Interesting, the reflector should be flat or parallel to the ground over basically the entire US and maybe you can tilt it 10deg or so from vertical from your location when receiving sats close to the horizon. The main lobe off that antenna is not in line with the PVC tube, it actually has a null in line with the tube. The radiation pattern a doughnut that is about 40deg off the reflector surface covering a useable 20 to 60deg up in the air to cover most calculated UHF satcom orbital slots from the US.