OK using this image as a reference,
http://i67.tinypic.com/28mpzkh.jpg
Ok the yagis are 8 elements on 2 meters and 21 elements on 70 cm. Similar boom lengths.
Now when vertically polarized and stacked side by side as in the top picture how close can they get to each other before starting to mess with each other.
Same thing in next image but horizontally polarized so above and below each other.
Now if they are 90 deg in rotation IE: one is vertically polarized and the other horizontal, I'm thinking they could even be on the same boom correct?
So that brings in the third drawing same antennas but at 45 deg to the horizon but 90 to each other, How close can they get without bugging the other?
Now with the 45 deg angle thing, how much will a metal cross boom mess with them?
Joe WB9SBD