Results from FlightAware 1090 MHz ADS-B Antenna - 26 in

FlightAware ADS-B Flight Tracking
44

Default is maximum possible gain.

But adjusting gain is never a bad idea.

For Beginners - How-to SSH to RPi - Setup Putty in Windows - #19 by SoNic67
For Beginners - How to Set / Change Gain
Thoughts on optimizing gain - #2 by wiedehopf