New Towers at VE3KG

Despite the scale of my own station I also do tower work for friends. When I was young it seemed that I was on someone's tower nearly every weekend. I enjoyed helping other hams with their tower work, no matter the size. The accumulated knowledge and experience came in handy when building my current large station.

This has never been a business for me. I have never charged any ham in need and there are many times that I refused offers to pay me. That said, I rarely turned down a meal after the job! I was a hungry lad, unmarried and new to the city. Home cooking was an irresistible attraction.

These days there isn't a lot of tower work to be done. The average age of hams is quite high it is far more common for hams to downsize than to build upward. Many elderly hams have taken down their towers down or have gotten out of the hobby entirely. That's unfortunate but understandable. Therefore I take some joy in seeing hams that are putting up towers.

An old friend of mine, Dave VE3KG, recently moved back to this area after retiring. Most recently he was VE9CB and at various times he has had call signs in VE2, VE3 and VO1, and he has DXed and contested from locales as far flung as BY, 6W, ZL7 and VO2. He now has a few acres 20 km north of my QTH. Several of us helped him to build his new station.

I won't give a detailed account of the planning and building process since it is little different from what I've already written up for this blog. Like me, he ran into trouble with the excavations due to the slow percolation of rain and snow melt into the bedrock and the endless quantity of large rocks buried in the soil. On the bright side, we didn't hit bedrock. That's always a worry since the Canadian Shield rock lurks below ground in this area. 

In many places the bedrock rises above the surface, which makes planting towers a challenge. Many years ago I ran into that with my own station -- 1 foot of soil over shale -- and others in this area. Powered breakers are needed to penetrate the rock. Shale is unsuitable for rock anchors so it must be removed.

The water problem was solved by waiting until late summer. The rocks were broken and removed by hand tools, or lifted out with the assistance of a friendly neighbour eager to play with his new backhoe. Even so we didn't get down quite enough per the manufacturer's foundation specification. Instead the volume was increased to match. This is acceptable if you don't deviate far from the spec.

Both towers are identical to my first tower at this QTH: Trylon T400 with 9 × 8' sections, coming to just under 70' (21 m) above grade. Following my example he used the same cradle design for setting the base sections in the foundation holes. Again it worked well to hold the base sections for the concrete pour. No adjustment was necessary during the pour, and I checked often.

One of the holes was out of reach of the truck so we endured the amusing spectacle of several gray-haired hams carting an endless succession of wheelbarrow loads 30 meters across the lawn. There were minor mishaps that were fodder for laughter.

Tower sections were rapidly lifted with vehicle muscle, just as I did for raising my large guyed towers. I was joined on the tower by fellow contesters VE3JM and VE3FU to splice the sections and push the gin pole skyward. Other local hams provided critical support on the ground. Each tower took a day to raise. One advantage of using a vehicle was that masts and rotators could be attached to the tower sections on the ground. The extra weight was no problem for the vehicle or the gin pole.

The gin pole is almost the same as what I built for raising my Trylon tower. It is 2' (60 cm) taller to accommodate the 10' sections for my LR20 guyed towers. The shorter 8' Trylon sections could be lifted from the top which helped to keep the wide lower sections more vertical and managable when maneuvering them into position for bolting.

Antennas are fragile and were lifted separately to avoid damage. Tag lines kept the antennas away from the tower during each lift. None of the antennas could be lifted straight up because the bottom sections of the tower are wider than the antenna element spacing. It takes choreography to equalize the force when two people manipulate each tag line. It was clumsy but we got it done.

At right you can see me working on the hookup for the Cushcraft X7 on one of the towers. That is the only HF yagi at present. The tower will support wires for the lower bands. The other tower is currently only for VHF and UHF antennas. From top to bottom (below): 6 m, 70 cm, 1.25 m and 2 m. There is space at the bottom of the mast for a future HF antenna. 

Disciplining the rotation loops is difficult when there is no yagi near the top of the tower. The bundle of 4 lengths of RG213 naturally sag and will snag the "ears" of the tower legs. No matter how you secure the other end of the loops on the tower the descending run will not reliably clear those ears.

The top plate holding the thrust bearing on Trylon Titan towers is mounted below the splice bolt holes for the next smaller section. Even if it was easy to move the plate to the top edge of the legs there would be chafing as the rotation loops develop enough tension to scrape over the corner of the triangle.

We solved the problem by mounting a short fake boom on the mast to which the descending cables are attached. It acts as an arm to hold the rotation loop clear of the tower. You can see the upper edge of the support plate for the fake boom in the photo above.

There are other ways to clear the tower but this one is desirable since there will be a yagi in that position there. When it's installed the cable bundle can simply be transferred from the fake boom to the real one. We tested the rotation loops on both towers while I was up top so that I could make adjustments for best operation.

When there are multiple cables on the tower it is helpful to organize them. Dave colour coded the cables for each yagi. To make maintenance easier, including swapping of main coax runs, he asked me to place the connectors for the rotation loops at one level. Since the lengths did not line up on their own, the excess lengths were coiled (off the left of the picture). 

The main runs were individually tied to the tower diagonals. More cable ties and tape are required but that is only pennies spent to have a cleaner installation that is easier to maintain. The downside is that the job took longer and I was racing against sunset. Connectors were weatherproofed after each run and antenna were tested. One run failed the test and was lowered for repair.

Several carabiners threaded with long ropes were prepared beforehand and attached to the tops of the towers. This will let Dave raise and experiment with low band wire antennas with a minimum amount of tower climbing. I've done this for other hams and it works pretty well. It is important that the carabiners can't sag against the tower or twist or the rope will jam. Pulleys make pulling easier but there is greater risk of trapping small diameter ropes.

As I said, it was sunset. A final picture of the completed towers seemed appropriate, along with one of Dave VE3KG in front of the north tower (left).

Notice that the bottom section is painted blue. That section comes from the estate of Don VE3RM. I only met Don once many years ago, but several other notable local contesters knew him well. He opened his station to them for contests back in the years when I was out of amateur radio. It is appropriate that his towers are seeing new life in those contesters' stations.

With that job out of the way, it's time to get back to work on my own station. Winter is coming.