The 20 metre amateur radio band, covering 14.000 MHz to 14.350 MHz, is one of the most popular and important bands in amateur radio. It’s well known for its long-distance communication capabilities, allowing radio amateurs to contact stations thousands of miles away using relatively modest transmitting power and antennas. For many decades, 20 metres has been regarded as the premier worldwide DX (long-distance) amateur band.
Unlike the 160 metre and 80 metre bands, which are particularly effective at night, 20 metres is primarily a daytime long-distance band, although it can remain open well into the night.
History of the 20 metre band
The history of 20 metres goes back to the pioneering days of amateur shortwave radio in the 1920s. During the early years of wireless, wavelengths below approximately 200 metres were often considered of little practical value for serious long-distance communication.
Radio amateurs challenged that assumption. Experiments during the 1920s demonstrated that short wavelengths could travel enormous distances by using the ionosphere to return radio signals to Earth.
The discoveries transformed both amateur and commercial radio. By the late 1920s, the 14 MHz region had become established as an important amateur allocation internationally.
During the 1930s, radio amateurs were making regular intercontinental contacts using Morse code and relatively simple valve transmitters. After the Second World War, 20 metres became increasingly popular as surplus military equipment, improved communications receivers and amateur-built transmitters became widely available.
During the 1950s and 1960s, the introduction of single sideband (SSB) transformed the band, allowing efficient international voice communication. By the 1970s, 20 metres was firmly established as one of the world’s principal amateur DX bands.
Propagation
The 20 metre band relies mainly on the Earth’s ionosphere, particularly the F region, to return radio signals to Earth. A transmitted signal travels upwards, is refracted back towards the surface, and may repeat this process over several hops. This allows contacts well beyond the horizon.
Typical operating characteristics include:
- Daytime: Excellent opportunities for European and intercontinental contacts.
- Early evening: Long-distance paths often remain open after sunset.
- Night: The band may close, particularly during periods of low solar activity.
- Solar maximum: Worldwide communication may be possible for much of the day and night.
- Solar minimum: Daylight DX is often still possible, making 20 metres considerably more dependable than some higher HF bands.
For British operators, favourable conditions can allow communication with North America, South America, Africa, Asia and Australia.
An interesting feature is that nearby stations can sometimes be difficult to hear while much more distant stations are received clearly. This results from the relatively long skip distances commonly experienced on 14 MHz.
Aerials
One reason for the popularity of 20 metres is that efficient antennas are much more manageable than those required for 80 or 160 metres. A half-wave dipole for 14.2 MHz is approximately 10 metres long, while a quarter-wave vertical is approximately 5 metres tall. Common antennas include dipoles, verticals, end-fed wires and directional Yagi beams. Even relatively simple antennas can provide impressive international results when propagation conditions are favourable.