Author Topic: Screened power cable question  (Read 1070 times)

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Offline Chris WilsonTopic starter

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Screened power cable question
« on: February 24, 2017, 11:51:24 am »
I have Googled this, honest!!

Naive question, say I want to screen a 12V supply to a PCB from a bench supply 5 feet away. Can I use simple co-axial cable, say RG-58 with -ve on the braid and +ve on the inner? Or do I need at least a two core cable with the braid grounded and +ve and -ve on the two cores? I am dubious which is better as the -ve 12V supply is ground anyway... Thanks. My goal is ensuring the 12V supply cannot pick up the large amount of RF floating about when I TX. Low frequency stuff, 136kHz. Yes, this damned amp I often post about  still.... ;)
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                 Chris Wilson.
 

Offline Richard Crowley

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Re: Screened power cable question
« Reply #1 on: February 24, 2017, 12:36:57 pm »
Is your "large amount of RF" being INDUCTIVELY coupled into the power wiring?  If so, it is indeed very strong and using shielded cable won't help.  But if it is CAPACITIVELY coupled, then shielding MAY help depending on other factors not in evidence here.  Perhaps we should also ask why you don't simply consider using proper entrance filtering at the load end of the power wiring?  That way you wouldn't be dependent on using a particular kind of wiring.  Without knowing the full picture (and what "large amount" means), it can only be discussed in very general terms.
 

Offline bharatcs

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Re: Screened power cable question
« Reply #2 on: February 24, 2017, 02:49:10 pm »
 :D Hello
          You don't need need a co-axial cable here its not designed to carry power.
           Just use a twisted pair wire or get creative and make your own,simply twist two long wires one around the other  ;)
 


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