SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/ham-10m-f-region-time

When is 10 meters usually best for long-distance F region propagation?

Dawn to just after sunset, with high sunspots.

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  1. Sunset to dawn, with high sunspots
  2. Dawn to just after sunset, with low sunspots
  3. Dawn to just after sunset, with high sunspots ✔

Why: Sunlight charges up the ionosphere's F region during the day. When sunspot activity is high, it bends 10-meter signals back to Earth far away.

Huh, didn't know that: The sunspot cycle runs about 11 years from peak to peak.

The dad joke
10 meters is like me on vacation: great all day, done right after sunset.
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References

Answer: Dawn to just after sunset, with high sunspots. Sunlight charges up the ionosphere's F region during the day. When sunspot activity is high, it bends 10-meter signals back to Earth far away.

  1. HamStudy 2026 Technician pool, T3C09 hamstudy.org/browse/E2_2026/T3C
    From dawn to shortly after sunset during periods of high sunspot activity
    Checked 2026-10-09.

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