Shortwave listening

The high frequency (HF) portion of radio spectrum, at the frequencies between 3 and 30 MHz, is at times called as shortwave. This is a misnomer by contemporary standards; the waves are long compared with the microwaves (a few millimeters) or IR (a small fraction of one millimeter), which are commonly used in the wireless devices. A frequency of 3 MHz corresponds to wavelength of 100 meters in free space; 30 MHz corresponds to 10 meters. But in early years of radio when shortwave band got its name, the wavelengths in between 3 and 30 MHz were short compared  with  wavelengths of most broadcast and communications signals, which had wavelengths in kilometer range.

Anyone can obtain a shortwave or general coverage radio receiver, install the modest outdoor antenna, and listen to signals from all around world. This hobby is called as shortwave listening or SWLing. In United States, proliferation of computers and on line communications has, to some extent, overshadowed SWLing, and young people grow up today ignorant of a realm of the broadcasting and communications which still predominates in much of world. But some people are still fascinated by the idea that the people can contact each other by wireless devices without the requirement of any human-made infrastructure other than an antenna at source and another antenna at destination. The ionosphere returns shortwave signals to earth’s surface and allows reliable global broadcasting and communication to take place, like it always has, and like it always will.

There are several commercially manufactured shortwave receivers on market today, and some of them are inexpensive. An outdoor wire antenna costs almost nothing. Most electronics stores carry one or more models of shortwave receiver, along with the antenna equipment, for the complete installation. One problem with the low priced shortwave receivers is that they lack the mode flexibility usually, selectivity, and sensitivity necessary to engage in serious SWLing. If you are interested in this and want to obtain high end equipment, shop around in the consumer electronics and amateur radio magazines. Most electronics and book stores carry periodicals and books for beginner and experienced SWLer. A library can be a good source of information, especially if you are interested in antique shortwave receivers, some of which are found at amateur radio conventions and flea markets.