Re: [TowerTalk] [RFI] Back of desk grounding buss

[Jim Lux <jimlux@earthlink.net>]

On 3/21/14 11:01 AM, Jim Brown wrote:
> On 3/21/2014 9:02 AM, Jim Lux wrote:
> > So, maybe we should be focusing more on 60 Hz bonding and whether it
> > can take the fault current from a MV distribution line that contacts
> > your antenna.
> Hi Jim,
>
> I think most would agree that we should prevent that possibility by how
> we locate antennas.
>
> With respect to your earlier post, "short, fat" to me means the braid
> stripped from TX coax, which is roughly equivalent #10, or #12 stranded.
> Yes indeed, at the frequencies of lightning, inductance dominates. But
> the emphasis on low resistance is for bonding to minimize potential
> differences between equipment with unbalanced connections for baseband
> signals (audio, control, data) that are the result of mains power
> leakage currents. When you do this bonding, and do it well (short, fat)
> you completely eliminate the need for transformers to kill power line
> "buzz."
I agree.. if you're looking at power line, then R will be dominant over 
L and "shorter is better"


> It is a REALLY bad idea to tie each piece of gear separately to a single
> ground rod -- that creates a really big loop when that equipment has
> cables running between them. Those who advise against "daisy-chain"
> bonding are missing this.

Yes indeed.. I think the real choice is between something like "bar 
along the back" or "one big grounding lug in the middle of the back".
A star ground with 20 foot long wires from each piece of equipment to 
the antenna entrance panel would be a recipe for disaster, loop wise.

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