The following is some of the info I gathered in my attempts to
understand and build a Lattin. As I said in my previous post, I was
never able to get it to work as Mr. Lattin described. I wish that
when I tried to build it, I would of had access to todays "Antenna
Analyzer" test instruments.

It has been patented, filed Feb 13, 1948. Patent # 2,535,298 My
local library had the patent on microfiche, and I was able to get it
copied. I have a copy of his patent, with illustrations/drawings, on
file here.

Lattin described this antenna in QST in December of 1960.

July 1960 issue of "CQ" mag has a related antenna project, by
Richmond, W1CEJ, called "A Portable Dipole"

Vincent Lear, G3TKN has also worked with the Lattin design, and was
published in RSGB.

July 1992 issue of "73" mag has another article "Six-band linear trap
antenna" by Brumbaugh KB4ZGC..........using approx the same idea.

September 1986 issue of "73" mag has Lattin type antenna project
described...."The Texas Tango Antenna" by Garrett K5BTV.

Maybe the above info will stimulate some more experimentation and/or
modelling of the
Lattin. I sure hope so.

Lee Carkenord KA0FPJ

(Lee Carkenord) wrote in message . com...
The following is some of the info I gathered in my attempts to
understand and build a Lattin. As I said in my previous post, I was
never able to get it to work as Mr. Lattin described. I wish that
when I tried to build it, I would of had access to todays "Antenna
Analyzer" test instruments.

It has been patented, filed Feb 13, 1948. Patent # 2,535,298 My
local library had the patent on microfiche, and I was able to get it
copied. I have a copy of his patent, with illustrations/drawings, on
file here.

Lattin described this antenna in QST in December of 1960.

July 1960 issue of "CQ" mag has a related antenna project, by
Richmond, W1CEJ, called "A Portable Dipole"

Vincent Lear, G3TKN has also worked with the Lattin design, and was
published in RSGB.

July 1992 issue of "73" mag has another article "Six-band linear trap
antenna" by Brumbaugh KB4ZGC..........using approx the same idea.

September 1986 issue of "73" mag has Lattin type antenna project
described...."The Texas Tango Antenna" by Garrett K5BTV.

See also:

http://www.dxzone.com/cgi-bin/search...D=7496&ID=7496

Maybe the above info will stimulate some more experimentation and/or
modelling of the
Lattin. I sure hope so.

It seems to me that there are two major issues with the Lattin/W4JRW
antenna:

1) Mechanically, it can be challenging. Regular Twin Lead with one of
the wires cut is just too flimsy. If you use spreaders and such it's
not simple any more. What's really needed is for somebody to make
"tubular" Twin Lead with, say #16 or even #14 copperweld conductors.

2) The velocity factor of the Twin Lead is a challenge to model
because the stub sections radiate on some frequencies but not others.

The thing is really just another form of trap antenna.

I get the feeling that Lattin either went through serious math pushups
to get his design, or cut up a lot of Twin Lead, or both.


73 de Jim, N2EY

On 9 Apr 2004 13:44:16 -0700, (N2EY) wrote:
I get the feeling that Lattin either went through serious math pushups
to get his design, or cut up a lot of Twin Lead, or both.

Hi Jim,

I am working on the design, however the premise appears to be
"academic." In other words, there are some who can tell you how it
should work, but not why it doesn't.

Your description above suits the modeling to a T - serious math
pushups. I don't think anyone could stumble onto a 5 band antenna by
simple cut and try.

73's
Richard Clark, KB7QHC

In article , Richard Clark
writes:

On 9 Apr 2004 13:44:16 -0700, (N2EY) wrote:
I get the feeling that Lattin either went through serious math pushups
to get his design, or cut up a lot of Twin Lead, or both.

Hi Jim,

I am working on the design, however the premise appears to be
"academic." In other words, there are some who can tell you how it
should work, but not why it doesn't.

I *like* that turn of phrase!

"There are some who can tell you how it should work, but not why it doesn't."

Perfect companion to:

"If it happens, it must be possible."

Your description above suits the modeling to a T - serious math
pushups.

Thanks.

I don't think anyone could stumble onto a 5 band antenna by
simple cut and try.

I disagree! I think it not only could happen, but probably has happened
already, through a fortuitous combination of many factors.

But being able to come up with such a design that is well-documented and
reproducible is a whole 'nother thing. The Lattin antenna is a perfect example
of that.

73 de Jim, N2EY

On 10 Apr 2004 14:59:24 GMT, PAMNO (N2EY) wrote:
I don't think anyone could stumble onto a 5 band antenna by
simple cut and try.
I disagree! I think it not only could happen, but probably has happened
already, through a fortuitous combination of many factors.

Name one that works. And by works, is resonant in each band, and not
simply tuneable (as would be a common doublet).

But being able to come up with such a design that is well-documented and
reproducible is a whole 'nother thing. The Lattin antenna is a perfect example
of that.

Hi Jim,

The notion of a trapped antenna on the basis of resonant stubs
constructions is not shown in the data of my work to date, and
certainly not in the Lattin (insofar as the only interpretation
generally available on the net, setting the patent aside that is).

One of the key points goes to this notion of stub action. However,
the stub is not excited across its mouth, but along its length. This
is very distinctly exhibited in the numbers (the lack of correlation
of stub geometry to resonances). The constructions merely appear to
fatten a thin radiator and add capacitances and inductances that are
basically opportunistic - certainly no one has shown any correlations
that fit the geometries to the bands they are presumed to resonate to.

Hence my statement that caught your fancy. The Stub resonances
"should" explain the bands obtainable, and yet there has been
absolutely no supporting evidence to demonstrate that this occurs.

It does hold my interest, however, and I am hardly one to be put off
by failure's of other's theories - not with my more than 300 pages of
fractal data published in the face of fractal fools who confine
themselves to bragging about their science.

73's
Richard Clark, KB7QHC

In article , Richard Clark
writes:

On 10 Apr 2004 14:59:24 GMT, PAMNO (N2EY) wrote:
I don't think anyone could stumble onto a 5 band antenna by
simple cut and try.
I disagree! I think it not only could happen, but probably has happened
already, through a fortuitous combination of many factors.

Name one that works. And by works, is resonant in each band, and not
simply tuneable (as would be a common doublet).

Some forms of trap dipole and parallel dipole I have encountered were clearly
the result of cut-and-try rather than analysis and mathematical design.

But being able to come up with such a design that is well-documented and
reproducible is a whole 'nother thing. The Lattin antenna is a perfect
example of that.

Hi Jim,

The notion of a trapped antenna on the basis of resonant stubs
constructions is not shown in the data of my work to date, and
certainly not in the Lattin (insofar as the only interpretation
generally available on the net, setting the patent aside that is).

The title of the QST article (December, 1960) is "Multiband Antennas Using
Decoupling Stubs".

One of the key points goes to this notion of stub action. However,
the stub is not excited across its mouth, but along its length. This
is very distinctly exhibited in the numbers (the lack of correlation
of stub geometry to resonances). The constructions merely appear to
fatten a thin radiator and add capacitances and inductances that are
basically opportunistic - certainly no one has shown any correlations
that fit the geometries to the bands they are presumed to resonate to.

Hence my statement that caught your fancy. The Stub resonances
"should" explain the bands obtainable, and yet there has been
absolutely no supporting evidence to demonstrate that this occurs.

The claims of the QST article are that the stubs work as traps. It also
explains that the velocity factor is important in the whole design. The article
refers repeatedly to "tubular Twin Lead" as the optimum material for
construction because of its velocity factor of 0.8.

It does hold my interest, however, and I am hardly one to be put off
by failure's of other's theories - not with my more than 300 pages of
fractal data published in the face of fractal fools who confine
themselves to bragging about their science.

(grin)

73 de Jim, N2EY

It seems to me that there are two major issues with the Lattin/W4JRW
antenna: 1) Mechanically, it can be challenging. Regular Twin Lead with one of
the wires cut is just too flimsy.

When I tried to build a working version of the Lattin, I had 2
partners. The 3 of us, collectively, have a decent amount of
experience with home-brew antennas.
Our first attempt was done using flat TV twin-lead. It was fragile
and hard to work with, mechanically. Electrically, it was just
confusing. Unpredictable. I never felt that we were close to getting
a good workable multi-band antenna.

Some time passed, and we decided to try again. This time we used the
much sturdier ladder line (for traps/radiator) as a starting point.
Mechanically, this was a fairly robust device. Electrically, it was
the same as our previous attempt. We spent a lot of time with it.
Cut up a lot of wire. We finally reluctantly gave up. We _WANTED_
it to work, but we were just not able to get anything accomplished.
Again, we felt that we were never close to having a workable, 50 ohm
coax-fed, multi-band antenna.

Lee Carkenord KA0FPJ Denver CO

In article ,
(Lee Carkenord) writes:

It seems to me that there are two major issues with the Lattin/W4JRW
antenna: 1) Mechanically, it can be challenging. Regular Twin Lead with
one of
the wires cut is just too flimsy.

When I tried to build a working version of the Lattin, I had 2
partners. The 3 of us, collectively, have a decent amount of
experience with home-brew antennas.
Our first attempt was done using flat TV twin-lead. It was fragile
and hard to work with, mechanically. Electrically, it was just
confusing. Unpredictable. I never felt that we were close to getting
a good workable multi-band antenna.

Some time passed, and we decided to try again. This time we used the
much sturdier ladder line (for traps/radiator) as a starting point.
Mechanically, this was a fairly robust device. Electrically, it was
the same as our previous attempt. We spent a lot of time with it.
Cut up a lot of wire. We finally reluctantly gave up. We _WANTED_
it to work, but we were just not able to get anything accomplished.
Again, we felt that we were never close to having a workable, 50 ohm
coax-fed, multi-band antenna.

That's quite understandable, given that the original Lattin designed used
tubular Twin Lead and countd on a velocity factor of 0.8.

What sort of test gear and design methods did you folks use?

73 de Jim, N2EY

On 10 Apr 2004 14:59:24 GMT, PAMNO (N2EY) wrote:
That's quite understandable, given that the original Lattin designed used
tubular Twin Lead and countd on a velocity factor of 0.8.

What sort of test gear and design methods did you folks use?

Hi Jim,

This hard to accept given the timelines offered by those who have
reported the references. For one, the antenna was invented in the
late 40's and patented 26 Dec. 1950, and reported in 1960. ALL such
dates precede the introduction of tubular Twin Lead in the mid 60s.

73's
Richard Clark, KB7QHC

In article , Richard Clark
writes:

On 10 Apr 2004 14:59:24 GMT, PAMNO (N2EY) wrote:
That's quite understandable, given that the original Lattin designed used
tubular Twin Lead and countd on a velocity factor of 0.8.

What sort of test gear and design methods did you folks use?

Hi Jim,

This hard to accept given the timelines offered by those who have
reported the references. For one, the antenna was invented in the
late 40's and patented 26 Dec. 1950, and reported in 1960. ALL such
dates precede the introduction of tubular Twin Lead in the mid 60s.

Hello again!

Direct quotes from the 1960 QST article:

"If open line with a velocity factor near unity is used for the stubs, the
over-all lenght for a two-band antenna would be nearly a full free-space
wavelength at the higher frequency and and the whole antenna would resonate at
something less than half that frequency. Very fortunately, the the velocity
factor of 300-ohm tubular Twin-Lead (0.8) gives such lenghts for the stubs that
that, in most cases, the adding the stub makes the antenna resonate at just
half the original frequency."

"Fig. 3 shows how tubular Twin-Lead can be used for the antenna itself as well
as the stubs and includes dimensions for 10- and 20-meter operation. The
foam-filled type of Twin-Lead is recommended to keep out moisture."

So it must have existed when W4JRW wrote the article, some time before the
December 1960 QST went to press.

In addition, my 1953-54 RESCO (Radio Electronic Service Company, once a great
source of all things radio and TV here in the Philly area) catalog lists
Amphenol "flat and tubular Twin Lead". The tubular stuff is number 14-271 and
was 5 cents a foot - less in quantities of 100, 500 or 1000 feet. And it wasn't
a new item.

All of this supports both your experiences and those of others. If the exact
characteristics of tubular Twin Lead are important to the design, it's no
wonder that the reported results cannot be obtained.

One more point. The SWR graphs shown for the 5 band version show quite narrow
SWR bandwidths. If anyone is interested I can report them in a future post.

73 de Jim, N2EY