Topband
[Top] [All Lists]

Re: Topband: Modeling "Ground" and losses

To: Richard Fry <rfry@adams.net>
Subject: Re: Topband: Modeling "Ground" and losses
From: Guy Olinger K2AV <k2av.guy@gmail.com>
Date: Wed, 25 Feb 2015 13:44:07 -0500
List-post: <topband@contesting.com">mailto:topband@contesting.com>
There is a bit of explanation and clarity in BL&E regarding standing waves
on radials that does not show up until page 781 and figure 42. ** Emphasis
added.

"The current in the buried wires **for an antenna height of 88 degrees**
and radials wires 135 feet long is shown in Fig. 42. We see that the
current persists in 113 wires much further from the antenna than it does
for a smaller number of wires Fig. 43 whows similar results for the same
ground system and a **22-degree antenna.** "

Figure 42 clearly shows standing waves for 113 radials, the hint of
standing waves for 60 and 30 radials, while figure 43 shows only the
slightest hint of that. Height of the antenna is clearly involved in the
production of standing waves.

We also must remember these tests were done at 3 MHz, with an assumption
that there were not any paradigm shifts going from the lower broadcast band
to 3 Mhz. All of us are aware these days of many differences between low BC
band and eighty meters, and indeed of differences between 160 and 80. .

For all practical purposes, BL&E was a series of tests run at 80 meters.
Extrapolate to 160 with caution.

73, Guy

On Wed, Feb 25, 2015 at 9:58 AM, Richard Fry <rfry@adams.net> wrote:

> Additional from the BL&E paper on the subject of standing waves on buried
> radial wires...
>
> Figure 11 linked below is based on the r-f currents measured along the
> radial lengths shown in Figure 7.
>
> http://s20.postimg.org/k05j5r3al/BL_E_Fig_11.jpg
>
>
> R. Fry
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
_________________
Topband Reflector Archives - http://www.contesting.com/_topband

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