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[TowerTalk] Stacks on Roof Towers?

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Subject: [TowerTalk] Stacks on Roof Towers?
From: (Eric Rosenberg)
Date: Mon, 07 Apr 1997 22:03:56 -0400
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 

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