Remember when some jokers started selling Faraday cages for Wi-Fi routers on Amazon, claiming that it would protect the user from wireless signals?
Protection
Submitted 3 days ago by HikingVet@lemmy.ca to [deleted]
https://lemmy.ca/pictrs/image/c684c3ed-3bf9-4f74-b805-b817349c626f.jpeg
Comments
j4k3@lemmy.world 3 days ago
This is a 2.4 GHz directional WiFi antenna. Only the back element is connected to the transceiver. All of the other elements are there to focus the signal. Anything metallic within a few feet of an antenna will have a substantial effect on the signal. Think of it as light, because it is, only transparency of materials is a bit weird. The biggest issues will come from metallic materials that are earth grounded and anything with a wire length that is close to the wavelength of the radio light or below, especially around half and a quarter of the wavelength. That pictured wire pitch is spaced very close to the approximate 2.4 GHz wave length. For example most antenna are an insulated trace on a circuit board that is insulated with ground up to a point and then there is a small circuit element that stops the ground and the actual antenna trace continues for the respective light wavelength to transmit or receive. All an antenna is here is an exposed length of single conductor wire.
SupraMario@lemmy.world 3 days ago
That’s just an AP. That’s not a directional antenna for a wireless bridge. You can even read the AP sticker on it.
TachyonTele@piefed.social 3 days ago
All those confident words they typed... for nothing. Lol
SteveTech@programming.dev 3 days ago
I think they were trying to say that the cage in front with the AP behind, acts as a directional antenna. Similar to how Yagi antennas have metal elements that aren’t connected in front of the actual antenna.
But I don’t know enough antenna theory to know if that’s correct.
tgxn@lemmy.tgxn.net 2 days ago
Yeah, It looks like a Cisco Aironet 2702i WAP.
Tja@programming.dev 2 days ago
Even if this was right, which it isn’t, wifi stopped being 2.4Ghz exclusive almost 20 years ago. You have 5Ghz and since 5 year ago or so, 6Ghz, with significantly shorter wavelengths.
zaphod@sopuli.xyz 2 days ago
And if I look at the frequency spectrum I see that all my neighbours use 2.4GHz (9 wifis in channel 8) and I got the entire 5GHz spectrum to myself.
Justdaveisfine@midwest.social 3 days ago
Hmm I don’t think I get this one.
Is it because its in a cage? I don’t think that will do much to block the WiFi antenna.
deegeese@sopuli.xyz 3 days ago
The bar spacing is smaller than 2.4GHz radio waves. It absolutely will affect signal. Should have used a plastic cage.
SnotFlickerman@lemmy.blahaj.zone 3 days ago
Grostleton@lemm.ee 3 days ago
Faraday cages cannot block stable or slowly varying magnetic fields, such as the Earth’s magnetic field (a compass will still work inside one). To a large degree, however, they shield the interior from external electromagnetic radiation if the conductor is thick enough and any holes are significantly smaller than the wavelength of the radiation
I’m certainly no expert, but something tells me the cage in OP’s pic doesn’t fit the criteria to act as a faraday cage.
JasonDJ@lemmy.zip 3 days ago
Wifi is a fickle beast, though you may be right.
The elements of the cage will probably interfere, but won’t straight up block the signal. To be an effective faraday cage, holes in the material must be no bigger than 1/10th the wavelength.
2.4GHz wifi has a wavelength of 12cm, and 5GHz is about 5cm…so holes in the cage should be no bigger than 1.2cm for 2.4GHz, or 0.5cm for 5GHz.
Problem #1 is this AP is oriented vertically on a wall. The antennas in these models are designed to be parallel to the floor, and usually not much higher than 15ft.
TriflingToad@sh.itjust.works 3 days ago
2.4GHz wifi has a wavelength of 12cm
that’s actually massive, I thought it would be like half a centimeter at most
some_guy@lemmy.sdf.org 3 days ago
Maybe if use smaller, tighter squares.
ZeroGravitas@lemmy.dbzer0.com 3 days ago
Faraday was here!
marighost@piefed.social 3 days ago
I'm just impressed they labelled the WAP.
assassinatedbyCIA@lemmy.world 2 days ago
Get a bucket and a mop for that wireless access point
Kolanaki@pawb.social 2 days ago
*Wet Access Point.
ThePantser@sh.itjust.works 3 days ago
They need more “I” in their IT, plastic protectors exist.
Empricorn@feddit.nl 3 days ago
it’s higher than eye-level, they don’t need a cage for it at all. It’s not even locked, just use any old Phillips screwdriver to remove the 4 screws!
JimVanDeventer@lemmy.world 3 days ago
The cage is to protect it from flying balls.
Coreidan@lemmy.world 2 days ago
Why would it be locked???
possumparty@lemm.ee 2 days ago
Yeah boss the RSSI numbers look great!
PixelPilgrim@lemmings.world 3 days ago
The mesh is just about the size of the wifi wage length
pewpew@feddit.it 3 days ago
Oh I see the issue… They forgot to ground the cage
EvilFonzy@lemmy.world 3 days ago
“I see the problem, your AP is in the Faraday Chasity Cage. Closing ticket.”
match@pawb.social 2 days ago
Putting my horny robots in the faraday chastity cage