The tower base installation was the most nervewracking piece of this project. I had had absolutely no experience with any kind of concrete work, much less installing a tower, and I agonized over all the possible things that could go wrong. There were so many things to consider:
With much trepadation, I called city hall and spoke with a fellow in the city planning department. He told me that city ordinance allowed for a height up to 35 feet, which is the building height of 30 feet plus an additional 5 feet for "antennas". I told him this was actually an antenna support mast (didn't want to use the word "tower") and he said, "Oh, then that's like a flagpole, and the limit is still 35 feet". So much for that issue. A number of people have told me, in retrospect, that I should have gotten it in writing, but by then it was too late.
I got the hole for the base dug on July 17, 2003. We had a gardner who was willing to do the job, and I borrowed some digging tools (spike and posthole digger) from Carter. The poor guy labored in the sun for hours just to dig a 2 foot by 2 foot by 4 foot deep hole. That glacial till is really nasty stuff, it's just full of rocks ranging from baseball to football size. I took several photos of the hole in case the city came by to check on it later, but I'll be darned if I know where they went. I probably took them with an old film camera and they're stashed in and envelope somewhere.
I then went out to figure out how to get the concrete here and to get it in the hole. I figured it would be too expensive to have a concrete truck come by, if they would even consider filling such a dinky hole, and besides there was no way for a truck to get into the area. I finally went over to Home Depot and ordered a half a pallet of dry concrete bags - I think it worked out to 2 yards. They dropped the pallet off and now the clock was ticking to get the concrete into the hole before it might rain.
I had also bought a bag of sand and a bag of river gravel for the bottom of the hole. I put the sand down first, then the gravel, and then I dropped the three-foot section of hinged Rohn base, that I purchased from Texas Towers, onto that. I had also connected one 10-foot secton of tower to the hinged base and attached 2x4s to that to prop it into true vertical.
I didn't have any idea how to get the concrete mixed and into the hole, and fortunately Carter came to my rescue once again. He had a portable concrete mixer and volunteered to come over and help. But he suggested that I should hire a day laborer to do the heavy lifting. I checked around and found a local charitable organization called "The Millionare Club" and arranged for a fellow for the day.
We started the concrete on August 6, 2003. I picked the day labor guy up at the bus stop on the north end of the island and brought him here. By then Carter had set up his concrete mixer and we were ready to go. Carter had a great eye for the right mixture of concrete and water, and the helper hauled the bags over and dumped them into the mixer. Then the helper and I poured the concrete while Carter supervised and made sure the tower was remaining true vertical. We poured about half the hole then decided to take a break for lunch. I ordered some pizzas and soads, and we had a nice picnic in the backyard.
By the time we got back to work, the first half of the concrete had already set up pretty well. I'm really glad we made sure the tower was true to vertical before we stopped - I had no idea that soupy sludge would start setting up so fast. We finished the rest of the hole and still had a lot of concrete left. So I cobbled up a frame to make a little square pedestal about and inch high for the base. The day labor guy did a really nice job of smoothing the concrete out as it started to set up - otherwise it would have been all lumpy and uneven. I carved my callsign into it and the job was done!
The photos here are maybe a week later, after I had removed the wood forms around the base. Now it's just a matter of letting the concrete cure for about a month.
The tower base close up. This looked pretty ugly at first, but is now filled around with the soil that came out of the hole.
The tower base from a side angle. The pile of dirt on the left came out of the hole and was used to fill in around the base so that it all looks smooth and level now.
The tower base from the street view.
While the concrete was setting up, it was time to work on refubishing the Hi-Gain TH3MkIII triband yagi. All of the original nuts and bolts were in a terrible rusted condition, and the plastic boots on the traps had completely disintegrated. I contacted Hy-Gain, now a subsidiary of MFJ Enerprises, and was told by a very helpful technician that I could purchase a "plastics kit" and a "stainless steel hardware kit" replacment parts for the antenna. I bought those and the antenna was completely refurbished by the weekend before we raised the tower.
The Hi-Gain beam antenna after refurbishing, but before adding the trap elements. When I added the trap elements I set the center frequency a little below the midpoint of the 20, 15 and 10 meter bands - primariy for the Extra phone and the PSK31 segments. Bill had had it tuned to the General phone portions, which was his license class. To test it, I tried a trick I had hear about. I placed the antenna vertically with the resting reflector on the ground, and the SWR came in just about where I expected it.
<< Back Next >>