I've used Davis RF for rope and coax. http://www.davisrf.com/dacron.php
3/16ths and 5/16ths.
I have it run up the tower and through pulleys currently near the top.
http://www.rogerhalstead.com/ham_files/AntennaSpreader1.htm The 40 meter
sloper is supported the same way off the NE side of the tower, but isn't
easily seen in this photo.
When the tribander, or 40M3 are in place with the 7L C3i 6-meter Yagi 12
to 15 feet above which ever, the attach points will be lowered abt 10'
to the 90' level and the ends of the antennas will be farther from the
tower to minimize interaction. The other ends of the antennas are
anchored to trees, using 5/16ths Dacron Rope to lag bolts with forged eyes.
The double weave 5/16ths Dacron ropes come down the outside of the
tower to the bottom section where they go inside and are anchored
around a cross brace about 3' above ground level, with three or 4
wraps. I pull it as tight as I can easily do, then holding the end of
the rope in one hand, grab a section above and pull out with the other
hand. Then take up the slack by pulling on the end as I let the rope
back into the tower. By repeating this this, I can easily put several
hundred pounds of tension on the antenna which is needed to keep it
relatively straight with the choke and LMR-400 cable hanging from the
center. This requires a substantial center connection as well as
strong antenna wires!
I use Copper split nuts on wire connections "up there"
http://www.rogerhalstead.com/ham_files/AntennaFeed2.htm I need more
cores and more turns as I had to add a second choke back at the tower.
There are 7 turns rather than 6. You can see 6 external loops, but the
coax makes 7 passes through the cores.
I'm going to change the anchor method to simple, inexpensive spur gear
drive winches so I can get the tension with only one hand. Using the
pulley near the top of a 100' tower requires at least an extra 100 feet
of rope to lower the antennas. The winches, neatly, take care of that
extra rope which just gets piled up at the base of the tower at
present. With 2, 3, or 4 antennas that makes for a tangled mess.
DANGER:
As an added safety note, I use a kitchen match to light the ends of the
poly rope. Once melted, while wearing leather gloves I massage it into a
ball. The gloves are a necessity! That melted poly can cause some
serious burns and once stuck to skin it's really difficult to remove.
If you don't move fast enough you can end up with the rope welded to a
glove. With a double weave rope, make sure that the jacket gets bonded
to the core.
73
Roger (K8RI)
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