Depends.
You could just keep adding radials when you can afford more copper until
things stop improving.
(Whatever "stop improving" means to you.)
Copper's expensive.

My SteppIR vertical is on an aluminum roof.
(Just my approach to the problem)

And Walt's right.
What is trivially obvious to us wasn't so in 1937.
Maxwell's equations weren't 100 years old yet.
It had only been a few years since Gibbs wrote them in the modern form we
use.
Radio was barely understood by only a few people.

73
H.

NQ5H
"Wayne" wrote in message
news:L0Nwg.5924$yN3.4270@trnddc04...
These are very good points. I am reading these postings to try to
understand the behavior of actual implementations that lie somewhere
between the extremes you pointed out. In other words, what gets you the
most bang for the buck.... How fast does performance change with
increased radial length and number of radials.


"H. Adam Stevens, NQ5H" wrote in message
...
I'm often confronted with problems as a physicist where one can only get
a handle on upper and lower bounds.
Lower bound:
I'd say the minimum number and length of radials is 3 (must define a
plane) and 1/4 wavelength (satisfies boundary conditions).

Upper (infinite sheet of copper)
As Walt and Reg have debated, the "Cleese extreme" (to steal from Reg's
post) is trying to duplicate the "infinite perfectly conducting plane" of
our elementary physics books.
Cheers and beers
H.

73, NQ5H

On Sun, 23 Jul 2006 11:35:42 -0500, "H. Adam Stevens, NQ5H"
wrote:

Depends.
You could just keep adding radials when you can afford more copper until
things stop improving.
(Whatever "stop improving" means to you.)
Copper's expensive.

My SteppIR vertical is on an aluminum roof.
(Just my approach to the problem)

And Walt's right.
What is trivially obvious to us wasn't so in 1937.
Maxwell's equations weren't 100 years old yet.
It had only been a few years since Gibbs wrote them in the modern form we
use.
Radio was barely understood by only a few people.


Hi OM,

In fact, how "many" people knew is immaterial to what was known a good
twenty five years before the BLE paper.

From my "Standard Handbook for Electrical Engineers," 1912,
Sec. 21, Radiotelegraphy, Method of Exciting the Antenna, part 283
Antenna Ground Connections:
"The outward and inward movement of the lines of electric force
during the oscillations in the antenna give rise to earth
currents. These earth currents are most intense in the immediate
neighborhood of the antenna, and if the earth is a poor conductor
a large waste of energy ensues. To guard against this loss, a
radiating network of wire is place beneath and around the antenna.
In the case of a flat-top antenna, the radius of this wire net
should not be less than the length of the horizontal portion of
the antenna."

I shouldn't have to point out that a handbook is not the place where
new science appears, but where tested science is aggregated. Earth
currents, screens, and lost power were not unfamiliar a century ago.

What is "Bleeding obvious" about the BLE paper, is that it puts
numbers to the quoted paragraph above in the face of its mocking:
At risk of upsetting a great number of patriotic USA citizens, all BLE
hero-worshippers
It is quite evident that the merit of the BLE paper serves the true
spirit of Lord Kelvin, and that in the context of this group, it is
USA citizens who honor his precepts in the face of this last piece of
British trolling of Reggie's who is more interested in juvenile
posturing than celebrating his heritage's expression in a fine work.

73's
Richard Clark, KB7QHC