↑ HF skywave propagation tutorial
for radio amateurs

By Doron Tal, 4X4XM

Radio amateurs use various propagation modes.

    For example:
  1. Space Wave propagation is the direct radio wave transmission in a line-of-sight.
  2. Ground Wave Propagation (surface waves) is a property that allows communication even behind a hill or across the horizon.
  3. Skywaves enable communication over extremely long distances, sometimes on the other side of the globe.

How is Skywave propagation possible?

Skywaves travel through the Earth's upper atmosphere via reflections off the ionosphere.

The ionosphere gets ionized due to EUV radiation especially during periods of strong solar activity, when more sunspots are observed.
Sunopots Pictures were published by UCAR - Center for Science Education
Compare Sunspots and Flares
See explanations here
On the average HF radio propagation improves when suspots' number exceed 100. However this may also indicate higher chance for solar storms that may block HF radio communication on Earth.

A number of variables, such as the time of day, the seasons, and solar activity, have an impact on HF radio propagation. During the day HF radio waves travel longer distances than at night.

In conclusion, HF radio propagation is an important topic for radio amateurs who use HF bands for communication. Successful HF radio communications require an understanding of the various propagation modes and the elements that govern HF radio propagation.

See a useful overview and tutorials about HF propagation conditions.
See also an index for HF Radio Propagarion.

HF Radio Propagation tutorial dedicated for radio amateurs

If no flags are displayed, it means that the s01.flagcounter.com server is down!