Need help in making a faraday cage protect against 2.4/5G Hz wifi.
I am trying to make a faraday cage that shields against wifi but it is not working the slightest. The cage is made of stainless steel mesh with 4-4.5mm hole size. The bottom has aluminium foil to ensure continuity and I also grounded the cage but somehow it just does not work. Any suggestions please I am desperate
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I tested this by putting my phone inside and using a wifi analysing app to see if the wifi strength has gone down. I notice that the wifi strength does not react much but the signal has relaibly always dropped down by one bar which is somewhat progress i guess?
I wonder if it's related to the electrical length of the steel wires being longer, because of the really, REALLY low conductivity...maybe try adding a layer of aluminum window-screen?
Something like this? I dont know why i didnt think of this since it has better conductivity
why not regular screen for windows & screen doors? should be plenty inexpensive, and the holes are something around 10-mesh.
https://www.lowes.com/pd/M-D-3-ft-x-7-ft-Brite-Aluminum-Screen-Mesh/1000873354
ohhh okok I see
I can work with that, its gna take some time to deliver do you have any other suggestions to improve my cage while I wait for the new screen?
cover the cave with alu foil from inside and your cage is very thin
cage not cave XD auto correction
maybe heavier wire from the cage to GND...its really hard to "overdo" a good, solid, low-resistance, minimum-length path to GND.
kind of hard to see the screen then, no?
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@robherc gnd is not needed
@robherc with simple phone call can test if it isolated š
please stop...you obviously have no knowledge in this area
@robherc yeh Mrs enistein and you stop making peopel look stupide with your comment
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yep, using a YT vid as a reference...you need no help as you just proved my point RESOUNDINGLY!
...have fun with your FCC fines when you realize that an un-grounded non-Faraday cage only changes polarization.
@robherc go down dont look peopel from hight
stop interfering with misinformation where you weren't asked for & you won't have to be shut down by your betters.
down down
blocked...any further interference will result in reports.
go and report you are always triying with your comment to put peopel down and try to make other look like stupide
@arvincible back on-topic & in the world where physics still follows predictable laws, please try placing the phone at least 1/4-wave distance away from the cage on all sides. ...maybe even just by setting it up on some legos, or a dry chunk of 2"x4", to keep the phone's antenna from being close enough to one flat surface of the Faraday Cage to couple the signal to that one surface preferentially enough to "push through" and radiate in/out efficiently still.
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@ElectrOnooB first rom is correct. You are incorect. Next do not be useing hate speach.
@arvincible as I'm sure you noticed. You will most likely need to be grounded in some manner. And not all screens are the same. Imo copper is great. Aluminum can work, but metal for sure.
What a vague does is obsorm the rf.... if it's not grounded/earthen then it just becomes a capacitor. And over time it's potential rises.
When that happends, it can not longer block rf ans it's efficiency drops letting in rf.
Farter more solid media like a metal box/ aluminum foil/ etc does nothing but dampen the signal.
If you did something like the rushing nesting dalls with box after box inside of each other... yes it will block the signal..if grounded... but if you then picture that design... you have mor or less made a Screen out of solid boxes... so no solid things WITHEN REASON will NOT make a Faraday cague..
I worked in a bank hvalt for a while. And it had to be sealed... keep in mind this was over 12 inches. 1/3m of steal iron concrete and layers and layers....
I had not only wifi in there. But also full cell signal.... proof.
@nis @ElectrOnooB @robherc facts. Droped.
man I was taking a nap what did I wake up to damn
Alright thank you all @Maderdash @nis @Turkish Mercury @robherc @/adeb for the inputs so some improvements I can make rn is
1. Elevate / make distance / insulation between the phone and the overall cage for better results
2. Use a screen / mesh with thicker metal thickness
3. Use a shorter GND wire (Btw where I live we use 3 pin plugs so what I did was just take that plug and just connect the cage to the gnd cord of the 3 pin plug and I just plugged it into the wall outlet just fyi)
Correct me if I am wrong but my takeaway from this is that grounding is important right? I also tried putting my phone in the microwave since I read that its technically a faradays cage and my phone still had wifi and signal inside (Microwave was turned off)
I will update you guys tomorrow when I try again tho it would take a week for the new cage screen to come. I will also try it out with my esp32 reading out the wifi strength while inside and compare the results
I'm sorry, I didn't mean for the window screen to cost you a week. The intention was that it would be something you could pick up at your nearest hardware store š
@arvincible correct u need grounding.
Incorect on the microwave. It's designed to contain high levels of energy.
A microwave is 900. To 1400 watts.
The phone is in the 0.1w range. At its highest.
So 99 percent of 1400 breaks down to letting out.1.4w ish. And as the phone is only 0.1w then that is way under that range.
Keep in mine I'm just useing rough math not actual figures.
I am back and I feel more betrayed then ever...
So some improvements I made to the cage from the last time I was here I did
Added grounding
Improved base to ensure continuity
Layered 2 aluminium meshes instead of a single stainless steel one
Mesh hole size is now 3mm ish
Last week when everything was assembled and done it worked wonders. It obliterated wifi and brought my signal down to 1 bar when it was around 4 without the cage (See pictures for reference)
Now when I test it again the wifi budges slightly and the signal is not bothered at all I really dont know why its the same exact setup.
If it matters my grounding is just a wire connected to the gnd of the 3 pin socket.
Before putting it in the cage (Picture below)
After putting it in the cage notice the signal and the graph showing the wifi strength of nearby networks (Picture below)
This is the setup
I have never felt so betrayed from an inanimate object
or cage
can you show a pic with the phone inside the cage?
...are you using the same outlet each time, or might this be showing you a potential building-wiring problem?
ah sorry I cant take a pic of the phone in the cage because I only have one phone and the screenshot which shows the data when the cage is engaged was taken as fast as I could after taking out the cage since I cant rly put my hands inside and take the screenshot while the cage is closed
I am using the same outlet each time. I also thought it was a wiring problem though its the same setup as last time. Any idea how to troubleshoot to see if its a wiring problem? I can confirm my cage is in contiuity with the base because I did a continuity test
hmmmm....this is part of why I Like "room-sized" cages soo much more...easier ti test when you can open the door, walk in, & close the door behind you, while holding the pgone the whole time š¤£
(also easier to ground at multiple points, because it "feels more reasonable" to drill a few holes thru the floor & sink GND rods through them when you're building a (semi) permanent Faraday-cage ROOM in your lab...lol)
Speaking of which, maybe you you try setting this up on a table outside, with 2-3 GND wires going to metal stakes that you can sink at least 1'(or 30cm) through the grass in a "not drought devastated dry patch"?
Ah sorry for the late reply but that isnt possible. I have to present this and the venue is indoors so I really dont have access to outside. Any other possible solutions Im really scared I spent alot of time prototyping and it worked but now it doesnt and the deadline is nearing
is there room inside the cage for a small "stand" to rest the phone on, maybe even at an angle?
(would look to bystanders like it's just to make viewing easier, but by keeping the phone NOT perfectly centered & also not right next to/against one wall, it should allow the cage to work "at its best" better.
Unfortunately, making indoor Faraday cages, with no available access to "direct grounding" dies tend to open up this problem.
as a "cheat" you could set a cellphone charger inside "to keep the phone charged" & connect the GND shielding from the charge cable to the cage. Having the phone plugged into a charger, with the charger's GND connected to the cage should ground the cage, relative to the phone, & makeup for a "potentially less than ideal" grounding to the building.
yes there is I can make one
oh wow thats creative I will try that js gotta find a way to make their gnds connect
With Faraday cages, if you are using metal with holes in it, the holes need to be smaller than the wavelength of the signal you are trying to block. Make sure there are no gaps at the door. Also, insulating material inside the cage for your phone to sit on - it must not touch the metal of the cage. And ground the cage.
And the word 'cage' can be misleading. Some Faraday 'cages' are solid, thick metal with absolutely no holes.
1/8th of the wavelength for good effect...if the holes are a full-wave wide, your cage will block less than 30% of the signal.