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CCIR System G, also known as the "Gerber Standard", is an analog broadcast television system used in sixty countries around the world for 
At a CCIR Geneva meeting in July 1950, Dr. Gerber (a Swiss engineer), proposed a modified 625-lines system with a 7 MHz channel bandwidth (based on work by Telefunken and Walter Bruch). Known as the "Gerber Standard", it was initially approved for VHF broadcasts, and eventually adapted for UHF.
Usually paired with
World Analogue Television Standards and Waveforms
{{Analogue TV transmitter topics ITU-R recommendations Television technology Video formats Broadcast engineering CCIR System
CCIR System G, also known as the "Gerber Standard", is an analog broadcast television system used in sixty countries around the world for UHF
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter ...
channels. System G is generally associated with System B for VHF.
At a CCIR Geneva meeting in July 1950, Dr. Gerber (a Swiss engineer), proposed a modified 625-lines system with a 7 MHz channel bandwidth (based on work by Telefunken and Walter Bruch). Known as the "Gerber Standard", it was initially approved for VHF broadcasts, and eventually adapted for UHF.
Usually paired with PAL
Phase Alternating Line (PAL) is a color encoding system for analog television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...
colour, it was also used with SECAM
SECAM, also written SÉCAM (, ''Séquentiel de couleur à mémoire'', French for ''sequential colour memory''), is an analog color television system that was used in France, Russia and some other countries or territories of Europe and Africa. ...
in Egypt
Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...
, Iran
Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...
and Saudi Arabia
Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in West Asia. Located in the centre of the Middle East, it covers the bulk of the Arabian Peninsula and has a land area of about , making it the List of Asian countries ...
.
Specifications
Some of the important specs are listed below: *Frame rate
Frame rate, most commonly expressed in frame/s, or FPS, is typically the frequency (rate) at which consecutive images (Film frame, frames) are captured or displayed. This definition applies to film and video cameras, computer animation, and moti ...
: 25 Hz
* Interlace: 2/1
* Field rate
Field may refer to:
Expanses of open ground
* Field (agriculture), an area of land used for agricultural purposes
* Airfield, an aerodrome that lacks the infrastructure of an airport
* Battlefield
* Lawn, an area of mowed grass
* Meadow, a gras ...
: 50 Hz
* Lines/frame: 625
* Line rate
In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time.
The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction w ...
: 15.625 kHzNot an independent value: 25 Hz×625=15.625 kHz
* Visual bandwidth: 5 MHz
* Vision modulation: AC3 negative
* Preemphasis: 50 μs
* Sound modulation: F3
* Sound offset: 5.5 MHz
* Channel bandwidth: 8 MHz
A frame is the total picture. The frame rate is the number of pictures displayed in one second. But each frame is actually scanned twice interleaving odd and even lines. Each scan is known as a field (odd and even fields.) So field rate is twice the frame rate. In each frame there are 625 lines (or 312.5 lines in a field.) So line rate (line frequency) is 625 times the frame frequency or 625×25=15625 Hz.
The RF parameters of the transmitted signal are exactly the same as those for System B which is used on the 7.0 MHz wide channels of the VHF bands. The only difference is the width of the guard band between the channels, which on System G is 1.0 MHz wider than for System B: in other words 1.15 MHz (assuming the worst case which is when NICAM
Near Instantaneous Companded Audio Multiplex (NICAM) is an early form of lossy compression for digital audio. It was originally developed in the early 1970s for point-to-point links within broadcasting networks.Croll, M.G., Osborne, D.W. and Spi ...
sound is in use).
System H
A few countries (Belgium
Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...
, Luxembourg
Luxembourg, officially the Grand Duchy of Luxembourg, is a landlocked country in Western Europe. It is bordered by Belgium to the west and north, Germany to the east, and France on the south. Its capital and most populous city, Luxembour ...
and Netherlands
, Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...
) use a variant of system G which is known as System H. System H is similar to system G but the lower (vestigial) side band is 500 kHz wider. This makes much better use of the 8.0 MHz channels of the UHF bands by reducing the width of the guard-band by 500 kHz to the still perfectly generous value of 650 kHz.
See also
*Broadcast television systems
Broadcast television systems (or terrestrial television systems outside the US and Canada) are the encoding or formatting systems for the transmission and reception of terrestrial television signals.
Analog television systems were standardized ...
* Television transmitter
A television transmitter is a transmitter that is used for terrestrial television, terrestrial (over-the-air) television broadcasting. It is an electronic device that radiates radio waves that carry a video signal representing moving images, alon ...
* Transposer
In broadcasting, a transposer or translator is a device in or beyond the service area of a radio or television station transmitter that rebroadcasts signals to receivers which can’t properly receive the signals of the transmitter because of a p ...
* Television channel frequencies
The following tables show the frequencies assigned to analog broadcast television channels in various regions of the world, along with the ITU letter designator for the transmission system used. The frequencies shown are for the channel limits an ...
Notes and references
External links
World Analogue Television Standards and Waveforms
{{Analogue TV transmitter topics ITU-R recommendations Television technology Video formats Broadcast engineering CCIR System