On Saturday, January 25, 2014 7:41:18 PM UTC-6, Jeff Liebermann wrote:


Not everyone agrees. See item #4:

http://lists.contesting.com/_topband/2002-04/msg00010.html

He's not really giving much of a reason though. I think he's
more interested in avoiding digging slots for radials, than
he is the difference in ground loss. :/
The BC stations bury a large number for day in, day out stability.
They are required to do that by the FCC.

But as a general rule, the farther away from the lossy earth,
the lower the ground loss for a given number of equal length
1/4 wave radials. And I've read that in more than one book.
I didn't just make it up, although I have pretty much verified
it in the real world by testing. But if elevated, they should be
resonant and tuned, which is not needed with buried radials.
They are de-tuned by the ground anyway.

But I'm also one that disagrees with people who expect a low
number of elevated radials at a low height above ground in
wavelength, to have some magical property that allows them to
use say 4-8 radials just above the ground and equal a large
number on the ground. It just won't pan out very well. :+

There is no free lunch.

If you want to use four radials with good results, you need to
be at at least 1/4 wave up. Which say on 160m would be about
120 ft up. That should equal about 60 radials on the ground,
which is not bad at all. Four radials at 1/2 wave is about equal
to 120 on the ground.
But some people will run four radials at 5-10-20 feet off the ground
running on 80 or 160m, and then wonder why they are not browning the
food.

I ran a full size 40m GP at 36 ft, which is about 1/4 wave up.
Used four radials. It totally smoked the same 32 ft whip ground
mounted with 32 radials. But lower the mast and radials down to
15 ft, and the performance dropped off greatly.