West Tower Repairs 2006 - October 29, 2006 Work Party

Station Engineer John Fore W6LD, reports another successful work party on Sunday, October 29, 2006 at Site 530.
  1. We bracketed the lower point of the mast (to permit removal of the lower thrust bearing and rotator) using our custom-build bracket system;
  2. We moved the rotator shelf and lower thrust bearing to a point 42" below their original placement in the tower; and
  3. We removed the rotator for some maintenance and repair work (e.g., painting where there is some rust and repairs to the mast-to-rotator coupling to eliminate the "weathervaning" of the antenna over about a 15 degree angle that was a result of a defect in the original installation and has resulted in constant and inappropriate "wear and tear" on the entire antenna system).
  4. We also made progress on installation of an all-weather box at the center pole of the 80 meter 4 square -- which is needed as a first step to repair the 4 square by finally putting in place permanent connections for the relay control system, dummy load and phasing system -- thanks to the efforts to Larry and Dave when they were not actively helping with the tower work.

It was a beautiful day and a lovely way to spend a Sunday afternoon and we had a great turn-out.
Next steps:
  1. We are ready to bring a crane in for removal of the damaged mast and installation of the new mast. As soon as we find our way through the appropriate University process, we'll schedule it; probably next week or the week thereafter during the work week. Please keep posted as we'll need some help and most folks with have conflicts during the work week.
  2. Meanwhile, Randy Ahlkvist is completing the machining of the top plate/3" thrust bearing adaptor plate and repairs and maintenance on the rotator.

Notes Regarding Some Other Near-Term Projects:
We have a number of deferred projects. Some of the key ones which I view as nearer term are:
  1. 4 square repair - this is something we will be moving forward with in the coming weeks. We have most of the materials and equipment. We will be purchasing a surplus dummy load to replace the dummy load that was burned out at an approximate cost of $300.
  2. Replacement of truss support systems on the 4 element 40 meter yagi and the 6 element 20 meter yagi - this project should be completed this year to ensure survival of the antennas. We need to purchase some inexpensive hardware (which we already have for the 40 meter yagi) and then use the University bucket truck for the work. It will make sense to schedule this as soon as possible following the completion of the repairs to the West tower.
  3. Removal of six meter yagi to the telephone pole to North side of building - requires installation of brackets (already purchased) and rotator (need to purchase) on the telephone pole. We can use a mast that is surplus from our damaged mast from the West tower. Then we move the yagi from the UHF/VHF tower to that location. We need to get this done before winter storms; pending completion of this project we will need to remove the six meter yagi from the tower for the winter season to ensure that the tower is not overloaded during a storm. Contact me if you are interested in helping make this project happen.
  4. Installation of permanent feedlines to UHF/VHF antennas -this can be done as soon as we remove the six meter yagi from the tower. All the feedline and hardline has been purchased (very expensive Andrew Heliax 1/2" superflex and connectors). Contact me if you are interested in helping make this project happen.
  5. Removal of Pro67A beam and installation of repaired upper bracket with thrust bearing, new mast (salvage from West tower mast), new feedline and rotator control cable and refurbished rotator. All parts are on hand, except that we need to send one of our currently unused older rotators back to RotorDoctor to be refurbished before proceeding. Contact me if you are interested in helping plan out this project and make it happen.

We will stage projects as time and interest of club members permits. Meanwhile, if there is a repair or improvement you are interested in making happen, contact me and we'll talk about the details including timing and availability of support.

That's the update for now. For the moment, the really great news is the old fractured boom to mast plate has been replaced and much of the load on the damaged mast removed.

For now, the 15 and 20 meter yagis on the West tower are set fixed at about 75 degrees.

  • THE ROTATOR AND TOWER POWER HAS BEEN SWITCHED OFF.
  • DO NOT ATTEMPT TO REACTIVATE OR USE.

    Thanks and 73,

    John, W6LD


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