Finally. Yes, I finally got around to making a cantenna. Years ago I read about the now famous Pringles Cantenna which I've always thought was a cool concept and has been something I've wanted to do. Now it's a bit of use to me since I enjoy using my laptop on the move using NetStumbler to locate open access points.
I began with a bit of reading and looking up what all is needed to construct a Pringles cantenna, and before long I learned that the Pringles isn't really the best way to go. Nope, instead I found that the Pringles design was out performed by a Cantenna made from a can of beef stew! Not only does it perform better, it's way easier to make. In fact, after buying the ready-made 1.21" radiating element from jefatech.com, this construction was probably the easiest project I've attempted. I found out that a large can of Dinty Moore is the same size as the "Nally's Beef Stew", so guess what I had for dinner one night? I cleaned out the can, and went to the machine lab the next day to use a drill press to pop a 5/8" hole for the N-connector. Took it home and tried it out. Wow! I went from seeing 1 AP (mine) to 20, just in my front yard. Not bad for just a can with a connector on it. I then took a stroll to see what the neighborhood has to offer and found an open Netgear access point. After zeroing in on the source, I found that it was about 120yds from my original location and across a street! (...and that was being able to use it, I was able to detect at a further distance.)
Fine and dandy, but the can just wasn't good enough on its own. I had to do more. I added a 6"-to-4" heat pipe coupler to the front end to funnel in more signal, which I had seen on a cantenna made from a Pirouette can. (Yeah, I made one of those too. Just today, in fact.) The funnel gave me a noticeable difference in signal strength when I'm at a distance. I think I remember seeing it jump about 3dB in signal strength after I slipped it on. (That's a doubling of power!)
In case you missed the links:
Here's the original can.
Here it is with the funnel (kinda looks like a flashlight)
Inside the cantenna (radiating element is about 1.21" long)
The new Pirouette model (yet to be field tested)
Grendel sez: For those wanting to make one too, I just learned that the large 40oz can of Walmart brand ravioli comes in a similar can and it's a couple bucks cheaper. (guess it depends on how much you like beef stew vs. ravioli.)
FYI - Can dimensions: 3.9" diameter, 6" long