art wrote:
On 26 Mar, 21:49, (Richard Harrison) wrote:
Art wrote:

"Any thoughts as to why it sgould be so and the scientific facts to
support it?"

We have plumb lines and bubble levels which allow easy determination of
vertical and horizontal directions.

We often inhabit a nearly horizontal plane

If we are as likely as not to communicate with any particular direction,
an omidirectional vertical antenna makes sense. An inclined wire would
favor some direction to the detriment of another. Sure a slopimg wire
works but doesn`t reach maximum height or length as effectively as a
vertical or horizontal wire would.

Why a straight dipole and not a V-shaped element? The V-shape corrupts
the nulls at the ends of the straight wire.

Vertical and horizontal antennas are not solely accidents of history.

Best regards, Richard Harrison, KB5WZI

But the question is why?

Because except for some very specialized applications there is
nothing to be gained by using anything other than horizontal
or vertical elements and it is the simplest way to make things.

Have you ever heard of a helix?

snip crap

--
Jim Pennino

Remove .spam.sux to reply.

Jim Pennino wrote:
"Have you ever heard of a helix?"

Most would likely enjoy Kraus` story of his invention of the axial-mode
helix in his 3rd edition of "Antennas". This is a choice book!

Best regards, Richard Harrison, KB5WZI

On 27 Mar, 10:20, (Richard Harrison) wrote:
Jim Pennino wrote:

"Have you ever heard of a helix?"

Most would likely enjoy Kraus` story of his invention of the axial-mode
helix in his 3rd edition of "Antennas". This is a choice book!

Best regards, Richard Harrison, KB5WZI

I have his second edition and I find no mention of radiation from the
beginning where current is applied onwards. Have you found anything
that can
contribute other than empirical grounds? You have avoided the question
so far

Richard Harrison wrote:
Jim Pennino wrote:
"Have you ever heard of a helix?"

Most would likely enjoy Kraus` story of his invention of the axial-mode
helix in his 3rd edition of "Antennas".

' "No," he replied, "I've tried it and it doesn't work."'

Art wrote:
"---yet I am not finding any documented proof other than emperical
work."

As usual, Terman has answers. See page 882 of his 1955 opus: "Effect of
Ground on the Directional Pattern of Ungrounded Antennas - Image
Antennas."

It`s in the book; math, diagrams, tables, as needed to imagine what
happens.

Best regards, Richard Harrison, KB5WZI

On 27 Mar, 09:55, (Richard Harrison) wrote:
Art wrote:

"---yet I am not finding any documented proof other than emperical
work."

As usual, Terman has answers. See page 882 of his 1955 opus: "Effect of
Ground on the Directional Pattern of Ungrounded Antennas - Image
Antennas."

It`s in the book; math, diagrams, tables, as needed to imagine what
happens.

Best regards, Richard Harrison, KB5WZI

Thank you for that I will get right on it. I presume it does give
direct relationships between electrical and magnetic vectors relative
to the conductor and ground !

On 27 Mar 2007 10:51:27 -0700, "art" wrote:

I presume it does give
direct relationships between electrical and magnetic vectors relative
to the conductor and ground !

Hi Art,

As this is all very elementary stuff, of course Terman does.

73's
Richard Clark, KB7QHC

Art wrote:
"I have his (Kraus`) second edition (Antennas) and I find no mention of
radiation from the beginning where current is applied onward."

I think I have that edition too. If you review the chapter on "Point
Sources" you`ll find: power patterns, a power theorem and its
application to isotropic sources, rediation intensity, source with
hemispheric power pattern, unidirectional cosine power pattern, etc.,
etc..

The new, now available 3rd ed. of "Antennas" by Kraus, Marhefka, and a
host of others is greatly expanded and improved. It is worth the
investment.

Being uncertain of what Art really wants, doesn`t stop me from advising
him to start by having a look at the famous Sommerfeld formula on page
804 of Terman`s 1955 opus.
It predicts 1 kilowatt will produce 186 mv per m at a distance of 1 mile
from a short vertical transmitting antenna given a certain ground
conductivity and other conditions.

Best regards, Richard Harrison, KB5WZI

On 27 Mar, 09:55, (Richard Harrison) wrote:
Art wrote:

"---yet I am not finding any documented proof other than emperical
work."

As usual, Terman has answers. See page 882 of his 1955 opus: "Effect of
Ground on the Directional Pattern of Ungrounded Antennas - Image
Antennas."

It`s in the book; math, diagrams, tables, as needed to imagine what
happens.

Best regards, Richard Harrison, KB5WZI

Richard, look up Google and look for NEC-LIST A guy has tipped a
dipole to get rid of horizontal polarization using NEC-2 and is asking
the true experts around the world for comments. We shall now see which
of us is correct regarding tipping. I don't think anybody else on this
net will understand either way except yourself.
Regards
Art

On 26 Mar, 21:49, (Richard Harrison) wrote:
Art wrote:

"Any thoughts as to why it sgould be so and the scientific facts to
support it?"

We have plumb lines and bubble levels which allow easy determination of
vertical and horizontal directions.

We often inhabit a nearly horizontal plane

If we are as likely as not to communicate with any particular direction,
an omidirectional vertical antenna makes sense. An inclined wire would
favor some direction to the detriment of another. Sure a slopimg wire
works but doesn`t reach maximum height or length as effectively as a
vertical or horizontal wire would.

Why a straight dipole and not a V-shaped element? The V-shape corrupts
the nulls at the ends of the straight wire.

Vertical and horizontal antennas are not solely accidents of history.

Best regards, Richard Harrison, KB5WZI

Richard,
It is well known that near maximum "overall" polarity gain can be
obtained by placing a vertical at right angles with respect to earth.
Now -a -days maximum gain is required of a certain polarity which
requires a specific accuracy of less than 1 degree . So yes, in your
working years straight up is good enough but these days of WiFi and
all that concentration is applied for purity of polarity which
requires a resonance at around 3 degrees to the vertical. This can be
determined arithematically according to known laws. Ofcourse as one
moves higher this offset angle changes. This same phenomina or tilt
angle applies for all polarities where maximum gain is required for
purity of polarization.The days have gone where just putting up a wire
satisfies all.
Regards
Art