Thierry wrote:
Thanks for all comments.

I did a mistakle in my specs because they are no traps on the windom (I
confused with W4DZZ).

In fact I thought that both designs being wire antennas of almost the same
length, they 'd display the same radiation pattern at a few percent.
But I was focused on the shortest segment (1/3) of the windom and wonder
whether it could cause or not additional problems or display drawbacks
compared to a real dipole...
In all case I will test it in 2 weeks.
Problem with dipole3, the influence of a shorter segment is not taken into
account. I don't know if that could be important, probably not much, but it
'd have been interesting to add some additional parameters like the length
of each segment and the tilt of the tilt too to get a more accurate result.

Addition:
My believe is founded. I just find some radiation patterns and comments in
the ARRL antenna book ch7-8. The windom is much more omnidirectional than a
dipole. They say that "the system (windom) takes advantage of the asymmetry
of the horizontal wires to induce current onto the braid of the vertical
coax section.... The radiation pattern... tends to fill in the deep nulls
that 'd be present ... if horizontally center fed".
globally they consider that the windom give better results due to the
omnidirectional pattern or so than a true dipole.
Anyway, if I have the courage I will try to simulate the windom in Multinec.


Thanks for the help
Thierry, ON4SKY


"Reg Edwards" wrote in message
...

Taking one band with another and one direction with another, the

difference

between a Windom and G5RV will be entirely undetectable.

They will both have somewhat poorer performance than a simple random

length

dipole of about the same length and height fed over a random length, high
impedance, any Zo, open-wire line.

Following the study you have given to the subject, you may be disappointed
at the responses to your question, But you did ask.

And there's no reason why you should be deterred from experimenting with
either or both types of antenna. You will then be at least as wise as us
Old Wive's.

If you should like playing with just a few numbers then amuse yourself

with

small programs DIPOLE3 and ENDFEED. Download from website below in a few
seconds and run immediately. They provide lots of data but the most
important thing is the single number - radiating efficiency!
---
................................................ ...........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
................................................ ...........





Hi Thierry:

The only draw back of the off center fed dipole is the possibility of
introducing radiation from the feedline which can make for R.F. in the
Shack if not properly acconted for , it also makes predicting the
radiation pattern a little skewed to the long end of the dipole. I Use
two off center fed dipoles (miss nomer windoms) here one is cut for 40m
long the other 20m long the 40m long one is fed with a 4:1 balun and 75
ohm coax the 20m long is fed with 300 ohm open wire line to a tuner.
both antennas do a good job for me. I do mostly causual dxing (but as
one poster has already said you'll have to decide which propagation mode
you are seeking if grayline put up a vertical or other lowangle radiator
for 80meters.) They are mounted at 90 degrees to each other. I've been
able to work lots of dx on these antennas .. I had two g5rv's up prior
to these and from a pure operational veiw point find them a little
better at my location.

hope this is of some help.
73 Dave

"Cecil Moore" wrote in message
...
Walter Maxwell wrote:
If I may put in my two-cents worth, a dipole is a dipole. The G5RV is a
dipole
and the Caroling Windom is a dipole.

Hi Walt, I don't know if you know or not, but the Carolina Windom
is designed for the vertical section to radiate so it has a
radiation pattern which is a combination of a dipole and a vertical.


Indeed, all the interest of the thing..., hence my question.
But I wonder also about the QRM pick-up along this vertical segment...
I will have the answer in two weeks.

Thierry, ON4SKY

--
73, Cecil, W5DXP


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"KC1DI" wrote in message ...
Thierry wrote:
Thanks for all comments.
...
I Use
two off center fed dipoles (miss nomer windoms) here one is cut for 40m
long the other 20m long the 40m long one is fed with a 4:1 balun and 75
ohm coax the 20m long is fed with 300 ohm open wire line to a tuner.
both antennas do a good job for me. I do mostly causual dxing (but as
one poster has already said you'll have to decide which propagation mode
you are seeking if grayline put up a vertical or other lowangle radiator
for 80meters.) They are mounted at 90 degrees to each other. I've been
able to work lots of dx on these antennas .. I had two g5rv's up prior
to these and from a pure operational veiw point find them a little
better at my location.

For sure the location add a bias factor, soil, rock, sand, trees, etc affect
the radiation pattern, all the more that on my Windom the coax segment will
be at 50% in trees... although the ladder line of my G5RV was in the air,
off trees...
Anyway, I will have the confirmation in a few weeks.
If results are "unattended" I will post a new msg.

73
Thierry, ON4SKY


hope this is of some help.
73 Dave

I have used 160M Carolina windoms for the past 5 years or so and have
found them to be really good performers. The higher you can get the
vertical element off the ground the better (I have had good results
with it only 20' off the gorund....Radioworks recommends more). I have
never modeled it, nor had experience with G5RV, but compared to a half
wave dipole at similar height, my "impression" is that it performs at
least as well, probably better, plus multiband. Beward you will need
to use a tuner with it, and if you are running legal limit, be careful
of your SWR's as you can burn out the balun or RF choke (they are not
traps). There has been a lot of debate about this antenna, but I can
tell you the 160M version works quite well on all bandsl.
GL es 73
Dan (k0dan)

On Fri, 17 Sep 2004 15:35:28 +0200, "Thierry"
http://www.astrosurf.com/lombry wrote:


"Cecil Moore" wrote in message
...
Walter Maxwell wrote:
If I may put in my two-cents worth, a dipole is a dipole. The G5RV is a
dipole
and the Caroling Windom is a dipole.

Hi Walt, I don't know if you know or not, but the Carolina Windom
is designed for the vertical section to radiate so it has a
radiation pattern which is a combination of a dipole and a vertical.


Indeed, all the interest of the thing..., hence my question.
But I wonder also about the QRM pick-up along this vertical segment...
I will have the answer in two weeks.

Thierry, ON4SKY

--
73, Cecil, W5DXP


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

The original windom of the 1920's had a single wire (vertical)
feedline. The Carolina Windom as sold by Radioworks has RF radiation
from the feedline which is a deliberate design consideration of this
antenna; it has a vertical element (the piece of coax hanging off the
balun) which is designed to radiate,. and which creates the low angle
lobes. The RF radiation is STOPPED at the RF choke which is at the end
of the "feedline". Then YOU feedline connects here and essentially
does not radiate.

There is alot of information on this antenna at
http://www.radioworks.com/, some of which contradicts some of the
mythology which appears in the NG's and reflectors..
73
Dan (k0dan)


Hi Thierry:

The only draw back of the off center fed dipole is the possibility of
introducing radiation from the feedline which can make for R.F. in the
Shack if not properly acconted for , it also makes predicting the
radiation pattern a little skewed to the long end of the dipole. I Use
two off center fed dipoles (miss nomer windoms) here one is cut for 40m
long the other 20m long the 40m long one is fed with a 4:1 balun and 75
ohm coax the 20m long is fed with 300 ohm open wire line to a tuner.
both antennas do a good job for me. I do mostly causual dxing (but as
one poster has already said you'll have to decide which propagation mode
you are seeking if grayline put up a vertical or other lowangle radiator
for 80meters.) They are mounted at 90 degrees to each other. I've been
able to work lots of dx on these antennas .. I had two g5rv's up prior
to these and from a pure operational veiw point find them a little
better at my location.

hope this is of some help.
73 Dave

Indeed, all the interest of the thing..., hence my question.
But I wonder also about the QRM pick-up along this vertical segment...
I will have the answer in two weeks.

Thierry, ON4SKY

Why would QRM be a problem ? The beter the antenna the more signal it will
pick up. Maybe you ment QRN (noise) instead of M (undesired radio signals)
?

"Thierry" http://www.astrosurf.com/lombry wrote in message ...
Ok Mark, for sure for DXing a dipole or a windom is not a beam...

I'd rather have the coax fed dipole over the windom any day though...I
bet many people would think it's a beam , the way it will most likely
trounce the average windom.
I tried one "windom" at a field day against a coax fed dipole. The
dipole won by 2 s units in any direction. Thats about what you would
see going from a coax dipole to an average beam...:/ Or by changing
from 100w to 500w-1 KW...



My objective is Dxing first as for local QSOs this is not a problem to get
S9+.

If it's working local, why would it not be working dx ok? Why the
change to an antenna which basically will be the same, assuming
element lengths are fairly close for a given band, barring any changes
in feedline efficiency? IE: I assume you are going to switch from a
G5RV to a windom....
Thinking about either one of those antennas makes me want to take up
golf...
I don't like either one. It's no secret though....
The only thing the G5RV has going for it, is it is nearly a EDZ on
20m. But it's a reduced efficiency version compared to one fed in a
normal manner...
Coax to a choke to ladder line as a feedline is no way to live for a
serious dx'er who wants most of his power to actually be radiated by
the antenna element...The windom is not much better in this
regard....Or at least the ones I've seen.

I know very well that DX performances will be more than limited, all the
more in SSB, but this is a temporary solution waiting for a small beam 3-or
4 ele.

You still don't mention which band/s though... There are fairly simple
wire antennas much better for dx than the usual all band compromise
wire antenna. IE: extended double zepps, phased parallel dipoles, etc,
etc. I would use something along those lines if I wanted to dx say 20m
or up...If you want to dx 80/40, you might consider a bobtail curtain
or variant, or a good vertical. Trying to increase the dx potential by
changing from one semi lame antenna , to another semi lame antenna
strikes me as counterproductive. But, it's your yard and $$$.... :/
MK

"dmr" wrote in message
...
I have used 160M Carolina windoms for the past 5 years or so and have
found them to be really good performers. The higher you can get the
vertical element off the ground the better (I have had good results
with it only 20' off the gorund....Radioworks recommends more). I have
never modeled it, nor had experience with G5RV, but compared to a half
wave dipole at similar height, my "impression" is that it performs at
least as well, probably better, plus multiband. Beward you will need
to use a tuner with it, and if you are running legal limit, be careful
of your SWR's as you can burn out the balun or RF choke (they are not
traps).

Hi,

160m long 20' high ? That must be interesting and u had to confirm over 100
dx with such a length...
I very well know these problems of SWR etc,and many others. I am an OT you
know,... Hi! I learnt the lesson in the past in experimenting live a bad
SWR... youth errors as one tells... but interesting because I never more
forget the lesson, like many others in experimenting myself.
With some respect it it far better to be chocke a second and get a little
blister due to a SWR over 5:1 using a kW amp that having hours of theory...
because you cannot fix your idea on concrete things.

For the rest, of course the heigth (and length) are VERY important, all
using a dipole or windom all work fine or almost from 8m high and 20m long
and up. Below your radiation pattern is seriously affected compared to the
ideal solution (say 2-lamba over 12m high). And you feel that very well when
trying to call CQ DX and even simple CQ up to 5000 km away.
To get an idea simulate these specs in modeling software like multiprop that
use a VOACAP engine, or even nec, hfant and others.

See my best site for detail.
Thanks for the help.

73
Thierry, ON4SKY

There has been a lot of debate about this antenna, but I can
tell you the 160M version works quite well on all bandsl.
GL es 73
Dan (k0dan)

On Fri, 17 Sep 2004 15:35:28 +0200, "Thierry"
http://www.astrosurf.com/lombry wrote:


"Cecil Moore" wrote in message
...
Walter Maxwell wrote:
If I may put in my two-cents worth, a dipole is a dipole. The G5RV is
a
dipole
and the Caroling Windom is a dipole.

Hi Walt, I don't know if you know or not, but the Carolina Windom
is designed for the vertical section to radiate so it has a
radiation pattern which is a combination of a dipole and a vertical.


Indeed, all the interest of the thing..., hence my question.
But I wonder also about the QRM pick-up along this vertical segment...
I will have the answer in two weeks.

Thierry, ON4SKY

--
73, Cecil, W5DXP


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

"Ralph Mowery" wrote in message
ink.net...
Indeed, all the interest of the thing..., hence my question.
But I wonder also about the QRM pick-up along this vertical segment...
I will have the answer in two weeks.

Thierry, ON4SKY

Why would QRM be a problem ? The beter the antenna the more signal it
will
pick up. Maybe you ment QRN (noise) instead of M (undesired radio
signals)
?

No ! I speak of QRM, made made, due to vertical segment (vertical polarized
I believed) that, i thougth, 'd pick up more QRM, in the same way as a
vertical antenna coupled to a dipole tight horizontally e.g..
But in this case it doesn't as this is a common-mode choke balun ; there is
no RF radiation form the coax.
In all cases I will see the result in the field very soon, adn could
appreciate both designs (dipole vs. windom).

Thierry, ON4SKY

"dmr" wrote in message
...
The original windom of the 1920's had a single wire (vertical)
feedline. The Carolina Windom as sold by Radioworks has RF radiation
from the feedline which is a deliberate design consideration of this
antenna; it has a vertical element (the piece of coax hanging off the
balun) which is designed to radiate,. and which creates the low angle
lobes. The RF radiation is STOPPED at the RF choke which is at the end
of the "feedline". Then YOU feedline connects here and essentially
does not radiate.

I use a common chocke balun. the coax doesn radiates RF.

Thierry

There is alot of information on this antenna at
http://www.radioworks.com/, some of which contradicts some of the
mythology which appears in the NG's and reflectors..
73
Dan (k0dan)


Hi Thierry:

The only draw back of the off center fed dipole is the possibility of
introducing radiation from the feedline which can make for R.F. in the
Shack if not properly acconted for , it also makes predicting the
radiation pattern a little skewed to the long end of the dipole. I Use
two off center fed dipoles (miss nomer windoms) here one is cut for 40m
long the other 20m long the 40m long one is fed with a 4:1 balun and 75
ohm coax the 20m long is fed with 300 ohm open wire line to a tuner.
both antennas do a good job for me. I do mostly causual dxing (but as
one poster has already said you'll have to decide which propagation mode
you are seeking if grayline put up a vertical or other lowangle radiator
for 80meters.) They are mounted at 90 degrees to each other. I've been
able to work lots of dx on these antennas .. I had two g5rv's up prior
to these and from a pure operational veiw point find them a little
better at my location.

hope this is of some help.
73 Dave