RadioBanter - View Single Post - Lattin antenna.............more info sources

April 23rd 04, 01:46 AM

On 22 Apr 2004 07:19:37 -0700, (N2EY) wrote:

Like I said, I've done some measures and added a dozen more since.
The results are interesting. I can come up with a four band antenna
without too much trouble; however, getting those bands into Ham
regions (all of them) is another matter. I can do this with a simple
run of twin lead, and one strategically placed short between them.

Which is not what Lattin did at all. Your design sounds far superior.
Is it on the web anywhere?

Hi Jim,

You should take care with my perverse generalizations, especially when
you follow it with:
The main attraction of the Lattin is its claim to multiband operation.
Otherwise one might as well go with a plain dipole.

A plain dipole is already mutibanded. This particular claim is easy
to achieve. It may not fall within interesting bands, but history
already suggests one dipole often serves more than one ham band if one
can accept the short comings (wrong directionality being key).

This is more a matter of the dichotomy of need: match and launch.
There may be more matching options than actual application of where it
is launched (too many lobes in the wrong directions).

In this sense, the trap serves to shorten the antenna to RESTRICT its
physical to electrical wavelength ratio to a quarter or less, thus
guaranteeing a mediocre performance from precious air space and
real-estate. If Art hadn't been nailed for a design 17dB below a
simple vertical, he would be here howling efficiency per unit length
(but, unfortunately in the wrong aspect - that's how you lose 17dB
behind the sofa).

Frankly, the Lattin has yet to prove to me that the notion of a
longitudinal stub as "trap" really holds any water. I've seen the
same "theory" applied to diametrically opposed designs. It is
pleasing to the arm-chair designer to mutter these ideas, but these
so-called streamers needed to make it work just yell foul on every
street corner. It is an ad-hoc design draped with academic mumblings
to lend it the appearance of legitimacy.

To extend my quote above, I have added yet another dozen measurements
to have nailed down patterns that emerged with the basis of a
consistent building paradigm (yeah, I know, gobbldygook). I seek to
generalize such claims as the Lattin makes and reduce them to a
practical minimum that are robust and repeatable. This is not to say
entirely useful, nor optimal.

I did the same thing with the fractal with 300 or more measurements
and reduced that junk science to a simple observation: you can push
more resonances into a length of wire, the more you kink it. Useful?
The test of time has shown that no one has made any money from those
same published 300 pages - why would I expect the Lattin to emerge
from 5 decades of neglect to eclipse that record? Frankly, the Lattin
simply confirms this simple observation, but is more controlled. It
may mature to a more repeatable design, but I doubt its inventor would
recognize it.

73's
Richard Clark, KB7QHC