I'll second the view that the HDX-589 is a good choice. With K7LXC's
help I put up two of them 2 years ago and no issues so far. My lot is 5
acres also and partially wooded, with the two towers in a clear space.
Access was good for me. Two 589's are almost a wash in cost for a
HDX689 if you want max load on a single 89' tower.
Several things to consider:
1. the "standard" HDX589 foundation goes down 9'. That takes a good
size excavator or extend-a-hoe backhoe and you need a ingress/egress
path. You may need a different foundation if a soils test is required
and the engineer designs one.
2. what to do with about 9 cubic yards of dirt from the hole, in my case
gooey clay which was a real mess to dispose of. My water table was at
5' and much pumping was needed. And then two abandoned septic tanks
were encountered for one foundation and 18 yards of concrete went into
that hole.
3. how to pump the concrete from the truck to the foundation
4. how to unload and move the tower. I had to shuttle it from the
flatbed to my house on my 20' flatbed trailer as there is no turn around
for a semi closer than 1/2 mile. You are responsible for unloading. I
own a 4k# capacity forklift so that was easy. Buy some slings, you will
need them several times.
5. rental yards are your friend - I use a 40' 4wd boom lift (JLG, Genie,
etc) to place the antennas and work on them; you will need a rough
terrain forklift or 4wd reach lift (JLG, Gradall) or large backhoe with
enough capacity to move the tower. Plan for at least a week long
project with at least 2 full time laborers. (and then a 30 day wait for
the concrete cure before attaching the tower to the base)
6. You will have to get the rebar for the cage commercially bent, its
too heavy for hand bending. After fabricating it you will need a
machine to lift it into the hole. While not on the UST drawings,
diagonal rebars on the sides will make it a much more stable structure.
I think it very unlikely that an inspector will complain about "too much
rebar".
7. LXC had me tack weld the 6 anchor bolts to a frame of 3/8 rebar so
they wouldn't move in the concrete. I welded with the bolts tightened
on the base as the fixture. This assembly JUST fits inside the UST spec
rebar cage. Think about the tilt orientation and plan the base hole
accordingly. Wire tie everything together super strong since there will
be climbing into the hole. Have strong forms around the above grade
concrete and make sure they stay level.
8. King County, WA wanted ice calcs and UST promptly provided them at no
cost.
9. Several special inspections were called out - rebar structure and
placement, concrete slump and PSI testing. No problems except $.
10. the Armstrong tilt over winch is good exercise
Good luck on the environmental issues, often they are designed to stop you.
Search the forum for the discussions about crank up cable lubrication.
Buy K7LXC's book "Up the Tower" for lots of other good stuff.
UST was happy to reschedule the shipment since I was delayed by the ice
calc resubmission. They sell a fair number of these towers so I one of
mine made somebody else happy while they built another one for me. They
are built to order.
Grant KZ1W
On 3/29/2013 10:27 AM, Steve Jones wrote:
Wayne-
I have been happy with US Tower's HDX-589. Their structural engineer was
very helpful on the phone, answering the many questions I had regarding
antenna loading, foundation work, maintenance, etc. It has a manual
tilt-over winch which is tedious to raise & lower, but I don't tilt it over
that often. I contacted Karl Tashjian at Tashjian Towers, but he wasn't
very responsive or helpful.
Regarding trees, I had to remove several large fir trees to install my
tower. That was covered in my county permit. The permit required that I
complete an environmental check list which addressed the types of endangered
critters that might live in the trees, the effects on rain runoff with the
trees removed, effects on the health of the forest, etc. If they didn't
like the results, they might have asked for a full EIR report, but the
impacts were all "less than significant" or "less than significant with
mitigations". And San Mateo County, CA is a very environmentally conscious
area! So you still might think about removing a few critical trees, it's
just a lot of paperwork.
Make sure there's no arrowheads laying around before the archeologist
arrives!
73,
Steve
N6SJ
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Wayne
Willenberg
Sent: Friday, March 29, 2013 8:09 AM
To: towertalk@contesting.com
Subject: [TowerTalk] Need Tips on Selecting A Crank-up Tower
For several years I have been dreaming of a 90' tower next to my home
located near the coast in South Carolina. But, I could never find a
practical way around my county's requirement that any tower must meet a
130MPH 3-sec gust. A further problem is I live on a 5 acre heavily wooded
lot. The county requires a permit to cut down a single tree. That made it
impossible to get a crane into my backyard to erect the tower. If it
weren't for that problem, I would have gone with something like a Big Bertha
that I understand can meet this wind loading requirement. However, there is
a trail from the road to near the tower site that is wide enough to allow a
Bob Cat and a back-hoe or the like to get to the site.
Fortunately, I subscribe to this reflector because a couple of other hams on
the reflector suggested a crank-up tower. They suggested I could try to
sell the county on the fact that a fully retracted tower can meet the 130MPH
requirement.
Yesterday, I met with all 5 members of the county planning department and
presented this "nested" approach. I circulated a photo of the nested tower
(I didn't pass around a photo of the tower fully extended) and further
explained how I might be helpful for communication in an emergency
condition. Something won them over and now I am jumping through all the
other hoops they have, like an archaeological survey!
I need some tips on selecting a motorized crank-up tower that can hinge near
the base to allow the tower to be horizontal. I would like to have an
electric motor to also control the hinging function. (I don't mean to spark
a debate over which manufacturer makes the best tower.) I am so new to this
that *any *constructive suggestions will be helpful. I am at a point where
I know so little about these towers I don't know how to ask intelligent
questions. If you own a tower like I am describing, where have you had
problems? Does it go up and down as smoothly and effortlessly as
it seems? Even suggestions like the diameter and material of the cable
that pulls the antenna up would be helpful. How much maintenance am I
getting into?
Thanks for your help.
73, Wayne KK6BT
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