Simple rule for selection of HF bandThe 9 MHz rule: search above 9 MHz in the morning and early daytime hours, and search below 9 MHz in the late afternoon and evening hours.
Last Solar Month's Solar-Terrestrial Data, N0NBH
- 304A: Ultraviolet radiation at 304 Ångström due to ionized helium in the sun's photosphere. One value measured by the Solar Dynamics Observatory's EVE instrument, and the other by the SOHO satellite's SEM instrument. Responsible for about half of the F layer ionization.
- X-Ray: Intensity of hard X-rays hitting the earth’s ionosphere. Impacts primarily the D-layer (HF absorption). Value from A0.0 to X9.9. The letter indicates the order of magnitude (A, B, C, M and X), where A is the lowest. The number further defines the level of radiation.
|K-index (48 hrs):|
One Year Solar-Terrestrial Activity Report
- Live "on air" beacon page, IZ0IEN
- Monitoring stations all over the world