All I need some help please, I have a 3d printer 24v switch mode power supply (Chinese switch mode) as soon as I turn on the PSU I get interference across all HF bands visible on the scope of my radio I have FAIR-RITE TYPE 31 FERRITE CORE 0431177081 (monster) http://www.m0nwk.co.uk/mains-electricit ... -reduction on the mains entering the shack, I've tried a second one on the power cord to the psu and a 3rd going from the psu to the 3d printer none of which has reduced the interference it is emitting, does anyone have any ideas I could utilise to stop it, obvious its something inside the psu, would more casing shield / keep the interference inside the psu?

Cheers
Craig
M3CRJ

You're probably on long chase with this if the ferrite's not blocking it at source.

I've got a Creality Ender 3v2 here, that runs 24v and it's quiet. The PSU is a Meanwell brand, maybe you can source one of them, they're quite popular.

Have you established whether the interference is coming from the mains side or the 24V side?

Or checked it is the PSU and not the printer?

You probably have but not said so, hence the question.

I have a couple of cheap chinese 24V supplies, and they are very quiet.

Have a look at the PSU board and see if there are missing components. They are very good at leaving filter components out to save money.

thanks for the repsonses, it's definitley the PSU giving out the interference, not sure if its from the input or output as noise doesn't change when i put te ferrites on either input/output side or disconnect the printer, just means i'll have to print when not on the radio if i can't sort it or put up with the noise,

Cheers

If it doesn't change when you disconnect the printer, then it is not the printer, and unless you have very long leads on the printer side of the PSU, then it probably isn't coming from the DC side of the printer.

Is the PSU case properly grounded? (assuming it is metal)

It sounds as if you need a proper filter on the mains input, probably been left out to save money.
Maybe cheaper and easier to buy a new PSU as suggested before.

Sad as it is, a replacement PSU is quite probably cheaper than the ferrite and components required to cure the OEM PSU.

Maybe something here https://ooznest.co.uk/product-category/ ... -supplies/ that'll do the job.