Topband
[Top] [All Lists]

Re: Topband: Monopole Elev Pattern w.r.t. Earth Conductivity

To: Tom W8JI <w8ji@w8ji.com>
Subject: Re: Topband: Monopole Elev Pattern w.r.t. Earth Conductivity
From: Mike Armstrong <armstrmj@aol.com>
Date: Wed, 24 Oct 2012 20:08:19 -0700
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Dang Tom..... I just sent out a more wordy version of what you just said.  This 
is getting strange.  Not sure why it hasn't been disseminated yet (my email), 
but I swear I sent it just moments before  your email hit my system. 

You just added some fuel to my fire.  Short version: I, with my rather 
inexperienced eye (160 experience, that is) is seeing a pattern that seems to 
indicate what we would call low radiation angles aren't really optimum for long 
range 160 communications.  The other email goes into a little more detail in 
why I am thinking this way.  Morning enhancement, especially with high angle 
radiators (like mine) where I am working Japan and Chile on a radiator that can 
very truthfully be called an NVIS antenna.  On higher frequencies, a scaled 
version of my antenna wouldn't radiate a signal out of the southwest region, 
much less thousands of miles distant.

Just a thought!  Again, my other email expounds a little more, but this was the 
conclusion in a nutshell.  Maybe "low horizontal" antennas really ARE better on 
160 than they should be..... Given our experience with low antennas on the 
higher bands, it seems counter-intuitive..... But there it is.

Mike AB7ZU

Kuhi no ka lima, hele no ka maka

On Oct 24, 2012, at 17:12, "Tom W8JI" <w8ji@w8ji.com> wrote:

>> If we knew those, then we could calculate the location and distance of the
>> signal hops. That might give us some insight as to why some people have
>> found a taller monopole to be worse than a shorter one at a given distance.
> 
> Back in the 70's or 80's there was speculation a low angle was lossy from 
> grazing along, based on others having poor experiences with taller verticals. 
> The top of my tall tower had some antennas and side arms which top loaded it 
> a bit, but not much. Certainly the wave refracts gradually at a minimum, and 
> so I think distance would not tell anyone much. There have been a host of 
> theories since the 1960's, even some from Stew the real W1BB. :-)
> 
> I don't know what happens when it gets up in the soup, although people like 
> K9LA should be pretty well versed on it. I only know things behave 
> differently all the time, and what antenna generally works most of the time.
> 
> For example, at sunrise most of the time almost anything reasonably efficient 
> works about the same here. It's more a matter of ERP at any not-too-low angle 
> and any polarization.
> 
> 73 Tom 
> _______________________________________________
> Topband reflector - topband@contesting.com
_______________________________________________
Topband reflector - topband@contesting.com

<Prev in Thread] Current Thread [Next in Thread>