On 5/17/2012 11:31 AM, John wrote:
> I thought I had read that radial spacing may be more important than length
> and that radials may not have much effect past the 1/4 wave point.
I am a vertical antenna maven...
My studies tend to confirm what you have read.
As a general rule, it is better to have many, shorter,
radials... than a few longer radials... for the same
total length of wire. The ground will de-tune any
radial system, so tuning for a particular band is more
trial and error than a matter of measurement, although
elevated radials can more easily, and actually should be,
cut to frequency.
But, yes, more closely short radials is preferred over
fewer, longer yet wider spaced radials.
Although the thought of establishing (consuming the back yard) as a RF
base for a vertical antenna is
> certainly interesting.
That is not as silly as you might think...
Our friend and mentor, Rob Sherwood, wrote a
magazine article about using lawn fabric or the like to
make a ground screen for his vertical antenna - and after
talking with him a couple of years ago - I seriously contemplated
laying a huge grid of galvanized lawn fabric (the kind where
the cross members are welded and not just woven together.)
My bride was not particularly exuberant over the prospect of
laying so much metal over an existing lawn, so we laid 65
wire radials, instead. (Yes... she helped... the photo of her
digging part of the trench to bury to coax feed line is one of
my most prized ham possessions!)
Parenthetically, I have truly appreciated the detailed
correspondence I had with several learned hams, including
Rob Sherwood, Phil Salas, AD5X, who has written loads of
articles for QST, and Rudy Severns, N6LF, who has conducted
extensive field testing and written several articles on the nature
and number of ground radials for vertical antennas, and even
Rick DJ0IP of our group. Giants of the hobby who gave me
some individual attention.
Similarly, I also appreciate the huge help Bob, K4TAX, and
Jim Brown K9YC, Jeff, N8CC, and many others from this
group too numerous to mention, have given me along the way.
That is Just My Take...
====================== K8JHR ===================
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