Skip zones are defined as the region between:

Skip zones are defined as the region between:

• A. The end of the ground wave and the first sky wave return to Earth.
• B. The direct wave path and the horizon.
• C. The surface wave and the ionosphere.
• D. The transmitter and receiver.

Answer: (A)

Propagation on HF involves two main paths: a surface (ground) wave that travels along the Earth's surface and attenuates with distance, and a sky wave that is reflected back to Earth by the ionosphere. The ground wave reaches a certain distance before it becomes too weak to be received. The first sky-wave reflection, however, returns to Earth at a farther distance. The region between the farthest extent of the ground wave and the point where that first sky wave returns is the skip zone—neither path provides reliable reception there. This gap explains why signals can disappear in that middle range even though they may be present closer in or much farther away.

Propagation on HF involves two main paths: a surface (ground) wave that travels along the Earth's surface and attenuates with distance, and a sky wave that is reflected back to Earth by the ionosphere. The ground wave reaches a certain distance before it becomes too weak to be received. The first sky-wave reflection, however, returns to Earth at a farther distance. The region between the farthest extent of the ground wave and the point where that first sky wave returns is the skip zone—neither path provides reliable reception there. This gap explains why signals can disappear in that middle range even though they may be present closer in or much farther away.