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