[TowerTalk] "Magic" length from tower to first insulator

[jimlux]

On 3/16/16 11:39 AM, Larry Loen wrote:
> I could imaginably insulate my guys from the tower sections, because I am
> using the Rohn brackets to attach them.  I would have to find some suitable
> material before the tower went up, but I have time for that if I know what
> to select (would want it to be UV resistant if possible, though the bracket
> itself will give some sun protection).
>
> I _think_ this helps or at least simplifies the analysis, because it should
> take the tower sections themselves out of the picture.  If I understand the
> discussion, it would also mean that it restores the tacit assumptions of
> the original ARRL paper (albeit without Mr. London's sophisticated
> modelling and analysis).
>
> I also wonder if the second set of guys are grounded (which I intend to do
> anyway), makes a difference in how the secondary lengths resonate?
>

The easy way is to do a quick model in NEC.. you're not looking for 
gnat's eyelash precision.. just "does the pattern or resonance change" 
(or for that matter, you can do it by looking at the current in the guy 
segments).


Once you get your model set up, it's easy to change segment lengths, run 
the sim, and see what it looks like.