The AM HD all digital test, part III

Continued from part II:

Can the AM broadcast service be revitalized and returned to relevancy?  If so, how?  The previous post demonstrated that AM radio service problems are multigenerational and multifaceted.  There is no one solution that will make everything better.  Pushing an all-digital solution will not solve electrical noise issues or overcrowding issues on the AM band.  It will not address the paucity of the local, unique programming that is the bread and butter of successful AM operators.  Because the issues that face AM operators cover many different areas of broadcasting, any proposed solution must address every aspect.  Any proposal that simply addresses the poor fidelity, for example, will simply be another band-aid (no pun intended), placed on top of numerous others which have been previously ineffective.

The FCC is looking for deregulatory solutions to the AM problem.  Deregulation and the FCC’s lasissez-faire attitude is exactly why the AM broadcast band is in the condition it is today.  Relaxed technical standards have allowed the creeping crud to take over like Kudzu.  Further deregulation will only exacerbate the problems.

In broad categories, AM radio’s problems are:

  • Noise and interference
  • Low fidelity
  • Lack of ratings
  • Low profitability

Electrical Noise on AM broadcast band

In order for any solution to be effective, this problem must be addressed first.  Noise and interference are at the heart of the technical issues confronting the typical AM radio listener.  These problems come from multiple sources, but the worst of which are electrical devices such as CFLs and other fluorescent lights, LED lamps, street lights, utility company wires, computers, computer monitors, TVs, power line communication, appliances, and other intentional emitters.  The FCC has, within it current powers, the ability to address at least some of these noise generators.  Devices like CFLs, LED lamps, computers, and others are regulated under Part 15 and 18 of the FCC rules.  While there is little that can be done with fluorescent lights (they work using an internal electrical arc), other emission standards can be tightened and better, more specific warning labels can be implemented on the packaging.

Station-to-station interference on the AM broadcast band

Another aspect of this problem is mutual interference on the AM broadcast band.  In short, too many stations are licensed to a small slice of the electromagnetic spectrum.  The increasingly poor condition of many directional antenna systems ensures that there is a cacophony of interference at night.  While this is a politically sticky situation, some tough love is needed to solve these problems.  There are many underperforming AM stations on the air that are junkyards of last-ditch formats that have little or no hope of success.  These stations are often technical disasters that pollute the spectrum with interfering signals.  Compounding this issue is the transmission of IBOC at night.  The current iteration of IBOC (HD radio) intentionally transmits on adjacent channels creating more problems than it solves.

Confronting any of these issues is almost certain to be a non-starter and that is a shame because real, meaningful steps can be taken here.

One scenario would be a one-time test, applied during the next license renewal cycle, that allows station owners to assess their operations.  Those that do not pass the test would be able to surrender their license for a tax credit.  This type of culling is not unprecedented, as the FRC did something very similar during the early days of broadcasting when the AM band became a free for all.  The test should have three areas of consideration; technical operations, programming, and business profitability.  Something like this would be a reasonable example of a re-licensing test:

Technical operations
Test Points
Does the
license 2
Is antenna array being maintained, field mowed, trees cut, tower fences secure, signage posted, catwalks or access roadways maintained 1
Does station have a working backup transmitter 1
Does station have a working backup STL 1
Does station have a working emergency generator 1
Does station have a current transmitter maintenance log 1
Are NRSC measurements up to date 1
Are monitor points measured at least biannually 1
Minimum score to pass technical operations: 5 points
Test Points
Does station originate local programing 1 point per average weekly hour
Does station have local news 1 point per average weekly quarter hour
Does station appear in market ratings survey 1 point per survey period (or 4 points for continuous survey markets)
Minimum score to pass programming test: 5 points
Is the station profitable ¼ point for every profitable quarter during last license period
Minimum score to pass business test: 3.5 points
Minimum overall score for all three tests combined: 16 points

This is a fairly low bar to get over. I generally do not advocated more government regulations and regulatory burden. However, this is one case where relaxed regulations lead to the problems currently being encountered. Perhaps a one time re-regulation would be warranted in the public interest.

Audio quality and other technical improvements

There are several areas where new technology can be used to improve AM stations technical quality.  There is a common misconception that AM broadcasting has low fidelity due to inferior bandwidth.  Truth be told, AM broadcasting can pass 15-20 KHz audio.  It is restricted to less than 10 KHz because of the aforementioned band congestion problems.  Since the NAB and the FCC has made exceptions to the NRSC-1 requirement in order to transmit HD radio, perhaps other wide bandwidth uses can be considered.  One possibility would be to allow transmission of 15 KHz audio during daytime hours, switching back to NRSC-1 standard after dark.  This may not work on local (class C) channels but for regional and what remains of cleared channels, it may offer some improvement.  Also, turning off IBOC hybrid analog/digital transmissions after dark should be examined regardless of whether an all digital solution is sought.  Hybrid IBOC is a part of the night time noise problem and not a viable solution, particularly troublesome are class A skywave signals.

Also, much benefit could be derived from requiring that all AM stations sync their carriers to GPS.  If all of the stations on the same channel are on exactly the same frequency, it will eliminate carrier squeals, growls and whines.  This is something that can be done very easily and inexpensively, especially with newer transmitters.

Double sideband AM is wasteful, as both lower and upper sidebands contain the same information.  Suppressing the lower sideband and transmitting just the carrier and upper sideband would free up quite a bid of bandwidth and reduce adjacent channel interference.  Most simple diode detectors demodulate the upper sideband anyway.

A concerted effort must be made to restore all of the technically deficient antenna systems.  Not only fixing out of tolerance DAs but also addressing bandwidth issues, general maintenance, ground systems, clearing away brush and undergrowth can all have noticeable positive effects on signal performance.

At the same time, better receivers are making their way into the market place.  Receivers that have auto variable IF bandwidth based on signal strength could greatly improve audio quality.  The auto bandwidth function could be overridden by user selected bandwidth, if desired.  I know that wider IF bandwidths are in the current chipset because of IBOC and DRM, I do not know to what extent they can be adjusted, but it is something that receiver manufactures should consider.

None of these solutions are Earth shattering, nor would they require great sums of money to implement.

AM to FM Translators

The current thought process is that using FM translators for AM stations is a fantastically great development.  For a class D AM station with little or no night time power, an FM translator is a good way to maintain service to the community.  For class C or some class B AM stations where night time interference greatly degrades the station’s service area, an FM translator is a good way to maintain service to the community.  Does a 50 KW blow torch really need a 250 watt (or less) FM translator to aide with reception in its city of license?  No.  Yet, this is how the AM to FM translator service will be rolled out, those that already have sound technical operations will be given FM authorizations.  This does nothing to actually fix AM broadcasting technical issues, it is a well meaning measure that will be incorrectly applied by the broadcasters that need it least.


All of the technology and gadgets will not solve the problem of poor programming.  This is an area where the FCC should not tread, however, broadcasting associations can assist their members with local programming issues.  Broadcasters need to understand that good local programming that is unique will attract listeners, worthless junk will not.

Continued in part IV

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10 thoughts on “The AM HD all digital test, part III”

  1. I’m not sure stations should receive points for doing things that are required by the rules, such as annual EPMs and quarterly monitor points. How about losing points for things they aren’t doing, that other stations have received NOVs for, like not monitoring the tower lights, not having the towers painted, operating the wrong pattern or power at night, etc. Maybe they could get one point if they pass an alternate or FCC inspection.

    You know that telling some of these mom-and-pop stations that they must cease operation will be strenuously fought in court, and the big boy stations won’t want to lose their precious little 1kw stations that prevent more useful programming from being heard.

    Unfortunately it’s probably a no-win situation.

    Bob M.

  2. Bob, you would be surprised how many stations do not comply with simple rules, seems those that undergo the ABIP are more likely to view it as a three year free pass on compliance.

    Mom and pops can fall on either side of this line, but the one thing that mom and pops generally do well is local programming.

    As I said in the article, it is likely a non-starter, but congestion is a major part of the problem for AM.

  3. I’m living in Germany and AM doesn’t play a great role down here, but we don’t had to face the problems of the telecommunications act of 1996 (in my oppinion a great failure in competition law when it comes to the broadcasting industry).

    Maybe we have a different view on broadcasting things, but some are comparable to what Paul said. Programming plays the most important role! Research told us, that music is the most important thing. Then comes the whole presenter-stuff like attitude, good voice… Local/Regional information only plays a subordinate role but is also important. No one cares about things happening a few 100 miles away if they don’t have an impact on your audience’s life.

    Some politicians try to switch off FM (VHF-Band) by law in order to force digital broadcasting like DAB+. To my taste, this is burned money. No one here seems to demand digital broadcasting because FM offers a good audio quality and coverage and the digital offerings (like some of the HD2-Channels in the US) do not promise a benefit to the audience.

    To my taste a switch to FM (where applicable) can solve many problems (less interference, superior sound quality) regarding the technical stuff. But as stated: It’s always the programming that matters!

  4. And some history has to be added: Germany lost many of its AM frequencies after the 2nd World War. First, there were only public broadcasters (not financed by taxes to prevent the government to do have an impact on the programming but financing was done by the population. So the licensing fees are directly payed to the broadcasters. Nowadays almost every household has to pay a fee to the public broadcasting system to ensure a basic service with culture, information, education and also entertainment). This enables the public broadcasters to be – as much as possible – independent from governmental and commercial influence.

    Things changed when privately owned stations signed the air in the early 1980s. Competition (concerning ratings) increased, but AM never played a great role. There were some guys, who thought, that Digital-AM (like DRM broadcasting) would lead to a great coverage and a good sound quality. But the listeners didn’t accept the digital AM-Service, so the stations trying this model soon got bankrupt or their investors stopped their activities. Maybe the marketing-gurus made a bad job. We don’t know. Probably FM offers enough variety and quality.

    Therefore we often look to the US and see that things can be a bit different 😉

  5. This is a good start to clean up the AM nightmare.

    The FCC is responsible for making the situation WORSE by allowing too many stations on the air! It’s that simple!

    The overlap noise is horrifying! Why would most consumers tolerate it?

    Answer is…they don’t! Another reason FM is on top!

  6. @Chris R, I have read that radioink article before. Color me a bit skeptical that auto makers will completely ditch AM/FM radio in two years, especially in favor of HD radio.

  7. Always an interesting topic-and one near and dear to my heart. The town I grew up in was just south of the transmitters of 4 local AM stations. At night they would direct their signals north-where the people lived when these stations went on the air. My family moved to the suburbs as did many in the 50s and 60s relegating the nighttime signals as less than optimal. Enter the rest of the issues as listed here and you see AM radio in a heap of hurt. The issues here stem from the NAB and its lack of doing what it’s supposed to do-protecting broadcasters. The FCC has failed the original purpose of radio-to serve the local community. My 2nd job was at a daytime only station that utilized some of the most talented HIGH SCHOOL STUDENTS to fill out the staff. They were known and respected in the community and did a really good job. We were selling $5 spots-and the station was fairly profitable. With the proliferation of online “podcasters” and the eagerness of millenials to find a way to communicate, a radio station can serve its community, be local all the time, be live as much as possible and make a profit. Radio has to become competitive with itself, and do what we ask our advertisers to do. MARKET the product. The fun concept of seeing (and eventually becoming part of) the “magic” that came from those towers will still be there. We just have to make sure the public is reminded of that.

    Many European countries do not have any more MW AM stations at all. But there are some fresh intentions “on air” to vitalize the situation for ex. in the Netherlands where such everyman´s low power stations can be set up; with 1 Watt, 5 Watt or 100 watt. It is very interesting to see how the trial will succeed.

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