Buck wrote:
On Sun, 06 Feb 2005 15:29:04 -0800, Roy Lewallen
wrote:

Nope, you didn't. My analysis was for buried, not above ground,
radials.
And the loss increases, rather than drops, as the number increases.
This
has been well known since at least 1937.

This has me confused...I must be missing something...I checked the
previous
posts, but still doesn't make sense to me...Seems the ground losses
would
decrease as the number of radials increase....Thats what your model
showed.
I thought anyway....


Thanks for the correction. As a Novice I learned that underground
radials were better than above ground radials. I couldn't be sure
which you were using so I re-iterated it to be sure.

For a given radial, above ground is better than in ground. But it has
to
be resonant. In that case, you are running a very low ground plane.
If it's just one radial, it should radiate as much as the vertical
element. In that case, it's more of a perverted dipole, than a ground
plane. A true ground plane really needs at least two radials to get a
fairly unlopsided omni pattern. Three radials are better.
If you use 120 radials on medium ground as a benchmark, any height
above
ground will reduce the number of radials required to equal the same
degree of loss. But once the radials are elevated, they must be tuned.
Radials on or in the ground do not need to be resonant.
If you ran a vertical, and can only use a very few radials, having them
tuned and a bit off the ground is better than the same in the ground.
Of course, the YL will probably want to strangle you with one, the
first
time she trips over one...But some run them around the lower frames of
houses, wood fences, etc...
One thing....It's not a magic wand to suddenly make low 4 radials a dx
buster...At 1/8 wave up, it takes appx 60 radials to equal 120 on the
ground. On 40m, thats 16 ft or so... At 2 ft off the ground, you still
probably need maybe 90? radials to equal the 120 on the ground.
So you have to consider that, when you run 4 radials at 2 ft, and don't
brown the food in every direction. It is a bit better than 4 in the
ground though, and Roy's model pretty much agreed...I think anyway...:/
MK