On Tue, 21 Jun 2005 11:37:57 -0400, "Walter Maxwell"
wrote:

Thanx big time for considering my data worthy of your time for further
examination. You've already made me anxious to see what interesting results
might come from your delving into my data with Mathcad.

Hi Walt,

Even on simple examination, it proves useful. It obviously exhibits
the wire wavelength altering effect of the proximity of earth. This
is something Reg has harped on for years and which he curiously
rejects as being incapable of demonstration in just such as your data.

Perhaps this curious twist is explainable. There seems to be a new
vogue of posting errant hypothesis these days so the authors can prove
themselves wrong. I've seen three such admissions in just the last
week.

73's
Richard Clark, KB7QHC

Walter Maxwell, W2DU wrote:
"At this height above ground (0.35 wavelength) the dipole is spaced 0.7
wavelength from its image in the perfect ground plane."

I accept that, but cannot reconcile page and figure numbers. I have only
the 1950 and 2003 editions of "Antennas". They are prticeless to me
though I`m not as familiar with them as I am with Terman.

I suggested determining ground resistance by the attenuation it adds to
the ground wave. I neglected to say that the time to do so would be when
sky wave propagation was small to none. Midday when using medium wave
signals for signal strength measurements unless the measurement sites
were close enough to the transmitter to make sky wave unimportant. I
used to make medium wave broadcast station monitoring point field
strength measurements within a few miles from the station, daytime,
nighttime, or anytime because at this short range there is no chance of
sky wave interference. You would be much more considerate of the time of
day 200 miles from the station. If HF signal attenuation versus distance
from the transmitter is used to determine earth resistance, for
practical purposes ground wave propagation is nearly negligible,
especially at the high end of the HF spectrum. I believe B, L, and E.
used 3 MHz which produces some ground wave.

Best regards, Richard Harrison, KB5WZI

Anecdotally, I have noticed, I have no problem working Europe, ZS, VK, and
ZL on 75 running 90 watts. I am typically 5-9 or better in to Great Britain.
My antenna is 38 feet in the center and 20 feet on both ends. Actually I
have two 132 foot dipoles that are orientated 90 degrees from each other.
They share a common relay box for switching in additional ladderline. That
is the input to the relay box is selected by a separate relay. The unused
antenna is grounded. I have tried it both grounded and ungrounded and it
"seems" to be better when the unused antenna is grounded.

My next set of relays will tie them both together as a big capacity hat on
160. Have not got around to doing it yet.

I can push a 10 foot ground rod into the ground by hand. If I don't wet it
down, I can rotate it by hand when it is 9.75 feet in the ground. If a
rabbit gets in the garden, one is in dire straits trying to find a rock to
throw at it.

A sand pit down the road from me is over 200 feet deep and they have not hit
anything other than sand in over 20 years of digging.





"Roy Lewallen" wrote in message
...
Fred W4JLE wrote:
It would be interesting to recreate the measurements at other locations.
My
location has 500 feet of sand below me. It would be a great improvement
just
to have poor soil.

Depends on your objective. For NVIS operation with a horizontal antenna,
where you need the reflection, that's probably true. But for a vertical
or for DX with a horizontal antenna, you're better off with the sand.
Perfect ground has no loss; free space has no loss. There's an
intermediate quality of ground at which the loss is maximum at a given
frequency. Unfortunately, this happens to be in the range of ordinary
ground characteristics in the HF range. Your ground should be very low
loss. And your pattern should resemble free space, with a very strong
field at very low radiation angles.

Roy Lewallen, W7EL

"Richard Harrison" wrote in message
...
Walter Maxwell, W2DU wrote:
"At this height above ground (0.35 wavelength) the dipole is spaced 0.7
wavelength from its image in the perfect ground plane."

I accept that, but cannot reconcile page and figure numbers. I have only
the 1950 and 2003 editions of "Antennas". They are prticeless to me
though I`m not as familiar with them as I am with Terman.

I suggested determining ground resistance by the attenuation it adds to
the ground wave. I neglected to say that the time to do so would be when
sky wave propagation was small to none. Midday when using medium wave
signals for signal strength measurements unless the measurement sites
were close enough to the transmitter to make sky wave unimportant. I
used to make medium wave broadcast station monitoring point field
strength measurements within a few miles from the station, daytime,
nighttime, or anytime because at this short range there is no chance of
sky wave interference. You would be much more considerate of the time of
day 200 miles from the station. If HF signal attenuation versus distance
from the transmitter is used to determine earth resistance, for
practical purposes ground wave propagation is nearly negligible,
especially at the high end of the HF spectrum. I believe B, L, and E.
used 3 MHz which produces some ground wave.

Best regards, Richard Harrison, KB5WZI

Richard, I don't understand why you can't reconcile the Page numbers. I have the
same editions of Kraus as you, but the edition of Kraus I'm referencing is
the1950, the same as yours.

Walt

Walter, W2DU wrote:
"Richard, I don`t understamd why you can`t reconcile the page numbers."

I don`t understand either, but it may be blindness and senility. Now,
I`ve found everything fight where Walt said it would be!

Best regards, Richard Harrison, KB5WZI

"Richard Harrison" wrote in message
...
Walter, W2DU wrote:
"Richard, I don`t understamd why you can`t reconcile the page numbers."

I don`t understand either, but it may be blindness and senility. Now,
I`ve found everything fight where Walt said it would be!

Best regards, Richard Harrison, KB5WZI

Richard, that's called a 'senior moment'. Except when I do it they tell me it's
my Alzheimer's Syndrome raising its ugly head.

Walt

"Richard Clark" wrote in message
...
On Mon, 20 Jun 2005 23:17:40 -0400, "Walter Maxwell"
wrote:

Hi All,

Reg asked if I could send my data as an email, so I converted the file to text
format to be able to present the data in full here in this msg.

I checked to see that the tabular format remained intact, and it did in
Outlook
Express, so here it is. I hope the tabular format will remain intact in your
browsers. Be sure to give your screen maximum width. If it doesn't, let me
know
and I'll resend in PDF format.

I'd like to hear your comments.

Hi Walt,

Thanx big time for this work of dedication. I have other projects to
attend to, but I am sure looking forward to close examination of this
trove of data by hunkering down with Mathcad and casting up some
charts. Hope to do that within the week if not sooner.

73's
Richard Clark, KB7QHC

Hi Richard,

Your mentioning Mathcad, (I have 2000i ed.) made me think of using Excel to
produce some graphs of the data, however, there are two other projects that must
come first. I have used Mathcad only to solve problems using the equations one
can build there, and have not explored the graphing possibilities. With both
Excel and Mathcad available do you think I should spend the time learning
graphics with Mathcad, or stick with Excel which I already know how to use?

Walt

"Walter Maxwell" wrote
You've presented a very interesting way of measuring soil
characteristics. When
I return to Florida in November I'm going to use your method of
measuring the
soil underneath the dipole

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

Walt, would it be possible for somebody to go to B.L & E's original
site and measure the soil charateristics which they completely forgot
all about. Presumably, they were not aware that the type of soil had
any effect on their measurments. At what time of the year did they
conduct their famous experiments?

Pity we shall have to wait till November for you to re-visit Florida.
In view of the high temperature coefficient of soil resistivity and
probability on permittivity, don't forget to take a thermometer.

What was the soil temperature when you made your HF measurements
versus height? Soil temperate discrepancies might be of greater order
and swamp the effects of considerable changes in antenna height.

But I suggest we are more interested in change of antenna impedance
versus height above ground than we are in apparent change in soil
characteristics versus frequency.
----
Reg, G4FGQ

"Walter Maxwell" wrote
Richard, that's called a 'senior moment'. Except when I do it they
tell me it's
my Alzheimer's Syndrome raising its ugly head.

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

I too am afflicted with Alzheimer's. I forget what I said at the
beginning of a vocal sentence before I get to the end. Also I have
recently had a very minor stroke which has affected the small and next
fingers of my left hand. This has slowed down my keyboard dexterity.

But it's quite normal for my time of life and it doesn't worry me.
Least of all does KB7QHC's lying slander worry me.
----
Reg, G4FGQ

Reg Edwards wrote:

Walt, would it be possible for somebody to go to B.L & E's original
site and measure the soil charateristics which they completely forgot
all about. . .

But what would that tell us about the soil conditions to, say, three
skin depths -- or even one? What conclusions could we draw from that
information?

Roy Lewallen, W7EL