Coffee Cans ... Point to Point (focussed Wireless)

[XtremeModifier]

Hey,

Between two sites, I have a Linksys Wireless AP with latest flash (patches) and Bridge, and the antenna's are stuck in a hole in the bottom of the coffee cans to concentrate the wireless radio waves in a linear controlled direction in which the cans are a distance appart of about 100 feet and on the roofs of both buildings pointed directly at each other by use of a laser pointer to align. 

I am using the most secure method of wireless with WPA and No SSID Broadcast, and of course changed the password from its default.  The cans work pretty good at focussing the signal between sites and a site survey from the ground before and after the coffee cans shows that it does weaken the signal to unwanted guests at the ground with dead areas, however even with the coffee cans to focus the waves point to point, there is still some stray wave affect.  I am guessing either its bleeding through the metal of the can due to amplitude in a confined space or bouncing eradically our the end  of the can in a somewhat linear, but spanned out vector direction at possibly 45 degrees from the lip of the cans.

Anyone have any suggestions to better focus the signal point to point so that the 45 degree spanning of the waves from the cans wont occur.  This spanning is causing a potential 1 to 4mbps connection at a point directly between sites and where both 45 degree angles from each of the cans meet.

Maybe I need t do away with the coffee cans and try to find two dishes with a controllable focal point for a connection at 100 feet appart without the stray affect like the coffee can.

Too bad I couldnt run cat5 from point to point.  Boss probably wouldnt like that strung from building to building . . .  ha ha   AND... I would get nervous during storms that it could blow out hardware at both ends even with transorbs or MOV's to surge supress a direct hit.

Thanks. . .

Dave

[Sparda]

Anyone have any suggestions to better focus the signal point to point so that the 45 degree spanning of the waves from the cans wont occur.  This spanning is causing a potential 1 to 4mbps connection at a point directly between sites and where both 45 degree angles from each of the cans meet.

Parabolic antenna

A coffee can antenna won't focus the signal, it will only make most it it go in the right directionish, at the very least it will ensure the signal that went the completely wrong direction no longer does. Additionally, because of the physics of how radiation travels through space and around objects it's nearly impossible to ensure all of it goes exacly where you want.

[metatron]

24dBi parabolic mesh antennas are cheap (under £40, I’ve seen a few 30dBi grid antennas but they are expensive). Unless your a RF engineer I highly doubt anyone’s ability to produces a better antenna. You will also need to run the correct cable as if you do it half assed and use cheap shit the signal loss over the run can make the antennas pointless.

[Xidus]

If you had way to much time, a vacuum pump of some kind, some carbon fibre and epoxy, you could make your own parabolic antenna....