Dr. Bob said:
It really grates me to hear people complain about the availability of HD radios when the technology, in many ways, parallels the acceptance of FM and color television. They conveniently forget the FM was a higher priced option in the early 70's on most cars and that color television didn't really become mainstream until RCA decided to accept reduced patent royalties so the price and availability of sets came down.
Some autos may have had AM stereo "standard" but the developers of the systems expected a return on investment. That return was generally the broadcast equipment manufactures paying royalties to the developers and passing them on as increased costs to the stations purchasing the equipment although Motorola did have royalties on their stereo decoder ICs for some time.
You want digital radio to be free for anyone to build transmitters and receivers without the developers being able to get a return on investment?
Bob
How many stations are operating in AM stereo now? They are free to install the equipment
The main differences between FM stereo, color television, and HD radio are that:
1) Both were things the consumer actually WANTED. Color on television was spurred by color in the movies. People wanted that experience at home, and are still wanting the home cinema experience now. Stereo was something people wanted in music - they had stereo on albums, and there needed to be a way to broadcast it than simulcast on AM and FM stations. People do not want HD radio - the sound improvement is only noticeable on very high end audio systems. They want HD-2 formats, but stations around the country are finding that people want the format, but on a second FM station they can receive with their present radio.
2) The FM stereo system, color television system did not degrade the bands. Both were elegant engineering solutions made by engineers who understood the necessity of not degrading the existing service in any way. HD radio was a kludged together mess made by engineers who did not take the time to adequately test the system and discover problems that are all too apparent now: HD radio degrades first adjacents on FM, and first and second adjacents on AM. It reduces coverage on both bands. Higher power levels on FM sidebands make a bad self-noise situation on FM much worse. The system is not robust, coverage is terrible, dropouts frequent, and recovery lock periods long. The introduction of the system on AM coincided with the introduction of cheap wideband AM radios that allow 10-15 kHz noise to bleed through the cheap tiny speakers and earbuds, making an AM HD station virtually unlistenable on $5 cheapie radios. The HD engineers solution to the problem? Insult and marginalize anybody pointing out the obvious problems, alienate the technical community of DX'ers as outmoded, wierd geeks who are out of touch with the modern world and reality - and concoct ridiculous studies carefully slanted to ignore the problems.
AM stereo was a fairly inexpensive addition. HD capability is much more expensive - percentage wise - to add to a station and to a radio. The only reasons why AM stereo failed to catch on is that by the time it was introduced, music listeners had moved on to FM, and AM had become the domain of blithering idiots of talk and slobs of sports. And the FCC did not help by being wishy washy on adopting a standard. AM stereo had become an irrelevancy.
I don't give a rodent's posterior about whether iBiquity make a return on investment or not. The system they foisted on the American public is defective and destructive to reception - they ought to go bankrupt. If somebody did a good job of digital radio, they needed a clear business plan showing how they would make a return on investment. One that did not depend on high pressure scare sales tactics, and on consumer acceptance and enthusiasm - which was a tremendous unknown and now has bitten them in the posterior.