Well, I rebuilt the dish and found the focal point. the dish can really be anything including pots and metal dog dishes, but focal point is critical...I am finding out for optimum results. Formula is...D2/16d that is Diameter squared, divided by 16Xdepth. Should be pretty close, within 1/4 inch. Here is some homemade Wi-Fi amplifiers
http://www.usbwifi.orcon.net.nz/