39 relations: Amateur radio, Antenna (radio), Bandwidth (signal processing), Capacitance, Corona discharge, Counterpoise (ground system), Dipole antenna, Displacement current, Electrical length, Electrical reactance, Ground (electricity), Impedance matching, LC circuit, Litz wire, Loading coil, Longwave, Low frequency, Mast radiator, Medium frequency, Medium wave, Monopole antenna, Omnidirectional antenna, Polarization (waves), Q factor, Radiation pattern, Radiation resistance, Radio masts and towers, Radio receiver, Resonance, Shortwave listening, Shortwave radio, Skywave, Standing wave ratio, Surface wave, Transmitter, Umbrella antenna, Very low frequency, Wavelength, Wireless telegraphy.
Amateur radio, also known as ham radio, describes the use of radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communication.
In radio, an antenna is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver.
Bandwidth is the difference between the upper and lower frequencies in a continuous band of frequencies.
Capacitance is the ratio of the change in an electric charge in a system to the corresponding change in its electric potential.
A corona discharge is an electrical discharge brought on by the ionization of a fluid such as air surrounding a conductor that is electrically charged.
In electronics and radio communication a counterpoise is a network of suspended horizontal wires or cables (or a metal screen), used as a substitute for an earth (ground) connection in a radio antenna system.
In radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna.
In electromagnetism, displacement current density is the quantity appearing in Maxwell's equations that is defined in terms of the rate of change of, the electric displacement field.
In telecommunications and electrical engineering, electrical length (or phase length) refers to the length of an electrical conductor in terms of the phase shift introduced by transmission over that conductor at some frequency.
In electrical and electronic systems, reactance is the opposition of a circuit element to a change in current or voltage, due to that element's inductance or capacitance.
In electrical engineering, ground or earth is the reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the earth.
In electronics, impedance matching is the practice of designing the input impedance of an electrical load or the output impedance of its corresponding signal source to maximize the power transfer or minimize signal reflection from the load.
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, is an electric circuit consisting of an inductor, represented by the letter L, and a capacitor, represented by the letter C, connected together.
Litz wire is a type of specialized multistrand wire or cable used in electronics to carry alternating current (AC) at radio frequencies.
A loading coil or load coil is an inductor that is inserted into an electronic circuit to increase its inductance.
In radio, longwave, long wave or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with wavelengths longer than what was originally called the medium-wave broadcasting band.
Low frequency (low freq) or LF is the ITU designation for radio frequencies (RF) in the range of 30 kilohertz (kHz)–300 kHz.
A mast radiator (or radiating tower) is a radio mast or tower in which the entire structure functions as an antenna.
Medium frequency (MF) is the ITU designation for radio frequencies (RF) in the range of 300 kilohertz (kHz) to 3 megahertz (MHz).
Medium wave (MW) is the part of the medium frequency (MF) radio band used mainly for AM radio broadcasting.
A monopole antenna is a class of radio antenna consisting of a straight rod-shaped conductor, often mounted perpendicularly over some type of conductive surface, called a ground plane.
In radio communication, an omnidirectional antenna is a class of antenna which have an axis about which radio wave power is radiated symmetrically, and, upon that axis, is zero.
Polarization (also polarisation) is a property applying to transverse waves that specifies the geometrical orientation of the oscillations.
In physics and engineering the quality factor or Q factor is a dimensionless parameter that describes how underdamped an oscillator or resonator is, and characterizes a resonator's bandwidth relative to its centre frequency.
In the field of antenna design the term radiation pattern (or antenna pattern or far-field pattern) refers to the directional (angular) dependence of the strength of the radio waves from the antenna or other source.
Radiation resistance is that part of an antenna's feedpoint resistance that is caused by the radiation of electromagnetic waves from the antenna, as opposed to loss resistance (also called ohmic resistance) which generally causes the antenna to heat up.
Radio masts and towers are, typically, tall structures designed to support antennas (also known as aerials) for telecommunications and broadcasting, including television.
In radio communications, a radio receiver (receiver or simply radio) is an electronic device that receives radio waves and converts the information carried by them to a usable form.
In physics, resonance is a phenomenon in which a vibrating system or external force drives another system to oscillate with greater amplitude at specific frequencies.
Shortwave listening, or SWLing, is the hobby of listening to shortwave radio broadcasts located on frequencies between 1700 kHz and 30 MHz.
Shortwave radio is radio transmission using shortwave radio frequencies.
In radio communication, skywave or skip refers to the propagation of radio waves reflected or refracted back toward Earth from the ionosphere, an electrically charged layer of the upper atmosphere.
In radio engineering and telecommunications, standing wave ratio (SWR) is a measure of impedance matching of loads to the characteristic impedance of a transmission line or waveguide.
In physics, a surface wave is a mechanical wave that propagates along the interface between differing media.
In electronics and telecommunications, a transmitter or radio transmitter is an electronic device which produces radio waves with an antenna.
An umbrella antenna is a top-loaded electrically lengthened monopole antenna, consisting in most cases of a mast fed at the ground end, to which a number of radial wires are connected at the top, sloping downwards.
Very low frequency or VLF is the ITU designation for radio frequencies (RF) in the range of 3 to 30 kilohertz (kHz), corresponding to wavelengths from 100 to 10 kilometers, respectively.
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
Wireless telegraphy is the transmission of telegraphy signals from one point to another by means of an electromagnetic, electrostatic or magnetic field, or by electrical current through the earth or water.