I just saw somebody mention (on an amazon review for an Aukey charger) that their USB-C car charger was interfering with TPMS system on their car. That's a little scary. Hopefully they'll get it ironed out soon.
I realize TPMS is not 2.4gz but thought that was relevant to interference concerns
There's actually a ton of RF interference out there, just that it doesn't impact enough people on a regular basis for anyone to do anything about it.
The 2 meter radio I have in my car goes crazy with RF(up to S9) when I drive through the local Starbucks. That said bringing it up with anyone will probably get you a couple funny looks and not much else.
Notably, powerline ethernet destroys nearly the entire HF range, from 3 to 30MHz. This isn't just bad for radio hams, it ruins shortwave and some AM radio too.
The issue is that as you and others use powerline ethernet, you leak electromagnetic interference patterns back into the powerlines. This buildup of interference from multiple homes creates problems around your area, even if you don't notice it yourself.
Except unless you have some sort of an impedance follower you'll probably just end up attenuating your powerline networking to the point of not working.
Most of the useful signal in the system is going directly from one circuit to another. The signal headed out toward the power meter is mostly dead, and you might even improve the networking by getting rid of those extra echoes.
I'd be really surprised if it works that way. I'm not a power systems engineer but I've worked a fair bit on the low voltage side of things.
My guess is that the connection to your house to the service wires in incredibly low impedance, otherwise you'd see all sorts of voltage sags when you used a large appliance with an inductive load(or power tool). So any change large enough to affect the service line is going to go straight into your house. Circuits aren't directional(unless you have a diode or voltage/impedance follower) hence why it would impact the quality of power-line networking.
Additionally any sort of low pass filter(RC, LC or RLC) involves putting a inductor(P) or resistor(R) in series with the circuit(AKA your transmission wires) which isn't simple or cheap.
The impedance going to all your neighbors is pretty low too, but I don't think the system relies on signals going out that far and echoing back. High frequencies have more of a transmission line model, which is pretty directional. There's free impedance everywhere.
My understanding is that you mostly care about the minor reflections caused by wire junctions in a system like this, and that line headed outside is more or less a signal sink no matter what. It's possible a capacitor would need to be a bit further away than directly at the breaker box, but by the time you reach the pole I'm reasonably confident that absorbing the entire signal with $.50 of components and no inductor would be fine.
So, let's say that even what you're proposing is correct(which I'm pretty dubious about).
Is your house longer than 32ft/64ft? Those lengths are halfwave on 20m/40m and make a great radiator. For reference all I need is 5w to get out ~400mi so I'm sure these things are kicking off a ton of RF on those frequencies.
Fundamentally if you have an unshielded wire and you're driving these frequencies across it you're going to see RFI along those frequences(along with the harmonics).
Well I think it's a multifaceted issue, but I am not educated on how your home itself contributes to the radiation profile so I left that bit of speculation out.
Radio interference from switching voltage regulators, power supplies etc. is normal as most of them work from several hundred KHz to above 1 MHz generating PWM square waves whose harmonics fill the spectrum up to hundreds of MHz and beyond. They're circuit-wise very close to RF transmitters, so it's a normal behaviour. The RF junk they produce however can be filtered out both by putting them behind good screening and by filtering both their input and output lines. This cost money though so cheap ones will perform much worse, and some of them don't employ any method at all to reduce interference.
My favorite source of noise was a Korean fluorescent lamp with power factor correction (makes the inductive lamp load look resistive to prevent parasitic current flow in the power lines). It was square wave chopping the 120-240VAC=175-350Vpp input to the ballast at the plug with a variable frequency (100kHz-1MHZ) based on input voltage phase. A very simple circuit that efficiently coupled >1Wrms into a narrow band (~10kHz fundamental)swept square-wave into a 2m antenna.
I integrated the total power with a spectrum analyzer... but any radio I tested (including GPS, FM, WiFi & GSM maybe due to IF or saturation?) would stop working within 10ft=3m of the lamp. Driving around I could tell if the lamp was on using my AM radio (set to any station) due to the 120Hz buzz from several blocks away.
As far as I could tell it had passed Korean FCC equivalent, several tens of thousands were imported, and sold (at Frys at one point) around the country.
I destroyed ours, but sometimes, just driving around, I think I can hear one when I switch to AM.
Did you report it to the FCC? I understand if you didn't, as a consumer, and this is not an attack on you. But this kind of thing should be punished, and one of the main ways to do this is to bring this to the attention of the regulating authorities.
We can only keep the spectrum in good shape by, as a producer or designer, test and design to comply. As an importer, require and check certifications on what we import. As a consumer, report when we find something being funky. (again, not blaming you)
Any device operating at those frequencies should have an FCC sticker, meaning they've been tested to make sure radiated RF is below some legal limits. If the cheap devices don't have the sticker or have a fake sticker or were materially changed after passing the tests, they're illegal in the US.
On some vehicles (Honda, IIRC) if the TPMS isn't working (dead sensor battery, interference, etc) the stability control system will assume the tire on that wheel can't be trusted to apply grip when correcting the vehicle's trajectory, so you might not stay on the road in an oversteer/understeer situation.
I realize TPMS is not 2.4gz but thought that was relevant to interference concerns