G3C05 Why is long distance communication on the 40, 60, 80 and 160 meter bands more difficult during the day?
A. The F layer absorbs signals at these frequencies during daylight hours
B. The F layer is unstable during daylight hours
C. The D layer absorbs signals at these frequencies during daylight hours
D. The E layer is unstable during daylight hours
- Think of the D region as the "Darned Daylight" region. Instead of bending high frequency signals back to Earth, it absorbs energy from them. Signals at lower frequencies (longer wavelengths such as 160, 80, 60 and 40 meters) are absorbed more than at higher frequencies. The ionization created by the sunlight does not last very long in the D region, disappearing by sunset.