- 1 Band Plans
- 2 The Bands
- 2.1 Extremely Low Frequency (ELF)
- 2.2 Super Low Frequency (SLF)
- 2.3 Ultra Low Frequency (ULF)
- 2.4 Very Low Frequency (VLF)
- 2.5 Low Frequency (LF)
- 2.6 Medium Frequency (MF)
- 2.7 High frequency (HF)
- 2.8 Very High Frequency (VHF)
- 2.9 Ultra High Frequency (UHF)
- 2.10 Super High Frequency (SHF)
- 2.11 Extremely High Frequency (EHF)
In Amateur Radio, a band plan refers to a voluntary division of a band to avoid interference between incompatible modes. ie What to use where - both from a privileges viewpoint and a propagation, condition or mode perspective.
This link will take you to the ARRL Amateur Band Plan.
- ARRL's US Amateur Allocation chart The 'famous' color chart showing what frequencies and modes are allowed for each license class. Suitable for printing.
Sidebands - upper or lower?
In amateur radio, LSB is traditionally used below 10 MHz and USB is used above 10 MHz. Except for RTTY - see the digital page for details.
IARU Region 2 MF/HF Band Plan – Effective since September 27, 2013 The IARU Region 2 has established the IARU Region 2 Band Plan as the way to better organize the use of our bands efficiently. To the extent possible, this band plan is harmonized this with those of the other regions. It is suggested that Member Societies, in coordination with the authorities, incorporate it in their regulations and promote it widely with their radio amateur communities.Band Plan
- IARU Region 2 HF Band Plan PDF file of the IARU R2 Band Plan
- FCC map of the IARU regions From the FCC's web site, a map showing the 3 IARU regions.
FCC allocations cover all non government use of spectrum - not just ham radio. There's a LOT of information here. Over 140 pages worth.
FCC Radio Spectrum home page
A bureau of the U.S. Department of Commerce, the National Telecommunications and Information Administration (NTIA) is the President's principal adviser on telecommunications and information policy issues, and in this role frequently works with other Executive Branch agencies to develop and present the Administration's position on these issues. Since its creation in 1978, NTIA has been at the cutting edge of critical issues. In addition to representing the Executive Branch in both domestic and international telecommunications and information policy activities, NTIA also manages the Federal use of spectrum; performs cutting-edge telecommunications research and engineering, including resolving technical telecommunications issues for the Federal government and private sector; and administers infrastructure and public telecommunications facilities grants.
NTIA band plans don't directly affect Amateur Operations. However, they provide a chart of the entire RF spectrum that is quite handy and informative. It helps to put it 'all into perspective' Find it here.
Some of the bands described here are not normally considered Amateur Radio bands. Please, verify your privileges before transmitting on any band!
Extremely Low Frequency (ELF)
- 3 to 30 Hz – At one time used by the US Navy and Soviet/Russian Navy to communicate with submerged submarines.
Super Low Frequency (SLF)
- 30 hertz and 300 hertz – This frequency range includes the frequencies of AC power grids (50 hertz and 60 hertz). The radio services Seafarer (USA) on 76 hertz and ZEVS (Russia) on 82 hertz operate in this range, which is often incorrectly called Extremely Low Frequency (ELF). They both provide communication services for submarines at a certain depth. PCs with sound cards are increasingly being used instead of radio receivers for this frequency range, because of their much smaller size and lower cost. Signals received by the sound card with a coil or a wire antenna are analysed by a software Fast Fourier Transform algorithm and converted into audible sound.
Ultra Low Frequency (ULF)
- 300 hertz and 3 kilohertz – Used for communications in mines, as it can penetrate the earth.
Very Low Frequency (VLF)
- 3 kHz to 30 kHz – Since there is not much bandwidth in this band of the radio spectrum, only the very simplest signals are used, such as for radio navigation. The frequency range below 9 kHz is not allocated by the International Telecommunication Union and may be used in some nations license-free. Many natural radio emissions, such as whistlers, can also be heard in this band.
Directly audible when converted to sound (below ca. 20 kHz)
Low Frequency (LF)
- 30 kHz–300 kHz – In the United States there is a special license free allocation in the longwave range called LowFER. This experimental allocation between 160 kHz and 190 kHz is sometimes called the "Lost Band". Unlicensed operation by the public is permitted south of 60 degrees north latitude, except where interference would occur to ten licensed location service stations located along the coasts. Regulations for use include a power output of no more than 1 watt, a combined antenna/ground-lead length of no more than 15 meters, and a field strength of no more than 4.9 microvolts/meter. Also, emissions outside of the 160 kHz–190 kHz band must be attenuated by at least 20 dB below the level of the unmodulated carrier. Many experimenters in this band are amateur radio operators.
Medium Frequency (MF)
160m is the lower end of the traditional Ham Bands.
- 160 meters – 1.8-2 MHz(1800–2000 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 (HF)
- 80 meters – 3.5-4 MHz (3500–4000 kHz) – Best at night, with significant daytime signal absorption. Works best in winter due to atmospheric noise in summer. 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. In the US and Canada the upper end of the subband from 3600–4000 kHz, which permits use of single-sideband voice, is often referred to as 75 meters. Operators in this sub-band have a reputation for rowdiness similar to CB operators.
- 60 meters – 5 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.
- 40 meters – 7.0–7.3 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.
LSB is traditionally used below 10 MHz and USB is used above 10 MHz.
- 30 meters – 10.1–10.15 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. Due to its location in the center 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 meters – 14.0–14.35 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 Slow-scan television (SSTV) activity is centered around 14.230 MHz.
- 17 meters – 18.068–18.168 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 meters – 21–21.45 MHz – Most useful during solar maximum, and generally a daytime band.
- 12 meters – 24.89–24.99 MHz – Mostly useful during daytime, but opens up for DX activity at night during solar maximum. 12 meters is a WARC band.
- 10 meters – 28–29.7 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.
WARC bands are so called due to the special World Amateur Radio Conference allocation of these newer bands to amateur radio use. Almost all radio amateur contests are not allowed on all three WARC bands.
Very High Frequency (VHF)
- 6 meters – 50 MHz to 54 MHz – In the lower part of the VHF band, 6m occasionally displays some propagation mechanisms of the lower High Frequency bands. This normally occurs close to sunspot maximum when solar activity increases ionization levels in the upper atmosphere. The mix of VHF and HF characteristics has led to 6 meters being dubbed the "magic band."
- 2 meters – 144.000 MHz to 148.000 MHz – Because it is local and reliable, and because the licensing requirements to transmit on the 2-meter band are easy to meet, this band is one of the most popular non-HF ham bands. This popularity, the compact size of needed radios and antennas, and this band's ability to provide easy reliable local communications also means that it is also the most used band for local emergency communications efforts, such as providing communications between Red Cross shelters and local authorities. In the U.S., that role in emergency communications is furthered by the fact that seemingly every amateur-radio operator has a 2 meter mobile radio or walkie-talkie.
- 1.25 meter – 222Mhz to 225Mhz (secondary 219-220Mhz) – If one assumes that the transmitting antenna's wavelength, height above average terrain and effective radiated power is equal, a transmitted signal on 1.25 meters will usually travel equally as far as that same signal would if transmitted on 2 meters, as well as exhibiting an equally low susceptibility to multipathing. On the other hand, the wavelength of 1.25 meters is closer to that of 70 centimeters, thus it tends to have building penetration and noise floor characteristics that more resemble those of 70 centimeters.
Ultra High Frequency (UHF)
- 70 Centimeters – 420 Mhz to 450 Mhz – Propagation characteristics lie midway between 2m and 33cm (900 MHz) bands. As the frequency increases, penetration through windows and other openings in buildings becomes easier because the openings are larger relative to a wavelength. It also means that smaller obstacles block the signal, or can reflect it. The higher frequency also results in a lower noise floor overcoming both natural and man made noises which are prevalent in urban environments.
One practical concern when comparing 70cm to 2m is that a quarter-wave antenna is much less unwieldy at 70cm than it is at 2m. Portable antennas for 2m are generally continuously loaded coil spring or "rubber duck" types while on 70cm they can be full quarter-wave. The difference can be as much as 8 dB. The primary advantage of 70cm is that base station antennas of very significant gain (up to 11 dB or so) are practical while 6 dB is about the practical limit on 2m. The extra 5 dB of receive and transmit gain are often critical for long range communication.
A problem found with all UHF or higher frequencies is the prevalence of multipath signals. The reflective properties of the 70cm band allow signals to be reflected by dense and solid material such as cement or rock. This creates a slight time delay between the primary signal and reflected signal(s) causing cancellations as the direct and reflected signals are combined in the receiving antenna. This can cause "picket fencing" or rapid fluctuations in signal strength to be experienced by stations in motion.
- 33 Centimeters – 902 to 928 Mhz – An allocation unique to ITU Region 2. Signal propagation on the 33 centimeter band is very dependent on the transmitting and receiving antenna's line of sight. Because of this, many wide-area coverage systems like repeaters are located on top of large hills and mountains which overlook a vast area. This ensures that the transmitting antenna is higher than terrestrial obstructions such as trees and buildings. Assuming that the transmitting antenna's wavelength, height above average terrain, and effective radiated power is equal, a transmitted signal on 33 centimeters will, generally speaking, usually travel about 3/4 of the distance that the same signal would if transmitted on the 70 centimeter band.
The 33 centimeter band offers excellent building penetration characteristics since the wavelength is relatively small and can fit through windows easier than signals lower in frequency.
In many areas, the 33 centimeter band also has a very low noise floor as compared to bands lower in frequency.
- 23 Centimeters – 1240 and 1300 MHz (1325 MHz in some areas) – Most all modes of communication used in amateur radio can be found in the 23 cm band. Some of the more common modes include FM voice, Packet, as well as ATV.
- 13 Centimeters – 2.300 to 2.310 GHz, and 2.390 to 2.450 GHz – WiFi (802.11g) uses frequencies from 2.402 to 2.472 under Part 15 rules. That means Licensed Amateurs can use more power and higher gain antennas on 802.11 channels 1 through 7. All other rules still apply - ie. Identification. Setting your WAP's SSID to your call sign should suffice. You'll need to take proactive steps to block dis-allowed communications, such as SPAM, vulgarity and porn.
Super High Frequency (SHF)
- 9 centimeters (3.3 - 3.5 GHz)
- 5 centimeters (5.65 - 5.925 GHz)
- 3 centimeters (10.0 - 10.5 GHz)
- 1.2 centimeters (24.00 - 24.25 GHz)
US amateurs must check Sections 97.301, 97.303, 97.305 and 97.307 for sharing requirements before operating above 10.5Ghz.
Extremely High Frequency (EHF)
- 6 millimeters (47.0 - 47.2 GHz)
- 4 millimeters (75.5 - 81.0 GHz)
- 2.5 millimeters (119.98 - 120.02 GHz)
- 2 millimeters (142 - 149 GHz)
- 1 millimeter (241 - 250 GHz)