Joe is correct. One should install a tower by the manufactures spec for the details of the design were made for that installation. For free standing install as free standing. If guyed then put on guys. For towers like Rohn 25 there are a few options such as guyed or a house bracket, but always do as the manufacture specifies.
One other item that must be looked at is the type of soil being installed in. There are 3 major catagories. We in Florida with the loose sand we have one of the poorest quality soil for structures. At my home one can dig a nice hole for a tower with ones fingers...no tools required. Tools do make it easier and cleaner, but the point is the soil is very loose. When looking for plans for a tower base make sure you are looking for the details about the type of soil. 73, ron, n9ee/r >From: MCH <[EMAIL PROTECTED]> >Date: 2007/07/29 Sun PM 09:17:58 CDT >To: [email protected] >Subject: Re: [Repeater-Builder] Rohn 25g Tower > >Actually, if the tower is designed to be self-supporting, anchoring it >anywhere could compromise the structural integrity. It's designed to >give some across the entire structure, and if you tie one point to a >fixed point, it will flex more at that point and eventually could fail >there - much like flexing a piece of wire in one point too much. > >Joe M. > >Jack Taylor wrote: >> >> Depending upon the wind loading on the tower, I would be cautious about >> fastening *anything* to the fascia board of a modern day house! If your >> tower >> is self supporting, design the base to handle the load. Don't rely on the >> house >> else over time you may end up with cracks in the interior walls. If the >> tower >> is to by guyed, don't use the house for an anchor :-) >> >> But on the otherhand if it is a short tower with little wind load, have at >> it! >> >> Jack - N7OO >> >> ----- Original Message ----- >> From: Eric Lemmon >> To: [email protected] >> Sent: Sunday, July 29, 2007 6:36 PM >> Subject: RE: [Repeater-Builder] Rohn 25g Tower >> >> Don, >> >> As others have mentioned, it is best to first attach the house bracket to >> the house, and then install the tower. >> >> I did exactly that at my house, with a 25G tower comprising two 10-foot >> sections and a 5-foot embedment section. Once I knew roughly where the >> tower would be, I put a 50-inch section of heavy aluminum channel behind the >> fascia board, and lag-bolted it to each of four roof trusses. I then >> drilled through the fascia board and the aluminum channel for several >> 3/8-inch stainless steel bolts to hold the house bracket solidly to the >> fascia board. Then I set a tower section in place to see where the hole >> needed to be, with the section perfectly plumb. Once the hole was dug per >> Rohn's foundation drawing, I added the rebar and set the embedment section >> in place with one tower section clamped into the house bracket. After >> triple-checking that the tower was plumb, I poured the concrete. Although I >> bought an electric concrete mixer from Harbor Freight just for this job, >> after going through 26 ninety-pound bags of ready-mix concrete, I was >> pooped! If I ever do this again, I am gonna hire a ready-mix truck and a >> concrete pumper to do the work. >> >> 73, Eric Lemmon WB6FLY >> >> -----Original Message----- >> From: [email protected] >> [mailto:[EMAIL PROTECTED] On Behalf Of Don KA9QJG >> Sent: Sunday, July 29, 2007 3:26 PM >> To: [email protected] >> Subject: [Repeater-Builder] Rohn 25g Tower >> >> On a Rohn 25g Tower that will be put on the Side of the House can anyone >> Tell Me if the Rohn House Bracket Has to be Mounted First, or can the Tower >> Be put up First. >> >> Thanks Don >> >> KA9QJG >> >> >> Yahoo! Groups Links >> >> >> > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
