[TowerTalk] Fwd: Shielded shack

[Jim Lux]

On 9/28/13 11:56 AM, Roger (K8RI) on TT wrote:
> On 9/28/2013 1:27 PM, Hans Hammarquist wrote:
>> The idea is not to let any current through the aluminum foil. ALL
>> connections to the foil is in ONE point, the point there everything is
>> entering the shack. I do not believe tht the foil would protect the
>> shack from a direct lightning strike. What is the possibility that
>> will happened anyhow with a 85 foot tower next to it. OK, never say
>> never!
>
> This is where the Single Point Ground (SPG) is important and that every
> lead coming into the shack is protected. Power, if multiple circuits
> needs to follow the sane routes for their entire lengths. Use a
> relatively large, grounded, "bulkhead" through which all leads must
> pass.  Grounding and bypassing all leads is to insure the induced
> voltage from nearby strikes causes the voltage on all lines to rise at
> the same rate and to the same potential.  Your common grounding sounds
> good.

One should abolish the term single point "GROUND", because it isn't 
ground.  "common voltage reference point" would be a better term.

But the description here of everything (power, phone, data, coax) coming 
in tied to a common point is sound.  It doesn't physically have to be 
through some sort of bulkhead.  But it does need a low resistance, 
reasonably short connection.