I´m planning to build a new multi-band antenna, and found something
entirely new to me , an antenna like a w3dzz but with ´stubs´instead of
traps. Take a look at www.g3ycc.koroo.net/lattin.htm
Should be possible to build with wires and spacers?
Anyone know (and uses!) this antenna?
I also have been thinking of a T2FD-ant, tips on
inductance-free resistors tnx, someone built a smart T2FD?
(smart meaning simple solutions for R and feeding (coax) )
Comments please!

Happy Newyear etc / per / sm7aha

pegge wrote:
I=B4m planning to build a new multi-band antenna, and found something
entirely new to me , an antenna like a w3dzz but with =B4stubs=B4
instead of traps. Take a look at www.g3ycc.koroo.net/lattin.htm

Last I heard, no one has independently verified that it works as
advertised. A/B comparisons to a dipole would be nice as would a
simulation model.
--
73, Cecil http://www.qsl.net/w5dxp

pegge wrote:
I=B4m planning to build a new multi-band antenna, and found something
entirely new to me , an antenna like a w3dzz but with =B4stubs=B4
instead of traps. Take a look at www.g3ycc.koroo.net/lattin.htm

Just noticed that the URL should be:

http://www.g3ycc.karoo.net/lattin.htm

Here's an earlier quote that might interest you:

Lee Carkenord KA0FPJ Denver CO wrote: 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.
--
73, Cecil http://www.qsl.net/w5dxp

On Sun, 02 Jan 2005 14:19:17 GMT, "pegge"
wrote:
I´m planning to build a new multi-band antenna, and found something
entirely new to me , an antenna like a w3dzz but with ´stubs´instead of
traps.
http://www.g3ycc.karoo.net/lattin.htm

Hi Pegge,

This is one of those designs that has elements of authenticity, but
poor implementation. In other words, it does not work in the way it
is described (and is notorious for not working at all).

The elements of authenticity are with stubs as you have noted. Open
and closed stubs do replace lumped circuits of inductors and
capacitors to function as traps and loads. The poor implementation is
that you do not construct stubs to replace those traps or loads in the
ways commonly described (and the added stringer wires only compound
the poor logic).

Every implementation I've observed consists of building the stub
without feeding it across its mouth, but along its body. This makes
the other half of the stub (the total structure now no longer a stub)
simply a parasitic wire with no particular merit.

Proper stubs on VHF/UHF antennas that can support them, give the
proper orientation of being at 90° to the radiating structure (unlike
the Lattin). Sometimes the stub is compressed by folding or rolling
its length around the antenna, but the mouth is always in series with
the radiating element. In other words (use fixed font to view one
half of a dipole, source on the left as § ):
§------------------ -------------------
| |
| |
| |
--
But not:
§-----------------------------------------
|
---------

To build the Lattin style with mouth fed stubs (and probably not
functioning as traps), would require three wire constructions:
§---------------------------
|
---------
|
-----------------------
Which is now verging on the concept of a Franklin Antenna which you
should research in place of Lattin styles. However, I would point out
that the Franklin is a single band gain antenna. I only mention it to
study as it gives a better theoretical description (and works because
of it).

73's
Richard Clark, KB7QHC

"pegge" wrote in message
...
I´m planning to build a new multi-band antenna, and found something
entirely new to me , an antenna like a w3dzz but with ´stubs´instead of
traps. Take a look at www.g3ycc.koroo.net/lattin.htm
Should be possible to build with wires and spacers?
Anyone know (and uses!) this antenna?
I also have been thinking of a T2FD-ant, tips on
inductance-free resistors tnx, someone built a smart T2FD?
(smart meaning simple solutions for R and feeding (coax) )
Comments please!

Happy Newyear etc / per / sm7aha



hi pegge

the link didn't work for me

an example of stubs alone is the KLM beam

http://www.postech.ac.kr/~hl5nlq/ham/kt34a.htm

an example of stubs and traps is the Cushcraft R8 vertical

http://www.cushcraft.com/amateur/details.asp?catid=157

73
H.

On Sun, 02 Jan 2005 14:19:17 GMT, "pegge"
wrote:

I´m planning to build a new multi-band antenna, and found something
entirely new to me , an antenna like a w3dzz but with ´stubs´instead of
traps. Take a look at www.g3ycc.koroo.net/lattin.htm
Should be possible to build with wires and spacers?
Anyone know (and uses!) this antenna?
I also have been thinking of a T2FD-ant, tips on
inductance-free resistors tnx, someone built a smart T2FD?
(smart meaning simple solutions for R and feeding (coax) )


The URL above is in error - it should be
www.g3ycc.karoo.net/lattin.htm

I have built such an antenna, but I used the 1 inch wide window line
(450 ohm) instead of the 300 ohm foam filled. This should have 0.95
velocity factor instead of 0.8, so the sections had to be
proportionally longer. My dimensions are as follows:

A = 9.9 meters
B = 5.0 meters
C = 2.5 meters
D = 2.9 meters

I built it to be used as a hanging vertical fed against ground, but
have not been able to get it hung properly as yet. At the moment, for
test purposes only, it is hanging in a catenary with the high end
about 15 ft above ground and the feed point is at ground level and fed
agains a good earth ground.

Resonances occur at 2.96 MHz, 6.52 MHz, 10.12 MHz, 12.5 MHz, 19.46
MHz, and 28.57 MHz as measured with an MFJ Antenna Analyzer. I explain
the low frequency resonances being lower than the design values as
being due to the fact that the antenna is almost horizontal and not
very high. If I can get it hung vertically, I expect it exhibit
resonances closer to the design values.


Bob, W9DMK, Dahlgren, VA
http://www.qsl.net/w9dmk

"W9DMK (Robert Lay)" wrote in message
...
On Sun, 02 Jan 2005 14:19:17 GMT, "pegge"
wrote:

I´m planning to build a new multi-band antenna, and found something
entirely new to me , an antenna like a w3dzz but with ´stubs´instead of
traps. Take a look at www.g3ycc.koroo.net/lattin.htm
Should be possible to build with wires and spacers?
Anyone know (and uses!) this antenna?
I also have been thinking of a T2FD-ant, tips on
inductance-free resistors tnx, someone built a smart T2FD?
(smart meaning simple solutions for R and feeding (coax) )


The URL above is in error - it should be
www.g3ycc.karoo.net/lattin.htm

I have built such an antenna, but I used the 1 inch wide window line
(450 ohm) instead of the 300 ohm foam filled. This should have 0.95
velocity factor instead of 0.8, so the sections had to be
proportionally longer. My dimensions are as follows:

A = 9.9 meters
B = 5.0 meters
C = 2.5 meters
D = 2.9 meters

I built it to be used as a hanging vertical fed against ground, but
have not been able to get it hung properly as yet. At the moment, for
test purposes only, it is hanging in a catenary with the high end
about 15 ft above ground and the feed point is at ground level and fed
agains a good earth ground.

Resonances occur at 2.96 MHz, 6.52 MHz, 10.12 MHz, 12.5 MHz, 19.46
MHz, and 28.57 MHz as measured with an MFJ Antenna Analyzer. I explain
the low frequency resonances being lower than the design values as
being due to the fact that the antenna is almost horizontal and not
very high. If I can get it hung vertically, I expect it exhibit
resonances closer to the design values.


Bob, W9DMK, Dahlgren, VA
http://www.qsl.net/w9dmk

Thanks for sorting out the link.
Looks like a sound design.
Careful construction and measurement should yield a successful antenna.
73
H.

Hi, all concerned:

www.g3ycc.karoo.net/lattin.html

is the corrected url.

If the dimensions are added up, the overall physical length approaches that
of an 80M dipole. "Loading-effect" of the "fat-wire" dipole could be helped
along if needed on 80M by additional wire length past A.

The A-stubs reduce the electrical lengths each side to overall
40M-dipole-size.

Ditto B-stubs on 20M.

Ditto C-stubs on 15M.

Changing the D-lengths to single wires, or shorting both inner ends,
completes the 10M-dipole section.

Editorial comments:

The feed shown is "incorrect". Stubs at D are not needed, unless one wishes
to add higher-frequency capability. Single wires are sufficient for the 10M
portions of the dipole.

This Lattin antenna is not easily constructed or tuned, and it reminds me of
something from the category of solutions running around looking for
problems.

The current amateur application that I can think of which is done "properly"
is the KLM h-f tribander. The stubs are of open-construction, and the first
stubs, at the outside end the 10M portions of the antenna elements, can be
seen easily, even in pictures.

73, Dave, N3HE


"pegge" wrote in message
...
I´m planning to build a new multi-band antenna, and found something
SNIP

While a stub can be made to act just like a resonant circuit at one
frequency, and almost like one over a range of frequencies, it behaves
quite differently at frequencies which are quite different from the
resonant frequency -- such as on other bands. That is, the stub will act
like a trap at one band, but not at all like a conventional trap at
other bands. There's no inherent disadvantage in this, but it means you
can't simply replace traps with stubs and have the antenna behave the
same as before on all bands. Considerable redesign or adjustment might
be required.

Another caution is that a stub is likely to have lower Q than a good
trap. This can, but doesn't necessarily, result in significant loss on
some bands. Careful modeling can give a pretty realistic idea of the
loss you can expect.

Finally, if you model a stub in an application like this, you can't use
NEC or EZNEC transmission line models, because the currents on the wires
aren't equal and opposite -- you have to make the stub models out of
wires. And be sure to include wire loss if you want the model to give a
realistic assessment of loss.

Roy Lewallen, W7EL

pegge wrote:
I´m planning to build a new multi-band antenna, and found something
entirely new to me , an antenna like a w3dzz but with ´stubs´instead of
traps. Take a look at www.g3ycc.koroo.net/lattin.htm
Should be possible to build with wires and spacers?
Anyone know (and uses!) this antenna?
I also have been thinking of a T2FD-ant, tips on
inductance-free resistors tnx, someone built a smart T2FD?
(smart meaning simple solutions for R and feeding (coax) )
Comments please!

Happy Newyear etc / per / sm7aha

On Sun, 2 Jan 2005 16:03:08 -0500, "David J Windisch"
wrote:

Hi, all concerned:

www.g3ycc.karoo.net/lattin.html

is the corrected url.

If the dimensions are added up, the overall physical length approaches that
of an 80M dipole. "Loading-effect" of the "fat-wire" dipole could be helped
along if needed on 80M by additional wire length past A.

The A-stubs reduce the electrical lengths each side to overall
40M-dipole-size.

Ditto B-stubs on 20M.

Ditto C-stubs on 15M.

Changing the D-lengths to single wires, or shorting both inner ends,
completes the 10M-dipole section.

Editorial comments:

The feed shown is "incorrect". Stubs at D are not needed, unless one wishes
to add higher-frequency capability. Single wires are sufficient for the 10M
portions of the dipole.

This Lattin antenna is not easily constructed or tuned, and it reminds me of
something from the category of solutions running around looking for
problems.

The current amateur application that I can think of which is done "properly"
is the KLM h-f tribander. The stubs are of open-construction, and the first
stubs, at the outside end the 10M portions of the antenna elements, can be
seen easily, even in pictures.

Dear Dave,

I could certainly be wrong, but my calculations indicate that the "C"
stubs are designed to produce a trap for 10 meters - not 15 meters.

The feed shown is at worst ambiguous. Actually, according to my
measurements and according to common sense, the "D" stubs perform no
useful function. You can feed from either wire or you can twist those
two wires together and feed jointly - same result.

I think the purpose in carrying the same material all the way through
the design was the real point, but section D is just wire for the 10
meter dipole. There may have been some subtle reason for having a stub
at position D that resonates at 25 MHz, but I don't see it.


Bob, W9DMK, Dahlgren, VA
http://www.qsl.net/w9dmk