An amateur radio propagation beacon is a radio beacon, whose purpose is the investigation of the

propagation Propagation can refer to: * Chain propagation in a chemical reaction mechanism *Crack propagation, the growth of a crack during the fracture of materials * Propaganda, non-objective information used to further an agenda * Reproduction, and other fo ...

of radio signals. Most radio propagation beacons use amateur radio frequencies. They can be found on LF, MF, HF, VHF, UHF, and

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

frequencies. Microwave beacons are also used as signal sources to test and calibrate antennas and receivers. The

International Amateur Radio Union The International Amateur Radio Union (IARU) is an international confederation of national organisations that allows a forum for common matters of concern to amateur radio operators worldwide, and collectively represents matters to the Internatio ...

(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 assign ...

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 Radioteletype (RTTY) is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations connected by radio rather than a wired link. Radioteletype evolved from earlier landline teleprinter ...

(F1B) and

PSK31 PSK31 or " Phase Shift Keying, 31 Baud", also BPSK31 and QPSK31, is a popular computer-sound card-generated radioteletype mode, used primarily by amateur radio operators to conduct real-time keyboard-to-keyboard chat, most often using frequencies ...

(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 ("

LowFER LowFER (Low-Frequency Experimental Radio) refers to experimental radio communication practiced by hobbyists on frequency, frequencies below 300 kHz, a part of the radio spectrum known as low frequency. The practitioners are known as "''LowFERs ...

s") 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 ''north ...

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 sout ...

) 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 The 10-meter band is a portion of the shortwave radio spectrum internationally allocated to amateur radio and amateur satellite use on a primary basis. The band consists of frequencies stretching from 28.000 to 29.700 MHz. History The 10 ...

(28 MHz), where they are good indicators of

Sporadic E Sporadic E (usually abbreviated E) is an unusual form of radio propagation using a low level of the Earth's ionosphere that normally does not refract radio waves. Sporadic E propagation reflects signals off relatively small "clouds" in ...

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 states, a federal district, five major unincorporated territori ...

, 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 jurisdicti ...

(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 have access to frequencies in the 70 MHz region, called the

4-meter band The 4-metre (70 MHz) band is an amateur radio band within the lower part of the very high frequency (VHF) band. As only a few countries within and outside of Europe have allocated the band for amateur radio access, the availability of dedica ...

. 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

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

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

(IARU).

IARU Beacon Project

The International Beacon Project (IBP), which is coordinated by th
Northern California DX Foundation
and the

, 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 The Deutscher Amateur Radio Club e.V. (DARC) (in English language, English, German Amateur Radio Club) is a national non-profit organization for amateur radio enthusiasts in Germany. As of 9 July 2019, the organization had 34,009 members, appro ...

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 ...

(). 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 Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic ...

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 ().

The GB3RAL VHF Beacon Cluster

GB3RAL, which is located at the

Rutherford Appleton Laboratory The Rutherford Appleton Laboratory (RAL) is one of the national scientific research laboratories in the UK operated by the Science and Technology Facilities Council (STFC). It began as the Rutherford High Energy Laboratory, merged with the Atlas ...

, 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.