[Elecraft] ?OT? Grounding/Protection question...

[k4wtf@enterzone.net]

On Fri, 23 May 2003, Vic Rosenthal wrote:

> Stuart Rohre wrote:
> > John, your set up for protection sounds pretty good, but 16 feet between

> Lightning grounds are an entirely different animal than RF grounds.  A 
> ground rod or group thereof is a very poor RF ground, although 
> functional for lightning protection purposes.  Depending on the type of 
> antenna, no additional RF ground may be required (dipoles or beams with 
> baluns, for example).  Vertical monopoles, of course, do require RF 
> ground systems.

Unless I'm somehow mistaken, the lightning grounds and RF grounds should
be tied together anyway so, it is all one system.  Some designing a
"Lightning Only" ground system may not have a "Star" or "Multiple
Star" type system that you may see from someone with a couple of ground
mounted verticals but, in both events, the "ground system" is going to be
used to shed energy from a strike.

If I ever get a tower (not for a while, I'm sure, unless the Tower Fairy
visits my QTH), I'll attach a run from the existing ground bus out to the
base of the vertical and then create a "star" of ground radials from the
end of that run.  I'll still put ground rods every 16ft though since from
what I understand, the additional ground rods won't make the RF ground
radials perform any worse (or any better?) but, they will certainly give
the lightning ground system a serious boost in the load shed capacity
area.

> 
> It is possible to make a combined RF/lightning ground (e.g., you could 
> make several of the buried radials for your vertical out of no. 4 copper 
> and string some ground rods along those radials) but in general the 
> structures are different.  Even in this special case, the ground rods 

OK.  Now I'm getting the picture.  I suppose that most "RF grounds" that
people lay to run verticals against aren't constructed out of #4 solid
bare copper.  That explains why they don't do too good when it comes to
shedding a lightning load.

Does anyone know if my "double protection" (polyphaser at the "dog
house" and also at the SPG panel) will double my load shedding
capacity?  I'm not certain.  I don't think that it can hurt anything
though and unless someone tells me it will, it is going to be a bit of a
"security blanket" for me.

73, John - K4WTF