[TowerTalk] Carolina Windom

[Thor Hallen]

This type of antenna is described as an Off Center Fed (OCF) dipole in the 
ARRL antenna book. It is not restricted to even harmonics and will provide 
low SWR on both 80 and 40 meters if fed 25% from one end. The drive point 
impedance is a good match for 200 ohms. I use a 4:1 current mode balun to 
provide a good match to 50 ohm coax and prevent RF current from flowing on 
the coax. I have cut mine to be resonant slightly above the 40 meter band 
and slightly lower than the 75 meter band as a compromise. This enables me 
to match all bands from 80 to 6 meters using the automatic antenna tuner in 
my Icom 756Pro xcvr. The major lobes are broadside on 75 and off the ends 
on 40 meters. This antenna makes a great stealth antenna because it doesn't 
need visible traps. One side of mine is 32 feet across the roof to the feed 
point at the edge of the roof and the other side is 95 feet to the edge of 
my lot. I use #18 wire painted flat black and the antenna is essentially 
invisible from the street. The balun is mounted on the side of the house 
and connects to the antenna through a short 4 foot length of 200 ohm twin 
lead.

- Thor Hallen K5AGE

-----Original Message-----
From:	n4kg@juno.com [SMTP:n4kg@juno.com]
Sent:	Friday, October 20, 2000 4:16 AM
To:	TOWERTALK@contesting.com; jfleming@shelbynet.net
Subject:	Re: [TowerTalk] Carolina Windom

Is the Carolina Windom fed 1/3 of the distance from the end?

I saw an article from the 1950's (Radio and TV News?) that
demonstrated that a wire that is 1/2 WL long at the lowest
frequency of use will exhibit a 300 Ohm feed impedance
at that frequency and all EVEN harmonics.  This type
of antenna has also been reported in QST and CQ. The
pattern of course will depend on the electrical length, i.e.,
it will behave as a halfwave dipole on the lowest frequency,
a 1 WL LW on the second harmonic (4 lobes), a 2 WL LW
on the 4th harmonic (8 lobes, major lobes ~30 degrees
from the wire), and a 4WL LW on the 8th harmonic.
(WL=Wave Length,  LW=Long Wire).  With coax feed
hanging straight down there is NO feedline radiation.

de  Tom  N4KG


On Tue, 17 Oct 2000  "WA9ALS - John" <jfleming@shelbynet.net> writes:
>
>
> > A ham has asked me to comment on the Radio Works Carolina
> Windom(cw).  I
> > have one of these, and have used it for a couple of years,
> interchanged with my G5RV and ladderline fed dipole.
> >
>
> I was afraid this antenna would come up in the thread on vertical
> radiators - HI.  Considering the lengthy discussion about the G5RV,
> surely there will be no end to it regarding the CW!  HI  I'm not sure
> ANYone really
> knows how it works, exactly, but theories absolutely abound and have
> been discussed in other forums.
>
> I have the 265 ft version.  I will only comment that it works great
> (most huge wire antennas would do pretty good).  It's a gangbuster on
> 160M.  I did lose 2 of the "Dedicated Matching Units" (proprietary
balun) -
> ?lightning once, ?unknown the othr time, maybe too much power despite
the
> specs. Depending how it's suspended, it's not easy to use BIG coax to
feed
> it. Radio Works says that you can use RG-58 even at full power, but we
> know that's stretching things a bit.  On my third DMU, I've limited my
> high duty cycle power (RTTY) to 500W and haven't lost another.
(Replacing the
> DMU with a rowboat is tricky!)
>
> Mine initially had a 2:1 SWR EVERYWHERE in the 10-160 ham bands.
> With "age", I now need a tuner on some bands.  FOr the money and space
> considerations, it's a great antenna, especially if you don't run
> too much power or op heavy duty cycle.  I tune mine with the
Nye-Viking.
>
> IMHO, TT would not be the best forum to get into a looonnng thread
> about whether it radiates vertically or not...  Doubt there's much
proof
> out there!  73
>
>

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