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 frequencies. They can be found on LF, MF, HF, VHF, UHF, and microwave frequencies. Microwave beacons are also used as signal sources to test and calibrate antennas and receivers. [1] [2]
The International Amateur Radio Union (IARU) and its member societies coordinate beacons established by radio amateurs.
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).
In the US, unattended beacons on frequencies lower than the 10-meter band are not legal. [3]
Amateur experiments in the 2200-meter band (135.7–137.8 kHz) often involve operating temporary beacons.
In the United States and Canada, unlicensed experimenters ("LowFERs") establish low power beacons on radio frequencies between 160 kHz and 190 kHz.
The International Amateur Radio Union Region 2 (North and South America) bandplan for the 160-meter band reserves the range 1999 kHz to 2000 kHz for propagation 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:
IARU Region | Beacon Sub-bands (MHz) |
---|---|
R1 |
|
R2 [4] |
|
R3 |
|
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. [4] [5] 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. [6]
Amateur beacons at 50 MHz have also been used as signal sources for academic propagation research [7]
Several countries in ITU Region 1 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; [5] however, in countries where this segment is not allocated to Amateur Radio, beacons may operate elsewhere in the band.
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.
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.
Band | Beacon Sub-band (MHz) | ||
---|---|---|---|
ITU Region 1 | ITU Region 2 | ITU Region 3 | |
2 m | 144.400–144.491 [5] | 144.275–144.300 [4] [9] | none [10] |
1.25 m | — | 222.050–222.060 [4] [9] | — |
70 cm | 432.400–432.490 [5] | 432.300–432.400 [4] [9] | none [10] |
33 cm | — | 903.000–903.100 [4] [9] | — |
23 cm | 1,296.800–1,296.994 [5] | 1,296.200–1,296.400 [4] [9] | none [10] |
13 cm | 2,320.800–2,321.000 [5] | 2,304.300–2,304.400 [4] [9] | 2,304.300–2,304.400 [10] |
The beacon sub-bands in the United Kingdom also reflect IARU Region 1 recommendations. [11]
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.
Band | Beacon Sub-band (MHz) | ||
---|---|---|---|
ITU Region 1 | ITU Region 2 | ITU Region 3 | |
9 cm | 3,400.800–3,400.995 [5] | 3,456.300–3,457.000 [4] [9] | 3,456.300–3,457.000 [10] |
5 cm | 5,760.800–5,760.990 [5] | 5,760.300–5,761.000 [4] [9] | 5,760.300–5,761.000 [10] |
3 cm | 10,368.800–10,368.990 [5] | 10,368.300–10,368.400 [4] [9] | 10.368.300–10.368.400 [10] |
1.2 cm | 24,048.800–24,048.995 [5] | 24,048.750–24,048.995 [4] | 24,048.750–24,048.995 [10] |
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).
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. [12]
The Deutscher Amateur-Radio-Club sponsors two beacons which transmit from Scheggerott, near Kiel ( JO44vq). [13] 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. [14] DK0WCY operates also a limited service beacon on 3579 kHz at 0720–0900 and 1600–1900 local time.
The Radio Society of Great Britain 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 ( IO89ja).
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. [15]
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. [16]
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. [17]
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: CS1 maint: multiple names: authors list (link)Shortwave radio is radio transmission using shortwave (SW) radio frequencies. There is no official definition of the band, but the range always includes all of the high frequency band (HF), which extends from 3 to 30 MHz ; above the medium frequency band (MF), to the bottom of the VHF band.
Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter. Frequencies immediately below VHF are denoted high frequency (HF), and the next higher frequencies are known as ultra high frequency (UHF).
Medium frequency (MF) is the ITU designation for radio frequencies (RF) in the range of 300 kilohertz (kHz) to 3 megahertz (MHz). Part of this band is the medium wave (MW) AM broadcast band. The MF band is also known as the hectometer band as the wavelengths range from ten to one hectometers. Frequencies immediately below MF are denoted low frequency (LF), while the first band of higher frequencies is known as high frequency (HF). MF is mostly used for AM radio broadcasting, navigational radio beacons, maritime ship-to-shore communication, and transoceanic air traffic control.
The FM broadcast band is a range of radio frequencies used for FM broadcasting by radio stations. The range of frequencies used differs between different parts of the world. In Europe and Africa and in Australia and New Zealand, it spans from 87.5 to 108 megahertz (MHz) - also known as VHF Band II - while in the Americas it ranges from 88 to 108 MHz. The FM broadcast band in Japan uses 76 to 95 MHz, and in Brazil, 76 to 108 MHz. The International Radio and Television Organisation (OIRT) band in Eastern Europe is from 65.9 to 74.0 MHz, although these countries now primarily use the 87.5 to 108 MHz band, as in the case of Russia. Some other countries have already discontinued the OIRT band and have changed to the 87.5 to 108 MHz band.
In radio communication, skywave or skip refers to the propagation of radio waves reflected or refracted back toward Earth from the ionosphere, an electrically charged layer of the upper atmosphere. Since it is not limited by the curvature of the Earth, skywave propagation can be used to communicate beyond the horizon, at intercontinental distances. It is mostly used in the shortwave frequency bands.
The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz). Electromagnetic waves in this frequency range, called radio waves, are widely used in modern technology, particularly in telecommunication. To prevent interference between different users, the generation and transmission of radio waves is strictly regulated by national laws, coordinated by an international body, the International Telecommunication Union (ITU).
The 6-meter band is the lowest portion of the very high frequency (VHF) radio spectrum internationally allocated to amateur radio use. The term refers to the average signal wavelength of 6 meters.
160-meter band refers to the band of radio frequencies between 1.8 and 2 MHz, just above the medium wave broadcast band. For many decades the lowest radio frequency band allocated for use by amateur radio, before the adoption, at the beginning of the 21st century in most countries, of the 630- and 2200-meter bands. Amateur operators often refer to 160 meters as the Top Band It is also sometimes nicknamed the "Gentleman's Band" in contrast to the often-freewheeling activity in the 80-, 40- and 20-meter bands.
The 80-meter or 3.5 MHz band is a band of radio frequencies allocated for amateur radio use, from 3.5 to 4.0 MHz in IARU Region 2, and generally 3.5 to 3.8 or 3.9 MHz in Regions 1 and 3 respectively. The upper portion of the band, which is usually used for phone (voice), is sometimes referred to as 75 meters. In Europe, 75m is a shortwave broadcast band, with a number of national radio services operating between 3.9 and 4.0 MHz.
The 40-meter or 7-MHz band is an amateur radio frequency band, spanning 7.000-7.300 MHz in ITU Region 2, and 7.000-7.200 MHz in Regions 1 & 3. It is allocated to radio amateurs worldwide on a primary basis; however, only 7.000-7.200 MHz is exclusively allocated to amateur radio worldwide. Shortwave broadcasters and land mobile users also have primary allocations in some countries, and amateur stations must share the band with these users.
The 20-meter or 14-MHz amateur radio band is a portion of the shortwave radio spectrum, comprising frequencies stretching from 14.000 MHz to 14.350 MHz. The 20-meter band is widely considered among the best for long-distance communication (DXing), and is one of the most popular—and crowded—during contests. Several factors contribute to this, including the band's large size, the relatively small size of antennas tuned to it and its good potential for daytime DX operation even in unfavorable propagation conditions.
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.
The 60-meter band or 5 MHz band is a relatively new amateur radio allocation, first introduced in 2002, that was originally only available in a few countries, such as the United States, United Kingdom, Norway, Finland, Denmark, Ireland and Iceland. Over a number of years however, an increasing proportion of countries' telecommunications administrations – together with their government and military users – have permitted Amateur Radio operation in the 5 MHz area on a short or longer-term basis, ranging from discrete channels to a frequency band allocation.
Amateur radio frequency allocation is done by national telecommunication authorities. Globally, the International Telecommunication Union (ITU) oversees how much radio spectrum is set aside for amateur radio transmissions. Individual amateur stations are free to use any frequency within authorized frequency ranges; authorized bands may vary by the class of the station license.
The World Administrative Radio Conference (WARC) bands are three portions of the shortwave radio spectrum used by licensed and/or certified amateur radio operators. They consist of 30 meters (10.100–10.150 MHz), 17 meters (18.068–18.168 MHz) and 12 meters (24.890–24.990 MHz). They were named after the World Administrative Radio Conference, which in 1979 created a worldwide allocation of these bands for amateur use. The bands were opened for use in the early 1980s. Due to their relatively small bandwidth of 100 kHz or less, there is a gentlemen's agreement that the WARC bands may not be used for general contesting. This agreement has been codified in official recommendations, such as the IARU Region 1 HF Manager's Handbook, which states: "Contest activity shall not take place on the 5, 10, 18 and 24 MHz bands."
An international distress frequency is a radio frequency that is designated for emergency communication by international agreement.
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 3,000 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is widely used in modern technology, in radio communication, radar, radio navigation, remote control, remote sensing, and other applications.
The 3-centimeter or 10 GHz band is a portion of the SHF (microwave) radio spectrum internationally allocated to amateur radio and amateur satellite use on a secondary basis. The amateur radio band is between 10.00 GHz and 10.50 GHz, and the amateur satellite band is between 10.45 GHz and 10.50 GHz. The allocations are the same in all three ITU regions.
The 5-meter band (60 MHz) is the middle portion of the very high frequency (VHF) radio spectrum allocated to amateur radio use.
The 8-meter band (40 MHz) is the lowest portion of the very high frequency (VHF) radio spectrum allocated to amateur radio use. The term refers to the average signal wavelength of 8 meters.