First off, thanks so much to the people that have contributed to this thread. It's been super helpful, and I hope it will help me secure my seat at PSA soon.

Just a question.

On the 10-9 for Charlotte, the ground frequencies are split into headings, 360-179 is one frequency, 180-359 is another. How does this work? I've seen airports split in half with a frequency for each side, never seen this. None of the people I normally go to with questions like these know either.

Thanks again for the help.