I find that article glosses over a lot of points. In particular - a statement like this: “You can put your translator antenna on top of someone’s 2,000-foot TV tower, and have a signal that rivals a Class A FM in many smaller markets,” If this were really true, why wouldn't the big stations on the tower "power down" to save on their electric bill? The issue I see is one of building and house penetration. While outdoor line of sight might get the same coverage even with the low power, it just doesn't have any ability to penetrate compared to a 100kW class C, for example. A lot of hype is made about Houston's "super translator" on top of a 2000 foot tower on 95.1. It does respectably well in my car, but get behind an obstruction and I am getting KNDE from College Station instead. The super translator may be a lot closer on a tall tower, but KNDE has a lot more juice behind its signal.
I'm still not convinced that this "FM translator for every AM" idea is going to work. When I look at the coverage map for WBAP
http://radio-locator.com/cgi-bin/patg?id=WBAP-AM, the coverage for its 99.5 HD-2 (assuming the HD-2 coverage equals the analog footprint), I already see a significantly smaller footprint:
http://radio-locator.com/cgi-bin/patg?id=KPLX-FM. Assuming somebody has a really good radio, I've had 70 mile HD reception - but that is under best case scenario with an excellent radio and antenna. 70 miles is still enough to cover their service area, but based on the HD in my daughter's car (stock radio, shark fin, the range is probably closer to 40 miles. Parts of the metroplex go unserved even with HD-2. Now - let's propose that they get their own FM translator on top of a Cedar Hill tower. Probably only about 30 mile range outdoors, no obstructions. Most of the metroplex is not covered, especially the affluent suburbs of Richardson, Plano, Allen McKinney, Frisco, etc. The more likely scenario for most translators is a short stick somewhere, wedged in between existing allocations. Maybe a little ten mile diameter circle. If that happens to be in the downtown area, you serve a lot of people. But in the average population density - put that little 10 mile diameter circle anywhere you like - the vast majority of the metroplex isn't served. HD-2 as the primary reception vehicle for listeners make a lot more sense. The article shows a nice optimistic graph of HD listenership increasing, maybe it is even true. But there are the newer cars coming on the market that ditch HD. My daughter was in an accident, and the repair shop is milking the job. So what, you say? We have had to rent her several rent cars during this period. No HD in 2 out of five - new models, major US auto makers - no HD. But she can pair her bluetooth phone in all of them, the backup camera and GPS is there, Pandora was there in one of them. Satellite in all of them but the subscription wasn't active. A blank spot on the LCD where HD used to be - at least that is my theory. I look for HD when I rent a car here because I listen to HD-2's. two out of five. This is an issue for the HD alliance. What WAS a sure thing in cars is being dumped in cost reducing measures. So that FM signal for big AM's may not be as sure a thing as this article assumes. I also notice one of their examples was Decatur, IL - hardly a large market, definitely a compact market where miserably small translators cover the whole thing. But LA, Dallas, Houston, etc. - vast land areas. HD-2 and translators - won't cover the whole thing.
The biggest indicator that HD-2 is not making it in the consumer market is the lack of commercials, and the presence of unpopular, marginalized formats. If HD radio was really catching on, the HD-2 formats would be more of the same that is on HD-1 and analog. As things stand now, broadcasters can afford to program a niche with a fanatical following to garner some loyalty among its listeners. They can't sell commercials - as David has pointed out advertising agencies don't care about selling to old folks, so oldies goes without commercials. Same with the other niche formats on HD-2. If HD radio really gets popular, those niche formats are GONE in favor of ones that can be monetized.