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4-metre band

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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 dedicated commercially manufactured equipment is limited. Most radio amateurs active on the band are interested in home construction or the modification of private mobile radio (PMR) equipment. As a result, communication on the 4-metre band tends to focus on technical topics, with long 'rag chews' being the norm as long as there is some local activity.

History

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Historical Overview

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The 4-meter band, occupying the 70 MHz frequency range, has been historically significant for various regional radio services. Post-World War II, the United Kingdom allocated a segment of the band, specifically 56-68 MHz, to British community radio stations, a provision that lasted until 1949. This allocation was subsequently reassigned for television broadcasting by the BBC. Later developments saw the band's usage extend to France until 1961.

The Radio Society of Great Britain (RSGB) was instrumental in advocating for the allocation of the 4-meter band to British community radio stations in 1956, replacing the 5-meter band. This reallocation provided a mere 200 kHz bandwidth initially, from 70.2–70.4 MHz. It wasn't until later years that the allocation expanded to the current standard of 500 kHz, ranging from 70.0–70.5 MHz.

International attention to the 4-meter band increased during the International Geophysical Year of 1957–1958, with several European countries being assigned frequencies within the 70 to 72.8 MHz spectrum.

International Frequency Allocations

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During the 1990s, the European Radio Communications Office (now ECC) of the CEPT conducted a thorough spectrum analysis, which included the 4-meter band among other frequencies. The investigation's findings, published in 1995, recommended the consideration of the 70 MHz frequency as an amateur radio band, aligning with existing amateur radio service allocations.

For a detailed overview of country-specific allocations within the 4-meter band, refer to the comprehensive table updated regularly on the Four Metres Website (70MHz.org).

Expanding Access and Regulatory Developments

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Several European and African nations have since broadened the 4-meter band's access to amateur radio operators. This shift from traditional commercial usage signifies the band's evolving role in radio communication. The CEPT has recognised the value of the 70 MHz band, leading to regulatory updates that support its use as a secondary amateur service.

Country Allocation Country Allocation Country Allocation
Austria 70 MHz (special licences)
Finland 70.2–70.3 MHz Germany 70.3–70.4 MHz Ireland 70.575–70.775 MHz
The Netherlands 70.3–70.4 MHz Norway 70.6–72.0 MHz Yugoslavia 72.0–72.8 MHz

In March 1993 the European Radio Communications Office (now ECC) of the CEPT launched Phase II of a detailed spectrum investigation (DSI) covering the frequency range 29.7–960.0 MHz. The results were presented in March 1995. Regarding the Amateur Radio Service the DSI management team recommended (among other things) that 70 MHz be considered as an amateur band.

Allocations

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A chart showing how television channel frequencies in various countries relate to the 4 metre amateur band.

The 4-meter band is gaining traction across various regions, with usage extending to amateur radio operators in Europe and Africa. Historically limited to the UK, Gibraltar, and British Military Bases in Cyprus, the band's allocation has evolved due to changes in technology and regulatory stances. The CEPT's recognition of the band for amateur radio use, facilitated by the regulatory footnote "ECA9," has been a significant factor in this growth. CEPT administrations may now authorise the band's usage between 69.9–70.5 MHz for amateur services on a secondary basis.[1]

Regular updates on the allocations are provided on the dedicated Four Metres Website (70MHz.org), reflecting the dynamic nature of frequency management.[2]

Propagation Characteristics

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The propagation characteristics of the 4-meter band are influenced by its position adjacent to the 6-meter band. Propagation primarily occurs via the F2 layer of the ionosphere, similar to higher frequencies, and is augmented by sporadic E layers. The band also experiences unique conditions such as Aurora Borealis and meteor scatter effects, contributing to its versatility.[3]

In Europe, sporadic E permits continent-wide communication, and while the band doesn't typically support the same propagation mechanisms seen in the 6-meter band, its higher frequency allows for more reliable contacts, particularly in northern latitudes.[4]

Propagation

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The propagation characteristics of the 4-meter band are influenced by its position adjacent to the 6-meter band. Propagation primarily occurs via the F2 layer of the ionosphere, similar to higher frequencies, and is augmented by sporadic E layers. The band also experiences unique conditions such as Aurora Borealis and meteor scatter effects, contributing to its versatility.[3]

In Europe, sporadic E permits continent-wide communication, and while the band doesn't typically support the same propagation mechanisms seen in the 6-meter band, its higher frequency allows for more reliable contacts, particularly in northern latitudes.

Equipment and power

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Access to the 4-meter band is somewhat limited due to the scarcity of commercially produced transceivers specifically for this range. However, enthusiasts often utilise equipment that was originally designed for other purposes, modifying it to suit the 70 MHz band. For instance, devices like the Philips FM1000 and the Ascom SE550, while not expressly made for the 4-meter band, are popular among hobbyists for their adaptability and sufficient range for local communications.[1]

Historically, there have been purpose-built amateur radio transceivers for the band, but these are less common today. Notably, some amateur radio operators have repurposed equipment to access the 4-meter frequencies, demonstrating the innovative spirit of the community.[2]

Power Regulations

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The power output of equipment used on the 4-meter band is subject to regulatory constraints to prevent interference with other services. Typically, radio enthusiasts adhere to the stipulated maximum power levels to maintain harmonious use of the spectrum. It's crucial that operators are familiar with and comply with their country's specific regulations regarding power limits for the 4-meter band.[5][6][7]

Activity

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United Kingdom

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In the UK the band has a mix of AM, FM and DX activity, assisted by the recent support for 70 MHz in newer amateur radio equipment. In the UK, the band is also used for emergency communications, Internet Radio Linking Project links (IRLP), data links and low powered remote control.

Ireland

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There is considerable AM activity in the Dublin area. As band occupancy is relatively low, FM operation tends to take place on the 70.45 MHz calling frequency, and AM operation on the 70.26 MHz calling frequency.[citation needed]

Continental Europe

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In Europe the band is still primarily used for more serious DX operation. Cross-band working between the 6-metre band or the 10-metre band is common to make contacts countries where the band is not allocated.[citation needed]

DX operation across Europe and beyond

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During the European summer season, the band is frequently open for DX work across the continent, with the centre of activity for long-distance voice and digital/data communication situated in the lower part of the band. The compact size of both horizontal and vertical antennas designed for the 70 MHz band is beneficial to radio amateurs who enjoy DX work but have insufficient space for larger multi-element antennas designed for lower frequencies.

DX voice traffic in SSB mode can be found around the SSB calling frequency of 70.2 MHz, whereas AM/FM contacts tend can be initiated at the 70.26 MHz AM/FM centre of activity. When the band conditions are poor or in cases where stations operator are able to transmit with modest power levels only, modern digital modes, capable of decoding transmissions down to a -12 dB s/n level, such as PSK31, Thor or Olivia, still permit reliable keyboard-to-keyboard free text communications at relatively large distances. Other more resilient digital modes capable of decoding signal down to -20 dB s/n, such as FT8, JT9 and JT65, offer reliable signal report exchanges at distances of up to several hundred or several thousand kilometres, depending on band conditions.

Countries in which operation is permitted

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Red regions designate areas with known allocations. Blue regions designate areas with experimental allocations.
70 MHz amateur radio allocations by country

Countries with a known band allocation:[8]

Countries with past or current experimental operation

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In "experimental" countries, authorities authorised amateur radio experiments on the band for a limited period of time.

  • Germany 2007-2010 (69.950 MHz center frequency) under a special ("DI2xx") licence.

For class "A" operators in 2014, 70.000-70.030 MHz, and in 2015, 2017, & 2018, 70.150-70.180 MHz were allocated under specific restrictions (25 W ERP, Horiz. polarisation, 12 kHz maximum bandwidth, no portable operation, non interference basis, all transmissions to be logged with frequency, antenna direction, date/time, call signs) for four months, Starting May 2 and ending at the end of August each year (effectively for the sporadic-E season).

On December 19, 2018, BNetzA (the German regulator) published announcement 414/2018 issuing immediate access to 70.150-70.200 MHz for German class "A" (full) licencees up until December 31, 2019, with the same rules as shown above.

  • Sovereign UK bases in Cyprus (70.000–70.500 MHz)
  • An automatic beacon has also been authorised in Austria, Cyprus, and Hungary
  • North Macedonia 70.000 MHz, 70.075 MHz, 70.125 MHz and 70.275 MHz Starting in May 2019, N. Macedonia amateurs may apply for a one-year experimental permit granting access to 4 meters.
  • Italy (70.0875–70.1125, 70.1875–70.2125, and 70.2875–70.3125 MHz) only on temporary basis during 2007-2008-2010-2012-2014-2023 (August 6-December 31), also 70.3875-704125 MHz in 2024 (August 30-December 31)
  • Bonaire 70.000-70.500 MHz on a temporary basis from December 2022 until December 2023, might be renewed.
  • Sweden 70.125-70.150 MHz authorised only for a few stations with special permits (status 9/2024)

Others

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  • United States has one experimental transmitter, station WE9XFT in Virginia, transmitting CW on 70.005 MHz. The beacon continues to be operated under the Experimental radio service call sign WG2XPN and is active as of March 2021.[32][33]
  • A petition was filed with the U.S. Federal Communications Commission on 27 January 2010 to create a new U.S. 4-meter amateur radio allocation at 70 MHz to parallel those in Europe and other parts of the world.[34] This petition was subsequently rejected by the FCC.

Common uses of the 4-metre band

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References

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  1. ^ a b "CEPT ECC Recommendation (05)06," Electronic Communications Committee (ECC) within the European Conference of Postal and Telecommunications Administrations (CEPT)
  2. ^ a b "National Frequency Allocations," Four Metres Website (70MHz.org)
  3. ^ a b "Understanding Radio Wave Propagation," [Author's Name], Journal of Radio Sciences
  4. ^ "Propagation of Radio Waves," [Author's Name], [Title of the Publication]
  5. ^ "Modified Equipment for the 4-meter Band," [Author's Name], [Title of the Publication]
  6. ^ "Innovations in Amateur Radio Equipment," [Author's Name], [Journal Name]
  7. ^ "Regulatory Framework for the 70 MHz Band," [Regulatory Body], [Document Title]
  8. ^ "International 70 MHz allocations". The Four Metres Website. Archived from the original on 8 June 2009. Retrieved 15 November 2009.
  9. ^ "Frequentiebanden en technische eigenschappen toegestaan voor de verschillende klassen van radioamateurvergunningen" (PDF). bipt.be. Archived from the original (PDF) on 2016-03-08. Retrieved 2016-03-07.
  10. ^ "Government Gazette September 23 2024 page 1461". gov.ky. Retrieved 2024-10-24.
  11. ^ retsinformation.dk, BEK nr 829 af 09/08/2019: Bekendtgørelse om anvendelse af radiofrekvenser uden tilladelse samt om amatørradioprøver og kaldesignaler m.v., backup
  12. ^ oz1ln.dk: 70 MHz Repeaters in Denmark
  13. ^ "Amatöörraadioside raadiosagedusalad, saateliigid, kiirgusklassid ja suurimad saatevõimsused" (PDF). Riigi Teataja (in Estonian). 28 March 2005.
  14. ^ "Radioamatöörimääräys" (PDF). The Finnish Communications Regulatory Authority (FICORA). 4 November 2009. pp. 11, 13. Retrieved 15 November 2009.
  15. ^ "Amateurfunkdienst; befristeter Zugang im Frequenzbereich 70,150 – 70,200 MHz" (PDF). bundesnetzagentur.de. Archived (PDF) from the original on 18 January 2022.
  16. ^ "Licensing". The National Radio Amateur Association of Greece. Archived from the original on January 1, 2006. Retrieved 15 December 2015.
  17. ^ "Ανάρτηση Πράξεων στο Διαδίκτυο | Πρόγραμμα Δι@ύγεια -".
  18. ^ "Radio Amateur Technical Licence Conditions". Amateur Station License Guidelines. ComReg. 5 February 2016. Reference Number 09/45 R4. Retrieved 23 April 2018.
  19. ^ "National Radio Frequency Plan".
  20. ^ "Monaco gets 70 MHz allocation". The Southgate Amateur Radio Club. March 2006. Archived from the original on 15 April 2013. Retrieved 15 November 2009.
  21. ^ "Regeling van de Minister van Economische Zaken, Landbouw en Innovatie van 20 december 2011, nr. AT-EL&I/6621235, tot wijziging van de Regeling gebruik van frequentieruimte zonder vergunning 2008 in verband met de implementatie van twee besluiten van de Commissie van de Europese Gemeenschappen en het vergunningvrij maken van het gebruik van grond- en muur penetrerende radar". overheid.nl. 2011-12-30. Retrieved 2012-03-01.
  22. ^ "Forskrift om radioamatørlisens". The Norwegian Law Gazette. 2019-05-03. Retrieved 2021-10-06.
  23. ^ "International 70 MHz allocations". 70mhz.org. 2017-07-13. Retrieved 2018-04-22.
  24. ^ "Faixa dos 70 MHz". ANACOM. 4 June 2007. Archived from the original on 22 October 2007. Retrieved 15 November 2009.
  25. ^ "Serbia gets on 4m". September 2020.
  26. ^ "VYHLÁŠKA Úradu pre reguláciu elektronických komunikácií a poštových služieb z 22. augusta 2022, ktorou sa ustanovujú prevádzkové podmienky pre amatérske stanice" (PDF). Zbierka zákonov Slovenskej republiky. 1 Sep 2022. Retrieved 15 December 2022.
  27. ^ "70 MHz Band Plan for South Africa". The South African Radio League. 2017. Archived from the original on 28 April 2010. Retrieved 24 October 2021.
  28. ^ "Telecommunications Act of 1996, as amended" (PDF). The South African Radio League. February 2005. p. 23. Archived from the original (PDF) on 2016-01-12. Retrieved 15 November 2009. 70.000-70.300 Secondary
  29. ^ "Libéralisation de la bande 4m en Suisse dès le 1er janvier 2023". USKA. December 2022.
  30. ^ "United Kingdom Table of Radio Frequency Allocations". Ofcom. Retrieved 15 November 2009. The band 70.0-70.5 MHz is allocated to the Amateur service.
  31. ^ "UK Interface Requirement 2028 - Amateur Radio Licences – Foundation, Intermediate, and Full" (PDF). Ofcom. January 2007. p. 12. Archived from the original (PDF) on 31 March 2010. Retrieved 15 November 2009.
  32. ^ "WG2XPN Callsign Page". QRZ Callsign Database.
  33. ^ "OET Experimental Licensing System Generic Search". apps.fcc.gov.
  34. ^ "FCC petition for 4-metre band". QRZ.com. January 2010. Retrieved 27 January 2010.
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