[TowerTalk] Stringing dipoles?
Eugene Hertz
ehertz at tcaf.org
Wed Oct 11 10:15:41 EDT 2006
Ok, this may be the simplest question I will ever ask here so here goes.
During my research for OCF dipoles, I have read about some horror stories of dipoles breaking or coming apart due to the stress of wind, weight and other factors. Especially I've heard that the carolina windoms, with their extra weight in the center caused by the matching unit, the isolator, and the length of feedline can cause a big sag at the feedpoint. Several folks I've corresponded with indicated that they attempted to "lift up" the feedpoint as high as possible by putting more tension on the wires (legs) to hoist it higher. This was for people that did not have a convenient center mounting location like a tower or tree or house.
In thinking about this, it seems that these antennas have lots of phyiscal stress on them from both gravity as well as tension on the ends of the wires in the horizontal plane to try to counteract gavity.
My thought was this: By using one rope (dacron etc) to connect leg1 to a tree and another rope to connect to leg2 to a tree (with pulleys and weights, of course), this is putting lots of "horizontal" stress on these wires and the center matching conductor/insulator thingy. This force is always trying to pull apart the antenna.
Why not take one very long rope, thread it through the leg1 insulator, the center insulator/matching unit and then the leg2 insulator? Surely the two ends of the wires would have to be attached somewhat taught to the rope, but this could be done with some black wire-ties along the length of each wire. Or tie some knots in the rope somehow to hold the insulators in place.
My thought was, this would all but eliminate any horizonatal stress normally put onto these wires and we would be left only with the stress of gravity vertically. I would imagine too, that this would help keep the center up a big better than nothing going through the center point.
Any thoughts? Could this work? What am I missing?
Eugene
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