Nebraska Section Technical Specialists
RF Exposure Guidelines for Amateur Radio
Solar Cycle 25
The solar cycle is the cycle that the Sun's magnetic field goes through approximately every 11 years. Our Sun is a huge ball of electrically-charged hot gas. This charged gas moves, generating a powerful magnetic field. The Sun's magnetic field goes through a cycle, called the solar cycle. NASA SCIENCE SPACE PLACE
The Sun is in the rising part of its 11-year cycle of activity. NOAA recently confirmed that Cycle 25 is outperforming the official forecast. As of January 2022, actual sunspot counts to date are stronger than predicted. almanac
Space weather impacts radio communication in a number of ways. At frequencies in the 1 to 30 mega Hertz range (known as “High Frequency” or HF radio), the changes in ionospheric density and structure modify the transmission path and even block transmission of HF radio signals completely. These frequencies are used by amateur (ham) radio operators and many industries such as commercial airlines. They are also used by a number of government agencies such as the Federal Emergency Management Agency and the Department of Defense. NOAA HF RADIO COMMUNICATIONS
ARRL ' Propagation of RF Signals' and links to a cornucopia of QST articles and other resources.