Ian White wrote:
"The real technical question is how many, and how long, will be "just
enough" for "here"?"

Reminds me of the trailer house designer pulling out reaces until the
whole projkect collapses, then rebuilding with only the last brace
removed reinstalled.

You don`t need any radials with a horizontal dipole. Broadcasters are
launching ground waves to reach a local audience. Amateurs may want ro
reach DX with sky waves.
For radials under an earth mounted vertical, there`s no magic number or
length. You can add to the count until resistance elimination fades. You
can lengthen them until the current at their tips is almost zero. Or,
you can just decide how much you will spend on wire. I read that
quantity of radials is better than longer radials.

If you want some idea of how conductive soil is, I read that a Variac,
ground rods , ammeter and voltmeter is the way to go. Adjust current
between the rods to one ampere with the Variac. Resistance between the
rods is then the volts between them.

Terman has already supplied Table 22-1 "TYPICAL GROUND CONSTANTS" on
page 308 of his 1955 edition for estimating dielectric constant and
ground conductivity.

At high frequencies, poor ground conductivity takes eome energy from the
reflected wave and the combined direct and reflected wave can`t be a
complete cancellation. The direct wave alone is stronger than its
combination with an out of phase wave. Ground wave propagetion fades in
a short distance at high freqiuencies. So what use does the DXer have
for soil conductivity? Isn`t something like Terman`s Table good enough,
unless he is considering laying his antenna on or near the soil?

Best regards, Richard Harrison, KB5WZI

On Wed, 22 Jun 2005 16:12:28 -0500, (Richard
Harrison) wrote:

Ian White wrote:
"The real technical question is how many, and how long, will be "just
enough" for "here"?"

Reminds me of the trailer house designer pulling out reaces until the
whole projkect collapses, then rebuilding with only the last brace
removed reinstalled.

Sounds like the guy works for Fleetwood.

Here's an example of their fine American craftsmanship used on my
fifth-wheel trailer. Actually I think they probably have a crew of
illegal aliens doing the work but who knows.

http://users.triconet.org/wesandlind...yFleetwood.jpg

The awning upright kept the sheet from tearing off completely and
landing in the middle of I-10 (75 mph limit). Adding insult to
injury, I had just increased my insurance deductable before the trip
from $200 to $1K to "save money."

Wes, N7WS wrote:
"Sounds like the guy who works for Fleetwood."

Did not expect to hit a nerve with my story of "Value Engineering".
Fleetwood could be called Fleetaluminum after Wes` skin peeled and
sailed down I-10 at 75 mph.

When you are making many examples of a product it makes sense to
minimize cost if you don`t compromise the product.

A guy in my college class was hired by a car radio manufacturer. He
spent most of his first 18 months with the company eliminating a single
nut and bolt in a vibrator. His starting salery probably wasn`t much,
but I doubt they ever produced enough vibrators to recoup the cost of
their design improvement which saved a single fastener. His work must
have been akin to that of T.A. Edison finding the right stuff for the
filament of an incandescent lamp, finding a thousand things that didn`t
work before finding one which did.

Best regards, Richard Harrison, KB5WZI

On Wed, 22 Jun 2005 20:30:20 -0500, (Richard
Harrison) wrote:

His work must
have been akin to that of T.A. Edison finding the right stuff for the
filament of an incandescent lamp

Hi Richard,

Right kind of hymn, wrong inventor for the chorus. It was Ford who
was approached by his engineers with a carburetor with two screws
holding it together. He challenged them to return only when they had
reduced it to one screw.

73's
Richard Clark, KB7QHC