Category Archives: Propagation

Sunspots And Reception In 1939



Historical article:

The apparent effect which “sun-spots” have on radio reception makes their study of special interest to the radio engineer. This article was submitted to Radio and Hobbies by a reader in England, and gives some interesting information on a special subject.



SUNSPOTS are one indication of high solar activity, which is, however, also indicated by other phenomena. The most important of these are the clouds of hydrogen and of calcium vapour – called hydrogen or calcium flocculi – which appear on the sun’s surface, having been erupted from its interior, usually in the vicinity of sunspots.

Modified Views On Shortwave Propagation


Historical article from May 1943 Australasian Radio World

TWO abstracts from technical papers of German origin which have recently appeared in “Wireless Engineer” deal with matters of particular interest to those engaged in short-wave work.

The first of these is from a paper by B. Beckmann, W. Menzel and F. Vilbig, and gives details of a particular form of “scattering” in the ionosphere, which results in strong signals being obtained within the skip distance of a transmitter.

The Atmosphere’s Electrical Fringe

Radio Review

Historical Article: How the Ionosphere Affects Radio Transmission

From the Radio Review of Australia (June 1938)

EVERY reader of this journal must have encountered at least one reference to the vagaries of the ionosphere” in the course of his reading, and he is also bound to have come across references to ‘sun-spots” and their effect on terrestrial conditions. It is quite possible that these references, usually of the incomplete newspaper” variety, have left him wondering what it is all about. The following article, which is by a scientist of the Carnegie Institution, Washington, U.S.A., sums up present knowledge of the ionosphere, sun-spots, and their relation to radio transmission, very neatly and will give the reader a much more intelligent appreciation of what is happening next time he hears of a ‘solar hydrogen eruption” or a “sun-spot cycle.

Amazing Sunspot Picture

From the website comes this amazing photo of the almost dahlia-like photo of a sunspot.