haha thanks for answer.
i think that the signal is more positive above sea level.without antennas and interference.
Day by day i have been more expert.take a look above the video.i fly 1300m far first time above sea level haha yeaaaaaa
secondly i made flight recor .i fly with 2 new batteries 25 min with 1832 gr heavy. i didn't find same video.the other quads are not so heavy like mine
here is the vid.its poor quality because 25 min it will be about 4 giga.so i made it 150mb lol