But you probably knew that. The sun has finally shown signs of increasing activity as the next 11 year solar activity cycle begins. Changes in short-wave propagation are becoming obvious. Solar flux numbers and maximum usable frequencies are rising. Daytime absorption levels cause weaker signals on daylight paths at lower frequencies.
Higher frequencies remain useful long after the sun has set.
This month begins a multipart article to explain the art of predicting short-wave radio propagation. Solar radiation and eruptions can disturb or enhance ionospheric refraction of short-wave signals. After reading this series, you should be able to understand and apply the information to improve your short-wave DXing hobby. You will also learn how scientists predict future short-wave radio propagation conditions. The reports are sent to the transmitter site in message form.