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Well, It finally happened I had to take down the tree in my backyard that was the center for my OFC Dipole and as it was the only tree in my yard I need to find a new way to get my Antenna up.
I was thinking of a fiberglass mast placed against the side of my house. The problem is I can’t seem to find any fiberglass masts that are sufficiently high that are not out of stock or on back order.
Can anyone offer any other suggestions as to what I might use for a 40 or so foot mast that I can put against my house?
Right now I’m totally off the air until I can get this issue resolved.
Thanks,
Anthony Rizzolo/KC1DXL
Hi Anthony,
Light duty fiberglass masts are not a good idea for semi-permanent installations. I some experience using them for antenna testing over a period of weeks through rain and high winds in FL. If you do decide to use them, I’d suggest that you tape all of the joints with electrical tape to keep the water out of the sections. It is really bad news once water gets inside these masts.
The other downside is loading. They are really meant to support vertical wires for such things as end fed verticals and end fed half wave antennas for which they are plenty strong enough for short periods of time if you do not use the fragile top sections.
When I used three vertical fiberglass masts in a row for antenna tests, guyed all of them at two levels and used back-guys on the outer two in order to offset the horizontal wire loading. Please see my QRZ page under for photos (link below). Inverted Vee’s are usually okay for a short period of time.
Have you looked for masts from Spider Beam and Max Gain Systems?
I would have suggested a metal mast, but you state that your antenna has to be OCF. That would not be such a good idea to put a metal mast near a voltage point on the dipole. A metal mast might be okay for a center fed dipole in which case the support would be near the current point on the antenna. Rohn makes a metal, telescoping 34 footer and you could raise it an additional 6 feet off the ground. Grounding the mast would be a very good idea, particularly if you don’t want to void your fire insurance. You could also buy metal or fiberglass mast sections and make your own which is what I did for my flag pole antenna.
I made a flag pole antenna sleeve from fiberglass sections purchased from DX Engineering. There was a 6BTV vertical inside the sleeve. DX Engineering sells very strong fiberglass tubing. You can see what I built on my QRZ site. I had my flagpole up for over two years without any problems. I could raise and lower it during hurricanes. Sections of the antenna were assembled with short sleeves and RTV adhesive to keep water out of the sections while still allowing for disassembly at some of the joints. Raising and lowering a heavy 40′ mast will be a bit of a challenge, but that is to be expected. If you paint the mast with a good marine enamel like the kind they use of fiberglass hulls, the mast will last a lot longer.
How about a telescoping flagpole used as a mast? Could be metal or fiberglass. There are lots of suppliers for those on the Internet. There are still a lot of options in spite of supply shortages.
Let me know how you do.
Regards, Marty, K1FQL
Hi Anthony,
You could use a metal telescoping mast like the one that Rohn makes, or you could make a heavy duty fiberglass mast of your own.
I made one from tubing purchased from DX Engineering. I show pictures of it on my QRZ site, and I have attached a PDF file below.
You can also buy telescoping metal and fiberglass flag poles from numerous suppliers. There are still plenty of options in spite of supply chain issues.
This is my first response to a post on the club site, so I don’t know if it is instant or has to be moderated.
Good luck. Marty K1FQL
Thanks Martin…yah, I hadn’t considered metal for a number of reasons the most important that we get a lot of electrical storms and I am planning on mounting this on my house so really don’t want a lightning rod that close.
I looked at your Flag Pole vertical project and it looks interesting but I think I need to be at 32 ft so 25′ may not be tall enough. I did try using some elements and put it up at 20′ and the SWR was pretty bad. I hadn’t thought to search for fiberglass sections and the search for mast on DXEngineering didn’t give the same thing.
Wondering if this from DX Engineering might serve my needs:
https://www.dxengineering.com/parts/dxe-tfk46-hd
It says its: “DX Engineering DXE-TFK46-HD – DX Engineering Complete Fiberglass Tubing and Cam Lock Clamp Kits” Cost is $239 and they actually have them in stock. I probably would not raise it much over 30′ and even at that would need to guy it so it doesn’t fall over.
I actually wasn’t that concerned about loading because it will be mounted on the side of my house and I was thinking that the wind load for the antenna and the post isn’t that much, but I suppose I should do the analysis.
Yes, definitely thought I would need a cap on the Antenna to keep water out and perhaps some drain holes at the bottom to keep the mast from filling with water.
I would love to put some kind of a tower up, but I have something harder to work out than an HOA, my wife is dead set against it. 🙂 .
Plus I’m thinking it would be prohibitively expensive to put up a tower at this point.
Thanks for the advice its really helpful. Have a nice day.
73,
Anthony Rizzolo
Did a bit of hunting.
Here are two options. They are a bit pricey.
https://www.dxengineering.com/parts/dxe-tfk46-hd
https://www.dxengineering.com/parts/dxe-tfk46Hello Anthony,
Our posts must have crossed. That 46′ mast was one of the ones in my last post. Those masts are meant for temporary installation. It is not enough to drill holes in it for drainage. Any holes drilled in the tubing will weaken it. The water has to be prevented from entering the sections where the clamps are, and that would require you to tape them up. The tape won’t stay on forever. On my antenna range in Florida the tape only stayed on for 3 weeks.
I made my flag pole mast by “splicing” sections of fiberglass tubing together with 2′-long fiberglass sections of tubing the next diameter up so that there was a sliding fit. I applied RTV on the upper part of the sleeve, only, so that I could take the sections apart. The RTV on the upper part of the sleeve prevented water from running into the joint from the top. I found that capillary action from the bottom of each sleeve was not an issue. Since the sections of tubing are butted together, the weight of the mast is borne downward and the structure is in compression. If you were to use some side mounting brackets on the tubing, that might take care of any lower guying that might be necessary, but an upper guy might be required.
If in doubt, you could always hire a PE to do an engineering calculation for you because you are going to attach the structure to your house. They might also analyze any shear and recommend what adhesive should be used. You never can tell – the PE might tell you not to do it at all! A 40′ mast has to be really strong. Please don’t underestimate the wind loading of a piece of large diameter tubing. It is far greater than you may think.
Maybe, when your spouse hears what you have to go through to attach something to the house, they may have a change of heart about a tower for which the structural analysis will have already been performed. Maybe, you could put up a free-standing tower on your lot as a compromise? If you think a tower is expensive, you might consider the cost of property damage if something that you built were to come down.
There are plenty of good, used tower sections for sale out there, so the cost of a tower should not be an issue. You might even find someone who will give you a self-supporting 40′ tower if you help take it down and haul it away! Try the next flea market or hamfest. Best of luck. K1FQL
Also watching. I don’t know if I can get notifications without posting a reply so here is a reply. 🙂
Watching here, too. BTW, I know you are looking to put up a mast at the side of your house, but here’s another thought suggested to me by n1fd member Hamilton Stewart – a catenary (support) rope between tall trees at the opposite ends of my backyard. In my case, I put up a 160′ long rope (up about 65′ at each end) and suspended my 7 band OCF from the middle. The rope sags a little, but OCF itself is still up 50′ in the middle, works well, and survived some heavy wet snows this winter.
Marv KC1LML
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