In a message dated 97-02-19 12:43:01 EST, email@example.com (Pat Barthelow)
> We at the N6IJ contest station in Marina CA, have been
>offered a dismantled broadcast tower for use at our contest
>station. It is 7 ea., 20 ft. sections of heavy steel triangular
>tower, 15" face width. The vertical are 1 - 5/8" steel tubing,
>and the cross braces are only the horizontal type (no diagonals,
>like Rohn) but heavy, 1/4" thick, 2 inches wide, and spaced
>every 23". At the top and bottom of each section, there are
>heavy, (3/8" thick) welded, triangular gusset plates/flanges at
>the inside of each corner, and are drilled to accept 3/4"
>assembly bolts. The base has a conical ceramic insulator, which
>we may just choose to not use, and bury the first section in a
>poured concrete base.
Hi, guys --
Please install with the base insulator in tact. More hassle but much
more useful in loading up that mutha on 80 and 160M.
> Our wish is to use this at the site, guyed, at the full height,
>to mount a large Yagi Array. We have a KLM-Derived, dual band
>Yagi, 3 element 40, 5 element 20 meter, with a 56 foot boom
>for the top Yagi. Perhaps rotate the whole tower/perhaps using
>a Tic-Ring Rotator for intermediate level yagis. We inherited from
>the Ft. Ord military base large amounts of 5/16" ehs guy strand,
>still on new spools, and 10 ft. guy anchors, with steel
>expandable bottom fixtures. (Will these anchors with the expandable
>fixtures (approx 12- 15" expanded diamater) be strong enough to anchor the
>tower in compacted sand, or will we need to use concrete?)
I'd suggest using an equivalent Rohn tower and specs to give you an idea
what you need.
The surplus 5/16" EHS sounds grea if it's germane to your tower
installation. The screw anchors don't. If you know the geological soil
classification and soil holding power, the screw-in anchors may be
okay...but I doubt it. Loose fine sand and even coarse sand has little
> The tower donor is a Crane company, (that took down the
>tower) owned by a newly licensed ham, who will offer to use his 110 ft
>crane to help assemble the tower. We are looking for expertise
>in tower construction to advise us of pitfalls, safety issues, and
>structural capabilities of this tower. We have large open areas
>on the top of a hill, (guying is no problem, space wise) and
>sandy soil. We will hire a PE to do the design calcs, (obviously)
>but would like to have some idea of what this PE certification
>will cost, not having done this before.
In 25 words or less?? This is a big topic with lots of things to take
into consideration. Talk to W6EEN who is a PhD EE and PE for further
California info (firstname.lastname@example.org).
The actual erection with a crane (the best way to do it) is further
down the road until you get some of the initial issues resolved.
73, Steve K7LXC
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