Ethernet cables - YOUR LISTENING Shooutout Summary

A dCS engineer’s opinion is not a universal truth.

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That’s correct Gerben, but my point was (in that post) if you are selling a Cat6a with a floating screen, why have metal shrouded RJ45’s. That question has been answered by Michaelb.

As it happens I have a Pearl in my ‘spares’ collection & have just checked it, and you’re correct the screen is not connected end to end, but it doesn’t read correctly. It should read infinity (open circuit) but it shows a very high resistance (continuity between the plugs) & strangely the resistance value constantly changes considerably, almost like it has a capacitance characteristic.

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CatSnake Fever…aka Ted Nugent :ok_hand:

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I’m sorry but the resistance schould be infinite when floating. If it was floating you would measure low resistance, lets say 0-0.5 ohm.

My Pearl is also in th sparebox. Get my Fluke and check this out.

That is what I said. Low resistance equals not floating

The Fluke measures infinite and it is stable.
It’s the same value as when leaving the probes unconnected. What multimeter did you use?

The engineer was probably assuming that if shielded then the shield would not be “floating”.

The other comment is frequently made vs. very noisy industrial environments. But if someone finds one cable sounds better than another, then that’s that. There will be many variables involved, solid or stranded, twist rate, bonding or not, and so on as well as shielding material/s, so I don’t think it’s very easy for any of us to be sure about what is actually making the difference… or not actually doing any harm, whether completely unnecessary or not…

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Fluke 79
I will investigate sometime in future, but have ‘better’ things to do today.

Low resistance is the opposite of infinite resistance. When resistance is zero (Nul) than you speak of superconductivity. Only possible in situation were you have a minus 240°C.

Agreed
In a respectful question - do you have any network engineering background?
I know several of our members do.

No, but I have a pair of ears, the only qualifications relevant in this particular debate.

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The first yes, approximately (strictly thst would be zero resistance). And low resistance indicates that a conductor, presumed to be the shielding, connects the two plug shells, which is not floating. Which is what @Dozey said. Infinite resistance indicating open circuit would indicate that tgey are not connected, which is floating.

As for superconductivity, that would be zero resistance, rather than low resistance - but within the readability of common multimeters low resistance as with a few meters of well connected copper cable may read zero, although technically not truly being zero.

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When you are measuring a very high, but constantly changing value (megaohms), and measuring the metal outer part of a ethernet cable, with two hands, I guess you’re just measuring the resistance of your body, from fingers of left hand to the right hand. Or the other way around. When measuring very high values, or open loop, keep in mind not to touch the measuring probes, or you are influencing the measurement, basically measuring your own electrical resistance.

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Let’s all stop this meaningless discussion about the screen connection, and return to impressions of the sound of various ethernet cables.

Hear, hear!

Indeed it is.
If you have a multimeter with an ‘open or short’ reading on the dispay it wil problerby display 0 or 1, or an acoustic ‘peep’ on short.
This is were my confusion starred; I was thinking in Ohm’s.
Thank you…

No didn’t. See posted pichtere fluke.
I’m into electronics all my life , It’s my job.:wink:

Ohhh…this is so interesting. More please about multimeters and measuring resistance. :crazy_face:

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Absolutely. That’s the whole point of this thread. It would be a shame for it to descend into ‘my multimeter is bigger than your multimeter’. There are too many who deploy the ‘I’m an engineer and therefore I know best’ argument and it’s wholly unhelpful.