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[TowerTalk] TX-472MDP cable replacement

To: <towertalk@contesting.com>
Subject: [TowerTalk] TX-472MDP cable replacement
From: <fritz@k4oaq.com>
Date: Sun, 2 May 2021 09:18:44 -0400
List-post: <mailto:towertalk@contesting.com>
Hi guys,

I believe that dreaded day has arrived.

Background:

I have a US Tower TX-472MDP a little over 20 years old.

Most of those years it's only gone up for the 3-4 major CW contests.

This past year it's been up & down a lot.

The cables have never been replaced. 

Last year I got some PreLube 6 & applied it & did not notice any fraying or
breaks in the cable at that time.

Coinciding with that I loaded my Steppir DB-36/80 & NN4ZZ tilt-plate onto
it.

After some issues with getting it starting to go up, I realized I had more
weight on it than the recommend max of 200 lbs.

I have approximately 225 lbs + rotor, bearing & cables.

I discovered that the belt was a little loose but that after a little boost
to get it started & holding a board against the belt to make it tighter,

it wud go on up just fine. 

About a month ago I noticed a single strand of the cable flopping around as
it went thru the gears.

So, I started paying more attention as I raised it & I'm seeing in 3
different places multiple feet apart where a single strand is broken.

I have cut off several inches of the strand that was flopping around in 2 of
the spots. The third was not flopping arnd . yet.

I have stopped raising & lowering the tower.

My Definitions: My cable appears to be composed of 5-6 strands with each
"strand" composed of 12-14 "wires". (the 12-14 cud be more)

I found Steve's K7LXC post of Mar 2017 (pasted at bottom) describing when
cable needs to be replaced.

I'm confused over terminology but I'm pretty sure my cable needs replacing.

I have several questions.

1-WPX CW is coming up. I assume raising it for that wud be too risky.
Correct?

2-Did the extra weight cause the strands to break? Is there some other
problem causing them to break that needs to be addressed? Or is it just "old
age"?

3-Does a very detailed description of how to replace cables exist? The task
looks very daunting to me. 

4-Shud a stronger cable be used to accommodate the extra weight? There was
shipping damage when the tower was originally shipped. US Tower sent me
replacement cables at that time to reimburse for the damage.

73,

Fritz K4OAQ

 

Steve's Mar2017 post:

The 3 reasons why you would replace them are: 1)  damage - kinking or 

flattening of the cable; 2) excessive broken strands -  you're allowed up to


7 before needing replacement; and 3) rust - cancerous rust,  not surface 

rust. I'll bet you a nickel that you don't have any of those  conditions. 

 Cheers,

Steve    K7LXC

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