Switching power supply emission the electromagnetic waves

Thread Starter


Joined Jun 21, 2018
Whenever i turn on my computer, the radio is being jammed
i known the reason is the switching power supply inside the computer
when it work, it emission the electromagnetic waves
My question is:
- What is the electronic component of the power supply make the emission
- If i use a power supply with higher capacity, is the emission decreased?

thanks a lot


Joined Sep 22, 2013
"computer".....now days can mean many things. If available......turn on "spread spectrum" in BIOS.

If your computer was manufactured.....the power supply should be well filtered to allow processor function.

It could be other things. But without details and measurements.....it's hard to tell.

The only solution might be to remove radio from computer vicinity.


Joined Mar 30, 2018
As BR-549 says it may not be the switch mode power supply, it could very well be the rf emissions from the PC motherboard – emitted due to the MHz frequencies on the PCB tracks.

Switch mode power supplies do have a propensity to give off rf emissions, the main cause is the high frequency switching of the rectified mains voltage (340V) at around 40KHz and the resultant higher frequency harmonics.

A better quality PSU is more likely to reduce the rf emissions (than higher capacity unit) – I have encountered ATX PSU’s that do not comply with legal rfi limits.

Marc Sugrue

Joined Jan 19, 2018
Sound like a fault to me. No PC should be emitting rf such that is blocks radio. Typically the PC components are housed in a metallic housing to aid emi. Do you have a fault power cable with no earth present? If it is genuinely the power supply it sounds like it's a low spec, non compliant part.