@roadfun
Due to high gain, FA Antenna picks up lot of cell phone and TV signals and overloads the Dongle. This results in moderate to severe reduction in performance.
To overcome this problem, there is a two step solution.
First step is to reduce gain as suggested by @dongerrard204.
Use different values of gain like 50, 45, 40, 35, 30.
At each setting watch for some time to see the performance.
This way you will find the best setting for gain. It is quiet likely that by reducing gain, the performance of FA Antenna improves considerably.
Second step is to add a Filter, which will cut off most of interfering Cell and TV signals. This will make a big difference in performance if you have strong Cell Phone & TV signals in your location.