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I believe the issue is more that the increasing amount of EM noise in the AM band from electric auto components (particularly EV power inverters) means they wou

I believe the issue is more that the increasing amount of EM noise in the AM band from electric auto components (particularly EV power inverters) means they would have to invest more engineering in to filtering that noise out.

woodruffw 3y ago
That's helpful context, thank you!
jhoechtl 3y ago
That's the reason, yes. That makes cars mote expensive. On the other side there are levels for unwanted radio emissions, how do the cars pass them? How do cheap cell phone chargers pass them? Or is nobody looking at this?
- jeroenhd 3y ago
  Compliance can be easy if you're designing a form of Faraday cage. Just make sure the car captures enough of the noise within its frame and you've got a pretty good start. Your car will comply with most (far from all) EM regulations as long as it doesn't disturb things outside the car. The AM radio exists within the car. It probably even exists within the parts of the car that normally just get a metal box around it to shield the components. It's also very sensitive by its nature. It's hardly an impossible feat, but car manufacturers will save every penny they can. Pretending to be "on your side" against the damn oppressive government forcing them to build provisions for areas without cell reception will probably also score some points with the public which mostly lives in areas where you don't need AM radio for important information.
  - ke88y 3y ago
    > Compliance can be easy if you're designing a form of Faraday cage. Just make sure the car captures enough of the noise within its frame and you've got a pretty good start. Your car will comply with most (far from all) EM regulations as long as it doesn't disturb things outside the car. This complies with existing regulations. The proposed regulations state the AM radio needs to work from within the car. So this wouldn't be sufficient according to the proposed rules. > It's hardly an impossible feat, but car manufacturers will save every penny they can. Good? I don't want to pay a tax on every new car purchase in order to subsidize owners of AM spectrum and their rapidly dwindling customer base.
  - jhoechtl 3y ago
    > The AM radio exists within the car. It probably even exists within the parts of the car that normally just get a metal box around it to shield the components. It When I was young I remember mopeda creating interfernces as far as 500 meters from the TV antenna. Car manufactureres managed to completely quieten that RF noise. So I would say it's doable.
- ke88y 3y ago
  > On the other side there are levels for unwanted radio emissions, how do the cars pass them? How do cheap cell phone chargers pass them? Or is nobody looking at this? Regulators do pay attention to automotive components. I'm sure some of the cheap chargers don't bother with FCC Certification Testing. The TL;DR is that unintentional and even intentional radiation must remain under certain field strength and/or power limits. That's why you're allowed to use those little aux-to-FM radio dongles to transmit on licensed spectrum, for example. A "useful lie" explanation of the rules goes something like: "If the interference generated by the car stays within a very small radius (say, the car itself, or less than a few meters around the car) then the FCC doesn't care."
- TheLoafOfBread 3y ago
  > How do cheap cell phone chargers pass them? Or is nobody looking at this? You will build a prototype with all the filters and let it pass EMI tests in national laboratory. Then you will start supplying consumers with much cheaper electronics but in same package like your expensive prototype. Who is going to look into ultrasound welded plastic box? Nobody.
JohnFen 3y ago
> means they would have to invest more engineering in to filtering that noise out. Maybe they could take some of the money they're wasting making horrible things like touchscreen controls and use that to do some useful engineering instead.
- jalk 3y ago
  And here I was, thinking they all did touchscreens because they were way cheaper and can easily work across different car models
  - JohnFen 3y ago
    Yes, I should have said "actually useful to the customers".
    - jalk 3y ago
      I'm with you on that
    - mrguyorama 3y ago
      What are the customers going to do, buy someone else's car that also has a terrible touch screen from the same manufacturer? American businesses are hell bent of ignoring anything but the dollar sign at the bottom of the balance sheet, and since they all use the exact same value and prioritization system, they can all do the exact same thing without technically colluding, preventing any consumer from ever doing the free market thing and buying something better.
      - JohnFen 3y ago
        > What are the customers going to do, buy someone else's car that also has a terrible touch screen from the same manufacturer? Well, what I do (not only because of this, but those touch screens certainly contribute) is to not buy new cars.
  - clnq 3y ago
throw0101b 3y ago
> […] means they would have to invest more engineering in to filtering that noise out. Wouldn't this mostly be a one-time charge, and then just cookie-cutter the solution going forward? (I say this as someone living in Toronto, Canada, where we have streetcars/trams with overhead wires, which play havoc with (AM) radio when they go by.)
Gordonjcp 3y ago
Good. With a fairly modest amateur radio setup I can pick up electric and hybrid cars moving around half a kilometer away, without really trying.

woodruffw 3y ago

That's helpful context, thank you!

jhoechtl 3y ago

That's the reason, yes. That makes cars mote expensive. On the other side there are levels for unwanted radio emissions, how do the cars pass them? How do cheap cell phone chargers pass them? Or is nobody looking at this?

jeroenhd 3y ago
Compliance can be easy if you're designing a form of Faraday cage. Just make sure the car captures enough of the noise within its frame and you've got a pretty good start. Your car will comply with most (far from all) EM regulations as long as it doesn't disturb things outside the car. The AM radio exists within the car. It probably even exists within the parts of the car that normally just get a metal box around it to shield the components. It's also very sensitive by its nature. It's hardly an impossible feat, but car manufacturers will save every penny they can. Pretending to be "on your side" against the damn oppressive government forcing them to build provisions for areas without cell reception will probably also score some points with the public which mostly lives in areas where you don't need AM radio for important information.
- ke88y 3y ago
  > Compliance can be easy if you're designing a form of Faraday cage. Just make sure the car captures enough of the noise within its frame and you've got a pretty good start. Your car will comply with most (far from all) EM regulations as long as it doesn't disturb things outside the car. This complies with existing regulations. The proposed regulations state the AM radio needs to work from within the car. So this wouldn't be sufficient according to the proposed rules. > It's hardly an impossible feat, but car manufacturers will save every penny they can. Good? I don't want to pay a tax on every new car purchase in order to subsidize owners of AM spectrum and their rapidly dwindling customer base.
- jhoechtl 3y ago
  > The AM radio exists within the car. It probably even exists within the parts of the car that normally just get a metal box around it to shield the components. It When I was young I remember mopeda creating interfernces as far as 500 meters from the TV antenna. Car manufactureres managed to completely quieten that RF noise. So I would say it's doable.
ke88y 3y ago
> On the other side there are levels for unwanted radio emissions, how do the cars pass them? How do cheap cell phone chargers pass them? Or is nobody looking at this? Regulators do pay attention to automotive components. I'm sure some of the cheap chargers don't bother with FCC Certification Testing. The TL;DR is that unintentional and even intentional radiation must remain under certain field strength and/or power limits. That's why you're allowed to use those little aux-to-FM radio dongles to transmit on licensed spectrum, for example. A "useful lie" explanation of the rules goes something like: "If the interference generated by the car stays within a very small radius (say, the car itself, or less than a few meters around the car) then the FCC doesn't care."
TheLoafOfBread 3y ago
> How do cheap cell phone chargers pass them? Or is nobody looking at this? You will build a prototype with all the filters and let it pass EMI tests in national laboratory. Then you will start supplying consumers with much cheaper electronics but in same package like your expensive prototype. Who is going to look into ultrasound welded plastic box? Nobody.

JohnFen 3y ago

> means they would have to invest more engineering in to filtering that noise out. Maybe they could take some of the money they're wasting making horrible things like touchscreen controls and use that to do some useful engineering instead.

jalk 3y ago
And here I was, thinking they all did touchscreens because they were way cheaper and can easily work across different car models
- JohnFen 3y ago
  Yes, I should have said "actually useful to the customers".
  - jalk 3y ago
    I'm with you on that
  - mrguyorama 3y ago
    What are the customers going to do, buy someone else's car that also has a terrible touch screen from the same manufacturer? American businesses are hell bent of ignoring anything but the dollar sign at the bottom of the balance sheet, and since they all use the exact same value and prioritization system, they can all do the exact same thing without technically colluding, preventing any consumer from ever doing the free market thing and buying something better.
    - JohnFen 3y ago
      > What are the customers going to do, buy someone else's car that also has a terrible touch screen from the same manufacturer? Well, what I do (not only because of this, but those touch screens certainly contribute) is to not buy new cars.
- clnq 3y ago

throw0101b 3y ago

> […] means they would have to invest more engineering in to filtering that noise out. Wouldn't this mostly be a one-time charge, and then just cookie-cutter the solution going forward? (I say this as someone living in Toronto, Canada, where we have streetcars/trams with overhead wires, which play havoc with (AM) radio when they go by.)

Gordonjcp 3y ago

Good. With a fairly modest amateur radio setup I can pick up electric and hybrid cars moving around half a kilometer away, without really trying.