On 6/28/2023 8:37 AM, Radio KH6O wrote:
Because theory and actual practice don't always agree.
Those who believe that don't know enough about one or other. That is,
real world problems are far more complex than simplified examples for
which formulas have been developed, and whose behaviors have been
studied. All antennas exist within their surroundings, they have
feedlines attached. All of these variables are part of the science of
how antennas work, and are clearly understood.
I spent much of a summer 10 years ago studying the interaction of my
160M antennas with towers, and setting up conditions so that I could
make use of their directivity. Before that, I observed and studied their
interaction with the coax feedlines of high dipoles (at 125 ft), which I
eliminated by adding common mode chokes both at the antenna and at a
second point along the line to act as an "egg insulator" would break up
guy wires (another example of taking all the variables into account).
> (Also, you left out Jasik and Kraus.)
There are multiple fine texts on antennas. My focus was on those written
for and widely available to hams.
73, Jim K9YC
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