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[CQ-Contest] Question regarding crank-up tower feedlines

To: cq-contest@contesting.com
Subject: [CQ-Contest] Question regarding crank-up tower feedlines
From: Jim George <n3bb@mindspring.com>
Date: Sun, 25 Dec 2016 13:04:04 -0600
List-post: <cq-contest@contesting.com">mailto:cq-contest@contesting.com>
I've had a three-section crank-up tower (it used to be called the LM-354) that's 54 feet tall when fully extended. For a long time, I used it in a permanent fully-extended manner, with phased ten meter yagis at the top and half-way up. Now, it will have a triband yagi and a two-element 40 yagi on it, above the thrust bearing, and I wish to keep it at least semi-nested between contests to avoid storm damage. What is the recommended way of bringing down two the coax feedlines and the rotator cable for a tower that will go up and down fairly regularly? I'm going to use the three original "stand-offs" to keep the coax and the rotator cable hanging vertically as these three standoffs are positioned such that they nest properly when the tower is down. Is it okay simply to hang the feedlines and the rotator cable down through the top standoff, which seems to rotate around as the rotator moves the mast, and simply let the coax and cable drop down vertically? In this case, there would be no traditional rotator loop. That configuration has worked okayrecently with only the small 40 meter yagi on the top.

Another possibility would be to form a five or ten foot "rotator loop" with the feedlines and rotator cable and then route them back up onto the top standoff and down vertically through the other two. In this way, the system would not require that top standoff to move around on its tower leg as the mast and antennas rotate. Not sure if I described this in a clear way. If I were sure that the top standoff would move around on its tower leg, that would work, but if the top standoff got stuck and didn't move, then the feedlines and rotator cable could get stretched and damaged. For some reason, I haven't seen anything on this, or have forgotten. Any recommendations?

Thanks in advance, and all the best at the Christmas and other holiday breaks and new year.

73, Jim George N3BB

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