MAINS FILTER FOR EMC & NOISE REDUCTION

[warpie]

I'm not sure where I should post this...

Has anyone tried this or anything similar? Is it helpful for audio gear or only for RF gear?  It seems pretty straight forward and it will probably make the need for powerstrips with filtering unnecessary.


http://www.m0nwk.co.uk/mains-electricity-filter-for-emc-noise-reduction/

 

[abbey road d enfer]

Analog equipment does not produce significant EMI/RFI, but may need to be protected against them if RF.digital equipment is in their vicinity.
SMPS, which are more and more common in analog gear need mains filtering.Minimum requirement is X and Y capacitors, but the addition of common-mode and/or diff-mode inductors maybe desirable, particularly in very sensitive equipment.

 

[JohnRoberts]

Power transformers are generally bandpass filters so can automatically filter out HF mains noise. But once inside the chassis it can corrupt other circuits. Mains filters require special voltage rated (X/Y) caps, etc.

Not much of an issue, unless it is.

JR 

 

[warpie]

You lost me there gentlemen...

I want to connect test equipment (scopes, generators, etc..) as well as some audio gear and from what I understood this simple filter will "clean" the mains. Is it worth doing it?

Powerstrips with both filtering and surge protection tend to be pricey especially if you need a few of these.

 

[Scodiddly]

The question is how much of the noise comes from inside your own house.  Switching power supplies, LED lights, refrigerator motors kicking on and off, all sources of AC line noise.

 

[Bo Deadly]

No. Wrapping mains wires around a ferrite torriod like that is great for filtering RF but it isn't going to do anything at audio frequencies. RF can indirectly cause LF noise but RF is more likely to enter through signal wires. So just make sure your shielding and grounding and such is correct. Pin 1 of XLRs should be connected to the chassis using the shortest possible wire. This is why there are some XLR connectors that have a metal spike in the screw hole connected to pin 1 so that when you tighten the screw it stabs that metal chassis and makes for a very short shunt path for RF.

 

[warpie]

Thank you.