The FCC’s plan to revitalize the AM band is a very hot topic in our industry right now. And the part of the plan that will impact the big booming AMs heard all across the country has generated an interesting debate, often between those owning or operating AM radio stations. Our coverage of the topic yesterday generated a ton of feedback, including this very detailed piece by Doc Searls.
(By Doc Searls) By reducing the coverage areas of Class A stations to be protected from interference, what the FCC proposes is not “revitalization” for AM, or even life support. Instead it’s just another way to make a bad thing — skywave interference — even worse.
Any veteran engineer can tell you that adding more stations, more power to stations, and more hours with more power to stations, only makes what was originally an AM feature into an even worse bug. The FCC has a long history of doing this over and over again. More stations, more power, more interference, every time.
To grok the problem, consider the existing 750-mile protection zone for Class A stations. This was a “revitalization” move years ago that got rid of the “clear channel” designation (which gave a station exclusive use of a channel at night, when AM signals can travel hundreds or thousands of miles). This allowed lots of new stations to show up where skywave coverage by distant stations had been protected for the entire past. For one example of what this causes, consider 890KHz. For many years WLS in Chicago was the only station radiating on that channel at night. Once WLS was protected only to 750 miles from its transmitter, WAMG in Dedham (a Boston suburb) could show up on the same channel, just across the 750-mile limit, with a directional 6000-watt night signal aimed straight at Boston by a line of five half-wave towers. WAMG protected WLS’s coverage inside the 750-mile radius, but did nothing to stop WLS’s 50,000 watt signal from continuing to pound into Boston. So at night, WAMG sounds like crap over much of the Boston metro. So it was no surprise, when WAMG went off the air from September to December 2009, to find WLS sounding fine at night in Boston.
The new proposed rules do away with the whole 750-mile thing, and just protects existing Class A stations where their signals are strongest on the ground. Essentially the rules tell the Class As that their coverage will be reduced to allow other stations on the same or adjacent channels to increase their own power at night, and improve local service.
But the result will be better local coverage where signals are super-strong, and increased skywave interference to far-off places on the same channels.
So the real story here isn’t failure to protect existing skywaves, but increased interference by every station that increases its night power.
In fact there are also many other problems endemic to AM broadcasting that no “revitalization” can fix:
1) A band that’s nearly useless for data.
2) Increasing environmental noise, mostly coming from computing devices of all kinds.
3) Terrible receiver circuitry, especially in portable and home devices.
4) Car makers getting rid of whip antennas, which are required for the best AM reception.
5) Abandonment of both AM and FM by people (especially young ones) for whom the finite quantity of live radio stations are vastly outnumbered by zillions of other radio-like choices on computers and mobile devices.
6) Real estate under towers proving more valuable than stations themselves.
7) Woeful inadequacies of FM translators, most of which have fractions of the power and coverage enjoyed by competing stations on the same band.
8) Poor sound, thanks partly to the nature of the medium and mostly to the awfulness of receivers.
9) Abandonment of AM in electric cars, which generate levels of computing noise too high for AM to tolerate. (In fact, AM is already gone in Teslas and one BMW.)
For a sobering view of AM’s future in the U.S., look toward Europe, where AM transmitters are being clear-cut like a diseased forest. Even the legendary million-watt Radio Luxembourg, once Europe’s top rock-and-roll station, went off the air at the end of last year, and its towers were dropped earlier this month. For a death-watch diary of AM around the world, read Ydun’s Mediumwave Info: http://mediumwave.info/news.html. (Outside North America, AM is called medium wave, or MW.)
The best strategy for the FCC is to do whatever it can (which might be nothing) to encourage AM and FM stations to become as digital as possible as soon as possible. That means they should maximize streaming, podcasting, and on-demand offerings, and then prepare for the day when digital finishes doing to FM what FM has long been doing to AM — plus a glut of “content” from an infinitude of competitors.
Two reasons why digital audio hasn’t wounded over-the-air radio enough to induce full panic:
1) There are too many apps for too many stations, and they’re all different.
2) No apps “tune” as easily as a real radio. When we get one or more of those, watch out.
The only places where AM may continue to make full sense in the U.S. are central time zone states with high ground conductivity. (See the map here. Look at the numbers: 15 and 30 are the best.) Across the AM-friendly lands of Texas, Oklahoma, Iowa, Nebraska, and the Dakotas, even a weak AM signal can travel hundreds of miles in the daytime. With just 5,000 watts (1/10th the max licensed), KFYR/550 in Bismark puts a good signal across all of North Dakota and half of South Dakota. KLIF/570 reaches from Austin to Oklahoma City. There are lots of areas left in those states that are absent of cellular data coverage, required for digital radio streaming. But you can still get satellite radio, and for many listeners that might be enough.
Don’t be surprised when the FCC finally heaves a big sigh and sunsets the whole AM band. Hey: Look at what happened to analog TV, and will also happen to what’s left of over the air (OTA) TV after stations sell off their spectra.
The FCC giveth, and the FCC taketh away.
Doc Searls, a former radio guy, is the Director of ProjectVRM, Berkman Center for Internet & Society, Harvard University. He can be reached at firstname.lastname@example.org