The 630 meter (or 600 meter) amateur radio band is a frequency band allocated by the International Telecommunication Union (ITU) to amateur radio operators, and it ranges from 472 to 479 kHz, or equivalently 625.9 to 635.1 meters wavelength. It was formally allocated to amateurs at the 2012 World Radiocommunication Conference (WRC-12). The band is available on a secondary basis in all ITU regions with the limitation that amateur stations have maximum radiated power of 1 Watt effective isotropic radiated power (EIRP); however, stations more than 800 km from certain countries may be permitted to use 5 Watts EIRP.
The new WRC-12 allocation did not take formal effect until 1 January 2013. However, several countries previously allocated the WRC-12 band to amateurs domestically. Previously, several other countries have authorized temporary allocations or experimental operations on nearby frequencies.
During the 2012 World Radiocommunication Conference (WRC-12) of the International Telecommunication Union, a 15 kHz allocation to the amateur radio service was considered on a secondary use basis. The frequencies studied were between 415 kHz and 526.5 kHz. The result was that 472–479 kHz was identified as agreeable for all three ITU Regions, except for some countries such as Russia, China and Arab states. WRC-12 re-allocated the original 500 kHz frequency back to exclusive maritime mobile use for new navigation systems. On 14 February 2012, the delegates at WRC-12 formally approved allocating 472–479 kHz to the amateur radio service; however, this new allocation will not take effect until it is entered into the ITU's Radio Regulations. Following that, individual regulatory authorities need to implement the change nationally in order to make the allocation available to radio amateurs under their jurisdiction.
Recently amateurs have experimented with weak-signal radio communication near 474.2 kHz, utilising WSPR.
Countries in which operation is permitted
Countries with a known band allocation
In Australia amateurs now have an allocation from 472 to 479 kHz, known as the 630 metre band. The maximum EIRP is 5 Watts.
In Belgium, on 14 August 2013, a new allocation of 472 to 479 kHz has been added to the existing allocation of 501 to 504 kHz for ham-radio operators holding a HAREC-class license. The maximum EIRP is 5 Watts. All modes are permitted. 
In the United States of America, the Federal Communications Commission approved allocating 472 to 479 kHz on a secondary basis to the amateur service, in a report and order released on 29 March 2017. Amateurs wishing to operate on the band will need to notify the Utilities Technology Council (UTC) and be separated at least 1 km from electric transmission lines that carry Power line Communication (PLC) signals that use the same band. The maximum EIRP is 5 Watts with the transmitter output power not exceeding 1,500 Watts PEP. CW, RTTY, data, phone, and image emissions are allowed. The first US amateur stations activated the band on Friday 13 October 2017.
As of December 2012, amateurs in some other countries continue to operate on their pre-WRC-12 permits on other frequencies.
Allocations before WRC-12
In Belgium, amateurs were allocated 501–504 kHz on a secondary basis on 15 January 2008. Only CW may be used with a maximum ERP of 5 W. On 14 August 2013, an additional allocation for 472 to 479 kHz has been added allowing all modes of transmission.
In Norway, the band 493–510 kHz was allocated to radio amateurs on 6 November 2009. Only radiotelegraphy is permitted. After WRC-12, this allocation was replaced with an allocation of 472 to 479 kHz.
In New Zealand, the band 505–515 kHz was allocated to amateur radio temporarily, "pending an international frequency allocation", on 1 March 2010. Amateur use is on a non-interference basis, and transmissions are limited to 25 Watts EIRP, with a bandwidth not exceeding 200 Hz. Now that an international frequency allocation has been made by the ITU and subsequently implemented in New Zealand, this temporary band is being phased out. A transition period of one year was given for amateurs to move to the new allocation. Use of this band will not be permitted after 31 December 2013.
Countries with past or current experimental operation
Other regions have granted experimental uses for selected licensees in advance of any international frequency allocation.
The U.S. Federal Communications Commission (FCC) granted the American Radio Relay League an experimental license to explore such uses in September 2006. Eleven years later, the US FCC granted access to all amateurs with a general (or higher) license, effective 13 October 2017.
Countries in which operation is prohibited
As part of the compromise to allocate the band, a new footnote was added to the ITU's Table of Frequency Allocations, which prohibits amateur operation between 472 and 479 kHz in many countries:
- Maritime band, or 500 kHz
- Maritime mobile amateur radio
- Medium frequency radio propagation
- Radio propagation
- §5.80A: The maximum equivalent isotropically radiated power (EIRP) of stations in the Amateur Service using frequencies in the band 472-479 kHz shall not exceed 1 W. Administrations may increase this limit of EIRP to 5 W in portions of their territory which are at a distance of more than 800 km from the borders of Algeria, Saudi Arabia, Azerbaijan, Bahrain, Belarus, China, Comoros, Djibouti, Egypt, United Arab Emirates, the Russian Federation, Iran, Iraq, Jordan, Kazakhstan, Kuwait, Lebanon, Libya, Morocco, Mauritania, Oman, Uzbekistan, Qatar, Syrian Arab Republic, Kyrgyzstan, Somalia, Sudan, Tunisia, Ukraine and Yemen. In this frequency band, stations in the amateur service shall not cause harmful interference to, or claim protection from, stations of the aeronautical radionavigation service. (WRC-12)
- Sumner, David (2012-04-01). Ford, Steve, ed. "A New Band is Born!". QST. Newington, CT: American Radio Relay League. 96 (4): 9. ISSN 0033-4812.
- Keane, S Khrystyne (2012-04-01). Ford, Steve, ed. "Happenings". QST. Newington, CT: American Radio Relay League. 96 (4): 77. ISSN 0033-4812.
- Sumner, David (2012-05-01). Ford, Steve, ed. "WRC-12 Results in New Amateur MF Allocation". QST. Newington, CT: American Radio Relay League. 96 (5): 62–66. ISSN 0033-4812.
- "Amateur MF Allocation Moves a Step Closer". ARRL. 2011-02-24. Retrieved 2011-02-25.
- "Amateur Radio Gets Secondary MF Allocation at WRC-12". 2012-02-14. Retrieved 2012-02-14.
- "Radio Amateurs in Spain, Argentina Gain New and Extended Bands". arrl.org. American Radio Relay League. Retrieved 11 April 2018.
- "BIPT - Besluit van de Raad van het BIPT van 13 Augustus 2013 betreffende de toegang van de radioamateurs tot de frequentiebanden 472,000-479,000 kHz en 70,1900-70,4125 MHz" (in Dutch). Retrieved 2013-09-07.
- "Canadian Table of Frequency Allocations". 2014. Retrieved 2015-02-15.
- Canadian radio amateurs gain new 472-479khz band ARRL.org
- "Décision no 2013-1515" [Decision No. 2013-1515] (PDF) (Press release) (in French). Autorité de Régulation des Communications Électroniques et des Postes. Réseau des Émetteurs Français. 2013-12-17. pp. 4–5. Archived (PDF) from the original on 2014-03-17. Retrieved 2014-03-17.
- "German radio hams gain access to 472-479 kHz". Southgate Amateur Radio Club. 2012-06-14. Retrieved 2012-08-22.
- "Radiocommunications Regulations (General User Radio Licence for Amateur Radio Operators) Notice 2012". New Zealand Government Website. 2012-12-07. Retrieved 2012-12-12.
- "Forskrift om radioamatørlisens" (in Norwegian). Lovdata. Retrieved 2014-04-16.
- "Philippine Radio Hams get 7,200-7,300 kHz". Southgate Amateur Radio Club. 2012-09-01. Retrieved 2012-09-02.
- "Pierwsze eksperymenty w paśmie 630 m" (in Polish). 2014-02-23. Retrieved 2015-02-12.
- "472-479 kHz in Monaco". International Amateur Radio Union - Region 1. 2012-05-29. Retrieved 2012-09-04.
- "FCC Report and Order 17-33" (PDF). Federal Communications Commission (published 29 March 2017). 27 March 2017. Retrieved 31 March 2017.
- "New ham bands spring to life; Veteran LF experimenter denied amateur access to 2200 meters". Newington, CT: ARRL. 2017-10-17. Retrieved 2017-10-20.
- Colin Thomas, G3PSM; Hans Timmerman, PB2T (2010-08-15). "500 kHz". IARU Region 1. Retrieved 2012-04-15.
- "Forskrift om radioamatørlisens (Amateur Radio Regulations)" (in Norwegian). Lovdata. Retrieved 2009-11-08.
- Roy Symon, ZL2KH (2010-02-24). "2010 NZ Amateurs Granted Access to 600 metre Band". NZART. Retrieved 2012-04-15.
- "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. 2012-12-30. Retrieved 2012-01-03.
- QST. American Radio Relay League: 62. 2006-12-01.
- "New ham bands spring to life". Newington, CT: American Radio Relay League. Retrieved 2017-10-22.
- FCC 17-33 (PDF). Report and Order. Washington, DC: Federal Communications Commission (published 29 March 2017). 27 March 2017.
- "Special Research Permits in the region of 501 kHz". RSGB. Retrieved 2011-02-25.
- §5.80B: The use of the frequency band 472-479 kHz in Algeria, Saudi Arabia, Azerbaijan, Bahrain, Belarus, China, Comoros, Djibouti, Egypt, United Arab Emirates, the Russian Federation, Iraq, Jordan, Kazakhstan, Kuwait, Lebanon, Libya, Mauritania, Oman, Uzbekistan, Qatar, Syrian Arab Republic, Kyrgyzstan, Somalia, Sudan, Tunisia and Yemen is limited to the maritime mobile and aeronautical radionavigation services. The Amateur Service shall not be used in the above-mentioned countries in this frequency band, and this should be taken into account by the countries authorizing such use. (WRC-12)
- Proposal for experimental amateur radio access to 500 kHz by the Radio Society of Great Britain
- The 500 KC Experimental Group for Amateur Radio
- International Telecommunication Union
|Range||Band||ITU Region 1||ITU Region 2||ITU Region 3|
|LF||2200 m||135.7 kHz – 137.8 kHz|
|MF||630 m||472 kHz – 479 kHz|
|160 m||1.810 MHz – 1.850 MHz||1.800 MHz – 2.000 MHz|
|HF||80 / 75 m||3.500 MHz – 3.800 MHz||3.500 MHz – 4.000 MHz||3.500 MHz – 3.900 MHz|
|60 m||5.3515 MHz – 5.3665 MHz|
|40 m||7.000 MHz – 7.200 MHz||7.000 MHz – 7.300 MHz||7.000 MHz – 7.200 MHz|
|30 m[w]||10.100 MHz – 10.150 MHz|
|20 m||14.000 MHz – 14.350 MHz|
|17 m[w]||18.068 MHz – 18.168 MHz|
|15 m||21.000 MHz – 21.450 MHz|
|12 m[w]||24.890 MHz – 24.990 MHz|
|10 m||28.000 MHz – 29.700 MHz|
|VHF||6 m||50.000 MHz – 52.000 MHz[x]||50.000 MHz – 54.000 MHz|
|4 m[x]||70.000 MHz – 70.500 MHz||N/A|
|2 m||144.000 MHz – 146.000 MHz||144.000 MHz – 148.000 MHz|
|1.25 m||N/A||220.000 MHz – 225.000 MHz||N/A|
|UHF||70 cm||430.000 MHz – 440.000 MHz||430.000 MHz – 440.000 MHz|
(420.000 MHz – 450.000 MHz)[y]
|33 cm||N/A||902.000 MHz – 928.000 MHz||N/A|
|23 cm||1.240 GHz – 1.300 GHz|
|13 cm||2.300 GHz – 2.450 GHz|
|SHF||9 cm||3.400 GHz – 3.475 GHz[y]||3.300 GHz – 3.500 GHz|
|5 cm||5.650 GHz – 5.850 GHz||5.650 GHz – 5.925 GHz||5.650 GHz – 5.850 GHz|
|3 cm||10.000 GHz – 10.500 GHz|
|1.2 cm||24.000 GHz – 24.250 GHz|
|EHF||6 mm||47.000 GHz – 47.200 GHz|
|4 mm[y]||75.500 GHz[x] – 81.500 GHz||76.000 GHz – 81.500 GHz|
|2.5 mm||122.250 GHz – 123.000 GHz|
|2 mm||134.000 GHz – 141.000 GHz|
|1 mm||241.000 GHz – 250.000 GHz|
|THF||Sub-mm||Some administrations have authorized spectrum for amateur use in this region;|
others have declined to regulate frequencies above 300 GHz, leaving them available by default.
[w] HF allocation created at the 1979 World Administrative Radio Conference. These are commonly called the "WARC bands".
|See also: Radio spectrum, Electromagnetic spectrum|