DXing is the hobby of making two way radio contact with distant stations in amateur radio. Many DXers also attempt to receive written verifications of reception (sometimes referred to as “QSLs” from the stations heard). The name of the hobby comes from DX, telegraphic shorthand for “distance” or “distant”.
DX Station
Although the classic definition of DX is “distance”, today it generally means contacting amateur radio stations in far-away places. On the HF (also known as shortwave) bands, DX stations are those in foreign countries. On the VHF/UHF bands, DX stations can be within the same country or continent, since making a long-distance VHF contact, without the help of a satellite, can be very difficult.
For award purposes, other areas than just political countries can be classified as “DX countries”. For example, the French protectorate of Reunion Island in the Indian Ocean is counted as a DX country, even though it is a territory of France. The rules for determining what is a DX country can be quite complex and to avoid potential confusion, radio amateurs often use the term entity instead of country. In addition to entities, some awards are based on island groups in the world’s oceans. On the VHF/UHF bands, many radio amateurs pursue awards based on Maidenhead grid locators.
For the most rare locations, DX-peditions are often organized to allow radio amateurs to “work a new one”.
There are frequent contests where radio amateurs operate their stations on certain dates for a fixed period of time to try to communicate with as many DX stations as possible.
In addition, many clubs offer awards for communicating with a certain number of DX stations. For example, the ARRL offers the DX Century Club award, or DXCC. The basic certificate is awarded for working and confirming at least 100 entities on the ARRL DXCC List.
DX Clubs
Many radio enthusiasts are members of DX clubs. There are many DX clubs in many countries around the world. They are useful places to find information about up-to-date news relating to international radio. Many people also enjoy social events, which can form a large part of the enjoyment that people can get out of the radio hobby.
DX Communication
DX communication is communication over great distances using the ionosphere to refract the transmitted radio beam. The beam returns to the Earth’s surface, and may then be reflected back into the ionosphere for a second bounce. Ionospheric refraction is generally only feasible for frequencies below about 50 MHz, and is highly dependent upon atmospheric conditions, the time of day, and the eleven-year sunspot cycle. It is also affected by solar storms and some other solar events, which can alter the Earth’s ionosphere by ejecting a shower of charged particles.
The angle of refraction places a minimum on the distance at which the refracted beam will first return to Earth. This distance increases with frequency. As a result, any station employing DX will be surrounded by an annular dead zone where they can’t hear other stations or be heard by them.
This is the phenomenon that allows short wave radio reception to occur beyond the limits of line of sight. It is utilized by amateur radio enthusiasts (hams), shortwave broadcast stations (such as BBC and Voice of America) and others. This is what allows you to hear AM (MW) stations from locations far from your location. It is one of the backups to failure of long distance communication by satellites, when their operation is affected by electromagnetic storms from the sun.
References
1. Introduction To DXing
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