[Luke_VE3ZXF]

Hello! I am planning to set up my HF rig and am considering building an antenna mast out of toprail fencing material. This mast would anchor an antenna about 66" long made of 12 gauge sheathed wire. One end would be attached to a toprail extending upwards from my (unused) chimney, and head out to the mast itself.  

My question is: how tall (how many 10ft segments) can a mast be without requiring guy wires? Would appreciate anyones thoughts!

Thanks

[Bernie ve3bqm]

Hi Luke

A 40-foot mast requires two sets of guy wires (one set around 20–25 feet, another near the top) for stability, with 3 or 4 wires per set. Using 4 wires (spaced 90° apart) is recommended for better security, although 3 wires (120° apart) is standard for lighter load.

[Richard VE3OZW]

Luke, if you are already off of a chimney then you may not need more than one or two toprails.  They are 10' long and two together get to be quite unstable.  I am doing that in my backyard for a temporary antenna and it is quite "wobbly" but works well.  I would say just one would be sufficient.

[Tom VA3TS]

The antenna itself can be a guy wire since it is securely mounted. Weight also becomes a consideration especially with #12 wire...it's not only the wire, it's the wind pushing on it, it's birds sitting on it and it's ice from freezing rain. If you have room for 120 feet of wire, then 80m will be easily doable. Are there any trees handy?
 good luck

[Luke_VE3ZXF]

The antenna itself can be a guy wire since it is securely mounted. Weight also becomes a consideration especially with #12 wire...it's not only the wire, it's the wind pushing on it, it's birds sitting on it and it's ice from freezing rain. If you have room for 120 feet of wire, then 80m will be easily doable. Are there any trees handy?
 good luck

 Thanks Tom & Richard & Bernie!

Since I posted (I didn't get any notifications of your replies lol) I purchased a used 40 foot communications tower. And now have a different set of questions:

-The tower has 4 10 foot sections, with the last section having a extendable pole to add another 10 feet
-The sections are all the same length and width (no taper), about 10 1/2 inches
-They are all very light,maybe weighing like 30lbs max
-I don't have any documentation about the tower, manufacture etc...
-Everything I have found online so far is mostly for Rohn towers, but they seem much heavier duty (even the 'light weight' versions, seem to be hundreds of pounds)
-So I am trying to figure out what would be required to mount this, the person I purchased it from said it could be freestanding
-Any thoughts on resources to identify a very light weight tower?

Thanks!

[Tom VA3TS]

Usually you see these tv type towers mounted against the house on the eave somewhere. Mount a couple of pulleys at the top so you can raise and lower wire antennas from the ground. Self support??  I don't think I would be brave enough to climb it

[Luke_VE3ZXF]

Usually you see these tv type towers mounted against the house on the eave somewhere. Mount a couple of pulleys at the top so you can raise and lower wire antennas from the ground. Self support??  I don't think I would be brave enough to climb it

[Tom VA3TS]

If the plan is just to have a skyhook, then maybe just put it in the ground a few feet, pack it in well. I had one in the ground years ago...what a chore it was getting it out of the ground. If the intention is to support some sort of beam, then that may need a more stable base. But this is Keppel, digging a hole around here is easier said than done.  73

[Luke_VE3ZXF]

Usually you see these tv type towers mounted against the house on the eave somewhere. Mount a couple of pulleys at the top so you can raise and lower wire antennas from the ground. Self support??  I don't think I would be brave enough to climb it

[Tom VA3TS]

Here's a tip when replying to posts... 

https://www.gbarc.ca/ForumBB/showthread.php?tid=1541

73

[Richard VE3OZW]

Luke, I have the same type of tower.  It is a TV tower and is not freestanding aside from the fact that it must be supported somehow and can only have 2 sections above the supported section.  So if you left it as a freestanding tower, you could essentially have one section and then the mast or top section.  They do not have to be mounted in cement, however I did mount mine in cement and I did overkill it because I intended to climb it.  The hole I made was approximately 4 cubic feet.  If they are supported at the eaves of a house etc, there are support stakes that can be used to anchor it to the ground but I found the cement was cheaper in the end.  Maximum weight is about 300lbs and I used to have the spec sheet for these towers so if I find it, I will attach it here or send it to you...  I plan to put a tip over base on my tower.

[Luke_VE3ZXF]

Thanks Richard, very helpful! So if I want the full height it needs to be braced at the top of the second section (out of 4 sections). It won't be near my house or any structure, so I would have to figure something out, some guy wires or something.

[Richard VE3OZW]

I can't remember, if you are climbing it, I wouldn't put any faith in guy wires if you are.  The manual doesn't speak to guy wires, it speaks to supports against a building or structure. Thought has to be given to any structures or power lines around you in the event that the tower were to fall over.

[Luke_VE3ZXF]

So here is my current thinking: I will use 3 sections, the top third section will have the extendable pole/mast; this will be a total of 40 ft. The tower will be concreted into a 12inch x 4 foot hole, which is roughly 450 lbs of concrete. The tower will be braced at the junction of the 1st and 2nd section, instead of using guy wires I will use a 16" 6x6 brace, which itself will be solidly concreted into the ground offset from the tower by a distance (~4 feet or so), I may possibly use a second at a right angle. I have some long 6x6's from a previous project. I think this will brace it enough, since I wont ever climb it and it will only ever be an anchor for wire antennas. It also only leaves two sections above the brace point, I am unsure if the mast is counted as another section. It is the requisite 1.5 lengths away from electrical wires.

Your feedback is helpful, this wont really get going for a month or two.