The advise you have been given is good.
I will tell you my experience of Windoms. I built my own via info in the
Radio communications handbook, loads of info is on the net anyway. I have a
4-1 balun at the point where the 2 horizontal wires meet and a 1-1 balun at
22ft down from this. My antenna elements run as horizontal as possible and
the downlead drops down and as far away from any object that I could make
it. It works brilliant THROUGH A TUNER. In my opinion you will never get the
swr quoted by all the manuafactured windoms without a tuner.
BUT dont worry about the swr being a little high. All multiband antennas are
a compromise, but how many of us can put up a dipole for each band.
Good luck youll find the windom works well. Basically Im saying use a tuner
and dont get stressed out about the swr.
Les
"Richard Clark" wrote in message
...
On Sun, 25 Apr 2004 13:54:28 -0500, "Pat Myers"
wrote:
At first I thought to try the old stand-by, the G5RV, but in doing my
Internet research on the issue, I came across this "Carolina Windom"
multiband antenna, which seemed to give more bangs for the buck.
There are simpler, cheaper ways to accomplish the same end, so let's
just make the best of what you got.
After making up the 100 or so foot feed line (RG-8X) and grounding the
rig
(8' copper ground rod), I hooked up my Yaesu FT-890...and the SWR was
through the roof on all bands.
A copper ground rod is only good for an AC safety ground. If you want
an RF ground, you need some radials. We will skip this for the time
being.
Anything more than a few watts, on 80 through 10m, made the radio shut
down.
This is a symptom of Common Mode problems. Your feedline is
radiating. How much is immaterial until it causes the shut down. It
is apparent that the BalUn is a conventional 4:1 with no choking
action (no point in asking them why not). Put a 1:1 Current BalUn
just before it, or wrap your coax into 6-8 loops of 6 inches (at the
feed point).
Except for power and phone lines running along the back property line
(and
the slinky antenna I put up later is no further away from those than the
Windom was, and I am having no problems with it), there was nothing
metallic
nearby to detune the antenna, and even if there was, I can't imagine even
that would create the high SWR I am seeing.
None of these will be so disruptive. It is Common Mode problems.
I called the manufacturer up and after telling me there was nothing wrong
with the antenna based on what I told them, they just said to send the
antenna back to them and they would "check it out".
A waste of everyone's time.
Given how much I will pay out further on shipping the antenna both ways
and
the like, I am wondering if I would be better off simply buying a decent
4:1
balun, replace the existing "matching transformer" with it, and use the
rest
of the antenna components (wire, coax, RF choke), and if so, is this more
likely to work? Based on my research, the original Windom antenna design
used a 4:1 balun, and the wire lengths of the antenna I bought look to be
pretty close to specs per that design, which is why I suggest this
option.
The choke (or added 1:1 Current BalUn) should fix it to the point you
can tune it in. You ARE using a tuner are you not? This isn't a
magic antenna.
The only multiband wire antennas (with names) that do not require
tuners are the ones that come with resistors built in. You did not
purchase this option. You WILL need a tuner.
73's
Richard Clark, KB7QHC
|