[TowerTalk] ground and conductivity

[Tom Rauch]

> I was under the impression that soil conductivity mattered
a great
> deal when using vertical polarization. With respect to
horizontal
> polarization, however, I would agree that it doesn't
matter all that
> much.

If you are working groundwave, it matters a great deal. That
because the very long path accumulates attenuation as the
signal follows the lossy media over a very large distance.
Any small change eventually produces a large change when the
groundwave path is long.

The fact is a change from 5 to 20 mS/m isn't going to make
or break any vertical system for skywave performance. Now a
change from typical soil to saltwater (near 5000mS/m) can be
large, maybe 3 - 5 dB, at very low sky wave angles. At
higher angles it means much less.

IMO people worry way to much about things like soil. If we
were working groundwave like AM BC stations it would be
another story.

People will give up 5-6dB of antenna efficiency by using
four elevated radials while deluding themselves into
thinking they have a good ground, and in the next breath
worry about giving up less than one dB at 15 degrees because
of soil.

73 Tom