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4km WiFi Range w/ $5 DIY Antenna
Mignon writes "This industrious fellow in New Zealand made his own WiFi antenna using a USB WiFi adapter and a Chinese 'spider skimmer mesh scoop.' He got about 17 dB signal improvement for about US $5 in materials." Update: 05/25 23:09 GMT by T : Reader
John Stockdale offers a U.S. hosted mirror of the site. Update: 05/26 13:58 GMT by T : Reader Jared Mauch contributes another mirror.
All he needs now is a signal to pick up. {laugh - it's funny}
OS/2 - because choice is a terrible thing to waste.
If it was omni-directional, then I'll be very impressed, but you can make a pringles antenna for very cheap, and get about 10 miles range (line of sight).
The best way to predict the future is to invent it. -Alan Kay
There was a story about freecache, but no one here on slashdot ever uses it in stories. Here's a pre-cached link, in case the main NZ server goes up in smoke. http://www.freecache.org/http://www.usbwifi.orcon. net.nz/
Still, impressive gain for $5 worth of parts. Makes me wonder what I'll get if I can ever find the right connector for my Linksys wireless router to hook it up to standard coax and a pizza dish I took out of a dumpster.
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
General Tso's Access Point.
The only acceptable defense of scientific results is to say that they were the product of the Scientific Method.
it has other uses as well. If you wrap your head in this spider silk mesh it is even more effective at blocking the evil thought control waves than tin foil!
I wonder if there are hidden shortcomings to this technique. If it only costs $5, I would think that manufacturers of wireless access points would have implemented this a long time ago (or at least made it available as a $40 add on). After all, there *is* a market for it, and at least some people would buy such a device.
I guess it's a neat hack if that's the only way to communicate with your friend 4Km away, and you only have one friend (or your one friend has a nice network connection to the rest of the world and is willing to share).
Am I part of the core demographic for Swedish Fish?
http://www.stanford.edu/~jstockdl/tmp/usbwifi.orco n.net.nz/
...
Mirrored as much as I could of the images before the server was smoked.
-S
**AA: a bunch of mindless jerks who'll be the first against the wall when the revolution comes
Good to know some people are still trying to improve technology remembering that not everybody has 1 trilion dollars a month to spend on over-priced gadgets.
Good work!
Piece of number eight wire reputation.
Hmm, now I feel sadly parochial.
In theory for a transmitting antenna, there is no limit to how much gain you can get. Gain is the ratio of received power to the power you would get with an isotropic radiator. To get gain, you just focus the beam tighter. The limit to how tight you can focus the beam is set by the aperture of the antenna. The gain of a receiving antenna is set by its effective area. Gain isn't hard to get.
The bigger problem is to get line of sight. At this frequency, if you can't get line of sight, all the gain in the world won't help.
I lived in Wellington, New Zealand for a while, and I sure hope this guy is using this to steal access from somebody else, not to share his bandwidth with other people. Internet connectivity was very expensive down there, and metered (we had dsl through Telstra). Even the much-hyped CityLink wireless service is pay-as-you-go. But with his $5 setup, this guy can scan around his neighborhood until he finds somebody with an open network, and presto! Free 'net access.
Someone sent up us the Slashdotting
The super cantenna is only 12 db. 17 is more impressive, and should result in greater range.
Range itself is hard to compare, as it depends on environment, the radios used (cheap 35 mW? 200 mW with good receive sensitivity?), whether the same antenna is used on both ends, and the subjective evaluation of what exactly constitutes a "useable signal".
-jim
The airport base station doesn't have a range anywhere NEAR 14km. There are lots of antenna out there for lots of base stations (including the Airport ones) that will give you that range, but Apple has not "had this for years" any more than every other vendor that sells products with the option of adding an antenna.
Hell, Cisco has products that have 25 MILE ranges, with the right antenna.
My sig is blank, I typed this by hand.
Also, to those confused about how antenna gain works. The gain is measured in comparison to the output of an isotropic radiator, basically something that puts out the same signal strength in all directions. So that means that any unamped antenna with a gain higher than 1dBi is directional in some sense, because the total radiated power is still the same. So-called omnidirectional antennas really are only omnidirectional in the horizontal plane, if you go up or down their signal strength drops off rapidly.
"Chinese parabolic cookware"
OMFG is that funny.
- Zav - Imagine a Beowulf cluster of insensitive clods...
I just took a long car trip, relying mostly on (purchased and municipally provided*) 802.11 access, and in preparation for that trip bought a highish-end 802.11 card and extrernal patch antenna, which indeed came in handy.
:)
I considered one of the USB 802.11 donglers, but passed on account of ignorance: Are any of them of Linux-friendly? Are some brands better than others? Can anyone provide reception figures or anecdotes?
It certainly would be nice to have a rooftop mount on my station wagon to which I could as necessary string up a 15' USB cable and thumb-drive-style 802.11 thing
timothy
*Thanks, taxpayers and politicians of Salt Lake City!
jrnl: http://tinyurl.com/c2l8yr / foes: http://tinyurl.com/ckjno5
Yes it does. I've been accessing my Apple base station sitting in my apartment in San Fran from where I work in Oakland for YEARS now. In fact, I even access my base station from AIRPLANES while flying overhead!!!! Apple is THAT GOOD! Obviously you don't use Apple so you wouldn't understand. So SHUT UP.
Of course different areas have different rules, but just about everywhere there are restrictions on antenna gain and power for 802.11. Especially if you are not a licensed amateur radio operator.
These things are unlicensed part 15 devices which have strict restrictions on power output (which includes any gain from directional antennas) and can not interfere with licensed devices like amateur radio operators.
I'll leave it up to the reader to Google for what the limits are in your area since it varies. Just remember that you can't just slap on any super-high-gain antenna and remain legal.
The ratio of people to cake is too big
Not political dangers, not legal dangers, but health risks. This is an unshielded piece of metal that's surely producing signal all over the place. Wi-Fi is microwave radiation. While it's not a big deal for the tiny antennas in cards or bigger antennas that are found on access points, when you start boosting the gain and have directional focus, it's critical for your long-term well being to not spend extended periods of time (or, for higher-gain antennas, any time whatsoever) in the "blast" of the beam. There are well-documented health risks from microwave radiation exposure but only at high levels and short distances.
Because this ad hoc device hasn't been checked out in any fashion, it's possible that even with it facing away from you, you could be subjecting yourself to cellular damage from the microwave radiation. I wouldn't recommend this. The cantenna design is much simpler and safer. Other ad hoc designs at least have parameters that prevent so much signal spew. This one worries me.
Freelance tech journalist for the Economist, MIT Technology Review, Macworld, and others
If he is getting that kind of gain from the scooper, imagine if he used the wok...
Once you've connected to the network, you'll just need to connect again in an hour or two.
Bluejack
I already built one of these things after the site first surfaced a couple of weeks ago. The neat thing about it is that it's modular insofar as your choice of radio goes. Unplug the 802.11b tranceiver, replace it with a usb Bluetooth tranceiver, aim at the nearest bus stop, and wa-la, bluejack city. Want to use 802.11g, or heaven forbid, 802.11a, plug one in! It's the ultimate in modular l33+ hax0r radio toys. Why, I reckon you could even plug an usb IrDA adaptor in there...
No, wait... :-)
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I didn't shop around for best price, etc, etc, 'cos I knew that once this thing hit slashdot, there was gonna be a worldwide stockout on the chinese cookware. I could have gotten things a bit cheaper if I had shopped around, but short of an AUD$1200+ aeroplane ticket to Guangzhou and buying direct from manufacturers, there was no way this setup would cost $5.00 of anyone's money. With time and petrol and driving around, I guess it cost AUD$100.00. Good fun tho, and worth every cent.
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Actually, a lot of products have really long ranges -- right out of the box! I got a Linksys WiFi router and it seems like I can pick up my SSID "linksys" network all over the place!
Heh heh..
There's nothing stopping you (if you leave out the legal), but it wouldn't be all that useful. While an amplifier would boost your output, it will do nearly nothing to increase the signal that you recieve i.e. you will be speaking louder but the person talking to you will still be speaking at the same volume. You may well ask then how an antenna's gain works out overall then, as you are still basically just boosting the wattage of your signal, not the other guy's. The answer there comes from the directionality of the antenna - while the other guy isn't speaking any louder the directional antenna allows you to filter out the noise coming from everywhere else, making it easier to hear what he's saying. Thus with a directional antenna, you're getting two good effects, while with the amp you're really only getting one. Now, OTOH, if you stuck an amp on your rig AND the other guy's rig, then you'd be talking :-)