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  2. Non-directional beacon - Wikipedia

    en.wikipedia.org/wiki/Non-directional_beacon

    A non-directional beacon (NDB) or non-directional radio beacon is a radio beacon which does not include inherent directional information. Radio beacons are radio transmitters at a known location, used as an aviation or marine navigational aid. NDB are in contrast to directional radio beacons and other navigational aids, such as low-frequency ...

  3. 10-meter band - Wikipedia

    en.wikipedia.org/wiki/10-meter_band

    Because the propagation on 10 meters can vary drastically throughout the day, propagation beacons are very important to gauge the current conditions of the band. With some differences in each ITU Regions and also from country to country, the beacon sub-bands fall between 28.100–28.300 MHz. ITU Region 1 is generally 28.190-28.225 MHz and ITU ...

  4. Amateur radio propagation beacon - Wikipedia

    en.wikipedia.org/wiki/Amateur_radio_propagation...

    An amateur radio propagation beacon is a radio beacon, whose purpose is the investigation of the propagation of radio signals. Most radio propagation beacons use amateur radio frequencies. They can be found on LF, MF, HF, VHF, UHF, and microwave frequencies. Microwave beacons are also used as signal sources to test and calibrate antennas and ...

  5. Radio beacon - Wikipedia

    en.wikipedia.org/wiki/Radio_beacon

    In navigation, a radio beacon or radiobeacon is a kind of beacon, a device that marks a fixed location and allows direction-finding equipment to find relative bearing. But instead of employing visible light, radio beacons transmit electromagnetic radiation in the radio wave band. They are used for direction-finding systems on ships, aircraft ...

  6. Amateur radio frequency allocations - Wikipedia

    en.wikipedia.org/wiki/Amateur_radio_frequency...

    e. 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 ...

  7. Emergency position-indicating radiobeacon - Wikipedia

    en.wikipedia.org/wiki/Emergency_position...

    An emergency position-indicating radiobeacon (EPIRB) is a type of emergency locator beacon for commercial and recreational boats, a portable, battery-powered radio transmitter used in emergencies to locate boaters in distress and in need of immediate rescue. In the event of an emergency, such as a ship sinking or medical emergency onboard, the ...

  8. Radio navigation - Wikipedia

    en.wikipedia.org/wiki/Radio_navigation

    As the LF/MF signals used by NDBs can follow the curvature of earth, NDB has a much greater range than VOR which travels only in line of sight. NDB can be categorized as long range or short range depending on their power. The frequency band allotted to non-directional beacons is 190–1750 kHz, but the same system can be used with any common AM ...

  9. Marker beacon - Wikipedia

    en.wikipedia.org/wiki/Marker_beacon

    Marker beacon. Locator Outer Marker (LOM), a High Frequency (HF) Non-Directional Beacon, co-located with an "outer marker" (OM) 75-MHz Marker Beacon. A marker beacon is a particular type of VHF radio beacon used in aviation, usually in conjunction with an instrument landing system (ILS), to give pilots a means to determine position along an ...