A TALE OF TWO OLD WIVES

There are two cantankerous old wives:

One old wife asserts it is obvious radiation occurs mainly from the middle
portion of a dipole because that's where the current is strongest and the
magnetic field is most concentrated.

The other old wife asserts it is obvious radiation occurs mainly from the
ends of a dipole because that's where the highest voltages occur and the
electric field is most intense.

Since the pair of arguments are logically identical in form they are of
equal validity. But because it is impossible to reconcile the two women ....
they cannot BOTH be right .... only one conclusion can be drawn ...

.... both arguments are false!

The old wives are telling tales. Citizens - drag 'em off to that old English
custom - the ducking stool.

On Sat, 6 Mar 2004 18:45:48 +0000 (UTC), "Reg Edwards"
wrote:

A TALE OF TWO OLD WIVES

There are two cantankerous old wives:

One old wife asserts it is obvious radiation occurs mainly from the middle
portion of a dipole because that's where the current is strongest and the
magnetic field is most concentrated.

The other old wife asserts it is obvious radiation occurs mainly from the
ends of a dipole because that's where the highest voltages occur and the
electric field is most intense.

Then there is our THIRD OLD WIFE who sitting at her kitchen table
looking out the window at the first two, takes notes of their
argument, sets them aside and returns to measuring mud's recuperative
powers and bottling it as a nostrum at the next fair.

What is the Q of her mud?

When the early English author, Samuel Richardson, wrote his ground
breaking novel "Pamela, or Virtue Rewarded" it was met immediately by
Henry Fielding's sardonic "Shamela." Fielding was responding to the
arrogance of the subtitles in that first work: "Aggressive Chastity"
and "Provocative Prudence"; dare I point out the parallels (non
resonant) that attract me to these current ironies?

73's,
Richard Clark, KB7QHC

p.s. for those who take umbrage at favourable quotation of eminent
British authors (oddly enough, Brits), please note this missive has
been sprinkled with on-topic references of: ground[breaking],
Field[ing], parallel[s], resonant, current and one technical enquiry
for Q that will no doubt be ignored in favor of off-topic
condemnations of these sources. ;-)

Richard Clark wrote:
"What is the Q of her mud?"

First, the Q of mud is likely less useful than antenna Q. That is, not
worth much.

Second, Q depends on mud consistency, temperature, location, and
frequency of interest.

The earth behaves like a lossy capacitor. Above 10 MHz, the capacitnce
in ordinary soil bypasses the resistance of the soil. Below 10 MHz,
conductance of the soil shunts the capacitance making soil capacitance
(permittivity) less important.

Soil as a lossy dielectric has a dielectric constant which is defined
as the capacitance with dielectric material filling the void versus the
capacitance without the dielectric material.

Thickness of a mud layer is relevant. At medium wave and lower
frequencies, where the earth is mainly resistive, r-f renetration of the
earth, not sea water, is so deep that rain wetting has little effect on
propagation or refleection. But, at h-f, penetration of the earth is
shallow. Water and salt content are significant to penetration and loss.

An ideal capacitor is lossless. There`s no dielectric leakage nor
conductor loss resistance. Earth is not ideal.

Capacitor quality is judged by how much its current`s phase angle
deviates from 90-degrees lead of the applied voltage. This deviation
angle is called the capacitor`s "phase angle". The tangent of this angle
is called the "dissipation factor". The reciprocal of this dissipation
factor is the Q of the capacitor.

As mud is wet soil, it has Q, but not just one Q value.

Best regards, Richard Harrison, KB5WZI

and the Fourth Old wife said "its really the force exerted on a far point,
as you sum up effect of each current in each part of the antenna" as she
pulled down the laundry off of the longwire. "It is a summation of all the
little ones (she means currents), and then you get a field" says she,
walking back the the radio shack with he head just a buzzing with
electrons.(yea ... she bonkers) She was my Fields Proff too.


"Richard Harrison" wrote in message
...
Richard Clark wrote:
"What is the Q of her mud?"

First, the Q of mud is likely less useful than antenna Q. That is, not
worth much.

Second, Q depends on mud consistency, temperature, location, and
frequency of interest.

The earth behaves like a lossy capacitor. Above 10 MHz, the capacitnce
in ordinary soil bypasses the resistance of the soil. Below 10 MHz,
conductance of the soil shunts the capacitance making soil capacitance
(permittivity) less important.

Soil as a lossy dielectric has a dielectric constant which is defined
as the capacitance with dielectric material filling the void versus the
capacitance without the dielectric material.

Thickness of a mud layer is relevant. At medium wave and lower
frequencies, where the earth is mainly resistive, r-f renetration of the
earth, not sea water, is so deep that rain wetting has little effect on
propagation or refleection. But, at h-f, penetration of the earth is
shallow. Water and salt content are significant to penetration and loss.

An ideal capacitor is lossless. There`s no dielectric leakage nor
conductor loss resistance. Earth is not ideal.

Capacitor quality is judged by how much its current`s phase angle
deviates from 90-degrees lead of the applied voltage. This deviation
angle is called the capacitor`s "phase angle". The tangent of this angle
is called the "dissipation factor". The reciprocal of this dissipation
factor is the Q of the capacitor.

As mud is wet soil, it has Q, but not just one Q value.

Best regards, Richard Harrison, KB5WZI

On Sat, 6 Mar 2004 21:26:26 -0600 (CST),
(Richard Harrison) wrote:
As mud is wet soil, it has Q, but not just one Q value.

Hi Richard,

Well, as usual, Reggie asks more questions than he can field, and too
often those of the "first principles" has him gummed up in areas he so
loudly touts (how many threads does he spin on about the antenna as
transmission line only to have him turn it into a half wave inductor?)

As to the wet soil. a point well taken. If we learn anything from the
experience of the robots now traversing the Martian landscape (and
politely stepping around the issue of the european hulks littering it
nearby), measurements do indeed reveal our planet and its water
constitute a ball of mud in comparison.

Another shortfall of Reggie's mocking tones is when he demands numbers
when he tires of pontifications (I note no numbers from his holiness
of late). As such, we might rely on a book ( -gasp!- ) which serves
these purposes. I would further note that our two greatest
anti-intellectualists share a common trait confounding their heritage
- anglophobia (railing against popular British poets and writers to
clear their spleen it seems). I shan't be poetic with my recitation
however. ;-)

One of the finest books to serve as an RF reference is found with
"TV and Other Receiving Antennas,"
Arnold B. Bailey

It literally delivers its promise offered in its sub-title:
"Theory and Practice"

[do I hear teeth grinding over another American author?]

In regard to my question of the Q of mud, it answers with many, many
examples offered in both numbers and graphical form (Fig. 5-13 which
Richard can confirm and/or amplify).

Here we find the Q of dry soil (which in the comparison to Martian
samples is literally dripping with water) stands at
Q = 1 @ .5MHz
Q = 4 @ 1.5MHz
Q = 40 @ 20MHz
Q = 400 @ 200MHz

The Q of wet soil
Q = 0.1 @ .5MHz
Q = 1 @ 5MHz
Q = 4 @ 20MHz
Q = 40 @ 200MHz

Let's go further because Reggie's divertissimo has been drained of its
entertainment and we really should be getting into real and useful
information instead. The Q of water!

The Q of fresh water
Q = 1 @ .2MHz
Q = 10 @ 2MHz
Q = 100 @ 20MHz

The Q of ocean water
Q = 0.004 @ 1MHz
Q = 0.04 @ 10MHz
Q = 0.4 @ 100MHz

I would suggest many ponder these last two samples as they run
contrary to many myths offered here about conductivity and the
pleasures of an ocean front home and the rationale of DX. I will
leave that as a teaser....

73's
Richard Clark, KB7QHC

In view of the nil replies to the following posting it's safe to say that's
another old wives' tale which bites the dust.

The next ingrained tale on the list is the so-called SWR meter nonsense
versus the TLI.

=========================

A TALE OF TWO OLD WIVES

There are two cantankerous old wives:

One old wife asserts it is obvious radiation occurs mainly from the middle
portion of a dipole because that's where the current is strongest and the
magnetic field is most concentrated.

The other old wife asserts it is obvious radiation occurs mainly from the
ends of a dipole because that's where the highest voltages occur and the
electric field is most intense.

Since the pair of arguments are logically identical in form they are of
equal validity. But because it is impossible to reconcile the two women
.....
they cannot BOTH be right .... only one conclusion can be drawn ...

... both arguments are false!

The old wives are telling tales. Citizens - drag 'em off to that old
English
custom - the ducking stool.

"Reg Edwards" wrote in message
...
In view of the nil replies to the following posting it's safe to say
that's
another old wives' tale which bites the dust.

The next ingrained tale on the list is the so-called SWR meter nonsense
versus the TLI.

=========================

A TALE OF TWO OLD WIVES

There are two cantankerous old wives:

One old wife asserts it is obvious radiation occurs mainly from the
middle
portion of a dipole because that's where the current is strongest and
the
magnetic field is most concentrated.

The other old wife asserts it is obvious radiation occurs mainly from
the
ends of a dipole because that's where the highest voltages occur and the
electric field is most intense.

Since the pair of arguments are logically identical in form they are of
equal validity. But because it is impossible to reconcile the two women
....
they cannot BOTH be right .... only one conclusion can be drawn ...

... both arguments are false!

The old wives are telling tales. Citizens - drag 'em off to that old
English
custom - the ducking stool.

Reg:

Compared to current, voltage is just so ephemeral....

Voltage is a line integral, it depends upon the path over which one
evaluates the integral.

While current is something more substantial... one does not have to
plan the path of integration to know the current.

What?

--
Peter K1PO


"Reg Edwards" wrote in message
...
In view of the nil replies to the following posting it's safe to say
that's
another old wives' tale which bites the dust.

The next ingrained tale on the list is the so-called SWR meter nonsense
versus the TLI.

=========================

A TALE OF TWO OLD WIVES

There are two cantankerous old wives:

One old wife asserts it is obvious radiation occurs mainly from the
middle
portion of a dipole because that's where the current is strongest and
the
magnetic field is most concentrated.

The other old wife asserts it is obvious radiation occurs mainly from
the
ends of a dipole because that's where the highest voltages occur and the
electric field is most intense.

Since the pair of arguments are logically identical in form they are of
equal validity. But because it is impossible to reconcile the two women
....
they cannot BOTH be right .... only one conclusion can be drawn ...

... both arguments are false!

The old wives are telling tales. Citizens - drag 'em off to that old
English
custom - the ducking stool.

Reg Edwards wrote:
In view of the nil replies to the following posting it's safe to say that's
another old wives' tale which bites the dust.

Reg, we have a clear example of where the high voltage part of the
antenna is not allowed to radiate (much). That would be a balanced
top hat. Not allowing the high voltage part of the antenna to radiate
leaves the high current part to do most of the radiating. We know from
field strength measurements that a mobile antenna with a balanced top
hat can radiate as well (or better than) an antenna equipped with a
radiating high voltage top section.

If you keep the high voltage portion of the antenna and replace the
high current portion with an antenna tuner, the field strength falls
by some 12 dB.

Lengthening the high current section under the loading coil has a
much greater effect than lengthening the high-voltage section on top
of the loading coil.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Cec, I don't doubt your experimental results. It's your extrapolated
imagination and logic which worries me. ;o)
----
Yours, Reg.