The 600 meter (or 630 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.
The band is in the Medium Frequency (MF) region, within the greater 415–526.5 kHz maritime band.
With maritime traffic largely displaced from 500 kHz band, some countries had taken steps prior to 2012 to allocate frequencies at or near 500 kHz to amateur radio use.
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.
Germany allocated the frequencies to amateur radio based on the WRC-12 conference, effective 13 June 2012.
The Principality of Monaco allocated 472–479 kHz to the amateur service on 18 May 2012.
The Philippines allocated 472–479 kHz to amateur radio, with an effective date of 30 August 2012.
In New Zealand, the band 472 kHz to 479 kHz was allocated to amateur radio, on a secondary basis, with an effective date of 20 December 2012. Amateur transmissions are limited to 25 watts EIRP.
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 France (including the French Overseas Departments and Territories) amateurs have access to 472–479 kHz, with 1 Watt EIRP.
In Norway, including Svalbard, Jan Mayen, and the Bouvet Island, amateurs have an allocation of 472-479 kHz on a secondary basis. Maximum output power is 100 watts, and maximum EIRP of 1 Watt.
In Poland, amateurs have an allocation from 472 to 479 kHz since 18 February 2014. The maximum EIRP is 1 Watt.
In Canada, amateurs have a secondary allocation from 472 to 479 kHz beginning 1 April 2014. The maximum EIRP is 1W.
As of December 2012, amateurs in some other countries continue to operate on their pre-WRC-12 permits on other frequencies.
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 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.
In the Netherlands 501–505 kHz was allocated to Amateur Radio operators, with a maximum of 100 Watts PEP, on 1 January 2012.
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. In 2015 the FCC proposed rules to permit amateur use of 630 and 2200 meters in line with decisions made at the World Radiocommunication Conference 2012.
Subsequently, the UK started to issue Special Research Permits for amateurs to use 501–504 kHz.
Ireland has allowed individuals to apply for Test Licenses in the 501 to 504 kHz frequency range.
Canada has allowed individuals to apply for use in the 504 to 509 kHz frequency range.
Other regions with experimental operations include Croatia, Czech Republic, Denmark, Iceland, Sweden, Spain and Slovenia.
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: