Hex Beam Installation
Hex Beam Installation
After giving up on my 35 year old Cushcraft A4, I ordered a Hex Beam from NA4RR.
I Settled on this beam after reading many reviews and getting recommendations from friends. I like the simple, no-trap design, and the coverage of the WARC bands. While a traditional tribander might give a little more gain, I think the tradeoffs are worth it.
I ordered the beam, and received a shipping notice the next day. It would take approximately 1 week to arrive from Florida to Arizona. So we loaded up the truck and headed to the mountains to cool off for a few days.
After returning to Mesa, the beam arrived a couple of days later, one day past the original estimate provided by UPS. It arrived in two packages, one with the fiberglass supports and center mast, and one with hardware, wires and the baseplate.
Since it had arrived at dusk, we had to wait until the next morning to begin construction. I started by using my old rotator as a mast mount close to the ground. The we slipped the baseplate over the 1-1/2″ mast to begin assembly.
Next, we installed the center feedpoint mast to the top of the baseplate.
Next, the fiberglass supports were inserted into the baseplate, with smaller sections inserted into the larger ones to the pre-installed hose clams that marked the correct length of each piece. All rings face up.
Once this was complete, the pre-cut lengths of rope were installed from the ends of the fiberglass supports to the top of the center mast, causing the fiberglass supports to bow.
The S-Hooks on the ends of the support ropes were clamped in place with hose clamps, and the S-hooks on the center mast eyebolt were bent together with long nosed pliers to make sure they don’t fall off.
Next, starting with the inner-most 6-meter rings, the wires for each band were attached to the center post, strung around through the support rings on the fiberglass masts, and connected on the other end to the center post opposite terminal. All of the bundles of wire came labeled so you knew which band each wire assembly was for.
We strung the 6-meter, followed by 10, 12, 15, 17 and 20 meter wires.
At this point, I moved the rings out a bit on some of the bands, to make sure that the wires were taught on the supports, with little sag. All hardware was checked for tightness (some clamps were loose and needed to be tightened). The 20-meter wires were tie-wrapped to the rings at the ends of the fiberglass supports. Craig had experienced his beam moving out of shape a bit after heavy winds. We hope this will prevent that problem. I built the balun kit that I had ordered with the antenna (BA-8). This consists of 6 split ferrite beads which are clamped around the coax near the SO-239 feedpoint of the antenna. The Balun Kit came with large heat shrink to place over the ferrite beads, but I had the box sitting in the sun, which caused it to shrink too small to fit over the beads. So I used Electrical Tape, instead. It all seems to work ok.
Next I hooked up my antenna analyzer to the antenna. Starting on 20 meters, I checked each band edge for SWR and looked for the lowest SWR in each band.
For 20 meters, the low end measured 1.5 SWR, the center (lowest) was 1.1, and the high end was at 2.0 to 1.
on 17 meters, the low end (lowest) was at 1.3 : 1, while the high end was at 1.4 : 1
On 15 meters, we had 1.1: 1 at the low end (lowest), 1.9:1 in the middle, and 2.4:1 at the high end.
On 12 meters, we had 1.7:1 on the low end, and 1.3:1 (lowest) on the high end.
On 10 meters, we had 1.6:1 in the CW portion, 1.0:1 (lowest) in the SSB section, 1.9:1 near 29 Mhz, and 4.0:1 at the upper band edge.
Finally, on 6-meters, we had 1.3:1 in the CW portion of the band, 2.2:1 near 51 mhz, 3.4:1 in the FM portion of the band, and 5.6:1 at the upper band edge (54 Mhz).
After these checks, we worked to raise the antenna off the ground and onto the tower. We tied a rope onto the center feed mast near the baseplate, with the other end tied near the top of the feedpoint. the center of the rope was long enough to form a triangle, with the apex nearer to the baseplate than the top. A loop was formed here, and this is where the rope from the top of the gin-pole was attached. This allowed the antenna to hang next to the tower, without resting against it for the most part. I did have to swing it away from the tower a couple of time on the way up.
With My friends Craig (NV1O) and John (WB0WHO) on the ground, I climbed up the tower, guiding the antenna away from the house roof and tower on the way up, while Craig and John winched the antenna up and kept it from tangling with the pool pump and pool fence. It all went up much easier than I anticipated.
Once it was near the top, the hook on the end of the winch cable was against the winch, so they could not use that any more. With them manually pulling on the rope below and me manually pulling from the top, we managed to raise it the final 5 feet, at which point I was able to grab it and swing it onto the mast at the top of the tower. After placing a bolt through the mast and antenna baseplate, I tightened it down and we were ready to being rotator alignment.
John worked the rotator in the shack at my command, and we managed to get the antenna pointing in the same position as the rotator controller said it was pointing.
We lowered the gin-pole and began assembly of the mast that supports the 2-meter J-Pole, the 70 cm ground plane and the 80-40-30 trap dipole. Once those were attached to the tower, we lowered the gin-pole and ropes, and I made my way back down the tower.
Initial tests of the antennas show that all are working as expected. I have a little too much loss on the 70-cm antenna, as it does not have UHF grade coax feeding it, but it works just fine. Craig and I did simplex tests on all bands between 40 meters and 70-cm (except 222mhz) and were really pleased with the outcome. Later QSOs on 17, 20 and 6 meters indicate that the hex beam is working well.
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