AM Deserves “Urgent Regulatory Relief,” Engineers Say
     

Do what you can do now; and do it soon.

That’s a shorthand version of what U.S. broadcast engineers are asking the FCC to do about the country’s AM band, through comments filed by the Society of Broadcast Engineers.

Among the many comments being filed about AM revitalization, SBE’s are of particular interest to Radio World readers. We summarize them here as part of our series compiled at radioworld.com/amcomments.

SBE supports elimination of the ratchet rule. It backs the use of Modulation Dependent Carrier Level control technologies or algorithms, and supports the relaxation, though not elimination, of AM antenna efficiency standards. It calls for a “multi-faceted initiative” to reduce the serious problem of RF noise in the medium-wave bands. It also laid out several rule or policy changes that would help the situation.

“There are other proposals in this proceeding that will inevitably improve AM broadcasting,” the organization wrote, “but SBE considers the issues addressed herein to be the most urgent of these.”

Among specific recommendations, SBE said the FCC should allow AMs to use short antennas where local regulations allow, even though these may be less efficient. “The Notice proposes to permit up to a 25 percent reduction in antenna efficiency. This appears to be the proper measured approach.” But it does not want to do away with the idea of a minimum level of performance of an AM antenna system.

SBE supports a reduction of the minimum effective field strength standard that the commission uses, to give AMs more flexibility in antenna system design and site selection.

Regarding the big question of RF noise from consumer electronics, power lines and such, the society says regulatory relief is “absolutely necessary” and cautioned that the FCC should not be “overly fatalistic,” meaning it should not just accept that continued growth in such noise sources is inevitable.

“The goal of AM revitalization will never be realized in the medium and long term in the face of the headwind of a worsening RF noise environment in the AM broadcast band.” The group feels that the FCC has never had a complete understanding of “ambient RF noise levels and trends over time,” and that regulations, policies and enforcement are uneven. “When an AM listener receives interference, he or she will not suffer it. They will simply utilize different media,” SBE wrote (italics are in the original).

AM broadcast band interference is not well-documented, and the FCC isn’t equipped to enforce it if it were, SBE feels.

Importantly, existing regulations should be better enforced and new regulations created. SBE says the FCC should do the following:

-Enact radiated emission limits below 30 MHz in Part 15 rules for unintentional emitters such as plasma television receivers.

-Lower the limits for LED light bulbs in line with those for fluorescent bulbs in Part 18.

-Order better external labeling on packaging for Part 18 fluorescent bulbs and ballasts.

-Enact specific radiated and/or conducted emission limits for incidental emitters such motors or power lines.

-Enact conducted emission limits on pulse-width motor controllers used in appliances.

-Substantially increase enforcement in power line interference cases, and make that enforcement more visible. Describing the experience of ham radio operators with power line noise, SBE wrote: “Power line radiation in the HF and MF Amateur allocations will in most cases directly translate to preclusive noise in the AM broadcast band.”

The society also described its concerns with certain other strategies. It believes there are “inherent inequities” in any plan that is primarily focused on FM translators. “Such a plan would disserve AM broadcasters for whom an FM translator is not available due to FM band channel scarcity. Furthermore, that solution focuses listeners’ attention away from the AM band.”

Another popular notion is relocation of the AM broadcast band. SBE believes this “would take so long to effectuate that it would not be helpful to the current generation of AM licensees. AM revitalization should have both short-term and long-term elements.”

SBE also took pains to mention the impact of AM’s problems on engineers, and it lobbied for quick action. It asked the commission not to “treat this proceeding in the nature of a Notice of Inquiry. The adverse circumstances of AM broadcasters and skilled AM broadcast engineers call for some urgent regulatory relief.”

SBE thinks AM still has a potentially bright future but that the FCC plays a “substantial” role in allowing it to happen “without delay.”

The filing was signed by SBE President Joseph Snelson, Government Relations Committee Chairman Ched Keiler and General Counsel Chris Imlay.

Read the SBE comments:
Read RW summaries of other AM comments:

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Comment List:

Surprised the SBE would be behind the idea of reduced efficiency in antenna systems and think that this is a "proper measured approach." I believe the reasons for reduced efficiency of a radiator is another way to say it's shortened. From my experience, this will lead to greater vertical radiation. In the daytime this is of no great concern, but as it pertains to nighttime, it's just going add to the channels noise level. Claiming relocation to a new band "would take so long... and not be helpful in the short term." Cleaning up the existing band is certainly no small undertaking. Frankly, the attempt to polish rust will not get you that shiny bumper we'd all like to have. The only way the AM band gets cleaned up from man-made noises is to shut off those noises. That would be monumental!
By Scott Clifton on 2/7/2014
AMs could use less efficient short antennas, but this doesn't automatically translate to reduced coverage area. Simply measure the reduction in field strength with the short antenna and then allow the transmitter to run enough power to return the field strength to what it would have been with a standard full size radiator at the standard power level.
By Donald Chester on 2/6/2014
Here's a horror story from my radio partner. He lives in a senior housing facility. He gets AM interference that blankets most of the AM dial, and therefore has quit listening to AM. The interference appeared to be coming from the power line and curtailed AM listening at the entire apartment complex. It took SIX MONTHS to get the power company out to check it. They isolated it to a main circuit breaker panel for most of the apartments. Here's the fun part: They jiggled the main breaker, and proved it was the breaker (or connections to it) because the static changed upon jiggling. They then left the building, congratulating themselves on a job well done. Loose connections? This may turn into a fire story some day.
By Bro Duke on 2/2/2014
Per the above article, the SBE comments are dead-on. Before trying to police every single mediumwave signal, its characteristics and daytime/nighttime coverage, the playing field must be levelled in the form of RFI eradication from all human sources. Some are horse-out-the-barn problems - cheaply-manufactured devices that consumers are unlikely to turn in for suppression or replacement with "clean" appliances. It's an endless list of devices that have proliferated over the years. Even in 1934, interference on AM led FM's inventor, Major Armstrong, to declare that his medium would surely outstrip and replace its mediumwave cousin and its static. RFI is a power company problem, too, as well as an inefficiency that deserves immediate resolution.
By Rich Phoenix on 2/1/2014

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