Posting this here for anyone wondering what that second antenna is all about.
Just got my H520 and in the box was a second, flat, square shaped antenna. I was unsure what this was and couldn't see much on here about it so gave Yuneec UK a quick call and they clarified that the standard 'mushroom' antenna is the best omni-directional one to use and the new 'flat' antenna is directional, it needs to be angled at the H520 but should offer better range.
Just got my H520 and in the box was a second, flat, square shaped antenna. I was unsure what this was and couldn't see much on here about it so gave Yuneec UK a quick call and they clarified that the standard 'mushroom' antenna is the best omni-directional one to use and the new 'flat' antenna is directional, it needs to be angled at the H520 but should offer better range.