I installed 30' of Rohn 25G in the early 90's. It is self supporting with 3' of
the base in concrete (3x3x3'). I had two Channel Master antennas on it.
Now that I am into ham radio, I want to heighten the tower to 50' (actually
47') guy it and put a beam or two on it.
Here are my questions:
1. Over the years, the tower has started leaning- probably from the shifting of
our soil. When I guy it, how much should I try to straighten it? I would guess
that it is leaning about 5 degrees, as it is visible with the naked eye.
2. I will have to replace the current 25ag top section so as to use a 2" mast.
I am looking at the 25ag4 flat top and tb-3 thrust bearing instead of the
25ag2. My reasons being- the flat top has tabs for guys avoiding the need for
me to buy a star bracket or other assembly and two, the flat top will be a good
place to stand while attaching antennas. Also the bearing makes less work and
strain for the rotor. Comments?
3. Due to space restrictions I can set the guys 30' from the tower base. They
will be attached to 7' of heavy pipe with 3' in the ground in concrete. Is this
adequate? I will use two guys per side. 4' high for the guys should help
increase the guy angle as well as increase their height to keep things from
hitting them.
4. I plan on running the coax down the tower to about the 15' level then across
the air into the gable end of my shack. I will run a piece of guy wire to
support it and then loosely tie the coax and rotor cable to it with cable ties
(like a clothes line). It is about a 40' run so I am sure that it will sway
some in the wind. Should I use LMR400 or LMR400 flex so that it will not break
in the wind? The total run will be about 125', is LMR400 adequate or should I
run something better?
Thanks
W5DWH
_________________________________________________________________
You live life online. So we put Windows on the web.
http://clk.atdmt.com/MRT/go/127032869/direct/01/
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|