Hi,
If you want to increase your range in a very simple way, I would advice you to simply apply the Papatita (Magic Power) mod.
It's free, quick, simple and does not require any hardware modification. It's a 100% software modification which basically boosts the strength of the wifi 2,4 Ghz signal (so for the video signal).
Everyone who tried (including me) are very satisfied with the result.
As an example : I nearly went further than 300m before the mod. After the mod, I've never had the balls to push my bird to its limit, but I've already reached 600m (which is way enough for me!!) without any loose of signal.
Julien