Hello again gang,
I have two older (but in very good shape) HyGain crank up towers. A 37
ft.
and a 52 ft. As far as I know, they are not of the "positive pull down"
type. (If I am wrong, please tell me so I can get on with the project!) They
are both on the ground and I am working to get them up within the next few
months so I am doing my layout work and retrofit work as we speak.
Can they be made into "positive pull down" types without a major
rebuild?
If so, does anyone know where I might get that information? Does anyone
know who makes replacement cable kits for these?, or can I just take a
sample of the old cable to a cable vendor and have them make a replacement?
(I don't know crap about cable.) Is stainless steel better than the
original?
Perhaps it is just my impending fear of the cable snapping and having
all
my hard work at antenna building come crashing down and snapping like a twig
that makes me ask questions that may seem a bit ridicules to the well
schooled, but it does concern me! I just want to do this right the first
time, not over and over and over. Too expensive (and potentially dangerous)
to do it wrong.
These towers were not made with an electric winch system and used a
type of
(boat?) winch to erect them. Not my favorite, so I plan to change the winch
out for a worm gear drive winch and use a small pulley and belt system like
a swamp cooler to raise and lower it. (I am not getting up at 5am to start
cranking the antenna up so I can work the long path on 40, then use the
other arm to crank it down with and have to spend the rest of the day with
an ICY HOT pack on both shoulders!! Way too much work!!) ;>) Anyone else
got a cheep but useful method of doing this they would like to suggest?
Can anyone tell me if there is a way to equate rebar material
strength/stretch to comparable bolt materials? IE: 1/2 inch rebar and 1/2
inch anchor bolt? Grade? And what is the grade of anchor bolt material?
When I go to Home Depot and ask these questions, I get that "dog watching TV
look" followed by "Huh?". ;>)
The reason for the question is simple and not so simple.
The original anchor method for the towers is a piece of 2" X 3/8" flat
stock about 10" long welded to a piece of #8 rebar that is about 4 ft. which
makes up the reinforcing cage in the concrete. Each leg fits into a
matching "U" shaped piece of similar material welded to each leg of the
tower and they are bolted with 2 bolts on each leg using 3/4 inch bolts.
Obviously a lot of towers were put up and stayed up for a long time using
this arrangement. Due to a slightly different set of circumstances, I intend
to use a slightly different arrangement because I intend to leave the
erection fixture in place so I can tip the tower over to work on the
antennas at my whim. This is not a part of the original design but is
borrowed from other mfg. (US Tower). I was thinking of using a piece of 1/2
or 3/4 inch plate with the straps welded through it for the tower to mount
on and suspend that plate over another plate with nuts and washers on both
sides which is anchored to the rebar cage and into the slab. That way I can
fine tune the tower to vertical and use the base as the anchor for one end
of the erection fixture.
What size/type/material do I use for the anchor bolts? Just plane old
Home
Depot type 1/2 inch bolts as long as I can get them? or do I need to go to a
mfger of bolts stuff and get Grade 8 ? is B7 bolt stock used on pipe flanges
wrong/overkill? Stainless steel??? What?
I ask because a friend put up a telescoping pole tower a few years ago
using the Mfger recommended stuff and last year the wind bent the tower over
about 20 deg by stretching the bolts!!!
After construction of all of the welded materials including the rebar
cage,
I plan to take it to a local plating company and have the entire mess hot
dipped galvanized. I don't want rust to be my enemy. (Yeah, I know, sort of
stupid perhaps here in Peoria ARIZONA to worry about rust, but.)
OK, gang, I know this is a bit long but while I am thinking about all
this
stuff I need to get some consensus otherwise I will end up like what Scotty
on Star Trek said. "The more they Hi Tech the plumbing, the easier it is to
stop up the drain."
Looking forward to your input pro or con.
Thanks in advance.
Mike Baker K7DD
k7ddmjb@qwest.net
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