|
On Sun, 6 Feb 2005 12:12:40 -0600, "Richard Fry"
wrote: "Richard Clark" wrote in message On Sun, 6 Feb 2005 15:59:36 -0000, "Dave" wrote: leading edge of a step from 0 to some 'static' value ...negates the usage of "static" - clearly. You mis-read. Hi OM, Your failure to reconcile the meaning of static with a non-static description is as much as I need read. This class of discussion is revealed in the hallmark re-definition of terms to suit poor arguments. 73's Richard Clark, KB7QHC |
"Richard Clark" wrote in message ... On Sun, 6 Feb 2005 15:59:36 -0000, "Dave" wrote: leading edge of a step from 0 to some 'static' value Hi Dave, ...negates the usage of "static" - clearly. A step pulse is not "static" and in fact contains an infinite range of frequencies all of which are NOT DC. This is called the genii out of the bottle and no one here can (but no doubt will try to) put it back. 73's Richard Clark, KB7QHC you will of course note that i quoted the term 'static' to denote that it was indeed not static in the infinite sense of mathematics, but in the real sense of it being a constant value over some measured time period. the other obvious thing you are missing is that DC is a frequency... and it does come out in the Fourier transform as a frequency of zero with some finite magnitude for any waveform who's average value is not zero. it does not even require that the waveform stay at some value forever, a short pulse going from 0v to 1v and back to 0v will have a DC component in its spectrum both mathematically and on any meter that can properly respond to it. |
On Sun, 6 Feb 2005 19:35:55 -0000, "Dave" wrote:
you will of course note that i quoted the term 'static' to denote that it was indeed not static in the infinite sense of mathematics, but in the real sense of it being a constant value over some measured time period. Hi Dave, This is fine as an elaboration that grows beyond the horizon of the question. But it really serves no purpose but to embroider a glaring lack of facts. the other obvious thing you are missing is that DC is a frequency... and it does come out in the Fourier transform as a frequency of zero with some finite magnitude for any waveform who's average value is not zero. it does not even require that the waveform stay at some value forever, a short pulse going from 0v to 1v and back to 0v will have a DC component in its spectrum both mathematically and on any meter that can properly respond to it. After having done a quite rigorous contract with HP deeply involved in both the strict math and the mechanics of Fourier, I am well versed to know how not all Fourier Transforms offer equal outcomes - especially with, or without D.C. as a product. Pure Fourier mandates a waveform constant throughout all time (from its inception to its end) and is strictly one of those "thought experiments" when it comes to transients - obviously. This has been, and is the first issue that comes with its classic requirements clashing with utility. Practical Fourier mandates that you remove all D.C. components through what is called "windowing" your data. You can choose not to and enjoy all the artifacts of spurious behavior (like frequency folding, frequency blurring, and false baselines) and translate those results into blighted proofs too. With transients, practical Fourier techniques mandate the presumption that they are periodic through all time by literally forcing the data set (through extensive reworking) to fit this requirement (which returns us to classic expectation). Such reworking of original data demands that you make a choice: you either discard amplitude accuracy for the sake of frequency accuracy, or discard frequency accuracy for the sake of amplitude accuracy. The irony of this choice is that you have already discard D.C. and its appearance within the product of results is imbued with error. Need I ask if you know how much error? Ignorance to what accuracy your transforms bring reduce arguments to platitudes. Simple, day to day, practical applications of Fourier discard these issues as trivialities immediately and offer no pretense of "accuracy" because you couldn't appreciate it anyway (unless the designer of an IIR or FIR was so incompetent as to be that obvious). However, this goes beyond the pale to justify a glaring presumption "average signal magnitude not zero" with the trappings of Fourier. For one, absolutely no one knows what is meant by "impulsive wideband signal (500 - 2.5 GHz)." This is so extremely vague as to be supportable by a multitude of waveforms that have wildly different Fourier results. For instance, there is the classic impulse of physics, lightning, which is notoriously low in frequency content over the interval cited. Clearly such impulsions suffered are not from nature. But this begs forcing the nomenclature to fit the problem. There are other impulses like a gated sine wave (which obviously renders a zero average), or a swept sine wave (same obvious average), or a ramp wave, or a saw tooth wave, or a triangle wave, or chirp wave. The list of impulsive wideband signals is exhausting, but hardly accommodating to the same universal expectation. If our correspondent, Galilea, cannot come to terms with responding to technical issues when seeking help, the growth of forced speculation creates its own illusory discussion that is best limited to idle conversation overheard in a ticket line waiting for a movie box office to open. 73's Richard Clark, KB7QHC |
"Richard Clark" wrote in message ... On Sun, 6 Feb 2005 12:12:40 -0600, "Richard Fry" wrote: "Richard Clark" wrote in message On Sun, 6 Feb 2005 15:59:36 -0000, "Dave" wrote: leading edge of a step from 0 to some 'static' value ...negates the usage of "static" - clearly. You mis-read. Hi OM, Your failure to reconcile the meaning of static with a non-static description is as much as I need read. This class of discussion is revealed in the hallmark re-definition of terms to suit poor arguments. 73's Richard Clark, KB7QHC ________________ Your rhetoric is evasive and blustery -- no doubt so you won't have to admit publicly to an incomplete understanding of what you are responding to. RF |
Richard,
Utter nonsense. 73, Gene W4SZ Richard Clark wrote: On Sun, 6 Feb 2005 19:35:55 -0000, "Dave" wrote: you will of course note that i quoted the term 'static' to denote that it was indeed not static in the infinite sense of mathematics, but in the real sense of it being a constant value over some measured time period. Hi Dave, This is fine as an elaboration that grows beyond the horizon of the question. But it really serves no purpose but to embroider a glaring lack of facts. the other obvious thing you are missing is that DC is a frequency... and it does come out in the Fourier transform as a frequency of zero with some finite magnitude for any waveform who's average value is not zero. it does not even require that the waveform stay at some value forever, a short pulse going from 0v to 1v and back to 0v will have a DC component in its spectrum both mathematically and on any meter that can properly respond to it. After having done a quite rigorous contract with HP deeply involved in both the strict math and the mechanics of Fourier, I am well versed to know how not all Fourier Transforms offer equal outcomes - especially with, or without D.C. as a product. Pure Fourier mandates a waveform constant throughout all time (from its inception to its end) and is strictly one of those "thought experiments" when it comes to transients - obviously. This has been, and is the first issue that comes with its classic requirements clashing with utility. Practical Fourier mandates that you remove all D.C. components through what is called "windowing" your data. You can choose not to and enjoy all the artifacts of spurious behavior (like frequency folding, frequency blurring, and false baselines) and translate those results into blighted proofs too. With transients, practical Fourier techniques mandate the presumption that they are periodic through all time by literally forcing the data set (through extensive reworking) to fit this requirement (which returns us to classic expectation). Such reworking of original data demands that you make a choice: you either discard amplitude accuracy for the sake of frequency accuracy, or discard frequency accuracy for the sake of amplitude accuracy. The irony of this choice is that you have already discard D.C. and its appearance within the product of results is imbued with error. Need I ask if you know how much error? Ignorance to what accuracy your transforms bring reduce arguments to platitudes. Simple, day to day, practical applications of Fourier discard these issues as trivialities immediately and offer no pretense of "accuracy" because you couldn't appreciate it anyway (unless the designer of an IIR or FIR was so incompetent as to be that obvious). However, this goes beyond the pale to justify a glaring presumption "average signal magnitude not zero" with the trappings of Fourier. For one, absolutely no one knows what is meant by "impulsive wideband signal (500 - 2.5 GHz)." This is so extremely vague as to be supportable by a multitude of waveforms that have wildly different Fourier results. For instance, there is the classic impulse of physics, lightning, which is notoriously low in frequency content over the interval cited. Clearly such impulsions suffered are not from nature. But this begs forcing the nomenclature to fit the problem. There are other impulses like a gated sine wave (which obviously renders a zero average), or a swept sine wave (same obvious average), or a ramp wave, or a saw tooth wave, or a triangle wave, or chirp wave. The list of impulsive wideband signals is exhausting, but hardly accommodating to the same universal expectation. If our correspondent, Galilea, cannot come to terms with responding to technical issues when seeking help, the growth of forced speculation creates its own illusory discussion that is best limited to idle conversation overheard in a ticket line waiting for a movie box office to open. 73's Richard Clark, KB7QHC |
Richard,
Utter nonsense. 73, Gene W4SZ Richard Clark wrote: On Sun, 6 Feb 2005 19:35:55 -0000, "Dave" wrote: you will of course note that i quoted the term 'static' to denote that it was indeed not static in the infinite sense of mathematics, but in the real sense of it being a constant value over some measured time period. Hi Dave, This is fine as an elaboration that grows beyond the horizon of the question. But it really serves no purpose but to embroider a glaring lack of facts. the other obvious thing you are missing is that DC is a frequency... and it does come out in the Fourier transform as a frequency of zero with some finite magnitude for any waveform who's average value is not zero. it does not even require that the waveform stay at some value forever, a short pulse going from 0v to 1v and back to 0v will have a DC component in its spectrum both mathematically and on any meter that can properly respond to it. After having done a quite rigorous contract with HP deeply involved in both the strict math and the mechanics of Fourier, I am well versed to know how not all Fourier Transforms offer equal outcomes - especially with, or without D.C. as a product. Pure Fourier mandates a waveform constant throughout all time (from its inception to its end) and is strictly one of those "thought experiments" when it comes to transients - obviously. This has been, and is the first issue that comes with its classic requirements clashing with utility. Practical Fourier mandates that you remove all D.C. components through what is called "windowing" your data. You can choose not to and enjoy all the artifacts of spurious behavior (like frequency folding, frequency blurring, and false baselines) and translate those results into blighted proofs too. With transients, practical Fourier techniques mandate the presumption that they are periodic through all time by literally forcing the data set (through extensive reworking) to fit this requirement (which returns us to classic expectation). Such reworking of original data demands that you make a choice: you either discard amplitude accuracy for the sake of frequency accuracy, or discard frequency accuracy for the sake of amplitude accuracy. The irony of this choice is that you have already discard D.C. and its appearance within the product of results is imbued with error. Need I ask if you know how much error? Ignorance to what accuracy your transforms bring reduce arguments to platitudes. Simple, day to day, practical applications of Fourier discard these issues as trivialities immediately and offer no pretense of "accuracy" because you couldn't appreciate it anyway (unless the designer of an IIR or FIR was so incompetent as to be that obvious). However, this goes beyond the pale to justify a glaring presumption "average signal magnitude not zero" with the trappings of Fourier. For one, absolutely no one knows what is meant by "impulsive wideband signal (500 - 2.5 GHz)." This is so extremely vague as to be supportable by a multitude of waveforms that have wildly different Fourier results. For instance, there is the classic impulse of physics, lightning, which is notoriously low in frequency content over the interval cited. Clearly such impulsions suffered are not from nature. But this begs forcing the nomenclature to fit the problem. There are other impulses like a gated sine wave (which obviously renders a zero average), or a swept sine wave (same obvious average), or a ramp wave, or a saw tooth wave, or a triangle wave, or chirp wave. The list of impulsive wideband signals is exhausting, but hardly accommodating to the same universal expectation. If our correspondent, Galilea, cannot come to terms with responding to technical issues when seeking help, the growth of forced speculation creates its own illusory discussion that is best limited to idle conversation overheard in a ticket line waiting for a movie box office to open. 73's Richard Clark, KB7QHC |
Richard,
Utter nonsense. 73, Gene W4SZ Richard Clark wrote: On Sun, 6 Feb 2005 19:35:55 -0000, "Dave" wrote: you will of course note that i quoted the term 'static' to denote that it was indeed not static in the infinite sense of mathematics, but in the real sense of it being a constant value over some measured time period. Hi Dave, This is fine as an elaboration that grows beyond the horizon of the question. But it really serves no purpose but to embroider a glaring lack of facts. the other obvious thing you are missing is that DC is a frequency... and it does come out in the Fourier transform as a frequency of zero with some finite magnitude for any waveform who's average value is not zero. it does not even require that the waveform stay at some value forever, a short pulse going from 0v to 1v and back to 0v will have a DC component in its spectrum both mathematically and on any meter that can properly respond to it. After having done a quite rigorous contract with HP deeply involved in both the strict math and the mechanics of Fourier, I am well versed to know how not all Fourier Transforms offer equal outcomes - especially with, or without D.C. as a product. Pure Fourier mandates a waveform constant throughout all time (from its inception to its end) and is strictly one of those "thought experiments" when it comes to transients - obviously. This has been, and is the first issue that comes with its classic requirements clashing with utility. Practical Fourier mandates that you remove all D.C. components through what is called "windowing" your data. You can choose not to and enjoy all the artifacts of spurious behavior (like frequency folding, frequency blurring, and false baselines) and translate those results into blighted proofs too. With transients, practical Fourier techniques mandate the presumption that they are periodic through all time by literally forcing the data set (through extensive reworking) to fit this requirement (which returns us to classic expectation). Such reworking of original data demands that you make a choice: you either discard amplitude accuracy for the sake of frequency accuracy, or discard frequency accuracy for the sake of amplitude accuracy. The irony of this choice is that you have already discard D.C. and its appearance within the product of results is imbued with error. Need I ask if you know how much error? Ignorance to what accuracy your transforms bring reduce arguments to platitudes. Simple, day to day, practical applications of Fourier discard these issues as trivialities immediately and offer no pretense of "accuracy" because you couldn't appreciate it anyway (unless the designer of an IIR or FIR was so incompetent as to be that obvious). However, this goes beyond the pale to justify a glaring presumption "average signal magnitude not zero" with the trappings of Fourier. For one, absolutely no one knows what is meant by "impulsive wideband signal (500 - 2.5 GHz)." This is so extremely vague as to be supportable by a multitude of waveforms that have wildly different Fourier results. For instance, there is the classic impulse of physics, lightning, which is notoriously low in frequency content over the interval cited. Clearly such impulsions suffered are not from nature. But this begs forcing the nomenclature to fit the problem. There are other impulses like a gated sine wave (which obviously renders a zero average), or a swept sine wave (same obvious average), or a ramp wave, or a saw tooth wave, or a triangle wave, or chirp wave. The list of impulsive wideband signals is exhausting, but hardly accommodating to the same universal expectation. If our correspondent, Galilea, cannot come to terms with responding to technical issues when seeking help, the growth of forced speculation creates its own illusory discussion that is best limited to idle conversation overheard in a ticket line waiting for a movie box office to open. 73's Richard Clark, KB7QHC |
On Sun, 06 Feb 2005 21:58:05 GMT, Gene Fuller
wrote: Utter nonsense. Hi Gene, You had to post that three times? Oh well, seems the season for deeply insightful criticism that appears to be following the value of the dollar in the world market. Was that your 1½¢ worth? Barring any discussion of conflicting experience, I would say it was worth every penny. You can put it into a privatized SS account and recoup massive earnings - if the dollar would just tread water. Don't invest in cotton or rice futures though.... [Feb. 5 - President Bush will seek deep cuts in farm and commodity programs in his new budget] 73's Richard Clark, KB7QHC |
obviously this discussion has ended... we are down to the 'just poo poo'
what you don't understand level... next comes name calling and personal attacks, so its time to leave. "Gene Fuller" wrote in message ... Richard, Utter nonsense. 73, Gene W4SZ Richard Clark wrote: On Sun, 6 Feb 2005 19:35:55 -0000, "Dave" wrote: you will of course note that i quoted the term 'static' to denote that it was indeed not static in the infinite sense of mathematics, but in the real sense of it being a constant value over some measured time period. Hi Dave, This is fine as an elaboration that grows beyond the horizon of the question. But it really serves no purpose but to embroider a glaring lack of facts. the other obvious thing you are missing is that DC is a frequency... and it does come out in the Fourier transform as a frequency of zero with some finite magnitude for any waveform who's average value is not zero. it does not even require that the waveform stay at some value forever, a short pulse going from 0v to 1v and back to 0v will have a DC component in its spectrum both mathematically and on any meter that can properly respond to it. After having done a quite rigorous contract with HP deeply involved in both the strict math and the mechanics of Fourier, I am well versed to know how not all Fourier Transforms offer equal outcomes - especially with, or without D.C. as a product. Pure Fourier mandates a waveform constant throughout all time (from its inception to its end) and is strictly one of those "thought experiments" when it comes to transients - obviously. This has been, and is the first issue that comes with its classic requirements clashing with utility. Practical Fourier mandates that you remove all D.C. components through what is called "windowing" your data. You can choose not to and enjoy all the artifacts of spurious behavior (like frequency folding, frequency blurring, and false baselines) and translate those results into blighted proofs too. With transients, practical Fourier techniques mandate the presumption that they are periodic through all time by literally forcing the data set (through extensive reworking) to fit this requirement (which returns us to classic expectation). Such reworking of original data demands that you make a choice: you either discard amplitude accuracy for the sake of frequency accuracy, or discard frequency accuracy for the sake of amplitude accuracy. The irony of this choice is that you have already discard D.C. and its appearance within the product of results is imbued with error. Need I ask if you know how much error? Ignorance to what accuracy your transforms bring reduce arguments to platitudes. Simple, day to day, practical applications of Fourier discard these issues as trivialities immediately and offer no pretense of "accuracy" because you couldn't appreciate it anyway (unless the designer of an IIR or FIR was so incompetent as to be that obvious). However, this goes beyond the pale to justify a glaring presumption "average signal magnitude not zero" with the trappings of Fourier. For one, absolutely no one knows what is meant by "impulsive wideband signal (500 - 2.5 GHz)." This is so extremely vague as to be supportable by a multitude of waveforms that have wildly different Fourier results. For instance, there is the classic impulse of physics, lightning, which is notoriously low in frequency content over the interval cited. Clearly such impulsions suffered are not from nature. But this begs forcing the nomenclature to fit the problem. There are other impulses like a gated sine wave (which obviously renders a zero average), or a swept sine wave (same obvious average), or a ramp wave, or a saw tooth wave, or a triangle wave, or chirp wave. The list of impulsive wideband signals is exhausting, but hardly accommodating to the same universal expectation. If our correspondent, Galilea, cannot come to terms with responding to technical issues when seeking help, the growth of forced speculation creates its own illusory discussion that is best limited to idle conversation overheard in a ticket line waiting for a movie box office to open. 73's Richard Clark, KB7QHC |
Gene Fuller wrote:
Richard, Utter nonsense. I don't think so, Gene. I have to read Richards posts twice on occasion, but this is pretty spot on. - Mike KB3EIA - Richard Clark wrote: On Sun, 6 Feb 2005 19:35:55 -0000, "Dave" wrote: you will of course note that i quoted the term 'static' to denote that it was indeed not static in the infinite sense of mathematics, but in the real sense of it being a constant value over some measured time period. Hi Dave, This is fine as an elaboration that grows beyond the horizon of the question. But it really serves no purpose but to embroider a glaring lack of facts. rest snipped |
| All times are GMT +1. The time now is 04:26 PM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com