[TowerTalk] Uneven Ground

[john at kk9a.com]

You did not say what tower you had but one option would be to use stronger
tower which allows more distance between guy points. Look at the guy specs
for Rohn 45GSR or 65G.  Another option may be to bend the element that
collides with the guy wire or shorten it with a load coil.

John KK9A



Rich Assarabowski K1CC wrote:

My tower was put up on the side of a hill, I tried to maintain a constant
angle of the guys relative to the tower as best as I could, without the use
of any surveying instruments.   It came out pretty close, and yes, the guys
did cross on one side.   I just offset the anchors slightly so the guys
wouldn't rub.

The big issue with any tower (especially one on sloped ground) is getting
sufficient clearance from the top guys in order to rotate a lower antenna.
I had a side-mounted tribander (CL-33) when I first put it up in the late
80's which I was able to rotate (barely) on a side-arm.   I took down the
tower some years ago because of concern about the rusted guys (and just
general rust).   

Now that I want to put a tower back up, the issue is that tribanders are now
trapless, so their turning radius is significantly bigger and it will no
longer be possible to rotate the lower antenna without hitting guy wires.
The limiting factor are the extreme downhill upper guys which hit the
full-size 20m reflector.   

The solution is to elevate the anchors on the downhill guys.   That means
burying an I-beam and raising the guy attachment 5 or 6 ft or probably more.
The best example of towers on a slope is 4O3A's station, which has an
EXTREME dropoff.   What Ranko did is to use short towers as downhill guy
anchor points for the big towers.  The short towers have their own set of
guys.   Pretty clever, but there's just no other way to do it.  I visited
Ranko a few years ago, it is the most breathtaking view I have ever seen
from a ham location.

I have yet to put the tower back up because I would really like to have
stacked trapless tribanders but don't relish the effort of putting in new
elevated downhill anchors.   The ground is rocky and digging a sufficiently
deep hole for a buried elevated anchor would be hit or miss.   

One solution would be to shorten the 20m reflector mechanically on the lower
antenna and still maintain the same electrical characteristics as the
full-size upper antenna.   I'm not enough of an antenna modeler to do this.
The tribander of choice for side-mounting is the JK C31XR-JK with ample
clearance in the center to allow complete rotation around the tower, whether
using a ring rotor or a side arm.

Any suggestions or ideas?   Terrain modeling of my hill shows some
significant gains in various directions from a tribander stack, I would hate
to compromise and just fix the lower antenna to Europe, or fix it south ...


--- Rich K1CC