Why can't you watch TV stations that are below the horizon?

Answer 1

because waves run/travel straight. The earth is round therefore the waves doesn't bend on its curves, just like we couldnt see the things past the horizon because light waves doesn't bend on the earth's curves.

To cope with this we use satellite or cable to bring t.v broadcast over the horizon.

This is also the reason why we use TALL towers... the taller the tower, the higher the radius of the waves will travel. This is also the reason why we see more further in high places than lower places.

Answer 2

You could try some of the 'underground' stations.