We must account for the fluctuations in the ionosphere when we are DX-ing. Depending on the hour, the ionosphere either absorbs a signal or reflect it over the horizon. In the daytime, the 20, 17, 15, 12, and 10 meter bands, called the high bands, tend to be OPEN ( support propogation) to DX stations. Before daylight, signals begin to appear from the east, beginning with 20 meters and progessing to the higher bands over a few hours. After a sunset, the signal linger from the south and west for several hours with the highest frequency bands closing first in reverse order. Daytime Dxers tend to follow the Maximun Useable Frequency (MUF), the highest signal the ionosphere reflects. These reflections are at very low angle and so can travel the longest distance for the single reflection ( one reflection is called a hop) and have the highest signal strengths. by Ward Silver, N0AX
GOOD LUCK FOR YOUR DXING!!!!!