[TowerTalk] More on radials

[Jim Brown]

Hi Rudy,

It certainly is possible to model that tower with all the antennas, at 
least to a first approximation, if you take the time to do so. It's all 
XYZ coordinates. The only aluminum that matters is what has a DC 
connection to the tower, so insulated elements don't need to be modeled.

 From your description, I'd say that tower is likely to be resonant 
below 160M, which would make it an excellent reflector. My sloping 
radiators are fed about 60 ft from my tower, and need only a bit of 
inductive loading to resonate them. They are insulated from the tower by 
a 10 ft piece of 4-in PVC conduit, so their top is about 5 ft from the 
tower.

You'll need good radial systems to get the gain -- lots of radials for 
the tower on the ground and at least four on the feedpoint of each of 
the sloping wires. I have one sloping to about 70 degrees and one to 
about 270 degrees. I feed them one at a time, with the other shorted. I 
provide the short in the shack through a suitable length of feedline 
(close to a half wave).

73, Jim K9YC

On 9/5/2017 6:12 PM, Rudy Bakalov via TowerTalk wrote:
> I don't really know. Seriously, the tower itself is 90' BUT there is a KT36XA at ~65', then 4 el 40m M2 at 90', and finally another KT36XA at about ~105'. I don't think any model can properly factor in all this extra aluminum so I will have to actually measure it.