[TowerTalk] 40 mtr dipole spacing above tribander

[Robert Harmon]

I have been looking though the archives
in tower talk for info and haven't found anything as yet about my spacing question.
I also emailed Force 12 but haven't received a response yet.
I have a Force 12 C3 and just acquired a used Cushcraft D40 rotatable dipole for 40 meters.
I want to mount the 40 meter dipole above the C3 on the same mast.  I would like to know 
the minimum spacing to avoid interaction and also if I should orient the dipole so it is 
parallel with the boom of the C3.  Anyone have experience with spacing the same or similar 
antennas ?

thanks,
Bob
K6UJ