I have had four types of temporary towers:
#1) 40ft Tower without guys using oversized baseplate into a deep hole-
Use a standard baseplate and add a 3 foot to 6 foot square plate to it.
I had my backhoe guy dig a 6 to 8 foot deep hole. Next we used a
chain to lift a pre-assembled 20 foot tower with that large base plate
into the hole. Fill the hole back in. Add to two, three or four more sections.
My tower done this way has a 4ft square plate added, 44ft total length
37 feet are above ground. It has a KLM 6L10, 6L6M is 5 feet above it and
at 25ft I have a 3L15 Hygain fixed south. The tower does not move when I am on
it. (250#)
#2) 70ft Rohn 45G Tower with oversized baseplate and pier pin
This was put up on a filled guy anchor hole that I added a pier pin to.
Guyed at two levels to one set of screw-in guy anchors.
The tower does not move when I am on it. (250#)
I only had a 2L40 and a Tailtwister on this for 8 years before a tree fell
on the guy wire and pulled it over bending the last 1 foot of the legs.
I will sawzall the bent legs off and re-do the baseplate. It will be re-erected
this winter.
I had planned to add 4L-over-4L 20 yagi's to it also. This time I will use one
set of screw-in
guy anchors for each guying level. This may not save the tower from the next
falling wooden
missile from taking down the tower, but it will last a long time. I'm 54 yrs
old and this may
be my last tower builds....
#3 and #4)
75 foot 80M insulated vertical Rohn 25G tower in 55 gallon drum with concrete
placed on-ground.
40-70 foot Rohn 25G tower in 55 gallon drum with concrete placed into deep
hole.
This type has several variations:
Base section placed into a form to hold 3 to 6 feet of concrete.
Use as buried in-ground or placed on-ground.
You can also apply the buried base method here too relying on the weight of the
concrete to
steady the base instead of the oversized wide metal baseplate.
The on-ground concrete base must be guyed.
Place a straight base section or straight section into a 3 to 6 foot high form
and add concrete.
Mine were a single section inverted with the intention of using them to accept
home-brew insulators
to become the base of an 80M Rohn 25G tower vertical 4-Square.
Use any type of form and after curing you may remove it. A metal 55 gallon drum
for example.
You could even use a large sonotube type of concrete form too.
http://www.sonotube.com/
Any container that would hold the weight of the concrete for the one or two
week curing time
will work fine. I used a plastic 55 gallon drum known here as a pickle barrel
filled half way or more.
(Remember if you use it as an on-ground base, then the height of the concrete
will have to be
climbed in order to climb the tower. So, you may need to build a few wooden
steps or bring
a ladder to climb this type of on-ground tower base.)
You can also apply the buried base method here too relying on the weight of the
concrete to
steady the base the hole instead of the oversized wide metal baseplate.
The half filled concrete form version for my 80M verticals weighed about what
two or three
men could drag o ut into a fresh-water swamp in the back end of my property. We
also talked
about using a guywire tram line between two trees or off the big tower near-by
to lift and move
these base sections with concrete into position in the swamp.
Using the buried concrete section may be safe up to 40 feet high, but any
higher will require guys.
The on-ground method will require guys when higher than 20 feet.
-Charlie N1RR
----- Original Message -----
From: "Ken Fritz" <ken.fritz@gmail.com>
To: "TowerTalk" <towertalk@contesting.com>
Sent: Tuesday, August 16, 2016 11:43:23 AM
Subject: [TowerTalk] Temporary tower installation
Hi all,
I'm looking to erect a temporary tower for CQ WW SSB. I have 40ft of Rohn
25G and an A3S that I'd like to put up. I've seen a number of ways to do
it but I'd like to hear from those who have some experience. What's the
easiest and safest way to do something like this?
I've looked into plenty of options so far but I'd like to keep the question
open-ended to see what you all think.
Thanks!
Ken
N3WAX
--
____________________
Ken Fritz, NRP, EMT-P
Paramedic
(484) 368-9739 (c)
ken.fritz@gmail.com
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