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KC0KBH
09-05-2006, 12:11 AM
Hi,
I have access to a LOT of 1" 3/16" thick steel tubing, and I can have as much as I want. It is good tubing; I've used it for a snow plow mount, and though rusty, it still has a lot of strength left in it. My plans for it are to weld up a crank up triangular tower. I know it would be very heavy, but, as the material for it is free, I don't care. I can devise a way to drop it (winch, tractor, etc). I'm thinking of going 50-60', if I can get my hands on that much tubing. I sat and looked at a large crank up tower a while back, but can't recall how exactly it worked. It was triangular. Here's my questions about it-
First off, how exactly does the cable and winch system work on it? Any helpful links?
Second, if I were to use the heavy tubing, and used it as the "cross pieces" (for lack of a better term), could I only put one in every couple feet, to cut down on weight? I plan to put a Tri-band beam on it, and maybe a vert. on the side. Or maybe another antenna on it, since I have a 3-antenna antenna relay. Or maybe I'd use it to switch between my GAP Titan and 2 other antennas. Anyway, the wouldn't be a lot of wind load on the tower.
One more thing-
Could a rat shack style tv antenna rotator (actually, Menards; it was free) handle a typical tri band beam?

Thanks.

WA4NMS
09-05-2006, 01:42 AM
A 50-60 ft seat-of-the-pants tower, (crank up or otherwise), is a scary thing. It could be a WMD in some cases. There would be appreciable wind load with no antenna at all. The rat shack rotator could be used maybe with a small 2m rig, or a medium vertical. (I know, I know).

Dave Marshall
WA4NMS

KC9JIQ
09-05-2006, 02:57 AM
I would build a "swing over" tower out of the tubing and use regular tower for the tower, just use the excess steel as the fulcrum support for the tower.

I've seen CB'ers use Oilfield pipe to make a support and the tower is hinged on the support and a boat winch he can swing the entire tower over and work on his beam(a shooting star)

If I was going to build a 50 ft tower, I would pattern my design after antenna tower with the zig zags and get dimensions, and build it as the companies do, cause they designed them for strengh, I would follow their patterns.

K7FE
09-05-2006, 06:38 AM
You do not want to do this.
A 50 to 60 foot tower has structural requirements that you are not prepared to calculate or deal with unless you are a PE doing tower work. Towers are welded by "certified welders" and dip galvanized in very large tanks for long rust free life. The winch used is rated for "vertical lifting" unlike boat winches which are rated for "pulling."

Please do your "next of kin" a favor and buy a good used tower or take out a large term life insurance policy so your wife's next husband would not have to work too hard.

In this case SK would stand for "structures kill."

73,
Terry, K7FE

K9KJM
09-05-2006, 09:04 AM
I agree that this is NOT something that you should attempt.
You will be much further off finding a used Rohn 25 tower that is no longer being used for television reception and just refurbishing that.......... #
I HAVE built a few towers over the years, And when all is said and done, It is time not very well spent.
If you insist on attempting to build one, The "zig-zag" crossmembers should be 5/16"-3/8" steel rod.......... #If you have access to rural junkyard stuff, Old water well "pump rods" would be a natural for the zig zag part.
Menards sells RustOleum "Zinc Galvanize" in spray cans to galvanize it. (Good stuff)
Just look at a Rohn 25 or 45 tower and "copy" the way they are constructed.
I would never consider a "crank up" tower...... #Having worked on a number of them over the years I simply do NOT like them....... #A simple guyed tower is much stronger and safer.
IF you move forward and do build one, I am very sure that by the time you are done, You will decide like I have that your time would have been better spent simply earning the money to buy a properly hot dip galvanized tower that will be stronger, safer, and look great many years longer than your homemade will........
IF you have access to an almost "unlimited" amount of steel, At todays scrap steel prices, Just sell it for scrap and BUY a good tower to start with!

N3MVF
09-05-2006, 11:40 AM
Depending upon your local municipality, you may have to submit engineering drawings and calculations before getting it approved for installation. My municipality required a certified engineering copy of the drawings for a Universal crank-up tower before granting a permit to put it up. This w/out a house w/in 300-400 feet of the tower if it would fall.

Do yourself a favor and don't risk it. But, I commend you on your "grit".

73
Greg

WA9CWX
09-05-2006, 02:44 PM
Yep, by all means build it.

I have plans for building a skyscraper here in my little town.
I can get the scrap metal and some left over driveway cement for free.
I also have an 'in' with the local painting contractor, and can get left over paint for half price.
I will soon be doing a 'google' search for 'Skyscraper plans'.
I figure only 40 or 50 stories high, don't want to overdo it.
Should be ready to rent out next year.

Give me a call, I would like to put up one of them home made towers on the roof.

WA9CWX
09-05-2006, 02:59 PM
ACTUALLY.. I too commend you on the ambition. AND people DO build their own towers. The cover of QST had a home built tower on the cover some 20 years ago. 180 foot high as I recall, with the top 20 feet being rotated Rohn 25, holding the antennas.
The guy was in Michigan.
However, IF you have to ask on QRZ for info, you are likely so far from having all of the technical savvy that this project takes, that it would be insane to even start.

People get killed and injured every year doing things that they have no business doing. Even though a commendable project, this sounds like the possible start of one of those outcomes.
Buy a used Rohn. CHECK it for rust, especially if it has been painted over.......( they can rust from INSIDE the legs, and become VERY dangerous).

Better yet, buy a NEW Rohn, READ the instructions, and install it with HELP. Experienced HAM help.

Best of luck, and find some other use for that tubing. http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

K7MH
09-05-2006, 03:47 PM
Make sure that when you put up you scratchbuilt tower and before you climb it, that your family knows that Costco has caskets you can buy online and delivered in 3 days. They are very nice ones, pretty first class, and your family can save about $2,000 over the price of a comparable one from your local mortuary or funeral home. They are required to let you use one not purchased from them and cannot charge any special fees because of it. If your family is not a member, It is worth joining if only for this one transaction. You can pick your own out online since you know when you will be sk. Also there is an an article in the April 1941 issue of Radio magazine (#258) on building "An Inexpensive Beam Rotator from Old Washing Machine Parts" written by W8BYV. It would probably far outperform the one you are thinking of using. I can scan it and e-mail it to you if you would like.

WB2WIK
09-05-2006, 05:18 PM
Assuming the original post was serious, this is a truly bad idea.

Towers are made from high strength steel alloy, not just any old tubular steel that happens to be around. The stress on a crank-up tower is much more than on a fixed guyed or bracketed tower, since a crank-up should be self-supporting.

Most tower manufacturers determined decades ago that the cross bracing between tower uprights (legs) should be zig-zag bracing in the form of the letter "Z" or "W," using solid rod welded in place in order to provide torsion strength that simple horizontal cross-members cannot provide. That's why all modern crank-up steel towers have such bracing.

And it's unlikely you could get a building permit for a homebrew tower unless a professional engineer (P.E.) licensed in your state stamps and signs the blueprints and engineering documents.

With used documented (certified) towers being as inexpensive as they are, it seems silly to save money this way. I'd save it other ways, like homebrewing all the antennas or other station accessories.

WB2WIK/6

KA0GKT
09-08-2006, 05:30 AM
Here is what you need to do BEFORE you start to construct your tower.

1) Buy a $1,000,000.00 umbrella insurance policy.

2) Update your will.

3) Purchase additional life insurance for you and the members of your family who might be in the vicinity of the tower.

You'll notice that I haven't used any smilies here. Home Brew steel towers, designed and manufactured by people without a structural engineering background are definately NOT a good idea.

Use your cache of steel tubing for other projects, buy certified tower sections to support your antenna.

Be safe, you are the only you for your loved ones.

73 DE KAGKT/7

--Steve


4)

WA9CWX
09-08-2006, 11:03 PM
NAAAA,
just build the damn thing.

ACTUALLY, I HAVE a home built tower, sitting in my back yard, I listed it for FREE here on QRZ last year, pick up only. No takers, but some phone calls, one guy really wanted it, but could not get a trailer, and never called back.

This tower is 26 feet high, tubular and angle steel. Welded rotor and top sections, Stainless steel bolted bottom sections. It is triangular, self supporting, and built like a tank, by my friend (SK) several years ago. It held a 7 element HF beam, and did him good service for several years.

It could use some paint, but is in overall very good shape, and will NOT collapse, it is also VERY heavy.

However, it is by no means a 'crank up' anything. It is similiar to one of those farm towers used for wells. My friend was a maintenance repair man, and expert welder.

He built things to last.

My YL has wanted it trashed for years, I do not have the heart to toss it. I would LOVE to see a ham use it for something, even a dipole support.
Again, it IS well built, and IS free to anyone who wants it.
Ok, a little prejudice here, to any one who wants it for anything #EXCEPT #11 meters. # http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

KC9JIQ
09-09-2006, 12:25 AM
Quote[/b] (wa9cwx @ Sep. 08 2006,16:03)]NAAAA,
just build the damn thing.

ACTUALLY, I HAVE a home built tower, sitting in my back yard, I listed it for FREE here on QRZ last year, pick up only. No takers, but some phone calls, one guy really wanted it, but could not get a trailer, and never called back.

This tower is 26 feet high, tubular and angle steel. Welded rotor and top sections, Stainless steel bolted bottom sections. It is triangular, self supporting, and built like a tank, by my friend (SK) several years ago. It held a 7 element HF beam, and did him good service for several years.

It could use some paint, but is in overall very good shape, and will NOT collapse, it is also VERY heavy.

However, it is by no means a 'crank up' anything. It is similiar to one of those farm towers used for wells. My friend was a maintenance repair man, and expert welder.

He built things to last.

My YL has wanted it trashed for years, I do not have the heart to toss it. I would LOVE to see a ham use it for something, even a dipole support.
Again, it IS well built, and IS free to anyone who wants it.
Ok, a little prejudice here, to any one who wants it for anything EXCEPT 11 meters. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
Yeah, just build it, you see hommade T.V. antenna towers, just make it for ham....!

anyhow I would do a 50 ft tower, no higher.

I've seen all sorts of home made towers, one is a flagpole that is cemented into the ground, at the top there is a hinge and another flagpole that can be rotated by winch down for service, this tower is self supporting.

another tower I've seen is 5"-6" Oilfield pipe screwed together and chained to the house(the "rotor" is a bent bar at the bottom by the pourch, manual rotation!)

also I've seen supporting rods welded to the sides of 6" oilfield pipe, like at the bottom the rod is welded directly to the main mast pipe, then slowly tapers out and is connected to a horzontal bar connecting the mast pipe to the support bar, then the bar tapers back in and welded to the pipe, this makes the pipe more rigid.

KC0KBH
09-09-2006, 01:13 PM
I can stick weld OK, I can MIG weld not too bad. My dad used to weld at the local granite company (granite is big in this area). He can weld incredibly well. Nobody would ever be near it, except maybe 2 times per week for a brief period of time, when mowing the lawn. It wouldn't actually be located in the lawn, it'd just be near it (If I did make it just 30', not crank up, it wouldn't come near anything. My GAP is a few hundred feet from my shack.

K5RCD
09-09-2006, 08:32 PM
It sounds like you are trying to talk yourself into it despite good advice to the contrary from most who have replied to your post.

This is a MAJOR project, and no matter how strong your welds are, nothing can make up for lack of structural integrity from improper engineering. Gravity is NOT your friend here. You may have access to enough tubing to build an AIRPLANE, but that isn't a good idea either.

I hope you will abandon this undertaking (pun intended). Sure would hate to see KC0KBH listed on the "Silent Keys" page. # http://www.qrz.com/iB_html/non-cgi/emoticons/sad.gif

WA9CWX
09-10-2006, 12:26 AM
Yep, unless you are going to be making it VERY strong and VERY short, with no fancy folding or tilting, I would forget it.

As far as 50 feet and folding, like I said, sounds like the start of an injury or worse type tale...

In the old handbooks, they had a 'tower' of sorts made from wood, braced and leaning into itself. I wonder today how THAT would work, with this incredibly weak, soft, fast-grown wood used today...?

Whatever you do, keep non-standard type potentialy dangerous things AWAY from the public, including your neighbors' ANYTHING... http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

WA9CWX
09-10-2006, 12:41 AM
All this does bring to mind, however, just how MANY flaky tower set-ups I have seen over the years.

MOST common is people who evidently can NOT read.

They use Rohn towers, welding pieces of angle iron as extensions, with '20' stuck on 25 for additional height.... I have seen one WELL known ham who has a '25' stuck on top of a power pole....I have also seen legs BENT to meet smaller legs, towers stuck in dirt, towers stuck INTO cement with no draining of the legs possible, etc.

Most common is the totally insane use of guy wires, one , two, two on one side, 3 on one side, another at right angles, some at 45 degs, with the
other legs guyed at 20 degree angles.

Just LOOKING at some of the eccentric forces gives me the whillies.

Anyway, good luck with whatever you do. PLEASE be carefull and get some experienced help to review your project if you have not done this before. AND #keep it SHORT !

KC0KBH
09-10-2006, 01:53 AM
I'm now thinking just a straight 30' tower. It'd be well away from anyone, and now that I think of where exactly it would be, someone would come near it (besides me) maybe 5 time max, per year. Anything I make would have to be stronger than the light TV tower we have for TV (aluminum tubing, very thin, with aluminum rod bent to form triangles. It's 50', has withstood 50 or so MPH winds, and was free (got it used). It has a couple small cracks forming in the base, and one of these days, a Diamond Antenna discone I got free is going on the top of it. When it's down, I'll MIG weld up the cracks, and reinforce the cracks (welder is a Hobart 140, with I believe 4043 aluminum wire, and argon).

KC9JIQ
09-10-2006, 03:02 AM
Hey what's wrong with just sitting tower on bricks?? My parents had a 30 ft guyed tower sitting on bricks and a "T" post with wire secuing the tower to the T-post.

I've ALWAYS wanted to get a old Farm Windmill tower and use that for antennas, self supporting and climbable. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

WA9CWX
09-10-2006, 05:35 PM
JIQ,

SOOOO....Pick up mine, it is waiting for you...
you will need a flat trailer, a red flag, and gas money.

But the tower is free.

Frank

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