I think that AM has to change in a few ways, and those involved aren't really working on it, they're kind of just letting things happen rather than fight. I'm not sure why broadcasters aren't more political, pushing to have AM stereo when FM got stereo in the early 1960s, or standing their ground for a stereo system when it did finally happen. If all of the systems were acceptable, why didn't AM broadcasters test them and say which they wanted?
Another loss was NRSC, which mandated a 75 microsecond pre-emphasis curve, and a 10 khz cutoff frequency on the audio. I didn't think the pre-emphasis was bad, FM uses it, and plenty of audio processors were already out there to handle the curve at the stations.
The 10 khz cutoff seemed like a good idea from all of the press it was getting at the time, thanks to the NRSC. Did it really help? I never saw proof that it reduced interference, and as an AM dxer I didn't hear a change once all stations were running it. More than that, I saw it as a loss of something AM broadcasters did once have, frequency response to 15 khz, matching FM. Innovonics, who made the 222 AM compliance processor, probably scored the most out of anyone.
The NRSC said that most receivers already had frequency response much less than 10 khz anyway, so listeners wouldn't hear the difference, not a good vote of confidence. In front of other broadcast services and receiver manufacturers, AM radio lost status when that happened. Mandating 10 khz also didn't look to future developments in digital signal processing that could do a lot to bring up fidelity and reduce noise. Another insult is that now they allow AM HD stations to have wider than 10 khz bandwidth now, so why can't analog have it again?
I think Tha Dood has some good ideas, and in the past I've wished that Part 15 AM antenna stations could have more power, but I think we'd benefit more from less ambiguous rules, since it seems that both stations and the FCC are exploiting the situation to some level.
I don't know if a power increase would be that good, right now Part 15 is pretty underground, yet still can cover a neighborhood when done well. Increasing power ten times to 1 watt, or even higher as some have asked for, might cause the national broadcast groups to take notice and poach the frequencies from community broadcasters.
I think we'd do better to clear up the issues over grounding, letting people ground whatever they want and getting the most effectiveness out of the power we have now. That would get signal range for the motivated hobbyist wanting to serve their own community, not allowing someone to just stick an antenna on a tower like they do now with FM translators.
I'd like to see more happening with carrier current, I think it has a lot of potential that people haven't seen yet. The old model was carrier current as a campus radio station for students, so schools would broadcast in a way that kept signals inside of school buildings. It can be used differently in the community, where you push the signals outside of the broadcasting building and into the local area, you're not broadcasting to just your own building, a different way of thinking. Methods are being developed where you don't even have to couple the RF signal directly into the power lines any longer, making it safer and even more efficient.
Reducing antenna efficiency standards for licensed stations could be a great idea, allowing shorter antennas and smaller ground systems. It will make some stations into local broadcasters, but my idea is having more vitality and variety on the AM band can only help with listenership.
I have a feeling that even the NAB would agree at this point, someone from the NAB recently was in favor of widening the current 3 khz audio on TIS stations to give them more fidelity, something that NAB had been opposed to before. I think he's seeing something, when AM was top Dog, they had every reason to want to eliminate competition, but now bringing in more programs, more uses can help save the band.
Don't give up, we don't have to just throw in the towel on AM, but we could be positive and innovate.
Boomer
