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Sunday, August 26, 2012

The Great Tower Upgrade of 2012

So this is where it begins. I currently have a Cushcraft A3S with the A743 40M dipole extension and a Cushcraft D3W rotatable dipole.  These antennas are mounted to a Hazer H2 tram system with a Hygain HAM IV rotator.

The antenna has worked well but was damaged in a wind storm about 2 weeks after installation.  The repairs to the antenna have kept it in the air and functional but I just have not been happy with the performance.

The Hazer tram is a great device for the ability to maintain the antenna system.  It has worked well for me but tends to be a bit noisy in the wind (it clanks and bangs a bit).  The tram is being removed in this antenna upgrade.  It will be placed up for sale at the very next available hamfest/swapmeet.  Believe me, I like these trams.  I installed one on my fathers tower and it has been a god send at his QTH.  They are perfect for the older ham that can no longer climb his tower.  I am planning a slightly bigger load on this tower than the H2 can handle.  It can simply not handle the new load.

 I have purchased a new 3 element Steppir beam for installation on the tower. I will be extending the tower by 8 feet. The tower will be a total of 48 feet high. This should put me slightly above the tree line on my property. I will be adding a new elevated guy system as well.

 The Steppir is due to arrive October 5. In addition to the antenna, I have purchased the 6 meter parasitic element and the SDA100 auto tune kit for my Flex 5000. I am looking forward to the enhanced performance of the new antenna.

The elevated guy system will be installed on the sides of my home.  I have purchased 2 ea 6.625" diameter 10 foot long pipes.  They have 0.28" thick walls and are 197 lbs each!  I am burying them in cement in a hole that will be dug 18" by 5 feet deep.  The pipes will extend 5 feet above my property grade and will attach to the guy lines at that point.  Once they are vertical in the cement I am planning to fill them with cement.  This will enhance the stiffness of the pipes.  The guys themselves are 4000lb test Phillystran.  The stiff pipes were important because Phillystran tend to stretch a bit.  The tower will be guyed at the 45 foot level. The whole system was simulated with Grape Finite Element Analysis and appears to be well with in design spec for the tower up to about 90 MPH winds.

The tower extension is to be accomplished with a new section of Rohn 25AG4.  I am putting a new rotator plate inside the 25AG4 section and will be mounting my HAM IV to it at about the midpoint.  I already have a 10 foot mast that is currently in use on the old antenna.

I will be adding posts to this blog as the work progresses.  This should be fun.


73 and CU on the air!!!

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