[Top] [All Lists]

Re: [TowerTalk] Force-12 LPT-1242 Cable Replacement experiences?

To: "Tower and HF antenna construction topics." <>
Subject: Re: [TowerTalk] Force-12 LPT-1242 Cable Replacement experiences?
From: "Leigh L. Klotz, Jr WA5ZNU" <>
Reply-to: "Tower and HF antenna construction topics." <>
Date: Wed, 17 Mar 2010 22:37:20 -0700
List-post: <">>
This messages provides some, but not all, details about the cable 
replacement process for a Force-12 LPT-1242.
As the cables are internal to the structure, it's an involved operation.

I had JV K6JHU and Bob K6XX from the Santa Cruz, CA area replace the two 
non-winch cables in my Force-12 LPT-1242.
(Steve K7LXC who originally did the installation was unavailable during 
the time I needed the work done.)

For documentation, I received a PDF drawing from Mark at the new 
Force-12, but it was a broad outline only, and didn't specify routing, 
parts, or tolerances.  I ended up purchasing 100ft of 1/8" 7x19 
galvanized wire rope and matching Nicopress sleeves (zinc-plated 
copper).  It appeared the original cable was 3/16" but had grown a bit 
in some spots, so I mistook it for 1/8".  The 1/8" cable fits fine on 
the fiber pulleys, though, so we (by we, I mean mostly JV and Bob, while 
I watched) used it.  We used two crimped Nicopress sleeves for each wire 
termination, and bolt cutters ($20) to cut the wire rope cleanly.

The four Delrin bumpers at the top of the top two sections had to be 
removed, and their rivets drilled out, in order to disassemble the tower 
for cable replacement.  For replacement, 1/2" long rivets were too long, 
so we used two washers on the exterior of the tower to keep the rivet 
shaft from going through the Delrin bumper and scraping against the 
aluminum mast.  The washers were next to the rivets at Home Depot, 
though not in stack at Orchard Supply Hardware.

There are some obstacles to navigate through as well, getting past the 
bumpers.  I won't describe the internal cable routing.

One of the wire ropes somehow wasn't taut once when we put the tower 
back up, and that stopped the tower rise because it became fouled in the 
pulley inside the tower.   Luckily, it's possible to make it taut again 
by removing the Nicopress sleeves (not a fun task) and shortening the 
cable from the outside.

The tower itself had about a half-gallon of water collected inside the 
base, even though there was a drain hole in the center, and the base was 
mounted on washers giving ground clearance.  The hole appeared to be 
plugged with mud.  We drilled four more base holes in the bottom plate.



TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>