Results: Carolina Windom
 

I thought I'd post the results of my recent little project to put up a
Carolina Windom for 80/40/20.

Didn't work very well. :-(

At least, not yet. ;-)

I cut it for 3.6 MHz, and according to everything I read that should give
decent performance on or about 7.2, 14.4, and 28.8 MHz.

Instead, I got 3.6 MHz (as expected), then I got about 6.6 and about 14.9.

I followed the instructions I found in one website article that said to
cut the legs for 37.8 percent and 62.2 percent.

Other articles I've read say to cut for 1/3 and 2/3 of a half wavelength,
i.e. feed the antenna 1/3 of the way from one end.

Since I'm a high precision sort of a dude ;-), I figured 37.8 and 62.2
were more precise than 1/3 and 2/3, so I tried them.

Like I said ... works well on 3.6 (and most of the rest of the 80 meter
band) but not anywhere else.

It is built with a W2AU balun (4:1), 22 feet of RG-8X, an MFJ "line
isolator" (1:1 current-type unun), then about 25 feet of RG-8X to the
shack.

I guess I'll have to go back up there next nice day and try the 1/3 2/3
way.

Results: Carolina Windom
 

In article ,
says...



I thought I'd post the results of my recent little project to put up a
Carolina Windom for 80/40/20.

Didn't work very well. :-(

At least, not yet. ;-)

I cut it for 3.6 MHz, and according to everything I read that should give
decent performance on or about 7.2, 14.4, and 28.8 MHz.

Instead, I got 3.6 MHz (as expected), then I got about 6.6 and about 14.9.

I followed the instructions I found in one website article that said to
cut the legs for 37.8 percent and 62.2 percent.

Other articles I've read say to cut for 1/3 and 2/3 of a half wavelength,
i.e. feed the antenna 1/3 of the way from one end.

Since I'm a high precision sort of a dude ;-), I figured 37.8 and 62.2
were more precise than 1/3 and 2/3, so I tried them.

Like I said ... works well on 3.6 (and most of the rest of the 80 meter
band) but not anywhere else.

It is built with a W2AU balun (4:1), 22 feet of RG-8X, an MFJ "line
isolator" (1:1 current-type unun), then about 25 feet of RG-8X to the
shack.

I guess I'll have to go back up there next nice day and try the 1/3 2/3
way.

The 14.9 MHz sounds about right, but the 6.6 MHz sounds
very weird. I would have believed 7.6. In general, the
40-meter resonance point will not be exactly twice what
it was on 80 meters, nor will the 20-meter resonance point
be exactly four times what it was on 80 meters. Generally,
it will be higher in frequency.

I have had good success in the past using the 1/3 and 2/3
leg lengths with a Spiro 4:1 balun and a bead balun right
at the feed point. However, if you really want this to
work on 40 and 20 meters, you will want to make your antenna
longer than you have.

I used legs of 45 and 90 feet. The SWR was about 1.0 at
3.5 MHz and 1.3 at 3.6 MHz. Actually, it didn't reach 2.0
until about 3.75 MHz. Lowest SWR on 40 meters was at 7.2 MHz
at about 1.0 and was low across the band. The lowest SWR on
20 meters was at 14.35 MHz at about 1.0, but was 1.8 at the
bottom of the band. By the way, it didn't look nearly so good
on 10 meters, where the lowest SWR was 1.8 and quickly rose
to over 2 at 200 kHz either side of 28.6 MHz.

Good luck with whatever you try.

73,
Bob
K3PH

Results: Carolina Windom
 

I think I see the problem, you were using metric % instead of American %.
(wink)

Ed, NM2K



"Rick (W-A-one-R-K-T)" wrote in message
.. .

I thought I'd post the results of my recent little project to put up a
Carolina Windom for 80/40/20.

Didn't work very well. :-(

At least, not yet. ;-)

I cut it for 3.6 MHz, and according to everything I read that should give
decent performance on or about 7.2, 14.4, and 28.8 MHz.

Instead, I got 3.6 MHz (as expected), then I got about 6.6 and about 14.9.

I followed the instructions I found in one website article that said to
cut the legs for 37.8 percent and 62.2 percent.

Other articles I've read say to cut for 1/3 and 2/3 of a half wavelength,
i.e. feed the antenna 1/3 of the way from one end.

Since I'm a high precision sort of a dude ;-), I figured 37.8 and 62.2
were more precise than 1/3 and 2/3, so I tried them.

Like I said ... works well on 3.6 (and most of the rest of the 80 meter
band) but not anywhere else.

It is built with a W2AU balun (4:1), 22 feet of RG-8X, an MFJ "line
isolator" (1:1 current-type unun), then about 25 feet of RG-8X to the
shack.

I guess I'll have to go back up there next nice day and try the 1/3 2/3
way.

Results: Carolina Windom
 

Thanks, Bob, I will try your measurements.

I don't really care much about 10 meters and if I ever do get interested
in it I'll probably just toss up a ground plane.

The SWR figures you mentioned sound fine to me, the autotuner in the
TS-940S can handle the SWRs I'm getting now so it'll be able to handle
those while never breaking a sweat.

I don't understand the 6.6 MHz either, very strange.

Results: Carolina Windom
 

On Wed, 05 Sep 2007 20:34:40 -0400, Bob Schreibmaier wrote:

I used legs of 45 and 90 feet. The SWR was about 1.0 at
3.5 MHz and 1.3 at 3.6 MHz. Actually, it didn't reach 2.0
until about 3.75 MHz. Lowest SWR on 40 meters was at 7.2 MHz
at about 1.0 and was low across the band. The lowest SWR on
20 meters was at 14.35 MHz at about 1.0, but was 1.8 at the
bottom of the band.

Good afternoon, Bob.

Since it's 92 degrees and about 95 percent humidity out, I decided now was
a good time to go outside and do some antenna work. :-)

I reduced one leg and increased the other to get the 45 and 90 feet you
suggest, but I must have cut it a bit long, because I'm getting SWR dips
of 1.12 at 3350, 1.1 at 6.701, and 1.4 at 14.4.

Band edges a

3.50 -- 1.5
4.00 -- 3.8
7.00 -- 1.75
7.30 -- 2.8
14.00 -- 1.9
14.35 -- 1.44

This is the Carolina Windom configuration (more or less...) 4:1 W2AU type
balun, 22 feet of RG-8X, and a 1:1 current unun, then 25 feet of feedline
which is currently sort of looped back on itself (really only need about 8
feet).

I was really hoping to get the antenna up higher than it is, because right
now the bottom 3 or 4 feet of the 22-foot segment, and the unun, are lying
on the roof, but it's as high as I'm going to be able to get it for the
foreseeable future.

Performance seems on a par with, or slightly inferior to, my 180-foot
inverted V fed with ladder line and an LDG autotuner. But, I haven't
really had a chance to test it yet. And, the inverted V connects to my
old IC-735 which has far and away the very BEST non-DSP noise blanker I've
ever used, much better than the one on the TS-940S which currently hosts
the CW.

When I get a chance I'll dig out a coax switch and connect both antennas
to the same radio for some apples to apples comparison tests.