[Jingo Lingo]

I plan on making a 3.5mm to RCA cable that connects my sound card to my audio receiver, and would like to know if it would need to be shielded, or would some sought of 4 wire braid do the trick? The cable will be about 2m long and will going past a bunch of electrical equipment like my monitor etc.

I'm a bit new to this kind of thing, and I'm aware that speaker cables aren't significantly affected by EMI so I'm wondering if this will be the same.

Thanks.

 

[heatmizer]

Shielded cable would be good, Twisted pair(Cat5) is good, 4 wire braid (correctly done) would also be good. Anything that blocks or cancels rf

 

[JLMaestro]

Is it ok to connect the shield to the signal ground? Wouldn't all the noise pollute the ground plane?
Or is it better (but trickier to wire) to tie it to earth ground?

 

[navi]

Quote:

Originally Posted by JLMaestro /img/forum/go_quote.gif Is it ok to connect the shield to the signal ground? Wouldn't all the noise pollute the ground plane? Or is it better (but trickier to wire) to tie it to earth ground?

Connect the Shield to the ground at the source end only- You want the noise to go to the ground so it doesn't go to te signal.

 

[vixr]

Quote:

Originally Posted by navi /img/forum/go_quote.gif Connect the Shield to the ground at the source end only- You want the noise to go to the ground so it doesn't go to te signal.

thats interesting... all the FLIR cables I build have the shields and foil drains common to the backshell of the connector, which is common to the case ground which is earth ground on both ends. there is no audio on these cables, only video and power wires...

 

[JLMaestro]

So what's the best way? Connect the sheild to earth ground, or signal ground??

 

[Jingo Lingo]

Whats the difference between earth ground and signal ground?

 

[navi]

Quote:

Originally Posted by Jingo Lingo /img/forum/go_quote.gif Whats the difference between earth ground and signal ground?

all on the same little piece of wire on rca cables and head phone cables

 

[navi]

guys see rca diagram on this link

connect the shield like the drain wire. the shield does not carry any signal.

so for a 3.5mm to rca:
on the 3.5mm jack
1 wire for (L)
1 wire for (R)
2 wires for the (ground/signal return)
connect the shield to the ground/signal return

on RCAs (each one)
1 wire (L) or (R)
1 wire (ground /signal return)
the Shield is NOT connected at all at this end. make sure it doesn't touch the RCA plug or any exposed wire - you can do this by isolating them with teflon tape (plumbers tape) or heat shrink