I have made a few of the cantennas myself. The coax cables most people use are problem because a 2.4 gig signal will have loss if it's more than a few feet long. I use a USB wireless with an antenna that is about 2 inches long (it came with the card). Then I cut a hole about the size of a USA quarter in the side of the can about one inch from the back. Then I just taped the USB card to the can with the antenna sticking through the hole. Now you can use a USB extention cable as long as you want without any loss at at all. You just need to weather proof it somehow. With a clear line of sight I have good results up to about a mile. I tried attaching the can to an 18 inch dish. This improved it some, but not a lot. Then I tried using a 40 inch primestar dish, now that makes a dramatic improvement! I never tried any long distance tests, but just testing it on the nieghbors about a block away, here's the results: Signal strength with just stock antenna: about 10%, with a cantenna, about 30-40%, with 40 inch dish, 100%. The can is about 4 inches wide and 5 inches long.
All of the small satellite dishes, Direct TV, Dish Network, Primestar, etc. are offset dishes. So if you use them to try and get a signal that is parrellel to the ground, you might think that you should have the face of the dish at a straight right angle to the ground. But because of the offset, the dish will have to face the ground somewhat to work well. Just like when you see a Direct TV dish it may look as if it's pointed at a satallite that's low in the southern sky, it actually is receiving it's signal from a satallite much higher than it would apprear. That's assuming you mount your can in the same place as the original LNB that came with your dish.
