On 26 Nov, 10:46, John Smith wrote:
Richard Fry wrote:

...

I just looked at that patent, and saw nothing about that. I did see
many references to the need for a good r-f ground for the DLM.

As a variation, the patent describes putting two DLMs back to back to
create a dipole. Of course, that form is no longer a DLM, it is a
loaded dipole.

Can you refer me to the page(s) of that patent that describe(s) what you
are writing about?

RF

Well, give me a bit, and remind me if I don't get back to you in a
couple of days ...

However, I have a 10m and a 20m 1/2-wave DLM I am using now, I
constructed them from the info. gleamed from the patent, conversation
with Vincent, web, ...

Hold on ... just overloaded after the holidays--except for quick
comments ...

Regards,
JS

The post that originated this thread stated that the antenna was
unbalanced and therefore should have a ground system.
Fry had some comments that were not related or in conflict
with what was stated, he just doesn't read to well.
Back to the originating post.The antenna is unbalanced but without a
connected ground system such that current will flow on the outside of
the coax braid. If this braid is buried this current will leak to the
ground(capacitive coupling). Question. At what distance does the coax
have to travel such that current on the outside does not exist?
Art

art wrote:

...
The post that originated this thread stated that the antenna was
unbalanced and therefore should have a ground system.
Fry had some comments that were not related or in conflict
with what was stated, he just doesn't read to well.
Back to the originating post.The antenna is unbalanced but without a
connected ground system such that current will flow on the outside of
the coax braid. If this braid is buried this current will leak to the
ground(capacitive coupling). Question. At what distance does the coax
have to travel such that current on the outside does not exist?
Art

I understand this Art. However, I am sure you won't mind a bit of side
conversation--don't mean to hijack your thread. ;-)

Regards,
JS

On Mon, 26 Nov 2007 11:06:29 -0800 (PST), art
wrote:

At what distance does the coax
have to travel such that current on the outside does not exist?

Hi Arthur,

According to Brown, Lewis, and Epstein's work, the currents absorbed
by ground dissipate radial wire current (what is flowing on the
exterior of a coax) in a very short interval.

However, just where it "does not exist" is like the problem you have
with skin effect. The current diminishes asymptotically towards zero,
but most would agree that the practical current is gone within less
than a quarter wave length. The convergence with the asymptote could
be described to be infinitely far away - especially when the current
levels induced in far receiver antennas is so miniscule in comparison
to the diminished radial currents (4,5 or 6 orders of magnitude?).

73's
Richard Clark, KB7QHC

"art" wrote
The antenna is unbalanced but without a connected
ground system such that current will flow on the
outside of the coax braid.
______________

Following in its odd style is one of the many references in the DLM patent
to the need/use of a "connected ground system" for it.

QUOTE In this embodiment the antenna is shown grounded to earth through a
grounding rod, ground wire and connected to the base of the antenna and
electrically connected using a ground clamp. Radial wires extending above
ground or buried in the ground are electrically connected to the antenna
using the ground wire and the ground rod and extend from the antenna base
for a uniform distance but not limited to any specific length. END QUOTE.

So another one of your cherished beliefs is shown to be untrue.

RF