Today, much information is to be had on the net in the form of latest MUF Charts, propagation prediction computer programmes, HF radio beacons and other useful information on likely radio propagation into all regions of the globe. Having a good knowledge and understanding of these resources is certainly an asset to any radio operator. This site is for 11- Meter operators who want to know the most likely times when communications to a particular region is possible, subject of course to certain solar disturbances which are impossible to predict. Hopefully, you will find this site useful and add to the thrill of DX-ing on Eleven Meters.
SUNSPOTS AND IONOSPHERIC STORMS
Sunspot eruptions on the surface of the sun can cause disturbances in the ionosphere known as ionospheric storms, and these are usually followed by other disturbances in the earth's magnetic field.
These storms have a great effect on radio communications. On the lower frequencies, they decrease the daytime absorption of signals and thus increase the signal strength. During night time, the signal strength is below normal.
On the higher frequencies, such as 11 Meters, communications become impossible depending on the intensity of the storm. These storms can cause "radio blackouts" and are most common during the peak of the eleven year sunspot cycle; often referred to as the Solar Max. |
