Historically basements are problematic locations for antenna reception. Television signals will not penetrate the ground and in most cases basement walls are concrete with steel rebar inside them for support. Yet another signal blocker. If your basement has windows above ground, place the antenna in the window. If that doesn’t provide good reception, try moving the antenna higher, either by taping it to the basement ceiling near the window, or moving it up one floor and running the coaxial cable down to the basement TV. Remember to redo the channel scan every time you move the antenna.
In most basement situations a roof/attic mounted antenna is a great option since it gets your antenna up and over any blockages.