I have a similar setup on my house right now, I used 2x6 across the inside
roof trusses to back up the threaded rod that goes through the roof tower
foot pads-if you use large washers inside and out, and at least 3/8 threaded
rod on each leg, that should be more than strong enough. Mine doesn't even
budge- has a ta-33, 2 uhf yagis, 2 fiberglass gain omni antennas, and a
scanner antenna on it. Been up for 2.5 years through several hurricane force
winds too.
Good luck
Scott
KA1CLX
At 10:03 PM 4/7/97 -0400, Eric Rosenberg wrote:
>I have a 6 ft Alinco Roof tower on my roof, holding up a
>mid-side VHF/UHF satellite array:
>
>4 ft above the thrust bearing is the elevation rotor which holds
>a 10 ft fiberglass crossboom.
>
>At opposing ends of the crossboom are a 7el horiz x 7 el vert
>2m yagi (circular polarized on a single 10 ft boom) and a 10 ft
>long 16 turn helix with a 60 cm square screen reflector.
>
>The roof tower itself has 4 foot pads (3"x3") attached directly
>to the roof, each one held down with 4 1/4" threaded rods that
>are bolted underneath the roof's wooden sheath and then go
>through 2x4's that straddle the rafters.
>
>I'd like to move things around by adding a small (14' or less
>turning radius) tribander just above the thrust bearing move the
>satellite array up a couple of feet.
>
>My questions are simply whether or not the roof will take the
>additional weight (I can't imagine 30 or 40 pounds would make a
>difference) and added stress in a wind storm (we recently had
>40+ mph winds here in Washington, DC) as the tower is presently
>mounted, OR will I have to take it all down and add 2x4's or
>2x6's between the roof and roof tower as mentioned in the
>oft-quoted CQ magazine article of a last year.
>
>As far as the yagi is concerned, I'm looking at a TH3jr or
>TA33jr or a Th2 or Fritzel 2 el full-sized yagi.
>
>Thoughts, ideas?
>
>I'll summarize for those interested.
>
>Thanks in advance,
>
>Eric WD3Q
>Washington, DC
>wd3q@erols.com
>
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