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#41
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More cable questions!
"Don Pearce" wrote in message
... So from a purely theoretical perspective, how do these different cable structures lead to greater or lesser inductance in the cable, assuming a consistent overall gauge? Thanks, Colin They don't. Braiding the cables closely together leads - as you would expect - to greater capacitance, not lower inductance. However, the net effect in network terms is that the overall reactance is less inductive. This is of course the same thing as more capacitive. We might need to define braiding. If the + wire is braided with itself and the - wire is braided with itself but the two never exchange places then the inductance probably doesn't change much (and probably not the capacitance either). However, if the + and - wires swap places ala twisted pair then the inductance most certainly changes since the mutual inductance terms partially cancel. Capacitance may or may not go up. In the instance of a long twisted pair the inductance drops dramatically over untwisted and the capacitance doesn't change (the capacitance per unit length does increase slightly since twisting the cable shortens it but not anywhere near the magnitude of inductance decrease). Of course, unless you have a pathologically deficient amplifier none of this matters to audio. |
#42
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More cable questions!
"Don Pearce" wrote in message
... So from a purely theoretical perspective, how do these different cable structures lead to greater or lesser inductance in the cable, assuming a consistent overall gauge? Thanks, Colin They don't. Braiding the cables closely together leads - as you would expect - to greater capacitance, not lower inductance. However, the net effect in network terms is that the overall reactance is less inductive. This is of course the same thing as more capacitive. We might need to define braiding. If the + wire is braided with itself and the - wire is braided with itself but the two never exchange places then the inductance probably doesn't change much (and probably not the capacitance either). However, if the + and - wires swap places ala twisted pair then the inductance most certainly changes since the mutual inductance terms partially cancel. Capacitance may or may not go up. In the instance of a long twisted pair the inductance drops dramatically over untwisted and the capacitance doesn't change (the capacitance per unit length does increase slightly since twisting the cable shortens it but not anywhere near the magnitude of inductance decrease). Of course, unless you have a pathologically deficient amplifier none of this matters to audio. |
#43
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More cable questions!
"Don Pearce" wrote in message
... So from a purely theoretical perspective, how do these different cable structures lead to greater or lesser inductance in the cable, assuming a consistent overall gauge? Thanks, Colin They don't. Braiding the cables closely together leads - as you would expect - to greater capacitance, not lower inductance. However, the net effect in network terms is that the overall reactance is less inductive. This is of course the same thing as more capacitive. We might need to define braiding. If the + wire is braided with itself and the - wire is braided with itself but the two never exchange places then the inductance probably doesn't change much (and probably not the capacitance either). However, if the + and - wires swap places ala twisted pair then the inductance most certainly changes since the mutual inductance terms partially cancel. Capacitance may or may not go up. In the instance of a long twisted pair the inductance drops dramatically over untwisted and the capacitance doesn't change (the capacitance per unit length does increase slightly since twisting the cable shortens it but not anywhere near the magnitude of inductance decrease). Of course, unless you have a pathologically deficient amplifier none of this matters to audio. |
#44
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On Wed, 31 Dec 2003 01:30:26 -0600, "Rusty Boudreaux"
wrote: "Don Pearce" wrote in message .. . So from a purely theoretical perspective, how do these different cable structures lead to greater or lesser inductance in the cable, assuming a consistent overall gauge? Thanks, Colin They don't. Braiding the cables closely together leads - as you would expect - to greater capacitance, not lower inductance. However, the net effect in network terms is that the overall reactance is less inductive. This is of course the same thing as more capacitive. We might need to define braiding. If the + wire is braided with itself and the - wire is braided with itself but the two never exchange places then the inductance probably doesn't change much (and probably not the capacitance either). However, if the + and - wires swap places ala twisted pair then the inductance most certainly changes since the mutual inductance terms partially cancel. Capacitance may or may not go up. In the instance of a long twisted pair the inductance drops dramatically over untwisted and the capacitance doesn't change (the capacitance per unit length does increase slightly since twisting the cable shortens it but not anywhere near the magnitude of inductance decrease). Of course, unless you have a pathologically deficient amplifier none of this matters to audio. I'm really not sure what you are saying here. Capacitance increases because the cable is shortened? No. Also, study the equation relating conductor area and separation and you will find that the best way to increase capacitance between two conductors is to bring the closer to each other. There is no question of "may or may not go up". With the question of twisted vs untwisted pair, neither inductance nor capacitance changes. What does happen with a twisted pair is that coupling to external fields cancels at each half twist, but that is another matter entirely. d _____________________________ http://www.pearce.uk.com |
#45
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On Wed, 31 Dec 2003 01:30:26 -0600, "Rusty Boudreaux"
wrote: "Don Pearce" wrote in message .. . So from a purely theoretical perspective, how do these different cable structures lead to greater or lesser inductance in the cable, assuming a consistent overall gauge? Thanks, Colin They don't. Braiding the cables closely together leads - as you would expect - to greater capacitance, not lower inductance. However, the net effect in network terms is that the overall reactance is less inductive. This is of course the same thing as more capacitive. We might need to define braiding. If the + wire is braided with itself and the - wire is braided with itself but the two never exchange places then the inductance probably doesn't change much (and probably not the capacitance either). However, if the + and - wires swap places ala twisted pair then the inductance most certainly changes since the mutual inductance terms partially cancel. Capacitance may or may not go up. In the instance of a long twisted pair the inductance drops dramatically over untwisted and the capacitance doesn't change (the capacitance per unit length does increase slightly since twisting the cable shortens it but not anywhere near the magnitude of inductance decrease). Of course, unless you have a pathologically deficient amplifier none of this matters to audio. I'm really not sure what you are saying here. Capacitance increases because the cable is shortened? No. Also, study the equation relating conductor area and separation and you will find that the best way to increase capacitance between two conductors is to bring the closer to each other. There is no question of "may or may not go up". With the question of twisted vs untwisted pair, neither inductance nor capacitance changes. What does happen with a twisted pair is that coupling to external fields cancels at each half twist, but that is another matter entirely. d _____________________________ http://www.pearce.uk.com |
#46
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More cable questions!
On Wed, 31 Dec 2003 01:30:26 -0600, "Rusty Boudreaux"
wrote: "Don Pearce" wrote in message .. . So from a purely theoretical perspective, how do these different cable structures lead to greater or lesser inductance in the cable, assuming a consistent overall gauge? Thanks, Colin They don't. Braiding the cables closely together leads - as you would expect - to greater capacitance, not lower inductance. However, the net effect in network terms is that the overall reactance is less inductive. This is of course the same thing as more capacitive. We might need to define braiding. If the + wire is braided with itself and the - wire is braided with itself but the two never exchange places then the inductance probably doesn't change much (and probably not the capacitance either). However, if the + and - wires swap places ala twisted pair then the inductance most certainly changes since the mutual inductance terms partially cancel. Capacitance may or may not go up. In the instance of a long twisted pair the inductance drops dramatically over untwisted and the capacitance doesn't change (the capacitance per unit length does increase slightly since twisting the cable shortens it but not anywhere near the magnitude of inductance decrease). Of course, unless you have a pathologically deficient amplifier none of this matters to audio. I'm really not sure what you are saying here. Capacitance increases because the cable is shortened? No. Also, study the equation relating conductor area and separation and you will find that the best way to increase capacitance between two conductors is to bring the closer to each other. There is no question of "may or may not go up". With the question of twisted vs untwisted pair, neither inductance nor capacitance changes. What does happen with a twisted pair is that coupling to external fields cancels at each half twist, but that is another matter entirely. d _____________________________ http://www.pearce.uk.com |
#47
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"Don Pearce" wrote in message
... I'm really not sure what you are saying here. Capacitance increases because the cable is shortened? No. Yes. Take a 1 foot long untwisted cable with zero conductor OD spacing (i.e. the insulation of both wires is touching) you will have some inductance and some capacitance. Now take that same 1 foot section and twist the wires. Total capacitance will remain unchanged since the spacing between conductors did not change. However, the capacitance per foot increases because twisting shortened the cable to something less than a foot. However, even with heavy twisting the length is only shortened by maybe 10% or so. So the capacitance per foot increases by the same amount (say 10%). Also, study the equation relating conductor area and separation and you will find that the best way to increase capacitance between two conductors is to bring the closer to each other. There is no question of "may or may not go up". Reread what I said. In the case above the total capacitance is the same but the capacitance/length increases. If the twisting method brings the wires closer together then capacitance increases. However, it's just as easy to take two parallel conductors, twist them loosely, and get lower capacitance (both total and per unit length)...because the separation distance increases. So capacitance per unit length can go up or down depending on changes in separation distance and amount of twisting. With the question of twisted vs untwisted pair, neither inductance nor capacitance changes. What does happen with a twisted pair is that coupling to external fields cancels at each half twist, but that is another matter entirely. With twisted pair not only does the external coupling cancel but the mutual inductance between the two wires cancels. Inductance is defined as the algebraic sum of self inductance and mutual inductance. Your analysis neglects the effect of mutual inductance. As you point out self inductance does not change with twisting (assuming conductor diameter and separation do not change). However, mutual inductance drops dramatically and in the ideal case becomes zero. The inductance of untwisted parallel wires is proportional to x*(ln(s/r)+log(s/r)) where x is length, s is separation, and r is conductor radius. For twisted pair the log term goes to zero (ideal case). If you don't believe me take a run of zip cord put it on an LCR meter and measure inductance before and after twisting. Capacitance can go up or down depending on conductor separation before and after twisting and the increased capacitance/length due to length shortening. |
#48
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"Don Pearce" wrote in message
... I'm really not sure what you are saying here. Capacitance increases because the cable is shortened? No. Yes. Take a 1 foot long untwisted cable with zero conductor OD spacing (i.e. the insulation of both wires is touching) you will have some inductance and some capacitance. Now take that same 1 foot section and twist the wires. Total capacitance will remain unchanged since the spacing between conductors did not change. However, the capacitance per foot increases because twisting shortened the cable to something less than a foot. However, even with heavy twisting the length is only shortened by maybe 10% or so. So the capacitance per foot increases by the same amount (say 10%). Also, study the equation relating conductor area and separation and you will find that the best way to increase capacitance between two conductors is to bring the closer to each other. There is no question of "may or may not go up". Reread what I said. In the case above the total capacitance is the same but the capacitance/length increases. If the twisting method brings the wires closer together then capacitance increases. However, it's just as easy to take two parallel conductors, twist them loosely, and get lower capacitance (both total and per unit length)...because the separation distance increases. So capacitance per unit length can go up or down depending on changes in separation distance and amount of twisting. With the question of twisted vs untwisted pair, neither inductance nor capacitance changes. What does happen with a twisted pair is that coupling to external fields cancels at each half twist, but that is another matter entirely. With twisted pair not only does the external coupling cancel but the mutual inductance between the two wires cancels. Inductance is defined as the algebraic sum of self inductance and mutual inductance. Your analysis neglects the effect of mutual inductance. As you point out self inductance does not change with twisting (assuming conductor diameter and separation do not change). However, mutual inductance drops dramatically and in the ideal case becomes zero. The inductance of untwisted parallel wires is proportional to x*(ln(s/r)+log(s/r)) where x is length, s is separation, and r is conductor radius. For twisted pair the log term goes to zero (ideal case). If you don't believe me take a run of zip cord put it on an LCR meter and measure inductance before and after twisting. Capacitance can go up or down depending on conductor separation before and after twisting and the increased capacitance/length due to length shortening. |
#49
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"Don Pearce" wrote in message
... I'm really not sure what you are saying here. Capacitance increases because the cable is shortened? No. Yes. Take a 1 foot long untwisted cable with zero conductor OD spacing (i.e. the insulation of both wires is touching) you will have some inductance and some capacitance. Now take that same 1 foot section and twist the wires. Total capacitance will remain unchanged since the spacing between conductors did not change. However, the capacitance per foot increases because twisting shortened the cable to something less than a foot. However, even with heavy twisting the length is only shortened by maybe 10% or so. So the capacitance per foot increases by the same amount (say 10%). Also, study the equation relating conductor area and separation and you will find that the best way to increase capacitance between two conductors is to bring the closer to each other. There is no question of "may or may not go up". Reread what I said. In the case above the total capacitance is the same but the capacitance/length increases. If the twisting method brings the wires closer together then capacitance increases. However, it's just as easy to take two parallel conductors, twist them loosely, and get lower capacitance (both total and per unit length)...because the separation distance increases. So capacitance per unit length can go up or down depending on changes in separation distance and amount of twisting. With the question of twisted vs untwisted pair, neither inductance nor capacitance changes. What does happen with a twisted pair is that coupling to external fields cancels at each half twist, but that is another matter entirely. With twisted pair not only does the external coupling cancel but the mutual inductance between the two wires cancels. Inductance is defined as the algebraic sum of self inductance and mutual inductance. Your analysis neglects the effect of mutual inductance. As you point out self inductance does not change with twisting (assuming conductor diameter and separation do not change). However, mutual inductance drops dramatically and in the ideal case becomes zero. The inductance of untwisted parallel wires is proportional to x*(ln(s/r)+log(s/r)) where x is length, s is separation, and r is conductor radius. For twisted pair the log term goes to zero (ideal case). If you don't believe me take a run of zip cord put it on an LCR meter and measure inductance before and after twisting. Capacitance can go up or down depending on conductor separation before and after twisting and the increased capacitance/length due to length shortening. |
#50
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Hi,
In message , Richard Crowley writes wrote ... Now to partly answer my own question, I came across a great website that discusses the issues I'm pondering. He titles the articles "Skin effect" but in fact spends very little time on true skin effect. http://www.st-andrews.ac.uk/~www_pa/...io/Analog.html He does provide many graphs showing very clear effects of different cable construction--all at about 100kHz, and most less than 0.1dB-- but measurable and predictable, nonetheless. But NOT audible. This is the kind of "pathological" wacko "pseudo-science" that people get hung up with when trying to avoid the real world (for whatever reason?) The website appears to do a good job of explaining the physics, but it doesn't follow through with what effect (or not) you will actually HEAR at audio frequencies. That's Jim Lesurf's site. You'll find he's a regular poster in uk.rec.audio, and he's by no means pathological. He would probably point out that the information on the site is just that - information from experimental observation. He deliberately does not draw conclusions (probably, but I'm guessing, because he doesn't want to fan the flames). He's a very good and thorough scientist, judging from his posts and his books. I believe he once designed amplifiers for Armstrong, and he's a very knowledgeable chap. I think the website doesn't 'follow through' because Jim simply didn't want it to. -- Regards, Glenn Booth |
#51
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More cable questions!
Hi,
In message , Richard Crowley writes wrote ... Now to partly answer my own question, I came across a great website that discusses the issues I'm pondering. He titles the articles "Skin effect" but in fact spends very little time on true skin effect. http://www.st-andrews.ac.uk/~www_pa/...io/Analog.html He does provide many graphs showing very clear effects of different cable construction--all at about 100kHz, and most less than 0.1dB-- but measurable and predictable, nonetheless. But NOT audible. This is the kind of "pathological" wacko "pseudo-science" that people get hung up with when trying to avoid the real world (for whatever reason?) The website appears to do a good job of explaining the physics, but it doesn't follow through with what effect (or not) you will actually HEAR at audio frequencies. That's Jim Lesurf's site. You'll find he's a regular poster in uk.rec.audio, and he's by no means pathological. He would probably point out that the information on the site is just that - information from experimental observation. He deliberately does not draw conclusions (probably, but I'm guessing, because he doesn't want to fan the flames). He's a very good and thorough scientist, judging from his posts and his books. I believe he once designed amplifiers for Armstrong, and he's a very knowledgeable chap. I think the website doesn't 'follow through' because Jim simply didn't want it to. -- Regards, Glenn Booth |
#52
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More cable questions!
Hi,
In message , Richard Crowley writes wrote ... Now to partly answer my own question, I came across a great website that discusses the issues I'm pondering. He titles the articles "Skin effect" but in fact spends very little time on true skin effect. http://www.st-andrews.ac.uk/~www_pa/...io/Analog.html He does provide many graphs showing very clear effects of different cable construction--all at about 100kHz, and most less than 0.1dB-- but measurable and predictable, nonetheless. But NOT audible. This is the kind of "pathological" wacko "pseudo-science" that people get hung up with when trying to avoid the real world (for whatever reason?) The website appears to do a good job of explaining the physics, but it doesn't follow through with what effect (or not) you will actually HEAR at audio frequencies. That's Jim Lesurf's site. You'll find he's a regular poster in uk.rec.audio, and he's by no means pathological. He would probably point out that the information on the site is just that - information from experimental observation. He deliberately does not draw conclusions (probably, but I'm guessing, because he doesn't want to fan the flames). He's a very good and thorough scientist, judging from his posts and his books. I believe he once designed amplifiers for Armstrong, and he's a very knowledgeable chap. I think the website doesn't 'follow through' because Jim simply didn't want it to. -- Regards, Glenn Booth |
#53
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"Glenn Booth" wrote ...
That's Jim Lesurf's site. You'll find he's a regular poster in uk.rec.audio, and he's by no means pathological. He would probably point out that the information on the site is just that - information from experimental observation. He deliberately does not draw conclusions (probably, but I'm guessing, because he doesn't want to fan the flames). He's a very good and thorough scientist, judging from his posts and his books. I believe he once designed amplifiers for Armstrong, and he's a very knowledgeable chap. I think the website doesn't 'follow through' because Jim simply didn't want it to. Thanks for the additional info. I was intending not to criticize Mr. Lesurf's excellent website, but to warn readers against drawing unwarranted extrapolations from it. |
#54
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More cable questions!
"Glenn Booth" wrote ...
That's Jim Lesurf's site. You'll find he's a regular poster in uk.rec.audio, and he's by no means pathological. He would probably point out that the information on the site is just that - information from experimental observation. He deliberately does not draw conclusions (probably, but I'm guessing, because he doesn't want to fan the flames). He's a very good and thorough scientist, judging from his posts and his books. I believe he once designed amplifiers for Armstrong, and he's a very knowledgeable chap. I think the website doesn't 'follow through' because Jim simply didn't want it to. Thanks for the additional info. I was intending not to criticize Mr. Lesurf's excellent website, but to warn readers against drawing unwarranted extrapolations from it. |
#55
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More cable questions!
"Glenn Booth" wrote ...
That's Jim Lesurf's site. You'll find he's a regular poster in uk.rec.audio, and he's by no means pathological. He would probably point out that the information on the site is just that - information from experimental observation. He deliberately does not draw conclusions (probably, but I'm guessing, because he doesn't want to fan the flames). He's a very good and thorough scientist, judging from his posts and his books. I believe he once designed amplifiers for Armstrong, and he's a very knowledgeable chap. I think the website doesn't 'follow through' because Jim simply didn't want it to. Thanks for the additional info. I was intending not to criticize Mr. Lesurf's excellent website, but to warn readers against drawing unwarranted extrapolations from it. |
#56
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#57
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#58
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#60
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(Bob-Stanton) wrote in
om: wrote in message I've got well designed gear (in my opinion--intelligent solid-state pre- and power- amps), and I'm not looking for audible effects. I'm just mucking about, trying to understand the theory here, short of taking a full electronics refresher course. The effective inductance, at a given frequency, for a given load, is a function of the distributed capacitance as well as the physical size of the conductors. You would need to use transmission line theory to calculate it accuratly. (A discrete element equivalent circuit will also give close results.) Transmission line theory is useless below about a 1/10 wavelength. At 20 kHz, this is several thousand feet. Why would anyone want to worry about 100kHz, when most people can no longer hear 20kHz? |
#61
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(Bob-Stanton) wrote in
om: wrote in message I've got well designed gear (in my opinion--intelligent solid-state pre- and power- amps), and I'm not looking for audible effects. I'm just mucking about, trying to understand the theory here, short of taking a full electronics refresher course. The effective inductance, at a given frequency, for a given load, is a function of the distributed capacitance as well as the physical size of the conductors. You would need to use transmission line theory to calculate it accuratly. (A discrete element equivalent circuit will also give close results.) Transmission line theory is useless below about a 1/10 wavelength. At 20 kHz, this is several thousand feet. Why would anyone want to worry about 100kHz, when most people can no longer hear 20kHz? |
#62
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"Bruce" wrote ...
Transmission line theory is useless below about a 1/10 wavelength. At 20 kHz, this is several thousand feet. Why would anyone want to worry about 100kHz, when most people can no longer hear 20kHz? If you have to ask then you'll never get it! :-)) |
#63
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"Bruce" wrote ...
Transmission line theory is useless below about a 1/10 wavelength. At 20 kHz, this is several thousand feet. Why would anyone want to worry about 100kHz, when most people can no longer hear 20kHz? If you have to ask then you'll never get it! :-)) |
#64
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"Bruce" wrote ...
Transmission line theory is useless below about a 1/10 wavelength. At 20 kHz, this is several thousand feet. Why would anyone want to worry about 100kHz, when most people can no longer hear 20kHz? If you have to ask then you'll never get it! :-)) |
#65
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Bruce wrote in message ...
(Bob-Stanton) wrote in om: wrote in message I've got well designed gear (in my opinion--intelligent solid-state pre- and power- amps), and I'm not looking for audible effects. I'm just mucking about, trying to understand the theory here, short of taking a full electronics refresher course. The effective inductance, at a given frequency, for a given load, is a function of the distributed capacitance as well as the physical size of the conductors. You would need to use transmission line theory to calculate it accuratly. (A discrete element equivalent circuit will also give close results.) Transmission line theory is useless below about a 1/10 wavelength. At 20 kHz, this is several thousand feet. It's not "useless" per se. It just is no more useful than a properly done lumped-parameter model, is often times significantly more difficult to use, even though it comes up with pretty much the same answers. People on this forum and others have shouted mightely about how only the transmission line model is any good, and then have utterly failed to show ANY supporting data from the real word that supports such a contention. One vocal and strident adherent of this view even said, in effect, that real data has no relevance to his "theory." |
#66
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Bruce wrote in message ...
(Bob-Stanton) wrote in om: wrote in message I've got well designed gear (in my opinion--intelligent solid-state pre- and power- amps), and I'm not looking for audible effects. I'm just mucking about, trying to understand the theory here, short of taking a full electronics refresher course. The effective inductance, at a given frequency, for a given load, is a function of the distributed capacitance as well as the physical size of the conductors. You would need to use transmission line theory to calculate it accuratly. (A discrete element equivalent circuit will also give close results.) Transmission line theory is useless below about a 1/10 wavelength. At 20 kHz, this is several thousand feet. It's not "useless" per se. It just is no more useful than a properly done lumped-parameter model, is often times significantly more difficult to use, even though it comes up with pretty much the same answers. People on this forum and others have shouted mightely about how only the transmission line model is any good, and then have utterly failed to show ANY supporting data from the real word that supports such a contention. One vocal and strident adherent of this view even said, in effect, that real data has no relevance to his "theory." |
#67
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Bruce wrote in message ...
(Bob-Stanton) wrote in om: wrote in message I've got well designed gear (in my opinion--intelligent solid-state pre- and power- amps), and I'm not looking for audible effects. I'm just mucking about, trying to understand the theory here, short of taking a full electronics refresher course. The effective inductance, at a given frequency, for a given load, is a function of the distributed capacitance as well as the physical size of the conductors. You would need to use transmission line theory to calculate it accuratly. (A discrete element equivalent circuit will also give close results.) Transmission line theory is useless below about a 1/10 wavelength. At 20 kHz, this is several thousand feet. It's not "useless" per se. It just is no more useful than a properly done lumped-parameter model, is often times significantly more difficult to use, even though it comes up with pretty much the same answers. People on this forum and others have shouted mightely about how only the transmission line model is any good, and then have utterly failed to show ANY supporting data from the real word that supports such a contention. One vocal and strident adherent of this view even said, in effect, that real data has no relevance to his "theory." |
#68
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Bruce wrote in message
Transmission line theory is useless below about a 1/10 wavelength. Transmission line theory works at any wavelenght. What you said above, is a common misconception. Bob Stanton |
#69
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Bruce wrote in message
Transmission line theory is useless below about a 1/10 wavelength. Transmission line theory works at any wavelenght. What you said above, is a common misconception. Bob Stanton |
#70
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Bruce wrote in message
Transmission line theory is useless below about a 1/10 wavelength. Transmission line theory works at any wavelenght. What you said above, is a common misconception. Bob Stanton |
#71
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#72
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#73
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#74
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"Bob-Stanton" wrote in message
om... I agree with you that a lumped element model is quite accurate. A true transmission line model is just only *slightly* more accurate. But, creating a true transmission line model is easy. One just enters (into a computer) the length of cable, the characteristic impedance, and the termination (load) impedance. What could be easier? So how do you enter into the computer the load impedance being it is a complex fuction of frequency? |
#75
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"Bob-Stanton" wrote in message
om... I agree with you that a lumped element model is quite accurate. A true transmission line model is just only *slightly* more accurate. But, creating a true transmission line model is easy. One just enters (into a computer) the length of cable, the characteristic impedance, and the termination (load) impedance. What could be easier? So how do you enter into the computer the load impedance being it is a complex fuction of frequency? |
#76
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"Bob-Stanton" wrote in message
om... I agree with you that a lumped element model is quite accurate. A true transmission line model is just only *slightly* more accurate. But, creating a true transmission line model is easy. One just enters (into a computer) the length of cable, the characteristic impedance, and the termination (load) impedance. What could be easier? So how do you enter into the computer the load impedance being it is a complex fuction of frequency? |
#77
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Kevin McMurtrie wrote in message ...
It's all irrelevant for audio frequencies and normal lengths of wire. Having the two conductors side by side is perfectly good. Just don't split the wires and route them to the speaker along opposite walls. Just curious, but what *would* happen if you did that? |
#78
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Kevin McMurtrie wrote in message ...
It's all irrelevant for audio frequencies and normal lengths of wire. Having the two conductors side by side is perfectly good. Just don't split the wires and route them to the speaker along opposite walls. Just curious, but what *would* happen if you did that? |
#79
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Kevin McMurtrie wrote in message ...
It's all irrelevant for audio frequencies and normal lengths of wire. Having the two conductors side by side is perfectly good. Just don't split the wires and route them to the speaker along opposite walls. Just curious, but what *would* happen if you did that? |
#80
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More cable questions!
"dangling entity" wrote in message m... Kevin McMurtrie wrote in message ... It's all irrelevant for audio frequencies and normal lengths of wire. Having the two conductors side by side is perfectly good. Just don't split the wires and route them to the speaker along opposite walls. Just curious, but what *would* happen if you did that? The listener(s) would be inside a 1-turn magnetic loop. Actually, some hearing-assist systems work by exactly that method. They use "receivers" with pickup coils and amps that drive the headphones. And some hearing aids will pick it up directly (from the coils they use to pick up telephone receiver audio.) |
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