15 ms·
I amplified my home's Wi-Fi with aluminum foil
- kleer001 9y agoPut 'em just behind the antenna like a dish aimed toward where you want to bend the signal to. It's not great, but it's cheap and easy.
- niwde 9y agoHave you tried something similar before? Does it work?
- nugi 9y agoI have, it is hit and miss. But was enough pf a hit to stay in use for over a year back in the 802.11b days. Grounding the reflector should also help iirc.
- bonzini 9y agoWhen I had my WiFi router in the basement I placed it in an aluminum oven dish, so that the reflection went towards the ground floor. It was a small but noticeable improvement.
- godelmachine 9y agoI am using my neighbors WiFi, which I can only catch in my balcony. He stays above me, but diagonally opposite, so the source is quite away. Any way I can amplify the WiFi strength? So I need the source to be around in order to amplify?
- FreeFull 9y agoYou can put the dish on either end, although if you don't have some sort of external wifi antenna, it'll be trickier
- godelmachine 9y agoI am using my neighbors WiFi, which I can only catch in my balcony. He stays above me, but diagonally opposite, so the source is quite away. Any way I can amplify the WiFi strength? So I need the source to be around in order to amplify?
- niwde 9y agoI think the source needs to be strong. I'm currently using a wifi extender and noticed the speed isn't good when I move the extender to a room further from the source.
- walshemj 9y agoThat is because range extenders just rebroadcast so you cut your bandwidth in half with every hop
- cipherzero 9y agoLookup cantenna which was popular back in the day for catching WiFi from further away spots.
- ourmandave 9y agoSaw a vid on youtube where a guy uses a metal kitchen strainer as a dish antenna for his laptop wifi out in the middle of farm field. The 'available networks' list shrinks and grows as he points it in various directions.
- godelmachine 9y agoWould you kindly post link to that video?
- knolan 9y agoFirst thing that crossed my mind.
- slantyyz 9y ago
- sarreph 9y agoI was thinking of doing something similar a few days ago but came to the conclusion — perhaps wrongly — that the inevitable creases in a DIY aluminium foil sheet would render it ineffective as a dish, due to the scatter created. Anyone more knowledgeable able to chime-in on the effect of creases here? I couldn’t find any mention of it in the article...
- ohazi 9y agospeed of light / 5 GHz / 4 ~= 1.5 cm. If you can keep the size of the largest crease/feature/defect in your foil smaller than this, you should be okay.
- sarreph 9y agoWow, thanks for this — I did HS-physics but much of my knowledge has since left me... :) Would love to dig into the science behind this a bit more — I don't really know where to start — i.e. why you're dividing by four. So as not to waste your time, is there a named phenomenon that you can link me to to learn more about this? Thanks again!
- dukes_haven 9y agoI would also like to know this. I don't know if there's a save function in h.news or not so leaving a comment
- sp332 9y agoIf you click through to the comment, you can "favorite" it and then it shows up in https://news.ycombinator.com/favorites?id=dukes_haven&comments=t https://news.ycombinator.com/favorites?id=dukes_haven&commen... which you can also find on your profile page under "favorite comments".
- j1elo 9y agoWow. I'm one of today's lucky 10,000. Thanks!
- NicoJuicy 9y agoDid that a while ago, when the trees have leaves, I hardly receive WiFi in my shed. So I put a aluminum foil when I went to the back around the router. It worked, but other directions are difficult. I also had success by changing the channel with less interference in my router settings.
- joniels 9y agoWhat´s the 'household shelter' for?
- always_a_novice 9y agosome countries mandate civil defense shelters in private dwellings, switzerland and singapore both come to mind.
- hopscotch 9y agoSwiss law does not require shelters in all private dwellings, (you can pay a small amount at the time of construction for a place in a communal shelter) and I'm not sure that even that is required any more. Large public buildings maybe still need shelters by law.
- tinytim69 9y agoMandatory in Singapore houses. Practically used for live-in maid or general storage. But effectively involves a massive metal box in the middle of your house. Given the information (a.o. Sunlight as a electrical contractor) in the blog the OP is living in Singapore. The red circle in his first image will like be much more distorted in practice by the bomb shelter, meaning his home WiFi will have a lot of trouble reaching whats behind the shelter (i.e. the bathroom and the Mr Bedroom in particular). Basically he got a pretty horrible spot for his router. Study/bedroom3 would have been substantial better.
- JustSomeNobody 9y agoI have done that before except I went to HD and bought some aluminum flashing and made a corner reflector. Worked really, well and looked a bit ... tidier.
- aknfo1341 9y agobetter off just getting some patch antennas and using them.. though that's more expensive then foil, it does give you better control of the directions.
- oleh 9y agoDo not tilt the antenna though. Maximum emission of an dipole is perpendicular to its axis.
- flattone 9y agoThat seems intuitive and useful.
- jacquesm 9y agoOn occasion, going against the grain (in case of interference from another transmitter) can help if you can polarize the signal somehow. https://en.wikipedia.org/wiki/Dipole_antenna https://en.wikipedia.org/wiki/Dipole_antenna Of course you'd have to do the same thing at the receiver.
- walshemj 9y agoyou can for point to point use multiple ap with anteneas using differently polarised antenas - to increase the bandwidth
- pimlottc 9y agoA bit off topic, but what is this page doing, loading almost 500K in 2 XHR calls for approximately 9K of text... Egads, all the images are inlined data URIs! I was staring at a blank page with a single image for over 10 seconds before the article text loaded. No loading indicator or anything.
- spiznnx 9y agoThanks, I tried multiple browsers before I read your comment. It took 30s for me.
- zeep 9y agotook about 2 seconds for me but yeah, it almost feels like they are using huge web fonts with no default local fonts... (probably not the case because I usually disable web fonts)
- Sir_Cmpwn 9y agoThere's no reason for this content to use JavaScript at all. I'm going to start holding this up as an example of why browsers shouldn't have JavaScript at all - many developers simply don't understand when not to use it. Educating them one at a time won't fix it.
- Raphmedia 9y ago> There's no reason for this content to use JavaScript at all. How else would you add live comments without JS? This page is effectively a big chatroom. You can write at the bottom of the page and the website fetches the new messages async. Don't tell me you would have a big http refresh every 5 seconds to load in the new chat messages, that's even worst than using JS.
- Sir_Cmpwn 9y ago>How else would you add live comments without JS? This page is effectively a big chatroom. You can write at the bottom of the page and the website fetches the new messages async. Why on Earth does it need to be some kind of live chatroom? Just render them server-side and add live updates as a nice-to-have if JavaScript is enabled.
- mrtksn 9y agoIt 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 that it was a Romanian one. Every now and then the connection would have had slowed down and I would do some "Voodoo magic" on the aluminum foil to fix it(Not sure if it was me though, it seemed like if I move the dish slightly or fix a bump in the foil the connection would improve). This was probably like 7-8 years ago and I was able to get something close to 6-7Mbps as far as I remember.
- gchokov 9y agoAre you from Svishtov? Cheers buddy. I did something similar to OMV free wi-fi from my balcony :)
- throwaway613834 9y agoThis seems great for sending but how does it work for receiving? Or did you somehow do this on both ends?
- gonzo 9y agoMost antennae are retro directive. Gain is gain.
- throwaway613834 9y agoI replied here: https://news.ycombinator.com/item?id=16012484 https://news.ycombinator.com/item?id=16012484
- aylons 9y agoIt'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, the 3dB would be added again in both reception and transmission, for a total gain of 6dB each direction.
- hallz 9y agoThis kind of hack was really popular when wifi was first being adopted. These reflectors work best when they are spaced according to the wavelength. Here is a template I remember seeing years ago: http://www.freeantennas.com/projects/template2/ http://www.freeantennas.com/projects/template2/
- girishso 9y agoYes, I was using this freeantennas antenna few years back. Worked pretty well to extend the range.
- Toast_25 9y agot looks neat, but it doesn't tell you how far away you should place it or how big to make it. Am I misssing something?
- tripzilch 9y agoI'm going to guess that the image is supposed to be printed on a standard-sized piece of printer paper (before laminating). Going to guess "US Letter" 8.5x10" (215.9x279.4mm), but to be certain check the aspect ratio, if it's close to 1.414 then it's probably supposed to be A4 (210x297mm). And make sure that the square prints as a square :) Then you follow the assembly instructions, which are indeed a bit minimal; The six "bumps" (called "tabs" in the instruction) sticking out the "Windsurfer" part are probably supposed to stick into the six cut-lines of the rounded rectangle piece you cut out from the bottom of the sheet. This will make the "Windsurfer" part a particular curved shape. I suppose this is the "reflector", so you probably should glue the aluminium foil only to this part. Then there's the two crosses on the "Windsurfer" part, which you also cut out with a sharp knife, and seem to me to be just the right kind of holes to pierce the whole thing on a wifi-antenna. Get the picture? Some kind of photo of the finished end-result would have been nice indeed :) Disclaimer: I know almost nothing about radio signals or antennas etc, the above is just my interpretation of the instructions on the site.
- myrandomcomment 9y agoThe geek in me loves stuff like this. The old and jaded techie in me says just get something designed to solve the issue like: https://eero.com https://eero.com or the UniFi Mesh :)
- city41 9y agoFrom eero’s site: “From the window to the wall” — using pop culture references is risky when you don’t understand them.
- dmourati 9y agoSkeet skeet skeet.
- kbenson 9y agoThe 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.
- walshemj 9y agoBeware 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.
- kbenson 9y agoI 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.
- barbersturgeon 9y ago
- Nux 9y agoReminds me of this guy who used the same technique on the receiver: https://youtu.be/VZKc3PBs67c https://youtu.be/VZKc3PBs67c
- libeclipse 9y agoAha I did something similar to this a while back. Had an ancient computer with a $2 WiFi dongle very far from the access point. It could barely sustain a connection, never mind actually doing anything. So I cut up the neck of a bottle, covered with aluminium foil, and even added a little reciever at the focus point of the dish. Signal bars went to a solid usable III.
- Aloha 9y agoI 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 lowering the noise floor that gives the extra coverage.
- pishpash 9y agoYeah, 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.
- B1FF_PSUVM 9y ago> If you made your house/apartment a Faraday cage Might put a crimp on your cell phone reception ...
- komali2 9y agoIs there a way to build your Faraday cage to block out wifi wavelengths but not cell phone ones? How far apart are they?
- bitdivision 9y agoYou could likely block anything over 2.3 GHz and get away with it: https://en.wikipedia.org/wiki/Cellular_frequencies_in_the_US https://en.wikipedia.org/wiki/Cellular_frequencies_in_the_US
- Aloha 9y agounless you have Sprint ;-)
- 9y ago
- desireco42 9y agoI got this guy and this allows me to read / play games in my bathtub https://www.aliexpress.com/item/Original-Portable-Light-Weight-Xiaomi-Mi-WiFi-300M-Amplifier-2-Expander-for-Mi-Router/32789948233.html https://www.aliexpress.com/item/Original-Portable-Light-Weig...
- snowpanda 9y agoHow is this only $6? It looks great.
- arghwhat 9y agoIf you want to to do this "properly", see http://ham-radio.com/k6sti/wifiyagi.htm 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.
- jacquesm 9y ago> antenna calculations are tricky. Especially at high frequencies. One of the first things I did when I got access to a computer as a kid was to write an antenna calculation program for Yagi antennae. Impressive gain by the way, a factor of 8 (almost 9 dB) from that super simple mod.
- topspin 9y agoDone wrong this will increase reflected energy at the feed point and make the transceiver run hotter than it is supposed to, possibly leading to an early failure. Measuring SWR at 2.4/5 GHz requires some expensive instruments; note that the link you provided has only "calculated" SWR, not measured. Wifi doesn't involve much power, but these low cost Wifi transceivers are engineered with rather limited headroom for reflected energy and shipped with antennas that work within those limits, so if you do this you're a test pilot; there is no complaining if it lunches itself.
- arghwhat 9y agoAs long as you're not running a high-power transceiver (i.e. not consumer gear or consumer gear out of legal spec), I would not be worrying about SWR problems. Consumer Wi-Fi chipsets are designed to be fairly rugged. They normally operate nowhere near their limits.
- alinspired 9y agoThis 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)
- arxpoetica 9y agoWhen we were kids we took massive mesh wire frames and wrapped them around the receivers of these kind [1] of dinky walkie talkies. It fully extended the range by a whole two blocks. We thought we'd invented sliced bread. [1] https://img.segundamano.mx/medium/32/3227658794.jpg https://img.segundamano.mx/medium/32/3227658794.jpg
- stygiansonic 9y agoWow, I had the exact same set of walkie talkies as a kid! That image certainly brought back some memories! :)
- logicallee 9y agotheoretically, are there any regulatory issues on a piece of aluminum sold (and marketed) for this purpose? if not, why aren't there cheap and effective such designs on alibaba - why have to DIY?
- ars 9y agoNo regulatory issues. The aluminum acts to increase the antenna gain (i.e. concentrate the signal in a particular direction). The total power does not increase instead you take some from one place and add it to another. There are tons of products for sale. You can get a replacement antenna that is a directional dish for example, instead of the typical omnidirectional dipole (stick).
- cesarb 9y ago> No regulatory issues. The aluminum acts to increase the antenna gain (i.e. concentrate the signal in a particular direction). AFAIK, many countries limit the EIRP, which increases with the antenna gain.
- tzs 9y agoCorrect. In the US, for example, for 2.4 GHz point-to-multipoint, EIRP is limited to 4 watts, and maximum power to the antenna is limited to 1 watt. So, if your router does 1 watt, you are limited to a maximum 6 dBi antenna gain. Lower the router power, and you can use higher gain antennas. It's more complicated for 2.4 GHz point-to-point. At 1 watt transmitter power you are allowed a 6 dBi antenna. But for every 1 dBi you reduce transmitter power, you are allowed an additional 3 dBI of antenna gain to a maximum of 30 dBi antenna gain at 160 mW transmitter power. 5 GHz has even more complicated rules, I believe. See: https://www.air802.com/fcc-rules-and-regulations.html https://www.air802.com/fcc-rules-and-regulations.html
- vvanders 9y agoOr if you get your ham license you have a limit of 1500W PEP[1], just plug your callsign into the router ID and away you go. However that means you're also subject to no encryption or business related traffic. [1] http://www.qsl.net/kb9mwr/projects/wireless/allocations.html http://www.qsl.net/kb9mwr/projects/wireless/allocations.html
- agoodthrowaway 9y agoSlight nit there's no amplification here just focusing to make the field more directional.
- jacquesm 9y agoGain 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).
- walshemj 9y agoBut technically there are legal maximum emitted powers unless you are "a professional"
- jacquesm 9y agoFortunately 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.
- k__ 9y agodoes this stuff work with walls? I have a basement with thick walls.
- elliottcarlson 9y agoIt would mostly depend on what is in the walls
- k__ 9y agoBricks and concrete, I guess
- yarg 9y agohttps://www.youtube.com/watch?v=LY8Wi7XRXCA https://www.youtube.com/watch?v=LY8Wi7XRXCA
- shmerl 9y agoI've heard it works for 802.11n. Does it work for 802.11ac?
- SagelyGuru 9y agoFor optimal results, place the reflector at distance d = c / 2f behind the antenna (half wavelength). Where c is the speed of light and f is the frequency of your wifi. For example, for 5 Ghertz signal, that will be 30mm.
- stinos 9y agoHow exactly does this work? Especially in the case of a signal which isn't a perfect sine Wifi where (AFAIK) 5Ghz is merely the frequency of the carrier which is then modulated or so? Or maybe it's like 'close enough'?
- Havoc 9y agoIt has an effect, but much smaller than hoped in my experience
- aryamaan 9y agoIs there a way to see the tangible output of the coverage? How is the author drawing those diagrams? Can I map my room with the strength of wifi signals at different points? I want to do these small hacks but also want to see the change validated in some way. Any pointers will be appreciated.
- kebman 9y agoI only use aluminium foil on my head! To prevent mind reading, of course!!!!1!
- fulafel 9y agoSee also: http://mentalfloss.com/article/515193/researchers-develop-cheap-way-improve-wi-fi-coverage-aluminum-foil http://mentalfloss.com/article/515193/researchers-develop-ch... ("Researchers Develop a Cheap Way to Improve Wi-Fi Coverage With Aluminum Foil")
- jerianasmith 9y agoThat reminds of an article written by Amit Agarwal in which advocated the use of aluminum foil to increase Wi-Fi signal. The more things change, the more they remain the same.
- lpmay 9y agoFor the antenna case (and I believe for the optics case too, but I'm not an optics guy) the beam disperses as 1/r^2 in both cases. In transmit , the reflector provides focusing, which puts more power in less of the volume. In receive, the increased aperture allows the antenna to capture a greater area of the incoming wave giving more receive power. The effects are equal and usually just thought of as"gain" which is reciprocal for transmit and receive.
- erikb 9y agoIt's a little bit a shame, that this is not a standard solution for most IT related people, wouldn't you say?
- jypepin 9y agoI just got back home for the holidays and made fun of my dad for doing this. Seems like it is working tho!
- madengr 9y agoJust keep in mind you need some antenna diversity for the MIMO to work. Adding the foil increases the directivity, which you don’t want for MIMO. Though it improves fringe reception, it may reduce the data rate for devices that already have sufficient SNR.
- presto8 9y agoThis blog is missing a lot of details before we can consider this experiment successful. Most importantly, what is the usable throughput of a station in the "improved" coverage area? I would recommend using iperf before/after to see if there is any practical benefit.
- doomjunky 9y agoThis is called Beamforming. Look it up.