Why not:

___ ___
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
___| |___|


etc.

A "flattened" coil, first time I see one used is Vincents' DLM, anyone?

Regards,
JS

P.S. Excuse the bad ascii graphics ...

On Dec 2, 7:09 pm, John Smith wrote:
Why not:

___ ___
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
___| |___|

etc.

A "flattened" coil, first time I see one used is Vincents' DLM, anyone?

Regards,
JS

P.S. Excuse the bad ascii graphics ...

Not a very efficient "coil." Consider what the magnetic fields are
from each wire segment. A flat _spiral_ is sometimes used, e.g. by
etching it into a PCB, though they are generally not as good as
traditional helical or toroidal coils. A stub of transmission line
less than a quarter wave long and shorted at the far end looks
inductive, too, but at HF it's a pretty inefficient way to get
inductance. They're much more useful at UHF and above.

K7ITM wrote:
On Dec 2, 7:09 pm, John Smith wrote:
Why not:

___ ___
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
___| |___|

etc.

A "flattened" coil, first time I see one used is Vincents' DLM, anyone?

Regards,
JS

P.S. Excuse the bad ascii graphics ...

Not a very efficient "coil." Consider what the magnetic fields are
from each wire segment. A flat _spiral_ is sometimes used, e.g. by
etching it into a PCB, though they are generally not as good as
traditional helical or toroidal coils. A stub of transmission line
less than a quarter wave long and shorted at the far end looks
inductive, too, but at HF it's a pretty inefficient way to get
inductance. They're much more useful at UHF and above.

Interesting response. The "major efficiency" you are stating is?

1) Inductance per length of conductor?

2) Space required for inductor?

3) Losses?

4) Other?

Regards,
JS

John Smith wrote:
"The "major efficiency" you are stating is?"

Q is the usual statement of inductor efficiency.

Libear loading has its advocates. My edition of John Devoldere, ON4UN`s
"Low-Band DXing" is from 1994. On page 9-36 is Fig 9-46, Two-Band (80
and 160-m) vertical system using linear loading to bring the antenna to
resonance on 160 meters.

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:
John Smith wrote:
"The "major efficiency" you are stating is?"

Q is the usual statement of inductor efficiency.

Libear loading has its advocates. My edition of John Devoldere, ON4UN`s
"Low-Band DXing" is from 1994. On page 9-36 is Fig 9-46, Two-Band (80
and 160-m) vertical system using linear loading to bring the antenna to
resonance on 160 meters.

Best regards, Richard Harrison, KB5WZI


Thanks Richard, I will see if I can locate an issue that old.

Regards,
JS

(Richard Harrison) wrote in news:24417-
:

John Smith wrote:
"The "major efficiency" you are stating is?"

Q is the usual statement of inductor efficiency.

Not to imply that Efficiency=Q.

In very simple terms, in the case of a coil, the inductance is
proportional to the cross sectional area of the coil. A circular coil
uses the least wire and hence the least resistance to achieve that area.
Techniques that increase the conductor length for the same inductance are
likely to produce a lossier (ie less efficient) inductor.


Libear loading has its advocates. My edition of John Devoldere, ON4UN`s
"Low-Band DXing" is from 1994. On page 9-36 is Fig 9-46, Two-Band (80
and 160-m) vertical system using linear loading to bring the antenna to
resonance on 160 meters.

Linear loading does have its advocates. The claims sometimes made
regarding efficiency are perhaps unjustified. My article at
http://www.vk1od.net/cobra/index.htm explores NEC based system models of
the Cobra antenna system (a linear loaded multiband antenna system) and
the loading mechanism is not inherently lossless.

The case of a non-inductive wire wound resistor is an extreme case of
inefficiency as a result of "linear loading". The objective is to arrange
the conductor so that incremental magnetising forces cancel and just the
loss is retained.

Owen

Owen wrote:
"Not to imply that Efficiency = Q."

It does.

Q = energy stored per cycle / energy lost per cycle. Q = XsubL / R

Efficiency = output / input.

Output is the energy given back by the coil when its field collapses.

Input is the energy required to charge the inductor`s field plus the
energy required to supply the losses.

Net output is equivalent to coil reactance and net input is equivalent
to the effective series resistance loss. Therefo Q = Efficiency.

Best regards, Richard Harrison, KB5WZI

John Smith wrote:

Poor old W8JI has taken quite a beating, it is best to realize if
mistakes are made, so should it be, we are only human.

However, this individual has prepared some nice pages, he has a nice way
of writing which are easy to logically follow. Newbies, if they stumble
upon his pages, must surely benefit tremendously.

Now, as I have stated, I have no real horse in the particular argument
which dominates this group--I simply wish to recognise his good work and
give him proper credit. If unknowingly slight men of good intentions we
may lose them--NOT a good thing ...

http://www.w8ji.com/loading_inductors.htm

Warm regards to all,
JS

"John Smith" wrote in message
...
John Smith wrote:

Poor old W8JI has taken quite a beating, it is best to realize if mistakes
are made, so should it be, we are only human.


He is not poor and not that old. He does not take the "beating" for no
reason, but in response to some of his extreme statements or fallacies that
he proclaims as a gospel on his web site and on the reflectors. If he was
more human, he would realize some of the mistakes in his
thinking/knowledge/proselytizing, correct them and GIVE a credit where it's
due.

However, this individual has prepared some nice pages, he has a nice way
of writing which are easy to logically follow. Newbies, if they stumble
upon his pages, must surely benefit tremendously.


That is nice and to many useful (better source is ARRL Handbook), but
included in that are some errors and misinformation trumpeted as a gospel
according to W8JI which does not serve the ham community well. He is doing
his web "service" not from purely ham philanthropic reasons, but making
business and monetary gains via "W8JI Engineering" and lately "DX
Engineering" products and promotion. (Using "Engineering" label without
having engineering degree, college degree or being member for engineers
association, required by most states.)


Now, as I have stated, I have no real horse in the particular argument
which dominates this group--I simply wish to recognize his good work and
give him proper credit. If unknowingly slight men of good intentions we
may lose them--NOT a good thing ...

I have a horse in some of the arguments, because when I saw some fallacies
being propagated or when I was attacked by him for some of my statements
about my findings and him trying to play in public forum as "all-knowing
guru" to this "know-nothing" real engineer (with some awarded design
experience and bunch of world records), I simply don't take the crap and
react.
Just a brief unpsychological profile of W8JI: he never admits to be wrong,
he jumps on "dummies" from his high horse, if he finds he might have been
wrong, he will never admit it, but obfuscates the issue, fogs it with smoke
and mirrors, goes quiet for a while and later emerges as a guru
appropriating the critic's idea and proclaiming it as new gospel on his
pages. He likes to criticize the other sources as misleading, while himself
has a plenty of it on his pages. Been there about 5 times and I would be
critical about his "gospel". (And you don't not know about some of the
stuff and backstabbing that goes on off the web pages.)


http://www.w8ji.com/loading_inductors.htm


Prime example of another "wrongo".
The main problem with loading stubs in antenna situations is that they have
RF current flowing on the loading wires, which interact (cancellation) with
the element they are "serving" especially when folded back or forward on the
element (3 wires interacting). The best way, if must to use loading stubs,
is to have them to go 90 degrees off the element. The coil does not have
that effect, there is just drop of current across the coil, while rest of
the current along the element is not disturbed.
This effect is magnified when using in arrays, which was verified in real
life by W6?? when they replaced loading stubs with coils and saw dramatic
improvement in the 3 el. KLM 80 m beam - better gain and remarkable
improvement in the pattern, F/B.


Warm regards to all,

That too, from snowy NE!

JS

73 Yuri, K3BU.us

Yuri Blanarovich wrote:
...
73 Yuri, K3BU.us

Yuri, I don't know if we are dealing with cultural differences or not,
but damn dude, you are TOO BIG OF A WASTE OF MY TIME ...

PLONK BIG TIME!

Now ....

Warm regards,
JS

P.S. But still, plonk!