[TowerTalk] Indirect Coupling to tower helps vert. polarization?

[RLVZ@aol.com]

Hi guys,
 
Got a question I'd love to run by you:
 
At another QTH I had a 160-m. inverted vee with apex at 60' on a  Rohn 25 
tower.  Had a Tribander mounted 3' up above it.  Not much of  an antenna on 160 
but this particular antenna worked DX well ... much  better than it should 
have.  Such as, a KL7 told me that I typically  was the first station East of the 
Mississippi he heard on 160.  
 
For a center insulator I was using a Unadilla 1:1 balun... the one with the  
ground strap attached for lightning protection.  The ground strap was  
attached to one leg of the tower.
I am wondering if somehow the DC ground strap was also coupling some RF  into 
the tower?
(it would appear possible as I was never able to get the SWR on that  
particular setup under 1.7 to 1 and usually it's quite easy to get a  lower SWR than 
that)  Or would everyone agree that if I  had in-direct coupling taking place 
that it was via the top mounted  tribander just a few feet above the apex of 
the Inv. V? 
 
With the way the low Inverted V worked so well on DX q's it would seem  
certain that somehow the Vee was getting indirectly coupled to the tower...  
thereby giving it some vertical polarization.  
 
Question:  Are there any proven ways of mounting a Dipole or  Inverted V on a 
tower so that some indirect coupling to the tower and  therefore some 
vertical polarization can be derived from the  tower?     
 
Thanks!
 
73, Dick- K9OM