This may be a shrinking niche, but it's potentially a last bastion of AM radio usefulness.
In my opinion, those stations actually make AM seem much worse than it really is. That scheme backfired in the long run.
[1] 47 CFR 90.242(b)(8) <https://www.ecfr.gov/current/title-47/chapter-I/subchapter-D...>
FM is WAY better sound quality. It's not even close.
[1] 47 CFR 15.211 <https://www.ecfr.gov/current/title-47/chapter-I/subchapter-A...>
Also, very little data would fit in such a tiny spectrum window.
> nearly 90 percent of Americans ages 12 and older — totaling hundreds of millions of people — listened to AM or FM radio each week, higher than the percentage that watch television (56 percent) or own a computer (77 percent)
Admittedly it seems dubious but if true I'm surprised by basically every one of these numbers
Because that's about the limit of my usage of any terrestrial radio.
Most independently owned retail and eating establishments also qualify for a copyright infringement exemption if they play music originated by a radio or television broadcast station licensed by the FCC [1].
[1] 17 US Code §110(5) <https://www.law.cornell.edu/uscode/text/17/110>
[1] <https://www.westwoodone.com/blog/2022/11/21/edisons-share-of...>
https://www.statista.com/statistics/612660/paid-services-bro...
I can't say how long it has been since I checked the AM dial while driving (basically hit it by accident), but years it he most appropriate unit. What I heard (northeastern US) seemed to support some data I read that it is mostly taken over by religious and Limbaugh-type right-wing talk radio. So, that strongly left- Sen. Markey is supporting it so strongly says something. But, if there are actually high listener ship, then for sure, it could be a critical emergency communications channel, and worthwhile just for that
In the same ratings book, the religious and right-wing talk radio on AM continued with a poor performance. I think that generally content is more important than the technology delivering the audio (although probably anything would perform better to at least some extent on FM).
Then some big corpo (cumulus?) snapped up the station and the cast changed significantly, with the station swinging to the right very noticeably.
I switched it off permanently soon after. This was around the time I discovered I get more useful traffic information from my phone anyway.
As a middle-schooler living in the Washington DC area, I would regularly pick up WLS in Chicago, some 700 miles away, on my little crystal set at night.
I don't know the theory, though I did make one as a child.
It was the non-tuning type, and would pull in only the strongest-broadcasting local AM channel.
It's also possible to create a tuner which can pull in a specific station (or more accurately: frequency). These can also operate without a battery, though battery-powered radio is of course more versatile.
https://en.wikipedia.org/wiki/Clear-channel_station
https://worldradiohistory.com/Archive-Station-Albums/WSM/Cle...
Stations like KGO receive special status to protect against interference, and in return are required to transmit 10,000 Watts minimum. Most transmit at 50,000 Watts. The idea was to make sure even the most remote parts of the country with no local stations would be able to receive one of the clear-channel stations at night.
That might work if your station's reach is the typical 10--50 miles of an American FM broadcast (notable exception: San Francisco's KQED which can be picked up by direct line-of-sight at least 120 miles away as one approaches Yosemite on CA-120 near and east of Groveland, CA.
There's a similar issue I find with online news items from local broadcast (usually television) stations, which similarly utterly fail to note the city and state in which a story occurs, though at least in this case it's usually possible to punch the call signs into Wikipedia to find out where the station is located, something that's not always possible traveling remote regions by car at night. (Though to be fair, far more possible now than it was several decades ago.)
I can still get music radio from Algeria on AM, or rock, sport and news from the UK (I believe from stations emitting from Swansea and London) I used to listen to Deutschlandfunk, France Inter, BBC4 LW on the LW band (only the latter is still active today, others were switched off in the 2010s)
Also, I love that radio is a media that is so hard to regulate. There is always some novelty to what you can listen. There used to be rock-music pirate radios in the 60s, emitting from the international waters. Some small countries like Luxembourg and Monaco would also have commercial radios to break government monopolies from neighboring countries. Then there were the pirate FM radios in the 70s and 80s
Monaco is still broadcasting some stations that don't comply with French regulations on music (Riviera radio serves mainstream English pop songs). It allows you to listen to some different music in your car. (this one is in FM, tho, so it's very local)
Some authoritarian governments were challenged by the radio too. Nazi Germany couldn't stop the BBC during WWII, for example. And you can get a lot of American radios all over the world, even when the internet is controlled. At last, none of the radio you listen to on AM end up in the history that profiles you. You can listen to a radio a night without being served the same music over and over afterwards.
AM radio won't be mainstream. But I'm convinced it still has a role for media plurality, and as a line of Defense for the democracy (and yeah, I know you can get much more from internet radios, like Anime music and everything, but it doesn't feel the same)
DRM (no not that DRM--Digital Radio Mondiale) is a modern digital standard that promises much better spectral efficiency, power efficiency and range. See https://www.drm.org/. It is similar in concept to DAB, using an OFDM carrier, but with more robust error correction and equalisation, and lower bit rate codec to handle larger broadcast areas.
There is a hope that this could upgrade existing AM broadcast infrastructure, allowing rapid coverage of large areas without the expense of building out new towers.
The MW/HF bands are great for coverage because of the longer wavelength, relative to the VHF bands used for FM and DAB.
That's why DAB is crap. Because people are greedy and don't care about quality.
Amplitude modulation is a historically important technology, because it was technically very simple to receive in the early history of radio, and because it was more bandwidth-efficient than FM. But it remains utterly badly suited for mobile reception, because it is highly sensitive for multi-path interference (unlike FM).
We have now far better modern, digital modulation schemes, including DAB and DVB-T2 for VHF and DRM for long, medium, and short-wave transmission. They provide (thanks to OFDM) much better audio quality and interference resistance than the old analogue modulation schemes, and they are also far more power efficient, which substantially reduces the enormous electricity bills of the transmitter stations. They also are very bandwidth efficient, and can be used in single-frequency networks.
It might be easier on a DIY level, but on a commercial level complexity is free, substance and power are expensive.
The real cost problem in 2022 is the size of the antenna. The entire tower, or array of towers, is the antenna. They can take up many acres of land. It is hard to justify not selling out and replacing those towers with more lucrative residential, retail or industrial development.
A single station's antenna could be 5 properly spaced towers, each hundreds of feet high.
The characteristics of AM (i.e., daytime groundwave and nighttime skywave) provide service that other services can not.
I wonder if there's something useful to do with that range. It's a big chunk of lower frequencies right there, in the range that reliably does over-the-horizon propagation (although better at night perhaps according to wikipedia?)
The benefit of AM being super simple to build a receiver for is less relevant nowadays, FM is trivial to get radios for now, and ham radio uses SSB for voice for the most part in the lower frequency ranges.
In Seattle, half a million people listened to KIRO-AM 710 last month [1]. In Boston, 454,600 people listened to WBZ-AM 1030 [2]. In Los Angeles, 625,500 people listened to KFI-AM 640 [3].
It's difficult to justify discontinuing an audio service that is performing as a top conduit for audio (more than Spotify or Pandora, for example) because of a perception that the service is no longer viable.
[1] <https://radioinsight.com/ratings/seattle-tacoma/> [2] <https://radioinsight.com/ratings/boston/> [3] <https://radioinsight.com/ratings/los-angeles/>
Non-directional beacons! In Nth America NDBs are 190–535 kHz, but elsewhere they are 190–1750 kHz, overlapping the AM radio band. Keep decommissioning the more expensive VOR stations in favour of satnav (and release the spectrum), but keep NDB transmitters as a low-tech/low-cost backup.
They won’t just interfere with medium wave broadcast.
[1] - https://www.theguardian.com/world/2017/dec/13/norway-becomes...
I'm guessing you had a mandate that all new cars need to have DAB receivers.. when did that come in action? Because here in slovenia, you could still buy a new car without DAB just a few years ago. Basically, i'm just wandering if all your cars sold in the last 10+ years already have dab (by mandate) and the turn-off wasn't a real pain for most, or if like 80%+ of your cars on the street just lost radio reception?
We need AM radio. AM radio is simple. It is better than having an overly complicated and badly made digital radio needing licensing and difficulty of implementation etc.
I believe that explains quite a bit. Without being snarky, AM radio is home to political opinion that is largely sympathetic to a conservative viewpoint and I suspect that is one reason that Markey wants car manufacturers to keep it (and why perhaps other lawmakers would be indifferent or even eager to see it disappear)
Not an adherent to the views commonly espoused on AM talk radio, I nevertheless see the utility for some kind of low-tech broadcast format which is easy and inexpensive to tune in and broadcast over. AM fits the bill, and has much longer range than FM
Also, to your second point, due to the size of the antennas required, AM is very expensive to broadcast over unless you're using an inefficient antenna. The shortest quarter wavelength antenna (at 1700 kHz) would be 137 feet high. An AM (medium wave) array would take up acres of land.
