I am doing a project where I will be re-purposing an old TV satellite dish as a directional Wi-Fi antenna. The dish is circular in shape, not oval. The dish has an arm coming from the bottom that makes a 90 degree angle with the dish. I will be adding a second arm to the end of the dish's arm that will allow me to mount an SMA antenna connected with RG-59 cable precisely where it will utilize the dish's geometry. I need to figure out the proper position of the antenna on the dish. I want the dish to receive signal directionally where there is a zero signal elevation angle. From my previous understanding, dishes receive their signal from space where there is an angle of elevation from the transmitter and the receiver part of the dish.
I created a diagram that illustrates my plan with dimensions and calculations. I need some verification with my diagram and suggestions on how to maximize the reception strength.
I think that the antennae should be placed somewhere along line C in the diagram but I want to be sure before I start modifying the dish.
EDIT: I've calculated the focal point on the dish to be approximately 320 mm.
PS:I just realized that the 75 ohm impedance of the RG-59 cable is not optimal for the Wi-Fi adapter. I only need about 6 inches of cable so I will try it with and without the jumper cable and compare signal levels.