A Cantenna is an antenna made out of a simple can which in most cases can amplify WiFi signals from 5dB to 22dB. Besides amplifying signals it can also increase range of the WiFi network. Making a Cantenna is a very popular DIY antenna technique practiced by a number of networking enthusiasts. To make a simple Cantenna things you need are an empty and dry can, a N type female chassis mount, RP-TNC extension cable, small bit drill and little copper wire.
Here is how to make a Cantenna:
1. Get a tin can whose diameter is under 4 inches or ideally 3.25 to 3.75 inches. Cantennas are directional antennas and therefore the longer the can is, more will be the range and less will be the sweep. With such a decrease in sweep, interference reduces significantly but it raises the need to point the antenna more accurately. A 6 to 10 inch long antenna will increase the antenna gain drastically. If you cannot find a can that is big enough, you can always solder two of them to improve range and reliability of the network.
2. In the centre of the body of the can, drill a hole that is big enough to accommodate the female end of the N type chassis mount connector. In case the can has ribs on its body, your task becomes simple and you just have to punch the hole in the center rib. Since these cans rip off easily, it is wise to avoid a hole-saw and instead use a narrow bit drill. After you have drilled the hole with the drill, it can be widened using a brad point drill bit or a rat-tail knife.
3. Insert a 12 gauge copper wire of 1 ¼ inches length on one side of the N type chassis mount connector. Place the entire setup inside the can with the exposed copper wire going in the can through the hole and secure the N connector to the can using glue or by sealing the edges of the connector in the hole with some garden hose rubber.
4. Take the RP-TNC extension cable and mount it on the RP-TNC female connector. Connect its other end to the WiFi card.
5. Fix the can on a tripod using tape or clamp and make sure you can move it around to catch signals around you.
6. The best possible signals are received when you aim at the source. These signals are much better that what you would have ever been able to achieve with a whip antenna. To make the signals even better, cut out a 2’X1’ sheet of lathing screen with holes and curve it slightly to resemble a satellite TV dish. Thereafter instead of pointing the Cantenna towards the signal source, point it at the screen with the back of the Cantenna towards the source of signals and let the screen point towards the source. If you can get the distance of the can from the dish anywhere near the focal length, you can multiply your signals by two to three times. The entire setup of screen and Cantenna can be held together by some wooden setup.
With this simple DIY antenna called Cantenna you can enhance your connectivity to get better access to the world wide web.