Radio propagation beacon

A 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 HF, VHF, UHF, and microwave frequencies. Microwave beacons are also used as signal sources to test and calibrate antennas and receivers.[1][2]

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).

160 meters 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 meters 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:

IARU Region Beacon Sub-bands
R1
  • 28190-28199 Regional Time Shared
  • 28199-28201 WW Time Shared
  • 28201-28225 Continuous Duty
R2[3]
  • 28190-28199 Regional Time Shared
  • 28199-28201 IBP/NCDXF
  • 28201-28225 Beacons, continuous duty
  • 28225-28300 Shared
R3
  • 28190-28200 IBP

6 meters beacons

In the 6 meters (50 MHz) band, beacons operate in the lower part of the band, in the range 50000 kHz to 50080 kHz. In the United States, the Federal Communications Commission (FCC) only permits unattended 6 meter beacon stations to operate between 50060  and 50080 kHz.[4] 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 meters 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 70,030 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.

Band Beacon Sub-band (MHz)
ITU Region 1 ITU Region 2 ITU Region 3
2 m 144.400-144.490 144.275–144.300 Unknown
1.25 m N/A 222.050–222.060 N/A
70 cm 432.800-432.990 432.300–432.400 Unknown
33 cm N/A Varies Locally N/A
23 cm 1,296.800-1,296.990 1,296.070-1,296.080 Unknown
13 cm 2,320.800-2,320.990 2,304.300-2,304.400 Unknown

The beacon sub-bands in the United Kingdom, also reflect IARU Region 1 recommendations.[5]

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.

Band Beacon Sub-band (MHz)
ITU Region 1 ITU Region 2 ITU Region 3
9 cm 3,400.800-3,400.995 3,456.300-3,456.400 Unknown
5 cm 5,760.800-5,760.995 5,760.300-5,760.400 Unknown
3 cm 10,368.800-10,368.995 10,368.300-10,368.400 Unknown
1.2 cm Beacons are rare

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 Telecommunications Union and the International Amateur Radio Union.

IARU Beacon Project

Beacons from Finland and Madeira on 14.100 MHz

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.[6]

DARC beacon project

The Deutscher Amateur-Radio-Club sponsors two beacons which transmit from Scheggerott, near Kiel ( ​JO44vq).[7] 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.[8] 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).[9]

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.[10]

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.[11] Since 2002, there have been no reception reports for these beacons and the relevant ITU web pages have been removed.[12]

See also

Notes and references

  1. ↑ Andy Talbot, G4JNT (May 2008). "Amateur Beacons". Radio User 3 (5): 56–58. ISSN 1748-8117. The article includes the following definition for beacons licensed in the Amateur Radio service: A station in the Amateur Service or Amateur Satellite Service that autonomously transmits in a fixed format, which may include repeated data or information, for the study of propagation, determination of frequency or bearing, or for other experimental purposes.
  2. ↑ Andy Talbot, G4JNT (August 2008). "Amateur Beacons". Radio User 3 (8): 30–33. ISSN 1748-8117.
  3. ↑ New IARU Region 2 bandplan introduced in January 2008
  4. ↑ 47 C.F.R. § 97.203(d)
  5. ↑ "Amateur Radio UK VHF Bandplan". Great Yarmouth Radio Club. Retrieved 2008-04-27.
  6. ↑ "International Beacon Project". Northern California DX Foundation. 2008. Archived from the original on 2007-12-27. Retrieved 2008-02-27.
  7. ↑ "Aurora beacon DKØWCY". Deutscher Amateur-Radio-Club e.V. (DARC). 2004. Retrieved 2008-05-03.
  8. ↑ Pat Hawker, G3VA (2008). "The DK0WCY/DRA5 Propagation Beacons". Technical Topics Scrapbook - All 50 years. Potters Bar, UK: Radio Society of Great Britain. p. 98. ISBN 978-1-905086-39-9.
  9. ↑ Mike Willis, G0MJW (April 2008). "The GB3RAL VHF Beacon cluster". RadCom (Radio Society of Great Britain) 84 (4): 65–69.
  10. ↑ "WSPRnet".
  11. ↑ "HF 0-20 MHz". Retrieved 2008-03-14.
  12. ↑ "Resolution ITU-R 27: HF Field-strength measurement campaign" (PDF). 1993. Retrieved 2008-03-12.

Further reading

  • R.Wilkinson, G6GVI; S.Cooper, GM4AFF; B. Hansen, OZ2M. "The 70 MHz Beacon List". The Four Metres Website. Retrieved 2008-04-27.
  • John Jaminet, W3HMS and Charlie Heisler, K3VDB (2007). "Building a beacon for 2401 MHz". CQ VHF (CQ Communications, Inc) 10 (3): 44–46. ISSN 1085-0708.