DB is right of course. He's the expert.
Here's what I gather from seven months of reading threads like this:
1) You need a good solid mod. No mistakes, no "hey that's probably close enough" deals. You need all the right tools beforehand, and you need patience. And you'll make some mistakes and have to buy new boards or whatever. When you're done, it has to be perfect or better than perfect.
2) You need a good directional antenna.
3) You need to aim it perfectly. Precisely. Exactly. Whatever word you want to use. Holding the controller at your hip is probably not good enough.
4) Then and only then should you be thinking about amps, and at that point, taking in all the above, the amp will help fairly significantly, provided you have very limited if any interference (which hopefully would be mostly solved with your directional antenna). But with this relative increase in range, you're probably not going to see God or anything. My point is, the first three things above are much more important than the amp.*
5) Testicles. Sorry, but that's part of it. That means you don't head back the instant you lose FPV. You don't head back the second you see a big red DISCONNECTED on the app. You push it bit further. Maybe it'll reconnect. What about wind and battery percentage? Those two things kinda work together. Nice head wind means you can afford to use some extra battery. Do the math. Take a chance. You gotta be willing to risk losing your aircraft if you want good distance. Otherwise you're not gonna push it to the edge.
*Finally - re amps, with an initial amp mod of say 2.5 watts, you're increasing power from 100 mw to 2500 mw, so that's a significant increase in raw power. So you should expect a decent range increase. But to move from 2500 mw to 4000 mw, percentagewise, that's really not much of an increase. Your range will increase, but only by a very little bit. Maybe something like 10-12 % range increase.
