The 10 m beacon segment, 28.2 to 28.3 MHz: dozens of beacons that say the band is open

What you hear

On a dead day the segment is a blank strip of waterfall, 100 kHz wide, with nothing but noise. On a good day it fills with thin lines, each a beacon somewhere on the planet, and tuning from one to the next is like reading a map of the ionosphere. Most beacons send the same thing in slow Morse: their callsign, often preceded by "VVV DE", then the Maidenhead locator that pins them to a square a few kilometres across, sometimes the power and the antenna, sometimes the name of the town. Many finish with a long dash of ten seconds or more, which is there so that you can judge how strong and how steady the signal is, and then the message starts again. The pace is leisurely, usually 10 to 15 words per minute, so that anyone can read them, even by ear at the edge of audibility.

Some beacons run all the time, others switch on only in daylight or share a frequency with a partner in another country by taking turns. Powers range from under a watt to a hundred, with a few watts into a simple vertical or dipole being typical, and that is exactly what makes them useful: if a 5 W beacon in Brazil is audible in Finland, a modest station can work the path.

Who transmits and why

The segment from 28.2 to 28.3 MHz is set aside for beacons in the band plans of all three IARU regions, which is why beacons from every continent crowd into it. They are run by radio clubs, universities, national societies and individual amateurs under their own callsigns, unattended, on rooftops and hilltops. Their job is to make the 10 m band observable: it is the most unpredictable band on shortwave, open to the whole world every day in some years and shut for months in others, and a beacon that sends its callsign at all hours is the only honest witness. Beacon lists are kept by amateur groups and updated as stations come and go. Right in the middle of the segment, on 28200 kHz, the NCDXF chain with its GPS timing and power steps has its own catalogue entry: NCDXF beacons 10 m.

When and where to listen

In daylight, and the years around a solar maximum are the time of plenty: from Europe the segment fills with Africa and South America around midday, with North America in the afternoon and early evening, and with the Caribbean, Asia and Australia on the best days. In autumn and winter the openings are the longest and the most distant. At a solar minimum the band still opens in summer through sporadic E, in bursts of an hour or two, with beacons from one or two thousand kilometres away suddenly loud and then gone; from May to August it is worth checking the segment every afternoon for that reason.

The practical way to use the segment is to look rather than listen: put the receiver's waterfall across 28200 to 28300 kHz, wait a minute and click on whatever lines appear. CW with a narrow filter then reads each one. On an empty band, try a receiver on another continent, where it may be the middle of a good day.

In ShackDeck

Station catalogue → Beacons → 10 m beacons 28.2–28.3. The program picks a public receiver that covers the 10 m band, tunes it to 28250 kHz in CW, the middle of the segment, and shows the waterfall, where the beacons are the thin lines; tune to each one to read its callsign. No receiver, antenna or account of your own is needed.