"A",
"B",
"C",
"D",
"E",
"F",
"G"/"H",
"I"/"J"/"K"/"L",
"M"/"N"/"O",
"P"/"Q",
"R",
"S",
"T"/"U"/"V"/"W"/"X"/"Y"/"Z"
Take-off angle: The angle measured from the Earth’s surface or horizontal up to the direction of propagation towards the ionosphere.
Three-Element Array: An array with two parasitic elements (reflector and director) and a driven element.
Transistor: A minute electronic device that permits a small current to control the flow of a larger current. [Transistor Manufacturers]
Transmission line: A conductor that transfers radio frequency RF energy from the transmitter to the antenna or from the antenna to the receiver.
Transmitter: A piece of equipment that generates and amplifies a radio frequency, adds intelligence to this signal, and then sends it out into the air as a radio frequency wave.
Troposphere: The region of the Earth’s atmosphere from the surface to a height of about 10 km.
Tuning: The process of adjusting a radio circuit so that it resonates at the desired frequency.
Turnstile Antenna: A type of antenna used in vhf communications that is omni-directional and consists of two horizontal half-wave antennas mounted at right angles to each other in the same horizontal plane.
Twin-lead transmission line: A balanced transmission line generally used with balanced antennas.
Two element array: An antenna composed of two element antennas. Ultrahigh frequency: Frequencies between 300 and 3,000 MHz.
Unbalanced transmission line: A transmission line one of whose conductors is grounded.
Unidirectional: In one direction only.
Unidirectional Array: An array that radiates in only one general direction.
Uniform Linear Array: An antenna composed of a relatively large number of usually identical elements arranged in a single line or in a plane with uniform spacing and usually with a uniform feed system.
Vee antenna: Two long-wire antennas connected to form a vee. [Antenna Dictionary]
Velocity: The speed of a radio wave through the dielectric medium it is in.
Vertical dipole: A balanced or dipole antenna oriented vertically.
Vertical polarization: Transmission of radio waves in such a way that the electric lines of force are vertical (perpendicular to the Earth’s surface).
Vertical quarter-wave antenna: A monopole (whip) antenna that is oriented vertically. [Antenna Dictionary]
Very high frequency: Frequencies between 30 and 300 MHz; transmissions that follow the line of sight path.
Voltage: Electrical pressure, expressed in volts, which is the result of squeezing electrons together.
Voltage standing-wave ratio: [VSWR] The ratio of the amplitude of the electric field or voltage at a voltage maximum to that at an adjacent voltage minimum. Also called VSWR.
Waveguide: A hollow metal tube used as a transmission line to guide energy from one point to another. [WaveGuide Manufacturers]
Wavelength: The distance a wave travels during one complete cycle. It is equal to the velocity divided by the frequency. wave propagation—The transmission of RF energy through space.
Whip antenna: A vertical monopole. A flexible rod antenna, usually between 1/10 and 5/8 wavelength long, supported on a base insulator. [Antenna Manufacturers]
Wire: Conductors in one of many different sizes with different kinds of insulation. [Wire Manufacturers]
Yagi antenna: A combination of dipoles to increase the gain.
