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As far as I can tell, electric cars are regular old FCC 15b devices, but the emission limits are generous enough that an AM radio can't operate from inside of o

As far as I can tell, electric cars are regular old FCC 15b devices, but the emission limits are generous enough that an AM radio can't operate from inside of one, the same way you wouldn't expect an AM radio sitting on top of a generator to do well.

jcgrillo 2y ago
Thanks this is interesting context
imoverclocked 2y ago
That is interesting from a mass-implementation standpoint. I wonder how many Tesla vehicles working right next to each other would squash AM reception for a given radius around the group of cars with current EM emissions.
- bcoates 2y ago
  In theory, they could form some sort of phased array beamforming to fuck one guy in particular, but ignoring that sort of targeted malice, and assuming non-correlated noise and a non-directional receiving antenna, the inverse square law would dominate and the overwhelming majority of the interference would just be the closest Tesla, not the total volume of Teslas.
  - imoverclocked 2y ago
    Any chance they could unintentionally synchronize by interfering with each other? Many systems naturally do this but I'm unfamiliar with inverters on this level so I have no idea if it's feasible or not. Maybe car manufacturers have thought of this and intentionally use slightly different frequencies across vehicles or just shield their clock source from interference? It would not surprise me in the slightest if someone has considered using coherent wave forming from electric vehicles as a targeting mechanism. In a malicious-actor scenario, EVs often have GPS which can provide a pretty accurate time-synchronization mechanism. With enough collected GPS points to eliminate significant error and fine-control over the inverter phase/frequency it seems that it would definitely be a possibility given the number of EVs in many urban areas. Heck, most EVs are even internet connected for software updates.
blisterpeanuts 2y ago
I have (my kid has actually) a 2022 Nissan Leaf with AM receiver. Perhaps newer EV designs are different in some way, such as the placement of the electric motors. Stellantis has stated they moved the radio receiver components away from the EV related systems to maintain good reception.
_hyn3 2y ago
AM antennae are simple affairs -- usually just a stick of carbon with a tiny spool of wire around it. Seems like you could just relocate it to an end of the vehicle and put a bit of shielding around it. If that doesn't do it, then the car is a massive emissions vehicle. (pun intended)

jcgrillo 2y ago

Thanks this is interesting context

imoverclocked 2y ago

That is interesting from a mass-implementation standpoint. I wonder how many Tesla vehicles working right next to each other would squash AM reception for a given radius around the group of cars with current EM emissions.

bcoates 2y ago
In theory, they could form some sort of phased array beamforming to fuck one guy in particular, but ignoring that sort of targeted malice, and assuming non-correlated noise and a non-directional receiving antenna, the inverse square law would dominate and the overwhelming majority of the interference would just be the closest Tesla, not the total volume of Teslas.
- imoverclocked 2y ago
  Any chance they could unintentionally synchronize by interfering with each other? Many systems naturally do this but I'm unfamiliar with inverters on this level so I have no idea if it's feasible or not. Maybe car manufacturers have thought of this and intentionally use slightly different frequencies across vehicles or just shield their clock source from interference? It would not surprise me in the slightest if someone has considered using coherent wave forming from electric vehicles as a targeting mechanism. In a malicious-actor scenario, EVs often have GPS which can provide a pretty accurate time-synchronization mechanism. With enough collected GPS points to eliminate significant error and fine-control over the inverter phase/frequency it seems that it would definitely be a possibility given the number of EVs in many urban areas. Heck, most EVs are even internet connected for software updates.

blisterpeanuts 2y ago

I have (my kid has actually) a 2022 Nissan Leaf with AM receiver. Perhaps newer EV designs are different in some way, such as the placement of the electric motors. Stellantis has stated they moved the radio receiver components away from the EV related systems to maintain good reception.

_hyn3 2y ago

AM antennae are simple affairs -- usually just a stick of carbon with a tiny spool of wire around it. Seems like you could just relocate it to an end of the vehicle and put a bit of shielding around it. If that doesn't do it, then the car is a massive emissions vehicle. (pun intended)