Hey there,
I just took a listen to all your feeds, the volume level is a little low however it's OK. What I do hear is
a loud HUM along with the transmissions. I don't know a thing about the Raspberry Pi things...yet.
Just sounds like a mismatch and or audio settings are set wrong. By the way, the ATC transmitters
are somewhere else on the field, the antennas on the tower are for receiving only.
I found the transmitter antennas, there on the west side of N. Lakewood Blvd., just south of E. Spring St.
Good luck
Kel