Time for a Tower! Thoughts and Ideas?

[W1TAV]

I am putting up a tower. I have been waffling about one for 30+ years and have made up my mind!   Who has recently  bought one?

I am looking at 30' (maybe 40') of 25G with a hinged base(?) or maybe a hinged section(?) and 10' X 2" mast. Tower will be wall
bracketed at 12 feet. If necessary I can guy it.  Planed rotor is a Yeasu G800-DAX turning a Cushcraft A3S and
6/2/440 beam at the top.  12.6 SF wind load (10.1 and 2.5)

Where did you find your best deals, how did shipping workout?  This is appears to be a closed market item without a lot of price differences between vendors , so I guess quality of service/helpfulness will play into who to go with.  I am open to ideas!  

Steve W1TAV  

[Pete, WA2CWA]

The first thing I would do is to check your local town ordinances on the installation of a tower.

[flintstone mop]

What Pete said and are you going to be digging the hole with the colder WX in the next 5- 6 days??
The WX heading this way may not be great for curing concrete. I'm not talking about the Christmas weather we are getting into now. The WX starting Tuesday, DEC 30th.
As I read your post closer you mention bracketing the tower to the house......so you are not digging a hole?
You will be stressing the house structure to be the main support for the tower. I had the same short cut thought and was warned about damage to the house/garage.
The A3S about 2 feet up the mast and the VHF/UHF at the very top?
Are you on a hill that your tower plans are so low? The VHF/UHF bands work better with a lot more height.
50 feet.
The A3S will be ok at 30 feet. Pretty much minimal for HF performance.
Fred

PS for antenna WX::: I have a choice to modify my dipole to become a 5/8 wave inverted "L". But it's getting the goodies together and start something on Thurs (Christmas),,,doubt it, or Friday, Saturday, or Sunday.
Monday for Western Pa. it will all change.

[KL7OF]

Craigslist for towers.....

[w1vtp]

When I put up my 70 foot tower / mast, I checked with the city ordinances.  They deferred to the FAA as far as glide path regulations - sweet!   

Seriously, check quietly with city ordinances.  My electrician thought there were restrictions - he was wrong.  Good luck. 

Just be careful when buying used towers.  Better new and in top notch condition then cheap and defective.

Al

[Pete, WA2CWA]

In some towns you even need a construction permit to put up a tower.

[w1vtp]

In some towns you even need a construction permit to put up a tower.

Yup, I'm sure.  Quietly check your city / town ordinances! Make sure, it can be an expensive oversight

[n1ps]

You can tie the tower to your house or garage.  Have done it many times.  My tower (40 ft) is supported by the house on the gable end at about 20 ft.  The trick is to spread the load over several feet and several studs.  I used a double 2x10, 6 ft long and 5/8 threaded rod with fender washers to prevent any pull through concerns.  Small towers actually present fairly small loads to a house, on the order of 2-10 sq ft depending on the height, cables and antennas.  But make sure the wall is in good shape and all the studs are tied together with plywood on both sides.  You do want some sort of foundation to counter any lateral loads at the base.  If you have any reservations have a local struct eng look things over.

My .02 Steve.

Pete

[W1TAV]

Thanks to all so far.. Seems like 25G will be ok. Still looking for thoughts  on the best places to order towers from.  The city/town issues are covered,  A few years back the town drafted tower rules and regulations. As a member of the building and planning board, we made sure  the rules specifically exempt amateur radio installations under 200'      As for mounting,  Having some what of a tendency to overbuild,  the front of the garage has a 22'X 20'  steel reinforced 12" concrete  pad with 24"  footing that I can anchor the base plate to.  The gable end of the garage was double trussed, it too will have no issue with taking a gusseted wall bracket.  As for height, I am in a fairly flat area, while I am not locked on 30' I don't think I would go above 40'.  The A3 selection is not locked in stone either, indeed I have been looking at what's come along in the last 40 years.  My main interest it getting something up with modest gain on 6 & 2 meters. If I am going to do that, I might as well put up a  tribander.

[Jim, W5JO]

Try to buy as close to you as possible.  Freight on a tower can be monstrous.  If there is a place that sells close, a 10/12 ft. trailer can haul it, and 25G sections are not that heavy.

Renting a trailer or using a pickup then driving under an hour or two may save.  Check the freight costs before you buy.

[KA2DZT]

I have the Rohn tower book.  The 25G is rated to free stand (IIRC) 32ft above the last support with a 2sq ft wind load.  Larger wind loads would require a reduction in that rating.  I'll dig out the manual and recheck the rating.  I installed a number of 25Gs supported to walls.  Each installation required making special steel brackets to braced the tower to the wall.  Some of these brackets were bolted through walls into existing steel beams in the building.  Others were bolted through wooded walls using long bolts to bridge across a number of vertical 2x4 beams (in an attic) with a 2x8 on the other side of the 2x4s. You may add some additional bracing of the 2x4s if needed.  Each tower install may require different things, use your judgement.

Best way to install such a tower is to install the bracket first, then dig the hole for the base (1 cubic yard).  Set up the lower sections of the tower and base unit from the bracket down to the base.  Get everything level and vertical then pour the concrete into the hole.  You should also have about 4 ins of stone at the bottom of the hole.   Let the concrete cure for a number of days or longer.  Then use a gin pole to erect the remaining tower sections.  If it's a hinge base type set up then use other methods to complete the tower.  Usually, you'll need some help installing a tower (unless you're JJ, then you can put up 200 footers by yourself ).

Another thing is the tower should be away from the building somewhat.  This distance should be a foot or more, this is where specially made brackets come into play.

Fred

[Pete, WA2CWA]

You can read or download the complete Rohn product catalog:
http://m.rohnproducts.com/products-and-services/catalog/english.html

[K1JJ]

Sounds good, Steve.

A few comments:

Do you already have up a 75M dipole at 60' in the trees?  If not, then consider Rohn 45 and going up to 60'.  I have a 60' Rohn 45 next to the house that is bracketed at 30' to the house. I climb all the way to the top with little sway.   Rohn 45 is OK with a small load when free standing 30' above guys or bracketing.

Usually, it pays to go a little bigger than we first plan.... you will certainly grow into it...

The town here required a zoning board variance for my 190'ers free standing towers. In addition, I had to have the design approved by TWO independent structural engineering firms. The second one actually came out and inspected the rebar/hole before the concrete was poured.   PIA.  Anything over 60' requires two CT engr stamps.

BTW, that's a cool picture.   I should give a heads up to any newbies who have not done much bench work.    Many years ago I knew of a ham who was electrocuted through the head because of wearing headphones while working on HV. The guy pictured has both hands in the rig with headphones on. Yikes...

** Marley (pictured in your first post) is a beautiful dog - what a face!

Good luck with the project, Steve.

T

[w1vtp]

You can tie the tower to your house or garage.  Have done it many times. <snip>
My .02 Steve.

Pete

Here's how Matt KC1XX did mine.  He had free reign over the entire project from the beginning of the new shack.  Perfect timing

Al

[w1vtp]

"BUT WAIT!  THERE'S MORE"

[flintstone mop]

OK Al, on the bracket. The tower is set in concrete or sitting on something substantial?
How high is your tower?
I'm no engineer but the one brace point would worry me.

Fred

[Steve - K4HX]

K7LXC. Get it, read it.

[w1vtp]

OK Al, on the bracket. The tower is set in concrete or sitting on something substantial?
How high is your tower?
I'm no engineer but the one brace point would worry me.

Fred

Fred.  I sent you an email response - didn't want it to seem like an advertisement for Matt on the forum..

The total height of the tower / thick walled masted affair is 70'   It supports my 75 meter dipole

The base is 4' deep by 3' x 3'  4' is the accepted depth in this area for avoiding a frost heaves

Al 

[W1TAV]

Again, Thanks to all! Weighing all the thoughts and recommendations received.   Going with Steve's recommendation 1st regarding K7LXC's publication on towers, just ordered it on line.  In the meantime I'll be on the lookout for ideas and equipment.   

Mike WA1MNQ was over yesterday and bought pictures of his fold over, push up tower he had on his Pus-Bus back in the 90's.. More ideas   

[W1RKW]

Why no concerns about lightning with a tower secured to a structure?

[w1vtp]

Why no concerns about lightning with a tower secured to a structure?

Not a properly grounded tower.  We had a 100' tower atop a lean too which was attached to a horse barn for our repeater site (900' elevation).  Direct hits several times and the tower took it with no problems.

But that's a separate (and good) topic for discussion: The proper grounding of towers.

Al

[W1RKW]

I don't know. Lightning behavior being as bizarre as it can be and taking unusual paths to ground, I wouldn't be so inclined to think the structure would be safe from fire no matter how well the ground system may seem. I have a problem with my ant ground being attached to the service entrance ground rods with the ground rods being inches away from the foundation. My fear is the right amount of "juice" could blow a hole in the concrete rather being dispersed equally into the soil. Guess I should consider extra measures by adding additional rods away from the service entrance ground system.

[flintstone mop]

I don't know. Lightning behavior being as bizarre as it can be and taking unusual paths to ground, I wouldn't be so inclined to think the structure would be safe from fire no matter how well the ground system may seem. I have a problem with my ant ground being attached to the service entrance ground rods with the ground rods being inches away from the foundation. My fear is the right amount of "juice" could blow a hole in the concrete rather being dispersed equally into the soil. Guess I should consider extra measures by adding additional rods away from the service entrance ground system.

You're description for a direct hit from lightning is very accurate. NO grounding system will be able to dissipate all of that juice from the sky, and it will literally blow holes, and worse into adjoining structures, in a typical Ham installation.
Extra rods aren't going to help. The tower should have been erected a hundred feet from the house, or as far as you as your property and neighbors allow.

Fred

[KB2WIG]

F,

" NO grounding system will be able to dissipate all of that juice from the sky. "

Not so.....  

The first pic is from a house with normal lightning protection. Note that the Sat ants are only a bit schorched. Then notice pictures #2 and #3. Hit by lightning, and still standing without major damage. What #2 and  #3 have in common is that they are slightly overbuilt. And they are really just shaped like large lightning rods. Franklin was right.

klc

[W1ITT]

Our Uncle Sam has an ongoing program at our military sites called GBSLP (pronounced gibslip), and it stands for grounding-bonding-shielding-and-lightning-protection.  I was involved in the radio tower part of it.  It's all open source stuff; no secrets will be revealed. 
For 100 foot towers with rotary log-periodics, they call for two 3/4" ground rods at the base of the tower, just outside the foundation.  At the perimeter fence, about a 25 foot square, there are four rods, connected with 1/0 in a square.  Out at the four guy anchors, there are four more rods, which are also connected to guy wires above the turnbuckles.  All of these rods are connected together with 1/0 copper, cad-welded at each joint, and there are runs under each guy wire back to the base.     And all the 1/0 is buried at least 18 inches.  Coaxes are grounded to a similar building perimeter where they enter the ops building.

I don't use 1/0, but I have a perimeter run around my house, and multiple rods  with some runs leading to rods away from the house.  After paying for Uncle to use that 1/0 all over the world, that's all I can afford.  The point is...  one crappy ground rod isn't enough.  If you can afford a tower, you need to put in a good ground system.  At the very least, run additional grounds out to your guy anchors and tie the guy wires (assuming you don't use Phillystran) to a rod at each anchor.  As someone pointed out, there is no 100% sure guarantee against direct hit damage, but most of us can do a better job than what we get away with.

By the way, I have wondered  why the electrical code does not recommend a ground wire to run out along the septic leach field where used.  In many places in New England it would end up being a much better ground at 60 hz than the two rods near the service entrance. If I were ever to build a new house, I'd do it, connected to a perimeter ring.  And on 160m, just push the lever for an extra decibel or two....