I would like to thank everyone who contributed to my connecting wire inquiry. I don't at this time have any excessive need for a new hookup wire. I have plenty in my lab, but I like to know what is available. Gothom (sp) looks like a good bet, if I wanted something from Switzerland, but it does not seem better than any good hook-up wire.
Litz wire was experimented with over the decades and mostly discarded, because it tends to sound 'bright' when made into cables. We started out in this direction, 40 years ago.
As far as the Forwood book is concerned, I would have posted most of the pages of interest, as I have done several times on this website over the decade(s) if I could find it on my computer, but Gpapag you are going to see a book that is above and beyond what it normally discussed here, and it should be enlightening.
Litz wire was experimented with over the decades and mostly discarded, because it tends to sound 'bright' when made into cables. We started out in this direction, 40 years ago.
As far as the Forwood book is concerned, I would have posted most of the pages of interest, as I have done several times on this website over the decade(s) if I could find it on my computer, but Gpapag you are going to see a book that is above and beyond what it normally discussed here, and it should be enlightening.
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Does it? Is that a fact? You state it as if it is, is it a well know fact, i.e. there is proof?
A top quality wire is properly annealed after cold drawing, not the case with el cheapos we usually have. You can get studies for change in mechanical properties such as ductility, sadly studies on change in electrical properties are not readily available. As I mentioned, who will benefit?
Gotcha, directionally as in diameter and length, of course, silly me.
Hi-fi (high fidelity) in sound replaying electronics, the degree of output's faithfulness to input is what determines the performance quality. Higher the better. I never said anything about Per-fi (perfect fidelity).
Hypothesis, evidence? Remember the "charge" and the electrons are not the same.
Skin effect is an EM phenomena the touchy feely electrons flow like water on the rocky shore analogy does not apply.Hypothesis, evidence? Remember the "charge" and the electrons are not the same.
And does charge or waves flow the same when there is no conductor?
And if I show you a picture of the building where I work, it will be evident to all that the wires are done correctly without confounders or loops???
The devil is in the details.. I recall JC also had issues with loops and ground.
You say you drive shield and core with the same signal from a different resistor divider, does that mean you keep the voltage the same, differential, what? And, all that internal electronics, how did you isolate drive and receive?
full schematic, build pictures, performance evaluation.....nothing less can do..
jn
Pretty much what was in the article. The shield and the core see the same signal but isolated as the signal driver is fed into two different resistor dividers to get down to the target signal voltage.
How do you have a skin effect with no conductor? The analogies don't hold water.
You still have not answered, are you making this up as you go along or are there some references we can read?So what. Try stretching a wire by pulling only one end. The force has to be in both directions, so how does the cable become "directional?
I found that the biggest difference is created by connectors. Change from well crimped BNC to RCA makes bigger difference than several meters of a coaxial cable. 1-2cm of shield that is soldered in one point to RCA body is worse than 2m of a standard coaxial cable, re added interference voltage. Even a very short cable does not help if it is terminated by RCA's. Same inside the instruments.
I would like to pose a few questions to the cable specialists:
1 - Any known very directional wires/cables one can buy or easily build from scratch?
3 - Would directionality (the direction A vs B difference) typically be an error closely correlated to the signal, that is, not random enough to be reduced considerably by precise time-domain averaging which is used as a method to dig down deep in the uncorrelated noise?
Note that correlated noise signatures (like excess current noise from mediocre resistors) still appear in spite of the heavy averaging (on the order of 10,000 blocks of sample data, typically).
2 - Would directionality appear in cable loopback with an integrated single DAC/ADC device, that is, when freed from many typical other noise/error sources like RF ingress and balancing currents?
I'm asking because I'm in a process of constantly refining my measurement strategies and time-domain averaging techniques enabling a view down at least some 40dB below the analog noise floor in the signal and especially in diff test residuals, having a virtual analog resolution of around 30bits. With a fully arbitrary test signal, actually.
So if (at least come) cable directionality effect is real and fulfils the above criteria (and maybe others?) it should be possible to measure and quantify under very real working conditions with "real" signals (to avoid any potential pitfalls of steady-state type of measurements), should't it?
Point is, it's an almost ideal candidate to exploit the power of differential testing because "standard" linear/nonlinear phenomena should remain unchanged. No trimming or post-processing needed to empirically match gross changes (like from different cables) which greatly increases robustness of the method. Some special care is needed though, for the automatic switching matrix that is required to implement this (still under construction).
1 - Any known very directional wires/cables one can buy or easily build from scratch?
3 - Would directionality (the direction A vs B difference) typically be an error closely correlated to the signal, that is, not random enough to be reduced considerably by precise time-domain averaging which is used as a method to dig down deep in the uncorrelated noise?
Note that correlated noise signatures (like excess current noise from mediocre resistors) still appear in spite of the heavy averaging (on the order of 10,000 blocks of sample data, typically).
2 - Would directionality appear in cable loopback with an integrated single DAC/ADC device, that is, when freed from many typical other noise/error sources like RF ingress and balancing currents?
I'm asking because I'm in a process of constantly refining my measurement strategies and time-domain averaging techniques enabling a view down at least some 40dB below the analog noise floor in the signal and especially in diff test residuals, having a virtual analog resolution of around 30bits. With a fully arbitrary test signal, actually.
So if (at least come) cable directionality effect is real and fulfils the above criteria (and maybe others?) it should be possible to measure and quantify under very real working conditions with "real" signals (to avoid any potential pitfalls of steady-state type of measurements), should't it?
Point is, it's an almost ideal candidate to exploit the power of differential testing because "standard" linear/nonlinear phenomena should remain unchanged. No trimming or post-processing needed to empirically match gross changes (like from different cables) which greatly increases robustness of the method. Some special care is needed though, for the automatic switching matrix that is required to implement this (still under construction).
I'm on it as much as time allows and hope to do more real measurements (the shown one was more like a demonstrating example with no additional characterization of the current, the shield impedance, lots of unknown from the several adapters used, etc).
Hi all,
In order to keep from wasting a lot of time, we need only to investigate wire directionality, not cable system directionality. A complete patch cable assy (as we find out quickly at RF frequencies) is a system consisting of the connector, shield and center conductor(s), or launcher and waveguide at higher frequencies. You cannot properly quantify any one part while it is assembled into a complete cable assy.
There is no doubt regarding cable system directionality. Having the shield terminated at the driven end only is an essential characteristic of shielded, balanced signal transfer in some uses. Hybrid coax assys of different impedances combined to form matching sections show directional impedance characteristics. Sweeping cables for shield integrity will show up poor shield terminations on one end compared to the other.
This is why I suggested only soldering wires, to get the connectors out of the picture and just test the bulk wire. Yes, much more of a PITA, but to do anything else is to confound the situation.
Test wires, not cable assys.
Howie
In order to keep from wasting a lot of time, we need only to investigate wire directionality, not cable system directionality. A complete patch cable assy (as we find out quickly at RF frequencies) is a system consisting of the connector, shield and center conductor(s), or launcher and waveguide at higher frequencies. You cannot properly quantify any one part while it is assembled into a complete cable assy.
There is no doubt regarding cable system directionality. Having the shield terminated at the driven end only is an essential characteristic of shielded, balanced signal transfer in some uses. Hybrid coax assys of different impedances combined to form matching sections show directional impedance characteristics. Sweeping cables for shield integrity will show up poor shield terminations on one end compared to the other.
This is why I suggested only soldering wires, to get the connectors out of the picture and just test the bulk wire. Yes, much more of a PITA, but to do anything else is to confound the situation.
Test wires, not cable assys.
Howie
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