[TowerTalk] Stack modeling help needed

[Markhasin, Vitaly]

Hi All,
After a few problems my 150' tower is finally up!
I plan to use it for future 40 m stack of M2 40M3L (3 el 40m monobander) and
presently owned XM-240.
How high up the tower I have to run the feed line to the stack-mach?
What is the optimum spacing between these two antennas? The top antenna
(40M3L) can be anywhere
between 152' and about 162' (chrom-moly mast). The lower antenna (XM-240)
will be fixed to EU or PAC.
Can somebody model this set-up?
Thank you for your help.
73! Vitaly (VE6JO)