Earlier this summer Radio World published one of its occasional special “e-books,” this one called “HD Radio From the Ground Up” (form-filling required to download). Like most industry trade publications, it’s a celebratory document that seeks to paint the U.S. digital broadcast system in the best possible light.

Kicking things off is a tech-centric column from Scott Fybush in which he talks with various enginerring principals about the efficiency of today’s FM-HD Radio systems. Unlike the first few generations of the tech, which involved wildly inefficient combination of the analog and digital signals, improvements to the HD system now make for a better marriage. In HD’s early years, more than 30 percent of the power that went into the analog/digital combination process was lost as waste heat; now that number is down to something like 10 percent.

However, one piece of received wisdom seems to be falling out of favor: the separate broadcasting of analog and digital FM signals. Fybush notes that this transmission-configuration, especially at higher digital power levels, can often result in “undesirable digital-to-analog interference.” Many stations adopted this configuration but are now changing over to a high-level combined analog/digital signal; no word on how much such a retrofit costs, or how much additional costs are incurred through other recommended transmission improvements that often go hand-in-hand with such projects — like the installation of “heavy-duty cooling systems you might find in a data center—and the same sort of remote control and monitoring, too,” in addition to “robust” uninterruptible power supplies.

Additionally, best-practices now call for stations to co-locate their analog and digital program-streams for most effective combination, thereby reducing the chance of misalignment which causes skipping or stuttering as an FM-HD receiver blends from analog to digital and back. According to Jeff Detweiler, the chief broadcast engineer at iBiquity-owned DTS, the prior practice of sending analog and digital audio feeds from separate locations was “a myth” that “never worked.” The new recommendation is for all combination (both audio and RF) to be done at the transmitter site.

Don’t forget the FM-HD license fee, either — most stations pay an initial up-front cost of $10,000 for the right to broadcast digitally, while some of the technology’s features (such as multicasting using HD-2/3/4 channels) involve an ongoing fee payment if you are a commercial broadcaster.

According to the e-book, HD Radio has been implemented (both AM and FM) by some 2,300 stations in the United States, 54 stations in Mexico, and 10 (authorized experimentally) in Canada. In penetration-terms, that works out to a rate of about 15% in the U.S., 4% in Mexico, and almost 8% in Canada. iBiquity/DTS also claims that some 28 million U.S. vehicles — or 11% of all cars on the road — have built-in HD capability. As always, there is no way to independently verify these figures. What is clear is that this rate of growth is a snail’s pace, as it has been for the last decade.

Similarly, iBiquity/DTS general automotive manager Jeff Jury claims that listening to FM-HD-2/3/4 channels “has grown more than 350 percent, according to Nielsen data” since 2011 — but critically omits the fact that the majority of listening to these program streams takes place in analog via FM translator stations. (Both HD-centric and analog FM listening to these subchannels are combined in Nielsen data.)

Historically, growth of HD adoption by U.S. broadcasters remains uninspired for the decade, after a slight decline in prior years. Canadian regulators do not plan on making a decision to formally certify HD Radio for wider adoption until the end of next year. And in Mexico, regulators have already stated that they will not require broadcasters to adopt HD, leaving it (like in the U.S.) for the market to decide the technology’s fate. Flowery language aside, the proportion of HD-capable receivers in circulation in all three countries remains extremely low relative to the number of analog radios, with the vast majority of digital uptake happening in the automotive sector.

Both Canadian and Mexican broadcasters actually sound relatively nomncommittal. According to Rogers Radio SVP Julie Adam, Canada’s radio industry still has “to decide whether we believe this is a part of our long-term future (and if it is), then work together as a broadcast community to make HD Radio succeed.” In Mexico, Instituto Mexicano de la Radio engineering director Miguel Fernández Arias is a bit blunter: “[D]evelopment of this new technology is being limited by the lack of receivers in the market, and this is what broadcasters do not like — lack of receivers on the one hand, and on the other they have not seen the possiblity of new business with HD2, HD3 and HD4 channels.” IMER and DTS are actually giving away HD receivers as a part of a promotional exercise — a strategy that was actually banned in the U.S. due to HD’s overly restrictive licensing regime, of which some terms have been left behind on the international market for reasons never explained.

Meanwhile back in the U.S., much hay is being made about Ford’s decision to put more than one radio antenna in their new cars going forward. This will most definitely help improve FM reception, which often suffers from a condition called multipath interference, especially in areas of tall buildings or other terrain — but wasn’t the FM-HD system designed in part to eliminate this problem? Thus, Ford is actually improving the radio reception in its vehicles more for the improvement of analog rather than digital listening.

Considering that we’re basically two decades into the digital transition now, it’s hard to find the evidence for happy-hype.