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Amateur radio frequency allocation is done by national telecommunication authorities. Globally, the International Telecommunication Union ITU oversees how much radio spectrum is set aside for amateur radio transmissions. Individual amateur stations are free to use any frequency within authorized frequency ranges; authorized bands may vary by the class of the station license.

Radio amateurs use a variety of transmission modes, including Morse coderadioteletypedata, and voice. Specific frequency allocations vary from country to country and ham radio band plan chart ITU regions as specified in the current ITU HF frequency allocations for amateur radio. The modes and types of allocations within each frequency band is called a bandplan ; it may be determined by regulation, but most typically is set by agreements between amateur radio operators.

National authorities regulate amateur usage of radio bands. Some bands may not be available or may have restrictions on usage in certain countries or regions. International agreements assign amateur radio bands which differ by region.

The allocated bands for amateurs are many megahertz wide, allowing for high-fidelity audio transmission modes FM and very fast data transmission modes that are unfeasible for the kilohertz -wide allocations in the HF bands. While "line of sight" propagation is a primary factor for range calculation, much of the interest in the bands above HF comes from use of other propagation modes.

Ham operators seek to exploit the limits of the frequencies usual characteristics looking to learn, understand, and experiment with the possibilities of these enhanced propagation modes.

Occasionally, several different ionospheric conditions allow signals to travel beyond the ordinary line-of-sight limits. Some amateurs on VHF seek to take advantage of "band openings" where natural occurrences in the atmosphere and ionosphere extend radio transmission distances well over their normal range. Many hams listen for hours hoping to take advantage of these occasional extended propagation "openings".

The ionospheric conditions are called Sporadic E and Ham radio band plan chart enhancement. Less frequently used anomalous modes are tropospheric scatter and Aurora Borealis Northern Lights. When overhead, moon bounce and satellite relay are also possible. Some openings are caused by islands of intense ionization of the upper atmosphere ham radio band plan chart as the E Layer ionosphere.

This phenomenon occurs during the fall months, although not as often. Band openings are sometimes caused by a weather phenomenon known as a tropospheric "inversion"where a stagnant high pressure area causes alternating stratified layers of warm and cold air generally trapping the colder air beneath.

Radio signals have been known to travel hundreds, even thousands of kilometers due to these unique weather conditions. Using relatively high power and a high gain antenna, this propagation will give marginal enhanced over-the-horizon VHF and UHF communications up ham radio band plan chart several hundred kilometers. During the s commercial "scatter site" operators using ham radio band plan chart parabolic antennas and high power used this mode successfully for telephone communications services into remote Alaska and Canadian northern communities.

Satellite, buried fiber optic, and terrestrial microwave access have relegated commercial use of tropo-scatter to the history books. Because of high cost and complexity this mode is usually out of reach ham radio band plan chart the average amateur radio operator. Signals are often distorted and on the lower frequencies give a curious "watery sound" to normally propagated HF signals. Peak signals usually come from the north, even though the station you are talking to is east or west of you.

Amateurs do successfully communicate by bouncing their signals off the surface of the moon, called Earth-Moon-Earth EME transmission. Return signals are weak and distorted because of the relative velocities of the transmitting station, moon and the receiving station. The moon's surface is also very rocky and irregular. Because of the weak, distorted return signals, Moon bounce communications use digital modes.

For example, old-fashioned Ham radio band plan chart code or modern JT65designed for working with weak signals. Satellite relay is not really a propagation mode, but rather an active repeater system. Amateurs have sponsored the launch of dozens of communications satellites since the s. Also, the ISS has amateur radio repeaters and radio location services on board.

Amateur television ATV is the hobby of transmitting broadcast - compatible video and audio by amateur radio. It also includes the study and building of such transmitters and receivers and the propagation between these two. See also slow-scan television. Historically, amateur stations have rarely been allowed to operate on frequencies lower than the medium-wave broadcast bandbut in recent times, as the historic users of these low frequencies have been vacating the spectrum, limited space has opened up to allow for new amateur radio allocations and special experimental operations.

Many countries, however, continue to restrict these frequencies which were historically reserved for maritime and aviation distress calls. Unlike the US, slots for the various transmission modes are not set by the amateur's license but most users do follow these guidelines. The Report and Order also allows the use of modes that comply with emission designator 2K80J2D, which includes any digital mode with a bandwidth of 2.

On 60 meters hams are restricted to only one signal per channel and automatic operation is not permitted. In addition, the FCC continues to require that all ham radio band plan chart transmissions be centered on the channel-center frequencies, which the Report and Order defines as being 1.

As amateur radio ham radio band plan chart displays the carrier frequency, it is important for operators to understand correct frequency calculations for digital "sound-card" modes to ensure compliance with the channel-center requirement. RAC has a chart showing the frequencies available to amateurs in Canada. Canadian operators are restricted to watts PEP. Not all Member Unions follow this plan. The Japanese have charts for Amateur frequencies in Japan [10]. Radio amateurs may engage in satellite and space craft communications; however, the frequencies allowed for such activities are allocated separately from more general use radio amateur bands.

As such, the Amateur Radio Service is not permitted to engage in satellite operations; however, a sister radio service, called the Amateur Satellite Serviceexists which allows satellite operations for the same purposes as the Amateur Radio Service.

In most countries, an amateur radio license conveys operating privileges in both services, and in practice, the legal distinction between the two services is transparent to the average licensee. The primary reason the two services are separate is to limit the frequencies available for satellite operations.

Due to the shared nature of the ham radio band plan chart radio allocations internationally, and the nature of satellites to roam worldwide, the ITU ham radio band plan chart not consider all amateur radio bands appropriate for satellite operations. All the allocations are within amateur radio bands, and with one exception, the allocations are the same in all three ITU regions. Some of the allocations are limited by the ITU in what direction transmissions may be sent EG: "Earth-to-space" or up-links only.

Looking for fwb in cartagena amateur satellite operations occur within the allocations tabled below, except for AO-7which has an up-link from Use is only allowed on a non-interference basis to other users, as per ITU footnote 5.

These are commonly called the " WARC bands ". ITU Radio Regulations. See the appropriate Wiki page for further information.

These allocations may only apply to a group of countries. From Wikipedia, the free encyclopedia. Amateur radio. See also: Low frequency. See also: Medium frequency. See also: High frequency. Main article: Amateur television. See also: meter band. See also: amateur radio satellite. Retrieved 10 November Archived from the original on 4 June Retrieved 27 June Wolfgang et al. Archived from the original on 16 October Retrieved 17 Girls wanting sex in zaysan International Amateur Radio Union - Region 3.

Archived from the original on 16 December Retrieved 12 January Federal Communications Commission. Retrieved 4 August International amateur radio frequency allocations. Shortwave radio Amateur radio operator Q ham radio band plan chart. Coaxial cable Fiber-optic communication optical fiber Free-space optical communication Molecular communication Radio waves wireless Transmission line data transmission circuit telecommunication circuit.

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