CCIR System M
analog broadcast television system
CCIR System M, sometimes called 525–line, NTSC, NTSC-M, or CCIR-M, is the analog broadcast television system standardized by CCIR and approved by the FCC (upon recommendation by the National Television System Committee - NTSC) for use in the United States since July 1, 1941, replacing the 441-line TV system introduced in 1938. It is also known as EIA standard 170. System M comprises a total of 525 interlaced lines of video, of which 486 contain the image information, at 30 frames per second. Video is amplitude modulated and audio is frequency modulated, with a total bandwidth of 6 MHz for each channel, including a guard band.
It was also adopted in the Americas and Caribbean; Myanmar, Philippines, South Korea, Taiwan, Thailand, and Japan (here with minor differences, informally referred to as System J). System M doesn't specify a color system, but NTSC color encoding was normally used, with some exceptions: NTSC-J in Japan, PAL-M in Brazil and SECAM-M in Cambodia, Laos, and Vietnam (see Color standards section below).
The letter M designation was attributed by the ITU at the 1961 Stockholm meeting (see ITU identification scheme).
In 1965, Thailand decided to replace System M with the 625-line CCIR System B, which began implementation in 1967 and eventually adopted the PAL color standard.
Circa 2003, the transition from analog System M to digital television broadcasting began, and in 2009 the United States ended high power analog transmissions. Other nations such as Japan, South Korea, and Taiwan also transitioned to digital while the Philippines remain on analog transmissions with digital simulcasts.
This brief starts where responsible research should: with the source description of “CCIR System M” as analog broadcast television system. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the arts & letters register because the source frames it as analog broadcast television system. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Attribution, date and provenance are strongest when supported by the original work, a catalogue record and documented transmission. The source revision retrieved here is dated May 21, 2026. The linked authority identifier is Q5009598. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1941, 1938, 1961 and 1965.
Later fame can flatten the distinction between original context, subsequent adaptation and institutional collecting history. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Separate the work, its editions or performances, and its later reception. Catalogue records, publication histories and object files often preserve different parts of that story.
- Identifying works and editions
- Tracing reception history
- Finding collection records
The original object or edition, catalogue raisonné, performance record, rights file and holding institution.
Three-step research path
- Establish the record: confirm the title “CCIR System M”, its source revision and the description used here.
- Expand the search: follow CCIR System M primary sources, CCIR System M archive and CCIR research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “CCIR System M”?
- How did later circulation or interpretation alter the work’s reception?
- Which edition, object, performance or recording is being described?
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This entry incorporates text from “CCIR System M” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.