that don't want to bear the financial impact of compliance), and half the world hates the FCC for not creating strong enough regulations and enforcing them properly (the half that wants to use the RF spectrum for what it was intended for).

Local content died a long time ago, too. Nobody wanted to work for minimum wage and owners could make more money "simulcasting" something. Used to be the FCC had rules to limit ownership and encourage local origination from a diverse set of players.

It all boils down to money. The FCC eliminated the ownership and content rules to help investors and big corporations make more profit. They minimize interference rules for the same reason (besides the fact that the commissioners are government appointed attorneys, not engineers).

Welcome to the Brave New World.

Yes, about all I want from radio is music (classical for me), but using RF spectrum to distribute music is actually rather stupid if you stop to think about it, since almost all of it is pre-recorded. I wonder when the last time was that anyone actually thought about what radio should be and how it should be used?

And yes, HD has both wins and losses, but then most content comes from MP3 these days, and that itself is a lossy compression scheme. Anyone with a half decent ear that listens to orchestra or brass can readily hear the intermodulation distortion and harshness. Part of media for the masses. Most people don't notice or care, just fit lots of songs on my flash drive.

on Feb 22, 2016

Lots of good comments, but the real problem is RECEIVER USER INTERFACES.

Look at any car radio - first you choose a band, then you select stations. You program buttons that select stations *within a single band*.

So if 90% of the time you listen to FM for music, switching to AM requires first switching band, then choosing a station.

If receivers just let you program buttons to assign stations without regard to what band they're on, AM would be listened to a lot more.

on Feb 23, 2016

I work in the business as an engineer and have skin in the game, so to speak. Yes, AM is a challenge. Rising RF noise levels have made it difficult to enjoy my ham radio hobby and to satisfy our AM listeners. In our market, our AM station still pulls very good ratings within a certain demographic, but is non-existent to listeners under a certain age. IMO, that does not mean AM radio is going to expire when the last few listeners expire. To me, it means that until a person reaches a certain age, things like newscasts are not as important as the latest music or patter from a popular DJ. Speaking of music, another writer mentioned that it was silly to transmit music over the radio. From a purely Shannon point of view, this is correct. Why not just store the music on the device and have the DJ trigger a playback after the patter ends? Much more bandwidth efficient than transmitting the same musical information over and over multiple times a day. The station could transmit new songs to be stored on the receiving device at a lower priority than the packets devoted to real time announcements. This would mean a conversion to datacasting, obviously, not amplitude modulation. MF has some advantage over VHF in regards to wide area coverage with the same power levels. It just needs a more robust modulation scheme to overcome the noise, or the noise needs to be eliminated. Do whatever makes the most sense. Or just move it all to LTE 4G or 5G. Just kidding! Those schemes are fantastic accomplishments, but will never be as reliable as one hardened transmitter site delivering millivolts of RF energy to thousands of simple receivers. One person can maintain the infrastructure. Can one person keep a 4G network running?

on Feb 23, 2016

Medium wave broadcasting needs to be preserved regardless of the modulation method used. Frequencies above around 2 MHz become useless immediately following a Nuclear Detonation due to the ionization of the atmosphere. I have often suspected that the reason Amateurs have kept their allocation in the 160 meter wavelength band was for this reason. Amplitude Modulation may, in the end go away.

Those who believe that AM doesn't have the fidelity available from FM are in error. Back before bandwidth constraints were placed on AM broadcasters, High fidelity frequency response was broadcast by those stations using Ampliphase transmitters (so long as they were kept tuned correctly) Transmitters using digital AM Modulation techniques today have the ability as well; however it is due to governmental bandwidth restrictions that a high fidelity AM broadcast isn't made...that and the lack of good design in "Modern" AM receivers.

The frequency response of FM broadcasts do not come close to the 20 Hz to 20 KHz "Hi-Fi" response people see in the specs of their (albeit older) receivers. FM Stereo limits the upper audio bandwith edge to 15 KHz in order to protect the 19 KHz stereo pilot which is (was) used to demodulate the 38 KHz L-R subcarrier. There was a time when "Classical" stations broadcast in Monaural to provide a better high frequency response, but those days are now long gone.

In the end, I believe that the Medium Wave "Standard" Broadcast Band's salvation may lie in requiring that members of the Federal Communications Commission be Engineers instead of Lawyers. I know a number of good broadcast Law professionals who hold both BSEE and JD degrees...But they'd have to take a major reduction in pay to work for the government.

I remain,

The Old Soldering Gunslinger

on Feb 23, 2016

The AM owners have wanted it all. They try to keep analog along with digital. That has not worked out since the digital IBOC (in band on channel) idea is really IBOSEC or in band on some else’s channel.
Why not start a transition to all digital. If the station has to turn off or reduce power at night let them run at normal daytime power in digital drm only in their nominal 10kHz channel. When there are enough digital receivers or demand run digital all the time. This would reduce the night time coverage of the full time stations but I don't see any reason a station needs to be hear 700 miles away, only at night. I would also suggest the full power stations reduce power at night to keep their local city covered and reduce interference to co-channel stations. Another suggestion would be to have all stations use omni patterns only so they cover their city and give up the idea one station can be heard across half the country at night.

on Feb 23, 2016

Many good points. As far as programming goes, original content only exists in local talk radio and some PBS TV stations these days. Almost all music is linked from satellite feeds from national networks. Along with those networks come more ads on top of the local ads ad nauseam. Worst of all these networks all try to compete by being the same only different, rather than being unique, which make listening even more tedious.

on Feb 23, 2016

Nostalgia aside, "broadcasting" is no longer the way the public wishes to receive content. With the advent of cell phones, WiFi-enabled devices, and wearable technology, the emphasis has moved toward what is sometimes called "narrowcasting."

As the possessor of a cell phone, YOU can choose the content YOU want to listen to, rather than have to wait for content someone else wants to deliver to you. The same can be said for internet news feeds, blogs, etc. that allow individuals to only experience what THEY choose.

With regards to radio broadcasting, the greater concern is one of public safety. The operators of WiFi hotspots, and cell phone operators are really not interested in addressing the topic of wide-area public safety. They are in the business of delivering content to you at whatever price the market will bear. In fact, many cell phone chip sets have (or had, until recently) internal FM tuners that were effectively disabled by the cell phone providers. Why, you may ask? Well, be cause broadcast FM competes with their streaming content business model. The cell phone providers want you to get all of your content through them, and pay your monthly bill in a timely manner. Unless Congress mandates that the cell phone providers and manufacturers support reception of radio signals (AM or FM) for emergency applications, this capability will die on the vine in developed countries such as the USA.

Broadcasting still has relevance in the developing world where infrastructure is still not readily available and affordable. It's one of the reasons The Voice of America and Radio Free Asia still maintain shortwave broadcast capabilities targeting select countries. Providing a $20-$50 AM/FM/SW radio to someone in the developing world offers access to content they otherwise would be unable to get through other means. This will probably continue for a few more decades until cell phone and wireless networks can be deployed on a larger scale and made economically feasible for the masses.

on Feb 23, 2016

The limits comes from filtering. Analog TV was AM (actually VSB but AM anyway) and could pass at least 3 MHz, while it should pass full 4.2 MHz for color. So it is not AM, is filtering. On MW, the tuning house and the modulator filter sets the bandwidth. So, at least in theory, it can sound as FM does. But SNR may be worse, and noise levels have definitely increased. I believe HD RAdio is not a good solution and DRM / DRM + is a better one. Sandwiching AM limited to 5 kHz within two digital sidebands in HD Radio is a bad idea and a disservice to AM radio. Also, content is another head of such a hydra... I am afraid that including a decent AM radio in a USB dongle is quite difficult and hardly competitive. An SDR could do it but is not going to be dirt cheap.

on May 25, 2016

To clarify for US readers: DRM in this post is Digital Radio Mondiale, a standard for digital radio broadcasting, not Digital Rights (or Restrictions) Management. The latter use of the acronym is much more common here.

A fundamental difference between the two standards: nearly all DRM broadcasting is digital-only and nearly all HD Radio is hybrid analog-digital. DRM has a hybrid mode that is in use in India. HD Radio has a pure digital mode but it is not authorized for use in the US, which is the primary market for HD Radio; the FCC only allows hybrid broadcasting.

On the AM band, hybrid broadcasting is the worst of both worlds. It doesn't allow a high enough bit rate for really high fidelity, and the digital sidebands interfere with adjacent stations and also reduce the quality of analog reception of the station itself.

on Feb 23, 2016

The limits comes from filtering. Analog TV was AM (actually VSB but AM anyway) and could pass at least 3 MHz, while it should pass full 4.2 MHz for color. So it is not AM, is filtering. On MW, the tuning house and the modulator filter sets the bandwidth. So, at least in theory, it can sound as FM does. But SNR may be worse, and noise levels have definitely increased. I believe HD RAdio is not a good solution and DRM / DRM + is a better one. Sandwiching AM limited to 5 kHz within two digital sidebands in HD Radio is a bad idea and a disservice to AM radio. Also, content is another head of such a hydra... I am afraid that including a decent AM radio in a USB dongle is quite difficult and hardly competitive. A SDR could do it but is not going to be dirt cheap.

on Feb 24, 2016

There is no loss of fidelity in AM except due to broadcast band limitation per channel. FM Broadcst is allowed 200kHz per channel whereas AM Broadcasting is limited to 8kHz or 12kHz for AM Stereo.
Of course noise is the biggest culprit in addition to co- and adjacent channel interference, especially at night when AM range increase tremendously. FM has the inherent ability to kill any signal on the same frequency- stronger signal persists!!!

on Feb 27, 2016

I grew up in Northern New Jersey in the 1950's, listening to N.Y.C. on my parent's 1949 Magnavox AM analog vacuum tube console set. Aside from the fact that much of that was some of the best music ever recorded, it was analog and was reproduced through tubes, not solid-state or transistors and certainly not digital. I think what they have done digitally with visuals is wonderful, simply because the eye uses MUCH higher frequencies than does the ear, and does not notice the "compressed" or "antiseptic" effect that you get with the sound of digital audio. Hence, it is bad enough that the AM programming is now just sports and political bitterness in place of music. What is worse is that AM is vanishing all together. My new SUV has digital radio ("Serius", is it?), which I have never listened to, even once. I don't like digitally remastered CD's, and there are enough younger (and older) folks leaning towards vinyl discs and turntables to tell me that I am not alone. I have even seen the two different waveforms on the oscilloscope and they are dissimilar. There are a couple of stations in the Buffalo, N.Y. / Toronto areas that still play music. When that fails, I stream AM 1420 WIZZ Radio out of Greenfield, Mass., and transmit it through a small and legal transmitter I have, to all the German and American tube radios I have throughout the house. How sweet it is. I hope I am gone before the last AM station is. I belong to the Buffalo Broadcasters Assn. (BBA) and I am in good company. Analog FM is great, but may God bless AM!
Michael K. Tremper KC2HFR
Cheektowaga, N.Y.

on Mar 3, 2016

The economic effects have become apparent on our local AM stations as they move to infomercials and canned music programming. The infomercials provide revenue, the music programming is cheap, and neither require a paid staff. Medium Wave AM transmissions need to stay alive for the simple reason that they provide a means of mass communication in the case of a widespread disaster. Cheap battery and alternative energy receivers can receive news and instructions from a local generator-powered transmitter or a distant transmitter outside of the disaster area.

on Mar 18, 2016

AM radio and the broadcast band (BC) should be saved and maintained for several reasons:
1) Breadth and quantity of radios enabled to receive broadcast band AM
2) Simplicity - for the same reasons a CD cannot be played with a nail like vinyl - a simple crystal set without power can receive AM
3) Cost - ownership, maintenance, and support (ignoring government regulations) is significantly less than comparable satellite and FM land based stations.

on Apr 25, 2016

In crisis- situations ,when power grids are out of order, AM stations with emergency powergenerators are the only way to inform the population over a wider radius than with with FM. Instead of tearing down unused AM-stations they shoud be kept in an operational state for the case of emergency. In Germany a lot of AM-transmitting sites had been torn down (e.g. Deutsche Welle, Bayrischer Rundfunk, etc.).
I wonder how long digital- terrestrial- broadcast-service is possible in times of grid-failure. Emergency-power- Generators are costly and are likely to be optimized away today. Even portable DAB-Receivers are much more power-hungry than AM/FM-Receivers, so battery-operation is possible for few hours only even with a fresh set of cells.

on Apr 25, 2016

How about a 1/1/1 rule? If you can only own one station then all the pablum content spewed today (even by FM and TV) would become unavailable forcing a return to locally generated content. Outlawing all forms of broadband over power-line (BPL) schemes and extending EMI limits all the way down to DC for unintentional radiators like computers and cell phones would help to reduce the noise floor in the SW, LW, and MW bands. Until recently, the only way I could still get good reception in my Ham Shack is to turn off everything except the radio and log my contacts with pen and paper. After hardening one of my computers from leaking RFI I can now use it for logging contacts. This required a new custom made shielded enclosure for the computer, new shielded cables for everything attached to it, and Spray on EMI coatings to the various peripherals. Printer is kept inside a shielded enclosure. All enclosures are bonded to a multi ground-rod grounding system built with wide copper straps which also serves as the ground system for my radios. Soon, all lighting in the shop will be LEDs running on DC with no PWM dimming. That and the fact that my nearest neighbor is about 200 yards distant all help to reduce the noise floor to the point where my 1946 Hammarlund HQ-129 can still receive WWV in Fort Collins Colorado on 10 MHZ. The Hammarlund also serves as a space heater for the shack on colder days.

on May 3, 2016

Why Am I attached to Am ? Familiarity, I used to work in an AM station, I am becoming an old timer, nosie ? so what it makes it more fun..................
The internet is ok, but in radio you cannot control your listeners, on the internet everything is monitored , am radio nobody knows Im listening, it is just more free, also one can dx with Am radio.........., all reasons fro am radio

on May 25, 2016

The declining number of AM radio stations is actually a healthy development. One of the big problems with AM as it currently exists is that the FCC licensed too many stations, and cut back on the big "clear channel" ones that used to be the anchors of the band. The result is a jumbled mess where it's difficult to get clear reception of anything. AM can't match the fidelity of FM radio but it is capable of providing a good listening experience for talk-oriented programming - but most stations can't currently provide that under the present conditions on the band.

Another current problem with AM right now is HD Radio. The problem is that it causes substantial interference to adjacent stations. That has led to further shrinkage of the listening options on the band. HD Radio is less problematic on FM, though there are a few boundary cases where it has caused problems for listeners.

Yet another problem for AM is the declining quality of AM radios in cars, which are a prime listening location for radio. Manufacturers no longer make it a design priority, the noise from all the car electronics make reception more challenging, and the smaller antennas used in modern cars (for both design and aerodynamic reasons) are less effective.

For AM to return to health, it needs stations that can be received over a wider area - an entire metropolitan area at the very least, and at least a few that can blanket an entire region at night. Stations like that, especially ones that focus on news (perhaps because it's one niche that satellite radio can't displace; satellite doesn't offer local news, weather, or traffic information), continue to thrive. There is also a place for smaller community stations, but not as many as we had at the peak.

on May 28, 2016

What a cranky bunch. Calling Talk Radio "angry old men" as if it is not a reaction to lefty newspapers and most media? Hey, first amendment here. Rush Limbaugh has more listeners than any media news show. They all can't be angry old men.
AM is needed i;n the West primarily due to mountains which stop Terrestrial TV and FM signals. DTV also does not have the distance capability that analog TV had. AM stations are still the primary source for many small towns. In my area there is original programing on our AM station, as there is on all the AM stations in the large city 60 miles distant. FM is similarly programmed in our town and the the larger city. Some FM stations use programming services for music. I don't think that rip and read exists anywhere. It is too easy to feed news from a news service. All talk stations in the area feature local news and at least one local talk show. only two AM stations have closed operations and both were 10KW. You have quite a power bill and the antenna requirements are sometimes onerous. Stereo AM never sold here. No interest. It is more important to have the type of programming receivable at a distance than to a local audience with AM. FM has all the bells and whistles. At a distance FM Stereo quits and has to be used as mono.
I, too worked at a local station as a high school kid, 1000W/250W rip and read. Then a stint in a larger place on a 5KW/1KW in a college town with a Jazz show. As a ham as a kid I earned a Conditional (General Class by mail) class license and got a First Phone FCC license so I could make transmitter adjustments like changing power. My final days as a DJ were at a large city Country station which was also a 5KW/1KW but also 6850W ERP FM. A lot better money but nothing compared to EE. Never worked in Radio again.
IMHO AM in rural and mountain areas is needed as are CC AMs as enjoyable friends on long drives at night or when camping in remote locations. CC Crane sells a lot of AM radios. I think if you live in a large city you could think that their time has come and gone, but I do not.

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What's Communiqué?

Blogs on topics such as wired and wireless networking.


Lou Frenzel

Lou Frenzel writes articles and blogs on the wireless, communications and networking sectors for Electronic Design. Formerly, Lou was professor and department head at Austin Community College...
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