An amateur radio propagation beacon is a radio beacon, whose purpose is the investigation of the propagation of radio signals. Most radio propagation beacons use

amateur radio Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communi ...

frequencies. They can be found on LF, MF, HF,

VHF Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter. Frequencies immediately below VHF ...

UHF Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (on ...

, and

microwave Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequency, frequencies between 300 MHz and 300 GHz respectively. Different sources define different fre ...

frequencies. Microwave beacons are also used as signal sources to test and calibrate antennas and receivers. The International Amateur Radio Union (IARU) and its member societies coordinate beacons established by radio amateurs.

Transmission characteristics

Most beacons operate in continuous wave (A1A) and transmit their identification (

call sign In broadcasting and radio communications, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a unique identifier for a transmitter station. A call sign can be formally assig ...

and location). Some of them send long dashes to facilitate signal strength measurement. A small number of beacons transmit

Morse code Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one ...

by frequency-shift keying (F1A). A few beacons transmit signals in digital modulation modes, like radioteletype (F1B) and PSK31 (G1B).

Legality

In the US, unattended beacons on frequencies lower than the 10-meter band are not legal.

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 (" 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 North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''no ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

) bandplan for the 160-meter band 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-meter band (28 MHz), 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

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 6-meter band (50 MHz) openings. Beacons traditionally operate in the lower part of the band, in the range 50.000 MHz to 50.080 MHz. IARU Region 1 is encouraging individual beacons to move to 50.4 MHz to 50.5 MHz. In the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

, the

Federal Communications Commission The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisd ...

(FCC) only permits unattended 6-meter beacon stations to operate between 50.060 and 50.080 MHz. Amateur beacons at 50 MHz have also been used as signal sources for academic propagation research

4-meter beacons

Several countries in

ITU Region 1 The International Telecommunication Union (ITU), in its International Radio Regulations, divides the world into three ITU regions for the purposes of managing the global radio spectrum. Each region has its own set of frequency allocations, the ma ...

have access to frequencies in the 70 MHz region, called the 4-meter band. The band shares many propagation characteristics with 6 meters. The preferred location for beacons is 70.000–70.090 MHz; however, in countries where this segment is not allocated to Amateur Radio, beacons may operate elsewhere in the band.

United States

Brian Justin, WA1ZMS, of Forest, Virginia, applied for an experimental license to operate a propagation beacon on 4m with the FCC in January 2010. It was approved, and at 1200 UTC on Monday, May 3, 2010, the beacon went operational under the callsign WE9XFT. The beacon sits on Apple Orchard Mountain (4200 feet above sea level), a mountain along the Blueridge Parkway in Maidenhead grid square FM07fm, near Bedford, Virginia. Because there is no amateur band on 70 MHz in the United States, the beacon runs 24 hours a day under a non-amateur experimental license. Justin told the ARRL that he had no plans to introduce the 4-meter band to the United States, despite the fact that numerous European governments allow amateurs rights on the band. He said, "This beacon is solely for radio scientific usage as an E-skip detecting device" On 70.005 MHz, WE9XFT is transmitting 3 kW ERP to Europe. At the same location, Justin runs a 144 MHz remote-controlled transmitter, WA1ZMS. It is GPS locked and uses two 5-element stacked Yagis beaming at 60 degrees with a 500 W transmitter running at 7 kW ERP. Both signals are audible in the United States and Europe.

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

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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-centimeter 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).

IARU Beacon Project

The International Beacon Project (IBP), which is coordinated by th
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 Kiel () is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 246,243 (2021). Kiel lies approximately north of Hamburg. Due to its geographic location in the southeast of the Jutland pe ...

(). 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 The Radio Society of Great Britain (RSGB) is the United Kingdom's recognised national society for amateur radio operators. The society was founded in 1913 as the London Wireless Club, making it one of the oldest organisations of its kind in the ...

operates a radio propagation beacon GB3ORK on 5290 kHz, transmitting every 15 minutes commencing at 2 minutes past the hour. It is located in the

Orkney Islands Orkney (; sco, Orkney; on, Orkneyjar; nrn, Orknøjar), also known as the Orkney Islands, is an archipelago in the Northern Isles of Scotland, situated off the north coast of the island of Great Britain. Orkney is 10 miles (16 km) no ...

().

The GB3RAL VHF Beacon Cluster

GB3RAL, which is located at the Rutherford Appleton Laboratory, transmits continuously on a number of low-band and mid-band VHF frequencies 40050, 50050, 60050 and 70050 kHz as well as 28215 kHz in the 10-meter amateur band.

Weak Signal Propagation Reporter Network (WSPR)

A large-scale 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.

Synchronized Beacon Project

The Synchronized Beacon Project (SBP) is an effort to deploy coordinated beacon transmitters on 50 MHz using a one-minute transmitting sequence of PI4, CW, and unmodulated carrier. Since modern beacon transmitters are multi-mode and frequency-agile, beacons that normally transmit on other time-multiplexed modes such as WSPR can take part in the SBP when not transmitting in their primary mode. Beacons alternating between frequencies on the same band should sign CALL/S when transmitting on the SBP frequency to ensure unique entries in band-specific propagation report databases.