[Elecraft] Update on my progress - Now General RF Issue

[Don Wilhelm]

Don,

Your "green wire mistake" was not a mistake at all.  Everything in the 
shack should have its chassis bonded together - by a connection to a 
"single point ground" - that includes computers, power supplies, and 
yes, the chassis of your 12 volt equipment too.  That "single point 
ground" should be bonded to the green wire ground too.

If you have a heavy wire to an earth driven ground rod from that single 
point ground, all the better, BUT that driven ground rod must be also 
connected to the Utility Entrance Ground - preferably by a wire outside 
the house.  See the Safety chapter in a 2010 or newer ARRL Handbook for 
more information.

You should not rely entirely on the internal "green wire" at your shack 
receptacles - it wanders about in your house wiring, and the only 
requirement for AC safety is that it be all connected together - and it 
sometimes fails.  An annual check with one of the inexpensive testers is 
a good thing.

You are quite correct that the above grounding schemes are for safety 
ground and for protection from surges from nearby lightning.  To survive 
a direct strike, something much more extensive is required.
Those grounds are in no way an RF ground point and are not intended to 
be.  Other means will be required to establish an RF ground (actually a 
low impedance point for RF).

One way to establish that low impedance point for RF in a 2nd floor 
environment with 1/4 wave wires for all bands that you intend to 
operate, and it may be the only practical way if you cannot keep common 
mode RF off your antenna feedlines.

73,
Don W3FPR

On 10/23/2011 9:13 AM, goldtr8 at charter.net wrote:
> First I had made a significant error in the basic grounding of my shack.
> This error I will call the green wire mistake.  What I had done was add
> the chassis ground of all my 12v devices  and tuner to the green wire
> ground of the house electrical system.  This is in fact a signficant
> error and has been corrected.  What I have learned that there is a
> difference for a saftey ground for lightening protection and so on and
> it has nothing to do with an RF ground.  So green wire error fixed, long
> term a total revamp of the system for a safety ground.
>
>