Beacon observation in amateur radio
Efficient DX connections by checking the radio propagation conditionsImagine you finally have some time on your hands and really want to live out your amateur radio hobby. How nice would it be if you ended up with as many DX contacts as possible? Even to rare stations in remote areas of the world! Is it even worth turning on the radio today? What are the current propagation conditions like? This can be found out by listening closely to the bands, but it takes a lot of time. Alternatively, you can look at the theoretical propagation forecasts on the Internet or in an amateur radio magazine, or check the DX cluster reports. However, to get a real, first hand status of the current radio propagation just listen to some propagation beacons. For example, the NCDXF beacon system provides a perfect overview in just 3 minutes. And that's what this exciting article is all about!
Your key to efficient radio propagation insight
A propagation beacon is a radio beacon that is used to assess the current radio 'weather' and propagation conditions. They are operated by radio amateurs as individual beacons on permanently assigned amateur radio frequencies from the long wave to the microwave range. The identifier and a preceding “VVV de”, often just a “de”, as well as further information about the location, such as the name of the town or QTH locator, are transmitted in CW A1 or A2. At the end, one or more dashes (CW carrier) with graduated transmission power can follow, which allow a qualified assessment of the propagation conditions, whether a connection can only be established with higher power or whether QRP operation is also possible.
By listening to different beacons, you can quickly gain an overview of the directions and frequencies in which successful propagation is currently possible. This is the predominant application and form of use of these beacons in amateur radio. The oldest propagation beacon still in operation today is operating in Denmark under the amateur radio call sign OZ7IGY. It dates back to the International Geophysical Year 1957 and currently transmits on 12 amateur radio bands from 28 MHz to 24 GHz. Another very well-known beacon is DK0WCY on 10.144 MHz. It also broadcasts information on the current radio weather in plain text.
Lost treasures of aviation and marine radio as useful aids for radio amateurs
The abbreviation NDB stands for “non-directional beacon”, i.e. with omnidirectional radiation. In commercial aeronautical and marine radio, they are the equivalent of propagation beacons in amateur radio. However, they are used for other purposes. These beacons mark a fixed, known location and are therefore used for direction finding purposes. With a few exceptions, however, they have lost their significance in aviation and marine radio today. Many of the former NDBs have now been deactivated. For the time being, the remaining beacons can still be used by radio amateurs as an indicator of propagation conditions.
A revolution in amateur radio since 1980
The Northern California DX Foundation NCDXF [1] is a DX interest group of American radio amateurs. Together with the IARU (International Amateur Radio Union), it has been operating the “NCDXF beacon system” (also known as the “IBP International Beacon Project”) on shortwave since 1980. Already planned at the end of the 1970s, the system consisted of 5 or 6 beacons at the beginning of the 1980s. In 1995, the number of beacons was increased to 18. To use the NCDXF or IBP beacons, all you need is a shortwave receiver that covers the upper amateur radio bands between 14 and 30 MHz and a simple antenna that is as vertically polarized as possible and therefore suitable for omnidirectional reception. OM Ekki Plicht, DF4OR has written a very easy-to-understand description of how the beacon system works on [2]. To avoid having to reinvent the wheel, we have largely adopted his article, revised it and added further information. The beacon system and the observation work as follows:
18 beacons are distributed relatively evenly in the northern and southern hemispheres around the world.
Each of these beacons transmits in a fixed time schedule and a fixed sequence one after the other on the 5 bands: 20, 17, 15, 12 and 10 meters.
Each transmission lasts 10 secondsand contains the callsign and 4 dashes, each lasting one second with decreasing transmission power. The callsign and the first dash are transmitted with 100 W, the subsequent dashes with 10 W, 1 W and 100 mW respectively.
Precise timing is controlled by GPS; each beacon is equipped with a GPS receiver and an accuratereal-time clock.
To keep the signals from the beacons comparable, they all use similar hardware. The transmission power is set exactly the same and an omnidirectional antenna is used at all locations.
The transmission scheme gives you a complete overview of the propagation conditions in all directions on a band in 3 minutes (18 x 10 seconds). If you follow a beacon from band to band, you can find out in 50 seconds which band currently has the best propagation conditions in a particular direction. For this reason, it makes sense to store all five beacon frequencies one after the other in the radio's memory.
As the transmission sequence of the beacons is fixed and controlled to the second, it is easy to recognize which beacon is currently transmitting. If you can't hear anything, the band in that direction is closed or the beacon (or your receiver) is faulty. The last transmission with 100 mW power can usually not be heard, at least under average propagation conditions. It can only be heard in extremely good propagation conditions.
The global broadcasting schedule overview
4U1UN
UN Building New York, USA
VE8AT
North Canada
W6WX
California, USA
KH6RS
Island of Maui, USA
ZL6B
North Island New Zealand
VK6RBP
Perth, Western Australia
JA2IGY
Tokyo, Japanese main island
RR9O
Novosibirsk, Russia
VR2B
Hong Kong
4S7B
Colombo, Sri Lanka
ZS6DN
Pretoria, South Africa
5Z4B
Nairobi, Kenya
4X6TU
Tel Aviv, Israel
OH2B
Helsinki, Finland
CS3B
Madeira Island
LU4AA
Buenos Aires, Argentina
OA4B
Lima, Peru
YV5B
Caracas, Venezuela
NCDXF beacon frequencies
14100 kHz
20 m band
18110 kHz
17 m band
21150 kHz
15 m band
24930 kHz
12 m band
28200 kHz
10 m band
Challenges and dedication: the stability of the global wireless network
It does happen that one beacon or another fails due to a defect. Some systems have even been “off the air” for several months because no local supervisor could be found to repair the transmitter or antenna. Unfortunately, this is sometimes unavoidable in a hobby project.
The operation of the global system, which not only provides radio amateurs with up-to-date propagation conditions, costs a lot of commitment and money. The next time you don't know where to make a meaningful donation, the NCDXF will be happy to receive any support.
Tools for effective monitoring of the NCDXF beacon system
There are a number of useful tools available for monitoring and evaluating the NCDXF beacons, a few of which are briefly presented here:
The NCDXF website shows which beacon is currently transmitting to the second.
The VFDB Westphalia district association offers an NCDXF beacon app for smartphones to download.
The evolution of radio monitoring in amateur radio
Of course, time hasn't stood still and you might think that propagation beacons are old hat by now! What are RBN and WSPR for?
The "Reverse Beacon Network" (RBN) and the Weak Signal Propagation Reporter WSPR are, so to speak, the reverse principle of beacon observation. You actively send out test signals yourself and the stations on the other side of the action have become automatic receivers, the so-called spotters, whose feedback can be called up via the Internet. This is a wonderful thing for experiments and antenna comparisons, as well as for an extensive recording of propagation conditions. But back to the situation in the introduction: By the time you have done this job with RBN for all bands from 20 to 10 m, the NCDXF beacon system will probably give you an overview of a large frequency spectrum of the upper shortwave in less time. So - have fun and success with band observation using the NCDXF beacon system.
Literature and references
[1] https://www.ncdxf.org
[2] https://www.hamspirit.de/5884/das-internationale-ncdxf-baken-system-auf-kurzwelle
[3] https://www.ncdxf.org/beacon/beaconSchedule.htm
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FAQ on beacon observation in amateur radio
A propagation beacon is a radio beacon that is used to assess the radio weather and propagation conditions. It transmits signals on permanently assigned amateur radio frequencies and thus provides information about the current propagation conditions. These signals contain information such as the callsign, the location and the transmission power, which is transmitted in graduated dashes in order to assess the propagation conditions.
The NCDXF beacon system, operated by the Northern California DX Foundation and the IARU, consists of 18 beacons that transmit on a fixed time schedule and on five different amateur radio bands. Each beacon transmits sequentially on the 20, 17, 15, 12 and 10 meter bands. The signals provide information about the propagation conditions through their graduated transmission power (from 100 W to 100 mW). By listening to these beacons, radio amateurs can quickly determine which bands and directions currently offer good propagation conditions.
Each beacon transmits on a fixed schedule, with each transmission lasting 10 seconds. The timing is controlled by GPS, which means that the transmission times are precisely synchronized. Radio amateurs can use the schedule to know which beacon is currently transmitting. In addition, there are tools such as apps and websites that show which beacon is currently active.
There are several tools available to monitor the NCDXF beacon system, including:
The NCDXF website, which shows which beacon is transmitting to the second.
Apps for Android and iOS that show the current activity of the beacons.
Programs for Windows, Linux and Mac to support beacon monitoring.
Information in the DX cluster about the activity of the NCDXF beacons.
The NCDXF beacon system transmits fixed signals that radio amateurs receive to assess propagation conditions. In contrast, the Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporter (WSPR) work on the opposite principle. With RBN and WSPR, radio amateurs themselves send out test signals which are received by automatic receivers (spotters) and the data is made available via the Internet. These systems are particularly useful for experiments and antenna comparisons, but do not provide the same quick overview of the upper shortwave bands as the NCDXF beacon system.
