>Well its only 11-1/2 months till Field Day and I would like to erect our
>towers a bit safer next year. Building hinged base plates for the towers is
>on the list of things to do. My concern is the interface between the top
>plate of the base and the tower itself. I have some R-20 tower that we use.
> Not having a Rohn catalog to browse....I was wondering if Rohn makes such
>an animal...or is there a cheaper way to go...or do they manufacture a top
>plate that can be used as a bottom plate.
>
>Suggestions...ideas...Im not proud. The 60 ft Texas Tower (aluminum) is
>solved as I just use the top plate...turn the tower up side down and bolt it
>to the top of the hinged base. I dont want to do that with the Rohn towers
>so need a good interface method.
>
>Thanks.
>
>73, Hank/K2UVG
>jkahrs@delphi.com
>(FD Chair*2)^5 .. 2 clubs, 5th time
Hi Hank,
Rohn does make a hinged base (BPH25G) but it is made to mount to a flat
concrete pad. Not ideal for Field Day. Rohn also makes a "drive-in base"
(SDB25G) That has a angle iron spike on the bottom. Typically, you would
drive this base into the ground with a sledge hammer and build the tower up
from there using a good guying system all the way. The drive-in base is not
specified to hold up even a single section of Rohn 25 without guys.
A combination of these two items would seem to be just about ideal for field
day. Unfortunately, Rohn does make a "drive-in hinged base" but you could
fabricate one by welding the angle iron spike onto the bottom of a standard
hinged base. Installation would be a little tricky as you raised the tower
using the hinged base. You would have to make sure that the spike did not
pull out of the ground at the crucial moment!! One thing you could do is
weld some horizontal bars on the top surface of the hinged base that lay on
top of the ground and park a car on them on each side of the tower to keep
the base in the ground while raising and lowering the tower using the hinged
base.
Just be careful and try to anticipate any possible disaster.
Stan w7ni@teleport.com
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