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Topic: Can I use alufoil as a cable shield ? (Read 304 times) previous topic - next topic

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  • sven_Bent
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Can I use alufoil as a cable shield ?
I have a PC chassis where the little front output for headphones are connected to the motherboard by a unshielded cables and it seems to pickup some annoying noise on it. i am considering to do an DIY solutions

- unmount the cable and wrap it in household alu foil
- connect a small wire from the alu foil to the chassis

hoping to create a grounded shield. Am I totally in the wrong here ?
Sven Bent - Denmark

  • bennetng
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Re: Can I use alufoil as a cable shield ?
Reply #1

  • saratoga
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Re: Can I use alufoil as a cable shield ?
Reply #2
hoping to create a grounded shield. Am I totally in the wrong here ?

Very unlikely to help because:

1)  Good RF shielding requires tight, highly conductive enclosures, while foil is very thin and rarely wraps air-tight around a cable.
2)  The problem is probably not RF pick up through the air, but line noise coupling in through the power traces on the motherboard. 

I suggest just getting a sound card or using a low sensitivity pair of headphones until the next time you upgrade your motherboard.

Re: Can I use alufoil as a cable shield ?
Reply #3
I have a PC chassis where the little front output for headphones are connected to the motherboard by a unshielded cables and it seems to pickup some annoying noise on it. i am considering to do an DIY solutions

- unmount the cable and wrap it in household alu foil
- connect a small wire from the alu foil to the chassis

hoping to create a grounded shield. Am I totally in the wrong here ?

Why not pick up a few feet of actual shielded cable?

  • bennetng
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Re: Can I use alufoil as a cable shield ?
Reply #4
Or just use the jack on the motherboard, with an optional 3.5mm extension cable.

  • DVDdoug
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Re: Can I use alufoil as a cable shield ?
Reply #5
Shielding is not the problem...    You probably need a different soundcard. 

Headphones are low-impedance with a relatively high signal level and you can't "inject" noise without a direct connection.     For example, if you leave the headphones plugged into the front panel jack and unplug the unshielded wire from the motherboard, the noise will go away.


  • Makaki
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Re: Can I use alufoil as a cable shield ?
Reply #6
I have the same problem, my solution was a long cable to the rear jack. But I've read somewhere could be the way the Audio Ground is shared (or not shared) with the Chassis Ground.

In the end, This would require modifying a small PCB in the front of the chassis. And I couldn't confirm the "Correct" way it should be (Industry-Wise). Also what would be the PROs and CONs of making the change. So I went with the minimal impact option.

LINK 1:
https://www.techpowerup.com/forums/threads/article-fix-front-panel-audio-emi-noise.187276/

LINK 2:
https://www.youtube.com/watch?v=0FWu_MrRQ28

  • sven_Bent
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Re: Can I use alufoil as a cable shield ?
Reply #7
I have the same problem, my solution was a long cable to the rear jack. But I've read somewhere could be the way the Audio Ground is shared (or not shared) with the Chassis Ground.

In the end, This would require modifying a small PCB in the front of the chassis. And I couldn't confirm the "Correct" way it should be (Industry-Wise). Also what would be the PROs and CONs of making the change. So I went with the minimal impact option.

LINK 1:
https://www.techpowerup.com/forums/threads/article-fix-front-panel-audio-emi-noise.187276/

LINK 2:
https://www.youtube.com/watch?v=0FWu_MrRQ28


That was interesting.

For all others. I am just curious for the solutions. Mostly because i just like to try out stuff.
Like i do my own PSU internal cables where I braid the 3.3v, 5v and 12v wires for just the fun of it.
Sven Bent - Denmark