The 2200 meter or 136 kHz band is the lowest frequency band in which amateur radio operators are allowed to transmit. It is available for use in several countries, and at the 2007 World Radiocommunication Conference (WRC-07), it was made the newest world wide amateur allocation. 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.
The 2200 meter band is in the low frequency (LF) region, just below the 153–279 kHz longwave broadcasting band. Before its introduction in the UK in 1998, operation on the even lower frequency of 73 kHz had been allowed from 1996 until 2003.
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A number of European countries have already allocated the zone 135.7-137.8 kHz to amateur radio use based on CEPT/ERC Recommendation 62-01 E ("Use of the band 135.7-137.8 kHz by the Amateur Service", Mainz 1997). The allocation is on a secondary basis with a maximum e.r.p. power of 1 W. Otherwise the band 130-148.5 is allocated on a primary base to the Maritime Mobile Service and the Fixed Service. The main users are naval one-way transmissions and radiolocation systems.
The International Telecommunication Union's 2007 World Radiocommunication Conference (WRC-07) in Geneva agreed a secondary allocation 135.7-137.8 kHz to the Amateur Service on Friday November 9 (LowFER).
Such low frequency transmissions require specialist, and therefore usually home made, equipment. In countries where it is allowed, maximum transmission radiated power is usually limited to 1 watt (0 dBW), but even this can be extremely difficult to achieve from practical home made equipment and antennas. Reception also poses problems due to considerable natural and man-made noise and interference (QRN and QRM).
Many users and experimenters have settled on extremely slow, computer-generated and displayed morse code as the most common transmission mode. This mode is known as QRSS, where the doubling of the S emphasises the extreme slowness. The international Q code QRS already stood for "Please send more slowly", or "slow morse" in radio jargon.
The 2005 IARU Region 1 Conference defined the band as follows [1]:
There is no 136 kHz amateur allocation in the United States.
In 1998, the Federal Communications Commission rejected an ARRL petition for LF allocations at 135.7 - 137.8 kHz and 160 – 190 kHz.
In 2002, indications from the FCC had been that 136 kHz privileges would be authorized soon. On May 14, 2003, however, the FCC declined to grant these privileges citing concerns over potential interference with power line communications used by electrical utilities to control the power grid.
The FCC added that amateurs wishing to experiment with 136 kHz communications may apply for experimental licenses or operate within existing Part 15 regulations for this part of the electromagnetic spectrum. In the case of Part 15, the field strength measured 300 meters from the antenna may not exceed 2400 microvolts per meter divided by the frequency in kilohertz, or approximately 17 microvolts per meter.
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Range | Band | ITU Region 1 | ITU Region 2 | ITU Region 3 |
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LF | 2200 m | 135.7 kHz - 137.8 kHz | ||
MF | 160 m | 1.810 MHz - 1.850 MHz | 1.800 MHz - 2.000 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 m1 | 5.250 MHz - 5.450 MHz | |||
40 m | 7.000 MHz - 7.200 MHz | 7.000 MHz - 7.300 MHz | 7.000 MHz - 7.200 MHz | |
30 m2 | 10.100 MHz - 10.150 MHz | |||
20 m | 14.000 MHz - 14.350 MHz | |||
17 m2 | 18.068 MHz - 18.168 MHz | |||
15 m | 21.000 MHz - 21.450 MHz | |||
12 m2 | 24.890 MHz - 24.990 MHz | |||
10 m | 28.000 MHz - 29.700 MHz | |||
VHF | 6 m | 50.000 MHz - 52.000 MHz1 | 50.000 MHz - 54.000 MHz | 50.000 MHz - 54.000 MHz |
4 m1 | 70.000 MHz - 70.500 MHz | |||
2 m | 144.000 MHz - 146.000 MHz | 144.000 MHz - 148.000 MHz | 144.000 MHz - 148.000 MHz | |
1.25 m | 220.000 MHz - 225.000 MHz | |||
UHF | 70 cm | 430.000 MHz - 440.000 MHz | 420.000 MHz - 450.000 MHz3 | 420.000 MHz - 450.000 MHz3 |
33 cm | 902.000 MHz - 928.000 MHz | |||
23 cm | 1.240 GHz - 1.300 GHz | |||
13 cm | 2.300 GHz - 2.450 GHz | |||
SHF | 9 cm | 3.400 GHz - 3.475 GHz3 | 3.300 GHz - 3.500 GHz | 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 mm3 | 75.500 GHz1 - 81.500 GHz | 76.000 GHz - 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. | ||
1 This is not mentioned in the ITU's Table of Frequency Allocations, but it is a de facto international amateur radio allocation. |
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See also: Radio spectrum · Electromagnetic spectrum |