In the spring of 1980, Tom and I decided to
build up a killer six meter station. We already had the
transceiver and Amplifier, so what we needed was a better antenna.
Up until then we had been using a single Cush Craft Yagi on a
separate tower about 50 feet up. Tom had gotten ahold of a nice 50 foot section of Rohn SS tower and already had it installed in a concrete block and guyed at the top. It was out in the field in front of the house, so quite a ways away from all the other antennas. After kicking around a number of ideas, we decided to mount a rotating tower at the top of the SS and build up an H frame for four Cush Craft 11 element Yagis. The Yagis were 26 feet long, so we decided they needed to be spaced 26 feet apart, both horizontally and vertically! We used a 3 section length of Rohn 55 as the rotating tower. I had access to a huge bearing from a damaged hydraulic crane that my Dad had, so we mounted that at the top of the SS tower by fabricating a 5/8 inch thick steel plate with a huge hole in it to hold the bearing. Once that was in place, we mounted a prop pitch motor in the SS tower and used a short army truck drive shaft to turn the tower. (That was the first of a number of motors and drive combinations we had to use with that monster.) |
With rotation, and some servo motors installed
for direction indication, we could now proceed to build the H-Frame.
The cross boom was a 30 foot length of Rohn 45 tower, and the uprights
were each 20 foot lengths of Rohn 25 tower, extended at the tops and
bottoms by a few feet of 2 inch aluminum tubing, to give the needed 26
feet of vertical separation, and room for the antenna support wires at
the top. In the meanwhile I located a piece of copper tubing, 5 feet long and 3 inches in diameter, for the 1/4 wave power divider. The center conductor was 2 inches in diameter to provide the 25 Ohm impedance needed to match the four paralleled 50 Ohm antennas to the 50 Ohm transmission line. The end caps were made from 1/4 copper plate, machined on my Dad's lathe to just fit into the ends of the power divider, and soldered tight after the divider was completed. With four type N connectors at one end and one at the input, we had our six meter power divider. I believe that power divider is still in Tom's basement. You can see it in some of the pictures. All of that preparation and building took us into late autumn. We wanted to be able to use the antenna for the upcoming January contest, so we continued working on it through the end of the year and on into January.
By the evening of January 16, 1981, we had the H Frame fully assembled and laying in the snow near the tower. Now, Tom always would work on equipment if something needed fixing, even if a contest was in progress. He liked contesting but he liked working on equipment even more. So, on the 17th, by the start of the contest, it was no surprise that he wanted to complete the installation. It was a very cold day, fortunately with little wind, but we had to wear heavy winter coats and gloves for all outdoor work. Finally, late in the afternoon, we had everything ready to raise the H frame. The frame was hoisted into the air high enough to install the four antennas and feed lines. The top antennas had to be mounted and aligned from the tower but the bottoms we could install from the ground. The ropes holding up the assembly were attached to Tom's pickup truck and the whole thing was supported from the gin pole at the top of the rotating tower. This picture shows the arrangement as we were just starting to raise the H Frame, but before attaching the antennas. Finally, we started raising the completed assembly. I was the tower man so up I went with my heavy winter coat, hood, gloves and heavy winter boots. It was a slow process. We had enlisted several area hams to help out with manning the ropes to hold the assembly away from the tower, and maneuver the antennas past the guy wires while raising. Tom manned the truck while I guided things from the tower via Motorola HT (this was before cell phones!) Just before dark, we had the frame raised to the mounting position half way up the rotating tower. I had to attach the mounting plate to the tower using the U bolts that were nestled in my coat pockets. I had to remove my gloves for this operation because I could not start the nuts onto the clamps with them on. The temperature at this time was about 15 degrees above zero and I could only keep the gloves off for a few minutes at a time. With much jockeying around to get the frame positioned so that each U clamp would slide into proper position, we finally got the H Frame mounted and secured. We had an assembly of portable lights on the ground, shining up to the tower to give us the ability to work in the dark. Once the H Frame was mounted, the Yagis had to be aligned and tightened down. We had to pull up the feed line and get it strapped to the tower and connected, and weather proofed. The Support stays for the cross boom also had to be connected. Finally, at 10 PM, it was all done. I was barely able to make my legs work as I climbed down the tower. I had been up there for six hours. When I got into the garage, I was unable to remove my safety belt due to my stiff fingers and the belt itself being stiff and hard from the cold. I had to get one of the guys to remove the safety belt for me. It was +6 degrees! But we had done it! After us all getting warmed up we went down to the shack to see if it worked. The SWR was good and it looked like we were on the air! But then we discovered that the selsyns to show the antenna position were not working. Tom had made up a nice display, a frame holding a world map, with the selsyn swinging a pointer over the map. But something was wrong with the wiring. There was no way to see the antennas from the shack in the basement, so we were unable to use the rotator. We operated the rest of contest with the antennas pointed west. Conditions were not good and since we had missed half of the contest already, we did not bother turning in a score. I wish we had, as I cannot remember anything about how well we did on six, or on other bands. I did look up the scores for Jan 1981, and saw that the single operator high score was Ron, WA3AXV, whom I did not know yet at that time. Ron had 80,770 points on the 50, 144, 220, 432, and 1296 bands. Below are some pictures of the completed array, and some close-ups of some of the parts. |
Top: Completed array, morning after installation.
Middle: Cross boom and power divider. Bottom: Top left
antenna mounting.
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Afterwards: Of course we eventually did get
the selsyns fixed and we found this array to be a 'Band Opener'.
We worked everything there was to be worked. At that time a
popular way to discover six meter propagation was to get on 10 meters,
on 28.885, and then transmit on six to see who was hearing you. I
will never forget the thrill of calling on a 'dead band', and suddenly
hearing the 10 meter speaker come alive with "We Have Propagation", and
hearing our CQ coming back to us, loud and clear, from South America, on
10 meters! We were often the first ones heard when the band was
opening. With that antenna I completed my WAS on six meters, and
we worked a ton of DX. But the array was a huge wind catcher. Our setup was on the top of a 1920 foot 'mountain' in western NY (now known as FN02LA), near the town of Frewsburg, NY, and just above the Pennsylvania state line. Thunderstorms would form in the valley below and come roaring up over the top very fast, and often with no warning. One fine summer afternoon I was up the tower and had climbed out the cross boom and part way up one of the vertical H Frame sections, to do some work on the 432 MHz array we had put there. Suddenly I heard a sound like 'crack', or 'snap'. I thought about it for a few seconds and decided I better get down off the tower - it sounded like a static discharge to me! I had barely made it to the ground when the storm came sweeping up from the valley below, Lightning and rain and huge booms of thunder. That time there was no damage to the equipment, but other storms did cause the driveshaft from the prop pitch motor to the antenna to twist up like a pretzel. And it was very difficult to keep water and ice out of the gearing and the selsyn drives during the winters. We ended up putting stronger and stronger drives on, but nothing could stand the tremendous forces that the wind applied to the array for more than a year or so. Finally the antennas themselves started falling apart and the array was done. But what an experience building and using that antenna was for us. I really feel very happy and fortunate to have had Tom Mott, W2DRZ, for my best friend. If not for him and his way of trying for almost impossible achievements I would never have accomplished as much as I have in my life. Rest in Peace Tom |