Aloha Jim
The rotary dipole would be simple, but I have no more room on the tower. Last
set of guys is at 84 ft. I have a 4 el 40 at 85, and at the top of the tower,
at 94 feet is the tribander.
Only about 5 or 6 feet will converge toward the tower since I have the ability
to pull the ends of the ropes out a ways. So it would seem that will not be an
issue. Again no way to know for sure. I do have room for a rx array but I
know about minimal distance.
In the end, I don't have many choices other than to put it up. The location
terrain and the resulting HFTA I've run for the Yagis is outstanding and I am
hoping it will help mitigate any problems that arise. I'm not expecting the
optimal 25 dB F/B, and I can settle for less, since I'm using an rx antenna.
The main thing I want is gain and from what I've heard that isn't as easily
degraded. We'll see. Lots of work ahead in any case.
73 Bill
## The loaded 80m rotary dipole, may well be a lot simpler..and quieter.
With a tornado drive on it, it will tune the entire band. Feedpoint is right
at
the mast, so any CM choke, helical hairpin, coax is easy to get to. Mounted
inline with any yagi booms above or below it, there is no interaction with
other
yagis on the same mast. Windload is a moot point, since with yagi eles
broadside
to the wind, the 80m dipole is pointed into the wind. No snow or ice in KH6.
## The 80m 4 square, hanging from the tower, will have the obvious advantage of
instant direction switching. I assume the tops of all the 80m verts will
converge a bit
towards the tower? How much effect, if any, does that have ? Do you
have room
for a dedicated 80m RX ant array ? If any dedicated 80m RX array is used, then
you
also have to get the RX array a min distance away from the TX array.
Jim VE7RF
------------------------------
Message: 2
Date: Sat, 22 Jul 2017 11:56:00 -0400
From: K7LXC@aol.com
To: towertalk@contesting.com, keepwalking188@ac0c.com
Subject: Re: [TowerTalk] Latteral load capability of T2X in mast
mounted configuration
Message-ID: <14e5c.5e822a39.46a4cf90@aol.com>
Content-Type: text/plain; charset="US-ASCII"
> I am using a mobile crank-up / tilt tower for some antenna testing that
has a top section too small to get a ham4 rotor in. Unfortunately that
means I need to mount the rotor on a pole that extends from the top of the
tower.
> The good thing about this setup is the tower nests and the tilts down
essentially parallel to the ground, allowing you to mount the antenna while
standing on the ground. The bad thing about that setup is the rotor has
got to be stout enough to hold the antenna weight while the rotor is
temporarily horizontal.
> Would the tailtwister would be happy holding that much weight off the
nose when it?s temporarily horizontal?
I worked for Hy-Gain/Telex some years ago and we destruction tested a T2X
to determine the lateral load capacity (page 156 of my UP THE TOWER book
available from championradio.com). The rotator took 3000 foot-lbs. before it
broke. I'd say you shouldn't have a problem with your proposed situation.
Cheers,
Steve K7LXC
TOWER TECH
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