I have a Rohn 45G tower with one run each of 1/2" and 1 5/8" Heliax
inside the tower plus a run of 3/4" CATV hardline. Another 45G with a
run of 7/8" Heliax. It really goes in fairly easily. I rigged a pulley
just below the middle of the rotor plate to pull up the coax. Someone
needs to climb with the coax as it goes up as the end will inevitably
snag on rungs on the way up. Someone needs to feed the cable in the
tower at the bottom as someone/something pulls the coax up with the rope
slowly.
Heliax jacket is strong and somewhat slick so it slides in the tower
fairly easily at the bottom with the help of someone pushing it into the
tower as someone pulls on the rope. 1/2" and 7/8" Heliax aren't so thick
that they couldn't be damaged if one pulled hard on the rope without
someone feeding in the coax at the bottom. My CATV hardline has no
jacket and the aluminum shield is kind of soft so extra care (read go
very slow) is needed. 1 5/8" Heliax would perhaps break you before you
broke it. :-) But if you are using a device with mechanical advantage to
pull it up (advisable, it's heavy) you could probably do some damage to
something.
I rather foolishly installed all these coaxes by myself. I fed a couple
of feet of coax in the tower, pulled the rope a little with my truck and
climbed up the tower a few times when the ends snagged. It wasn't a lot
of fun by myself but I am kind of hardheaded when I want to get
something done. Get a couple of friends over, feed in a couple of feet
of cable at the bottom at a time and it should go smoothly (well as
smoothly as antenna work ever goes).
Oh if you use really big hardline you might not be able to get it in a
the very bottom of the tower. My 1 5/8" goes in the tower about three
feet above ground. But likely could have gone in one rung lower. I would
suggest putting it in the tower where you have the entire distance
between two rungs. Although with smaller sizes you might be able to get
away with less distance if you go slow. Just don't try anything that
even comes remotely comes close to kinking the cable. If in doubt back
it out a couple of feet and try again. You will get the feel for what
will or won't work pretty quickly and it isn't that hard.
73, Jay K0GU
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