Whoa! We're sliding away from reality in this thread:
snip> Does anyone remember if a straight tower section is/was made to
extend a Rohn HDBX 48 into a HDBX 56??? Either Rohn or after
market mfg??? There is a local ham looking for one. I don't ever remember
seeing/reading about anything like this. <snip>
Rohn purchased the Spaulding product line of riveted, self supporting, light
duty towers. The Rohn spec used the largest sections to produce a 48' tower
which would hold a small tribander, or large TV antenna. The boom length
is limited to 10', because the torque tended to rip out the rivets.
If you extend the tower with another 8' section, it is stepped in to a
smaller
face dimension. It is derated. They called it an HBX56, not HBDX...the 'D'
standing for heavy duty.
Basically, you cannot put a 3 el tribander on this tower, at any height, due
to the 10' boom limitation. Conservatively rated? I'm sure. Rohn's
insurance
carrier drove a lot of conservativism in their specs. Could you get away
with
overloading the tower? Probably, for a while.
If you could put it someplace where nobody can get hurt, you could take your
chances.
Personally, I wouldn't.
Oh...and they're a bitch to climb. skinny metal legs at an angle.
If the local ham feels another 8' is going to make significant difference in
performance (questionable)... go get a 24' aluminum mast of .250 wall.
Lower
the rotor down one more section in the tower...and let 12' stick out the
top.
That will both raise the antenna, and couple the rotor torque into a larger
structure, minimizing the chance of failure.
N2EA
Jim Jarvis, President
The Morse Group, LLC
Helping organizations manage strategic change.
732 548 5573 office
443 618 5560 cell
jimjarvis@themorsegroup.net
www.themorsegroup.net
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