Just a quick correction to the article: The Guinness World Book of Records distance for a wi-fi link is 310 kilometers, and was set by the Swedish company Alvarion.

Alvarion is not Swedish (in fact, it's basically BreezeCom in new clothing), but the record was set with the help of SSC, the Swedish Space Corporation. Slashdot story link here [slashdot.org].

Photo of anntena and team [adversaria...ncelab.net]. Its look pretty cool.

... for the metric users

I couldn't move a single bit of data between two WinXP Home systems sitting RIGHT NEXT to each other! The damn thing doesn't support netwroking...

Errrmmm...yes, actually it DOES support networking.

The shape of the pyramids is fine - IF you're trying to pick up a signal from the center of the earth... the entire angled shape of the horn is designed to focus the inbound radiation smoothly towards the center (peak) of the pyramid shape, where a little tiny antenna actually receives the radiation. Somehow I doubt you can pick up much RF thru 3000 miles of rock. And it's awful hard to beam-steer with a multi-trillion-pound pile of stacked rocks.

Hm, the adversarial science lab site seems to be /.'ed.. On another note, pringles tubes make very good single-axis antennas for wi-fi applications, I've managed to get about a 3 mile range using them!

While it *is* impressive that these people are doing this over 36 miles (56 kms) from non-commercial equipment, IIT Kanpur has already done this [iitk.ac.in] over 40 kms (25 miles) using ordinarily available parabolic antennae (no Pringles available ;)

And, IIRC, there was a project a while back to do the same over 72 miles (which also succeeded)

The once ubiquitous C-band satellite dishes make killer 2.4GHz antennas. Coffee can feed with hairpin and a skyline view of the city = zippy /. participation. These things can be had, usually free for the asking from suburban yards and in exchange for a case or two of beer if the house is on wheels. With a 200mw output power from your card, if my math is right, the effective radiate power will be at least 200Watts for an 8' dish.

and highly illegal, to boot. 200W EIRP is, oh, 196W too much for a PTMP link, although you can play tricks if you're doing a PTP link.

Impressive yes, but typical of what ham radio operators do all the time. (Many of the ASL team members are hams, as was mentioned in the story.) We're always building equipment out of such mundane stuff as tuna fish cans [qsl.net] and coat hangers [freeservers.com], and making contacts around the world.

Except the Pyramids were made of nonconducting sandstone and limestone, and were about as good antennas as say, a small mountain. I.e. they block electromagnetic waves rather than concentrating them. Now if the pyramids were made out of aluminum and duct tape, you may have had something.

How is this informative? So far the most powerful can antenna made without making a custom "can" is made from something like a dinty moore chunky stew can, and it just blows the pringles can away. For those who need more gusto, a used primestar dish and some other kind of can (I think it was a juice can) makes an antenna which, in pairs, can reach ten miles with near-11Mbps-throughput. (Using the cheap stuff.) Those persons just now noticing pringles cans are over a year behind.

I'm sure their success is attributed more to knowing what you are doing in a McGyver'ish way than simply hacking.

Yeah, antennas don't respond well to guesswork.

Most people don't know that an antenna rings electrically the way a tuning fork rings mechanically. There's only a very limited frequency range that an antenna will handle well.

On top of that, as the frequency increases, radio waves behave more and more like light. And problems like stray capacitance and stray inductance - tiny values in farads and henries - become very important design considerations as the frequency increases.

But a well-designed amateur antenna can be very capable. The radio waves don't care if you make the elements out of silver encrusted canine feces, if they're the right lengths.

UHF TV band, around 450MHz. Design is extremely critical here. But by doing a little math first, I designed and built a 12-element Yagi (looks like an ordinary rooftop TV antenna but with more elements) which is tuned to channel 29. It's very directional, meaning I have to be pointed within a few degrees of the transmitter. But I can also watch WUTV Fox 29 from Buffalo, in Ottawa Canada, without shelling out for cable. Cost? Scrap of wood, old coat hanger wire trimmed to within 1/16" of the design dimensions, plastic tubing and clips to hold the elements to the board, old 75-300 ohm matching transformer gutted for its balun and soldered directly to the driven elements and feeding coax. Essentially free. Not waterproof, so it lives in my attic.

It looks like 5G Wireless took the commercial category at the wifi shootout---14.8 mile coverage using their commercially available antenna. I'm not sure how widely known this is but Mcdonalds has a pilot in upstate NY according to this --feb 03 http://www.wirelessweek.com/index.asp?layout=artic le&articleid=CA274448 trades for a few pennies on the OTC bulletin board under FGWC were any of these other wifi shootout companies public? "CATEGORY 5 - Enhanced power, (omni or directional) commercially made antenna Base Camp GPS Coordinates: N36 39.698, W114 55.431 Field Site GPS Coordinates: N36 52.523, W114 57.389 At the base camp: Apple G4 800 MHz Notebook, with 10.2.6 ftpserver, 5G single panel AP, 3-foot tripod, 15-foot mast, angle ~150. At the field site: 4ms 4.26 Mbps, Toshiba Satellite 1135-s1552, P4M 2.0 GHz 512 meg ram, Windows XP Pro ftp command prompt only, 5G CPE 800 mW, 16 dbi circular polarity antenna, RSSI -67 dbm, Noise f