Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online.Shortwave listening is the hobby of tuning for shortwave radio broadcasts located on shortwave frequencies, usually thought of as those from 1700 kHz to 30 MHz. Listening to shortwave broadcast stations for news and information programming is common, but for many shortwave listeners, the goal is to receive as many stations from as many countries as possible, also known as DXing. "DXers" routinely test the limits of their antenna systems, radios and radio propagation knowledge. Specialized interests of shortwave listeners may include listening for shortwave utility, or "ute", transmissions such as shipping, sailing, naval, aviation, or military signals, listening for intelligence signals, or tuning in amateur radio stations.