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Post by whitetail on Apr 4, 2018 13:56:56 GMT -5
Needing some advice o guying a tower. Quick rundown on what Iam working with here. I have a 3 legged 40' tower fold over style with an Imax 2000 on top. The tower bottom plate is mounted to a concrete pad with anchors sticking out from the top. guying was always a thought in mind, but until you experience the wind gusts it makes you want to prob guy this thing. We had some big 60 mph gusts and constant winds around 30mph all last night and all day today. From what Iam seeing here the The antenna is 90% of why the tower sways in the wind when the wind blows, because of the flex of the Imax, like a wet noodle. Now how do I go about guying this thing? There is not to much information that I found on guying towers. Would I be able to use some tough nylon rope to guy down? And as for the anchor point on the ground, can I get away with a ground rod or pipe in the ground and tie the rope to that? Also I dont know what effect it will have on grounding using cable wires? Any advice is appreciated. I got a quick lesson here but dont know if it is right. www.youtube.com/watch?v=Bnjvs3TrJVg
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Sandbagger
Administrator/The Boss
Posts: 6,245
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Post by Sandbagger on Apr 5, 2018 19:12:16 GMT -5
Needing some advice o guying a tower. Quick rundown on what Iam working with here. I have a 3 legged 40' tower fold over style with an Imax 2000 on top. The tower bottom plate is mounted to a concrete pad with anchors sticking out from the top. guying was always a thought in mind, but until you experience the wind gusts it makes you want to prob guy this thing. We had some big 60 mph gusts and constant winds around 30mph all last night and all day today. From what Iam seeing here the The antenna is 90% of why the tower sways in the wind when the wind blows, because of the flex of the Imax, like a wet noodle. Now how do I go about guying this thing? There is not to much information that I found on guying towers. Would I be able to use some tough nylon rope to guy down? And as for the anchor point on the ground, can I get away with a ground rod or pipe in the ground and tie the rope to that? Also I dont know what effect it will have on grounding using cable wires? Any advice is appreciated. I got a quick lesson here but dont know if it is right. www.youtube.com/watch?v=Bnjvs3TrJVgThe Imax has probably the least amount of wind loading of any typical CB antenna. If your tower sways with an Imax, don't even think about putting a beam up there. Guying the tower is a good idea. I would recommend visiting the websites of the tower manufacturers to see their suggestions on how to guy the tower. Since they make them, they would know best how to properly install them.
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Post by whitetail on Apr 6, 2018 5:53:58 GMT -5
Needing some advice o guying a tower. Quick rundown on what Iam working with here. I have a 3 legged 40' tower fold over style with an Imax 2000 on top. The tower bottom plate is mounted to a concrete pad with anchors sticking out from the top. guying was always a thought in mind, but until you experience the wind gusts it makes you want to prob guy this thing. We had some big 60 mph gusts and constant winds around 30mph all last night and all day today. From what Iam seeing here the The antenna is 90% of why the tower sways in the wind when the wind blows, because of the flex of the Imax, like a wet noodle. Now how do I go about guying this thing? There is not to much information that I found on guying towers. Would I be able to use some tough nylon rope to guy down? And as for the anchor point on the ground, can I get away with a ground rod or pipe in the ground and tie the rope to that? Also I dont know what effect it will have on grounding using cable wires? Any advice is appreciated. I got a quick lesson here but dont know if it is right. www.youtube.com/watch?v=Bnjvs3TrJVgThe Imax has probably the least amount of wind loading of any typical CB antenna. If your tower sways with an Imax, don't even think about putting a beam up there. Guying the tower is a good idea. I would recommend visiting the websites of the tower manufacturers to see their suggestions on how to guy the tower. Since they make them, they would know best how to properly install them. I dont know the manufacture of the tower, Its a 3 leg that held up a tv antenna back in the day at a camp. The location where it was at was right beside the camp and tied in to the peak of the roof somewhere around mid height of the tower. The tower stands great and handles winds up to 40 -45 ok but when it really starts blowing 60+ it gets a little scarey So what do i do from here without a company name of this thing? Think about it there is alot of weight up there just free standing. What to do from here?
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Post by thehobo on Apr 6, 2018 8:22:03 GMT -5
say hey whitetail, if i was you and in my experance in putting up towers, id guy the tower in two places.. first at the 20 foot level and then within 5 feet of the top.. id use a 3 way guy system, like put your guy wire at each leg of the tower and on thr ground at least about 30 feet out from the base.. should make it secured?? as far as guy wire, if this is one you mite take down in a year or 2or3.. if its to be up longer go to a cable much stronger.. like 3/8s cable.. should hold till the sun goes down.. lol.. my nickles worth
thehobo
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Sandbagger
Administrator/The Boss
Posts: 6,245
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Post by Sandbagger on Apr 6, 2018 19:50:09 GMT -5
The Imax has probably the least amount of wind loading of any typical CB antenna. If your tower sways with an Imax, don't even think about putting a beam up there. Guying the tower is a good idea. I would recommend visiting the websites of the tower manufacturers to see their suggestions on how to guy the tower. Since they make them, they would know best how to properly install them. I dont know the manufacture of the tower, Its a 3 leg that held up a tv antenna back in the day at a camp. The location where it was at was right beside the camp and tied in to the peak of the roof somewhere around mid height of the tower. The tower stands great and handles winds up to 40 -45 ok but when it really starts blowing 60+ it gets a little scarey So what do i do from here without a company name of this thing? Think about it there is alot of weight up there just free standing. What to do from here? Try this out: www.3starinc.com/manuals/25G-5.pdf
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Post by ytradio on Apr 7, 2018 10:27:19 GMT -5
Another reference is American tower, which show slightly different, but similar specs to the Rohn towers. About those specs, they are all designed for "maximum" load carrying. For instance, for your 40' tower the Rohn specs calls for 3 anchor points 32' from the base of the tower at 1.33 yards of concrete each!!! Keep in mind that is to carry a wind load of 22 square feet at the top of the tower in a 90 mile per hour wind. This is to help keep them out of legal trouble. Is it overkill in your case, yes it is, so long as you know the load that you will be putting on this tower in the future and don't get carried away. I have guyed towers with the 4 foot long auger anchors from Tractor Supply by just twisting them into the ground at 80% distance from the tower base. Guying with 3/16 galvanized steel cable and burying 3' of the first section (or a short base section) in the ground with a small concrete pad in the bottom of the hole for the tower to set on. However, I have built a lot of things in my time, and know what I am comfortable with, and also don't get ridiculous with the height or wind load. I have used anchor points on houses that were not nearly as strong as the auger anchor point, but for the application it was used on worked out just fine. I am not alone, as I know many who have been Ham operators for years and gotten by with things I would not want to climb. I currently have 30' of Rohn tower bracketed at 9' and no guys, "Not" what Rohn recommends. But I am comfortable with it, It has stood up to 95 MPH gusts. One note on the hollow type TV tower, a lot of this stuff is old, most time how old is any ones guess. A lot of this stuff was not galvanize dipped, or maybe not galvanized at all. It tends to rust from the inside out, and can be very dangerous. I was taking some of this down a few years back for my cousin on a place he had bought a year before. It had stood 40' high through high wind only a week before. I would not climb it, but decided to unbolt it from the chimney bracket and lower it down. The first tug on the wrench it snapped off above the bracket and came down. That is why I use Rohn tower, it has solid zigzag bars that cant rust from the inside. Don't do anything you are not comfortable with. 73 Whitey
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Post by whitetail on Apr 28, 2018 8:03:51 GMT -5
Sandbagger- thanks for the link it did help out alot and it got me going in the right direction
thehobo- thanks for the input, I was considering doing just what you said, with a 2 spot guy on each leg. This way the middle would be braced or balanced and it would be even. I do have a question the 3 wires coming off the top will be somewhere around 30' out from the base with an anchor point there, I got that part. Now at the 20' level with the 3 cables attached 1 to each leg can I run the cable to the anchor point at 30' out where the top cable's are connected? Thank you.
ytradio- Thanks for your input, the tower is in good condition when I got it, just a bit of surface rust thats it, 2 summers ago I lightly sanded it down and primed the heck out of all the sections all priming and painting was done with a brush. I have alot of time in this project, from digging the hole 4'x4'x 50" deep, with rebar in the bottom and pounded into the ground below several feet. Just like you said we know what we a comfortable with our design. Each section of tower took 1.1/2 hours each to sand, prime, & 2 coats of paint. I also took fluid film its a rust prevention oil ( they undercoat vehicles with it and anything that is in the weather) I sprayed in each leg and coated the inside really good, so rust doesnt creep up from the inside out. I would rather be overkill then not enough. I believe that these guy wires will help out tremendously. Thanks
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