Home » Propagation » 21 » b The 80 metre band is useful for working:   a.   in the summer at midday during high sunspot activity   b.   long distance during daylight hours when absorption is not significant   c.   all points on the earth's surface   d.   up to several thousand kilometres in darkness but atmospheric and man-made noises tend to be high Your answer "b" is not correct. "d" is the right answer. Next