Bill, I am curious if you are aware of ON4UN's Low Band Dx-ing book ? It
is considered to be the bible of low band dx-ing, especially for 160 and 80
meters. The author is the "King" of 80 meter dx work. Just google
ON4UN, and you will get the info for the book.

Chap 11 is about "vertical arrays."

I am not an expert, but I have just directed you to the top one on this
subject.

Good luck !!

73 de Jim K4PYT