G

G
Gain : How much more effective an antenna is as a radiator than a half wave dipole (dBd) or a theoretical point source (dBi). A more directional antenna is considered to have higher gain.

Gel cell : A small sealed lead-acid rechargeable battery which uses a gel instead of a liquid electrolyte. Often used as backup power in applications such as alarm panel installations.

 GHz : Gigahertz - one billion Hertz (1 000 000 000 Hz)

General coverage : The ability of a receiver to tune outside the amateur radio bands, typically over an extended continuous frequency range, to receive signals from non-amateur services such as shortwave broadcast or marine weather.

GMT : Greenwich Mean Time - the time at Greenwich UK. Related to Zulu and UTC.

GOTA : (1) Get On The Air - a station available for supervised public use at Field Day events,

GOTA : (2) Guides On The Air - a programme sponsored by YL organisations to introduce Girl Guides to amateur radio (see also: Jamboree on the Air)

Grey Line also Gray Line : a band around the earth that separates night from day.

Ground : A direct connection from electrical equipment to the Earth - often achieved by driving a conducting spike into the ground, and connecting equipment to it.

Ground (2): A common zero voltage reference point.

Ground-plane Antenna : a quarter wavelength vertical antenna with radials extending horizontally from its base.

Groud wave propagation : Propagation via radio waves that travel along the surface of the earth.

G-TOR (Golay - TOR) : A digital FSK mode that offers faster transfer rate than PACTOR. Rarely used by ham radio operators.