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Comment by stu2010 | Hacker News Reader

stu2010

I haven't seen much discussion about how AM gets used for local road condition or emergency communication. When you're driving and see a sign that says "TUNE TO 1610 AM" and the car has no AM receiver, what do you do?

This may be a shrinking niche, but it's potentially a last bastion of AM radio usefulness.

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Those low power highway information stations are actually required to be low quality audio [1]. My understanding is that back in the day, broadcasters insisted that these stations were low quality so they would not compete with commercial broadcasters.

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...>

There was (is?) a commercial station in the bay area that broadcasts simultaneously on AM and FM. I could tune the car radio to the correct frequency on each and then compare the sound quality by flipping the AM/FM switch.

FM is WAY better sound quality. It's not even close.

You're talking apples and oranges.

FM is absolutely better sound quality than AM. That's why music is mostly on FM. (On the other hand, AM uses less bandwidth and travels farther, since it's in the MF band and can bounce off the ionosphere. That's the tradeoff.)

At the same time, the highway information stations the parent poster is talking about are low power AM stations designed to play a road condition message within a distance of 3-5 miles from the antenna. The audio is often very poor quality, even for AM, because of the transmit power restrictions placed on them.

That said, it's worth noting the places you need these highway information stations most are also often places with some of the worst cellular coverage. If you drive in the mountains, they can be essential.

But, if you ever hear AM Stereo you'd be amazed.

Although FM has a higher bandwidth, from a listeners perspective its more likely that you were experiencing a narrowband monaural AM - hence the massive difference to your ear.

Stereo or wideband AM is much clearer:

http://www.amstereo.org/sound.htm

Could have just been the stereo tricking your brain into thinking it sounded better. For example, in the late 1980's my family had a car that had an AM-only radio. One day while channel hopping one station just sounded so much better than anything we'd ever heard on this radio. Someone finally noticed a little STEREO light had lit up, because that station had recently started stereo broadcasts. Eventually we moved and later got a different car and I've never again seen a little light like that on an AM station.

I don’t live in the bay anymore but know for a fact sports radio knbr 680 also has an fm station, think it’s 104.5

I’ve actually taken a bit to AM lately to listen to different sporting events when outside of fm range

Not vouching for it and I wouldn’t care if am was deprecated as a vehicle radio feature (my vehicles are ‘88 and ‘02) but it still serves a purpose for sure

TIS stations have low-pass filters from 3-20kHz, but it looks like most AM stations have low-pass filters from 5-20kHz anyways to avoid interference with neighboring channels: https://casetext.com/federal-register/audio-filtering-requir...

What about sports broadcasts? I often listen to games in my car on AM.

As do many people. AM stations that run play-by-play sports programming do very well in the ratings, and do very well with the station's sales team.

The skill of the broadcast announcers is remarkable. They paint the scene with audio-only in an amazing way.

My father (and my grandfather before him) takes a little battery-powered AM radio with him to games (football, baseball, etc) and listen to it while watching the game live. They've even muted the TV and used TV picture with radio sound to get a better experience. That makes it easy to take naps and close your eyes without missing key parts of the game.

One thing that makes a radio-TV combination work less well nowadays is latency in the TV feed. Running 15 to 20 seconds or even more behind the radio is not uncommon with all the processing and distribution layers that go on with a modern video feed. I've heard of setups where someone plugs a radio receiver into a computer with software to buffer and apply the same delay.

Also, the mandated delays in USA for TV and radio to allow censoring (and thereby reduce the risk that Something Untoward is enacted on a live broadcast) . IIRC, radio has a 10 second delay, while TV has a 30 second delay. This allowed a Lt. Col. I knew to hear the conclusion of any play before the television image was even close to definitive. Even with "pure broadcast" TV and radio (no digitising, no cable, no satellite…). Processing delays, such as for DVR or streaming, only add to the overall delay.

Hank Azaria (played the title character on Brockman) joked a few times that baseball announcers could say whatever they wanted as long as it ended in a pitch count.

I think that adds to the effect of "being at the game" with the announcer; go to a ballgame with a friend you haven't seen in a few weeks and you'll end up talking about random stuff too.

Love it! Had he not been so wildly talented at voice-work, he could have been a damn good announcer himself (as evidenced by his work as announcers in the Simpson's), so that's extra great

If you haven't seen this, a great recent interview with him: https://www.youtube.com/watch?v=O5TaYFi4UVA

Recently the Vikings posted this clip of their PxP announcer Paul Allen doing his thing. Even though I don’t care one lick about American football, I still found this clip to be great fun to watch. The skill, passion, and joy he has is infectious.

https://twitter.com/PatMcAfeeShow/status/1592980588608487424

I grew up listening to baseball on AM radio. Can't stand to watch the game on TV. Too boring. But on radio? I can go into the garage or the shop and work on something and listen to the game.

I listen to football games in a pinch. Sometimes I have errands to run while a game is on and so I listen in on radio. It's amazing how they call a game. That's a talent that's going to be sad to see die.

Tunnels near me just say "Turn on your radio" and blast the whole FM spectrum at least (might try it with AM too!). Guess you can do this in a tunnel!

Fun fact! In the US, a Tunnel Radio System may operate in any mode on any frequency provided the signal does not leak from the tunnel[1].

[1] 47 CFR 15.211 <https://www.ecfr.gov/current/title-47/chapter-I/subchapter-A...>

In a sample size of maybe 10, every time I’ve seen one of those highway signs and tuned to the station, the quality was so bad I couldn’t make out any words and so got no useful information. If that’s the last bastion of AM usefulness, scrap it and give that spectrum to the wireless carriers. Frankly, for stuff like road closure information I’m a lot more likely to get that from Waze (delivered over a 5G connection) now anyway.

I don't think wireless carriers would want 1.2 MHz at that low of a frequency. They'd have the same issues with interference that broadcast stations have. The transmit antennas would take up acres of land (each element hundreds of feet long). Receiver antennas would also need to be large.

Also, very little data would fit in such a tiny spectrum window.

The wireless carriers wouldn't be able to do anything with the AM broadcast band. It's in the MF range - not useful for cellular at all due to limited bandwidth, giant antenna requirements, and ionospheric bounce.

Low speed informational text message would be good use tho

Since the antenna would not be able to fit in anyone's pocket, the best placement for a medium wave text receiver would be in the car or a fixed location, like a home. And that brings you right back to the interference problem.

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