TopBand: Elevated Radials

[Tom Rauch]

> Date:          Wed, 18 Mar 1998 17:15:57 -0500
> From:          Paul Christensen <paulc@mediaone.net>

Hi Paul,
 
> >Higher frequencies were never a part of this discussion.  Let us please
> >ALL contain our selves to 160M...not BCB...Not "other  frequencies".
> 
> Excellent point Carl.  The discussion and testing should be limited to only
> the 160M band.  Modeling on MW broadcast, 80M or 10 M as someone else
> suggested last week, may yield completely different results from 160M due to
> earth effects.

The difference in soil behavior between 1.6 and 2 MHz is 
immeasurable.  The famous RCA report was done at 3 MHz, and it's 
results have been found flawless when dealing with 550 kHz and lower.

Now it the test was on 50 MHz, I'd agree. It would be invalid on 1.8 
MHz.

> Also, it seems to me that radiation of the entire vertical profile should be
> considered as well.  For instance, If one takes FS measurements at 1km and
> the results favor the 60+ ground mounted radial antenna, does that
> necessarily mean that an elevated-radial radiator with a 5-degree launch
> angle is inferior, even though its main lobe may in fact produce greater
> field intensity at 5 degrees than the 60+ radial radiator at 0 degrees?  

That's been gone over a lot, but I'll repeat it. The FS at one point 
is directly related to the size of the overall pattern (efficiency). 
The only way to change wave angle is by changing the ground several 
wavelengths away from the antenna or if the ground is actually 
radiating like an antenna.

73, Tom W8JI
w8ji.tom@MCIONE.com

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