ND2E's Blog

Hexbeam

Well, it has happened again. The winter winds came and the HexBeam went. During the summer I performed some repairs to the antenna because it had come loose from the rotator … the center shaft had been eaten by the teeth of the rotator clamp. I repaired the problem area by epoxiying a bit of aluminum to the affected areas hoping that that would reduce the wear until a proper fix could be made next summer.

The fix evidently worked well, The antenna stayed in place and rotated properly for several months. It even survived several high wind events. But last week, the high winter winds took their toll and the center shaft failed.

When I did the repair, I forgot about the loss of strength that the fiberglass center shaft tubing suffered when the teeth notched the shaft. The wind bit hard and the shaft sheared where the teeth had been. The epoxy paste I used did not provide sufficient strength to prevent the catastrophic failure of the center shaft even though it was strong enough to prevent rotation.

The antenna is now on the ground with yet another broken limb and a broken center shaft.

I will rebuild come Spring, but until then I will be using my 35 foot vertical as well as my NVIS 40M hamstick dipole.

Although this is yet another chapter in the ongoing saga of how not to build a fiberglass-based antenna, there are many lessons to be learned. And I am sure that there will be many more. The most important one that I have learned so far is: DON’T USE A FIBERGLASS MAST WITHOUT USING SOME SORT OF ARMOR! The next center shaft I build for the antenna will be aluminum tube over the fiberglass tube. Not only will this save wear and tear on the rotator clamping area but will also be a good clamp base where the limb baseplate mates with the center shaft.

I intend to do a full rebuild on the antenna and possibly add a 6M section. I also want to revisit the mast and its erection/mounting method. As currently configured, the antenna must be lifted vertically over 10 feet and placed in the rotator clamp. I had used a very primitive ginpole to handle this as well as the extension of the pushup mast. I is exceedingly difficult for me and the XYL to handle this task. I originally had the help of a local Ham but I really hate to keep bumming help when there should be an engineering solution to the problem.

So, during the rebuild, I will try to build some sort of tilt-over mechanism for the mast so I can mount the antenna with everything on the ground. I also want to find a way to mechanize the extension of the pushup pole once the antenna is mounted. If I am successful with the mast revisions, I will be able to bring the antenna down when High winds are expected and possibly not have to rebuild the antenna again.

It has been a long dry summer, I design and build Joomla-based web sites for several organizations. I am really quite new at web site design and operation so it should not be a shock when one of the sites was hacked. It has taken me a long time to understand how it was done and what was needed to slow down the attacks. The version of Joomla that I was using was really easy to hack, as was this blog. So to cut down on things I was forced to turn off comments and do several things that made several sites less useful. I am slowly returning things to normal after rebuilding, modifying, and adding security to the sites. The web security activities have not left me with much time to do Ham radio things.

I was able to work Field Day from home. I think I did better this year than the last two years. Hopefully I have learned a bit and become a better operator.

Just before Field Day I noticed that my hexbeam was not looking right. It was slouching off at a strange angle and the beam was not facing the same direction as the rotator. I managed to get through Field Day without everything falling down but my main antenna definitely needed a lot of work.

So this month I have made it a priority to get the radio things in order for the winter season.

I lowered the antenna and found that the fiberglass mast I was using had been eaten by the mast clamps on the rotator. I had expected a bit of wear but the clamps had removed enough material that the antenna was almost falling out of the rotator.

I modified the clamps and mast by epoxying an aluminum protective skin to the clamping surface. I also shimmed the spider to the mast and epoxied it in place.

So far the modifications seem to work. We have gone through one major wind storm and the antenna stayed facing the proper direction and there was no apparent wind forced movement of the various parts. Hopefully, that will solve the problem for a couple of years. I expect that the antenna will need to be rebuilt in a couple of years but until then I think it will survive.

There has been some recent solar activity and there is a chance that the higher bands will come back this coming year. Thinking that 6meters might be a useful band again, I built a 6meter dipole to be added to the short mast that carries my NVIS 40meter hamstick dipole.

I also want to finally get my 40ish foot vertical working in time for this winter. I had been using that aluminum mast as the 2m/70cm mast for the J-pole. I was having doubts that the vertical and the J-pole could co-exist without putting a lot of RF back on one or the other of the feed lines, so the J-pole had to come down.

The solution was to get my four-band mobile vertical out of storage and mount it on top of the short mast. I knew that the 2m/70cm sections would work as they were complete antennas but suspected that the 6 and 10meter sections would not be really effective since they were 1/4-wave sections. I was hoping that the 20ish foot mast would be enough of a ground for the 6- and 10meter sections to be somewhat useful but knowing that I had 10-meters available on the Hexbeam and a new 6-meter dipole gave be a chance to play with the verticals. I am running out of feed lines to the antenna farm so I put the 6meter and 40meter dipoles on the same feed with no attempt to phase them. So far both tune up well using the autotuner in the K3.

The aluminum vertical is now up but has no feed lines and the SGC coupler has not been mounted nor have the radials been run. If we have a couple of sunny days, I will get that done before the winter rains start.

Hopefully, all the antennas will survive the winter and I will have time to play with the radio.

The HexBeam is up and working, thanks to the help of Dave Wilson, N4DW. He came over Friday and helped me put the antenna on the mast. I spent the rest of the day pushing and pulling things around until the antenna was at the limits of the mast, 30 ft up in the air. All the guys are tight, although sometime in July I will need to check the tension. Hopefully the antenna is up and won’t get blown down like the last time.

I spent about eight hours over the weekend playing radio during Field Day. I put my big battery pack on the power bus and ran 1E. Logged 84 contacts (4 duplicates) during those 8 hours. Did PSK and RTTY with no voice or CW operations. The more often I work contests, the more I understand the rules and work at improving my score through better operation.

I wanted to run digital since it scores the same as CW. So for the first hour I ran PSK. During that hour I logged 21 contacts all PSK. With the HexBeam running it was possible to hold the frequency. Running 40-50 watts with a beam really gives you command.

During the next hour I logged 15 contacts-14 PSK, 1 RTTY. The limited number of PSK stations was making it more difficult to find non-dupe stations to contact.

By the third hour I only had four contacts-all PSK. The fifth hour was four also, RTTY only. Sixth hour was four RTTY and three PSK.

I went to dinner and came back several hours later, so starting at 00:30Z ish I continued to log between four and five contacts per hour until I gave up at 02:45Z. I did a little better Sunday morning running about six per hour evenly mixed between RTTY and PSK. Again after taking a break for church and lunch, I came back and ran for another 30 minutes…That finally got my total up to the 80s.

Moral of the story, for field day at least you cant run digital mode without CW capabilities if you want to place well. Also being limited to 20M and up – no 40M or 80M antenna of any type, limits the number of stations that are available during the night-and night seems like it is the majority of the contest. I know that it isn’t the biggest part but when the traffic slows down it sure seems long.

One other issue, LotW should be the final depository of all of our logs. I like eQSL and now that CQ Magazine is honoring eQSL QSLs they have a nice advantage but as an ARRL member I sure wish we would use our native logging depository. I do both LotW and eQSL. Good logging programs can handle uploads to both systems so there should be no hesitation in using both.

Today was a long day that should have been short. Started out this morning to safety check the rigging before putting the antenna up top. The last thing I want is for the beast to collapse while I am underneath it. All checked out, had to redo some of the rigging knots because I prefer bolines to fisherman knots on line that absolutely will be under strain.

Seems that I forgot to prep any coax…duh. Well going through my stock of things trying to find just the right stuff. Had 2 lengths of RG-213…that is about 1.6dB loss per 100 feet. Need something better. I have a 100 feet of LMR 240 UF – about 2 dB loss, not good. How about some LMR 400? Nothing long enough. Either I am going to use the RG or I will have to break out my stash of Heilax.

I have several lengths of 1/2 inch heilax that was donated by friends in Dallas before I moved. But, do I have connectors and adapters? After much scrounging around in the junk box I found the adapters to go from the Heliax Ns to UHFs so I can get the coax past the house connectors. I will have to change things one of these days when I finally get everything installed.

So, I spent several hours hunting for thngs before I got to the task of terminating the Heliax. Of course the hunk of coax I chose ws the oddball 1/2 inch superflex not the standard half inch stuff. Now where are the other connector?

All is done, the coax is hanging from the underside of the deck and tomorrow the XYL and I will put the antenna on the mast. That will leave Friday to test and get ready for Field Day on Saturday. Hopefully I will operate here, in Kingsport with the Kingsport Club and hopefully with the Johnson City club. It will be a busy Saturday running here and there and at 6:30 running down to the Maple Grove in Unicoi for a Morris family reunion.

Well yesterday was fun. Finally got every thing working. Today’s chore is to get the 2nd level guys, the rotator and the 3rd level guys in place so I can install the antenna and push the mast up to its full height.

The last time I did not set the guys tight enough to overcome the initial stretch in the double braid dacron line, this time I will set them tight. Hopefully the mast will stay up during the East TN winds.

Have the 2nd and 3rd level guys up and very lightly tensioned so I can push the pole up and bring it back down. Tomorow is fix a couple of things like turn the rotator to the proper direction, test it to make sure it is still working, and rearrange one of the guys to relocate one of the turnbuckles.

All looks ok so far but I still need to make sure it stays vertical.