On Tue, 25 Dec 2007 12:19:11 -0600, AD5VJ Bob wrote:
>I have two 10 footers of ROHN25 with an 8 footer top section
right
>now, but dont have it installed yet.
>Looks like I am going to need 4 more sections of ten feet before
>its all over.
If all you want is a vertical for 160 and/or 80, there are lots of
ways to build them from relatively simple and cheap telescoping
tubing, TV mast sections, etc. with suitable guying and electrical
bonding together of the sections. I've seen some very nice miltary
surplus mast sections that would work very well. Use copper for
the top guys to form the top loading, rope for the others. Just
be careful that they can't fall where they cross a power line,
hurt someone, or break something. :)
Those masts that were holding wires on my house and garage in
Chicago were el-cheapo TV mast on el-cheapo tripods. Let's say you
put two 10-ft sections on the corner of the peak of your roof, run
a wire from it down to the ground, and use that as your feedpoint.
You've got the length of that wire plus the length of the mast,
and you put top-loading on that.
One caution with the rope -- don't let rope contact the antenna at
a high voltage point. I've had my 160 dipole drop when the antenna
arced to the moist rope and melted it (with 1 kW).
73,
Jim K9YC
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|