Jim Lux wrote:
Michael Coslo wrote:
wrote:

Thoughts?

Maybe time to download EZnec?

The OCF antenna can work very well. I put one up once because the
place where the coax dropped was really handy to my shack entrance. It
worked "well". I did some QRP into California on 80 meters during a
contest, and I worked what I heard. That doesn't specifically mean
that the antenna performed well, but it does mean that I worked QRP
into California on 80 from the middle of PA.



How will you model the radiating feedline? I suppose one could just put
a "wire" in the model to represent the coax shield (which is what
radiates) and tie it to something useful. Someone's probably figured
out what the equivalent impedances are for the "isolator" and "balun"
that form part of that antenna. Maybe googling "NEC model Carolina
Windom" might turn up something useful.

That's pretty much what I would do re the wire. I suspect that the
pattern would be complex in any event. Richard was closest to correct
when he advised to listen to the manufacturer.

At first blush, I would think that the antenna is probably not far from
omnidirectional, but the horizontal component might skew it a bit. Any
rate, I don't think that his issues with working EU are antenna related.

- 73 de Mike N3LI -

On Oct 16, 2:28*pm, wrote:
Hi Steve,

Thanks for the azimuth plot. This was just what I was looking for.

It would be useful to have azimuth plots for 40 and 80 for this antenna;
if for nothing else than a starting point.

Rick
W9ZD

Rick,

On 80m it's almost omni-directional; worst-case eccentricity is around
4.5dB at 26 degrees elevation angle. The preferred directions are
broadside.

On 40m the pattern is more complex. At medium elevation angles (40-70
degrees) end-to-end is slightly better than broadside; at lower
elevation angles the pattern develops into 4 lobes NE/NW/SE/SW
(ssuming the antenna runs N-S)

Hope that helps,

Steve G3TXQ

I have a Carolina Short 80 formerly called the Carolina 80 Beam up. Its been
up since about 1990 and is a good performer.

On 80 it does good off the ends but has a skewed figure 8. My antenna is
broadside N and S. K4UEE told me that from the Juan Fernandez operation a
few years back I was about the loudest on 75 SSB. I regularly worked EM1
from near the South pole with 9+ both ways. On 20 the pattern is still a
figure 8 but with a big lobe off the ends so I worked VK and ZL from Georgia
one year in the Oceania Contest.

I have two vertical short dipoles on 75 and 80 and another Carolina Short 80
broadside say NE/SW would probably do as good. To be really effective you
have to get it up at lesat 50 feet and higher is better!

My version of the Short 80 is only 84 feet horizontal.
I have the three vertical sections with the one at the feedpoint radiating.
The DMU matching 52 ohm coax to the 300 ohm point. The DMU also lets the
shield radiate. The 22 foot piece of coax teminates in a Line Isolator
balun to cut the radiation to the shack at that point.

Just wish Radio Works would fully explain the antenna. It is very difficult
to model but thanks to Dr. Dave then W0MHS (now W7FB) he ran it on his
mainframe modeling program. We never got NEC to show us anything beyond a
OCF windom model.

Dave K4JRB