To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
Languages
Recent
Show all languages
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

From Wikipedia, the free encyclopedia

Television line count by nation; countries that are using System M or J currently or have used them prior to digital switchover, are in green.
Television line count by nation; countries that are using System M or J currently or have used them prior to digital switchover, are in green.

CCIR System M, sometimes called 525 line or monochrome NTSC, is the analog broadcast television system approved by the FCC (upon recommendation by the National Television Systems Committee - NTSC)[1] for use in the United States since July 1, 1941,[2][3] replacing the 441-line TV system introduced in 1938.[3] System M displays a total of 525 lines of video (with 480 carrying visible image information) at 30 frames per second using 6 MHz spacing between channel numbers, and is used for both VHF and UHF channels.

It was also adopted in most of the Americas and Caribbean, South Korea,Taiwan and Japan (here with minor differences, informally referred to as System J). System M doesn't specify a color system, but NTSC (NTSC-M) was normally used, with some exceptions: NTSC-J in Japan, PAL-M in Brazil and SECAM-M on Cambodia and Vietnam (see Color standards section below).

The letter M designation was attributed by the ITU on the 1961 Stockholm meeting (see ITU identification scheme).[4]

Since 2015, System M is being replaced by digital broadcasting, in countries such as the Americas, Japan, South Korea, Taiwan and the Philippines.

Specifications

Radio spectrum of a System M television channel with NTSC color
Radio spectrum of a System M television channel with NTSC color
Plan showing VHF frequency ranges for ITU Systems
Plan showing VHF frequency ranges for ITU Systems
World television systems
System(CCIR) Lines (total) Lines (visible) Frame rate (fps) Channel bandwidth (MHz) Visual bandwidth (MHz) Sound offset (MHz) Vestigial sideband (MHz) Vision modulation Sound modulation Notes
M 525 480 29.97 (NTSC color) 6 4.2 +4.5 0.75 Negative FM Most of the Americas and Caribbean; Myanmar, Philippines, South Korea, Taiwan (all NTSC-M)
Japan (NTSC-J)
Brazil (PAL-M)
Cambodia, Vietnam (SECAM-M).
30 (original)

Color standards

Television color encoding by nation; Brazil (PAL-M) and all green countries (NTSC) are based on monochrome System M.
Television color encoding by nation; Brazil (PAL-M) and all green countries (NTSC) are based on monochrome System M.

NTSC-M and NTSC-J

Strictly speaking, System M does not designate how color is transmitted. However, in nearly every System M country NTSC is used for color television. This combination called is called NTSC-M, but usually simply referred to as "NTSC", because of the relative lack of importance of black-and-white television. In NTSC-M and Japan's NTSC-J, the frame rate is offset slightly, becoming 301.001 frames per second, usually labeled as the rounded number 29.97.

PAL-M

The main exception to NTSC is Brazil, where PAL color is used instead, resulting in the PAL-M combination unique to that country. It is monochrome-compatible with other System M countries, but not compatible with other PAL countries, which use 652-line based systems.

SECAM-M

Between 1970 and 1991 a variation of the SECAM color system, known as SECAM-M, was used in Cambodia and Vietnam (Hanoi and other northern cities).

References

  1. ^ Pursell, Carroll (April 30, 2008). A Companion to American Technology. John Wiley & Sons. ISBN 9780470695333 – via Google Books.
  2. ^ Herbert, Stephen (June 21, 2004). A History of Early Television. Taylor & Francis. ISBN 9780415326681 – via Google Books.
  3. ^ a b Meadow, Charles T. (February 11, 2002). Making Connections: Communication through the Ages. Scarecrow Press. ISBN 9781461706915 – via Google Books.
  4. ^ Final acts of the European Broadcasting Conference in the VHF and UHF bands. Stockholm, 1961.

See also

This page was last edited on 1 July 2022, at 08:09
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.