[TowerTalk] Adding a second tribander?

[Douglas Ruz]

Hello,

I am new to the list. I am Doug, EA3DZ.

I would like to add a second tribander to a 22m (66ft) self supporting
tower. I have an Optibeam OB-16-4 on top of the tower.

This tower is a little bit wide, so, probably I will add something like an
OB-7-3 or similar with 1 meter or more free area in the central part of the
antenna.

The tower has piramidal shape. It is about 50cm wide in the top section
(5m) and about 90cm (3ft) in the zone 10m below the OB-16-4.

What is the minimum distance allow between antennas to avoid interaction
with the top tribander?

Any idea?

Thanks,

Doug, EA3DZ