[TowerTalk] 160M antenna advise

[Jim Brown]

On 2/7/2013 10:15 AM, Guy Molinari wrote:
> Pros/Cons?

I like K1TTT's comments.  But -- those grounded towers will interact 
with anything you put up, so be sure to include them in an NEC model.  
If the only ground for these towers are some rods, I'd add a load of 
about 20 ohms in series with their base to simulate ground losses.  That 
interaction can be good or bad, and you can eliminate or reduce it by 
detuning the tower(s).

One way to use the tower(s) is to drive only one inverted L (or a Tee) 
and use one or both of the towers as passive elements.  You could also 
load one or both of the towers, using the other as a passive element. 
These towers are tall enough, especially by the time you consider the 
aluminum on top, to feed pretty far above ground, which means that 
elevated radials at the feedpoint could be pretty efficient.

A tower will have the greatest effect as a passive element when it is 
near resonance, and when it has the lowest resistance to earth. That 
does not mean rods, it means radials.

73, Jim K9YC