Faraday cage for coil building / calibration

[cristiano.sar]

I live in an EMI infested area, lots of wi-fi networks and some powerlines (low voltage: 220v).
I was thinking about making a faraday cage to test my built coils.
Has someone did something similar?
I'm thinking using a screen like that in the image, or should I use one with smaller holes? Also, should I connect the cage to ground?

Thanks.

[Nightryder]

I have never done anything similar. But I would definitely try aluminum foil first and see before I buy anything expensive. Who knows, it might just save the day. I'm not sure how big you want to go with the cage, but I would start with a mid-size box or even a large one like dishwasher or fridge kind of large. I do not know anything about the screen in the image, but I assume you made sure it's a non-ferrous metal and meant for your kind of project. Grounding any Faraday Cage is not a bad idea (in general) safety wise, it's not necessary though but you've got to ask the obvious question: what if the cage itself is going to be detected by the MD coil?

If you proceed with this project, I hope you share it in the forum as I think you are the first person who does it here. Any info, regardless of failure or success, would help all of those who follow your lead. They even might call it Cristiano Cage

GoodLuck!

[EL NINO]

Some time ago I thought about making a folding shielding shelter - for testing EMI detectors .. - where I would use a metal shielding insect net with very small meshes ... 1.8x1.8mm ..

something similar to this metal insect screen..

https://www.kinekus.sk/siet-na-hmyz-zn-100-cm-x-30-m/

[nejdet]

https://www.youtube.com/watch?v=0hGTZBBpHBs&t=613s

Watch the video from the 10th minute on.

[cristiano.sar]

https://www.youtube.com/watch?v=0hGTZBBpHBs&t=613s

Watch the video from the 10th minute on.

Nice video! Thanks for sharing, I have seen that video in the past but never payed attention to that part.

Thanks.

[Carl-NC]

When I was at White's I had the maintenance guys build a second screen room. As is turns out, it required 2 layers of screen mesh: one steel mesh and one copper mesh. Both are the kind you put on windows. The copper stuff is pricey so we tried with steel only, didn't work well. Then we tried a 2nd layer of steel, still not very good. Removed the 2nd steel layer and added the copper layer, worked good.

[cristiano.sar]

When I was at White's I had the maintenance guys build a second screen room. As is turns out, it required 2 layers of screen mesh: one steel mesh and one copper mesh. Both are the kind you put on windows. The copper stuff is pricey so we tried with steel only, didn't work well. Then we tried a 2nd layer of steel, still not very good. Removed the 2nd steel layer and added the copper layer, worked good.

Thanks, I will do some tests with some materials because copper is really expensive.

[Riss]

aluminum foil for cooking purposes – https://drebolii.com/aluminevo-folio . it is cheap . the mesh must have holes smaller than the wavelength – for 60 GHz -0.5 cm ( 5G )

[Skippy]

I agree with Riss : no holes, or small holes, as the freqs you are trying to block will certainly be up to 2.4Ghz. And if you use sheet material, like kitchen aluminium foil, you will need to solder any overlaps pretty thoroughly, a solder join every 2cm or closer.

There is an e-book pdf of an EMC book by Henry Ott out there on the webs. That may contain some relevant information in its pages.
Here's one source:
Books Archives - Electrovolt

( I don't know if it is legit or pirated, apologies if I shouldn't have posted the link )

[Riss]

I have this book from a student and I highly recommend it - very understandable and clearly written..

[EL NINO]

That's why I suggested.a metal. insect screen,, with meshes around 2mm...

Sure. a really good move is also.as Carl suggests..you can use double shielding..for even more thorough elimination of Emi...

[Alexismex]

It is very difficult to isolate cellular I-phone with mesh inside a box , you must try!!! , only is very closed copper double meshes works !!!You will have doubts about the wavelength theory!!!