The manual states 5.2ghz to 5.8ghz. It only gives a distance not a power. As the unit complies with the EU and Australian AMCA regulations then it is limited to 25mw and data of 1w. Remember range is not only a factor of power but antenna sensitivity too.
Yep, I understand. I've designed and built many antennas. Typically the circularly polarized antennas provide the overall best reception when it comes changing polarization angles, but the trade off is a lack of antenna gain. I use circularly polarized antennas on my Phantom with a 600mw transmitter, and the similar antenna Fat Shark googles and diversity receiver.