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

[DJED1 at aol.com]

For quarter-wave verticals, opening the antenna at the base (current max)  
will minimize the effect of the antenna on nearby radiators.  This, of  
course, will not provide max lightning protection, so grounding through an  
inductor with a reactance much greater than the resonant antenna resistance  
(typically 30 ohms or so) will be effective.  
Ed  W2EMN