And all the arm waving aside the important graph in N6LF's paper is the
one on page 12 which to to the original posters conundrum about what to
do with his small yard one can conclude the following:
1) That for 80M,� for radials 8 feet high,� from� .1 wavelength to .3
wavelength in length there is less than .5db difference in the "overall
gain"� from 2 radials up to 16 radials when dealing with "Average Soil"
(.005/13) .
What this DOES NOT speak to is
1) What happens with different soil types , my soil here in Florida ( as
measured using N6LF's "OWL probe" approach) is typically .001/7 to
.002/12 depending on a recent rains and changes back and forth quite
quickly.
2) What happens on 160M? If you read N6LF considerable body of work over
the years he will be the first to tell you that conductivity and Er of
soil can vary considerably with frequency depending on a number of
factors. For my extremely poor sandy soil here in Florida there is not (
as measured) much difference between 160 and 80, for the original
poster's soils this may not be the case ( one size DOES NOT fit all)
3) The graph is for AVERAGE GAIN if chasing DX is your thing you might
want to look more specifically at simulations that arrival angles on
10-15 degrees on 80M and 20 degrees on 160M. This of course ignores some
of the semi unexplained phenomena of very high angle arrival� of signals
at gray line.� I worked a G station the other day on 80 ..... 2 hours
after his sunrise... he was using a low Inverted-V (~40feet)� .. He was
the ONLY EU I heard on the band.
4) As I think it was K9AY (?... my apology if I miss remembered your
call) pointed out a few weeks ago that for verticals and especially
inverted L's that one needs to be considering the the VERTICAL portion
of the gain NOT the AVERAGE!
5) Most of N6LF's graphs as I understand it were the product of NEC
simulations which depending on many factors may not represent ones
actual environment ( trees, houses with wiring in them, nearby power
lines, etc etc etc).
The bottom line in the real world ..... put it up and try it ...if that
doesn't work put something else up and try that ...that IMO is where the
real fun still lies in amateur radio
And the list goes on
Dave
NR1DX
On 3/15/2021 5:55 PM, Joe Subich, W4TV wrote:
> N4ZR wrote:
This is the second allusion to 1/8 wave elevated radials that I've
read, but I've been unable to find anything further, in the usual
sources. Any leads?
Google found N6LF's work on elevated ground systems:
<https://rudys.typepad.com/files/elevated-ground-systems-article-final-version.pdf>
Rudy's bibliography includes:
Dick Weber, K5IU, �Optimum Elevated Radial Vertical Antennas,�
Communication Quarterly, Spring 1997, pp 9 - 27
73,
�� ... Joe, W4TV
On 2021-03-15 5:42 PM, john@kk9a.com wrote:
I had the same small lot ground radial issue at my Aruba home but it
still
somewhat worked. Another option might be the K2AV single wire folded
counterpoise.
N4ZR wrote:
This is the second allusion to 1/8 wave elevated radials that I've read,
but I've been unable to find anything further, in the usual sources.
Any leads?� I have an inverted L, but really don't have room for 1/4
wave elevated radials and am told that my 8 x 70 foot radials on the
ground really aren't worth much.
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