More sunspots are associated with increased solar flux, which cause ionization in the upper atmosphere. HF (3-30MHz) communication is generally enhanced by inc

More sunspots are associated with increased solar flux, which cause ionization in the upper atmosphere. HF (3-30MHz) communication is generally enhanced by increased ionization (to a coarse first-order approximation -- the nuances fill many books and are not entirely understood.) At other frequencies, sunspots may or may not be a good or bad thing, depending on your definition of "good" and "bad".