2.5-millimeter band

Amateur radio frequency band The 2.5-millimeter or 122 GHz band is a portion of the EHF (microwave) radio spectrum internationally allocated to amateur radio use between 122.250 GHz and 123.000 GHz. The band is close to a molecular resonance of oxygen at 120 GHz, which causes significant atmospheric propagation losses, similar to that found at 60 GHz. Due to the lack of commercial off the shelf radios, amateurs who operate on the 2.5 mm band must design and construct their own equipment, and those who do, often attempt to set communication distance records for the band. Allocation The International Telecommunication Union allocates 122.250 GHz and 123.000 GHz to amateur radio on a secondary basis. As secondary users, amateurs must protect the fixed, mobile and inter-satellite services from harmful interference, which share the band with amateurs. In addition, 122 GHz to 123 GHz is an ISM band, and all users must accept interference caused by ISM devices. Amateur satellite operations are not permitted, and the ITU's allocations are the same in all three ITU Regions. List of notable frequencies 122.250 to 122.251 GHz Narrow band modes 122.5 GHz ISM band center frequency Distance records The current world distance record on the 2.5 mm band is 139 km mi set by stations K6ML, KB6BA and N9JIM on February 17, 2020.http://www.arrl.org/news/new-world-distance-record-claimed-on-122-ghz New World Distance Record Claimed on 122 GHZ The previous world distance record on the 2.5 mm band was 132 km mi set by Austrian stations OE5VRL and OE3WOG on October 19, 2013. The previous United States distance record was 114 km mi set by stations WA1ZMS and W4WWQ on January 18, 2005. The longest distance achieved on 2.5 mm in the United Kingdom was 51.9 km mi between stations G8CUB and G0FDZ in January 2023. In Australia, the 2.5 mm distance record was 69.6 km mi set by stations VK4FB and VK4CSD on July 18, 2019. See also Amateur radio frequency allocations References http://transition.fcc.gov/oet/spectrum/table/fcctable.pdf FCC Online Table of Frequency Allocations May 7, 2019 47 C.F.R. Federal Communications Commission August 7, 2019 http://www.iaru-r2.org/documents/explorer/files/Plan%20de%20bandas%20%7C%20Band-plan/R2%20Band%20Plan%202016.pdf IARU Region 2 Band Plan International Amateur Radio Union Region 2 16 October 14, 2016 http://www.iaru-r1.org/index.php/documents/func-download/580/chk,f9e4e4a0053473343dfd0d809805d442/no_html,1/ VHF Managers Handbook 7 International Amateur Radio Union Region 1 PDF 54 January 2015 October 27, 2015 June 17, 2018 https://web.archive.org/web/20180617050730/http://www.iaru-r1.org/index.php/documents/func-download/580/chk,f9e4e4a0053473343dfd0d809805d442/no_html,1 dead http://www.arrl.org/files/file/WA50-Standings/Distance-Records-5-April-2020.pdf Distance Records April 5, 2020 Amateur Radio Relay League September 6, 2020 https://www.microwavers.org/index.htm?records.htm Microwave Distance Records Day Peter Quarmby John January 21, 2023 UK Microwave Group January 25, 2023 https://www.wia.org.au/members/records/data/documents/VHF%20Records%20210123.pdf Australian VHF - UHF Records January 23, 2021 Wireless Institute of Australia July 31, 2021 live August 1, 2021 https://web.archive.org/web/20210801025628/https://www.wia.org.au/members/records/data/documents/VHF%20Records%20210123.pdf External links UK Microwave Group's 122 GHz page First 122 GHz VUCC - Mount Greylock Expeditionary Force Category:Amateur radio bands