Amateur radio band allocation

Raffaello Tesi

Low frequency

  • 136 kHz135 – 137 kHz – The lowest frequency band alloted for ham radio use

Medium frequency

  • 160 meters1800–2000 kHz – Often taken up as a technical challenge in a manner similar to 6m. Most useful at night, though notoriously noisy. In many locations, a separate specialized receive-only antenna (such as a shielded loop) is necessary for successful operation on the band. Also known as the “top band” and the “Gentlemen’s Band”, in apparent contrast to the supposedly freewheeling 80m allocation. Allocations in this band vary widely from country to country.

High frequency

  • 80 meters3500–4000 kHz – Best at night, with significant daytime signal absorption. Works best in winter due to atmospheric noise in summer. 80m phone operators have a reputation for rowdiness similar to CB operators. Only countries in the Americas and few others have access to all of this band, in other parts of the world amateurs are limited to the bottom 300 kHz or less. The upper end of the subband from 3600–4000 kHz, which permits use of single-sideband voice, is often referred to 75 meters.
  • 60 meters5 MHz region – A relatively new allocation and only available in a small number of countries such as the United States, United Kingdom, Norway and Iceland. In most countries, the allocation is channelized, and in the USA it is mandatory to operate in upper sideband mode. Amateur equipment made in Japan or China often does not support this allocation, since it is not available in those countries.
  • 40 meters7.000–7.300 MHz – Considered the most reliable all-season DX band, and most popular at night, and extremely useful for medium distance contacts during the day. Much of this band is shared with broadcasters, and in most countries only the bottom 100 kHz or 200 kHz are available to amateurs.
  • 30 meters10.100–10.150 MHz – a very narrow band, which is shared with non-amateur services. It is recommended that only Morse Code and data transmissions be used here, and in some countries amateur voice transmission is actually prohibited. Not released for amateur use in a small number of countries such as Oman and Thailand. Due to its location in the centre of the shortwave spectrum, provides significant opportunities for long-distance communication at all points of the solar cycle. 30 meters is a WARC band.
  • 20 meters14.000–14.350 MHz – Considered the most popular DX band; usually most popular during daytime. QRP operators recognize 14.060 MHz as their primary calling frequency in that band. Users of the PSK31 data mode tend to congregate around 14.071 MHz. Analog SSTV activity is centered around 14.230 MHz.
  • 17 meters18.068–18.168 MHz – Similar to 20m, but more sensitive to solar conditions. By unofficial agreement, this band is not used for amateur contesting, which makes it a fairly quiet place. It is often used for extended, informal chats known as “ragchews”. 17 meters is a WARC band.
  • 15 meters21–21.450 MHz – Most useful during solar maximum, and generally a daytime band
  • 12 meters24.890–24.990 MHz – Mostly useful during daytime, but opens up for DX activity at night during solar maximum. 12 meters is a WARC band.
  • 10 meters28–29.700 MHz – Best activity is during solar maximum; during periods of moderate solar activity the best activity is found at low latitudes. The band offers useful short- to medium-range groundwave propagation, day or night. Also the site of frequent illegal unlicensed operation (“bootlegging”) and freeband activity by operators using modified Citizen’s Band equipment.

Very high frequency

  • 6 meters50–54 MHz – 6 Meters is notable for its unusual long-range propagation characteristics largely mediated by solar weather. 6m has useful short-range groundwave propagation characteristics. The wavelength is well-suited to antenna experimentation, as a 1/2 wavelength dipole is 9.8ft (3m) tip-to-tip. Known as the “magic band”, DXing on the band is largely done as a technical challenge. A simple antenna and modest power (5 to 10 Watts) are sufficient for long-range communication when the band opens, thus earning its nickname “magic band”. Usage may be restricted in some countries to protect television broadcasts still using these frequencies.
  • 4 meters70 – 70.5 MHz
  • 2 meters144 – 146 or 148 MHz
  • 1.25 meters – 220 or 222 – 225MHz

Ultra high frequency

  • 13 cm2300 – 2450 MHz
  • 23 cm1240 – 1300 MHz
  • 33 cm902 – 928 MHz (ITU Region 2)
  • 70 cm420 – 450 MHz (band limits vary)

Super high frequency

Extremely high frequency

Source: http://en.wikipedia.org/wiki/Amateur_radio_bands