MAY 30 2016 VHS TECHNICAL DETAILS : SIGNAL STANDARDS
VHS can record and play back all varieties of analog television signals in existence at the time VHS was devised. However, a machine must be designed to record a given standard. Typically, a VHS machine can only handle signals of the country it was sold in. The following signal varieties exist in conventional VHS:
* SECAM/625/25 (SECAM, French variety)
* MESECAM/625/25 (most other SECAM countries, notably the former Soviet Union and Middle East)
* NTSC/525/30 (Most parts of Americas, Japan, South Korea)
* PAL/525/30 (i.e., PAL-M, Brazil)
* PAL/625/25 (most of Western Europe, Australia, New Zealand, many parts of Asia such as China and India, some parts of South America such as Argentina, Uruguay and the Falklands, and Africa). Note that PAL/625/25 VCRs allow playback of SECAM (and MESECAM) tapes with a monochrome (black and white) picture (and vice-versa) as the line standard is the same. Since the 1990s, dual- and multi-standard VHS machines have become more and more common. These can handle VHS tapes of more than one standard. For example, regular VHS machines sold in Australia and Europe nowadays can typically handle PAL, MESECAM for record and playback, plus NTSC for playback only (provided the TV is able to display NTSC's 525/30 line standard - most can). Dedicated multistandard machines can usually handle all standards listed, some high end models can even convert a tape from one standard to another by using a built-in standards converter. S-VHS only exists in PAL/625/25 and NTSC/525/30. S-VHS machines sold in SECAM markets record internally in PAL, and convert to/from SECAM during record/playback, respectively. Likewise, S-VHS machines for the Brazilian market record in NTSC and convert to/from PAL-M. A small number of VHS decks are able to decode closed captions on prerecorded video cassettes. A smaller number still are able, additionally, to record subtitles transmitted with world standard teletext signals (on pre-digital services), simultaneously with the associated program.