[amsat-bb] Crossed Yagi boom separation

HI all .... I'm setting up a field day station with my old 2M & 70CM Cushcraft crossed yagis ....

Assuming a NON-metallic cross boom, neglecting structural constraints, how far from the center (i.e. elevation rotor and vertical mast) should the antennas be mounted?

My google juice isn't working this morning ... but I seem to recall >= 1/2 Wavelength being sufficent.

Thanks,

--> Rob, KA2PBT