[TowerTalk] 40 and 20 at 15 ft apart

["Felipe J. Hernández"]

Guys,

Theres a great  benefit from turning the antennas 90 deg off.
but Ive heard that, when you have a 40 and a 20 on the same tower, the 
interaction
is never dissipated by the 90 deg offset.

Is that true?

Thinking of setting up a xm240 with a 3 or 4 el force 20 mtr monobander 
abt 15 ft apart..

Thanks

Felipe
NP4Z