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#401
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Floyd L. Davidson wrote:
... ... Indeed, if we do look at a "valid standard definition" for the term of art, quantization: A process in which the continuous range of values of an analog signal is sampled and divided into nonoverlapping (but not necessarily equal) subranges, and a discrete, unique value is assigned to each subrange. From Federal Standard 1037C. We can see that it *clearly* does mean to make it digital. That is the *only* purpose for quantization. This only addresses values, it does not address time. So how would you classify this signal: the output of a standard 1V/oct (voltage control) music keyboard - a monophonic (= non-overlapping) series of stepped voltages corresponding precisely to the 12-tone equal-termperament subdivisions of the octave. This control signal is typically applied to the frequency control input of an analogue voltage-controlled oscillator (VCO; think MiniMoog), in order to synthesise tones at the specified frequency. Thus, values are quantized. There is no time quantization (no clock) - the notes can be played at any time, and changed at any speed (presumably within the limits of the human player). I would call this an analogue signal; it meets exactly the definition above, it is only you who extrapolates from it the notion of "digital". And manifestly, making a digital signal is ~not~ the only purpose for quantization! And if the Federal Standard had meant to make it mean "digital" surely, given its importance, they would have said so. Richard Dobson |
#403
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
(Don Pearce) wrote:
On Fri, 24 Aug 2007 17:15:40 -0800, (Floyd L. Davidson) wrote: (Don Pearce) wrote: On Fri, 24 Aug 2007 12:38:04 -0800, (Floyd L. Davidson) wrote: I'm still unable to comprehend how you think that was a "howler". Once again have yet to explicitly state what you thought was wrong with the definiton provided and you do not give an alternate. Right let me spell it out for you. That glossary explained the Nyquist frequency. As part of that definition it explicitly gave the requirement that the Nyquist frequency be EQUAL to twice the highest frequency being reproduced. Here is the definition it has of the *rate* (you incorrectly call it the Nyquist "frequency"): Nyquist rate: The reciprocal of the Nyquist interval, i.e., the minimum theoretical sampling rate that fully describes a given signal, i.e., enables its faithful reconstruction from the samples. Note: The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process. Here is the theorem: Nyquist's theorem: A theorem, developed by H. Nyquist, which states that an analog signal waveform may be uniquely reconstructed, without error, from samples taken at equal time intervals. The sampling rate must be equal to, or greater than, twice the highest frequency component in the analog signal. Synonym sampling theorem. It appears that you are somewhat confused as to what is being defined. The definition for the Nyquist rate says absolutely nothing about being equal to anything. Instead it says it is the minimum rate that will "fully describe" the signal. That is 100%, definitively incorrect. What is not correct about it. What do you claim is correct instead? Explain *your* definition. (Oh, and do so for all values of sampling rate as the size of the quantum steps approach zero.) Whatever, I can't tell what you are disagreeing with. You read one definition and claim it is something else, you don't say what you think is wrong with it or what would be right. Maybe you disagree with the way the words are spelled, with the use of the term "analog" or you just can't understand what it says... It is a howler made by many people who don't understand sampling. To find it in a list that you regard as definitive must give you cause to consider the quality of the rest of the list. You are the howler. You probably should look up Shannon's "Communication in the Presence of Noise" from 1949. Over to you - your turn to explain to me how that was in fact correct. It appears to me that the definition they gave is precisely correct, and again *you* are abjectly clueless. I guessed you would think it was correct. You can't sample at a rate equal to twice the frequency you are sampling. The wanted signal has collided with its image and you can't disambiguate them. Thank you for showing us that you are clueless. The definition they have for Nyquist Rate does not suggest anything different. Nyquist rate: The reciprocal of the Nyquist interval, i.e., the minimum theoretical sampling rate that fully describes a given signal, i.e., enables its faithful reconstruction from the samples. Note: The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process. It does not say what you claimed it does. -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#404
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
(Don Pearce) wrote:
On Fri, 24 Aug 2007 20:54:55 -0800, (Floyd L. Davidson) wrote: "Bob Myers" wrote: "Randy Yates" wrote in message ... One thing that's incorrect and has been discussed many times here before is that the inequality must be strict. That is, the wording should have omitted "equal to". That's one error. It's not the only one. So demonstrate where there is another! No need. You claim your definitions to be correct because they appear to be borne out by a list you claim to be definitive. The list has been shown to be errored, so your authority has vanished. Deal with it. All you would need to show the definitions I posted are not valid is provide a conflicting definition of each from an authoritative source. You haven't, because there are none. You claim that the list itself is errored, but you cannot show an error in it other than one of your own imagination, where you think one definition implies that of another... except it does not and the specific "error" that you claim exists is not part of the definition given for the term in question. The point still remains that even if you can find some error some place in the list, the agrument from authority is valid for the definitions of the terms "analog" and "digital" until you can show some other expert source that disagrees. You can't. You apparently can't learn the rules of logic either, as that has all been explained previously. -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#405
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
On Sat, 25 Aug 2007 06:16:10 -0800, (Floyd L.
Davidson) wrote: I guessed you would think it was correct. You can't sample at a rate equal to twice the frequency you are sampling. The wanted signal has collided with its image and you can't disambiguate them. Thank you for showing us that you are clueless. The definition they have for Nyquist Rate does not suggest anything different. Nyquist rate: The reciprocal of the Nyquist interval, i.e., the minimum theoretical sampling rate that fully describes a given signal, i.e., enables its faithful reconstruction from the samples. Note: The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process. It does not say what you claimed it does. -- Floyd, be a good boy and **** off you lying little toad. Don't bother replying any more because you are now in my killfile along with Phil Alison. Why is it always the six-fingered inbreds from the outback that cause the most grief around here? d -- Pearce Consulting http://www.pearce.uk.com |
#406
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Richard Dobson wrote:
Floyd L. Davidson wrote: .. .. Indeed, if we do look at a "valid standard definition" for the term of art, quantization: A process in which the continuous range of values of an analog signal is sampled and divided into nonoverlapping (but not necessarily equal) subranges, and a discrete, unique value is assigned to each subrange. From Federal Standard 1037C. We can see that it *clearly* does mean to make it digital. That is the *only* purpose for quantization. This only addresses values, it does not address time. So how would you classify this signal: the output of a standard 1V/oct (voltage control) music keyboard - a monophonic (= non-overlapping) series of Monophonic measn one channel. The output could be monophonic and still be overlapping. stepped voltages corresponding precisely to the 12-tone equal-termperament subdivisions of the octave. This It is a digital output if there are precisely 12 voltages per octave. control signal is typically applied to the frequency control input of an analogue voltage-controlled oscillator (VCO; think MiniMoog), in order to synthesise tones at the specified frequency. An analog output device, that has a digital control circuit. Thus, values are quantized. The DC control voltage is quantized. It is digital. The tone output from the VCO is not quantized and is analog. from it the notion of "digital". And manifestly, making a digital signal is ~not~ the only purpose for quantization! And if the Federal Standard had meant to make it mean "digital" surely, given its importance, they would have said so. I believe that what you had to say there demonstrates why you are so utterly confused on the topic of analog and digital. -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#407
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Randy Yates wrote:
(Floyd L. Davidson) writes: Randy Yates wrote: (Floyd L. Davidson) writes: [...] Nyquist's theorem: A theorem, developed by H. Nyquist, which states that an analog signal waveform may be uniquely reconstructed, without error, from samples taken at equal time intervals. The sampling rate must be equal to, or greater than, twice the highest frequency component in the analog signal. Synonym sampling theorem. [...] You are looking at the definition of the Theorem, not the definition of the rate, and then saying the definition of "Nyquist Rate" should not have the words "equal to". I agree this is a definition of the theorem, but in the definition of the theorem it states the definition of the rate, and that statement is wrong. It does not define the rate. There *is* a formal definition of the rate provided, and it is absolutely correct. If *you* read something into it that is clearly in conflict with what they say, it is time to question your interpretation of what you read into it. I can see, though, that you and others in this thread have become very unbalanced. Sorry sonny, but gratuitous insults are almost always a reflection of the mental state of the people who make them. They indicate self fears by those who make them. One of the things that should be obvious from the length of this thread is that *I* am not the one wallowing all over creation with a variety of different and conflicting attempts, all of which fail, to prove something that obviously isn't true. I have simply been able to followup on the initial statements that I made with *logical* and rational continuations of exactly the same thing, without contradictions, without variations, and without wearing a tin foil hat. It's not good for your mental health. You're in Alaska, right? Get outside and go bear hunting or something! Pull your chair away from the computer! You might be right about mental health problems. Given the amount of therapeutic noise that you and others have generated as you slam back and forth trying to imagine a hole in the basic wall you've butted up against... you probably should seek a professional evaluation. -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#408
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
(Don Pearce) wrote:
On Sat, 25 Aug 2007 06:16:10 -0800, (Floyd L. Davidson) wrote: I guessed you would think it was correct. You can't sample at a rate equal to twice the frequency you are sampling. The wanted signal has collided with its image and you can't disambiguate them. Thank you for showing us that you are clueless. The definition they have for Nyquist Rate does not suggest anything different. Nyquist rate: The reciprocal of the Nyquist interval, i.e., the minimum theoretical sampling rate that fully describes a given signal, i.e., enables its faithful reconstruction from the samples. Note: The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process. It does not say what you claimed it does. -- Floyd, be a good boy and **** off you lying little toad. Don't bother replying any more because you are now in my killfile along with Phil Alison. Why is it always the six-fingered inbreds from the outback that cause the most grief around here? I see that you find it difficult to handle facts and logic when you meet up with someone who can sort them out at the drop of a hat. Gratuitous insults are virtually always a fair indication of the reflection the writer sees in a mirror, so my only comment on your statements above is that you seem to have a truly horrifying mental image of yourself to use as an example when you want to insult someone. Whatever, if you had had your facts straight to begin with, you wouldn't feel so crushed now. -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#409
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
On 8/25/07 7:30 AM, in article , "Don
Pearce" wrote: On Sat, 25 Aug 2007 06:16:10 -0800, (Floyd L. Davidson) wrote: I guessed you would think it was correct. You can't sample at a rate equal to twice the frequency you are sampling. The wanted signal has collided with its image and you can't disambiguate them. Thank you for showing us that you are clueless. The definition they have for Nyquist Rate does not suggest anything different. Nyquist rate: The reciprocal of the Nyquist interval, i.e., the minimum theoretical sampling rate that fully describes a given signal, i.e., enables its faithful reconstruction from the samples. Note: The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process. It does not say what you claimed it does. -- Floyd, be a good boy and **** off you lying little toad. Don't bother replying any more because you are now in my killfile along with Phil Alison. Why is it always the six-fingered inbreds from the outback that cause the most grief around here? d The problem with people like Floyd is that, when you get frustrated from his moronic misleading replies and lies, he will internalize that he has "won," and will feel empowered to continue in kind. Someone else posted that his goal is to win at any cost (including his veracity) and facts will be twisted or ignored to meet that goal. It would be unfortunate if he posts his views to Wikapedia. Phil, on the other hand, seems to be technically correct, though sometimes vague. The latter is, I believe, to leave something for the OP to finish. I always read his posts. |
#410
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech
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Questions about equivalents of audio/video and digital/analog.
On Fri, 24 Aug 2007 13:55:54 -0700, Jim Kelley
wrote: "Floyd L. Davidson" wrote: So when will any of you be able to cite credible support for your claims that the standard definitions of analog and digital signals/data are not valid. Here are some valid standard defintions: "quantize - to subdivide into small but measurable increments." (Merriam Webster's Collegiate Dictionary, Tenth Edition) Note that in the definition, there appears no mention of assigning a value. Assigning a value would then be considered a part of a separate and distinct process of converting to digital form, as in "digital - of, or relating to data in the form of numerical digits", and as opposed to "analog - of, relating to, or being a mechanism in which data is represented by continuously variable physical quantities." There's a huge difference between the jargon of experts and the language of common people. Doctors and surgeons don't restrict themselves to the definitions found in ordinary dictionaries. Neither do experts in communications theory. If that's the best cite the audiophiles have, then they're admitting they're hobbiests. -- Al in St. Lou |
#411
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
On Sat, 25 Aug 2007 08:37:40 -0700, Don Bowey
wrote: On 8/25/07 7:30 AM, in article , "Don Pearce" wrote: On Sat, 25 Aug 2007 06:16:10 -0800, (Floyd L. Davidson) wrote: I guessed you would think it was correct. You can't sample at a rate equal to twice the frequency you are sampling. The wanted signal has collided with its image and you can't disambiguate them. Thank you for showing us that you are clueless. The definition they have for Nyquist Rate does not suggest anything different. Nyquist rate: The reciprocal of the Nyquist interval, i.e., the minimum theoretical sampling rate that fully describes a given signal, i.e., enables its faithful reconstruction from the samples. Note: The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process. It does not say what you claimed it does. -- Floyd, be a good boy and **** off you lying little toad. Don't bother replying any more because you are now in my killfile along with Phil Alison. Why is it always the six-fingered inbreds from the outback that cause the most grief around here? d The problem with people like Floyd is that, when you get frustrated from his moronic misleading replies and lies, he will internalize that he has "won," and will feel empowered to continue in kind. Someone else posted that his goal is to win at any cost (including his veracity) and facts will be twisted or ignored to meet that goal. It would be unfortunate if he posts his views to Wikapedia. Phil, on the other hand, seems to be technically correct, though sometimes vague. The latter is, I believe, to leave something for the OP to finish. I always read his posts. Indeed Phil is usually technically correct, but his posts are simply so strewn with the filthiest invective that I am prepared to forego the occasional nugget. Floyd, unfortunately, doesn't have even that redeeming feature. d -- Pearce Consulting http://www.pearce.uk.com |
#412
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech
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Questions about equivalents of audio/video and digital/analog.
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#413
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Floyd L. Davidson wrote:
... It is a digital output if there are precisely 12 voltages per octave. Users may insert a simple control (may be called "Key Follow" but is basically just an analogue level control) that can reduce/expand the size of the steps so that 24 notes, say, cover one octave; or 11 notes cover an octave and a fifth. This is of course an analogue control, as the amount of key follow (and hence the division of the octave achieved by each step) is continuously variable. Which is another way of saying that the quantization itself is infinitely variable. The VCO is calibrated such that a change of one octave results in a pitch change of one octave. Users may well subvert that calibration (and the whole 12-note octave convention) for creative purposes. control signal is typically applied to the frequency control input of an analogue voltage-controlled oscillator (VCO; think MiniMoog), in order to synthesise tones at the specified frequency. An analog output device, that has a digital control circuit. The key aspect of Voltage Control (as designed by Robert Moog) is that any module can control (and be controlled by) any other. Inputs are content-agnostic - the VCO does not have a "digital control circuit" - just a control circuit to which can be connected any analogue input. In short - the VCO's control inputs are all analogue; so that, for example, by inserting a filter (slew-rate limiter) between the keyboard output and the VCO input, you get a portamento from one note to the next, not a straight jump. You can equally connect the output of one VCO to the frequency input of another one, to do FM (Vibrato etc). These are ~all~ analogue signals, being handled by analogue electronics. The electronics, indeed, on many early synths was notorious for being somewhat unstable, so that oscillator frequencies adn voltage ranges could drift as the machine warmed up or cooled down. Later technology brought in the DCO - the Digitally-Controlled analogue Oscillator, to eliminate such instabilities. You might find this company's products interesting: http://www.analoguesystems.co.uk/modules.htm See for example the "Voltage Quantiser" and "Voltage controlled slew limiter" modules. Richard Dobson |
#414
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Richard Dobson wrote:
Floyd L. Davidson wrote: .. It is a digital output if there are precisely 12 voltages per octave. Users may insert a simple control (may be called "Key Follow" but is basically just an analogue level control) that can reduce/expand the size of the steps so that 24 So there are not precisely 12 voltages per octave, but rather there are now ever many you choose, and the adjustment is continuously variable. You described one device before, and now describe a different device... How do you expect a valid answer if you purposely distort the question with false information? -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#415
Posted to sci.electronics.basics,comp.dsp,rec.audio.tech
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Questions about equivalents of audio/video and digital/analog.
On Fri, 24 Aug 2007 23:32:21 GMT, Richard Dobson
wrote: Don Pearce wrote: .. And I guess someone will ask "how does one decide this or that source is 'valid'? ". Wikipedia? Opportunities for more fruitless bipolar arguments there, I fancy! There is another way. Work it out for yourself, from first principles. Well, I seem to have spent my life doing that, as much as I am able. But agreeing upon terminology, the core vocabulary of the subject, is by definition a group exercise. Otherwise, people take a term and arbitrarily make it mean what they want it to mean, which seems to be the issue here. Converging to an agreement would be great, but after an avalanche of posts on this thread, people seem no closer now that at the start. Calling each other "delusional"! First principles? Which ones?! :-) Richard Dobson Floyd's been beaten up about this before, but he just keeps coming back for more. "Standards" and associated definitions are created for their own use in a specific context within the scope of the standard, and no further. Stating that there is "a standard" definition that should apply to everyone, everywhere, belies a substantial misunderstanding of what "standards" are and how they work. Get enough experienced, competent, expert comm people in the same room and pretty soon you'll have enough different points of view that you'll have some pretty substantial disagreements on the meaning of things as fundamental as SNR. All that means is that it's smart to have a short dialogue to synch up contexts and definitions before you proceed, and if you do sense that communication is breaking down due to different definitions, you stop for just long enough to synch up and then move on. Pounding one's fist on the table and demanding that one definition is superior to another is not productive, IMHO. Clearly it's important to understand what one means when using a term, but there's certainly no central global clearinghouse that magically decides what terms mean. If there was it'd be obsolete in a week because the technology and the areas where it's used is constantly changing. If one can't just express what they mean or manage to synch up somehow with the folks with whom they're communicating, then that individual is just going to have a harder time making progress with people. I think the current thread is a pretty good example of that. For those sick *******s among us that like this sort of thing it's been pretty doggone amusing, too. Ah, well, this is the sort of thing that'll just always be an issue as long as people are involved. Eric Jacobsen Minister of Algorithms Abineau Communications http://www.ericjacobsen.org |
#416
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Floyd L. Davidson wrote:
... Users may insert a simple control (may be called "Key Follow" but is basically just an analogue level control) that can reduce/expand the size of the steps so that 24 So there are not precisely 12 voltages per octave, but rather there are now ever many you choose, and the adjustment is continuously variable. You described one device before, and now describe a different device... How do you expect a valid answer if you purposely distort the question with false information? Good grief man, it's the SAME DEVICE! The same cable, the same modules, the same everything. All that changes is that the user tweaks a pot. So I suppose we have to define "device" now as well as everything else. I gave you a picture, a micrograph, of a system that ~can~ produce a signal of precisely stepped voltages. You promptly pronounce that as "digital". Then I zoom out, give you a broader picture of the same system, and all of a sudden we discover sginals that can morph seamlessly between stepped and non-stepped - between "digital" and "analogue". Perhaps that simply doesn't arise in your universe. Away now for a week, so you will have to figure the rest out by yourself! Richard Dobson |
#417
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
(Floyd L. Davidson) writes:
Floyd: Have a nice day. Come visit me if you're ever in Fuquay, NC, and I think you'll find me somewhat different than the usenet monster you seem to imagine me to be. -- % Randy Yates % "...the answer lies within your soul %% Fuquay-Varina, NC % 'cause no one knows which side %%% 919-577-9882 % the coin will fall." %%%% % 'Big Wheels', *Out of the Blue*, ELO http://home.earthlink.net/~yatescr |
#418
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Questions about equivalents of audio/video and digital/analog.
On Fri, 24 Aug 2007 20:54:15 -0800, (Floyd L.
Davidson) wrote: I don't believe you understand the theorem. Incidentally, Nyquist didn't come up with the theorem, hence you really don't want to look at what Nyquist wrote much as at Shannon's mathematical proof of what Nyquist proposed. Floyd, you're out of your league here. Nyquist's and Shannon's careers overlapped a little bit at Bell Labs and they collaborated a bit on some things...Nyquist reviewed a lot of Shannon's early work, IIRC. In any case, Nyquist clearly created the defining early work in this area, and the correctness of that work has given it a lot of staying power. It's not really been superceded by anything. Saying "you really don't want to look at what Nyquist wrote" belies a deficiency in your own understanding and makes me suspect that your motivation is primarily to poison that well for anyone else who might want to reference it. You seem to like to define your own playing field smaller and smaller and claim "I'm absolutely correct in this tiny little circle" and somehow try to make that relevant to everybody else. At least, that's my take on it. Shannon's work was primarily in laying the foundation for Information Theory, and his sampling theorem was pretty much just re-working Nyquist's theorem from an Information Theory perspective. That's important partly because context changes interpretation. e.g., you can't expect a single definition of a term to apply universally to all possible cases when the contexts and technologies are constantly changing. Eric Jacobsen Minister of Algorithms Abineau Communications http://www.ericjacobsen.org |
#419
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech
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Questions about equivalents of audio/video and digital/analog.
"Eric Jacobsen" wrote in message ... "Pearls before swine". However, I understand that the reason you do it is to keep people like Floyd from confusing the less-informed readers who will come along later. I have a rule that changes the color of messages from certain posters to Hot Pink, and marks them Read and Ignored. Floyd is a charter member of that group and he is really very pretty in pink ;-) |
#420
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
"Floyd L. Davidson" wrote in message ... "Bob Myers" wrote: "Floyd L. Davidson" wrote in message ... Here is the theorem: Nyquist's theorem: A theorem, developed by H. Nyquist, which states that an analog signal waveform may be uniquely reconstructed, without error, from samples taken at equal time intervals. The sampling rate must be equal to, or greater than, twice the highest frequency component in the analog signal. Synonym sampling theorem. The standard definition of Nyquist Rate from the glossary is not incorrect. It is most definitely incorrect, and since you've now had more than adequate time to identify and discuss the error, I guess I'll have to point it out. The key item in question from the definition you gave is: The sampling rate must be equal to, or greater than, twice the highest frequency component in the analog signal. ....and it contains a very common misunderstanding of Nyquist's theorem. The sampling rate is NOT required to be "equal to or greater than twice the highest frequency component in the analog signal," even ignoring the problematic "equal to" case in the above. Rather, the sampling rate must be twice the BANDWIDTH of the signal in question. For example, if one is sampling an AM signal which comprises a 10 MHz carrier modulated by an audio signal of 0 - 5 kHz, the highest frequency component would be expected to be at 10.005 MHz - yet sampling at 20.010 MHz or higher is NOT required to fully recover the information contained within this signal. The carrier itself carries no information, so that's all there is to it. The AM signal in question could be sampled at a MUCH lower rate (in this case, a bit greater than 10 kHz would suffice), and still be fully captured. This in fact forms the basis for what's often referred to as "digital downcoversion" in receivers, and also is the basis for the "equivalent-time sampling" operation of digital sampling oscilloscopes. To be sure, if you were trying to accurately capture the form of a single cycle (or even a few cycles) of a "10 MHz signal," you'd need a sampling rate far in excess of 20 MHz - but that is also per the theorem, since such signals' complete spectrums are very, very wide. As you seem to accept such things only if "authoritative sources" are cited, I'd suggest you check the application notes provided by either Agilent Technologies or Tektronix on their web sites, re their digital oscilloscopes. Hopefully, you will consider either of these companies as knowing a bit about what they're talking about in this area. Bob M. |
#421
Posted to sci.electronics.basics,comp.dsp,rec.audio.tech
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Questions about equivalents of audio/video and digital/analog.
"Eric Jacobsen" wrote in message ... Floyd's been beaten up about this before, but he just keeps coming back for more. "Standards" and associated definitions are created for their own use in a specific context within the scope of the standard, and no further. Stating that there is "a standard" definition that should apply to everyone, everywhere, belies a substantial misunderstanding of what "standards" are and how they work. Yes, if there's one thing that's become adequately clear from this discussion, it's the fact that Floyd has never ever seen any actual standards-setting body at work. It puts one in mind of what is traditionally said about not wanting to watch either sausage or law being made... Bob M. |
#422
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Richard Dobson wrote:
Floyd L. Davidson wrote: .. Users may insert a simple control (may be called "Key Follow" but is basically just an analogue level control) that can reduce/expand the size of the steps so that 24 So there are not precisely 12 voltages per octave, but rather there are now ever many you choose, and the adjustment is continuously variable. You described one device before, and now describe a different device... How do you expect a valid answer if you purposely distort the question with false information? Good grief man, it's the SAME DEVICE! The same cable, the same modules, the same everything. All that changes is that the user tweaks a pot. You didn't accurately describe the device the first time. Which is *exactly* why my answer was conditional on there being *precisely* 12 voltages per octave. Then you admit that there are not, that it can be any of an infinite number of voltages because it is actually continuously variable. You just aren't ready to be honest at all, are you. So I suppose we have to define "device" now as well as everything else. Somebody else uses that game... I gave you a picture, a micrograph, of a system that ~can~ produce a signal of precisely stepped voltages. You promptly pronounce that as "digital". Then No, I did not. I said *if* what you described was accurate. It wasn't, and the difference negates everything. Why not be honest? I zoom out, give you a broader picture of the same system, and all of a sudden we discover sginals that can morph seamlessly between stepped and non-stepped - A, yes... a "continuous" set of values... which clearly makes it analog. If it had actually been just 12 levels, as you initially said, it would be digital. But you just had to be dishonest. between "digital" and "analogue". Perhaps that simply doesn't arise in your universe. How anyone could miss the distinction is beyond me. But worse yet, it is *obvious* that you have not missed that distinction, and instead are merely trying to make a point with deceitful and abject dishonesty. Away now for a week, so you will have to figure the rest out by yourself! How hard did you think it would be to figure you out? -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#423
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Randy Yates wrote:
(Floyd L. Davidson) writes: Floyd: Have a nice day. Come visit me if you're ever in Fuquay, NC, and I think you'll find me somewhat different than the usenet monster you seem to imagine me to be. I don't doubt that for a minute, and don't believe for a second that you are a "usenet monster". We could talk politics! (Or, maybe we shouldn't... ;-) -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#424
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
"Bob Myers" wrote:
"Floyd L. Davidson" wrote in message ... "Bob Myers" wrote: "Floyd L. Davidson" wrote in message ... Here is the theorem: Nyquist's theorem: A theorem, developed by H. Nyquist, which states that an analog signal waveform may be uniquely reconstructed, without error, from samples taken at equal time intervals. The sampling rate must be equal to, or greater than, twice the highest frequency component in the analog signal. Synonym sampling theorem. The standard definition of Nyquist Rate from the glossary is not incorrect. Above is the definition of Nyquist's theorem. That is not claimed to be the standard definition of the Nyquist Rate, which I keep quoting and you continue to snip in another dishonest attempt to make it appear other than it is. It is most definitely incorrect, and since you've now had more than adequate time to identify and discuss the error, I guess I'll have to point it out. The key item in question from the definition you gave is: The sampling rate must be equal to, or greater than, twice the highest frequency component in the analog signal. That is not to be found in the standard defintion, which I gave, for Nyquist Rate. Why is it you must be so damned dishonest? The standard definition of Nyquist Rate, as I have shown several times now, is (from Federal Standard 1037C): Nyquist rate: The reciprocal of the Nyquist interval, i.e., the minimum theoretical sampling rate that fully describes a given signal, i.e., enables its faithful reconstruction from the samples. It says *nothing* that is not absolutely correct. We might note though, that your discussion was not absolutely correct either. You merely require the sampling rate to be greater than 2 times the highest frequency to be sampled. In fact, there is a measurable amount greater that is required, which depends on the quantum size. Just being greater is *not* enough. I won't attempt to explain that to you, because it is clearly too technical. ;-) Here's another standard definition from FS-1037C: Nyquist interval: The maximum time interval between equally spaced samples of a signal that will enable the signal waveform to be completely determined. (188) Note 1: The Nyquist interval is equal to the reciprocal of twice the highest frequency component of the sampled signal. Note 2: In practice, when analog signals are sampled for the purpose of digital transmission or other processing, the sampling rate must be more frequent than that defined by Nyquist's theorem, because of quantization error introduced by the digitizing process. The required sampling rate is determined by the accuracy of the digitizing process. Again, I'll point out that the Theorem is a mathematical proof of all cases, including as the quantum size approaches zero; practical examples of sampling must have 1) greater than zero range of size for quantized levels, and 2) will have errors in the range (sizes will actually vary). -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#425
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Floyd L. Davidson wrote:
.. You didn't accurately describe the device the first time. Which is *exactly* why my answer was conditional on there being *precisely* 12 voltages per octave. Then you admit that there are not, that it can be any of an infinite number of voltages because it is actually continuously variable. When it is used as I described, in its "standard" arrangement, it ~is~ exactly quantised to 12 voltages per octave. Just like the frets on a guitar. At other times, it may be quantized in some different way, or all smoothed out. Same hardware, same cable, same interface. Only you claimed this describes a digital signal. Perhaps you were too quick to jump to conclusions, and not ask necessary clarifying questions? ... A, yes... a "continuous" set of values... which clearly makes it analog. If it had actually been just 12 levels, as you initially said, it would be digital. ... So we have at last reached a consensus, that that a signal can be quantized, just as I have described, and nevertheless be analogue. "Quantized" of itself is not a sufficient condition for a signal to be classed as digital. You would require further information to make that determination. As you have yourself now clearly indicated. The term "digital" can at last be reserved for where it is truly appropriate. "Quantized" is a subset, an aspect of, "digital", but it is manifestly not the same as "digital". QED. Isn't music wonderful, that it can demonstrate such things! Richard Dobson |
#426
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Richard Dobson wrote:
Floyd L. Davidson wrote: . You didn't accurately describe the device the first time. Which is *exactly* why my answer was conditional on there being *precisely* 12 voltages per octave. Then you admit that there are not, that it can be any of an infinite number of voltages because it is actually continuously variable. When it is used as I described, in its "standard" arrangement, it ~is~ exactly quantised to 12 voltages If it is quantized, it is digital. (I cannot see how what you are describing is quantized though.) All you have done is adjusted the range of an analog signal to have 12 steps over a given voltage range. That has nothing at all to do with quantization. per octave. Just like the frets on a guitar. At other times, it may be quantized in some different way, or all smoothed out. Same hardware, same cable, same interface. Only you claimed this describes a digital signal. I claimed that if you quantize something to a set of only 12 voltages, that it is digitized. That is a true fact. If you adjust the range of an analog signal to have 12 steps, that is not quantizing it and it is not digital. Perhaps you were too quick to jump to conclusions, and not ask necessary clarifying questions? Why do you thing I put the "if" in my response? Obviously I know you aren't likely to be honest or clueful either one. A, yes... a "continuous" set of values... which clearly makes it analog. If it had actually been just 12 levels, as you initially said, it would be digital. .. So we have at last reached a consensus, that that a signal can be quantized, just as I have described, and nevertheless be analogue. If the signal is quantized, it is digital. That is a fact, by the very definition of quantized. "Quantized" of itself is not a sufficient condition for a signal to be classed as digital. You would require It absolutely is. further information to make that determination. As you have yourself now clearly indicated. The term "digital" can at last be reserved for where it is truly appropriate. "Quantized" is a subset, an aspect of, "digital", but it is manifestly not the same as "digital". Look up any standard definition you like for "quantized", and every one of them will indicate changing a continuous range of values to a discrete value from a finite set. That of course defines digital too, as you find if you look at *any* standard definition of the term. Of course if you make up your own definitions, it can mean anything you like. I won't know what it is, and neither will anyone else. You won't be able to communicate, and will be reduced to posting even more nonsense. -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#427
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
"Floyd L. Davidson" wrote in message ... That is not to be found in the standard defintion, which I gave, for Nyquist Rate. Why is it you must be so damned dishonest? I'M being dishonest? Floyd, I didn't type those words - YOU did. If you don't agree with them now, that's not my problem. Or if you intended something else, simply say so. But if anyone is being dishonest, or at the very least doing a rather transparent job of back-pedaling like a madman, it's clearly you. It says *nothing* that is not absolutely correct. We might note though, that your discussion was not absolutely correct either. You merely require the sampling rate to be greater than 2 times the highest frequency to be sampled. In fact, there is a measurable amount greater that is required, which depends on the quantum size. Just being greater is *not* enough. And you're doing it again. I am not the one who said anything about it relating to the "highest frequency to be sampled." It's quite plain that I related the minimum sampling rate to the bandwidth of the signal to be sampled, not its "highest frequency." And when this correct form is used, all comes out correctly. Funny how that happens. I won't attempt to explain that to you, because it is clearly too technical. ;-) For one who complains loudly and longly when others use what you consider to be "insults," you are certainly quick yourself with the snide and sarcastic comments. Are you familiar with the story of the pot and the kettle discussing their color? Here's another standard definition from FS-1037C: Nyquist interval: The maximum time interval between equally spaced samples of a signal that will enable the signal waveform to be completely determined. (188) Note 1: The Nyquist interval is equal to the reciprocal of twice the highest frequency component of the sampled signal. And again, "highest frequency component" is at best misleading, and at worst completely incorrect. Note 2: In practice, when analog signals are sampled for the purpose of digital transmission or other processing, the sampling rate must be more frequent than that defined by Nyquist's theorem, because of quantization error introduced by the digitizing process. The required sampling rate is determined by the accuracy of the digitizing process. You comments to date, though, have demonstrated nothing but a complete lack of understanding of just what the above actually means. At this point, Floyd, it should be obvious to the few hardy souls still following this thread that it is you against basically everyone else. This is either due to your being the sole person in the entire readership of this group who understands these matters - which I find highly unlikely, especially given your inability to actually explain anything - or, as most have appear to have already agreed to be the case, that you are simply an utterly unimaginative wretch who attempts to use recitation of texts learned by rote to make up for a lack of any real understanding or a willingness to even attempt to learn something. In any event, you're simply no longer worth the time, especially when others who might have picked up something worthwhile from this thread have moved on. It would seem that the best thing to do is to follow the lead of other, no doubt wiser heads, and simply killfile you and move on. Please understand the I bear you no ill will personally, despite the ill will that you have demonstrated toward myself and others. If anything, you strike me as a sad case. As has already been said by another, were you to actually meet and chat with any of the rest of us, you might find that we're hardly the ignorant monsters of the internet that you seem to think - but it seems you are very unlikely to ever know that, either. In any case, this is the end of the line. I've wasted more than enough time here, and it's ending now. Bob M. |
#428
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
"Bob Myers" wrote:
"Floyd L. Davidson" wrote in message ... That is not to be found in the standard defintion, which I gave, for Nyquist Rate. Why is it you must be so damned dishonest? I'M being dishonest? Floyd, I didn't type those words - YOU did. You stated the definition was for the Nyquist Rate, which indeed something I had posted. But what you quoted was not that definition but one for the Nyquist Theorem, and claimed it gives the standard definition for the Nyquist Rate. It doesn't, and that was very clearly a less than honest attempt to make it appear to be ambiguous. It isn't. If you don't agree with them now, that's not my problem. It is is if you quote A and claim it is B. Or if you intended something else, simply say so. But if anyone is being dishonest, or at the very least doing a rather transparent job of back-pedaling like a madman, it's clearly you. You are not winning points for integrity there either. It says *nothing* that is not absolutely correct. We might note though, that your discussion was not absolutely correct either. You merely require the sampling rate to be greater than 2 times the highest frequency to be sampled. In fact, there is a measurable amount greater that is required, which depends on the quantum size. Just being greater is *not* enough. And you're doing it again. I am not the one who said anything about it relating to the "highest frequency to be sampled." It's quite plain that I related the minimum sampling rate to the bandwidth of the signal to be sampled, not its "highest frequency." And when this correct form is used, all comes out correctly. Funny how that happens. Read what you said again. Regardless, it is not merely twice the bandwidth either and that is just as wrong as what you did say. I won't attempt to explain that to you, because it is clearly too technical. ;-) For one who complains loudly and longly when others use what you consider to be "insults," you are certainly I don't complain about insults. I do complain when they are gratuitous. The above is not a gratuitous insult, it is simply the truth based on what you have posted. If you cannot get the basics right, we cannot go on to anything more technical. I'm sorry if that insults you, but that a valid statement based only on what you have said here, and is not at all gratuitous. quick yourself with the snide and sarcastic comments. Are you familiar with the story of the pot and the kettle discussing their color? I'm sorry that you either do not read English or cannot be honest. Take your pick, it has to be one or the other. I have *never* complained just because someone said something insulting. Here's another standard definition from FS-1037C: Nyquist interval: The maximum time interval between equally spaced samples of a signal that will enable the signal waveform to be completely determined. (188) Note 1: The Nyquist interval is equal to the reciprocal of twice the highest frequency component of the sampled signal. And again, "highest frequency component" is at best misleading, and at worst completely incorrect. You'd think you would learn by now. A whole lot of industry experts agreed to putting *that* definition into the Federal Standard 1037C glossary. I'm sure you know better than all of them... and that is why I can find several references to cite that support exactly what I've claimed, and you can't cite even a single reference... Note 2: In practice, when analog signals are sampled for the purpose of digital transmission or other processing, the sampling rate must be more frequent than that defined by Nyquist's theorem, because of quantization error introduced by the digitizing process. The required sampling rate is determined by the accuracy of the digitizing process. You comments to date, though, have demonstrated nothing but a complete lack of understanding of just what the above actually means. So you say, but then you haven't demonstrated nearly the understanding that I have. At this point, Floyd, it should be obvious to the few hardy souls still following this thread that it is you against basically everyone else. First, that isn't true at all. Second, I guess it wouldn't be surprising that you might think a head count of posters on Usenet has logical significance, given your other illogical argumentation. I do grant that you are supported by the loudest and most ignorant of the people who posted. What does that say for you? This is either due to your being the sole person in the entire readership of this group who understands Or that you can't count? these matters - which I find highly unlikely, especially given your inability to actually explain anything - or, as most have appear to have already agreed to be the case, that you are simply an utterly unimaginative wretch who attempts to use Hmmm... gratuitousness is not a blessing when it comes to insults. recitation of texts learned by rote to make up for a lack of any real understanding or a willingness to even attempt to learn something. In fact I've probably been working with digital systems for significantly longer than most of those who have demonstrated their lack of understanding, including you. But I am not dumb enough to cite my own opinion as the sole source of information. You are. I'm not so silly as to state my opinion without providing references to authoritative sources that support it. You are. Now you have the audacity to say that because I can and do cite authoritative sources to support my opinions, that it is *I* who has a lack of understanding. You on the other hand have yet to cite *anything*, supporting or otherwise. You can't, we all know it; because there are no authoritative sources that agree with you. Try being at least a little bit rational in your comments, please. It is embarrassing for me to have people who do understand this topic read a thread where I actually continue stubbornly to argue with someone who comes up with the above sort of comment and actually thinks it is valid. .... In any case, this is the end of the line. I've wasted more than enough time here, and it's ending now. You wasted a lot of *everyone's* time. I hope you are finally being honest, and do cease posting nonsense. -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#429
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Floyd L. Davidson wrote:
... It isn't "telephone system thinking", it's Information Theory. That applies to a great deal more than high fidelity audio. So Information Theory tells us that a quantized signal is digital? Consider the output of the limiters in an FM IF driving a Foster-Seely discriminator. It has two states -- saturated and zero -- before the tank that smooths the edges. I guess Information theory says that FM radio is digital (maybe unless you use an Avins-Seely ratio detector, but even those work better with at least one limiter). Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ |
#430
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Randy Yates wrote:
"Bob Myers" writes: "Floyd L. Davidson" wrote in message ... Lets be clear... The definitions I cited are standard. I posted 5 or 6 varied references to the same definitions. And everyone knows, ""standards" are holy. Not that I necessarily agree or disagree with Floyd's original point, but citing a written reference holds more water than a post from an individual on a usenet newsgroup, in my opinion. Floyd maintains that any signal whose values are restricted to a finite set -- IOW, "quantized" -- is digital. I cited a two-level analog signal and I can demonstrate a digital signal with a relatively large continuous range of values. His definitions are simply too restrictive to accommodate those, and he seems to be having a fit. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ |
#431
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Jerry Avins writes:
Randy Yates wrote: "Bob Myers" writes: "Floyd L. Davidson" wrote in message ... Lets be clear... The definitions I cited are standard. I posted 5 or 6 varied references to the same definitions. And everyone knows, ""standards" are holy. Not that I necessarily agree or disagree with Floyd's original point, but citing a written reference holds more water than a post from an individual on a usenet newsgroup, in my opinion. Floyd maintains that any signal whose values are restricted to a finite set -- IOW, "quantized" -- is digital. I cited a two-level analog signal and I can demonstrate a digital signal with a relatively large continuous range of values. His definitions are simply too restrictive to accommodate those, and he seems to be having a fit. I've decided that it's not fruitful to continue this discussion since the knowledge I work with admits anough understanding to get a lot of real work done. These sorts of discussions take too much time and produce little or no fruit. My ability to do work does not depend on others' judgement of the correctness of my definitions. -- % Randy Yates % "She has an IQ of 1001, she has a jumpsuit %% Fuquay-Varina, NC % on, and she's also a telephone." %%% 919-577-9882 % %%%% % 'Yours Truly, 2095', *Time*, ELO http://home.earthlink.net/~yatescr |
#432
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Floyd L. Davidson wrote:
... Nyquist rate: The reciprocal of the Nyquist interval, i.e., the minimum theoretical sampling rate that fully describes a given signal, i.e., enables its faithful reconstruction from the samples. Note: The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process. It does not say what you claimed it does. Do you buy the "because clause? I don't. "The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process." All qualified practitioners will recognize that as wrong. Are you qualified? Jerry Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ |
#433
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Jerry Avins wrote:
Floyd L. Davidson wrote: ... It isn't "telephone system thinking", it's Information Theory. That applies to a great deal more than high fidelity audio. So Information Theory tells us that a quantized signal is digital? Consider the output of the limiters in an FM IF driving a Foster-Seely discriminator. It has two states -- saturated and zero -- before the tank that smooths the edges. I guess Information theory says that FM radio is digital (maybe unless you use an Avins-Seely ratio detector, but even those work better with at least one limiter). You aren't making a lick of sense Jerry. That suggests you don't have even a foggy notion of what you are talking about. Tell us exactly what information is encoded in those "saturated and zero" states? -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#434
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Floyd L. Davidson wrote:
Jerry Avins wrote: Floyd L. Davidson wrote: ... It isn't "telephone system thinking", it's Information Theory. That applies to a great deal more than high fidelity audio. So Information Theory tells us that a quantized signal is digital? Consider the output of the limiters in an FM IF driving a Foster-Seely discriminator. It has two states -- saturated and zero -- before the tank that smooths the edges. I guess Information theory says that FM radio is digital (maybe unless you use an Avins-Seely ratio detector, but even those work better with at least one limiter). You aren't making a lick of sense Jerry. That suggests you don't have even a foggy notion of what you are talking about. Tell us exactly what information is encoded in those "saturated and zero" states? Very little; the information is in the zero crossings. The signal is quantized in amplitude. Is it digital or not? If not, does your definition hold? Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ |
#435
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Jerry Avins wrote:
Floyd maintains that any signal whose values are restricted to a finite set -- IOW, "quantized" -- is digital. I cited a two-level analog signal and I can demonstrate a digital signal with a relatively large continuous range of values. His definitions are simply too restrictive to accommodate those, and he seems to be having a fit. I'll admit to a really great fit of laughter at that one! You are so thoroughly confused that it is hilarious. The recognized standard definitions say that a quantized signal is digital. You can indeed have a two-level analog signal, but the fact is that the *possible* values are infinite (all values between your two listed ones, for example). You cannot possibly have a digital signal with a continuous range of values (large or small, relative or otherwise). I've cited multiple credible sources that agree with what I say. You can't cite even one. There are none. -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#436
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Jerry Avins wrote:
Floyd L. Davidson wrote: ... Nyquist rate: The reciprocal of the Nyquist interval, i.e., the minimum theoretical sampling rate that fully describes a given signal, i.e., enables its faithful reconstruction from the samples. Note: The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process. It does not say what you claimed it does. Do you buy the "because clause? I don't. "The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process." All qualified practitioners will recognize that as wrong. Are you qualified? All qualified practitioners will recognize that you are wrong, and obviously unqualified. It is in fact a correct statement. Do you know what quantization distortion is? -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#437
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Jerry Avins wrote:
Floyd L. Davidson wrote: Jerry Avins wrote: So Information Theory tells us that a quantized signal is digital? Consider the output of the limiters in an FM IF driving a Foster-Seely discriminator. It has two states -- saturated and zero -- before the tank that smooths the edges. I guess Information theory says that FM radio is digital (maybe unless you use an Avins-Seely ratio detector, but even those work better with at least one limiter). You aren't making a lick of sense Jerry. That suggests you don't have even a foggy notion of what you are talking about. Tell us exactly what information is encoded in those "saturated and zero" states? Very little; the information is in the zero crossings. The voltage amplitude has nothing to do with whether the signal is digital or analog. It can be anything, with any characteristics you'd like to imagine. That is because it carries no information. The signal is quantized in amplitude. First, it is not. It varies between two voltages, and does so continuously (and apparently too quickly for a slow person to follow, eh?). But since the variations contain no information and therefore do not represent symbols of any kind, the amplitude does not determine whether the signal is digital or analog. Is it digital or not? If not, does your definition hold? We can't tell Jerry. You have not stated anything that describes the symbols set. The information is carried by some other characteristic of that signal (e.g., phase or frequency). Not knowing if it carries only discrete values from a finite set, or if the symbols are continuously variable, we just don't know what it is. This is *very* basic... -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#438
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
glen herrmannsfeldt wrote:
Jerry Avins wrote: (snip) So Information Theory tells us that a quantized signal is digital? Consider the output of the limiters in an FM IF driving a Foster-Seely discriminator. It has two states -- saturated and zero -- before the tank that smooths the edges. I guess Information theory says that FM radio is digital (maybe unless you use an Avins-Seely ratio detector, but even those work better with at least one limiter). This sounds like what I previously tried to describe as quantized but not sampled. The signal has two states, but the transition can happen at any time. Jerry's signal does not have two states. Voltage amplitude is *not* what determines signal "state" (value) with an FM signal. -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
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Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
Jerry Avins wrote:
(snip) So Information Theory tells us that a quantized signal is digital? Consider the output of the limiters in an FM IF driving a Foster-Seely discriminator. It has two states -- saturated and zero -- before the tank that smooths the edges. I guess Information theory says that FM radio is digital (maybe unless you use an Avins-Seely ratio detector, but even those work better with at least one limiter). This sounds like what I previously tried to describe as quantized but not sampled. The signal has two states, but the transition can happen at any time. -- glen |
#440
Posted to sci.electronics.basics,rec.video.desktop,comp.dsp,rec.audio.tech,rec.photo.digital
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Questions about equivalents of audio/video and digital/analog.
"Jerry Avins" wrote in message
Floyd L. Davidson wrote: ... Nyquist rate: The reciprocal of the Nyquist interval, i.e., the minimum theoretical sampling rate that fully describes a given signal, i.e., enables its faithful reconstruction from the samples. Note: The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process. It does not say what you claimed it does. Do you buy the "because clause? I don't. You do well to disagree with it. It is false. The errors that are introduced are aliasing, not quantization errors. You could change the size of the quantization steps any which way you want, and the aliasing would still be there. "The actual sampling rate required to reconstruct the original signal will be somewhat higher than the Nyquist rate, because of quantization errors introduced by the sampling process." All qualified practitioners will recognize that as wrong. Agreed. It's an incorrect statement for the reason I stated above. |
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