On Sep 26, 3:46?pm, "Howard Lester" wrote:
"AF6AY" wrote

Lots of good stuff snipped....

Now ANY impedance-matching tuner will let one load up just
about anything. All that serves is to transfer the most RF power
into a load. What is NOT known is WHERE all that RF is going.
Unless some ham has a balloon-borne sensor and data transfer
gizmo, NOBODY can know just where the pattern is going to be.
Big trees WILL affect the pattern, especially changing it between
dry and wet climate times and between different kinds of trees.
So will structures and assorted conductive things (aluminum
patio covers, small garden sheds, power, phone, and TV cables)
all within the near-field (within five or so wavelengths). Even
some houses which have had aluminum siding added on
compared to similar houses with just wood or stucco or brick
siding.
Everyone's residential location varies greatly and only a very
few are "perfect" (as to the antenna analyzer programs). One
can load up practically anything with a tuner but only the shape
and arrangement of conductive elements is going to determine
where most of the RF goes to (or comes from). No tuner can
help that.

I had to leave the important stuff... sorry to make everyone scroll down....
Len, I'm confused as to just what you're specifically referring to. Do you
mean a doublet fed with balanced line (300 or 450 ohm window line) to a
transmatch in the shack is something you don't recommend? Or are you
referring to this system fed with coax to an autotuner? It'd seem to me
that, as long as the system (fed with window line to keep the serious losses
down to negligible) is in the clear, the transmission line is 90 degrees to
the doublet for the "required" distance... all should be fine and the
radiation pattern should emanate properly from the antenna itself, not so
much the transmission line. ?

I'm trying to point out that any good tuner can "load up" to
ANYTHING...i.e., transfer RF power out of the transmitter
and into whatever the "load" is. If the "load" is just a
transmission line, a very lonnnnng one, the tuner will "load
up" on that. If the "load" is your favorite antenna type, it
will "load up" on that.

Once the RF power has been transferred into this load,
then it is up to the conductors in the "load" to radiate it
into whichever direction you expect it will go. But, do NOT
expect ANY antenna to behave properly (for radiation) if
its near field is impugned by nearby dielectric material
or conductors.

Mostly I was making a comment on "loading up" phrases
which I consider an incomplete description of what is
really happening. A tuner, any tuner, will do the job of
transferring RF into the "load." That isn't the whole story.
Next is what the "load" does with it to create the EM
wavefront. No tuner can help that.

If you are satisfied with your particular method of getting
RF out of the transmitter and into some antenna, fine.
Satisfaction is all part of the game. Such satisfaction is
not the example to set for all. It seems to me that every-
one's location is different and each presents a unique
problem to solve for the more-optimum EM wavefront
launch direction in that location.

Anyone who says that one kind of antenna is the "best"
or one should "always" use a certain kind of balanced
transmission line isn't looking at the whole picture. They
are probably describing just the only (or a few) antenna
installations they used. Yes, some antennas "work
better" than others. In a particular location.

For someone just starting out, I would suggest just a
vertical for HF. It is the least obtrusive to neighbors (can
be described as a "flagpole") and most will perform
adequately (to launch an EM wavefront) with a few radials
for the "ground." No, it won't win awards or work DX
"better" than Brand Y using Brand T transmission line,
but it WILL radiate adquately...and that's the whole name
of the game, ain't it? :-)

73, Len AF6AY