Short-wave          UTC          Radios          Antennas          Frequencies & Bands          AM & SSB

Radio For Peace International is a shortwave station. There is no reason to be intimidated by shortwave. It is only marginally different from the radio you are probably accustomed to using daily. Here are a few tips on receiving shortwave stations.

What is Shortwave?

Unlike AM and FM radio, which carry only a limited distance, shortwave easily traverses oceans and continents. FM transmissions, for example, follow the surface of the earth for a hundred miles at most. Then the waves shoot out over the horizon, penetrate the atmosphere, and leave the planet. In contrast, shortwave transmissions, because of their lower frequency, do not escape the earth. An electrically charged layer of the upper atmosphere, called the ionosphere, reflects them like a mirror, so that they bounce back to earth. The angle of their reflection from the sky returns them to earth far from their point of origin, often thousands of miles away. Without cables, relays, or satellites, short-wave signals reach millions of listeners around the world, enabling citizens in faraway countries to listen without the permission of their respective governments. This is why shortwave radio has been referred to as, ``the only unstoppable medium of mass communications.''

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What are Frequencies and Bands?

The radio spectrum is divided up irregularly in divisions known as bands. Further divisions - frequencies - fall within these bands, like inches on a yardstick. International shortwave broadcasters use 13 bands, a small portion of the radio spectrum, to beam their signals throughout the world. What is commonly known as AM radio is another band, which is referred to technically as medium wave (MW). VHF & UHF-TV and FM are others, as well as maritime, aeronautical, etc. The meter-band has to do with the length of the radio wave. The band use, location in frequency, and width (how many frequencies are included) are determined by the ITU (International Telecommunications Union). However, shortwave broadcast stations are sometimes found just outside the ITU recognized bands. This is becoming more common as the shortwave bands get more crowded, and there are international legal provisions that allow it.

It is necessary to know the frequency on which a station transmits in order to tune the station in on your receiver. Frequencies are expressed either in kiloHertz (kHz) or MegaHertz (MHz). The difference between kiloHertz and MegaHertz is simply that a MegaHertz is 1000 kiloHertz. The same frequency can be written using either unit (i.e. 7385 kHz = 7.385 MHz).

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What Do AM and SSB Mean?

There are currently two modes of transmission used in shortwave broadcasting. The mode is the method of placing the audio onto the radio frequency carrier. The mode most commonly used is AM or Amplitude Modulation. This mode is also used in the MW band, from whence AM radio gets its name. The other mode is SSB - single sideband. In SSB, only a portion of the AM signal is used. There are both USB (Upper Sideband) and LSB (Lower Sideband). SSB is only used by a few stations worldwide, but has many advantages. By being narrower, this mode conserves space on the shortwave band, allowing twice as many stations on a given band. It also has the advantage of improved reception during fading conditions and consumes less energy at the transmitter site. Not all radios have the capability of receiving this mode. On those that do, there is some type of switch which must be in the proper position for receiving. If you try to listen to an SSB signal in the AM mode on your receiver, it will sound very distorted. If, however, you listen to an AM signal in either the USB or LSB receiving mode, it will be intelligible, but with reduced fidelity.

What is UTC?

Shortwave radio stations change frequencies in order to optimize reception for their listeners. Different bands are received better in certain parts of the world at certain times of day. As these broadcasts are international, a common time reference is required. Most use the 24 hour clock of Coordinated Universal Time or UTC. A trend of late is to shorten the name to Universal Time (UT). In practice, UTC is the same as Greenwich Mean Time (GMT). You will need to convert your local time to UTC in order to read a program schedule and know which frequency to look for or when to catch a certain program. The following chart is showing how this works. Watch out because date changes get tricky. A program schedule may list 0300 UTC Monday for the broadcast time of a program, which is actually still Sunday evening in North America. For the Atomic Web Clock or more Information including how to synchronize your pc's clock to the NIST Atomic clock: National Institute of Standards and Technology (NIST). For specific information about local times anywhere in the world visit World time.

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What Options Do I Have in Radios?

Shortwave radios range in price from $50 to several thousand dollars. The better the radio, the more often you will be able to enjoy a clear signal. For a basic digital radio, the Sony ICF- SW35 or ICF-SW40 or the Sangean ATS-404 are good (approx. cost US$100). These will give good reception of RFPI's 7445 transmitter in the southern US & fair reception in the north. Portables with SSB capabilities include the following: Sony ICF-SW 7600GR, Sangean ATS-909, or Grundig YB-400PF. These will provide reception of all our transmitters anywhere, under good conditions. They cost from $220 to $250. Another popular radio is the Sony ICF-2010 for $350. For its filtering capabilities and synchronous detection, it's well worth the price. Any of these radios may be ordered through:

• Grove Enterprises, 800-438-8155
• Universal Radio, 800-431-3939
• C. Crane Company, 800-522-8863

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Do I Need a Fancy Antenna?

Good antennas will give you better sensitivity, allowing you to hear stations which are less powerful or further away. Start with the built-in telescopic, then play around with other set-ups. Building antennas is fun. One simple trick is to hang a wire out the window or up a chimney and connect it to the built-in antenna with a clip. Many radios also come with an external antenna plug which is easy to wire up. A spool of cheap wire run between two trees or along your roof will do wonders, away from metal & insulated from trees with a rope, if possible. Radio Shack also sells some kits that work well.

Much additional info can be found in the rec.radio.shortwave archives. If that site is busy, here's an alternate site.

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