It sounds like it is already an issue for K9RX, I would not be comfortable
having bent bolts in my rotating base.
John KK9A
Bill K4XS wrote:
Over the years I've had four K0XG systems, two of them Rohn 55 and two
Rohn 65. Three were 200 footers and one was a 90 footer. All of them
were pretty loaded.
The building dep't made me go to 3/4 inch J-bolts. However, what these
guys know about towers you could put in a thimble. They're the same guys
who wanted a 5 by 5 by 5 foot hole totally filled with concrete for the
anchors on a 90 foot Rohn 45 tower.
Back in FL I used only 1/2 inch J-bolts and never had an issue with them.
Out here the 3/4 inch ones have not been an issue either. Of course, we
have not had any Cat-5 come through either. The J-bolts are of course
galvanized so no issues with rust. Using grade 8 bolts might be an issue
if not galvanized.
Final thought on this. Unless you have some really tough antennas, things
start to disassemble around 80-90 MPH, which of course takes the strain
off the tower and associated hardware, so beefing up the bolts may not be
an issue.
Bill KH7XS/K4XS
Today's Topics:
1. K0XG rotating tower bolt issue... (StellarCAT)
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Message: 1
Date: Fri, 25 Jan 2019 09:03:13 -0500
From: Gary K9RX
Anyone else have issues with the bolts that hold the tower baseplate to
the main gear? I went to grade 8 bolts here as to me this is not a good
idea to have those VERY long bolts (7?) holding these two things together
? and they?re only 1/2? diameter! One of mine is obviously BENT! I don?t
know how I could enlarge the holes now that it is together ? I?d MUCH
prefer these were 3/4? or at least 5/8? bolts. I?ve not had heavy winds
here since it went up in October of ?16... maybe 60 Mph tops. I?m also
considering going with a stainless tube ? 1/2? ID and maybe 3/16? walls,
as a sleeve around the bolts ? but it would need to be tight fitting to
make any difference, both on the ID as well as the length (height).
Another down side of doing this is that the grade 8 bolts are zinc
chromate ? they?re pristine now ? but put them in a tube, what might end
up being a sealed system if properly done (tight enough) might trap enough
moisture to corrode them (much?) faster...
Gary
K9RX
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