Which bands may provide long-distance communications via the ionosphere's F region at the peak of the sunspot cycle?

The interval of 6 and 10 meters is known for enabling long-distance communications, particularly during the peak of the sunspot cycle when ionospheric propagation is at its strongest. During this period, the F region of the ionosphere becomes more reflective for radio waves, allowing signals to travel much longer distances than during times of lower solar activity. The 6-meter band, operating around 50 MHz, and the 10-meter band, around 28 MHz, both utilize this phenomenon effectively.

While the other bands, such as those in the 23 centimeters, 70 centimeters, and 1.25 meters ranges, are used for communication, they typically rely more on line-of-sight propagation rather than ionospheric reflections. Thus, during the peak of the sunspot cycle, they do not take full advantage of the F region for long-distance communication in the same way the 6 and 10 meters bands do. Therefore, the best choice for long-distance communications via the ionosphere’s F region in this context is indeed the 6 and 10 meters bands.