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Today's Topics:
1. Re: Rohn 45 (john@kk9a.com)
2. Re: Insulating towers (john@kk9a.com)
3. Re: Raising Towers (Jim Lux)
4. Re: Insulating towers (Jim Lux)
5. Re: Insulating towers (Jim Lux)
6. Re: TowerTalk] Rohn 45 (Chuck Smallhouse)
7. Re: Raising Towers (Michael Tope)
8. Re: Raising Towers (K7LXC@aol.com)
----------------------------------------------------------------------
Message: 1
Date: Thu, 26 Dec 2013 15:58:51 -0500
From: john@kk9a.com
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Rohn 45
Message-ID: <072febe180fc8f6ba5bb42b38c9d0299.squirrel@www11.qth.com>
Content-Type: text/plain;charset=iso-8859-1
If you are investing in four 6m beams, maybe $500 each, a rotator $1k?.
plus an H frame, etc, skimping on the tower just to get them in the air
seems foolish. There are plenty of 30' towers that are rated for this
windload and they are not much more expensive than the proposed Rohn 45
sections. Besides if it falls there is still risk to humans and animals
should they have the misfortune of being in the wrong spot at the wrong
time.
John KK9A
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Rohn 45
From: Jim Lux <jimlux@earthlink.net>
Date: Thu, 26 Dec 2013 07:58:18 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On 12/26/13 4:42 AM, Gregg Seidl wrote:
One thing to think about is whether you care if it falls down in an
extreme wind event. You might be willing to take the risk, in exchange for
getting your antennas on the air.
Sounds like an interesting project, especially if you're somewhat failure
tolerant.
------------------------------
Message: 2
Date: Thu, 26 Dec 2013 16:08:02 -0500
From: john@kk9a.com
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Insulating towers
Message-ID: <58a0c08f76e94b1157680b74f1934644.squirrel@www11.qth.com>
Content-Type: text/plain;charset=iso-8859-1
Wny not purchase an insulator designed for this purpose? WB0W and Array
Solutions among others make them.
John KK9A
To: towertalk@contesting.com
Subject: [TowerTalk] Insulating towers
From: "Patrick Greenlee" <patrick_g@windstream.net>
Date: Thu, 26 Dec 2013 13:39:15 -0600
Any thoughts on insulating a tower? I have some Rohn 25 that I want to use
to make a home brew version of a Hy-Gain Hy-Tower multi-band vertical. I
am considering two approaches:
1. Buy a plastic cutting board to cut up for material to home brew
insulators to be electrically between the tilt base and the tower proper.
(I have a friend with MS Mech Eng and 35 years hands on experience who
will, if asked, consult on this or help me design it.)
2. Pay the $ and buy 3 insulators from Hy-Gain as replacement parts for a
HY-Gain Hy-Tower antenna.
Any thoughts on item 1 or other ideas to git 'er done.
Patrick NJ5G
------------------------------
Message: 3
Date: Thu, 26 Dec 2013 13:37:32 -0800
From: Jim Lux <jimlux@earthlink.net>
To: "Hector Garcia,XE2K" <j_hector_garcia@sbcglobal.net>,
"towertalk@contesting.com" <towertalk@contesting.com>
Subject: Re: [TowerTalk] Raising Towers
Message-ID: <52BCA19C.3060506@earthlink.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 12/26/13 11:27 AM, Hector Garcia,XE2K wrote:
This is exactly an example of what is happening in the last months in
the reflector
CRITICIZE others post an not a positive output
My comments weren't intended as criticism.. Just as another viewpoint.
I was pointing a few possible problems to show to others what can happen
or give another possibility
to do not put in risk life or property but what was the response?
supportive? destructive?
Indeed.. but one aspect that comes up a LOT on TT is the whole thing of
"code compliance" or "good engineering practice". Whether it's guying,
strength of materials, or grounding practices, there's a huge amount of
room to maneuver, depending on what one's risk acceptance strategy is.
I think that the original topic here was an excellent example of someone
who has a situation where "if it falls down, nobody will care, other
than the builder", which is decidedly not the case when the local
planning department is asking for wet stamped drawings from a PE (or
maybe it is, and asking for excessive documentation is a way to restrict
antennas and towers).
I didn't see anything fundamentally "unsafe" in the pictures. Unlike a
lot of field day pictures you see, there's nobody standing underneath
the towers being pulled up, so if his manky tow rope does fail, he winds
up with some bent scrap metal, not a trip to the ER or a call to the
coroner.
One can be "over-cautious" ( I think that characterizes much of what I
do at JPL.. we are definitely risk-averse), and the most useful
discussions on TT are where one finds out where one can do something
that is "not the optimum".
And a lot we do in ham radio, as a matter of course, is not
"code-compliant" and that's hopefully done with an appreciation of the
risks being taken.
I'll bet very few people with wire antennas follow all the electrical
code requirements (copper clad steel, AWG12, etc), but one hopes that
they realize the trade they are making: the antenna might come down in a
strong wind or when a big bird lands on it; and if it does, hopefully
they've situated it so that it doesn't wrap around the local 14.4kV
medium voltage feeder. And if it does, hopefully, they've got a decent
protective unit bonded to the safety ground system.
If this ham owns all AZ, not a close neighbor and his tower fall and
kill him , his dog or his wife and safety advice before can be good?
I think, based on the pictures, that he does have that appreciation.
your comments are well taken, but I think have been addressed by the ham
in question.
I was thinking this reflector was to HELP others to make good or right
things, to avoid problems
or save some time and money and keep them ALIVE not just to criticize
with no positive output
Criticize is good but giving a better result or to fix others wrong doing
My intention is not to start a war, just share my point and no intention
to offend others with my words, if for some reason are crude
possible is the result the spanish to english translation process in my
brain
but I try to share and help and give my opinion with the intention to
help.
J.Hector Garcia XE2K / AD6D
Mexicali B.C DM22fp */ *El Centro
P.O.Box 73
El Centro CA 92244-0073
http://xe2k.net
Tweeter @XE2K
------------------------------------------------------------------------
*From:* Jim Lux <jimlux@earthlink.net>
*To:* towertalk@contesting.com
*Sent:* Thursday, December 26, 2013 10:58 AM
*Subject:* Re: [TowerTalk] Raising Towers
On 12/26/13 10:41 AM, Hector Garcia,XE2K wrote:
> Some very interesting ideas, very ingenious and a lot to avoid
> I got scare with his double braid rope as lanyard @200ft tower
Well, if you're raising it in your (big) backyard, and you're aware of
the risks, then you can use dental floss if you think it will work.
> not FAA lights on 200ft towers?
That would be a problem.. Maybe his "200 foot" tower is actually 199
ft, 6", and exempt.
> those bungee cords as insulators or for tension ?
I'm thinking some sort of shock absorption.
> the anchor in the wash
> no insulators in the guy wires.
if the guy doesn't happen to be "the wrong length", then there's no
particular reason for insulators (unless you're feeding the tower as the
radiator)
> some good things to use and some ones to avoid from my point of view
> be safe
>
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------------------------------
Message: 4
Date: Thu, 26 Dec 2013 13:41:47 -0800
From: Jim Lux <jimlux@earthlink.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Insulating towers
Message-ID: <52BCA29B.8020407@earthlink.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 12/26/13 11:39 AM, Patrick Greenlee wrote:
Any thoughts on insulating a tower? I have some Rohn 25 that I want to
use to make a home brew version of a Hy-Gain Hy-Tower multi-band
vertical. I am considering two approaches:
1. Buy a plastic cutting board to cut up for material to home brew
insulators to be electrically between the tilt base and the tower
proper. (I have a friend with MS Mech Eng and 35 years hands on
experience who will, if asked, consult on this or help me design it.)
2. Pay the $ and buy 3 insulators from Hy-Gain as replacement parts for
a HY-Gain Hy-Tower antenna.
Any thoughts on item 1 or other ideas to git 'er done.
Cutting board (HDPE) is a great insulator. You're probably not looking
at more than 10 kV, so almost any thickness will work, as long as the
surface creepage path is long enough.
HDPE is NOT a great structural material, though. You could use
fiberglass bolts to clamp HDPE in between layers.
You can also buy fiberglass tubing (Extren is one brand): McMaster-Carr
has a lot of it in various shapes and sizes. Again, creepage path is
your primary thing to worry about, breakdown-wise.
------------------------------
Message: 5
Date: Thu, 26 Dec 2013 13:46:36 -0800
From: Jim Lux <jimlux@earthlink.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Insulating towers
Message-ID: <52BCA3BC.2030107@earthlink.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 12/26/13 12:36 PM, Charlie Gallo wrote:
On 12/26/2013 Patrick Greenlee wrote:
Any thoughts on insulating a tower? I have some Rohn 25 that I want to
use
to make a home brew version of a Hy-Gain Hy-Tower multi-band vertical.
I am
considering two approaches:
1. Buy a plastic cutting board to cut up for material to home brew
insulators to be electrically between the tilt base and the tower
proper. (I
have a friend with MS Mech Eng and 35 years hands on experience who
will, if
asked, consult on this or help me design it.)
The issue with plastic cutting boards is that they are made from High
Density Polyethylene (HDPE) HDPE will "cold flow" (technically called
Creep), and is known for "Poor weathering resistance"
You may want to look at one of the "filled" versions, or some other
filled engineering grade plastics - or use something like PEEK, PES or
even Phenolic
Definitely..
Get something that is designed as a structural material.
http://www.mcmaster.com/#fiberglass-hollow-rods/
You may find that it's easier to just buy the premade insulators than to
figure out how to fabricate something out of the raw materials.
To a first order, structural fiberglass is a lot like aluminum, in terms
of strength. It's a lot less stiff, though.
There are very nice structural, electrical insulators out there that
look like a lump of plastic with two threaded bolts sticking out of it.
The trick, as always, is knowing what breakdown voltage you need, and
designing for that.
------------------------------
Message: 6
Date: Thu, 26 Dec 2013 14:59:11 -0700
From: Chuck Smallhouse <w7cs@theriver.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] TowerTalk] Rohn 45
Message-ID: <20131226135914.4FF2AFF8@dm0219.mta.everyone.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed
Gary, Jim,
Yes the strut "guying" is the way to go and also not only provides
the strongest support but also occupies the least amount of ground
area, as well as the least interference with your array. I dare say,
with your planned medium sized 6M array of four yagis, that you might
not need to replace your Rohn 25 with a 45, using this technique.
More than thirty years ago Lance, (now W7GJ, MT) installed a large 2M
array using 16 long yagis (30' each?) on about a 30' tall Rohn 45 and
supported that structure with three, about 20' long, pieces of 1 1/5"
black pipe. They were attached about 2/3 the way up the tower and
about 10' away from the base. It's still up and has considerably
more wind loading than your 6M array will have.
I used his work/ideas for my own R & C, EME array project, consisting
of 8 very long 2M yagis on 30' of Rohn 45, again a higher wind load
than your array. Instead of black water pipe, I used the top railing
material for chain link fencing. It's about 1 7/8" in diameter and
relatively thin wall and light, but quite strong. It comes in
either 20' or 24' lengths The top of this tubing was attached at
about the 20' position on the the 45, using HB saddle mount brackets
attached to the tower legs with U-Bolts. The bottoms of these
struts, using similar brackets, were attached to two 18" "J Bolts"
set into concrete pillars in the ground. These pillars were about
14" in diameter and no more than two feet deep, and placed less than
10' away from the tower center. This close in spacing easily allows
the clearance of your 6M yagis when they are being elevated. This
array was up for at least 12 years, until I moved to this AZ QTH.
BTW, R & C stands for: Research and Copy !
If you still want to use Rohn 45 replacement, you can consider using
a large steel plate (3/16" to 1/2" thick) welded onto the Rohn 25
stubs extending from the existing base. This base plate needs to be
and large enough in diameter, to weld the base of the 45 to, and also
to weld strengthening stiffeners. These can be steel angle of at
least 2" on a side, along it's outside edges to prevent oil can
bending of the plate. Don't ask why you need to do this !!
I have done a similar installation, to my N. CA one, at this QTH, to
support 16 of my now 28' boom 2M yagis.
GL es 73, Chuck,, W7CS
------------------------------
Message: 7
Date: Thu, 26 Dec 2013 15:16:28 -0800
From: Michael Tope <W4EF@ca.rr.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Raising Towers
Message-ID: <52BCB8CC.1090608@ca.rr.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 12/26/2013 1:37 PM, Jim Lux wrote:
I was pointing a few possible problems to show to others what can happen
or give another possibility
to do not put in risk life or property but what was the response?
supportive? destructive?
Indeed.. but one aspect that comes up a LOT on TT is the whole thing
of "code compliance" or "good engineering practice". Whether it's
guying, strength of materials, or grounding practices, there's a huge
amount of room to maneuver, depending on what one's risk acceptance
strategy is.
I think that the original topic here was an excellent example of
someone who has a situation where "if it falls down, nobody will care,
other than the builder", which is decidedly not the case when the
local planning department is asking for wet stamped drawings from a PE
(or maybe it is, and asking for excessive documentation is a way to
restrict antennas and towers).
I didn't see anything fundamentally "unsafe" in the pictures. Unlike a
lot of field day pictures you see, there's nobody standing underneath
the towers being pulled up, so if his manky tow rope does fail, he
winds up with some bent scrap metal, not a trip to the ER or a call to
the coroner.
Jim, I had somewhat the same feeling until I scrolled down to the
"selfie" of the guy taken from the top of one of those homebrew 200'
towers made from chain-link fence top-rail. You can clearly see the
safety lanyard made from dacron rope with frayed ends that is holding
him in place. While I greatly admire the vigor of an 85 year old guy who
fabricates and installs 200' towers by himself, nobody should be under
any allusions that what he is doing is remotely safe (at least when it
comes to the climbing part of it).
73, Mike W4EF............
------------------------------
Message: 8
Date: Thu, 26 Dec 2013 18:49:39 -0500 (EST)
From: K7LXC@aol.com
To: towertalk@contesting.com, w7ry@centurytel.net
Subject: Re: [TowerTalk] Raising Towers
Message-ID: <6d10f.337f4e33.3fee1a92@aol.com>
Content-Type: text/plain; charset="US-ASCII"
Now this guy knows how to raise a tower! All by himself..
http://w7yrv.blogspot.com/2013/10/cheapest-towers.html
Check out the "Mishaps" button. Into each life a little rain must
fall.
Cheers,
Steve K7LXC
TOWER TECH
------------------------------
Subject: Digest Footer
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End of TowerTalk Digest, Vol 132, Issue 73
******************************************