Radio propagation beacon

Transmission characteristics

Most beacons operate in continuous wave (A1A) and transmit their identification (call sign and location). Some of them send long dashes to facilitate signal strength measurement. A small number of beacons transmit Morse code by frequency shift keying (F1A). A few beacons transmit signals in digital modulation modes, like radioteletype (F1B) and PSK31 (G1B).

2200 meter beacons

Amateur experiments in the 2200-meter band (135.7-137.8 kHz) often involve operating temporary beacons.

1750 meter beacons

In the United States and Canada, unlicensed experimenters called Lowfers establish low power beacons on radio frequencies between 160 kHz and 190 kHz.

160 meter beacons

The International Amateur Radio Union Region 2 (North and South America) bandplan for 160 meters reserves the range 1999 kHz to 2000 kHz for propagation beacons.

10 meter beacons

Most high frequency radio propagation beacons are found in the 10 meters (28 MHz) frequency band, where they are good indicators of Sporadic E ionospheric propagation. According to IARU bandplans, the following 28 MHz frequencies are allocated to radio propagation beacons:

6 meter beacons

In the 6 meter (50 MHz) band, beacons operate in the lower part of the band, traditionally in the range 50.000 MHz to 50.080 MHz. The IARU is encouraging individual beacons to move to 50.4 MHz to 50.5 MHz to assist with the establishment of the Synchronised 50 MHz Beacon Project. In the United States, the Federal Communications Commission (FCC) only permits unattended 6 meter beacon stations to operate between 50.060  and 50.080 MHz. Due to unpredictable and intermittent long distance propagation, usually achieved by a combination of ionospheric conditions, beacons are very important in providing early warning for 50 MHz openings.

4 meter beacons

Several countries in ITU Region 1 have access to frequencies in the 70 MHz region, called the 4 meters band. The band shares many propagation characteristics with 6 meters. The preferred location for beacons is 70,000  to 70,090 kHz; however, in countries where this segment is not allocated to Amateur Radio, beacons may operate elsewhere in the band.

VHF/UHF beacons

Beacons on 144 MHz and higher frequencies are mainly used to identify tropospheric radio propagation openings. It is not uncommon for VHF and UHF beacons to use directional antennas. Frequencies set aside for beacons on VHF and UHF bands vary widely in different ITU regions and countries.

The beacon sub-bands in the United Kingdom, also reflect IARU Region 1 recommendations.

SHF/Microwave beacons

In addition to identifying propagation, microwave beacons are also used as signal sources to test and calibrate antennas and receivers. SHF beacons are not as common as beacons on the lower bands, and beacons above the 3 centimeters band (10 GHz) are unusual.

Beacon projects

Most radio propagation beacons are operated by individual radio amateurs or amateur radio societies and clubs. As a result, there are frequent additions and deletions to the lists of beacons. There are, however a few major projects coordinated by organizations like the International Amateur Radio Union.

IARU Beacon Project

Main article: International Beacon Project

The International Beacon Project (IBP), which is coordinated by the Northern California DX Foundation and the International Amateur Radio Union, consists of 18 high frequency propagation beacons worldwide, which transmit in turns on 14.100 MHz, 18.110 MHz, 21.150 MHz, 24.930 MHz, and 28.200 MHz.

DARC beacon project

The Deutscher Amateur-Radio-Club sponsors two beacons which transmit from Scheggerott, near Kiel ( ​JO44vq). These beacons are DRA5 on 5195 kHz and DK0WCY on 10144 kHz. In addition to identification and location, every 10 minutes these beacons transmit solar and geomagnetic bulletins. Transmissions are in Morse code for aural reception, RTTY and PSK31. DK0WCY operates also a limited service beacon on 3579 kHz at 0720–0900 and 1600–1900 local time.

RSGB 5 MHz beacon project

The Radio Society of Great Britain operates three radio propagation beacons on 5290 kHz, which transmit in sequence, for one minute each, every 15 minutes. The project includes GB3RAL near Didcot ( ​IO91in), GB3WES in Cumbria ( ​IO84qn) and GB3ORK in the Orkney Islands ( ​IO89ja). GB3RAL, which is located at the Rutherford-Appleton Laboratory, also transmits continuously on 28215 kHz and on a number of low VHF frequencies (40050, 50050, 60050 and 70050 kHz).

Weak Signal Propagation Reporter Network

A large-scale amateur radio propagation beacon project is underway using the WSPR transmission scheme included with the WSJT software suite. The loosely coordinated beacon transmitters and receivers, collectively known as the WSPRnet, report the real-time propagation characteristics of a number of frequency bands and geographical locations via the Internet. The WSPRnet website provides detailed propagation report databases and real-time graphical maps of propagation paths.

Past Beacon Projects

As part of an International Telecommunications Union-funded project, radio propagation beacons were installed by national authorities at Sveio, Norway (callsign LN2A, ​JO29po) and at Darwin, Australia (callsign VL8IPS, ​PH57pj). The beacons operated on frequencies 5471.5 kHz, 7871.5 kHz, 10408.5 kHz, 14396.5 kHz, and 20948.5 kHz. Since 2002, there have been no reception reports for these beacons and the relevant ITU web pages have been removed.