Funniest snake oil theories

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#3,663
Tvrgeek, it is not that the cable has an impedance of let's say 100 Ohms for current passing through it.

It is the value of the terminating resistor required so that all the energy stored in the cable by an alternating current can be absorbed at the ends without over- or undershoot. We call the value of the optimum termination resistance of a cable it's characteristic impedance.
 
#3,664
tvrgeek said:
You are the one who is claiming the cable has an impedance of 100 Ohms at audio frequencies. When I went to school, impedance was still a function of frequency.
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Maybe his terminology was a bit sloppy. What he meant was that zip cord has a characteristic impedance of about 100 Ohms. Sounds about right to me.

ishiru said:
i'm watching and don't get any idea 😕
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JN is talking about characteristic impedance. See here: Characteristic impedance - Wikipedia, the free encyclopedia
 
#3,665
tvrgeek said:
No, never said that. You are the one who is claiming the cable has an impedance of 100 Ohms at audio frequencies. When I went to school, impedance was still a function of frequency.
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The impedance of a cable is Z = SQR (L/C).

Zip runs very close to that.

godfrey said:
Maybe his terminology was a bit sloppy. What he meant was that zip cord has a characteristic impedance of about 100 Ohms. Sounds about right to me.

Possible. However, since that has been the discussion all along, bringing in the series resistance of the conductor as being the impedance of zip is woefully bad.

I hope that it will not be necessary to preface every single post in a discussion with a set of definitions. It should suffice to continue along the line of discussion without such repetition.

godfrey said:
JN is talking about characteristic impedance. See here: Characteristic impedance - Wikipedia, the free encyclopedia
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Yes.

jn
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#3,666
gpapag said:
DF96
I don’t mean to start a debate and I will not feed a discussion as I am not up to this but I would like to ask you if you are aware of Heaviside’s writings over this ‘misconseption’ .
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To be honest, I can't remember. I may have read Heaviside on this; I have certainly read him on other matters.

The heat in a resistor is caused by the electrons getting scattered and giving up their energy. They gained their energy from the electric field across the resistor, arising from the potential difference across it. This PD comes from conductors attached to a source of PD. Should I forget about electrons being scattered and just believe that the heat is somehow beamed into the resistor by swirling Poynting vectors? (Yes, they do swirl even for a simple DC circuit of battery and resistor).
 
#3,671
godfrey said:
Maybe his terminology was a bit sloppy. What he meant was that zip cord has a characteristic impedance of about 100 Ohms. Sounds about right to me.


JN is talking about characteristic impedance. See here: Characteristic impedance - Wikipedia, the free encyclopedia
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If you notice in the WIKI page for the definition of a transmission line charismatic impedance, the little Greek "w". That means frequency. As lossless lines do not exist, the frequency component does not cancel out.
 
#3,672
tvrgeek said:
If you notice in the WIKI page for the definition of a transmission line charismatic impedance, the little Greek "w". That means frequency. As lossless lines do not exist, the frequency component does not cancel out.
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Your response answers absolutely nothing. Nobody has said lossless line. Nobody has said the frequency component cancels out.

Do you actually understand this topic? Or is this a weird attempt at diversion?

As I stated, when the load and source are far lower than the impedance of the transmission line, the settling time of the system will be roughly 3 orders of magnitude slower than the transit time.

And by impedance, I mean the characteristic impedance.

Charisma has nothing to do with transmission lines...unless they are very elegant...then maybe, charisma...😉

jn
 
#3,673
Post 3665 would suggest so.

I am contending the characteristic impedance of a speaker cable at AF is not 100 Ohms, but is far lower so the problem you are trying to address in moot. I have seen nothing presented to change this basic understanding. Even if your settling time is 1000 times longer, and even though the propagation is .5 to .6 C, it is still not an issue for AF as you are still talking uS.


Spelling checkers can be quite entertaining.
 
#3,675
I actually had a power cord that affected my sound. The terminals were not soldered or crimped correctly and it started arcing, then smoking, then the sound went away. ( big effect) Made in China.


Nice touch, the wood block. Maybe it s just another college student experiment in sociology? Maybe not.
 
#3,678
😕 I am always surprised by the number of '9' in the copper purity. I learned long ago that electronic grade copper purity is > 99.99%. Where do all the '9' come from. Do they reprocess the copper in a space lab orbiting Earth?😀 The cable is supposed to improve noise floor: do they mean noise from the carpet, the wooden floor...? 😕 What about the noise generated by the walls through which power cables are running? Mmmmh, we need to develop a cure against that noise too. Anyway, it is highly entertaining, please keep up the oil pumping. 😉
Cheers,
Serge
 
#3,679
tvrgeek said:
I am contending the characteristic impedance of a speaker cable at AF is not 100 Ohms, but is far lower so the problem you are trying to address in moot.
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The characteristic impedance of most speaker cable at audio frequencies is much higher than 100 ohms and quite reactive. This is because series resistance dominates over inductance. See the formula in the Wikipedia article linked by someone earlier.
 
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