Mast-Supported Doublet at Carolina Management Area

I wanted a quick Sunday-morning activation and another field test of the 58-foot doublet I had built the day before. Carolina Trout Pond, inside Carolina Wildlife Management Area, US-7716, turned out to be an excellent backup plan: a shaded picnic table at the edge of a quiet pond, with just enough room to weave the antenna through the trees.

The entire activation fit into 24 minutes. I made 12 five-watt CW contacts, split evenly between 30 and 20 meters, while the unchanged doublet again showed that the KX2 could find a usable 20-meter match.

At a glance

• Where: Carolina Trout Pond in Carolina Wildlife Management Area, US-7716, Rhode Island
• When: August 9, 2026; contacts from 10:26 to 10:50 a.m. EDT
• Activation: 12 five-watt CW QSOs on 30 and 20 meters
• Radio: Elecraft KX2
• Antenna: Unmodified homebrew 58-foot portable doublet with two 29-foot legs and 28 feet of balanced feed line
• Support: 20-foot GigaParts Explorer POTA20 carbon-fiber mast, fully extended
• Geometry: Feed point about 20 feet high; both wire ends roughly 5 feet high; radiator axis approximately 048/228 degrees but not perfectly straight
• Operating position: A shaded picnic table beside Carolina Trout Pond

A mast-supported test in the trees

This was the second deployment of the same 58-foot doublet I had tested at Pulaski State Park the day before. I did not fold or cut the radiator, and I left the balanced feed line at its original 28-foot length. The important change was the support: instead of hanging the center from a high branch, I raised it on the fully extended POTA20 mast.

The pond-side site was beautiful, but it was not an open lawn. The mast stood beside the narrow path, the radiator passed through the surrounding trees, and the balanced line climbed almost vertically from the operating position. I still do not have the clips I want for the feed-line spacers or wire ends, so I improvised. Each end of the radiator was simply wrapped around a small branch and left roughly five feet above the ground.

One leg ran approximately 048 degrees from the center and the other headed in the broadly reciprocal direction, although the two were not perfectly collinear. The feed point and feed line also pulled somewhat toward one leg. With a 20-foot center, five-foot ends, and two perfectly straight 29-foot legs, the included apex angle would be about 118 degrees. The actual angle was probably somewhat smaller because of the azimuth skew, sag, trees, and off-center pull.

None of that informal geometry kept the antenna from working. It was quick to put up, stayed out of the way, and fit the site without needing a throw line or a broad open span.

Twenty meters found its match again

The first deployment had made 20 meters look more troublesome than it was. At Pulaski, the first KXAT2 search stopped around 2.7 to 3.0:1, but tapping ATU a second time within five seconds started the documented deeper search and reached 1.0:1.

At Carolina, one 20-meter frequency matched after the first search and another needed the second. My working theory is that the difference has more to do with the tuner beginning from whatever network it remembered for a nearby frequency and a previously connected antenna than with a fundamental problem in the doublet. Two outings are not enough to prove that explanation, but the practical result is consistent: when the first search is not good enough, the second search finds a usable match.

That further reduces my concern that the doublet needs a different feed-line length merely to work on 20 meters. The original 58-foot radiator and 28-foot line remained unchanged, the tuner found matches, and the signal got out.

The Reverse Beacon Network provides a useful check without requiring a catalog of every spot. It recorded 14 reports from 10 skimmers during the 30-meter run, covering roughly 80 to 408 miles, followed by 10 reports from eight skimmers on 20 meters, reaching roughly 264 to 873 miles. Those reports do not measure antenna efficiency, but their regional coverage on 30 and longer reach on 20 are good evidence that the improvised installation was radiating normally.

Twelve contacts in 24 minutes

I started on 30 meters at 10.112 MHz and made six contacts. I then moved to 14.059 MHz for six more on 20 meters:

The first contact was at 10:26 a.m. EDT and the last at 10:50. The log reached stations from Florida to Missouri, plus VE3YTX in Ontario. KG1A found me on both bands.

This was not a precision antenna experiment, and the trees guaranteed that the geometry was only approximate. It was still exactly the field evidence I wanted. The doublet deployed cleanly from its intended 20-foot mast, tolerated low and improvised end supports, matched on both operating bands, and produced a complete QRP activation before I needed to head home.