[TowerTalk] Max Unguyed Rohn 25 height to support dipole end

[john at kk9a.com]

If you raise the ends to the same height as the center, assuming it's 100' 
high or so, you will have a bi-directional antenna instead of an 
omni-directional one.   You'll gain about 2dB's broadside and loose on the 
ends and unless the antenna is 200'+ high, most of your signal will go 
straight up.  Is this what you are looking for?

John KK9A




To: TowerTalk at contesting.com>
Subject: Re: [TowerTalk] Max Unguyed Rohn 25 height to support dipole end
From: "Michael Tope"
Date: Sun, 12 Nov 2006 09:08:13 -0800
List-post: <mailto:towertalk at contesting.com>

----- Original Message ----- 
From: <hdmc38 at bellsouth.net>
To: TowerTalk at contesting.com>
Sent: Sunday, November 12, 2006 5:28 AM
Subject: Re: [TowerTalk] Max Unguyed Rohn 25 height to support dipole end


> Hello Ken
>       I think you would over load that 40' when you climb it.20 to 30 feet
> of 25G is pretty shakey when your on top with no guys.Just my .02 cents.
>
>                                          Joe K4XZ
>>

That's why I recommend 20' of unsupported R25 followed by 20' of
reinforced aluminum mast. I use a couple of rotator clamp shells on
the rotator shelf of the R25 short top section along with an old TB-3
thrust bearing on the top plate to support the mast (grabs the mast
in two places about 1.5 feet apart). You can loosen the gib bolts on
the TB-3 and then loosen rotator clamp shells and drop the mast
down through the rotator cable pass thru in the rotator shelf if you
want to attach anything to the top of the mast (like for changing
pulley's for instance). That way you never have to climb more than
20 feet of unsupported R25.

73, Mike W4EF.........................