My journey with EMI/RFI, a list of tested fixes

[felhuy]

Waiting for my toroid cores to arrive to test. Another thing that gave me huge improvement today was unplugging everything from my front usb ports on my pc and only using the back, and unplugging my USB audio dac which i used to play guitar with, although not sure if these improvements are from the ferrites or not

I also minimized the number of usb devices plugged in, in case I need my webcam I can always connect it back for example. I had lots of spare usb adapters (usb to usb-c), I plugged them into empty ports as well, has anyone tried to see if they make a difference, in my case they do. It's weird where you can find small improvements.

[astroasis]

Waiting for my toroid cores to arrive to test. Another thing that gave me huge improvement today was unplugging everything from my front usb ports on my pc and only using the back, and unplugging my USB audio dac which i used to play guitar with, although not sure if these improvements are from the ferrites or not

I also minimized the number of usb devices plugged in, in case I need my webcam I can always connect it back for example. I had lots of spare usb adapters (usb to usb-c), I plugged them into empty ports as well, has anyone tried to see if they make a difference, in my case they do. It's weird where you can find small improvements.

Nice, a large part of this issue seems to be potentially related to the usb ports, at least for me and possibly you. Its as if certain usb devices or the ports themselves are picking up signals either radiated in the air or conducted in the cables

[Sirkiwi]

As an update, I followed Sirkiwi advice and tied my main power cable (going to my power strip) multiple times around a core and had much better results than a single clamp-on ferrite. I did the same with my display cables also seeing a nice improvement. There has to be a maximum area needed for maximal RF dissipation, I suppose a small clamp-on ferrite was not enough in my case.

Funnily enough I had better results putting ferrite clamps inside the PC case on the gpu connector just before it goes in and the 24 pin atx, on the cables didnt do much, im also going to try the mix 31 and 43 as recommended here

Yes, this is a good advice, it helps

That's a good sign. What type of ferrites are you using? I recommend mix-31 material for attenuating RFI/EMI between 1 MHz and 300 MHz and mix-43 material for RFI/EMI between 20 MHz and 250 MHz.

Now i plan to buy a 220V isolation transformer and connect it to a circuit with two 110V lines, 180° out of phase, to eliminate any connection to the PEN (neutral-ground of the installation). My idea is to create a completely isolated TN-S system, grounding one of the output phases to create a new neutral with a good 0V reference.
I

[felhuy]

Waiting for my toroid cores to arrive to test. Another thing that gave me huge improvement today was unplugging everything from my front usb ports on my pc and only using the back, and unplugging my USB audio dac which i used to play guitar with, although not sure if these improvements are from the ferrites or not

I also minimized the number of usb devices plugged in, in case I need my webcam I can always connect it back for example. I had lots of spare usb adapters (usb to usb-c), I plugged them into empty ports as well, has anyone tried to see if they make a difference, in my case they do. It's weird where you can find small improvements.

Nice, a large part of this issue seems to be potentially related to the usb ports, at least for me and possibly you. Its as if certain usb devices or the ports themselves are picking up signals either radiated in the air or conducted in the cables

Yes, they absolutely induce parasitic currents, you don't even need a device, an extension cable in the front panel usb hub just laying bare is enough. This has nothing to do with usb polling, its all EMI, I have all usb ports hard disabled in bios minus the ones i use or intend to use. Try to remove cables, plug devices only as needed.

Also I forgot to mention an even more important measure, moving the pc to a new location in the house. My office has two ideal spots for setting my desk, I don't know if it was the outlet, but I suspect the fact that the bad spot was facing windows, while the better one was in the opposite corner facing a wall, made a big difference. Even moving around devices on the desk itself changes the response, like trying to find the optimal orientation for wifi antennas, but in reverse.

[Mr1991]

Has this been a permanent fix for you?

[ZINZIRIO]

As an update, I followed Sirkiwi advice and tied my main power cable (going to my power strip) multiple times around a core and had much better results than a single clamp-on ferrite. I did the same with my display cables also seeing a nice improvement. There has to be a maximum area needed for maximal RF dissipation, I suppose a small clamp-on ferrite was not enough in my case.

Funnily enough I had better results putting ferrite clamps inside the PC case on the gpu connector just before it goes in and the 24 pin atx, on the cables didnt do much, im also going to try the mix 31 and 43 as recommended here

Yes, this is a good advice, it helps

That's a good sign. What type of ferrites are you using? I recommend mix-31 material for attenuating RFI/EMI between 1 MHz and 300 MHz and mix-43 material for RFI/EMI between 20 MHz and 250 MHz.

Now i plan to buy a 220V isolation transformer and connect it to a circuit with two 110V lines, 180° out of phase, to eliminate any connection to the PEN (neutral-ground of the installation). My idea is to create a completely isolated TN-S system, grounding one of the output phases to create a new neutral with a good 0V reference.
I

I have exactly the same electrical network as you, and I tried the separate neutral system with an isolation transformer... The results made no difference, so I don't recommend investing in one since it doesn't filter common-mode noise, which is what's causing the problem.

[MK92]

Of course it made no difference, you cannot "separate" anything in a TN-C system...even if you separate PEN in your distribtuion box and run a dedicated circuit to your room with 3 wires, the shared neutrals in the building would STILL be used unless you connect your own neutral wire and ground wire from your apartment to the main distribution box in the building, so it wouldn't be shared with anything....but this would be both techically impossible as you would have to open all the walls in the building and would be illegal, you cannot tamper with building electrical system like that.