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I got into a discussion and some persisted that Ch 7# where the highest analog channels. I thought this was b/c that is all they have ever encountered. Since my TV goes up to 120 or beyond for analog stations. So what are the possible channels for analog TV in the US and elsewhere. Both Broadcast / and Cable etc. EDIT I guess this site says Broadcast is 2 - 83. http://electronics.howstuffworks.com/dtv3.htm How about cable though can it go all the way to 12#? TY
This doesn't seem fair!!! What about all the people who don't have the equipment to receive digital broadcasts??? What are we supposed to tell them??? Sounds a little "right-wing", don't you think??? -- WIKISCRIPPS 07 SUN SEP 24 2006 2:43 PM EDT
Some have said the real reason for getting rid of analog TV is for more bandwidth for cell phone. if that is the case, we would be better served by not letting every idiot and 10-year old kid off the street from having one. 1 phone per household is fine, but 1 person= 1 phone is assinine. -WK- 139.78.96.57 ( talk) 00:24, 28 December 2007 (UTC)
Here's the deal: Those who still have analog TVs without tuners capable of getting ATSC signals, will likely be given a set-top box at discount. That, though will be a minimal problem, as the law already mandates that any television over 27 inches (around that at least) must have an ATSC compatible tuner.
I think smaller TVs will be required to have this compatibility soon enough. At the rate most people go through televisions, ATSC, Digital TV and HDTV will come on the scene with much fewer problems than you think. Serkali 06:24, 7 December 2006 (UTC)
Does this article seem biased towards analog TV to anyone else? - 216.138.38.86 15:45, 26 January 2007 (UTC)
It is very difficult to compare analogue and digital television picture 'dynamics' quality by viewing as current day broadcasts, the best that can be done at present is to find VHS recordings of TV programs made when the analog signal was maintained, such as in the early 90's. If you don't beleive me, try it and see for yourself- look for the picture movement, one looks more like real-life, the other looks like moving computer graphics. Analogue RF signals nowdays are not maintained, they are allowed to degrade, making it difficult to see the picture without snow and of course is still subject to the effects of digital compression which may be used now to save bandwidth in the transport feed. The difference A and D TV can be equated to the difference between an original audio CD and an 'all-digitally-mastered' MP3 download of the same 70's or early 80's track, the latter of course sounds as though it is heard through short-wave radio, listen for the varying timbre of fuzz-guitar which MP3 cannot recreate very well. Comparing a CD with a vinyl record in order to illustrate the difference between A and D TV is completely absurd, because an audio CD is still the analogue representation of sound waveform, just as is vinyl record is. It would be fairer to compare the vinyl record (equivalent to 1 gigabyte of data) to MP3 (typically 0.08 gigabyte). If MP3 was relased in the early 80's instead of the Philips Audio Compact Disc, it would most certainly of flopped, as magazine shelves were full of 'hi-fi enthusiasts' magazines which had articles on listening tests tonal qualities of loudspeaker cables on the most expensive gear in the world. Mass-market digital camera technology is beginning to catch up with professional camera film, (medium-format ektachrome 25 is equivalent to something like 200 megapixels). In the same way, digital TV will one day in the future not need to rely so heavily on bandwidth compression to deliver a stream, it could allow more naturally appearing movement, if more bandwidth is available. The primitive digital tv of today is currently in the dark ages, it has a long way to go yet.
A flower growing is nature's highest form of digital compression. The image of it on our retina is nature's analogue TV. Which is the best compromise of these two to project the image of a flower swaying in a breeze? The answer will always change, depending on current technology, the accountants, market forces. We are presently at the stage of manipulated computer graphics representing the flower, for HD we are increasing the number of pixels. -- MarkRBarker 19:51, 20 March 2007 (UTC)
The http://www.ee.washington.edu/conselec/CE/kuhn/ntsc/95x4.htm link is broken. It should be removed or someone should find where it has been moved to. —The preceding unsigned comment was added by 91.120.69.76 ( talk) 09:54, 26 February 2007 (UTC).
Why bother? The full resolution of 525 lines (4 Mhz) on NTSC equipement has never been realized.
Most good VHS machines rarely give anything higher than 300. Even NTSC DVD players only output about 400.
Even at the peak, commercial broadcasts in strong signal areas of good quality only gave 450 or so.
If the system had been used to its full capacity, this may not have been so big a deal. WK 139.78.96.57 ( talk) 00:20, 28 December 2007 (UTC)
Aside from the comments on POV already, with the tedious discussion above. There are a few things in this section which I don't think are true at all. A few points if I may.
Analogue and digital tv signals, in standard definition at least, are both formed of 50/60 interlaced fields per second. No difference in frame rate. I'd also query the comment on redundancy in the picture signal, an analogous representation of something is inherently redundant since it is an analogue of something and does not resemble a white noise signal which has the highest information density.
The MPEG compression used in digital TV has chroma subsampling (as do most other compressed video formats) comparable in many ways to the lesser bandwidth used for colour information in PAL/NTSC analogue signals.
The point on the uncompressed data rate of a digital signal is arguable superflous since the main argument in favour of digital television (or as far as the authorities are concerned at least) is the reduction in bandwith used. Transmitting an uncompressed signal would be impractical and pointless. Needless to say it is nowhere near as large as 250Gb/sec. Also note that 250Gb/sec does not in any way nescessarily equate to 250Ghz of bandwidth, this would depend on the modulation used and could be vastly less, though this is irrelevant anyway. I have no idea where the 250 number has come from. (Actually I think I've worked out where this may have come from now, 720 * 576 * 3 * 25 * 8 is 248832000, is about 250 Mbit/s though this assumes no chroma subsampling with 24 bits per pixel, still out by a multiple of 1000 though) (One further addition, 250Mbit/s could comfortably fit in a 6Mhz wide channel with some not too rediculously dense modulation, although this signal would not be very robust and no space would have been saved)
The last paragraph should be scrapped I think also. The degredation of an analogue signal in less than perfect conditions may be more pleasant to watch but it is in no way "predictable". As far as the unpacking of audio whilst constructing a picture, the complexity of the process should not be a point against it as long as it works. In my mind the signal processing of an analogue picture is in no way simple either. (unsigned)
Too many people here seem to base this article's 'facts' on what they see at home, and even drag old VHS recordings and Big Ben in to prove points. There are quite a few very subjective statements made, which have nothing to do with the true quality of digital (or analog) TV. These WK editors are blaming the Titanic for the ice berg.
Many cable and satellite stations will (re)compress digital video signals to be able to carry more data (= channels) on the same bandwidth. This obviously reduces picture quality. However, that doesn't mean digital TV is poor. It only is when it is mis-used, re-compressed, improperly transported, etc, etc, like in the example above. Just like analog signals can be distorted. The quality of digital TV is better than that of analog. There's simply no denying that. However, you can't properly judge it by watching your TV at home.
Go to a professional digital edit suite, watch the edited master on a decent studio monitor, and compare it to an analog edited master. Then you can judge what you're talking about. Jerky movement? Nonsense. Poor lip-sync? Blame your local distributor. Paint-by-numbers? Bad re-compression.
I've edited digital broadcast video for national TV for almost a decade. Do you really think we'd buy all that expensive studio hardware if digital is as bad as Wikipedia claims it is? Dudes, please... That paragraph should go. Rien Post 23:57, 6 May 2007 (UTC)
I've now removed this entire section, which was full of inaccuracies about both digital and analog TV standards, and is better off being rewritten from scratch. And yes, the whole TV production chain has been digital (and mostly compressed digital where storage is involved) for many years. -- Karada 17:44, 17 July 2007 (UTC)
I dont really understand how an analog television broadcast can have a resolution per se, because it isn't it just like film in that it depends on what resolution you scan it at to determin the acutall resolution? Rodrigue 13:31, 24 March 2007 (UTC)
Sorry for making so many edits, but I think I got this thing a bit cleared up. Some of the information is clearly made up by the person who edited it before me, but I can't find anything proving or disproving it. As for the ammount of 'citations needed', I cleared a few of them out and added a bit more info... The problem with some of the info in there is that there are absolutely no references on the internet, anywhere, it is just the way it's always been so no one talks about it. W/e, I'm done caring :P —The preceding unsigned comment was added by Gripen40k ( talk • contribs) 17:39, 15 May 2007 (UTC).
Can analog television owners still watch satellite and cable broadcasts with out any difficulty? Does the change only effect televisions recieving network broadcasting? Mustang6172 22:01, 28 June 2007 (UTC)
I've removed the analog television reference links from the University of Washington's College of Engineering as they no longer existed. Someone attempted to retrieve them from Google's cache, but the links were found to be dead when I inspected them last. Because of the fact, can anyone please cite proper sources on analog television technology that are static, no pun intended, links to information that will not be moved or removed. -- Mnemnoch 07:21, 29 July 2007 (UTC)
How will the advent of digital TV affect channel allocations of stations already on air? WAVY 10 19:24, 24 September 2007 (UTC)
Please take a look at Talk:Technology of television. I'd like to have some discussion about possible reorganisation of the many television technology pages there are floating about.
IanHarvey ( talk) 10:23, 22 January 2008 (UTC)
Please see Talk:Technology_of_television#Proposed_Changes which I am going to implement shortly if no-one speaks up. IanHarvey ( talk) 12:42, 20 February 2008 (UTC)
Analog televisions have historical significance far beyond digital, to be honest.
Some of the most important events of the Twentieth Century were on the television. The only thing that picked those things up were Analog TV sets. The Apollo moon landing and the Nixon election campaign were both on Analog TV. They had three channels with that thing (plus local stations), and for about forty to sixty years, they were happy.
As we all know, Analog is going to be banned this June, forcing all analog owners to buy a government conversion unit.
This article should not be merged because it is a key part of the television's history. It is a highly notable article. I've seen mergers go through before, most of the information is cut out and lost to readers.
The price of those converters are fifty dollars at a Radio Shack, and they've got coupons at the Digital Transition website. These can send the price way down.
However, analog television holds history because my father, grandfather, and ancestors watched with it, and it's one thing I, as a fifteen-year-old teenager, do not wish to see lost to history.
My grandfather jokes about some of my generation "thinking that food comes from the grocery store,unaware of cows and farms and such". I always found that funny, but he may have a point.
As such, this is a really good article, written quite well. It is indeed notable, as aforementioned, because it was the only thing until the eighties. Cable came after. It's actually pretty much forgotton, with antennas and such being relics. This article is notable, and even historically significant.
Three channels! I don't know how I could have handled that television. My ancestors did, and that is intriging to me. This article deserves to stay for its significance, not just for me, but for all of the old people who come here.
When I see something I love on Wikipedia (turtles, The Slowskys, ect. ect.), it puts such a smile on my face. I think all viewers, young and old, deserve that happiness of seeing something important to them sitting as an article here on the Wikipedia. It's pleasing to me.
I read to my grandfather the Super Bowl history article. He recalled it all, the article as accurate as his memory. It was an enjoyable time.
These are 1-paragraph context-less stubs that would be better off merged here. There's a good diagram showing the definition and the cnocepts have little meaning outside of the context of a television scan line. Similarly, the synchronization material needs to be better integrated, since it is largely repetitive. -- Wtshymanski ( talk) 21:46, 6 October 2010 (UTC)
Oppose Front and back porches have almost nothing with analog TV. The porches are certains portions of the VF signal. If this much is sufficient for the merging, than everything related to VF signal should also be merged to Analog TV like sync pulse, chrominance, black level, luminance, frame (video) etc, etc. Then by this logic, why do we leave out the AF signal. Nedim Ardoğa ( talk) 09:40, 9 November 2010 (UTC)
I trained in, and qualified in Television and Electronics. I worked with analogue (English) /analog (Amaerican) television technology since 1963. From days of valve projection single channel receivers to todays flat screen LED (not LCD) displays. (Have 42" Panasonic LED TV.). I`m a bit of a "techie" in many fields...Plus .. I`m retired, makes me a good candidate to spend this winter exercising the dying "grey cells", (and the failing eyes), to add the refs. and my knowledge to this fine article. Francis E Williams ( talk) 21:19, 23 November 2010 (UTC)
I correctly included power supply design to augment the section entitled Power supply. I note that you have removed this contribution and have renamed the section CRT power supply now. Had this been correctly labled in the first instance I would not have added any material about the DC supplies for Analogue Television. This added content is SPECIFIC to analogue TV development and design. The EHT voltage multiplier is correctly named and is attributed to Cockcrofts design. Having been technically qualified in this field for over 47 years I can speak with some competence and authority on this subject. This technically oriented article is going to have little merit and credibility without accurate and verifiable content. If it is to be an Historical article, then it will require Historical verifiable content. See WP:OWN Francis E Williams ( talk) 21:52, 23 November 2010 (UTC)
I have at last stopped being a "Techie" based editor with this article. I now think the article should focus more on the differences in image processing aspects of analog transmissions, rather than the technological changes that have taken place with the hardware. Some historical hardware detail has to be included of course, to make the article more complete, more accurate, and informative to the technical reader. Should this be the way forward with this article, if so what do you think? I quote this rather observant editors comment, "after a few years of accretion someone has to go through and bubble-sort everything to put it into some logical sequence". Francis E Williams ( talk) 22:00, 25 November 2010 (UTC)
Can there be a section discussing the problems with red over-saturation in NTSC video? I know that intense red is not handled well, and can lead to smearing/bleeding of the red across the scan line. There is probably a technical explanation for it, but I am not enough of an expert to talk about it. DMahalko ( talk) 18:32, 22 December 2010 (UTC)
Vsync redirects to this article, but it does nothing to answer my question. I'm trying to learn what the setting I see in numerous PC games does and what are the (dis)advantages to enabling it.-- 69.110.0.210 ( talk) 01:32, 31 January 2011 (UTC)
This article contradicts the article on Digital television transition. The latter article states that the Netherlands was the first country in Europe to switch to digital television, but this article states that it was Luxembourg. ACEOREVIVED ( talk) 00:30, 24 February 2012 (UTC)
In the section, "Color video signal extraction", I would like to see a change to the paragraph that begins with "Instead, the RGB signals are converted into YUV form, where the Y signal represents ...". The new version I believe clears up some details by using well documented technical facts. Here's the new version: Ohgddfp ( talk) 16:22, 27 April 2014 (UTC)
Instead, the RGB signals are converted into YUV form, where the Y signal represents the lightness and darkness (luminance) of the colors in the image. Because the rendering of colors in this way is the goal of both black and white (monochrome) film and black and white (monochrome) television systems, the Y signal is ideal for transmission as the luminance signal. This ensures a monochrome receiver will display a correct picture in black and white. The U and V signals are "color difference" signals. The U signal is the difference between the B signal and the Y signal, also known as B minus Y (B-Y), and the V signal is the difference between the R signal, also known as R minus Y (R-Y). The U signal then represents how "purplish-blue" or its complementary color "yellowish-green" the color is, and the V signal how "purplish-red" or its complementary "greenish-cyan" it is. The advantage of this scheme is that the U and V signals are zero when the picture has no color content. Since the human eye is more sensitive to errors in luminance than in color, the U and V signals can be transmitted in a relatively lossy (specifically: bandwidth-limited) way with acceptable results. Ohgddfp ( talk) 16:22, 27 April 2014 (UTC)
Different combinations of U and V can be directly extracted in the receiver using demodulator circuits. For example, the RCA Victor CTC-4 chassis used one (R-Y) demodulator circuit and one (G-Y) demodulator circuit. The (B-Y) demodulator circuit was done away with, and so the (B-Y) signal was derived by electronically combining the (R-Y) and (G-Y) signals in a particular combination. Other schemes, including (R-Y)/(B-Y), (R-Y)/(B-Y)/(G-Y), I/Q, (R-Y)/Q, and various flavors of X/Z were used. In all cases, (R-Y), (B-Y), and (G-Y) are all recovered in the end. Ohgddfp ( talk) 16:22, 27 April 2014 (UTC)
The R,G,B signals in the receiver needed for the display device (CRT, Plasma display or LCD display) are electronically derived by matrixing as follows: R is the additive combination of (R-Y) with Y, G is the additive combination of (G-Y) with Y, and B is the additive combination of (B-Y) with Y. All of this is accomplished electronically. It can be seen that in the combining process, the low resolution portion of the Y signals cancel out, leaving R,G, and B signals able to render a low-resolution image in full color. However, the higher resolution portions of the Y signals do not cancel out, and so are equally present in R, G, and B, producing the higher definition (higher resolution) image detail in monochrome, although it appears to the human eye as a full-color and full resolution picture. Ohgddfp ( talk) 16:22, 27 April 2014 (UTC)
About "The carrier is never shut off altogether; this is to ensure that intercarrier sound demodulation can still occur.": This is a fallacy. The reality is that not allowing the carrier to go below 15 or 25 percent for the white reference (minimum picture carrier) was being pushed back in 1941 and even earlier. The Intercarrier sound recovery technique was invented in 1944/1945. There is an 1948 patent on intercarrier sound. But this fallacy goes even further. You don't need an on-air continuous picture carrier to use the intercarrier sound recovery technique. Let's say reference white was standardized at zero percent carrier. In a movie about a snow storm, you will have a frequency spectrum that includes the carrier and sidebands. If inside the receiver the picture carrier is narrow-band filtered to less than 30 Hz, the flywheel effect of the filter would produce a continuous picture carrier at the filter output from the intermittent picture carrier received over the air. The new continuous picture carrier would then be applied to effect the intercarrier operation, producing a clean 4.5 MHz sound IF. To fix this in the article, I would simply remove the sentence. Ohgddfp ( talk) 21:56, 27 April 2014 (UTC)
The very first paragraph has a problematic phrase: "... one in which the information to be transmitted, the brightness and colors of the points in the image and the sound waves of the audio signal are represented by continuous variations of some aspect of the signal; ...". The problem is that the exact same thing can be said of 8VSB digital television. On the air, the DTV signal is a continuous-time signal. But one might say that the DTV signal represents a discrete-time list of values streamed over the air, which it does, and so the continuous-time on-air signal and the discrete-time digital signal inside the digital receiver both represent the same information. But that doesn't distinguish analog from digital either, because any real analog signal also represents a discrete time list of values, where both discrete-time analog and continuous-time analog represent the exact same information. To find out what exactly that discrete time list of analog values are, just sample the continuous analog signal. The result is analog (not digital) samples.
So what makes an analog signal analog? At any given point in time, an analog signal can take on any one of an infinite number of possible values.
So the sense of the word "continuous" as used in the opening paragraph to mean continuous-time, does not distinguish analog from digital. Rather, it is "continuous" in a very different sense that makes the difference. And that requires a different explanation. The value of each analog sample is continuously variable, meaning that its value is taken from a continuous range of possible values. That means an analog sample can take on any one of an infinite number of possible values, or the possible value of a single given analog sample is infinitely or continuously variable. In contrast, a digital sample can be any one of only a limited number of possible values. So here is the recommended fix:
Analog (or analogue) television is the analog transmission that involves the broadcasting of encoded analog audio and analog video signal:[1] one in which the information to be transmitted, the brightness and colors of the points in the image and the sound waves of the audio signal are represented by some aspect of the signal; its amplitude, frequency or phase, the values of which, at a given point in time, is any one of an infinite number of possible values. Ohgddfp ( talk) 02:28, 29 April 2014 (UTC)
Wide screen 16:9 aspect ratio CRT-based receivers were available for a while for reception of digital television signals. So flyback power supply design, which is specific to CRT-based receivers, applies equally to analog and digital. Since the title of this article is "Analog Television", the reader expects information that is unique to analog. This section is so long that a link to flyback power supply design by far makes the most sense. I'm planning to move it to the appropriate article. Ohgddfp ( talk) 02:22, 30 April 2014 (UTC)
There is --- maybe in all the english Wikipedia articles ? --- a confusion between the system of transmission and the color coding.
The official systems of transmission are named : A, B, C, D, E, F, G, H, I, K, K1, L, M and N. These systems determine the Number of lines, Channel width, Vision bandwidth, vision/sound separation, etc.
The colour coding which may be used of those systems are NTSC, SECAM and PAL.
So, I'm sorry for Wikipedia but this is the official situation.
-- AXRL ( talk) 14:25, 9 May 2014 (UTC)
Just finished skimming the article and I agree that it should remain as a summary of the different types of transmission and reception systems which were in use. That being said, the words Television and TV generally refer to the receiver in American English. Renaming the article to Analog (Analogue) Television Systems would inform both American and Commonwealth English readers that this is a general overview article with links to more in-depth articles. Divercth ( talk) 21:35, 29 January 2015 (UTC)
About a particular existing paragraph in "Standards": Ohgddfp ( talk) 16:52, 21 March 2020 (UTC)
"For this reason many people refer to any 625/25 type signal as "PAL" and to any 525/30 signal as "NTSC", even when referring to digital signals; for example, on DVD-Video, which does not contain any analog color encoding, and thus no PAL or NTSC signals at all. Even though this usage is common, it is misleading, as that is not the original meaning of the terms PAL/SECAM/NTSC.": Ohgddfp ( talk) 16:52, 21 March 2020 (UTC)
I would replace it with the following 2 paragraphs: Ohgddfp ( talk) 16:52, 21 March 2020 (UTC)
For this reason many people refer to any 625/25 type signal as "PAL" and to any 525/30 signal as "NTSC", even when referring to digital signals which actually do not have these type signals in original form. However, those digital signals do have some commonality with those analog "NTSC" and analog "PAL" formats because when the digital signal is directly converted to an analog signal, digital "NTSC" and analog NTSC both have lines and frame rates as 525/30. The same is true for PAL, with digital and analog versions both having lines and frame rates as 625/25. This is important because all but "international" analog Televisions/Monitors work only with analog NTSC or analog PAL, but not both. So DVD players, where most digital "NTSC" and digital "PAL" signals come from, have a corresponding analog NTSC or analog PAL output connector for connection to an analog TV/Monitor. A given DVD player does not have both kinds, so the analog TV/Monitor must match up NTSC or PAL to the DVD player, or a scrambled picture, and/or loss of color is the likely result. Ohgddfp ( talk) 16:52, 21 March 2020 (UTC)
When using certain kinds of digital equipment, with no analog equipment involved, digital format conversions can and usually do take place. The conversion can increase or decrease the number of pixel rows (lines), change the frame rate, and convert from interlace scan to progressive scan, making the designations of "NTSC" or "PAL" almost meaningless to the consumer, except that "NTSC" or "PAL" indicates to the consumer a picture quality that has a hard limitation in vertical resolution. Both kinds of conversions to a new digital format, from digital NTSC or from digital PAL, do not always give perfect picture quality, and years ago, such converting equipment was expensive in hardware, and very demanding in computer resources as digital software. Ohgddfp ( talk) 16:52, 21 March 2020 (UTC)
The article says: Thus with analog, a moderately weak signal becomes snowy and subject to interference. In contrast, a moderately weak digital television (DTV) signal and a very strong digital signal transmit equal picture quality. Depending on the definition of moderately, this is true. The problem is that moderately weak might be below the ability to decode, in which case you get nothing, or, more usual, flashing on and off, as it does, and then does not, have a decodable signal. With analog, it gets weaker and snowier. This is well known, and part of come FCC rules, as there are places that had a strong enough analog signal, but too weak in digital. Gah4 ( talk) 21:35, 20 May 2020 (UTC)
The article says: brightness, colors and sound are represented by rapid variations of either the amplitude, frequency or phase of the signal. This doesn't seem quite right. A given brightness or color is represented by an amplitude, frequency, or phase. Rapid change in brightness or color by a rapid change in those quantities. The screen can be one brightness and color, in which case the amplitude, frequency, or phase is not changing. Sound, on the other hand, is always represented by something changing, though maybe not so rapidly. Some might say that 20Hz isn't rapid. Gah4 ( talk) 21:41, 20 May 2020 (UTC)
Quote from article "Horizontal and Vertical Hold controls were rarely used in CRT-based computer monitors", This is patently wrong. Most monitors from a CBM PET to a TRS-80 model 4 to a DEC VT420 to a IBM 5153 monitor, all have both sync controls. Some accessible without removing the case, some only as maintenance controls, but they still had them. — Preceding unsigned comment added by 192.149.117.67 ( talk) 04:44, 31 July 2020 (UTC)
I am looking at the diagram and comparing it with the image of the oscilloscope. They appear to contradict each other. The diagram puts the "rear porch" in front of the line of signal, whereas the same area is labelled "front porch" on the oscilloscope image - which seems more likely to be correct. Additionally, the illustration has a hue that changes from reddish to greenish along the line and is labeled "chroma", but I'm fairly certain that is not how chroma works and the color is more defined by the width of the lines. Further, the color burst has a similar change in hue, but is the color burst not a single frequency? Maury Markowitz ( talk) 21:45, 19 May 2021 (UTC)
@ Kvng: I'm pretty sure the effects being referred to in the text you removed in this edit are mostly flesh tone problems, although I can't immediately find a source for that. What certainly can be sourced is that the NTSC system suffered from this problem, so much so that North American sets were commonly fitted with a "flesh tone" knob to allow the user to correct the picture. RGB with its much wider bandwidth would be much more susceptible to channel attenuation differences than NTSC. The PAL system largely overcomes this issue and Brit engineers rudely referred to NTSC as "Never Twice the Same Colour". Spinning Spark 10:40, 16 March 2022 (UTC)
The article says: amplitude, phase and frequency. For US NTSC, video is amplitude and phase, but audio is frequency (FM). That wouldn't be so bad, but the link is to phase and frequency as one article. I believe some system(s) use FM for video, though. Can we have separate links for phase and frequency? Gah4 ( talk) 20:51, 6 April 2023 (UTC)
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I got into a discussion and some persisted that Ch 7# where the highest analog channels. I thought this was b/c that is all they have ever encountered. Since my TV goes up to 120 or beyond for analog stations. So what are the possible channels for analog TV in the US and elsewhere. Both Broadcast / and Cable etc. EDIT I guess this site says Broadcast is 2 - 83. http://electronics.howstuffworks.com/dtv3.htm How about cable though can it go all the way to 12#? TY
This doesn't seem fair!!! What about all the people who don't have the equipment to receive digital broadcasts??? What are we supposed to tell them??? Sounds a little "right-wing", don't you think??? -- WIKISCRIPPS 07 SUN SEP 24 2006 2:43 PM EDT
Some have said the real reason for getting rid of analog TV is for more bandwidth for cell phone. if that is the case, we would be better served by not letting every idiot and 10-year old kid off the street from having one. 1 phone per household is fine, but 1 person= 1 phone is assinine. -WK- 139.78.96.57 ( talk) 00:24, 28 December 2007 (UTC)
Here's the deal: Those who still have analog TVs without tuners capable of getting ATSC signals, will likely be given a set-top box at discount. That, though will be a minimal problem, as the law already mandates that any television over 27 inches (around that at least) must have an ATSC compatible tuner.
I think smaller TVs will be required to have this compatibility soon enough. At the rate most people go through televisions, ATSC, Digital TV and HDTV will come on the scene with much fewer problems than you think. Serkali 06:24, 7 December 2006 (UTC)
Does this article seem biased towards analog TV to anyone else? - 216.138.38.86 15:45, 26 January 2007 (UTC)
It is very difficult to compare analogue and digital television picture 'dynamics' quality by viewing as current day broadcasts, the best that can be done at present is to find VHS recordings of TV programs made when the analog signal was maintained, such as in the early 90's. If you don't beleive me, try it and see for yourself- look for the picture movement, one looks more like real-life, the other looks like moving computer graphics. Analogue RF signals nowdays are not maintained, they are allowed to degrade, making it difficult to see the picture without snow and of course is still subject to the effects of digital compression which may be used now to save bandwidth in the transport feed. The difference A and D TV can be equated to the difference between an original audio CD and an 'all-digitally-mastered' MP3 download of the same 70's or early 80's track, the latter of course sounds as though it is heard through short-wave radio, listen for the varying timbre of fuzz-guitar which MP3 cannot recreate very well. Comparing a CD with a vinyl record in order to illustrate the difference between A and D TV is completely absurd, because an audio CD is still the analogue representation of sound waveform, just as is vinyl record is. It would be fairer to compare the vinyl record (equivalent to 1 gigabyte of data) to MP3 (typically 0.08 gigabyte). If MP3 was relased in the early 80's instead of the Philips Audio Compact Disc, it would most certainly of flopped, as magazine shelves were full of 'hi-fi enthusiasts' magazines which had articles on listening tests tonal qualities of loudspeaker cables on the most expensive gear in the world. Mass-market digital camera technology is beginning to catch up with professional camera film, (medium-format ektachrome 25 is equivalent to something like 200 megapixels). In the same way, digital TV will one day in the future not need to rely so heavily on bandwidth compression to deliver a stream, it could allow more naturally appearing movement, if more bandwidth is available. The primitive digital tv of today is currently in the dark ages, it has a long way to go yet.
A flower growing is nature's highest form of digital compression. The image of it on our retina is nature's analogue TV. Which is the best compromise of these two to project the image of a flower swaying in a breeze? The answer will always change, depending on current technology, the accountants, market forces. We are presently at the stage of manipulated computer graphics representing the flower, for HD we are increasing the number of pixels. -- MarkRBarker 19:51, 20 March 2007 (UTC)
The http://www.ee.washington.edu/conselec/CE/kuhn/ntsc/95x4.htm link is broken. It should be removed or someone should find where it has been moved to. —The preceding unsigned comment was added by 91.120.69.76 ( talk) 09:54, 26 February 2007 (UTC).
Why bother? The full resolution of 525 lines (4 Mhz) on NTSC equipement has never been realized.
Most good VHS machines rarely give anything higher than 300. Even NTSC DVD players only output about 400.
Even at the peak, commercial broadcasts in strong signal areas of good quality only gave 450 or so.
If the system had been used to its full capacity, this may not have been so big a deal. WK 139.78.96.57 ( talk) 00:20, 28 December 2007 (UTC)
Aside from the comments on POV already, with the tedious discussion above. There are a few things in this section which I don't think are true at all. A few points if I may.
Analogue and digital tv signals, in standard definition at least, are both formed of 50/60 interlaced fields per second. No difference in frame rate. I'd also query the comment on redundancy in the picture signal, an analogous representation of something is inherently redundant since it is an analogue of something and does not resemble a white noise signal which has the highest information density.
The MPEG compression used in digital TV has chroma subsampling (as do most other compressed video formats) comparable in many ways to the lesser bandwidth used for colour information in PAL/NTSC analogue signals.
The point on the uncompressed data rate of a digital signal is arguable superflous since the main argument in favour of digital television (or as far as the authorities are concerned at least) is the reduction in bandwith used. Transmitting an uncompressed signal would be impractical and pointless. Needless to say it is nowhere near as large as 250Gb/sec. Also note that 250Gb/sec does not in any way nescessarily equate to 250Ghz of bandwidth, this would depend on the modulation used and could be vastly less, though this is irrelevant anyway. I have no idea where the 250 number has come from. (Actually I think I've worked out where this may have come from now, 720 * 576 * 3 * 25 * 8 is 248832000, is about 250 Mbit/s though this assumes no chroma subsampling with 24 bits per pixel, still out by a multiple of 1000 though) (One further addition, 250Mbit/s could comfortably fit in a 6Mhz wide channel with some not too rediculously dense modulation, although this signal would not be very robust and no space would have been saved)
The last paragraph should be scrapped I think also. The degredation of an analogue signal in less than perfect conditions may be more pleasant to watch but it is in no way "predictable". As far as the unpacking of audio whilst constructing a picture, the complexity of the process should not be a point against it as long as it works. In my mind the signal processing of an analogue picture is in no way simple either. (unsigned)
Too many people here seem to base this article's 'facts' on what they see at home, and even drag old VHS recordings and Big Ben in to prove points. There are quite a few very subjective statements made, which have nothing to do with the true quality of digital (or analog) TV. These WK editors are blaming the Titanic for the ice berg.
Many cable and satellite stations will (re)compress digital video signals to be able to carry more data (= channels) on the same bandwidth. This obviously reduces picture quality. However, that doesn't mean digital TV is poor. It only is when it is mis-used, re-compressed, improperly transported, etc, etc, like in the example above. Just like analog signals can be distorted. The quality of digital TV is better than that of analog. There's simply no denying that. However, you can't properly judge it by watching your TV at home.
Go to a professional digital edit suite, watch the edited master on a decent studio monitor, and compare it to an analog edited master. Then you can judge what you're talking about. Jerky movement? Nonsense. Poor lip-sync? Blame your local distributor. Paint-by-numbers? Bad re-compression.
I've edited digital broadcast video for national TV for almost a decade. Do you really think we'd buy all that expensive studio hardware if digital is as bad as Wikipedia claims it is? Dudes, please... That paragraph should go. Rien Post 23:57, 6 May 2007 (UTC)
I've now removed this entire section, which was full of inaccuracies about both digital and analog TV standards, and is better off being rewritten from scratch. And yes, the whole TV production chain has been digital (and mostly compressed digital where storage is involved) for many years. -- Karada 17:44, 17 July 2007 (UTC)
I dont really understand how an analog television broadcast can have a resolution per se, because it isn't it just like film in that it depends on what resolution you scan it at to determin the acutall resolution? Rodrigue 13:31, 24 March 2007 (UTC)
Sorry for making so many edits, but I think I got this thing a bit cleared up. Some of the information is clearly made up by the person who edited it before me, but I can't find anything proving or disproving it. As for the ammount of 'citations needed', I cleared a few of them out and added a bit more info... The problem with some of the info in there is that there are absolutely no references on the internet, anywhere, it is just the way it's always been so no one talks about it. W/e, I'm done caring :P —The preceding unsigned comment was added by Gripen40k ( talk • contribs) 17:39, 15 May 2007 (UTC).
Can analog television owners still watch satellite and cable broadcasts with out any difficulty? Does the change only effect televisions recieving network broadcasting? Mustang6172 22:01, 28 June 2007 (UTC)
I've removed the analog television reference links from the University of Washington's College of Engineering as they no longer existed. Someone attempted to retrieve them from Google's cache, but the links were found to be dead when I inspected them last. Because of the fact, can anyone please cite proper sources on analog television technology that are static, no pun intended, links to information that will not be moved or removed. -- Mnemnoch 07:21, 29 July 2007 (UTC)
How will the advent of digital TV affect channel allocations of stations already on air? WAVY 10 19:24, 24 September 2007 (UTC)
Please take a look at Talk:Technology of television. I'd like to have some discussion about possible reorganisation of the many television technology pages there are floating about.
IanHarvey ( talk) 10:23, 22 January 2008 (UTC)
Please see Talk:Technology_of_television#Proposed_Changes which I am going to implement shortly if no-one speaks up. IanHarvey ( talk) 12:42, 20 February 2008 (UTC)
Analog televisions have historical significance far beyond digital, to be honest.
Some of the most important events of the Twentieth Century were on the television. The only thing that picked those things up were Analog TV sets. The Apollo moon landing and the Nixon election campaign were both on Analog TV. They had three channels with that thing (plus local stations), and for about forty to sixty years, they were happy.
As we all know, Analog is going to be banned this June, forcing all analog owners to buy a government conversion unit.
This article should not be merged because it is a key part of the television's history. It is a highly notable article. I've seen mergers go through before, most of the information is cut out and lost to readers.
The price of those converters are fifty dollars at a Radio Shack, and they've got coupons at the Digital Transition website. These can send the price way down.
However, analog television holds history because my father, grandfather, and ancestors watched with it, and it's one thing I, as a fifteen-year-old teenager, do not wish to see lost to history.
My grandfather jokes about some of my generation "thinking that food comes from the grocery store,unaware of cows and farms and such". I always found that funny, but he may have a point.
As such, this is a really good article, written quite well. It is indeed notable, as aforementioned, because it was the only thing until the eighties. Cable came after. It's actually pretty much forgotton, with antennas and such being relics. This article is notable, and even historically significant.
Three channels! I don't know how I could have handled that television. My ancestors did, and that is intriging to me. This article deserves to stay for its significance, not just for me, but for all of the old people who come here.
When I see something I love on Wikipedia (turtles, The Slowskys, ect. ect.), it puts such a smile on my face. I think all viewers, young and old, deserve that happiness of seeing something important to them sitting as an article here on the Wikipedia. It's pleasing to me.
I read to my grandfather the Super Bowl history article. He recalled it all, the article as accurate as his memory. It was an enjoyable time.
These are 1-paragraph context-less stubs that would be better off merged here. There's a good diagram showing the definition and the cnocepts have little meaning outside of the context of a television scan line. Similarly, the synchronization material needs to be better integrated, since it is largely repetitive. -- Wtshymanski ( talk) 21:46, 6 October 2010 (UTC)
Oppose Front and back porches have almost nothing with analog TV. The porches are certains portions of the VF signal. If this much is sufficient for the merging, than everything related to VF signal should also be merged to Analog TV like sync pulse, chrominance, black level, luminance, frame (video) etc, etc. Then by this logic, why do we leave out the AF signal. Nedim Ardoğa ( talk) 09:40, 9 November 2010 (UTC)
I trained in, and qualified in Television and Electronics. I worked with analogue (English) /analog (Amaerican) television technology since 1963. From days of valve projection single channel receivers to todays flat screen LED (not LCD) displays. (Have 42" Panasonic LED TV.). I`m a bit of a "techie" in many fields...Plus .. I`m retired, makes me a good candidate to spend this winter exercising the dying "grey cells", (and the failing eyes), to add the refs. and my knowledge to this fine article. Francis E Williams ( talk) 21:19, 23 November 2010 (UTC)
I correctly included power supply design to augment the section entitled Power supply. I note that you have removed this contribution and have renamed the section CRT power supply now. Had this been correctly labled in the first instance I would not have added any material about the DC supplies for Analogue Television. This added content is SPECIFIC to analogue TV development and design. The EHT voltage multiplier is correctly named and is attributed to Cockcrofts design. Having been technically qualified in this field for over 47 years I can speak with some competence and authority on this subject. This technically oriented article is going to have little merit and credibility without accurate and verifiable content. If it is to be an Historical article, then it will require Historical verifiable content. See WP:OWN Francis E Williams ( talk) 21:52, 23 November 2010 (UTC)
I have at last stopped being a "Techie" based editor with this article. I now think the article should focus more on the differences in image processing aspects of analog transmissions, rather than the technological changes that have taken place with the hardware. Some historical hardware detail has to be included of course, to make the article more complete, more accurate, and informative to the technical reader. Should this be the way forward with this article, if so what do you think? I quote this rather observant editors comment, "after a few years of accretion someone has to go through and bubble-sort everything to put it into some logical sequence". Francis E Williams ( talk) 22:00, 25 November 2010 (UTC)
Can there be a section discussing the problems with red over-saturation in NTSC video? I know that intense red is not handled well, and can lead to smearing/bleeding of the red across the scan line. There is probably a technical explanation for it, but I am not enough of an expert to talk about it. DMahalko ( talk) 18:32, 22 December 2010 (UTC)
Vsync redirects to this article, but it does nothing to answer my question. I'm trying to learn what the setting I see in numerous PC games does and what are the (dis)advantages to enabling it.-- 69.110.0.210 ( talk) 01:32, 31 January 2011 (UTC)
This article contradicts the article on Digital television transition. The latter article states that the Netherlands was the first country in Europe to switch to digital television, but this article states that it was Luxembourg. ACEOREVIVED ( talk) 00:30, 24 February 2012 (UTC)
In the section, "Color video signal extraction", I would like to see a change to the paragraph that begins with "Instead, the RGB signals are converted into YUV form, where the Y signal represents ...". The new version I believe clears up some details by using well documented technical facts. Here's the new version: Ohgddfp ( talk) 16:22, 27 April 2014 (UTC)
Instead, the RGB signals are converted into YUV form, where the Y signal represents the lightness and darkness (luminance) of the colors in the image. Because the rendering of colors in this way is the goal of both black and white (monochrome) film and black and white (monochrome) television systems, the Y signal is ideal for transmission as the luminance signal. This ensures a monochrome receiver will display a correct picture in black and white. The U and V signals are "color difference" signals. The U signal is the difference between the B signal and the Y signal, also known as B minus Y (B-Y), and the V signal is the difference between the R signal, also known as R minus Y (R-Y). The U signal then represents how "purplish-blue" or its complementary color "yellowish-green" the color is, and the V signal how "purplish-red" or its complementary "greenish-cyan" it is. The advantage of this scheme is that the U and V signals are zero when the picture has no color content. Since the human eye is more sensitive to errors in luminance than in color, the U and V signals can be transmitted in a relatively lossy (specifically: bandwidth-limited) way with acceptable results. Ohgddfp ( talk) 16:22, 27 April 2014 (UTC)
Different combinations of U and V can be directly extracted in the receiver using demodulator circuits. For example, the RCA Victor CTC-4 chassis used one (R-Y) demodulator circuit and one (G-Y) demodulator circuit. The (B-Y) demodulator circuit was done away with, and so the (B-Y) signal was derived by electronically combining the (R-Y) and (G-Y) signals in a particular combination. Other schemes, including (R-Y)/(B-Y), (R-Y)/(B-Y)/(G-Y), I/Q, (R-Y)/Q, and various flavors of X/Z were used. In all cases, (R-Y), (B-Y), and (G-Y) are all recovered in the end. Ohgddfp ( talk) 16:22, 27 April 2014 (UTC)
The R,G,B signals in the receiver needed for the display device (CRT, Plasma display or LCD display) are electronically derived by matrixing as follows: R is the additive combination of (R-Y) with Y, G is the additive combination of (G-Y) with Y, and B is the additive combination of (B-Y) with Y. All of this is accomplished electronically. It can be seen that in the combining process, the low resolution portion of the Y signals cancel out, leaving R,G, and B signals able to render a low-resolution image in full color. However, the higher resolution portions of the Y signals do not cancel out, and so are equally present in R, G, and B, producing the higher definition (higher resolution) image detail in monochrome, although it appears to the human eye as a full-color and full resolution picture. Ohgddfp ( talk) 16:22, 27 April 2014 (UTC)
About "The carrier is never shut off altogether; this is to ensure that intercarrier sound demodulation can still occur.": This is a fallacy. The reality is that not allowing the carrier to go below 15 or 25 percent for the white reference (minimum picture carrier) was being pushed back in 1941 and even earlier. The Intercarrier sound recovery technique was invented in 1944/1945. There is an 1948 patent on intercarrier sound. But this fallacy goes even further. You don't need an on-air continuous picture carrier to use the intercarrier sound recovery technique. Let's say reference white was standardized at zero percent carrier. In a movie about a snow storm, you will have a frequency spectrum that includes the carrier and sidebands. If inside the receiver the picture carrier is narrow-band filtered to less than 30 Hz, the flywheel effect of the filter would produce a continuous picture carrier at the filter output from the intermittent picture carrier received over the air. The new continuous picture carrier would then be applied to effect the intercarrier operation, producing a clean 4.5 MHz sound IF. To fix this in the article, I would simply remove the sentence. Ohgddfp ( talk) 21:56, 27 April 2014 (UTC)
The very first paragraph has a problematic phrase: "... one in which the information to be transmitted, the brightness and colors of the points in the image and the sound waves of the audio signal are represented by continuous variations of some aspect of the signal; ...". The problem is that the exact same thing can be said of 8VSB digital television. On the air, the DTV signal is a continuous-time signal. But one might say that the DTV signal represents a discrete-time list of values streamed over the air, which it does, and so the continuous-time on-air signal and the discrete-time digital signal inside the digital receiver both represent the same information. But that doesn't distinguish analog from digital either, because any real analog signal also represents a discrete time list of values, where both discrete-time analog and continuous-time analog represent the exact same information. To find out what exactly that discrete time list of analog values are, just sample the continuous analog signal. The result is analog (not digital) samples.
So what makes an analog signal analog? At any given point in time, an analog signal can take on any one of an infinite number of possible values.
So the sense of the word "continuous" as used in the opening paragraph to mean continuous-time, does not distinguish analog from digital. Rather, it is "continuous" in a very different sense that makes the difference. And that requires a different explanation. The value of each analog sample is continuously variable, meaning that its value is taken from a continuous range of possible values. That means an analog sample can take on any one of an infinite number of possible values, or the possible value of a single given analog sample is infinitely or continuously variable. In contrast, a digital sample can be any one of only a limited number of possible values. So here is the recommended fix:
Analog (or analogue) television is the analog transmission that involves the broadcasting of encoded analog audio and analog video signal:[1] one in which the information to be transmitted, the brightness and colors of the points in the image and the sound waves of the audio signal are represented by some aspect of the signal; its amplitude, frequency or phase, the values of which, at a given point in time, is any one of an infinite number of possible values. Ohgddfp ( talk) 02:28, 29 April 2014 (UTC)
Wide screen 16:9 aspect ratio CRT-based receivers were available for a while for reception of digital television signals. So flyback power supply design, which is specific to CRT-based receivers, applies equally to analog and digital. Since the title of this article is "Analog Television", the reader expects information that is unique to analog. This section is so long that a link to flyback power supply design by far makes the most sense. I'm planning to move it to the appropriate article. Ohgddfp ( talk) 02:22, 30 April 2014 (UTC)
There is --- maybe in all the english Wikipedia articles ? --- a confusion between the system of transmission and the color coding.
The official systems of transmission are named : A, B, C, D, E, F, G, H, I, K, K1, L, M and N. These systems determine the Number of lines, Channel width, Vision bandwidth, vision/sound separation, etc.
The colour coding which may be used of those systems are NTSC, SECAM and PAL.
So, I'm sorry for Wikipedia but this is the official situation.
-- AXRL ( talk) 14:25, 9 May 2014 (UTC)
Just finished skimming the article and I agree that it should remain as a summary of the different types of transmission and reception systems which were in use. That being said, the words Television and TV generally refer to the receiver in American English. Renaming the article to Analog (Analogue) Television Systems would inform both American and Commonwealth English readers that this is a general overview article with links to more in-depth articles. Divercth ( talk) 21:35, 29 January 2015 (UTC)
About a particular existing paragraph in "Standards": Ohgddfp ( talk) 16:52, 21 March 2020 (UTC)
"For this reason many people refer to any 625/25 type signal as "PAL" and to any 525/30 signal as "NTSC", even when referring to digital signals; for example, on DVD-Video, which does not contain any analog color encoding, and thus no PAL or NTSC signals at all. Even though this usage is common, it is misleading, as that is not the original meaning of the terms PAL/SECAM/NTSC.": Ohgddfp ( talk) 16:52, 21 March 2020 (UTC)
I would replace it with the following 2 paragraphs: Ohgddfp ( talk) 16:52, 21 March 2020 (UTC)
For this reason many people refer to any 625/25 type signal as "PAL" and to any 525/30 signal as "NTSC", even when referring to digital signals which actually do not have these type signals in original form. However, those digital signals do have some commonality with those analog "NTSC" and analog "PAL" formats because when the digital signal is directly converted to an analog signal, digital "NTSC" and analog NTSC both have lines and frame rates as 525/30. The same is true for PAL, with digital and analog versions both having lines and frame rates as 625/25. This is important because all but "international" analog Televisions/Monitors work only with analog NTSC or analog PAL, but not both. So DVD players, where most digital "NTSC" and digital "PAL" signals come from, have a corresponding analog NTSC or analog PAL output connector for connection to an analog TV/Monitor. A given DVD player does not have both kinds, so the analog TV/Monitor must match up NTSC or PAL to the DVD player, or a scrambled picture, and/or loss of color is the likely result. Ohgddfp ( talk) 16:52, 21 March 2020 (UTC)
When using certain kinds of digital equipment, with no analog equipment involved, digital format conversions can and usually do take place. The conversion can increase or decrease the number of pixel rows (lines), change the frame rate, and convert from interlace scan to progressive scan, making the designations of "NTSC" or "PAL" almost meaningless to the consumer, except that "NTSC" or "PAL" indicates to the consumer a picture quality that has a hard limitation in vertical resolution. Both kinds of conversions to a new digital format, from digital NTSC or from digital PAL, do not always give perfect picture quality, and years ago, such converting equipment was expensive in hardware, and very demanding in computer resources as digital software. Ohgddfp ( talk) 16:52, 21 March 2020 (UTC)
The article says: Thus with analog, a moderately weak signal becomes snowy and subject to interference. In contrast, a moderately weak digital television (DTV) signal and a very strong digital signal transmit equal picture quality. Depending on the definition of moderately, this is true. The problem is that moderately weak might be below the ability to decode, in which case you get nothing, or, more usual, flashing on and off, as it does, and then does not, have a decodable signal. With analog, it gets weaker and snowier. This is well known, and part of come FCC rules, as there are places that had a strong enough analog signal, but too weak in digital. Gah4 ( talk) 21:35, 20 May 2020 (UTC)
The article says: brightness, colors and sound are represented by rapid variations of either the amplitude, frequency or phase of the signal. This doesn't seem quite right. A given brightness or color is represented by an amplitude, frequency, or phase. Rapid change in brightness or color by a rapid change in those quantities. The screen can be one brightness and color, in which case the amplitude, frequency, or phase is not changing. Sound, on the other hand, is always represented by something changing, though maybe not so rapidly. Some might say that 20Hz isn't rapid. Gah4 ( talk) 21:41, 20 May 2020 (UTC)
Quote from article "Horizontal and Vertical Hold controls were rarely used in CRT-based computer monitors", This is patently wrong. Most monitors from a CBM PET to a TRS-80 model 4 to a DEC VT420 to a IBM 5153 monitor, all have both sync controls. Some accessible without removing the case, some only as maintenance controls, but they still had them. — Preceding unsigned comment added by 192.149.117.67 ( talk) 04:44, 31 July 2020 (UTC)
I am looking at the diagram and comparing it with the image of the oscilloscope. They appear to contradict each other. The diagram puts the "rear porch" in front of the line of signal, whereas the same area is labelled "front porch" on the oscilloscope image - which seems more likely to be correct. Additionally, the illustration has a hue that changes from reddish to greenish along the line and is labeled "chroma", but I'm fairly certain that is not how chroma works and the color is more defined by the width of the lines. Further, the color burst has a similar change in hue, but is the color burst not a single frequency? Maury Markowitz ( talk) 21:45, 19 May 2021 (UTC)
@ Kvng: I'm pretty sure the effects being referred to in the text you removed in this edit are mostly flesh tone problems, although I can't immediately find a source for that. What certainly can be sourced is that the NTSC system suffered from this problem, so much so that North American sets were commonly fitted with a "flesh tone" knob to allow the user to correct the picture. RGB with its much wider bandwidth would be much more susceptible to channel attenuation differences than NTSC. The PAL system largely overcomes this issue and Brit engineers rudely referred to NTSC as "Never Twice the Same Colour". Spinning Spark 10:40, 16 March 2022 (UTC)
The article says: amplitude, phase and frequency. For US NTSC, video is amplitude and phase, but audio is frequency (FM). That wouldn't be so bad, but the link is to phase and frequency as one article. I believe some system(s) use FM for video, though. Can we have separate links for phase and frequency? Gah4 ( talk) 20:51, 6 April 2023 (UTC)