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#31
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Paul Burridge wrote:
With all due respect, I would guess you don't have an EE B.S. degree. Cut the chest puffing. Chest-puffing is one of Kev's more prominent character traits, I'm afraid. In fact one often gets the impression that his contributions to these threads is more contrived to show off his knowledge of electonics and mathematics Not at all. The purpose of my contributions are as a means of getting attention to my product, thereby gaining me much Guinness. than to help others out of pure, selfless altruism. Where on earth did you get this daft idea that I post for the good of the people? As I have noted many times, there is no such thing as selfless altruism, its all for ulterior motives. We are all inherently selfish. I absolute agree that everything I do is ultimately geared toward my self interest, or to be more exact, the self interest of my genes. I have never claimed otherwise. Anyone who claims that they take action for the benefit of others, at a net determinate to themselves are either, liars, fools, or deluded. Anyway, personal insults aside, I for one am lurking with interest to see who prevails in this linearity argument. It's a pity some heavyweight like Win can't step in and judge who's in the right on With all due respect to you here, why do you suppose that Win, and with all due respect to Winfred, is more qualified than myself on electronics matters.? this one but I rather suspect he has better things to do with his time. This one is easy. I'm right. As far as the class A amp goes, its a no contest. It can't possible form a modulator without relying on the non-linear behaviour of the transistor. Its not debatable. I have explained the details already. Regarding the definition of linearity, it is an open book. There is no single absolute correct definition. What we have here is a play on words, where some one is claiming that his version of the word definition is the only valid one, even whem most don't use it that way. A linear operator in mathematics, or linearity, is used in a different sense then it is used in analogue design. An object that satisfies the definition of a linear system in mathematics, is not one that is usually applicable to analogue design, and as used by, essentially, all analogue designers. The analogue definition of linearity is much more restrictive. For example, a linear amplifier in electronics is generally restricted to those amplifiers such that the output voltage or current is a simple constant times the input voltage or current, with or without an offset. That is, there is a *linear* = *straight* *line* relation between output and input. This is equivalent to requiring that the output only contains frequencies present at its input, i.e. no distortion. Some other mathematical definitions of linearity would not be so restrictive. For example, suppose a signal is fed through a magic analogue Fourier transform device that converts the input voltage to that of its Fourier transform. You would be hard pressed to get someone to agree that the output signal is not a gross distortion of its input, despite the fact that the Fourier transform is mathematically a linear transform. Sure, some high brow might like to claim that his definition is the "real" one, but words only mean what the majority means by them, and in this case, a "linear" system, is one with a straight/linear line relation between input and output. Kevin Aylward http://www.anasoft.co.uk SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design. |
#32
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Paul Burridge wrote:
With all due respect, I would guess you don't have an EE B.S. degree. Cut the chest puffing. Chest-puffing is one of Kev's more prominent character traits, I'm afraid. In fact one often gets the impression that his contributions to these threads is more contrived to show off his knowledge of electonics and mathematics Not at all. The purpose of my contributions are as a means of getting attention to my product, thereby gaining me much Guinness. than to help others out of pure, selfless altruism. Where on earth did you get this daft idea that I post for the good of the people? As I have noted many times, there is no such thing as selfless altruism, its all for ulterior motives. We are all inherently selfish. I absolute agree that everything I do is ultimately geared toward my self interest, or to be more exact, the self interest of my genes. I have never claimed otherwise. Anyone who claims that they take action for the benefit of others, at a net determinate to themselves are either, liars, fools, or deluded. Anyway, personal insults aside, I for one am lurking with interest to see who prevails in this linearity argument. It's a pity some heavyweight like Win can't step in and judge who's in the right on With all due respect to you here, why do you suppose that Win, and with all due respect to Winfred, is more qualified than myself on electronics matters.? this one but I rather suspect he has better things to do with his time. This one is easy. I'm right. As far as the class A amp goes, its a no contest. It can't possible form a modulator without relying on the non-linear behaviour of the transistor. Its not debatable. I have explained the details already. Regarding the definition of linearity, it is an open book. There is no single absolute correct definition. What we have here is a play on words, where some one is claiming that his version of the word definition is the only valid one, even whem most don't use it that way. A linear operator in mathematics, or linearity, is used in a different sense then it is used in analogue design. An object that satisfies the definition of a linear system in mathematics, is not one that is usually applicable to analogue design, and as used by, essentially, all analogue designers. The analogue definition of linearity is much more restrictive. For example, a linear amplifier in electronics is generally restricted to those amplifiers such that the output voltage or current is a simple constant times the input voltage or current, with or without an offset. That is, there is a *linear* = *straight* *line* relation between output and input. This is equivalent to requiring that the output only contains frequencies present at its input, i.e. no distortion. Some other mathematical definitions of linearity would not be so restrictive. For example, suppose a signal is fed through a magic analogue Fourier transform device that converts the input voltage to that of its Fourier transform. You would be hard pressed to get someone to agree that the output signal is not a gross distortion of its input, despite the fact that the Fourier transform is mathematically a linear transform. Sure, some high brow might like to claim that his definition is the "real" one, but words only mean what the majority means by them, and in this case, a "linear" system, is one with a straight/linear line relation between input and output. Kevin Aylward http://www.anasoft.co.uk SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design. |
#33
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On Sat, 6 Sep 2003 16:29:49 +0100, "Kevin Aylward"
wrote: Not at all. The purpose of my contributions are as a means of getting attention to my product, thereby gaining me much Guinness. Oh yes. There's the product-plugging as well. I'd forgotten about that. Where on earth did you get this daft idea that I post for the good of the people? As I have noted many times, there is no such thing as selfless altruism, its all for ulterior motives. We are all inherently selfish. I absolute agree that everything I do is ultimately geared toward my self interest, or to be more exact, the self interest of my genes. I have never claimed otherwise. Anyone who claims that they take action for the benefit of others, at a net determinate to themselves are either, liars, fools, or deluded. I disagree. You personally may well be motivated by selfishness as I don't doubt are very many people. But to say that everyone's like you is nonsense, quite frankly. There have been ample demonstrations of others' ability to be helpful for no self-gain whatsoever on this newsgroup alone. But I give you credit for making no bones about your motivations anyway. :-) With all due respect to you here, why do you suppose that Win, and with all due respect to Winfred, is more qualified than myself on electronics matters.? Er, the guy's a senior professor of electonics at Harvard, Kev. He probably knows more about the subject than the rest of us put together. This one is easy. I'm right. As far as the class A amp goes, its a no contest. It can't possible form a modulator without relying on the non-linear behaviour of the transistor. Its not debatable. I have explained the details already. Well clearly it *is* debatable from what I've seen in this thread! You simply believe you know best and that's that. Regarding the definition of linearity, it is an open book. There is no single absolute correct definition. What we have here is a play on words, where some one is claiming that his version of the word definition is the only valid one, even whem most don't use it that way. A linear operator in mathematics, or linearity, is used in a different sense then it is used in analogue design. An object that satisfies the definition of a linear system in mathematics, is not one that is usually applicable to analogue design, and as used by, essentially, all analogue designers. The analogue definition of linearity is much more restrictive. For example, a linear amplifier in electronics is generally restricted to those amplifiers such that the output voltage or current is a simple constant times the input voltage or current, with or without an offset. That is, there is a *linear* = *straight* *line* relation between output and input. This is equivalent to requiring that the output only contains frequencies present at its input, i.e. no distortion. Some other mathematical definitions of linearity would not be so restrictive. For example, suppose a signal is fed through a magic analogue Fourier transform device that converts the input voltage to that of its Fourier transform. You would be hard pressed to get someone to agree that the output signal is not a gross distortion of its input, despite the fact that the Fourier transform is mathematically a linear transform. Sure, some high brow might like to claim that his definition is the "real" one, but words only mean what the majority means by them, and in this case, a "linear" system, is one with a straight/linear line relation between input and output. I can't argue with any of that, but there again I'm no expert. I have to say, though, that I've always found it very curious that radio hams refer to their bolt-on, high-power, aftermarket boosters as "linear amplifiers." You can't get any *less* linear than class C! Or can you? -- "I believe history will be kind to me, since I intend to write it." - Winston Churchill |
#34
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On Sat, 6 Sep 2003 16:29:49 +0100, "Kevin Aylward"
wrote: Not at all. The purpose of my contributions are as a means of getting attention to my product, thereby gaining me much Guinness. Oh yes. There's the product-plugging as well. I'd forgotten about that. Where on earth did you get this daft idea that I post for the good of the people? As I have noted many times, there is no such thing as selfless altruism, its all for ulterior motives. We are all inherently selfish. I absolute agree that everything I do is ultimately geared toward my self interest, or to be more exact, the self interest of my genes. I have never claimed otherwise. Anyone who claims that they take action for the benefit of others, at a net determinate to themselves are either, liars, fools, or deluded. I disagree. You personally may well be motivated by selfishness as I don't doubt are very many people. But to say that everyone's like you is nonsense, quite frankly. There have been ample demonstrations of others' ability to be helpful for no self-gain whatsoever on this newsgroup alone. But I give you credit for making no bones about your motivations anyway. :-) With all due respect to you here, why do you suppose that Win, and with all due respect to Winfred, is more qualified than myself on electronics matters.? Er, the guy's a senior professor of electonics at Harvard, Kev. He probably knows more about the subject than the rest of us put together. This one is easy. I'm right. As far as the class A amp goes, its a no contest. It can't possible form a modulator without relying on the non-linear behaviour of the transistor. Its not debatable. I have explained the details already. Well clearly it *is* debatable from what I've seen in this thread! You simply believe you know best and that's that. Regarding the definition of linearity, it is an open book. There is no single absolute correct definition. What we have here is a play on words, where some one is claiming that his version of the word definition is the only valid one, even whem most don't use it that way. A linear operator in mathematics, or linearity, is used in a different sense then it is used in analogue design. An object that satisfies the definition of a linear system in mathematics, is not one that is usually applicable to analogue design, and as used by, essentially, all analogue designers. The analogue definition of linearity is much more restrictive. For example, a linear amplifier in electronics is generally restricted to those amplifiers such that the output voltage or current is a simple constant times the input voltage or current, with or without an offset. That is, there is a *linear* = *straight* *line* relation between output and input. This is equivalent to requiring that the output only contains frequencies present at its input, i.e. no distortion. Some other mathematical definitions of linearity would not be so restrictive. For example, suppose a signal is fed through a magic analogue Fourier transform device that converts the input voltage to that of its Fourier transform. You would be hard pressed to get someone to agree that the output signal is not a gross distortion of its input, despite the fact that the Fourier transform is mathematically a linear transform. Sure, some high brow might like to claim that his definition is the "real" one, but words only mean what the majority means by them, and in this case, a "linear" system, is one with a straight/linear line relation between input and output. I can't argue with any of that, but there again I'm no expert. I have to say, though, that I've always found it very curious that radio hams refer to their bolt-on, high-power, aftermarket boosters as "linear amplifiers." You can't get any *less* linear than class C! Or can you? -- "I believe history will be kind to me, since I intend to write it." - Winston Churchill |
#35
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Paul Burridge wrote:
On Sat, 6 Sep 2003 16:29:49 +0100, "Kevin Aylward" wrote: Not at all. The purpose of my contributions are as a means of getting attention to my product, thereby gaining me much Guinness. Oh yes. There's the product-plugging as well. I'd forgotten about that. Where on earth did you get this daft idea that I post for the good of the people? As I have noted many times, there is no such thing as selfless altruism, its all for ulterior motives. We are all inherently selfish. I absolute agree that everything I do is ultimately geared toward my self interest, or to be more exact, the self interest of my genes. I have never claimed otherwise. Anyone who claims that they take action for the benefit of others, at a net determinate to themselves are either, liars, fools, or deluded. I disagree. You personally may well be motivated by selfishness as I don't doubt are very many people. Er.. we all are. Its explained in "The selfish gene" by Richard Dawkins. Its a basic tenet of the modern theory of evolution. But to say that everyone's like you is nonsense, quite frankly. Not at all. You must be one of the deluded ones. That is, you haven't really thought about or studied evolution in enough detail. I am sure you are genuine in this belief, but you are wrong. Of course, if you are a believer in god or some other religion, then nothing I can say will convince you otherwise. There have been ample demonstrations of others' ability to be helpful for no self-gain whatsoever on this newsgroup alone. You miss the point. The term is *net* benefit or advantage. You need to look at this *much* more deeply. Its only an illusion that one does things for the benefit of others. I have explained this quite a few times. Its based on the theory of replicators. Axioms: 1 Traits are passed on to offspring. 2 Traits are randamlly generated. 3 Traits are selected by the environment. Now consider replicater A, that replicates *consistently* better than replicater B, say by 1%, due to a certain trait. After 1000 generations, what is the distribution of A/B? This all takes time to explain in detail, but the gist is if any replicater takes an action that results in a *net* *final* disadvantage, the other replicators, will replicate themselves better. Its simple math. We can only observe the best replicators. Obviously, it gets quite complicated, if doing some good to another, can result in a net beifit by returned favours, then a replicater will do so. Nevertheless its still inherently "selfish". In addition, a trait might not be consistently better, e.g. the larger one gets that enables one to fend for themselves better, is mitigated by the fact that one needs more food and other resources. Have a look on the web for "the selfish gene" or get the book. But I give you credit for making no bones about your motivations anyway. :-) I was not suggesting that I am always consciously doing things in a selfish manner. I am accepting the fact that its inherent from millions of years of evolution that we are all basically selfish, and there not much we can do about it. With all due respect to you here, why do you suppose that Win, and with all due respect to Winfred, is more qualified than myself on electronics matters.? Er, the guy's a senior professor of electonics at Harvard, Kev. He probably knows more about the subject than the rest of us put together. Whilst, I do agree that Win is very knowledgeable and an expert, I am also an expert. I have been doing this rather a long time as well you know. The fact that I am not an academic is not relevant. In all honesty, there is not much I don't know about general analogue design, although, obviously, I don't claim to know it all. Does Win know more than me? Unlikely. Or do I know more than Win. Unlikely. However, we may well know different things. This one is easy. I'm right. As far as the class A amp goes, its a no contest. It can't possible form a modulator without relying on the non-linear behaviour of the transistor. Its not debatable. I have explained the details already. Well clearly it *is* debatable from what I've seen in this thread! You simply believe you know best and that's that. But this part of it isnt. I gave the analysis of how the class A modulator actually works. Its a fact. Its a standard and accepted result by anyone knowledgably in the field. I don't claim that gwhite's definition of linearity is inherently wrong, only that it is not the one used in general analogue design. My argument was not about the definition of linearity, it was about gwhite's claim that his class A amp achieved a modulation function *without* relying on the inherent non linearity of the transistors emitter current verses vbe. This claim is absolutely false. Regarding the definition of linearity, it is an open book. There is no single absolute correct definition. What we have here is a play on words, where some one is claiming that his version of the word definition is the only valid one, even whem most don't use it that way. A linear operator in mathematics, or linearity, is used in a different sense then it is used in analogue design. An object that satisfies the definition of a linear system in mathematics, is not one that is usually applicable to analogue design, and as used by, essentially, all analogue designers. The analogue definition of linearity is much more restrictive. For example, a linear amplifier in electronics is generally restricted to those amplifiers such that the output voltage or current is a simple constant times the input voltage or current, with or without an offset. That is, there is a *linear* = *straight* *line* relation between output and input. This is equivalent to requiring that the output only contains frequencies present at its input, i.e. no distortion. Some other mathematical definitions of linearity would not be so restrictive. For example, suppose a signal is fed through a magic analogue Fourier transform device that converts the input voltage to that of its Fourier transform. You would be hard pressed to get someone to agree that the output signal is not a gross distortion of its input, despite the fact that the Fourier transform is mathematically a linear transform. Sure, some high brow might like to claim that his definition is the "real" one, but words only mean what the majority means by them, and in this case, a "linear" system, is one with a straight/linear line relation between input and output. I can't argue with any of that, but there again I'm no expert. I have to say, though, that I've always found it very curious that radio hams refer to their bolt-on, high-power, aftermarket boosters as "linear amplifiers." You can't get any *less* linear than class C! Or can you? And that illustrates the point very well. Linearity is up for grabs. Just what is the term "linear" being applied to. Average power, instantaneous voltage... Kevin Aylward http://www.anasoft.co.uk SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design. |
#36
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Paul Burridge wrote:
On Sat, 6 Sep 2003 16:29:49 +0100, "Kevin Aylward" wrote: Not at all. The purpose of my contributions are as a means of getting attention to my product, thereby gaining me much Guinness. Oh yes. There's the product-plugging as well. I'd forgotten about that. Where on earth did you get this daft idea that I post for the good of the people? As I have noted many times, there is no such thing as selfless altruism, its all for ulterior motives. We are all inherently selfish. I absolute agree that everything I do is ultimately geared toward my self interest, or to be more exact, the self interest of my genes. I have never claimed otherwise. Anyone who claims that they take action for the benefit of others, at a net determinate to themselves are either, liars, fools, or deluded. I disagree. You personally may well be motivated by selfishness as I don't doubt are very many people. Er.. we all are. Its explained in "The selfish gene" by Richard Dawkins. Its a basic tenet of the modern theory of evolution. But to say that everyone's like you is nonsense, quite frankly. Not at all. You must be one of the deluded ones. That is, you haven't really thought about or studied evolution in enough detail. I am sure you are genuine in this belief, but you are wrong. Of course, if you are a believer in god or some other religion, then nothing I can say will convince you otherwise. There have been ample demonstrations of others' ability to be helpful for no self-gain whatsoever on this newsgroup alone. You miss the point. The term is *net* benefit or advantage. You need to look at this *much* more deeply. Its only an illusion that one does things for the benefit of others. I have explained this quite a few times. Its based on the theory of replicators. Axioms: 1 Traits are passed on to offspring. 2 Traits are randamlly generated. 3 Traits are selected by the environment. Now consider replicater A, that replicates *consistently* better than replicater B, say by 1%, due to a certain trait. After 1000 generations, what is the distribution of A/B? This all takes time to explain in detail, but the gist is if any replicater takes an action that results in a *net* *final* disadvantage, the other replicators, will replicate themselves better. Its simple math. We can only observe the best replicators. Obviously, it gets quite complicated, if doing some good to another, can result in a net beifit by returned favours, then a replicater will do so. Nevertheless its still inherently "selfish". In addition, a trait might not be consistently better, e.g. the larger one gets that enables one to fend for themselves better, is mitigated by the fact that one needs more food and other resources. Have a look on the web for "the selfish gene" or get the book. But I give you credit for making no bones about your motivations anyway. :-) I was not suggesting that I am always consciously doing things in a selfish manner. I am accepting the fact that its inherent from millions of years of evolution that we are all basically selfish, and there not much we can do about it. With all due respect to you here, why do you suppose that Win, and with all due respect to Winfred, is more qualified than myself on electronics matters.? Er, the guy's a senior professor of electonics at Harvard, Kev. He probably knows more about the subject than the rest of us put together. Whilst, I do agree that Win is very knowledgeable and an expert, I am also an expert. I have been doing this rather a long time as well you know. The fact that I am not an academic is not relevant. In all honesty, there is not much I don't know about general analogue design, although, obviously, I don't claim to know it all. Does Win know more than me? Unlikely. Or do I know more than Win. Unlikely. However, we may well know different things. This one is easy. I'm right. As far as the class A amp goes, its a no contest. It can't possible form a modulator without relying on the non-linear behaviour of the transistor. Its not debatable. I have explained the details already. Well clearly it *is* debatable from what I've seen in this thread! You simply believe you know best and that's that. But this part of it isnt. I gave the analysis of how the class A modulator actually works. Its a fact. Its a standard and accepted result by anyone knowledgably in the field. I don't claim that gwhite's definition of linearity is inherently wrong, only that it is not the one used in general analogue design. My argument was not about the definition of linearity, it was about gwhite's claim that his class A amp achieved a modulation function *without* relying on the inherent non linearity of the transistors emitter current verses vbe. This claim is absolutely false. Regarding the definition of linearity, it is an open book. There is no single absolute correct definition. What we have here is a play on words, where some one is claiming that his version of the word definition is the only valid one, even whem most don't use it that way. A linear operator in mathematics, or linearity, is used in a different sense then it is used in analogue design. An object that satisfies the definition of a linear system in mathematics, is not one that is usually applicable to analogue design, and as used by, essentially, all analogue designers. The analogue definition of linearity is much more restrictive. For example, a linear amplifier in electronics is generally restricted to those amplifiers such that the output voltage or current is a simple constant times the input voltage or current, with or without an offset. That is, there is a *linear* = *straight* *line* relation between output and input. This is equivalent to requiring that the output only contains frequencies present at its input, i.e. no distortion. Some other mathematical definitions of linearity would not be so restrictive. For example, suppose a signal is fed through a magic analogue Fourier transform device that converts the input voltage to that of its Fourier transform. You would be hard pressed to get someone to agree that the output signal is not a gross distortion of its input, despite the fact that the Fourier transform is mathematically a linear transform. Sure, some high brow might like to claim that his definition is the "real" one, but words only mean what the majority means by them, and in this case, a "linear" system, is one with a straight/linear line relation between input and output. I can't argue with any of that, but there again I'm no expert. I have to say, though, that I've always found it very curious that radio hams refer to their bolt-on, high-power, aftermarket boosters as "linear amplifiers." You can't get any *less* linear than class C! Or can you? And that illustrates the point very well. Linearity is up for grabs. Just what is the term "linear" being applied to. Average power, instantaneous voltage... Kevin Aylward http://www.anasoft.co.uk SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design. |
#37
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"Dick Carroll;" ) writes:
Paul Burridge wrote: I have to say, though, that I've always found it very curious that radio hams refer to their bolt-on, high-power, aftermarket boosters as "linear amplifiers." You can't get any *less* linear than class C! ??? ....I won't speak for the rest of ham radio, but I've never operated a linear amplifier in Class C. Dick Well when you've got it on 2meters and are feeding it with an FM rig, of course it's silly to call it a "linear amplifier". Michael VE2BVW |
#38
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"Dick Carroll;" ) writes:
Paul Burridge wrote: I have to say, though, that I've always found it very curious that radio hams refer to their bolt-on, high-power, aftermarket boosters as "linear amplifiers." You can't get any *less* linear than class C! ??? ....I won't speak for the rest of ham radio, but I've never operated a linear amplifier in Class C. Dick Well when you've got it on 2meters and are feeding it with an FM rig, of course it's silly to call it a "linear amplifier". Michael VE2BVW |
#39
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Paul Burridge wrote:
On Sat, 6 Sep 2003 16:29:49 +0100, "Kevin Aylward" wrote: Not at all. The purpose of my contributions are as a means of getting attention to my product, thereby gaining me much Guinness. Oh yes. There's the product-plugging as well. I'd forgotten about that. Where on earth did you get this daft idea that I post for the good of the people? As I have noted many times, there is no such thing as selfless altruism, its all for ulterior motives. We are all inherently selfish. I absolute agree that everything I do is ultimately geared toward my self interest, or to be more exact, the self interest of my genes. I have never claimed otherwise. Anyone who claims that they take action for the benefit of others, at a net determinate to themselves are either, liars, fools, or deluded. I disagree. You personally may well be motivated by selfishness as I don't doubt are very many people. Er.. we all are. Its explained in "The selfish gene" by Richard Dawkins. Its a basic tenet of the modern theory of evolution. But to say that everyone's like you is nonsense, quite frankly. Not at all. You must be one of the deluded ones. That is, you haven't really thought about or studied evolution in enough detail. I am sure you are genuine in this belief, but you are wrong. Of course, if you are a believer in god or some other religion, then nothing I can say will convince you otherwise. There have been ample demonstrations of others' ability to be helpful for no self-gain whatsoever on this newsgroup alone. You miss the point. The term is *net* benefit or advantage. You need to look at this *much* more deeply. Its only an illusion that one does things for the benefit of others. I have explained this quite a few times. Its based on the theory of replicators. Axioms: 1 Traits are passed on to offspring. 2 Traits are randamlly generated. 3 Traits are selected by the environment. Now consider replicater A, that replicates *consistently* better than replicater B, say by 1%, due to a certain trait. After 1000 generations, what is the distribution of A/B? This all takes time to explain in detail, but the gist is if any replicater takes an action that results in a *net* *final* disadvantage, the other replicators, will replicate themselves better. Its simple math. We can only observe the best replicators. Obviously, it gets quite complicated, if doing some good to another, can result in a net beifit by returned favours, then a replicater will do so. Nevertheless its still inherently "selfish". In addition, a trait might not be consistently better, e.g. the larger one gets that enables one to fend for themselves better, is mitigated by the fact that one needs more food and other resources. Have a look on the web for "the selfish gene" or get the book. But I give you credit for making no bones about your motivations anyway. :-) I was not suggesting that I am always consciously doing things in a selfish manner. I am accepting the fact that its inherent from millions of years of evolution that we are all basically selfish, and there not much we can do about it. With all due respect to you here, why do you suppose that Win, and with all due respect to Winfred, is more qualified than myself on electronics matters.? Er, the guy's a senior professor of electonics at Harvard, Kev. He probably knows more about the subject than the rest of us put together. Whilst, I do agree that Win is very knowledgeable and an expert, I am also an expert. I have been doing this rather a long time as well you know. The fact that I am not an academic is not relevant. In all honesty, there is not much I don't know about general analogue design, although, obviously, I don't claim to know it all. Does Win know more than me? Unlikely. Or do I know more than Win. Unlikely. However, we may well know different things. This one is easy. I'm right. As far as the class A amp goes, its a no contest. It can't possible form a modulator without relying on the non-linear behaviour of the transistor. Its not debatable. I have explained the details already. Well clearly it *is* debatable from what I've seen in this thread! You simply believe you know best and that's that. But this part of it isnt. I gave the analysis of how the class A modulator actually works. Its a fact. Its a standard and accepted result by anyone knowledgably in the field. I don't claim that gwhite's definition of linearity is inherently wrong, only that it is not the one used in general analogue design. My argument was not about the definition of linearity, it was about gwhite's claim that his class A amp achieved a modulation function *without* relying on the inherent non linearity of the transistors emitter current verses vbe. This claim is absolutely false. Regarding the definition of linearity, it is an open book. There is no single absolute correct definition. What we have here is a play on words, where some one is claiming that his version of the word definition is the only valid one, even whem most don't use it that way. A linear operator in mathematics, or linearity, is used in a different sense then it is used in analogue design. An object that satisfies the definition of a linear system in mathematics, is not one that is usually applicable to analogue design, and as used by, essentially, all analogue designers. The analogue definition of linearity is much more restrictive. For example, a linear amplifier in electronics is generally restricted to those amplifiers such that the output voltage or current is a simple constant times the input voltage or current, with or without an offset. That is, there is a *linear* = *straight* *line* relation between output and input. This is equivalent to requiring that the output only contains frequencies present at its input, i.e. no distortion. Some other mathematical definitions of linearity would not be so restrictive. For example, suppose a signal is fed through a magic analogue Fourier transform device that converts the input voltage to that of its Fourier transform. You would be hard pressed to get someone to agree that the output signal is not a gross distortion of its input, despite the fact that the Fourier transform is mathematically a linear transform. Sure, some high brow might like to claim that his definition is the "real" one, but words only mean what the majority means by them, and in this case, a "linear" system, is one with a straight/linear line relation between input and output. I can't argue with any of that, but there again I'm no expert. I have to say, though, that I've always found it very curious that radio hams refer to their bolt-on, high-power, aftermarket boosters as "linear amplifiers." You can't get any *less* linear than class C! Or can you? And that illustrates the point very well. Linearity is up for grabs. Just what is the term "linear" being applied to. The class c amplifier is non linear in detailed operation but the envelope of the output is still linearly related to the modulating input signal. Kevin Aylward http://www.anasoft.co.uk SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design. |
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Paul Burridge wrote:
On Sat, 6 Sep 2003 16:29:49 +0100, "Kevin Aylward" wrote: Not at all. The purpose of my contributions are as a means of getting attention to my product, thereby gaining me much Guinness. Oh yes. There's the product-plugging as well. I'd forgotten about that. Where on earth did you get this daft idea that I post for the good of the people? As I have noted many times, there is no such thing as selfless altruism, its all for ulterior motives. We are all inherently selfish. I absolute agree that everything I do is ultimately geared toward my self interest, or to be more exact, the self interest of my genes. I have never claimed otherwise. Anyone who claims that they take action for the benefit of others, at a net determinate to themselves are either, liars, fools, or deluded. I disagree. You personally may well be motivated by selfishness as I don't doubt are very many people. Er.. we all are. Its explained in "The selfish gene" by Richard Dawkins. Its a basic tenet of the modern theory of evolution. But to say that everyone's like you is nonsense, quite frankly. Not at all. You must be one of the deluded ones. That is, you haven't really thought about or studied evolution in enough detail. I am sure you are genuine in this belief, but you are wrong. Of course, if you are a believer in god or some other religion, then nothing I can say will convince you otherwise. There have been ample demonstrations of others' ability to be helpful for no self-gain whatsoever on this newsgroup alone. You miss the point. The term is *net* benefit or advantage. You need to look at this *much* more deeply. Its only an illusion that one does things for the benefit of others. I have explained this quite a few times. Its based on the theory of replicators. Axioms: 1 Traits are passed on to offspring. 2 Traits are randamlly generated. 3 Traits are selected by the environment. Now consider replicater A, that replicates *consistently* better than replicater B, say by 1%, due to a certain trait. After 1000 generations, what is the distribution of A/B? This all takes time to explain in detail, but the gist is if any replicater takes an action that results in a *net* *final* disadvantage, the other replicators, will replicate themselves better. Its simple math. We can only observe the best replicators. Obviously, it gets quite complicated, if doing some good to another, can result in a net beifit by returned favours, then a replicater will do so. Nevertheless its still inherently "selfish". In addition, a trait might not be consistently better, e.g. the larger one gets that enables one to fend for themselves better, is mitigated by the fact that one needs more food and other resources. Have a look on the web for "the selfish gene" or get the book. But I give you credit for making no bones about your motivations anyway. :-) I was not suggesting that I am always consciously doing things in a selfish manner. I am accepting the fact that its inherent from millions of years of evolution that we are all basically selfish, and there not much we can do about it. With all due respect to you here, why do you suppose that Win, and with all due respect to Winfred, is more qualified than myself on electronics matters.? Er, the guy's a senior professor of electonics at Harvard, Kev. He probably knows more about the subject than the rest of us put together. Whilst, I do agree that Win is very knowledgeable and an expert, I am also an expert. I have been doing this rather a long time as well you know. The fact that I am not an academic is not relevant. In all honesty, there is not much I don't know about general analogue design, although, obviously, I don't claim to know it all. Does Win know more than me? Unlikely. Or do I know more than Win. Unlikely. However, we may well know different things. This one is easy. I'm right. As far as the class A amp goes, its a no contest. It can't possible form a modulator without relying on the non-linear behaviour of the transistor. Its not debatable. I have explained the details already. Well clearly it *is* debatable from what I've seen in this thread! You simply believe you know best and that's that. But this part of it isnt. I gave the analysis of how the class A modulator actually works. Its a fact. Its a standard and accepted result by anyone knowledgably in the field. I don't claim that gwhite's definition of linearity is inherently wrong, only that it is not the one used in general analogue design. My argument was not about the definition of linearity, it was about gwhite's claim that his class A amp achieved a modulation function *without* relying on the inherent non linearity of the transistors emitter current verses vbe. This claim is absolutely false. Regarding the definition of linearity, it is an open book. There is no single absolute correct definition. What we have here is a play on words, where some one is claiming that his version of the word definition is the only valid one, even whem most don't use it that way. A linear operator in mathematics, or linearity, is used in a different sense then it is used in analogue design. An object that satisfies the definition of a linear system in mathematics, is not one that is usually applicable to analogue design, and as used by, essentially, all analogue designers. The analogue definition of linearity is much more restrictive. For example, a linear amplifier in electronics is generally restricted to those amplifiers such that the output voltage or current is a simple constant times the input voltage or current, with or without an offset. That is, there is a *linear* = *straight* *line* relation between output and input. This is equivalent to requiring that the output only contains frequencies present at its input, i.e. no distortion. Some other mathematical definitions of linearity would not be so restrictive. For example, suppose a signal is fed through a magic analogue Fourier transform device that converts the input voltage to that of its Fourier transform. You would be hard pressed to get someone to agree that the output signal is not a gross distortion of its input, despite the fact that the Fourier transform is mathematically a linear transform. Sure, some high brow might like to claim that his definition is the "real" one, but words only mean what the majority means by them, and in this case, a "linear" system, is one with a straight/linear line relation between input and output. I can't argue with any of that, but there again I'm no expert. I have to say, though, that I've always found it very curious that radio hams refer to their bolt-on, high-power, aftermarket boosters as "linear amplifiers." You can't get any *less* linear than class C! Or can you? And that illustrates the point very well. Linearity is up for grabs. Just what is the term "linear" being applied to. The class c amplifier is non linear in detailed operation but the envelope of the output is still linearly related to the modulating input signal. Kevin Aylward http://www.anasoft.co.uk SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design. |
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