[Antennas] Unused resonant antennas - shorted to ground or floating?

[Ron Youvan]

> OK, I see this stuff and don't pay a lot of attention to it and now I will need to know.
> Example: Do I ground an unused 40 meter vertical antenna to make it be "invisible" and 
> not affect the pattern (mostly) of another antenna that is 1/4 wave away and also on 40 meters (or do I let it "float")?  
> Is it "good enough" to have it grounded by the Delta switch in the shack or does if have to be grounded AT the antenna? 

   I don't know for sure, but broadcast towers (D.A.) are grounded when not part of the pattern, and 
this is normally done in the switching panel or the phasor. (power splitter, phase shifting network)
   I have seen a grounded tower at a 3 tower 5kW array throw a 1/4 inch R.F. arc to a key in 
someones hand. (only one tower hot for the ND pattern)
-- 
    Ron  KA4INM - Of what you see in books, believe 75%.  Of newspapers, believe 50%.
                  And of TV news, believe 25% --
                  make that 5% if the anchorman wears a blazer.