Did a rough comparison between the quad patch antenna, and the standard dipole today.
The F550 quad was flown out to just over 300m away, and hovering at 25m AGL.
SMA attenuators were inserted in series with the patch, until similar copy was received on both antennas.
It was determined that the gain of the patch was at least ~ 7dB over the dipole, ie; ~ 9.2dBi.
This is within the manufacturers specification of 9 – 11dBi.
The patch antenna’s pattern was broader than expected, in both planes, so for FPV use, this was a welcome surprise.
As the 2.4 GHz control link starts issuing low RSSI warnings @ >400m away, it’s pointless striving for more gain in the video link.