Re: Topband: EZNEC Ground Errors

[Grant Saviers <grants2@pacbell.net>]

For a literal "pair of radio wave glasses":

Given the vertical gain of a practical 160 dipole is pretty much cloud 
burner and a decent 160 vertical is pretty much low angle, IF you know 
the actual real gain patterns, then it is possible to compare signal 
amplitudes (probably real time considering QSB) and deduce approximate 
arrival angles.
At least one analysis of 80m arrival angles on the West Coast from EU 
was derived this way.
Grant KZ1W

On 12/11/2020 06:38, Artek Manuals wrote:
> OR
>
> The propagation mode on 160 is not what we have popularly come to "Accept".
>
> There is a growing body of evidence that particularly at gray line that 
> signals often arrive at a higher angles. This is often attributed to 
> "ducting" . Maybe a lot more of 160 intercontinental propagation is  due 
> ducting rather than the more commonly thought of low angle earth to F 
> layer hop/multi-hop stuff seen at higher frequencies?
> Where do i get a pair of those glasses that lets me look at radio waves 
> so I actually see them arrive
> Dave
> NR1DX
>
> On 12/11/2020 8:58 AM, Roger Kennedy wrote:
> > Guy I have ALWAYS thought that the various Computer-based modelling of
> > Ground and its effect on Antennas is WAY off . . .
> >
> > And surely the errors are MOST significant on 160m, not just because
> > Antennas are near the ground (in wavelength terms) . . . but also because
> > even the ground 130 ft deep is still going to have an effect . . . and 
> > there
> > is no way EZNEC can possibly take that into account, even if you KNEW 
> > what
> > was underneath your topsoil !
> >
> > In my particular case it's not the effect on Verticals on 160m that 
> > interest
> > me . . . it's the effect on a Low Dipole.
> >
> > Any DX stations I work on 160m will confirm I put out a pretty 
> > respectable
> > signal . . . my signal reports around the world and more recently I am 
> > able
> > to compare my RBN Reports across NA and they tend to be very similar 
> > to the
> > other British DXers.
> >
> > However, most people are surprised to discover that for the last 50 
> > years I
> > have always used a Horizontal Half Wave dipole on 160m, at around 50ft.
> >
> > BUT I believe that EZNEC plots showing that most of the RF is just 
> > very High
> > Angle is WRONG . . . that's because in practice the Ground underneath 
> > it is
> > rubbish . . . so the Dipole's effective height above Ground is much 
> > higher.
> > And in fact, it seems that most people who have Dipoles on 160m 
> > mounted over
> > or near a very comprehensive Radial system DO get poor results using them
> > for DX . . . but that goes to confirm my theory (which is all based on my
> > actual experience on Top Band)
> >
> > Roger G3YRO
> >
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