Topband: Radials, EZNEC and far field

[n0tt1 at juno.com]

>Having walked around on the beach with a battery K2 listening to
incoming
signals on a short antenna, walking 50 feet from the water drops signals
multiple S units."

Perhaps the handheld radio has a better ground connection, capacity
coupled
or not, through you and into the salt water + sand at the beach.  Then,
walking away from the beach
that connection is greatly diminished.

73,
Charlie, N0TT

On Tue, 20 Dec 2022 08:58:23 -0500 Guy Olinger K2AV <k2av.guy at gmail.com>
writes:
> Having walked around on the beach with a battery K2 listening to 
> incoming
> signals on a short antenna, walking 50 feet from the water drops 
> signals
> multiple S units. Over the beach there is an absorption zone 
> starting at
> the sand at water’s edge which goes higher and higher the farther 
> from the
> water. This isn’t EZNEC, just observation on Core Banks, NC during 
> a number
> of IOTA contests. Very easy with all those signals to hear what was 
> going
> on.
> 
> On 40m there was a big difference between a doublet at 40’ and 
> 50’, back
> from the beach about 200’.
> 
> Apparently sand wetted with salt water is quite lossy.
> 
> But even not optimal at the beach smacks the snot out inland 
> locations.
> Which IMHO explains the wide variety of beach-based reports.
> 
> Also a very short vertical radiator away from water’s edge will 
> not hear as
> much as a tall one as the tall wire has more intercept outside the
> absorption zone next to the sand.
> 
> It’s really quite a complex subject.
> 
> 73, Guy K2AV
> 
> On Tue, Dec 20, 2022 at 7:28 AM <n4is at comcast.net> wrote:
> 
> > Hi Frank
> >
> > You wrote " .  A vertical over a salt marsh or within about a 
> wavelength of
> > salt water will produce
> > 6 dB or more of gain at low angles compared to a vertical with 
> poorly
> > conducting soil in its reflection zone
> > "
> >
> > The assumption that "next to the water" is the same as "in the 
> water" , is
> > a
> > not right.  It is not the same !
> >
> > I listen to George signal with vertical "in the water " and the 10 
> db
> > difference in signal is real.  Moving the antenna on the beach and 
> you lose
> > 10 db or even more on practice, not on paper.
> >
> > I see that on my S  meter more than a dozen times.
> >
> > George has a vertical on his house in Miami, the ground plane is 
> just a
> > plate down the water. The vertical is made with fiberglass pole 
> 18m high.
> > My
> > antenna is a full size vertical with a good radial system over the
> > Everglade
> > land, if I dig 2 Ft I have water from the Everglade underground 
> river.
> >
> > George can run a pile up from Europe with 10W, I can keep up with 
> him
> > running legal limit power. We are talking about 160m only.
> >
> > 73's
> > JC
> > N4IS
> >
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