One pony needs to get into one drag radio car and drive around the ocean
front, over the bridges, back over the land and watch the S-meter and
listen to the bands. Observant would see 10 - 20 dB difference in signal
levels in "lousy" mobile, especially on low angle propagation.
Examples: Driving around Sydney, NS and listening to Disney 1670 AM in
NJ - no signals over land, full quieting solid signal while driving on
bridge over salt water.
While contesting as N2EE from Cape Hatteras, NC on 10m in contest, was
told by ZS6EZ to be the first NA he heard, with vertical on the beach.
Results of "Team Vertical" speak for themselves.
Some of us do know. The reverse beacons testing can verify or legitimize
modeling program's "calculated guessing".
Yuri, K3BU.us
On Sun, Aug 10, 2014 at 11:02 PM, Tom W8JI wrote:
> My point is if no one else is on, we really don't how other signals
would be. It's like a drag race with just one car, or a pony show with
one horse.
----- Original Message ----- From: "Hardy Landskov" To: "Tom W8JI" ;
"TopBand List" Sent: Sunday, August 10, 2014 9:08 PM
Subject: Re: Topband: Modeling the proverbial "vertical on a beach"
Tom,
I was totallly not expecting any station from that direction, just
thought I'd work a few locals with high incident angles before Sunset
here. Then I heard the 6Y2 guys and it was amazing. He was the only
station--no KV4FZ, NP4A, etc and certainly no EU at our time. Made me
a believer in beach verticals.
73 N7RT
----- Original Message ----- From: "Tom W8JI" To: "TopBand List"
Sent: Sunday, August 10, 2014 5:20 PM
Subject: Re: Topband: Modeling the proverbial "vertical on a beach"
How was his signal compared to someone from a similar heading and
distance at the same time who was not on the beach?
----- Original Message ----- From: "Hardy Landskov" To: "Guy Olinger
K2AV" ; "Richard Fry"
Cc: "TopBand List" Sent: Sunday, August 10, 2014 7:35 PM
Subject: Re: Topband: Modeling the proverbial "vertical on a beach"
Just an observation to all:
When Tom, N6BT went to Jaimaca and operated 6Y2J (I think was the
call) with verticals on the beach I was blown away. I heard them 2
hours before Sunset here on 160....nuff said. The proof is in the
pudding.
73 N7RT
----- Original Message ----- From: "Guy Olinger K2AV" To: "Richard
Fry" Cc: "TopBand List" Sent: Saturday, August 09, 2014 8:35 PM
Subject: Re: Topband: Modeling the proverbial "vertical on a beach"
Just to mention that the prior opinion is controversial and not
universally
agreed upon. Nor to date has anyone surfaced with actual
measurements made
at the distances (25 to 50 km) and with span of altitudes (0 to 10
km) to
either prove or disprove either side.
It remains unproven modelling from NEC at those distances either
way. This
situation may, alas, persist this way, because the precise subject
resolution appears to be without benefit to any commercial
interest and
therefore without funds to pay for some pretty expensive
experimenting
involving precision measurements from aircraft.
Additionally, there is considerable suspicion that moving from LF
to MF in
this general subject involves a ground modal change of some sort
that would
render 50x10 km measurments at 0.5 or 1 MHz unlike those at 2 MHz,
rendering commercial measurements at low and possibly high BC of
no value
for extrapolation to ham use.
Arguments on both sides remain basically intuitive. I have
"reasonable"
arguments to BOTH concur with Richard AND to not. NEC near field
calculations over sea water at 50 km follow Richard's assertions,
and the
same over "average" ground does not. The model clearly thinks that
50 km
over most types of ground slowly dissipates low angles resulting
in the
controversial "notch" in low angle elevation patterns.
So NEC based modelling cannot be used as a proof text to decide an
argument
NEC has with itself.
73, Guy K2AV.
On Sat, Aug 9, 2014 at 7:23 PM, Richard Fry wrote:
Just to note that the low-angle radiation produced by monopoles
is not
accurately shown by a NEC model/study that does not include the
surface
wave, regardless of whether one or two ground-plane media are
specified in
the model.
Below is a link to a NEC study of the low-angle fields of a
monopole
__including the surface wave__ for three values of earth
conductivity
ranging from extremely good to very poor.
The curves there all show maximum relative field in the
horizontal plane.
If the surface wave had not been included in these studies then
all of
those fields would have a zero value in the horizontal plane, and
reduced
fields at low angles just above the horizontal plane.
Reality is that radiation leaving the monopole at elevation
angles of at
least 5 degrees decays at a 1/r rate. Therefore that radiation
is a space
wave which propagates in a ~ straight line to reach the
ionosphere, where
(with suitable conditions) it can return to the earth as a
skywave.
NEC analyses of a vertical monopole of 5/8-lambda and less, and
not
including the fields of the NEC surface wave do not recognize the
radiation
sector capable of producing the greatest single-hop skywave
service range
that can be provided by that monopole.
http://s20.postimg.org/9xqgzu9d9/Monopole_Low_Angle_Radiation.jpg
R. Fry
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