Cantenna for City-wide WiFi

[bill.n1vux at gmail.com (Bill Ricker)]

Optimum permanent can-based antennas for multi-block wifi
infrastructure was discussed at the InstallFest. Another mailing list
just had linkage to a how-to.
http://www.turnpoint.net/wireless/cantennahowto.html

(The necessary cable connector is usually available at the MIT swap
fest, 3rd Sunday of the month, April-October.)

The Pringles can is too small a diameter to be used as an optimal
waveguide, but it's close and it's cheap. There is debate as to
whether the "metallic foil" lining is an active part of the antenna.
If it is, and the waveguide is just below cutoff, there will be some
attenuation cancelling the directive gain, which is born out in the
"shoot out". The long cardboard tube is still a useful mechanical
aiming device, and the directivity will reduce noise/interference even
if the waveguide cutoff undoes the gain. Modern pringles designs are
not pure waveguide designs any longer but  highly directive  yagi-uda
using washers on a boom as passive director elements.

For permanent installation as opposed to war-driving, the
stew/coffeecan designs are much more desirable anyway.


--
Bill
n1vux at arrl.net bill.n1vux at gmail.com