After moving to Denair, CA in 2020 I promptly put up my hex-beam antenna in the back yard of the new house. It worked fine. I made enough contacts to be awarded the Worked All States (WAS) certificate. This was during the time when the 11-year sunspot cycle was just coming back toward the high side, meaning that signals were getting better and would be good for several years. Since some days were not so good, I found that a digital mode called "FT8" was much more reliable for making a confirmed contact than a single sideband (SSB) voice call. FT8 pulls very weak signals out of the ether. It is a computer-to-computer mode, but the contacts count towards the many awards available. I had always wanted a yagi or "beam" antenna. This would be the next step up and would provide me with a lot more gain or signal strength for both receiving and transmitting than the hex beam.
Another issue with the hex beam is that it was mounted on a pushup pole and was very difficult for me to raise by myself. The antenna itself is not heavy but the pole is. It was awkward to stand on a stepladder while pushing a telescoping mast straight up, and it got progressively heavier as it went up. I hate to admit it, but I'm not as strong as I used to be. My neighbor helped a couple of times, but I was uncomfortable asking for assistance on regular basis. I had lowered it following a wind storm to make a few repairs and that's where it stayed. It still worked pretty well resting on the roof of my shed.
Also on the negative side, the hex beam is rather fragile compared to a yagi. The fiberglass spreaders can crack and splinter after continued exposure to sunlight. The wires require realignment after a strong wind as they slip through the loops that loosely attach them to the spreaders. I would be nervous about installing it on a tower or other location where it could not be easily lowered for maintenance.
The yagi I chose is extremely strong, built from heavy gauge materials and is much better suited for a permanent perch high on a tower. It is a 4-element model that works on all amateur bands from 10 meters through 20 meters, including the WARC bands. It is made by Mosely Antennas, a company that has been around longer than I have been a ham, and is often described as "the best antenna you can buy". It is made of very stout aluminum tubing and brags of an average of 27 years before requiring maintenance. So to get this thing into the air at an optimum height of at least 40 feet, the push-up mast is not going to be up to the task. This job requires a heavy duty tower. I decided early on in the project that I would do everything "by the book" as recommended by Rohn, the tower manufacturer. No skimping on materials or installation. Rushing the job would not be allowed.
One of the first things on the list was the foundation. Rohn decreed that I needed a 4' X 4' X 4' hole in the ground, filled to the top with concrete. That's a lot of concrete and a lot of hole. But the tower is self supporting up to 40' with that massive base. I have a part time landscaper who does the jobs that require more energy than I have. He and a friend also did some concrete sidewalk work for us previously, so I gave him both jobs. The ground here is hard pan just below the surface. It's like concrete itself. He had to use an electric jack hammer to get through it. Anyway, he got the hole dug back at the end of November, 2020 and ordered the concrete the next day.
Meanwhile, he prepared the rebar cage that surrounds the 5' tower section that will be encased in cement. Just the top few inches will show above the surface as the mix dries. At the bottom of the pit we added about 5-inches of pea gravel, per the specs for drainage. It was important to keep the tower section plumb. A small error here would be magnified at the top of the tower. By the way, we live in the county now, so there are no restrictions or permits needed up to 60' for a non-commercial tower.
The concrete arrived in the morning. By chance and somewhat by plan, the tower is in a part of the yard where we could back the towable mixer right up to the hole. One section of the 3-car garage is a pass through with rollup doors on both ends. I normally park my truck in that part because it is longer than the other side. So the mixer was backed all the way from the street to the hole site with no difficulty. You will see from the photo that these guys knew what they were doing.
Once the foundation was complete and allowed to cure for a month, I began putting up the sections. Each section is 10' long. The first one was easy. I walked it up to the slab and set it down on the protruding base section. Two galvanized bolts in each leg and it was done.
Since I was waiting for parts and the antenna itself is not scheduled to arrive before the end of April, I stopped at the 30' level and attached a TV antenna and a VHF/UHF stick on top. The TV antenna works great at that height pulling in stations from Sacramento. I have it connected to a Tivo Roamio to augment the streaming channels we watch.
Later, when the last section goes up the TV antenna will be raised even higher. Now I have all of the parts gathered except the yagi antenna, so I can proceed at a leisurely pace. I plan to mount a thrust bearing on the top plate, and that arrived yesterday. Its purpose is to take all of the vertical weight of the top mast off of the rotor. OK, if you didn't follow that, the rotor or rotator is a geared motor that mounts inside the tower near the top. It clamps onto the bottom of the mast that will protrude about 8' above the top plate. Its purpose is to turn the mast along with any attached antennas. It is connected to a controller that sits on the operating desk. In addition to moving the antenna 360°, it shows which way the antenna is pointed. This is desirable because the beam has a lot of "forward gain", so wherever you point it that's where the most signal goes. At the same time, the back of the antenna and the sides have decreased receiving (and sending) capability so you want to be able to point the front of the beam for best reception of another station. The one I ordered is a Mosley Classic 33MW. The “W” means it has an additional 4th element for the Warc bands. This model has a "boom" or backbone of 2" aluminum and is 18' long. The longest element is 27'. The horizontal boom mounts to the 2" mast on the tower so the weight is balanced at that point. In case you crave further details, here is the Mosley website: Mosley Website If your browser complains, just try http, not https in the URL.
Now I am waiting for the antenna to arrive. My plan from the beginning has been to rent a lift so I would have a platform to stand on while attaching the yagi to the mast, There are a lot of other little tasks that precede and follow the yagi installation, so I think I will get my money's worth out of the rental.
The new Mosley antenna finally arrived on May 5. I had ordered it in mid- January. They were backed up due to material shortages and shipping issues. It's here now so I will start posting some photos of the assembly process. I'm taking my time putting the pieces together. My backyard is pretty small and the side yard where the tower is located is even smaller. So there are some logistic concerns about whether I will assemble it fully or move it to the staging area in sections.
The Mosely Classic 33MW was assembled on the ground in the backyard. Everything went into place easily and I had no parts left over (a good sign). I had been thinking for weeks about how I would get it up the tower and tightened down on the mast at 40+ feet in the air. The side yard where the tower is located is a lot smaller, so I pictured standing the antenna on the reflector end and leaning it against the tower before hoisting it to the top with the gin pole. This brought on a few sleepless nights wrestling with all the reasons why I did NOT want to do it that way. Also, the uninstalled top section which would be unwieldy because of the heavy top plate, thrust bearing and rotor plate would be nearly impossible to wrestle in place while I was strapped to the side of the tower.
I had done some research on boom lifts. A bucket truck would be too big to get close to the tower, but it looked like I could get a 45 foot electric lift that would drive through the garage and out the other side as we had done with the concrete mixer. I knew from past experience that I could rent equipment for the weekend from a local outfit and be charged for just one day of rental. I called and made the arrangements for the weekend of June 3rd, with a forecast for cloudy days... perfect for tower work. The only surprise was that it was too big for me to tow on one of their rental trailers. It had to be delivered on a tilting, flat bed trailer, which cost almost as much as the rental of the lift for a day. Here is the machine that I rented.
The machine arrived around noon on Friday, which gave me an extra half day to get started on placing the top section. After a few minutes of getting familiar with the controls, I moved carefully through the garage then maneuvered into place. The first thing I did was to raise the platform all the way to the top of the existing tower to survey the job ahead of me. Then I returned to the ground, loaded up with tools, nuts, bolts and the top section. Being able to keep the base at eye level or a little below helped tremendously. It was easy to balance and after some initial struggling, it eased down over the three legs of the section below. Once it was bolted in place, I spent the rest of the afternoon planning and gathering the tools I would need for the rest of the job.
Bright and early Saturday morning I was up in the air again. The next step was to install the rotor and place the mast in the thrust bearing from above. This bearing takes the weight off the rotor so it isn't straining. On top of the mast is a vertical antenna for the 2 meters and 440 Mhz bands.
I had anticipated the mounting of the elements to be the most difficult part of the project, but they turned out to be pretty easy. Each one is attached with a saddle and U-bolt. The end elements were really easy. With the U-bolts loosened they slid right over the ends of the boom. I should mention that building a large antenna like this in the air is a bit unconventional. I surveyed a couple of groups on FB and only had a couple of guys say they had done it this way. Most congratulated me for being innovative. After the elements were fastened down, I routed the coax cable per the instructions.
Sunday was for attaching the TV antenna and the mount for a dipole antenna to be hoisted up later. Carol did a great job on this last photo, placing the flag in the foreground. The lift worked perfectly the whole time and made this a one man job. I look forward to many years of fun talking to other hams all over the globe.
