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CCIR System H is an analog broadcast television system used in
The RF parameters of the transmitted signal are almost the same as those for System B which is used on the 7.0 MHz wide channels of the VHF bands. The only difference to the RF spectrum of the signal is that the vestigial sideband is 500 kHz wider at 1.25 MHz. Due to this and the extra width of the channel allocations at UHF, the width of the guard band between the channels is 650 kHz (assuming the worst case which is when NICAM sound is in use).
World Analogue Television Standards and Waveforms
{{Analogue TV transmitter topics ITU-R recommendations Television technology Video formats Broadcast engineering CCIR System
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 ...
, Bosnia and Herzegovina
Bosnia and Herzegovina, sometimes known as Bosnia-Herzegovina and informally as Bosnia, is a country in Southeast Europe. Situated on the Balkans, Balkan Peninsula, it borders Serbia to the east, Montenegro to the southeast, and Croatia to th ...
, Croatia
Croatia, officially the Republic of Croatia, is a country in Central Europe, Central and Southeast Europe, on the coast of the Adriatic Sea. It borders Slovenia to the northwest, Hungary to the northeast, Serbia to the east, Bosnia and Herze ...
, Malta
Malta, officially the Republic of Malta, is an island country in Southern Europe located in the Mediterranean Sea, between Sicily and North Africa. It consists of an archipelago south of Italy, east of Tunisia, and north of Libya. The two ...
, Slovenia
Slovenia, officially the Republic of Slovenia, is a country in Central Europe. It borders Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the south and southeast, and a short (46.6 km) coastline within the Adriati ...
and Liberia
Liberia, officially the Republic of Liberia, is a country on the West African coast. It is bordered by Sierra Leone to Liberia–Sierra Leone border, its northwest, Guinea to Guinea–Liberia border, its north, Ivory Coast to Ivory Coast–Lib ...
on UHF bands, paired with System B on VHF. It was associated 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.
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: 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 almost the same as those for System B which is used on the 7.0 MHz wide channels of the VHF bands. The only difference to the RF spectrum of the signal is that the vestigial sideband is 500 kHz wider at 1.25 MHz. Due to this and the extra width of the channel allocations at UHF, the width of the guard band between the channels is 650 kHz (assuming the worst case which is when NICAM sound is in use).
System G
Many countries use a variant of system H which is known as System G. System G is similar to system H but the lower (vestigial) side band is 500 kHz narrower. This makes poor use of the 8.0 MHz channels of the UHF bands by merely increasing the width of the guard-band by 500 kHz to 1.15 MHz. The advantage(?) is that the RF spectrum of system G (on UHF) is the same as system B (on VHF), simplifying the band-switching circuitry in VHF/UHF televisions.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
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