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Shielding components from EMI/RFI... Help please

A recent experiment with a product designed to reduce EMI/RFI left me curious about other ways to reduce EMI/RFI in my system. In the past ten days, I've stepped onto a slippery slope, at the bottom of which is surely some kind of insanity...

I've been experimenting with copper plates in an effort to absorb, deflect, diffract, and block EMI/RFI. I've tried copper plates under components, on top of components, and inside components.

This is the point where you tell me I don't know what I'm doing and I'm likely to short circuit something and/or electrocute myself. Consider me duly warned. This is also the point where you tell me to get some balanced interconnects, or at least to get some shielded interconnects for Chrissake. Consider me duly informed. Moving on...

I'm hoping you can help me make the most of this experiment, and help me avoid killing a component or myself. My strategy so far has been to:

1. Place copper plates at locations that generate a lot of EMI/RFI, e.g., components with switching mode power supplies or high frequency clocks. The system has a total of 3 SMPS and 3 clocks.

2. Place copper plates at locations that are vulnerable to EMI/RFI, e.g., under the amp, near the transformer.

3. Place copper plates inside noisy components -- in particular, my Meridian G68 preamp/processor. I've begun to build 2 partial Faraday cages, one for the SMPS, and one for the analog output stage.

4. Ground the copper plates either to the component chassis (when plates are used inside a component) or to an independent ground point (when plates are used above/below a component).

Has anyone tried this sort of thing?

Bryon
bryoncunningham
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almarg
9,670 posts
 
Hi Bryon,

It can't hurt to put a ferrite on DC, and it conceivably could provide some benefit. The ferrite will have no effect on the DC itself, but would provide some amount of attenuation of RF noise that might be riding on it, the RF perhaps being generated within the wall wart itself if it is the non-linear (switching) type.

Best regards,
-- Al
bryoncunningham OP
890 posts
 
Thanks, Al.
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davehrab
380 posts
 
Funny story ... a few weeks back I attempted to leave you this link FERRITES on Ferrites ... thought it might be helpful at that time and I knew you would be very interested

The post was very short something like ... Check [this] out ...

After a day or so .. my post never appeared in your thread ... and I couldn’t figure out what was so derogatory or in conflict ???

Shortly after that I received a email from A/gon a day or so later saying ... Thank you for your submission but we are afraid we can post it as it is .. “To Short” .. and would take up valuable space in the archives ... please lengthen your post and resubmit

So this is my attempt at lengthening the post and getting you the info I know you will appreciate

Here’s another link at chasing RF sources in your house RF interference

HTH Dave

bryoncunningham OP
890 posts
 
Hi Dave - Thanks for those links. They are very informative.

As far as A'gon rejecting your post because it was "too short," that is just strange. And arbitrary. My last post on this thread was two words long.

What's more, it seems like I've been hearing more and more A'gon stories of people whose posts are being rejected for one reason or another. Maybe there is new management in Moderatorland.

While I certainly understand the need to moderate forums for content that is truly objectionable, one of the things I always liked about A'gon is that it erred on the side of permissiveness rather than censorship. Not long ago, I joined another audiophile site, where 3 out of my first 15 posts were edited by a moderator. It was creepy. I stopped posting there altogether.

Whether it's in the virtual world or the real world, the excessive control of speech has a chilling effect on the exchange and progression of ideas. Let's hope this trend doesn't continue.

Bryon
bryoncunningham OP
890 posts
 
Update for anyone still interested in my adventures in EMI/RFI reduction...

Three more changes:

--I replaced the unshielded power cords for the power conditioner, the preamp, and the amp with shielded power cords. An improvement, even though I went from three $1100 cords (Shunyata Pythons) to three $100 cords (Pangea AC-9's).

--I added copper "sleeves" to the ends of all power cords in the system, as described here.

--I wrapped the external hard drive where my music is stored with TI Shield.

All three were improvements, but the biggest and most surprising improvement was wrapping the external drive with TI Shield. Don't know what to make of that.

FWIW.

Bryon
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