Glossary Glossary · 1 min
Glossary
The words radio people use, each with its own address you can link to.
Draft. Not yet checked by an editor.
Every term below has its own link. Articles in Learn point here the first time they use one.
Carrier
The steady wave a transmitter sends at its frequency. Sound is carried by changing it (see modulation).
#Modulation
Changing a carrier so it carries information: its strength in AM, its frequency in FM.
#Skywave
A signal that reaches you by bouncing off the ionosphere rather than travelling along the ground. Skywave is why shortwave and night-time AM cross oceans.
#Groundwave
A signal that follows the curve of the Earth near the surface. Medium-wave stations reach their local audience by groundwave in daytime.
#Ionosphere
Layers of the upper atmosphere, roughly 60 to 1,000 km up, ionised by the Sun. They reflect some radio frequencies back to Earth and absorb others, and they change through the day and the solar cycle.
#DX
Listening to (or contacting) distant stations. A "DXer" chases far-off signals for the pleasure of hearing them.
#QSL card
A card a station sends to confirm that a listener or operator heard it, traditionally in return for a reception report.
#Call sign
The identifier a licensing authority assigns to a station or an amateur operator, such as a US broadcaster's four letters or an amateur's letters and digits.
#