Hmmm, let's see...
"Inter modulation noise" at 60, 120, 180, 240, 300???
Sigh.
Go to Europe, I suspect cables over there will have "inter modulation noise" at 50, 100, 150, 200, 250...
Golly, they must make their cables different, no?
Jn
Ps. Are we really having a discussion about line harmonics as "inter modulation noise"????
Really?
Yes, the difference.....the outputs should be identical but in practice of course they never will be (residual is strictly not the correct term perhaps, oops).
I am relying on all four earth connections to be 'optimal'.
I understand that any earth contact resistances will alter the relationship between center and braid currents for both cables.
You mentioned about this recently....what is the effect on the signals when the earth/braid currents are effectively mono'd, iow neither of the braid currents exactly matching the respective center active currents ?.
What happens when the earth currents are effectively skewed to one braid because of slightly higher resistance at one contact, and which contact ?.
What do you mean 'reactance break point ' in this context ?.
Dan
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There is a diagram in my gallery which shows the electrical equivalent of an IC and pc's forming a ground loop. The reactance so of each loop determine how the return current returns.
Two shielded IC's will split the DC return current 50/50.
When the frequency is high enough, the return current will be confined to the sending IC.
Until that breakpoint, the return path will be very dependent on the physical arrangement of the two cables. Space them farther apart, the break frequency becomes lower.
It is a confounder to any test of this type.
For balanced, the equations are more complex, but the effect can still be there.
Jn
Two shielded IC's will split the DC return current 50/50.
When the frequency is high enough, the return current will be confined to the sending IC.
Until that breakpoint, the return path will be very dependent on the physical arrangement of the two cables. Space them farther apart, the break frequency becomes lower.
It is a confounder to any test of this type.
For balanced, the equations are more complex, but the effect can still be there.
Jn
Yes the stuff at 3K where the intermodulation occurs. The silver wire bty was just a bare wire the other two were shielded cables.
Chasing faeries again.
The scientific, rational process is to FIRST show an effect (the plural of anecdote is not data) THEN look for mechanisms.
There's so much theory that you can go nuts dreaming up possible explanations. (Especially when you have no guidance from prodding the reproducible, captured effect.)
And it gets even worse when you have smart / experienced people doing it because you can dream up more and increasingly complex explanations.
...
Ya know, that's what's wrong with the Internet: like-minded smart people spinning endless explanations for things that haven't even been shown to exist or need explanations!
An intellectual circle-jerk of navel gazing!
Cheers,
Jeff
PS And get off my lawn!
The scientific, rational process is to FIRST show an effect (the plural of anecdote is not data) THEN look for mechanisms.
There's so much theory that you can go nuts dreaming up possible explanations. (Especially when you have no guidance from prodding the reproducible, captured effect.)
And it gets even worse when you have smart / experienced people doing it because you can dream up more and increasingly complex explanations.
...
Ya know, that's what's wrong with the Internet: like-minded smart people spinning endless explanations for things that haven't even been shown to exist or need explanations!
An intellectual circle-jerk of navel gazing!
Cheers,
Jeff
PS And get off my lawn!
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Chasing faeries again.
The scientific, rational process is to FIRST show an effect (the plural of anecdote is not data) THEN look for mechanisms.
There's so much theory that you can go nuts dreaming up possible explanations.
And it gets even worse when you have smart / experienced people doing it because you can dream up more and more complex explanations.
That's what's wrong with the internet: like-minded smart people spinning endless explanations for things that haven't even been shown to exist or need explanations!
An intellectual circle-jerk of navel gazing!
Cheers,
Jeff
PS And get off my lawn!
Measurement was ten years ago.
Ed, that,s even worse.
If you would like some assistance with design of experiment and test measurement accuracy, please just ask, many here would help you.
Owning an AP does not automatically mean the owner knows what they are doing.
Your mis-interpretation of results boggles the imagination.
Jn
So you changed a lot more than wire diameter. Were they all equal length but different resistance, or all equal resistance but different length? For the unshielded wire, where was the return?
I want to know how a noise bump at 3khz is now called "intermodulation noise".
If it's at 6khz, is it called "double intermodulation noise?"
After the first plot, I would have stopped and figured out why so much line noise... And I would have looked for the equipment that was making the 3khz hash.
You know, a DC motor, a VSD, maybe a lathe, CNC...
You know, the standard culprits..
Jn
Edit: as opposed to attempting to redefine subatomic physics using verbage from an ill understood book.
If it's at 6khz, is it called "double intermodulation noise?"
After the first plot, I would have stopped and figured out why so much line noise... And I would have looked for the equipment that was making the 3khz hash.
You know, a DC motor, a VSD, maybe a lathe, CNC...
You know, the standard culprits..
Jn
Edit: as opposed to attempting to redefine subatomic physics using verbage from an ill understood book.
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The two were 1 meter standard audio cables. There is power line noise basically everywhere when you are looking at levels this low. The noise floor rises at the frequency of interest as there is a filter there. The AP is only displaying the test results. The source of the signal is a purpose built gizmo that produces two signals around 90,000 cycles but around 3,000 cycles apart and mixes them, then sourcing about 10 mV RMS into the cable. A low noise differential amplifier looks from the input to the output and this difference is amplified and filtered. There is also a log meter on the front panel to show differences. Here the output feeds the AP after the filter.
I see power line harmonics, a rise in noise floor and in the frequency range of interest the cables behaving differently. The original experiment was to see if there was a difference in solder joints using different leaded and lead free solder. Test boards were made up with 200 joints per board. No significant difference was noted. Then for fun I tried audio interconnects and was quite surprised by the results.
Pretty sure level is an important contributing factor. Clean vs not recently cleaned connectors makes a much bigger difference.
But it does seem there is some contribution from wire gauge, material and purity.
I see power line harmonics, a rise in noise floor and in the frequency range of interest the cables behaving differently. The original experiment was to see if there was a difference in solder joints using different leaded and lead free solder. Test boards were made up with 200 joints per board. No significant difference was noted. Then for fun I tried audio interconnects and was quite surprised by the results.
Pretty sure level is an important contributing factor. Clean vs not recently cleaned connectors makes a much bigger difference.
But it does seem there is some contribution from wire gauge, material and purity.
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The confounders here are not to be believed.
You have absolutely no idea where the signal currents are going. Where do you think the 90khz signals are?
Sigh.
You actually connected the inputs to the differential amp at the far ends of a cable, and neglected the loop itself?
You have to fix the test setup first.
Jn
The differential amplifier looks across the cable. That is why power line noise is expected. The frequencies were chosen to be below skin effect signicance and far enough away from the intermodulation frequency to allow effective filtering.
The same cable give the same results in multiple runs over years. Different cables give different results.
The same cable give the same results in multiple runs over years. Different cables give different results.
You mean you can hear a residual that no equipment can measure?
Any observation on "single vs multi strand" and connectors?
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Your test setup is badly designed, very simple. You did not control the current paths.
Fix that first, your "data" is not useful until you do.
No matter how many times I hit my head on the countertop, it still hurts
You understand the definition of insanity, no?
Jn
By definition, his setup is presenting content which should have zero'd out. So it is measurable.
Jn
What is that, and what are you measuring? You are showing a static signal, as usual what are you showing looks like that sea of mains junk confounders again.
Please present enough information for a reproducible experiment, and maybe a mathematical description of the hypothesis with calculated predicted results. A possible interpretation is that a 5W wire wound resistor has more distortion than a 1/2W one
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Your test setup is badly designed, very simple. You did not control the current paths.
Fix that first, your "data" is not useful until you do.
No matter how many times I hit my head on the countertop, it still hurts
You understand the definition of insanity, no?
Jn
When back in the office I will post the schematic. Not sure how you conclude I didn't control the current paths. The send side is powered by two 12 volt gel cells and the receive side by another two. The circuit common is controlled.
BTY how many times did you hit your head?
One volt. The gizmo has gain ahead of that. I will check that out when in the office.
Ed, thanks for the clarification of the measurement that you put up. It appears to show that silver, in this measurement is better than cheap copper coax or even industrial grade copper coax. If I am reading it correctly, it is the definitive difference between silver and copper that I have ever seen.
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