DX is a term for a long distance contact. Increased sunspot activity results in increasing ionosphere ionization, resulting in an increase in the refracting po

DX is a term for a long distance contact. Increased sunspot activity results in increasing ionosphere ionization, resulting in an increase in the refracting power of the ionosphere. Higher refracting power means radio waves can be bent more, resulting in longer distance communication (also, the ionosphere bends lower frequencies better, so you get an increase in the MUF, or Maximum Usable Frequency that will get bent back to the earth.)