Unlike their microradio cousins operating on the FM dial, shortwave pirate broadcasters aren't in the game to serve a specific community - unless you include those who've turned the hobby of scanning the shortwave bands into a science.
Shortwave radio broadcasting and listening is a very different sport from low power FM. Both types of broadcasters use only dozens of watts to get a signal out but FM signals are very localized. They only travel in a line-of-sight fashion, at best covering dozens of miles.
Shortwave radio, on the other hand, takes advantage of the upper levels of the atmosphere to extend their range. Using the electrically charged particles in the ionosphere, it is possible for a shortwave signal to "skip" through this layer and be heard hundreds or thousands of miles away.
This provides a fascinating challenge to the shortwave listener, who must optimize their receiving antennas and other equipment to best pick up these whispers of pirate radio.
Not only is it sometimes difficult to pull in a shortwave pirate signal, but such broadcasts typically last only a couple hours or less. Shortwave broadcasts, because of their large potential coverage area, are much easier to pinpoint and track down. The FCC has a network of automated monitoring stations scattered throughout the United States that have proven quite efficient at pinpointing the locations of shortwave stations.
As a result, shortwave pirates pack a lot of punch into a quick show, and are often celebrated for their creativity. Some will spend hours of painstaking work assembling and producing unique comedy and parody, engaging commentary, and mind-blowing music mixes.
Shortwave pirates are active year-round but it's easiest to listen in the winter months, when the threat of thunderstorms diminishes. Thunderstorms contain lightning, and large electric discharges can wreak havoc on a listener's ability to tune the shortwave band. Storms also destroy the possibility of good "signal skip" conditions.
The shortwave scene has been especially busy lately: holidays such as Christmas and New Year's always bring out lots of broadcasters (Halloween is the #1 shortwave pirate holiday).
In the last week there have been more than a dozen shortwave pirates on the air. Some of the most prolific include WMFQ (Where's My Motherf*ckin' QSL), WMNM ("Slim Shady Radio"), Radio Crunch (has a penchant for big band music), Z100 (classic rock), and Melvin Malfunction Radio (whose announcer is a computer-generated voice).
Shortwave pirates in Europe have been using quiet atmospheric conditions to skip signals across the Atlantic as well. Alfa Lima International in the Netherlands made successful test broadcasts heard in the eastern half of the United States over recent weekends. At least one pirate in South America was also heard recently in the U.S.
Most domestic pirates broadcast between 6940 and 6955 kHz on the shortwave band. Pirates in other parts of the world use frequencies around 21890 and 11440 kHz. The best way to monitor these pirates is to tune around these frequencies (especially during the evening/overnight hours on weekends) using a radio receiver equipped to tune the shortwave bands. Extending the antenna length on the receiver (usually by stringing a long wire outside your home) greatly improves your chances of reception.