A range of broadcast radio frequencies used by noncommercial government broadcasters (such as the BBC World Service), commercial broadcasters, religious broadcasters, amateur radio operators, unlicensed ("pirate") stations, and utility stations broadcasting the time and maritime weather forecasts. As recently as a couple of decades ago they were also quite commonly used for maritime navigational beacons, maritime distress and rescue communications, international spy communications, transcontinental telephone feeds, news wire service radio-teletype feeds, and many other so-called utility broadcasts, but these uses of the shortwave bands are nowadays rare and have mostly been supplanted by sattelite communications since the late 1980s and by the Internet. The shortwave spectrum is usually referred to as consisting of several bands: the 49 meter band, 41 meter band, 19 meter band, etc. In terms of other radio bands, AM radio lies just below the lowest shortwave frequencies, and CB radio lies just above the highest shortwave frequencies. Stations on these bands sometimes have international or transcontinental reach, depending on atmospheric conditions, although signals cannot be received truly worldwide because atmospheric conditions vary around the world based on time of day and other variables. Unlike stations on the AM and FM bands, shortwave stations as a rule do not make continuous 24-hour broadcasts on the same frequency, but change frequencies throughout the day to compensate for the change in reception conditions, and many of them only broadcast for a few hours each day. Stations are constantly changing their programming schedules and which frequencies they use. The book Passport to World Band Radio, which is issued every year, is a popular guide to current shortwave stations and their programming schedules.
Shortwave bands intended for radio broadcasts to the public are allocated by international agreements. The main broadcast bands used for international broadcasts are:
- 60 meter band - 4400 to 5100 kHz
- 49 meter band - 5800 to 6300 kHz
- 41 meter band - 7100 to 7600 kHz
- 31 meter band - 9250 to 9995 kHz
- 25 meter band - 11500 to 12160 kHz
- 19 meter band - 15000 to 15825 kHz
- 16 meter band - 17480 to 17900 kHz
- 13 meter band - 21450 to 21850 kHz
In general, reception in the 60, 49, and 41 meter bands is excellent at night and poor during the day; reception in the 19, 16, and 13 meter bands is excellent during the day and poor at night; and reception in the 31 and 25 meter bands tends to peak in the morning and evening, but becomes poor during the mid-day and after dark. Other factors such as sunspot cycles, weather conditions, and the time of day at the location the station is broadcasting from also affect reception.
There also exist several other bands which are less commonly used.
Since World War II the shortwave bands have been used by governments seeking to break through the local government censorship of radio in other countries, to broadcast propaganda, or to broadcast to their own citizens living abroad. An example of this is the BBC World Service, which was a major source of Allied broadcasts into Nazi Germany, Fascist Italy and occupied territories during WWII. The Voice of America, operated by the U.S. government, also began broadcasting directed at Europe during this time.
During the Cold War, Radio Moscow and the Voice of America could both be heard on numerous frequencies across the shortwave bands at any given time. Since 1990, Radio Moscow has been replaced by the Voice of Russia with a much scaled-back broadcast schedule, and Voice of America broadcasts have also been scaled back.
In recent years the BBC World Service, Radio Netherlands, and Radio Canada International, among other widely respected international broadcasters, have scaled back their English-language broadcasts in favor of moving them to public radio stations, sattelite radio, and streaming over the Internet. These stations do still broadcast over shortwave but are mostly now directed at the developing world, where shortwave radio still serves as a popular medium for those without Internet or sattelite radio access.
Private broadcasters in the U.S.
Privately owned shortwave radio in the U.S. was limited to a few already-existing religious stations (mainly, WINB in Pennsylvania, and Family Radio's WYFR in Florida) and subjected to FCC restrictions which essentially barred granting any new licenses until the early 1980s when these restrictions were lifted. The first new station to go on the air in the early 1980s was the now-defunct WRNO Worldwide with a rock music format. However, this led to a rush by fundamentalist Christian groups to put new stations on the air. While WRNO's rock music format and that of similar stations broadcasting from Salt Lake City and Texas became commercial failures, the fundamentalist-owned stations became successful by brokering airtime to paid religious programs.
Starting in the early 1990s, right-wing extremist groups, whose programming was too extreme for even the AM talk stations which were by then carrying the likes of Rush Limbaugh, took advantage of this and started buying airtime on religious shortwave stations, which were all too willing to sell them airtime. For much of the 1990s, private shortwave broadcasters in the United States offered a smorgasbord of right-wing programming, including the likes of rabidly anti-gay preachers like R.G. Stair, Pete Peters (author of the book Death Penalty for Homosexuals Is Prescribed in the Bible) who makes Stair look mild by comparison, anti-Semitic ranter Hal Turner, and an openly neo-Nazi program produced by the National Alliance. Pete Peters is still widely heard over the shortwave bands and buys large blocs of airtime on some of the religious stations.
One of the private stations, WBCQ in Monticello, Maine, is a refreshing exception for the most part, with several progressive, eclectic music, and variety shows. WBCQ is, unlike the others, not a religious station. But WBCQ became controversial at first because they also sold airtime to Stair, Turner, and other extreme right-wingers. They have since dropped these shows and adopted an anti-hate speech policy. However, WBCQ still brokers a good deal of airtime to conservatives and religious shows. Most of the programming of progressive interest can be heard on 7415 kHz.
Progressive privately owned stations in other countries
Radio for Peace International was a privately-owned station broadcasting out of Costa Rica during the 1990s. The station has since gone off the air. It offered a lineup of completely progressive programming similar to that found on the Pacifica Radio FM stations in the U.S.
The demise of Radio for Peace International leaves very few outlets for progressive talk on the shortwave bands, and no non-governmental outlets at all save for WBCQ. Some government-run stations like Radio Netherlands can be quite progressive. Radio Havana Cuba, since the end of the Cold War, has shifted its tone away from the pro-Moscow line it was known for, to one more resembling the old Radio for Peace International.
The most widely listened to utility stations in the U.S. are the time broadcasts from WWV (Ft. Collins, Colorado) and WWVH (Hawaii), on 2500, 5000, 10000, 15000, and 20000 kHz. These broadcast the time in Coordinated Universal Time (which equates to the time in Greenwich, England), and they also broadcast maritime weather and storm warnings, and atmospheric conditions, at selected times each hour. WWV is operated by the National Institute of Standards and Technology of the U.S. government. A satire website presents what WWV might sound like if it were taken over by Clear Channel Communications: