What is medium frequency (MF)?
Medium frequency ( MF) is the ITU designation for radio frequencies (RF) in the range of 300 kilohertz (kHz) to 3 megahertz (MHz). Part of this band is the medium wave (MW) AM broadcast band.
What is MF/HF radio frequency range?
- Orbitshub What is MF/HF radio frequency range? MF/HF radio frequency- Using DSC, radiotelephony, and NBDP, an MF/HF radio can transmit and receive distress and safety signals on all distress and safety frequencies in the bands between 1 605 kHz and 4000 kHz and between 4000 kHz and 27500 kHz.
What is medium frequency AM broadcast?
Medium frequency. Part of this band is the medium wave (MW) AM broadcast band. The MF band is also known as the hectometer band as the wavelengths range from ten to one hectometer (1,000 to 100 m). Frequencies immediately below MF are denoted low frequency (LF), while the first band of higher frequencies is known as high frequency (HF).
What is the frequency range for non directional radio beacons?
Non-directional navigational radio beacons (NDBs) for maritime and aircraft navigation occupy a band from 190 to 435 kHz, which overlaps from the LF into the bottom part of the MF band. 2182 kHz is the international calling and distress frequency for SSB maritime voice communication (radiotelephony).
What is the low frequency of a radio signal?
Low frequency is in the range of 30 KHz to 300 KHz. One of the important properties of LF signals is that it will get reflected by earth’s ionosphere and thus it is suitable for long distance communication. Since it’s long wavelength and less attenuation from big terrains like mountains, it is generally called ground waves.
What is the frequency of a high frequency signal?
High frequency signals ranges between 3 MHz and 30 Mhz. This frequency band is also known as short wave. It also gets reflected by earth’s ionosphere and it is one of the suitable band for long distance communication. High frequency band is mostly used by aviation industry, near field communication (NFC), government systems, amateur radio operators and weather broadcasting stations.
What is the frequency of a super high frequency?
Super High Frequency (SHF) Super high frequency is in the range of 3 GHz to 30 GHz.
What is ultra high frequency?
Ultra high frequency is the most important frequency bands for modern wireless communication systems. It begins from 300 MHz to 3 GHz and extremely complicated to design and implement the system. It has many sub frequency bands, some are restricted and assigned only for particular applications. It is used in GPS navigation systems, satellites, pagers, Wi-Fi, Bluetooth, television broadcasting, and most importantly GSM, CDMA and LTE mobile transmission.
What is the highest frequency band in the RF spectrum?
Extremely high fre quency band is the highest in RF frequency spectrum which range between 30 GHz and 300 GHz. EHF is only used in advanced communication systems due to its complex nature and line of sight requirement. EHF is used in radio astronomy and remote sensing (weather analysis). It is suggested to use for high speed internet systems like 5G technology for future transmission networks due to large bandwidth availability.
What is the frequency band used for aviation?
High frequency band is mostly used by aviation industry, near field communication (NFC), government systems, amateur radio operators and weather broadcasting stations. Very High Frequency (VHF) Very high frequency is one of the most commonly used bands which has an operating range from 30 MHz to 300 MHz.
What is the frequency of radio waves?
It spreads in the range between 3 KHz and 300 GHz.
What frequency is a MF radio?
An MF radio installation capable of transmitting and receiving, for distress and safety purposes, on the frequencies 2 187.5 kHz using DSC; and 2 182 kHz using radiotelephony and an HF DSC system (may be replaced by an EPIRB or an Inmarsat ship earth station).
What is DSC on a ship?
IMO has designated Digital Selective Calling (DSC) on MF, HF and VHF marine radios as a part of the GMDSS system. DSC is a mandatory equipment both for coast stations included in the GMDSS system, and for ships making voyages in any navigation areas. Primarily, DSC is designed to set up ship-to-ship, ship-to-shore and shore-to-ship radiotelephone and MF/HF radiotelex calls. DSC calls can also be made to individual stations, groups of stations, or “all stations” on the same radio band. Each DSC radio on a ship is programmed once and forever with a unique 9 digit ID number (Maritime Mobile Service Identity – MMSI code). The correct programming of the MMSI code is to be verified during the GMDSS survey.
What are the requirements for a ship?
A ship shall be provided with: 1 An Inmarsat-C ship earth station and 2 An MF radio installation capable of transmitting and receiving, for distress and safety purposes, on the frequencies: 2 187.5 kHz using DSC, and 2 182 kHz using radiotelephony 3 A DSC watchkeeping receiver operating on 2187.5 kHz 4 An HF DSC system
What is MF/HF on a ship?
MF/HF on board the ship provides radiotelephony, narrow-band direct printing and DSC over long distances. An MF/HF radio installation with DSC should be installed with a TELEX terminal. The system is subject to mandatory annual GMDSS survey.
What is the FCC requirement for marine radiotelephones?
The FCC requires that all new types of marine VHF and MF/HF radiotelephones accepted after June 1999 have at least a basic DSC capability.
How far is A1 from the coast?
A1 - approximately 20-30 miles from the coast station. This zone is covered by the on-shore VHF radio stations with DSC. A2 - approximately 150 miles. Maritime communications in the range of onshore radio stations with DSC + A1.
What is the A3 latitude?
A3 - to about 70 degrees north and south latitude. The vessels are in the area of operation of the INMARSAT + A1 and A2 system.
Overview
Uses and applications
A major use of these frequencies is AM broadcasting; AM radio stations are allocated frequencies in the medium wave broadcast band from 526.5 kHz to 1606.5 kHz in Europe; in North America this extends from 525 kHz to 1705 kHz Some countries also allow broadcasting in the 120-meter band from 2300 to 2495 kHz; these frequencies are mostly used in tropical areas. Although these …
Propagation
Radio waves at MF wavelengths propagate via ground waves and reflection from the ionosphere (called skywaves). Ground waves follow the curvature of Earth. At these wavelengths they can bend (diffract) over hills, and travel beyond the visual horizon, although they may be blocked by mountain ranges. Typical MF radio stations can cover a radius of several hundred miles from the transmitter, with longer distances over water and damp earth. MF broadcasting stations use grou…
Antennas
Transmitting antennas commonly used on this band include monopole mast radiators, top-loaded wire monopole antennas such as the inverted-L and T antennas, and wire dipole antennas. Ground wave propagation, the most widely used type at these frequencies, requires vertically polarized antennas like monopoles.
See also
• Electromagnetic spectrum
• Global Maritime Distress Safety System
• Maritime broadcast communications net
• Navtex
Further reading
• Charles Allen Wright and Albert Frederick Puchstein, "Telephone communication, with particular application to medium-frequency alternating currents and electro-motive forces". New York [etc.] McGraw-Hill Book Company, inc., 1st ed., 1925. LCCN 25008275
External links
• Tomislav Stimac, "Definition of frequency bands (VLF, ELF... etc.)". IK1QFK Home Page (vlf.it).