I am planning a two band antenna for 30 and 80m using linear traps.
The idea is to build the antenna of zip-cord type line 140ohm vf 0.73.
Trap is made using 1/4 wave shorted stub, decoupling occurs at the open end.
My question:
Is there any difference if the shorted end is pointing to the center or to
the tip of dipole.
Only the stub portion has two wires in parallell, the rest is only one wire.

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OR

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73 Jouko OH5RM

On Apr 12, 11:54*am, "JN" wrote:
I am planning a two band antenna for 30 and 80m using linear traps.
73 Jouko OH5RM

Jouko.......you might try to GOOGLE:

"lattin antenna"

That may lead you to useful information.

Lee KA0FPJ

Jouko.......you might try to GOOGLE:

"lattin antenna"

That may lead you to useful information.

Lee KA0FPJ


Yes Lee, Google found quite a lot of hits, but they all refer to one 5band
antenna design with no much
real information. So my question still remains open. Could some modelling
program give the answer?
I think those two alternatives differ at least in how much inductive loadind
they are causing to the lower frequency
and so shortening the total length of antenna.

Jouko OH5RM

On Tue, 15 Apr 2008 11:39:04 +0300, "JN" wrote:



Jouko.......you might try to GOOGLE:

"lattin antenna"

That may lead you to useful information.

Yes Lee, Google found quite a lot of hits, but they all refer to one 5band
antenna design with no much
real information. So my question still remains open. Could some modelling
program give the answer?
I think those two alternatives differ at least in how much inductive loadind
they are causing to the lower frequency
and so shortening the total length of antenna.

Hi Jouko OH5RM

Yes modeling can give an answer:
NO

It does not work.

73's
Richard Clark, KB7QHC

Hi Jouko OH5RM

Yes modeling can give an answer:
NO

It does not work.

73's
Richard Clark, KB7QHC

Hi Richard,

Sorry I didnt quite understand your short answer.
What does not work? The whole principe of decoupling stubs?
Unfortenately I myself have no modelling program.

73 Jouko OH5RM

On Tue, 15 Apr 2008 19:48:53 +0300, "JN" wrote:

Hi Jouko OH5RM

Yes modeling can give an answer:
NO

It does not work.

73's
Richard Clark, KB7QHC

Hi Richard,

Sorry I didnt quite understand your short answer.
What does not work? The whole principe of decoupling stubs?
Unfortenately I myself have no modelling program.

Hi Jouko,

Basically, what you describe was discussed here last week as the W9INN
dipole, and recently as the Lattin dipole. Being the same thing as
your twin line (parallel line, or folded stub, or whatever); the
premise is these elements resonate and thus trap an antenna for
multiband operation. Those stubs are not oriented correctly.

Let's take this by degrees. Any dipole is a multiband antenna. Those
bands might be useful, and they might not. The point is that being
multiband is nothing remarkable in itself. What is remarkable is if
that antenna is useful in every band you want to use it in. This is
the "Holy Grail." Nearly 60 years ago, a Ham invented the Lattin
antenna. We cannot say it was designed because it never performed
according to claims (and I do mean NEVER). It was even patented.

Designs do work, inventions rarely do. We get inventors here every
week, some hang around for years. The bottom line is that if these
inventions worked, we would be using them (and that is 2% of the goal
of these inventors, the other 98% is seeking validation as being
eminent thinkers). The Lattin antenna's balance sheet shows 1PPM
usage, and no pursuit of validation (the inventor is dead, but some
still keep the vigil and change the flowers at Internet memorial
sites).

You can try your hand at modeling by visiting:
http://www.eznec.com/
The Lattin design is easily constructed by a model, I've done several
dozen variations. You can also model stubs that are oriented
correctly and that will work.

73's
Richard Clark, KB7QHC

..

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I_________

OR

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________I


73 Jouko OH5RM


Different text sizes seem to destroy the graphics, I used the medium size in
Outlook express.
Anyway the upper is OK , the lower should look like this

______________________________________/center/_____
___________I

OH5RM

On Wed, 16 Apr 2008 09:21:13 +0300, "JN" wrote:

.

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I_________

OR

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73 Jouko OH5RM


Different text sizes seem to destroy the graphics, I used the medium size in
Outlook express.
Anyway the upper is OK , the lower should look like this

______________________________________/center/_____
___________I

OH5RM


from OP
My question:
Is there any difference if the shorted end is pointing to the center or to
the tip of dipole.
Only the stub portion has two wires in parallell, the rest is only one wire.

Jouko, I noticed this thread took a detour, but I never saw anyone
actually try to answer your question. I too, am looking to see the
answer on this.

It is amazing, all this talk about a Lattin antenna, that appears to
have lots of sites talking about how it works, but no one actually
having built one or used one, and a simple "yes" or "no" would answer
your question.

I don't have the answers or the means of testing one at this time. If
you get the answer direct, please post it here.

Thanks
Buck
N4PGW
--
73 for now
Buck, N4PGW

www.lumpuckeroo.com

"Small - broadband - efficient: pick any two."

Jouko, I noticed this thread took a detour, but I never saw anyone
actually try to answer your question. I too, am looking to see the
answer on this.

73 for now
Buck, N4PGW

www.lumpuckeroo.com

Yes Buck it is often difficult to get an answer just to the question you are
asking.
Anyway very soon all snow has melted away here and then its possible to
testbuild it.

73 Jouko OH5RM

"JN" wrote in message
...
Jouko, I noticed this thread took a detour, but I never saw anyone
actually try to answer your question. I too, am looking to see the
answer on this.

73 for now
Buck, N4PGW

www.lumpuckeroo.com

Yes Buck it is often difficult to get an answer just to the question you
are asking.
Anyway very soon all snow has melted away here and then its possible to
testbuild it.

73 Jouko OH5RM

Hi Jouko

I thought Richard's statement that modeling would tell you about how the
design might perform, was good advice. If you use EZNEC, I'd be willing to
help you if you dont already know how to use it to model your antenna.

Jerry KD6JDJ