Tuesday, May 8, 2012

Radio Tower Troubles

A couple days ago I got tired of complaints from fellow ham radio operators that my  received signal was sometimes strong, sometimes weak.  I went out to the backyard tower and checked out the radios inside,and all seemed well.  However, when I stepped outside to look up at the antennas to make sure they were still there after the last couple days of winds, I noticed the top section of my 2 meter VHF antenna was bent over.  As I focused on it with my cataract-weary eyes, the breeze picked up and changed direction and the bent antenna section flopped over to the other direction.  I realized it wasn't just bent, it was broken and wobbling.  I started to climb the tower on the spur of the moment but the wind picked up even worse and I thought I'd best wait for a calmer day.  Later in the evening the wind had slacked off so I climbed the tower to re-attach the wobbly antenna part.  I did so, but noticed the guy wires at the point of contact with the upper part of the tower were frayed, with 2 or more of the 8 strands broken.  I decided to take the first opportunity to repair or replace the guy cables to prevent the tower from actually falling down, as it did during a Thanksgiving windstorm about 8 years ago.
Today, Tuesday, the wind was only a  very mild breeze, so I donned my climbing belt, gathered up tools, bolts,. and spare guy cables.  I climbed the tower and installed the first new guy cable, thinking to install new ones one at a time before removing the old frayed ones.  Bemoaning the effects of old age and quickly tiring, I took a break after tightening up the first cable and snarfed a snack.  I then installed the second cable, noting the third and last one wasn't even frayed at the tower end and thus, I thought, could  likely wait for "tomorrow".  As I started to climb the tower to remove and drop the second frayed cable, though, I thought:  "Dummy, you're climbing the tower one more time anyway, why not take the last (third) cable up and mount it?  And so I did.
I was shocked, SHOCKED, and experienced a thrill of alarm when I noticed the third and last guy wire, the only one not yet replaced, was HANGING by ONE small strand of cable about 3 feet AWAY from the tower.

The loop around the tower leg was solid and looked good and previously that's all; I'd noticed.  Here I was almost to the tower top, and my weight and all the tower was depending on a SINGLE small strand of cable to prevent collapse... and the breeze was picking up.  I carefully installed the remaining 3rd guy and gingerly climbed down again to fasten the cable to the ground anchor.  As I descended, I noticed a loose bolt and a MISSING bolt at one leg of the tower one section below where the guys were attached above.  So I had to go hunt up another spare bolt;  these Rohn tower hardware bolts are special and I wanted to get the proper bolt installed for a replacement.  Everything all good, nothing fell apart while I was on the tower.  Evidently Heavenly Father had gotten my attention with the broken antenna to wake me up to the risk of a faulty and damaged tower (which is 50 feet tall;  10 sections, by itself.  With the antennas mounted on top it is almost 70 feet tall).
As a final shock, when I was rolling up the frayed cables to clean up the area underneath the tower, I found the SECOND guy cable I'd removed was ALSO frayed, albeit down to 2 strands (!), about 5 feet from the bottom end... I had not realized it was frayed anywhere but at the contact points on each end where the friction occurs when the tower rocks and vibrates under wind stress.  Mercy.  Now in addition to inspecting the ENDS of the guys where I used to think all the stress took place, I must now make sure I focus on the entire length of each guy to make sure they aren't separating in the middle.  I'm unsure what causes such breaks in the cables.  Maybe partial lightning damage?  (Sigh)


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