My 5BTV is like the Bumble Bee that defies 100 years of aviation theory that
says it can't fly.
Of course a pair of 3–500ZGs can help with that. It was an old recommendation
from Wayne Green.
Best regards - Brian Carling
AF4K Crystals Co.
117 Sterling Pine St.
Sanford, FL 32773
Tel: +USA 321-262-5471
> On Jan 19, 2015, at 5:28 PM, <ve4xt@mymts.net> <ve4xt@mymts.net> wrote:
>
> There are any number of reasons why an antenna system might trick you into
> thinking it's defying 100 years of antenna engineering.
>
> Common-mode currents, unintended interactions, etc. Plus, you didn't mention
> what vertical it was: if it's a vertical dipole or a end-fed half-wave design
> (F12, Cushcraft R-series of verticals, etc.), it's very likely you'd see
> little benefit from the addition of two — I assume you meant — radials.
>
> If it's a traditional 1/4-wave monopole (5BTV, DX-88, HF-9V, etc.), then
> likely what's happening is stuff in your home and yard is behaving like
> radials behind your back.
>
> Which is not to say you can't or shouldn't accept a very well-working system
> when you happen upon one. Lots of people have great success with
> half-slopers, even though it's not the greatest of antenna designs.
>
> Finally, it's very likely that even with no interactions or common-mode
> currents, two radials will have very little impact.
>
> 73, kelly
> ve4xt
>
> > From: bcarling@cfl.rr.com
> > Date: Mon, 19 Jan 2015 16:54:04 -0500
> > To: jimlux@earthlink.net
> > CC: towertalk@contesting.com
> > Subject: Re: [TowerTalk] w7ekb & ground rods
> >
> > 910 micro Henry sounds like a very useful loading coil to me!! I have had
> > no difficulty using a ground rod as a counterpoise to my vertical. In fact
> > it's done extremely well. I added two radios because the experts said it
> > would make it work better. It didn't.
> >
> > Best regards - Brian Carling
> > AF4K Crystals Co.
> > 117 Sterling Pine St.
> > Sanford, FL 32773
> >
> > Tel: +USA 321-262-5471
> >
> >
> >
> >
> > > On Jan 19, 2015, at 12:15 PM, Jim Lux <jimlux@earthlink.net> wrote:
> > >
> > >> On 1/19/15 8:45 AM, Ken wrote:
> > >> It seems to me that the ground above my rock layer (@ 36-40”) gets
> > >> really dry during the summer. Does that dry dirt have enough
> > >> conductivity to be useful? I do not know the answer to that question.
> > >>
> > >> Are there different answers depending on why we have the ground rod? (RF
> > >> ground, power line ground, or lightning protection)
> > >
> > > Yes..
> > >
> > > ground rods make terrible RF grounds, in general (where RF is HF and up):
> > > skin effect means that wires and rods have high ac resistance. (skin
> > > depth in copper at 10 MHz is about 0.8 mils/0.02 mm.)
> > >
> > > They also have significant series L (1 microhenry/meter for a wire.. so a
> > > 30 foot run to the rod is a 10 uH inductor, that's 600 ohms reactive
> > > impedance.
> > >
> > > Rods are really for electrical safety ground and/or lightning ground. And
> > > they don't work all that well for that, unless deployed in large numbers.
> > > The advantage of a rod is that it's easy to install by driving, but as an
> > > electrical connection to the earth, it's just not that wonderful: the
> > > surface area is quite small (8 foot rod, 1" in diameter is only 300
> > > square inches. You could probably do better, electrically, by burying a 1
> > > foot square plate (288 square inches).
> > >
> > >
> > > Rods are also used in phone and power line applications.. you drive a rod
> > > at every pole (or wrap the ground wire around the foot of the pole when
> > > planting it). Even if any one rod has crummy characteristics, there's
> > > lots of other rods in the circuit to help establish the common voltage
> > > reference and provide a fault current return. I've had telco installers
> > > drive a new rod next to the existing rods on the general principle that
> > > at least they knew the new rod was in good condition: faster to just do a
> > > new rod than to test the existing one.
> > >
> > >
> > >
> > > _______________________________________________
> > >
> > >
> > >
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> >
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