Analog television encodes television picture information as an analog signal, that is, by varying the voltages and/or frequencies of the signal. All systems preceding digital television can be considered analog. For the Analog Science Fiction and Science Fact publication, see Astounding Magazine. ... In the physical sciences, potential difference is the difference in potential between two points in a conservative vector field. ... Sine waves of various frequencies; the lower waves have higher frequencies than those above. ... A signal is an abstract element of information, or (more commonly) a flow of information (in one or more dimensions). ... Digital television (DTV) uses digital modulation and compression to broadcast video, audio and data signals to television sets. ...

Common analog television systems:

• NTSC
• PAL
• SÉCAM
• Slow-scan television
• Narrow-bandwidth television

NTSC is the analog television system in use in the United States and some other places, mostly the Americas (see map). ... For other meanings of PAL see PAL (disambiguation). ... // SÉCAM (Séquentiel couleur avec mémoire, French for sequential colour with memory) is an analog color television system first used in France. ... Slow-scan television (SSTV) is used by amateur radio operators, to transmit and receive static pictures in monochrome (black & white) or colour. ... Narrow-bandwidth television (NBTV) is a type of television designed to fit into a low-bandwidth channel, in the extreme case using amateur radio voice frequency channels that only range up to a few kilohertz (though channels ranging into a few tens of kilohertz and beyond can also be used). ...

See also

• Broadcast television system
• Terrestrial television

There are several broadcast television systems in use in the world today. ... Terrestrial television (also known as over-the-air or OTA) is the traditional method of television broadcast signal delivery, by radio waves. ...

External links

• Conventional Analog Television - An Introduction