Shielded cable question...

N64CUBE · January 26, 2016

Under what circumstances is it recommended that you use shielded Ethernet cables.

gazabi · January 26, 2016

Under what circumstances is it recommended that you use shielded Ethernet cables.

In areas where there is high amount of EM interference.

N64CUBE · January 26, 2016

In areas where there is high amount of EM interference.

what is that though, I googled it I just don't get it.

Naeaes · January 26, 2016

Shielded is best for fixed runs. Like if you build it inside a wall. They're stiffer and thicker and more fragile, that's why. Especially they shine when there are high voltage AC cables near by. Or stupid crazy stuff like radars or other pulsating electromagnetic thingimajigs.

If it's one of those STP cables with the foil on the outside(you can tell by the metal in the connector), the shielding has to be terminated into a ground preferably at both ends so it's a bad idea for like a laptop or other temporary runs.

N64CUBE · January 26, 2016

Shielded is best for fixed runs. Like if you build it inside a wall. They're stiffer and thicker and more fragile, that's why. Especially they shine when there are high voltage AC cables near by. Or stupid crazy stuff like radars or other pulsating electromagnetic thingimajigs.

If it's one of those STP cables with the foil on the outside(you can tell by the metal in the connector), the shielding has to be terminated into a ground preferably at both ends so it's a bad idea for like a laptop or other temporary runs.

oh okay thank you

Naeaes · January 26, 2016

what is that though, I googled it I just don't get it.

EM = electromagnetic

Without going to much depth about this, lets just say, there cannot be one without the other.

All electricity generates a magnetic field and all pulsating/rotating/moving magnetic fields generate electricity.

So if a magnetic field is pulsating on and off near an un-shielded cable, a current will be generated in the cable. But since there's data running in the cable, that's a really bad thing. Zero-bits are supposed to have no or very little current but if the interference is generating current in the cable, all the zeroes start to look like ones.