18 ms·

There arent any alternatives for major catastrophes that can top amplitude modulated radio. if you are in a car fleeing for your life from a wildfire, major st

There arent any alternatives for major catastrophes that can top amplitude modulated radio. if you are in a car fleeing for your life from a wildfire, major storm, or war, AM radio is available sometimes hundreds of miles from your location to provide timely instruction and lifesaving updates. if you need electricity for a radio, your car has fuel and can provide a radio signal to you for quite some time. AM radio can be transmitted with a roll of wire and a relatively simple transciever from an FOB or refugee camp. digital radio requires codecs, licenses, and specialty equipment. Satellite radio may, or may not be available as the ground stations that power it require even more advanced transcievers and software to operate and could take months to repair if attacked or destroyed. Cellular towers require special beamforming antenna that can take months to rebuild or procure in an emergency and rely on an advanced system of transcievers and software to provide a signal. its not Dolby quality, but if you need clean water and shelter it will guide you. Arguably you could mandate a VHF receiver in every car for FM based NOAA/EAS alerts, but AM is still cheaper.

Gigachad 2y ago
I had read in a previous thread that some cars had been dropping it as the modern electronics in cars were generating too much interference for AM radio to work.
- giantg2 2y ago
  I heard it was the EV vehicles drive systems, not the modern electronics. Either way, they should fix the shielding if it's really that noisy.
  - dvhh 2y ago
    And that's probably the gist of it, manufacturer find it cheaper to get rid of a legacy piece of infrastructure than "fixing the shielding" (and also support the vehicle that are already out there).
    - giantg2 2y ago
      The funny thing is, some EVs like the Prius had AM radios all along. It seems like some manufacturers might be taking short cuts. I guess maybe interference regulations aren't strict enough to force the shielding issue.
      - Workaccount2 2y ago
        A prius has an electric drive unit that is about 1/4 the power of a full EV. It also is only really used for getting the car off from stops.
    - ngneer 2y ago
      Great analysis. This must be the crux of it, meaning the engineering tradeoff between good EMI mitigation and lower cost. Shielding is one way to go. I do not know the details here for cars, but in digital systems people tend to use spread spectrum clocking (SSC) to lessen the interference. Others on the thread seem to suggest the culprit is not the electronics, though, so that technique probably is not applicable.
- mnw21cam 2y ago
  Spark plugs triggered by an ignition coil and a distributor (AKA what cars were doing 100 years ago) is an arrangement that logically should produce so much interference, I struggle to think how modern electronics can top it.
kstrauser 2y ago
While that’s all true, why is being in a car a special case? If I’m at home without power, I can’t access online information sources any more than I could if I were driving somewhere without cell data coverage. Should building codes require my house to have a radio installed? No one is legislating that tents have built in radios, but if I’m camping I’m in even more need of emergency information than if I’m already in a car and driving. Someone might rightfully tell me that it’s my responsibility to take a radio with me while I’m camping. Why does Toyota have to provide me with a radio while driving? I ham a ham extra license. I like radio and see its value. I think it would be more appropriate to tell people to pack an AM radio in the disaster bag we’re all suppose to keep in the trunk.
- giantg2 2y ago
  I think it's more like a radio in a plane. You sometimes have travel advisories and signs telling you to tune to an AM frequency when flashing. A radio in the trunk doesn't do you any good and could lead to a real mess if everyone had to pull over to use it. If you're already putting FM radios and stuff in the car, it shouldn't be a problem to put an AM radio in. If interference is an issue, then they should be working to clean that up with better shielding.
  - LorenPechtel 2y ago
    And the intended purpose is emergency use. It doesn't matter if the audio isn't spectacular, all that matters is that a human voice be understood. And note that AM is much more forgiving of terrain than FM. You can still be shadowed but the lower the frequency the less likely you are to be shadowed from the transmitter.
- wslh 2y ago
  > If I’m at home without power... You can use a crystal radio for that case [1]. [1] https://en.wikipedia.org/wiki/Crystal_radio https://en.wikipedia.org/wiki/Crystal_radio
  - onion2k 2y ago
wslh 2y ago
And, don't miss crystal radios for AM [1]. [1] https://en.wikipedia.org/wiki/Crystal_radio https://en.wikipedia.org/wiki/Crystal_radio
jalk 2y ago
Yes there are plenty of good reason for AM based emergency radio, but the fixation on cars is pretty odd. Plenty of scenarios where the car is not accessible, so should radios also be mandated in peoples homes? Here is a free one for you Elon: Throw a small usb-chargeable AM radio in the glove compartment and just move on.
- giantg2 2y ago
  Isn't their problem that the car is a noisy interference emitter? They'd have to fix the shielding issues to let the radio work while driving.
  - cr125rider 2y ago
    Well apparently they’ve already solved this since AM radio in cars has been a thing for like 90 years.
    - jtc331 2y ago
      The issue is with inverter based EV drive systems.
- deleted 2y ago
  [deleted]
jcgrillo 2y ago
If you're fleeing a disaster in your EV you may soon end up on foot anyway. I'd hate to think what the grid demand would be if, say, New York or LA suddenly all headed to the hills in EVs simultaneously. Especially if that infrastructure is taking battle damage.
- edb_123 2y ago
  I guess you could say the same about fossil fuel cars and gas stations? I doubt that everyone keeps their tanks full at all times. And just imagine the amount of traffic on roads in such a situation, regardless of your preferred energy source. You'd be struggling to get anywhere at all, unless you're among the first few fleeing town.
  - jcgrillo 2y ago
    If your gas or diesel engine is old enough you could build yourself a wood/coal gasifier[1] and get yourself down the road. With a fairly simple regulator engines can be made to run well enough on natural gas, propane, maybe acetylene? Diesels will burn just about any liquid hydrocarbon, at least for a time before they succumb to injector pump damage or excessive carbon buildup. EDIT: sure would love to know why y'all're downvoting... Is anything I wrote incorrect? Speaking from experience having crossed the US more than once burning various waste oils I'm pretty sure everything I wrote above is correct and factually accurate.. [1] https://en.m.wikipedia.org/wiki/Wood_gas_generator https://en.m.wikipedia.org/wiki/Wood_gas_generator
    - vel0city 2y ago
      Because its massively impractical to think the average person is going to get the notice "you've got anywhere from an hour to an afternoon to evacuate" and be ready to convert their vehicle to goal gas and have plenty of wood/coal to actually get through the evacuation.
      - jcgrillo 2y ago
        Yes, this is impossible. If having a vehicle connotes survival such people will perish. My point was only to illustrate there are many ways to make a piston engine go brr and only one way to make an EV mobile.
kelnos 2y ago
> Satellite radio may, or may not be available as the ground stations that power it require even more advanced transcievers and software to operate and could take months to repair if attacked or destroyed Not just the ground stations! If we're talking about an attack, the attacker very well might have the capability to shoot down the satellites themselves, too. AM radio is portable and decentralized. Sure, it can be jammed, but so can pretty much anything else that requires you to send information through the air.
- zie 2y ago
  Shooting down satellites is still a very hard, expensive problem. If you have more than a few, chances are nobody will work that hard, without a very good reason.
  - _hyn3 2y ago
    Still expensive, but now a solved problem. Funny how everyone's focused on satellites and nobody's talking about the society-ending EMP that would probably be triggered here on Terra though. https://www.csis.org/analysis/there-path-counter-russias-space-weapons https://www.csis.org/analysis/there-path-counter-russias-spa...
    - zie 2y ago
      I agree it can be done, but it's still a hard, expensive problem to actually make happen.
- hypeatei 2y ago
  Any world where satellites are being shot down most likely isn't going to be around much longer regardless.
michaelteter 2y ago
If you are in a car, and you're under the age of 40, you probably don't even know how to switch to your AM radio. Unless you are one of the rare drivers who knows about AM radio and uses it, it's not going to be something you think of using while fleeing a catastophe. It may have technical merits, just as horseshoes still do (because we do still use horses), but that doesn't mean we should force every car to have it. It certainly could be an option for those who see value in it.
- rblatz 2y ago
  I’m in my 40s and have no way to receive AM broadcasts. My wife and I both have Teslas, and we don’t have any radio tuners in the house. I wouldn’t even notic if the Tesla didn’t have FM either, I’ve lived in my current city for 12 years and couldn’t tell you a single radio station in the city. AM is dead, and FM is nearly there as well.
  - lubujackson 2y ago
    I just listened to the 49ers game on AM today while driving, so YMMV. Anyone in the Bay Area should have a go bag for earthquakes and it should probably have an AM radio in it. Old, stable tech is uncool until it is necessary.
  - grogenaut 2y ago
    I live in a city. All of my vehicles except my motorcycle (no radio) can recieve FM and AM. All of my current and old android phones can get AM/FM. The old boombox I have in the shed, several of my ham radios, clock radio, and some bluetooth swim headphones. And 2 of my TVs. Also I don't assume that my life experience represents everyone else's but then I don't drive a tesla or go on HN to tell people why they're wrong. The last one is a lie, but the rest is true.
  - hetman 2y ago
    So your car relies on the very things that may be unavailable in a major disaster scenario? I wonder if we're building insufficient redundancy into our civilisation always assuming all the modern niceties must always be there.
WalterBright 2y ago
I discovered that simply attaching a long wire to the phono input on an amplifier enabled me to hear AM radio.
- jojobas 2y ago
  That would have to be all AM radio at once, or perhaps a local cable radio?
  - WalterBright 2y ago
    The AM station with the strongest signal drowned out the others.
msla 2y ago
> There arent any alternatives for major catastrophes that can top amplitude modulated radio. OK, then ensure the radio stations actually have people in them. Otherwise, it's a false sense of security: https://en.wikipedia.org/wiki/Minot_train_derailment https://en.wikipedia.org/wiki/Minot_train_derailment > Because it was the middle of the night, there were few people at local radio stations, all operated by Clear Channel with mostly automated programming. No formal emergency warnings were issued for several hours while Minot officials located station managers at home.
amelius 2y ago
It would be pretty easy for (say) a Chinese car maker to jam all AM radio in the entire country.
- dartos 2y ago
  Sure, but that’s not a good argument against its usefulness in an extreme natural disaster. Also like… I doubt regulations would stop them from doing that, if that was their goal.
cameronh90 2y ago
Maybe we need a standard AM emergency broadcast frequency akin to 121.5 on aircraft. Legislate that all fixed and car radio receivers are always tuned to it and activate automatically if there’s a broadcast. Then scrap the rest of the analogue radio broadcasting band.
- squarefoot 2y ago
  > Then scrap the rest of the analogue radio broadcasting band. Please, no. In case of disaster, I could dismantle a tool, take its motor, fix it to a fan propeller, connect it to a rectifier stage and obtain a wind/water generator, then I could take parts from low tech stuff not even remotely related to a radio and build a crude but functioning transmitter to send a SOS. Problem is that making it work on a certain frequency would be hard without instrumentation, therefore the more ears on multiple frequencies the best chances that some of them will hear my dit dah by mistake.
  - _hyn3 2y ago
    Exactly. We are on Hacker News, after all. If there's any place that should be understanding of the need for ears on amplitude modulated frequencies, it should be us.
  - cameronh90 2y ago
    As it stands, ~nobody is listening to AM radio. The only people listening are radio geeks, and I doubt that number would change if the analogue radio broadcasting band was scrapped. Having an emergency frequency that devices auto-tune to would at least mean if you did manage to broadcast on that frequency, someone will actually hear it.
psychlops 2y ago
It's good to have some sort of communication during a disaster. There are many solutions, but you do not really have a reason to have AM legislated into a car.
iamwpj 2y ago
I don't understand why people are arguing against this. It's pennies to continue the service and utilizing an established system. All you have to do is say "yep, looks good". Why close this door?! There's literally no upside.
zooq_ai 2y ago
Why can't Emergency Alert System provide the same service. As we continue to expand our Satellite System, this becomes even moot as we can broadcast via SOS text messages
MisterTea 2y ago
> AM radio can be transmitted with a roll of wire and a relatively simple transciever from an FOB or refugee camp. Don't forget it can be listened to using a crystal radio set that is powered from the radio waves. No batteries needed and it can't be detected. https://en.wikipedia.org/wiki/Crystal_radio#%22Foxhole_radios%22 https://en.wikipedia.org/wiki/Crystal_radio#%22Foxhole_radio...
deleted 2y ago
[deleted]
II2II 2y ago
I don't know what the situation is like in the US, but I was shocked to discover that there are no AM stations in my part of Canada. It is cool in tje sense that I can direct my antenna and pick up stations in Newfoundland and New York on a good evening, without dealing with interference from local stationd, but it would be positively useless in emergency situations. Even if distant stations broadcast useful information during an emergency, picking it up in a vehicle is unreliable. If the antenna is directional, the strength of the signal is going to vary wildly based upon the vehicle's orientation. If the antenna is not directional, you are going to have trouble with interference. Don't get me wrong, I absolutely believe that broadcast radio is an essential tool during emergencies. I buy phones with FM receivers and have backup battery packs. I have an AM/FM/SW reveiver with backup batteries. I have a VHF transceiver, and am licensed to use it in both amateur and maritime bands. But, realistically, I don't see how most people would benefit from the few advantages that the AM broadcast band offers. You would likely be better off improving the resiliance of FM broadcast infrastructure. Even then one must accept its days are numbered.
askvictor 2y ago
I was hiking in remote Tasmania once, using an AM radio to try to get weather forecasts as there was possibility of snow which would affect one part of our walk. I was getting up pre-dawn to listen, and found that I could not tune in to any local stations, but was able to pick one up from about 2000km away. I figure this is due to the radio waves bouncing off the ionosphere (as intended), but the angle possible with this is relatively shallow, so a greater distance is better than a shorter distance when you haven't got line of sight (there were mountains in the way of most nearby cities). The moral of the story is to ensure that the broadcasting station needs to describe its location clearly (and the listener to listen for the station's location), as it may be a _long_ way away.

Gigachad 2y ago

I had read in a previous thread that some cars had been dropping it as the modern electronics in cars were generating too much interference for AM radio to work.

giantg2 2y ago
I heard it was the EV vehicles drive systems, not the modern electronics. Either way, they should fix the shielding if it's really that noisy.
- dvhh 2y ago
  And that's probably the gist of it, manufacturer find it cheaper to get rid of a legacy piece of infrastructure than "fixing the shielding" (and also support the vehicle that are already out there).
  - giantg2 2y ago
    The funny thing is, some EVs like the Prius had AM radios all along. It seems like some manufacturers might be taking short cuts. I guess maybe interference regulations aren't strict enough to force the shielding issue.
    - Workaccount2 2y ago
      A prius has an electric drive unit that is about 1/4 the power of a full EV. It also is only really used for getting the car off from stops.
  - ngneer 2y ago
    Great analysis. This must be the crux of it, meaning the engineering tradeoff between good EMI mitigation and lower cost. Shielding is one way to go. I do not know the details here for cars, but in digital systems people tend to use spread spectrum clocking (SSC) to lessen the interference. Others on the thread seem to suggest the culprit is not the electronics, though, so that technique probably is not applicable.
mnw21cam 2y ago
Spark plugs triggered by an ignition coil and a distributor (AKA what cars were doing 100 years ago) is an arrangement that logically should produce so much interference, I struggle to think how modern electronics can top it.

kstrauser 2y ago

While that’s all true, why is being in a car a special case? If I’m at home without power, I can’t access online information sources any more than I could if I were driving somewhere without cell data coverage. Should building codes require my house to have a radio installed? No one is legislating that tents have built in radios, but if I’m camping I’m in even more need of emergency information than if I’m already in a car and driving. Someone might rightfully tell me that it’s my responsibility to take a radio with me while I’m camping. Why does Toyota have to provide me with a radio while driving? I ham a ham extra license. I like radio and see its value. I think it would be more appropriate to tell people to pack an AM radio in the disaster bag we’re all suppose to keep in the trunk.

giantg2 2y ago
I think it's more like a radio in a plane. You sometimes have travel advisories and signs telling you to tune to an AM frequency when flashing. A radio in the trunk doesn't do you any good and could lead to a real mess if everyone had to pull over to use it. If you're already putting FM radios and stuff in the car, it shouldn't be a problem to put an AM radio in. If interference is an issue, then they should be working to clean that up with better shielding.
- LorenPechtel 2y ago
  And the intended purpose is emergency use. It doesn't matter if the audio isn't spectacular, all that matters is that a human voice be understood. And note that AM is much more forgiving of terrain than FM. You can still be shadowed but the lower the frequency the less likely you are to be shadowed from the transmitter.
wslh 2y ago
> If I’m at home without power... You can use a crystal radio for that case [1]. [1] https://en.wikipedia.org/wiki/Crystal_radio https://en.wikipedia.org/wiki/Crystal_radio
- onion2k 2y ago

wslh 2y ago

And, don't miss crystal radios for AM [1]. [1] https://en.wikipedia.org/wiki/Crystal_radio https://en.wikipedia.org/wiki/Crystal_radio

jalk 2y ago

Yes there are plenty of good reason for AM based emergency radio, but the fixation on cars is pretty odd. Plenty of scenarios where the car is not accessible, so should radios also be mandated in peoples homes? Here is a free one for you Elon: Throw a small usb-chargeable AM radio in the glove compartment and just move on.

giantg2 2y ago
Isn't their problem that the car is a noisy interference emitter? They'd have to fix the shielding issues to let the radio work while driving.
- cr125rider 2y ago
  Well apparently they’ve already solved this since AM radio in cars has been a thing for like 90 years.
  - jtc331 2y ago
    The issue is with inverter based EV drive systems.
deleted 2y ago
[deleted]

jcgrillo 2y ago

If you're fleeing a disaster in your EV you may soon end up on foot anyway. I'd hate to think what the grid demand would be if, say, New York or LA suddenly all headed to the hills in EVs simultaneously. Especially if that infrastructure is taking battle damage.

edb_123 2y ago
I guess you could say the same about fossil fuel cars and gas stations? I doubt that everyone keeps their tanks full at all times. And just imagine the amount of traffic on roads in such a situation, regardless of your preferred energy source. You'd be struggling to get anywhere at all, unless you're among the first few fleeing town.
- jcgrillo 2y ago
  If your gas or diesel engine is old enough you could build yourself a wood/coal gasifier[1] and get yourself down the road. With a fairly simple regulator engines can be made to run well enough on natural gas, propane, maybe acetylene? Diesels will burn just about any liquid hydrocarbon, at least for a time before they succumb to injector pump damage or excessive carbon buildup. EDIT: sure would love to know why y'all're downvoting... Is anything I wrote incorrect? Speaking from experience having crossed the US more than once burning various waste oils I'm pretty sure everything I wrote above is correct and factually accurate.. [1] https://en.m.wikipedia.org/wiki/Wood_gas_generator https://en.m.wikipedia.org/wiki/Wood_gas_generator
  - vel0city 2y ago
    Because its massively impractical to think the average person is going to get the notice "you've got anywhere from an hour to an afternoon to evacuate" and be ready to convert their vehicle to goal gas and have plenty of wood/coal to actually get through the evacuation.
    - jcgrillo 2y ago
      Yes, this is impossible. If having a vehicle connotes survival such people will perish. My point was only to illustrate there are many ways to make a piston engine go brr and only one way to make an EV mobile.

kelnos 2y ago

> Satellite radio may, or may not be available as the ground stations that power it require even more advanced transcievers and software to operate and could take months to repair if attacked or destroyed Not just the ground stations! If we're talking about an attack, the attacker very well might have the capability to shoot down the satellites themselves, too. AM radio is portable and decentralized. Sure, it can be jammed, but so can pretty much anything else that requires you to send information through the air.

zie 2y ago
Shooting down satellites is still a very hard, expensive problem. If you have more than a few, chances are nobody will work that hard, without a very good reason.
- _hyn3 2y ago
  Still expensive, but now a solved problem. Funny how everyone's focused on satellites and nobody's talking about the society-ending EMP that would probably be triggered here on Terra though. https://www.csis.org/analysis/there-path-counter-russias-space-weapons https://www.csis.org/analysis/there-path-counter-russias-spa...
  - zie 2y ago
    I agree it can be done, but it's still a hard, expensive problem to actually make happen.
hypeatei 2y ago
Any world where satellites are being shot down most likely isn't going to be around much longer regardless.

michaelteter 2y ago

If you are in a car, and you're under the age of 40, you probably don't even know how to switch to your AM radio. Unless you are one of the rare drivers who knows about AM radio and uses it, it's not going to be something you think of using while fleeing a catastophe. It may have technical merits, just as horseshoes still do (because we do still use horses), but that doesn't mean we should force every car to have it. It certainly could be an option for those who see value in it.

rblatz 2y ago
I’m in my 40s and have no way to receive AM broadcasts. My wife and I both have Teslas, and we don’t have any radio tuners in the house. I wouldn’t even notic if the Tesla didn’t have FM either, I’ve lived in my current city for 12 years and couldn’t tell you a single radio station in the city. AM is dead, and FM is nearly there as well.
- lubujackson 2y ago
  I just listened to the 49ers game on AM today while driving, so YMMV. Anyone in the Bay Area should have a go bag for earthquakes and it should probably have an AM radio in it. Old, stable tech is uncool until it is necessary.
- grogenaut 2y ago
  I live in a city. All of my vehicles except my motorcycle (no radio) can recieve FM and AM. All of my current and old android phones can get AM/FM. The old boombox I have in the shed, several of my ham radios, clock radio, and some bluetooth swim headphones. And 2 of my TVs. Also I don't assume that my life experience represents everyone else's but then I don't drive a tesla or go on HN to tell people why they're wrong. The last one is a lie, but the rest is true.
- hetman 2y ago
  So your car relies on the very things that may be unavailable in a major disaster scenario? I wonder if we're building insufficient redundancy into our civilisation always assuming all the modern niceties must always be there.

WalterBright 2y ago

I discovered that simply attaching a long wire to the phono input on an amplifier enabled me to hear AM radio.

jojobas 2y ago
That would have to be all AM radio at once, or perhaps a local cable radio?
- WalterBright 2y ago
  The AM station with the strongest signal drowned out the others.

msla 2y ago

> There arent any alternatives for major catastrophes that can top amplitude modulated radio. OK, then ensure the radio stations actually have people in them. Otherwise, it's a false sense of security: https://en.wikipedia.org/wiki/Minot_train_derailment https://en.wikipedia.org/wiki/Minot_train_derailment > Because it was the middle of the night, there were few people at local radio stations, all operated by Clear Channel with mostly automated programming. No formal emergency warnings were issued for several hours while Minot officials located station managers at home.

amelius 2y ago

It would be pretty easy for (say) a Chinese car maker to jam all AM radio in the entire country.

dartos 2y ago
Sure, but that’s not a good argument against its usefulness in an extreme natural disaster. Also like… I doubt regulations would stop them from doing that, if that was their goal.

cameronh90 2y ago

Maybe we need a standard AM emergency broadcast frequency akin to 121.5 on aircraft. Legislate that all fixed and car radio receivers are always tuned to it and activate automatically if there’s a broadcast. Then scrap the rest of the analogue radio broadcasting band.

squarefoot 2y ago
> Then scrap the rest of the analogue radio broadcasting band. Please, no. In case of disaster, I could dismantle a tool, take its motor, fix it to a fan propeller, connect it to a rectifier stage and obtain a wind/water generator, then I could take parts from low tech stuff not even remotely related to a radio and build a crude but functioning transmitter to send a SOS. Problem is that making it work on a certain frequency would be hard without instrumentation, therefore the more ears on multiple frequencies the best chances that some of them will hear my dit dah by mistake.
- _hyn3 2y ago
  Exactly. We are on Hacker News, after all. If there's any place that should be understanding of the need for ears on amplitude modulated frequencies, it should be us.
- cameronh90 2y ago
  As it stands, ~nobody is listening to AM radio. The only people listening are radio geeks, and I doubt that number would change if the analogue radio broadcasting band was scrapped. Having an emergency frequency that devices auto-tune to would at least mean if you did manage to broadcast on that frequency, someone will actually hear it.

psychlops 2y ago

It's good to have some sort of communication during a disaster. There are many solutions, but you do not really have a reason to have AM legislated into a car.

iamwpj 2y ago

I don't understand why people are arguing against this. It's pennies to continue the service and utilizing an established system. All you have to do is say "yep, looks good". Why close this door?! There's literally no upside.

zooq_ai 2y ago

Why can't Emergency Alert System provide the same service. As we continue to expand our Satellite System, this becomes even moot as we can broadcast via SOS text messages

MisterTea 2y ago

> AM radio can be transmitted with a roll of wire and a relatively simple transciever from an FOB or refugee camp. Don't forget it can be listened to using a crystal radio set that is powered from the radio waves. No batteries needed and it can't be detected. https://en.wikipedia.org/wiki/Crystal_radio#%22Foxhole_radios%22 https://en.wikipedia.org/wiki/Crystal_radio#%22Foxhole_radio...

deleted 2y ago

[deleted]

II2II 2y ago

I don't know what the situation is like in the US, but I was shocked to discover that there are no AM stations in my part of Canada. It is cool in tje sense that I can direct my antenna and pick up stations in Newfoundland and New York on a good evening, without dealing with interference from local stationd, but it would be positively useless in emergency situations. Even if distant stations broadcast useful information during an emergency, picking it up in a vehicle is unreliable. If the antenna is directional, the strength of the signal is going to vary wildly based upon the vehicle's orientation. If the antenna is not directional, you are going to have trouble with interference. Don't get me wrong, I absolutely believe that broadcast radio is an essential tool during emergencies. I buy phones with FM receivers and have backup battery packs. I have an AM/FM/SW reveiver with backup batteries. I have a VHF transceiver, and am licensed to use it in both amateur and maritime bands. But, realistically, I don't see how most people would benefit from the few advantages that the AM broadcast band offers. You would likely be better off improving the resiliance of FM broadcast infrastructure. Even then one must accept its days are numbered.

askvictor 2y ago

I was hiking in remote Tasmania once, using an AM radio to try to get weather forecasts as there was possibility of snow which would affect one part of our walk. I was getting up pre-dawn to listen, and found that I could not tune in to any local stations, but was able to pick one up from about 2000km away. I figure this is due to the radio waves bouncing off the ionosphere (as intended), but the angle possible with this is relatively shallow, so a greater distance is better than a shorter distance when you haven't got line of sight (there were mountains in the way of most nearby cities). The moral of the story is to ensure that the broadcasting station needs to describe its location clearly (and the listener to listen for the station's location), as it may be a _long_ way away.