So i have a phantom vision that i just got .i am not happy with the range i got with the fpv. About 300feet before wifi connection was lost.I ordered the parts for the antenna mods for the wifi extender and my controller. I live on a hill right outside of downtown (about .5 mile away). i would like to take advantage of this and put some type of directional antenna on my roof for longer range regarding the fpv. what are my options ? bigger the better. id like to get it off ebay .maybe someone could send me a link thank you.