G - Golf - dah-dah-dit
G.
Shorthand notation for multiply by 1,000,000,000 or Giga.
G5RV.
Possibly the most common HF wire antenna in the world. Devised by Louis Varney (short history) in 1946 and bearing his callsign for it's name.
Gain.
An increase over original level. This could be:- An increase in the effective power radiated by an antenna, for example a Directional Antenna.
- An increase in received signal strength, for example with a Pre-Amplifier.
- An increase in Audio level. Etc.
Gateway.
General-Coverage Receiver.
A receiver used to listen to a wide range of frequencies. Most general-coverage
receivers tune from frequencies below the standard-broadcast band to at least 30 MHz. These frequencies include the shortwave-broadcast bands and the amateur bands from 160 to 10 meters.
Geomagnetic Disturbance.
A dramatic change in the Earth's magnetic field that occurs over a short time.
Geostationary Satellite Orbit / Geostationary Orbit (GSO).
A circular orbit approximately 35,900 km above the earth, in the plane of the earth's equator, in which a satellite revolves around the earth in the same time that the earth rotates on its axis; thus the satellite appears approximately stationary over one point on the earth.
Giga.
The metric prefix for 109, or times 1,000,000,000.
Gray Line.
A band around the Earth that separates daylight from darkness. It is a transition region between day and night.
Great Circle Map (Great Circle DX Map).
Great-Circle Path.
Either one of two direct paths between two points on the surface of the Earth. Great-circle paths can be visualized if you think of a globe with a rubber band stretched around it, connecting the two points. One of the great-circle paths is the shortest distance between those two points and is the usual path for DX, contact via the other path is known as Long Path Communication.
Ground Connection.
A connection made to the earth for electrical safety. This connection can be made inside (to a metal cold-water pipe) or outside (to a ground rod).
Ground Plane.
An artifical 'ground' for an omni-directional antenna. Usually 3 or 4 radials, of at least ¼ wavelength each, equidistantly spaced around base of the antenna and connected to the ground connection of the feeder. In mobile installations the vehicle bodywork is usually the ground plane.
Ground Plane Antenna.
A vertical antenna built with the central radiating element one-quarter-wavelength long and several radials extending horizontally from the base. The radials are slightly longer than one-quarter wave, and may droop toward the ground.
Ground Rod.
A copper or copper-clad steel rod that is driven into the earth. A heavy copperwire from the ham shack connects all station equipment to the ground rod.
Ground-Wave Propagation.
The method by which radio waves travel along the Earth's surface.
GSO.
GTOR.
(Golay -TOR) is an FSK mode that offers a fast transfer rate compared to PACTOR. It incorporates a data inter-leaving system that assists in minimizing the effects of atmospheric noise and has the ability to fix garbled data. GTOR tries to perform all transmissions at 300 baud but drops to 200 baud if difficulties are encountered and finally to 100 baud. (The protocol that brought back those good photos of Saturn and Jupiter from the Voyager space shots was devised by M.Golay and now adapted for ham radio use.) GTOR is a proprietary mode developed by Kantronics. Because it is only available with Kantronics multi-mode TNCs, it has never gained in popularity and is rarely used by radio amateurs.
See also: Digital Modes page.