[RFI] Single-point grounding

Jim Brown jim at audiosystemsgroup.com
Mon Jul 2 08:54:56 PDT 2012

On 7/2/2012 4:35 AM, David Robbins wrote:
> one thing to watch for if you have problems like pete's with control circuits is the unintentional loop that is closed by the control signal cable.

To clarify, what Dave has correctly observed is the MAGNETIC loop formed 
by the signal return in the control cable and the bonding path. And, as 
he observed, the induced voltage and current are proportional to the 
loop area, so making the control cables (and audio cables) long enough 
to follow the bonding path would tend to minimize magnetic induction.

While I believe that nearly all authorities agree that more bonding and 
more parallel paths are better because they tend to keep all parts of a 
premises and a system closer to the SAME voltage in the event of a 
strike, there still can be magnetically induced voltage and current on 
those bonding conductors.

73, Jim K9YC

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