If you read this blog regularly, you are aware that HDradio has a new owner. I am beginning to view this as a positive development. In many ways, HDradio was designed to fail – and so far the FCC has not done what it did for the introduction of FM radio around 1960. The FCC used its authority over approving electronic devices to require ALL radios sold in the United States to include FM. That’s why suddenly AM/FM radios started appearing in automobiles – it was not because of consumer demand and not because the carmakers thought it was a good idea. Coercing Radio manufacturers to incorporate FM was what it took to make it happen. You would have to work pretty hard to find anyone who thinks FM radio was a mistake – other than owners of a few legacy AM radio stations.
NBC radio – a.k.a. RCA – was in the business of selling radios. They opposed the introduction of FM Radio because Edwin Armstrong had invented a far superior product that RCA did not own, at least initially. Retooling factories costs a lot of money. Practical FM radio required using transisters, which were created by AT&T, not RCA.
The problem with mandating HDradio in all radios is that it is proprietary technology and requires licensing fees to use. This is the opposite approach of SiriusXM which pays the automobile companies to put their radios in virtually every car made in the last 10 years. “Over the air” radio saw no financial reason to push HDradio – radio is “free” after all. Taking your one license and splitting it into four streams made no business sense – there are few potential listeners, and you just increased your programming expenses by 300% if you wanted comparable quality programming. Fracturing your country music station and airing four different types of country music creates zero increase in the ad revenue. Most sane listeners only listen to one radio station at a time.
Here is a compromise to make everyone angry – have the FCC mandate that all future radios must include both HD radio and SiriusXM, but with serious limits on the HD radio patent royalties, or maybe even pay them from radio station license fees paid to the FCC. Moving AM stations to ubiquitous HD radios could be the correct answer to “save AM radio” for a relatively modest amount of money.
I think I have HD Radio, but I am not sure how to tell. Everything is digital now and so I see station ID’s on the display and occasionally the “acquiring signal” message. What is it that HD radio was supposed to accomplish? If it isn’t higher quality audio, then they may have missed the target.
What the FCC wanted and what the radio stations wanted were probably different things.
I’ve just been rereading the info over at Wikipedia. Digital signals are all or nothing – if it gets a too high bit error rate, it has to drop back to the original analog. The digital signal was initially only 1% of the analog signal – below the level where it disrupts the analog carrier. The max is now 4% to improve digital range.
FM stations are allocated .2 MB of spectrum. The published frequency is the center of the 200 kHz – so a station at 100.5 MHz “owns” from 100.4 to 100.6. Stations on adjacent channels would not cause overlapping audio like on AM, but instead creates spurious signals generated by the receiver that would create out of band interference. The 200 kHz of spectrum gives 100 kHz of signal. That is pretty good stereo and room for things you may not be aware even exist, like stock tickers, reading services for the blind, etc
With IBOC at 4% power, the signal is given 300 kHz of spectrum – going from 100.35 to 100.65 MHz. The “intrusion” works because FCC rules mean the 4% power won’t be strong enough to interfere with the stations separated based on the FCC spacing rules for analog FM.
The 300 kHz gives 300 kb/sec digital signal – instead of splitting out subchannels by frequency filters, all of the subchannels are combined using multiplexing, then digital compression applied to the combined signals. The result is a total of much more bandwidth than the spectrum can hold in analog.
If you take away the analog signal, full digital FM can have 7 channels within the same transmitter separation of one analog station, four being full zCD quality.
My ears can’t hear anything over 7500 hz, no matter how loud it is, so 128 kb/sec sampling rates (CD quality) are lost on me – but the world doesn’t revolve around me 😉 I would prefer 7 Chevrolets over 1 BMW, but the marketplace will sort that out.
It sounds like most new cars are now shipping HD capable, which is different than a few years ago.
How Ibiquity gets paid, and probably answers the “why isn’t AM rebroadcast more in HD2?” the manaufacturer pays a royalty on transmitter. The radio station pays a one time royalty for setting up HD1. For the HDx channels, Ibiquity gets 3% of the “incremental gross revenue” from the channel. If I add WCBS-AM to WCBS FM/HD2, how do you calculate how much more ad revenue WCBS-AM brought in because of being on HD2? It’s much simpler to have a dedicated revenue stream for an HD-Only channel and keeps Ibiquity from demanding to audit your books. So Ibiquity or its new owners will get a 3% of revenue from the 97.3 The Outlaw – or will they? I’m not sure. I’m listening to K229CC analog.