G3C05:

Why is long-distance communication on the 40-meter, 60-meter, 80-meter, and 160-meter bands more difficult during the day?

  1. The F layer absorbs signals at these frequencies during daylight hours
  2. The F layer is unstable during daylight hours
  3. The D layer absorbs signals at these frequencies during daylight hours
  4. The E layer is unstable during daylight hours