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I amplified my home's Wi-Fi with aluminum foil

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Re: I amplified my home's Wi-Fi with aluminum foil

#171

Post by kbenson »

walshemj wrote: post #163
kbenson wrote: post #47

Earlier quoted context omitted.

The consumer and frugal shopper in me sees the $400 price point, and doesn't think it compares favorable with a few dollars worth of aluminum foil.

Beware cheaping out on wifi kit I have bitter experiance of trying to use POS dlink kit to provide wifi in our new office. But for home use multiple AP's with powerline to connect them is actualy a simpler solution than mesh as using wifi for the DS (distribution system ) is always going to be slower than a wired.

I agree, and I have multiple through a wired back end, but due to very congested spectrum usage in my neighborhood, I I have less than stellar reception at certain times in my home office (a walk in closet with no physical network hookups) which is about 30 feet over and up a floor from the closest AP. A little coaxing of the waves might go a long way for me.

Re: I amplified my home's Wi-Fi with aluminum foil

#172

Post by jacquesm »

walshemj wrote: post #161
jacquesm wrote: post #84

Earlier quoted context omitted.

Gain is effectively the same as amplification, any kind of gain achieved in a passive manner indicates some kind of directional compromise. It also should work equally well when receiving and transmitting, whereas an amplifier would work for only one direction (so you'd need two, one to output more power, another to amplify the received signal).

But technically there are legal maximum emitted powers unless you are "a professional"

Fortunately the legal maximum is total radiated power and not 'power radiated in one particular direction'.

I did some pretty interesting stuff with 19 element Yagi's and very low power transmitters.

Re: I amplified my home's Wi-Fi with aluminum foil

#173

Post by jdietrich »

pishpash wrote: post #50
Aloha wrote: post #49

I don't think this is working the way he thinks it does. What he's likely do is shielding the wifi receiver from co-channel interference, which is likely reducing the noise floor at the AP - which is giving him effectively more range, because now the AP can hear stations that are further away with greater ease. I don't think this is giving expanded tx coverage lobes as his diagram indicates, its likely a function of…

Yeah, something so imprecise isn't likely to work as he thinks. Proper shielding can do a lot more. If you made your house/apartment a Faraday cage and eliminated neighbors' AP's that would already solve most problems.

Just move to the 5.8ghz band. There's an extra 50MHz of bandwidth available and these frequencies are much more strongly attenuated by walls. There's also usually much less interference from other unlicensed equipment like cordless phones, baby monitors and microwave ovens, although you can occasionally get hosed by a dodgy Chinese video sender operating at well above the legal limit.

You might need to replace a couple of older pieces of equipment, but it's a hell of a lot cheaper than turning your house into a Faraday cage.

Re: I amplified my home's Wi-Fi with aluminum foil

#174

Post by alinspired »

arghwhat wrote: post #168
alinspired wrote: post #110

Earlier quoted context omitted.

This particular example of yagi for wifi - what's the logic to customize it for my router ? In short, I'm looking for logic to repeat this for my router's dipole antenna and possibly with custom wires (not #14 or paperclips of unknown thickness mentioned there)

As you already have a working dipole (which you have in this case), the primary thing to consider is the element lengths and spacings. If you don't have one of those routers with massive (and empty!) plastic antennas, there's probably a good chance that you can use the authors design parameters. Otherwise, there's plenty of 3-element Yagi-Uda calculators online where you can stuff in various amounts of parameters and…

Thank you, arghwhat

Re: I amplified my home's Wi-Fi with aluminum foil

#175

Post by arghwhat »

jedimastert wrote: post #139
arghwhat wrote: post #56

If you want to to do this "properly", see http://ham-radio.com/k6sti/wifiyagi.htm When messing with antennas, things like distance needs to be thoroughly calculated. Foil can help in many ways, but it can also make things worse—antenna calculations are tricky.

Does anyone know what program the author is using? It looks interesting.

I don't know that specific one, but there is plenty antenna simulation/modeler/optimizer software out there.

Re: I amplified my home's Wi-Fi with aluminum foil

#176

Post by i386 »

jpalomaki wrote: post #116
mrtksn wrote: post #37

It can work surprisingly well, I made a "dish" with an aluminum foil that was able to connect to a Romanian Wi-Fi hotspot from Bulgaria, according to Google Maps it should be something like 20KM distance. I should note that I had direct view of the town as I had significantly higher altitude. The hotspot was some kind of public service provided by the Romanian town as it's name suggested. The ip WhoIs also confirmed…

Old trick is to use Pringles (or other) can as directional antenna: https://www.makeuseof.com/tag/how-to-make-a-wifi-antenna-out...

I used one of these for six months when I moved out of home at 18. I was broke and saving for a wireless connection fee (expensive back in 2005!). When the AP I was using went secure, I'd just point to a different part of the city and repeat.

Re: I amplified my home's Wi-Fi with aluminum foil

#177

Post by e12e »

pjc50 wrote: post #127
throwaway613834 wrote: post #96

Earlier quoted context omitted.

> It's not needed to do it in both ends. Naturally, improving both antennas is better than doing in only one, but every improvement in sending is completely equivalent in receiving for a system that uses the same antennas for both directions of communication. Does this actually make sense to you? Gain is a factor; it needs to be multiplied by something. Here's the obvious thought-experiment: consider an (ideal) parab…

> Light will come out parallel No it won't, it's diffraction-limited. The best you can theoretically do is an https://en.wikipedia.org/wiki/Airy_disk You cannot construct, with any arrangement of mirrors or lasers, a beam that does not diverge.

I'm not going to get into to the "gain wars" (yes, text bok, real-world you can have just one "good" (high gain) antenna, and it will work just fine for send and receive) - but your answer prompts the obvious question: What about lasers? Turns out, before optical lasers there were masers - microwave lasers, bit they were (are?) very limited power:

https://www.scientificamerican.com/article/first-practical-m...

Re: I amplified my home's Wi-Fi with aluminum foil

#178

Post by Foivos »

aylons wrote: post #94
throwaway613834 wrote: post #86

Earlier quoted context omitted.

This seems great for sending but how does it work for receiving? Or did you somehow do this on both ends?

It's not needed to do it in both ends. Naturally, improving both antennas is better than doing in only one, but every improvement in sending is completely equivalent in receiving for a system that uses the same antennas for both directions of communication. So, if a new antenna in client side improves signal reception by 3dB, it also improves transmitted power by 3dB. If you used the same antenna on the other side, t…

It has been ten years, since I had antenna classes in the uni, so I might be wrong, but I do not completely agree.

Gain is the same in both ends, but my concern about receiving is that gain is applied to everything. This includes interference and noise. So at the receiving end if the SINR is already bad, the antenna gain is not going to help much. This is why you apply the "Low Noise Amplifier" right after the antenna. To make sure that an already bad SINR will not get even worse in the rest of the receiving stages.

Re: I amplified my home's Wi-Fi with aluminum foil

#179

Post by orionblastar »

coolandsmartrr wrote: post #152
jpalomaki wrote: post #116

Earlier quoted context omitted.

Old trick is to use Pringles (or other) can as directional antenna: https://www.makeuseof.com/tag/how-to-make-a-wifi-antenna-out...

I remember seeing that in Mr. Robot.

Mr Robot tries to stay as true to hacking as it can.
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