[Elecraft] Grounding question on remote tuner

[Don Wilhelm]

Randy,

The RF does not need a ground other than the obvious connection to your 
radial connection point.

I would dispense with the "unun" and connect the antenna wire and radial 
connection point directly to your tuner.  A few feet of wire from your 
tuner to those points will not make a big difference since your antenna 
is not resonant.

The only reason I can think of to connect your tuner to "station ground" 
is for lightning protection.  While that is a consideration not to be 
taken lightly, be aware that *all* ground rods must be connected by 
heavy wire to the utility entrance ground rod.  That heavy wire is #6 
bare copper but #4 is preferred.  That connection is for AC mains 
safety, not for lightning protection or anything having to do with RF.

The concept for lightning protection is to spread as much of the charge 
as possible over as large an area of the earth as is possible.  Your 
radial system will help do that *if* the wires are large enough to 
withstand the surge without evaporating the copper.

73,
Don W3FPR

On 4/5/2017 2:19 PM, Randy Cook wrote:
> Weather damage repair time. I am rewiring my ~84 foot inverted L antenna system, Up a SpiderPole about 31 feet, out about 53 additional feet. Still tuning length.
> I have mounted a remote MFJ tuner on a post about 3 feet from the antenna base. Antenna wire goes down the pole, connects to 4:1 Unun input lug, then goes via coax to tuner. Out of the tuner to a long coax run to my shack. Choke at the rig end of the coax run.
> Radials mount on ground connection lug on the Unun.
> I was a bit confused with the tuner wiring. The manual says to connect ground lug to the ‘system ground’, I assume that means the radial collection point. But, isn’t the tuner already connected to the ‘system ground’ via the coax shield? Is it necessary to run another wire from the tuner ground to the radial connection ground?