Radial attenuation
 

Cecil,

There has been a temporary improvement in my Alzeimer's affliction.

The attenuation along a radial is given by =

Attenuation = ( R / Ro + G * Ro ) / 2 nepers.

Where -

R = HF Conductor resistance.
G = Shunt leakance or conductance, related to soil conductivity.
Ro = Resistive component of line impedance Zo.

One neper = 8.686 dB.

If I published the source code you would be asking even more questions
and Richard Clark would again unjustly accuse me of trolling. ;o)
----
Reg.

Radiating Efficiency
 

Reg Edwards wrote:
Cecil, could you or somebody, please use Eznec or something, to
determine the radiating efficiency of a 9.0 meter long vertical
antenna with a ground-loss connection resistance of 5 ohms, at its
1/4-wave resonant frequency slightly above 8 MHz.

Is the 5 ohms of ground loss the only loss in the system?
i.e. should perfect ground be used? Or should it be done
in free space with a 5 ohm load going to the radials.

Will integrating the area of the omnidirectional elevation
envelope yield a value proportional to the radiated power?
--
73, Cecil http://www.qsl.net/w5dxp

Radiating Efficiency
 

Will integrating the area of the omnidirectional elevation
envelope yield a value proportional to the radiated power?
--
73, Cecil http://www.qsl.net/w5dxp

Cecil, that is what I did with NEC, and got an efficiency
of about 35%. Using the ratio of Rr/(Rr+Rloss)
produces a totally different answer.

NEC 4 computes a normalized far field, at 1 m, in units
of volts. NEC 2 incorrectly shows units of V/m.

Frank

Radiating Efficiency
 

Frank's wrote:
Will integrating the area of the omnidirectional elevation
envelope yield a value proportional to the radiated power?

Cecil, that is what I did with NEC, and got an efficiency
of about 35%. Using the ratio of Rr/(Rr+Rloss)
produces a totally different answer.

NEC 4 computes a normalized far field, at 1 m, in units
of volts. NEC 2 incorrectly shows units of V/m.

W7EL tells us that EZNEC doesn't display the surface
wave which obviously contains power. Would that affect
the efficiency using the integration technique?
--
73, Cecil http://www.qsl.net/w5dxp

Radial attenuation
 

On Tue, 25 Jul 2006 12:22:38 +0100, "Reg Edwards"
wrote:

and Richard Clark would again unjustly accuse me of trolling. ;o)

Hi Reggie,

Do those nails in your palms really 'urt that much?

73's
Richard Clark, KB7QHC
(rolling dice at the bottom of Reggie's posts)

Radial attenuation
 

On Tue, 25 Jul 2006 12:22:38 +0100, "Reg Edwards"
wrote:

Cecil,

There has been a temporary improvement in my Alzeimer's affliction.

The attenuation along a radial is given by =

Attenuation = ( R / Ro + G * Ro ) / 2 nepers.

Where -

R = HF Conductor resistance.
G = Shunt leakance or conductance, related to soil conductivity.
Ro = Resistive component of line impedance Zo.

One neper = 8.686 dB.

If I published the source code you would be asking even more questions
and Richard Clark would again unjustly accuse me of trolling. ;o)
----
Reg.

Hi Reg,

I believe your temporary Alzhiemers affliction began some time ago, when you
repeatedly reminded me that BLE forgot to indicate the ground conditions. Even
though the conditions are irrelevant when sufficient radials effect a
near-perfect ground, you either skimmed BLE too quickly, or the Alzhiemers
effect had already taken place. I'm going to quote from two BLE pages below:

"Fig 7 earth conductivity = 0.2 x 10^-4 mhos/cm^3
Fig 8 earth conductivity = 1.0 x 10^-4 mhos/cm^3
Fig 9 earth conductivity = 0.2 x 10^-4 mhos/cm^3
Fig 10 earth conductivity =1.0 x 10^-4 mhos/cm^3"

"Fig 18 shows the distribution of earth loss for G = 22 degrees, and G = 88
degrees, for 15 and 113 radial wires, when the frequency was 3000 kilocycles and
the earth conductivity is 0.2 x 10^-4 mhos per cm^3."

It's true they didn't mention permittivity, but at least they did recognize
conductivity, and reported it.

On the other hand, concerning the difference in results between using BLE or
Radials3, unless I missed the critical point somewhere along the way, perhaps
the difference has been misunderstood, where Radials 3 shows usefulness drops
off more quickly with distance from the radiator than BLE. As I understand it,
when only a few radials are present, the longer length is unnecessary. I now
quote again from BLE:

"Fig. 6 shows the actual current in the earth for the same conditions. These
diagrams show that the ground system consisting of only 15 radial wires need not
be more than 0.1 wavelength long, while the system consisting of 113 radials is
still effective out to 0.5 wavelength."

Does this not agree with Reg's Radials3? If not, please tell me what I'm
missing. (I do not have Radials3, and am only commenting from what I've read in
the various posts.)

Walt, W2DU

Radial attenuation
 

"Walter Maxwell" wrote
... I now quote again from BLE:
"Fig. 6 shows the actual current in the earth for the same conditions.
These
diagrams show that the ground system consisting of only 15 radial wires
need not
be more than 0.1 wavelength long, while the system consisting of 113
radials is
still effective out to 0.5 wavelength."

Does this not agree with Reg's Radials3? If not, please tell me what I'm
missing. (I do not have Radials3, and am only commenting from what I've
read in
the various posts.)
___________

Possibly not. Here is a paste of one the early responses to the first
thread started by Reg on this subject , which shows that with radials_3,
radiation efficiency doesn't just stop improving with longer radials, it can
also get worse.

QUOTE

Reg, a bit confused by these results from RADIAL_3

96 radials, 7MHz, antenna height 10.72m. Soil 500ohm*m, permittivity
13\

Radials and antenna 1.024mm (18AWG), radials 3mm deep(surface)

Radial Length, %Efficiency

2m, 93.19%
3m, 93.83%
4m, 92.47%
5m, 86.01%
6m, 80.39%
7m, 85.92%
8m, 89.06%
9m, 89.59%
10m, 88.22%
11m, 85.99%
12m, 85.51%
13m, 86.67%

??

Dan

END QUOTE

/RF

Radial attenuation
 

On Tue, 25 Jul 2006 12:32:49 -0400, Walter Maxwell
wrote:

you either skimmed BLE too quickly, or the Alzhiemers
effect had already taken place.

Hi Walt,

Reggie's only defense against plagiarism (a charge he loves to bandy
about) is claiming to have NOT read BLE. It mimics his railing
against software users as intellectual cripples when he has a trove of
software offered like dope to school children on the playground.

Reggie,

It is amazing how you can spit in the faces of those commending you
for your software; and you do it with full vigor and glee. You may
want to ponder your legacy as a maker of crutches (un-referenced
executables) or leaving a testimony in open source code. Even with
these positive examples you sneer at your source to gain the
rhetorical advantage, and yes, that makes you a troll (and this is
decidedly different from what the Brit's call eccentrics, or what we
call characters).

The one complaint I've heard frequently from you when you are asked to
write something comprehensive (there are models in history from
Heavysides that you similarly dismiss) is that there is not enough
time. You seem to have plenty enough time to anticipate my banter, or
to otherwise respond to/with trivialities. This has got to be the
height of decadence.

73's
Richard Clark, KB7QHC

Radiating Efficiency
 

Cecil, that is what I did with NEC, and got an efficiency
of about 35%. Using the ratio of Rr/(Rr+Rloss)
produces a totally different answer.

NEC 4 computes a normalized far field, at 1 m, in units
of volts. NEC 2 incorrectly shows units of V/m.

W7EL tells us that EZNEC doesn't display the surface
wave which obviously contains power. Would that affect
the efficiency using the integration technique?
--
73, Cecil http://www.qsl.net/w5dxp

Good point Cecil, I forgot about the surface wave. Will have to
find a way of including it.

Frank

Radial attenuation
 

On Tue, 25 Jul 2006 11:11:28 -0700, Richard Clark wrote:

On Tue, 25 Jul 2006 12:32:49 -0400, Walter Maxwell
wrote:

you either skimmed BLE too quickly, or the Alzhiemers
effect had already taken place.

Hi Walt,

Reggie's only defense against plagiarism (a charge he loves to bandy
about) is claiming to have NOT read BLE. It mimics his railing
against software users as intellectual cripples when he has a trove of
software offered like dope to school children on the playground.

Reggie,

It is amazing how you can spit in the faces of those commending you
for your software; and you do it with full vigor and glee. You may
want to ponder your legacy as a maker of crutches (un-referenced
executables) or leaving a testimony in open source code. Even with
these positive examples you sneer at your source to gain the
rhetorical advantage, and yes, that makes you a troll (and this is
decidedly different from what the Brit's call eccentrics, or what we
call characters).

The one complaint I've heard frequently from you when you are asked to
write something comprehensive (there are models in history from
Heavysides that you similarly dismiss) is that there is not enough
time. You seem to have plenty enough time to anticipate my banter, or
to otherwise respond to/with trivialities. This has got to be the
height of decadence.

73's
Richard Clark, KB7QHC

Richard, what a masterful discourse on Reggie's character, oops, I mean
eccentricities!

Quite similarly, your earlier admonition to his lack of appreciation of BLE in
your stately defense of it as a document worthy of Lord Kelvin. Bravo!

Walt, W2DU