New Carolina Windom

The New Carolina Windom

The New Carolina Windom

The New Carolina Windom uses a horizontal, OCF element and with balun / choke spacing, will radiate on the vertical feed line space between, the balun and choke. The Carolina Windom uses a ratio of 37.8% for the short horizontal element and a ratio of 62.2% for the longest horizontal element.

The New Carolina Windom is, a Half Wave length antenna at it's total length and can be used on other harmonically related bands without a tuner. The New Caroline Windom can be setup to run on 160, 80/75, 40 or any other band using the calculation formula below.

468 / Freq. = Total length

Total length X 37.8% = short side

Total length X 62.2% = long side

Vertical length @ 4:1 ratio = band meter / 4 = Balun to Choke spacing

1.900 MHz (160 Meters) Band Center

468 / 1.9 MHz = 264.315 (rounded to 265')

short side length - .378 ( 37.8% ) x 264.315 = 99.91' = 100' rounded

Long side length - .622 ( 62.2% ) x 264.315 = 164.40' = 165' rounded

Vertical length @ 4:1 ratio = 160 / 4 = 41'

3.75 MHz (80/75 Meters) Band center

468 / 3.75 MHz = 124.8' (rounded to 125')

Short side length - .378 (37.8%) x 124.8 = 47.1744' = 48' rounded

Long side length - .622 (62.2%) x 120.8 = 77.6256' = 78' rounded

Vertical length 4:1 ratio 80 / 4 = 20'

3.9 MHz (80/75 Meters)
468 / 3.9 MHz = 120'
Short side length = .378 (37.8%) X 120 = 45.36' = 46' rounded
Longest side length = .622 (62.2%) X 120 = 74.64' = 75' rounded
Vertical length 4:1 ratio = 80 / 4 = 20'

7.1 MHz (40 Meters)

468 / 7.1 MHz = 65.9' (rounded to 66')
Short side length = .378 (37.8%) X 66 = 24.9' = 25' rounded
Long side length = .622 (62.2%) X 66 = 41.05' = 41' rounded

Vertical length 4:1 ratio = 40 meters / 4 = 10'

I decided to setup an antenna cut for 40 Meters and used the exact formula for the 40 Meter antenna. I had been looking for an antenna which, would be simple to setup in the field and have good performance!

The first thing I did was wrap a 4:1 voltage balun. I used two, FT240-31 toroids which, were epoxied together. I wrapped the toroids with twelve turns of AWG 14 motor winding wire, encased in silicone tubing using the method pictured below.

I found a water proof, project box online and drilled it out for all the fittings I wanted to add to it. I used an SO-239 (5/8” hole) so, I could add and remove a coax feed line in the field easily. I decided to use AWG 12 THHN stranded electrical wire for the horizontal elements and RG-8X for the feed line. Two Rubber Grommets for 9/16" Hole Diameter and 1/8" Material Thickness, 1/8" ID, were used to help keep out water in case it rained.

I cut 80' of 3/16” Dacron rope and ran it straight through the top hole (5/32”), in the box; tight fit, to keep out rain. I added two quick disconnects to the end of one side of the rope and hung it up at six feet. I added another quick disconnect to the other side of the rope and hung it up at six feet and pulled the rope tight with a pulley line.

Using the short element side first, I calculated where the balun box would need to be placed on the rope (80' – 66' = 14' / 2 = 7' + 25' = 32'). The center of the box was placed at 32' then, two all plastic zip-ties were added to the rope, inside the box so, it would not slide out of place.

I added the short wire element through the grommet and left enough slack for soldering the balun in later. I wrapped the wire around the rope toward the end, adding a zip-tie every 3' feet or so with one at the end leaving 4” of wire hanging over. Then I did the same thing for the long wire element side.

Then, I dropped the antenna down and took it inside, to solder in the balun. Once, the elements and SO-239 was soldered into the box, I took the antenna, back outside and hung it up again. I added a choke to the coax feed line at the balun box with 3 ferrite snap on beads. The RG-8X was 75' and was connected to the SO-239 and then, I connected the other end to the Mini600 antenna analyzer to, see how it checks out.

Below are some screen shots of the bands.

NOTE: After I tested all the bands, I did make some contacts with only, 100 watts and the internal tuner of the Icom IC-7300. I only used 20 meters on both days. On Jan. 1st, I worked Julie, KB6DRB, in Riverside, CA (2225 Miles). and on Jan. 2nd, I worked Scot, N6ZT, in Los Angeles, CA (2275 Miles). I also made contacts in NY, AR and OH. Needless to say, the antenna works and can be matched with an antenna tuner. I used an MFJ-969 although, a little touchy (tight) to tune, It did get me on other bands and I was able to make other contacts but, not as far as Califonia. Also, I was able to make some contacts on two, local repeaters, on the 2 Meter band, using my BaoFeng F8-HP walkie talkie, connected to the windom, as well! When, I have a chance to get more screen shots, at heights up above 15', I will add them to this page.

01/01/2021		01/02/2021
80 meters @ 5' Choke @ 0' from balun		80 meters @ 15' Choke @ 10' from balun


60 meters @ 5' Choke @ 0' from balun		60 meters @ 15' Choke @ 10' from balun


40 meters @ 5' Choke @ 0' from balun		40 meters @ 15' Choke @ 10' from balun


30 meters @ 5' Choke @ 0' from balun		30 meters @ 15' Choke @ 10' from balun


20 meters @ 5' Choke @ 0' from balun		20 meters @ 15' Choke @ 10' from balun


17 meters @ 5' Choke @ 0' from balun		17 meters @ 15' Choke @ 10' from balun


15 meters @ 5' Choke @ 0' from balun		15 meters @ 15' Choke @ 10' from balun


12 meters @ 5' Choke @ 0' from balun		12 meters @ 15' Choke @ 10' from balun


10 meters @ 5' Choke @ 0' from balun		10 meters @ 15' Choke @ 10' from balun


6 meters @ 5' Choke @ 0' from balun		6 meters @ 15' Choke @ 10' from balun


2 meters @ 5' Choke @ 0' from balun		2 meters @ 15' Choke @ 10' from balun


1.25 meters @ 5' Choke @ 0' from balun		1.25 meters @ 15' Choke @ 10' from balun


70 Centimeters @ 5' Choke @ 0' from balun		70 Centimeters @ 15' Choke @ 10' from balun

More to come soon!!!